SemaOverload.cpp revision 7ea491cd10c4ea5bf54b9dc15a07ff49cc8a44c6
1//===--- SemaOverload.cpp - C++ Overloading -------------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Sema/Overload.h" 15#include "clang/AST/ASTContext.h" 16#include "clang/AST/CXXInheritance.h" 17#include "clang/AST/DeclObjC.h" 18#include "clang/AST/Expr.h" 19#include "clang/AST/ExprCXX.h" 20#include "clang/AST/ExprObjC.h" 21#include "clang/AST/TypeOrdering.h" 22#include "clang/Basic/Diagnostic.h" 23#include "clang/Basic/PartialDiagnostic.h" 24#include "clang/Lex/Preprocessor.h" 25#include "clang/Sema/Initialization.h" 26#include "clang/Sema/Lookup.h" 27#include "clang/Sema/SemaInternal.h" 28#include "clang/Sema/Template.h" 29#include "clang/Sema/TemplateDeduction.h" 30#include "llvm/ADT/DenseSet.h" 31#include "llvm/ADT/STLExtras.h" 32#include "llvm/ADT/SmallPtrSet.h" 33#include "llvm/ADT/SmallString.h" 34#include <algorithm> 35 36namespace clang { 37using namespace sema; 38 39/// A convenience routine for creating a decayed reference to a function. 40static ExprResult 41CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, NamedDecl *FoundDecl, 42 bool HadMultipleCandidates, 43 SourceLocation Loc = SourceLocation(), 44 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){ 45 if (S.DiagnoseUseOfDecl(FoundDecl, Loc)) 46 return ExprError(); 47 // If FoundDecl is different from Fn (such as if one is a template 48 // and the other a specialization), make sure DiagnoseUseOfDecl is 49 // called on both. 50 // FIXME: This would be more comprehensively addressed by modifying 51 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl 52 // being used. 53 if (FoundDecl != Fn && S.DiagnoseUseOfDecl(Fn, Loc)) 54 return ExprError(); 55 DeclRefExpr *DRE = new (S.Context) DeclRefExpr(Fn, false, Fn->getType(), 56 VK_LValue, Loc, LocInfo); 57 if (HadMultipleCandidates) 58 DRE->setHadMultipleCandidates(true); 59 60 S.MarkDeclRefReferenced(DRE); 61 62 ExprResult E = S.Owned(DRE); 63 E = S.DefaultFunctionArrayConversion(E.take()); 64 if (E.isInvalid()) 65 return ExprError(); 66 return E; 67} 68 69static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 70 bool InOverloadResolution, 71 StandardConversionSequence &SCS, 72 bool CStyle, 73 bool AllowObjCWritebackConversion); 74 75static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From, 76 QualType &ToType, 77 bool InOverloadResolution, 78 StandardConversionSequence &SCS, 79 bool CStyle); 80static OverloadingResult 81IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 82 UserDefinedConversionSequence& User, 83 OverloadCandidateSet& Conversions, 84 bool AllowExplicit); 85 86 87static ImplicitConversionSequence::CompareKind 88CompareStandardConversionSequences(Sema &S, 89 const StandardConversionSequence& SCS1, 90 const StandardConversionSequence& SCS2); 91 92static ImplicitConversionSequence::CompareKind 93CompareQualificationConversions(Sema &S, 94 const StandardConversionSequence& SCS1, 95 const StandardConversionSequence& SCS2); 96 97static ImplicitConversionSequence::CompareKind 98CompareDerivedToBaseConversions(Sema &S, 99 const StandardConversionSequence& SCS1, 100 const StandardConversionSequence& SCS2); 101 102 103 104/// GetConversionCategory - Retrieve the implicit conversion 105/// category corresponding to the given implicit conversion kind. 106ImplicitConversionCategory 107GetConversionCategory(ImplicitConversionKind Kind) { 108 static const ImplicitConversionCategory 109 Category[(int)ICK_Num_Conversion_Kinds] = { 110 ICC_Identity, 111 ICC_Lvalue_Transformation, 112 ICC_Lvalue_Transformation, 113 ICC_Lvalue_Transformation, 114 ICC_Identity, 115 ICC_Qualification_Adjustment, 116 ICC_Promotion, 117 ICC_Promotion, 118 ICC_Promotion, 119 ICC_Conversion, 120 ICC_Conversion, 121 ICC_Conversion, 122 ICC_Conversion, 123 ICC_Conversion, 124 ICC_Conversion, 125 ICC_Conversion, 126 ICC_Conversion, 127 ICC_Conversion, 128 ICC_Conversion, 129 ICC_Conversion, 130 ICC_Conversion, 131 ICC_Conversion 132 }; 133 return Category[(int)Kind]; 134} 135 136/// GetConversionRank - Retrieve the implicit conversion rank 137/// corresponding to the given implicit conversion kind. 138ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 139 static const ImplicitConversionRank 140 Rank[(int)ICK_Num_Conversion_Kinds] = { 141 ICR_Exact_Match, 142 ICR_Exact_Match, 143 ICR_Exact_Match, 144 ICR_Exact_Match, 145 ICR_Exact_Match, 146 ICR_Exact_Match, 147 ICR_Promotion, 148 ICR_Promotion, 149 ICR_Promotion, 150 ICR_Conversion, 151 ICR_Conversion, 152 ICR_Conversion, 153 ICR_Conversion, 154 ICR_Conversion, 155 ICR_Conversion, 156 ICR_Conversion, 157 ICR_Conversion, 158 ICR_Conversion, 159 ICR_Conversion, 160 ICR_Conversion, 161 ICR_Complex_Real_Conversion, 162 ICR_Conversion, 163 ICR_Conversion, 164 ICR_Writeback_Conversion 165 }; 166 return Rank[(int)Kind]; 167} 168 169/// GetImplicitConversionName - Return the name of this kind of 170/// implicit conversion. 171const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 172 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 173 "No conversion", 174 "Lvalue-to-rvalue", 175 "Array-to-pointer", 176 "Function-to-pointer", 177 "Noreturn adjustment", 178 "Qualification", 179 "Integral promotion", 180 "Floating point promotion", 181 "Complex promotion", 182 "Integral conversion", 183 "Floating conversion", 184 "Complex conversion", 185 "Floating-integral conversion", 186 "Pointer conversion", 187 "Pointer-to-member conversion", 188 "Boolean conversion", 189 "Compatible-types conversion", 190 "Derived-to-base conversion", 191 "Vector conversion", 192 "Vector splat", 193 "Complex-real conversion", 194 "Block Pointer conversion", 195 "Transparent Union Conversion" 196 "Writeback conversion" 197 }; 198 return Name[Kind]; 199} 200 201/// StandardConversionSequence - Set the standard conversion 202/// sequence to the identity conversion. 203void StandardConversionSequence::setAsIdentityConversion() { 204 First = ICK_Identity; 205 Second = ICK_Identity; 206 Third = ICK_Identity; 207 DeprecatedStringLiteralToCharPtr = false; 208 QualificationIncludesObjCLifetime = false; 209 ReferenceBinding = false; 210 DirectBinding = false; 211 IsLvalueReference = true; 212 BindsToFunctionLvalue = false; 213 BindsToRvalue = false; 214 BindsImplicitObjectArgumentWithoutRefQualifier = false; 215 ObjCLifetimeConversionBinding = false; 216 CopyConstructor = 0; 217} 218 219/// getRank - Retrieve the rank of this standard conversion sequence 220/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 221/// implicit conversions. 222ImplicitConversionRank StandardConversionSequence::getRank() const { 223 ImplicitConversionRank Rank = ICR_Exact_Match; 224 if (GetConversionRank(First) > Rank) 225 Rank = GetConversionRank(First); 226 if (GetConversionRank(Second) > Rank) 227 Rank = GetConversionRank(Second); 228 if (GetConversionRank(Third) > Rank) 229 Rank = GetConversionRank(Third); 230 return Rank; 231} 232 233/// isPointerConversionToBool - Determines whether this conversion is 234/// a conversion of a pointer or pointer-to-member to bool. This is 235/// used as part of the ranking of standard conversion sequences 236/// (C++ 13.3.3.2p4). 237bool StandardConversionSequence::isPointerConversionToBool() const { 238 // Note that FromType has not necessarily been transformed by the 239 // array-to-pointer or function-to-pointer implicit conversions, so 240 // check for their presence as well as checking whether FromType is 241 // a pointer. 242 if (getToType(1)->isBooleanType() && 243 (getFromType()->isPointerType() || 244 getFromType()->isObjCObjectPointerType() || 245 getFromType()->isBlockPointerType() || 246 getFromType()->isNullPtrType() || 247 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 248 return true; 249 250 return false; 251} 252 253/// isPointerConversionToVoidPointer - Determines whether this 254/// conversion is a conversion of a pointer to a void pointer. This is 255/// used as part of the ranking of standard conversion sequences (C++ 256/// 13.3.3.2p4). 257bool 258StandardConversionSequence:: 259isPointerConversionToVoidPointer(ASTContext& Context) const { 260 QualType FromType = getFromType(); 261 QualType ToType = getToType(1); 262 263 // Note that FromType has not necessarily been transformed by the 264 // array-to-pointer implicit conversion, so check for its presence 265 // and redo the conversion to get a pointer. 266 if (First == ICK_Array_To_Pointer) 267 FromType = Context.getArrayDecayedType(FromType); 268 269 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType()) 270 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 271 return ToPtrType->getPointeeType()->isVoidType(); 272 273 return false; 274} 275 276/// Skip any implicit casts which could be either part of a narrowing conversion 277/// or after one in an implicit conversion. 278static const Expr *IgnoreNarrowingConversion(const Expr *Converted) { 279 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) { 280 switch (ICE->getCastKind()) { 281 case CK_NoOp: 282 case CK_IntegralCast: 283 case CK_IntegralToBoolean: 284 case CK_IntegralToFloating: 285 case CK_FloatingToIntegral: 286 case CK_FloatingToBoolean: 287 case CK_FloatingCast: 288 Converted = ICE->getSubExpr(); 289 continue; 290 291 default: 292 return Converted; 293 } 294 } 295 296 return Converted; 297} 298 299/// Check if this standard conversion sequence represents a narrowing 300/// conversion, according to C++11 [dcl.init.list]p7. 301/// 302/// \param Ctx The AST context. 303/// \param Converted The result of applying this standard conversion sequence. 304/// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the 305/// value of the expression prior to the narrowing conversion. 306/// \param ConstantType If this is an NK_Constant_Narrowing conversion, the 307/// type of the expression prior to the narrowing conversion. 308NarrowingKind 309StandardConversionSequence::getNarrowingKind(ASTContext &Ctx, 310 const Expr *Converted, 311 APValue &ConstantValue, 312 QualType &ConstantType) const { 313 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++"); 314 315 // C++11 [dcl.init.list]p7: 316 // A narrowing conversion is an implicit conversion ... 317 QualType FromType = getToType(0); 318 QualType ToType = getToType(1); 319 switch (Second) { 320 // -- from a floating-point type to an integer type, or 321 // 322 // -- from an integer type or unscoped enumeration type to a floating-point 323 // type, except where the source is a constant expression and the actual 324 // value after conversion will fit into the target type and will produce 325 // the original value when converted back to the original type, or 326 case ICK_Floating_Integral: 327 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) { 328 return NK_Type_Narrowing; 329 } else if (FromType->isIntegralType(Ctx) && ToType->isRealFloatingType()) { 330 llvm::APSInt IntConstantValue; 331 const Expr *Initializer = IgnoreNarrowingConversion(Converted); 332 if (Initializer && 333 Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) { 334 // Convert the integer to the floating type. 335 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType)); 336 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(), 337 llvm::APFloat::rmNearestTiesToEven); 338 // And back. 339 llvm::APSInt ConvertedValue = IntConstantValue; 340 bool ignored; 341 Result.convertToInteger(ConvertedValue, 342 llvm::APFloat::rmTowardZero, &ignored); 343 // If the resulting value is different, this was a narrowing conversion. 344 if (IntConstantValue != ConvertedValue) { 345 ConstantValue = APValue(IntConstantValue); 346 ConstantType = Initializer->getType(); 347 return NK_Constant_Narrowing; 348 } 349 } else { 350 // Variables are always narrowings. 351 return NK_Variable_Narrowing; 352 } 353 } 354 return NK_Not_Narrowing; 355 356 // -- from long double to double or float, or from double to float, except 357 // where the source is a constant expression and the actual value after 358 // conversion is within the range of values that can be represented (even 359 // if it cannot be represented exactly), or 360 case ICK_Floating_Conversion: 361 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() && 362 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) { 363 // FromType is larger than ToType. 364 const Expr *Initializer = IgnoreNarrowingConversion(Converted); 365 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) { 366 // Constant! 367 assert(ConstantValue.isFloat()); 368 llvm::APFloat FloatVal = ConstantValue.getFloat(); 369 // Convert the source value into the target type. 370 bool ignored; 371 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert( 372 Ctx.getFloatTypeSemantics(ToType), 373 llvm::APFloat::rmNearestTiesToEven, &ignored); 374 // If there was no overflow, the source value is within the range of 375 // values that can be represented. 376 if (ConvertStatus & llvm::APFloat::opOverflow) { 377 ConstantType = Initializer->getType(); 378 return NK_Constant_Narrowing; 379 } 380 } else { 381 return NK_Variable_Narrowing; 382 } 383 } 384 return NK_Not_Narrowing; 385 386 // -- from an integer type or unscoped enumeration type to an integer type 387 // that cannot represent all the values of the original type, except where 388 // the source is a constant expression and the actual value after 389 // conversion will fit into the target type and will produce the original 390 // value when converted back to the original type. 391 case ICK_Boolean_Conversion: // Bools are integers too. 392 if (!FromType->isIntegralOrUnscopedEnumerationType()) { 393 // Boolean conversions can be from pointers and pointers to members 394 // [conv.bool], and those aren't considered narrowing conversions. 395 return NK_Not_Narrowing; 396 } // Otherwise, fall through to the integral case. 397 case ICK_Integral_Conversion: { 398 assert(FromType->isIntegralOrUnscopedEnumerationType()); 399 assert(ToType->isIntegralOrUnscopedEnumerationType()); 400 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType(); 401 const unsigned FromWidth = Ctx.getIntWidth(FromType); 402 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType(); 403 const unsigned ToWidth = Ctx.getIntWidth(ToType); 404 405 if (FromWidth > ToWidth || 406 (FromWidth == ToWidth && FromSigned != ToSigned) || 407 (FromSigned && !ToSigned)) { 408 // Not all values of FromType can be represented in ToType. 409 llvm::APSInt InitializerValue; 410 const Expr *Initializer = IgnoreNarrowingConversion(Converted); 411 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) { 412 // Such conversions on variables are always narrowing. 413 return NK_Variable_Narrowing; 414 } 415 bool Narrowing = false; 416 if (FromWidth < ToWidth) { 417 // Negative -> unsigned is narrowing. Otherwise, more bits is never 418 // narrowing. 419 if (InitializerValue.isSigned() && InitializerValue.isNegative()) 420 Narrowing = true; 421 } else { 422 // Add a bit to the InitializerValue so we don't have to worry about 423 // signed vs. unsigned comparisons. 424 InitializerValue = InitializerValue.extend( 425 InitializerValue.getBitWidth() + 1); 426 // Convert the initializer to and from the target width and signed-ness. 427 llvm::APSInt ConvertedValue = InitializerValue; 428 ConvertedValue = ConvertedValue.trunc(ToWidth); 429 ConvertedValue.setIsSigned(ToSigned); 430 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth()); 431 ConvertedValue.setIsSigned(InitializerValue.isSigned()); 432 // If the result is different, this was a narrowing conversion. 433 if (ConvertedValue != InitializerValue) 434 Narrowing = true; 435 } 436 if (Narrowing) { 437 ConstantType = Initializer->getType(); 438 ConstantValue = APValue(InitializerValue); 439 return NK_Constant_Narrowing; 440 } 441 } 442 return NK_Not_Narrowing; 443 } 444 445 default: 446 // Other kinds of conversions are not narrowings. 447 return NK_Not_Narrowing; 448 } 449} 450 451/// DebugPrint - Print this standard conversion sequence to standard 452/// error. Useful for debugging overloading issues. 453void StandardConversionSequence::DebugPrint() const { 454 raw_ostream &OS = llvm::errs(); 455 bool PrintedSomething = false; 456 if (First != ICK_Identity) { 457 OS << GetImplicitConversionName(First); 458 PrintedSomething = true; 459 } 460 461 if (Second != ICK_Identity) { 462 if (PrintedSomething) { 463 OS << " -> "; 464 } 465 OS << GetImplicitConversionName(Second); 466 467 if (CopyConstructor) { 468 OS << " (by copy constructor)"; 469 } else if (DirectBinding) { 470 OS << " (direct reference binding)"; 471 } else if (ReferenceBinding) { 472 OS << " (reference binding)"; 473 } 474 PrintedSomething = true; 475 } 476 477 if (Third != ICK_Identity) { 478 if (PrintedSomething) { 479 OS << " -> "; 480 } 481 OS << GetImplicitConversionName(Third); 482 PrintedSomething = true; 483 } 484 485 if (!PrintedSomething) { 486 OS << "No conversions required"; 487 } 488} 489 490/// DebugPrint - Print this user-defined conversion sequence to standard 491/// error. Useful for debugging overloading issues. 492void UserDefinedConversionSequence::DebugPrint() const { 493 raw_ostream &OS = llvm::errs(); 494 if (Before.First || Before.Second || Before.Third) { 495 Before.DebugPrint(); 496 OS << " -> "; 497 } 498 if (ConversionFunction) 499 OS << '\'' << *ConversionFunction << '\''; 500 else 501 OS << "aggregate initialization"; 502 if (After.First || After.Second || After.Third) { 503 OS << " -> "; 504 After.DebugPrint(); 505 } 506} 507 508/// DebugPrint - Print this implicit conversion sequence to standard 509/// error. Useful for debugging overloading issues. 510void ImplicitConversionSequence::DebugPrint() const { 511 raw_ostream &OS = llvm::errs(); 512 switch (ConversionKind) { 513 case StandardConversion: 514 OS << "Standard conversion: "; 515 Standard.DebugPrint(); 516 break; 517 case UserDefinedConversion: 518 OS << "User-defined conversion: "; 519 UserDefined.DebugPrint(); 520 break; 521 case EllipsisConversion: 522 OS << "Ellipsis conversion"; 523 break; 524 case AmbiguousConversion: 525 OS << "Ambiguous conversion"; 526 break; 527 case BadConversion: 528 OS << "Bad conversion"; 529 break; 530 } 531 532 OS << "\n"; 533} 534 535void AmbiguousConversionSequence::construct() { 536 new (&conversions()) ConversionSet(); 537} 538 539void AmbiguousConversionSequence::destruct() { 540 conversions().~ConversionSet(); 541} 542 543void 544AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 545 FromTypePtr = O.FromTypePtr; 546 ToTypePtr = O.ToTypePtr; 547 new (&conversions()) ConversionSet(O.conversions()); 548} 549 550namespace { 551 // Structure used by DeductionFailureInfo to store 552 // template argument information. 553 struct DFIArguments { 554 TemplateArgument FirstArg; 555 TemplateArgument SecondArg; 556 }; 557 // Structure used by DeductionFailureInfo to store 558 // template parameter and template argument information. 559 struct DFIParamWithArguments : DFIArguments { 560 TemplateParameter Param; 561 }; 562} 563 564/// \brief Convert from Sema's representation of template deduction information 565/// to the form used in overload-candidate information. 566DeductionFailureInfo MakeDeductionFailureInfo(ASTContext &Context, 567 Sema::TemplateDeductionResult TDK, 568 TemplateDeductionInfo &Info) { 569 DeductionFailureInfo Result; 570 Result.Result = static_cast<unsigned>(TDK); 571 Result.HasDiagnostic = false; 572 Result.Data = 0; 573 switch (TDK) { 574 case Sema::TDK_Success: 575 case Sema::TDK_Invalid: 576 case Sema::TDK_InstantiationDepth: 577 case Sema::TDK_TooManyArguments: 578 case Sema::TDK_TooFewArguments: 579 break; 580 581 case Sema::TDK_Incomplete: 582 case Sema::TDK_InvalidExplicitArguments: 583 Result.Data = Info.Param.getOpaqueValue(); 584 break; 585 586 case Sema::TDK_NonDeducedMismatch: { 587 // FIXME: Should allocate from normal heap so that we can free this later. 588 DFIArguments *Saved = new (Context) DFIArguments; 589 Saved->FirstArg = Info.FirstArg; 590 Saved->SecondArg = Info.SecondArg; 591 Result.Data = Saved; 592 break; 593 } 594 595 case Sema::TDK_Inconsistent: 596 case Sema::TDK_Underqualified: { 597 // FIXME: Should allocate from normal heap so that we can free this later. 598 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 599 Saved->Param = Info.Param; 600 Saved->FirstArg = Info.FirstArg; 601 Saved->SecondArg = Info.SecondArg; 602 Result.Data = Saved; 603 break; 604 } 605 606 case Sema::TDK_SubstitutionFailure: 607 Result.Data = Info.take(); 608 if (Info.hasSFINAEDiagnostic()) { 609 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt( 610 SourceLocation(), PartialDiagnostic::NullDiagnostic()); 611 Info.takeSFINAEDiagnostic(*Diag); 612 Result.HasDiagnostic = true; 613 } 614 break; 615 616 case Sema::TDK_FailedOverloadResolution: 617 Result.Data = Info.Expression; 618 break; 619 620 case Sema::TDK_MiscellaneousDeductionFailure: 621 break; 622 } 623 624 return Result; 625} 626 627void DeductionFailureInfo::Destroy() { 628 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 629 case Sema::TDK_Success: 630 case Sema::TDK_Invalid: 631 case Sema::TDK_InstantiationDepth: 632 case Sema::TDK_Incomplete: 633 case Sema::TDK_TooManyArguments: 634 case Sema::TDK_TooFewArguments: 635 case Sema::TDK_InvalidExplicitArguments: 636 case Sema::TDK_FailedOverloadResolution: 637 break; 638 639 case Sema::TDK_Inconsistent: 640 case Sema::TDK_Underqualified: 641 case Sema::TDK_NonDeducedMismatch: 642 // FIXME: Destroy the data? 643 Data = 0; 644 break; 645 646 case Sema::TDK_SubstitutionFailure: 647 // FIXME: Destroy the template argument list? 648 Data = 0; 649 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) { 650 Diag->~PartialDiagnosticAt(); 651 HasDiagnostic = false; 652 } 653 break; 654 655 // Unhandled 656 case Sema::TDK_MiscellaneousDeductionFailure: 657 break; 658 } 659} 660 661PartialDiagnosticAt *DeductionFailureInfo::getSFINAEDiagnostic() { 662 if (HasDiagnostic) 663 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic)); 664 return 0; 665} 666 667TemplateParameter DeductionFailureInfo::getTemplateParameter() { 668 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 669 case Sema::TDK_Success: 670 case Sema::TDK_Invalid: 671 case Sema::TDK_InstantiationDepth: 672 case Sema::TDK_TooManyArguments: 673 case Sema::TDK_TooFewArguments: 674 case Sema::TDK_SubstitutionFailure: 675 case Sema::TDK_NonDeducedMismatch: 676 case Sema::TDK_FailedOverloadResolution: 677 return TemplateParameter(); 678 679 case Sema::TDK_Incomplete: 680 case Sema::TDK_InvalidExplicitArguments: 681 return TemplateParameter::getFromOpaqueValue(Data); 682 683 case Sema::TDK_Inconsistent: 684 case Sema::TDK_Underqualified: 685 return static_cast<DFIParamWithArguments*>(Data)->Param; 686 687 // Unhandled 688 case Sema::TDK_MiscellaneousDeductionFailure: 689 break; 690 } 691 692 return TemplateParameter(); 693} 694 695TemplateArgumentList *DeductionFailureInfo::getTemplateArgumentList() { 696 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 697 case Sema::TDK_Success: 698 case Sema::TDK_Invalid: 699 case Sema::TDK_InstantiationDepth: 700 case Sema::TDK_TooManyArguments: 701 case Sema::TDK_TooFewArguments: 702 case Sema::TDK_Incomplete: 703 case Sema::TDK_InvalidExplicitArguments: 704 case Sema::TDK_Inconsistent: 705 case Sema::TDK_Underqualified: 706 case Sema::TDK_NonDeducedMismatch: 707 case Sema::TDK_FailedOverloadResolution: 708 return 0; 709 710 case Sema::TDK_SubstitutionFailure: 711 return static_cast<TemplateArgumentList*>(Data); 712 713 // Unhandled 714 case Sema::TDK_MiscellaneousDeductionFailure: 715 break; 716 } 717 718 return 0; 719} 720 721const TemplateArgument *DeductionFailureInfo::getFirstArg() { 722 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 723 case Sema::TDK_Success: 724 case Sema::TDK_Invalid: 725 case Sema::TDK_InstantiationDepth: 726 case Sema::TDK_Incomplete: 727 case Sema::TDK_TooManyArguments: 728 case Sema::TDK_TooFewArguments: 729 case Sema::TDK_InvalidExplicitArguments: 730 case Sema::TDK_SubstitutionFailure: 731 case Sema::TDK_FailedOverloadResolution: 732 return 0; 733 734 case Sema::TDK_Inconsistent: 735 case Sema::TDK_Underqualified: 736 case Sema::TDK_NonDeducedMismatch: 737 return &static_cast<DFIArguments*>(Data)->FirstArg; 738 739 // Unhandled 740 case Sema::TDK_MiscellaneousDeductionFailure: 741 break; 742 } 743 744 return 0; 745} 746 747const TemplateArgument *DeductionFailureInfo::getSecondArg() { 748 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 749 case Sema::TDK_Success: 750 case Sema::TDK_Invalid: 751 case Sema::TDK_InstantiationDepth: 752 case Sema::TDK_Incomplete: 753 case Sema::TDK_TooManyArguments: 754 case Sema::TDK_TooFewArguments: 755 case Sema::TDK_InvalidExplicitArguments: 756 case Sema::TDK_SubstitutionFailure: 757 case Sema::TDK_FailedOverloadResolution: 758 return 0; 759 760 case Sema::TDK_Inconsistent: 761 case Sema::TDK_Underqualified: 762 case Sema::TDK_NonDeducedMismatch: 763 return &static_cast<DFIArguments*>(Data)->SecondArg; 764 765 // Unhandled 766 case Sema::TDK_MiscellaneousDeductionFailure: 767 break; 768 } 769 770 return 0; 771} 772 773Expr *DeductionFailureInfo::getExpr() { 774 if (static_cast<Sema::TemplateDeductionResult>(Result) == 775 Sema::TDK_FailedOverloadResolution) 776 return static_cast<Expr*>(Data); 777 778 return 0; 779} 780 781void OverloadCandidateSet::destroyCandidates() { 782 for (iterator i = begin(), e = end(); i != e; ++i) { 783 for (unsigned ii = 0, ie = i->NumConversions; ii != ie; ++ii) 784 i->Conversions[ii].~ImplicitConversionSequence(); 785 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction) 786 i->DeductionFailure.Destroy(); 787 } 788} 789 790void OverloadCandidateSet::clear() { 791 destroyCandidates(); 792 NumInlineSequences = 0; 793 Candidates.clear(); 794 Functions.clear(); 795} 796 797namespace { 798 class UnbridgedCastsSet { 799 struct Entry { 800 Expr **Addr; 801 Expr *Saved; 802 }; 803 SmallVector<Entry, 2> Entries; 804 805 public: 806 void save(Sema &S, Expr *&E) { 807 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)); 808 Entry entry = { &E, E }; 809 Entries.push_back(entry); 810 E = S.stripARCUnbridgedCast(E); 811 } 812 813 void restore() { 814 for (SmallVectorImpl<Entry>::iterator 815 i = Entries.begin(), e = Entries.end(); i != e; ++i) 816 *i->Addr = i->Saved; 817 } 818 }; 819} 820 821/// checkPlaceholderForOverload - Do any interesting placeholder-like 822/// preprocessing on the given expression. 823/// 824/// \param unbridgedCasts a collection to which to add unbridged casts; 825/// without this, they will be immediately diagnosed as errors 826/// 827/// Return true on unrecoverable error. 828static bool checkPlaceholderForOverload(Sema &S, Expr *&E, 829 UnbridgedCastsSet *unbridgedCasts = 0) { 830 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) { 831 // We can't handle overloaded expressions here because overload 832 // resolution might reasonably tweak them. 833 if (placeholder->getKind() == BuiltinType::Overload) return false; 834 835 // If the context potentially accepts unbridged ARC casts, strip 836 // the unbridged cast and add it to the collection for later restoration. 837 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast && 838 unbridgedCasts) { 839 unbridgedCasts->save(S, E); 840 return false; 841 } 842 843 // Go ahead and check everything else. 844 ExprResult result = S.CheckPlaceholderExpr(E); 845 if (result.isInvalid()) 846 return true; 847 848 E = result.take(); 849 return false; 850 } 851 852 // Nothing to do. 853 return false; 854} 855 856/// checkArgPlaceholdersForOverload - Check a set of call operands for 857/// placeholders. 858static bool checkArgPlaceholdersForOverload(Sema &S, 859 MultiExprArg Args, 860 UnbridgedCastsSet &unbridged) { 861 for (unsigned i = 0, e = Args.size(); i != e; ++i) 862 if (checkPlaceholderForOverload(S, Args[i], &unbridged)) 863 return true; 864 865 return false; 866} 867 868// IsOverload - Determine whether the given New declaration is an 869// overload of the declarations in Old. This routine returns false if 870// New and Old cannot be overloaded, e.g., if New has the same 871// signature as some function in Old (C++ 1.3.10) or if the Old 872// declarations aren't functions (or function templates) at all. When 873// it does return false, MatchedDecl will point to the decl that New 874// cannot be overloaded with. This decl may be a UsingShadowDecl on 875// top of the underlying declaration. 876// 877// Example: Given the following input: 878// 879// void f(int, float); // #1 880// void f(int, int); // #2 881// int f(int, int); // #3 882// 883// When we process #1, there is no previous declaration of "f", 884// so IsOverload will not be used. 885// 886// When we process #2, Old contains only the FunctionDecl for #1. By 887// comparing the parameter types, we see that #1 and #2 are overloaded 888// (since they have different signatures), so this routine returns 889// false; MatchedDecl is unchanged. 890// 891// When we process #3, Old is an overload set containing #1 and #2. We 892// compare the signatures of #3 to #1 (they're overloaded, so we do 893// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 894// identical (return types of functions are not part of the 895// signature), IsOverload returns false and MatchedDecl will be set to 896// point to the FunctionDecl for #2. 897// 898// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 899// into a class by a using declaration. The rules for whether to hide 900// shadow declarations ignore some properties which otherwise figure 901// into a function template's signature. 902Sema::OverloadKind 903Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 904 NamedDecl *&Match, bool NewIsUsingDecl) { 905 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 906 I != E; ++I) { 907 NamedDecl *OldD = *I; 908 909 bool OldIsUsingDecl = false; 910 if (isa<UsingShadowDecl>(OldD)) { 911 OldIsUsingDecl = true; 912 913 // We can always introduce two using declarations into the same 914 // context, even if they have identical signatures. 915 if (NewIsUsingDecl) continue; 916 917 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 918 } 919 920 // If either declaration was introduced by a using declaration, 921 // we'll need to use slightly different rules for matching. 922 // Essentially, these rules are the normal rules, except that 923 // function templates hide function templates with different 924 // return types or template parameter lists. 925 bool UseMemberUsingDeclRules = 926 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() && 927 !New->getFriendObjectKind(); 928 929 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 930 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 931 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 932 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 933 continue; 934 } 935 936 Match = *I; 937 return Ovl_Match; 938 } 939 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 940 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 941 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 942 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 943 continue; 944 } 945 946 if (!shouldLinkPossiblyHiddenDecl(*I, New)) 947 continue; 948 949 Match = *I; 950 return Ovl_Match; 951 } 952 } else if (isa<UsingDecl>(OldD)) { 953 // We can overload with these, which can show up when doing 954 // redeclaration checks for UsingDecls. 955 assert(Old.getLookupKind() == LookupUsingDeclName); 956 } else if (isa<TagDecl>(OldD)) { 957 // We can always overload with tags by hiding them. 958 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 959 // Optimistically assume that an unresolved using decl will 960 // overload; if it doesn't, we'll have to diagnose during 961 // template instantiation. 962 } else { 963 // (C++ 13p1): 964 // Only function declarations can be overloaded; object and type 965 // declarations cannot be overloaded. 966 Match = *I; 967 return Ovl_NonFunction; 968 } 969 } 970 971 return Ovl_Overload; 972} 973 974bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 975 bool UseUsingDeclRules) { 976 // C++ [basic.start.main]p2: This function shall not be overloaded. 977 if (New->isMain()) 978 return false; 979 980 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 981 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 982 983 // C++ [temp.fct]p2: 984 // A function template can be overloaded with other function templates 985 // and with normal (non-template) functions. 986 if ((OldTemplate == 0) != (NewTemplate == 0)) 987 return true; 988 989 // Is the function New an overload of the function Old? 990 QualType OldQType = Context.getCanonicalType(Old->getType()); 991 QualType NewQType = Context.getCanonicalType(New->getType()); 992 993 // Compare the signatures (C++ 1.3.10) of the two functions to 994 // determine whether they are overloads. If we find any mismatch 995 // in the signature, they are overloads. 996 997 // If either of these functions is a K&R-style function (no 998 // prototype), then we consider them to have matching signatures. 999 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 1000 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 1001 return false; 1002 1003 const FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 1004 const FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 1005 1006 // The signature of a function includes the types of its 1007 // parameters (C++ 1.3.10), which includes the presence or absence 1008 // of the ellipsis; see C++ DR 357). 1009 if (OldQType != NewQType && 1010 (OldType->getNumArgs() != NewType->getNumArgs() || 1011 OldType->isVariadic() != NewType->isVariadic() || 1012 !FunctionArgTypesAreEqual(OldType, NewType))) 1013 return true; 1014 1015 // C++ [temp.over.link]p4: 1016 // The signature of a function template consists of its function 1017 // signature, its return type and its template parameter list. The names 1018 // of the template parameters are significant only for establishing the 1019 // relationship between the template parameters and the rest of the 1020 // signature. 1021 // 1022 // We check the return type and template parameter lists for function 1023 // templates first; the remaining checks follow. 1024 // 1025 // However, we don't consider either of these when deciding whether 1026 // a member introduced by a shadow declaration is hidden. 1027 if (!UseUsingDeclRules && NewTemplate && 1028 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 1029 OldTemplate->getTemplateParameters(), 1030 false, TPL_TemplateMatch) || 1031 OldType->getResultType() != NewType->getResultType())) 1032 return true; 1033 1034 // If the function is a class member, its signature includes the 1035 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. 1036 // 1037 // As part of this, also check whether one of the member functions 1038 // is static, in which case they are not overloads (C++ 1039 // 13.1p2). While not part of the definition of the signature, 1040 // this check is important to determine whether these functions 1041 // can be overloaded. 1042 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old); 1043 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New); 1044 if (OldMethod && NewMethod && 1045 !OldMethod->isStatic() && !NewMethod->isStatic()) { 1046 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) { 1047 if (!UseUsingDeclRules && 1048 (OldMethod->getRefQualifier() == RQ_None || 1049 NewMethod->getRefQualifier() == RQ_None)) { 1050 // C++0x [over.load]p2: 1051 // - Member function declarations with the same name and the same 1052 // parameter-type-list as well as member function template 1053 // declarations with the same name, the same parameter-type-list, and 1054 // the same template parameter lists cannot be overloaded if any of 1055 // them, but not all, have a ref-qualifier (8.3.5). 1056 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) 1057 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); 1058 Diag(OldMethod->getLocation(), diag::note_previous_declaration); 1059 } 1060 return true; 1061 } 1062 1063 // We may not have applied the implicit const for a constexpr member 1064 // function yet (because we haven't yet resolved whether this is a static 1065 // or non-static member function). Add it now, on the assumption that this 1066 // is a redeclaration of OldMethod. 1067 unsigned NewQuals = NewMethod->getTypeQualifiers(); 1068 if (!getLangOpts().CPlusPlus1y && NewMethod->isConstexpr() && 1069 !isa<CXXConstructorDecl>(NewMethod)) 1070 NewQuals |= Qualifiers::Const; 1071 if (OldMethod->getTypeQualifiers() != NewQuals) 1072 return true; 1073 } 1074 1075 // The signatures match; this is not an overload. 1076 return false; 1077} 1078 1079/// \brief Checks availability of the function depending on the current 1080/// function context. Inside an unavailable function, unavailability is ignored. 1081/// 1082/// \returns true if \arg FD is unavailable and current context is inside 1083/// an available function, false otherwise. 1084bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) { 1085 return FD->isUnavailable() && !cast<Decl>(CurContext)->isUnavailable(); 1086} 1087 1088/// \brief Tries a user-defined conversion from From to ToType. 1089/// 1090/// Produces an implicit conversion sequence for when a standard conversion 1091/// is not an option. See TryImplicitConversion for more information. 1092static ImplicitConversionSequence 1093TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 1094 bool SuppressUserConversions, 1095 bool AllowExplicit, 1096 bool InOverloadResolution, 1097 bool CStyle, 1098 bool AllowObjCWritebackConversion) { 1099 ImplicitConversionSequence ICS; 1100 1101 if (SuppressUserConversions) { 1102 // We're not in the case above, so there is no conversion that 1103 // we can perform. 1104 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 1105 return ICS; 1106 } 1107 1108 // Attempt user-defined conversion. 1109 OverloadCandidateSet Conversions(From->getExprLoc()); 1110 OverloadingResult UserDefResult 1111 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 1112 AllowExplicit); 1113 1114 if (UserDefResult == OR_Success) { 1115 ICS.setUserDefined(); 1116 // C++ [over.ics.user]p4: 1117 // A conversion of an expression of class type to the same class 1118 // type is given Exact Match rank, and a conversion of an 1119 // expression of class type to a base class of that type is 1120 // given Conversion rank, in spite of the fact that a copy 1121 // constructor (i.e., a user-defined conversion function) is 1122 // called for those cases. 1123 if (CXXConstructorDecl *Constructor 1124 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 1125 QualType FromCanon 1126 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 1127 QualType ToCanon 1128 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 1129 if (Constructor->isCopyConstructor() && 1130 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 1131 // Turn this into a "standard" conversion sequence, so that it 1132 // gets ranked with standard conversion sequences. 1133 ICS.setStandard(); 1134 ICS.Standard.setAsIdentityConversion(); 1135 ICS.Standard.setFromType(From->getType()); 1136 ICS.Standard.setAllToTypes(ToType); 1137 ICS.Standard.CopyConstructor = Constructor; 1138 if (ToCanon != FromCanon) 1139 ICS.Standard.Second = ICK_Derived_To_Base; 1140 } 1141 } 1142 1143 // C++ [over.best.ics]p4: 1144 // However, when considering the argument of a user-defined 1145 // conversion function that is a candidate by 13.3.1.3 when 1146 // invoked for the copying of the temporary in the second step 1147 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 1148 // 13.3.1.6 in all cases, only standard conversion sequences and 1149 // ellipsis conversion sequences are allowed. 1150 if (SuppressUserConversions && ICS.isUserDefined()) { 1151 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 1152 } 1153 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 1154 ICS.setAmbiguous(); 1155 ICS.Ambiguous.setFromType(From->getType()); 1156 ICS.Ambiguous.setToType(ToType); 1157 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 1158 Cand != Conversions.end(); ++Cand) 1159 if (Cand->Viable) 1160 ICS.Ambiguous.addConversion(Cand->Function); 1161 } else { 1162 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 1163 } 1164 1165 return ICS; 1166} 1167 1168/// TryImplicitConversion - Attempt to perform an implicit conversion 1169/// from the given expression (Expr) to the given type (ToType). This 1170/// function returns an implicit conversion sequence that can be used 1171/// to perform the initialization. Given 1172/// 1173/// void f(float f); 1174/// void g(int i) { f(i); } 1175/// 1176/// this routine would produce an implicit conversion sequence to 1177/// describe the initialization of f from i, which will be a standard 1178/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 1179/// 4.1) followed by a floating-integral conversion (C++ 4.9). 1180// 1181/// Note that this routine only determines how the conversion can be 1182/// performed; it does not actually perform the conversion. As such, 1183/// it will not produce any diagnostics if no conversion is available, 1184/// but will instead return an implicit conversion sequence of kind 1185/// "BadConversion". 1186/// 1187/// If @p SuppressUserConversions, then user-defined conversions are 1188/// not permitted. 1189/// If @p AllowExplicit, then explicit user-defined conversions are 1190/// permitted. 1191/// 1192/// \param AllowObjCWritebackConversion Whether we allow the Objective-C 1193/// writeback conversion, which allows __autoreleasing id* parameters to 1194/// be initialized with __strong id* or __weak id* arguments. 1195static ImplicitConversionSequence 1196TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 1197 bool SuppressUserConversions, 1198 bool AllowExplicit, 1199 bool InOverloadResolution, 1200 bool CStyle, 1201 bool AllowObjCWritebackConversion) { 1202 ImplicitConversionSequence ICS; 1203 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 1204 ICS.Standard, CStyle, AllowObjCWritebackConversion)){ 1205 ICS.setStandard(); 1206 return ICS; 1207 } 1208 1209 if (!S.getLangOpts().CPlusPlus) { 1210 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 1211 return ICS; 1212 } 1213 1214 // C++ [over.ics.user]p4: 1215 // A conversion of an expression of class type to the same class 1216 // type is given Exact Match rank, and a conversion of an 1217 // expression of class type to a base class of that type is 1218 // given Conversion rank, in spite of the fact that a copy/move 1219 // constructor (i.e., a user-defined conversion function) is 1220 // called for those cases. 1221 QualType FromType = From->getType(); 1222 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 1223 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 1224 S.IsDerivedFrom(FromType, ToType))) { 1225 ICS.setStandard(); 1226 ICS.Standard.setAsIdentityConversion(); 1227 ICS.Standard.setFromType(FromType); 1228 ICS.Standard.setAllToTypes(ToType); 1229 1230 // We don't actually check at this point whether there is a valid 1231 // copy/move constructor, since overloading just assumes that it 1232 // exists. When we actually perform initialization, we'll find the 1233 // appropriate constructor to copy the returned object, if needed. 1234 ICS.Standard.CopyConstructor = 0; 1235 1236 // Determine whether this is considered a derived-to-base conversion. 1237 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 1238 ICS.Standard.Second = ICK_Derived_To_Base; 1239 1240 return ICS; 1241 } 1242 1243 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, 1244 AllowExplicit, InOverloadResolution, CStyle, 1245 AllowObjCWritebackConversion); 1246} 1247 1248ImplicitConversionSequence 1249Sema::TryImplicitConversion(Expr *From, QualType ToType, 1250 bool SuppressUserConversions, 1251 bool AllowExplicit, 1252 bool InOverloadResolution, 1253 bool CStyle, 1254 bool AllowObjCWritebackConversion) { 1255 return clang::TryImplicitConversion(*this, From, ToType, 1256 SuppressUserConversions, AllowExplicit, 1257 InOverloadResolution, CStyle, 1258 AllowObjCWritebackConversion); 1259} 1260 1261/// PerformImplicitConversion - Perform an implicit conversion of the 1262/// expression From to the type ToType. Returns the 1263/// converted expression. Flavor is the kind of conversion we're 1264/// performing, used in the error message. If @p AllowExplicit, 1265/// explicit user-defined conversions are permitted. 1266ExprResult 1267Sema::PerformImplicitConversion(Expr *From, QualType ToType, 1268 AssignmentAction Action, bool AllowExplicit) { 1269 ImplicitConversionSequence ICS; 1270 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 1271} 1272 1273ExprResult 1274Sema::PerformImplicitConversion(Expr *From, QualType ToType, 1275 AssignmentAction Action, bool AllowExplicit, 1276 ImplicitConversionSequence& ICS) { 1277 if (checkPlaceholderForOverload(*this, From)) 1278 return ExprError(); 1279 1280 // Objective-C ARC: Determine whether we will allow the writeback conversion. 1281 bool AllowObjCWritebackConversion 1282 = getLangOpts().ObjCAutoRefCount && 1283 (Action == AA_Passing || Action == AA_Sending); 1284 1285 ICS = clang::TryImplicitConversion(*this, From, ToType, 1286 /*SuppressUserConversions=*/false, 1287 AllowExplicit, 1288 /*InOverloadResolution=*/false, 1289 /*CStyle=*/false, 1290 AllowObjCWritebackConversion); 1291 return PerformImplicitConversion(From, ToType, ICS, Action); 1292} 1293 1294/// \brief Determine whether the conversion from FromType to ToType is a valid 1295/// conversion that strips "noreturn" off the nested function type. 1296bool Sema::IsNoReturnConversion(QualType FromType, QualType ToType, 1297 QualType &ResultTy) { 1298 if (Context.hasSameUnqualifiedType(FromType, ToType)) 1299 return false; 1300 1301 // Permit the conversion F(t __attribute__((noreturn))) -> F(t) 1302 // where F adds one of the following at most once: 1303 // - a pointer 1304 // - a member pointer 1305 // - a block pointer 1306 CanQualType CanTo = Context.getCanonicalType(ToType); 1307 CanQualType CanFrom = Context.getCanonicalType(FromType); 1308 Type::TypeClass TyClass = CanTo->getTypeClass(); 1309 if (TyClass != CanFrom->getTypeClass()) return false; 1310 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { 1311 if (TyClass == Type::Pointer) { 1312 CanTo = CanTo.getAs<PointerType>()->getPointeeType(); 1313 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType(); 1314 } else if (TyClass == Type::BlockPointer) { 1315 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType(); 1316 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType(); 1317 } else if (TyClass == Type::MemberPointer) { 1318 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType(); 1319 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType(); 1320 } else { 1321 return false; 1322 } 1323 1324 TyClass = CanTo->getTypeClass(); 1325 if (TyClass != CanFrom->getTypeClass()) return false; 1326 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) 1327 return false; 1328 } 1329 1330 const FunctionType *FromFn = cast<FunctionType>(CanFrom); 1331 FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); 1332 if (!EInfo.getNoReturn()) return false; 1333 1334 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); 1335 assert(QualType(FromFn, 0).isCanonical()); 1336 if (QualType(FromFn, 0) != CanTo) return false; 1337 1338 ResultTy = ToType; 1339 return true; 1340} 1341 1342/// \brief Determine whether the conversion from FromType to ToType is a valid 1343/// vector conversion. 1344/// 1345/// \param ICK Will be set to the vector conversion kind, if this is a vector 1346/// conversion. 1347static bool IsVectorConversion(ASTContext &Context, QualType FromType, 1348 QualType ToType, ImplicitConversionKind &ICK) { 1349 // We need at least one of these types to be a vector type to have a vector 1350 // conversion. 1351 if (!ToType->isVectorType() && !FromType->isVectorType()) 1352 return false; 1353 1354 // Identical types require no conversions. 1355 if (Context.hasSameUnqualifiedType(FromType, ToType)) 1356 return false; 1357 1358 // There are no conversions between extended vector types, only identity. 1359 if (ToType->isExtVectorType()) { 1360 // There are no conversions between extended vector types other than the 1361 // identity conversion. 1362 if (FromType->isExtVectorType()) 1363 return false; 1364 1365 // Vector splat from any arithmetic type to a vector. 1366 if (FromType->isArithmeticType()) { 1367 ICK = ICK_Vector_Splat; 1368 return true; 1369 } 1370 } 1371 1372 // We can perform the conversion between vector types in the following cases: 1373 // 1)vector types are equivalent AltiVec and GCC vector types 1374 // 2)lax vector conversions are permitted and the vector types are of the 1375 // same size 1376 if (ToType->isVectorType() && FromType->isVectorType()) { 1377 if (Context.areCompatibleVectorTypes(FromType, ToType) || 1378 (Context.getLangOpts().LaxVectorConversions && 1379 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 1380 ICK = ICK_Vector_Conversion; 1381 return true; 1382 } 1383 } 1384 1385 return false; 1386} 1387 1388static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType, 1389 bool InOverloadResolution, 1390 StandardConversionSequence &SCS, 1391 bool CStyle); 1392 1393/// IsStandardConversion - Determines whether there is a standard 1394/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 1395/// expression From to the type ToType. Standard conversion sequences 1396/// only consider non-class types; for conversions that involve class 1397/// types, use TryImplicitConversion. If a conversion exists, SCS will 1398/// contain the standard conversion sequence required to perform this 1399/// conversion and this routine will return true. Otherwise, this 1400/// routine will return false and the value of SCS is unspecified. 1401static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 1402 bool InOverloadResolution, 1403 StandardConversionSequence &SCS, 1404 bool CStyle, 1405 bool AllowObjCWritebackConversion) { 1406 QualType FromType = From->getType(); 1407 1408 // Standard conversions (C++ [conv]) 1409 SCS.setAsIdentityConversion(); 1410 SCS.DeprecatedStringLiteralToCharPtr = false; 1411 SCS.IncompatibleObjC = false; 1412 SCS.setFromType(FromType); 1413 SCS.CopyConstructor = 0; 1414 1415 // There are no standard conversions for class types in C++, so 1416 // abort early. When overloading in C, however, we do permit 1417 if (FromType->isRecordType() || ToType->isRecordType()) { 1418 if (S.getLangOpts().CPlusPlus) 1419 return false; 1420 1421 // When we're overloading in C, we allow, as standard conversions, 1422 } 1423 1424 // The first conversion can be an lvalue-to-rvalue conversion, 1425 // array-to-pointer conversion, or function-to-pointer conversion 1426 // (C++ 4p1). 1427 1428 if (FromType == S.Context.OverloadTy) { 1429 DeclAccessPair AccessPair; 1430 if (FunctionDecl *Fn 1431 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 1432 AccessPair)) { 1433 // We were able to resolve the address of the overloaded function, 1434 // so we can convert to the type of that function. 1435 FromType = Fn->getType(); 1436 1437 // we can sometimes resolve &foo<int> regardless of ToType, so check 1438 // if the type matches (identity) or we are converting to bool 1439 if (!S.Context.hasSameUnqualifiedType( 1440 S.ExtractUnqualifiedFunctionType(ToType), FromType)) { 1441 QualType resultTy; 1442 // if the function type matches except for [[noreturn]], it's ok 1443 if (!S.IsNoReturnConversion(FromType, 1444 S.ExtractUnqualifiedFunctionType(ToType), resultTy)) 1445 // otherwise, only a boolean conversion is standard 1446 if (!ToType->isBooleanType()) 1447 return false; 1448 } 1449 1450 // Check if the "from" expression is taking the address of an overloaded 1451 // function and recompute the FromType accordingly. Take advantage of the 1452 // fact that non-static member functions *must* have such an address-of 1453 // expression. 1454 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn); 1455 if (Method && !Method->isStatic()) { 1456 assert(isa<UnaryOperator>(From->IgnoreParens()) && 1457 "Non-unary operator on non-static member address"); 1458 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() 1459 == UO_AddrOf && 1460 "Non-address-of operator on non-static member address"); 1461 const Type *ClassType 1462 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1463 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1464 } else if (isa<UnaryOperator>(From->IgnoreParens())) { 1465 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == 1466 UO_AddrOf && 1467 "Non-address-of operator for overloaded function expression"); 1468 FromType = S.Context.getPointerType(FromType); 1469 } 1470 1471 // Check that we've computed the proper type after overload resolution. 1472 assert(S.Context.hasSameType( 1473 FromType, 1474 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1475 } else { 1476 return false; 1477 } 1478 } 1479 // Lvalue-to-rvalue conversion (C++11 4.1): 1480 // A glvalue (3.10) of a non-function, non-array type T can 1481 // be converted to a prvalue. 1482 bool argIsLValue = From->isGLValue(); 1483 if (argIsLValue && 1484 !FromType->isFunctionType() && !FromType->isArrayType() && 1485 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1486 SCS.First = ICK_Lvalue_To_Rvalue; 1487 1488 // C11 6.3.2.1p2: 1489 // ... if the lvalue has atomic type, the value has the non-atomic version 1490 // of the type of the lvalue ... 1491 if (const AtomicType *Atomic = FromType->getAs<AtomicType>()) 1492 FromType = Atomic->getValueType(); 1493 1494 // If T is a non-class type, the type of the rvalue is the 1495 // cv-unqualified version of T. Otherwise, the type of the rvalue 1496 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1497 // just strip the qualifiers because they don't matter. 1498 FromType = FromType.getUnqualifiedType(); 1499 } else if (FromType->isArrayType()) { 1500 // Array-to-pointer conversion (C++ 4.2) 1501 SCS.First = ICK_Array_To_Pointer; 1502 1503 // An lvalue or rvalue of type "array of N T" or "array of unknown 1504 // bound of T" can be converted to an rvalue of type "pointer to 1505 // T" (C++ 4.2p1). 1506 FromType = S.Context.getArrayDecayedType(FromType); 1507 1508 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1509 // This conversion is deprecated. (C++ D.4). 1510 SCS.DeprecatedStringLiteralToCharPtr = true; 1511 1512 // For the purpose of ranking in overload resolution 1513 // (13.3.3.1.1), this conversion is considered an 1514 // array-to-pointer conversion followed by a qualification 1515 // conversion (4.4). (C++ 4.2p2) 1516 SCS.Second = ICK_Identity; 1517 SCS.Third = ICK_Qualification; 1518 SCS.QualificationIncludesObjCLifetime = false; 1519 SCS.setAllToTypes(FromType); 1520 return true; 1521 } 1522 } else if (FromType->isFunctionType() && argIsLValue) { 1523 // Function-to-pointer conversion (C++ 4.3). 1524 SCS.First = ICK_Function_To_Pointer; 1525 1526 // An lvalue of function type T can be converted to an rvalue of 1527 // type "pointer to T." The result is a pointer to the 1528 // function. (C++ 4.3p1). 1529 FromType = S.Context.getPointerType(FromType); 1530 } else { 1531 // We don't require any conversions for the first step. 1532 SCS.First = ICK_Identity; 1533 } 1534 SCS.setToType(0, FromType); 1535 1536 // The second conversion can be an integral promotion, floating 1537 // point promotion, integral conversion, floating point conversion, 1538 // floating-integral conversion, pointer conversion, 1539 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1540 // For overloading in C, this can also be a "compatible-type" 1541 // conversion. 1542 bool IncompatibleObjC = false; 1543 ImplicitConversionKind SecondICK = ICK_Identity; 1544 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1545 // The unqualified versions of the types are the same: there's no 1546 // conversion to do. 1547 SCS.Second = ICK_Identity; 1548 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1549 // Integral promotion (C++ 4.5). 1550 SCS.Second = ICK_Integral_Promotion; 1551 FromType = ToType.getUnqualifiedType(); 1552 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1553 // Floating point promotion (C++ 4.6). 1554 SCS.Second = ICK_Floating_Promotion; 1555 FromType = ToType.getUnqualifiedType(); 1556 } else if (S.IsComplexPromotion(FromType, ToType)) { 1557 // Complex promotion (Clang extension) 1558 SCS.Second = ICK_Complex_Promotion; 1559 FromType = ToType.getUnqualifiedType(); 1560 } else if (ToType->isBooleanType() && 1561 (FromType->isArithmeticType() || 1562 FromType->isAnyPointerType() || 1563 FromType->isBlockPointerType() || 1564 FromType->isMemberPointerType() || 1565 FromType->isNullPtrType())) { 1566 // Boolean conversions (C++ 4.12). 1567 SCS.Second = ICK_Boolean_Conversion; 1568 FromType = S.Context.BoolTy; 1569 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1570 ToType->isIntegralType(S.Context)) { 1571 // Integral conversions (C++ 4.7). 1572 SCS.Second = ICK_Integral_Conversion; 1573 FromType = ToType.getUnqualifiedType(); 1574 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) { 1575 // Complex conversions (C99 6.3.1.6) 1576 SCS.Second = ICK_Complex_Conversion; 1577 FromType = ToType.getUnqualifiedType(); 1578 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1579 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1580 // Complex-real conversions (C99 6.3.1.7) 1581 SCS.Second = ICK_Complex_Real; 1582 FromType = ToType.getUnqualifiedType(); 1583 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1584 // Floating point conversions (C++ 4.8). 1585 SCS.Second = ICK_Floating_Conversion; 1586 FromType = ToType.getUnqualifiedType(); 1587 } else if ((FromType->isRealFloatingType() && 1588 ToType->isIntegralType(S.Context)) || 1589 (FromType->isIntegralOrUnscopedEnumerationType() && 1590 ToType->isRealFloatingType())) { 1591 // Floating-integral conversions (C++ 4.9). 1592 SCS.Second = ICK_Floating_Integral; 1593 FromType = ToType.getUnqualifiedType(); 1594 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { 1595 SCS.Second = ICK_Block_Pointer_Conversion; 1596 } else if (AllowObjCWritebackConversion && 1597 S.isObjCWritebackConversion(FromType, ToType, FromType)) { 1598 SCS.Second = ICK_Writeback_Conversion; 1599 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1600 FromType, IncompatibleObjC)) { 1601 // Pointer conversions (C++ 4.10). 1602 SCS.Second = ICK_Pointer_Conversion; 1603 SCS.IncompatibleObjC = IncompatibleObjC; 1604 FromType = FromType.getUnqualifiedType(); 1605 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1606 InOverloadResolution, FromType)) { 1607 // Pointer to member conversions (4.11). 1608 SCS.Second = ICK_Pointer_Member; 1609 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1610 SCS.Second = SecondICK; 1611 FromType = ToType.getUnqualifiedType(); 1612 } else if (!S.getLangOpts().CPlusPlus && 1613 S.Context.typesAreCompatible(ToType, FromType)) { 1614 // Compatible conversions (Clang extension for C function overloading) 1615 SCS.Second = ICK_Compatible_Conversion; 1616 FromType = ToType.getUnqualifiedType(); 1617 } else if (S.IsNoReturnConversion(FromType, ToType, FromType)) { 1618 // Treat a conversion that strips "noreturn" as an identity conversion. 1619 SCS.Second = ICK_NoReturn_Adjustment; 1620 } else if (IsTransparentUnionStandardConversion(S, From, ToType, 1621 InOverloadResolution, 1622 SCS, CStyle)) { 1623 SCS.Second = ICK_TransparentUnionConversion; 1624 FromType = ToType; 1625 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS, 1626 CStyle)) { 1627 // tryAtomicConversion has updated the standard conversion sequence 1628 // appropriately. 1629 return true; 1630 } else if (ToType->isEventT() && 1631 From->isIntegerConstantExpr(S.getASTContext()) && 1632 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) { 1633 SCS.Second = ICK_Zero_Event_Conversion; 1634 FromType = ToType; 1635 } else { 1636 // No second conversion required. 1637 SCS.Second = ICK_Identity; 1638 } 1639 SCS.setToType(1, FromType); 1640 1641 QualType CanonFrom; 1642 QualType CanonTo; 1643 // The third conversion can be a qualification conversion (C++ 4p1). 1644 bool ObjCLifetimeConversion; 1645 if (S.IsQualificationConversion(FromType, ToType, CStyle, 1646 ObjCLifetimeConversion)) { 1647 SCS.Third = ICK_Qualification; 1648 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion; 1649 FromType = ToType; 1650 CanonFrom = S.Context.getCanonicalType(FromType); 1651 CanonTo = S.Context.getCanonicalType(ToType); 1652 } else { 1653 // No conversion required 1654 SCS.Third = ICK_Identity; 1655 1656 // C++ [over.best.ics]p6: 1657 // [...] Any difference in top-level cv-qualification is 1658 // subsumed by the initialization itself and does not constitute 1659 // a conversion. [...] 1660 CanonFrom = S.Context.getCanonicalType(FromType); 1661 CanonTo = S.Context.getCanonicalType(ToType); 1662 if (CanonFrom.getLocalUnqualifiedType() 1663 == CanonTo.getLocalUnqualifiedType() && 1664 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) { 1665 FromType = ToType; 1666 CanonFrom = CanonTo; 1667 } 1668 } 1669 SCS.setToType(2, FromType); 1670 1671 // If we have not converted the argument type to the parameter type, 1672 // this is a bad conversion sequence. 1673 if (CanonFrom != CanonTo) 1674 return false; 1675 1676 return true; 1677} 1678 1679static bool 1680IsTransparentUnionStandardConversion(Sema &S, Expr* From, 1681 QualType &ToType, 1682 bool InOverloadResolution, 1683 StandardConversionSequence &SCS, 1684 bool CStyle) { 1685 1686 const RecordType *UT = ToType->getAsUnionType(); 1687 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 1688 return false; 1689 // The field to initialize within the transparent union. 1690 RecordDecl *UD = UT->getDecl(); 1691 // It's compatible if the expression matches any of the fields. 1692 for (RecordDecl::field_iterator it = UD->field_begin(), 1693 itend = UD->field_end(); 1694 it != itend; ++it) { 1695 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, 1696 CStyle, /*ObjCWritebackConversion=*/false)) { 1697 ToType = it->getType(); 1698 return true; 1699 } 1700 } 1701 return false; 1702} 1703 1704/// IsIntegralPromotion - Determines whether the conversion from the 1705/// expression From (whose potentially-adjusted type is FromType) to 1706/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1707/// sets PromotedType to the promoted type. 1708bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1709 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1710 // All integers are built-in. 1711 if (!To) { 1712 return false; 1713 } 1714 1715 // An rvalue of type char, signed char, unsigned char, short int, or 1716 // unsigned short int can be converted to an rvalue of type int if 1717 // int can represent all the values of the source type; otherwise, 1718 // the source rvalue can be converted to an rvalue of type unsigned 1719 // int (C++ 4.5p1). 1720 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1721 !FromType->isEnumeralType()) { 1722 if (// We can promote any signed, promotable integer type to an int 1723 (FromType->isSignedIntegerType() || 1724 // We can promote any unsigned integer type whose size is 1725 // less than int to an int. 1726 (!FromType->isSignedIntegerType() && 1727 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1728 return To->getKind() == BuiltinType::Int; 1729 } 1730 1731 return To->getKind() == BuiltinType::UInt; 1732 } 1733 1734 // C++11 [conv.prom]p3: 1735 // A prvalue of an unscoped enumeration type whose underlying type is not 1736 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1737 // following types that can represent all the values of the enumeration 1738 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1739 // unsigned int, long int, unsigned long int, long long int, or unsigned 1740 // long long int. If none of the types in that list can represent all the 1741 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1742 // type can be converted to an rvalue a prvalue of the extended integer type 1743 // with lowest integer conversion rank (4.13) greater than the rank of long 1744 // long in which all the values of the enumeration can be represented. If 1745 // there are two such extended types, the signed one is chosen. 1746 // C++11 [conv.prom]p4: 1747 // A prvalue of an unscoped enumeration type whose underlying type is fixed 1748 // can be converted to a prvalue of its underlying type. Moreover, if 1749 // integral promotion can be applied to its underlying type, a prvalue of an 1750 // unscoped enumeration type whose underlying type is fixed can also be 1751 // converted to a prvalue of the promoted underlying type. 1752 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1753 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1754 // provided for a scoped enumeration. 1755 if (FromEnumType->getDecl()->isScoped()) 1756 return false; 1757 1758 // We can perform an integral promotion to the underlying type of the enum, 1759 // even if that's not the promoted type. 1760 if (FromEnumType->getDecl()->isFixed()) { 1761 QualType Underlying = FromEnumType->getDecl()->getIntegerType(); 1762 return Context.hasSameUnqualifiedType(Underlying, ToType) || 1763 IsIntegralPromotion(From, Underlying, ToType); 1764 } 1765 1766 // We have already pre-calculated the promotion type, so this is trivial. 1767 if (ToType->isIntegerType() && 1768 !RequireCompleteType(From->getLocStart(), FromType, 0)) 1769 return Context.hasSameUnqualifiedType(ToType, 1770 FromEnumType->getDecl()->getPromotionType()); 1771 } 1772 1773 // C++0x [conv.prom]p2: 1774 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1775 // to an rvalue a prvalue of the first of the following types that can 1776 // represent all the values of its underlying type: int, unsigned int, 1777 // long int, unsigned long int, long long int, or unsigned long long int. 1778 // If none of the types in that list can represent all the values of its 1779 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1780 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1781 // type. 1782 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1783 ToType->isIntegerType()) { 1784 // Determine whether the type we're converting from is signed or 1785 // unsigned. 1786 bool FromIsSigned = FromType->isSignedIntegerType(); 1787 uint64_t FromSize = Context.getTypeSize(FromType); 1788 1789 // The types we'll try to promote to, in the appropriate 1790 // order. Try each of these types. 1791 QualType PromoteTypes[6] = { 1792 Context.IntTy, Context.UnsignedIntTy, 1793 Context.LongTy, Context.UnsignedLongTy , 1794 Context.LongLongTy, Context.UnsignedLongLongTy 1795 }; 1796 for (int Idx = 0; Idx < 6; ++Idx) { 1797 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1798 if (FromSize < ToSize || 1799 (FromSize == ToSize && 1800 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1801 // We found the type that we can promote to. If this is the 1802 // type we wanted, we have a promotion. Otherwise, no 1803 // promotion. 1804 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1805 } 1806 } 1807 } 1808 1809 // An rvalue for an integral bit-field (9.6) can be converted to an 1810 // rvalue of type int if int can represent all the values of the 1811 // bit-field; otherwise, it can be converted to unsigned int if 1812 // unsigned int can represent all the values of the bit-field. If 1813 // the bit-field is larger yet, no integral promotion applies to 1814 // it. If the bit-field has an enumerated type, it is treated as any 1815 // other value of that type for promotion purposes (C++ 4.5p3). 1816 // FIXME: We should delay checking of bit-fields until we actually perform the 1817 // conversion. 1818 using llvm::APSInt; 1819 if (From) 1820 if (FieldDecl *MemberDecl = From->getSourceBitField()) { 1821 APSInt BitWidth; 1822 if (FromType->isIntegralType(Context) && 1823 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1824 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1825 ToSize = Context.getTypeSize(ToType); 1826 1827 // Are we promoting to an int from a bitfield that fits in an int? 1828 if (BitWidth < ToSize || 1829 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1830 return To->getKind() == BuiltinType::Int; 1831 } 1832 1833 // Are we promoting to an unsigned int from an unsigned bitfield 1834 // that fits into an unsigned int? 1835 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1836 return To->getKind() == BuiltinType::UInt; 1837 } 1838 1839 return false; 1840 } 1841 } 1842 1843 // An rvalue of type bool can be converted to an rvalue of type int, 1844 // with false becoming zero and true becoming one (C++ 4.5p4). 1845 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1846 return true; 1847 } 1848 1849 return false; 1850} 1851 1852/// IsFloatingPointPromotion - Determines whether the conversion from 1853/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1854/// returns true and sets PromotedType to the promoted type. 1855bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1856 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1857 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1858 /// An rvalue of type float can be converted to an rvalue of type 1859 /// double. (C++ 4.6p1). 1860 if (FromBuiltin->getKind() == BuiltinType::Float && 1861 ToBuiltin->getKind() == BuiltinType::Double) 1862 return true; 1863 1864 // C99 6.3.1.5p1: 1865 // When a float is promoted to double or long double, or a 1866 // double is promoted to long double [...]. 1867 if (!getLangOpts().CPlusPlus && 1868 (FromBuiltin->getKind() == BuiltinType::Float || 1869 FromBuiltin->getKind() == BuiltinType::Double) && 1870 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1871 return true; 1872 1873 // Half can be promoted to float. 1874 if (!getLangOpts().NativeHalfType && 1875 FromBuiltin->getKind() == BuiltinType::Half && 1876 ToBuiltin->getKind() == BuiltinType::Float) 1877 return true; 1878 } 1879 1880 return false; 1881} 1882 1883/// \brief Determine if a conversion is a complex promotion. 1884/// 1885/// A complex promotion is defined as a complex -> complex conversion 1886/// where the conversion between the underlying real types is a 1887/// floating-point or integral promotion. 1888bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1889 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1890 if (!FromComplex) 1891 return false; 1892 1893 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1894 if (!ToComplex) 1895 return false; 1896 1897 return IsFloatingPointPromotion(FromComplex->getElementType(), 1898 ToComplex->getElementType()) || 1899 IsIntegralPromotion(0, FromComplex->getElementType(), 1900 ToComplex->getElementType()); 1901} 1902 1903/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1904/// the pointer type FromPtr to a pointer to type ToPointee, with the 1905/// same type qualifiers as FromPtr has on its pointee type. ToType, 1906/// if non-empty, will be a pointer to ToType that may or may not have 1907/// the right set of qualifiers on its pointee. 1908/// 1909static QualType 1910BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1911 QualType ToPointee, QualType ToType, 1912 ASTContext &Context, 1913 bool StripObjCLifetime = false) { 1914 assert((FromPtr->getTypeClass() == Type::Pointer || 1915 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1916 "Invalid similarly-qualified pointer type"); 1917 1918 /// Conversions to 'id' subsume cv-qualifier conversions. 1919 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1920 return ToType.getUnqualifiedType(); 1921 1922 QualType CanonFromPointee 1923 = Context.getCanonicalType(FromPtr->getPointeeType()); 1924 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1925 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1926 1927 if (StripObjCLifetime) 1928 Quals.removeObjCLifetime(); 1929 1930 // Exact qualifier match -> return the pointer type we're converting to. 1931 if (CanonToPointee.getLocalQualifiers() == Quals) { 1932 // ToType is exactly what we need. Return it. 1933 if (!ToType.isNull()) 1934 return ToType.getUnqualifiedType(); 1935 1936 // Build a pointer to ToPointee. It has the right qualifiers 1937 // already. 1938 if (isa<ObjCObjectPointerType>(ToType)) 1939 return Context.getObjCObjectPointerType(ToPointee); 1940 return Context.getPointerType(ToPointee); 1941 } 1942 1943 // Just build a canonical type that has the right qualifiers. 1944 QualType QualifiedCanonToPointee 1945 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1946 1947 if (isa<ObjCObjectPointerType>(ToType)) 1948 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1949 return Context.getPointerType(QualifiedCanonToPointee); 1950} 1951 1952static bool isNullPointerConstantForConversion(Expr *Expr, 1953 bool InOverloadResolution, 1954 ASTContext &Context) { 1955 // Handle value-dependent integral null pointer constants correctly. 1956 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1957 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1958 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1959 return !InOverloadResolution; 1960 1961 return Expr->isNullPointerConstant(Context, 1962 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1963 : Expr::NPC_ValueDependentIsNull); 1964} 1965 1966/// IsPointerConversion - Determines whether the conversion of the 1967/// expression From, which has the (possibly adjusted) type FromType, 1968/// can be converted to the type ToType via a pointer conversion (C++ 1969/// 4.10). If so, returns true and places the converted type (that 1970/// might differ from ToType in its cv-qualifiers at some level) into 1971/// ConvertedType. 1972/// 1973/// This routine also supports conversions to and from block pointers 1974/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1975/// pointers to interfaces. FIXME: Once we've determined the 1976/// appropriate overloading rules for Objective-C, we may want to 1977/// split the Objective-C checks into a different routine; however, 1978/// GCC seems to consider all of these conversions to be pointer 1979/// conversions, so for now they live here. IncompatibleObjC will be 1980/// set if the conversion is an allowed Objective-C conversion that 1981/// should result in a warning. 1982bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1983 bool InOverloadResolution, 1984 QualType& ConvertedType, 1985 bool &IncompatibleObjC) { 1986 IncompatibleObjC = false; 1987 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 1988 IncompatibleObjC)) 1989 return true; 1990 1991 // Conversion from a null pointer constant to any Objective-C pointer type. 1992 if (ToType->isObjCObjectPointerType() && 1993 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1994 ConvertedType = ToType; 1995 return true; 1996 } 1997 1998 // Blocks: Block pointers can be converted to void*. 1999 if (FromType->isBlockPointerType() && ToType->isPointerType() && 2000 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 2001 ConvertedType = ToType; 2002 return true; 2003 } 2004 // Blocks: A null pointer constant can be converted to a block 2005 // pointer type. 2006 if (ToType->isBlockPointerType() && 2007 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 2008 ConvertedType = ToType; 2009 return true; 2010 } 2011 2012 // If the left-hand-side is nullptr_t, the right side can be a null 2013 // pointer constant. 2014 if (ToType->isNullPtrType() && 2015 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 2016 ConvertedType = ToType; 2017 return true; 2018 } 2019 2020 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 2021 if (!ToTypePtr) 2022 return false; 2023 2024 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 2025 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 2026 ConvertedType = ToType; 2027 return true; 2028 } 2029 2030 // Beyond this point, both types need to be pointers 2031 // , including objective-c pointers. 2032 QualType ToPointeeType = ToTypePtr->getPointeeType(); 2033 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() && 2034 !getLangOpts().ObjCAutoRefCount) { 2035 ConvertedType = BuildSimilarlyQualifiedPointerType( 2036 FromType->getAs<ObjCObjectPointerType>(), 2037 ToPointeeType, 2038 ToType, Context); 2039 return true; 2040 } 2041 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 2042 if (!FromTypePtr) 2043 return false; 2044 2045 QualType FromPointeeType = FromTypePtr->getPointeeType(); 2046 2047 // If the unqualified pointee types are the same, this can't be a 2048 // pointer conversion, so don't do all of the work below. 2049 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 2050 return false; 2051 2052 // An rvalue of type "pointer to cv T," where T is an object type, 2053 // can be converted to an rvalue of type "pointer to cv void" (C++ 2054 // 4.10p2). 2055 if (FromPointeeType->isIncompleteOrObjectType() && 2056 ToPointeeType->isVoidType()) { 2057 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2058 ToPointeeType, 2059 ToType, Context, 2060 /*StripObjCLifetime=*/true); 2061 return true; 2062 } 2063 2064 // MSVC allows implicit function to void* type conversion. 2065 if (getLangOpts().MicrosoftExt && FromPointeeType->isFunctionType() && 2066 ToPointeeType->isVoidType()) { 2067 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2068 ToPointeeType, 2069 ToType, Context); 2070 return true; 2071 } 2072 2073 // When we're overloading in C, we allow a special kind of pointer 2074 // conversion for compatible-but-not-identical pointee types. 2075 if (!getLangOpts().CPlusPlus && 2076 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 2077 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2078 ToPointeeType, 2079 ToType, Context); 2080 return true; 2081 } 2082 2083 // C++ [conv.ptr]p3: 2084 // 2085 // An rvalue of type "pointer to cv D," where D is a class type, 2086 // can be converted to an rvalue of type "pointer to cv B," where 2087 // B is a base class (clause 10) of D. If B is an inaccessible 2088 // (clause 11) or ambiguous (10.2) base class of D, a program that 2089 // necessitates this conversion is ill-formed. The result of the 2090 // conversion is a pointer to the base class sub-object of the 2091 // derived class object. The null pointer value is converted to 2092 // the null pointer value of the destination type. 2093 // 2094 // Note that we do not check for ambiguity or inaccessibility 2095 // here. That is handled by CheckPointerConversion. 2096 if (getLangOpts().CPlusPlus && 2097 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 2098 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 2099 !RequireCompleteType(From->getLocStart(), FromPointeeType, 0) && 2100 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 2101 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2102 ToPointeeType, 2103 ToType, Context); 2104 return true; 2105 } 2106 2107 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() && 2108 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) { 2109 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2110 ToPointeeType, 2111 ToType, Context); 2112 return true; 2113 } 2114 2115 return false; 2116} 2117 2118/// \brief Adopt the given qualifiers for the given type. 2119static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){ 2120 Qualifiers TQs = T.getQualifiers(); 2121 2122 // Check whether qualifiers already match. 2123 if (TQs == Qs) 2124 return T; 2125 2126 if (Qs.compatiblyIncludes(TQs)) 2127 return Context.getQualifiedType(T, Qs); 2128 2129 return Context.getQualifiedType(T.getUnqualifiedType(), Qs); 2130} 2131 2132/// isObjCPointerConversion - Determines whether this is an 2133/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 2134/// with the same arguments and return values. 2135bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 2136 QualType& ConvertedType, 2137 bool &IncompatibleObjC) { 2138 if (!getLangOpts().ObjC1) 2139 return false; 2140 2141 // The set of qualifiers on the type we're converting from. 2142 Qualifiers FromQualifiers = FromType.getQualifiers(); 2143 2144 // First, we handle all conversions on ObjC object pointer types. 2145 const ObjCObjectPointerType* ToObjCPtr = 2146 ToType->getAs<ObjCObjectPointerType>(); 2147 const ObjCObjectPointerType *FromObjCPtr = 2148 FromType->getAs<ObjCObjectPointerType>(); 2149 2150 if (ToObjCPtr && FromObjCPtr) { 2151 // If the pointee types are the same (ignoring qualifications), 2152 // then this is not a pointer conversion. 2153 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 2154 FromObjCPtr->getPointeeType())) 2155 return false; 2156 2157 // Check for compatible 2158 // Objective C++: We're able to convert between "id" or "Class" and a 2159 // pointer to any interface (in both directions). 2160 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 2161 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2162 return true; 2163 } 2164 // Conversions with Objective-C's id<...>. 2165 if ((FromObjCPtr->isObjCQualifiedIdType() || 2166 ToObjCPtr->isObjCQualifiedIdType()) && 2167 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 2168 /*compare=*/false)) { 2169 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2170 return true; 2171 } 2172 // Objective C++: We're able to convert from a pointer to an 2173 // interface to a pointer to a different interface. 2174 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 2175 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 2176 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 2177 if (getLangOpts().CPlusPlus && LHS && RHS && 2178 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 2179 FromObjCPtr->getPointeeType())) 2180 return false; 2181 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 2182 ToObjCPtr->getPointeeType(), 2183 ToType, Context); 2184 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2185 return true; 2186 } 2187 2188 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 2189 // Okay: this is some kind of implicit downcast of Objective-C 2190 // interfaces, which is permitted. However, we're going to 2191 // complain about it. 2192 IncompatibleObjC = true; 2193 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 2194 ToObjCPtr->getPointeeType(), 2195 ToType, Context); 2196 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2197 return true; 2198 } 2199 } 2200 // Beyond this point, both types need to be C pointers or block pointers. 2201 QualType ToPointeeType; 2202 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 2203 ToPointeeType = ToCPtr->getPointeeType(); 2204 else if (const BlockPointerType *ToBlockPtr = 2205 ToType->getAs<BlockPointerType>()) { 2206 // Objective C++: We're able to convert from a pointer to any object 2207 // to a block pointer type. 2208 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 2209 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2210 return true; 2211 } 2212 ToPointeeType = ToBlockPtr->getPointeeType(); 2213 } 2214 else if (FromType->getAs<BlockPointerType>() && 2215 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 2216 // Objective C++: We're able to convert from a block pointer type to a 2217 // pointer to any object. 2218 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2219 return true; 2220 } 2221 else 2222 return false; 2223 2224 QualType FromPointeeType; 2225 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 2226 FromPointeeType = FromCPtr->getPointeeType(); 2227 else if (const BlockPointerType *FromBlockPtr = 2228 FromType->getAs<BlockPointerType>()) 2229 FromPointeeType = FromBlockPtr->getPointeeType(); 2230 else 2231 return false; 2232 2233 // If we have pointers to pointers, recursively check whether this 2234 // is an Objective-C conversion. 2235 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 2236 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 2237 IncompatibleObjC)) { 2238 // We always complain about this conversion. 2239 IncompatibleObjC = true; 2240 ConvertedType = Context.getPointerType(ConvertedType); 2241 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2242 return true; 2243 } 2244 // Allow conversion of pointee being objective-c pointer to another one; 2245 // as in I* to id. 2246 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 2247 ToPointeeType->getAs<ObjCObjectPointerType>() && 2248 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 2249 IncompatibleObjC)) { 2250 2251 ConvertedType = Context.getPointerType(ConvertedType); 2252 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2253 return true; 2254 } 2255 2256 // If we have pointers to functions or blocks, check whether the only 2257 // differences in the argument and result types are in Objective-C 2258 // pointer conversions. If so, we permit the conversion (but 2259 // complain about it). 2260 const FunctionProtoType *FromFunctionType 2261 = FromPointeeType->getAs<FunctionProtoType>(); 2262 const FunctionProtoType *ToFunctionType 2263 = ToPointeeType->getAs<FunctionProtoType>(); 2264 if (FromFunctionType && ToFunctionType) { 2265 // If the function types are exactly the same, this isn't an 2266 // Objective-C pointer conversion. 2267 if (Context.getCanonicalType(FromPointeeType) 2268 == Context.getCanonicalType(ToPointeeType)) 2269 return false; 2270 2271 // Perform the quick checks that will tell us whether these 2272 // function types are obviously different. 2273 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 2274 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 2275 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 2276 return false; 2277 2278 bool HasObjCConversion = false; 2279 if (Context.getCanonicalType(FromFunctionType->getResultType()) 2280 == Context.getCanonicalType(ToFunctionType->getResultType())) { 2281 // Okay, the types match exactly. Nothing to do. 2282 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 2283 ToFunctionType->getResultType(), 2284 ConvertedType, IncompatibleObjC)) { 2285 // Okay, we have an Objective-C pointer conversion. 2286 HasObjCConversion = true; 2287 } else { 2288 // Function types are too different. Abort. 2289 return false; 2290 } 2291 2292 // Check argument types. 2293 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 2294 ArgIdx != NumArgs; ++ArgIdx) { 2295 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 2296 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 2297 if (Context.getCanonicalType(FromArgType) 2298 == Context.getCanonicalType(ToArgType)) { 2299 // Okay, the types match exactly. Nothing to do. 2300 } else if (isObjCPointerConversion(FromArgType, ToArgType, 2301 ConvertedType, IncompatibleObjC)) { 2302 // Okay, we have an Objective-C pointer conversion. 2303 HasObjCConversion = true; 2304 } else { 2305 // Argument types are too different. Abort. 2306 return false; 2307 } 2308 } 2309 2310 if (HasObjCConversion) { 2311 // We had an Objective-C conversion. Allow this pointer 2312 // conversion, but complain about it. 2313 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2314 IncompatibleObjC = true; 2315 return true; 2316 } 2317 } 2318 2319 return false; 2320} 2321 2322/// \brief Determine whether this is an Objective-C writeback conversion, 2323/// used for parameter passing when performing automatic reference counting. 2324/// 2325/// \param FromType The type we're converting form. 2326/// 2327/// \param ToType The type we're converting to. 2328/// 2329/// \param ConvertedType The type that will be produced after applying 2330/// this conversion. 2331bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType, 2332 QualType &ConvertedType) { 2333 if (!getLangOpts().ObjCAutoRefCount || 2334 Context.hasSameUnqualifiedType(FromType, ToType)) 2335 return false; 2336 2337 // Parameter must be a pointer to __autoreleasing (with no other qualifiers). 2338 QualType ToPointee; 2339 if (const PointerType *ToPointer = ToType->getAs<PointerType>()) 2340 ToPointee = ToPointer->getPointeeType(); 2341 else 2342 return false; 2343 2344 Qualifiers ToQuals = ToPointee.getQualifiers(); 2345 if (!ToPointee->isObjCLifetimeType() || 2346 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing || 2347 !ToQuals.withoutObjCLifetime().empty()) 2348 return false; 2349 2350 // Argument must be a pointer to __strong to __weak. 2351 QualType FromPointee; 2352 if (const PointerType *FromPointer = FromType->getAs<PointerType>()) 2353 FromPointee = FromPointer->getPointeeType(); 2354 else 2355 return false; 2356 2357 Qualifiers FromQuals = FromPointee.getQualifiers(); 2358 if (!FromPointee->isObjCLifetimeType() || 2359 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong && 2360 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak)) 2361 return false; 2362 2363 // Make sure that we have compatible qualifiers. 2364 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing); 2365 if (!ToQuals.compatiblyIncludes(FromQuals)) 2366 return false; 2367 2368 // Remove qualifiers from the pointee type we're converting from; they 2369 // aren't used in the compatibility check belong, and we'll be adding back 2370 // qualifiers (with __autoreleasing) if the compatibility check succeeds. 2371 FromPointee = FromPointee.getUnqualifiedType(); 2372 2373 // The unqualified form of the pointee types must be compatible. 2374 ToPointee = ToPointee.getUnqualifiedType(); 2375 bool IncompatibleObjC; 2376 if (Context.typesAreCompatible(FromPointee, ToPointee)) 2377 FromPointee = ToPointee; 2378 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee, 2379 IncompatibleObjC)) 2380 return false; 2381 2382 /// \brief Construct the type we're converting to, which is a pointer to 2383 /// __autoreleasing pointee. 2384 FromPointee = Context.getQualifiedType(FromPointee, FromQuals); 2385 ConvertedType = Context.getPointerType(FromPointee); 2386 return true; 2387} 2388 2389bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, 2390 QualType& ConvertedType) { 2391 QualType ToPointeeType; 2392 if (const BlockPointerType *ToBlockPtr = 2393 ToType->getAs<BlockPointerType>()) 2394 ToPointeeType = ToBlockPtr->getPointeeType(); 2395 else 2396 return false; 2397 2398 QualType FromPointeeType; 2399 if (const BlockPointerType *FromBlockPtr = 2400 FromType->getAs<BlockPointerType>()) 2401 FromPointeeType = FromBlockPtr->getPointeeType(); 2402 else 2403 return false; 2404 // We have pointer to blocks, check whether the only 2405 // differences in the argument and result types are in Objective-C 2406 // pointer conversions. If so, we permit the conversion. 2407 2408 const FunctionProtoType *FromFunctionType 2409 = FromPointeeType->getAs<FunctionProtoType>(); 2410 const FunctionProtoType *ToFunctionType 2411 = ToPointeeType->getAs<FunctionProtoType>(); 2412 2413 if (!FromFunctionType || !ToFunctionType) 2414 return false; 2415 2416 if (Context.hasSameType(FromPointeeType, ToPointeeType)) 2417 return true; 2418 2419 // Perform the quick checks that will tell us whether these 2420 // function types are obviously different. 2421 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 2422 FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) 2423 return false; 2424 2425 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); 2426 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); 2427 if (FromEInfo != ToEInfo) 2428 return false; 2429 2430 bool IncompatibleObjC = false; 2431 if (Context.hasSameType(FromFunctionType->getResultType(), 2432 ToFunctionType->getResultType())) { 2433 // Okay, the types match exactly. Nothing to do. 2434 } else { 2435 QualType RHS = FromFunctionType->getResultType(); 2436 QualType LHS = ToFunctionType->getResultType(); 2437 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) && 2438 !RHS.hasQualifiers() && LHS.hasQualifiers()) 2439 LHS = LHS.getUnqualifiedType(); 2440 2441 if (Context.hasSameType(RHS,LHS)) { 2442 // OK exact match. 2443 } else if (isObjCPointerConversion(RHS, LHS, 2444 ConvertedType, IncompatibleObjC)) { 2445 if (IncompatibleObjC) 2446 return false; 2447 // Okay, we have an Objective-C pointer conversion. 2448 } 2449 else 2450 return false; 2451 } 2452 2453 // Check argument types. 2454 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 2455 ArgIdx != NumArgs; ++ArgIdx) { 2456 IncompatibleObjC = false; 2457 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 2458 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 2459 if (Context.hasSameType(FromArgType, ToArgType)) { 2460 // Okay, the types match exactly. Nothing to do. 2461 } else if (isObjCPointerConversion(ToArgType, FromArgType, 2462 ConvertedType, IncompatibleObjC)) { 2463 if (IncompatibleObjC) 2464 return false; 2465 // Okay, we have an Objective-C pointer conversion. 2466 } else 2467 // Argument types are too different. Abort. 2468 return false; 2469 } 2470 if (LangOpts.ObjCAutoRefCount && 2471 !Context.FunctionTypesMatchOnNSConsumedAttrs(FromFunctionType, 2472 ToFunctionType)) 2473 return false; 2474 2475 ConvertedType = ToType; 2476 return true; 2477} 2478 2479enum { 2480 ft_default, 2481 ft_different_class, 2482 ft_parameter_arity, 2483 ft_parameter_mismatch, 2484 ft_return_type, 2485 ft_qualifer_mismatch 2486}; 2487 2488/// HandleFunctionTypeMismatch - Gives diagnostic information for differeing 2489/// function types. Catches different number of parameter, mismatch in 2490/// parameter types, and different return types. 2491void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag, 2492 QualType FromType, QualType ToType) { 2493 // If either type is not valid, include no extra info. 2494 if (FromType.isNull() || ToType.isNull()) { 2495 PDiag << ft_default; 2496 return; 2497 } 2498 2499 // Get the function type from the pointers. 2500 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) { 2501 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(), 2502 *ToMember = ToType->getAs<MemberPointerType>(); 2503 if (FromMember->getClass() != ToMember->getClass()) { 2504 PDiag << ft_different_class << QualType(ToMember->getClass(), 0) 2505 << QualType(FromMember->getClass(), 0); 2506 return; 2507 } 2508 FromType = FromMember->getPointeeType(); 2509 ToType = ToMember->getPointeeType(); 2510 } 2511 2512 if (FromType->isPointerType()) 2513 FromType = FromType->getPointeeType(); 2514 if (ToType->isPointerType()) 2515 ToType = ToType->getPointeeType(); 2516 2517 // Remove references. 2518 FromType = FromType.getNonReferenceType(); 2519 ToType = ToType.getNonReferenceType(); 2520 2521 // Don't print extra info for non-specialized template functions. 2522 if (FromType->isInstantiationDependentType() && 2523 !FromType->getAs<TemplateSpecializationType>()) { 2524 PDiag << ft_default; 2525 return; 2526 } 2527 2528 // No extra info for same types. 2529 if (Context.hasSameType(FromType, ToType)) { 2530 PDiag << ft_default; 2531 return; 2532 } 2533 2534 const FunctionProtoType *FromFunction = FromType->getAs<FunctionProtoType>(), 2535 *ToFunction = ToType->getAs<FunctionProtoType>(); 2536 2537 // Both types need to be function types. 2538 if (!FromFunction || !ToFunction) { 2539 PDiag << ft_default; 2540 return; 2541 } 2542 2543 if (FromFunction->getNumArgs() != ToFunction->getNumArgs()) { 2544 PDiag << ft_parameter_arity << ToFunction->getNumArgs() 2545 << FromFunction->getNumArgs(); 2546 return; 2547 } 2548 2549 // Handle different parameter types. 2550 unsigned ArgPos; 2551 if (!FunctionArgTypesAreEqual(FromFunction, ToFunction, &ArgPos)) { 2552 PDiag << ft_parameter_mismatch << ArgPos + 1 2553 << ToFunction->getArgType(ArgPos) 2554 << FromFunction->getArgType(ArgPos); 2555 return; 2556 } 2557 2558 // Handle different return type. 2559 if (!Context.hasSameType(FromFunction->getResultType(), 2560 ToFunction->getResultType())) { 2561 PDiag << ft_return_type << ToFunction->getResultType() 2562 << FromFunction->getResultType(); 2563 return; 2564 } 2565 2566 unsigned FromQuals = FromFunction->getTypeQuals(), 2567 ToQuals = ToFunction->getTypeQuals(); 2568 if (FromQuals != ToQuals) { 2569 PDiag << ft_qualifer_mismatch << ToQuals << FromQuals; 2570 return; 2571 } 2572 2573 // Unable to find a difference, so add no extra info. 2574 PDiag << ft_default; 2575} 2576 2577/// FunctionArgTypesAreEqual - This routine checks two function proto types 2578/// for equality of their argument types. Caller has already checked that 2579/// they have same number of arguments. If the parameters are different, 2580/// ArgPos will have the parameter index of the first different parameter. 2581bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, 2582 const FunctionProtoType *NewType, 2583 unsigned *ArgPos) { 2584 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 2585 N = NewType->arg_type_begin(), 2586 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 2587 if (!Context.hasSameType(O->getUnqualifiedType(), 2588 N->getUnqualifiedType())) { 2589 if (ArgPos) *ArgPos = O - OldType->arg_type_begin(); 2590 return false; 2591 } 2592 } 2593 return true; 2594} 2595 2596/// CheckPointerConversion - Check the pointer conversion from the 2597/// expression From to the type ToType. This routine checks for 2598/// ambiguous or inaccessible derived-to-base pointer 2599/// conversions for which IsPointerConversion has already returned 2600/// true. It returns true and produces a diagnostic if there was an 2601/// error, or returns false otherwise. 2602bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 2603 CastKind &Kind, 2604 CXXCastPath& BasePath, 2605 bool IgnoreBaseAccess) { 2606 QualType FromType = From->getType(); 2607 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 2608 2609 Kind = CK_BitCast; 2610 2611 if (!IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() && 2612 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) == 2613 Expr::NPCK_ZeroExpression) { 2614 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy)) 2615 DiagRuntimeBehavior(From->getExprLoc(), From, 2616 PDiag(diag::warn_impcast_bool_to_null_pointer) 2617 << ToType << From->getSourceRange()); 2618 else if (!isUnevaluatedContext()) 2619 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer) 2620 << ToType << From->getSourceRange(); 2621 } 2622 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 2623 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) { 2624 QualType FromPointeeType = FromPtrType->getPointeeType(), 2625 ToPointeeType = ToPtrType->getPointeeType(); 2626 2627 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 2628 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 2629 // We must have a derived-to-base conversion. Check an 2630 // ambiguous or inaccessible conversion. 2631 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 2632 From->getExprLoc(), 2633 From->getSourceRange(), &BasePath, 2634 IgnoreBaseAccess)) 2635 return true; 2636 2637 // The conversion was successful. 2638 Kind = CK_DerivedToBase; 2639 } 2640 } 2641 } else if (const ObjCObjectPointerType *ToPtrType = 2642 ToType->getAs<ObjCObjectPointerType>()) { 2643 if (const ObjCObjectPointerType *FromPtrType = 2644 FromType->getAs<ObjCObjectPointerType>()) { 2645 // Objective-C++ conversions are always okay. 2646 // FIXME: We should have a different class of conversions for the 2647 // Objective-C++ implicit conversions. 2648 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 2649 return false; 2650 } else if (FromType->isBlockPointerType()) { 2651 Kind = CK_BlockPointerToObjCPointerCast; 2652 } else { 2653 Kind = CK_CPointerToObjCPointerCast; 2654 } 2655 } else if (ToType->isBlockPointerType()) { 2656 if (!FromType->isBlockPointerType()) 2657 Kind = CK_AnyPointerToBlockPointerCast; 2658 } 2659 2660 // We shouldn't fall into this case unless it's valid for other 2661 // reasons. 2662 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 2663 Kind = CK_NullToPointer; 2664 2665 return false; 2666} 2667 2668/// IsMemberPointerConversion - Determines whether the conversion of the 2669/// expression From, which has the (possibly adjusted) type FromType, can be 2670/// converted to the type ToType via a member pointer conversion (C++ 4.11). 2671/// If so, returns true and places the converted type (that might differ from 2672/// ToType in its cv-qualifiers at some level) into ConvertedType. 2673bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 2674 QualType ToType, 2675 bool InOverloadResolution, 2676 QualType &ConvertedType) { 2677 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 2678 if (!ToTypePtr) 2679 return false; 2680 2681 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 2682 if (From->isNullPointerConstant(Context, 2683 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 2684 : Expr::NPC_ValueDependentIsNull)) { 2685 ConvertedType = ToType; 2686 return true; 2687 } 2688 2689 // Otherwise, both types have to be member pointers. 2690 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 2691 if (!FromTypePtr) 2692 return false; 2693 2694 // A pointer to member of B can be converted to a pointer to member of D, 2695 // where D is derived from B (C++ 4.11p2). 2696 QualType FromClass(FromTypePtr->getClass(), 0); 2697 QualType ToClass(ToTypePtr->getClass(), 0); 2698 2699 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && 2700 !RequireCompleteType(From->getLocStart(), ToClass, 0) && 2701 IsDerivedFrom(ToClass, FromClass)) { 2702 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 2703 ToClass.getTypePtr()); 2704 return true; 2705 } 2706 2707 return false; 2708} 2709 2710/// CheckMemberPointerConversion - Check the member pointer conversion from the 2711/// expression From to the type ToType. This routine checks for ambiguous or 2712/// virtual or inaccessible base-to-derived member pointer conversions 2713/// for which IsMemberPointerConversion has already returned true. It returns 2714/// true and produces a diagnostic if there was an error, or returns false 2715/// otherwise. 2716bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 2717 CastKind &Kind, 2718 CXXCastPath &BasePath, 2719 bool IgnoreBaseAccess) { 2720 QualType FromType = From->getType(); 2721 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 2722 if (!FromPtrType) { 2723 // This must be a null pointer to member pointer conversion 2724 assert(From->isNullPointerConstant(Context, 2725 Expr::NPC_ValueDependentIsNull) && 2726 "Expr must be null pointer constant!"); 2727 Kind = CK_NullToMemberPointer; 2728 return false; 2729 } 2730 2731 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 2732 assert(ToPtrType && "No member pointer cast has a target type " 2733 "that is not a member pointer."); 2734 2735 QualType FromClass = QualType(FromPtrType->getClass(), 0); 2736 QualType ToClass = QualType(ToPtrType->getClass(), 0); 2737 2738 // FIXME: What about dependent types? 2739 assert(FromClass->isRecordType() && "Pointer into non-class."); 2740 assert(ToClass->isRecordType() && "Pointer into non-class."); 2741 2742 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 2743 /*DetectVirtual=*/true); 2744 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 2745 assert(DerivationOkay && 2746 "Should not have been called if derivation isn't OK."); 2747 (void)DerivationOkay; 2748 2749 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 2750 getUnqualifiedType())) { 2751 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 2752 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 2753 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 2754 return true; 2755 } 2756 2757 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 2758 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 2759 << FromClass << ToClass << QualType(VBase, 0) 2760 << From->getSourceRange(); 2761 return true; 2762 } 2763 2764 if (!IgnoreBaseAccess) 2765 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 2766 Paths.front(), 2767 diag::err_downcast_from_inaccessible_base); 2768 2769 // Must be a base to derived member conversion. 2770 BuildBasePathArray(Paths, BasePath); 2771 Kind = CK_BaseToDerivedMemberPointer; 2772 return false; 2773} 2774 2775/// IsQualificationConversion - Determines whether the conversion from 2776/// an rvalue of type FromType to ToType is a qualification conversion 2777/// (C++ 4.4). 2778/// 2779/// \param ObjCLifetimeConversion Output parameter that will be set to indicate 2780/// when the qualification conversion involves a change in the Objective-C 2781/// object lifetime. 2782bool 2783Sema::IsQualificationConversion(QualType FromType, QualType ToType, 2784 bool CStyle, bool &ObjCLifetimeConversion) { 2785 FromType = Context.getCanonicalType(FromType); 2786 ToType = Context.getCanonicalType(ToType); 2787 ObjCLifetimeConversion = false; 2788 2789 // If FromType and ToType are the same type, this is not a 2790 // qualification conversion. 2791 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 2792 return false; 2793 2794 // (C++ 4.4p4): 2795 // A conversion can add cv-qualifiers at levels other than the first 2796 // in multi-level pointers, subject to the following rules: [...] 2797 bool PreviousToQualsIncludeConst = true; 2798 bool UnwrappedAnyPointer = false; 2799 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 2800 // Within each iteration of the loop, we check the qualifiers to 2801 // determine if this still looks like a qualification 2802 // conversion. Then, if all is well, we unwrap one more level of 2803 // pointers or pointers-to-members and do it all again 2804 // until there are no more pointers or pointers-to-members left to 2805 // unwrap. 2806 UnwrappedAnyPointer = true; 2807 2808 Qualifiers FromQuals = FromType.getQualifiers(); 2809 Qualifiers ToQuals = ToType.getQualifiers(); 2810 2811 // Objective-C ARC: 2812 // Check Objective-C lifetime conversions. 2813 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() && 2814 UnwrappedAnyPointer) { 2815 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) { 2816 ObjCLifetimeConversion = true; 2817 FromQuals.removeObjCLifetime(); 2818 ToQuals.removeObjCLifetime(); 2819 } else { 2820 // Qualification conversions cannot cast between different 2821 // Objective-C lifetime qualifiers. 2822 return false; 2823 } 2824 } 2825 2826 // Allow addition/removal of GC attributes but not changing GC attributes. 2827 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() && 2828 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) { 2829 FromQuals.removeObjCGCAttr(); 2830 ToQuals.removeObjCGCAttr(); 2831 } 2832 2833 // -- for every j > 0, if const is in cv 1,j then const is in cv 2834 // 2,j, and similarly for volatile. 2835 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals)) 2836 return false; 2837 2838 // -- if the cv 1,j and cv 2,j are different, then const is in 2839 // every cv for 0 < k < j. 2840 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers() 2841 && !PreviousToQualsIncludeConst) 2842 return false; 2843 2844 // Keep track of whether all prior cv-qualifiers in the "to" type 2845 // include const. 2846 PreviousToQualsIncludeConst 2847 = PreviousToQualsIncludeConst && ToQuals.hasConst(); 2848 } 2849 2850 // We are left with FromType and ToType being the pointee types 2851 // after unwrapping the original FromType and ToType the same number 2852 // of types. If we unwrapped any pointers, and if FromType and 2853 // ToType have the same unqualified type (since we checked 2854 // qualifiers above), then this is a qualification conversion. 2855 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2856} 2857 2858/// \brief - Determine whether this is a conversion from a scalar type to an 2859/// atomic type. 2860/// 2861/// If successful, updates \c SCS's second and third steps in the conversion 2862/// sequence to finish the conversion. 2863static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType, 2864 bool InOverloadResolution, 2865 StandardConversionSequence &SCS, 2866 bool CStyle) { 2867 const AtomicType *ToAtomic = ToType->getAs<AtomicType>(); 2868 if (!ToAtomic) 2869 return false; 2870 2871 StandardConversionSequence InnerSCS; 2872 if (!IsStandardConversion(S, From, ToAtomic->getValueType(), 2873 InOverloadResolution, InnerSCS, 2874 CStyle, /*AllowObjCWritebackConversion=*/false)) 2875 return false; 2876 2877 SCS.Second = InnerSCS.Second; 2878 SCS.setToType(1, InnerSCS.getToType(1)); 2879 SCS.Third = InnerSCS.Third; 2880 SCS.QualificationIncludesObjCLifetime 2881 = InnerSCS.QualificationIncludesObjCLifetime; 2882 SCS.setToType(2, InnerSCS.getToType(2)); 2883 return true; 2884} 2885 2886static bool isFirstArgumentCompatibleWithType(ASTContext &Context, 2887 CXXConstructorDecl *Constructor, 2888 QualType Type) { 2889 const FunctionProtoType *CtorType = 2890 Constructor->getType()->getAs<FunctionProtoType>(); 2891 if (CtorType->getNumArgs() > 0) { 2892 QualType FirstArg = CtorType->getArgType(0); 2893 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType())) 2894 return true; 2895 } 2896 return false; 2897} 2898 2899static OverloadingResult 2900IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType, 2901 CXXRecordDecl *To, 2902 UserDefinedConversionSequence &User, 2903 OverloadCandidateSet &CandidateSet, 2904 bool AllowExplicit) { 2905 DeclContext::lookup_result R = S.LookupConstructors(To); 2906 for (DeclContext::lookup_iterator Con = R.begin(), ConEnd = R.end(); 2907 Con != ConEnd; ++Con) { 2908 NamedDecl *D = *Con; 2909 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2910 2911 // Find the constructor (which may be a template). 2912 CXXConstructorDecl *Constructor = 0; 2913 FunctionTemplateDecl *ConstructorTmpl 2914 = dyn_cast<FunctionTemplateDecl>(D); 2915 if (ConstructorTmpl) 2916 Constructor 2917 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2918 else 2919 Constructor = cast<CXXConstructorDecl>(D); 2920 2921 bool Usable = !Constructor->isInvalidDecl() && 2922 S.isInitListConstructor(Constructor) && 2923 (AllowExplicit || !Constructor->isExplicit()); 2924 if (Usable) { 2925 // If the first argument is (a reference to) the target type, 2926 // suppress conversions. 2927 bool SuppressUserConversions = 2928 isFirstArgumentCompatibleWithType(S.Context, Constructor, ToType); 2929 if (ConstructorTmpl) 2930 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2931 /*ExplicitArgs*/ 0, 2932 From, CandidateSet, 2933 SuppressUserConversions); 2934 else 2935 S.AddOverloadCandidate(Constructor, FoundDecl, 2936 From, CandidateSet, 2937 SuppressUserConversions); 2938 } 2939 } 2940 2941 bool HadMultipleCandidates = (CandidateSet.size() > 1); 2942 2943 OverloadCandidateSet::iterator Best; 2944 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2945 case OR_Success: { 2946 // Record the standard conversion we used and the conversion function. 2947 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function); 2948 QualType ThisType = Constructor->getThisType(S.Context); 2949 // Initializer lists don't have conversions as such. 2950 User.Before.setAsIdentityConversion(); 2951 User.HadMultipleCandidates = HadMultipleCandidates; 2952 User.ConversionFunction = Constructor; 2953 User.FoundConversionFunction = Best->FoundDecl; 2954 User.After.setAsIdentityConversion(); 2955 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2956 User.After.setAllToTypes(ToType); 2957 return OR_Success; 2958 } 2959 2960 case OR_No_Viable_Function: 2961 return OR_No_Viable_Function; 2962 case OR_Deleted: 2963 return OR_Deleted; 2964 case OR_Ambiguous: 2965 return OR_Ambiguous; 2966 } 2967 2968 llvm_unreachable("Invalid OverloadResult!"); 2969} 2970 2971/// Determines whether there is a user-defined conversion sequence 2972/// (C++ [over.ics.user]) that converts expression From to the type 2973/// ToType. If such a conversion exists, User will contain the 2974/// user-defined conversion sequence that performs such a conversion 2975/// and this routine will return true. Otherwise, this routine returns 2976/// false and User is unspecified. 2977/// 2978/// \param AllowExplicit true if the conversion should consider C++0x 2979/// "explicit" conversion functions as well as non-explicit conversion 2980/// functions (C++0x [class.conv.fct]p2). 2981static OverloadingResult 2982IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 2983 UserDefinedConversionSequence &User, 2984 OverloadCandidateSet &CandidateSet, 2985 bool AllowExplicit) { 2986 // Whether we will only visit constructors. 2987 bool ConstructorsOnly = false; 2988 2989 // If the type we are conversion to is a class type, enumerate its 2990 // constructors. 2991 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 2992 // C++ [over.match.ctor]p1: 2993 // When objects of class type are direct-initialized (8.5), or 2994 // copy-initialized from an expression of the same or a 2995 // derived class type (8.5), overload resolution selects the 2996 // constructor. [...] For copy-initialization, the candidate 2997 // functions are all the converting constructors (12.3.1) of 2998 // that class. The argument list is the expression-list within 2999 // the parentheses of the initializer. 3000 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 3001 (From->getType()->getAs<RecordType>() && 3002 S.IsDerivedFrom(From->getType(), ToType))) 3003 ConstructorsOnly = true; 3004 3005 S.RequireCompleteType(From->getExprLoc(), ToType, 0); 3006 // RequireCompleteType may have returned true due to some invalid decl 3007 // during template instantiation, but ToType may be complete enough now 3008 // to try to recover. 3009 if (ToType->isIncompleteType()) { 3010 // We're not going to find any constructors. 3011 } else if (CXXRecordDecl *ToRecordDecl 3012 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 3013 3014 Expr **Args = &From; 3015 unsigned NumArgs = 1; 3016 bool ListInitializing = false; 3017 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) { 3018 // But first, see if there is an init-list-contructor that will work. 3019 OverloadingResult Result = IsInitializerListConstructorConversion( 3020 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit); 3021 if (Result != OR_No_Viable_Function) 3022 return Result; 3023 // Never mind. 3024 CandidateSet.clear(); 3025 3026 // If we're list-initializing, we pass the individual elements as 3027 // arguments, not the entire list. 3028 Args = InitList->getInits(); 3029 NumArgs = InitList->getNumInits(); 3030 ListInitializing = true; 3031 } 3032 3033 DeclContext::lookup_result R = S.LookupConstructors(ToRecordDecl); 3034 for (DeclContext::lookup_iterator Con = R.begin(), ConEnd = R.end(); 3035 Con != ConEnd; ++Con) { 3036 NamedDecl *D = *Con; 3037 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 3038 3039 // Find the constructor (which may be a template). 3040 CXXConstructorDecl *Constructor = 0; 3041 FunctionTemplateDecl *ConstructorTmpl 3042 = dyn_cast<FunctionTemplateDecl>(D); 3043 if (ConstructorTmpl) 3044 Constructor 3045 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 3046 else 3047 Constructor = cast<CXXConstructorDecl>(D); 3048 3049 bool Usable = !Constructor->isInvalidDecl(); 3050 if (ListInitializing) 3051 Usable = Usable && (AllowExplicit || !Constructor->isExplicit()); 3052 else 3053 Usable = Usable &&Constructor->isConvertingConstructor(AllowExplicit); 3054 if (Usable) { 3055 bool SuppressUserConversions = !ConstructorsOnly; 3056 if (SuppressUserConversions && ListInitializing) { 3057 SuppressUserConversions = false; 3058 if (NumArgs == 1) { 3059 // If the first argument is (a reference to) the target type, 3060 // suppress conversions. 3061 SuppressUserConversions = isFirstArgumentCompatibleWithType( 3062 S.Context, Constructor, ToType); 3063 } 3064 } 3065 if (ConstructorTmpl) 3066 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 3067 /*ExplicitArgs*/ 0, 3068 llvm::makeArrayRef(Args, NumArgs), 3069 CandidateSet, SuppressUserConversions); 3070 else 3071 // Allow one user-defined conversion when user specifies a 3072 // From->ToType conversion via an static cast (c-style, etc). 3073 S.AddOverloadCandidate(Constructor, FoundDecl, 3074 llvm::makeArrayRef(Args, NumArgs), 3075 CandidateSet, SuppressUserConversions); 3076 } 3077 } 3078 } 3079 } 3080 3081 // Enumerate conversion functions, if we're allowed to. 3082 if (ConstructorsOnly || isa<InitListExpr>(From)) { 3083 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 0)) { 3084 // No conversion functions from incomplete types. 3085 } else if (const RecordType *FromRecordType 3086 = From->getType()->getAs<RecordType>()) { 3087 if (CXXRecordDecl *FromRecordDecl 3088 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 3089 // Add all of the conversion functions as candidates. 3090 std::pair<CXXRecordDecl::conversion_iterator, 3091 CXXRecordDecl::conversion_iterator> 3092 Conversions = FromRecordDecl->getVisibleConversionFunctions(); 3093 for (CXXRecordDecl::conversion_iterator 3094 I = Conversions.first, E = Conversions.second; I != E; ++I) { 3095 DeclAccessPair FoundDecl = I.getPair(); 3096 NamedDecl *D = FoundDecl.getDecl(); 3097 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 3098 if (isa<UsingShadowDecl>(D)) 3099 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3100 3101 CXXConversionDecl *Conv; 3102 FunctionTemplateDecl *ConvTemplate; 3103 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 3104 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3105 else 3106 Conv = cast<CXXConversionDecl>(D); 3107 3108 if (AllowExplicit || !Conv->isExplicit()) { 3109 if (ConvTemplate) 3110 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 3111 ActingContext, From, ToType, 3112 CandidateSet); 3113 else 3114 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 3115 From, ToType, CandidateSet); 3116 } 3117 } 3118 } 3119 } 3120 3121 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3122 3123 OverloadCandidateSet::iterator Best; 3124 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 3125 case OR_Success: 3126 // Record the standard conversion we used and the conversion function. 3127 if (CXXConstructorDecl *Constructor 3128 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 3129 // C++ [over.ics.user]p1: 3130 // If the user-defined conversion is specified by a 3131 // constructor (12.3.1), the initial standard conversion 3132 // sequence converts the source type to the type required by 3133 // the argument of the constructor. 3134 // 3135 QualType ThisType = Constructor->getThisType(S.Context); 3136 if (isa<InitListExpr>(From)) { 3137 // Initializer lists don't have conversions as such. 3138 User.Before.setAsIdentityConversion(); 3139 } else { 3140 if (Best->Conversions[0].isEllipsis()) 3141 User.EllipsisConversion = true; 3142 else { 3143 User.Before = Best->Conversions[0].Standard; 3144 User.EllipsisConversion = false; 3145 } 3146 } 3147 User.HadMultipleCandidates = HadMultipleCandidates; 3148 User.ConversionFunction = Constructor; 3149 User.FoundConversionFunction = Best->FoundDecl; 3150 User.After.setAsIdentityConversion(); 3151 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 3152 User.After.setAllToTypes(ToType); 3153 return OR_Success; 3154 } 3155 if (CXXConversionDecl *Conversion 3156 = dyn_cast<CXXConversionDecl>(Best->Function)) { 3157 // C++ [over.ics.user]p1: 3158 // 3159 // [...] If the user-defined conversion is specified by a 3160 // conversion function (12.3.2), the initial standard 3161 // conversion sequence converts the source type to the 3162 // implicit object parameter of the conversion function. 3163 User.Before = Best->Conversions[0].Standard; 3164 User.HadMultipleCandidates = HadMultipleCandidates; 3165 User.ConversionFunction = Conversion; 3166 User.FoundConversionFunction = Best->FoundDecl; 3167 User.EllipsisConversion = false; 3168 3169 // C++ [over.ics.user]p2: 3170 // The second standard conversion sequence converts the 3171 // result of the user-defined conversion to the target type 3172 // for the sequence. Since an implicit conversion sequence 3173 // is an initialization, the special rules for 3174 // initialization by user-defined conversion apply when 3175 // selecting the best user-defined conversion for a 3176 // user-defined conversion sequence (see 13.3.3 and 3177 // 13.3.3.1). 3178 User.After = Best->FinalConversion; 3179 return OR_Success; 3180 } 3181 llvm_unreachable("Not a constructor or conversion function?"); 3182 3183 case OR_No_Viable_Function: 3184 return OR_No_Viable_Function; 3185 case OR_Deleted: 3186 // No conversion here! We're done. 3187 return OR_Deleted; 3188 3189 case OR_Ambiguous: 3190 return OR_Ambiguous; 3191 } 3192 3193 llvm_unreachable("Invalid OverloadResult!"); 3194} 3195 3196bool 3197Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 3198 ImplicitConversionSequence ICS; 3199 OverloadCandidateSet CandidateSet(From->getExprLoc()); 3200 OverloadingResult OvResult = 3201 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 3202 CandidateSet, false); 3203 if (OvResult == OR_Ambiguous) 3204 Diag(From->getLocStart(), 3205 diag::err_typecheck_ambiguous_condition) 3206 << From->getType() << ToType << From->getSourceRange(); 3207 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) { 3208 if (!RequireCompleteType(From->getLocStart(), ToType, 3209 diag::err_typecheck_nonviable_condition_incomplete, 3210 From->getType(), From->getSourceRange())) 3211 Diag(From->getLocStart(), 3212 diag::err_typecheck_nonviable_condition) 3213 << From->getType() << From->getSourceRange() << ToType; 3214 } 3215 else 3216 return false; 3217 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From); 3218 return true; 3219} 3220 3221/// \brief Compare the user-defined conversion functions or constructors 3222/// of two user-defined conversion sequences to determine whether any ordering 3223/// is possible. 3224static ImplicitConversionSequence::CompareKind 3225compareConversionFunctions(Sema &S, 3226 FunctionDecl *Function1, 3227 FunctionDecl *Function2) { 3228 if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus11) 3229 return ImplicitConversionSequence::Indistinguishable; 3230 3231 // Objective-C++: 3232 // If both conversion functions are implicitly-declared conversions from 3233 // a lambda closure type to a function pointer and a block pointer, 3234 // respectively, always prefer the conversion to a function pointer, 3235 // because the function pointer is more lightweight and is more likely 3236 // to keep code working. 3237 CXXConversionDecl *Conv1 = dyn_cast<CXXConversionDecl>(Function1); 3238 if (!Conv1) 3239 return ImplicitConversionSequence::Indistinguishable; 3240 3241 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2); 3242 if (!Conv2) 3243 return ImplicitConversionSequence::Indistinguishable; 3244 3245 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) { 3246 bool Block1 = Conv1->getConversionType()->isBlockPointerType(); 3247 bool Block2 = Conv2->getConversionType()->isBlockPointerType(); 3248 if (Block1 != Block2) 3249 return Block1? ImplicitConversionSequence::Worse 3250 : ImplicitConversionSequence::Better; 3251 } 3252 3253 return ImplicitConversionSequence::Indistinguishable; 3254} 3255 3256/// CompareImplicitConversionSequences - Compare two implicit 3257/// conversion sequences to determine whether one is better than the 3258/// other or if they are indistinguishable (C++ 13.3.3.2). 3259static ImplicitConversionSequence::CompareKind 3260CompareImplicitConversionSequences(Sema &S, 3261 const ImplicitConversionSequence& ICS1, 3262 const ImplicitConversionSequence& ICS2) 3263{ 3264 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 3265 // conversion sequences (as defined in 13.3.3.1) 3266 // -- a standard conversion sequence (13.3.3.1.1) is a better 3267 // conversion sequence than a user-defined conversion sequence or 3268 // an ellipsis conversion sequence, and 3269 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 3270 // conversion sequence than an ellipsis conversion sequence 3271 // (13.3.3.1.3). 3272 // 3273 // C++0x [over.best.ics]p10: 3274 // For the purpose of ranking implicit conversion sequences as 3275 // described in 13.3.3.2, the ambiguous conversion sequence is 3276 // treated as a user-defined sequence that is indistinguishable 3277 // from any other user-defined conversion sequence. 3278 if (ICS1.getKindRank() < ICS2.getKindRank()) 3279 return ImplicitConversionSequence::Better; 3280 if (ICS2.getKindRank() < ICS1.getKindRank()) 3281 return ImplicitConversionSequence::Worse; 3282 3283 // The following checks require both conversion sequences to be of 3284 // the same kind. 3285 if (ICS1.getKind() != ICS2.getKind()) 3286 return ImplicitConversionSequence::Indistinguishable; 3287 3288 ImplicitConversionSequence::CompareKind Result = 3289 ImplicitConversionSequence::Indistinguishable; 3290 3291 // Two implicit conversion sequences of the same form are 3292 // indistinguishable conversion sequences unless one of the 3293 // following rules apply: (C++ 13.3.3.2p3): 3294 if (ICS1.isStandard()) 3295 Result = CompareStandardConversionSequences(S, 3296 ICS1.Standard, ICS2.Standard); 3297 else if (ICS1.isUserDefined()) { 3298 // User-defined conversion sequence U1 is a better conversion 3299 // sequence than another user-defined conversion sequence U2 if 3300 // they contain the same user-defined conversion function or 3301 // constructor and if the second standard conversion sequence of 3302 // U1 is better than the second standard conversion sequence of 3303 // U2 (C++ 13.3.3.2p3). 3304 if (ICS1.UserDefined.ConversionFunction == 3305 ICS2.UserDefined.ConversionFunction) 3306 Result = CompareStandardConversionSequences(S, 3307 ICS1.UserDefined.After, 3308 ICS2.UserDefined.After); 3309 else 3310 Result = compareConversionFunctions(S, 3311 ICS1.UserDefined.ConversionFunction, 3312 ICS2.UserDefined.ConversionFunction); 3313 } 3314 3315 // List-initialization sequence L1 is a better conversion sequence than 3316 // list-initialization sequence L2 if L1 converts to std::initializer_list<X> 3317 // for some X and L2 does not. 3318 if (Result == ImplicitConversionSequence::Indistinguishable && 3319 !ICS1.isBad() && 3320 ICS1.isListInitializationSequence() && 3321 ICS2.isListInitializationSequence()) { 3322 if (ICS1.isStdInitializerListElement() && 3323 !ICS2.isStdInitializerListElement()) 3324 return ImplicitConversionSequence::Better; 3325 if (!ICS1.isStdInitializerListElement() && 3326 ICS2.isStdInitializerListElement()) 3327 return ImplicitConversionSequence::Worse; 3328 } 3329 3330 return Result; 3331} 3332 3333static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 3334 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 3335 Qualifiers Quals; 3336 T1 = Context.getUnqualifiedArrayType(T1, Quals); 3337 T2 = Context.getUnqualifiedArrayType(T2, Quals); 3338 } 3339 3340 return Context.hasSameUnqualifiedType(T1, T2); 3341} 3342 3343// Per 13.3.3.2p3, compare the given standard conversion sequences to 3344// determine if one is a proper subset of the other. 3345static ImplicitConversionSequence::CompareKind 3346compareStandardConversionSubsets(ASTContext &Context, 3347 const StandardConversionSequence& SCS1, 3348 const StandardConversionSequence& SCS2) { 3349 ImplicitConversionSequence::CompareKind Result 3350 = ImplicitConversionSequence::Indistinguishable; 3351 3352 // the identity conversion sequence is considered to be a subsequence of 3353 // any non-identity conversion sequence 3354 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 3355 return ImplicitConversionSequence::Better; 3356 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 3357 return ImplicitConversionSequence::Worse; 3358 3359 if (SCS1.Second != SCS2.Second) { 3360 if (SCS1.Second == ICK_Identity) 3361 Result = ImplicitConversionSequence::Better; 3362 else if (SCS2.Second == ICK_Identity) 3363 Result = ImplicitConversionSequence::Worse; 3364 else 3365 return ImplicitConversionSequence::Indistinguishable; 3366 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 3367 return ImplicitConversionSequence::Indistinguishable; 3368 3369 if (SCS1.Third == SCS2.Third) { 3370 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 3371 : ImplicitConversionSequence::Indistinguishable; 3372 } 3373 3374 if (SCS1.Third == ICK_Identity) 3375 return Result == ImplicitConversionSequence::Worse 3376 ? ImplicitConversionSequence::Indistinguishable 3377 : ImplicitConversionSequence::Better; 3378 3379 if (SCS2.Third == ICK_Identity) 3380 return Result == ImplicitConversionSequence::Better 3381 ? ImplicitConversionSequence::Indistinguishable 3382 : ImplicitConversionSequence::Worse; 3383 3384 return ImplicitConversionSequence::Indistinguishable; 3385} 3386 3387/// \brief Determine whether one of the given reference bindings is better 3388/// than the other based on what kind of bindings they are. 3389static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 3390 const StandardConversionSequence &SCS2) { 3391 // C++0x [over.ics.rank]p3b4: 3392 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 3393 // implicit object parameter of a non-static member function declared 3394 // without a ref-qualifier, and *either* S1 binds an rvalue reference 3395 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 3396 // lvalue reference to a function lvalue and S2 binds an rvalue 3397 // reference*. 3398 // 3399 // FIXME: Rvalue references. We're going rogue with the above edits, 3400 // because the semantics in the current C++0x working paper (N3225 at the 3401 // time of this writing) break the standard definition of std::forward 3402 // and std::reference_wrapper when dealing with references to functions. 3403 // Proposed wording changes submitted to CWG for consideration. 3404 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 3405 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 3406 return false; 3407 3408 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 3409 SCS2.IsLvalueReference) || 3410 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 3411 !SCS2.IsLvalueReference); 3412} 3413 3414/// CompareStandardConversionSequences - Compare two standard 3415/// conversion sequences to determine whether one is better than the 3416/// other or if they are indistinguishable (C++ 13.3.3.2p3). 3417static ImplicitConversionSequence::CompareKind 3418CompareStandardConversionSequences(Sema &S, 3419 const StandardConversionSequence& SCS1, 3420 const StandardConversionSequence& SCS2) 3421{ 3422 // Standard conversion sequence S1 is a better conversion sequence 3423 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 3424 3425 // -- S1 is a proper subsequence of S2 (comparing the conversion 3426 // sequences in the canonical form defined by 13.3.3.1.1, 3427 // excluding any Lvalue Transformation; the identity conversion 3428 // sequence is considered to be a subsequence of any 3429 // non-identity conversion sequence) or, if not that, 3430 if (ImplicitConversionSequence::CompareKind CK 3431 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 3432 return CK; 3433 3434 // -- the rank of S1 is better than the rank of S2 (by the rules 3435 // defined below), or, if not that, 3436 ImplicitConversionRank Rank1 = SCS1.getRank(); 3437 ImplicitConversionRank Rank2 = SCS2.getRank(); 3438 if (Rank1 < Rank2) 3439 return ImplicitConversionSequence::Better; 3440 else if (Rank2 < Rank1) 3441 return ImplicitConversionSequence::Worse; 3442 3443 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 3444 // are indistinguishable unless one of the following rules 3445 // applies: 3446 3447 // A conversion that is not a conversion of a pointer, or 3448 // pointer to member, to bool is better than another conversion 3449 // that is such a conversion. 3450 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 3451 return SCS2.isPointerConversionToBool() 3452 ? ImplicitConversionSequence::Better 3453 : ImplicitConversionSequence::Worse; 3454 3455 // C++ [over.ics.rank]p4b2: 3456 // 3457 // If class B is derived directly or indirectly from class A, 3458 // conversion of B* to A* is better than conversion of B* to 3459 // void*, and conversion of A* to void* is better than conversion 3460 // of B* to void*. 3461 bool SCS1ConvertsToVoid 3462 = SCS1.isPointerConversionToVoidPointer(S.Context); 3463 bool SCS2ConvertsToVoid 3464 = SCS2.isPointerConversionToVoidPointer(S.Context); 3465 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 3466 // Exactly one of the conversion sequences is a conversion to 3467 // a void pointer; it's the worse conversion. 3468 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 3469 : ImplicitConversionSequence::Worse; 3470 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 3471 // Neither conversion sequence converts to a void pointer; compare 3472 // their derived-to-base conversions. 3473 if (ImplicitConversionSequence::CompareKind DerivedCK 3474 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 3475 return DerivedCK; 3476 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid && 3477 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) { 3478 // Both conversion sequences are conversions to void 3479 // pointers. Compare the source types to determine if there's an 3480 // inheritance relationship in their sources. 3481 QualType FromType1 = SCS1.getFromType(); 3482 QualType FromType2 = SCS2.getFromType(); 3483 3484 // Adjust the types we're converting from via the array-to-pointer 3485 // conversion, if we need to. 3486 if (SCS1.First == ICK_Array_To_Pointer) 3487 FromType1 = S.Context.getArrayDecayedType(FromType1); 3488 if (SCS2.First == ICK_Array_To_Pointer) 3489 FromType2 = S.Context.getArrayDecayedType(FromType2); 3490 3491 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType(); 3492 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType(); 3493 3494 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3495 return ImplicitConversionSequence::Better; 3496 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3497 return ImplicitConversionSequence::Worse; 3498 3499 // Objective-C++: If one interface is more specific than the 3500 // other, it is the better one. 3501 const ObjCObjectPointerType* FromObjCPtr1 3502 = FromType1->getAs<ObjCObjectPointerType>(); 3503 const ObjCObjectPointerType* FromObjCPtr2 3504 = FromType2->getAs<ObjCObjectPointerType>(); 3505 if (FromObjCPtr1 && FromObjCPtr2) { 3506 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1, 3507 FromObjCPtr2); 3508 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2, 3509 FromObjCPtr1); 3510 if (AssignLeft != AssignRight) { 3511 return AssignLeft? ImplicitConversionSequence::Better 3512 : ImplicitConversionSequence::Worse; 3513 } 3514 } 3515 } 3516 3517 // Compare based on qualification conversions (C++ 13.3.3.2p3, 3518 // bullet 3). 3519 if (ImplicitConversionSequence::CompareKind QualCK 3520 = CompareQualificationConversions(S, SCS1, SCS2)) 3521 return QualCK; 3522 3523 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 3524 // Check for a better reference binding based on the kind of bindings. 3525 if (isBetterReferenceBindingKind(SCS1, SCS2)) 3526 return ImplicitConversionSequence::Better; 3527 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 3528 return ImplicitConversionSequence::Worse; 3529 3530 // C++ [over.ics.rank]p3b4: 3531 // -- S1 and S2 are reference bindings (8.5.3), and the types to 3532 // which the references refer are the same type except for 3533 // top-level cv-qualifiers, and the type to which the reference 3534 // initialized by S2 refers is more cv-qualified than the type 3535 // to which the reference initialized by S1 refers. 3536 QualType T1 = SCS1.getToType(2); 3537 QualType T2 = SCS2.getToType(2); 3538 T1 = S.Context.getCanonicalType(T1); 3539 T2 = S.Context.getCanonicalType(T2); 3540 Qualifiers T1Quals, T2Quals; 3541 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3542 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3543 if (UnqualT1 == UnqualT2) { 3544 // Objective-C++ ARC: If the references refer to objects with different 3545 // lifetimes, prefer bindings that don't change lifetime. 3546 if (SCS1.ObjCLifetimeConversionBinding != 3547 SCS2.ObjCLifetimeConversionBinding) { 3548 return SCS1.ObjCLifetimeConversionBinding 3549 ? ImplicitConversionSequence::Worse 3550 : ImplicitConversionSequence::Better; 3551 } 3552 3553 // If the type is an array type, promote the element qualifiers to the 3554 // type for comparison. 3555 if (isa<ArrayType>(T1) && T1Quals) 3556 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3557 if (isa<ArrayType>(T2) && T2Quals) 3558 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3559 if (T2.isMoreQualifiedThan(T1)) 3560 return ImplicitConversionSequence::Better; 3561 else if (T1.isMoreQualifiedThan(T2)) 3562 return ImplicitConversionSequence::Worse; 3563 } 3564 } 3565 3566 // In Microsoft mode, prefer an integral conversion to a 3567 // floating-to-integral conversion if the integral conversion 3568 // is between types of the same size. 3569 // For example: 3570 // void f(float); 3571 // void f(int); 3572 // int main { 3573 // long a; 3574 // f(a); 3575 // } 3576 // Here, MSVC will call f(int) instead of generating a compile error 3577 // as clang will do in standard mode. 3578 if (S.getLangOpts().MicrosoftMode && 3579 SCS1.Second == ICK_Integral_Conversion && 3580 SCS2.Second == ICK_Floating_Integral && 3581 S.Context.getTypeSize(SCS1.getFromType()) == 3582 S.Context.getTypeSize(SCS1.getToType(2))) 3583 return ImplicitConversionSequence::Better; 3584 3585 return ImplicitConversionSequence::Indistinguishable; 3586} 3587 3588/// CompareQualificationConversions - Compares two standard conversion 3589/// sequences to determine whether they can be ranked based on their 3590/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 3591ImplicitConversionSequence::CompareKind 3592CompareQualificationConversions(Sema &S, 3593 const StandardConversionSequence& SCS1, 3594 const StandardConversionSequence& SCS2) { 3595 // C++ 13.3.3.2p3: 3596 // -- S1 and S2 differ only in their qualification conversion and 3597 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 3598 // cv-qualification signature of type T1 is a proper subset of 3599 // the cv-qualification signature of type T2, and S1 is not the 3600 // deprecated string literal array-to-pointer conversion (4.2). 3601 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 3602 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 3603 return ImplicitConversionSequence::Indistinguishable; 3604 3605 // FIXME: the example in the standard doesn't use a qualification 3606 // conversion (!) 3607 QualType T1 = SCS1.getToType(2); 3608 QualType T2 = SCS2.getToType(2); 3609 T1 = S.Context.getCanonicalType(T1); 3610 T2 = S.Context.getCanonicalType(T2); 3611 Qualifiers T1Quals, T2Quals; 3612 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3613 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3614 3615 // If the types are the same, we won't learn anything by unwrapped 3616 // them. 3617 if (UnqualT1 == UnqualT2) 3618 return ImplicitConversionSequence::Indistinguishable; 3619 3620 // If the type is an array type, promote the element qualifiers to the type 3621 // for comparison. 3622 if (isa<ArrayType>(T1) && T1Quals) 3623 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3624 if (isa<ArrayType>(T2) && T2Quals) 3625 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3626 3627 ImplicitConversionSequence::CompareKind Result 3628 = ImplicitConversionSequence::Indistinguishable; 3629 3630 // Objective-C++ ARC: 3631 // Prefer qualification conversions not involving a change in lifetime 3632 // to qualification conversions that do not change lifetime. 3633 if (SCS1.QualificationIncludesObjCLifetime != 3634 SCS2.QualificationIncludesObjCLifetime) { 3635 Result = SCS1.QualificationIncludesObjCLifetime 3636 ? ImplicitConversionSequence::Worse 3637 : ImplicitConversionSequence::Better; 3638 } 3639 3640 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 3641 // Within each iteration of the loop, we check the qualifiers to 3642 // determine if this still looks like a qualification 3643 // conversion. Then, if all is well, we unwrap one more level of 3644 // pointers or pointers-to-members and do it all again 3645 // until there are no more pointers or pointers-to-members left 3646 // to unwrap. This essentially mimics what 3647 // IsQualificationConversion does, but here we're checking for a 3648 // strict subset of qualifiers. 3649 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 3650 // The qualifiers are the same, so this doesn't tell us anything 3651 // about how the sequences rank. 3652 ; 3653 else if (T2.isMoreQualifiedThan(T1)) { 3654 // T1 has fewer qualifiers, so it could be the better sequence. 3655 if (Result == ImplicitConversionSequence::Worse) 3656 // Neither has qualifiers that are a subset of the other's 3657 // qualifiers. 3658 return ImplicitConversionSequence::Indistinguishable; 3659 3660 Result = ImplicitConversionSequence::Better; 3661 } else if (T1.isMoreQualifiedThan(T2)) { 3662 // T2 has fewer qualifiers, so it could be the better sequence. 3663 if (Result == ImplicitConversionSequence::Better) 3664 // Neither has qualifiers that are a subset of the other's 3665 // qualifiers. 3666 return ImplicitConversionSequence::Indistinguishable; 3667 3668 Result = ImplicitConversionSequence::Worse; 3669 } else { 3670 // Qualifiers are disjoint. 3671 return ImplicitConversionSequence::Indistinguishable; 3672 } 3673 3674 // If the types after this point are equivalent, we're done. 3675 if (S.Context.hasSameUnqualifiedType(T1, T2)) 3676 break; 3677 } 3678 3679 // Check that the winning standard conversion sequence isn't using 3680 // the deprecated string literal array to pointer conversion. 3681 switch (Result) { 3682 case ImplicitConversionSequence::Better: 3683 if (SCS1.DeprecatedStringLiteralToCharPtr) 3684 Result = ImplicitConversionSequence::Indistinguishable; 3685 break; 3686 3687 case ImplicitConversionSequence::Indistinguishable: 3688 break; 3689 3690 case ImplicitConversionSequence::Worse: 3691 if (SCS2.DeprecatedStringLiteralToCharPtr) 3692 Result = ImplicitConversionSequence::Indistinguishable; 3693 break; 3694 } 3695 3696 return Result; 3697} 3698 3699/// CompareDerivedToBaseConversions - Compares two standard conversion 3700/// sequences to determine whether they can be ranked based on their 3701/// various kinds of derived-to-base conversions (C++ 3702/// [over.ics.rank]p4b3). As part of these checks, we also look at 3703/// conversions between Objective-C interface types. 3704ImplicitConversionSequence::CompareKind 3705CompareDerivedToBaseConversions(Sema &S, 3706 const StandardConversionSequence& SCS1, 3707 const StandardConversionSequence& SCS2) { 3708 QualType FromType1 = SCS1.getFromType(); 3709 QualType ToType1 = SCS1.getToType(1); 3710 QualType FromType2 = SCS2.getFromType(); 3711 QualType ToType2 = SCS2.getToType(1); 3712 3713 // Adjust the types we're converting from via the array-to-pointer 3714 // conversion, if we need to. 3715 if (SCS1.First == ICK_Array_To_Pointer) 3716 FromType1 = S.Context.getArrayDecayedType(FromType1); 3717 if (SCS2.First == ICK_Array_To_Pointer) 3718 FromType2 = S.Context.getArrayDecayedType(FromType2); 3719 3720 // Canonicalize all of the types. 3721 FromType1 = S.Context.getCanonicalType(FromType1); 3722 ToType1 = S.Context.getCanonicalType(ToType1); 3723 FromType2 = S.Context.getCanonicalType(FromType2); 3724 ToType2 = S.Context.getCanonicalType(ToType2); 3725 3726 // C++ [over.ics.rank]p4b3: 3727 // 3728 // If class B is derived directly or indirectly from class A and 3729 // class C is derived directly or indirectly from B, 3730 // 3731 // Compare based on pointer conversions. 3732 if (SCS1.Second == ICK_Pointer_Conversion && 3733 SCS2.Second == ICK_Pointer_Conversion && 3734 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 3735 FromType1->isPointerType() && FromType2->isPointerType() && 3736 ToType1->isPointerType() && ToType2->isPointerType()) { 3737 QualType FromPointee1 3738 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3739 QualType ToPointee1 3740 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3741 QualType FromPointee2 3742 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3743 QualType ToPointee2 3744 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3745 3746 // -- conversion of C* to B* is better than conversion of C* to A*, 3747 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3748 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3749 return ImplicitConversionSequence::Better; 3750 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3751 return ImplicitConversionSequence::Worse; 3752 } 3753 3754 // -- conversion of B* to A* is better than conversion of C* to A*, 3755 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 3756 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3757 return ImplicitConversionSequence::Better; 3758 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3759 return ImplicitConversionSequence::Worse; 3760 } 3761 } else if (SCS1.Second == ICK_Pointer_Conversion && 3762 SCS2.Second == ICK_Pointer_Conversion) { 3763 const ObjCObjectPointerType *FromPtr1 3764 = FromType1->getAs<ObjCObjectPointerType>(); 3765 const ObjCObjectPointerType *FromPtr2 3766 = FromType2->getAs<ObjCObjectPointerType>(); 3767 const ObjCObjectPointerType *ToPtr1 3768 = ToType1->getAs<ObjCObjectPointerType>(); 3769 const ObjCObjectPointerType *ToPtr2 3770 = ToType2->getAs<ObjCObjectPointerType>(); 3771 3772 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 3773 // Apply the same conversion ranking rules for Objective-C pointer types 3774 // that we do for C++ pointers to class types. However, we employ the 3775 // Objective-C pseudo-subtyping relationship used for assignment of 3776 // Objective-C pointer types. 3777 bool FromAssignLeft 3778 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 3779 bool FromAssignRight 3780 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 3781 bool ToAssignLeft 3782 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 3783 bool ToAssignRight 3784 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 3785 3786 // A conversion to an a non-id object pointer type or qualified 'id' 3787 // type is better than a conversion to 'id'. 3788 if (ToPtr1->isObjCIdType() && 3789 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 3790 return ImplicitConversionSequence::Worse; 3791 if (ToPtr2->isObjCIdType() && 3792 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 3793 return ImplicitConversionSequence::Better; 3794 3795 // A conversion to a non-id object pointer type is better than a 3796 // conversion to a qualified 'id' type 3797 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 3798 return ImplicitConversionSequence::Worse; 3799 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 3800 return ImplicitConversionSequence::Better; 3801 3802 // A conversion to an a non-Class object pointer type or qualified 'Class' 3803 // type is better than a conversion to 'Class'. 3804 if (ToPtr1->isObjCClassType() && 3805 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 3806 return ImplicitConversionSequence::Worse; 3807 if (ToPtr2->isObjCClassType() && 3808 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 3809 return ImplicitConversionSequence::Better; 3810 3811 // A conversion to a non-Class object pointer type is better than a 3812 // conversion to a qualified 'Class' type. 3813 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 3814 return ImplicitConversionSequence::Worse; 3815 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 3816 return ImplicitConversionSequence::Better; 3817 3818 // -- "conversion of C* to B* is better than conversion of C* to A*," 3819 if (S.Context.hasSameType(FromType1, FromType2) && 3820 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 3821 (ToAssignLeft != ToAssignRight)) 3822 return ToAssignLeft? ImplicitConversionSequence::Worse 3823 : ImplicitConversionSequence::Better; 3824 3825 // -- "conversion of B* to A* is better than conversion of C* to A*," 3826 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 3827 (FromAssignLeft != FromAssignRight)) 3828 return FromAssignLeft? ImplicitConversionSequence::Better 3829 : ImplicitConversionSequence::Worse; 3830 } 3831 } 3832 3833 // Ranking of member-pointer types. 3834 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 3835 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 3836 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 3837 const MemberPointerType * FromMemPointer1 = 3838 FromType1->getAs<MemberPointerType>(); 3839 const MemberPointerType * ToMemPointer1 = 3840 ToType1->getAs<MemberPointerType>(); 3841 const MemberPointerType * FromMemPointer2 = 3842 FromType2->getAs<MemberPointerType>(); 3843 const MemberPointerType * ToMemPointer2 = 3844 ToType2->getAs<MemberPointerType>(); 3845 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 3846 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 3847 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 3848 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 3849 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 3850 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 3851 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 3852 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 3853 // conversion of A::* to B::* is better than conversion of A::* to C::*, 3854 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3855 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3856 return ImplicitConversionSequence::Worse; 3857 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3858 return ImplicitConversionSequence::Better; 3859 } 3860 // conversion of B::* to C::* is better than conversion of A::* to C::* 3861 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 3862 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3863 return ImplicitConversionSequence::Better; 3864 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3865 return ImplicitConversionSequence::Worse; 3866 } 3867 } 3868 3869 if (SCS1.Second == ICK_Derived_To_Base) { 3870 // -- conversion of C to B is better than conversion of C to A, 3871 // -- binding of an expression of type C to a reference of type 3872 // B& is better than binding an expression of type C to a 3873 // reference of type A&, 3874 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3875 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3876 if (S.IsDerivedFrom(ToType1, ToType2)) 3877 return ImplicitConversionSequence::Better; 3878 else if (S.IsDerivedFrom(ToType2, ToType1)) 3879 return ImplicitConversionSequence::Worse; 3880 } 3881 3882 // -- conversion of B to A is better than conversion of C to A. 3883 // -- binding of an expression of type B to a reference of type 3884 // A& is better than binding an expression of type C to a 3885 // reference of type A&, 3886 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3887 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3888 if (S.IsDerivedFrom(FromType2, FromType1)) 3889 return ImplicitConversionSequence::Better; 3890 else if (S.IsDerivedFrom(FromType1, FromType2)) 3891 return ImplicitConversionSequence::Worse; 3892 } 3893 } 3894 3895 return ImplicitConversionSequence::Indistinguishable; 3896} 3897 3898/// \brief Determine whether the given type is valid, e.g., it is not an invalid 3899/// C++ class. 3900static bool isTypeValid(QualType T) { 3901 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) 3902 return !Record->isInvalidDecl(); 3903 3904 return true; 3905} 3906 3907/// CompareReferenceRelationship - Compare the two types T1 and T2 to 3908/// determine whether they are reference-related, 3909/// reference-compatible, reference-compatible with added 3910/// qualification, or incompatible, for use in C++ initialization by 3911/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 3912/// type, and the first type (T1) is the pointee type of the reference 3913/// type being initialized. 3914Sema::ReferenceCompareResult 3915Sema::CompareReferenceRelationship(SourceLocation Loc, 3916 QualType OrigT1, QualType OrigT2, 3917 bool &DerivedToBase, 3918 bool &ObjCConversion, 3919 bool &ObjCLifetimeConversion) { 3920 assert(!OrigT1->isReferenceType() && 3921 "T1 must be the pointee type of the reference type"); 3922 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 3923 3924 QualType T1 = Context.getCanonicalType(OrigT1); 3925 QualType T2 = Context.getCanonicalType(OrigT2); 3926 Qualifiers T1Quals, T2Quals; 3927 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 3928 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 3929 3930 // C++ [dcl.init.ref]p4: 3931 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 3932 // reference-related to "cv2 T2" if T1 is the same type as T2, or 3933 // T1 is a base class of T2. 3934 DerivedToBase = false; 3935 ObjCConversion = false; 3936 ObjCLifetimeConversion = false; 3937 if (UnqualT1 == UnqualT2) { 3938 // Nothing to do. 3939 } else if (!RequireCompleteType(Loc, OrigT2, 0) && 3940 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) && 3941 IsDerivedFrom(UnqualT2, UnqualT1)) 3942 DerivedToBase = true; 3943 else if (UnqualT1->isObjCObjectOrInterfaceType() && 3944 UnqualT2->isObjCObjectOrInterfaceType() && 3945 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 3946 ObjCConversion = true; 3947 else 3948 return Ref_Incompatible; 3949 3950 // At this point, we know that T1 and T2 are reference-related (at 3951 // least). 3952 3953 // If the type is an array type, promote the element qualifiers to the type 3954 // for comparison. 3955 if (isa<ArrayType>(T1) && T1Quals) 3956 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 3957 if (isa<ArrayType>(T2) && T2Quals) 3958 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 3959 3960 // C++ [dcl.init.ref]p4: 3961 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 3962 // reference-related to T2 and cv1 is the same cv-qualification 3963 // as, or greater cv-qualification than, cv2. For purposes of 3964 // overload resolution, cases for which cv1 is greater 3965 // cv-qualification than cv2 are identified as 3966 // reference-compatible with added qualification (see 13.3.3.2). 3967 // 3968 // Note that we also require equivalence of Objective-C GC and address-space 3969 // qualifiers when performing these computations, so that e.g., an int in 3970 // address space 1 is not reference-compatible with an int in address 3971 // space 2. 3972 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() && 3973 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) { 3974 T1Quals.removeObjCLifetime(); 3975 T2Quals.removeObjCLifetime(); 3976 ObjCLifetimeConversion = true; 3977 } 3978 3979 if (T1Quals == T2Quals) 3980 return Ref_Compatible; 3981 else if (T1Quals.compatiblyIncludes(T2Quals)) 3982 return Ref_Compatible_With_Added_Qualification; 3983 else 3984 return Ref_Related; 3985} 3986 3987/// \brief Look for a user-defined conversion to an value reference-compatible 3988/// with DeclType. Return true if something definite is found. 3989static bool 3990FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 3991 QualType DeclType, SourceLocation DeclLoc, 3992 Expr *Init, QualType T2, bool AllowRvalues, 3993 bool AllowExplicit) { 3994 assert(T2->isRecordType() && "Can only find conversions of record types."); 3995 CXXRecordDecl *T2RecordDecl 3996 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 3997 3998 OverloadCandidateSet CandidateSet(DeclLoc); 3999 std::pair<CXXRecordDecl::conversion_iterator, 4000 CXXRecordDecl::conversion_iterator> 4001 Conversions = T2RecordDecl->getVisibleConversionFunctions(); 4002 for (CXXRecordDecl::conversion_iterator 4003 I = Conversions.first, E = Conversions.second; I != E; ++I) { 4004 NamedDecl *D = *I; 4005 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 4006 if (isa<UsingShadowDecl>(D)) 4007 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4008 4009 FunctionTemplateDecl *ConvTemplate 4010 = dyn_cast<FunctionTemplateDecl>(D); 4011 CXXConversionDecl *Conv; 4012 if (ConvTemplate) 4013 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 4014 else 4015 Conv = cast<CXXConversionDecl>(D); 4016 4017 // If this is an explicit conversion, and we're not allowed to consider 4018 // explicit conversions, skip it. 4019 if (!AllowExplicit && Conv->isExplicit()) 4020 continue; 4021 4022 if (AllowRvalues) { 4023 bool DerivedToBase = false; 4024 bool ObjCConversion = false; 4025 bool ObjCLifetimeConversion = false; 4026 4027 // If we are initializing an rvalue reference, don't permit conversion 4028 // functions that return lvalues. 4029 if (!ConvTemplate && DeclType->isRValueReferenceType()) { 4030 const ReferenceType *RefType 4031 = Conv->getConversionType()->getAs<LValueReferenceType>(); 4032 if (RefType && !RefType->getPointeeType()->isFunctionType()) 4033 continue; 4034 } 4035 4036 if (!ConvTemplate && 4037 S.CompareReferenceRelationship( 4038 DeclLoc, 4039 Conv->getConversionType().getNonReferenceType() 4040 .getUnqualifiedType(), 4041 DeclType.getNonReferenceType().getUnqualifiedType(), 4042 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) == 4043 Sema::Ref_Incompatible) 4044 continue; 4045 } else { 4046 // If the conversion function doesn't return a reference type, 4047 // it can't be considered for this conversion. An rvalue reference 4048 // is only acceptable if its referencee is a function type. 4049 4050 const ReferenceType *RefType = 4051 Conv->getConversionType()->getAs<ReferenceType>(); 4052 if (!RefType || 4053 (!RefType->isLValueReferenceType() && 4054 !RefType->getPointeeType()->isFunctionType())) 4055 continue; 4056 } 4057 4058 if (ConvTemplate) 4059 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 4060 Init, DeclType, CandidateSet); 4061 else 4062 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 4063 DeclType, CandidateSet); 4064 } 4065 4066 bool HadMultipleCandidates = (CandidateSet.size() > 1); 4067 4068 OverloadCandidateSet::iterator Best; 4069 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 4070 case OR_Success: 4071 // C++ [over.ics.ref]p1: 4072 // 4073 // [...] If the parameter binds directly to the result of 4074 // applying a conversion function to the argument 4075 // expression, the implicit conversion sequence is a 4076 // user-defined conversion sequence (13.3.3.1.2), with the 4077 // second standard conversion sequence either an identity 4078 // conversion or, if the conversion function returns an 4079 // entity of a type that is a derived class of the parameter 4080 // type, a derived-to-base Conversion. 4081 if (!Best->FinalConversion.DirectBinding) 4082 return false; 4083 4084 ICS.setUserDefined(); 4085 ICS.UserDefined.Before = Best->Conversions[0].Standard; 4086 ICS.UserDefined.After = Best->FinalConversion; 4087 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates; 4088 ICS.UserDefined.ConversionFunction = Best->Function; 4089 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl; 4090 ICS.UserDefined.EllipsisConversion = false; 4091 assert(ICS.UserDefined.After.ReferenceBinding && 4092 ICS.UserDefined.After.DirectBinding && 4093 "Expected a direct reference binding!"); 4094 return true; 4095 4096 case OR_Ambiguous: 4097 ICS.setAmbiguous(); 4098 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4099 Cand != CandidateSet.end(); ++Cand) 4100 if (Cand->Viable) 4101 ICS.Ambiguous.addConversion(Cand->Function); 4102 return true; 4103 4104 case OR_No_Viable_Function: 4105 case OR_Deleted: 4106 // There was no suitable conversion, or we found a deleted 4107 // conversion; continue with other checks. 4108 return false; 4109 } 4110 4111 llvm_unreachable("Invalid OverloadResult!"); 4112} 4113 4114/// \brief Compute an implicit conversion sequence for reference 4115/// initialization. 4116static ImplicitConversionSequence 4117TryReferenceInit(Sema &S, Expr *Init, QualType DeclType, 4118 SourceLocation DeclLoc, 4119 bool SuppressUserConversions, 4120 bool AllowExplicit) { 4121 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 4122 4123 // Most paths end in a failed conversion. 4124 ImplicitConversionSequence ICS; 4125 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 4126 4127 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 4128 QualType T2 = Init->getType(); 4129 4130 // If the initializer is the address of an overloaded function, try 4131 // to resolve the overloaded function. If all goes well, T2 is the 4132 // type of the resulting function. 4133 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 4134 DeclAccessPair Found; 4135 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 4136 false, Found)) 4137 T2 = Fn->getType(); 4138 } 4139 4140 // Compute some basic properties of the types and the initializer. 4141 bool isRValRef = DeclType->isRValueReferenceType(); 4142 bool DerivedToBase = false; 4143 bool ObjCConversion = false; 4144 bool ObjCLifetimeConversion = false; 4145 Expr::Classification InitCategory = Init->Classify(S.Context); 4146 Sema::ReferenceCompareResult RefRelationship 4147 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 4148 ObjCConversion, ObjCLifetimeConversion); 4149 4150 4151 // C++0x [dcl.init.ref]p5: 4152 // A reference to type "cv1 T1" is initialized by an expression 4153 // of type "cv2 T2" as follows: 4154 4155 // -- If reference is an lvalue reference and the initializer expression 4156 if (!isRValRef) { 4157 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 4158 // reference-compatible with "cv2 T2," or 4159 // 4160 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 4161 if (InitCategory.isLValue() && 4162 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 4163 // C++ [over.ics.ref]p1: 4164 // When a parameter of reference type binds directly (8.5.3) 4165 // to an argument expression, the implicit conversion sequence 4166 // is the identity conversion, unless the argument expression 4167 // has a type that is a derived class of the parameter type, 4168 // in which case the implicit conversion sequence is a 4169 // derived-to-base Conversion (13.3.3.1). 4170 ICS.setStandard(); 4171 ICS.Standard.First = ICK_Identity; 4172 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 4173 : ObjCConversion? ICK_Compatible_Conversion 4174 : ICK_Identity; 4175 ICS.Standard.Third = ICK_Identity; 4176 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 4177 ICS.Standard.setToType(0, T2); 4178 ICS.Standard.setToType(1, T1); 4179 ICS.Standard.setToType(2, T1); 4180 ICS.Standard.ReferenceBinding = true; 4181 ICS.Standard.DirectBinding = true; 4182 ICS.Standard.IsLvalueReference = !isRValRef; 4183 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4184 ICS.Standard.BindsToRvalue = false; 4185 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4186 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 4187 ICS.Standard.CopyConstructor = 0; 4188 4189 // Nothing more to do: the inaccessibility/ambiguity check for 4190 // derived-to-base conversions is suppressed when we're 4191 // computing the implicit conversion sequence (C++ 4192 // [over.best.ics]p2). 4193 return ICS; 4194 } 4195 4196 // -- has a class type (i.e., T2 is a class type), where T1 is 4197 // not reference-related to T2, and can be implicitly 4198 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 4199 // is reference-compatible with "cv3 T3" 92) (this 4200 // conversion is selected by enumerating the applicable 4201 // conversion functions (13.3.1.6) and choosing the best 4202 // one through overload resolution (13.3)), 4203 if (!SuppressUserConversions && T2->isRecordType() && 4204 !S.RequireCompleteType(DeclLoc, T2, 0) && 4205 RefRelationship == Sema::Ref_Incompatible) { 4206 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 4207 Init, T2, /*AllowRvalues=*/false, 4208 AllowExplicit)) 4209 return ICS; 4210 } 4211 } 4212 4213 // -- Otherwise, the reference shall be an lvalue reference to a 4214 // non-volatile const type (i.e., cv1 shall be const), or the reference 4215 // shall be an rvalue reference. 4216 // 4217 // We actually handle one oddity of C++ [over.ics.ref] at this 4218 // point, which is that, due to p2 (which short-circuits reference 4219 // binding by only attempting a simple conversion for non-direct 4220 // bindings) and p3's strange wording, we allow a const volatile 4221 // reference to bind to an rvalue. Hence the check for the presence 4222 // of "const" rather than checking for "const" being the only 4223 // qualifier. 4224 // This is also the point where rvalue references and lvalue inits no longer 4225 // go together. 4226 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified())) 4227 return ICS; 4228 4229 // -- If the initializer expression 4230 // 4231 // -- is an xvalue, class prvalue, array prvalue or function 4232 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or 4233 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 4234 (InitCategory.isXValue() || 4235 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 4236 (InitCategory.isLValue() && T2->isFunctionType()))) { 4237 ICS.setStandard(); 4238 ICS.Standard.First = ICK_Identity; 4239 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 4240 : ObjCConversion? ICK_Compatible_Conversion 4241 : ICK_Identity; 4242 ICS.Standard.Third = ICK_Identity; 4243 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 4244 ICS.Standard.setToType(0, T2); 4245 ICS.Standard.setToType(1, T1); 4246 ICS.Standard.setToType(2, T1); 4247 ICS.Standard.ReferenceBinding = true; 4248 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 4249 // binding unless we're binding to a class prvalue. 4250 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 4251 // allow the use of rvalue references in C++98/03 for the benefit of 4252 // standard library implementors; therefore, we need the xvalue check here. 4253 ICS.Standard.DirectBinding = 4254 S.getLangOpts().CPlusPlus11 || 4255 (InitCategory.isPRValue() && !T2->isRecordType()); 4256 ICS.Standard.IsLvalueReference = !isRValRef; 4257 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4258 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 4259 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4260 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 4261 ICS.Standard.CopyConstructor = 0; 4262 return ICS; 4263 } 4264 4265 // -- has a class type (i.e., T2 is a class type), where T1 is not 4266 // reference-related to T2, and can be implicitly converted to 4267 // an xvalue, class prvalue, or function lvalue of type 4268 // "cv3 T3", where "cv1 T1" is reference-compatible with 4269 // "cv3 T3", 4270 // 4271 // then the reference is bound to the value of the initializer 4272 // expression in the first case and to the result of the conversion 4273 // in the second case (or, in either case, to an appropriate base 4274 // class subobject). 4275 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 4276 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 4277 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 4278 Init, T2, /*AllowRvalues=*/true, 4279 AllowExplicit)) { 4280 // In the second case, if the reference is an rvalue reference 4281 // and the second standard conversion sequence of the 4282 // user-defined conversion sequence includes an lvalue-to-rvalue 4283 // conversion, the program is ill-formed. 4284 if (ICS.isUserDefined() && isRValRef && 4285 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 4286 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 4287 4288 return ICS; 4289 } 4290 4291 // -- Otherwise, a temporary of type "cv1 T1" is created and 4292 // initialized from the initializer expression using the 4293 // rules for a non-reference copy initialization (8.5). The 4294 // reference is then bound to the temporary. If T1 is 4295 // reference-related to T2, cv1 must be the same 4296 // cv-qualification as, or greater cv-qualification than, 4297 // cv2; otherwise, the program is ill-formed. 4298 if (RefRelationship == Sema::Ref_Related) { 4299 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 4300 // we would be reference-compatible or reference-compatible with 4301 // added qualification. But that wasn't the case, so the reference 4302 // initialization fails. 4303 // 4304 // Note that we only want to check address spaces and cvr-qualifiers here. 4305 // ObjC GC and lifetime qualifiers aren't important. 4306 Qualifiers T1Quals = T1.getQualifiers(); 4307 Qualifiers T2Quals = T2.getQualifiers(); 4308 T1Quals.removeObjCGCAttr(); 4309 T1Quals.removeObjCLifetime(); 4310 T2Quals.removeObjCGCAttr(); 4311 T2Quals.removeObjCLifetime(); 4312 if (!T1Quals.compatiblyIncludes(T2Quals)) 4313 return ICS; 4314 } 4315 4316 // If at least one of the types is a class type, the types are not 4317 // related, and we aren't allowed any user conversions, the 4318 // reference binding fails. This case is important for breaking 4319 // recursion, since TryImplicitConversion below will attempt to 4320 // create a temporary through the use of a copy constructor. 4321 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 4322 (T1->isRecordType() || T2->isRecordType())) 4323 return ICS; 4324 4325 // If T1 is reference-related to T2 and the reference is an rvalue 4326 // reference, the initializer expression shall not be an lvalue. 4327 if (RefRelationship >= Sema::Ref_Related && 4328 isRValRef && Init->Classify(S.Context).isLValue()) 4329 return ICS; 4330 4331 // C++ [over.ics.ref]p2: 4332 // When a parameter of reference type is not bound directly to 4333 // an argument expression, the conversion sequence is the one 4334 // required to convert the argument expression to the 4335 // underlying type of the reference according to 4336 // 13.3.3.1. Conceptually, this conversion sequence corresponds 4337 // to copy-initializing a temporary of the underlying type with 4338 // the argument expression. Any difference in top-level 4339 // cv-qualification is subsumed by the initialization itself 4340 // and does not constitute a conversion. 4341 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 4342 /*AllowExplicit=*/false, 4343 /*InOverloadResolution=*/false, 4344 /*CStyle=*/false, 4345 /*AllowObjCWritebackConversion=*/false); 4346 4347 // Of course, that's still a reference binding. 4348 if (ICS.isStandard()) { 4349 ICS.Standard.ReferenceBinding = true; 4350 ICS.Standard.IsLvalueReference = !isRValRef; 4351 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4352 ICS.Standard.BindsToRvalue = true; 4353 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4354 ICS.Standard.ObjCLifetimeConversionBinding = false; 4355 } else if (ICS.isUserDefined()) { 4356 // Don't allow rvalue references to bind to lvalues. 4357 if (DeclType->isRValueReferenceType()) { 4358 if (const ReferenceType *RefType 4359 = ICS.UserDefined.ConversionFunction->getResultType() 4360 ->getAs<LValueReferenceType>()) { 4361 if (!RefType->getPointeeType()->isFunctionType()) { 4362 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, 4363 DeclType); 4364 return ICS; 4365 } 4366 } 4367 } 4368 4369 ICS.UserDefined.After.ReferenceBinding = true; 4370 ICS.UserDefined.After.IsLvalueReference = !isRValRef; 4371 ICS.UserDefined.After.BindsToFunctionLvalue = T2->isFunctionType(); 4372 ICS.UserDefined.After.BindsToRvalue = true; 4373 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4374 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false; 4375 } 4376 4377 return ICS; 4378} 4379 4380static ImplicitConversionSequence 4381TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 4382 bool SuppressUserConversions, 4383 bool InOverloadResolution, 4384 bool AllowObjCWritebackConversion, 4385 bool AllowExplicit = false); 4386 4387/// TryListConversion - Try to copy-initialize a value of type ToType from the 4388/// initializer list From. 4389static ImplicitConversionSequence 4390TryListConversion(Sema &S, InitListExpr *From, QualType ToType, 4391 bool SuppressUserConversions, 4392 bool InOverloadResolution, 4393 bool AllowObjCWritebackConversion) { 4394 // C++11 [over.ics.list]p1: 4395 // When an argument is an initializer list, it is not an expression and 4396 // special rules apply for converting it to a parameter type. 4397 4398 ImplicitConversionSequence Result; 4399 Result.setBad(BadConversionSequence::no_conversion, From, ToType); 4400 Result.setListInitializationSequence(); 4401 4402 // We need a complete type for what follows. Incomplete types can never be 4403 // initialized from init lists. 4404 if (S.RequireCompleteType(From->getLocStart(), ToType, 0)) 4405 return Result; 4406 4407 // C++11 [over.ics.list]p2: 4408 // If the parameter type is std::initializer_list<X> or "array of X" and 4409 // all the elements can be implicitly converted to X, the implicit 4410 // conversion sequence is the worst conversion necessary to convert an 4411 // element of the list to X. 4412 bool toStdInitializerList = false; 4413 QualType X; 4414 if (ToType->isArrayType()) 4415 X = S.Context.getAsArrayType(ToType)->getElementType(); 4416 else 4417 toStdInitializerList = S.isStdInitializerList(ToType, &X); 4418 if (!X.isNull()) { 4419 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) { 4420 Expr *Init = From->getInit(i); 4421 ImplicitConversionSequence ICS = 4422 TryCopyInitialization(S, Init, X, SuppressUserConversions, 4423 InOverloadResolution, 4424 AllowObjCWritebackConversion); 4425 // If a single element isn't convertible, fail. 4426 if (ICS.isBad()) { 4427 Result = ICS; 4428 break; 4429 } 4430 // Otherwise, look for the worst conversion. 4431 if (Result.isBad() || 4432 CompareImplicitConversionSequences(S, ICS, Result) == 4433 ImplicitConversionSequence::Worse) 4434 Result = ICS; 4435 } 4436 4437 // For an empty list, we won't have computed any conversion sequence. 4438 // Introduce the identity conversion sequence. 4439 if (From->getNumInits() == 0) { 4440 Result.setStandard(); 4441 Result.Standard.setAsIdentityConversion(); 4442 Result.Standard.setFromType(ToType); 4443 Result.Standard.setAllToTypes(ToType); 4444 } 4445 4446 Result.setListInitializationSequence(); 4447 Result.setStdInitializerListElement(toStdInitializerList); 4448 return Result; 4449 } 4450 4451 // C++11 [over.ics.list]p3: 4452 // Otherwise, if the parameter is a non-aggregate class X and overload 4453 // resolution chooses a single best constructor [...] the implicit 4454 // conversion sequence is a user-defined conversion sequence. If multiple 4455 // constructors are viable but none is better than the others, the 4456 // implicit conversion sequence is a user-defined conversion sequence. 4457 if (ToType->isRecordType() && !ToType->isAggregateType()) { 4458 // This function can deal with initializer lists. 4459 Result = TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, 4460 /*AllowExplicit=*/false, 4461 InOverloadResolution, /*CStyle=*/false, 4462 AllowObjCWritebackConversion); 4463 Result.setListInitializationSequence(); 4464 return Result; 4465 } 4466 4467 // C++11 [over.ics.list]p4: 4468 // Otherwise, if the parameter has an aggregate type which can be 4469 // initialized from the initializer list [...] the implicit conversion 4470 // sequence is a user-defined conversion sequence. 4471 if (ToType->isAggregateType()) { 4472 // Type is an aggregate, argument is an init list. At this point it comes 4473 // down to checking whether the initialization works. 4474 // FIXME: Find out whether this parameter is consumed or not. 4475 InitializedEntity Entity = 4476 InitializedEntity::InitializeParameter(S.Context, ToType, 4477 /*Consumed=*/false); 4478 if (S.CanPerformCopyInitialization(Entity, S.Owned(From))) { 4479 Result.setUserDefined(); 4480 Result.UserDefined.Before.setAsIdentityConversion(); 4481 // Initializer lists don't have a type. 4482 Result.UserDefined.Before.setFromType(QualType()); 4483 Result.UserDefined.Before.setAllToTypes(QualType()); 4484 4485 Result.UserDefined.After.setAsIdentityConversion(); 4486 Result.UserDefined.After.setFromType(ToType); 4487 Result.UserDefined.After.setAllToTypes(ToType); 4488 Result.UserDefined.ConversionFunction = 0; 4489 } 4490 return Result; 4491 } 4492 4493 // C++11 [over.ics.list]p5: 4494 // Otherwise, if the parameter is a reference, see 13.3.3.1.4. 4495 if (ToType->isReferenceType()) { 4496 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't 4497 // mention initializer lists in any way. So we go by what list- 4498 // initialization would do and try to extrapolate from that. 4499 4500 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType(); 4501 4502 // If the initializer list has a single element that is reference-related 4503 // to the parameter type, we initialize the reference from that. 4504 if (From->getNumInits() == 1) { 4505 Expr *Init = From->getInit(0); 4506 4507 QualType T2 = Init->getType(); 4508 4509 // If the initializer is the address of an overloaded function, try 4510 // to resolve the overloaded function. If all goes well, T2 is the 4511 // type of the resulting function. 4512 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 4513 DeclAccessPair Found; 4514 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction( 4515 Init, ToType, false, Found)) 4516 T2 = Fn->getType(); 4517 } 4518 4519 // Compute some basic properties of the types and the initializer. 4520 bool dummy1 = false; 4521 bool dummy2 = false; 4522 bool dummy3 = false; 4523 Sema::ReferenceCompareResult RefRelationship 4524 = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1, 4525 dummy2, dummy3); 4526 4527 if (RefRelationship >= Sema::Ref_Related) 4528 return TryReferenceInit(S, Init, ToType, 4529 /*FIXME:*/From->getLocStart(), 4530 SuppressUserConversions, 4531 /*AllowExplicit=*/false); 4532 } 4533 4534 // Otherwise, we bind the reference to a temporary created from the 4535 // initializer list. 4536 Result = TryListConversion(S, From, T1, SuppressUserConversions, 4537 InOverloadResolution, 4538 AllowObjCWritebackConversion); 4539 if (Result.isFailure()) 4540 return Result; 4541 assert(!Result.isEllipsis() && 4542 "Sub-initialization cannot result in ellipsis conversion."); 4543 4544 // Can we even bind to a temporary? 4545 if (ToType->isRValueReferenceType() || 4546 (T1.isConstQualified() && !T1.isVolatileQualified())) { 4547 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard : 4548 Result.UserDefined.After; 4549 SCS.ReferenceBinding = true; 4550 SCS.IsLvalueReference = ToType->isLValueReferenceType(); 4551 SCS.BindsToRvalue = true; 4552 SCS.BindsToFunctionLvalue = false; 4553 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4554 SCS.ObjCLifetimeConversionBinding = false; 4555 } else 4556 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue, 4557 From, ToType); 4558 return Result; 4559 } 4560 4561 // C++11 [over.ics.list]p6: 4562 // Otherwise, if the parameter type is not a class: 4563 if (!ToType->isRecordType()) { 4564 // - if the initializer list has one element, the implicit conversion 4565 // sequence is the one required to convert the element to the 4566 // parameter type. 4567 unsigned NumInits = From->getNumInits(); 4568 if (NumInits == 1) 4569 Result = TryCopyInitialization(S, From->getInit(0), ToType, 4570 SuppressUserConversions, 4571 InOverloadResolution, 4572 AllowObjCWritebackConversion); 4573 // - if the initializer list has no elements, the implicit conversion 4574 // sequence is the identity conversion. 4575 else if (NumInits == 0) { 4576 Result.setStandard(); 4577 Result.Standard.setAsIdentityConversion(); 4578 Result.Standard.setFromType(ToType); 4579 Result.Standard.setAllToTypes(ToType); 4580 } 4581 Result.setListInitializationSequence(); 4582 return Result; 4583 } 4584 4585 // C++11 [over.ics.list]p7: 4586 // In all cases other than those enumerated above, no conversion is possible 4587 return Result; 4588} 4589 4590/// TryCopyInitialization - Try to copy-initialize a value of type 4591/// ToType from the expression From. Return the implicit conversion 4592/// sequence required to pass this argument, which may be a bad 4593/// conversion sequence (meaning that the argument cannot be passed to 4594/// a parameter of this type). If @p SuppressUserConversions, then we 4595/// do not permit any user-defined conversion sequences. 4596static ImplicitConversionSequence 4597TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 4598 bool SuppressUserConversions, 4599 bool InOverloadResolution, 4600 bool AllowObjCWritebackConversion, 4601 bool AllowExplicit) { 4602 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From)) 4603 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions, 4604 InOverloadResolution,AllowObjCWritebackConversion); 4605 4606 if (ToType->isReferenceType()) 4607 return TryReferenceInit(S, From, ToType, 4608 /*FIXME:*/From->getLocStart(), 4609 SuppressUserConversions, 4610 AllowExplicit); 4611 4612 return TryImplicitConversion(S, From, ToType, 4613 SuppressUserConversions, 4614 /*AllowExplicit=*/false, 4615 InOverloadResolution, 4616 /*CStyle=*/false, 4617 AllowObjCWritebackConversion); 4618} 4619 4620static bool TryCopyInitialization(const CanQualType FromQTy, 4621 const CanQualType ToQTy, 4622 Sema &S, 4623 SourceLocation Loc, 4624 ExprValueKind FromVK) { 4625 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK); 4626 ImplicitConversionSequence ICS = 4627 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false); 4628 4629 return !ICS.isBad(); 4630} 4631 4632/// TryObjectArgumentInitialization - Try to initialize the object 4633/// parameter of the given member function (@c Method) from the 4634/// expression @p From. 4635static ImplicitConversionSequence 4636TryObjectArgumentInitialization(Sema &S, QualType FromType, 4637 Expr::Classification FromClassification, 4638 CXXMethodDecl *Method, 4639 CXXRecordDecl *ActingContext) { 4640 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 4641 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 4642 // const volatile object. 4643 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 4644 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 4645 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 4646 4647 // Set up the conversion sequence as a "bad" conversion, to allow us 4648 // to exit early. 4649 ImplicitConversionSequence ICS; 4650 4651 // We need to have an object of class type. 4652 if (const PointerType *PT = FromType->getAs<PointerType>()) { 4653 FromType = PT->getPointeeType(); 4654 4655 // When we had a pointer, it's implicitly dereferenced, so we 4656 // better have an lvalue. 4657 assert(FromClassification.isLValue()); 4658 } 4659 4660 assert(FromType->isRecordType()); 4661 4662 // C++0x [over.match.funcs]p4: 4663 // For non-static member functions, the type of the implicit object 4664 // parameter is 4665 // 4666 // - "lvalue reference to cv X" for functions declared without a 4667 // ref-qualifier or with the & ref-qualifier 4668 // - "rvalue reference to cv X" for functions declared with the && 4669 // ref-qualifier 4670 // 4671 // where X is the class of which the function is a member and cv is the 4672 // cv-qualification on the member function declaration. 4673 // 4674 // However, when finding an implicit conversion sequence for the argument, we 4675 // are not allowed to create temporaries or perform user-defined conversions 4676 // (C++ [over.match.funcs]p5). We perform a simplified version of 4677 // reference binding here, that allows class rvalues to bind to 4678 // non-constant references. 4679 4680 // First check the qualifiers. 4681 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 4682 if (ImplicitParamType.getCVRQualifiers() 4683 != FromTypeCanon.getLocalCVRQualifiers() && 4684 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 4685 ICS.setBad(BadConversionSequence::bad_qualifiers, 4686 FromType, ImplicitParamType); 4687 return ICS; 4688 } 4689 4690 // Check that we have either the same type or a derived type. It 4691 // affects the conversion rank. 4692 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 4693 ImplicitConversionKind SecondKind; 4694 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 4695 SecondKind = ICK_Identity; 4696 } else if (S.IsDerivedFrom(FromType, ClassType)) 4697 SecondKind = ICK_Derived_To_Base; 4698 else { 4699 ICS.setBad(BadConversionSequence::unrelated_class, 4700 FromType, ImplicitParamType); 4701 return ICS; 4702 } 4703 4704 // Check the ref-qualifier. 4705 switch (Method->getRefQualifier()) { 4706 case RQ_None: 4707 // Do nothing; we don't care about lvalueness or rvalueness. 4708 break; 4709 4710 case RQ_LValue: 4711 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 4712 // non-const lvalue reference cannot bind to an rvalue 4713 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 4714 ImplicitParamType); 4715 return ICS; 4716 } 4717 break; 4718 4719 case RQ_RValue: 4720 if (!FromClassification.isRValue()) { 4721 // rvalue reference cannot bind to an lvalue 4722 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 4723 ImplicitParamType); 4724 return ICS; 4725 } 4726 break; 4727 } 4728 4729 // Success. Mark this as a reference binding. 4730 ICS.setStandard(); 4731 ICS.Standard.setAsIdentityConversion(); 4732 ICS.Standard.Second = SecondKind; 4733 ICS.Standard.setFromType(FromType); 4734 ICS.Standard.setAllToTypes(ImplicitParamType); 4735 ICS.Standard.ReferenceBinding = true; 4736 ICS.Standard.DirectBinding = true; 4737 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 4738 ICS.Standard.BindsToFunctionLvalue = false; 4739 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 4740 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 4741 = (Method->getRefQualifier() == RQ_None); 4742 return ICS; 4743} 4744 4745/// PerformObjectArgumentInitialization - Perform initialization of 4746/// the implicit object parameter for the given Method with the given 4747/// expression. 4748ExprResult 4749Sema::PerformObjectArgumentInitialization(Expr *From, 4750 NestedNameSpecifier *Qualifier, 4751 NamedDecl *FoundDecl, 4752 CXXMethodDecl *Method) { 4753 QualType FromRecordType, DestType; 4754 QualType ImplicitParamRecordType = 4755 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 4756 4757 Expr::Classification FromClassification; 4758 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 4759 FromRecordType = PT->getPointeeType(); 4760 DestType = Method->getThisType(Context); 4761 FromClassification = Expr::Classification::makeSimpleLValue(); 4762 } else { 4763 FromRecordType = From->getType(); 4764 DestType = ImplicitParamRecordType; 4765 FromClassification = From->Classify(Context); 4766 } 4767 4768 // Note that we always use the true parent context when performing 4769 // the actual argument initialization. 4770 ImplicitConversionSequence ICS 4771 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 4772 Method, Method->getParent()); 4773 if (ICS.isBad()) { 4774 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 4775 Qualifiers FromQs = FromRecordType.getQualifiers(); 4776 Qualifiers ToQs = DestType.getQualifiers(); 4777 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4778 if (CVR) { 4779 Diag(From->getLocStart(), 4780 diag::err_member_function_call_bad_cvr) 4781 << Method->getDeclName() << FromRecordType << (CVR - 1) 4782 << From->getSourceRange(); 4783 Diag(Method->getLocation(), diag::note_previous_decl) 4784 << Method->getDeclName(); 4785 return ExprError(); 4786 } 4787 } 4788 4789 return Diag(From->getLocStart(), 4790 diag::err_implicit_object_parameter_init) 4791 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 4792 } 4793 4794 if (ICS.Standard.Second == ICK_Derived_To_Base) { 4795 ExprResult FromRes = 4796 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 4797 if (FromRes.isInvalid()) 4798 return ExprError(); 4799 From = FromRes.take(); 4800 } 4801 4802 if (!Context.hasSameType(From->getType(), DestType)) 4803 From = ImpCastExprToType(From, DestType, CK_NoOp, 4804 From->getValueKind()).take(); 4805 return Owned(From); 4806} 4807 4808/// TryContextuallyConvertToBool - Attempt to contextually convert the 4809/// expression From to bool (C++0x [conv]p3). 4810static ImplicitConversionSequence 4811TryContextuallyConvertToBool(Sema &S, Expr *From) { 4812 // FIXME: This is pretty broken. 4813 return TryImplicitConversion(S, From, S.Context.BoolTy, 4814 // FIXME: Are these flags correct? 4815 /*SuppressUserConversions=*/false, 4816 /*AllowExplicit=*/true, 4817 /*InOverloadResolution=*/false, 4818 /*CStyle=*/false, 4819 /*AllowObjCWritebackConversion=*/false); 4820} 4821 4822/// PerformContextuallyConvertToBool - Perform a contextual conversion 4823/// of the expression From to bool (C++0x [conv]p3). 4824ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) { 4825 if (checkPlaceholderForOverload(*this, From)) 4826 return ExprError(); 4827 4828 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 4829 if (!ICS.isBad()) 4830 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 4831 4832 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 4833 return Diag(From->getLocStart(), 4834 diag::err_typecheck_bool_condition) 4835 << From->getType() << From->getSourceRange(); 4836 return ExprError(); 4837} 4838 4839/// Check that the specified conversion is permitted in a converted constant 4840/// expression, according to C++11 [expr.const]p3. Return true if the conversion 4841/// is acceptable. 4842static bool CheckConvertedConstantConversions(Sema &S, 4843 StandardConversionSequence &SCS) { 4844 // Since we know that the target type is an integral or unscoped enumeration 4845 // type, most conversion kinds are impossible. All possible First and Third 4846 // conversions are fine. 4847 switch (SCS.Second) { 4848 case ICK_Identity: 4849 case ICK_Integral_Promotion: 4850 case ICK_Integral_Conversion: 4851 case ICK_Zero_Event_Conversion: 4852 return true; 4853 4854 case ICK_Boolean_Conversion: 4855 // Conversion from an integral or unscoped enumeration type to bool is 4856 // classified as ICK_Boolean_Conversion, but it's also an integral 4857 // conversion, so it's permitted in a converted constant expression. 4858 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() && 4859 SCS.getToType(2)->isBooleanType(); 4860 4861 case ICK_Floating_Integral: 4862 case ICK_Complex_Real: 4863 return false; 4864 4865 case ICK_Lvalue_To_Rvalue: 4866 case ICK_Array_To_Pointer: 4867 case ICK_Function_To_Pointer: 4868 case ICK_NoReturn_Adjustment: 4869 case ICK_Qualification: 4870 case ICK_Compatible_Conversion: 4871 case ICK_Vector_Conversion: 4872 case ICK_Vector_Splat: 4873 case ICK_Derived_To_Base: 4874 case ICK_Pointer_Conversion: 4875 case ICK_Pointer_Member: 4876 case ICK_Block_Pointer_Conversion: 4877 case ICK_Writeback_Conversion: 4878 case ICK_Floating_Promotion: 4879 case ICK_Complex_Promotion: 4880 case ICK_Complex_Conversion: 4881 case ICK_Floating_Conversion: 4882 case ICK_TransparentUnionConversion: 4883 llvm_unreachable("unexpected second conversion kind"); 4884 4885 case ICK_Num_Conversion_Kinds: 4886 break; 4887 } 4888 4889 llvm_unreachable("unknown conversion kind"); 4890} 4891 4892/// CheckConvertedConstantExpression - Check that the expression From is a 4893/// converted constant expression of type T, perform the conversion and produce 4894/// the converted expression, per C++11 [expr.const]p3. 4895ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T, 4896 llvm::APSInt &Value, 4897 CCEKind CCE) { 4898 assert(LangOpts.CPlusPlus11 && "converted constant expression outside C++11"); 4899 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type"); 4900 4901 if (checkPlaceholderForOverload(*this, From)) 4902 return ExprError(); 4903 4904 // C++11 [expr.const]p3 with proposed wording fixes: 4905 // A converted constant expression of type T is a core constant expression, 4906 // implicitly converted to a prvalue of type T, where the converted 4907 // expression is a literal constant expression and the implicit conversion 4908 // sequence contains only user-defined conversions, lvalue-to-rvalue 4909 // conversions, integral promotions, and integral conversions other than 4910 // narrowing conversions. 4911 ImplicitConversionSequence ICS = 4912 TryImplicitConversion(From, T, 4913 /*SuppressUserConversions=*/false, 4914 /*AllowExplicit=*/false, 4915 /*InOverloadResolution=*/false, 4916 /*CStyle=*/false, 4917 /*AllowObjcWritebackConversion=*/false); 4918 StandardConversionSequence *SCS = 0; 4919 switch (ICS.getKind()) { 4920 case ImplicitConversionSequence::StandardConversion: 4921 if (!CheckConvertedConstantConversions(*this, ICS.Standard)) 4922 return Diag(From->getLocStart(), 4923 diag::err_typecheck_converted_constant_expression_disallowed) 4924 << From->getType() << From->getSourceRange() << T; 4925 SCS = &ICS.Standard; 4926 break; 4927 case ImplicitConversionSequence::UserDefinedConversion: 4928 // We are converting from class type to an integral or enumeration type, so 4929 // the Before sequence must be trivial. 4930 if (!CheckConvertedConstantConversions(*this, ICS.UserDefined.After)) 4931 return Diag(From->getLocStart(), 4932 diag::err_typecheck_converted_constant_expression_disallowed) 4933 << From->getType() << From->getSourceRange() << T; 4934 SCS = &ICS.UserDefined.After; 4935 break; 4936 case ImplicitConversionSequence::AmbiguousConversion: 4937 case ImplicitConversionSequence::BadConversion: 4938 if (!DiagnoseMultipleUserDefinedConversion(From, T)) 4939 return Diag(From->getLocStart(), 4940 diag::err_typecheck_converted_constant_expression) 4941 << From->getType() << From->getSourceRange() << T; 4942 return ExprError(); 4943 4944 case ImplicitConversionSequence::EllipsisConversion: 4945 llvm_unreachable("ellipsis conversion in converted constant expression"); 4946 } 4947 4948 ExprResult Result = PerformImplicitConversion(From, T, ICS, AA_Converting); 4949 if (Result.isInvalid()) 4950 return Result; 4951 4952 // Check for a narrowing implicit conversion. 4953 APValue PreNarrowingValue; 4954 QualType PreNarrowingType; 4955 switch (SCS->getNarrowingKind(Context, Result.get(), PreNarrowingValue, 4956 PreNarrowingType)) { 4957 case NK_Variable_Narrowing: 4958 // Implicit conversion to a narrower type, and the value is not a constant 4959 // expression. We'll diagnose this in a moment. 4960 case NK_Not_Narrowing: 4961 break; 4962 4963 case NK_Constant_Narrowing: 4964 Diag(From->getLocStart(), 4965 isSFINAEContext() ? diag::err_cce_narrowing_sfinae : 4966 diag::err_cce_narrowing) 4967 << CCE << /*Constant*/1 4968 << PreNarrowingValue.getAsString(Context, PreNarrowingType) << T; 4969 break; 4970 4971 case NK_Type_Narrowing: 4972 Diag(From->getLocStart(), 4973 isSFINAEContext() ? diag::err_cce_narrowing_sfinae : 4974 diag::err_cce_narrowing) 4975 << CCE << /*Constant*/0 << From->getType() << T; 4976 break; 4977 } 4978 4979 // Check the expression is a constant expression. 4980 SmallVector<PartialDiagnosticAt, 8> Notes; 4981 Expr::EvalResult Eval; 4982 Eval.Diag = &Notes; 4983 4984 if (!Result.get()->EvaluateAsRValue(Eval, Context) || !Eval.Val.isInt()) { 4985 // The expression can't be folded, so we can't keep it at this position in 4986 // the AST. 4987 Result = ExprError(); 4988 } else { 4989 Value = Eval.Val.getInt(); 4990 4991 if (Notes.empty()) { 4992 // It's a constant expression. 4993 return Result; 4994 } 4995 } 4996 4997 // It's not a constant expression. Produce an appropriate diagnostic. 4998 if (Notes.size() == 1 && 4999 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr) 5000 Diag(Notes[0].first, diag::err_expr_not_cce) << CCE; 5001 else { 5002 Diag(From->getLocStart(), diag::err_expr_not_cce) 5003 << CCE << From->getSourceRange(); 5004 for (unsigned I = 0; I < Notes.size(); ++I) 5005 Diag(Notes[I].first, Notes[I].second); 5006 } 5007 return Result; 5008} 5009 5010/// dropPointerConversions - If the given standard conversion sequence 5011/// involves any pointer conversions, remove them. This may change 5012/// the result type of the conversion sequence. 5013static void dropPointerConversion(StandardConversionSequence &SCS) { 5014 if (SCS.Second == ICK_Pointer_Conversion) { 5015 SCS.Second = ICK_Identity; 5016 SCS.Third = ICK_Identity; 5017 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0]; 5018 } 5019} 5020 5021/// TryContextuallyConvertToObjCPointer - Attempt to contextually 5022/// convert the expression From to an Objective-C pointer type. 5023static ImplicitConversionSequence 5024TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) { 5025 // Do an implicit conversion to 'id'. 5026 QualType Ty = S.Context.getObjCIdType(); 5027 ImplicitConversionSequence ICS 5028 = TryImplicitConversion(S, From, Ty, 5029 // FIXME: Are these flags correct? 5030 /*SuppressUserConversions=*/false, 5031 /*AllowExplicit=*/true, 5032 /*InOverloadResolution=*/false, 5033 /*CStyle=*/false, 5034 /*AllowObjCWritebackConversion=*/false); 5035 5036 // Strip off any final conversions to 'id'. 5037 switch (ICS.getKind()) { 5038 case ImplicitConversionSequence::BadConversion: 5039 case ImplicitConversionSequence::AmbiguousConversion: 5040 case ImplicitConversionSequence::EllipsisConversion: 5041 break; 5042 5043 case ImplicitConversionSequence::UserDefinedConversion: 5044 dropPointerConversion(ICS.UserDefined.After); 5045 break; 5046 5047 case ImplicitConversionSequence::StandardConversion: 5048 dropPointerConversion(ICS.Standard); 5049 break; 5050 } 5051 5052 return ICS; 5053} 5054 5055/// PerformContextuallyConvertToObjCPointer - Perform a contextual 5056/// conversion of the expression From to an Objective-C pointer type. 5057ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) { 5058 if (checkPlaceholderForOverload(*this, From)) 5059 return ExprError(); 5060 5061 QualType Ty = Context.getObjCIdType(); 5062 ImplicitConversionSequence ICS = 5063 TryContextuallyConvertToObjCPointer(*this, From); 5064 if (!ICS.isBad()) 5065 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 5066 return ExprError(); 5067} 5068 5069/// Determine whether the provided type is an integral type, or an enumeration 5070/// type of a permitted flavor. 5071bool Sema::ICEConvertDiagnoser::match(QualType T) { 5072 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType() 5073 : T->isIntegralOrUnscopedEnumerationType(); 5074} 5075 5076static ExprResult 5077diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From, 5078 Sema::ContextualImplicitConverter &Converter, 5079 QualType T, UnresolvedSetImpl &ViableConversions) { 5080 5081 if (Converter.Suppress) 5082 return ExprError(); 5083 5084 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange(); 5085 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 5086 CXXConversionDecl *Conv = 5087 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 5088 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 5089 Converter.noteAmbiguous(SemaRef, Conv, ConvTy); 5090 } 5091 return SemaRef.Owned(From); 5092} 5093 5094static bool 5095diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From, 5096 Sema::ContextualImplicitConverter &Converter, 5097 QualType T, bool HadMultipleCandidates, 5098 UnresolvedSetImpl &ExplicitConversions) { 5099 if (ExplicitConversions.size() == 1 && !Converter.Suppress) { 5100 DeclAccessPair Found = ExplicitConversions[0]; 5101 CXXConversionDecl *Conversion = 5102 cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 5103 5104 // The user probably meant to invoke the given explicit 5105 // conversion; use it. 5106 QualType ConvTy = Conversion->getConversionType().getNonReferenceType(); 5107 std::string TypeStr; 5108 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy()); 5109 5110 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy) 5111 << FixItHint::CreateInsertion(From->getLocStart(), 5112 "static_cast<" + TypeStr + ">(") 5113 << FixItHint::CreateInsertion( 5114 SemaRef.PP.getLocForEndOfToken(From->getLocEnd()), ")"); 5115 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy); 5116 5117 // If we aren't in a SFINAE context, build a call to the 5118 // explicit conversion function. 5119 if (SemaRef.isSFINAEContext()) 5120 return true; 5121 5122 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 5123 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion, 5124 HadMultipleCandidates); 5125 if (Result.isInvalid()) 5126 return true; 5127 // Record usage of conversion in an implicit cast. 5128 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(), 5129 CK_UserDefinedConversion, Result.get(), 0, 5130 Result.get()->getValueKind()); 5131 } 5132 return false; 5133} 5134 5135static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From, 5136 Sema::ContextualImplicitConverter &Converter, 5137 QualType T, bool HadMultipleCandidates, 5138 DeclAccessPair &Found) { 5139 CXXConversionDecl *Conversion = 5140 cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 5141 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 5142 5143 QualType ToType = Conversion->getConversionType().getNonReferenceType(); 5144 if (!Converter.SuppressConversion) { 5145 if (SemaRef.isSFINAEContext()) 5146 return true; 5147 5148 Converter.diagnoseConversion(SemaRef, Loc, T, ToType) 5149 << From->getSourceRange(); 5150 } 5151 5152 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion, 5153 HadMultipleCandidates); 5154 if (Result.isInvalid()) 5155 return true; 5156 // Record usage of conversion in an implicit cast. 5157 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(), 5158 CK_UserDefinedConversion, Result.get(), 0, 5159 Result.get()->getValueKind()); 5160 return false; 5161} 5162 5163static ExprResult finishContextualImplicitConversion( 5164 Sema &SemaRef, SourceLocation Loc, Expr *From, 5165 Sema::ContextualImplicitConverter &Converter) { 5166 if (!Converter.match(From->getType()) && !Converter.Suppress) 5167 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType()) 5168 << From->getSourceRange(); 5169 5170 return SemaRef.DefaultLvalueConversion(From); 5171} 5172 5173static void 5174collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType, 5175 UnresolvedSetImpl &ViableConversions, 5176 OverloadCandidateSet &CandidateSet) { 5177 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 5178 DeclAccessPair FoundDecl = ViableConversions[I]; 5179 NamedDecl *D = FoundDecl.getDecl(); 5180 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 5181 if (isa<UsingShadowDecl>(D)) 5182 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 5183 5184 CXXConversionDecl *Conv; 5185 FunctionTemplateDecl *ConvTemplate; 5186 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 5187 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 5188 else 5189 Conv = cast<CXXConversionDecl>(D); 5190 5191 if (ConvTemplate) 5192 SemaRef.AddTemplateConversionCandidate( 5193 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet); 5194 else 5195 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From, 5196 ToType, CandidateSet); 5197 } 5198} 5199 5200/// \brief Attempt to convert the given expression to a type which is accepted 5201/// by the given converter. 5202/// 5203/// This routine will attempt to convert an expression of class type to a 5204/// type accepted by the specified converter. In C++11 and before, the class 5205/// must have a single non-explicit conversion function converting to a matching 5206/// type. In C++1y, there can be multiple such conversion functions, but only 5207/// one target type. 5208/// 5209/// \param Loc The source location of the construct that requires the 5210/// conversion. 5211/// 5212/// \param From The expression we're converting from. 5213/// 5214/// \param Converter Used to control and diagnose the conversion process. 5215/// 5216/// \returns The expression, converted to an integral or enumeration type if 5217/// successful. 5218ExprResult Sema::PerformContextualImplicitConversion( 5219 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) { 5220 // We can't perform any more checking for type-dependent expressions. 5221 if (From->isTypeDependent()) 5222 return Owned(From); 5223 5224 // Process placeholders immediately. 5225 if (From->hasPlaceholderType()) { 5226 ExprResult result = CheckPlaceholderExpr(From); 5227 if (result.isInvalid()) 5228 return result; 5229 From = result.take(); 5230 } 5231 5232 // If the expression already has a matching type, we're golden. 5233 QualType T = From->getType(); 5234 if (Converter.match(T)) 5235 return DefaultLvalueConversion(From); 5236 5237 // FIXME: Check for missing '()' if T is a function type? 5238 5239 // We can only perform contextual implicit conversions on objects of class 5240 // type. 5241 const RecordType *RecordTy = T->getAs<RecordType>(); 5242 if (!RecordTy || !getLangOpts().CPlusPlus) { 5243 if (!Converter.Suppress) 5244 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange(); 5245 return Owned(From); 5246 } 5247 5248 // We must have a complete class type. 5249 struct TypeDiagnoserPartialDiag : TypeDiagnoser { 5250 ContextualImplicitConverter &Converter; 5251 Expr *From; 5252 5253 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From) 5254 : TypeDiagnoser(Converter.Suppress), Converter(Converter), From(From) {} 5255 5256 virtual void diagnose(Sema &S, SourceLocation Loc, QualType T) { 5257 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange(); 5258 } 5259 } IncompleteDiagnoser(Converter, From); 5260 5261 if (RequireCompleteType(Loc, T, IncompleteDiagnoser)) 5262 return Owned(From); 5263 5264 // Look for a conversion to an integral or enumeration type. 5265 UnresolvedSet<4> 5266 ViableConversions; // These are *potentially* viable in C++1y. 5267 UnresolvedSet<4> ExplicitConversions; 5268 std::pair<CXXRecordDecl::conversion_iterator, 5269 CXXRecordDecl::conversion_iterator> Conversions = 5270 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 5271 5272 bool HadMultipleCandidates = 5273 (std::distance(Conversions.first, Conversions.second) > 1); 5274 5275 // To check that there is only one target type, in C++1y: 5276 QualType ToType; 5277 bool HasUniqueTargetType = true; 5278 5279 // Collect explicit or viable (potentially in C++1y) conversions. 5280 for (CXXRecordDecl::conversion_iterator I = Conversions.first, 5281 E = Conversions.second; 5282 I != E; ++I) { 5283 NamedDecl *D = (*I)->getUnderlyingDecl(); 5284 CXXConversionDecl *Conversion; 5285 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D); 5286 if (ConvTemplate) { 5287 if (getLangOpts().CPlusPlus1y) 5288 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 5289 else 5290 continue; // C++11 does not consider conversion operator templates(?). 5291 } else 5292 Conversion = cast<CXXConversionDecl>(D); 5293 5294 assert((!ConvTemplate || getLangOpts().CPlusPlus1y) && 5295 "Conversion operator templates are considered potentially " 5296 "viable in C++1y"); 5297 5298 QualType CurToType = Conversion->getConversionType().getNonReferenceType(); 5299 if (Converter.match(CurToType) || ConvTemplate) { 5300 5301 if (Conversion->isExplicit()) { 5302 // FIXME: For C++1y, do we need this restriction? 5303 // cf. diagnoseNoViableConversion() 5304 if (!ConvTemplate) 5305 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 5306 } else { 5307 if (!ConvTemplate && getLangOpts().CPlusPlus1y) { 5308 if (ToType.isNull()) 5309 ToType = CurToType.getUnqualifiedType(); 5310 else if (HasUniqueTargetType && 5311 (CurToType.getUnqualifiedType() != ToType)) 5312 HasUniqueTargetType = false; 5313 } 5314 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 5315 } 5316 } 5317 } 5318 5319 if (getLangOpts().CPlusPlus1y) { 5320 // C++1y [conv]p6: 5321 // ... An expression e of class type E appearing in such a context 5322 // is said to be contextually implicitly converted to a specified 5323 // type T and is well-formed if and only if e can be implicitly 5324 // converted to a type T that is determined as follows: E is searched 5325 // for conversion functions whose return type is cv T or reference to 5326 // cv T such that T is allowed by the context. There shall be 5327 // exactly one such T. 5328 5329 // If no unique T is found: 5330 if (ToType.isNull()) { 5331 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T, 5332 HadMultipleCandidates, 5333 ExplicitConversions)) 5334 return ExprError(); 5335 return finishContextualImplicitConversion(*this, Loc, From, Converter); 5336 } 5337 5338 // If more than one unique Ts are found: 5339 if (!HasUniqueTargetType) 5340 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T, 5341 ViableConversions); 5342 5343 // If one unique T is found: 5344 // First, build a candidate set from the previously recorded 5345 // potentially viable conversions. 5346 OverloadCandidateSet CandidateSet(Loc); 5347 collectViableConversionCandidates(*this, From, ToType, ViableConversions, 5348 CandidateSet); 5349 5350 // Then, perform overload resolution over the candidate set. 5351 OverloadCandidateSet::iterator Best; 5352 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) { 5353 case OR_Success: { 5354 // Apply this conversion. 5355 DeclAccessPair Found = 5356 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess()); 5357 if (recordConversion(*this, Loc, From, Converter, T, 5358 HadMultipleCandidates, Found)) 5359 return ExprError(); 5360 break; 5361 } 5362 case OR_Ambiguous: 5363 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T, 5364 ViableConversions); 5365 case OR_No_Viable_Function: 5366 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T, 5367 HadMultipleCandidates, 5368 ExplicitConversions)) 5369 return ExprError(); 5370 // fall through 'OR_Deleted' case. 5371 case OR_Deleted: 5372 // We'll complain below about a non-integral condition type. 5373 break; 5374 } 5375 } else { 5376 switch (ViableConversions.size()) { 5377 case 0: { 5378 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T, 5379 HadMultipleCandidates, 5380 ExplicitConversions)) 5381 return ExprError(); 5382 5383 // We'll complain below about a non-integral condition type. 5384 break; 5385 } 5386 case 1: { 5387 // Apply this conversion. 5388 DeclAccessPair Found = ViableConversions[0]; 5389 if (recordConversion(*this, Loc, From, Converter, T, 5390 HadMultipleCandidates, Found)) 5391 return ExprError(); 5392 break; 5393 } 5394 default: 5395 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T, 5396 ViableConversions); 5397 } 5398 } 5399 5400 return finishContextualImplicitConversion(*this, Loc, From, Converter); 5401} 5402 5403/// AddOverloadCandidate - Adds the given function to the set of 5404/// candidate functions, using the given function call arguments. If 5405/// @p SuppressUserConversions, then don't allow user-defined 5406/// conversions via constructors or conversion operators. 5407/// 5408/// \param PartialOverloading true if we are performing "partial" overloading 5409/// based on an incomplete set of function arguments. This feature is used by 5410/// code completion. 5411void 5412Sema::AddOverloadCandidate(FunctionDecl *Function, 5413 DeclAccessPair FoundDecl, 5414 ArrayRef<Expr *> Args, 5415 OverloadCandidateSet& CandidateSet, 5416 bool SuppressUserConversions, 5417 bool PartialOverloading, 5418 bool AllowExplicit) { 5419 const FunctionProtoType* Proto 5420 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 5421 assert(Proto && "Functions without a prototype cannot be overloaded"); 5422 assert(!Function->getDescribedFunctionTemplate() && 5423 "Use AddTemplateOverloadCandidate for function templates"); 5424 5425 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 5426 if (!isa<CXXConstructorDecl>(Method)) { 5427 // If we get here, it's because we're calling a member function 5428 // that is named without a member access expression (e.g., 5429 // "this->f") that was either written explicitly or created 5430 // implicitly. This can happen with a qualified call to a member 5431 // function, e.g., X::f(). We use an empty type for the implied 5432 // object argument (C++ [over.call.func]p3), and the acting context 5433 // is irrelevant. 5434 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 5435 QualType(), Expr::Classification::makeSimpleLValue(), 5436 Args, CandidateSet, SuppressUserConversions); 5437 return; 5438 } 5439 // We treat a constructor like a non-member function, since its object 5440 // argument doesn't participate in overload resolution. 5441 } 5442 5443 if (!CandidateSet.isNewCandidate(Function)) 5444 return; 5445 5446 // Overload resolution is always an unevaluated context. 5447 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5448 5449 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 5450 // C++ [class.copy]p3: 5451 // A member function template is never instantiated to perform the copy 5452 // of a class object to an object of its class type. 5453 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 5454 if (Args.size() == 1 && 5455 Constructor->isSpecializationCopyingObject() && 5456 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 5457 IsDerivedFrom(Args[0]->getType(), ClassType))) 5458 return; 5459 } 5460 5461 // Add this candidate 5462 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size()); 5463 Candidate.FoundDecl = FoundDecl; 5464 Candidate.Function = Function; 5465 Candidate.Viable = true; 5466 Candidate.IsSurrogate = false; 5467 Candidate.IgnoreObjectArgument = false; 5468 Candidate.ExplicitCallArguments = Args.size(); 5469 5470 unsigned NumArgsInProto = Proto->getNumArgs(); 5471 5472 // (C++ 13.3.2p2): A candidate function having fewer than m 5473 // parameters is viable only if it has an ellipsis in its parameter 5474 // list (8.3.5). 5475 if ((Args.size() + (PartialOverloading && Args.size())) > NumArgsInProto && 5476 !Proto->isVariadic()) { 5477 Candidate.Viable = false; 5478 Candidate.FailureKind = ovl_fail_too_many_arguments; 5479 return; 5480 } 5481 5482 // (C++ 13.3.2p2): A candidate function having more than m parameters 5483 // is viable only if the (m+1)st parameter has a default argument 5484 // (8.3.6). For the purposes of overload resolution, the 5485 // parameter list is truncated on the right, so that there are 5486 // exactly m parameters. 5487 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 5488 if (Args.size() < MinRequiredArgs && !PartialOverloading) { 5489 // Not enough arguments. 5490 Candidate.Viable = false; 5491 Candidate.FailureKind = ovl_fail_too_few_arguments; 5492 return; 5493 } 5494 5495 // (CUDA B.1): Check for invalid calls between targets. 5496 if (getLangOpts().CUDA) 5497 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext)) 5498 if (CheckCUDATarget(Caller, Function)) { 5499 Candidate.Viable = false; 5500 Candidate.FailureKind = ovl_fail_bad_target; 5501 return; 5502 } 5503 5504 // Determine the implicit conversion sequences for each of the 5505 // arguments. 5506 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5507 if (ArgIdx < NumArgsInProto) { 5508 // (C++ 13.3.2p3): for F to be a viable function, there shall 5509 // exist for each argument an implicit conversion sequence 5510 // (13.3.3.1) that converts that argument to the corresponding 5511 // parameter of F. 5512 QualType ParamType = Proto->getArgType(ArgIdx); 5513 Candidate.Conversions[ArgIdx] 5514 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5515 SuppressUserConversions, 5516 /*InOverloadResolution=*/true, 5517 /*AllowObjCWritebackConversion=*/ 5518 getLangOpts().ObjCAutoRefCount, 5519 AllowExplicit); 5520 if (Candidate.Conversions[ArgIdx].isBad()) { 5521 Candidate.Viable = false; 5522 Candidate.FailureKind = ovl_fail_bad_conversion; 5523 break; 5524 } 5525 } else { 5526 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5527 // argument for which there is no corresponding parameter is 5528 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5529 Candidate.Conversions[ArgIdx].setEllipsis(); 5530 } 5531 } 5532} 5533 5534/// \brief Add all of the function declarations in the given function set to 5535/// the overload canddiate set. 5536void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 5537 ArrayRef<Expr *> Args, 5538 OverloadCandidateSet& CandidateSet, 5539 bool SuppressUserConversions, 5540 TemplateArgumentListInfo *ExplicitTemplateArgs) { 5541 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 5542 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 5543 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 5544 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 5545 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 5546 cast<CXXMethodDecl>(FD)->getParent(), 5547 Args[0]->getType(), Args[0]->Classify(Context), 5548 Args.slice(1), CandidateSet, 5549 SuppressUserConversions); 5550 else 5551 AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet, 5552 SuppressUserConversions); 5553 } else { 5554 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 5555 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 5556 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 5557 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 5558 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 5559 ExplicitTemplateArgs, 5560 Args[0]->getType(), 5561 Args[0]->Classify(Context), Args.slice(1), 5562 CandidateSet, SuppressUserConversions); 5563 else 5564 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 5565 ExplicitTemplateArgs, Args, 5566 CandidateSet, SuppressUserConversions); 5567 } 5568 } 5569} 5570 5571/// AddMethodCandidate - Adds a named decl (which is some kind of 5572/// method) as a method candidate to the given overload set. 5573void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 5574 QualType ObjectType, 5575 Expr::Classification ObjectClassification, 5576 ArrayRef<Expr *> Args, 5577 OverloadCandidateSet& CandidateSet, 5578 bool SuppressUserConversions) { 5579 NamedDecl *Decl = FoundDecl.getDecl(); 5580 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 5581 5582 if (isa<UsingShadowDecl>(Decl)) 5583 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 5584 5585 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 5586 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 5587 "Expected a member function template"); 5588 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 5589 /*ExplicitArgs*/ 0, 5590 ObjectType, ObjectClassification, 5591 Args, CandidateSet, 5592 SuppressUserConversions); 5593 } else { 5594 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 5595 ObjectType, ObjectClassification, 5596 Args, 5597 CandidateSet, SuppressUserConversions); 5598 } 5599} 5600 5601/// AddMethodCandidate - Adds the given C++ member function to the set 5602/// of candidate functions, using the given function call arguments 5603/// and the object argument (@c Object). For example, in a call 5604/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 5605/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 5606/// allow user-defined conversions via constructors or conversion 5607/// operators. 5608void 5609Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 5610 CXXRecordDecl *ActingContext, QualType ObjectType, 5611 Expr::Classification ObjectClassification, 5612 ArrayRef<Expr *> Args, 5613 OverloadCandidateSet& CandidateSet, 5614 bool SuppressUserConversions) { 5615 const FunctionProtoType* Proto 5616 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 5617 assert(Proto && "Methods without a prototype cannot be overloaded"); 5618 assert(!isa<CXXConstructorDecl>(Method) && 5619 "Use AddOverloadCandidate for constructors"); 5620 5621 if (!CandidateSet.isNewCandidate(Method)) 5622 return; 5623 5624 // Overload resolution is always an unevaluated context. 5625 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5626 5627 // Add this candidate 5628 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); 5629 Candidate.FoundDecl = FoundDecl; 5630 Candidate.Function = Method; 5631 Candidate.IsSurrogate = false; 5632 Candidate.IgnoreObjectArgument = false; 5633 Candidate.ExplicitCallArguments = Args.size(); 5634 5635 unsigned NumArgsInProto = Proto->getNumArgs(); 5636 5637 // (C++ 13.3.2p2): A candidate function having fewer than m 5638 // parameters is viable only if it has an ellipsis in its parameter 5639 // list (8.3.5). 5640 if (Args.size() > NumArgsInProto && !Proto->isVariadic()) { 5641 Candidate.Viable = false; 5642 Candidate.FailureKind = ovl_fail_too_many_arguments; 5643 return; 5644 } 5645 5646 // (C++ 13.3.2p2): A candidate function having more than m parameters 5647 // is viable only if the (m+1)st parameter has a default argument 5648 // (8.3.6). For the purposes of overload resolution, the 5649 // parameter list is truncated on the right, so that there are 5650 // exactly m parameters. 5651 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 5652 if (Args.size() < MinRequiredArgs) { 5653 // Not enough arguments. 5654 Candidate.Viable = false; 5655 Candidate.FailureKind = ovl_fail_too_few_arguments; 5656 return; 5657 } 5658 5659 Candidate.Viable = true; 5660 5661 if (Method->isStatic() || ObjectType.isNull()) 5662 // The implicit object argument is ignored. 5663 Candidate.IgnoreObjectArgument = true; 5664 else { 5665 // Determine the implicit conversion sequence for the object 5666 // parameter. 5667 Candidate.Conversions[0] 5668 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 5669 Method, ActingContext); 5670 if (Candidate.Conversions[0].isBad()) { 5671 Candidate.Viable = false; 5672 Candidate.FailureKind = ovl_fail_bad_conversion; 5673 return; 5674 } 5675 } 5676 5677 // Determine the implicit conversion sequences for each of the 5678 // arguments. 5679 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5680 if (ArgIdx < NumArgsInProto) { 5681 // (C++ 13.3.2p3): for F to be a viable function, there shall 5682 // exist for each argument an implicit conversion sequence 5683 // (13.3.3.1) that converts that argument to the corresponding 5684 // parameter of F. 5685 QualType ParamType = Proto->getArgType(ArgIdx); 5686 Candidate.Conversions[ArgIdx + 1] 5687 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5688 SuppressUserConversions, 5689 /*InOverloadResolution=*/true, 5690 /*AllowObjCWritebackConversion=*/ 5691 getLangOpts().ObjCAutoRefCount); 5692 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 5693 Candidate.Viable = false; 5694 Candidate.FailureKind = ovl_fail_bad_conversion; 5695 break; 5696 } 5697 } else { 5698 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5699 // argument for which there is no corresponding parameter is 5700 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5701 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 5702 } 5703 } 5704} 5705 5706/// \brief Add a C++ member function template as a candidate to the candidate 5707/// set, using template argument deduction to produce an appropriate member 5708/// function template specialization. 5709void 5710Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 5711 DeclAccessPair FoundDecl, 5712 CXXRecordDecl *ActingContext, 5713 TemplateArgumentListInfo *ExplicitTemplateArgs, 5714 QualType ObjectType, 5715 Expr::Classification ObjectClassification, 5716 ArrayRef<Expr *> Args, 5717 OverloadCandidateSet& CandidateSet, 5718 bool SuppressUserConversions) { 5719 if (!CandidateSet.isNewCandidate(MethodTmpl)) 5720 return; 5721 5722 // C++ [over.match.funcs]p7: 5723 // In each case where a candidate is a function template, candidate 5724 // function template specializations are generated using template argument 5725 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 5726 // candidate functions in the usual way.113) A given name can refer to one 5727 // or more function templates and also to a set of overloaded non-template 5728 // functions. In such a case, the candidate functions generated from each 5729 // function template are combined with the set of non-template candidate 5730 // functions. 5731 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5732 FunctionDecl *Specialization = 0; 5733 if (TemplateDeductionResult Result 5734 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, Args, 5735 Specialization, Info)) { 5736 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5737 Candidate.FoundDecl = FoundDecl; 5738 Candidate.Function = MethodTmpl->getTemplatedDecl(); 5739 Candidate.Viable = false; 5740 Candidate.FailureKind = ovl_fail_bad_deduction; 5741 Candidate.IsSurrogate = false; 5742 Candidate.IgnoreObjectArgument = false; 5743 Candidate.ExplicitCallArguments = Args.size(); 5744 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5745 Info); 5746 return; 5747 } 5748 5749 // Add the function template specialization produced by template argument 5750 // deduction as a candidate. 5751 assert(Specialization && "Missing member function template specialization?"); 5752 assert(isa<CXXMethodDecl>(Specialization) && 5753 "Specialization is not a member function?"); 5754 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 5755 ActingContext, ObjectType, ObjectClassification, Args, 5756 CandidateSet, SuppressUserConversions); 5757} 5758 5759/// \brief Add a C++ function template specialization as a candidate 5760/// in the candidate set, using template argument deduction to produce 5761/// an appropriate function template specialization. 5762void 5763Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 5764 DeclAccessPair FoundDecl, 5765 TemplateArgumentListInfo *ExplicitTemplateArgs, 5766 ArrayRef<Expr *> Args, 5767 OverloadCandidateSet& CandidateSet, 5768 bool SuppressUserConversions) { 5769 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 5770 return; 5771 5772 // C++ [over.match.funcs]p7: 5773 // In each case where a candidate is a function template, candidate 5774 // function template specializations are generated using template argument 5775 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 5776 // candidate functions in the usual way.113) A given name can refer to one 5777 // or more function templates and also to a set of overloaded non-template 5778 // functions. In such a case, the candidate functions generated from each 5779 // function template are combined with the set of non-template candidate 5780 // functions. 5781 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5782 FunctionDecl *Specialization = 0; 5783 if (TemplateDeductionResult Result 5784 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, Args, 5785 Specialization, Info)) { 5786 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5787 Candidate.FoundDecl = FoundDecl; 5788 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 5789 Candidate.Viable = false; 5790 Candidate.FailureKind = ovl_fail_bad_deduction; 5791 Candidate.IsSurrogate = false; 5792 Candidate.IgnoreObjectArgument = false; 5793 Candidate.ExplicitCallArguments = Args.size(); 5794 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5795 Info); 5796 return; 5797 } 5798 5799 // Add the function template specialization produced by template argument 5800 // deduction as a candidate. 5801 assert(Specialization && "Missing function template specialization?"); 5802 AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet, 5803 SuppressUserConversions); 5804} 5805 5806/// AddConversionCandidate - Add a C++ conversion function as a 5807/// candidate in the candidate set (C++ [over.match.conv], 5808/// C++ [over.match.copy]). From is the expression we're converting from, 5809/// and ToType is the type that we're eventually trying to convert to 5810/// (which may or may not be the same type as the type that the 5811/// conversion function produces). 5812void 5813Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 5814 DeclAccessPair FoundDecl, 5815 CXXRecordDecl *ActingContext, 5816 Expr *From, QualType ToType, 5817 OverloadCandidateSet& CandidateSet) { 5818 assert(!Conversion->getDescribedFunctionTemplate() && 5819 "Conversion function templates use AddTemplateConversionCandidate"); 5820 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 5821 if (!CandidateSet.isNewCandidate(Conversion)) 5822 return; 5823 5824 // If the conversion function has an undeduced return type, trigger its 5825 // deduction now. 5826 if (getLangOpts().CPlusPlus1y && ConvType->isUndeducedType()) { 5827 if (DeduceReturnType(Conversion, From->getExprLoc())) 5828 return; 5829 ConvType = Conversion->getConversionType().getNonReferenceType(); 5830 } 5831 5832 // Overload resolution is always an unevaluated context. 5833 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5834 5835 // Add this candidate 5836 OverloadCandidate &Candidate = CandidateSet.addCandidate(1); 5837 Candidate.FoundDecl = FoundDecl; 5838 Candidate.Function = Conversion; 5839 Candidate.IsSurrogate = false; 5840 Candidate.IgnoreObjectArgument = false; 5841 Candidate.FinalConversion.setAsIdentityConversion(); 5842 Candidate.FinalConversion.setFromType(ConvType); 5843 Candidate.FinalConversion.setAllToTypes(ToType); 5844 Candidate.Viable = true; 5845 Candidate.ExplicitCallArguments = 1; 5846 5847 // C++ [over.match.funcs]p4: 5848 // For conversion functions, the function is considered to be a member of 5849 // the class of the implicit implied object argument for the purpose of 5850 // defining the type of the implicit object parameter. 5851 // 5852 // Determine the implicit conversion sequence for the implicit 5853 // object parameter. 5854 QualType ImplicitParamType = From->getType(); 5855 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 5856 ImplicitParamType = FromPtrType->getPointeeType(); 5857 CXXRecordDecl *ConversionContext 5858 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 5859 5860 Candidate.Conversions[0] 5861 = TryObjectArgumentInitialization(*this, From->getType(), 5862 From->Classify(Context), 5863 Conversion, ConversionContext); 5864 5865 if (Candidate.Conversions[0].isBad()) { 5866 Candidate.Viable = false; 5867 Candidate.FailureKind = ovl_fail_bad_conversion; 5868 return; 5869 } 5870 5871 // We won't go through a user-define type conversion function to convert a 5872 // derived to base as such conversions are given Conversion Rank. They only 5873 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 5874 QualType FromCanon 5875 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 5876 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 5877 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 5878 Candidate.Viable = false; 5879 Candidate.FailureKind = ovl_fail_trivial_conversion; 5880 return; 5881 } 5882 5883 // To determine what the conversion from the result of calling the 5884 // conversion function to the type we're eventually trying to 5885 // convert to (ToType), we need to synthesize a call to the 5886 // conversion function and attempt copy initialization from it. This 5887 // makes sure that we get the right semantics with respect to 5888 // lvalues/rvalues and the type. Fortunately, we can allocate this 5889 // call on the stack and we don't need its arguments to be 5890 // well-formed. 5891 DeclRefExpr ConversionRef(Conversion, false, Conversion->getType(), 5892 VK_LValue, From->getLocStart()); 5893 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 5894 Context.getPointerType(Conversion->getType()), 5895 CK_FunctionToPointerDecay, 5896 &ConversionRef, VK_RValue); 5897 5898 QualType ConversionType = Conversion->getConversionType(); 5899 if (RequireCompleteType(From->getLocStart(), ConversionType, 0)) { 5900 Candidate.Viable = false; 5901 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5902 return; 5903 } 5904 5905 ExprValueKind VK = Expr::getValueKindForType(ConversionType); 5906 5907 // Note that it is safe to allocate CallExpr on the stack here because 5908 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 5909 // allocator). 5910 QualType CallResultType = ConversionType.getNonLValueExprType(Context); 5911 CallExpr Call(Context, &ConversionFn, None, CallResultType, VK, 5912 From->getLocStart()); 5913 ImplicitConversionSequence ICS = 5914 TryCopyInitialization(*this, &Call, ToType, 5915 /*SuppressUserConversions=*/true, 5916 /*InOverloadResolution=*/false, 5917 /*AllowObjCWritebackConversion=*/false); 5918 5919 switch (ICS.getKind()) { 5920 case ImplicitConversionSequence::StandardConversion: 5921 Candidate.FinalConversion = ICS.Standard; 5922 5923 // C++ [over.ics.user]p3: 5924 // If the user-defined conversion is specified by a specialization of a 5925 // conversion function template, the second standard conversion sequence 5926 // shall have exact match rank. 5927 if (Conversion->getPrimaryTemplate() && 5928 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 5929 Candidate.Viable = false; 5930 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 5931 } 5932 5933 // C++0x [dcl.init.ref]p5: 5934 // In the second case, if the reference is an rvalue reference and 5935 // the second standard conversion sequence of the user-defined 5936 // conversion sequence includes an lvalue-to-rvalue conversion, the 5937 // program is ill-formed. 5938 if (ToType->isRValueReferenceType() && 5939 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 5940 Candidate.Viable = false; 5941 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5942 } 5943 break; 5944 5945 case ImplicitConversionSequence::BadConversion: 5946 Candidate.Viable = false; 5947 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5948 break; 5949 5950 default: 5951 llvm_unreachable( 5952 "Can only end up with a standard conversion sequence or failure"); 5953 } 5954} 5955 5956/// \brief Adds a conversion function template specialization 5957/// candidate to the overload set, using template argument deduction 5958/// to deduce the template arguments of the conversion function 5959/// template from the type that we are converting to (C++ 5960/// [temp.deduct.conv]). 5961void 5962Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 5963 DeclAccessPair FoundDecl, 5964 CXXRecordDecl *ActingDC, 5965 Expr *From, QualType ToType, 5966 OverloadCandidateSet &CandidateSet) { 5967 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 5968 "Only conversion function templates permitted here"); 5969 5970 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 5971 return; 5972 5973 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5974 CXXConversionDecl *Specialization = 0; 5975 if (TemplateDeductionResult Result 5976 = DeduceTemplateArguments(FunctionTemplate, ToType, 5977 Specialization, Info)) { 5978 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5979 Candidate.FoundDecl = FoundDecl; 5980 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 5981 Candidate.Viable = false; 5982 Candidate.FailureKind = ovl_fail_bad_deduction; 5983 Candidate.IsSurrogate = false; 5984 Candidate.IgnoreObjectArgument = false; 5985 Candidate.ExplicitCallArguments = 1; 5986 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5987 Info); 5988 return; 5989 } 5990 5991 // Add the conversion function template specialization produced by 5992 // template argument deduction as a candidate. 5993 assert(Specialization && "Missing function template specialization?"); 5994 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 5995 CandidateSet); 5996} 5997 5998/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 5999/// converts the given @c Object to a function pointer via the 6000/// conversion function @c Conversion, and then attempts to call it 6001/// with the given arguments (C++ [over.call.object]p2-4). Proto is 6002/// the type of function that we'll eventually be calling. 6003void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 6004 DeclAccessPair FoundDecl, 6005 CXXRecordDecl *ActingContext, 6006 const FunctionProtoType *Proto, 6007 Expr *Object, 6008 ArrayRef<Expr *> Args, 6009 OverloadCandidateSet& CandidateSet) { 6010 if (!CandidateSet.isNewCandidate(Conversion)) 6011 return; 6012 6013 // Overload resolution is always an unevaluated context. 6014 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 6015 6016 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); 6017 Candidate.FoundDecl = FoundDecl; 6018 Candidate.Function = 0; 6019 Candidate.Surrogate = Conversion; 6020 Candidate.Viable = true; 6021 Candidate.IsSurrogate = true; 6022 Candidate.IgnoreObjectArgument = false; 6023 Candidate.ExplicitCallArguments = Args.size(); 6024 6025 // Determine the implicit conversion sequence for the implicit 6026 // object parameter. 6027 ImplicitConversionSequence ObjectInit 6028 = TryObjectArgumentInitialization(*this, Object->getType(), 6029 Object->Classify(Context), 6030 Conversion, ActingContext); 6031 if (ObjectInit.isBad()) { 6032 Candidate.Viable = false; 6033 Candidate.FailureKind = ovl_fail_bad_conversion; 6034 Candidate.Conversions[0] = ObjectInit; 6035 return; 6036 } 6037 6038 // The first conversion is actually a user-defined conversion whose 6039 // first conversion is ObjectInit's standard conversion (which is 6040 // effectively a reference binding). Record it as such. 6041 Candidate.Conversions[0].setUserDefined(); 6042 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 6043 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 6044 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false; 6045 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 6046 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl; 6047 Candidate.Conversions[0].UserDefined.After 6048 = Candidate.Conversions[0].UserDefined.Before; 6049 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 6050 6051 // Find the 6052 unsigned NumArgsInProto = Proto->getNumArgs(); 6053 6054 // (C++ 13.3.2p2): A candidate function having fewer than m 6055 // parameters is viable only if it has an ellipsis in its parameter 6056 // list (8.3.5). 6057 if (Args.size() > NumArgsInProto && !Proto->isVariadic()) { 6058 Candidate.Viable = false; 6059 Candidate.FailureKind = ovl_fail_too_many_arguments; 6060 return; 6061 } 6062 6063 // Function types don't have any default arguments, so just check if 6064 // we have enough arguments. 6065 if (Args.size() < NumArgsInProto) { 6066 // Not enough arguments. 6067 Candidate.Viable = false; 6068 Candidate.FailureKind = ovl_fail_too_few_arguments; 6069 return; 6070 } 6071 6072 // Determine the implicit conversion sequences for each of the 6073 // arguments. 6074 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 6075 if (ArgIdx < NumArgsInProto) { 6076 // (C++ 13.3.2p3): for F to be a viable function, there shall 6077 // exist for each argument an implicit conversion sequence 6078 // (13.3.3.1) that converts that argument to the corresponding 6079 // parameter of F. 6080 QualType ParamType = Proto->getArgType(ArgIdx); 6081 Candidate.Conversions[ArgIdx + 1] 6082 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 6083 /*SuppressUserConversions=*/false, 6084 /*InOverloadResolution=*/false, 6085 /*AllowObjCWritebackConversion=*/ 6086 getLangOpts().ObjCAutoRefCount); 6087 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 6088 Candidate.Viable = false; 6089 Candidate.FailureKind = ovl_fail_bad_conversion; 6090 break; 6091 } 6092 } else { 6093 // (C++ 13.3.2p2): For the purposes of overload resolution, any 6094 // argument for which there is no corresponding parameter is 6095 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 6096 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 6097 } 6098 } 6099} 6100 6101/// \brief Add overload candidates for overloaded operators that are 6102/// member functions. 6103/// 6104/// Add the overloaded operator candidates that are member functions 6105/// for the operator Op that was used in an operator expression such 6106/// as "x Op y". , Args/NumArgs provides the operator arguments, and 6107/// CandidateSet will store the added overload candidates. (C++ 6108/// [over.match.oper]). 6109void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 6110 SourceLocation OpLoc, 6111 ArrayRef<Expr *> Args, 6112 OverloadCandidateSet& CandidateSet, 6113 SourceRange OpRange) { 6114 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6115 6116 // C++ [over.match.oper]p3: 6117 // For a unary operator @ with an operand of a type whose 6118 // cv-unqualified version is T1, and for a binary operator @ with 6119 // a left operand of a type whose cv-unqualified version is T1 and 6120 // a right operand of a type whose cv-unqualified version is T2, 6121 // three sets of candidate functions, designated member 6122 // candidates, non-member candidates and built-in candidates, are 6123 // constructed as follows: 6124 QualType T1 = Args[0]->getType(); 6125 6126 // -- If T1 is a complete class type or a class currently being 6127 // defined, the set of member candidates is the result of the 6128 // qualified lookup of T1::operator@ (13.3.1.1.1); otherwise, 6129 // the set of member candidates is empty. 6130 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 6131 // Complete the type if it can be completed. 6132 RequireCompleteType(OpLoc, T1, 0); 6133 // If the type is neither complete nor being defined, bail out now. 6134 if (!T1Rec->getDecl()->getDefinition()) 6135 return; 6136 6137 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 6138 LookupQualifiedName(Operators, T1Rec->getDecl()); 6139 Operators.suppressDiagnostics(); 6140 6141 for (LookupResult::iterator Oper = Operators.begin(), 6142 OperEnd = Operators.end(); 6143 Oper != OperEnd; 6144 ++Oper) 6145 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 6146 Args[0]->Classify(Context), 6147 Args.slice(1), 6148 CandidateSet, 6149 /* SuppressUserConversions = */ false); 6150 } 6151} 6152 6153/// AddBuiltinCandidate - Add a candidate for a built-in 6154/// operator. ResultTy and ParamTys are the result and parameter types 6155/// of the built-in candidate, respectively. Args and NumArgs are the 6156/// arguments being passed to the candidate. IsAssignmentOperator 6157/// should be true when this built-in candidate is an assignment 6158/// operator. NumContextualBoolArguments is the number of arguments 6159/// (at the beginning of the argument list) that will be contextually 6160/// converted to bool. 6161void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 6162 ArrayRef<Expr *> Args, 6163 OverloadCandidateSet& CandidateSet, 6164 bool IsAssignmentOperator, 6165 unsigned NumContextualBoolArguments) { 6166 // Overload resolution is always an unevaluated context. 6167 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 6168 6169 // Add this candidate 6170 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size()); 6171 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 6172 Candidate.Function = 0; 6173 Candidate.IsSurrogate = false; 6174 Candidate.IgnoreObjectArgument = false; 6175 Candidate.BuiltinTypes.ResultTy = ResultTy; 6176 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) 6177 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 6178 6179 // Determine the implicit conversion sequences for each of the 6180 // arguments. 6181 Candidate.Viable = true; 6182 Candidate.ExplicitCallArguments = Args.size(); 6183 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 6184 // C++ [over.match.oper]p4: 6185 // For the built-in assignment operators, conversions of the 6186 // left operand are restricted as follows: 6187 // -- no temporaries are introduced to hold the left operand, and 6188 // -- no user-defined conversions are applied to the left 6189 // operand to achieve a type match with the left-most 6190 // parameter of a built-in candidate. 6191 // 6192 // We block these conversions by turning off user-defined 6193 // conversions, since that is the only way that initialization of 6194 // a reference to a non-class type can occur from something that 6195 // is not of the same type. 6196 if (ArgIdx < NumContextualBoolArguments) { 6197 assert(ParamTys[ArgIdx] == Context.BoolTy && 6198 "Contextual conversion to bool requires bool type"); 6199 Candidate.Conversions[ArgIdx] 6200 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 6201 } else { 6202 Candidate.Conversions[ArgIdx] 6203 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 6204 ArgIdx == 0 && IsAssignmentOperator, 6205 /*InOverloadResolution=*/false, 6206 /*AllowObjCWritebackConversion=*/ 6207 getLangOpts().ObjCAutoRefCount); 6208 } 6209 if (Candidate.Conversions[ArgIdx].isBad()) { 6210 Candidate.Viable = false; 6211 Candidate.FailureKind = ovl_fail_bad_conversion; 6212 break; 6213 } 6214 } 6215} 6216 6217namespace { 6218 6219/// BuiltinCandidateTypeSet - A set of types that will be used for the 6220/// candidate operator functions for built-in operators (C++ 6221/// [over.built]). The types are separated into pointer types and 6222/// enumeration types. 6223class BuiltinCandidateTypeSet { 6224 /// TypeSet - A set of types. 6225 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 6226 6227 /// PointerTypes - The set of pointer types that will be used in the 6228 /// built-in candidates. 6229 TypeSet PointerTypes; 6230 6231 /// MemberPointerTypes - The set of member pointer types that will be 6232 /// used in the built-in candidates. 6233 TypeSet MemberPointerTypes; 6234 6235 /// EnumerationTypes - The set of enumeration types that will be 6236 /// used in the built-in candidates. 6237 TypeSet EnumerationTypes; 6238 6239 /// \brief The set of vector types that will be used in the built-in 6240 /// candidates. 6241 TypeSet VectorTypes; 6242 6243 /// \brief A flag indicating non-record types are viable candidates 6244 bool HasNonRecordTypes; 6245 6246 /// \brief A flag indicating whether either arithmetic or enumeration types 6247 /// were present in the candidate set. 6248 bool HasArithmeticOrEnumeralTypes; 6249 6250 /// \brief A flag indicating whether the nullptr type was present in the 6251 /// candidate set. 6252 bool HasNullPtrType; 6253 6254 /// Sema - The semantic analysis instance where we are building the 6255 /// candidate type set. 6256 Sema &SemaRef; 6257 6258 /// Context - The AST context in which we will build the type sets. 6259 ASTContext &Context; 6260 6261 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 6262 const Qualifiers &VisibleQuals); 6263 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 6264 6265public: 6266 /// iterator - Iterates through the types that are part of the set. 6267 typedef TypeSet::iterator iterator; 6268 6269 BuiltinCandidateTypeSet(Sema &SemaRef) 6270 : HasNonRecordTypes(false), 6271 HasArithmeticOrEnumeralTypes(false), 6272 HasNullPtrType(false), 6273 SemaRef(SemaRef), 6274 Context(SemaRef.Context) { } 6275 6276 void AddTypesConvertedFrom(QualType Ty, 6277 SourceLocation Loc, 6278 bool AllowUserConversions, 6279 bool AllowExplicitConversions, 6280 const Qualifiers &VisibleTypeConversionsQuals); 6281 6282 /// pointer_begin - First pointer type found; 6283 iterator pointer_begin() { return PointerTypes.begin(); } 6284 6285 /// pointer_end - Past the last pointer type found; 6286 iterator pointer_end() { return PointerTypes.end(); } 6287 6288 /// member_pointer_begin - First member pointer type found; 6289 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 6290 6291 /// member_pointer_end - Past the last member pointer type found; 6292 iterator member_pointer_end() { return MemberPointerTypes.end(); } 6293 6294 /// enumeration_begin - First enumeration type found; 6295 iterator enumeration_begin() { return EnumerationTypes.begin(); } 6296 6297 /// enumeration_end - Past the last enumeration type found; 6298 iterator enumeration_end() { return EnumerationTypes.end(); } 6299 6300 iterator vector_begin() { return VectorTypes.begin(); } 6301 iterator vector_end() { return VectorTypes.end(); } 6302 6303 bool hasNonRecordTypes() { return HasNonRecordTypes; } 6304 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 6305 bool hasNullPtrType() const { return HasNullPtrType; } 6306}; 6307 6308} // end anonymous namespace 6309 6310/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 6311/// the set of pointer types along with any more-qualified variants of 6312/// that type. For example, if @p Ty is "int const *", this routine 6313/// will add "int const *", "int const volatile *", "int const 6314/// restrict *", and "int const volatile restrict *" to the set of 6315/// pointer types. Returns true if the add of @p Ty itself succeeded, 6316/// false otherwise. 6317/// 6318/// FIXME: what to do about extended qualifiers? 6319bool 6320BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 6321 const Qualifiers &VisibleQuals) { 6322 6323 // Insert this type. 6324 if (!PointerTypes.insert(Ty)) 6325 return false; 6326 6327 QualType PointeeTy; 6328 const PointerType *PointerTy = Ty->getAs<PointerType>(); 6329 bool buildObjCPtr = false; 6330 if (!PointerTy) { 6331 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>(); 6332 PointeeTy = PTy->getPointeeType(); 6333 buildObjCPtr = true; 6334 } else { 6335 PointeeTy = PointerTy->getPointeeType(); 6336 } 6337 6338 // Don't add qualified variants of arrays. For one, they're not allowed 6339 // (the qualifier would sink to the element type), and for another, the 6340 // only overload situation where it matters is subscript or pointer +- int, 6341 // and those shouldn't have qualifier variants anyway. 6342 if (PointeeTy->isArrayType()) 6343 return true; 6344 6345 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 6346 bool hasVolatile = VisibleQuals.hasVolatile(); 6347 bool hasRestrict = VisibleQuals.hasRestrict(); 6348 6349 // Iterate through all strict supersets of BaseCVR. 6350 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 6351 if ((CVR | BaseCVR) != CVR) continue; 6352 // Skip over volatile if no volatile found anywhere in the types. 6353 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 6354 6355 // Skip over restrict if no restrict found anywhere in the types, or if 6356 // the type cannot be restrict-qualified. 6357 if ((CVR & Qualifiers::Restrict) && 6358 (!hasRestrict || 6359 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType())))) 6360 continue; 6361 6362 // Build qualified pointee type. 6363 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 6364 6365 // Build qualified pointer type. 6366 QualType QPointerTy; 6367 if (!buildObjCPtr) 6368 QPointerTy = Context.getPointerType(QPointeeTy); 6369 else 6370 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy); 6371 6372 // Insert qualified pointer type. 6373 PointerTypes.insert(QPointerTy); 6374 } 6375 6376 return true; 6377} 6378 6379/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 6380/// to the set of pointer types along with any more-qualified variants of 6381/// that type. For example, if @p Ty is "int const *", this routine 6382/// will add "int const *", "int const volatile *", "int const 6383/// restrict *", and "int const volatile restrict *" to the set of 6384/// pointer types. Returns true if the add of @p Ty itself succeeded, 6385/// false otherwise. 6386/// 6387/// FIXME: what to do about extended qualifiers? 6388bool 6389BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 6390 QualType Ty) { 6391 // Insert this type. 6392 if (!MemberPointerTypes.insert(Ty)) 6393 return false; 6394 6395 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 6396 assert(PointerTy && "type was not a member pointer type!"); 6397 6398 QualType PointeeTy = PointerTy->getPointeeType(); 6399 // Don't add qualified variants of arrays. For one, they're not allowed 6400 // (the qualifier would sink to the element type), and for another, the 6401 // only overload situation where it matters is subscript or pointer +- int, 6402 // and those shouldn't have qualifier variants anyway. 6403 if (PointeeTy->isArrayType()) 6404 return true; 6405 const Type *ClassTy = PointerTy->getClass(); 6406 6407 // Iterate through all strict supersets of the pointee type's CVR 6408 // qualifiers. 6409 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 6410 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 6411 if ((CVR | BaseCVR) != CVR) continue; 6412 6413 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 6414 MemberPointerTypes.insert( 6415 Context.getMemberPointerType(QPointeeTy, ClassTy)); 6416 } 6417 6418 return true; 6419} 6420 6421/// AddTypesConvertedFrom - Add each of the types to which the type @p 6422/// Ty can be implicit converted to the given set of @p Types. We're 6423/// primarily interested in pointer types and enumeration types. We also 6424/// take member pointer types, for the conditional operator. 6425/// AllowUserConversions is true if we should look at the conversion 6426/// functions of a class type, and AllowExplicitConversions if we 6427/// should also include the explicit conversion functions of a class 6428/// type. 6429void 6430BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 6431 SourceLocation Loc, 6432 bool AllowUserConversions, 6433 bool AllowExplicitConversions, 6434 const Qualifiers &VisibleQuals) { 6435 // Only deal with canonical types. 6436 Ty = Context.getCanonicalType(Ty); 6437 6438 // Look through reference types; they aren't part of the type of an 6439 // expression for the purposes of conversions. 6440 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 6441 Ty = RefTy->getPointeeType(); 6442 6443 // If we're dealing with an array type, decay to the pointer. 6444 if (Ty->isArrayType()) 6445 Ty = SemaRef.Context.getArrayDecayedType(Ty); 6446 6447 // Otherwise, we don't care about qualifiers on the type. 6448 Ty = Ty.getLocalUnqualifiedType(); 6449 6450 // Flag if we ever add a non-record type. 6451 const RecordType *TyRec = Ty->getAs<RecordType>(); 6452 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 6453 6454 // Flag if we encounter an arithmetic type. 6455 HasArithmeticOrEnumeralTypes = 6456 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 6457 6458 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 6459 PointerTypes.insert(Ty); 6460 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 6461 // Insert our type, and its more-qualified variants, into the set 6462 // of types. 6463 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 6464 return; 6465 } else if (Ty->isMemberPointerType()) { 6466 // Member pointers are far easier, since the pointee can't be converted. 6467 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 6468 return; 6469 } else if (Ty->isEnumeralType()) { 6470 HasArithmeticOrEnumeralTypes = true; 6471 EnumerationTypes.insert(Ty); 6472 } else if (Ty->isVectorType()) { 6473 // We treat vector types as arithmetic types in many contexts as an 6474 // extension. 6475 HasArithmeticOrEnumeralTypes = true; 6476 VectorTypes.insert(Ty); 6477 } else if (Ty->isNullPtrType()) { 6478 HasNullPtrType = true; 6479 } else if (AllowUserConversions && TyRec) { 6480 // No conversion functions in incomplete types. 6481 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 6482 return; 6483 6484 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 6485 std::pair<CXXRecordDecl::conversion_iterator, 6486 CXXRecordDecl::conversion_iterator> 6487 Conversions = ClassDecl->getVisibleConversionFunctions(); 6488 for (CXXRecordDecl::conversion_iterator 6489 I = Conversions.first, E = Conversions.second; I != E; ++I) { 6490 NamedDecl *D = I.getDecl(); 6491 if (isa<UsingShadowDecl>(D)) 6492 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6493 6494 // Skip conversion function templates; they don't tell us anything 6495 // about which builtin types we can convert to. 6496 if (isa<FunctionTemplateDecl>(D)) 6497 continue; 6498 6499 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6500 if (AllowExplicitConversions || !Conv->isExplicit()) { 6501 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 6502 VisibleQuals); 6503 } 6504 } 6505 } 6506} 6507 6508/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 6509/// the volatile- and non-volatile-qualified assignment operators for the 6510/// given type to the candidate set. 6511static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 6512 QualType T, 6513 ArrayRef<Expr *> Args, 6514 OverloadCandidateSet &CandidateSet) { 6515 QualType ParamTypes[2]; 6516 6517 // T& operator=(T&, T) 6518 ParamTypes[0] = S.Context.getLValueReferenceType(T); 6519 ParamTypes[1] = T; 6520 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 6521 /*IsAssignmentOperator=*/true); 6522 6523 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 6524 // volatile T& operator=(volatile T&, T) 6525 ParamTypes[0] 6526 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 6527 ParamTypes[1] = T; 6528 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 6529 /*IsAssignmentOperator=*/true); 6530 } 6531} 6532 6533/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 6534/// if any, found in visible type conversion functions found in ArgExpr's type. 6535static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 6536 Qualifiers VRQuals; 6537 const RecordType *TyRec; 6538 if (const MemberPointerType *RHSMPType = 6539 ArgExpr->getType()->getAs<MemberPointerType>()) 6540 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 6541 else 6542 TyRec = ArgExpr->getType()->getAs<RecordType>(); 6543 if (!TyRec) { 6544 // Just to be safe, assume the worst case. 6545 VRQuals.addVolatile(); 6546 VRQuals.addRestrict(); 6547 return VRQuals; 6548 } 6549 6550 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 6551 if (!ClassDecl->hasDefinition()) 6552 return VRQuals; 6553 6554 std::pair<CXXRecordDecl::conversion_iterator, 6555 CXXRecordDecl::conversion_iterator> 6556 Conversions = ClassDecl->getVisibleConversionFunctions(); 6557 6558 for (CXXRecordDecl::conversion_iterator 6559 I = Conversions.first, E = Conversions.second; I != E; ++I) { 6560 NamedDecl *D = I.getDecl(); 6561 if (isa<UsingShadowDecl>(D)) 6562 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6563 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 6564 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 6565 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 6566 CanTy = ResTypeRef->getPointeeType(); 6567 // Need to go down the pointer/mempointer chain and add qualifiers 6568 // as see them. 6569 bool done = false; 6570 while (!done) { 6571 if (CanTy.isRestrictQualified()) 6572 VRQuals.addRestrict(); 6573 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 6574 CanTy = ResTypePtr->getPointeeType(); 6575 else if (const MemberPointerType *ResTypeMPtr = 6576 CanTy->getAs<MemberPointerType>()) 6577 CanTy = ResTypeMPtr->getPointeeType(); 6578 else 6579 done = true; 6580 if (CanTy.isVolatileQualified()) 6581 VRQuals.addVolatile(); 6582 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 6583 return VRQuals; 6584 } 6585 } 6586 } 6587 return VRQuals; 6588} 6589 6590namespace { 6591 6592/// \brief Helper class to manage the addition of builtin operator overload 6593/// candidates. It provides shared state and utility methods used throughout 6594/// the process, as well as a helper method to add each group of builtin 6595/// operator overloads from the standard to a candidate set. 6596class BuiltinOperatorOverloadBuilder { 6597 // Common instance state available to all overload candidate addition methods. 6598 Sema &S; 6599 ArrayRef<Expr *> Args; 6600 Qualifiers VisibleTypeConversionsQuals; 6601 bool HasArithmeticOrEnumeralCandidateType; 6602 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 6603 OverloadCandidateSet &CandidateSet; 6604 6605 // Define some constants used to index and iterate over the arithemetic types 6606 // provided via the getArithmeticType() method below. 6607 // The "promoted arithmetic types" are the arithmetic 6608 // types are that preserved by promotion (C++ [over.built]p2). 6609 static const unsigned FirstIntegralType = 3; 6610 static const unsigned LastIntegralType = 20; 6611 static const unsigned FirstPromotedIntegralType = 3, 6612 LastPromotedIntegralType = 11; 6613 static const unsigned FirstPromotedArithmeticType = 0, 6614 LastPromotedArithmeticType = 11; 6615 static const unsigned NumArithmeticTypes = 20; 6616 6617 /// \brief Get the canonical type for a given arithmetic type index. 6618 CanQualType getArithmeticType(unsigned index) { 6619 assert(index < NumArithmeticTypes); 6620 static CanQualType ASTContext::* const 6621 ArithmeticTypes[NumArithmeticTypes] = { 6622 // Start of promoted types. 6623 &ASTContext::FloatTy, 6624 &ASTContext::DoubleTy, 6625 &ASTContext::LongDoubleTy, 6626 6627 // Start of integral types. 6628 &ASTContext::IntTy, 6629 &ASTContext::LongTy, 6630 &ASTContext::LongLongTy, 6631 &ASTContext::Int128Ty, 6632 &ASTContext::UnsignedIntTy, 6633 &ASTContext::UnsignedLongTy, 6634 &ASTContext::UnsignedLongLongTy, 6635 &ASTContext::UnsignedInt128Ty, 6636 // End of promoted types. 6637 6638 &ASTContext::BoolTy, 6639 &ASTContext::CharTy, 6640 &ASTContext::WCharTy, 6641 &ASTContext::Char16Ty, 6642 &ASTContext::Char32Ty, 6643 &ASTContext::SignedCharTy, 6644 &ASTContext::ShortTy, 6645 &ASTContext::UnsignedCharTy, 6646 &ASTContext::UnsignedShortTy, 6647 // End of integral types. 6648 // FIXME: What about complex? What about half? 6649 }; 6650 return S.Context.*ArithmeticTypes[index]; 6651 } 6652 6653 /// \brief Gets the canonical type resulting from the usual arithemetic 6654 /// converions for the given arithmetic types. 6655 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 6656 // Accelerator table for performing the usual arithmetic conversions. 6657 // The rules are basically: 6658 // - if either is floating-point, use the wider floating-point 6659 // - if same signedness, use the higher rank 6660 // - if same size, use unsigned of the higher rank 6661 // - use the larger type 6662 // These rules, together with the axiom that higher ranks are 6663 // never smaller, are sufficient to precompute all of these results 6664 // *except* when dealing with signed types of higher rank. 6665 // (we could precompute SLL x UI for all known platforms, but it's 6666 // better not to make any assumptions). 6667 // We assume that int128 has a higher rank than long long on all platforms. 6668 enum PromotedType { 6669 Dep=-1, 6670 Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 6671 }; 6672 static const PromotedType ConversionsTable[LastPromotedArithmeticType] 6673 [LastPromotedArithmeticType] = { 6674/* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt, Flt, Flt }, 6675/* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 6676/*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 6677/* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 }, 6678/* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, S128, Dep, UL, ULL, U128 }, 6679/* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, S128, Dep, Dep, ULL, U128 }, 6680/*S128*/ { Flt, Dbl, LDbl, S128, S128, S128, S128, S128, S128, S128, U128 }, 6681/* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, S128, UI, UL, ULL, U128 }, 6682/* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, S128, UL, UL, ULL, U128 }, 6683/* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, S128, ULL, ULL, ULL, U128 }, 6684/*U128*/ { Flt, Dbl, LDbl, U128, U128, U128, U128, U128, U128, U128, U128 }, 6685 }; 6686 6687 assert(L < LastPromotedArithmeticType); 6688 assert(R < LastPromotedArithmeticType); 6689 int Idx = ConversionsTable[L][R]; 6690 6691 // Fast path: the table gives us a concrete answer. 6692 if (Idx != Dep) return getArithmeticType(Idx); 6693 6694 // Slow path: we need to compare widths. 6695 // An invariant is that the signed type has higher rank. 6696 CanQualType LT = getArithmeticType(L), 6697 RT = getArithmeticType(R); 6698 unsigned LW = S.Context.getIntWidth(LT), 6699 RW = S.Context.getIntWidth(RT); 6700 6701 // If they're different widths, use the signed type. 6702 if (LW > RW) return LT; 6703 else if (LW < RW) return RT; 6704 6705 // Otherwise, use the unsigned type of the signed type's rank. 6706 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 6707 assert(L == SLL || R == SLL); 6708 return S.Context.UnsignedLongLongTy; 6709 } 6710 6711 /// \brief Helper method to factor out the common pattern of adding overloads 6712 /// for '++' and '--' builtin operators. 6713 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 6714 bool HasVolatile, 6715 bool HasRestrict) { 6716 QualType ParamTypes[2] = { 6717 S.Context.getLValueReferenceType(CandidateTy), 6718 S.Context.IntTy 6719 }; 6720 6721 // Non-volatile version. 6722 if (Args.size() == 1) 6723 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet); 6724 else 6725 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet); 6726 6727 // Use a heuristic to reduce number of builtin candidates in the set: 6728 // add volatile version only if there are conversions to a volatile type. 6729 if (HasVolatile) { 6730 ParamTypes[0] = 6731 S.Context.getLValueReferenceType( 6732 S.Context.getVolatileType(CandidateTy)); 6733 if (Args.size() == 1) 6734 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet); 6735 else 6736 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet); 6737 } 6738 6739 // Add restrict version only if there are conversions to a restrict type 6740 // and our candidate type is a non-restrict-qualified pointer. 6741 if (HasRestrict && CandidateTy->isAnyPointerType() && 6742 !CandidateTy.isRestrictQualified()) { 6743 ParamTypes[0] 6744 = S.Context.getLValueReferenceType( 6745 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict)); 6746 if (Args.size() == 1) 6747 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet); 6748 else 6749 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet); 6750 6751 if (HasVolatile) { 6752 ParamTypes[0] 6753 = S.Context.getLValueReferenceType( 6754 S.Context.getCVRQualifiedType(CandidateTy, 6755 (Qualifiers::Volatile | 6756 Qualifiers::Restrict))); 6757 if (Args.size() == 1) 6758 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet); 6759 else 6760 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet); 6761 } 6762 } 6763 6764 } 6765 6766public: 6767 BuiltinOperatorOverloadBuilder( 6768 Sema &S, ArrayRef<Expr *> Args, 6769 Qualifiers VisibleTypeConversionsQuals, 6770 bool HasArithmeticOrEnumeralCandidateType, 6771 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 6772 OverloadCandidateSet &CandidateSet) 6773 : S(S), Args(Args), 6774 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 6775 HasArithmeticOrEnumeralCandidateType( 6776 HasArithmeticOrEnumeralCandidateType), 6777 CandidateTypes(CandidateTypes), 6778 CandidateSet(CandidateSet) { 6779 // Validate some of our static helper constants in debug builds. 6780 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 6781 "Invalid first promoted integral type"); 6782 assert(getArithmeticType(LastPromotedIntegralType - 1) 6783 == S.Context.UnsignedInt128Ty && 6784 "Invalid last promoted integral type"); 6785 assert(getArithmeticType(FirstPromotedArithmeticType) 6786 == S.Context.FloatTy && 6787 "Invalid first promoted arithmetic type"); 6788 assert(getArithmeticType(LastPromotedArithmeticType - 1) 6789 == S.Context.UnsignedInt128Ty && 6790 "Invalid last promoted arithmetic type"); 6791 } 6792 6793 // C++ [over.built]p3: 6794 // 6795 // For every pair (T, VQ), where T is an arithmetic type, and VQ 6796 // is either volatile or empty, there exist candidate operator 6797 // functions of the form 6798 // 6799 // VQ T& operator++(VQ T&); 6800 // T operator++(VQ T&, int); 6801 // 6802 // C++ [over.built]p4: 6803 // 6804 // For every pair (T, VQ), where T is an arithmetic type other 6805 // than bool, and VQ is either volatile or empty, there exist 6806 // candidate operator functions of the form 6807 // 6808 // VQ T& operator--(VQ T&); 6809 // T operator--(VQ T&, int); 6810 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 6811 if (!HasArithmeticOrEnumeralCandidateType) 6812 return; 6813 6814 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 6815 Arith < NumArithmeticTypes; ++Arith) { 6816 addPlusPlusMinusMinusStyleOverloads( 6817 getArithmeticType(Arith), 6818 VisibleTypeConversionsQuals.hasVolatile(), 6819 VisibleTypeConversionsQuals.hasRestrict()); 6820 } 6821 } 6822 6823 // C++ [over.built]p5: 6824 // 6825 // For every pair (T, VQ), where T is a cv-qualified or 6826 // cv-unqualified object type, and VQ is either volatile or 6827 // empty, there exist candidate operator functions of the form 6828 // 6829 // T*VQ& operator++(T*VQ&); 6830 // T*VQ& operator--(T*VQ&); 6831 // T* operator++(T*VQ&, int); 6832 // T* operator--(T*VQ&, int); 6833 void addPlusPlusMinusMinusPointerOverloads() { 6834 for (BuiltinCandidateTypeSet::iterator 6835 Ptr = CandidateTypes[0].pointer_begin(), 6836 PtrEnd = CandidateTypes[0].pointer_end(); 6837 Ptr != PtrEnd; ++Ptr) { 6838 // Skip pointer types that aren't pointers to object types. 6839 if (!(*Ptr)->getPointeeType()->isObjectType()) 6840 continue; 6841 6842 addPlusPlusMinusMinusStyleOverloads(*Ptr, 6843 (!(*Ptr).isVolatileQualified() && 6844 VisibleTypeConversionsQuals.hasVolatile()), 6845 (!(*Ptr).isRestrictQualified() && 6846 VisibleTypeConversionsQuals.hasRestrict())); 6847 } 6848 } 6849 6850 // C++ [over.built]p6: 6851 // For every cv-qualified or cv-unqualified object type T, there 6852 // exist candidate operator functions of the form 6853 // 6854 // T& operator*(T*); 6855 // 6856 // C++ [over.built]p7: 6857 // For every function type T that does not have cv-qualifiers or a 6858 // ref-qualifier, there exist candidate operator functions of the form 6859 // T& operator*(T*); 6860 void addUnaryStarPointerOverloads() { 6861 for (BuiltinCandidateTypeSet::iterator 6862 Ptr = CandidateTypes[0].pointer_begin(), 6863 PtrEnd = CandidateTypes[0].pointer_end(); 6864 Ptr != PtrEnd; ++Ptr) { 6865 QualType ParamTy = *Ptr; 6866 QualType PointeeTy = ParamTy->getPointeeType(); 6867 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 6868 continue; 6869 6870 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 6871 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 6872 continue; 6873 6874 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 6875 &ParamTy, Args, CandidateSet); 6876 } 6877 } 6878 6879 // C++ [over.built]p9: 6880 // For every promoted arithmetic type T, there exist candidate 6881 // operator functions of the form 6882 // 6883 // T operator+(T); 6884 // T operator-(T); 6885 void addUnaryPlusOrMinusArithmeticOverloads() { 6886 if (!HasArithmeticOrEnumeralCandidateType) 6887 return; 6888 6889 for (unsigned Arith = FirstPromotedArithmeticType; 6890 Arith < LastPromotedArithmeticType; ++Arith) { 6891 QualType ArithTy = getArithmeticType(Arith); 6892 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, CandidateSet); 6893 } 6894 6895 // Extension: We also add these operators for vector types. 6896 for (BuiltinCandidateTypeSet::iterator 6897 Vec = CandidateTypes[0].vector_begin(), 6898 VecEnd = CandidateTypes[0].vector_end(); 6899 Vec != VecEnd; ++Vec) { 6900 QualType VecTy = *Vec; 6901 S.AddBuiltinCandidate(VecTy, &VecTy, Args, CandidateSet); 6902 } 6903 } 6904 6905 // C++ [over.built]p8: 6906 // For every type T, there exist candidate operator functions of 6907 // the form 6908 // 6909 // T* operator+(T*); 6910 void addUnaryPlusPointerOverloads() { 6911 for (BuiltinCandidateTypeSet::iterator 6912 Ptr = CandidateTypes[0].pointer_begin(), 6913 PtrEnd = CandidateTypes[0].pointer_end(); 6914 Ptr != PtrEnd; ++Ptr) { 6915 QualType ParamTy = *Ptr; 6916 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, CandidateSet); 6917 } 6918 } 6919 6920 // C++ [over.built]p10: 6921 // For every promoted integral type T, there exist candidate 6922 // operator functions of the form 6923 // 6924 // T operator~(T); 6925 void addUnaryTildePromotedIntegralOverloads() { 6926 if (!HasArithmeticOrEnumeralCandidateType) 6927 return; 6928 6929 for (unsigned Int = FirstPromotedIntegralType; 6930 Int < LastPromotedIntegralType; ++Int) { 6931 QualType IntTy = getArithmeticType(Int); 6932 S.AddBuiltinCandidate(IntTy, &IntTy, Args, CandidateSet); 6933 } 6934 6935 // Extension: We also add this operator for vector types. 6936 for (BuiltinCandidateTypeSet::iterator 6937 Vec = CandidateTypes[0].vector_begin(), 6938 VecEnd = CandidateTypes[0].vector_end(); 6939 Vec != VecEnd; ++Vec) { 6940 QualType VecTy = *Vec; 6941 S.AddBuiltinCandidate(VecTy, &VecTy, Args, CandidateSet); 6942 } 6943 } 6944 6945 // C++ [over.match.oper]p16: 6946 // For every pointer to member type T, there exist candidate operator 6947 // functions of the form 6948 // 6949 // bool operator==(T,T); 6950 // bool operator!=(T,T); 6951 void addEqualEqualOrNotEqualMemberPointerOverloads() { 6952 /// Set of (canonical) types that we've already handled. 6953 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6954 6955 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 6956 for (BuiltinCandidateTypeSet::iterator 6957 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 6958 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 6959 MemPtr != MemPtrEnd; 6960 ++MemPtr) { 6961 // Don't add the same builtin candidate twice. 6962 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 6963 continue; 6964 6965 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 6966 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet); 6967 } 6968 } 6969 } 6970 6971 // C++ [over.built]p15: 6972 // 6973 // For every T, where T is an enumeration type, a pointer type, or 6974 // std::nullptr_t, there exist candidate operator functions of the form 6975 // 6976 // bool operator<(T, T); 6977 // bool operator>(T, T); 6978 // bool operator<=(T, T); 6979 // bool operator>=(T, T); 6980 // bool operator==(T, T); 6981 // bool operator!=(T, T); 6982 void addRelationalPointerOrEnumeralOverloads() { 6983 // C++ [over.match.oper]p3: 6984 // [...]the built-in candidates include all of the candidate operator 6985 // functions defined in 13.6 that, compared to the given operator, [...] 6986 // do not have the same parameter-type-list as any non-template non-member 6987 // candidate. 6988 // 6989 // Note that in practice, this only affects enumeration types because there 6990 // aren't any built-in candidates of record type, and a user-defined operator 6991 // must have an operand of record or enumeration type. Also, the only other 6992 // overloaded operator with enumeration arguments, operator=, 6993 // cannot be overloaded for enumeration types, so this is the only place 6994 // where we must suppress candidates like this. 6995 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 6996 UserDefinedBinaryOperators; 6997 6998 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 6999 if (CandidateTypes[ArgIdx].enumeration_begin() != 7000 CandidateTypes[ArgIdx].enumeration_end()) { 7001 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 7002 CEnd = CandidateSet.end(); 7003 C != CEnd; ++C) { 7004 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 7005 continue; 7006 7007 if (C->Function->isFunctionTemplateSpecialization()) 7008 continue; 7009 7010 QualType FirstParamType = 7011 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 7012 QualType SecondParamType = 7013 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 7014 7015 // Skip if either parameter isn't of enumeral type. 7016 if (!FirstParamType->isEnumeralType() || 7017 !SecondParamType->isEnumeralType()) 7018 continue; 7019 7020 // Add this operator to the set of known user-defined operators. 7021 UserDefinedBinaryOperators.insert( 7022 std::make_pair(S.Context.getCanonicalType(FirstParamType), 7023 S.Context.getCanonicalType(SecondParamType))); 7024 } 7025 } 7026 } 7027 7028 /// Set of (canonical) types that we've already handled. 7029 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7030 7031 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 7032 for (BuiltinCandidateTypeSet::iterator 7033 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 7034 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 7035 Ptr != PtrEnd; ++Ptr) { 7036 // Don't add the same builtin candidate twice. 7037 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7038 continue; 7039 7040 QualType ParamTypes[2] = { *Ptr, *Ptr }; 7041 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet); 7042 } 7043 for (BuiltinCandidateTypeSet::iterator 7044 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 7045 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 7046 Enum != EnumEnd; ++Enum) { 7047 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 7048 7049 // Don't add the same builtin candidate twice, or if a user defined 7050 // candidate exists. 7051 if (!AddedTypes.insert(CanonType) || 7052 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 7053 CanonType))) 7054 continue; 7055 7056 QualType ParamTypes[2] = { *Enum, *Enum }; 7057 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet); 7058 } 7059 7060 if (CandidateTypes[ArgIdx].hasNullPtrType()) { 7061 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy); 7062 if (AddedTypes.insert(NullPtrTy) && 7063 !UserDefinedBinaryOperators.count(std::make_pair(NullPtrTy, 7064 NullPtrTy))) { 7065 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy }; 7066 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 7067 CandidateSet); 7068 } 7069 } 7070 } 7071 } 7072 7073 // C++ [over.built]p13: 7074 // 7075 // For every cv-qualified or cv-unqualified object type T 7076 // there exist candidate operator functions of the form 7077 // 7078 // T* operator+(T*, ptrdiff_t); 7079 // T& operator[](T*, ptrdiff_t); [BELOW] 7080 // T* operator-(T*, ptrdiff_t); 7081 // T* operator+(ptrdiff_t, T*); 7082 // T& operator[](ptrdiff_t, T*); [BELOW] 7083 // 7084 // C++ [over.built]p14: 7085 // 7086 // For every T, where T is a pointer to object type, there 7087 // exist candidate operator functions of the form 7088 // 7089 // ptrdiff_t operator-(T, T); 7090 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 7091 /// Set of (canonical) types that we've already handled. 7092 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7093 7094 for (int Arg = 0; Arg < 2; ++Arg) { 7095 QualType AsymetricParamTypes[2] = { 7096 S.Context.getPointerDiffType(), 7097 S.Context.getPointerDiffType(), 7098 }; 7099 for (BuiltinCandidateTypeSet::iterator 7100 Ptr = CandidateTypes[Arg].pointer_begin(), 7101 PtrEnd = CandidateTypes[Arg].pointer_end(); 7102 Ptr != PtrEnd; ++Ptr) { 7103 QualType PointeeTy = (*Ptr)->getPointeeType(); 7104 if (!PointeeTy->isObjectType()) 7105 continue; 7106 7107 AsymetricParamTypes[Arg] = *Ptr; 7108 if (Arg == 0 || Op == OO_Plus) { 7109 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 7110 // T* operator+(ptrdiff_t, T*); 7111 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, CandidateSet); 7112 } 7113 if (Op == OO_Minus) { 7114 // ptrdiff_t operator-(T, T); 7115 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7116 continue; 7117 7118 QualType ParamTypes[2] = { *Ptr, *Ptr }; 7119 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 7120 Args, CandidateSet); 7121 } 7122 } 7123 } 7124 } 7125 7126 // C++ [over.built]p12: 7127 // 7128 // For every pair of promoted arithmetic types L and R, there 7129 // exist candidate operator functions of the form 7130 // 7131 // LR operator*(L, R); 7132 // LR operator/(L, R); 7133 // LR operator+(L, R); 7134 // LR operator-(L, R); 7135 // bool operator<(L, R); 7136 // bool operator>(L, R); 7137 // bool operator<=(L, R); 7138 // bool operator>=(L, R); 7139 // bool operator==(L, R); 7140 // bool operator!=(L, R); 7141 // 7142 // where LR is the result of the usual arithmetic conversions 7143 // between types L and R. 7144 // 7145 // C++ [over.built]p24: 7146 // 7147 // For every pair of promoted arithmetic types L and R, there exist 7148 // candidate operator functions of the form 7149 // 7150 // LR operator?(bool, L, R); 7151 // 7152 // where LR is the result of the usual arithmetic conversions 7153 // between types L and R. 7154 // Our candidates ignore the first parameter. 7155 void addGenericBinaryArithmeticOverloads(bool isComparison) { 7156 if (!HasArithmeticOrEnumeralCandidateType) 7157 return; 7158 7159 for (unsigned Left = FirstPromotedArithmeticType; 7160 Left < LastPromotedArithmeticType; ++Left) { 7161 for (unsigned Right = FirstPromotedArithmeticType; 7162 Right < LastPromotedArithmeticType; ++Right) { 7163 QualType LandR[2] = { getArithmeticType(Left), 7164 getArithmeticType(Right) }; 7165 QualType Result = 7166 isComparison ? S.Context.BoolTy 7167 : getUsualArithmeticConversions(Left, Right); 7168 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet); 7169 } 7170 } 7171 7172 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 7173 // conditional operator for vector types. 7174 for (BuiltinCandidateTypeSet::iterator 7175 Vec1 = CandidateTypes[0].vector_begin(), 7176 Vec1End = CandidateTypes[0].vector_end(); 7177 Vec1 != Vec1End; ++Vec1) { 7178 for (BuiltinCandidateTypeSet::iterator 7179 Vec2 = CandidateTypes[1].vector_begin(), 7180 Vec2End = CandidateTypes[1].vector_end(); 7181 Vec2 != Vec2End; ++Vec2) { 7182 QualType LandR[2] = { *Vec1, *Vec2 }; 7183 QualType Result = S.Context.BoolTy; 7184 if (!isComparison) { 7185 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 7186 Result = *Vec1; 7187 else 7188 Result = *Vec2; 7189 } 7190 7191 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet); 7192 } 7193 } 7194 } 7195 7196 // C++ [over.built]p17: 7197 // 7198 // For every pair of promoted integral types L and R, there 7199 // exist candidate operator functions of the form 7200 // 7201 // LR operator%(L, R); 7202 // LR operator&(L, R); 7203 // LR operator^(L, R); 7204 // LR operator|(L, R); 7205 // L operator<<(L, R); 7206 // L operator>>(L, R); 7207 // 7208 // where LR is the result of the usual arithmetic conversions 7209 // between types L and R. 7210 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 7211 if (!HasArithmeticOrEnumeralCandidateType) 7212 return; 7213 7214 for (unsigned Left = FirstPromotedIntegralType; 7215 Left < LastPromotedIntegralType; ++Left) { 7216 for (unsigned Right = FirstPromotedIntegralType; 7217 Right < LastPromotedIntegralType; ++Right) { 7218 QualType LandR[2] = { getArithmeticType(Left), 7219 getArithmeticType(Right) }; 7220 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 7221 ? LandR[0] 7222 : getUsualArithmeticConversions(Left, Right); 7223 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet); 7224 } 7225 } 7226 } 7227 7228 // C++ [over.built]p20: 7229 // 7230 // For every pair (T, VQ), where T is an enumeration or 7231 // pointer to member type and VQ is either volatile or 7232 // empty, there exist candidate operator functions of the form 7233 // 7234 // VQ T& operator=(VQ T&, T); 7235 void addAssignmentMemberPointerOrEnumeralOverloads() { 7236 /// Set of (canonical) types that we've already handled. 7237 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7238 7239 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 7240 for (BuiltinCandidateTypeSet::iterator 7241 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 7242 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 7243 Enum != EnumEnd; ++Enum) { 7244 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 7245 continue; 7246 7247 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, CandidateSet); 7248 } 7249 7250 for (BuiltinCandidateTypeSet::iterator 7251 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 7252 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 7253 MemPtr != MemPtrEnd; ++MemPtr) { 7254 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 7255 continue; 7256 7257 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, CandidateSet); 7258 } 7259 } 7260 } 7261 7262 // C++ [over.built]p19: 7263 // 7264 // For every pair (T, VQ), where T is any type and VQ is either 7265 // volatile or empty, there exist candidate operator functions 7266 // of the form 7267 // 7268 // T*VQ& operator=(T*VQ&, T*); 7269 // 7270 // C++ [over.built]p21: 7271 // 7272 // For every pair (T, VQ), where T is a cv-qualified or 7273 // cv-unqualified object type and VQ is either volatile or 7274 // empty, there exist candidate operator functions of the form 7275 // 7276 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 7277 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 7278 void addAssignmentPointerOverloads(bool isEqualOp) { 7279 /// Set of (canonical) types that we've already handled. 7280 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7281 7282 for (BuiltinCandidateTypeSet::iterator 7283 Ptr = CandidateTypes[0].pointer_begin(), 7284 PtrEnd = CandidateTypes[0].pointer_end(); 7285 Ptr != PtrEnd; ++Ptr) { 7286 // If this is operator=, keep track of the builtin candidates we added. 7287 if (isEqualOp) 7288 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 7289 else if (!(*Ptr)->getPointeeType()->isObjectType()) 7290 continue; 7291 7292 // non-volatile version 7293 QualType ParamTypes[2] = { 7294 S.Context.getLValueReferenceType(*Ptr), 7295 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 7296 }; 7297 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7298 /*IsAssigmentOperator=*/ isEqualOp); 7299 7300 bool NeedVolatile = !(*Ptr).isVolatileQualified() && 7301 VisibleTypeConversionsQuals.hasVolatile(); 7302 if (NeedVolatile) { 7303 // volatile version 7304 ParamTypes[0] = 7305 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 7306 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7307 /*IsAssigmentOperator=*/isEqualOp); 7308 } 7309 7310 if (!(*Ptr).isRestrictQualified() && 7311 VisibleTypeConversionsQuals.hasRestrict()) { 7312 // restrict version 7313 ParamTypes[0] 7314 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr)); 7315 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7316 /*IsAssigmentOperator=*/isEqualOp); 7317 7318 if (NeedVolatile) { 7319 // volatile restrict version 7320 ParamTypes[0] 7321 = S.Context.getLValueReferenceType( 7322 S.Context.getCVRQualifiedType(*Ptr, 7323 (Qualifiers::Volatile | 7324 Qualifiers::Restrict))); 7325 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7326 /*IsAssigmentOperator=*/isEqualOp); 7327 } 7328 } 7329 } 7330 7331 if (isEqualOp) { 7332 for (BuiltinCandidateTypeSet::iterator 7333 Ptr = CandidateTypes[1].pointer_begin(), 7334 PtrEnd = CandidateTypes[1].pointer_end(); 7335 Ptr != PtrEnd; ++Ptr) { 7336 // Make sure we don't add the same candidate twice. 7337 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7338 continue; 7339 7340 QualType ParamTypes[2] = { 7341 S.Context.getLValueReferenceType(*Ptr), 7342 *Ptr, 7343 }; 7344 7345 // non-volatile version 7346 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7347 /*IsAssigmentOperator=*/true); 7348 7349 bool NeedVolatile = !(*Ptr).isVolatileQualified() && 7350 VisibleTypeConversionsQuals.hasVolatile(); 7351 if (NeedVolatile) { 7352 // volatile version 7353 ParamTypes[0] = 7354 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 7355 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7356 /*IsAssigmentOperator=*/true); 7357 } 7358 7359 if (!(*Ptr).isRestrictQualified() && 7360 VisibleTypeConversionsQuals.hasRestrict()) { 7361 // restrict version 7362 ParamTypes[0] 7363 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr)); 7364 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7365 /*IsAssigmentOperator=*/true); 7366 7367 if (NeedVolatile) { 7368 // volatile restrict version 7369 ParamTypes[0] 7370 = S.Context.getLValueReferenceType( 7371 S.Context.getCVRQualifiedType(*Ptr, 7372 (Qualifiers::Volatile | 7373 Qualifiers::Restrict))); 7374 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7375 /*IsAssigmentOperator=*/true); 7376 } 7377 } 7378 } 7379 } 7380 } 7381 7382 // C++ [over.built]p18: 7383 // 7384 // For every triple (L, VQ, R), where L is an arithmetic type, 7385 // VQ is either volatile or empty, and R is a promoted 7386 // arithmetic type, there exist candidate operator functions of 7387 // the form 7388 // 7389 // VQ L& operator=(VQ L&, R); 7390 // VQ L& operator*=(VQ L&, R); 7391 // VQ L& operator/=(VQ L&, R); 7392 // VQ L& operator+=(VQ L&, R); 7393 // VQ L& operator-=(VQ L&, R); 7394 void addAssignmentArithmeticOverloads(bool isEqualOp) { 7395 if (!HasArithmeticOrEnumeralCandidateType) 7396 return; 7397 7398 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 7399 for (unsigned Right = FirstPromotedArithmeticType; 7400 Right < LastPromotedArithmeticType; ++Right) { 7401 QualType ParamTypes[2]; 7402 ParamTypes[1] = getArithmeticType(Right); 7403 7404 // Add this built-in operator as a candidate (VQ is empty). 7405 ParamTypes[0] = 7406 S.Context.getLValueReferenceType(getArithmeticType(Left)); 7407 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7408 /*IsAssigmentOperator=*/isEqualOp); 7409 7410 // Add this built-in operator as a candidate (VQ is 'volatile'). 7411 if (VisibleTypeConversionsQuals.hasVolatile()) { 7412 ParamTypes[0] = 7413 S.Context.getVolatileType(getArithmeticType(Left)); 7414 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7415 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7416 /*IsAssigmentOperator=*/isEqualOp); 7417 } 7418 } 7419 } 7420 7421 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 7422 for (BuiltinCandidateTypeSet::iterator 7423 Vec1 = CandidateTypes[0].vector_begin(), 7424 Vec1End = CandidateTypes[0].vector_end(); 7425 Vec1 != Vec1End; ++Vec1) { 7426 for (BuiltinCandidateTypeSet::iterator 7427 Vec2 = CandidateTypes[1].vector_begin(), 7428 Vec2End = CandidateTypes[1].vector_end(); 7429 Vec2 != Vec2End; ++Vec2) { 7430 QualType ParamTypes[2]; 7431 ParamTypes[1] = *Vec2; 7432 // Add this built-in operator as a candidate (VQ is empty). 7433 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 7434 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7435 /*IsAssigmentOperator=*/isEqualOp); 7436 7437 // Add this built-in operator as a candidate (VQ is 'volatile'). 7438 if (VisibleTypeConversionsQuals.hasVolatile()) { 7439 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 7440 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7441 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7442 /*IsAssigmentOperator=*/isEqualOp); 7443 } 7444 } 7445 } 7446 } 7447 7448 // C++ [over.built]p22: 7449 // 7450 // For every triple (L, VQ, R), where L is an integral type, VQ 7451 // is either volatile or empty, and R is a promoted integral 7452 // type, there exist candidate operator functions of the form 7453 // 7454 // VQ L& operator%=(VQ L&, R); 7455 // VQ L& operator<<=(VQ L&, R); 7456 // VQ L& operator>>=(VQ L&, R); 7457 // VQ L& operator&=(VQ L&, R); 7458 // VQ L& operator^=(VQ L&, R); 7459 // VQ L& operator|=(VQ L&, R); 7460 void addAssignmentIntegralOverloads() { 7461 if (!HasArithmeticOrEnumeralCandidateType) 7462 return; 7463 7464 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 7465 for (unsigned Right = FirstPromotedIntegralType; 7466 Right < LastPromotedIntegralType; ++Right) { 7467 QualType ParamTypes[2]; 7468 ParamTypes[1] = getArithmeticType(Right); 7469 7470 // Add this built-in operator as a candidate (VQ is empty). 7471 ParamTypes[0] = 7472 S.Context.getLValueReferenceType(getArithmeticType(Left)); 7473 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet); 7474 if (VisibleTypeConversionsQuals.hasVolatile()) { 7475 // Add this built-in operator as a candidate (VQ is 'volatile'). 7476 ParamTypes[0] = getArithmeticType(Left); 7477 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 7478 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7479 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet); 7480 } 7481 } 7482 } 7483 } 7484 7485 // C++ [over.operator]p23: 7486 // 7487 // There also exist candidate operator functions of the form 7488 // 7489 // bool operator!(bool); 7490 // bool operator&&(bool, bool); 7491 // bool operator||(bool, bool); 7492 void addExclaimOverload() { 7493 QualType ParamTy = S.Context.BoolTy; 7494 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, CandidateSet, 7495 /*IsAssignmentOperator=*/false, 7496 /*NumContextualBoolArguments=*/1); 7497 } 7498 void addAmpAmpOrPipePipeOverload() { 7499 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 7500 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet, 7501 /*IsAssignmentOperator=*/false, 7502 /*NumContextualBoolArguments=*/2); 7503 } 7504 7505 // C++ [over.built]p13: 7506 // 7507 // For every cv-qualified or cv-unqualified object type T there 7508 // exist candidate operator functions of the form 7509 // 7510 // T* operator+(T*, ptrdiff_t); [ABOVE] 7511 // T& operator[](T*, ptrdiff_t); 7512 // T* operator-(T*, ptrdiff_t); [ABOVE] 7513 // T* operator+(ptrdiff_t, T*); [ABOVE] 7514 // T& operator[](ptrdiff_t, T*); 7515 void addSubscriptOverloads() { 7516 for (BuiltinCandidateTypeSet::iterator 7517 Ptr = CandidateTypes[0].pointer_begin(), 7518 PtrEnd = CandidateTypes[0].pointer_end(); 7519 Ptr != PtrEnd; ++Ptr) { 7520 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 7521 QualType PointeeType = (*Ptr)->getPointeeType(); 7522 if (!PointeeType->isObjectType()) 7523 continue; 7524 7525 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 7526 7527 // T& operator[](T*, ptrdiff_t) 7528 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet); 7529 } 7530 7531 for (BuiltinCandidateTypeSet::iterator 7532 Ptr = CandidateTypes[1].pointer_begin(), 7533 PtrEnd = CandidateTypes[1].pointer_end(); 7534 Ptr != PtrEnd; ++Ptr) { 7535 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 7536 QualType PointeeType = (*Ptr)->getPointeeType(); 7537 if (!PointeeType->isObjectType()) 7538 continue; 7539 7540 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 7541 7542 // T& operator[](ptrdiff_t, T*) 7543 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet); 7544 } 7545 } 7546 7547 // C++ [over.built]p11: 7548 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 7549 // C1 is the same type as C2 or is a derived class of C2, T is an object 7550 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 7551 // there exist candidate operator functions of the form 7552 // 7553 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 7554 // 7555 // where CV12 is the union of CV1 and CV2. 7556 void addArrowStarOverloads() { 7557 for (BuiltinCandidateTypeSet::iterator 7558 Ptr = CandidateTypes[0].pointer_begin(), 7559 PtrEnd = CandidateTypes[0].pointer_end(); 7560 Ptr != PtrEnd; ++Ptr) { 7561 QualType C1Ty = (*Ptr); 7562 QualType C1; 7563 QualifierCollector Q1; 7564 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 7565 if (!isa<RecordType>(C1)) 7566 continue; 7567 // heuristic to reduce number of builtin candidates in the set. 7568 // Add volatile/restrict version only if there are conversions to a 7569 // volatile/restrict type. 7570 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 7571 continue; 7572 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 7573 continue; 7574 for (BuiltinCandidateTypeSet::iterator 7575 MemPtr = CandidateTypes[1].member_pointer_begin(), 7576 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 7577 MemPtr != MemPtrEnd; ++MemPtr) { 7578 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 7579 QualType C2 = QualType(mptr->getClass(), 0); 7580 C2 = C2.getUnqualifiedType(); 7581 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 7582 break; 7583 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 7584 // build CV12 T& 7585 QualType T = mptr->getPointeeType(); 7586 if (!VisibleTypeConversionsQuals.hasVolatile() && 7587 T.isVolatileQualified()) 7588 continue; 7589 if (!VisibleTypeConversionsQuals.hasRestrict() && 7590 T.isRestrictQualified()) 7591 continue; 7592 T = Q1.apply(S.Context, T); 7593 QualType ResultTy = S.Context.getLValueReferenceType(T); 7594 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet); 7595 } 7596 } 7597 } 7598 7599 // Note that we don't consider the first argument, since it has been 7600 // contextually converted to bool long ago. The candidates below are 7601 // therefore added as binary. 7602 // 7603 // C++ [over.built]p25: 7604 // For every type T, where T is a pointer, pointer-to-member, or scoped 7605 // enumeration type, there exist candidate operator functions of the form 7606 // 7607 // T operator?(bool, T, T); 7608 // 7609 void addConditionalOperatorOverloads() { 7610 /// Set of (canonical) types that we've already handled. 7611 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7612 7613 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 7614 for (BuiltinCandidateTypeSet::iterator 7615 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 7616 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 7617 Ptr != PtrEnd; ++Ptr) { 7618 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7619 continue; 7620 7621 QualType ParamTypes[2] = { *Ptr, *Ptr }; 7622 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, CandidateSet); 7623 } 7624 7625 for (BuiltinCandidateTypeSet::iterator 7626 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 7627 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 7628 MemPtr != MemPtrEnd; ++MemPtr) { 7629 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 7630 continue; 7631 7632 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 7633 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, CandidateSet); 7634 } 7635 7636 if (S.getLangOpts().CPlusPlus11) { 7637 for (BuiltinCandidateTypeSet::iterator 7638 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 7639 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 7640 Enum != EnumEnd; ++Enum) { 7641 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 7642 continue; 7643 7644 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 7645 continue; 7646 7647 QualType ParamTypes[2] = { *Enum, *Enum }; 7648 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, CandidateSet); 7649 } 7650 } 7651 } 7652 } 7653}; 7654 7655} // end anonymous namespace 7656 7657/// AddBuiltinOperatorCandidates - Add the appropriate built-in 7658/// operator overloads to the candidate set (C++ [over.built]), based 7659/// on the operator @p Op and the arguments given. For example, if the 7660/// operator is a binary '+', this routine might add "int 7661/// operator+(int, int)" to cover integer addition. 7662void Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 7663 SourceLocation OpLoc, 7664 ArrayRef<Expr *> Args, 7665 OverloadCandidateSet &CandidateSet) { 7666 // Find all of the types that the arguments can convert to, but only 7667 // if the operator we're looking at has built-in operator candidates 7668 // that make use of these types. Also record whether we encounter non-record 7669 // candidate types or either arithmetic or enumeral candidate types. 7670 Qualifiers VisibleTypeConversionsQuals; 7671 VisibleTypeConversionsQuals.addConst(); 7672 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) 7673 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 7674 7675 bool HasNonRecordCandidateType = false; 7676 bool HasArithmeticOrEnumeralCandidateType = false; 7677 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 7678 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 7679 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 7680 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 7681 OpLoc, 7682 true, 7683 (Op == OO_Exclaim || 7684 Op == OO_AmpAmp || 7685 Op == OO_PipePipe), 7686 VisibleTypeConversionsQuals); 7687 HasNonRecordCandidateType = HasNonRecordCandidateType || 7688 CandidateTypes[ArgIdx].hasNonRecordTypes(); 7689 HasArithmeticOrEnumeralCandidateType = 7690 HasArithmeticOrEnumeralCandidateType || 7691 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 7692 } 7693 7694 // Exit early when no non-record types have been added to the candidate set 7695 // for any of the arguments to the operator. 7696 // 7697 // We can't exit early for !, ||, or &&, since there we have always have 7698 // 'bool' overloads. 7699 if (!HasNonRecordCandidateType && 7700 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe)) 7701 return; 7702 7703 // Setup an object to manage the common state for building overloads. 7704 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, 7705 VisibleTypeConversionsQuals, 7706 HasArithmeticOrEnumeralCandidateType, 7707 CandidateTypes, CandidateSet); 7708 7709 // Dispatch over the operation to add in only those overloads which apply. 7710 switch (Op) { 7711 case OO_None: 7712 case NUM_OVERLOADED_OPERATORS: 7713 llvm_unreachable("Expected an overloaded operator"); 7714 7715 case OO_New: 7716 case OO_Delete: 7717 case OO_Array_New: 7718 case OO_Array_Delete: 7719 case OO_Call: 7720 llvm_unreachable( 7721 "Special operators don't use AddBuiltinOperatorCandidates"); 7722 7723 case OO_Comma: 7724 case OO_Arrow: 7725 // C++ [over.match.oper]p3: 7726 // -- For the operator ',', the unary operator '&', or the 7727 // operator '->', the built-in candidates set is empty. 7728 break; 7729 7730 case OO_Plus: // '+' is either unary or binary 7731 if (Args.size() == 1) 7732 OpBuilder.addUnaryPlusPointerOverloads(); 7733 // Fall through. 7734 7735 case OO_Minus: // '-' is either unary or binary 7736 if (Args.size() == 1) { 7737 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 7738 } else { 7739 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 7740 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7741 } 7742 break; 7743 7744 case OO_Star: // '*' is either unary or binary 7745 if (Args.size() == 1) 7746 OpBuilder.addUnaryStarPointerOverloads(); 7747 else 7748 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7749 break; 7750 7751 case OO_Slash: 7752 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7753 break; 7754 7755 case OO_PlusPlus: 7756 case OO_MinusMinus: 7757 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 7758 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 7759 break; 7760 7761 case OO_EqualEqual: 7762 case OO_ExclaimEqual: 7763 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 7764 // Fall through. 7765 7766 case OO_Less: 7767 case OO_Greater: 7768 case OO_LessEqual: 7769 case OO_GreaterEqual: 7770 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 7771 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 7772 break; 7773 7774 case OO_Percent: 7775 case OO_Caret: 7776 case OO_Pipe: 7777 case OO_LessLess: 7778 case OO_GreaterGreater: 7779 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 7780 break; 7781 7782 case OO_Amp: // '&' is either unary or binary 7783 if (Args.size() == 1) 7784 // C++ [over.match.oper]p3: 7785 // -- For the operator ',', the unary operator '&', or the 7786 // operator '->', the built-in candidates set is empty. 7787 break; 7788 7789 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 7790 break; 7791 7792 case OO_Tilde: 7793 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 7794 break; 7795 7796 case OO_Equal: 7797 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 7798 // Fall through. 7799 7800 case OO_PlusEqual: 7801 case OO_MinusEqual: 7802 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 7803 // Fall through. 7804 7805 case OO_StarEqual: 7806 case OO_SlashEqual: 7807 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 7808 break; 7809 7810 case OO_PercentEqual: 7811 case OO_LessLessEqual: 7812 case OO_GreaterGreaterEqual: 7813 case OO_AmpEqual: 7814 case OO_CaretEqual: 7815 case OO_PipeEqual: 7816 OpBuilder.addAssignmentIntegralOverloads(); 7817 break; 7818 7819 case OO_Exclaim: 7820 OpBuilder.addExclaimOverload(); 7821 break; 7822 7823 case OO_AmpAmp: 7824 case OO_PipePipe: 7825 OpBuilder.addAmpAmpOrPipePipeOverload(); 7826 break; 7827 7828 case OO_Subscript: 7829 OpBuilder.addSubscriptOverloads(); 7830 break; 7831 7832 case OO_ArrowStar: 7833 OpBuilder.addArrowStarOverloads(); 7834 break; 7835 7836 case OO_Conditional: 7837 OpBuilder.addConditionalOperatorOverloads(); 7838 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7839 break; 7840 } 7841} 7842 7843/// \brief Add function candidates found via argument-dependent lookup 7844/// to the set of overloading candidates. 7845/// 7846/// This routine performs argument-dependent name lookup based on the 7847/// given function name (which may also be an operator name) and adds 7848/// all of the overload candidates found by ADL to the overload 7849/// candidate set (C++ [basic.lookup.argdep]). 7850void 7851Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 7852 bool Operator, SourceLocation Loc, 7853 ArrayRef<Expr *> Args, 7854 TemplateArgumentListInfo *ExplicitTemplateArgs, 7855 OverloadCandidateSet& CandidateSet, 7856 bool PartialOverloading) { 7857 ADLResult Fns; 7858 7859 // FIXME: This approach for uniquing ADL results (and removing 7860 // redundant candidates from the set) relies on pointer-equality, 7861 // which means we need to key off the canonical decl. However, 7862 // always going back to the canonical decl might not get us the 7863 // right set of default arguments. What default arguments are 7864 // we supposed to consider on ADL candidates, anyway? 7865 7866 // FIXME: Pass in the explicit template arguments? 7867 ArgumentDependentLookup(Name, Operator, Loc, Args, Fns); 7868 7869 // Erase all of the candidates we already knew about. 7870 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 7871 CandEnd = CandidateSet.end(); 7872 Cand != CandEnd; ++Cand) 7873 if (Cand->Function) { 7874 Fns.erase(Cand->Function); 7875 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 7876 Fns.erase(FunTmpl); 7877 } 7878 7879 // For each of the ADL candidates we found, add it to the overload 7880 // set. 7881 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 7882 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 7883 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 7884 if (ExplicitTemplateArgs) 7885 continue; 7886 7887 AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet, false, 7888 PartialOverloading); 7889 } else 7890 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 7891 FoundDecl, ExplicitTemplateArgs, 7892 Args, CandidateSet); 7893 } 7894} 7895 7896/// isBetterOverloadCandidate - Determines whether the first overload 7897/// candidate is a better candidate than the second (C++ 13.3.3p1). 7898bool 7899isBetterOverloadCandidate(Sema &S, 7900 const OverloadCandidate &Cand1, 7901 const OverloadCandidate &Cand2, 7902 SourceLocation Loc, 7903 bool UserDefinedConversion) { 7904 // Define viable functions to be better candidates than non-viable 7905 // functions. 7906 if (!Cand2.Viable) 7907 return Cand1.Viable; 7908 else if (!Cand1.Viable) 7909 return false; 7910 7911 // C++ [over.match.best]p1: 7912 // 7913 // -- if F is a static member function, ICS1(F) is defined such 7914 // that ICS1(F) is neither better nor worse than ICS1(G) for 7915 // any function G, and, symmetrically, ICS1(G) is neither 7916 // better nor worse than ICS1(F). 7917 unsigned StartArg = 0; 7918 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 7919 StartArg = 1; 7920 7921 // C++ [over.match.best]p1: 7922 // A viable function F1 is defined to be a better function than another 7923 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 7924 // conversion sequence than ICSi(F2), and then... 7925 unsigned NumArgs = Cand1.NumConversions; 7926 assert(Cand2.NumConversions == NumArgs && "Overload candidate mismatch"); 7927 bool HasBetterConversion = false; 7928 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 7929 switch (CompareImplicitConversionSequences(S, 7930 Cand1.Conversions[ArgIdx], 7931 Cand2.Conversions[ArgIdx])) { 7932 case ImplicitConversionSequence::Better: 7933 // Cand1 has a better conversion sequence. 7934 HasBetterConversion = true; 7935 break; 7936 7937 case ImplicitConversionSequence::Worse: 7938 // Cand1 can't be better than Cand2. 7939 return false; 7940 7941 case ImplicitConversionSequence::Indistinguishable: 7942 // Do nothing. 7943 break; 7944 } 7945 } 7946 7947 // -- for some argument j, ICSj(F1) is a better conversion sequence than 7948 // ICSj(F2), or, if not that, 7949 if (HasBetterConversion) 7950 return true; 7951 7952 // - F1 is a non-template function and F2 is a function template 7953 // specialization, or, if not that, 7954 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 7955 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 7956 return true; 7957 7958 // -- F1 and F2 are function template specializations, and the function 7959 // template for F1 is more specialized than the template for F2 7960 // according to the partial ordering rules described in 14.5.5.2, or, 7961 // if not that, 7962 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 7963 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 7964 if (FunctionTemplateDecl *BetterTemplate 7965 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 7966 Cand2.Function->getPrimaryTemplate(), 7967 Loc, 7968 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 7969 : TPOC_Call, 7970 Cand1.ExplicitCallArguments)) 7971 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 7972 } 7973 7974 // -- the context is an initialization by user-defined conversion 7975 // (see 8.5, 13.3.1.5) and the standard conversion sequence 7976 // from the return type of F1 to the destination type (i.e., 7977 // the type of the entity being initialized) is a better 7978 // conversion sequence than the standard conversion sequence 7979 // from the return type of F2 to the destination type. 7980 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 7981 isa<CXXConversionDecl>(Cand1.Function) && 7982 isa<CXXConversionDecl>(Cand2.Function)) { 7983 // First check whether we prefer one of the conversion functions over the 7984 // other. This only distinguishes the results in non-standard, extension 7985 // cases such as the conversion from a lambda closure type to a function 7986 // pointer or block. 7987 ImplicitConversionSequence::CompareKind FuncResult 7988 = compareConversionFunctions(S, Cand1.Function, Cand2.Function); 7989 if (FuncResult != ImplicitConversionSequence::Indistinguishable) 7990 return FuncResult; 7991 7992 switch (CompareStandardConversionSequences(S, 7993 Cand1.FinalConversion, 7994 Cand2.FinalConversion)) { 7995 case ImplicitConversionSequence::Better: 7996 // Cand1 has a better conversion sequence. 7997 return true; 7998 7999 case ImplicitConversionSequence::Worse: 8000 // Cand1 can't be better than Cand2. 8001 return false; 8002 8003 case ImplicitConversionSequence::Indistinguishable: 8004 // Do nothing 8005 break; 8006 } 8007 } 8008 8009 return false; 8010} 8011 8012/// \brief Computes the best viable function (C++ 13.3.3) 8013/// within an overload candidate set. 8014/// 8015/// \param Loc The location of the function name (or operator symbol) for 8016/// which overload resolution occurs. 8017/// 8018/// \param Best If overload resolution was successful or found a deleted 8019/// function, \p Best points to the candidate function found. 8020/// 8021/// \returns The result of overload resolution. 8022OverloadingResult 8023OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 8024 iterator &Best, 8025 bool UserDefinedConversion) { 8026 // Find the best viable function. 8027 Best = end(); 8028 for (iterator Cand = begin(); Cand != end(); ++Cand) { 8029 if (Cand->Viable) 8030 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 8031 UserDefinedConversion)) 8032 Best = Cand; 8033 } 8034 8035 // If we didn't find any viable functions, abort. 8036 if (Best == end()) 8037 return OR_No_Viable_Function; 8038 8039 // Make sure that this function is better than every other viable 8040 // function. If not, we have an ambiguity. 8041 for (iterator Cand = begin(); Cand != end(); ++Cand) { 8042 if (Cand->Viable && 8043 Cand != Best && 8044 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 8045 UserDefinedConversion)) { 8046 Best = end(); 8047 return OR_Ambiguous; 8048 } 8049 } 8050 8051 // Best is the best viable function. 8052 if (Best->Function && 8053 (Best->Function->isDeleted() || 8054 S.isFunctionConsideredUnavailable(Best->Function))) 8055 return OR_Deleted; 8056 8057 return OR_Success; 8058} 8059 8060namespace { 8061 8062enum OverloadCandidateKind { 8063 oc_function, 8064 oc_method, 8065 oc_constructor, 8066 oc_function_template, 8067 oc_method_template, 8068 oc_constructor_template, 8069 oc_implicit_default_constructor, 8070 oc_implicit_copy_constructor, 8071 oc_implicit_move_constructor, 8072 oc_implicit_copy_assignment, 8073 oc_implicit_move_assignment, 8074 oc_implicit_inherited_constructor 8075}; 8076 8077OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 8078 FunctionDecl *Fn, 8079 std::string &Description) { 8080 bool isTemplate = false; 8081 8082 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 8083 isTemplate = true; 8084 Description = S.getTemplateArgumentBindingsText( 8085 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 8086 } 8087 8088 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 8089 if (!Ctor->isImplicit()) 8090 return isTemplate ? oc_constructor_template : oc_constructor; 8091 8092 if (Ctor->getInheritedConstructor()) 8093 return oc_implicit_inherited_constructor; 8094 8095 if (Ctor->isDefaultConstructor()) 8096 return oc_implicit_default_constructor; 8097 8098 if (Ctor->isMoveConstructor()) 8099 return oc_implicit_move_constructor; 8100 8101 assert(Ctor->isCopyConstructor() && 8102 "unexpected sort of implicit constructor"); 8103 return oc_implicit_copy_constructor; 8104 } 8105 8106 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 8107 // This actually gets spelled 'candidate function' for now, but 8108 // it doesn't hurt to split it out. 8109 if (!Meth->isImplicit()) 8110 return isTemplate ? oc_method_template : oc_method; 8111 8112 if (Meth->isMoveAssignmentOperator()) 8113 return oc_implicit_move_assignment; 8114 8115 if (Meth->isCopyAssignmentOperator()) 8116 return oc_implicit_copy_assignment; 8117 8118 assert(isa<CXXConversionDecl>(Meth) && "expected conversion"); 8119 return oc_method; 8120 } 8121 8122 return isTemplate ? oc_function_template : oc_function; 8123} 8124 8125void MaybeEmitInheritedConstructorNote(Sema &S, Decl *Fn) { 8126 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 8127 if (!Ctor) return; 8128 8129 Ctor = Ctor->getInheritedConstructor(); 8130 if (!Ctor) return; 8131 8132 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 8133} 8134 8135} // end anonymous namespace 8136 8137// Notes the location of an overload candidate. 8138void Sema::NoteOverloadCandidate(FunctionDecl *Fn, QualType DestType) { 8139 std::string FnDesc; 8140 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 8141 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate) 8142 << (unsigned) K << FnDesc; 8143 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType); 8144 Diag(Fn->getLocation(), PD); 8145 MaybeEmitInheritedConstructorNote(*this, Fn); 8146} 8147 8148//Notes the location of all overload candidates designated through 8149// OverloadedExpr 8150void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr, QualType DestType) { 8151 assert(OverloadedExpr->getType() == Context.OverloadTy); 8152 8153 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); 8154 OverloadExpr *OvlExpr = Ovl.Expression; 8155 8156 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 8157 IEnd = OvlExpr->decls_end(); 8158 I != IEnd; ++I) { 8159 if (FunctionTemplateDecl *FunTmpl = 8160 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) { 8161 NoteOverloadCandidate(FunTmpl->getTemplatedDecl(), DestType); 8162 } else if (FunctionDecl *Fun 8163 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) { 8164 NoteOverloadCandidate(Fun, DestType); 8165 } 8166 } 8167} 8168 8169/// Diagnoses an ambiguous conversion. The partial diagnostic is the 8170/// "lead" diagnostic; it will be given two arguments, the source and 8171/// target types of the conversion. 8172void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 8173 Sema &S, 8174 SourceLocation CaretLoc, 8175 const PartialDiagnostic &PDiag) const { 8176 S.Diag(CaretLoc, PDiag) 8177 << Ambiguous.getFromType() << Ambiguous.getToType(); 8178 // FIXME: The note limiting machinery is borrowed from 8179 // OverloadCandidateSet::NoteCandidates; there's an opportunity for 8180 // refactoring here. 8181 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 8182 unsigned CandsShown = 0; 8183 AmbiguousConversionSequence::const_iterator I, E; 8184 for (I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 8185 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) 8186 break; 8187 ++CandsShown; 8188 S.NoteOverloadCandidate(*I); 8189 } 8190 if (I != E) 8191 S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I); 8192} 8193 8194namespace { 8195 8196void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 8197 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 8198 assert(Conv.isBad()); 8199 assert(Cand->Function && "for now, candidate must be a function"); 8200 FunctionDecl *Fn = Cand->Function; 8201 8202 // There's a conversion slot for the object argument if this is a 8203 // non-constructor method. Note that 'I' corresponds the 8204 // conversion-slot index. 8205 bool isObjectArgument = false; 8206 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 8207 if (I == 0) 8208 isObjectArgument = true; 8209 else 8210 I--; 8211 } 8212 8213 std::string FnDesc; 8214 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 8215 8216 Expr *FromExpr = Conv.Bad.FromExpr; 8217 QualType FromTy = Conv.Bad.getFromType(); 8218 QualType ToTy = Conv.Bad.getToType(); 8219 8220 if (FromTy == S.Context.OverloadTy) { 8221 assert(FromExpr && "overload set argument came from implicit argument?"); 8222 Expr *E = FromExpr->IgnoreParens(); 8223 if (isa<UnaryOperator>(E)) 8224 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 8225 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 8226 8227 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 8228 << (unsigned) FnKind << FnDesc 8229 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8230 << ToTy << Name << I+1; 8231 MaybeEmitInheritedConstructorNote(S, Fn); 8232 return; 8233 } 8234 8235 // Do some hand-waving analysis to see if the non-viability is due 8236 // to a qualifier mismatch. 8237 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 8238 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 8239 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 8240 CToTy = RT->getPointeeType(); 8241 else { 8242 // TODO: detect and diagnose the full richness of const mismatches. 8243 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 8244 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 8245 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 8246 } 8247 8248 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 8249 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 8250 Qualifiers FromQs = CFromTy.getQualifiers(); 8251 Qualifiers ToQs = CToTy.getQualifiers(); 8252 8253 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 8254 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 8255 << (unsigned) FnKind << FnDesc 8256 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8257 << FromTy 8258 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 8259 << (unsigned) isObjectArgument << I+1; 8260 MaybeEmitInheritedConstructorNote(S, Fn); 8261 return; 8262 } 8263 8264 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 8265 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership) 8266 << (unsigned) FnKind << FnDesc 8267 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8268 << FromTy 8269 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime() 8270 << (unsigned) isObjectArgument << I+1; 8271 MaybeEmitInheritedConstructorNote(S, Fn); 8272 return; 8273 } 8274 8275 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) { 8276 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc) 8277 << (unsigned) FnKind << FnDesc 8278 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8279 << FromTy 8280 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr() 8281 << (unsigned) isObjectArgument << I+1; 8282 MaybeEmitInheritedConstructorNote(S, Fn); 8283 return; 8284 } 8285 8286 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 8287 assert(CVR && "unexpected qualifiers mismatch"); 8288 8289 if (isObjectArgument) { 8290 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 8291 << (unsigned) FnKind << FnDesc 8292 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8293 << FromTy << (CVR - 1); 8294 } else { 8295 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 8296 << (unsigned) FnKind << FnDesc 8297 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8298 << FromTy << (CVR - 1) << I+1; 8299 } 8300 MaybeEmitInheritedConstructorNote(S, Fn); 8301 return; 8302 } 8303 8304 // Special diagnostic for failure to convert an initializer list, since 8305 // telling the user that it has type void is not useful. 8306 if (FromExpr && isa<InitListExpr>(FromExpr)) { 8307 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument) 8308 << (unsigned) FnKind << FnDesc 8309 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8310 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8311 MaybeEmitInheritedConstructorNote(S, Fn); 8312 return; 8313 } 8314 8315 // Diagnose references or pointers to incomplete types differently, 8316 // since it's far from impossible that the incompleteness triggered 8317 // the failure. 8318 QualType TempFromTy = FromTy.getNonReferenceType(); 8319 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 8320 TempFromTy = PTy->getPointeeType(); 8321 if (TempFromTy->isIncompleteType()) { 8322 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 8323 << (unsigned) FnKind << FnDesc 8324 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8325 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8326 MaybeEmitInheritedConstructorNote(S, Fn); 8327 return; 8328 } 8329 8330 // Diagnose base -> derived pointer conversions. 8331 unsigned BaseToDerivedConversion = 0; 8332 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 8333 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 8334 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 8335 FromPtrTy->getPointeeType()) && 8336 !FromPtrTy->getPointeeType()->isIncompleteType() && 8337 !ToPtrTy->getPointeeType()->isIncompleteType() && 8338 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 8339 FromPtrTy->getPointeeType())) 8340 BaseToDerivedConversion = 1; 8341 } 8342 } else if (const ObjCObjectPointerType *FromPtrTy 8343 = FromTy->getAs<ObjCObjectPointerType>()) { 8344 if (const ObjCObjectPointerType *ToPtrTy 8345 = ToTy->getAs<ObjCObjectPointerType>()) 8346 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 8347 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 8348 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 8349 FromPtrTy->getPointeeType()) && 8350 FromIface->isSuperClassOf(ToIface)) 8351 BaseToDerivedConversion = 2; 8352 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 8353 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 8354 !FromTy->isIncompleteType() && 8355 !ToRefTy->getPointeeType()->isIncompleteType() && 8356 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) { 8357 BaseToDerivedConversion = 3; 8358 } else if (ToTy->isLValueReferenceType() && !FromExpr->isLValue() && 8359 ToTy.getNonReferenceType().getCanonicalType() == 8360 FromTy.getNonReferenceType().getCanonicalType()) { 8361 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_lvalue) 8362 << (unsigned) FnKind << FnDesc 8363 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8364 << (unsigned) isObjectArgument << I + 1; 8365 MaybeEmitInheritedConstructorNote(S, Fn); 8366 return; 8367 } 8368 } 8369 8370 if (BaseToDerivedConversion) { 8371 S.Diag(Fn->getLocation(), 8372 diag::note_ovl_candidate_bad_base_to_derived_conv) 8373 << (unsigned) FnKind << FnDesc 8374 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8375 << (BaseToDerivedConversion - 1) 8376 << FromTy << ToTy << I+1; 8377 MaybeEmitInheritedConstructorNote(S, Fn); 8378 return; 8379 } 8380 8381 if (isa<ObjCObjectPointerType>(CFromTy) && 8382 isa<PointerType>(CToTy)) { 8383 Qualifiers FromQs = CFromTy.getQualifiers(); 8384 Qualifiers ToQs = CToTy.getQualifiers(); 8385 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 8386 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv) 8387 << (unsigned) FnKind << FnDesc 8388 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8389 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8390 MaybeEmitInheritedConstructorNote(S, Fn); 8391 return; 8392 } 8393 } 8394 8395 // Emit the generic diagnostic and, optionally, add the hints to it. 8396 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv); 8397 FDiag << (unsigned) FnKind << FnDesc 8398 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8399 << FromTy << ToTy << (unsigned) isObjectArgument << I + 1 8400 << (unsigned) (Cand->Fix.Kind); 8401 8402 // If we can fix the conversion, suggest the FixIts. 8403 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(), 8404 HE = Cand->Fix.Hints.end(); HI != HE; ++HI) 8405 FDiag << *HI; 8406 S.Diag(Fn->getLocation(), FDiag); 8407 8408 MaybeEmitInheritedConstructorNote(S, Fn); 8409} 8410 8411/// Additional arity mismatch diagnosis specific to a function overload 8412/// candidates. This is not covered by the more general DiagnoseArityMismatch() 8413/// over a candidate in any candidate set. 8414bool CheckArityMismatch(Sema &S, OverloadCandidate *Cand, 8415 unsigned NumArgs) { 8416 FunctionDecl *Fn = Cand->Function; 8417 unsigned MinParams = Fn->getMinRequiredArguments(); 8418 8419 // With invalid overloaded operators, it's possible that we think we 8420 // have an arity mismatch when in fact it looks like we have the 8421 // right number of arguments, because only overloaded operators have 8422 // the weird behavior of overloading member and non-member functions. 8423 // Just don't report anything. 8424 if (Fn->isInvalidDecl() && 8425 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName) 8426 return true; 8427 8428 if (NumArgs < MinParams) { 8429 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 8430 (Cand->FailureKind == ovl_fail_bad_deduction && 8431 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 8432 } else { 8433 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 8434 (Cand->FailureKind == ovl_fail_bad_deduction && 8435 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 8436 } 8437 8438 return false; 8439} 8440 8441/// General arity mismatch diagnosis over a candidate in a candidate set. 8442void DiagnoseArityMismatch(Sema &S, Decl *D, unsigned NumFormalArgs) { 8443 assert(isa<FunctionDecl>(D) && 8444 "The templated declaration should at least be a function" 8445 " when diagnosing bad template argument deduction due to too many" 8446 " or too few arguments"); 8447 8448 FunctionDecl *Fn = cast<FunctionDecl>(D); 8449 8450 // TODO: treat calls to a missing default constructor as a special case 8451 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 8452 unsigned MinParams = Fn->getMinRequiredArguments(); 8453 8454 // at least / at most / exactly 8455 unsigned mode, modeCount; 8456 if (NumFormalArgs < MinParams) { 8457 if (MinParams != FnTy->getNumArgs() || 8458 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 8459 mode = 0; // "at least" 8460 else 8461 mode = 2; // "exactly" 8462 modeCount = MinParams; 8463 } else { 8464 if (MinParams != FnTy->getNumArgs()) 8465 mode = 1; // "at most" 8466 else 8467 mode = 2; // "exactly" 8468 modeCount = FnTy->getNumArgs(); 8469 } 8470 8471 std::string Description; 8472 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 8473 8474 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName()) 8475 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one) 8476 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 8477 << Fn->getParamDecl(0) << NumFormalArgs; 8478 else 8479 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 8480 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 8481 << modeCount << NumFormalArgs; 8482 MaybeEmitInheritedConstructorNote(S, Fn); 8483} 8484 8485/// Arity mismatch diagnosis specific to a function overload candidate. 8486void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 8487 unsigned NumFormalArgs) { 8488 if (!CheckArityMismatch(S, Cand, NumFormalArgs)) 8489 DiagnoseArityMismatch(S, Cand->Function, NumFormalArgs); 8490} 8491 8492TemplateDecl *getDescribedTemplate(Decl *Templated) { 8493 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Templated)) 8494 return FD->getDescribedFunctionTemplate(); 8495 else if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Templated)) 8496 return RD->getDescribedClassTemplate(); 8497 8498 llvm_unreachable("Unsupported: Getting the described template declaration" 8499 " for bad deduction diagnosis"); 8500} 8501 8502/// Diagnose a failed template-argument deduction. 8503void DiagnoseBadDeduction(Sema &S, Decl *Templated, 8504 DeductionFailureInfo &DeductionFailure, 8505 unsigned NumArgs) { 8506 TemplateParameter Param = DeductionFailure.getTemplateParameter(); 8507 NamedDecl *ParamD; 8508 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 8509 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 8510 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 8511 switch (DeductionFailure.Result) { 8512 case Sema::TDK_Success: 8513 llvm_unreachable("TDK_success while diagnosing bad deduction"); 8514 8515 case Sema::TDK_Incomplete: { 8516 assert(ParamD && "no parameter found for incomplete deduction result"); 8517 S.Diag(Templated->getLocation(), 8518 diag::note_ovl_candidate_incomplete_deduction) 8519 << ParamD->getDeclName(); 8520 MaybeEmitInheritedConstructorNote(S, Templated); 8521 return; 8522 } 8523 8524 case Sema::TDK_Underqualified: { 8525 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 8526 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 8527 8528 QualType Param = DeductionFailure.getFirstArg()->getAsType(); 8529 8530 // Param will have been canonicalized, but it should just be a 8531 // qualified version of ParamD, so move the qualifiers to that. 8532 QualifierCollector Qs; 8533 Qs.strip(Param); 8534 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 8535 assert(S.Context.hasSameType(Param, NonCanonParam)); 8536 8537 // Arg has also been canonicalized, but there's nothing we can do 8538 // about that. It also doesn't matter as much, because it won't 8539 // have any template parameters in it (because deduction isn't 8540 // done on dependent types). 8541 QualType Arg = DeductionFailure.getSecondArg()->getAsType(); 8542 8543 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_underqualified) 8544 << ParamD->getDeclName() << Arg << NonCanonParam; 8545 MaybeEmitInheritedConstructorNote(S, Templated); 8546 return; 8547 } 8548 8549 case Sema::TDK_Inconsistent: { 8550 assert(ParamD && "no parameter found for inconsistent deduction result"); 8551 int which = 0; 8552 if (isa<TemplateTypeParmDecl>(ParamD)) 8553 which = 0; 8554 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 8555 which = 1; 8556 else { 8557 which = 2; 8558 } 8559 8560 S.Diag(Templated->getLocation(), 8561 diag::note_ovl_candidate_inconsistent_deduction) 8562 << which << ParamD->getDeclName() << *DeductionFailure.getFirstArg() 8563 << *DeductionFailure.getSecondArg(); 8564 MaybeEmitInheritedConstructorNote(S, Templated); 8565 return; 8566 } 8567 8568 case Sema::TDK_InvalidExplicitArguments: 8569 assert(ParamD && "no parameter found for invalid explicit arguments"); 8570 if (ParamD->getDeclName()) 8571 S.Diag(Templated->getLocation(), 8572 diag::note_ovl_candidate_explicit_arg_mismatch_named) 8573 << ParamD->getDeclName(); 8574 else { 8575 int index = 0; 8576 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 8577 index = TTP->getIndex(); 8578 else if (NonTypeTemplateParmDecl *NTTP 8579 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 8580 index = NTTP->getIndex(); 8581 else 8582 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 8583 S.Diag(Templated->getLocation(), 8584 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 8585 << (index + 1); 8586 } 8587 MaybeEmitInheritedConstructorNote(S, Templated); 8588 return; 8589 8590 case Sema::TDK_TooManyArguments: 8591 case Sema::TDK_TooFewArguments: 8592 DiagnoseArityMismatch(S, Templated, NumArgs); 8593 return; 8594 8595 case Sema::TDK_InstantiationDepth: 8596 S.Diag(Templated->getLocation(), 8597 diag::note_ovl_candidate_instantiation_depth); 8598 MaybeEmitInheritedConstructorNote(S, Templated); 8599 return; 8600 8601 case Sema::TDK_SubstitutionFailure: { 8602 // Format the template argument list into the argument string. 8603 SmallString<128> TemplateArgString; 8604 if (TemplateArgumentList *Args = 8605 DeductionFailure.getTemplateArgumentList()) { 8606 TemplateArgString = " "; 8607 TemplateArgString += S.getTemplateArgumentBindingsText( 8608 getDescribedTemplate(Templated)->getTemplateParameters(), *Args); 8609 } 8610 8611 // If this candidate was disabled by enable_if, say so. 8612 PartialDiagnosticAt *PDiag = DeductionFailure.getSFINAEDiagnostic(); 8613 if (PDiag && PDiag->second.getDiagID() == 8614 diag::err_typename_nested_not_found_enable_if) { 8615 // FIXME: Use the source range of the condition, and the fully-qualified 8616 // name of the enable_if template. These are both present in PDiag. 8617 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if) 8618 << "'enable_if'" << TemplateArgString; 8619 return; 8620 } 8621 8622 // Format the SFINAE diagnostic into the argument string. 8623 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s 8624 // formatted message in another diagnostic. 8625 SmallString<128> SFINAEArgString; 8626 SourceRange R; 8627 if (PDiag) { 8628 SFINAEArgString = ": "; 8629 R = SourceRange(PDiag->first, PDiag->first); 8630 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString); 8631 } 8632 8633 S.Diag(Templated->getLocation(), 8634 diag::note_ovl_candidate_substitution_failure) 8635 << TemplateArgString << SFINAEArgString << R; 8636 MaybeEmitInheritedConstructorNote(S, Templated); 8637 return; 8638 } 8639 8640 case Sema::TDK_FailedOverloadResolution: { 8641 OverloadExpr::FindResult R = OverloadExpr::find(DeductionFailure.getExpr()); 8642 S.Diag(Templated->getLocation(), 8643 diag::note_ovl_candidate_failed_overload_resolution) 8644 << R.Expression->getName(); 8645 return; 8646 } 8647 8648 case Sema::TDK_NonDeducedMismatch: { 8649 // FIXME: Provide a source location to indicate what we couldn't match. 8650 TemplateArgument FirstTA = *DeductionFailure.getFirstArg(); 8651 TemplateArgument SecondTA = *DeductionFailure.getSecondArg(); 8652 if (FirstTA.getKind() == TemplateArgument::Template && 8653 SecondTA.getKind() == TemplateArgument::Template) { 8654 TemplateName FirstTN = FirstTA.getAsTemplate(); 8655 TemplateName SecondTN = SecondTA.getAsTemplate(); 8656 if (FirstTN.getKind() == TemplateName::Template && 8657 SecondTN.getKind() == TemplateName::Template) { 8658 if (FirstTN.getAsTemplateDecl()->getName() == 8659 SecondTN.getAsTemplateDecl()->getName()) { 8660 // FIXME: This fixes a bad diagnostic where both templates are named 8661 // the same. This particular case is a bit difficult since: 8662 // 1) It is passed as a string to the diagnostic printer. 8663 // 2) The diagnostic printer only attempts to find a better 8664 // name for types, not decls. 8665 // Ideally, this should folded into the diagnostic printer. 8666 S.Diag(Templated->getLocation(), 8667 diag::note_ovl_candidate_non_deduced_mismatch_qualified) 8668 << FirstTN.getAsTemplateDecl() << SecondTN.getAsTemplateDecl(); 8669 return; 8670 } 8671 } 8672 } 8673 S.Diag(Templated->getLocation(), 8674 diag::note_ovl_candidate_non_deduced_mismatch) 8675 << FirstTA << SecondTA; 8676 return; 8677 } 8678 // TODO: diagnose these individually, then kill off 8679 // note_ovl_candidate_bad_deduction, which is uselessly vague. 8680 case Sema::TDK_MiscellaneousDeductionFailure: 8681 S.Diag(Templated->getLocation(), diag::note_ovl_candidate_bad_deduction); 8682 MaybeEmitInheritedConstructorNote(S, Templated); 8683 return; 8684 } 8685} 8686 8687/// Diagnose a failed template-argument deduction, for function calls. 8688void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, unsigned NumArgs) { 8689 unsigned TDK = Cand->DeductionFailure.Result; 8690 if (TDK == Sema::TDK_TooFewArguments || TDK == Sema::TDK_TooManyArguments) { 8691 if (CheckArityMismatch(S, Cand, NumArgs)) 8692 return; 8693 } 8694 DiagnoseBadDeduction(S, Cand->Function, // pattern 8695 Cand->DeductionFailure, NumArgs); 8696} 8697 8698/// CUDA: diagnose an invalid call across targets. 8699void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) { 8700 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext); 8701 FunctionDecl *Callee = Cand->Function; 8702 8703 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller), 8704 CalleeTarget = S.IdentifyCUDATarget(Callee); 8705 8706 std::string FnDesc; 8707 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Callee, FnDesc); 8708 8709 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target) 8710 << (unsigned) FnKind << CalleeTarget << CallerTarget; 8711} 8712 8713/// Generates a 'note' diagnostic for an overload candidate. We've 8714/// already generated a primary error at the call site. 8715/// 8716/// It really does need to be a single diagnostic with its caret 8717/// pointed at the candidate declaration. Yes, this creates some 8718/// major challenges of technical writing. Yes, this makes pointing 8719/// out problems with specific arguments quite awkward. It's still 8720/// better than generating twenty screens of text for every failed 8721/// overload. 8722/// 8723/// It would be great to be able to express per-candidate problems 8724/// more richly for those diagnostic clients that cared, but we'd 8725/// still have to be just as careful with the default diagnostics. 8726void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 8727 unsigned NumArgs) { 8728 FunctionDecl *Fn = Cand->Function; 8729 8730 // Note deleted candidates, but only if they're viable. 8731 if (Cand->Viable && (Fn->isDeleted() || 8732 S.isFunctionConsideredUnavailable(Fn))) { 8733 std::string FnDesc; 8734 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 8735 8736 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 8737 << FnKind << FnDesc 8738 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0); 8739 MaybeEmitInheritedConstructorNote(S, Fn); 8740 return; 8741 } 8742 8743 // We don't really have anything else to say about viable candidates. 8744 if (Cand->Viable) { 8745 S.NoteOverloadCandidate(Fn); 8746 return; 8747 } 8748 8749 switch (Cand->FailureKind) { 8750 case ovl_fail_too_many_arguments: 8751 case ovl_fail_too_few_arguments: 8752 return DiagnoseArityMismatch(S, Cand, NumArgs); 8753 8754 case ovl_fail_bad_deduction: 8755 return DiagnoseBadDeduction(S, Cand, NumArgs); 8756 8757 case ovl_fail_trivial_conversion: 8758 case ovl_fail_bad_final_conversion: 8759 case ovl_fail_final_conversion_not_exact: 8760 return S.NoteOverloadCandidate(Fn); 8761 8762 case ovl_fail_bad_conversion: { 8763 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 8764 for (unsigned N = Cand->NumConversions; I != N; ++I) 8765 if (Cand->Conversions[I].isBad()) 8766 return DiagnoseBadConversion(S, Cand, I); 8767 8768 // FIXME: this currently happens when we're called from SemaInit 8769 // when user-conversion overload fails. Figure out how to handle 8770 // those conditions and diagnose them well. 8771 return S.NoteOverloadCandidate(Fn); 8772 } 8773 8774 case ovl_fail_bad_target: 8775 return DiagnoseBadTarget(S, Cand); 8776 } 8777} 8778 8779void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 8780 // Desugar the type of the surrogate down to a function type, 8781 // retaining as many typedefs as possible while still showing 8782 // the function type (and, therefore, its parameter types). 8783 QualType FnType = Cand->Surrogate->getConversionType(); 8784 bool isLValueReference = false; 8785 bool isRValueReference = false; 8786 bool isPointer = false; 8787 if (const LValueReferenceType *FnTypeRef = 8788 FnType->getAs<LValueReferenceType>()) { 8789 FnType = FnTypeRef->getPointeeType(); 8790 isLValueReference = true; 8791 } else if (const RValueReferenceType *FnTypeRef = 8792 FnType->getAs<RValueReferenceType>()) { 8793 FnType = FnTypeRef->getPointeeType(); 8794 isRValueReference = true; 8795 } 8796 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 8797 FnType = FnTypePtr->getPointeeType(); 8798 isPointer = true; 8799 } 8800 // Desugar down to a function type. 8801 FnType = QualType(FnType->getAs<FunctionType>(), 0); 8802 // Reconstruct the pointer/reference as appropriate. 8803 if (isPointer) FnType = S.Context.getPointerType(FnType); 8804 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 8805 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 8806 8807 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 8808 << FnType; 8809 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 8810} 8811 8812void NoteBuiltinOperatorCandidate(Sema &S, 8813 StringRef Opc, 8814 SourceLocation OpLoc, 8815 OverloadCandidate *Cand) { 8816 assert(Cand->NumConversions <= 2 && "builtin operator is not binary"); 8817 std::string TypeStr("operator"); 8818 TypeStr += Opc; 8819 TypeStr += "("; 8820 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 8821 if (Cand->NumConversions == 1) { 8822 TypeStr += ")"; 8823 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 8824 } else { 8825 TypeStr += ", "; 8826 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 8827 TypeStr += ")"; 8828 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 8829 } 8830} 8831 8832void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 8833 OverloadCandidate *Cand) { 8834 unsigned NoOperands = Cand->NumConversions; 8835 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 8836 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 8837 if (ICS.isBad()) break; // all meaningless after first invalid 8838 if (!ICS.isAmbiguous()) continue; 8839 8840 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 8841 S.PDiag(diag::note_ambiguous_type_conversion)); 8842 } 8843} 8844 8845static SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 8846 if (Cand->Function) 8847 return Cand->Function->getLocation(); 8848 if (Cand->IsSurrogate) 8849 return Cand->Surrogate->getLocation(); 8850 return SourceLocation(); 8851} 8852 8853static unsigned RankDeductionFailure(const DeductionFailureInfo &DFI) { 8854 switch ((Sema::TemplateDeductionResult)DFI.Result) { 8855 case Sema::TDK_Success: 8856 llvm_unreachable("TDK_success while diagnosing bad deduction"); 8857 8858 case Sema::TDK_Invalid: 8859 case Sema::TDK_Incomplete: 8860 return 1; 8861 8862 case Sema::TDK_Underqualified: 8863 case Sema::TDK_Inconsistent: 8864 return 2; 8865 8866 case Sema::TDK_SubstitutionFailure: 8867 case Sema::TDK_NonDeducedMismatch: 8868 case Sema::TDK_MiscellaneousDeductionFailure: 8869 return 3; 8870 8871 case Sema::TDK_InstantiationDepth: 8872 case Sema::TDK_FailedOverloadResolution: 8873 return 4; 8874 8875 case Sema::TDK_InvalidExplicitArguments: 8876 return 5; 8877 8878 case Sema::TDK_TooManyArguments: 8879 case Sema::TDK_TooFewArguments: 8880 return 6; 8881 } 8882 llvm_unreachable("Unhandled deduction result"); 8883} 8884 8885struct CompareOverloadCandidatesForDisplay { 8886 Sema &S; 8887 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 8888 8889 bool operator()(const OverloadCandidate *L, 8890 const OverloadCandidate *R) { 8891 // Fast-path this check. 8892 if (L == R) return false; 8893 8894 // Order first by viability. 8895 if (L->Viable) { 8896 if (!R->Viable) return true; 8897 8898 // TODO: introduce a tri-valued comparison for overload 8899 // candidates. Would be more worthwhile if we had a sort 8900 // that could exploit it. 8901 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 8902 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 8903 } else if (R->Viable) 8904 return false; 8905 8906 assert(L->Viable == R->Viable); 8907 8908 // Criteria by which we can sort non-viable candidates: 8909 if (!L->Viable) { 8910 // 1. Arity mismatches come after other candidates. 8911 if (L->FailureKind == ovl_fail_too_many_arguments || 8912 L->FailureKind == ovl_fail_too_few_arguments) 8913 return false; 8914 if (R->FailureKind == ovl_fail_too_many_arguments || 8915 R->FailureKind == ovl_fail_too_few_arguments) 8916 return true; 8917 8918 // 2. Bad conversions come first and are ordered by the number 8919 // of bad conversions and quality of good conversions. 8920 if (L->FailureKind == ovl_fail_bad_conversion) { 8921 if (R->FailureKind != ovl_fail_bad_conversion) 8922 return true; 8923 8924 // The conversion that can be fixed with a smaller number of changes, 8925 // comes first. 8926 unsigned numLFixes = L->Fix.NumConversionsFixed; 8927 unsigned numRFixes = R->Fix.NumConversionsFixed; 8928 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes; 8929 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes; 8930 if (numLFixes != numRFixes) { 8931 if (numLFixes < numRFixes) 8932 return true; 8933 else 8934 return false; 8935 } 8936 8937 // If there's any ordering between the defined conversions... 8938 // FIXME: this might not be transitive. 8939 assert(L->NumConversions == R->NumConversions); 8940 8941 int leftBetter = 0; 8942 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 8943 for (unsigned E = L->NumConversions; I != E; ++I) { 8944 switch (CompareImplicitConversionSequences(S, 8945 L->Conversions[I], 8946 R->Conversions[I])) { 8947 case ImplicitConversionSequence::Better: 8948 leftBetter++; 8949 break; 8950 8951 case ImplicitConversionSequence::Worse: 8952 leftBetter--; 8953 break; 8954 8955 case ImplicitConversionSequence::Indistinguishable: 8956 break; 8957 } 8958 } 8959 if (leftBetter > 0) return true; 8960 if (leftBetter < 0) return false; 8961 8962 } else if (R->FailureKind == ovl_fail_bad_conversion) 8963 return false; 8964 8965 if (L->FailureKind == ovl_fail_bad_deduction) { 8966 if (R->FailureKind != ovl_fail_bad_deduction) 8967 return true; 8968 8969 if (L->DeductionFailure.Result != R->DeductionFailure.Result) 8970 return RankDeductionFailure(L->DeductionFailure) 8971 < RankDeductionFailure(R->DeductionFailure); 8972 } else if (R->FailureKind == ovl_fail_bad_deduction) 8973 return false; 8974 8975 // TODO: others? 8976 } 8977 8978 // Sort everything else by location. 8979 SourceLocation LLoc = GetLocationForCandidate(L); 8980 SourceLocation RLoc = GetLocationForCandidate(R); 8981 8982 // Put candidates without locations (e.g. builtins) at the end. 8983 if (LLoc.isInvalid()) return false; 8984 if (RLoc.isInvalid()) return true; 8985 8986 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 8987 } 8988}; 8989 8990/// CompleteNonViableCandidate - Normally, overload resolution only 8991/// computes up to the first. Produces the FixIt set if possible. 8992void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 8993 ArrayRef<Expr *> Args) { 8994 assert(!Cand->Viable); 8995 8996 // Don't do anything on failures other than bad conversion. 8997 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 8998 8999 // We only want the FixIts if all the arguments can be corrected. 9000 bool Unfixable = false; 9001 // Use a implicit copy initialization to check conversion fixes. 9002 Cand->Fix.setConversionChecker(TryCopyInitialization); 9003 9004 // Skip forward to the first bad conversion. 9005 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 9006 unsigned ConvCount = Cand->NumConversions; 9007 while (true) { 9008 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 9009 ConvIdx++; 9010 if (Cand->Conversions[ConvIdx - 1].isBad()) { 9011 Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S); 9012 break; 9013 } 9014 } 9015 9016 if (ConvIdx == ConvCount) 9017 return; 9018 9019 assert(!Cand->Conversions[ConvIdx].isInitialized() && 9020 "remaining conversion is initialized?"); 9021 9022 // FIXME: this should probably be preserved from the overload 9023 // operation somehow. 9024 bool SuppressUserConversions = false; 9025 9026 const FunctionProtoType* Proto; 9027 unsigned ArgIdx = ConvIdx; 9028 9029 if (Cand->IsSurrogate) { 9030 QualType ConvType 9031 = Cand->Surrogate->getConversionType().getNonReferenceType(); 9032 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 9033 ConvType = ConvPtrType->getPointeeType(); 9034 Proto = ConvType->getAs<FunctionProtoType>(); 9035 ArgIdx--; 9036 } else if (Cand->Function) { 9037 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 9038 if (isa<CXXMethodDecl>(Cand->Function) && 9039 !isa<CXXConstructorDecl>(Cand->Function)) 9040 ArgIdx--; 9041 } else { 9042 // Builtin binary operator with a bad first conversion. 9043 assert(ConvCount <= 3); 9044 for (; ConvIdx != ConvCount; ++ConvIdx) 9045 Cand->Conversions[ConvIdx] 9046 = TryCopyInitialization(S, Args[ConvIdx], 9047 Cand->BuiltinTypes.ParamTypes[ConvIdx], 9048 SuppressUserConversions, 9049 /*InOverloadResolution*/ true, 9050 /*AllowObjCWritebackConversion=*/ 9051 S.getLangOpts().ObjCAutoRefCount); 9052 return; 9053 } 9054 9055 // Fill in the rest of the conversions. 9056 unsigned NumArgsInProto = Proto->getNumArgs(); 9057 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 9058 if (ArgIdx < NumArgsInProto) { 9059 Cand->Conversions[ConvIdx] 9060 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 9061 SuppressUserConversions, 9062 /*InOverloadResolution=*/true, 9063 /*AllowObjCWritebackConversion=*/ 9064 S.getLangOpts().ObjCAutoRefCount); 9065 // Store the FixIt in the candidate if it exists. 9066 if (!Unfixable && Cand->Conversions[ConvIdx].isBad()) 9067 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S); 9068 } 9069 else 9070 Cand->Conversions[ConvIdx].setEllipsis(); 9071 } 9072} 9073 9074} // end anonymous namespace 9075 9076/// PrintOverloadCandidates - When overload resolution fails, prints 9077/// diagnostic messages containing the candidates in the candidate 9078/// set. 9079void OverloadCandidateSet::NoteCandidates(Sema &S, 9080 OverloadCandidateDisplayKind OCD, 9081 ArrayRef<Expr *> Args, 9082 StringRef Opc, 9083 SourceLocation OpLoc) { 9084 // Sort the candidates by viability and position. Sorting directly would 9085 // be prohibitive, so we make a set of pointers and sort those. 9086 SmallVector<OverloadCandidate*, 32> Cands; 9087 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 9088 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 9089 if (Cand->Viable) 9090 Cands.push_back(Cand); 9091 else if (OCD == OCD_AllCandidates) { 9092 CompleteNonViableCandidate(S, Cand, Args); 9093 if (Cand->Function || Cand->IsSurrogate) 9094 Cands.push_back(Cand); 9095 // Otherwise, this a non-viable builtin candidate. We do not, in general, 9096 // want to list every possible builtin candidate. 9097 } 9098 } 9099 9100 std::sort(Cands.begin(), Cands.end(), 9101 CompareOverloadCandidatesForDisplay(S)); 9102 9103 bool ReportedAmbiguousConversions = false; 9104 9105 SmallVectorImpl<OverloadCandidate*>::iterator I, E; 9106 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 9107 unsigned CandsShown = 0; 9108 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 9109 OverloadCandidate *Cand = *I; 9110 9111 // Set an arbitrary limit on the number of candidate functions we'll spam 9112 // the user with. FIXME: This limit should depend on details of the 9113 // candidate list. 9114 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) { 9115 break; 9116 } 9117 ++CandsShown; 9118 9119 if (Cand->Function) 9120 NoteFunctionCandidate(S, Cand, Args.size()); 9121 else if (Cand->IsSurrogate) 9122 NoteSurrogateCandidate(S, Cand); 9123 else { 9124 assert(Cand->Viable && 9125 "Non-viable built-in candidates are not added to Cands."); 9126 // Generally we only see ambiguities including viable builtin 9127 // operators if overload resolution got screwed up by an 9128 // ambiguous user-defined conversion. 9129 // 9130 // FIXME: It's quite possible for different conversions to see 9131 // different ambiguities, though. 9132 if (!ReportedAmbiguousConversions) { 9133 NoteAmbiguousUserConversions(S, OpLoc, Cand); 9134 ReportedAmbiguousConversions = true; 9135 } 9136 9137 // If this is a viable builtin, print it. 9138 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 9139 } 9140 } 9141 9142 if (I != E) 9143 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 9144} 9145 9146static SourceLocation 9147GetLocationForCandidate(const TemplateSpecCandidate *Cand) { 9148 return Cand->Specialization ? Cand->Specialization->getLocation() 9149 : SourceLocation(); 9150} 9151 9152struct CompareTemplateSpecCandidatesForDisplay { 9153 Sema &S; 9154 CompareTemplateSpecCandidatesForDisplay(Sema &S) : S(S) {} 9155 9156 bool operator()(const TemplateSpecCandidate *L, 9157 const TemplateSpecCandidate *R) { 9158 // Fast-path this check. 9159 if (L == R) 9160 return false; 9161 9162 // Assuming that both candidates are not matches... 9163 9164 // Sort by the ranking of deduction failures. 9165 if (L->DeductionFailure.Result != R->DeductionFailure.Result) 9166 return RankDeductionFailure(L->DeductionFailure) < 9167 RankDeductionFailure(R->DeductionFailure); 9168 9169 // Sort everything else by location. 9170 SourceLocation LLoc = GetLocationForCandidate(L); 9171 SourceLocation RLoc = GetLocationForCandidate(R); 9172 9173 // Put candidates without locations (e.g. builtins) at the end. 9174 if (LLoc.isInvalid()) 9175 return false; 9176 if (RLoc.isInvalid()) 9177 return true; 9178 9179 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 9180 } 9181}; 9182 9183/// Diagnose a template argument deduction failure. 9184/// We are treating these failures as overload failures due to bad 9185/// deductions. 9186void TemplateSpecCandidate::NoteDeductionFailure(Sema &S) { 9187 DiagnoseBadDeduction(S, Specialization, // pattern 9188 DeductionFailure, /*NumArgs=*/0); 9189} 9190 9191void TemplateSpecCandidateSet::destroyCandidates() { 9192 for (iterator i = begin(), e = end(); i != e; ++i) { 9193 i->DeductionFailure.Destroy(); 9194 } 9195} 9196 9197void TemplateSpecCandidateSet::clear() { 9198 destroyCandidates(); 9199 Candidates.clear(); 9200} 9201 9202/// NoteCandidates - When no template specialization match is found, prints 9203/// diagnostic messages containing the non-matching specializations that form 9204/// the candidate set. 9205/// This is analoguous to OverloadCandidateSet::NoteCandidates() with 9206/// OCD == OCD_AllCandidates and Cand->Viable == false. 9207void TemplateSpecCandidateSet::NoteCandidates(Sema &S, SourceLocation Loc) { 9208 // Sort the candidates by position (assuming no candidate is a match). 9209 // Sorting directly would be prohibitive, so we make a set of pointers 9210 // and sort those. 9211 SmallVector<TemplateSpecCandidate *, 32> Cands; 9212 Cands.reserve(size()); 9213 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 9214 if (Cand->Specialization) 9215 Cands.push_back(Cand); 9216 // Otherwise, this is a non matching builtin candidate. We do not, 9217 // in general, want to list every possible builtin candidate. 9218 } 9219 9220 std::sort(Cands.begin(), Cands.end(), 9221 CompareTemplateSpecCandidatesForDisplay(S)); 9222 9223 // FIXME: Perhaps rename OverloadsShown and getShowOverloads() 9224 // for generalization purposes (?). 9225 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 9226 9227 SmallVectorImpl<TemplateSpecCandidate *>::iterator I, E; 9228 unsigned CandsShown = 0; 9229 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 9230 TemplateSpecCandidate *Cand = *I; 9231 9232 // Set an arbitrary limit on the number of candidates we'll spam 9233 // the user with. FIXME: This limit should depend on details of the 9234 // candidate list. 9235 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) 9236 break; 9237 ++CandsShown; 9238 9239 assert(Cand->Specialization && 9240 "Non-matching built-in candidates are not added to Cands."); 9241 Cand->NoteDeductionFailure(S); 9242 } 9243 9244 if (I != E) 9245 S.Diag(Loc, diag::note_ovl_too_many_candidates) << int(E - I); 9246} 9247 9248// [PossiblyAFunctionType] --> [Return] 9249// NonFunctionType --> NonFunctionType 9250// R (A) --> R(A) 9251// R (*)(A) --> R (A) 9252// R (&)(A) --> R (A) 9253// R (S::*)(A) --> R (A) 9254QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { 9255 QualType Ret = PossiblyAFunctionType; 9256 if (const PointerType *ToTypePtr = 9257 PossiblyAFunctionType->getAs<PointerType>()) 9258 Ret = ToTypePtr->getPointeeType(); 9259 else if (const ReferenceType *ToTypeRef = 9260 PossiblyAFunctionType->getAs<ReferenceType>()) 9261 Ret = ToTypeRef->getPointeeType(); 9262 else if (const MemberPointerType *MemTypePtr = 9263 PossiblyAFunctionType->getAs<MemberPointerType>()) 9264 Ret = MemTypePtr->getPointeeType(); 9265 Ret = 9266 Context.getCanonicalType(Ret).getUnqualifiedType(); 9267 return Ret; 9268} 9269 9270// A helper class to help with address of function resolution 9271// - allows us to avoid passing around all those ugly parameters 9272class AddressOfFunctionResolver 9273{ 9274 Sema& S; 9275 Expr* SourceExpr; 9276 const QualType& TargetType; 9277 QualType TargetFunctionType; // Extracted function type from target type 9278 9279 bool Complain; 9280 //DeclAccessPair& ResultFunctionAccessPair; 9281 ASTContext& Context; 9282 9283 bool TargetTypeIsNonStaticMemberFunction; 9284 bool FoundNonTemplateFunction; 9285 bool StaticMemberFunctionFromBoundPointer; 9286 9287 OverloadExpr::FindResult OvlExprInfo; 9288 OverloadExpr *OvlExpr; 9289 TemplateArgumentListInfo OvlExplicitTemplateArgs; 9290 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 9291 TemplateSpecCandidateSet FailedCandidates; 9292 9293public: 9294 AddressOfFunctionResolver(Sema &S, Expr *SourceExpr, 9295 const QualType &TargetType, bool Complain) 9296 : S(S), SourceExpr(SourceExpr), TargetType(TargetType), 9297 Complain(Complain), Context(S.getASTContext()), 9298 TargetTypeIsNonStaticMemberFunction( 9299 !!TargetType->getAs<MemberPointerType>()), 9300 FoundNonTemplateFunction(false), 9301 StaticMemberFunctionFromBoundPointer(false), 9302 OvlExprInfo(OverloadExpr::find(SourceExpr)), 9303 OvlExpr(OvlExprInfo.Expression), 9304 FailedCandidates(OvlExpr->getNameLoc()) { 9305 ExtractUnqualifiedFunctionTypeFromTargetType(); 9306 9307 if (TargetFunctionType->isFunctionType()) { 9308 if (UnresolvedMemberExpr *UME = dyn_cast<UnresolvedMemberExpr>(OvlExpr)) 9309 if (!UME->isImplicitAccess() && 9310 !S.ResolveSingleFunctionTemplateSpecialization(UME)) 9311 StaticMemberFunctionFromBoundPointer = true; 9312 } else if (OvlExpr->hasExplicitTemplateArgs()) { 9313 DeclAccessPair dap; 9314 if (FunctionDecl *Fn = S.ResolveSingleFunctionTemplateSpecialization( 9315 OvlExpr, false, &dap)) { 9316 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) 9317 if (!Method->isStatic()) { 9318 // If the target type is a non-function type and the function found 9319 // is a non-static member function, pretend as if that was the 9320 // target, it's the only possible type to end up with. 9321 TargetTypeIsNonStaticMemberFunction = true; 9322 9323 // And skip adding the function if its not in the proper form. 9324 // We'll diagnose this due to an empty set of functions. 9325 if (!OvlExprInfo.HasFormOfMemberPointer) 9326 return; 9327 } 9328 9329 Matches.push_back(std::make_pair(dap, Fn)); 9330 } 9331 return; 9332 } 9333 9334 if (OvlExpr->hasExplicitTemplateArgs()) 9335 OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); 9336 9337 if (FindAllFunctionsThatMatchTargetTypeExactly()) { 9338 // C++ [over.over]p4: 9339 // If more than one function is selected, [...] 9340 if (Matches.size() > 1) { 9341 if (FoundNonTemplateFunction) 9342 EliminateAllTemplateMatches(); 9343 else 9344 EliminateAllExceptMostSpecializedTemplate(); 9345 } 9346 } 9347 } 9348 9349private: 9350 bool isTargetTypeAFunction() const { 9351 return TargetFunctionType->isFunctionType(); 9352 } 9353 9354 // [ToType] [Return] 9355 9356 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false 9357 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false 9358 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true 9359 void inline ExtractUnqualifiedFunctionTypeFromTargetType() { 9360 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); 9361 } 9362 9363 // return true if any matching specializations were found 9364 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, 9365 const DeclAccessPair& CurAccessFunPair) { 9366 if (CXXMethodDecl *Method 9367 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 9368 // Skip non-static function templates when converting to pointer, and 9369 // static when converting to member pointer. 9370 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 9371 return false; 9372 } 9373 else if (TargetTypeIsNonStaticMemberFunction) 9374 return false; 9375 9376 // C++ [over.over]p2: 9377 // If the name is a function template, template argument deduction is 9378 // done (14.8.2.2), and if the argument deduction succeeds, the 9379 // resulting template argument list is used to generate a single 9380 // function template specialization, which is added to the set of 9381 // overloaded functions considered. 9382 FunctionDecl *Specialization = 0; 9383 TemplateDeductionInfo Info(FailedCandidates.getLocation()); 9384 if (Sema::TemplateDeductionResult Result 9385 = S.DeduceTemplateArguments(FunctionTemplate, 9386 &OvlExplicitTemplateArgs, 9387 TargetFunctionType, Specialization, 9388 Info, /*InOverloadResolution=*/true)) { 9389 // Make a note of the failed deduction for diagnostics. 9390 FailedCandidates.addCandidate() 9391 .set(FunctionTemplate->getTemplatedDecl(), 9392 MakeDeductionFailureInfo(Context, Result, Info)); 9393 (void)Result; 9394 return false; 9395 } 9396 9397 // Template argument deduction ensures that we have an exact match or 9398 // compatible pointer-to-function arguments that would be adjusted by ICS. 9399 // This function template specicalization works. 9400 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 9401 assert(S.isSameOrCompatibleFunctionType( 9402 Context.getCanonicalType(Specialization->getType()), 9403 Context.getCanonicalType(TargetFunctionType))); 9404 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); 9405 return true; 9406 } 9407 9408 bool AddMatchingNonTemplateFunction(NamedDecl* Fn, 9409 const DeclAccessPair& CurAccessFunPair) { 9410 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 9411 // Skip non-static functions when converting to pointer, and static 9412 // when converting to member pointer. 9413 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 9414 return false; 9415 } 9416 else if (TargetTypeIsNonStaticMemberFunction) 9417 return false; 9418 9419 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 9420 if (S.getLangOpts().CUDA) 9421 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext)) 9422 if (S.CheckCUDATarget(Caller, FunDecl)) 9423 return false; 9424 9425 // If any candidate has a placeholder return type, trigger its deduction 9426 // now. 9427 if (S.getLangOpts().CPlusPlus1y && 9428 FunDecl->getResultType()->isUndeducedType() && 9429 S.DeduceReturnType(FunDecl, SourceExpr->getLocStart(), Complain)) 9430 return false; 9431 9432 QualType ResultTy; 9433 if (Context.hasSameUnqualifiedType(TargetFunctionType, 9434 FunDecl->getType()) || 9435 S.IsNoReturnConversion(FunDecl->getType(), TargetFunctionType, 9436 ResultTy)) { 9437 Matches.push_back(std::make_pair(CurAccessFunPair, 9438 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 9439 FoundNonTemplateFunction = true; 9440 return true; 9441 } 9442 } 9443 9444 return false; 9445 } 9446 9447 bool FindAllFunctionsThatMatchTargetTypeExactly() { 9448 bool Ret = false; 9449 9450 // If the overload expression doesn't have the form of a pointer to 9451 // member, don't try to convert it to a pointer-to-member type. 9452 if (IsInvalidFormOfPointerToMemberFunction()) 9453 return false; 9454 9455 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 9456 E = OvlExpr->decls_end(); 9457 I != E; ++I) { 9458 // Look through any using declarations to find the underlying function. 9459 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 9460 9461 // C++ [over.over]p3: 9462 // Non-member functions and static member functions match 9463 // targets of type "pointer-to-function" or "reference-to-function." 9464 // Nonstatic member functions match targets of 9465 // type "pointer-to-member-function." 9466 // Note that according to DR 247, the containing class does not matter. 9467 if (FunctionTemplateDecl *FunctionTemplate 9468 = dyn_cast<FunctionTemplateDecl>(Fn)) { 9469 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) 9470 Ret = true; 9471 } 9472 // If we have explicit template arguments supplied, skip non-templates. 9473 else if (!OvlExpr->hasExplicitTemplateArgs() && 9474 AddMatchingNonTemplateFunction(Fn, I.getPair())) 9475 Ret = true; 9476 } 9477 assert(Ret || Matches.empty()); 9478 return Ret; 9479 } 9480 9481 void EliminateAllExceptMostSpecializedTemplate() { 9482 // [...] and any given function template specialization F1 is 9483 // eliminated if the set contains a second function template 9484 // specialization whose function template is more specialized 9485 // than the function template of F1 according to the partial 9486 // ordering rules of 14.5.5.2. 9487 9488 // The algorithm specified above is quadratic. We instead use a 9489 // two-pass algorithm (similar to the one used to identify the 9490 // best viable function in an overload set) that identifies the 9491 // best function template (if it exists). 9492 9493 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 9494 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 9495 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 9496 9497 // TODO: It looks like FailedCandidates does not serve much purpose 9498 // here, since the no_viable diagnostic has index 0. 9499 UnresolvedSetIterator Result = S.getMostSpecialized( 9500 MatchesCopy.begin(), MatchesCopy.end(), FailedCandidates, TPOC_Other, 0, 9501 SourceExpr->getLocStart(), S.PDiag(), 9502 S.PDiag(diag::err_addr_ovl_ambiguous) << Matches[0] 9503 .second->getDeclName(), 9504 S.PDiag(diag::note_ovl_candidate) << (unsigned)oc_function_template, 9505 Complain, TargetFunctionType); 9506 9507 if (Result != MatchesCopy.end()) { 9508 // Make it the first and only element 9509 Matches[0].first = Matches[Result - MatchesCopy.begin()].first; 9510 Matches[0].second = cast<FunctionDecl>(*Result); 9511 Matches.resize(1); 9512 } 9513 } 9514 9515 void EliminateAllTemplateMatches() { 9516 // [...] any function template specializations in the set are 9517 // eliminated if the set also contains a non-template function, [...] 9518 for (unsigned I = 0, N = Matches.size(); I != N; ) { 9519 if (Matches[I].second->getPrimaryTemplate() == 0) 9520 ++I; 9521 else { 9522 Matches[I] = Matches[--N]; 9523 Matches.set_size(N); 9524 } 9525 } 9526 } 9527 9528public: 9529 void ComplainNoMatchesFound() const { 9530 assert(Matches.empty()); 9531 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) 9532 << OvlExpr->getName() << TargetFunctionType 9533 << OvlExpr->getSourceRange(); 9534 FailedCandidates.NoteCandidates(S, OvlExpr->getLocStart()); 9535 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); 9536 } 9537 9538 bool IsInvalidFormOfPointerToMemberFunction() const { 9539 return TargetTypeIsNonStaticMemberFunction && 9540 !OvlExprInfo.HasFormOfMemberPointer; 9541 } 9542 9543 void ComplainIsInvalidFormOfPointerToMemberFunction() const { 9544 // TODO: Should we condition this on whether any functions might 9545 // have matched, or is it more appropriate to do that in callers? 9546 // TODO: a fixit wouldn't hurt. 9547 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 9548 << TargetType << OvlExpr->getSourceRange(); 9549 } 9550 9551 bool IsStaticMemberFunctionFromBoundPointer() const { 9552 return StaticMemberFunctionFromBoundPointer; 9553 } 9554 9555 void ComplainIsStaticMemberFunctionFromBoundPointer() const { 9556 S.Diag(OvlExpr->getLocStart(), 9557 diag::err_invalid_form_pointer_member_function) 9558 << OvlExpr->getSourceRange(); 9559 } 9560 9561 void ComplainOfInvalidConversion() const { 9562 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 9563 << OvlExpr->getName() << TargetType; 9564 } 9565 9566 void ComplainMultipleMatchesFound() const { 9567 assert(Matches.size() > 1); 9568 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) 9569 << OvlExpr->getName() 9570 << OvlExpr->getSourceRange(); 9571 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); 9572 } 9573 9574 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); } 9575 9576 int getNumMatches() const { return Matches.size(); } 9577 9578 FunctionDecl* getMatchingFunctionDecl() const { 9579 if (Matches.size() != 1) return 0; 9580 return Matches[0].second; 9581 } 9582 9583 const DeclAccessPair* getMatchingFunctionAccessPair() const { 9584 if (Matches.size() != 1) return 0; 9585 return &Matches[0].first; 9586 } 9587}; 9588 9589/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 9590/// an overloaded function (C++ [over.over]), where @p From is an 9591/// expression with overloaded function type and @p ToType is the type 9592/// we're trying to resolve to. For example: 9593/// 9594/// @code 9595/// int f(double); 9596/// int f(int); 9597/// 9598/// int (*pfd)(double) = f; // selects f(double) 9599/// @endcode 9600/// 9601/// This routine returns the resulting FunctionDecl if it could be 9602/// resolved, and NULL otherwise. When @p Complain is true, this 9603/// routine will emit diagnostics if there is an error. 9604FunctionDecl * 9605Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, 9606 QualType TargetType, 9607 bool Complain, 9608 DeclAccessPair &FoundResult, 9609 bool *pHadMultipleCandidates) { 9610 assert(AddressOfExpr->getType() == Context.OverloadTy); 9611 9612 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, 9613 Complain); 9614 int NumMatches = Resolver.getNumMatches(); 9615 FunctionDecl* Fn = 0; 9616 if (NumMatches == 0 && Complain) { 9617 if (Resolver.IsInvalidFormOfPointerToMemberFunction()) 9618 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); 9619 else 9620 Resolver.ComplainNoMatchesFound(); 9621 } 9622 else if (NumMatches > 1 && Complain) 9623 Resolver.ComplainMultipleMatchesFound(); 9624 else if (NumMatches == 1) { 9625 Fn = Resolver.getMatchingFunctionDecl(); 9626 assert(Fn); 9627 FoundResult = *Resolver.getMatchingFunctionAccessPair(); 9628 if (Complain) { 9629 if (Resolver.IsStaticMemberFunctionFromBoundPointer()) 9630 Resolver.ComplainIsStaticMemberFunctionFromBoundPointer(); 9631 else 9632 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); 9633 } 9634 } 9635 9636 if (pHadMultipleCandidates) 9637 *pHadMultipleCandidates = Resolver.hadMultipleCandidates(); 9638 return Fn; 9639} 9640 9641/// \brief Given an expression that refers to an overloaded function, try to 9642/// resolve that overloaded function expression down to a single function. 9643/// 9644/// This routine can only resolve template-ids that refer to a single function 9645/// template, where that template-id refers to a single template whose template 9646/// arguments are either provided by the template-id or have defaults, 9647/// as described in C++0x [temp.arg.explicit]p3. 9648FunctionDecl * 9649Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl, 9650 bool Complain, 9651 DeclAccessPair *FoundResult) { 9652 // C++ [over.over]p1: 9653 // [...] [Note: any redundant set of parentheses surrounding the 9654 // overloaded function name is ignored (5.1). ] 9655 // C++ [over.over]p1: 9656 // [...] The overloaded function name can be preceded by the & 9657 // operator. 9658 9659 // If we didn't actually find any template-ids, we're done. 9660 if (!ovl->hasExplicitTemplateArgs()) 9661 return 0; 9662 9663 TemplateArgumentListInfo ExplicitTemplateArgs; 9664 ovl->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 9665 TemplateSpecCandidateSet FailedCandidates(ovl->getNameLoc()); 9666 9667 // Look through all of the overloaded functions, searching for one 9668 // whose type matches exactly. 9669 FunctionDecl *Matched = 0; 9670 for (UnresolvedSetIterator I = ovl->decls_begin(), 9671 E = ovl->decls_end(); I != E; ++I) { 9672 // C++0x [temp.arg.explicit]p3: 9673 // [...] In contexts where deduction is done and fails, or in contexts 9674 // where deduction is not done, if a template argument list is 9675 // specified and it, along with any default template arguments, 9676 // identifies a single function template specialization, then the 9677 // template-id is an lvalue for the function template specialization. 9678 FunctionTemplateDecl *FunctionTemplate 9679 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 9680 9681 // C++ [over.over]p2: 9682 // If the name is a function template, template argument deduction is 9683 // done (14.8.2.2), and if the argument deduction succeeds, the 9684 // resulting template argument list is used to generate a single 9685 // function template specialization, which is added to the set of 9686 // overloaded functions considered. 9687 FunctionDecl *Specialization = 0; 9688 TemplateDeductionInfo Info(FailedCandidates.getLocation()); 9689 if (TemplateDeductionResult Result 9690 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 9691 Specialization, Info, 9692 /*InOverloadResolution=*/true)) { 9693 // Make a note of the failed deduction for diagnostics. 9694 // TODO: Actually use the failed-deduction info? 9695 FailedCandidates.addCandidate() 9696 .set(FunctionTemplate->getTemplatedDecl(), 9697 MakeDeductionFailureInfo(Context, Result, Info)); 9698 (void)Result; 9699 continue; 9700 } 9701 9702 assert(Specialization && "no specialization and no error?"); 9703 9704 // Multiple matches; we can't resolve to a single declaration. 9705 if (Matched) { 9706 if (Complain) { 9707 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous) 9708 << ovl->getName(); 9709 NoteAllOverloadCandidates(ovl); 9710 } 9711 return 0; 9712 } 9713 9714 Matched = Specialization; 9715 if (FoundResult) *FoundResult = I.getPair(); 9716 } 9717 9718 if (Matched && getLangOpts().CPlusPlus1y && 9719 Matched->getResultType()->isUndeducedType() && 9720 DeduceReturnType(Matched, ovl->getExprLoc(), Complain)) 9721 return 0; 9722 9723 return Matched; 9724} 9725 9726 9727 9728 9729// Resolve and fix an overloaded expression that can be resolved 9730// because it identifies a single function template specialization. 9731// 9732// Last three arguments should only be supplied if Complain = true 9733// 9734// Return true if it was logically possible to so resolve the 9735// expression, regardless of whether or not it succeeded. Always 9736// returns true if 'complain' is set. 9737bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization( 9738 ExprResult &SrcExpr, bool doFunctionPointerConverion, 9739 bool complain, const SourceRange& OpRangeForComplaining, 9740 QualType DestTypeForComplaining, 9741 unsigned DiagIDForComplaining) { 9742 assert(SrcExpr.get()->getType() == Context.OverloadTy); 9743 9744 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get()); 9745 9746 DeclAccessPair found; 9747 ExprResult SingleFunctionExpression; 9748 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization( 9749 ovl.Expression, /*complain*/ false, &found)) { 9750 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getLocStart())) { 9751 SrcExpr = ExprError(); 9752 return true; 9753 } 9754 9755 // It is only correct to resolve to an instance method if we're 9756 // resolving a form that's permitted to be a pointer to member. 9757 // Otherwise we'll end up making a bound member expression, which 9758 // is illegal in all the contexts we resolve like this. 9759 if (!ovl.HasFormOfMemberPointer && 9760 isa<CXXMethodDecl>(fn) && 9761 cast<CXXMethodDecl>(fn)->isInstance()) { 9762 if (!complain) return false; 9763 9764 Diag(ovl.Expression->getExprLoc(), 9765 diag::err_bound_member_function) 9766 << 0 << ovl.Expression->getSourceRange(); 9767 9768 // TODO: I believe we only end up here if there's a mix of 9769 // static and non-static candidates (otherwise the expression 9770 // would have 'bound member' type, not 'overload' type). 9771 // Ideally we would note which candidate was chosen and why 9772 // the static candidates were rejected. 9773 SrcExpr = ExprError(); 9774 return true; 9775 } 9776 9777 // Fix the expression to refer to 'fn'. 9778 SingleFunctionExpression = 9779 Owned(FixOverloadedFunctionReference(SrcExpr.take(), found, fn)); 9780 9781 // If desired, do function-to-pointer decay. 9782 if (doFunctionPointerConverion) { 9783 SingleFunctionExpression = 9784 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.take()); 9785 if (SingleFunctionExpression.isInvalid()) { 9786 SrcExpr = ExprError(); 9787 return true; 9788 } 9789 } 9790 } 9791 9792 if (!SingleFunctionExpression.isUsable()) { 9793 if (complain) { 9794 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) 9795 << ovl.Expression->getName() 9796 << DestTypeForComplaining 9797 << OpRangeForComplaining 9798 << ovl.Expression->getQualifierLoc().getSourceRange(); 9799 NoteAllOverloadCandidates(SrcExpr.get()); 9800 9801 SrcExpr = ExprError(); 9802 return true; 9803 } 9804 9805 return false; 9806 } 9807 9808 SrcExpr = SingleFunctionExpression; 9809 return true; 9810} 9811 9812/// \brief Add a single candidate to the overload set. 9813static void AddOverloadedCallCandidate(Sema &S, 9814 DeclAccessPair FoundDecl, 9815 TemplateArgumentListInfo *ExplicitTemplateArgs, 9816 ArrayRef<Expr *> Args, 9817 OverloadCandidateSet &CandidateSet, 9818 bool PartialOverloading, 9819 bool KnownValid) { 9820 NamedDecl *Callee = FoundDecl.getDecl(); 9821 if (isa<UsingShadowDecl>(Callee)) 9822 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 9823 9824 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 9825 if (ExplicitTemplateArgs) { 9826 assert(!KnownValid && "Explicit template arguments?"); 9827 return; 9828 } 9829 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet, false, 9830 PartialOverloading); 9831 return; 9832 } 9833 9834 if (FunctionTemplateDecl *FuncTemplate 9835 = dyn_cast<FunctionTemplateDecl>(Callee)) { 9836 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 9837 ExplicitTemplateArgs, Args, CandidateSet); 9838 return; 9839 } 9840 9841 assert(!KnownValid && "unhandled case in overloaded call candidate"); 9842} 9843 9844/// \brief Add the overload candidates named by callee and/or found by argument 9845/// dependent lookup to the given overload set. 9846void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 9847 ArrayRef<Expr *> Args, 9848 OverloadCandidateSet &CandidateSet, 9849 bool PartialOverloading) { 9850 9851#ifndef NDEBUG 9852 // Verify that ArgumentDependentLookup is consistent with the rules 9853 // in C++0x [basic.lookup.argdep]p3: 9854 // 9855 // Let X be the lookup set produced by unqualified lookup (3.4.1) 9856 // and let Y be the lookup set produced by argument dependent 9857 // lookup (defined as follows). If X contains 9858 // 9859 // -- a declaration of a class member, or 9860 // 9861 // -- a block-scope function declaration that is not a 9862 // using-declaration, or 9863 // 9864 // -- a declaration that is neither a function or a function 9865 // template 9866 // 9867 // then Y is empty. 9868 9869 if (ULE->requiresADL()) { 9870 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 9871 E = ULE->decls_end(); I != E; ++I) { 9872 assert(!(*I)->getDeclContext()->isRecord()); 9873 assert(isa<UsingShadowDecl>(*I) || 9874 !(*I)->getDeclContext()->isFunctionOrMethod()); 9875 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 9876 } 9877 } 9878#endif 9879 9880 // It would be nice to avoid this copy. 9881 TemplateArgumentListInfo TABuffer; 9882 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 9883 if (ULE->hasExplicitTemplateArgs()) { 9884 ULE->copyTemplateArgumentsInto(TABuffer); 9885 ExplicitTemplateArgs = &TABuffer; 9886 } 9887 9888 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 9889 E = ULE->decls_end(); I != E; ++I) 9890 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args, 9891 CandidateSet, PartialOverloading, 9892 /*KnownValid*/ true); 9893 9894 if (ULE->requiresADL()) 9895 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 9896 ULE->getExprLoc(), 9897 Args, ExplicitTemplateArgs, 9898 CandidateSet, PartialOverloading); 9899} 9900 9901/// Determine whether a declaration with the specified name could be moved into 9902/// a different namespace. 9903static bool canBeDeclaredInNamespace(const DeclarationName &Name) { 9904 switch (Name.getCXXOverloadedOperator()) { 9905 case OO_New: case OO_Array_New: 9906 case OO_Delete: case OO_Array_Delete: 9907 return false; 9908 9909 default: 9910 return true; 9911 } 9912} 9913 9914/// Attempt to recover from an ill-formed use of a non-dependent name in a 9915/// template, where the non-dependent name was declared after the template 9916/// was defined. This is common in code written for a compilers which do not 9917/// correctly implement two-stage name lookup. 9918/// 9919/// Returns true if a viable candidate was found and a diagnostic was issued. 9920static bool 9921DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc, 9922 const CXXScopeSpec &SS, LookupResult &R, 9923 TemplateArgumentListInfo *ExplicitTemplateArgs, 9924 ArrayRef<Expr *> Args) { 9925 if (SemaRef.ActiveTemplateInstantiations.empty() || !SS.isEmpty()) 9926 return false; 9927 9928 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) { 9929 if (DC->isTransparentContext()) 9930 continue; 9931 9932 SemaRef.LookupQualifiedName(R, DC); 9933 9934 if (!R.empty()) { 9935 R.suppressDiagnostics(); 9936 9937 if (isa<CXXRecordDecl>(DC)) { 9938 // Don't diagnose names we find in classes; we get much better 9939 // diagnostics for these from DiagnoseEmptyLookup. 9940 R.clear(); 9941 return false; 9942 } 9943 9944 OverloadCandidateSet Candidates(FnLoc); 9945 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 9946 AddOverloadedCallCandidate(SemaRef, I.getPair(), 9947 ExplicitTemplateArgs, Args, 9948 Candidates, false, /*KnownValid*/ false); 9949 9950 OverloadCandidateSet::iterator Best; 9951 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) { 9952 // No viable functions. Don't bother the user with notes for functions 9953 // which don't work and shouldn't be found anyway. 9954 R.clear(); 9955 return false; 9956 } 9957 9958 // Find the namespaces where ADL would have looked, and suggest 9959 // declaring the function there instead. 9960 Sema::AssociatedNamespaceSet AssociatedNamespaces; 9961 Sema::AssociatedClassSet AssociatedClasses; 9962 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args, 9963 AssociatedNamespaces, 9964 AssociatedClasses); 9965 Sema::AssociatedNamespaceSet SuggestedNamespaces; 9966 if (canBeDeclaredInNamespace(R.getLookupName())) { 9967 DeclContext *Std = SemaRef.getStdNamespace(); 9968 for (Sema::AssociatedNamespaceSet::iterator 9969 it = AssociatedNamespaces.begin(), 9970 end = AssociatedNamespaces.end(); it != end; ++it) { 9971 // Never suggest declaring a function within namespace 'std'. 9972 if (Std && Std->Encloses(*it)) 9973 continue; 9974 9975 // Never suggest declaring a function within a namespace with a 9976 // reserved name, like __gnu_cxx. 9977 NamespaceDecl *NS = dyn_cast<NamespaceDecl>(*it); 9978 if (NS && 9979 NS->getQualifiedNameAsString().find("__") != std::string::npos) 9980 continue; 9981 9982 SuggestedNamespaces.insert(*it); 9983 } 9984 } 9985 9986 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup) 9987 << R.getLookupName(); 9988 if (SuggestedNamespaces.empty()) { 9989 SemaRef.Diag(Best->Function->getLocation(), 9990 diag::note_not_found_by_two_phase_lookup) 9991 << R.getLookupName() << 0; 9992 } else if (SuggestedNamespaces.size() == 1) { 9993 SemaRef.Diag(Best->Function->getLocation(), 9994 diag::note_not_found_by_two_phase_lookup) 9995 << R.getLookupName() << 1 << *SuggestedNamespaces.begin(); 9996 } else { 9997 // FIXME: It would be useful to list the associated namespaces here, 9998 // but the diagnostics infrastructure doesn't provide a way to produce 9999 // a localized representation of a list of items. 10000 SemaRef.Diag(Best->Function->getLocation(), 10001 diag::note_not_found_by_two_phase_lookup) 10002 << R.getLookupName() << 2; 10003 } 10004 10005 // Try to recover by calling this function. 10006 return true; 10007 } 10008 10009 R.clear(); 10010 } 10011 10012 return false; 10013} 10014 10015/// Attempt to recover from ill-formed use of a non-dependent operator in a 10016/// template, where the non-dependent operator was declared after the template 10017/// was defined. 10018/// 10019/// Returns true if a viable candidate was found and a diagnostic was issued. 10020static bool 10021DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op, 10022 SourceLocation OpLoc, 10023 ArrayRef<Expr *> Args) { 10024 DeclarationName OpName = 10025 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op); 10026 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName); 10027 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R, 10028 /*ExplicitTemplateArgs=*/0, Args); 10029} 10030 10031namespace { 10032class BuildRecoveryCallExprRAII { 10033 Sema &SemaRef; 10034public: 10035 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) { 10036 assert(SemaRef.IsBuildingRecoveryCallExpr == false); 10037 SemaRef.IsBuildingRecoveryCallExpr = true; 10038 } 10039 10040 ~BuildRecoveryCallExprRAII() { 10041 SemaRef.IsBuildingRecoveryCallExpr = false; 10042 } 10043}; 10044 10045} 10046 10047/// Attempts to recover from a call where no functions were found. 10048/// 10049/// Returns true if new candidates were found. 10050static ExprResult 10051BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 10052 UnresolvedLookupExpr *ULE, 10053 SourceLocation LParenLoc, 10054 llvm::MutableArrayRef<Expr *> Args, 10055 SourceLocation RParenLoc, 10056 bool EmptyLookup, bool AllowTypoCorrection) { 10057 // Do not try to recover if it is already building a recovery call. 10058 // This stops infinite loops for template instantiations like 10059 // 10060 // template <typename T> auto foo(T t) -> decltype(foo(t)) {} 10061 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {} 10062 // 10063 if (SemaRef.IsBuildingRecoveryCallExpr) 10064 return ExprError(); 10065 BuildRecoveryCallExprRAII RCE(SemaRef); 10066 10067 CXXScopeSpec SS; 10068 SS.Adopt(ULE->getQualifierLoc()); 10069 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc(); 10070 10071 TemplateArgumentListInfo TABuffer; 10072 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 10073 if (ULE->hasExplicitTemplateArgs()) { 10074 ULE->copyTemplateArgumentsInto(TABuffer); 10075 ExplicitTemplateArgs = &TABuffer; 10076 } 10077 10078 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 10079 Sema::LookupOrdinaryName); 10080 FunctionCallFilterCCC Validator(SemaRef, Args.size(), 10081 ExplicitTemplateArgs != 0); 10082 NoTypoCorrectionCCC RejectAll; 10083 CorrectionCandidateCallback *CCC = AllowTypoCorrection ? 10084 (CorrectionCandidateCallback*)&Validator : 10085 (CorrectionCandidateCallback*)&RejectAll; 10086 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R, 10087 ExplicitTemplateArgs, Args) && 10088 (!EmptyLookup || 10089 SemaRef.DiagnoseEmptyLookup(S, SS, R, *CCC, 10090 ExplicitTemplateArgs, Args))) 10091 return ExprError(); 10092 10093 assert(!R.empty() && "lookup results empty despite recovery"); 10094 10095 // Build an implicit member call if appropriate. Just drop the 10096 // casts and such from the call, we don't really care. 10097 ExprResult NewFn = ExprError(); 10098 if ((*R.begin())->isCXXClassMember()) 10099 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, 10100 R, ExplicitTemplateArgs); 10101 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid()) 10102 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false, 10103 ExplicitTemplateArgs); 10104 else 10105 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 10106 10107 if (NewFn.isInvalid()) 10108 return ExprError(); 10109 10110 // This shouldn't cause an infinite loop because we're giving it 10111 // an expression with viable lookup results, which should never 10112 // end up here. 10113 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 10114 MultiExprArg(Args.data(), Args.size()), 10115 RParenLoc); 10116} 10117 10118/// \brief Constructs and populates an OverloadedCandidateSet from 10119/// the given function. 10120/// \returns true when an the ExprResult output parameter has been set. 10121bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn, 10122 UnresolvedLookupExpr *ULE, 10123 MultiExprArg Args, 10124 SourceLocation RParenLoc, 10125 OverloadCandidateSet *CandidateSet, 10126 ExprResult *Result) { 10127#ifndef NDEBUG 10128 if (ULE->requiresADL()) { 10129 // To do ADL, we must have found an unqualified name. 10130 assert(!ULE->getQualifier() && "qualified name with ADL"); 10131 10132 // We don't perform ADL for implicit declarations of builtins. 10133 // Verify that this was correctly set up. 10134 FunctionDecl *F; 10135 if (ULE->decls_begin() + 1 == ULE->decls_end() && 10136 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 10137 F->getBuiltinID() && F->isImplicit()) 10138 llvm_unreachable("performing ADL for builtin"); 10139 10140 // We don't perform ADL in C. 10141 assert(getLangOpts().CPlusPlus && "ADL enabled in C"); 10142 } 10143#endif 10144 10145 UnbridgedCastsSet UnbridgedCasts; 10146 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) { 10147 *Result = ExprError(); 10148 return true; 10149 } 10150 10151 // Add the functions denoted by the callee to the set of candidate 10152 // functions, including those from argument-dependent lookup. 10153 AddOverloadedCallCandidates(ULE, Args, *CandidateSet); 10154 10155 // If we found nothing, try to recover. 10156 // BuildRecoveryCallExpr diagnoses the error itself, so we just bail 10157 // out if it fails. 10158 if (CandidateSet->empty()) { 10159 // In Microsoft mode, if we are inside a template class member function then 10160 // create a type dependent CallExpr. The goal is to postpone name lookup 10161 // to instantiation time to be able to search into type dependent base 10162 // classes. 10163 if (getLangOpts().MicrosoftMode && CurContext->isDependentContext() && 10164 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) { 10165 CallExpr *CE = new (Context) CallExpr(Context, Fn, Args, 10166 Context.DependentTy, VK_RValue, 10167 RParenLoc); 10168 CE->setTypeDependent(true); 10169 *Result = Owned(CE); 10170 return true; 10171 } 10172 return false; 10173 } 10174 10175 UnbridgedCasts.restore(); 10176 return false; 10177} 10178 10179/// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns 10180/// the completed call expression. If overload resolution fails, emits 10181/// diagnostics and returns ExprError() 10182static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 10183 UnresolvedLookupExpr *ULE, 10184 SourceLocation LParenLoc, 10185 MultiExprArg Args, 10186 SourceLocation RParenLoc, 10187 Expr *ExecConfig, 10188 OverloadCandidateSet *CandidateSet, 10189 OverloadCandidateSet::iterator *Best, 10190 OverloadingResult OverloadResult, 10191 bool AllowTypoCorrection) { 10192 if (CandidateSet->empty()) 10193 return BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, Args, 10194 RParenLoc, /*EmptyLookup=*/true, 10195 AllowTypoCorrection); 10196 10197 switch (OverloadResult) { 10198 case OR_Success: { 10199 FunctionDecl *FDecl = (*Best)->Function; 10200 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl); 10201 if (SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc())) 10202 return ExprError(); 10203 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl); 10204 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc, 10205 ExecConfig); 10206 } 10207 10208 case OR_No_Viable_Function: { 10209 // Try to recover by looking for viable functions which the user might 10210 // have meant to call. 10211 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, 10212 Args, RParenLoc, 10213 /*EmptyLookup=*/false, 10214 AllowTypoCorrection); 10215 if (!Recovery.isInvalid()) 10216 return Recovery; 10217 10218 SemaRef.Diag(Fn->getLocStart(), 10219 diag::err_ovl_no_viable_function_in_call) 10220 << ULE->getName() << Fn->getSourceRange(); 10221 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args); 10222 break; 10223 } 10224 10225 case OR_Ambiguous: 10226 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_ambiguous_call) 10227 << ULE->getName() << Fn->getSourceRange(); 10228 CandidateSet->NoteCandidates(SemaRef, OCD_ViableCandidates, Args); 10229 break; 10230 10231 case OR_Deleted: { 10232 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_deleted_call) 10233 << (*Best)->Function->isDeleted() 10234 << ULE->getName() 10235 << SemaRef.getDeletedOrUnavailableSuffix((*Best)->Function) 10236 << Fn->getSourceRange(); 10237 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args); 10238 10239 // We emitted an error for the unvailable/deleted function call but keep 10240 // the call in the AST. 10241 FunctionDecl *FDecl = (*Best)->Function; 10242 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl); 10243 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc, 10244 ExecConfig); 10245 } 10246 } 10247 10248 // Overload resolution failed. 10249 return ExprError(); 10250} 10251 10252/// BuildOverloadedCallExpr - Given the call expression that calls Fn 10253/// (which eventually refers to the declaration Func) and the call 10254/// arguments Args/NumArgs, attempt to resolve the function call down 10255/// to a specific function. If overload resolution succeeds, returns 10256/// the call expression produced by overload resolution. 10257/// Otherwise, emits diagnostics and returns ExprError. 10258ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, 10259 UnresolvedLookupExpr *ULE, 10260 SourceLocation LParenLoc, 10261 MultiExprArg Args, 10262 SourceLocation RParenLoc, 10263 Expr *ExecConfig, 10264 bool AllowTypoCorrection) { 10265 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 10266 ExprResult result; 10267 10268 if (buildOverloadedCallSet(S, Fn, ULE, Args, LParenLoc, &CandidateSet, 10269 &result)) 10270 return result; 10271 10272 OverloadCandidateSet::iterator Best; 10273 OverloadingResult OverloadResult = 10274 CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best); 10275 10276 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args, 10277 RParenLoc, ExecConfig, &CandidateSet, 10278 &Best, OverloadResult, 10279 AllowTypoCorrection); 10280} 10281 10282static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 10283 return Functions.size() > 1 || 10284 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 10285} 10286 10287/// \brief Create a unary operation that may resolve to an overloaded 10288/// operator. 10289/// 10290/// \param OpLoc The location of the operator itself (e.g., '*'). 10291/// 10292/// \param OpcIn The UnaryOperator::Opcode that describes this 10293/// operator. 10294/// 10295/// \param Fns The set of non-member functions that will be 10296/// considered by overload resolution. The caller needs to build this 10297/// set based on the context using, e.g., 10298/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 10299/// set should not contain any member functions; those will be added 10300/// by CreateOverloadedUnaryOp(). 10301/// 10302/// \param Input The input argument. 10303ExprResult 10304Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 10305 const UnresolvedSetImpl &Fns, 10306 Expr *Input) { 10307 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 10308 10309 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 10310 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 10311 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 10312 // TODO: provide better source location info. 10313 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 10314 10315 if (checkPlaceholderForOverload(*this, Input)) 10316 return ExprError(); 10317 10318 Expr *Args[2] = { Input, 0 }; 10319 unsigned NumArgs = 1; 10320 10321 // For post-increment and post-decrement, add the implicit '0' as 10322 // the second argument, so that we know this is a post-increment or 10323 // post-decrement. 10324 if (Opc == UO_PostInc || Opc == UO_PostDec) { 10325 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 10326 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 10327 SourceLocation()); 10328 NumArgs = 2; 10329 } 10330 10331 ArrayRef<Expr *> ArgsArray(Args, NumArgs); 10332 10333 if (Input->isTypeDependent()) { 10334 if (Fns.empty()) 10335 return Owned(new (Context) UnaryOperator(Input, 10336 Opc, 10337 Context.DependentTy, 10338 VK_RValue, OK_Ordinary, 10339 OpLoc)); 10340 10341 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10342 UnresolvedLookupExpr *Fn 10343 = UnresolvedLookupExpr::Create(Context, NamingClass, 10344 NestedNameSpecifierLoc(), OpNameInfo, 10345 /*ADL*/ true, IsOverloaded(Fns), 10346 Fns.begin(), Fns.end()); 10347 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, ArgsArray, 10348 Context.DependentTy, 10349 VK_RValue, 10350 OpLoc, false)); 10351 } 10352 10353 // Build an empty overload set. 10354 OverloadCandidateSet CandidateSet(OpLoc); 10355 10356 // Add the candidates from the given function set. 10357 AddFunctionCandidates(Fns, ArgsArray, CandidateSet, false); 10358 10359 // Add operator candidates that are member functions. 10360 AddMemberOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet); 10361 10362 // Add candidates from ADL. 10363 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, OpLoc, 10364 ArgsArray, /*ExplicitTemplateArgs*/ 0, 10365 CandidateSet); 10366 10367 // Add builtin operator candidates. 10368 AddBuiltinOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet); 10369 10370 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10371 10372 // Perform overload resolution. 10373 OverloadCandidateSet::iterator Best; 10374 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 10375 case OR_Success: { 10376 // We found a built-in operator or an overloaded operator. 10377 FunctionDecl *FnDecl = Best->Function; 10378 10379 if (FnDecl) { 10380 // We matched an overloaded operator. Build a call to that 10381 // operator. 10382 10383 // Convert the arguments. 10384 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 10385 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 10386 10387 ExprResult InputRes = 10388 PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 10389 Best->FoundDecl, Method); 10390 if (InputRes.isInvalid()) 10391 return ExprError(); 10392 Input = InputRes.take(); 10393 } else { 10394 // Convert the arguments. 10395 ExprResult InputInit 10396 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 10397 Context, 10398 FnDecl->getParamDecl(0)), 10399 SourceLocation(), 10400 Input); 10401 if (InputInit.isInvalid()) 10402 return ExprError(); 10403 Input = InputInit.take(); 10404 } 10405 10406 // Determine the result type. 10407 QualType ResultTy = FnDecl->getResultType(); 10408 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10409 ResultTy = ResultTy.getNonLValueExprType(Context); 10410 10411 // Build the actual expression node. 10412 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, Best->FoundDecl, 10413 HadMultipleCandidates, OpLoc); 10414 if (FnExpr.isInvalid()) 10415 return ExprError(); 10416 10417 Args[0] = Input; 10418 CallExpr *TheCall = 10419 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), ArgsArray, 10420 ResultTy, VK, OpLoc, false); 10421 10422 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 10423 FnDecl)) 10424 return ExprError(); 10425 10426 return MaybeBindToTemporary(TheCall); 10427 } else { 10428 // We matched a built-in operator. Convert the arguments, then 10429 // break out so that we will build the appropriate built-in 10430 // operator node. 10431 ExprResult InputRes = 10432 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 10433 Best->Conversions[0], AA_Passing); 10434 if (InputRes.isInvalid()) 10435 return ExprError(); 10436 Input = InputRes.take(); 10437 break; 10438 } 10439 } 10440 10441 case OR_No_Viable_Function: 10442 // This is an erroneous use of an operator which can be overloaded by 10443 // a non-member function. Check for non-member operators which were 10444 // defined too late to be candidates. 10445 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, ArgsArray)) 10446 // FIXME: Recover by calling the found function. 10447 return ExprError(); 10448 10449 // No viable function; fall through to handling this as a 10450 // built-in operator, which will produce an error message for us. 10451 break; 10452 10453 case OR_Ambiguous: 10454 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 10455 << UnaryOperator::getOpcodeStr(Opc) 10456 << Input->getType() 10457 << Input->getSourceRange(); 10458 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, ArgsArray, 10459 UnaryOperator::getOpcodeStr(Opc), OpLoc); 10460 return ExprError(); 10461 10462 case OR_Deleted: 10463 Diag(OpLoc, diag::err_ovl_deleted_oper) 10464 << Best->Function->isDeleted() 10465 << UnaryOperator::getOpcodeStr(Opc) 10466 << getDeletedOrUnavailableSuffix(Best->Function) 10467 << Input->getSourceRange(); 10468 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, ArgsArray, 10469 UnaryOperator::getOpcodeStr(Opc), OpLoc); 10470 return ExprError(); 10471 } 10472 10473 // Either we found no viable overloaded operator or we matched a 10474 // built-in operator. In either case, fall through to trying to 10475 // build a built-in operation. 10476 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 10477} 10478 10479/// \brief Create a binary operation that may resolve to an overloaded 10480/// operator. 10481/// 10482/// \param OpLoc The location of the operator itself (e.g., '+'). 10483/// 10484/// \param OpcIn The BinaryOperator::Opcode that describes this 10485/// operator. 10486/// 10487/// \param Fns The set of non-member functions that will be 10488/// considered by overload resolution. The caller needs to build this 10489/// set based on the context using, e.g., 10490/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 10491/// set should not contain any member functions; those will be added 10492/// by CreateOverloadedBinOp(). 10493/// 10494/// \param LHS Left-hand argument. 10495/// \param RHS Right-hand argument. 10496ExprResult 10497Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 10498 unsigned OpcIn, 10499 const UnresolvedSetImpl &Fns, 10500 Expr *LHS, Expr *RHS) { 10501 Expr *Args[2] = { LHS, RHS }; 10502 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 10503 10504 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 10505 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 10506 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 10507 10508 // If either side is type-dependent, create an appropriate dependent 10509 // expression. 10510 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 10511 if (Fns.empty()) { 10512 // If there are no functions to store, just build a dependent 10513 // BinaryOperator or CompoundAssignment. 10514 if (Opc <= BO_Assign || Opc > BO_OrAssign) 10515 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 10516 Context.DependentTy, 10517 VK_RValue, OK_Ordinary, 10518 OpLoc, 10519 FPFeatures.fp_contract)); 10520 10521 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 10522 Context.DependentTy, 10523 VK_LValue, 10524 OK_Ordinary, 10525 Context.DependentTy, 10526 Context.DependentTy, 10527 OpLoc, 10528 FPFeatures.fp_contract)); 10529 } 10530 10531 // FIXME: save results of ADL from here? 10532 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10533 // TODO: provide better source location info in DNLoc component. 10534 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 10535 UnresolvedLookupExpr *Fn 10536 = UnresolvedLookupExpr::Create(Context, NamingClass, 10537 NestedNameSpecifierLoc(), OpNameInfo, 10538 /*ADL*/ true, IsOverloaded(Fns), 10539 Fns.begin(), Fns.end()); 10540 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, Args, 10541 Context.DependentTy, VK_RValue, 10542 OpLoc, FPFeatures.fp_contract)); 10543 } 10544 10545 // Always do placeholder-like conversions on the RHS. 10546 if (checkPlaceholderForOverload(*this, Args[1])) 10547 return ExprError(); 10548 10549 // Do placeholder-like conversion on the LHS; note that we should 10550 // not get here with a PseudoObject LHS. 10551 assert(Args[0]->getObjectKind() != OK_ObjCProperty); 10552 if (checkPlaceholderForOverload(*this, Args[0])) 10553 return ExprError(); 10554 10555 // If this is the assignment operator, we only perform overload resolution 10556 // if the left-hand side is a class or enumeration type. This is actually 10557 // a hack. The standard requires that we do overload resolution between the 10558 // various built-in candidates, but as DR507 points out, this can lead to 10559 // problems. So we do it this way, which pretty much follows what GCC does. 10560 // Note that we go the traditional code path for compound assignment forms. 10561 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 10562 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10563 10564 // If this is the .* operator, which is not overloadable, just 10565 // create a built-in binary operator. 10566 if (Opc == BO_PtrMemD) 10567 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10568 10569 // Build an empty overload set. 10570 OverloadCandidateSet CandidateSet(OpLoc); 10571 10572 // Add the candidates from the given function set. 10573 AddFunctionCandidates(Fns, Args, CandidateSet, false); 10574 10575 // Add operator candidates that are member functions. 10576 AddMemberOperatorCandidates(Op, OpLoc, Args, CandidateSet); 10577 10578 // Add candidates from ADL. 10579 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 10580 OpLoc, Args, 10581 /*ExplicitTemplateArgs*/ 0, 10582 CandidateSet); 10583 10584 // Add builtin operator candidates. 10585 AddBuiltinOperatorCandidates(Op, OpLoc, Args, CandidateSet); 10586 10587 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10588 10589 // Perform overload resolution. 10590 OverloadCandidateSet::iterator Best; 10591 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 10592 case OR_Success: { 10593 // We found a built-in operator or an overloaded operator. 10594 FunctionDecl *FnDecl = Best->Function; 10595 10596 if (FnDecl) { 10597 // We matched an overloaded operator. Build a call to that 10598 // operator. 10599 10600 // Convert the arguments. 10601 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 10602 // Best->Access is only meaningful for class members. 10603 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 10604 10605 ExprResult Arg1 = 10606 PerformCopyInitialization( 10607 InitializedEntity::InitializeParameter(Context, 10608 FnDecl->getParamDecl(0)), 10609 SourceLocation(), Owned(Args[1])); 10610 if (Arg1.isInvalid()) 10611 return ExprError(); 10612 10613 ExprResult Arg0 = 10614 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 10615 Best->FoundDecl, Method); 10616 if (Arg0.isInvalid()) 10617 return ExprError(); 10618 Args[0] = Arg0.takeAs<Expr>(); 10619 Args[1] = RHS = Arg1.takeAs<Expr>(); 10620 } else { 10621 // Convert the arguments. 10622 ExprResult Arg0 = PerformCopyInitialization( 10623 InitializedEntity::InitializeParameter(Context, 10624 FnDecl->getParamDecl(0)), 10625 SourceLocation(), Owned(Args[0])); 10626 if (Arg0.isInvalid()) 10627 return ExprError(); 10628 10629 ExprResult Arg1 = 10630 PerformCopyInitialization( 10631 InitializedEntity::InitializeParameter(Context, 10632 FnDecl->getParamDecl(1)), 10633 SourceLocation(), Owned(Args[1])); 10634 if (Arg1.isInvalid()) 10635 return ExprError(); 10636 Args[0] = LHS = Arg0.takeAs<Expr>(); 10637 Args[1] = RHS = Arg1.takeAs<Expr>(); 10638 } 10639 10640 // Determine the result type. 10641 QualType ResultTy = FnDecl->getResultType(); 10642 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10643 ResultTy = ResultTy.getNonLValueExprType(Context); 10644 10645 // Build the actual expression node. 10646 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 10647 Best->FoundDecl, 10648 HadMultipleCandidates, OpLoc); 10649 if (FnExpr.isInvalid()) 10650 return ExprError(); 10651 10652 CXXOperatorCallExpr *TheCall = 10653 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 10654 Args, ResultTy, VK, OpLoc, 10655 FPFeatures.fp_contract); 10656 10657 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 10658 FnDecl)) 10659 return ExprError(); 10660 10661 ArrayRef<const Expr *> ArgsArray(Args, 2); 10662 // Cut off the implicit 'this'. 10663 if (isa<CXXMethodDecl>(FnDecl)) 10664 ArgsArray = ArgsArray.slice(1); 10665 checkCall(FnDecl, ArgsArray, 0, isa<CXXMethodDecl>(FnDecl), OpLoc, 10666 TheCall->getSourceRange(), VariadicDoesNotApply); 10667 10668 return MaybeBindToTemporary(TheCall); 10669 } else { 10670 // We matched a built-in operator. Convert the arguments, then 10671 // break out so that we will build the appropriate built-in 10672 // operator node. 10673 ExprResult ArgsRes0 = 10674 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 10675 Best->Conversions[0], AA_Passing); 10676 if (ArgsRes0.isInvalid()) 10677 return ExprError(); 10678 Args[0] = ArgsRes0.take(); 10679 10680 ExprResult ArgsRes1 = 10681 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 10682 Best->Conversions[1], AA_Passing); 10683 if (ArgsRes1.isInvalid()) 10684 return ExprError(); 10685 Args[1] = ArgsRes1.take(); 10686 break; 10687 } 10688 } 10689 10690 case OR_No_Viable_Function: { 10691 // C++ [over.match.oper]p9: 10692 // If the operator is the operator , [...] and there are no 10693 // viable functions, then the operator is assumed to be the 10694 // built-in operator and interpreted according to clause 5. 10695 if (Opc == BO_Comma) 10696 break; 10697 10698 // For class as left operand for assignment or compound assigment 10699 // operator do not fall through to handling in built-in, but report that 10700 // no overloaded assignment operator found 10701 ExprResult Result = ExprError(); 10702 if (Args[0]->getType()->isRecordType() && 10703 Opc >= BO_Assign && Opc <= BO_OrAssign) { 10704 Diag(OpLoc, diag::err_ovl_no_viable_oper) 10705 << BinaryOperator::getOpcodeStr(Opc) 10706 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10707 } else { 10708 // This is an erroneous use of an operator which can be overloaded by 10709 // a non-member function. Check for non-member operators which were 10710 // defined too late to be candidates. 10711 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args)) 10712 // FIXME: Recover by calling the found function. 10713 return ExprError(); 10714 10715 // No viable function; try to create a built-in operation, which will 10716 // produce an error. Then, show the non-viable candidates. 10717 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10718 } 10719 assert(Result.isInvalid() && 10720 "C++ binary operator overloading is missing candidates!"); 10721 if (Result.isInvalid()) 10722 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10723 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10724 return Result; 10725 } 10726 10727 case OR_Ambiguous: 10728 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 10729 << BinaryOperator::getOpcodeStr(Opc) 10730 << Args[0]->getType() << Args[1]->getType() 10731 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10732 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 10733 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10734 return ExprError(); 10735 10736 case OR_Deleted: 10737 if (isImplicitlyDeleted(Best->Function)) { 10738 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 10739 Diag(OpLoc, diag::err_ovl_deleted_special_oper) 10740 << Context.getRecordType(Method->getParent()) 10741 << getSpecialMember(Method); 10742 10743 // The user probably meant to call this special member. Just 10744 // explain why it's deleted. 10745 NoteDeletedFunction(Method); 10746 return ExprError(); 10747 } else { 10748 Diag(OpLoc, diag::err_ovl_deleted_oper) 10749 << Best->Function->isDeleted() 10750 << BinaryOperator::getOpcodeStr(Opc) 10751 << getDeletedOrUnavailableSuffix(Best->Function) 10752 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10753 } 10754 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10755 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10756 return ExprError(); 10757 } 10758 10759 // We matched a built-in operator; build it. 10760 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10761} 10762 10763ExprResult 10764Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 10765 SourceLocation RLoc, 10766 Expr *Base, Expr *Idx) { 10767 Expr *Args[2] = { Base, Idx }; 10768 DeclarationName OpName = 10769 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 10770 10771 // If either side is type-dependent, create an appropriate dependent 10772 // expression. 10773 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 10774 10775 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10776 // CHECKME: no 'operator' keyword? 10777 DeclarationNameInfo OpNameInfo(OpName, LLoc); 10778 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 10779 UnresolvedLookupExpr *Fn 10780 = UnresolvedLookupExpr::Create(Context, NamingClass, 10781 NestedNameSpecifierLoc(), OpNameInfo, 10782 /*ADL*/ true, /*Overloaded*/ false, 10783 UnresolvedSetIterator(), 10784 UnresolvedSetIterator()); 10785 // Can't add any actual overloads yet 10786 10787 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 10788 Args, 10789 Context.DependentTy, 10790 VK_RValue, 10791 RLoc, false)); 10792 } 10793 10794 // Handle placeholders on both operands. 10795 if (checkPlaceholderForOverload(*this, Args[0])) 10796 return ExprError(); 10797 if (checkPlaceholderForOverload(*this, Args[1])) 10798 return ExprError(); 10799 10800 // Build an empty overload set. 10801 OverloadCandidateSet CandidateSet(LLoc); 10802 10803 // Subscript can only be overloaded as a member function. 10804 10805 // Add operator candidates that are member functions. 10806 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet); 10807 10808 // Add builtin operator candidates. 10809 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet); 10810 10811 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10812 10813 // Perform overload resolution. 10814 OverloadCandidateSet::iterator Best; 10815 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 10816 case OR_Success: { 10817 // We found a built-in operator or an overloaded operator. 10818 FunctionDecl *FnDecl = Best->Function; 10819 10820 if (FnDecl) { 10821 // We matched an overloaded operator. Build a call to that 10822 // operator. 10823 10824 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 10825 10826 // Convert the arguments. 10827 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 10828 ExprResult Arg0 = 10829 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 10830 Best->FoundDecl, Method); 10831 if (Arg0.isInvalid()) 10832 return ExprError(); 10833 Args[0] = Arg0.take(); 10834 10835 // Convert the arguments. 10836 ExprResult InputInit 10837 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 10838 Context, 10839 FnDecl->getParamDecl(0)), 10840 SourceLocation(), 10841 Owned(Args[1])); 10842 if (InputInit.isInvalid()) 10843 return ExprError(); 10844 10845 Args[1] = InputInit.takeAs<Expr>(); 10846 10847 // Determine the result type 10848 QualType ResultTy = FnDecl->getResultType(); 10849 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10850 ResultTy = ResultTy.getNonLValueExprType(Context); 10851 10852 // Build the actual expression node. 10853 DeclarationNameInfo OpLocInfo(OpName, LLoc); 10854 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 10855 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 10856 Best->FoundDecl, 10857 HadMultipleCandidates, 10858 OpLocInfo.getLoc(), 10859 OpLocInfo.getInfo()); 10860 if (FnExpr.isInvalid()) 10861 return ExprError(); 10862 10863 CXXOperatorCallExpr *TheCall = 10864 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 10865 FnExpr.take(), Args, 10866 ResultTy, VK, RLoc, 10867 false); 10868 10869 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 10870 FnDecl)) 10871 return ExprError(); 10872 10873 return MaybeBindToTemporary(TheCall); 10874 } else { 10875 // We matched a built-in operator. Convert the arguments, then 10876 // break out so that we will build the appropriate built-in 10877 // operator node. 10878 ExprResult ArgsRes0 = 10879 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 10880 Best->Conversions[0], AA_Passing); 10881 if (ArgsRes0.isInvalid()) 10882 return ExprError(); 10883 Args[0] = ArgsRes0.take(); 10884 10885 ExprResult ArgsRes1 = 10886 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 10887 Best->Conversions[1], AA_Passing); 10888 if (ArgsRes1.isInvalid()) 10889 return ExprError(); 10890 Args[1] = ArgsRes1.take(); 10891 10892 break; 10893 } 10894 } 10895 10896 case OR_No_Viable_Function: { 10897 if (CandidateSet.empty()) 10898 Diag(LLoc, diag::err_ovl_no_oper) 10899 << Args[0]->getType() << /*subscript*/ 0 10900 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10901 else 10902 Diag(LLoc, diag::err_ovl_no_viable_subscript) 10903 << Args[0]->getType() 10904 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10905 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10906 "[]", LLoc); 10907 return ExprError(); 10908 } 10909 10910 case OR_Ambiguous: 10911 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 10912 << "[]" 10913 << Args[0]->getType() << Args[1]->getType() 10914 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10915 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 10916 "[]", LLoc); 10917 return ExprError(); 10918 10919 case OR_Deleted: 10920 Diag(LLoc, diag::err_ovl_deleted_oper) 10921 << Best->Function->isDeleted() << "[]" 10922 << getDeletedOrUnavailableSuffix(Best->Function) 10923 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10924 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10925 "[]", LLoc); 10926 return ExprError(); 10927 } 10928 10929 // We matched a built-in operator; build it. 10930 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 10931} 10932 10933/// BuildCallToMemberFunction - Build a call to a member 10934/// function. MemExpr is the expression that refers to the member 10935/// function (and includes the object parameter), Args/NumArgs are the 10936/// arguments to the function call (not including the object 10937/// parameter). The caller needs to validate that the member 10938/// expression refers to a non-static member function or an overloaded 10939/// member function. 10940ExprResult 10941Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 10942 SourceLocation LParenLoc, 10943 MultiExprArg Args, 10944 SourceLocation RParenLoc) { 10945 assert(MemExprE->getType() == Context.BoundMemberTy || 10946 MemExprE->getType() == Context.OverloadTy); 10947 10948 // Dig out the member expression. This holds both the object 10949 // argument and the member function we're referring to. 10950 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 10951 10952 // Determine whether this is a call to a pointer-to-member function. 10953 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) { 10954 assert(op->getType() == Context.BoundMemberTy); 10955 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI); 10956 10957 QualType fnType = 10958 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType(); 10959 10960 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>(); 10961 QualType resultType = proto->getCallResultType(Context); 10962 ExprValueKind valueKind = Expr::getValueKindForType(proto->getResultType()); 10963 10964 // Check that the object type isn't more qualified than the 10965 // member function we're calling. 10966 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals()); 10967 10968 QualType objectType = op->getLHS()->getType(); 10969 if (op->getOpcode() == BO_PtrMemI) 10970 objectType = objectType->castAs<PointerType>()->getPointeeType(); 10971 Qualifiers objectQuals = objectType.getQualifiers(); 10972 10973 Qualifiers difference = objectQuals - funcQuals; 10974 difference.removeObjCGCAttr(); 10975 difference.removeAddressSpace(); 10976 if (difference) { 10977 std::string qualsString = difference.getAsString(); 10978 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals) 10979 << fnType.getUnqualifiedType() 10980 << qualsString 10981 << (qualsString.find(' ') == std::string::npos ? 1 : 2); 10982 } 10983 10984 CXXMemberCallExpr *call 10985 = new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 10986 resultType, valueKind, RParenLoc); 10987 10988 if (CheckCallReturnType(proto->getResultType(), 10989 op->getRHS()->getLocStart(), 10990 call, 0)) 10991 return ExprError(); 10992 10993 if (ConvertArgumentsForCall(call, op, 0, proto, Args, RParenLoc)) 10994 return ExprError(); 10995 10996 if (CheckOtherCall(call, proto)) 10997 return ExprError(); 10998 10999 return MaybeBindToTemporary(call); 11000 } 11001 11002 UnbridgedCastsSet UnbridgedCasts; 11003 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) 11004 return ExprError(); 11005 11006 MemberExpr *MemExpr; 11007 CXXMethodDecl *Method = 0; 11008 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 11009 NestedNameSpecifier *Qualifier = 0; 11010 if (isa<MemberExpr>(NakedMemExpr)) { 11011 MemExpr = cast<MemberExpr>(NakedMemExpr); 11012 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 11013 FoundDecl = MemExpr->getFoundDecl(); 11014 Qualifier = MemExpr->getQualifier(); 11015 UnbridgedCasts.restore(); 11016 } else { 11017 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 11018 Qualifier = UnresExpr->getQualifier(); 11019 11020 QualType ObjectType = UnresExpr->getBaseType(); 11021 Expr::Classification ObjectClassification 11022 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 11023 : UnresExpr->getBase()->Classify(Context); 11024 11025 // Add overload candidates 11026 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 11027 11028 // FIXME: avoid copy. 11029 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 11030 if (UnresExpr->hasExplicitTemplateArgs()) { 11031 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 11032 TemplateArgs = &TemplateArgsBuffer; 11033 } 11034 11035 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 11036 E = UnresExpr->decls_end(); I != E; ++I) { 11037 11038 NamedDecl *Func = *I; 11039 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 11040 if (isa<UsingShadowDecl>(Func)) 11041 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 11042 11043 11044 // Microsoft supports direct constructor calls. 11045 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) { 11046 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), 11047 Args, CandidateSet); 11048 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 11049 // If explicit template arguments were provided, we can't call a 11050 // non-template member function. 11051 if (TemplateArgs) 11052 continue; 11053 11054 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 11055 ObjectClassification, Args, CandidateSet, 11056 /*SuppressUserConversions=*/false); 11057 } else { 11058 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 11059 I.getPair(), ActingDC, TemplateArgs, 11060 ObjectType, ObjectClassification, 11061 Args, CandidateSet, 11062 /*SuppressUsedConversions=*/false); 11063 } 11064 } 11065 11066 DeclarationName DeclName = UnresExpr->getMemberName(); 11067 11068 UnbridgedCasts.restore(); 11069 11070 OverloadCandidateSet::iterator Best; 11071 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 11072 Best)) { 11073 case OR_Success: 11074 Method = cast<CXXMethodDecl>(Best->Function); 11075 FoundDecl = Best->FoundDecl; 11076 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 11077 if (DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc())) 11078 return ExprError(); 11079 // If FoundDecl is different from Method (such as if one is a template 11080 // and the other a specialization), make sure DiagnoseUseOfDecl is 11081 // called on both. 11082 // FIXME: This would be more comprehensively addressed by modifying 11083 // DiagnoseUseOfDecl to accept both the FoundDecl and the decl 11084 // being used. 11085 if (Method != FoundDecl.getDecl() && 11086 DiagnoseUseOfDecl(Method, UnresExpr->getNameLoc())) 11087 return ExprError(); 11088 break; 11089 11090 case OR_No_Viable_Function: 11091 Diag(UnresExpr->getMemberLoc(), 11092 diag::err_ovl_no_viable_member_function_in_call) 11093 << DeclName << MemExprE->getSourceRange(); 11094 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11095 // FIXME: Leaking incoming expressions! 11096 return ExprError(); 11097 11098 case OR_Ambiguous: 11099 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 11100 << DeclName << MemExprE->getSourceRange(); 11101 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11102 // FIXME: Leaking incoming expressions! 11103 return ExprError(); 11104 11105 case OR_Deleted: 11106 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 11107 << Best->Function->isDeleted() 11108 << DeclName 11109 << getDeletedOrUnavailableSuffix(Best->Function) 11110 << MemExprE->getSourceRange(); 11111 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11112 // FIXME: Leaking incoming expressions! 11113 return ExprError(); 11114 } 11115 11116 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 11117 11118 // If overload resolution picked a static member, build a 11119 // non-member call based on that function. 11120 if (Method->isStatic()) { 11121 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, Args, 11122 RParenLoc); 11123 } 11124 11125 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 11126 } 11127 11128 QualType ResultType = Method->getResultType(); 11129 ExprValueKind VK = Expr::getValueKindForType(ResultType); 11130 ResultType = ResultType.getNonLValueExprType(Context); 11131 11132 assert(Method && "Member call to something that isn't a method?"); 11133 CXXMemberCallExpr *TheCall = 11134 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 11135 ResultType, VK, RParenLoc); 11136 11137 // Check for a valid return type. 11138 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 11139 TheCall, Method)) 11140 return ExprError(); 11141 11142 // Convert the object argument (for a non-static member function call). 11143 // We only need to do this if there was actually an overload; otherwise 11144 // it was done at lookup. 11145 if (!Method->isStatic()) { 11146 ExprResult ObjectArg = 11147 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier, 11148 FoundDecl, Method); 11149 if (ObjectArg.isInvalid()) 11150 return ExprError(); 11151 MemExpr->setBase(ObjectArg.take()); 11152 } 11153 11154 // Convert the rest of the arguments 11155 const FunctionProtoType *Proto = 11156 Method->getType()->getAs<FunctionProtoType>(); 11157 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, 11158 RParenLoc)) 11159 return ExprError(); 11160 11161 DiagnoseSentinelCalls(Method, LParenLoc, Args); 11162 11163 if (CheckFunctionCall(Method, TheCall, Proto)) 11164 return ExprError(); 11165 11166 if ((isa<CXXConstructorDecl>(CurContext) || 11167 isa<CXXDestructorDecl>(CurContext)) && 11168 TheCall->getMethodDecl()->isPure()) { 11169 const CXXMethodDecl *MD = TheCall->getMethodDecl(); 11170 11171 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts())) { 11172 Diag(MemExpr->getLocStart(), 11173 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor) 11174 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext) 11175 << MD->getParent()->getDeclName(); 11176 11177 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName(); 11178 } 11179 } 11180 return MaybeBindToTemporary(TheCall); 11181} 11182 11183/// BuildCallToObjectOfClassType - Build a call to an object of class 11184/// type (C++ [over.call.object]), which can end up invoking an 11185/// overloaded function call operator (@c operator()) or performing a 11186/// user-defined conversion on the object argument. 11187ExprResult 11188Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj, 11189 SourceLocation LParenLoc, 11190 MultiExprArg Args, 11191 SourceLocation RParenLoc) { 11192 if (checkPlaceholderForOverload(*this, Obj)) 11193 return ExprError(); 11194 ExprResult Object = Owned(Obj); 11195 11196 UnbridgedCastsSet UnbridgedCasts; 11197 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) 11198 return ExprError(); 11199 11200 assert(Object.get()->getType()->isRecordType() && "Requires object type argument"); 11201 const RecordType *Record = Object.get()->getType()->getAs<RecordType>(); 11202 11203 // C++ [over.call.object]p1: 11204 // If the primary-expression E in the function call syntax 11205 // evaluates to a class object of type "cv T", then the set of 11206 // candidate functions includes at least the function call 11207 // operators of T. The function call operators of T are obtained by 11208 // ordinary lookup of the name operator() in the context of 11209 // (E).operator(). 11210 OverloadCandidateSet CandidateSet(LParenLoc); 11211 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 11212 11213 if (RequireCompleteType(LParenLoc, Object.get()->getType(), 11214 diag::err_incomplete_object_call, Object.get())) 11215 return true; 11216 11217 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 11218 LookupQualifiedName(R, Record->getDecl()); 11219 R.suppressDiagnostics(); 11220 11221 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 11222 Oper != OperEnd; ++Oper) { 11223 AddMethodCandidate(Oper.getPair(), Object.get()->getType(), 11224 Object.get()->Classify(Context), 11225 Args, CandidateSet, 11226 /*SuppressUserConversions=*/ false); 11227 } 11228 11229 // C++ [over.call.object]p2: 11230 // In addition, for each (non-explicit in C++0x) conversion function 11231 // declared in T of the form 11232 // 11233 // operator conversion-type-id () cv-qualifier; 11234 // 11235 // where cv-qualifier is the same cv-qualification as, or a 11236 // greater cv-qualification than, cv, and where conversion-type-id 11237 // denotes the type "pointer to function of (P1,...,Pn) returning 11238 // R", or the type "reference to pointer to function of 11239 // (P1,...,Pn) returning R", or the type "reference to function 11240 // of (P1,...,Pn) returning R", a surrogate call function [...] 11241 // is also considered as a candidate function. Similarly, 11242 // surrogate call functions are added to the set of candidate 11243 // functions for each conversion function declared in an 11244 // accessible base class provided the function is not hidden 11245 // within T by another intervening declaration. 11246 std::pair<CXXRecordDecl::conversion_iterator, 11247 CXXRecordDecl::conversion_iterator> Conversions 11248 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 11249 for (CXXRecordDecl::conversion_iterator 11250 I = Conversions.first, E = Conversions.second; I != E; ++I) { 11251 NamedDecl *D = *I; 11252 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 11253 if (isa<UsingShadowDecl>(D)) 11254 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 11255 11256 // Skip over templated conversion functions; they aren't 11257 // surrogates. 11258 if (isa<FunctionTemplateDecl>(D)) 11259 continue; 11260 11261 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 11262 if (!Conv->isExplicit()) { 11263 // Strip the reference type (if any) and then the pointer type (if 11264 // any) to get down to what might be a function type. 11265 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 11266 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 11267 ConvType = ConvPtrType->getPointeeType(); 11268 11269 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 11270 { 11271 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 11272 Object.get(), Args, CandidateSet); 11273 } 11274 } 11275 } 11276 11277 bool HadMultipleCandidates = (CandidateSet.size() > 1); 11278 11279 // Perform overload resolution. 11280 OverloadCandidateSet::iterator Best; 11281 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(), 11282 Best)) { 11283 case OR_Success: 11284 // Overload resolution succeeded; we'll build the appropriate call 11285 // below. 11286 break; 11287 11288 case OR_No_Viable_Function: 11289 if (CandidateSet.empty()) 11290 Diag(Object.get()->getLocStart(), diag::err_ovl_no_oper) 11291 << Object.get()->getType() << /*call*/ 1 11292 << Object.get()->getSourceRange(); 11293 else 11294 Diag(Object.get()->getLocStart(), 11295 diag::err_ovl_no_viable_object_call) 11296 << Object.get()->getType() << Object.get()->getSourceRange(); 11297 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11298 break; 11299 11300 case OR_Ambiguous: 11301 Diag(Object.get()->getLocStart(), 11302 diag::err_ovl_ambiguous_object_call) 11303 << Object.get()->getType() << Object.get()->getSourceRange(); 11304 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args); 11305 break; 11306 11307 case OR_Deleted: 11308 Diag(Object.get()->getLocStart(), 11309 diag::err_ovl_deleted_object_call) 11310 << Best->Function->isDeleted() 11311 << Object.get()->getType() 11312 << getDeletedOrUnavailableSuffix(Best->Function) 11313 << Object.get()->getSourceRange(); 11314 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11315 break; 11316 } 11317 11318 if (Best == CandidateSet.end()) 11319 return true; 11320 11321 UnbridgedCasts.restore(); 11322 11323 if (Best->Function == 0) { 11324 // Since there is no function declaration, this is one of the 11325 // surrogate candidates. Dig out the conversion function. 11326 CXXConversionDecl *Conv 11327 = cast<CXXConversionDecl>( 11328 Best->Conversions[0].UserDefined.ConversionFunction); 11329 11330 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 11331 if (DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc)) 11332 return ExprError(); 11333 assert(Conv == Best->FoundDecl.getDecl() && 11334 "Found Decl & conversion-to-functionptr should be same, right?!"); 11335 // We selected one of the surrogate functions that converts the 11336 // object parameter to a function pointer. Perform the conversion 11337 // on the object argument, then let ActOnCallExpr finish the job. 11338 11339 // Create an implicit member expr to refer to the conversion operator. 11340 // and then call it. 11341 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl, 11342 Conv, HadMultipleCandidates); 11343 if (Call.isInvalid()) 11344 return ExprError(); 11345 // Record usage of conversion in an implicit cast. 11346 Call = Owned(ImplicitCastExpr::Create(Context, Call.get()->getType(), 11347 CK_UserDefinedConversion, 11348 Call.get(), 0, VK_RValue)); 11349 11350 return ActOnCallExpr(S, Call.get(), LParenLoc, Args, RParenLoc); 11351 } 11352 11353 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 11354 11355 // We found an overloaded operator(). Build a CXXOperatorCallExpr 11356 // that calls this method, using Object for the implicit object 11357 // parameter and passing along the remaining arguments. 11358 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 11359 11360 // An error diagnostic has already been printed when parsing the declaration. 11361 if (Method->isInvalidDecl()) 11362 return ExprError(); 11363 11364 const FunctionProtoType *Proto = 11365 Method->getType()->getAs<FunctionProtoType>(); 11366 11367 unsigned NumArgsInProto = Proto->getNumArgs(); 11368 unsigned NumArgsToCheck = Args.size(); 11369 11370 // Build the full argument list for the method call (the 11371 // implicit object parameter is placed at the beginning of the 11372 // list). 11373 Expr **MethodArgs; 11374 if (Args.size() < NumArgsInProto) { 11375 NumArgsToCheck = NumArgsInProto; 11376 MethodArgs = new Expr*[NumArgsInProto + 1]; 11377 } else { 11378 MethodArgs = new Expr*[Args.size() + 1]; 11379 } 11380 MethodArgs[0] = Object.get(); 11381 for (unsigned ArgIdx = 0, e = Args.size(); ArgIdx != e; ++ArgIdx) 11382 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 11383 11384 DeclarationNameInfo OpLocInfo( 11385 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc); 11386 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc)); 11387 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, Best->FoundDecl, 11388 HadMultipleCandidates, 11389 OpLocInfo.getLoc(), 11390 OpLocInfo.getInfo()); 11391 if (NewFn.isInvalid()) 11392 return true; 11393 11394 // Once we've built TheCall, all of the expressions are properly 11395 // owned. 11396 QualType ResultTy = Method->getResultType(); 11397 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11398 ResultTy = ResultTy.getNonLValueExprType(Context); 11399 11400 CXXOperatorCallExpr *TheCall = 11401 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn.take(), 11402 llvm::makeArrayRef(MethodArgs, Args.size()+1), 11403 ResultTy, VK, RParenLoc, false); 11404 delete [] MethodArgs; 11405 11406 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 11407 Method)) 11408 return true; 11409 11410 // We may have default arguments. If so, we need to allocate more 11411 // slots in the call for them. 11412 if (Args.size() < NumArgsInProto) 11413 TheCall->setNumArgs(Context, NumArgsInProto + 1); 11414 else if (Args.size() > NumArgsInProto) 11415 NumArgsToCheck = NumArgsInProto; 11416 11417 bool IsError = false; 11418 11419 // Initialize the implicit object parameter. 11420 ExprResult ObjRes = 11421 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/0, 11422 Best->FoundDecl, Method); 11423 if (ObjRes.isInvalid()) 11424 IsError = true; 11425 else 11426 Object = ObjRes; 11427 TheCall->setArg(0, Object.take()); 11428 11429 // Check the argument types. 11430 for (unsigned i = 0; i != NumArgsToCheck; i++) { 11431 Expr *Arg; 11432 if (i < Args.size()) { 11433 Arg = Args[i]; 11434 11435 // Pass the argument. 11436 11437 ExprResult InputInit 11438 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 11439 Context, 11440 Method->getParamDecl(i)), 11441 SourceLocation(), Arg); 11442 11443 IsError |= InputInit.isInvalid(); 11444 Arg = InputInit.takeAs<Expr>(); 11445 } else { 11446 ExprResult DefArg 11447 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 11448 if (DefArg.isInvalid()) { 11449 IsError = true; 11450 break; 11451 } 11452 11453 Arg = DefArg.takeAs<Expr>(); 11454 } 11455 11456 TheCall->setArg(i + 1, Arg); 11457 } 11458 11459 // If this is a variadic call, handle args passed through "...". 11460 if (Proto->isVariadic()) { 11461 // Promote the arguments (C99 6.5.2.2p7). 11462 for (unsigned i = NumArgsInProto, e = Args.size(); i < e; i++) { 11463 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod, 0); 11464 IsError |= Arg.isInvalid(); 11465 TheCall->setArg(i + 1, Arg.take()); 11466 } 11467 } 11468 11469 if (IsError) return true; 11470 11471 DiagnoseSentinelCalls(Method, LParenLoc, Args); 11472 11473 if (CheckFunctionCall(Method, TheCall, Proto)) 11474 return true; 11475 11476 return MaybeBindToTemporary(TheCall); 11477} 11478 11479/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 11480/// (if one exists), where @c Base is an expression of class type and 11481/// @c Member is the name of the member we're trying to find. 11482ExprResult 11483Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc, 11484 bool *NoArrowOperatorFound) { 11485 assert(Base->getType()->isRecordType() && 11486 "left-hand side must have class type"); 11487 11488 if (checkPlaceholderForOverload(*this, Base)) 11489 return ExprError(); 11490 11491 SourceLocation Loc = Base->getExprLoc(); 11492 11493 // C++ [over.ref]p1: 11494 // 11495 // [...] An expression x->m is interpreted as (x.operator->())->m 11496 // for a class object x of type T if T::operator->() exists and if 11497 // the operator is selected as the best match function by the 11498 // overload resolution mechanism (13.3). 11499 DeclarationName OpName = 11500 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 11501 OverloadCandidateSet CandidateSet(Loc); 11502 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 11503 11504 if (RequireCompleteType(Loc, Base->getType(), 11505 diag::err_typecheck_incomplete_tag, Base)) 11506 return ExprError(); 11507 11508 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 11509 LookupQualifiedName(R, BaseRecord->getDecl()); 11510 R.suppressDiagnostics(); 11511 11512 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 11513 Oper != OperEnd; ++Oper) { 11514 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 11515 None, CandidateSet, /*SuppressUserConversions=*/false); 11516 } 11517 11518 bool HadMultipleCandidates = (CandidateSet.size() > 1); 11519 11520 // Perform overload resolution. 11521 OverloadCandidateSet::iterator Best; 11522 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 11523 case OR_Success: 11524 // Overload resolution succeeded; we'll build the call below. 11525 break; 11526 11527 case OR_No_Viable_Function: 11528 if (CandidateSet.empty()) { 11529 QualType BaseType = Base->getType(); 11530 if (NoArrowOperatorFound) { 11531 // Report this specific error to the caller instead of emitting a 11532 // diagnostic, as requested. 11533 *NoArrowOperatorFound = true; 11534 return ExprError(); 11535 } 11536 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 11537 << BaseType << Base->getSourceRange(); 11538 if (BaseType->isRecordType() && !BaseType->isPointerType()) { 11539 Diag(OpLoc, diag::note_typecheck_member_reference_suggestion) 11540 << FixItHint::CreateReplacement(OpLoc, "."); 11541 } 11542 } else 11543 Diag(OpLoc, diag::err_ovl_no_viable_oper) 11544 << "operator->" << Base->getSourceRange(); 11545 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base); 11546 return ExprError(); 11547 11548 case OR_Ambiguous: 11549 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 11550 << "->" << Base->getType() << Base->getSourceRange(); 11551 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Base); 11552 return ExprError(); 11553 11554 case OR_Deleted: 11555 Diag(OpLoc, diag::err_ovl_deleted_oper) 11556 << Best->Function->isDeleted() 11557 << "->" 11558 << getDeletedOrUnavailableSuffix(Best->Function) 11559 << Base->getSourceRange(); 11560 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base); 11561 return ExprError(); 11562 } 11563 11564 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 11565 11566 // Convert the object parameter. 11567 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 11568 ExprResult BaseResult = 11569 PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 11570 Best->FoundDecl, Method); 11571 if (BaseResult.isInvalid()) 11572 return ExprError(); 11573 Base = BaseResult.take(); 11574 11575 // Build the operator call. 11576 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, Best->FoundDecl, 11577 HadMultipleCandidates, OpLoc); 11578 if (FnExpr.isInvalid()) 11579 return ExprError(); 11580 11581 QualType ResultTy = Method->getResultType(); 11582 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11583 ResultTy = ResultTy.getNonLValueExprType(Context); 11584 CXXOperatorCallExpr *TheCall = 11585 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.take(), 11586 Base, ResultTy, VK, OpLoc, false); 11587 11588 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 11589 Method)) 11590 return ExprError(); 11591 11592 return MaybeBindToTemporary(TheCall); 11593} 11594 11595/// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to 11596/// a literal operator described by the provided lookup results. 11597ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R, 11598 DeclarationNameInfo &SuffixInfo, 11599 ArrayRef<Expr*> Args, 11600 SourceLocation LitEndLoc, 11601 TemplateArgumentListInfo *TemplateArgs) { 11602 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc(); 11603 11604 OverloadCandidateSet CandidateSet(UDSuffixLoc); 11605 AddFunctionCandidates(R.asUnresolvedSet(), Args, CandidateSet, true, 11606 TemplateArgs); 11607 11608 bool HadMultipleCandidates = (CandidateSet.size() > 1); 11609 11610 // Perform overload resolution. This will usually be trivial, but might need 11611 // to perform substitutions for a literal operator template. 11612 OverloadCandidateSet::iterator Best; 11613 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) { 11614 case OR_Success: 11615 case OR_Deleted: 11616 break; 11617 11618 case OR_No_Viable_Function: 11619 Diag(UDSuffixLoc, diag::err_ovl_no_viable_function_in_call) 11620 << R.getLookupName(); 11621 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11622 return ExprError(); 11623 11624 case OR_Ambiguous: 11625 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName(); 11626 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args); 11627 return ExprError(); 11628 } 11629 11630 FunctionDecl *FD = Best->Function; 11631 ExprResult Fn = CreateFunctionRefExpr(*this, FD, Best->FoundDecl, 11632 HadMultipleCandidates, 11633 SuffixInfo.getLoc(), 11634 SuffixInfo.getInfo()); 11635 if (Fn.isInvalid()) 11636 return true; 11637 11638 // Check the argument types. This should almost always be a no-op, except 11639 // that array-to-pointer decay is applied to string literals. 11640 Expr *ConvArgs[2]; 11641 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 11642 ExprResult InputInit = PerformCopyInitialization( 11643 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)), 11644 SourceLocation(), Args[ArgIdx]); 11645 if (InputInit.isInvalid()) 11646 return true; 11647 ConvArgs[ArgIdx] = InputInit.take(); 11648 } 11649 11650 QualType ResultTy = FD->getResultType(); 11651 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11652 ResultTy = ResultTy.getNonLValueExprType(Context); 11653 11654 UserDefinedLiteral *UDL = 11655 new (Context) UserDefinedLiteral(Context, Fn.take(), 11656 llvm::makeArrayRef(ConvArgs, Args.size()), 11657 ResultTy, VK, LitEndLoc, UDSuffixLoc); 11658 11659 if (CheckCallReturnType(FD->getResultType(), UDSuffixLoc, UDL, FD)) 11660 return ExprError(); 11661 11662 if (CheckFunctionCall(FD, UDL, NULL)) 11663 return ExprError(); 11664 11665 return MaybeBindToTemporary(UDL); 11666} 11667 11668/// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the 11669/// given LookupResult is non-empty, it is assumed to describe a member which 11670/// will be invoked. Otherwise, the function will be found via argument 11671/// dependent lookup. 11672/// CallExpr is set to a valid expression and FRS_Success returned on success, 11673/// otherwise CallExpr is set to ExprError() and some non-success value 11674/// is returned. 11675Sema::ForRangeStatus 11676Sema::BuildForRangeBeginEndCall(Scope *S, SourceLocation Loc, 11677 SourceLocation RangeLoc, VarDecl *Decl, 11678 BeginEndFunction BEF, 11679 const DeclarationNameInfo &NameInfo, 11680 LookupResult &MemberLookup, 11681 OverloadCandidateSet *CandidateSet, 11682 Expr *Range, ExprResult *CallExpr) { 11683 CandidateSet->clear(); 11684 if (!MemberLookup.empty()) { 11685 ExprResult MemberRef = 11686 BuildMemberReferenceExpr(Range, Range->getType(), Loc, 11687 /*IsPtr=*/false, CXXScopeSpec(), 11688 /*TemplateKWLoc=*/SourceLocation(), 11689 /*FirstQualifierInScope=*/0, 11690 MemberLookup, 11691 /*TemplateArgs=*/0); 11692 if (MemberRef.isInvalid()) { 11693 *CallExpr = ExprError(); 11694 Diag(Range->getLocStart(), diag::note_in_for_range) 11695 << RangeLoc << BEF << Range->getType(); 11696 return FRS_DiagnosticIssued; 11697 } 11698 *CallExpr = ActOnCallExpr(S, MemberRef.get(), Loc, None, Loc, 0); 11699 if (CallExpr->isInvalid()) { 11700 *CallExpr = ExprError(); 11701 Diag(Range->getLocStart(), diag::note_in_for_range) 11702 << RangeLoc << BEF << Range->getType(); 11703 return FRS_DiagnosticIssued; 11704 } 11705 } else { 11706 UnresolvedSet<0> FoundNames; 11707 UnresolvedLookupExpr *Fn = 11708 UnresolvedLookupExpr::Create(Context, /*NamingClass=*/0, 11709 NestedNameSpecifierLoc(), NameInfo, 11710 /*NeedsADL=*/true, /*Overloaded=*/false, 11711 FoundNames.begin(), FoundNames.end()); 11712 11713 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, Range, Loc, 11714 CandidateSet, CallExpr); 11715 if (CandidateSet->empty() || CandidateSetError) { 11716 *CallExpr = ExprError(); 11717 return FRS_NoViableFunction; 11718 } 11719 OverloadCandidateSet::iterator Best; 11720 OverloadingResult OverloadResult = 11721 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best); 11722 11723 if (OverloadResult == OR_No_Viable_Function) { 11724 *CallExpr = ExprError(); 11725 return FRS_NoViableFunction; 11726 } 11727 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, Range, 11728 Loc, 0, CandidateSet, &Best, 11729 OverloadResult, 11730 /*AllowTypoCorrection=*/false); 11731 if (CallExpr->isInvalid() || OverloadResult != OR_Success) { 11732 *CallExpr = ExprError(); 11733 Diag(Range->getLocStart(), diag::note_in_for_range) 11734 << RangeLoc << BEF << Range->getType(); 11735 return FRS_DiagnosticIssued; 11736 } 11737 } 11738 return FRS_Success; 11739} 11740 11741 11742/// FixOverloadedFunctionReference - E is an expression that refers to 11743/// a C++ overloaded function (possibly with some parentheses and 11744/// perhaps a '&' around it). We have resolved the overloaded function 11745/// to the function declaration Fn, so patch up the expression E to 11746/// refer (possibly indirectly) to Fn. Returns the new expr. 11747Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 11748 FunctionDecl *Fn) { 11749 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 11750 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 11751 Found, Fn); 11752 if (SubExpr == PE->getSubExpr()) 11753 return PE; 11754 11755 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 11756 } 11757 11758 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 11759 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 11760 Found, Fn); 11761 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 11762 SubExpr->getType()) && 11763 "Implicit cast type cannot be determined from overload"); 11764 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 11765 if (SubExpr == ICE->getSubExpr()) 11766 return ICE; 11767 11768 return ImplicitCastExpr::Create(Context, ICE->getType(), 11769 ICE->getCastKind(), 11770 SubExpr, 0, 11771 ICE->getValueKind()); 11772 } 11773 11774 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 11775 assert(UnOp->getOpcode() == UO_AddrOf && 11776 "Can only take the address of an overloaded function"); 11777 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 11778 if (Method->isStatic()) { 11779 // Do nothing: static member functions aren't any different 11780 // from non-member functions. 11781 } else { 11782 // Fix the sub expression, which really has to be an 11783 // UnresolvedLookupExpr holding an overloaded member function 11784 // or template. 11785 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 11786 Found, Fn); 11787 if (SubExpr == UnOp->getSubExpr()) 11788 return UnOp; 11789 11790 assert(isa<DeclRefExpr>(SubExpr) 11791 && "fixed to something other than a decl ref"); 11792 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 11793 && "fixed to a member ref with no nested name qualifier"); 11794 11795 // We have taken the address of a pointer to member 11796 // function. Perform the computation here so that we get the 11797 // appropriate pointer to member type. 11798 QualType ClassType 11799 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 11800 QualType MemPtrType 11801 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 11802 11803 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 11804 VK_RValue, OK_Ordinary, 11805 UnOp->getOperatorLoc()); 11806 } 11807 } 11808 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 11809 Found, Fn); 11810 if (SubExpr == UnOp->getSubExpr()) 11811 return UnOp; 11812 11813 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 11814 Context.getPointerType(SubExpr->getType()), 11815 VK_RValue, OK_Ordinary, 11816 UnOp->getOperatorLoc()); 11817 } 11818 11819 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 11820 // FIXME: avoid copy. 11821 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 11822 if (ULE->hasExplicitTemplateArgs()) { 11823 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 11824 TemplateArgs = &TemplateArgsBuffer; 11825 } 11826 11827 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 11828 ULE->getQualifierLoc(), 11829 ULE->getTemplateKeywordLoc(), 11830 Fn, 11831 /*enclosing*/ false, // FIXME? 11832 ULE->getNameLoc(), 11833 Fn->getType(), 11834 VK_LValue, 11835 Found.getDecl(), 11836 TemplateArgs); 11837 MarkDeclRefReferenced(DRE); 11838 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1); 11839 return DRE; 11840 } 11841 11842 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 11843 // FIXME: avoid copy. 11844 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 11845 if (MemExpr->hasExplicitTemplateArgs()) { 11846 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 11847 TemplateArgs = &TemplateArgsBuffer; 11848 } 11849 11850 Expr *Base; 11851 11852 // If we're filling in a static method where we used to have an 11853 // implicit member access, rewrite to a simple decl ref. 11854 if (MemExpr->isImplicitAccess()) { 11855 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 11856 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 11857 MemExpr->getQualifierLoc(), 11858 MemExpr->getTemplateKeywordLoc(), 11859 Fn, 11860 /*enclosing*/ false, 11861 MemExpr->getMemberLoc(), 11862 Fn->getType(), 11863 VK_LValue, 11864 Found.getDecl(), 11865 TemplateArgs); 11866 MarkDeclRefReferenced(DRE); 11867 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1); 11868 return DRE; 11869 } else { 11870 SourceLocation Loc = MemExpr->getMemberLoc(); 11871 if (MemExpr->getQualifier()) 11872 Loc = MemExpr->getQualifierLoc().getBeginLoc(); 11873 CheckCXXThisCapture(Loc); 11874 Base = new (Context) CXXThisExpr(Loc, 11875 MemExpr->getBaseType(), 11876 /*isImplicit=*/true); 11877 } 11878 } else 11879 Base = MemExpr->getBase(); 11880 11881 ExprValueKind valueKind; 11882 QualType type; 11883 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 11884 valueKind = VK_LValue; 11885 type = Fn->getType(); 11886 } else { 11887 valueKind = VK_RValue; 11888 type = Context.BoundMemberTy; 11889 } 11890 11891 MemberExpr *ME = MemberExpr::Create(Context, Base, 11892 MemExpr->isArrow(), 11893 MemExpr->getQualifierLoc(), 11894 MemExpr->getTemplateKeywordLoc(), 11895 Fn, 11896 Found, 11897 MemExpr->getMemberNameInfo(), 11898 TemplateArgs, 11899 type, valueKind, OK_Ordinary); 11900 ME->setHadMultipleCandidates(true); 11901 MarkMemberReferenced(ME); 11902 return ME; 11903 } 11904 11905 llvm_unreachable("Invalid reference to overloaded function"); 11906} 11907 11908ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 11909 DeclAccessPair Found, 11910 FunctionDecl *Fn) { 11911 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 11912} 11913 11914} // end namespace clang 11915