SemaOverload.cpp revision d2fdd4256a2efc41365ccdd27a210d1d99a1fe3a
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 DeclRefExpr *DRE = new (S.Context) DeclRefExpr(Fn, false, Fn->getType(), 46 VK_LValue, Loc, LocInfo); 47 if (HadMultipleCandidates) 48 DRE->setHadMultipleCandidates(true); 49 50 S.MarkDeclRefReferenced(DRE); 51 S.DiagnoseUseOfDecl(FoundDecl, Loc); 52 53 ExprResult E = S.Owned(DRE); 54 E = S.DefaultFunctionArrayConversion(E.take()); 55 if (E.isInvalid()) 56 return ExprError(); 57 return E; 58} 59 60static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 61 bool InOverloadResolution, 62 StandardConversionSequence &SCS, 63 bool CStyle, 64 bool AllowObjCWritebackConversion); 65 66static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From, 67 QualType &ToType, 68 bool InOverloadResolution, 69 StandardConversionSequence &SCS, 70 bool CStyle); 71static OverloadingResult 72IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 73 UserDefinedConversionSequence& User, 74 OverloadCandidateSet& Conversions, 75 bool AllowExplicit); 76 77 78static ImplicitConversionSequence::CompareKind 79CompareStandardConversionSequences(Sema &S, 80 const StandardConversionSequence& SCS1, 81 const StandardConversionSequence& SCS2); 82 83static ImplicitConversionSequence::CompareKind 84CompareQualificationConversions(Sema &S, 85 const StandardConversionSequence& SCS1, 86 const StandardConversionSequence& SCS2); 87 88static ImplicitConversionSequence::CompareKind 89CompareDerivedToBaseConversions(Sema &S, 90 const StandardConversionSequence& SCS1, 91 const StandardConversionSequence& SCS2); 92 93 94 95/// GetConversionCategory - Retrieve the implicit conversion 96/// category corresponding to the given implicit conversion kind. 97ImplicitConversionCategory 98GetConversionCategory(ImplicitConversionKind Kind) { 99 static const ImplicitConversionCategory 100 Category[(int)ICK_Num_Conversion_Kinds] = { 101 ICC_Identity, 102 ICC_Lvalue_Transformation, 103 ICC_Lvalue_Transformation, 104 ICC_Lvalue_Transformation, 105 ICC_Identity, 106 ICC_Qualification_Adjustment, 107 ICC_Promotion, 108 ICC_Promotion, 109 ICC_Promotion, 110 ICC_Conversion, 111 ICC_Conversion, 112 ICC_Conversion, 113 ICC_Conversion, 114 ICC_Conversion, 115 ICC_Conversion, 116 ICC_Conversion, 117 ICC_Conversion, 118 ICC_Conversion, 119 ICC_Conversion, 120 ICC_Conversion, 121 ICC_Conversion, 122 ICC_Conversion 123 }; 124 return Category[(int)Kind]; 125} 126 127/// GetConversionRank - Retrieve the implicit conversion rank 128/// corresponding to the given implicit conversion kind. 129ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 130 static const ImplicitConversionRank 131 Rank[(int)ICK_Num_Conversion_Kinds] = { 132 ICR_Exact_Match, 133 ICR_Exact_Match, 134 ICR_Exact_Match, 135 ICR_Exact_Match, 136 ICR_Exact_Match, 137 ICR_Exact_Match, 138 ICR_Promotion, 139 ICR_Promotion, 140 ICR_Promotion, 141 ICR_Conversion, 142 ICR_Conversion, 143 ICR_Conversion, 144 ICR_Conversion, 145 ICR_Conversion, 146 ICR_Conversion, 147 ICR_Conversion, 148 ICR_Conversion, 149 ICR_Conversion, 150 ICR_Conversion, 151 ICR_Conversion, 152 ICR_Complex_Real_Conversion, 153 ICR_Conversion, 154 ICR_Conversion, 155 ICR_Writeback_Conversion 156 }; 157 return Rank[(int)Kind]; 158} 159 160/// GetImplicitConversionName - Return the name of this kind of 161/// implicit conversion. 162const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 163 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 164 "No conversion", 165 "Lvalue-to-rvalue", 166 "Array-to-pointer", 167 "Function-to-pointer", 168 "Noreturn adjustment", 169 "Qualification", 170 "Integral promotion", 171 "Floating point promotion", 172 "Complex promotion", 173 "Integral conversion", 174 "Floating conversion", 175 "Complex conversion", 176 "Floating-integral conversion", 177 "Pointer conversion", 178 "Pointer-to-member conversion", 179 "Boolean conversion", 180 "Compatible-types conversion", 181 "Derived-to-base conversion", 182 "Vector conversion", 183 "Vector splat", 184 "Complex-real conversion", 185 "Block Pointer conversion", 186 "Transparent Union Conversion" 187 "Writeback conversion" 188 }; 189 return Name[Kind]; 190} 191 192/// StandardConversionSequence - Set the standard conversion 193/// sequence to the identity conversion. 194void StandardConversionSequence::setAsIdentityConversion() { 195 First = ICK_Identity; 196 Second = ICK_Identity; 197 Third = ICK_Identity; 198 DeprecatedStringLiteralToCharPtr = false; 199 QualificationIncludesObjCLifetime = false; 200 ReferenceBinding = false; 201 DirectBinding = false; 202 IsLvalueReference = true; 203 BindsToFunctionLvalue = false; 204 BindsToRvalue = false; 205 BindsImplicitObjectArgumentWithoutRefQualifier = false; 206 ObjCLifetimeConversionBinding = false; 207 CopyConstructor = 0; 208} 209 210/// getRank - Retrieve the rank of this standard conversion sequence 211/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 212/// implicit conversions. 213ImplicitConversionRank StandardConversionSequence::getRank() const { 214 ImplicitConversionRank Rank = ICR_Exact_Match; 215 if (GetConversionRank(First) > Rank) 216 Rank = GetConversionRank(First); 217 if (GetConversionRank(Second) > Rank) 218 Rank = GetConversionRank(Second); 219 if (GetConversionRank(Third) > Rank) 220 Rank = GetConversionRank(Third); 221 return Rank; 222} 223 224/// isPointerConversionToBool - Determines whether this conversion is 225/// a conversion of a pointer or pointer-to-member to bool. This is 226/// used as part of the ranking of standard conversion sequences 227/// (C++ 13.3.3.2p4). 228bool StandardConversionSequence::isPointerConversionToBool() const { 229 // Note that FromType has not necessarily been transformed by the 230 // array-to-pointer or function-to-pointer implicit conversions, so 231 // check for their presence as well as checking whether FromType is 232 // a pointer. 233 if (getToType(1)->isBooleanType() && 234 (getFromType()->isPointerType() || 235 getFromType()->isObjCObjectPointerType() || 236 getFromType()->isBlockPointerType() || 237 getFromType()->isNullPtrType() || 238 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 239 return true; 240 241 return false; 242} 243 244/// isPointerConversionToVoidPointer - Determines whether this 245/// conversion is a conversion of a pointer to a void pointer. This is 246/// used as part of the ranking of standard conversion sequences (C++ 247/// 13.3.3.2p4). 248bool 249StandardConversionSequence:: 250isPointerConversionToVoidPointer(ASTContext& Context) const { 251 QualType FromType = getFromType(); 252 QualType ToType = getToType(1); 253 254 // Note that FromType has not necessarily been transformed by the 255 // array-to-pointer implicit conversion, so check for its presence 256 // and redo the conversion to get a pointer. 257 if (First == ICK_Array_To_Pointer) 258 FromType = Context.getArrayDecayedType(FromType); 259 260 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType()) 261 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 262 return ToPtrType->getPointeeType()->isVoidType(); 263 264 return false; 265} 266 267/// Skip any implicit casts which could be either part of a narrowing conversion 268/// or after one in an implicit conversion. 269static const Expr *IgnoreNarrowingConversion(const Expr *Converted) { 270 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) { 271 switch (ICE->getCastKind()) { 272 case CK_NoOp: 273 case CK_IntegralCast: 274 case CK_IntegralToBoolean: 275 case CK_IntegralToFloating: 276 case CK_FloatingToIntegral: 277 case CK_FloatingToBoolean: 278 case CK_FloatingCast: 279 Converted = ICE->getSubExpr(); 280 continue; 281 282 default: 283 return Converted; 284 } 285 } 286 287 return Converted; 288} 289 290/// Check if this standard conversion sequence represents a narrowing 291/// conversion, according to C++11 [dcl.init.list]p7. 292/// 293/// \param Ctx The AST context. 294/// \param Converted The result of applying this standard conversion sequence. 295/// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the 296/// value of the expression prior to the narrowing conversion. 297/// \param ConstantType If this is an NK_Constant_Narrowing conversion, the 298/// type of the expression prior to the narrowing conversion. 299NarrowingKind 300StandardConversionSequence::getNarrowingKind(ASTContext &Ctx, 301 const Expr *Converted, 302 APValue &ConstantValue, 303 QualType &ConstantType) const { 304 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++"); 305 306 // C++11 [dcl.init.list]p7: 307 // A narrowing conversion is an implicit conversion ... 308 QualType FromType = getToType(0); 309 QualType ToType = getToType(1); 310 switch (Second) { 311 // -- from a floating-point type to an integer type, or 312 // 313 // -- from an integer type or unscoped enumeration type to a floating-point 314 // type, except where the source is a constant expression and the actual 315 // value after conversion will fit into the target type and will produce 316 // the original value when converted back to the original type, or 317 case ICK_Floating_Integral: 318 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) { 319 return NK_Type_Narrowing; 320 } else if (FromType->isIntegralType(Ctx) && ToType->isRealFloatingType()) { 321 llvm::APSInt IntConstantValue; 322 const Expr *Initializer = IgnoreNarrowingConversion(Converted); 323 if (Initializer && 324 Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) { 325 // Convert the integer to the floating type. 326 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType)); 327 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(), 328 llvm::APFloat::rmNearestTiesToEven); 329 // And back. 330 llvm::APSInt ConvertedValue = IntConstantValue; 331 bool ignored; 332 Result.convertToInteger(ConvertedValue, 333 llvm::APFloat::rmTowardZero, &ignored); 334 // If the resulting value is different, this was a narrowing conversion. 335 if (IntConstantValue != ConvertedValue) { 336 ConstantValue = APValue(IntConstantValue); 337 ConstantType = Initializer->getType(); 338 return NK_Constant_Narrowing; 339 } 340 } else { 341 // Variables are always narrowings. 342 return NK_Variable_Narrowing; 343 } 344 } 345 return NK_Not_Narrowing; 346 347 // -- from long double to double or float, or from double to float, except 348 // where the source is a constant expression and the actual value after 349 // conversion is within the range of values that can be represented (even 350 // if it cannot be represented exactly), or 351 case ICK_Floating_Conversion: 352 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() && 353 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) { 354 // FromType is larger than ToType. 355 const Expr *Initializer = IgnoreNarrowingConversion(Converted); 356 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) { 357 // Constant! 358 assert(ConstantValue.isFloat()); 359 llvm::APFloat FloatVal = ConstantValue.getFloat(); 360 // Convert the source value into the target type. 361 bool ignored; 362 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert( 363 Ctx.getFloatTypeSemantics(ToType), 364 llvm::APFloat::rmNearestTiesToEven, &ignored); 365 // If there was no overflow, the source value is within the range of 366 // values that can be represented. 367 if (ConvertStatus & llvm::APFloat::opOverflow) { 368 ConstantType = Initializer->getType(); 369 return NK_Constant_Narrowing; 370 } 371 } else { 372 return NK_Variable_Narrowing; 373 } 374 } 375 return NK_Not_Narrowing; 376 377 // -- from an integer type or unscoped enumeration type to an integer type 378 // that cannot represent all the values of the original type, except where 379 // the source is a constant expression and the actual value after 380 // conversion will fit into the target type and will produce the original 381 // value when converted back to the original type. 382 case ICK_Boolean_Conversion: // Bools are integers too. 383 if (!FromType->isIntegralOrUnscopedEnumerationType()) { 384 // Boolean conversions can be from pointers and pointers to members 385 // [conv.bool], and those aren't considered narrowing conversions. 386 return NK_Not_Narrowing; 387 } // Otherwise, fall through to the integral case. 388 case ICK_Integral_Conversion: { 389 assert(FromType->isIntegralOrUnscopedEnumerationType()); 390 assert(ToType->isIntegralOrUnscopedEnumerationType()); 391 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType(); 392 const unsigned FromWidth = Ctx.getIntWidth(FromType); 393 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType(); 394 const unsigned ToWidth = Ctx.getIntWidth(ToType); 395 396 if (FromWidth > ToWidth || 397 (FromWidth == ToWidth && FromSigned != ToSigned) || 398 (FromSigned && !ToSigned)) { 399 // Not all values of FromType can be represented in ToType. 400 llvm::APSInt InitializerValue; 401 const Expr *Initializer = IgnoreNarrowingConversion(Converted); 402 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) { 403 // Such conversions on variables are always narrowing. 404 return NK_Variable_Narrowing; 405 } 406 bool Narrowing = false; 407 if (FromWidth < ToWidth) { 408 // Negative -> unsigned is narrowing. Otherwise, more bits is never 409 // narrowing. 410 if (InitializerValue.isSigned() && InitializerValue.isNegative()) 411 Narrowing = true; 412 } else { 413 // Add a bit to the InitializerValue so we don't have to worry about 414 // signed vs. unsigned comparisons. 415 InitializerValue = InitializerValue.extend( 416 InitializerValue.getBitWidth() + 1); 417 // Convert the initializer to and from the target width and signed-ness. 418 llvm::APSInt ConvertedValue = InitializerValue; 419 ConvertedValue = ConvertedValue.trunc(ToWidth); 420 ConvertedValue.setIsSigned(ToSigned); 421 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth()); 422 ConvertedValue.setIsSigned(InitializerValue.isSigned()); 423 // If the result is different, this was a narrowing conversion. 424 if (ConvertedValue != InitializerValue) 425 Narrowing = true; 426 } 427 if (Narrowing) { 428 ConstantType = Initializer->getType(); 429 ConstantValue = APValue(InitializerValue); 430 return NK_Constant_Narrowing; 431 } 432 } 433 return NK_Not_Narrowing; 434 } 435 436 default: 437 // Other kinds of conversions are not narrowings. 438 return NK_Not_Narrowing; 439 } 440} 441 442/// DebugPrint - Print this standard conversion sequence to standard 443/// error. Useful for debugging overloading issues. 444void StandardConversionSequence::DebugPrint() const { 445 raw_ostream &OS = llvm::errs(); 446 bool PrintedSomething = false; 447 if (First != ICK_Identity) { 448 OS << GetImplicitConversionName(First); 449 PrintedSomething = true; 450 } 451 452 if (Second != ICK_Identity) { 453 if (PrintedSomething) { 454 OS << " -> "; 455 } 456 OS << GetImplicitConversionName(Second); 457 458 if (CopyConstructor) { 459 OS << " (by copy constructor)"; 460 } else if (DirectBinding) { 461 OS << " (direct reference binding)"; 462 } else if (ReferenceBinding) { 463 OS << " (reference binding)"; 464 } 465 PrintedSomething = true; 466 } 467 468 if (Third != ICK_Identity) { 469 if (PrintedSomething) { 470 OS << " -> "; 471 } 472 OS << GetImplicitConversionName(Third); 473 PrintedSomething = true; 474 } 475 476 if (!PrintedSomething) { 477 OS << "No conversions required"; 478 } 479} 480 481/// DebugPrint - Print this user-defined conversion sequence to standard 482/// error. Useful for debugging overloading issues. 483void UserDefinedConversionSequence::DebugPrint() const { 484 raw_ostream &OS = llvm::errs(); 485 if (Before.First || Before.Second || Before.Third) { 486 Before.DebugPrint(); 487 OS << " -> "; 488 } 489 if (ConversionFunction) 490 OS << '\'' << *ConversionFunction << '\''; 491 else 492 OS << "aggregate initialization"; 493 if (After.First || After.Second || After.Third) { 494 OS << " -> "; 495 After.DebugPrint(); 496 } 497} 498 499/// DebugPrint - Print this implicit conversion sequence to standard 500/// error. Useful for debugging overloading issues. 501void ImplicitConversionSequence::DebugPrint() const { 502 raw_ostream &OS = llvm::errs(); 503 switch (ConversionKind) { 504 case StandardConversion: 505 OS << "Standard conversion: "; 506 Standard.DebugPrint(); 507 break; 508 case UserDefinedConversion: 509 OS << "User-defined conversion: "; 510 UserDefined.DebugPrint(); 511 break; 512 case EllipsisConversion: 513 OS << "Ellipsis conversion"; 514 break; 515 case AmbiguousConversion: 516 OS << "Ambiguous conversion"; 517 break; 518 case BadConversion: 519 OS << "Bad conversion"; 520 break; 521 } 522 523 OS << "\n"; 524} 525 526void AmbiguousConversionSequence::construct() { 527 new (&conversions()) ConversionSet(); 528} 529 530void AmbiguousConversionSequence::destruct() { 531 conversions().~ConversionSet(); 532} 533 534void 535AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 536 FromTypePtr = O.FromTypePtr; 537 ToTypePtr = O.ToTypePtr; 538 new (&conversions()) ConversionSet(O.conversions()); 539} 540 541namespace { 542 // Structure used by OverloadCandidate::DeductionFailureInfo to store 543 // template argument information. 544 struct DFIArguments { 545 TemplateArgument FirstArg; 546 TemplateArgument SecondArg; 547 }; 548 // Structure used by OverloadCandidate::DeductionFailureInfo to store 549 // template parameter and template argument information. 550 struct DFIParamWithArguments : DFIArguments { 551 TemplateParameter Param; 552 }; 553} 554 555/// \brief Convert from Sema's representation of template deduction information 556/// to the form used in overload-candidate information. 557OverloadCandidate::DeductionFailureInfo 558static MakeDeductionFailureInfo(ASTContext &Context, 559 Sema::TemplateDeductionResult TDK, 560 TemplateDeductionInfo &Info) { 561 OverloadCandidate::DeductionFailureInfo Result; 562 Result.Result = static_cast<unsigned>(TDK); 563 Result.HasDiagnostic = false; 564 Result.Data = 0; 565 switch (TDK) { 566 case Sema::TDK_Success: 567 case Sema::TDK_Invalid: 568 case Sema::TDK_InstantiationDepth: 569 case Sema::TDK_TooManyArguments: 570 case Sema::TDK_TooFewArguments: 571 break; 572 573 case Sema::TDK_Incomplete: 574 case Sema::TDK_InvalidExplicitArguments: 575 Result.Data = Info.Param.getOpaqueValue(); 576 break; 577 578 case Sema::TDK_NonDeducedMismatch: { 579 // FIXME: Should allocate from normal heap so that we can free this later. 580 DFIArguments *Saved = new (Context) DFIArguments; 581 Saved->FirstArg = Info.FirstArg; 582 Saved->SecondArg = Info.SecondArg; 583 Result.Data = Saved; 584 break; 585 } 586 587 case Sema::TDK_Inconsistent: 588 case Sema::TDK_Underqualified: { 589 // FIXME: Should allocate from normal heap so that we can free this later. 590 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 591 Saved->Param = Info.Param; 592 Saved->FirstArg = Info.FirstArg; 593 Saved->SecondArg = Info.SecondArg; 594 Result.Data = Saved; 595 break; 596 } 597 598 case Sema::TDK_SubstitutionFailure: 599 Result.Data = Info.take(); 600 if (Info.hasSFINAEDiagnostic()) { 601 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt( 602 SourceLocation(), PartialDiagnostic::NullDiagnostic()); 603 Info.takeSFINAEDiagnostic(*Diag); 604 Result.HasDiagnostic = true; 605 } 606 break; 607 608 case Sema::TDK_FailedOverloadResolution: 609 Result.Data = Info.Expression; 610 break; 611 612 case Sema::TDK_MiscellaneousDeductionFailure: 613 break; 614 } 615 616 return Result; 617} 618 619void OverloadCandidate::DeductionFailureInfo::Destroy() { 620 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 621 case Sema::TDK_Success: 622 case Sema::TDK_Invalid: 623 case Sema::TDK_InstantiationDepth: 624 case Sema::TDK_Incomplete: 625 case Sema::TDK_TooManyArguments: 626 case Sema::TDK_TooFewArguments: 627 case Sema::TDK_InvalidExplicitArguments: 628 case Sema::TDK_FailedOverloadResolution: 629 break; 630 631 case Sema::TDK_Inconsistent: 632 case Sema::TDK_Underqualified: 633 case Sema::TDK_NonDeducedMismatch: 634 // FIXME: Destroy the data? 635 Data = 0; 636 break; 637 638 case Sema::TDK_SubstitutionFailure: 639 // FIXME: Destroy the template argument list? 640 Data = 0; 641 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) { 642 Diag->~PartialDiagnosticAt(); 643 HasDiagnostic = false; 644 } 645 break; 646 647 // Unhandled 648 case Sema::TDK_MiscellaneousDeductionFailure: 649 break; 650 } 651} 652 653PartialDiagnosticAt * 654OverloadCandidate::DeductionFailureInfo::getSFINAEDiagnostic() { 655 if (HasDiagnostic) 656 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic)); 657 return 0; 658} 659 660TemplateParameter 661OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 662 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 663 case Sema::TDK_Success: 664 case Sema::TDK_Invalid: 665 case Sema::TDK_InstantiationDepth: 666 case Sema::TDK_TooManyArguments: 667 case Sema::TDK_TooFewArguments: 668 case Sema::TDK_SubstitutionFailure: 669 case Sema::TDK_NonDeducedMismatch: 670 case Sema::TDK_FailedOverloadResolution: 671 return TemplateParameter(); 672 673 case Sema::TDK_Incomplete: 674 case Sema::TDK_InvalidExplicitArguments: 675 return TemplateParameter::getFromOpaqueValue(Data); 676 677 case Sema::TDK_Inconsistent: 678 case Sema::TDK_Underqualified: 679 return static_cast<DFIParamWithArguments*>(Data)->Param; 680 681 // Unhandled 682 case Sema::TDK_MiscellaneousDeductionFailure: 683 break; 684 } 685 686 return TemplateParameter(); 687} 688 689TemplateArgumentList * 690OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 691 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 692 case Sema::TDK_Success: 693 case Sema::TDK_Invalid: 694 case Sema::TDK_InstantiationDepth: 695 case Sema::TDK_TooManyArguments: 696 case Sema::TDK_TooFewArguments: 697 case Sema::TDK_Incomplete: 698 case Sema::TDK_InvalidExplicitArguments: 699 case Sema::TDK_Inconsistent: 700 case Sema::TDK_Underqualified: 701 case Sema::TDK_NonDeducedMismatch: 702 case Sema::TDK_FailedOverloadResolution: 703 return 0; 704 705 case Sema::TDK_SubstitutionFailure: 706 return static_cast<TemplateArgumentList*>(Data); 707 708 // Unhandled 709 case Sema::TDK_MiscellaneousDeductionFailure: 710 break; 711 } 712 713 return 0; 714} 715 716const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 717 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 718 case Sema::TDK_Success: 719 case Sema::TDK_Invalid: 720 case Sema::TDK_InstantiationDepth: 721 case Sema::TDK_Incomplete: 722 case Sema::TDK_TooManyArguments: 723 case Sema::TDK_TooFewArguments: 724 case Sema::TDK_InvalidExplicitArguments: 725 case Sema::TDK_SubstitutionFailure: 726 case Sema::TDK_FailedOverloadResolution: 727 return 0; 728 729 case Sema::TDK_Inconsistent: 730 case Sema::TDK_Underqualified: 731 case Sema::TDK_NonDeducedMismatch: 732 return &static_cast<DFIArguments*>(Data)->FirstArg; 733 734 // Unhandled 735 case Sema::TDK_MiscellaneousDeductionFailure: 736 break; 737 } 738 739 return 0; 740} 741 742const TemplateArgument * 743OverloadCandidate::DeductionFailureInfo::getSecondArg() { 744 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 745 case Sema::TDK_Success: 746 case Sema::TDK_Invalid: 747 case Sema::TDK_InstantiationDepth: 748 case Sema::TDK_Incomplete: 749 case Sema::TDK_TooManyArguments: 750 case Sema::TDK_TooFewArguments: 751 case Sema::TDK_InvalidExplicitArguments: 752 case Sema::TDK_SubstitutionFailure: 753 case Sema::TDK_FailedOverloadResolution: 754 return 0; 755 756 case Sema::TDK_Inconsistent: 757 case Sema::TDK_Underqualified: 758 case Sema::TDK_NonDeducedMismatch: 759 return &static_cast<DFIArguments*>(Data)->SecondArg; 760 761 // Unhandled 762 case Sema::TDK_MiscellaneousDeductionFailure: 763 break; 764 } 765 766 return 0; 767} 768 769Expr * 770OverloadCandidate::DeductionFailureInfo::getExpr() { 771 if (static_cast<Sema::TemplateDeductionResult>(Result) == 772 Sema::TDK_FailedOverloadResolution) 773 return static_cast<Expr*>(Data); 774 775 return 0; 776} 777 778void OverloadCandidateSet::destroyCandidates() { 779 for (iterator i = begin(), e = end(); i != e; ++i) { 780 for (unsigned ii = 0, ie = i->NumConversions; ii != ie; ++ii) 781 i->Conversions[ii].~ImplicitConversionSequence(); 782 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction) 783 i->DeductionFailure.Destroy(); 784 } 785} 786 787void OverloadCandidateSet::clear() { 788 destroyCandidates(); 789 NumInlineSequences = 0; 790 Candidates.clear(); 791 Functions.clear(); 792} 793 794namespace { 795 class UnbridgedCastsSet { 796 struct Entry { 797 Expr **Addr; 798 Expr *Saved; 799 }; 800 SmallVector<Entry, 2> Entries; 801 802 public: 803 void save(Sema &S, Expr *&E) { 804 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)); 805 Entry entry = { &E, E }; 806 Entries.push_back(entry); 807 E = S.stripARCUnbridgedCast(E); 808 } 809 810 void restore() { 811 for (SmallVectorImpl<Entry>::iterator 812 i = Entries.begin(), e = Entries.end(); i != e; ++i) 813 *i->Addr = i->Saved; 814 } 815 }; 816} 817 818/// checkPlaceholderForOverload - Do any interesting placeholder-like 819/// preprocessing on the given expression. 820/// 821/// \param unbridgedCasts a collection to which to add unbridged casts; 822/// without this, they will be immediately diagnosed as errors 823/// 824/// Return true on unrecoverable error. 825static bool checkPlaceholderForOverload(Sema &S, Expr *&E, 826 UnbridgedCastsSet *unbridgedCasts = 0) { 827 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) { 828 // We can't handle overloaded expressions here because overload 829 // resolution might reasonably tweak them. 830 if (placeholder->getKind() == BuiltinType::Overload) return false; 831 832 // If the context potentially accepts unbridged ARC casts, strip 833 // the unbridged cast and add it to the collection for later restoration. 834 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast && 835 unbridgedCasts) { 836 unbridgedCasts->save(S, E); 837 return false; 838 } 839 840 // Go ahead and check everything else. 841 ExprResult result = S.CheckPlaceholderExpr(E); 842 if (result.isInvalid()) 843 return true; 844 845 E = result.take(); 846 return false; 847 } 848 849 // Nothing to do. 850 return false; 851} 852 853/// checkArgPlaceholdersForOverload - Check a set of call operands for 854/// placeholders. 855static bool checkArgPlaceholdersForOverload(Sema &S, Expr **args, 856 unsigned numArgs, 857 UnbridgedCastsSet &unbridged) { 858 for (unsigned i = 0; i != numArgs; ++i) 859 if (checkPlaceholderForOverload(S, args[i], &unbridged)) 860 return true; 861 862 return false; 863} 864 865// IsOverload - Determine whether the given New declaration is an 866// overload of the declarations in Old. This routine returns false if 867// New and Old cannot be overloaded, e.g., if New has the same 868// signature as some function in Old (C++ 1.3.10) or if the Old 869// declarations aren't functions (or function templates) at all. When 870// it does return false, MatchedDecl will point to the decl that New 871// cannot be overloaded with. This decl may be a UsingShadowDecl on 872// top of the underlying declaration. 873// 874// Example: Given the following input: 875// 876// void f(int, float); // #1 877// void f(int, int); // #2 878// int f(int, int); // #3 879// 880// When we process #1, there is no previous declaration of "f", 881// so IsOverload will not be used. 882// 883// When we process #2, Old contains only the FunctionDecl for #1. By 884// comparing the parameter types, we see that #1 and #2 are overloaded 885// (since they have different signatures), so this routine returns 886// false; MatchedDecl is unchanged. 887// 888// When we process #3, Old is an overload set containing #1 and #2. We 889// compare the signatures of #3 to #1 (they're overloaded, so we do 890// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 891// identical (return types of functions are not part of the 892// signature), IsOverload returns false and MatchedDecl will be set to 893// point to the FunctionDecl for #2. 894// 895// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 896// into a class by a using declaration. The rules for whether to hide 897// shadow declarations ignore some properties which otherwise figure 898// into a function template's signature. 899Sema::OverloadKind 900Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 901 NamedDecl *&Match, bool NewIsUsingDecl) { 902 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 903 I != E; ++I) { 904 NamedDecl *OldD = *I; 905 906 bool OldIsUsingDecl = false; 907 if (isa<UsingShadowDecl>(OldD)) { 908 OldIsUsingDecl = true; 909 910 // We can always introduce two using declarations into the same 911 // context, even if they have identical signatures. 912 if (NewIsUsingDecl) continue; 913 914 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 915 } 916 917 // If either declaration was introduced by a using declaration, 918 // we'll need to use slightly different rules for matching. 919 // Essentially, these rules are the normal rules, except that 920 // function templates hide function templates with different 921 // return types or template parameter lists. 922 bool UseMemberUsingDeclRules = 923 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 924 925 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 926 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 927 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 928 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 929 continue; 930 } 931 932 Match = *I; 933 return Ovl_Match; 934 } 935 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 936 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 937 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 938 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 939 continue; 940 } 941 942 Match = *I; 943 return Ovl_Match; 944 } 945 } else if (isa<UsingDecl>(OldD)) { 946 // We can overload with these, which can show up when doing 947 // redeclaration checks for UsingDecls. 948 assert(Old.getLookupKind() == LookupUsingDeclName); 949 } else if (isa<TagDecl>(OldD)) { 950 // We can always overload with tags by hiding them. 951 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 952 // Optimistically assume that an unresolved using decl will 953 // overload; if it doesn't, we'll have to diagnose during 954 // template instantiation. 955 } else { 956 // (C++ 13p1): 957 // Only function declarations can be overloaded; object and type 958 // declarations cannot be overloaded. 959 Match = *I; 960 return Ovl_NonFunction; 961 } 962 } 963 964 return Ovl_Overload; 965} 966 967static bool canBeOverloaded(const FunctionDecl &D) { 968 if (D.getAttr<OverloadableAttr>()) 969 return true; 970 if (D.isExternC()) 971 return false; 972 973 // Main cannot be overloaded (basic.start.main). 974 if (D.isMain()) 975 return false; 976 977 return true; 978} 979 980bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 981 bool UseUsingDeclRules) { 982 // If both of the functions are extern "C", then they are not 983 // overloads. 984 if (!canBeOverloaded(*Old) && !canBeOverloaded(*New)) 985 return false; 986 987 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 988 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 989 990 // C++ [temp.fct]p2: 991 // A function template can be overloaded with other function templates 992 // and with normal (non-template) functions. 993 if ((OldTemplate == 0) != (NewTemplate == 0)) 994 return true; 995 996 // Is the function New an overload of the function Old? 997 QualType OldQType = Context.getCanonicalType(Old->getType()); 998 QualType NewQType = Context.getCanonicalType(New->getType()); 999 1000 // Compare the signatures (C++ 1.3.10) of the two functions to 1001 // determine whether they are overloads. If we find any mismatch 1002 // in the signature, they are overloads. 1003 1004 // If either of these functions is a K&R-style function (no 1005 // prototype), then we consider them to have matching signatures. 1006 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 1007 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 1008 return false; 1009 1010 const FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 1011 const FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 1012 1013 // The signature of a function includes the types of its 1014 // parameters (C++ 1.3.10), which includes the presence or absence 1015 // of the ellipsis; see C++ DR 357). 1016 if (OldQType != NewQType && 1017 (OldType->getNumArgs() != NewType->getNumArgs() || 1018 OldType->isVariadic() != NewType->isVariadic() || 1019 !FunctionArgTypesAreEqual(OldType, NewType))) 1020 return true; 1021 1022 // C++ [temp.over.link]p4: 1023 // The signature of a function template consists of its function 1024 // signature, its return type and its template parameter list. The names 1025 // of the template parameters are significant only for establishing the 1026 // relationship between the template parameters and the rest of the 1027 // signature. 1028 // 1029 // We check the return type and template parameter lists for function 1030 // templates first; the remaining checks follow. 1031 // 1032 // However, we don't consider either of these when deciding whether 1033 // a member introduced by a shadow declaration is hidden. 1034 if (!UseUsingDeclRules && NewTemplate && 1035 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 1036 OldTemplate->getTemplateParameters(), 1037 false, TPL_TemplateMatch) || 1038 OldType->getResultType() != NewType->getResultType())) 1039 return true; 1040 1041 // If the function is a class member, its signature includes the 1042 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. 1043 // 1044 // As part of this, also check whether one of the member functions 1045 // is static, in which case they are not overloads (C++ 1046 // 13.1p2). While not part of the definition of the signature, 1047 // this check is important to determine whether these functions 1048 // can be overloaded. 1049 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old); 1050 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New); 1051 if (OldMethod && NewMethod && 1052 !OldMethod->isStatic() && !NewMethod->isStatic()) { 1053 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) { 1054 if (!UseUsingDeclRules && 1055 (OldMethod->getRefQualifier() == RQ_None || 1056 NewMethod->getRefQualifier() == RQ_None)) { 1057 // C++0x [over.load]p2: 1058 // - Member function declarations with the same name and the same 1059 // parameter-type-list as well as member function template 1060 // declarations with the same name, the same parameter-type-list, and 1061 // the same template parameter lists cannot be overloaded if any of 1062 // them, but not all, have a ref-qualifier (8.3.5). 1063 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) 1064 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); 1065 Diag(OldMethod->getLocation(), diag::note_previous_declaration); 1066 } 1067 return true; 1068 } 1069 1070 // We may not have applied the implicit const for a constexpr member 1071 // function yet (because we haven't yet resolved whether this is a static 1072 // or non-static member function). Add it now, on the assumption that this 1073 // is a redeclaration of OldMethod. 1074 unsigned NewQuals = NewMethod->getTypeQualifiers(); 1075 if (NewMethod->isConstexpr() && !isa<CXXConstructorDecl>(NewMethod)) 1076 NewQuals |= Qualifiers::Const; 1077 if (OldMethod->getTypeQualifiers() != NewQuals) 1078 return true; 1079 } 1080 1081 // The signatures match; this is not an overload. 1082 return false; 1083} 1084 1085/// \brief Checks availability of the function depending on the current 1086/// function context. Inside an unavailable function, unavailability is ignored. 1087/// 1088/// \returns true if \arg FD is unavailable and current context is inside 1089/// an available function, false otherwise. 1090bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) { 1091 return FD->isUnavailable() && !cast<Decl>(CurContext)->isUnavailable(); 1092} 1093 1094/// \brief Tries a user-defined conversion from From to ToType. 1095/// 1096/// Produces an implicit conversion sequence for when a standard conversion 1097/// is not an option. See TryImplicitConversion for more information. 1098static ImplicitConversionSequence 1099TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 1100 bool SuppressUserConversions, 1101 bool AllowExplicit, 1102 bool InOverloadResolution, 1103 bool CStyle, 1104 bool AllowObjCWritebackConversion) { 1105 ImplicitConversionSequence ICS; 1106 1107 if (SuppressUserConversions) { 1108 // We're not in the case above, so there is no conversion that 1109 // we can perform. 1110 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 1111 return ICS; 1112 } 1113 1114 // Attempt user-defined conversion. 1115 OverloadCandidateSet Conversions(From->getExprLoc()); 1116 OverloadingResult UserDefResult 1117 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 1118 AllowExplicit); 1119 1120 if (UserDefResult == OR_Success) { 1121 ICS.setUserDefined(); 1122 // C++ [over.ics.user]p4: 1123 // A conversion of an expression of class type to the same class 1124 // type is given Exact Match rank, and a conversion of an 1125 // expression of class type to a base class of that type is 1126 // given Conversion rank, in spite of the fact that a copy 1127 // constructor (i.e., a user-defined conversion function) is 1128 // called for those cases. 1129 if (CXXConstructorDecl *Constructor 1130 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 1131 QualType FromCanon 1132 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 1133 QualType ToCanon 1134 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 1135 if (Constructor->isCopyConstructor() && 1136 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 1137 // Turn this into a "standard" conversion sequence, so that it 1138 // gets ranked with standard conversion sequences. 1139 ICS.setStandard(); 1140 ICS.Standard.setAsIdentityConversion(); 1141 ICS.Standard.setFromType(From->getType()); 1142 ICS.Standard.setAllToTypes(ToType); 1143 ICS.Standard.CopyConstructor = Constructor; 1144 if (ToCanon != FromCanon) 1145 ICS.Standard.Second = ICK_Derived_To_Base; 1146 } 1147 } 1148 1149 // C++ [over.best.ics]p4: 1150 // However, when considering the argument of a user-defined 1151 // conversion function that is a candidate by 13.3.1.3 when 1152 // invoked for the copying of the temporary in the second step 1153 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 1154 // 13.3.1.6 in all cases, only standard conversion sequences and 1155 // ellipsis conversion sequences are allowed. 1156 if (SuppressUserConversions && ICS.isUserDefined()) { 1157 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 1158 } 1159 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 1160 ICS.setAmbiguous(); 1161 ICS.Ambiguous.setFromType(From->getType()); 1162 ICS.Ambiguous.setToType(ToType); 1163 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 1164 Cand != Conversions.end(); ++Cand) 1165 if (Cand->Viable) 1166 ICS.Ambiguous.addConversion(Cand->Function); 1167 } else { 1168 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 1169 } 1170 1171 return ICS; 1172} 1173 1174/// TryImplicitConversion - Attempt to perform an implicit conversion 1175/// from the given expression (Expr) to the given type (ToType). This 1176/// function returns an implicit conversion sequence that can be used 1177/// to perform the initialization. Given 1178/// 1179/// void f(float f); 1180/// void g(int i) { f(i); } 1181/// 1182/// this routine would produce an implicit conversion sequence to 1183/// describe the initialization of f from i, which will be a standard 1184/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 1185/// 4.1) followed by a floating-integral conversion (C++ 4.9). 1186// 1187/// Note that this routine only determines how the conversion can be 1188/// performed; it does not actually perform the conversion. As such, 1189/// it will not produce any diagnostics if no conversion is available, 1190/// but will instead return an implicit conversion sequence of kind 1191/// "BadConversion". 1192/// 1193/// If @p SuppressUserConversions, then user-defined conversions are 1194/// not permitted. 1195/// If @p AllowExplicit, then explicit user-defined conversions are 1196/// permitted. 1197/// 1198/// \param AllowObjCWritebackConversion Whether we allow the Objective-C 1199/// writeback conversion, which allows __autoreleasing id* parameters to 1200/// be initialized with __strong id* or __weak id* arguments. 1201static ImplicitConversionSequence 1202TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 1203 bool SuppressUserConversions, 1204 bool AllowExplicit, 1205 bool InOverloadResolution, 1206 bool CStyle, 1207 bool AllowObjCWritebackConversion) { 1208 ImplicitConversionSequence ICS; 1209 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 1210 ICS.Standard, CStyle, AllowObjCWritebackConversion)){ 1211 ICS.setStandard(); 1212 return ICS; 1213 } 1214 1215 if (!S.getLangOpts().CPlusPlus) { 1216 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 1217 return ICS; 1218 } 1219 1220 // C++ [over.ics.user]p4: 1221 // A conversion of an expression of class type to the same class 1222 // type is given Exact Match rank, and a conversion of an 1223 // expression of class type to a base class of that type is 1224 // given Conversion rank, in spite of the fact that a copy/move 1225 // constructor (i.e., a user-defined conversion function) is 1226 // called for those cases. 1227 QualType FromType = From->getType(); 1228 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 1229 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 1230 S.IsDerivedFrom(FromType, ToType))) { 1231 ICS.setStandard(); 1232 ICS.Standard.setAsIdentityConversion(); 1233 ICS.Standard.setFromType(FromType); 1234 ICS.Standard.setAllToTypes(ToType); 1235 1236 // We don't actually check at this point whether there is a valid 1237 // copy/move constructor, since overloading just assumes that it 1238 // exists. When we actually perform initialization, we'll find the 1239 // appropriate constructor to copy the returned object, if needed. 1240 ICS.Standard.CopyConstructor = 0; 1241 1242 // Determine whether this is considered a derived-to-base conversion. 1243 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 1244 ICS.Standard.Second = ICK_Derived_To_Base; 1245 1246 return ICS; 1247 } 1248 1249 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, 1250 AllowExplicit, InOverloadResolution, CStyle, 1251 AllowObjCWritebackConversion); 1252} 1253 1254ImplicitConversionSequence 1255Sema::TryImplicitConversion(Expr *From, QualType ToType, 1256 bool SuppressUserConversions, 1257 bool AllowExplicit, 1258 bool InOverloadResolution, 1259 bool CStyle, 1260 bool AllowObjCWritebackConversion) { 1261 return clang::TryImplicitConversion(*this, From, ToType, 1262 SuppressUserConversions, AllowExplicit, 1263 InOverloadResolution, CStyle, 1264 AllowObjCWritebackConversion); 1265} 1266 1267/// PerformImplicitConversion - Perform an implicit conversion of the 1268/// expression From to the type ToType. Returns the 1269/// converted expression. Flavor is the kind of conversion we're 1270/// performing, used in the error message. If @p AllowExplicit, 1271/// explicit user-defined conversions are permitted. 1272ExprResult 1273Sema::PerformImplicitConversion(Expr *From, QualType ToType, 1274 AssignmentAction Action, bool AllowExplicit) { 1275 ImplicitConversionSequence ICS; 1276 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 1277} 1278 1279ExprResult 1280Sema::PerformImplicitConversion(Expr *From, QualType ToType, 1281 AssignmentAction Action, bool AllowExplicit, 1282 ImplicitConversionSequence& ICS) { 1283 if (checkPlaceholderForOverload(*this, From)) 1284 return ExprError(); 1285 1286 // Objective-C ARC: Determine whether we will allow the writeback conversion. 1287 bool AllowObjCWritebackConversion 1288 = getLangOpts().ObjCAutoRefCount && 1289 (Action == AA_Passing || Action == AA_Sending); 1290 1291 ICS = clang::TryImplicitConversion(*this, From, ToType, 1292 /*SuppressUserConversions=*/false, 1293 AllowExplicit, 1294 /*InOverloadResolution=*/false, 1295 /*CStyle=*/false, 1296 AllowObjCWritebackConversion); 1297 return PerformImplicitConversion(From, ToType, ICS, Action); 1298} 1299 1300/// \brief Determine whether the conversion from FromType to ToType is a valid 1301/// conversion that strips "noreturn" off the nested function type. 1302bool Sema::IsNoReturnConversion(QualType FromType, QualType ToType, 1303 QualType &ResultTy) { 1304 if (Context.hasSameUnqualifiedType(FromType, ToType)) 1305 return false; 1306 1307 // Permit the conversion F(t __attribute__((noreturn))) -> F(t) 1308 // where F adds one of the following at most once: 1309 // - a pointer 1310 // - a member pointer 1311 // - a block pointer 1312 CanQualType CanTo = Context.getCanonicalType(ToType); 1313 CanQualType CanFrom = Context.getCanonicalType(FromType); 1314 Type::TypeClass TyClass = CanTo->getTypeClass(); 1315 if (TyClass != CanFrom->getTypeClass()) return false; 1316 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { 1317 if (TyClass == Type::Pointer) { 1318 CanTo = CanTo.getAs<PointerType>()->getPointeeType(); 1319 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType(); 1320 } else if (TyClass == Type::BlockPointer) { 1321 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType(); 1322 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType(); 1323 } else if (TyClass == Type::MemberPointer) { 1324 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType(); 1325 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType(); 1326 } else { 1327 return false; 1328 } 1329 1330 TyClass = CanTo->getTypeClass(); 1331 if (TyClass != CanFrom->getTypeClass()) return false; 1332 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) 1333 return false; 1334 } 1335 1336 const FunctionType *FromFn = cast<FunctionType>(CanFrom); 1337 FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); 1338 if (!EInfo.getNoReturn()) return false; 1339 1340 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); 1341 assert(QualType(FromFn, 0).isCanonical()); 1342 if (QualType(FromFn, 0) != CanTo) return false; 1343 1344 ResultTy = ToType; 1345 return true; 1346} 1347 1348/// \brief Determine whether the conversion from FromType to ToType is a valid 1349/// vector conversion. 1350/// 1351/// \param ICK Will be set to the vector conversion kind, if this is a vector 1352/// conversion. 1353static bool IsVectorConversion(ASTContext &Context, QualType FromType, 1354 QualType ToType, ImplicitConversionKind &ICK) { 1355 // We need at least one of these types to be a vector type to have a vector 1356 // conversion. 1357 if (!ToType->isVectorType() && !FromType->isVectorType()) 1358 return false; 1359 1360 // Identical types require no conversions. 1361 if (Context.hasSameUnqualifiedType(FromType, ToType)) 1362 return false; 1363 1364 // There are no conversions between extended vector types, only identity. 1365 if (ToType->isExtVectorType()) { 1366 // There are no conversions between extended vector types other than the 1367 // identity conversion. 1368 if (FromType->isExtVectorType()) 1369 return false; 1370 1371 // Vector splat from any arithmetic type to a vector. 1372 if (FromType->isArithmeticType()) { 1373 ICK = ICK_Vector_Splat; 1374 return true; 1375 } 1376 } 1377 1378 // We can perform the conversion between vector types in the following cases: 1379 // 1)vector types are equivalent AltiVec and GCC vector types 1380 // 2)lax vector conversions are permitted and the vector types are of the 1381 // same size 1382 if (ToType->isVectorType() && FromType->isVectorType()) { 1383 if (Context.areCompatibleVectorTypes(FromType, ToType) || 1384 (Context.getLangOpts().LaxVectorConversions && 1385 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 1386 ICK = ICK_Vector_Conversion; 1387 return true; 1388 } 1389 } 1390 1391 return false; 1392} 1393 1394static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType, 1395 bool InOverloadResolution, 1396 StandardConversionSequence &SCS, 1397 bool CStyle); 1398 1399/// IsStandardConversion - Determines whether there is a standard 1400/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 1401/// expression From to the type ToType. Standard conversion sequences 1402/// only consider non-class types; for conversions that involve class 1403/// types, use TryImplicitConversion. If a conversion exists, SCS will 1404/// contain the standard conversion sequence required to perform this 1405/// conversion and this routine will return true. Otherwise, this 1406/// routine will return false and the value of SCS is unspecified. 1407static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 1408 bool InOverloadResolution, 1409 StandardConversionSequence &SCS, 1410 bool CStyle, 1411 bool AllowObjCWritebackConversion) { 1412 QualType FromType = From->getType(); 1413 1414 // Standard conversions (C++ [conv]) 1415 SCS.setAsIdentityConversion(); 1416 SCS.DeprecatedStringLiteralToCharPtr = false; 1417 SCS.IncompatibleObjC = false; 1418 SCS.setFromType(FromType); 1419 SCS.CopyConstructor = 0; 1420 1421 // There are no standard conversions for class types in C++, so 1422 // abort early. When overloading in C, however, we do permit 1423 if (FromType->isRecordType() || ToType->isRecordType()) { 1424 if (S.getLangOpts().CPlusPlus) 1425 return false; 1426 1427 // When we're overloading in C, we allow, as standard conversions, 1428 } 1429 1430 // The first conversion can be an lvalue-to-rvalue conversion, 1431 // array-to-pointer conversion, or function-to-pointer conversion 1432 // (C++ 4p1). 1433 1434 if (FromType == S.Context.OverloadTy) { 1435 DeclAccessPair AccessPair; 1436 if (FunctionDecl *Fn 1437 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 1438 AccessPair)) { 1439 // We were able to resolve the address of the overloaded function, 1440 // so we can convert to the type of that function. 1441 FromType = Fn->getType(); 1442 1443 // we can sometimes resolve &foo<int> regardless of ToType, so check 1444 // if the type matches (identity) or we are converting to bool 1445 if (!S.Context.hasSameUnqualifiedType( 1446 S.ExtractUnqualifiedFunctionType(ToType), FromType)) { 1447 QualType resultTy; 1448 // if the function type matches except for [[noreturn]], it's ok 1449 if (!S.IsNoReturnConversion(FromType, 1450 S.ExtractUnqualifiedFunctionType(ToType), resultTy)) 1451 // otherwise, only a boolean conversion is standard 1452 if (!ToType->isBooleanType()) 1453 return false; 1454 } 1455 1456 // Check if the "from" expression is taking the address of an overloaded 1457 // function and recompute the FromType accordingly. Take advantage of the 1458 // fact that non-static member functions *must* have such an address-of 1459 // expression. 1460 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn); 1461 if (Method && !Method->isStatic()) { 1462 assert(isa<UnaryOperator>(From->IgnoreParens()) && 1463 "Non-unary operator on non-static member address"); 1464 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() 1465 == UO_AddrOf && 1466 "Non-address-of operator on non-static member address"); 1467 const Type *ClassType 1468 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1469 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1470 } else if (isa<UnaryOperator>(From->IgnoreParens())) { 1471 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == 1472 UO_AddrOf && 1473 "Non-address-of operator for overloaded function expression"); 1474 FromType = S.Context.getPointerType(FromType); 1475 } 1476 1477 // Check that we've computed the proper type after overload resolution. 1478 assert(S.Context.hasSameType( 1479 FromType, 1480 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1481 } else { 1482 return false; 1483 } 1484 } 1485 // Lvalue-to-rvalue conversion (C++11 4.1): 1486 // A glvalue (3.10) of a non-function, non-array type T can 1487 // be converted to a prvalue. 1488 bool argIsLValue = From->isGLValue(); 1489 if (argIsLValue && 1490 !FromType->isFunctionType() && !FromType->isArrayType() && 1491 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1492 SCS.First = ICK_Lvalue_To_Rvalue; 1493 1494 // C11 6.3.2.1p2: 1495 // ... if the lvalue has atomic type, the value has the non-atomic version 1496 // of the type of the lvalue ... 1497 if (const AtomicType *Atomic = FromType->getAs<AtomicType>()) 1498 FromType = Atomic->getValueType(); 1499 1500 // If T is a non-class type, the type of the rvalue is the 1501 // cv-unqualified version of T. Otherwise, the type of the rvalue 1502 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1503 // just strip the qualifiers because they don't matter. 1504 FromType = FromType.getUnqualifiedType(); 1505 } else if (FromType->isArrayType()) { 1506 // Array-to-pointer conversion (C++ 4.2) 1507 SCS.First = ICK_Array_To_Pointer; 1508 1509 // An lvalue or rvalue of type "array of N T" or "array of unknown 1510 // bound of T" can be converted to an rvalue of type "pointer to 1511 // T" (C++ 4.2p1). 1512 FromType = S.Context.getArrayDecayedType(FromType); 1513 1514 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1515 // This conversion is deprecated. (C++ D.4). 1516 SCS.DeprecatedStringLiteralToCharPtr = true; 1517 1518 // For the purpose of ranking in overload resolution 1519 // (13.3.3.1.1), this conversion is considered an 1520 // array-to-pointer conversion followed by a qualification 1521 // conversion (4.4). (C++ 4.2p2) 1522 SCS.Second = ICK_Identity; 1523 SCS.Third = ICK_Qualification; 1524 SCS.QualificationIncludesObjCLifetime = false; 1525 SCS.setAllToTypes(FromType); 1526 return true; 1527 } 1528 } else if (FromType->isFunctionType() && argIsLValue) { 1529 // Function-to-pointer conversion (C++ 4.3). 1530 SCS.First = ICK_Function_To_Pointer; 1531 1532 // An lvalue of function type T can be converted to an rvalue of 1533 // type "pointer to T." The result is a pointer to the 1534 // function. (C++ 4.3p1). 1535 FromType = S.Context.getPointerType(FromType); 1536 } else { 1537 // We don't require any conversions for the first step. 1538 SCS.First = ICK_Identity; 1539 } 1540 SCS.setToType(0, FromType); 1541 1542 // The second conversion can be an integral promotion, floating 1543 // point promotion, integral conversion, floating point conversion, 1544 // floating-integral conversion, pointer conversion, 1545 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1546 // For overloading in C, this can also be a "compatible-type" 1547 // conversion. 1548 bool IncompatibleObjC = false; 1549 ImplicitConversionKind SecondICK = ICK_Identity; 1550 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1551 // The unqualified versions of the types are the same: there's no 1552 // conversion to do. 1553 SCS.Second = ICK_Identity; 1554 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1555 // Integral promotion (C++ 4.5). 1556 SCS.Second = ICK_Integral_Promotion; 1557 FromType = ToType.getUnqualifiedType(); 1558 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1559 // Floating point promotion (C++ 4.6). 1560 SCS.Second = ICK_Floating_Promotion; 1561 FromType = ToType.getUnqualifiedType(); 1562 } else if (S.IsComplexPromotion(FromType, ToType)) { 1563 // Complex promotion (Clang extension) 1564 SCS.Second = ICK_Complex_Promotion; 1565 FromType = ToType.getUnqualifiedType(); 1566 } else if (ToType->isBooleanType() && 1567 (FromType->isArithmeticType() || 1568 FromType->isAnyPointerType() || 1569 FromType->isBlockPointerType() || 1570 FromType->isMemberPointerType() || 1571 FromType->isNullPtrType())) { 1572 // Boolean conversions (C++ 4.12). 1573 SCS.Second = ICK_Boolean_Conversion; 1574 FromType = S.Context.BoolTy; 1575 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1576 ToType->isIntegralType(S.Context)) { 1577 // Integral conversions (C++ 4.7). 1578 SCS.Second = ICK_Integral_Conversion; 1579 FromType = ToType.getUnqualifiedType(); 1580 } else if (FromType->isAnyComplexType() && ToType->isComplexType()) { 1581 // Complex conversions (C99 6.3.1.6) 1582 SCS.Second = ICK_Complex_Conversion; 1583 FromType = ToType.getUnqualifiedType(); 1584 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1585 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1586 // Complex-real conversions (C99 6.3.1.7) 1587 SCS.Second = ICK_Complex_Real; 1588 FromType = ToType.getUnqualifiedType(); 1589 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1590 // Floating point conversions (C++ 4.8). 1591 SCS.Second = ICK_Floating_Conversion; 1592 FromType = ToType.getUnqualifiedType(); 1593 } else if ((FromType->isRealFloatingType() && 1594 ToType->isIntegralType(S.Context)) || 1595 (FromType->isIntegralOrUnscopedEnumerationType() && 1596 ToType->isRealFloatingType())) { 1597 // Floating-integral conversions (C++ 4.9). 1598 SCS.Second = ICK_Floating_Integral; 1599 FromType = ToType.getUnqualifiedType(); 1600 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { 1601 SCS.Second = ICK_Block_Pointer_Conversion; 1602 } else if (AllowObjCWritebackConversion && 1603 S.isObjCWritebackConversion(FromType, ToType, FromType)) { 1604 SCS.Second = ICK_Writeback_Conversion; 1605 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1606 FromType, IncompatibleObjC)) { 1607 // Pointer conversions (C++ 4.10). 1608 SCS.Second = ICK_Pointer_Conversion; 1609 SCS.IncompatibleObjC = IncompatibleObjC; 1610 FromType = FromType.getUnqualifiedType(); 1611 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1612 InOverloadResolution, FromType)) { 1613 // Pointer to member conversions (4.11). 1614 SCS.Second = ICK_Pointer_Member; 1615 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1616 SCS.Second = SecondICK; 1617 FromType = ToType.getUnqualifiedType(); 1618 } else if (!S.getLangOpts().CPlusPlus && 1619 S.Context.typesAreCompatible(ToType, FromType)) { 1620 // Compatible conversions (Clang extension for C function overloading) 1621 SCS.Second = ICK_Compatible_Conversion; 1622 FromType = ToType.getUnqualifiedType(); 1623 } else if (S.IsNoReturnConversion(FromType, ToType, FromType)) { 1624 // Treat a conversion that strips "noreturn" as an identity conversion. 1625 SCS.Second = ICK_NoReturn_Adjustment; 1626 } else if (IsTransparentUnionStandardConversion(S, From, ToType, 1627 InOverloadResolution, 1628 SCS, CStyle)) { 1629 SCS.Second = ICK_TransparentUnionConversion; 1630 FromType = ToType; 1631 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS, 1632 CStyle)) { 1633 // tryAtomicConversion has updated the standard conversion sequence 1634 // appropriately. 1635 return true; 1636 } else if (ToType->isEventT() && 1637 From->isIntegerConstantExpr(S.getASTContext()) && 1638 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) { 1639 SCS.Second = ICK_Zero_Event_Conversion; 1640 FromType = ToType; 1641 } else { 1642 // No second conversion required. 1643 SCS.Second = ICK_Identity; 1644 } 1645 SCS.setToType(1, FromType); 1646 1647 QualType CanonFrom; 1648 QualType CanonTo; 1649 // The third conversion can be a qualification conversion (C++ 4p1). 1650 bool ObjCLifetimeConversion; 1651 if (S.IsQualificationConversion(FromType, ToType, CStyle, 1652 ObjCLifetimeConversion)) { 1653 SCS.Third = ICK_Qualification; 1654 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion; 1655 FromType = ToType; 1656 CanonFrom = S.Context.getCanonicalType(FromType); 1657 CanonTo = S.Context.getCanonicalType(ToType); 1658 } else { 1659 // No conversion required 1660 SCS.Third = ICK_Identity; 1661 1662 // C++ [over.best.ics]p6: 1663 // [...] Any difference in top-level cv-qualification is 1664 // subsumed by the initialization itself and does not constitute 1665 // a conversion. [...] 1666 CanonFrom = S.Context.getCanonicalType(FromType); 1667 CanonTo = S.Context.getCanonicalType(ToType); 1668 if (CanonFrom.getLocalUnqualifiedType() 1669 == CanonTo.getLocalUnqualifiedType() && 1670 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1671 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr() 1672 || CanonFrom.getObjCLifetime() != CanonTo.getObjCLifetime() 1673 || (CanonFrom->isSamplerT() && 1674 CanonFrom.getAddressSpace() != CanonTo.getAddressSpace()))) { 1675 FromType = ToType; 1676 CanonFrom = CanonTo; 1677 } 1678 } 1679 SCS.setToType(2, FromType); 1680 1681 // If we have not converted the argument type to the parameter type, 1682 // this is a bad conversion sequence. 1683 if (CanonFrom != CanonTo) 1684 return false; 1685 1686 return true; 1687} 1688 1689static bool 1690IsTransparentUnionStandardConversion(Sema &S, Expr* From, 1691 QualType &ToType, 1692 bool InOverloadResolution, 1693 StandardConversionSequence &SCS, 1694 bool CStyle) { 1695 1696 const RecordType *UT = ToType->getAsUnionType(); 1697 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 1698 return false; 1699 // The field to initialize within the transparent union. 1700 RecordDecl *UD = UT->getDecl(); 1701 // It's compatible if the expression matches any of the fields. 1702 for (RecordDecl::field_iterator it = UD->field_begin(), 1703 itend = UD->field_end(); 1704 it != itend; ++it) { 1705 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, 1706 CStyle, /*ObjCWritebackConversion=*/false)) { 1707 ToType = it->getType(); 1708 return true; 1709 } 1710 } 1711 return false; 1712} 1713 1714/// IsIntegralPromotion - Determines whether the conversion from the 1715/// expression From (whose potentially-adjusted type is FromType) to 1716/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1717/// sets PromotedType to the promoted type. 1718bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1719 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1720 // All integers are built-in. 1721 if (!To) { 1722 return false; 1723 } 1724 1725 // An rvalue of type char, signed char, unsigned char, short int, or 1726 // unsigned short int can be converted to an rvalue of type int if 1727 // int can represent all the values of the source type; otherwise, 1728 // the source rvalue can be converted to an rvalue of type unsigned 1729 // int (C++ 4.5p1). 1730 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1731 !FromType->isEnumeralType()) { 1732 if (// We can promote any signed, promotable integer type to an int 1733 (FromType->isSignedIntegerType() || 1734 // We can promote any unsigned integer type whose size is 1735 // less than int to an int. 1736 (!FromType->isSignedIntegerType() && 1737 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1738 return To->getKind() == BuiltinType::Int; 1739 } 1740 1741 return To->getKind() == BuiltinType::UInt; 1742 } 1743 1744 // C++11 [conv.prom]p3: 1745 // A prvalue of an unscoped enumeration type whose underlying type is not 1746 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1747 // following types that can represent all the values of the enumeration 1748 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1749 // unsigned int, long int, unsigned long int, long long int, or unsigned 1750 // long long int. If none of the types in that list can represent all the 1751 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1752 // type can be converted to an rvalue a prvalue of the extended integer type 1753 // with lowest integer conversion rank (4.13) greater than the rank of long 1754 // long in which all the values of the enumeration can be represented. If 1755 // there are two such extended types, the signed one is chosen. 1756 // C++11 [conv.prom]p4: 1757 // A prvalue of an unscoped enumeration type whose underlying type is fixed 1758 // can be converted to a prvalue of its underlying type. Moreover, if 1759 // integral promotion can be applied to its underlying type, a prvalue of an 1760 // unscoped enumeration type whose underlying type is fixed can also be 1761 // converted to a prvalue of the promoted underlying type. 1762 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1763 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1764 // provided for a scoped enumeration. 1765 if (FromEnumType->getDecl()->isScoped()) 1766 return false; 1767 1768 // We can perform an integral promotion to the underlying type of the enum, 1769 // even if that's not the promoted type. 1770 if (FromEnumType->getDecl()->isFixed()) { 1771 QualType Underlying = FromEnumType->getDecl()->getIntegerType(); 1772 return Context.hasSameUnqualifiedType(Underlying, ToType) || 1773 IsIntegralPromotion(From, Underlying, ToType); 1774 } 1775 1776 // We have already pre-calculated the promotion type, so this is trivial. 1777 if (ToType->isIntegerType() && 1778 !RequireCompleteType(From->getLocStart(), FromType, 0)) 1779 return Context.hasSameUnqualifiedType(ToType, 1780 FromEnumType->getDecl()->getPromotionType()); 1781 } 1782 1783 // C++0x [conv.prom]p2: 1784 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1785 // to an rvalue a prvalue of the first of the following types that can 1786 // represent all the values of its underlying type: int, unsigned int, 1787 // long int, unsigned long int, long long int, or unsigned long long int. 1788 // If none of the types in that list can represent all the values of its 1789 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1790 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1791 // type. 1792 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1793 ToType->isIntegerType()) { 1794 // Determine whether the type we're converting from is signed or 1795 // unsigned. 1796 bool FromIsSigned = FromType->isSignedIntegerType(); 1797 uint64_t FromSize = Context.getTypeSize(FromType); 1798 1799 // The types we'll try to promote to, in the appropriate 1800 // order. Try each of these types. 1801 QualType PromoteTypes[6] = { 1802 Context.IntTy, Context.UnsignedIntTy, 1803 Context.LongTy, Context.UnsignedLongTy , 1804 Context.LongLongTy, Context.UnsignedLongLongTy 1805 }; 1806 for (int Idx = 0; Idx < 6; ++Idx) { 1807 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1808 if (FromSize < ToSize || 1809 (FromSize == ToSize && 1810 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1811 // We found the type that we can promote to. If this is the 1812 // type we wanted, we have a promotion. Otherwise, no 1813 // promotion. 1814 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1815 } 1816 } 1817 } 1818 1819 // An rvalue for an integral bit-field (9.6) can be converted to an 1820 // rvalue of type int if int can represent all the values of the 1821 // bit-field; otherwise, it can be converted to unsigned int if 1822 // unsigned int can represent all the values of the bit-field. If 1823 // the bit-field is larger yet, no integral promotion applies to 1824 // it. If the bit-field has an enumerated type, it is treated as any 1825 // other value of that type for promotion purposes (C++ 4.5p3). 1826 // FIXME: We should delay checking of bit-fields until we actually perform the 1827 // conversion. 1828 using llvm::APSInt; 1829 if (From) 1830 if (FieldDecl *MemberDecl = From->getBitField()) { 1831 APSInt BitWidth; 1832 if (FromType->isIntegralType(Context) && 1833 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1834 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1835 ToSize = Context.getTypeSize(ToType); 1836 1837 // Are we promoting to an int from a bitfield that fits in an int? 1838 if (BitWidth < ToSize || 1839 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1840 return To->getKind() == BuiltinType::Int; 1841 } 1842 1843 // Are we promoting to an unsigned int from an unsigned bitfield 1844 // that fits into an unsigned int? 1845 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1846 return To->getKind() == BuiltinType::UInt; 1847 } 1848 1849 return false; 1850 } 1851 } 1852 1853 // An rvalue of type bool can be converted to an rvalue of type int, 1854 // with false becoming zero and true becoming one (C++ 4.5p4). 1855 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1856 return true; 1857 } 1858 1859 return false; 1860} 1861 1862/// IsFloatingPointPromotion - Determines whether the conversion from 1863/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1864/// returns true and sets PromotedType to the promoted type. 1865bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1866 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1867 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1868 /// An rvalue of type float can be converted to an rvalue of type 1869 /// double. (C++ 4.6p1). 1870 if (FromBuiltin->getKind() == BuiltinType::Float && 1871 ToBuiltin->getKind() == BuiltinType::Double) 1872 return true; 1873 1874 // C99 6.3.1.5p1: 1875 // When a float is promoted to double or long double, or a 1876 // double is promoted to long double [...]. 1877 if (!getLangOpts().CPlusPlus && 1878 (FromBuiltin->getKind() == BuiltinType::Float || 1879 FromBuiltin->getKind() == BuiltinType::Double) && 1880 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1881 return true; 1882 1883 // Half can be promoted to float. 1884 if (!getLangOpts().NativeHalfType && 1885 FromBuiltin->getKind() == BuiltinType::Half && 1886 ToBuiltin->getKind() == BuiltinType::Float) 1887 return true; 1888 } 1889 1890 return false; 1891} 1892 1893/// \brief Determine if a conversion is a complex promotion. 1894/// 1895/// A complex promotion is defined as a complex -> complex conversion 1896/// where the conversion between the underlying real types is a 1897/// floating-point or integral promotion. 1898bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1899 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1900 if (!FromComplex) 1901 return false; 1902 1903 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1904 if (!ToComplex) 1905 return false; 1906 1907 return IsFloatingPointPromotion(FromComplex->getElementType(), 1908 ToComplex->getElementType()) || 1909 IsIntegralPromotion(0, FromComplex->getElementType(), 1910 ToComplex->getElementType()); 1911} 1912 1913/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1914/// the pointer type FromPtr to a pointer to type ToPointee, with the 1915/// same type qualifiers as FromPtr has on its pointee type. ToType, 1916/// if non-empty, will be a pointer to ToType that may or may not have 1917/// the right set of qualifiers on its pointee. 1918/// 1919static QualType 1920BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1921 QualType ToPointee, QualType ToType, 1922 ASTContext &Context, 1923 bool StripObjCLifetime = false) { 1924 assert((FromPtr->getTypeClass() == Type::Pointer || 1925 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1926 "Invalid similarly-qualified pointer type"); 1927 1928 /// Conversions to 'id' subsume cv-qualifier conversions. 1929 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1930 return ToType.getUnqualifiedType(); 1931 1932 QualType CanonFromPointee 1933 = Context.getCanonicalType(FromPtr->getPointeeType()); 1934 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1935 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1936 1937 if (StripObjCLifetime) 1938 Quals.removeObjCLifetime(); 1939 1940 // Exact qualifier match -> return the pointer type we're converting to. 1941 if (CanonToPointee.getLocalQualifiers() == Quals) { 1942 // ToType is exactly what we need. Return it. 1943 if (!ToType.isNull()) 1944 return ToType.getUnqualifiedType(); 1945 1946 // Build a pointer to ToPointee. It has the right qualifiers 1947 // already. 1948 if (isa<ObjCObjectPointerType>(ToType)) 1949 return Context.getObjCObjectPointerType(ToPointee); 1950 return Context.getPointerType(ToPointee); 1951 } 1952 1953 // Just build a canonical type that has the right qualifiers. 1954 QualType QualifiedCanonToPointee 1955 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1956 1957 if (isa<ObjCObjectPointerType>(ToType)) 1958 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1959 return Context.getPointerType(QualifiedCanonToPointee); 1960} 1961 1962static bool isNullPointerConstantForConversion(Expr *Expr, 1963 bool InOverloadResolution, 1964 ASTContext &Context) { 1965 // Handle value-dependent integral null pointer constants correctly. 1966 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1967 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1968 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1969 return !InOverloadResolution; 1970 1971 return Expr->isNullPointerConstant(Context, 1972 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1973 : Expr::NPC_ValueDependentIsNull); 1974} 1975 1976/// IsPointerConversion - Determines whether the conversion of the 1977/// expression From, which has the (possibly adjusted) type FromType, 1978/// can be converted to the type ToType via a pointer conversion (C++ 1979/// 4.10). If so, returns true and places the converted type (that 1980/// might differ from ToType in its cv-qualifiers at some level) into 1981/// ConvertedType. 1982/// 1983/// This routine also supports conversions to and from block pointers 1984/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1985/// pointers to interfaces. FIXME: Once we've determined the 1986/// appropriate overloading rules for Objective-C, we may want to 1987/// split the Objective-C checks into a different routine; however, 1988/// GCC seems to consider all of these conversions to be pointer 1989/// conversions, so for now they live here. IncompatibleObjC will be 1990/// set if the conversion is an allowed Objective-C conversion that 1991/// should result in a warning. 1992bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1993 bool InOverloadResolution, 1994 QualType& ConvertedType, 1995 bool &IncompatibleObjC) { 1996 IncompatibleObjC = false; 1997 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 1998 IncompatibleObjC)) 1999 return true; 2000 2001 // Conversion from a null pointer constant to any Objective-C pointer type. 2002 if (ToType->isObjCObjectPointerType() && 2003 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 2004 ConvertedType = ToType; 2005 return true; 2006 } 2007 2008 // Blocks: Block pointers can be converted to void*. 2009 if (FromType->isBlockPointerType() && ToType->isPointerType() && 2010 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 2011 ConvertedType = ToType; 2012 return true; 2013 } 2014 // Blocks: A null pointer constant can be converted to a block 2015 // pointer type. 2016 if (ToType->isBlockPointerType() && 2017 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 2018 ConvertedType = ToType; 2019 return true; 2020 } 2021 2022 // If the left-hand-side is nullptr_t, the right side can be a null 2023 // pointer constant. 2024 if (ToType->isNullPtrType() && 2025 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 2026 ConvertedType = ToType; 2027 return true; 2028 } 2029 2030 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 2031 if (!ToTypePtr) 2032 return false; 2033 2034 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 2035 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 2036 ConvertedType = ToType; 2037 return true; 2038 } 2039 2040 // Beyond this point, both types need to be pointers 2041 // , including objective-c pointers. 2042 QualType ToPointeeType = ToTypePtr->getPointeeType(); 2043 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() && 2044 !getLangOpts().ObjCAutoRefCount) { 2045 ConvertedType = BuildSimilarlyQualifiedPointerType( 2046 FromType->getAs<ObjCObjectPointerType>(), 2047 ToPointeeType, 2048 ToType, Context); 2049 return true; 2050 } 2051 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 2052 if (!FromTypePtr) 2053 return false; 2054 2055 QualType FromPointeeType = FromTypePtr->getPointeeType(); 2056 2057 // If the unqualified pointee types are the same, this can't be a 2058 // pointer conversion, so don't do all of the work below. 2059 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 2060 return false; 2061 2062 // An rvalue of type "pointer to cv T," where T is an object type, 2063 // can be converted to an rvalue of type "pointer to cv void" (C++ 2064 // 4.10p2). 2065 if (FromPointeeType->isIncompleteOrObjectType() && 2066 ToPointeeType->isVoidType()) { 2067 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2068 ToPointeeType, 2069 ToType, Context, 2070 /*StripObjCLifetime=*/true); 2071 return true; 2072 } 2073 2074 // MSVC allows implicit function to void* type conversion. 2075 if (getLangOpts().MicrosoftExt && FromPointeeType->isFunctionType() && 2076 ToPointeeType->isVoidType()) { 2077 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2078 ToPointeeType, 2079 ToType, Context); 2080 return true; 2081 } 2082 2083 // When we're overloading in C, we allow a special kind of pointer 2084 // conversion for compatible-but-not-identical pointee types. 2085 if (!getLangOpts().CPlusPlus && 2086 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 2087 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2088 ToPointeeType, 2089 ToType, Context); 2090 return true; 2091 } 2092 2093 // C++ [conv.ptr]p3: 2094 // 2095 // An rvalue of type "pointer to cv D," where D is a class type, 2096 // can be converted to an rvalue of type "pointer to cv B," where 2097 // B is a base class (clause 10) of D. If B is an inaccessible 2098 // (clause 11) or ambiguous (10.2) base class of D, a program that 2099 // necessitates this conversion is ill-formed. The result of the 2100 // conversion is a pointer to the base class sub-object of the 2101 // derived class object. The null pointer value is converted to 2102 // the null pointer value of the destination type. 2103 // 2104 // Note that we do not check for ambiguity or inaccessibility 2105 // here. That is handled by CheckPointerConversion. 2106 if (getLangOpts().CPlusPlus && 2107 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 2108 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 2109 !RequireCompleteType(From->getLocStart(), FromPointeeType, 0) && 2110 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 2111 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2112 ToPointeeType, 2113 ToType, Context); 2114 return true; 2115 } 2116 2117 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() && 2118 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) { 2119 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2120 ToPointeeType, 2121 ToType, Context); 2122 return true; 2123 } 2124 2125 return false; 2126} 2127 2128/// \brief Adopt the given qualifiers for the given type. 2129static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){ 2130 Qualifiers TQs = T.getQualifiers(); 2131 2132 // Check whether qualifiers already match. 2133 if (TQs == Qs) 2134 return T; 2135 2136 if (Qs.compatiblyIncludes(TQs)) 2137 return Context.getQualifiedType(T, Qs); 2138 2139 return Context.getQualifiedType(T.getUnqualifiedType(), Qs); 2140} 2141 2142/// isObjCPointerConversion - Determines whether this is an 2143/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 2144/// with the same arguments and return values. 2145bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 2146 QualType& ConvertedType, 2147 bool &IncompatibleObjC) { 2148 if (!getLangOpts().ObjC1) 2149 return false; 2150 2151 // The set of qualifiers on the type we're converting from. 2152 Qualifiers FromQualifiers = FromType.getQualifiers(); 2153 2154 // First, we handle all conversions on ObjC object pointer types. 2155 const ObjCObjectPointerType* ToObjCPtr = 2156 ToType->getAs<ObjCObjectPointerType>(); 2157 const ObjCObjectPointerType *FromObjCPtr = 2158 FromType->getAs<ObjCObjectPointerType>(); 2159 2160 if (ToObjCPtr && FromObjCPtr) { 2161 // If the pointee types are the same (ignoring qualifications), 2162 // then this is not a pointer conversion. 2163 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 2164 FromObjCPtr->getPointeeType())) 2165 return false; 2166 2167 // Check for compatible 2168 // Objective C++: We're able to convert between "id" or "Class" and a 2169 // pointer to any interface (in both directions). 2170 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 2171 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2172 return true; 2173 } 2174 // Conversions with Objective-C's id<...>. 2175 if ((FromObjCPtr->isObjCQualifiedIdType() || 2176 ToObjCPtr->isObjCQualifiedIdType()) && 2177 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 2178 /*compare=*/false)) { 2179 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2180 return true; 2181 } 2182 // Objective C++: We're able to convert from a pointer to an 2183 // interface to a pointer to a different interface. 2184 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 2185 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 2186 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 2187 if (getLangOpts().CPlusPlus && LHS && RHS && 2188 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 2189 FromObjCPtr->getPointeeType())) 2190 return false; 2191 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 2192 ToObjCPtr->getPointeeType(), 2193 ToType, Context); 2194 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2195 return true; 2196 } 2197 2198 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 2199 // Okay: this is some kind of implicit downcast of Objective-C 2200 // interfaces, which is permitted. However, we're going to 2201 // complain about it. 2202 IncompatibleObjC = true; 2203 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 2204 ToObjCPtr->getPointeeType(), 2205 ToType, Context); 2206 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2207 return true; 2208 } 2209 } 2210 // Beyond this point, both types need to be C pointers or block pointers. 2211 QualType ToPointeeType; 2212 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 2213 ToPointeeType = ToCPtr->getPointeeType(); 2214 else if (const BlockPointerType *ToBlockPtr = 2215 ToType->getAs<BlockPointerType>()) { 2216 // Objective C++: We're able to convert from a pointer to any object 2217 // to a block pointer type. 2218 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 2219 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2220 return true; 2221 } 2222 ToPointeeType = ToBlockPtr->getPointeeType(); 2223 } 2224 else if (FromType->getAs<BlockPointerType>() && 2225 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 2226 // Objective C++: We're able to convert from a block pointer type to a 2227 // pointer to any object. 2228 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2229 return true; 2230 } 2231 else 2232 return false; 2233 2234 QualType FromPointeeType; 2235 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 2236 FromPointeeType = FromCPtr->getPointeeType(); 2237 else if (const BlockPointerType *FromBlockPtr = 2238 FromType->getAs<BlockPointerType>()) 2239 FromPointeeType = FromBlockPtr->getPointeeType(); 2240 else 2241 return false; 2242 2243 // If we have pointers to pointers, recursively check whether this 2244 // is an Objective-C conversion. 2245 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 2246 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 2247 IncompatibleObjC)) { 2248 // We always complain about this conversion. 2249 IncompatibleObjC = true; 2250 ConvertedType = Context.getPointerType(ConvertedType); 2251 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2252 return true; 2253 } 2254 // Allow conversion of pointee being objective-c pointer to another one; 2255 // as in I* to id. 2256 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 2257 ToPointeeType->getAs<ObjCObjectPointerType>() && 2258 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 2259 IncompatibleObjC)) { 2260 2261 ConvertedType = Context.getPointerType(ConvertedType); 2262 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2263 return true; 2264 } 2265 2266 // If we have pointers to functions or blocks, check whether the only 2267 // differences in the argument and result types are in Objective-C 2268 // pointer conversions. If so, we permit the conversion (but 2269 // complain about it). 2270 const FunctionProtoType *FromFunctionType 2271 = FromPointeeType->getAs<FunctionProtoType>(); 2272 const FunctionProtoType *ToFunctionType 2273 = ToPointeeType->getAs<FunctionProtoType>(); 2274 if (FromFunctionType && ToFunctionType) { 2275 // If the function types are exactly the same, this isn't an 2276 // Objective-C pointer conversion. 2277 if (Context.getCanonicalType(FromPointeeType) 2278 == Context.getCanonicalType(ToPointeeType)) 2279 return false; 2280 2281 // Perform the quick checks that will tell us whether these 2282 // function types are obviously different. 2283 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 2284 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 2285 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 2286 return false; 2287 2288 bool HasObjCConversion = false; 2289 if (Context.getCanonicalType(FromFunctionType->getResultType()) 2290 == Context.getCanonicalType(ToFunctionType->getResultType())) { 2291 // Okay, the types match exactly. Nothing to do. 2292 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 2293 ToFunctionType->getResultType(), 2294 ConvertedType, IncompatibleObjC)) { 2295 // Okay, we have an Objective-C pointer conversion. 2296 HasObjCConversion = true; 2297 } else { 2298 // Function types are too different. Abort. 2299 return false; 2300 } 2301 2302 // Check argument types. 2303 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 2304 ArgIdx != NumArgs; ++ArgIdx) { 2305 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 2306 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 2307 if (Context.getCanonicalType(FromArgType) 2308 == Context.getCanonicalType(ToArgType)) { 2309 // Okay, the types match exactly. Nothing to do. 2310 } else if (isObjCPointerConversion(FromArgType, ToArgType, 2311 ConvertedType, IncompatibleObjC)) { 2312 // Okay, we have an Objective-C pointer conversion. 2313 HasObjCConversion = true; 2314 } else { 2315 // Argument types are too different. Abort. 2316 return false; 2317 } 2318 } 2319 2320 if (HasObjCConversion) { 2321 // We had an Objective-C conversion. Allow this pointer 2322 // conversion, but complain about it. 2323 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2324 IncompatibleObjC = true; 2325 return true; 2326 } 2327 } 2328 2329 return false; 2330} 2331 2332/// \brief Determine whether this is an Objective-C writeback conversion, 2333/// used for parameter passing when performing automatic reference counting. 2334/// 2335/// \param FromType The type we're converting form. 2336/// 2337/// \param ToType The type we're converting to. 2338/// 2339/// \param ConvertedType The type that will be produced after applying 2340/// this conversion. 2341bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType, 2342 QualType &ConvertedType) { 2343 if (!getLangOpts().ObjCAutoRefCount || 2344 Context.hasSameUnqualifiedType(FromType, ToType)) 2345 return false; 2346 2347 // Parameter must be a pointer to __autoreleasing (with no other qualifiers). 2348 QualType ToPointee; 2349 if (const PointerType *ToPointer = ToType->getAs<PointerType>()) 2350 ToPointee = ToPointer->getPointeeType(); 2351 else 2352 return false; 2353 2354 Qualifiers ToQuals = ToPointee.getQualifiers(); 2355 if (!ToPointee->isObjCLifetimeType() || 2356 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing || 2357 !ToQuals.withoutObjCLifetime().empty()) 2358 return false; 2359 2360 // Argument must be a pointer to __strong to __weak. 2361 QualType FromPointee; 2362 if (const PointerType *FromPointer = FromType->getAs<PointerType>()) 2363 FromPointee = FromPointer->getPointeeType(); 2364 else 2365 return false; 2366 2367 Qualifiers FromQuals = FromPointee.getQualifiers(); 2368 if (!FromPointee->isObjCLifetimeType() || 2369 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong && 2370 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak)) 2371 return false; 2372 2373 // Make sure that we have compatible qualifiers. 2374 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing); 2375 if (!ToQuals.compatiblyIncludes(FromQuals)) 2376 return false; 2377 2378 // Remove qualifiers from the pointee type we're converting from; they 2379 // aren't used in the compatibility check belong, and we'll be adding back 2380 // qualifiers (with __autoreleasing) if the compatibility check succeeds. 2381 FromPointee = FromPointee.getUnqualifiedType(); 2382 2383 // The unqualified form of the pointee types must be compatible. 2384 ToPointee = ToPointee.getUnqualifiedType(); 2385 bool IncompatibleObjC; 2386 if (Context.typesAreCompatible(FromPointee, ToPointee)) 2387 FromPointee = ToPointee; 2388 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee, 2389 IncompatibleObjC)) 2390 return false; 2391 2392 /// \brief Construct the type we're converting to, which is a pointer to 2393 /// __autoreleasing pointee. 2394 FromPointee = Context.getQualifiedType(FromPointee, FromQuals); 2395 ConvertedType = Context.getPointerType(FromPointee); 2396 return true; 2397} 2398 2399bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, 2400 QualType& ConvertedType) { 2401 QualType ToPointeeType; 2402 if (const BlockPointerType *ToBlockPtr = 2403 ToType->getAs<BlockPointerType>()) 2404 ToPointeeType = ToBlockPtr->getPointeeType(); 2405 else 2406 return false; 2407 2408 QualType FromPointeeType; 2409 if (const BlockPointerType *FromBlockPtr = 2410 FromType->getAs<BlockPointerType>()) 2411 FromPointeeType = FromBlockPtr->getPointeeType(); 2412 else 2413 return false; 2414 // We have pointer to blocks, check whether the only 2415 // differences in the argument and result types are in Objective-C 2416 // pointer conversions. If so, we permit the conversion. 2417 2418 const FunctionProtoType *FromFunctionType 2419 = FromPointeeType->getAs<FunctionProtoType>(); 2420 const FunctionProtoType *ToFunctionType 2421 = ToPointeeType->getAs<FunctionProtoType>(); 2422 2423 if (!FromFunctionType || !ToFunctionType) 2424 return false; 2425 2426 if (Context.hasSameType(FromPointeeType, ToPointeeType)) 2427 return true; 2428 2429 // Perform the quick checks that will tell us whether these 2430 // function types are obviously different. 2431 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 2432 FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) 2433 return false; 2434 2435 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); 2436 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); 2437 if (FromEInfo != ToEInfo) 2438 return false; 2439 2440 bool IncompatibleObjC = false; 2441 if (Context.hasSameType(FromFunctionType->getResultType(), 2442 ToFunctionType->getResultType())) { 2443 // Okay, the types match exactly. Nothing to do. 2444 } else { 2445 QualType RHS = FromFunctionType->getResultType(); 2446 QualType LHS = ToFunctionType->getResultType(); 2447 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) && 2448 !RHS.hasQualifiers() && LHS.hasQualifiers()) 2449 LHS = LHS.getUnqualifiedType(); 2450 2451 if (Context.hasSameType(RHS,LHS)) { 2452 // OK exact match. 2453 } else if (isObjCPointerConversion(RHS, LHS, 2454 ConvertedType, IncompatibleObjC)) { 2455 if (IncompatibleObjC) 2456 return false; 2457 // Okay, we have an Objective-C pointer conversion. 2458 } 2459 else 2460 return false; 2461 } 2462 2463 // Check argument types. 2464 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 2465 ArgIdx != NumArgs; ++ArgIdx) { 2466 IncompatibleObjC = false; 2467 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 2468 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 2469 if (Context.hasSameType(FromArgType, ToArgType)) { 2470 // Okay, the types match exactly. Nothing to do. 2471 } else if (isObjCPointerConversion(ToArgType, FromArgType, 2472 ConvertedType, IncompatibleObjC)) { 2473 if (IncompatibleObjC) 2474 return false; 2475 // Okay, we have an Objective-C pointer conversion. 2476 } else 2477 // Argument types are too different. Abort. 2478 return false; 2479 } 2480 if (LangOpts.ObjCAutoRefCount && 2481 !Context.FunctionTypesMatchOnNSConsumedAttrs(FromFunctionType, 2482 ToFunctionType)) 2483 return false; 2484 2485 ConvertedType = ToType; 2486 return true; 2487} 2488 2489enum { 2490 ft_default, 2491 ft_different_class, 2492 ft_parameter_arity, 2493 ft_parameter_mismatch, 2494 ft_return_type, 2495 ft_qualifer_mismatch 2496}; 2497 2498/// HandleFunctionTypeMismatch - Gives diagnostic information for differeing 2499/// function types. Catches different number of parameter, mismatch in 2500/// parameter types, and different return types. 2501void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag, 2502 QualType FromType, QualType ToType) { 2503 // If either type is not valid, include no extra info. 2504 if (FromType.isNull() || ToType.isNull()) { 2505 PDiag << ft_default; 2506 return; 2507 } 2508 2509 // Get the function type from the pointers. 2510 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) { 2511 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(), 2512 *ToMember = ToType->getAs<MemberPointerType>(); 2513 if (FromMember->getClass() != ToMember->getClass()) { 2514 PDiag << ft_different_class << QualType(ToMember->getClass(), 0) 2515 << QualType(FromMember->getClass(), 0); 2516 return; 2517 } 2518 FromType = FromMember->getPointeeType(); 2519 ToType = ToMember->getPointeeType(); 2520 } 2521 2522 if (FromType->isPointerType()) 2523 FromType = FromType->getPointeeType(); 2524 if (ToType->isPointerType()) 2525 ToType = ToType->getPointeeType(); 2526 2527 // Remove references. 2528 FromType = FromType.getNonReferenceType(); 2529 ToType = ToType.getNonReferenceType(); 2530 2531 // Don't print extra info for non-specialized template functions. 2532 if (FromType->isInstantiationDependentType() && 2533 !FromType->getAs<TemplateSpecializationType>()) { 2534 PDiag << ft_default; 2535 return; 2536 } 2537 2538 // No extra info for same types. 2539 if (Context.hasSameType(FromType, ToType)) { 2540 PDiag << ft_default; 2541 return; 2542 } 2543 2544 const FunctionProtoType *FromFunction = FromType->getAs<FunctionProtoType>(), 2545 *ToFunction = ToType->getAs<FunctionProtoType>(); 2546 2547 // Both types need to be function types. 2548 if (!FromFunction || !ToFunction) { 2549 PDiag << ft_default; 2550 return; 2551 } 2552 2553 if (FromFunction->getNumArgs() != ToFunction->getNumArgs()) { 2554 PDiag << ft_parameter_arity << ToFunction->getNumArgs() 2555 << FromFunction->getNumArgs(); 2556 return; 2557 } 2558 2559 // Handle different parameter types. 2560 unsigned ArgPos; 2561 if (!FunctionArgTypesAreEqual(FromFunction, ToFunction, &ArgPos)) { 2562 PDiag << ft_parameter_mismatch << ArgPos + 1 2563 << ToFunction->getArgType(ArgPos) 2564 << FromFunction->getArgType(ArgPos); 2565 return; 2566 } 2567 2568 // Handle different return type. 2569 if (!Context.hasSameType(FromFunction->getResultType(), 2570 ToFunction->getResultType())) { 2571 PDiag << ft_return_type << ToFunction->getResultType() 2572 << FromFunction->getResultType(); 2573 return; 2574 } 2575 2576 unsigned FromQuals = FromFunction->getTypeQuals(), 2577 ToQuals = ToFunction->getTypeQuals(); 2578 if (FromQuals != ToQuals) { 2579 PDiag << ft_qualifer_mismatch << ToQuals << FromQuals; 2580 return; 2581 } 2582 2583 // Unable to find a difference, so add no extra info. 2584 PDiag << ft_default; 2585} 2586 2587/// FunctionArgTypesAreEqual - This routine checks two function proto types 2588/// for equality of their argument types. Caller has already checked that 2589/// they have same number of arguments. This routine assumes that Objective-C 2590/// pointer types which only differ in their protocol qualifiers are equal. 2591/// If the parameters are different, ArgPos will have the parameter index 2592/// of the first different parameter. 2593bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, 2594 const FunctionProtoType *NewType, 2595 unsigned *ArgPos) { 2596 if (!getLangOpts().ObjC1) { 2597 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 2598 N = NewType->arg_type_begin(), 2599 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 2600 if (!Context.hasSameType(*O, *N)) { 2601 if (ArgPos) *ArgPos = O - OldType->arg_type_begin(); 2602 return false; 2603 } 2604 } 2605 return true; 2606 } 2607 2608 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 2609 N = NewType->arg_type_begin(), 2610 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 2611 QualType ToType = (*O); 2612 QualType FromType = (*N); 2613 if (!Context.hasSameType(ToType, FromType)) { 2614 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 2615 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 2616 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 2617 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 2618 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 2619 PTFr->getPointeeType()->isObjCQualifiedClassType())) 2620 continue; 2621 } 2622 else if (const ObjCObjectPointerType *PTTo = 2623 ToType->getAs<ObjCObjectPointerType>()) { 2624 if (const ObjCObjectPointerType *PTFr = 2625 FromType->getAs<ObjCObjectPointerType>()) 2626 if (Context.hasSameUnqualifiedType( 2627 PTTo->getObjectType()->getBaseType(), 2628 PTFr->getObjectType()->getBaseType())) 2629 continue; 2630 } 2631 if (ArgPos) *ArgPos = O - OldType->arg_type_begin(); 2632 return false; 2633 } 2634 } 2635 return true; 2636} 2637 2638/// CheckPointerConversion - Check the pointer conversion from the 2639/// expression From to the type ToType. This routine checks for 2640/// ambiguous or inaccessible derived-to-base pointer 2641/// conversions for which IsPointerConversion has already returned 2642/// true. It returns true and produces a diagnostic if there was an 2643/// error, or returns false otherwise. 2644bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 2645 CastKind &Kind, 2646 CXXCastPath& BasePath, 2647 bool IgnoreBaseAccess) { 2648 QualType FromType = From->getType(); 2649 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 2650 2651 Kind = CK_BitCast; 2652 2653 if (!IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() && 2654 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) == 2655 Expr::NPCK_ZeroExpression) { 2656 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy)) 2657 DiagRuntimeBehavior(From->getExprLoc(), From, 2658 PDiag(diag::warn_impcast_bool_to_null_pointer) 2659 << ToType << From->getSourceRange()); 2660 else if (!isUnevaluatedContext()) 2661 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer) 2662 << ToType << From->getSourceRange(); 2663 } 2664 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 2665 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) { 2666 QualType FromPointeeType = FromPtrType->getPointeeType(), 2667 ToPointeeType = ToPtrType->getPointeeType(); 2668 2669 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 2670 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 2671 // We must have a derived-to-base conversion. Check an 2672 // ambiguous or inaccessible conversion. 2673 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 2674 From->getExprLoc(), 2675 From->getSourceRange(), &BasePath, 2676 IgnoreBaseAccess)) 2677 return true; 2678 2679 // The conversion was successful. 2680 Kind = CK_DerivedToBase; 2681 } 2682 } 2683 } else if (const ObjCObjectPointerType *ToPtrType = 2684 ToType->getAs<ObjCObjectPointerType>()) { 2685 if (const ObjCObjectPointerType *FromPtrType = 2686 FromType->getAs<ObjCObjectPointerType>()) { 2687 // Objective-C++ conversions are always okay. 2688 // FIXME: We should have a different class of conversions for the 2689 // Objective-C++ implicit conversions. 2690 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 2691 return false; 2692 } else if (FromType->isBlockPointerType()) { 2693 Kind = CK_BlockPointerToObjCPointerCast; 2694 } else { 2695 Kind = CK_CPointerToObjCPointerCast; 2696 } 2697 } else if (ToType->isBlockPointerType()) { 2698 if (!FromType->isBlockPointerType()) 2699 Kind = CK_AnyPointerToBlockPointerCast; 2700 } 2701 2702 // We shouldn't fall into this case unless it's valid for other 2703 // reasons. 2704 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 2705 Kind = CK_NullToPointer; 2706 2707 return false; 2708} 2709 2710/// IsMemberPointerConversion - Determines whether the conversion of the 2711/// expression From, which has the (possibly adjusted) type FromType, can be 2712/// converted to the type ToType via a member pointer conversion (C++ 4.11). 2713/// If so, returns true and places the converted type (that might differ from 2714/// ToType in its cv-qualifiers at some level) into ConvertedType. 2715bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 2716 QualType ToType, 2717 bool InOverloadResolution, 2718 QualType &ConvertedType) { 2719 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 2720 if (!ToTypePtr) 2721 return false; 2722 2723 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 2724 if (From->isNullPointerConstant(Context, 2725 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 2726 : Expr::NPC_ValueDependentIsNull)) { 2727 ConvertedType = ToType; 2728 return true; 2729 } 2730 2731 // Otherwise, both types have to be member pointers. 2732 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 2733 if (!FromTypePtr) 2734 return false; 2735 2736 // A pointer to member of B can be converted to a pointer to member of D, 2737 // where D is derived from B (C++ 4.11p2). 2738 QualType FromClass(FromTypePtr->getClass(), 0); 2739 QualType ToClass(ToTypePtr->getClass(), 0); 2740 2741 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && 2742 !RequireCompleteType(From->getLocStart(), ToClass, 0) && 2743 IsDerivedFrom(ToClass, FromClass)) { 2744 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 2745 ToClass.getTypePtr()); 2746 return true; 2747 } 2748 2749 return false; 2750} 2751 2752/// CheckMemberPointerConversion - Check the member pointer conversion from the 2753/// expression From to the type ToType. This routine checks for ambiguous or 2754/// virtual or inaccessible base-to-derived member pointer conversions 2755/// for which IsMemberPointerConversion has already returned true. It returns 2756/// true and produces a diagnostic if there was an error, or returns false 2757/// otherwise. 2758bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 2759 CastKind &Kind, 2760 CXXCastPath &BasePath, 2761 bool IgnoreBaseAccess) { 2762 QualType FromType = From->getType(); 2763 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 2764 if (!FromPtrType) { 2765 // This must be a null pointer to member pointer conversion 2766 assert(From->isNullPointerConstant(Context, 2767 Expr::NPC_ValueDependentIsNull) && 2768 "Expr must be null pointer constant!"); 2769 Kind = CK_NullToMemberPointer; 2770 return false; 2771 } 2772 2773 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 2774 assert(ToPtrType && "No member pointer cast has a target type " 2775 "that is not a member pointer."); 2776 2777 QualType FromClass = QualType(FromPtrType->getClass(), 0); 2778 QualType ToClass = QualType(ToPtrType->getClass(), 0); 2779 2780 // FIXME: What about dependent types? 2781 assert(FromClass->isRecordType() && "Pointer into non-class."); 2782 assert(ToClass->isRecordType() && "Pointer into non-class."); 2783 2784 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 2785 /*DetectVirtual=*/true); 2786 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 2787 assert(DerivationOkay && 2788 "Should not have been called if derivation isn't OK."); 2789 (void)DerivationOkay; 2790 2791 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 2792 getUnqualifiedType())) { 2793 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 2794 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 2795 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 2796 return true; 2797 } 2798 2799 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 2800 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 2801 << FromClass << ToClass << QualType(VBase, 0) 2802 << From->getSourceRange(); 2803 return true; 2804 } 2805 2806 if (!IgnoreBaseAccess) 2807 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 2808 Paths.front(), 2809 diag::err_downcast_from_inaccessible_base); 2810 2811 // Must be a base to derived member conversion. 2812 BuildBasePathArray(Paths, BasePath); 2813 Kind = CK_BaseToDerivedMemberPointer; 2814 return false; 2815} 2816 2817/// IsQualificationConversion - Determines whether the conversion from 2818/// an rvalue of type FromType to ToType is a qualification conversion 2819/// (C++ 4.4). 2820/// 2821/// \param ObjCLifetimeConversion Output parameter that will be set to indicate 2822/// when the qualification conversion involves a change in the Objective-C 2823/// object lifetime. 2824bool 2825Sema::IsQualificationConversion(QualType FromType, QualType ToType, 2826 bool CStyle, bool &ObjCLifetimeConversion) { 2827 FromType = Context.getCanonicalType(FromType); 2828 ToType = Context.getCanonicalType(ToType); 2829 ObjCLifetimeConversion = false; 2830 2831 // If FromType and ToType are the same type, this is not a 2832 // qualification conversion. 2833 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 2834 return false; 2835 2836 // (C++ 4.4p4): 2837 // A conversion can add cv-qualifiers at levels other than the first 2838 // in multi-level pointers, subject to the following rules: [...] 2839 bool PreviousToQualsIncludeConst = true; 2840 bool UnwrappedAnyPointer = false; 2841 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 2842 // Within each iteration of the loop, we check the qualifiers to 2843 // determine if this still looks like a qualification 2844 // conversion. Then, if all is well, we unwrap one more level of 2845 // pointers or pointers-to-members and do it all again 2846 // until there are no more pointers or pointers-to-members left to 2847 // unwrap. 2848 UnwrappedAnyPointer = true; 2849 2850 Qualifiers FromQuals = FromType.getQualifiers(); 2851 Qualifiers ToQuals = ToType.getQualifiers(); 2852 2853 // Objective-C ARC: 2854 // Check Objective-C lifetime conversions. 2855 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() && 2856 UnwrappedAnyPointer) { 2857 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) { 2858 ObjCLifetimeConversion = true; 2859 FromQuals.removeObjCLifetime(); 2860 ToQuals.removeObjCLifetime(); 2861 } else { 2862 // Qualification conversions cannot cast between different 2863 // Objective-C lifetime qualifiers. 2864 return false; 2865 } 2866 } 2867 2868 // Allow addition/removal of GC attributes but not changing GC attributes. 2869 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() && 2870 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) { 2871 FromQuals.removeObjCGCAttr(); 2872 ToQuals.removeObjCGCAttr(); 2873 } 2874 2875 // -- for every j > 0, if const is in cv 1,j then const is in cv 2876 // 2,j, and similarly for volatile. 2877 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals)) 2878 return false; 2879 2880 // -- if the cv 1,j and cv 2,j are different, then const is in 2881 // every cv for 0 < k < j. 2882 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers() 2883 && !PreviousToQualsIncludeConst) 2884 return false; 2885 2886 // Keep track of whether all prior cv-qualifiers in the "to" type 2887 // include const. 2888 PreviousToQualsIncludeConst 2889 = PreviousToQualsIncludeConst && ToQuals.hasConst(); 2890 } 2891 2892 // We are left with FromType and ToType being the pointee types 2893 // after unwrapping the original FromType and ToType the same number 2894 // of types. If we unwrapped any pointers, and if FromType and 2895 // ToType have the same unqualified type (since we checked 2896 // qualifiers above), then this is a qualification conversion. 2897 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2898} 2899 2900/// \brief - Determine whether this is a conversion from a scalar type to an 2901/// atomic type. 2902/// 2903/// If successful, updates \c SCS's second and third steps in the conversion 2904/// sequence to finish the conversion. 2905static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType, 2906 bool InOverloadResolution, 2907 StandardConversionSequence &SCS, 2908 bool CStyle) { 2909 const AtomicType *ToAtomic = ToType->getAs<AtomicType>(); 2910 if (!ToAtomic) 2911 return false; 2912 2913 StandardConversionSequence InnerSCS; 2914 if (!IsStandardConversion(S, From, ToAtomic->getValueType(), 2915 InOverloadResolution, InnerSCS, 2916 CStyle, /*AllowObjCWritebackConversion=*/false)) 2917 return false; 2918 2919 SCS.Second = InnerSCS.Second; 2920 SCS.setToType(1, InnerSCS.getToType(1)); 2921 SCS.Third = InnerSCS.Third; 2922 SCS.QualificationIncludesObjCLifetime 2923 = InnerSCS.QualificationIncludesObjCLifetime; 2924 SCS.setToType(2, InnerSCS.getToType(2)); 2925 return true; 2926} 2927 2928static bool isFirstArgumentCompatibleWithType(ASTContext &Context, 2929 CXXConstructorDecl *Constructor, 2930 QualType Type) { 2931 const FunctionProtoType *CtorType = 2932 Constructor->getType()->getAs<FunctionProtoType>(); 2933 if (CtorType->getNumArgs() > 0) { 2934 QualType FirstArg = CtorType->getArgType(0); 2935 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType())) 2936 return true; 2937 } 2938 return false; 2939} 2940 2941static OverloadingResult 2942IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType, 2943 CXXRecordDecl *To, 2944 UserDefinedConversionSequence &User, 2945 OverloadCandidateSet &CandidateSet, 2946 bool AllowExplicit) { 2947 DeclContext::lookup_result R = S.LookupConstructors(To); 2948 for (DeclContext::lookup_iterator Con = R.begin(), ConEnd = R.end(); 2949 Con != ConEnd; ++Con) { 2950 NamedDecl *D = *Con; 2951 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2952 2953 // Find the constructor (which may be a template). 2954 CXXConstructorDecl *Constructor = 0; 2955 FunctionTemplateDecl *ConstructorTmpl 2956 = dyn_cast<FunctionTemplateDecl>(D); 2957 if (ConstructorTmpl) 2958 Constructor 2959 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2960 else 2961 Constructor = cast<CXXConstructorDecl>(D); 2962 2963 bool Usable = !Constructor->isInvalidDecl() && 2964 S.isInitListConstructor(Constructor) && 2965 (AllowExplicit || !Constructor->isExplicit()); 2966 if (Usable) { 2967 // If the first argument is (a reference to) the target type, 2968 // suppress conversions. 2969 bool SuppressUserConversions = 2970 isFirstArgumentCompatibleWithType(S.Context, Constructor, ToType); 2971 if (ConstructorTmpl) 2972 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2973 /*ExplicitArgs*/ 0, 2974 From, CandidateSet, 2975 SuppressUserConversions); 2976 else 2977 S.AddOverloadCandidate(Constructor, FoundDecl, 2978 From, CandidateSet, 2979 SuppressUserConversions); 2980 } 2981 } 2982 2983 bool HadMultipleCandidates = (CandidateSet.size() > 1); 2984 2985 OverloadCandidateSet::iterator Best; 2986 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2987 case OR_Success: { 2988 // Record the standard conversion we used and the conversion function. 2989 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function); 2990 QualType ThisType = Constructor->getThisType(S.Context); 2991 // Initializer lists don't have conversions as such. 2992 User.Before.setAsIdentityConversion(); 2993 User.HadMultipleCandidates = HadMultipleCandidates; 2994 User.ConversionFunction = Constructor; 2995 User.FoundConversionFunction = Best->FoundDecl; 2996 User.After.setAsIdentityConversion(); 2997 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2998 User.After.setAllToTypes(ToType); 2999 return OR_Success; 3000 } 3001 3002 case OR_No_Viable_Function: 3003 return OR_No_Viable_Function; 3004 case OR_Deleted: 3005 return OR_Deleted; 3006 case OR_Ambiguous: 3007 return OR_Ambiguous; 3008 } 3009 3010 llvm_unreachable("Invalid OverloadResult!"); 3011} 3012 3013/// Determines whether there is a user-defined conversion sequence 3014/// (C++ [over.ics.user]) that converts expression From to the type 3015/// ToType. If such a conversion exists, User will contain the 3016/// user-defined conversion sequence that performs such a conversion 3017/// and this routine will return true. Otherwise, this routine returns 3018/// false and User is unspecified. 3019/// 3020/// \param AllowExplicit true if the conversion should consider C++0x 3021/// "explicit" conversion functions as well as non-explicit conversion 3022/// functions (C++0x [class.conv.fct]p2). 3023static OverloadingResult 3024IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 3025 UserDefinedConversionSequence &User, 3026 OverloadCandidateSet &CandidateSet, 3027 bool AllowExplicit) { 3028 // Whether we will only visit constructors. 3029 bool ConstructorsOnly = false; 3030 3031 // If the type we are conversion to is a class type, enumerate its 3032 // constructors. 3033 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 3034 // C++ [over.match.ctor]p1: 3035 // When objects of class type are direct-initialized (8.5), or 3036 // copy-initialized from an expression of the same or a 3037 // derived class type (8.5), overload resolution selects the 3038 // constructor. [...] For copy-initialization, the candidate 3039 // functions are all the converting constructors (12.3.1) of 3040 // that class. The argument list is the expression-list within 3041 // the parentheses of the initializer. 3042 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 3043 (From->getType()->getAs<RecordType>() && 3044 S.IsDerivedFrom(From->getType(), ToType))) 3045 ConstructorsOnly = true; 3046 3047 S.RequireCompleteType(From->getExprLoc(), ToType, 0); 3048 // RequireCompleteType may have returned true due to some invalid decl 3049 // during template instantiation, but ToType may be complete enough now 3050 // to try to recover. 3051 if (ToType->isIncompleteType()) { 3052 // We're not going to find any constructors. 3053 } else if (CXXRecordDecl *ToRecordDecl 3054 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 3055 3056 Expr **Args = &From; 3057 unsigned NumArgs = 1; 3058 bool ListInitializing = false; 3059 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) { 3060 // But first, see if there is an init-list-contructor that will work. 3061 OverloadingResult Result = IsInitializerListConstructorConversion( 3062 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit); 3063 if (Result != OR_No_Viable_Function) 3064 return Result; 3065 // Never mind. 3066 CandidateSet.clear(); 3067 3068 // If we're list-initializing, we pass the individual elements as 3069 // arguments, not the entire list. 3070 Args = InitList->getInits(); 3071 NumArgs = InitList->getNumInits(); 3072 ListInitializing = true; 3073 } 3074 3075 DeclContext::lookup_result R = S.LookupConstructors(ToRecordDecl); 3076 for (DeclContext::lookup_iterator Con = R.begin(), ConEnd = R.end(); 3077 Con != ConEnd; ++Con) { 3078 NamedDecl *D = *Con; 3079 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 3080 3081 // Find the constructor (which may be a template). 3082 CXXConstructorDecl *Constructor = 0; 3083 FunctionTemplateDecl *ConstructorTmpl 3084 = dyn_cast<FunctionTemplateDecl>(D); 3085 if (ConstructorTmpl) 3086 Constructor 3087 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 3088 else 3089 Constructor = cast<CXXConstructorDecl>(D); 3090 3091 bool Usable = !Constructor->isInvalidDecl(); 3092 if (ListInitializing) 3093 Usable = Usable && (AllowExplicit || !Constructor->isExplicit()); 3094 else 3095 Usable = Usable &&Constructor->isConvertingConstructor(AllowExplicit); 3096 if (Usable) { 3097 bool SuppressUserConversions = !ConstructorsOnly; 3098 if (SuppressUserConversions && ListInitializing) { 3099 SuppressUserConversions = false; 3100 if (NumArgs == 1) { 3101 // If the first argument is (a reference to) the target type, 3102 // suppress conversions. 3103 SuppressUserConversions = isFirstArgumentCompatibleWithType( 3104 S.Context, Constructor, ToType); 3105 } 3106 } 3107 if (ConstructorTmpl) 3108 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 3109 /*ExplicitArgs*/ 0, 3110 llvm::makeArrayRef(Args, NumArgs), 3111 CandidateSet, SuppressUserConversions); 3112 else 3113 // Allow one user-defined conversion when user specifies a 3114 // From->ToType conversion via an static cast (c-style, etc). 3115 S.AddOverloadCandidate(Constructor, FoundDecl, 3116 llvm::makeArrayRef(Args, NumArgs), 3117 CandidateSet, SuppressUserConversions); 3118 } 3119 } 3120 } 3121 } 3122 3123 // Enumerate conversion functions, if we're allowed to. 3124 if (ConstructorsOnly || isa<InitListExpr>(From)) { 3125 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 0)) { 3126 // No conversion functions from incomplete types. 3127 } else if (const RecordType *FromRecordType 3128 = From->getType()->getAs<RecordType>()) { 3129 if (CXXRecordDecl *FromRecordDecl 3130 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 3131 // Add all of the conversion functions as candidates. 3132 std::pair<CXXRecordDecl::conversion_iterator, 3133 CXXRecordDecl::conversion_iterator> 3134 Conversions = FromRecordDecl->getVisibleConversionFunctions(); 3135 for (CXXRecordDecl::conversion_iterator 3136 I = Conversions.first, E = Conversions.second; I != E; ++I) { 3137 DeclAccessPair FoundDecl = I.getPair(); 3138 NamedDecl *D = FoundDecl.getDecl(); 3139 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 3140 if (isa<UsingShadowDecl>(D)) 3141 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3142 3143 CXXConversionDecl *Conv; 3144 FunctionTemplateDecl *ConvTemplate; 3145 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 3146 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3147 else 3148 Conv = cast<CXXConversionDecl>(D); 3149 3150 if (AllowExplicit || !Conv->isExplicit()) { 3151 if (ConvTemplate) 3152 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 3153 ActingContext, From, ToType, 3154 CandidateSet); 3155 else 3156 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 3157 From, ToType, CandidateSet); 3158 } 3159 } 3160 } 3161 } 3162 3163 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3164 3165 OverloadCandidateSet::iterator Best; 3166 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 3167 case OR_Success: 3168 // Record the standard conversion we used and the conversion function. 3169 if (CXXConstructorDecl *Constructor 3170 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 3171 // C++ [over.ics.user]p1: 3172 // If the user-defined conversion is specified by a 3173 // constructor (12.3.1), the initial standard conversion 3174 // sequence converts the source type to the type required by 3175 // the argument of the constructor. 3176 // 3177 QualType ThisType = Constructor->getThisType(S.Context); 3178 if (isa<InitListExpr>(From)) { 3179 // Initializer lists don't have conversions as such. 3180 User.Before.setAsIdentityConversion(); 3181 } else { 3182 if (Best->Conversions[0].isEllipsis()) 3183 User.EllipsisConversion = true; 3184 else { 3185 User.Before = Best->Conversions[0].Standard; 3186 User.EllipsisConversion = false; 3187 } 3188 } 3189 User.HadMultipleCandidates = HadMultipleCandidates; 3190 User.ConversionFunction = Constructor; 3191 User.FoundConversionFunction = Best->FoundDecl; 3192 User.After.setAsIdentityConversion(); 3193 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 3194 User.After.setAllToTypes(ToType); 3195 return OR_Success; 3196 } 3197 if (CXXConversionDecl *Conversion 3198 = dyn_cast<CXXConversionDecl>(Best->Function)) { 3199 // C++ [over.ics.user]p1: 3200 // 3201 // [...] If the user-defined conversion is specified by a 3202 // conversion function (12.3.2), the initial standard 3203 // conversion sequence converts the source type to the 3204 // implicit object parameter of the conversion function. 3205 User.Before = Best->Conversions[0].Standard; 3206 User.HadMultipleCandidates = HadMultipleCandidates; 3207 User.ConversionFunction = Conversion; 3208 User.FoundConversionFunction = Best->FoundDecl; 3209 User.EllipsisConversion = false; 3210 3211 // C++ [over.ics.user]p2: 3212 // The second standard conversion sequence converts the 3213 // result of the user-defined conversion to the target type 3214 // for the sequence. Since an implicit conversion sequence 3215 // is an initialization, the special rules for 3216 // initialization by user-defined conversion apply when 3217 // selecting the best user-defined conversion for a 3218 // user-defined conversion sequence (see 13.3.3 and 3219 // 13.3.3.1). 3220 User.After = Best->FinalConversion; 3221 return OR_Success; 3222 } 3223 llvm_unreachable("Not a constructor or conversion function?"); 3224 3225 case OR_No_Viable_Function: 3226 return OR_No_Viable_Function; 3227 case OR_Deleted: 3228 // No conversion here! We're done. 3229 return OR_Deleted; 3230 3231 case OR_Ambiguous: 3232 return OR_Ambiguous; 3233 } 3234 3235 llvm_unreachable("Invalid OverloadResult!"); 3236} 3237 3238bool 3239Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 3240 ImplicitConversionSequence ICS; 3241 OverloadCandidateSet CandidateSet(From->getExprLoc()); 3242 OverloadingResult OvResult = 3243 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 3244 CandidateSet, false); 3245 if (OvResult == OR_Ambiguous) 3246 Diag(From->getLocStart(), 3247 diag::err_typecheck_ambiguous_condition) 3248 << From->getType() << ToType << From->getSourceRange(); 3249 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 3250 Diag(From->getLocStart(), 3251 diag::err_typecheck_nonviable_condition) 3252 << From->getType() << ToType << From->getSourceRange(); 3253 else 3254 return false; 3255 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From); 3256 return true; 3257} 3258 3259/// \brief Compare the user-defined conversion functions or constructors 3260/// of two user-defined conversion sequences to determine whether any ordering 3261/// is possible. 3262static ImplicitConversionSequence::CompareKind 3263compareConversionFunctions(Sema &S, 3264 FunctionDecl *Function1, 3265 FunctionDecl *Function2) { 3266 if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus11) 3267 return ImplicitConversionSequence::Indistinguishable; 3268 3269 // Objective-C++: 3270 // If both conversion functions are implicitly-declared conversions from 3271 // a lambda closure type to a function pointer and a block pointer, 3272 // respectively, always prefer the conversion to a function pointer, 3273 // because the function pointer is more lightweight and is more likely 3274 // to keep code working. 3275 CXXConversionDecl *Conv1 = dyn_cast<CXXConversionDecl>(Function1); 3276 if (!Conv1) 3277 return ImplicitConversionSequence::Indistinguishable; 3278 3279 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2); 3280 if (!Conv2) 3281 return ImplicitConversionSequence::Indistinguishable; 3282 3283 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) { 3284 bool Block1 = Conv1->getConversionType()->isBlockPointerType(); 3285 bool Block2 = Conv2->getConversionType()->isBlockPointerType(); 3286 if (Block1 != Block2) 3287 return Block1? ImplicitConversionSequence::Worse 3288 : ImplicitConversionSequence::Better; 3289 } 3290 3291 return ImplicitConversionSequence::Indistinguishable; 3292} 3293 3294/// CompareImplicitConversionSequences - Compare two implicit 3295/// conversion sequences to determine whether one is better than the 3296/// other or if they are indistinguishable (C++ 13.3.3.2). 3297static ImplicitConversionSequence::CompareKind 3298CompareImplicitConversionSequences(Sema &S, 3299 const ImplicitConversionSequence& ICS1, 3300 const ImplicitConversionSequence& ICS2) 3301{ 3302 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 3303 // conversion sequences (as defined in 13.3.3.1) 3304 // -- a standard conversion sequence (13.3.3.1.1) is a better 3305 // conversion sequence than a user-defined conversion sequence or 3306 // an ellipsis conversion sequence, and 3307 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 3308 // conversion sequence than an ellipsis conversion sequence 3309 // (13.3.3.1.3). 3310 // 3311 // C++0x [over.best.ics]p10: 3312 // For the purpose of ranking implicit conversion sequences as 3313 // described in 13.3.3.2, the ambiguous conversion sequence is 3314 // treated as a user-defined sequence that is indistinguishable 3315 // from any other user-defined conversion sequence. 3316 if (ICS1.getKindRank() < ICS2.getKindRank()) 3317 return ImplicitConversionSequence::Better; 3318 if (ICS2.getKindRank() < ICS1.getKindRank()) 3319 return ImplicitConversionSequence::Worse; 3320 3321 // The following checks require both conversion sequences to be of 3322 // the same kind. 3323 if (ICS1.getKind() != ICS2.getKind()) 3324 return ImplicitConversionSequence::Indistinguishable; 3325 3326 ImplicitConversionSequence::CompareKind Result = 3327 ImplicitConversionSequence::Indistinguishable; 3328 3329 // Two implicit conversion sequences of the same form are 3330 // indistinguishable conversion sequences unless one of the 3331 // following rules apply: (C++ 13.3.3.2p3): 3332 if (ICS1.isStandard()) 3333 Result = CompareStandardConversionSequences(S, 3334 ICS1.Standard, ICS2.Standard); 3335 else if (ICS1.isUserDefined()) { 3336 // User-defined conversion sequence U1 is a better conversion 3337 // sequence than another user-defined conversion sequence U2 if 3338 // they contain the same user-defined conversion function or 3339 // constructor and if the second standard conversion sequence of 3340 // U1 is better than the second standard conversion sequence of 3341 // U2 (C++ 13.3.3.2p3). 3342 if (ICS1.UserDefined.ConversionFunction == 3343 ICS2.UserDefined.ConversionFunction) 3344 Result = CompareStandardConversionSequences(S, 3345 ICS1.UserDefined.After, 3346 ICS2.UserDefined.After); 3347 else 3348 Result = compareConversionFunctions(S, 3349 ICS1.UserDefined.ConversionFunction, 3350 ICS2.UserDefined.ConversionFunction); 3351 } 3352 3353 // List-initialization sequence L1 is a better conversion sequence than 3354 // list-initialization sequence L2 if L1 converts to std::initializer_list<X> 3355 // for some X and L2 does not. 3356 if (Result == ImplicitConversionSequence::Indistinguishable && 3357 !ICS1.isBad() && 3358 ICS1.isListInitializationSequence() && 3359 ICS2.isListInitializationSequence()) { 3360 if (ICS1.isStdInitializerListElement() && 3361 !ICS2.isStdInitializerListElement()) 3362 return ImplicitConversionSequence::Better; 3363 if (!ICS1.isStdInitializerListElement() && 3364 ICS2.isStdInitializerListElement()) 3365 return ImplicitConversionSequence::Worse; 3366 } 3367 3368 return Result; 3369} 3370 3371static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 3372 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 3373 Qualifiers Quals; 3374 T1 = Context.getUnqualifiedArrayType(T1, Quals); 3375 T2 = Context.getUnqualifiedArrayType(T2, Quals); 3376 } 3377 3378 return Context.hasSameUnqualifiedType(T1, T2); 3379} 3380 3381// Per 13.3.3.2p3, compare the given standard conversion sequences to 3382// determine if one is a proper subset of the other. 3383static ImplicitConversionSequence::CompareKind 3384compareStandardConversionSubsets(ASTContext &Context, 3385 const StandardConversionSequence& SCS1, 3386 const StandardConversionSequence& SCS2) { 3387 ImplicitConversionSequence::CompareKind Result 3388 = ImplicitConversionSequence::Indistinguishable; 3389 3390 // the identity conversion sequence is considered to be a subsequence of 3391 // any non-identity conversion sequence 3392 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 3393 return ImplicitConversionSequence::Better; 3394 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 3395 return ImplicitConversionSequence::Worse; 3396 3397 if (SCS1.Second != SCS2.Second) { 3398 if (SCS1.Second == ICK_Identity) 3399 Result = ImplicitConversionSequence::Better; 3400 else if (SCS2.Second == ICK_Identity) 3401 Result = ImplicitConversionSequence::Worse; 3402 else 3403 return ImplicitConversionSequence::Indistinguishable; 3404 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 3405 return ImplicitConversionSequence::Indistinguishable; 3406 3407 if (SCS1.Third == SCS2.Third) { 3408 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 3409 : ImplicitConversionSequence::Indistinguishable; 3410 } 3411 3412 if (SCS1.Third == ICK_Identity) 3413 return Result == ImplicitConversionSequence::Worse 3414 ? ImplicitConversionSequence::Indistinguishable 3415 : ImplicitConversionSequence::Better; 3416 3417 if (SCS2.Third == ICK_Identity) 3418 return Result == ImplicitConversionSequence::Better 3419 ? ImplicitConversionSequence::Indistinguishable 3420 : ImplicitConversionSequence::Worse; 3421 3422 return ImplicitConversionSequence::Indistinguishable; 3423} 3424 3425/// \brief Determine whether one of the given reference bindings is better 3426/// than the other based on what kind of bindings they are. 3427static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 3428 const StandardConversionSequence &SCS2) { 3429 // C++0x [over.ics.rank]p3b4: 3430 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 3431 // implicit object parameter of a non-static member function declared 3432 // without a ref-qualifier, and *either* S1 binds an rvalue reference 3433 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 3434 // lvalue reference to a function lvalue and S2 binds an rvalue 3435 // reference*. 3436 // 3437 // FIXME: Rvalue references. We're going rogue with the above edits, 3438 // because the semantics in the current C++0x working paper (N3225 at the 3439 // time of this writing) break the standard definition of std::forward 3440 // and std::reference_wrapper when dealing with references to functions. 3441 // Proposed wording changes submitted to CWG for consideration. 3442 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 3443 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 3444 return false; 3445 3446 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 3447 SCS2.IsLvalueReference) || 3448 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 3449 !SCS2.IsLvalueReference); 3450} 3451 3452/// CompareStandardConversionSequences - Compare two standard 3453/// conversion sequences to determine whether one is better than the 3454/// other or if they are indistinguishable (C++ 13.3.3.2p3). 3455static ImplicitConversionSequence::CompareKind 3456CompareStandardConversionSequences(Sema &S, 3457 const StandardConversionSequence& SCS1, 3458 const StandardConversionSequence& SCS2) 3459{ 3460 // Standard conversion sequence S1 is a better conversion sequence 3461 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 3462 3463 // -- S1 is a proper subsequence of S2 (comparing the conversion 3464 // sequences in the canonical form defined by 13.3.3.1.1, 3465 // excluding any Lvalue Transformation; the identity conversion 3466 // sequence is considered to be a subsequence of any 3467 // non-identity conversion sequence) or, if not that, 3468 if (ImplicitConversionSequence::CompareKind CK 3469 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 3470 return CK; 3471 3472 // -- the rank of S1 is better than the rank of S2 (by the rules 3473 // defined below), or, if not that, 3474 ImplicitConversionRank Rank1 = SCS1.getRank(); 3475 ImplicitConversionRank Rank2 = SCS2.getRank(); 3476 if (Rank1 < Rank2) 3477 return ImplicitConversionSequence::Better; 3478 else if (Rank2 < Rank1) 3479 return ImplicitConversionSequence::Worse; 3480 3481 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 3482 // are indistinguishable unless one of the following rules 3483 // applies: 3484 3485 // A conversion that is not a conversion of a pointer, or 3486 // pointer to member, to bool is better than another conversion 3487 // that is such a conversion. 3488 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 3489 return SCS2.isPointerConversionToBool() 3490 ? ImplicitConversionSequence::Better 3491 : ImplicitConversionSequence::Worse; 3492 3493 // C++ [over.ics.rank]p4b2: 3494 // 3495 // If class B is derived directly or indirectly from class A, 3496 // conversion of B* to A* is better than conversion of B* to 3497 // void*, and conversion of A* to void* is better than conversion 3498 // of B* to void*. 3499 bool SCS1ConvertsToVoid 3500 = SCS1.isPointerConversionToVoidPointer(S.Context); 3501 bool SCS2ConvertsToVoid 3502 = SCS2.isPointerConversionToVoidPointer(S.Context); 3503 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 3504 // Exactly one of the conversion sequences is a conversion to 3505 // a void pointer; it's the worse conversion. 3506 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 3507 : ImplicitConversionSequence::Worse; 3508 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 3509 // Neither conversion sequence converts to a void pointer; compare 3510 // their derived-to-base conversions. 3511 if (ImplicitConversionSequence::CompareKind DerivedCK 3512 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 3513 return DerivedCK; 3514 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid && 3515 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) { 3516 // Both conversion sequences are conversions to void 3517 // pointers. Compare the source types to determine if there's an 3518 // inheritance relationship in their sources. 3519 QualType FromType1 = SCS1.getFromType(); 3520 QualType FromType2 = SCS2.getFromType(); 3521 3522 // Adjust the types we're converting from via the array-to-pointer 3523 // conversion, if we need to. 3524 if (SCS1.First == ICK_Array_To_Pointer) 3525 FromType1 = S.Context.getArrayDecayedType(FromType1); 3526 if (SCS2.First == ICK_Array_To_Pointer) 3527 FromType2 = S.Context.getArrayDecayedType(FromType2); 3528 3529 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType(); 3530 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType(); 3531 3532 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3533 return ImplicitConversionSequence::Better; 3534 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3535 return ImplicitConversionSequence::Worse; 3536 3537 // Objective-C++: If one interface is more specific than the 3538 // other, it is the better one. 3539 const ObjCObjectPointerType* FromObjCPtr1 3540 = FromType1->getAs<ObjCObjectPointerType>(); 3541 const ObjCObjectPointerType* FromObjCPtr2 3542 = FromType2->getAs<ObjCObjectPointerType>(); 3543 if (FromObjCPtr1 && FromObjCPtr2) { 3544 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1, 3545 FromObjCPtr2); 3546 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2, 3547 FromObjCPtr1); 3548 if (AssignLeft != AssignRight) { 3549 return AssignLeft? ImplicitConversionSequence::Better 3550 : ImplicitConversionSequence::Worse; 3551 } 3552 } 3553 } 3554 3555 // Compare based on qualification conversions (C++ 13.3.3.2p3, 3556 // bullet 3). 3557 if (ImplicitConversionSequence::CompareKind QualCK 3558 = CompareQualificationConversions(S, SCS1, SCS2)) 3559 return QualCK; 3560 3561 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 3562 // Check for a better reference binding based on the kind of bindings. 3563 if (isBetterReferenceBindingKind(SCS1, SCS2)) 3564 return ImplicitConversionSequence::Better; 3565 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 3566 return ImplicitConversionSequence::Worse; 3567 3568 // C++ [over.ics.rank]p3b4: 3569 // -- S1 and S2 are reference bindings (8.5.3), and the types to 3570 // which the references refer are the same type except for 3571 // top-level cv-qualifiers, and the type to which the reference 3572 // initialized by S2 refers is more cv-qualified than the type 3573 // to which the reference initialized by S1 refers. 3574 QualType T1 = SCS1.getToType(2); 3575 QualType T2 = SCS2.getToType(2); 3576 T1 = S.Context.getCanonicalType(T1); 3577 T2 = S.Context.getCanonicalType(T2); 3578 Qualifiers T1Quals, T2Quals; 3579 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3580 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3581 if (UnqualT1 == UnqualT2) { 3582 // Objective-C++ ARC: If the references refer to objects with different 3583 // lifetimes, prefer bindings that don't change lifetime. 3584 if (SCS1.ObjCLifetimeConversionBinding != 3585 SCS2.ObjCLifetimeConversionBinding) { 3586 return SCS1.ObjCLifetimeConversionBinding 3587 ? ImplicitConversionSequence::Worse 3588 : ImplicitConversionSequence::Better; 3589 } 3590 3591 // If the type is an array type, promote the element qualifiers to the 3592 // type for comparison. 3593 if (isa<ArrayType>(T1) && T1Quals) 3594 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3595 if (isa<ArrayType>(T2) && T2Quals) 3596 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3597 if (T2.isMoreQualifiedThan(T1)) 3598 return ImplicitConversionSequence::Better; 3599 else if (T1.isMoreQualifiedThan(T2)) 3600 return ImplicitConversionSequence::Worse; 3601 } 3602 } 3603 3604 // In Microsoft mode, prefer an integral conversion to a 3605 // floating-to-integral conversion if the integral conversion 3606 // is between types of the same size. 3607 // For example: 3608 // void f(float); 3609 // void f(int); 3610 // int main { 3611 // long a; 3612 // f(a); 3613 // } 3614 // Here, MSVC will call f(int) instead of generating a compile error 3615 // as clang will do in standard mode. 3616 if (S.getLangOpts().MicrosoftMode && 3617 SCS1.Second == ICK_Integral_Conversion && 3618 SCS2.Second == ICK_Floating_Integral && 3619 S.Context.getTypeSize(SCS1.getFromType()) == 3620 S.Context.getTypeSize(SCS1.getToType(2))) 3621 return ImplicitConversionSequence::Better; 3622 3623 return ImplicitConversionSequence::Indistinguishable; 3624} 3625 3626/// CompareQualificationConversions - Compares two standard conversion 3627/// sequences to determine whether they can be ranked based on their 3628/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 3629ImplicitConversionSequence::CompareKind 3630CompareQualificationConversions(Sema &S, 3631 const StandardConversionSequence& SCS1, 3632 const StandardConversionSequence& SCS2) { 3633 // C++ 13.3.3.2p3: 3634 // -- S1 and S2 differ only in their qualification conversion and 3635 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 3636 // cv-qualification signature of type T1 is a proper subset of 3637 // the cv-qualification signature of type T2, and S1 is not the 3638 // deprecated string literal array-to-pointer conversion (4.2). 3639 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 3640 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 3641 return ImplicitConversionSequence::Indistinguishable; 3642 3643 // FIXME: the example in the standard doesn't use a qualification 3644 // conversion (!) 3645 QualType T1 = SCS1.getToType(2); 3646 QualType T2 = SCS2.getToType(2); 3647 T1 = S.Context.getCanonicalType(T1); 3648 T2 = S.Context.getCanonicalType(T2); 3649 Qualifiers T1Quals, T2Quals; 3650 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3651 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3652 3653 // If the types are the same, we won't learn anything by unwrapped 3654 // them. 3655 if (UnqualT1 == UnqualT2) 3656 return ImplicitConversionSequence::Indistinguishable; 3657 3658 // If the type is an array type, promote the element qualifiers to the type 3659 // for comparison. 3660 if (isa<ArrayType>(T1) && T1Quals) 3661 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3662 if (isa<ArrayType>(T2) && T2Quals) 3663 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3664 3665 ImplicitConversionSequence::CompareKind Result 3666 = ImplicitConversionSequence::Indistinguishable; 3667 3668 // Objective-C++ ARC: 3669 // Prefer qualification conversions not involving a change in lifetime 3670 // to qualification conversions that do not change lifetime. 3671 if (SCS1.QualificationIncludesObjCLifetime != 3672 SCS2.QualificationIncludesObjCLifetime) { 3673 Result = SCS1.QualificationIncludesObjCLifetime 3674 ? ImplicitConversionSequence::Worse 3675 : ImplicitConversionSequence::Better; 3676 } 3677 3678 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 3679 // Within each iteration of the loop, we check the qualifiers to 3680 // determine if this still looks like a qualification 3681 // conversion. Then, if all is well, we unwrap one more level of 3682 // pointers or pointers-to-members and do it all again 3683 // until there are no more pointers or pointers-to-members left 3684 // to unwrap. This essentially mimics what 3685 // IsQualificationConversion does, but here we're checking for a 3686 // strict subset of qualifiers. 3687 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 3688 // The qualifiers are the same, so this doesn't tell us anything 3689 // about how the sequences rank. 3690 ; 3691 else if (T2.isMoreQualifiedThan(T1)) { 3692 // T1 has fewer qualifiers, so it could be the better sequence. 3693 if (Result == ImplicitConversionSequence::Worse) 3694 // Neither has qualifiers that are a subset of the other's 3695 // qualifiers. 3696 return ImplicitConversionSequence::Indistinguishable; 3697 3698 Result = ImplicitConversionSequence::Better; 3699 } else if (T1.isMoreQualifiedThan(T2)) { 3700 // T2 has fewer qualifiers, so it could be the better sequence. 3701 if (Result == ImplicitConversionSequence::Better) 3702 // Neither has qualifiers that are a subset of the other's 3703 // qualifiers. 3704 return ImplicitConversionSequence::Indistinguishable; 3705 3706 Result = ImplicitConversionSequence::Worse; 3707 } else { 3708 // Qualifiers are disjoint. 3709 return ImplicitConversionSequence::Indistinguishable; 3710 } 3711 3712 // If the types after this point are equivalent, we're done. 3713 if (S.Context.hasSameUnqualifiedType(T1, T2)) 3714 break; 3715 } 3716 3717 // Check that the winning standard conversion sequence isn't using 3718 // the deprecated string literal array to pointer conversion. 3719 switch (Result) { 3720 case ImplicitConversionSequence::Better: 3721 if (SCS1.DeprecatedStringLiteralToCharPtr) 3722 Result = ImplicitConversionSequence::Indistinguishable; 3723 break; 3724 3725 case ImplicitConversionSequence::Indistinguishable: 3726 break; 3727 3728 case ImplicitConversionSequence::Worse: 3729 if (SCS2.DeprecatedStringLiteralToCharPtr) 3730 Result = ImplicitConversionSequence::Indistinguishable; 3731 break; 3732 } 3733 3734 return Result; 3735} 3736 3737/// CompareDerivedToBaseConversions - Compares two standard conversion 3738/// sequences to determine whether they can be ranked based on their 3739/// various kinds of derived-to-base conversions (C++ 3740/// [over.ics.rank]p4b3). As part of these checks, we also look at 3741/// conversions between Objective-C interface types. 3742ImplicitConversionSequence::CompareKind 3743CompareDerivedToBaseConversions(Sema &S, 3744 const StandardConversionSequence& SCS1, 3745 const StandardConversionSequence& SCS2) { 3746 QualType FromType1 = SCS1.getFromType(); 3747 QualType ToType1 = SCS1.getToType(1); 3748 QualType FromType2 = SCS2.getFromType(); 3749 QualType ToType2 = SCS2.getToType(1); 3750 3751 // Adjust the types we're converting from via the array-to-pointer 3752 // conversion, if we need to. 3753 if (SCS1.First == ICK_Array_To_Pointer) 3754 FromType1 = S.Context.getArrayDecayedType(FromType1); 3755 if (SCS2.First == ICK_Array_To_Pointer) 3756 FromType2 = S.Context.getArrayDecayedType(FromType2); 3757 3758 // Canonicalize all of the types. 3759 FromType1 = S.Context.getCanonicalType(FromType1); 3760 ToType1 = S.Context.getCanonicalType(ToType1); 3761 FromType2 = S.Context.getCanonicalType(FromType2); 3762 ToType2 = S.Context.getCanonicalType(ToType2); 3763 3764 // C++ [over.ics.rank]p4b3: 3765 // 3766 // If class B is derived directly or indirectly from class A and 3767 // class C is derived directly or indirectly from B, 3768 // 3769 // Compare based on pointer conversions. 3770 if (SCS1.Second == ICK_Pointer_Conversion && 3771 SCS2.Second == ICK_Pointer_Conversion && 3772 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 3773 FromType1->isPointerType() && FromType2->isPointerType() && 3774 ToType1->isPointerType() && ToType2->isPointerType()) { 3775 QualType FromPointee1 3776 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3777 QualType ToPointee1 3778 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3779 QualType FromPointee2 3780 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3781 QualType ToPointee2 3782 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3783 3784 // -- conversion of C* to B* is better than conversion of C* to A*, 3785 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3786 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3787 return ImplicitConversionSequence::Better; 3788 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3789 return ImplicitConversionSequence::Worse; 3790 } 3791 3792 // -- conversion of B* to A* is better than conversion of C* to A*, 3793 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 3794 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3795 return ImplicitConversionSequence::Better; 3796 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3797 return ImplicitConversionSequence::Worse; 3798 } 3799 } else if (SCS1.Second == ICK_Pointer_Conversion && 3800 SCS2.Second == ICK_Pointer_Conversion) { 3801 const ObjCObjectPointerType *FromPtr1 3802 = FromType1->getAs<ObjCObjectPointerType>(); 3803 const ObjCObjectPointerType *FromPtr2 3804 = FromType2->getAs<ObjCObjectPointerType>(); 3805 const ObjCObjectPointerType *ToPtr1 3806 = ToType1->getAs<ObjCObjectPointerType>(); 3807 const ObjCObjectPointerType *ToPtr2 3808 = ToType2->getAs<ObjCObjectPointerType>(); 3809 3810 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 3811 // Apply the same conversion ranking rules for Objective-C pointer types 3812 // that we do for C++ pointers to class types. However, we employ the 3813 // Objective-C pseudo-subtyping relationship used for assignment of 3814 // Objective-C pointer types. 3815 bool FromAssignLeft 3816 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 3817 bool FromAssignRight 3818 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 3819 bool ToAssignLeft 3820 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 3821 bool ToAssignRight 3822 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 3823 3824 // A conversion to an a non-id object pointer type or qualified 'id' 3825 // type is better than a conversion to 'id'. 3826 if (ToPtr1->isObjCIdType() && 3827 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 3828 return ImplicitConversionSequence::Worse; 3829 if (ToPtr2->isObjCIdType() && 3830 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 3831 return ImplicitConversionSequence::Better; 3832 3833 // A conversion to a non-id object pointer type is better than a 3834 // conversion to a qualified 'id' type 3835 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 3836 return ImplicitConversionSequence::Worse; 3837 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 3838 return ImplicitConversionSequence::Better; 3839 3840 // A conversion to an a non-Class object pointer type or qualified 'Class' 3841 // type is better than a conversion to 'Class'. 3842 if (ToPtr1->isObjCClassType() && 3843 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 3844 return ImplicitConversionSequence::Worse; 3845 if (ToPtr2->isObjCClassType() && 3846 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 3847 return ImplicitConversionSequence::Better; 3848 3849 // A conversion to a non-Class object pointer type is better than a 3850 // conversion to a qualified 'Class' type. 3851 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 3852 return ImplicitConversionSequence::Worse; 3853 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 3854 return ImplicitConversionSequence::Better; 3855 3856 // -- "conversion of C* to B* is better than conversion of C* to A*," 3857 if (S.Context.hasSameType(FromType1, FromType2) && 3858 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 3859 (ToAssignLeft != ToAssignRight)) 3860 return ToAssignLeft? ImplicitConversionSequence::Worse 3861 : ImplicitConversionSequence::Better; 3862 3863 // -- "conversion of B* to A* is better than conversion of C* to A*," 3864 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 3865 (FromAssignLeft != FromAssignRight)) 3866 return FromAssignLeft? ImplicitConversionSequence::Better 3867 : ImplicitConversionSequence::Worse; 3868 } 3869 } 3870 3871 // Ranking of member-pointer types. 3872 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 3873 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 3874 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 3875 const MemberPointerType * FromMemPointer1 = 3876 FromType1->getAs<MemberPointerType>(); 3877 const MemberPointerType * ToMemPointer1 = 3878 ToType1->getAs<MemberPointerType>(); 3879 const MemberPointerType * FromMemPointer2 = 3880 FromType2->getAs<MemberPointerType>(); 3881 const MemberPointerType * ToMemPointer2 = 3882 ToType2->getAs<MemberPointerType>(); 3883 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 3884 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 3885 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 3886 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 3887 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 3888 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 3889 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 3890 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 3891 // conversion of A::* to B::* is better than conversion of A::* to C::*, 3892 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3893 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3894 return ImplicitConversionSequence::Worse; 3895 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3896 return ImplicitConversionSequence::Better; 3897 } 3898 // conversion of B::* to C::* is better than conversion of A::* to C::* 3899 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 3900 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3901 return ImplicitConversionSequence::Better; 3902 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3903 return ImplicitConversionSequence::Worse; 3904 } 3905 } 3906 3907 if (SCS1.Second == ICK_Derived_To_Base) { 3908 // -- conversion of C to B is better than conversion of C to A, 3909 // -- binding of an expression of type C to a reference of type 3910 // B& is better than binding an expression of type C to a 3911 // reference of type A&, 3912 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3913 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3914 if (S.IsDerivedFrom(ToType1, ToType2)) 3915 return ImplicitConversionSequence::Better; 3916 else if (S.IsDerivedFrom(ToType2, ToType1)) 3917 return ImplicitConversionSequence::Worse; 3918 } 3919 3920 // -- conversion of B to A is better than conversion of C to A. 3921 // -- binding of an expression of type B to a reference of type 3922 // A& is better than binding an expression of type C to a 3923 // reference of type A&, 3924 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3925 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3926 if (S.IsDerivedFrom(FromType2, FromType1)) 3927 return ImplicitConversionSequence::Better; 3928 else if (S.IsDerivedFrom(FromType1, FromType2)) 3929 return ImplicitConversionSequence::Worse; 3930 } 3931 } 3932 3933 return ImplicitConversionSequence::Indistinguishable; 3934} 3935 3936/// CompareReferenceRelationship - Compare the two types T1 and T2 to 3937/// determine whether they are reference-related, 3938/// reference-compatible, reference-compatible with added 3939/// qualification, or incompatible, for use in C++ initialization by 3940/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 3941/// type, and the first type (T1) is the pointee type of the reference 3942/// type being initialized. 3943Sema::ReferenceCompareResult 3944Sema::CompareReferenceRelationship(SourceLocation Loc, 3945 QualType OrigT1, QualType OrigT2, 3946 bool &DerivedToBase, 3947 bool &ObjCConversion, 3948 bool &ObjCLifetimeConversion) { 3949 assert(!OrigT1->isReferenceType() && 3950 "T1 must be the pointee type of the reference type"); 3951 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 3952 3953 QualType T1 = Context.getCanonicalType(OrigT1); 3954 QualType T2 = Context.getCanonicalType(OrigT2); 3955 Qualifiers T1Quals, T2Quals; 3956 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 3957 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 3958 3959 // C++ [dcl.init.ref]p4: 3960 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 3961 // reference-related to "cv2 T2" if T1 is the same type as T2, or 3962 // T1 is a base class of T2. 3963 DerivedToBase = false; 3964 ObjCConversion = false; 3965 ObjCLifetimeConversion = false; 3966 if (UnqualT1 == UnqualT2) { 3967 // Nothing to do. 3968 } else if (!RequireCompleteType(Loc, OrigT2, 0) && 3969 IsDerivedFrom(UnqualT2, UnqualT1)) 3970 DerivedToBase = true; 3971 else if (UnqualT1->isObjCObjectOrInterfaceType() && 3972 UnqualT2->isObjCObjectOrInterfaceType() && 3973 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 3974 ObjCConversion = true; 3975 else 3976 return Ref_Incompatible; 3977 3978 // At this point, we know that T1 and T2 are reference-related (at 3979 // least). 3980 3981 // If the type is an array type, promote the element qualifiers to the type 3982 // for comparison. 3983 if (isa<ArrayType>(T1) && T1Quals) 3984 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 3985 if (isa<ArrayType>(T2) && T2Quals) 3986 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 3987 3988 // C++ [dcl.init.ref]p4: 3989 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 3990 // reference-related to T2 and cv1 is the same cv-qualification 3991 // as, or greater cv-qualification than, cv2. For purposes of 3992 // overload resolution, cases for which cv1 is greater 3993 // cv-qualification than cv2 are identified as 3994 // reference-compatible with added qualification (see 13.3.3.2). 3995 // 3996 // Note that we also require equivalence of Objective-C GC and address-space 3997 // qualifiers when performing these computations, so that e.g., an int in 3998 // address space 1 is not reference-compatible with an int in address 3999 // space 2. 4000 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() && 4001 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) { 4002 T1Quals.removeObjCLifetime(); 4003 T2Quals.removeObjCLifetime(); 4004 ObjCLifetimeConversion = true; 4005 } 4006 4007 if (T1Quals == T2Quals) 4008 return Ref_Compatible; 4009 else if (T1Quals.compatiblyIncludes(T2Quals)) 4010 return Ref_Compatible_With_Added_Qualification; 4011 else 4012 return Ref_Related; 4013} 4014 4015/// \brief Look for a user-defined conversion to an value reference-compatible 4016/// with DeclType. Return true if something definite is found. 4017static bool 4018FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 4019 QualType DeclType, SourceLocation DeclLoc, 4020 Expr *Init, QualType T2, bool AllowRvalues, 4021 bool AllowExplicit) { 4022 assert(T2->isRecordType() && "Can only find conversions of record types."); 4023 CXXRecordDecl *T2RecordDecl 4024 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 4025 4026 OverloadCandidateSet CandidateSet(DeclLoc); 4027 std::pair<CXXRecordDecl::conversion_iterator, 4028 CXXRecordDecl::conversion_iterator> 4029 Conversions = T2RecordDecl->getVisibleConversionFunctions(); 4030 for (CXXRecordDecl::conversion_iterator 4031 I = Conversions.first, E = Conversions.second; I != E; ++I) { 4032 NamedDecl *D = *I; 4033 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 4034 if (isa<UsingShadowDecl>(D)) 4035 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4036 4037 FunctionTemplateDecl *ConvTemplate 4038 = dyn_cast<FunctionTemplateDecl>(D); 4039 CXXConversionDecl *Conv; 4040 if (ConvTemplate) 4041 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 4042 else 4043 Conv = cast<CXXConversionDecl>(D); 4044 4045 // If this is an explicit conversion, and we're not allowed to consider 4046 // explicit conversions, skip it. 4047 if (!AllowExplicit && Conv->isExplicit()) 4048 continue; 4049 4050 if (AllowRvalues) { 4051 bool DerivedToBase = false; 4052 bool ObjCConversion = false; 4053 bool ObjCLifetimeConversion = false; 4054 4055 // If we are initializing an rvalue reference, don't permit conversion 4056 // functions that return lvalues. 4057 if (!ConvTemplate && DeclType->isRValueReferenceType()) { 4058 const ReferenceType *RefType 4059 = Conv->getConversionType()->getAs<LValueReferenceType>(); 4060 if (RefType && !RefType->getPointeeType()->isFunctionType()) 4061 continue; 4062 } 4063 4064 if (!ConvTemplate && 4065 S.CompareReferenceRelationship( 4066 DeclLoc, 4067 Conv->getConversionType().getNonReferenceType() 4068 .getUnqualifiedType(), 4069 DeclType.getNonReferenceType().getUnqualifiedType(), 4070 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) == 4071 Sema::Ref_Incompatible) 4072 continue; 4073 } else { 4074 // If the conversion function doesn't return a reference type, 4075 // it can't be considered for this conversion. An rvalue reference 4076 // is only acceptable if its referencee is a function type. 4077 4078 const ReferenceType *RefType = 4079 Conv->getConversionType()->getAs<ReferenceType>(); 4080 if (!RefType || 4081 (!RefType->isLValueReferenceType() && 4082 !RefType->getPointeeType()->isFunctionType())) 4083 continue; 4084 } 4085 4086 if (ConvTemplate) 4087 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 4088 Init, DeclType, CandidateSet); 4089 else 4090 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 4091 DeclType, CandidateSet); 4092 } 4093 4094 bool HadMultipleCandidates = (CandidateSet.size() > 1); 4095 4096 OverloadCandidateSet::iterator Best; 4097 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 4098 case OR_Success: 4099 // C++ [over.ics.ref]p1: 4100 // 4101 // [...] If the parameter binds directly to the result of 4102 // applying a conversion function to the argument 4103 // expression, the implicit conversion sequence is a 4104 // user-defined conversion sequence (13.3.3.1.2), with the 4105 // second standard conversion sequence either an identity 4106 // conversion or, if the conversion function returns an 4107 // entity of a type that is a derived class of the parameter 4108 // type, a derived-to-base Conversion. 4109 if (!Best->FinalConversion.DirectBinding) 4110 return false; 4111 4112 ICS.setUserDefined(); 4113 ICS.UserDefined.Before = Best->Conversions[0].Standard; 4114 ICS.UserDefined.After = Best->FinalConversion; 4115 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates; 4116 ICS.UserDefined.ConversionFunction = Best->Function; 4117 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl; 4118 ICS.UserDefined.EllipsisConversion = false; 4119 assert(ICS.UserDefined.After.ReferenceBinding && 4120 ICS.UserDefined.After.DirectBinding && 4121 "Expected a direct reference binding!"); 4122 return true; 4123 4124 case OR_Ambiguous: 4125 ICS.setAmbiguous(); 4126 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4127 Cand != CandidateSet.end(); ++Cand) 4128 if (Cand->Viable) 4129 ICS.Ambiguous.addConversion(Cand->Function); 4130 return true; 4131 4132 case OR_No_Viable_Function: 4133 case OR_Deleted: 4134 // There was no suitable conversion, or we found a deleted 4135 // conversion; continue with other checks. 4136 return false; 4137 } 4138 4139 llvm_unreachable("Invalid OverloadResult!"); 4140} 4141 4142/// \brief Compute an implicit conversion sequence for reference 4143/// initialization. 4144static ImplicitConversionSequence 4145TryReferenceInit(Sema &S, Expr *Init, QualType DeclType, 4146 SourceLocation DeclLoc, 4147 bool SuppressUserConversions, 4148 bool AllowExplicit) { 4149 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 4150 4151 // Most paths end in a failed conversion. 4152 ImplicitConversionSequence ICS; 4153 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 4154 4155 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 4156 QualType T2 = Init->getType(); 4157 4158 // If the initializer is the address of an overloaded function, try 4159 // to resolve the overloaded function. If all goes well, T2 is the 4160 // type of the resulting function. 4161 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 4162 DeclAccessPair Found; 4163 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 4164 false, Found)) 4165 T2 = Fn->getType(); 4166 } 4167 4168 // Compute some basic properties of the types and the initializer. 4169 bool isRValRef = DeclType->isRValueReferenceType(); 4170 bool DerivedToBase = false; 4171 bool ObjCConversion = false; 4172 bool ObjCLifetimeConversion = false; 4173 Expr::Classification InitCategory = Init->Classify(S.Context); 4174 Sema::ReferenceCompareResult RefRelationship 4175 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 4176 ObjCConversion, ObjCLifetimeConversion); 4177 4178 4179 // C++0x [dcl.init.ref]p5: 4180 // A reference to type "cv1 T1" is initialized by an expression 4181 // of type "cv2 T2" as follows: 4182 4183 // -- If reference is an lvalue reference and the initializer expression 4184 if (!isRValRef) { 4185 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 4186 // reference-compatible with "cv2 T2," or 4187 // 4188 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 4189 if (InitCategory.isLValue() && 4190 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 4191 // C++ [over.ics.ref]p1: 4192 // When a parameter of reference type binds directly (8.5.3) 4193 // to an argument expression, the implicit conversion sequence 4194 // is the identity conversion, unless the argument expression 4195 // has a type that is a derived class of the parameter type, 4196 // in which case the implicit conversion sequence is a 4197 // derived-to-base Conversion (13.3.3.1). 4198 ICS.setStandard(); 4199 ICS.Standard.First = ICK_Identity; 4200 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 4201 : ObjCConversion? ICK_Compatible_Conversion 4202 : ICK_Identity; 4203 ICS.Standard.Third = ICK_Identity; 4204 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 4205 ICS.Standard.setToType(0, T2); 4206 ICS.Standard.setToType(1, T1); 4207 ICS.Standard.setToType(2, T1); 4208 ICS.Standard.ReferenceBinding = true; 4209 ICS.Standard.DirectBinding = true; 4210 ICS.Standard.IsLvalueReference = !isRValRef; 4211 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4212 ICS.Standard.BindsToRvalue = false; 4213 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4214 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 4215 ICS.Standard.CopyConstructor = 0; 4216 4217 // Nothing more to do: the inaccessibility/ambiguity check for 4218 // derived-to-base conversions is suppressed when we're 4219 // computing the implicit conversion sequence (C++ 4220 // [over.best.ics]p2). 4221 return ICS; 4222 } 4223 4224 // -- has a class type (i.e., T2 is a class type), where T1 is 4225 // not reference-related to T2, and can be implicitly 4226 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 4227 // is reference-compatible with "cv3 T3" 92) (this 4228 // conversion is selected by enumerating the applicable 4229 // conversion functions (13.3.1.6) and choosing the best 4230 // one through overload resolution (13.3)), 4231 if (!SuppressUserConversions && T2->isRecordType() && 4232 !S.RequireCompleteType(DeclLoc, T2, 0) && 4233 RefRelationship == Sema::Ref_Incompatible) { 4234 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 4235 Init, T2, /*AllowRvalues=*/false, 4236 AllowExplicit)) 4237 return ICS; 4238 } 4239 } 4240 4241 // -- Otherwise, the reference shall be an lvalue reference to a 4242 // non-volatile const type (i.e., cv1 shall be const), or the reference 4243 // shall be an rvalue reference. 4244 // 4245 // We actually handle one oddity of C++ [over.ics.ref] at this 4246 // point, which is that, due to p2 (which short-circuits reference 4247 // binding by only attempting a simple conversion for non-direct 4248 // bindings) and p3's strange wording, we allow a const volatile 4249 // reference to bind to an rvalue. Hence the check for the presence 4250 // of "const" rather than checking for "const" being the only 4251 // qualifier. 4252 // This is also the point where rvalue references and lvalue inits no longer 4253 // go together. 4254 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified())) 4255 return ICS; 4256 4257 // -- If the initializer expression 4258 // 4259 // -- is an xvalue, class prvalue, array prvalue or function 4260 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or 4261 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 4262 (InitCategory.isXValue() || 4263 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 4264 (InitCategory.isLValue() && T2->isFunctionType()))) { 4265 ICS.setStandard(); 4266 ICS.Standard.First = ICK_Identity; 4267 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 4268 : ObjCConversion? ICK_Compatible_Conversion 4269 : ICK_Identity; 4270 ICS.Standard.Third = ICK_Identity; 4271 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 4272 ICS.Standard.setToType(0, T2); 4273 ICS.Standard.setToType(1, T1); 4274 ICS.Standard.setToType(2, T1); 4275 ICS.Standard.ReferenceBinding = true; 4276 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 4277 // binding unless we're binding to a class prvalue. 4278 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 4279 // allow the use of rvalue references in C++98/03 for the benefit of 4280 // standard library implementors; therefore, we need the xvalue check here. 4281 ICS.Standard.DirectBinding = 4282 S.getLangOpts().CPlusPlus11 || 4283 (InitCategory.isPRValue() && !T2->isRecordType()); 4284 ICS.Standard.IsLvalueReference = !isRValRef; 4285 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4286 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 4287 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4288 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 4289 ICS.Standard.CopyConstructor = 0; 4290 return ICS; 4291 } 4292 4293 // -- has a class type (i.e., T2 is a class type), where T1 is not 4294 // reference-related to T2, and can be implicitly converted to 4295 // an xvalue, class prvalue, or function lvalue of type 4296 // "cv3 T3", where "cv1 T1" is reference-compatible with 4297 // "cv3 T3", 4298 // 4299 // then the reference is bound to the value of the initializer 4300 // expression in the first case and to the result of the conversion 4301 // in the second case (or, in either case, to an appropriate base 4302 // class subobject). 4303 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 4304 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 4305 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 4306 Init, T2, /*AllowRvalues=*/true, 4307 AllowExplicit)) { 4308 // In the second case, if the reference is an rvalue reference 4309 // and the second standard conversion sequence of the 4310 // user-defined conversion sequence includes an lvalue-to-rvalue 4311 // conversion, the program is ill-formed. 4312 if (ICS.isUserDefined() && isRValRef && 4313 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 4314 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 4315 4316 return ICS; 4317 } 4318 4319 // -- Otherwise, a temporary of type "cv1 T1" is created and 4320 // initialized from the initializer expression using the 4321 // rules for a non-reference copy initialization (8.5). The 4322 // reference is then bound to the temporary. If T1 is 4323 // reference-related to T2, cv1 must be the same 4324 // cv-qualification as, or greater cv-qualification than, 4325 // cv2; otherwise, the program is ill-formed. 4326 if (RefRelationship == Sema::Ref_Related) { 4327 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 4328 // we would be reference-compatible or reference-compatible with 4329 // added qualification. But that wasn't the case, so the reference 4330 // initialization fails. 4331 // 4332 // Note that we only want to check address spaces and cvr-qualifiers here. 4333 // ObjC GC and lifetime qualifiers aren't important. 4334 Qualifiers T1Quals = T1.getQualifiers(); 4335 Qualifiers T2Quals = T2.getQualifiers(); 4336 T1Quals.removeObjCGCAttr(); 4337 T1Quals.removeObjCLifetime(); 4338 T2Quals.removeObjCGCAttr(); 4339 T2Quals.removeObjCLifetime(); 4340 if (!T1Quals.compatiblyIncludes(T2Quals)) 4341 return ICS; 4342 } 4343 4344 // If at least one of the types is a class type, the types are not 4345 // related, and we aren't allowed any user conversions, the 4346 // reference binding fails. This case is important for breaking 4347 // recursion, since TryImplicitConversion below will attempt to 4348 // create a temporary through the use of a copy constructor. 4349 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 4350 (T1->isRecordType() || T2->isRecordType())) 4351 return ICS; 4352 4353 // If T1 is reference-related to T2 and the reference is an rvalue 4354 // reference, the initializer expression shall not be an lvalue. 4355 if (RefRelationship >= Sema::Ref_Related && 4356 isRValRef && Init->Classify(S.Context).isLValue()) 4357 return ICS; 4358 4359 // C++ [over.ics.ref]p2: 4360 // When a parameter of reference type is not bound directly to 4361 // an argument expression, the conversion sequence is the one 4362 // required to convert the argument expression to the 4363 // underlying type of the reference according to 4364 // 13.3.3.1. Conceptually, this conversion sequence corresponds 4365 // to copy-initializing a temporary of the underlying type with 4366 // the argument expression. Any difference in top-level 4367 // cv-qualification is subsumed by the initialization itself 4368 // and does not constitute a conversion. 4369 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 4370 /*AllowExplicit=*/false, 4371 /*InOverloadResolution=*/false, 4372 /*CStyle=*/false, 4373 /*AllowObjCWritebackConversion=*/false); 4374 4375 // Of course, that's still a reference binding. 4376 if (ICS.isStandard()) { 4377 ICS.Standard.ReferenceBinding = true; 4378 ICS.Standard.IsLvalueReference = !isRValRef; 4379 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4380 ICS.Standard.BindsToRvalue = true; 4381 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4382 ICS.Standard.ObjCLifetimeConversionBinding = false; 4383 } else if (ICS.isUserDefined()) { 4384 // Don't allow rvalue references to bind to lvalues. 4385 if (DeclType->isRValueReferenceType()) { 4386 if (const ReferenceType *RefType 4387 = ICS.UserDefined.ConversionFunction->getResultType() 4388 ->getAs<LValueReferenceType>()) { 4389 if (!RefType->getPointeeType()->isFunctionType()) { 4390 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, 4391 DeclType); 4392 return ICS; 4393 } 4394 } 4395 } 4396 4397 ICS.UserDefined.After.ReferenceBinding = true; 4398 ICS.UserDefined.After.IsLvalueReference = !isRValRef; 4399 ICS.UserDefined.After.BindsToFunctionLvalue = T2->isFunctionType(); 4400 ICS.UserDefined.After.BindsToRvalue = true; 4401 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4402 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false; 4403 } 4404 4405 return ICS; 4406} 4407 4408static ImplicitConversionSequence 4409TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 4410 bool SuppressUserConversions, 4411 bool InOverloadResolution, 4412 bool AllowObjCWritebackConversion, 4413 bool AllowExplicit = false); 4414 4415/// TryListConversion - Try to copy-initialize a value of type ToType from the 4416/// initializer list From. 4417static ImplicitConversionSequence 4418TryListConversion(Sema &S, InitListExpr *From, QualType ToType, 4419 bool SuppressUserConversions, 4420 bool InOverloadResolution, 4421 bool AllowObjCWritebackConversion) { 4422 // C++11 [over.ics.list]p1: 4423 // When an argument is an initializer list, it is not an expression and 4424 // special rules apply for converting it to a parameter type. 4425 4426 ImplicitConversionSequence Result; 4427 Result.setBad(BadConversionSequence::no_conversion, From, ToType); 4428 Result.setListInitializationSequence(); 4429 4430 // We need a complete type for what follows. Incomplete types can never be 4431 // initialized from init lists. 4432 if (S.RequireCompleteType(From->getLocStart(), ToType, 0)) 4433 return Result; 4434 4435 // C++11 [over.ics.list]p2: 4436 // If the parameter type is std::initializer_list<X> or "array of X" and 4437 // all the elements can be implicitly converted to X, the implicit 4438 // conversion sequence is the worst conversion necessary to convert an 4439 // element of the list to X. 4440 bool toStdInitializerList = false; 4441 QualType X; 4442 if (ToType->isArrayType()) 4443 X = S.Context.getAsArrayType(ToType)->getElementType(); 4444 else 4445 toStdInitializerList = S.isStdInitializerList(ToType, &X); 4446 if (!X.isNull()) { 4447 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) { 4448 Expr *Init = From->getInit(i); 4449 ImplicitConversionSequence ICS = 4450 TryCopyInitialization(S, Init, X, SuppressUserConversions, 4451 InOverloadResolution, 4452 AllowObjCWritebackConversion); 4453 // If a single element isn't convertible, fail. 4454 if (ICS.isBad()) { 4455 Result = ICS; 4456 break; 4457 } 4458 // Otherwise, look for the worst conversion. 4459 if (Result.isBad() || 4460 CompareImplicitConversionSequences(S, ICS, Result) == 4461 ImplicitConversionSequence::Worse) 4462 Result = ICS; 4463 } 4464 4465 // For an empty list, we won't have computed any conversion sequence. 4466 // Introduce the identity conversion sequence. 4467 if (From->getNumInits() == 0) { 4468 Result.setStandard(); 4469 Result.Standard.setAsIdentityConversion(); 4470 Result.Standard.setFromType(ToType); 4471 Result.Standard.setAllToTypes(ToType); 4472 } 4473 4474 Result.setListInitializationSequence(); 4475 Result.setStdInitializerListElement(toStdInitializerList); 4476 return Result; 4477 } 4478 4479 // C++11 [over.ics.list]p3: 4480 // Otherwise, if the parameter is a non-aggregate class X and overload 4481 // resolution chooses a single best constructor [...] the implicit 4482 // conversion sequence is a user-defined conversion sequence. If multiple 4483 // constructors are viable but none is better than the others, the 4484 // implicit conversion sequence is a user-defined conversion sequence. 4485 if (ToType->isRecordType() && !ToType->isAggregateType()) { 4486 // This function can deal with initializer lists. 4487 Result = TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, 4488 /*AllowExplicit=*/false, 4489 InOverloadResolution, /*CStyle=*/false, 4490 AllowObjCWritebackConversion); 4491 Result.setListInitializationSequence(); 4492 return Result; 4493 } 4494 4495 // C++11 [over.ics.list]p4: 4496 // Otherwise, if the parameter has an aggregate type which can be 4497 // initialized from the initializer list [...] the implicit conversion 4498 // sequence is a user-defined conversion sequence. 4499 if (ToType->isAggregateType()) { 4500 // Type is an aggregate, argument is an init list. At this point it comes 4501 // down to checking whether the initialization works. 4502 // FIXME: Find out whether this parameter is consumed or not. 4503 InitializedEntity Entity = 4504 InitializedEntity::InitializeParameter(S.Context, ToType, 4505 /*Consumed=*/false); 4506 if (S.CanPerformCopyInitialization(Entity, S.Owned(From))) { 4507 Result.setUserDefined(); 4508 Result.UserDefined.Before.setAsIdentityConversion(); 4509 // Initializer lists don't have a type. 4510 Result.UserDefined.Before.setFromType(QualType()); 4511 Result.UserDefined.Before.setAllToTypes(QualType()); 4512 4513 Result.UserDefined.After.setAsIdentityConversion(); 4514 Result.UserDefined.After.setFromType(ToType); 4515 Result.UserDefined.After.setAllToTypes(ToType); 4516 Result.UserDefined.ConversionFunction = 0; 4517 } 4518 return Result; 4519 } 4520 4521 // C++11 [over.ics.list]p5: 4522 // Otherwise, if the parameter is a reference, see 13.3.3.1.4. 4523 if (ToType->isReferenceType()) { 4524 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't 4525 // mention initializer lists in any way. So we go by what list- 4526 // initialization would do and try to extrapolate from that. 4527 4528 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType(); 4529 4530 // If the initializer list has a single element that is reference-related 4531 // to the parameter type, we initialize the reference from that. 4532 if (From->getNumInits() == 1) { 4533 Expr *Init = From->getInit(0); 4534 4535 QualType T2 = Init->getType(); 4536 4537 // If the initializer is the address of an overloaded function, try 4538 // to resolve the overloaded function. If all goes well, T2 is the 4539 // type of the resulting function. 4540 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 4541 DeclAccessPair Found; 4542 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction( 4543 Init, ToType, false, Found)) 4544 T2 = Fn->getType(); 4545 } 4546 4547 // Compute some basic properties of the types and the initializer. 4548 bool dummy1 = false; 4549 bool dummy2 = false; 4550 bool dummy3 = false; 4551 Sema::ReferenceCompareResult RefRelationship 4552 = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1, 4553 dummy2, dummy3); 4554 4555 if (RefRelationship >= Sema::Ref_Related) 4556 return TryReferenceInit(S, Init, ToType, 4557 /*FIXME:*/From->getLocStart(), 4558 SuppressUserConversions, 4559 /*AllowExplicit=*/false); 4560 } 4561 4562 // Otherwise, we bind the reference to a temporary created from the 4563 // initializer list. 4564 Result = TryListConversion(S, From, T1, SuppressUserConversions, 4565 InOverloadResolution, 4566 AllowObjCWritebackConversion); 4567 if (Result.isFailure()) 4568 return Result; 4569 assert(!Result.isEllipsis() && 4570 "Sub-initialization cannot result in ellipsis conversion."); 4571 4572 // Can we even bind to a temporary? 4573 if (ToType->isRValueReferenceType() || 4574 (T1.isConstQualified() && !T1.isVolatileQualified())) { 4575 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard : 4576 Result.UserDefined.After; 4577 SCS.ReferenceBinding = true; 4578 SCS.IsLvalueReference = ToType->isLValueReferenceType(); 4579 SCS.BindsToRvalue = true; 4580 SCS.BindsToFunctionLvalue = false; 4581 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4582 SCS.ObjCLifetimeConversionBinding = false; 4583 } else 4584 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue, 4585 From, ToType); 4586 return Result; 4587 } 4588 4589 // C++11 [over.ics.list]p6: 4590 // Otherwise, if the parameter type is not a class: 4591 if (!ToType->isRecordType()) { 4592 // - if the initializer list has one element, the implicit conversion 4593 // sequence is the one required to convert the element to the 4594 // parameter type. 4595 unsigned NumInits = From->getNumInits(); 4596 if (NumInits == 1) 4597 Result = TryCopyInitialization(S, From->getInit(0), ToType, 4598 SuppressUserConversions, 4599 InOverloadResolution, 4600 AllowObjCWritebackConversion); 4601 // - if the initializer list has no elements, the implicit conversion 4602 // sequence is the identity conversion. 4603 else if (NumInits == 0) { 4604 Result.setStandard(); 4605 Result.Standard.setAsIdentityConversion(); 4606 Result.Standard.setFromType(ToType); 4607 Result.Standard.setAllToTypes(ToType); 4608 } 4609 Result.setListInitializationSequence(); 4610 return Result; 4611 } 4612 4613 // C++11 [over.ics.list]p7: 4614 // In all cases other than those enumerated above, no conversion is possible 4615 return Result; 4616} 4617 4618/// TryCopyInitialization - Try to copy-initialize a value of type 4619/// ToType from the expression From. Return the implicit conversion 4620/// sequence required to pass this argument, which may be a bad 4621/// conversion sequence (meaning that the argument cannot be passed to 4622/// a parameter of this type). If @p SuppressUserConversions, then we 4623/// do not permit any user-defined conversion sequences. 4624static ImplicitConversionSequence 4625TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 4626 bool SuppressUserConversions, 4627 bool InOverloadResolution, 4628 bool AllowObjCWritebackConversion, 4629 bool AllowExplicit) { 4630 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From)) 4631 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions, 4632 InOverloadResolution,AllowObjCWritebackConversion); 4633 4634 if (ToType->isReferenceType()) 4635 return TryReferenceInit(S, From, ToType, 4636 /*FIXME:*/From->getLocStart(), 4637 SuppressUserConversions, 4638 AllowExplicit); 4639 4640 return TryImplicitConversion(S, From, ToType, 4641 SuppressUserConversions, 4642 /*AllowExplicit=*/false, 4643 InOverloadResolution, 4644 /*CStyle=*/false, 4645 AllowObjCWritebackConversion); 4646} 4647 4648static bool TryCopyInitialization(const CanQualType FromQTy, 4649 const CanQualType ToQTy, 4650 Sema &S, 4651 SourceLocation Loc, 4652 ExprValueKind FromVK) { 4653 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK); 4654 ImplicitConversionSequence ICS = 4655 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false); 4656 4657 return !ICS.isBad(); 4658} 4659 4660/// TryObjectArgumentInitialization - Try to initialize the object 4661/// parameter of the given member function (@c Method) from the 4662/// expression @p From. 4663static ImplicitConversionSequence 4664TryObjectArgumentInitialization(Sema &S, QualType FromType, 4665 Expr::Classification FromClassification, 4666 CXXMethodDecl *Method, 4667 CXXRecordDecl *ActingContext) { 4668 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 4669 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 4670 // const volatile object. 4671 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 4672 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 4673 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 4674 4675 // Set up the conversion sequence as a "bad" conversion, to allow us 4676 // to exit early. 4677 ImplicitConversionSequence ICS; 4678 4679 // We need to have an object of class type. 4680 if (const PointerType *PT = FromType->getAs<PointerType>()) { 4681 FromType = PT->getPointeeType(); 4682 4683 // When we had a pointer, it's implicitly dereferenced, so we 4684 // better have an lvalue. 4685 assert(FromClassification.isLValue()); 4686 } 4687 4688 assert(FromType->isRecordType()); 4689 4690 // C++0x [over.match.funcs]p4: 4691 // For non-static member functions, the type of the implicit object 4692 // parameter is 4693 // 4694 // - "lvalue reference to cv X" for functions declared without a 4695 // ref-qualifier or with the & ref-qualifier 4696 // - "rvalue reference to cv X" for functions declared with the && 4697 // ref-qualifier 4698 // 4699 // where X is the class of which the function is a member and cv is the 4700 // cv-qualification on the member function declaration. 4701 // 4702 // However, when finding an implicit conversion sequence for the argument, we 4703 // are not allowed to create temporaries or perform user-defined conversions 4704 // (C++ [over.match.funcs]p5). We perform a simplified version of 4705 // reference binding here, that allows class rvalues to bind to 4706 // non-constant references. 4707 4708 // First check the qualifiers. 4709 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 4710 if (ImplicitParamType.getCVRQualifiers() 4711 != FromTypeCanon.getLocalCVRQualifiers() && 4712 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 4713 ICS.setBad(BadConversionSequence::bad_qualifiers, 4714 FromType, ImplicitParamType); 4715 return ICS; 4716 } 4717 4718 // Check that we have either the same type or a derived type. It 4719 // affects the conversion rank. 4720 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 4721 ImplicitConversionKind SecondKind; 4722 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 4723 SecondKind = ICK_Identity; 4724 } else if (S.IsDerivedFrom(FromType, ClassType)) 4725 SecondKind = ICK_Derived_To_Base; 4726 else { 4727 ICS.setBad(BadConversionSequence::unrelated_class, 4728 FromType, ImplicitParamType); 4729 return ICS; 4730 } 4731 4732 // Check the ref-qualifier. 4733 switch (Method->getRefQualifier()) { 4734 case RQ_None: 4735 // Do nothing; we don't care about lvalueness or rvalueness. 4736 break; 4737 4738 case RQ_LValue: 4739 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 4740 // non-const lvalue reference cannot bind to an rvalue 4741 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 4742 ImplicitParamType); 4743 return ICS; 4744 } 4745 break; 4746 4747 case RQ_RValue: 4748 if (!FromClassification.isRValue()) { 4749 // rvalue reference cannot bind to an lvalue 4750 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 4751 ImplicitParamType); 4752 return ICS; 4753 } 4754 break; 4755 } 4756 4757 // Success. Mark this as a reference binding. 4758 ICS.setStandard(); 4759 ICS.Standard.setAsIdentityConversion(); 4760 ICS.Standard.Second = SecondKind; 4761 ICS.Standard.setFromType(FromType); 4762 ICS.Standard.setAllToTypes(ImplicitParamType); 4763 ICS.Standard.ReferenceBinding = true; 4764 ICS.Standard.DirectBinding = true; 4765 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 4766 ICS.Standard.BindsToFunctionLvalue = false; 4767 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 4768 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 4769 = (Method->getRefQualifier() == RQ_None); 4770 return ICS; 4771} 4772 4773/// PerformObjectArgumentInitialization - Perform initialization of 4774/// the implicit object parameter for the given Method with the given 4775/// expression. 4776ExprResult 4777Sema::PerformObjectArgumentInitialization(Expr *From, 4778 NestedNameSpecifier *Qualifier, 4779 NamedDecl *FoundDecl, 4780 CXXMethodDecl *Method) { 4781 QualType FromRecordType, DestType; 4782 QualType ImplicitParamRecordType = 4783 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 4784 4785 Expr::Classification FromClassification; 4786 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 4787 FromRecordType = PT->getPointeeType(); 4788 DestType = Method->getThisType(Context); 4789 FromClassification = Expr::Classification::makeSimpleLValue(); 4790 } else { 4791 FromRecordType = From->getType(); 4792 DestType = ImplicitParamRecordType; 4793 FromClassification = From->Classify(Context); 4794 } 4795 4796 // Note that we always use the true parent context when performing 4797 // the actual argument initialization. 4798 ImplicitConversionSequence ICS 4799 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 4800 Method, Method->getParent()); 4801 if (ICS.isBad()) { 4802 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 4803 Qualifiers FromQs = FromRecordType.getQualifiers(); 4804 Qualifiers ToQs = DestType.getQualifiers(); 4805 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4806 if (CVR) { 4807 Diag(From->getLocStart(), 4808 diag::err_member_function_call_bad_cvr) 4809 << Method->getDeclName() << FromRecordType << (CVR - 1) 4810 << From->getSourceRange(); 4811 Diag(Method->getLocation(), diag::note_previous_decl) 4812 << Method->getDeclName(); 4813 return ExprError(); 4814 } 4815 } 4816 4817 return Diag(From->getLocStart(), 4818 diag::err_implicit_object_parameter_init) 4819 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 4820 } 4821 4822 if (ICS.Standard.Second == ICK_Derived_To_Base) { 4823 ExprResult FromRes = 4824 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 4825 if (FromRes.isInvalid()) 4826 return ExprError(); 4827 From = FromRes.take(); 4828 } 4829 4830 if (!Context.hasSameType(From->getType(), DestType)) 4831 From = ImpCastExprToType(From, DestType, CK_NoOp, 4832 From->getValueKind()).take(); 4833 return Owned(From); 4834} 4835 4836/// TryContextuallyConvertToBool - Attempt to contextually convert the 4837/// expression From to bool (C++0x [conv]p3). 4838static ImplicitConversionSequence 4839TryContextuallyConvertToBool(Sema &S, Expr *From) { 4840 // FIXME: This is pretty broken. 4841 return TryImplicitConversion(S, From, S.Context.BoolTy, 4842 // FIXME: Are these flags correct? 4843 /*SuppressUserConversions=*/false, 4844 /*AllowExplicit=*/true, 4845 /*InOverloadResolution=*/false, 4846 /*CStyle=*/false, 4847 /*AllowObjCWritebackConversion=*/false); 4848} 4849 4850/// PerformContextuallyConvertToBool - Perform a contextual conversion 4851/// of the expression From to bool (C++0x [conv]p3). 4852ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) { 4853 if (checkPlaceholderForOverload(*this, From)) 4854 return ExprError(); 4855 4856 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 4857 if (!ICS.isBad()) 4858 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 4859 4860 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 4861 return Diag(From->getLocStart(), 4862 diag::err_typecheck_bool_condition) 4863 << From->getType() << From->getSourceRange(); 4864 return ExprError(); 4865} 4866 4867/// Check that the specified conversion is permitted in a converted constant 4868/// expression, according to C++11 [expr.const]p3. Return true if the conversion 4869/// is acceptable. 4870static bool CheckConvertedConstantConversions(Sema &S, 4871 StandardConversionSequence &SCS) { 4872 // Since we know that the target type is an integral or unscoped enumeration 4873 // type, most conversion kinds are impossible. All possible First and Third 4874 // conversions are fine. 4875 switch (SCS.Second) { 4876 case ICK_Identity: 4877 case ICK_Integral_Promotion: 4878 case ICK_Integral_Conversion: 4879 case ICK_Zero_Event_Conversion: 4880 return true; 4881 4882 case ICK_Boolean_Conversion: 4883 // Conversion from an integral or unscoped enumeration type to bool is 4884 // classified as ICK_Boolean_Conversion, but it's also an integral 4885 // conversion, so it's permitted in a converted constant expression. 4886 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() && 4887 SCS.getToType(2)->isBooleanType(); 4888 4889 case ICK_Floating_Integral: 4890 case ICK_Complex_Real: 4891 return false; 4892 4893 case ICK_Lvalue_To_Rvalue: 4894 case ICK_Array_To_Pointer: 4895 case ICK_Function_To_Pointer: 4896 case ICK_NoReturn_Adjustment: 4897 case ICK_Qualification: 4898 case ICK_Compatible_Conversion: 4899 case ICK_Vector_Conversion: 4900 case ICK_Vector_Splat: 4901 case ICK_Derived_To_Base: 4902 case ICK_Pointer_Conversion: 4903 case ICK_Pointer_Member: 4904 case ICK_Block_Pointer_Conversion: 4905 case ICK_Writeback_Conversion: 4906 case ICK_Floating_Promotion: 4907 case ICK_Complex_Promotion: 4908 case ICK_Complex_Conversion: 4909 case ICK_Floating_Conversion: 4910 case ICK_TransparentUnionConversion: 4911 llvm_unreachable("unexpected second conversion kind"); 4912 4913 case ICK_Num_Conversion_Kinds: 4914 break; 4915 } 4916 4917 llvm_unreachable("unknown conversion kind"); 4918} 4919 4920/// CheckConvertedConstantExpression - Check that the expression From is a 4921/// converted constant expression of type T, perform the conversion and produce 4922/// the converted expression, per C++11 [expr.const]p3. 4923ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T, 4924 llvm::APSInt &Value, 4925 CCEKind CCE) { 4926 assert(LangOpts.CPlusPlus11 && "converted constant expression outside C++11"); 4927 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type"); 4928 4929 if (checkPlaceholderForOverload(*this, From)) 4930 return ExprError(); 4931 4932 // C++11 [expr.const]p3 with proposed wording fixes: 4933 // A converted constant expression of type T is a core constant expression, 4934 // implicitly converted to a prvalue of type T, where the converted 4935 // expression is a literal constant expression and the implicit conversion 4936 // sequence contains only user-defined conversions, lvalue-to-rvalue 4937 // conversions, integral promotions, and integral conversions other than 4938 // narrowing conversions. 4939 ImplicitConversionSequence ICS = 4940 TryImplicitConversion(From, T, 4941 /*SuppressUserConversions=*/false, 4942 /*AllowExplicit=*/false, 4943 /*InOverloadResolution=*/false, 4944 /*CStyle=*/false, 4945 /*AllowObjcWritebackConversion=*/false); 4946 StandardConversionSequence *SCS = 0; 4947 switch (ICS.getKind()) { 4948 case ImplicitConversionSequence::StandardConversion: 4949 if (!CheckConvertedConstantConversions(*this, ICS.Standard)) 4950 return Diag(From->getLocStart(), 4951 diag::err_typecheck_converted_constant_expression_disallowed) 4952 << From->getType() << From->getSourceRange() << T; 4953 SCS = &ICS.Standard; 4954 break; 4955 case ImplicitConversionSequence::UserDefinedConversion: 4956 // We are converting from class type to an integral or enumeration type, so 4957 // the Before sequence must be trivial. 4958 if (!CheckConvertedConstantConversions(*this, ICS.UserDefined.After)) 4959 return Diag(From->getLocStart(), 4960 diag::err_typecheck_converted_constant_expression_disallowed) 4961 << From->getType() << From->getSourceRange() << T; 4962 SCS = &ICS.UserDefined.After; 4963 break; 4964 case ImplicitConversionSequence::AmbiguousConversion: 4965 case ImplicitConversionSequence::BadConversion: 4966 if (!DiagnoseMultipleUserDefinedConversion(From, T)) 4967 return Diag(From->getLocStart(), 4968 diag::err_typecheck_converted_constant_expression) 4969 << From->getType() << From->getSourceRange() << T; 4970 return ExprError(); 4971 4972 case ImplicitConversionSequence::EllipsisConversion: 4973 llvm_unreachable("ellipsis conversion in converted constant expression"); 4974 } 4975 4976 ExprResult Result = PerformImplicitConversion(From, T, ICS, AA_Converting); 4977 if (Result.isInvalid()) 4978 return Result; 4979 4980 // Check for a narrowing implicit conversion. 4981 APValue PreNarrowingValue; 4982 QualType PreNarrowingType; 4983 switch (SCS->getNarrowingKind(Context, Result.get(), PreNarrowingValue, 4984 PreNarrowingType)) { 4985 case NK_Variable_Narrowing: 4986 // Implicit conversion to a narrower type, and the value is not a constant 4987 // expression. We'll diagnose this in a moment. 4988 case NK_Not_Narrowing: 4989 break; 4990 4991 case NK_Constant_Narrowing: 4992 Diag(From->getLocStart(), 4993 isSFINAEContext() ? diag::err_cce_narrowing_sfinae : 4994 diag::err_cce_narrowing) 4995 << CCE << /*Constant*/1 4996 << PreNarrowingValue.getAsString(Context, PreNarrowingType) << T; 4997 break; 4998 4999 case NK_Type_Narrowing: 5000 Diag(From->getLocStart(), 5001 isSFINAEContext() ? diag::err_cce_narrowing_sfinae : 5002 diag::err_cce_narrowing) 5003 << CCE << /*Constant*/0 << From->getType() << T; 5004 break; 5005 } 5006 5007 // Check the expression is a constant expression. 5008 SmallVector<PartialDiagnosticAt, 8> Notes; 5009 Expr::EvalResult Eval; 5010 Eval.Diag = &Notes; 5011 5012 if (!Result.get()->EvaluateAsRValue(Eval, Context)) { 5013 // The expression can't be folded, so we can't keep it at this position in 5014 // the AST. 5015 Result = ExprError(); 5016 } else { 5017 Value = Eval.Val.getInt(); 5018 5019 if (Notes.empty()) { 5020 // It's a constant expression. 5021 return Result; 5022 } 5023 } 5024 5025 // It's not a constant expression. Produce an appropriate diagnostic. 5026 if (Notes.size() == 1 && 5027 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr) 5028 Diag(Notes[0].first, diag::err_expr_not_cce) << CCE; 5029 else { 5030 Diag(From->getLocStart(), diag::err_expr_not_cce) 5031 << CCE << From->getSourceRange(); 5032 for (unsigned I = 0; I < Notes.size(); ++I) 5033 Diag(Notes[I].first, Notes[I].second); 5034 } 5035 return Result; 5036} 5037 5038/// dropPointerConversions - If the given standard conversion sequence 5039/// involves any pointer conversions, remove them. This may change 5040/// the result type of the conversion sequence. 5041static void dropPointerConversion(StandardConversionSequence &SCS) { 5042 if (SCS.Second == ICK_Pointer_Conversion) { 5043 SCS.Second = ICK_Identity; 5044 SCS.Third = ICK_Identity; 5045 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0]; 5046 } 5047} 5048 5049/// TryContextuallyConvertToObjCPointer - Attempt to contextually 5050/// convert the expression From to an Objective-C pointer type. 5051static ImplicitConversionSequence 5052TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) { 5053 // Do an implicit conversion to 'id'. 5054 QualType Ty = S.Context.getObjCIdType(); 5055 ImplicitConversionSequence ICS 5056 = TryImplicitConversion(S, From, Ty, 5057 // FIXME: Are these flags correct? 5058 /*SuppressUserConversions=*/false, 5059 /*AllowExplicit=*/true, 5060 /*InOverloadResolution=*/false, 5061 /*CStyle=*/false, 5062 /*AllowObjCWritebackConversion=*/false); 5063 5064 // Strip off any final conversions to 'id'. 5065 switch (ICS.getKind()) { 5066 case ImplicitConversionSequence::BadConversion: 5067 case ImplicitConversionSequence::AmbiguousConversion: 5068 case ImplicitConversionSequence::EllipsisConversion: 5069 break; 5070 5071 case ImplicitConversionSequence::UserDefinedConversion: 5072 dropPointerConversion(ICS.UserDefined.After); 5073 break; 5074 5075 case ImplicitConversionSequence::StandardConversion: 5076 dropPointerConversion(ICS.Standard); 5077 break; 5078 } 5079 5080 return ICS; 5081} 5082 5083/// PerformContextuallyConvertToObjCPointer - Perform a contextual 5084/// conversion of the expression From to an Objective-C pointer type. 5085ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) { 5086 if (checkPlaceholderForOverload(*this, From)) 5087 return ExprError(); 5088 5089 QualType Ty = Context.getObjCIdType(); 5090 ImplicitConversionSequence ICS = 5091 TryContextuallyConvertToObjCPointer(*this, From); 5092 if (!ICS.isBad()) 5093 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 5094 return ExprError(); 5095} 5096 5097/// Determine whether the provided type is an integral type, or an enumeration 5098/// type of a permitted flavor. 5099static bool isIntegralOrEnumerationType(QualType T, bool AllowScopedEnum) { 5100 return AllowScopedEnum ? T->isIntegralOrEnumerationType() 5101 : T->isIntegralOrUnscopedEnumerationType(); 5102} 5103 5104/// \brief Attempt to convert the given expression to an integral or 5105/// enumeration type. 5106/// 5107/// This routine will attempt to convert an expression of class type to an 5108/// integral or enumeration type, if that class type only has a single 5109/// conversion to an integral or enumeration type. 5110/// 5111/// \param Loc The source location of the construct that requires the 5112/// conversion. 5113/// 5114/// \param From The expression we're converting from. 5115/// 5116/// \param Diagnoser Used to output any diagnostics. 5117/// 5118/// \param AllowScopedEnumerations Specifies whether conversions to scoped 5119/// enumerations should be considered. 5120/// 5121/// \returns The expression, converted to an integral or enumeration type if 5122/// successful. 5123ExprResult 5124Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 5125 ICEConvertDiagnoser &Diagnoser, 5126 bool AllowScopedEnumerations) { 5127 // We can't perform any more checking for type-dependent expressions. 5128 if (From->isTypeDependent()) 5129 return Owned(From); 5130 5131 // Process placeholders immediately. 5132 if (From->hasPlaceholderType()) { 5133 ExprResult result = CheckPlaceholderExpr(From); 5134 if (result.isInvalid()) return result; 5135 From = result.take(); 5136 } 5137 5138 // If the expression already has integral or enumeration type, we're golden. 5139 QualType T = From->getType(); 5140 if (isIntegralOrEnumerationType(T, AllowScopedEnumerations)) 5141 return DefaultLvalueConversion(From); 5142 5143 // FIXME: Check for missing '()' if T is a function type? 5144 5145 // If we don't have a class type in C++, there's no way we can get an 5146 // expression of integral or enumeration type. 5147 const RecordType *RecordTy = T->getAs<RecordType>(); 5148 if (!RecordTy || !getLangOpts().CPlusPlus) { 5149 if (!Diagnoser.Suppress) 5150 Diagnoser.diagnoseNotInt(*this, Loc, T) << From->getSourceRange(); 5151 return Owned(From); 5152 } 5153 5154 // We must have a complete class type. 5155 struct TypeDiagnoserPartialDiag : TypeDiagnoser { 5156 ICEConvertDiagnoser &Diagnoser; 5157 Expr *From; 5158 5159 TypeDiagnoserPartialDiag(ICEConvertDiagnoser &Diagnoser, Expr *From) 5160 : TypeDiagnoser(Diagnoser.Suppress), Diagnoser(Diagnoser), From(From) {} 5161 5162 virtual void diagnose(Sema &S, SourceLocation Loc, QualType T) { 5163 Diagnoser.diagnoseIncomplete(S, Loc, T) << From->getSourceRange(); 5164 } 5165 } IncompleteDiagnoser(Diagnoser, From); 5166 5167 if (RequireCompleteType(Loc, T, IncompleteDiagnoser)) 5168 return Owned(From); 5169 5170 // Look for a conversion to an integral or enumeration type. 5171 UnresolvedSet<4> ViableConversions; 5172 UnresolvedSet<4> ExplicitConversions; 5173 std::pair<CXXRecordDecl::conversion_iterator, 5174 CXXRecordDecl::conversion_iterator> Conversions 5175 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 5176 5177 bool HadMultipleCandidates 5178 = (std::distance(Conversions.first, Conversions.second) > 1); 5179 5180 for (CXXRecordDecl::conversion_iterator 5181 I = Conversions.first, E = Conversions.second; I != E; ++I) { 5182 if (CXXConversionDecl *Conversion 5183 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) { 5184 if (isIntegralOrEnumerationType( 5185 Conversion->getConversionType().getNonReferenceType(), 5186 AllowScopedEnumerations)) { 5187 if (Conversion->isExplicit()) 5188 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 5189 else 5190 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 5191 } 5192 } 5193 } 5194 5195 switch (ViableConversions.size()) { 5196 case 0: 5197 if (ExplicitConversions.size() == 1 && !Diagnoser.Suppress) { 5198 DeclAccessPair Found = ExplicitConversions[0]; 5199 CXXConversionDecl *Conversion 5200 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 5201 5202 // The user probably meant to invoke the given explicit 5203 // conversion; use it. 5204 QualType ConvTy 5205 = Conversion->getConversionType().getNonReferenceType(); 5206 std::string TypeStr; 5207 ConvTy.getAsStringInternal(TypeStr, getPrintingPolicy()); 5208 5209 Diagnoser.diagnoseExplicitConv(*this, Loc, T, ConvTy) 5210 << FixItHint::CreateInsertion(From->getLocStart(), 5211 "static_cast<" + TypeStr + ">(") 5212 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 5213 ")"); 5214 Diagnoser.noteExplicitConv(*this, Conversion, ConvTy); 5215 5216 // If we aren't in a SFINAE context, build a call to the 5217 // explicit conversion function. 5218 if (isSFINAEContext()) 5219 return ExprError(); 5220 5221 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 5222 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion, 5223 HadMultipleCandidates); 5224 if (Result.isInvalid()) 5225 return ExprError(); 5226 // Record usage of conversion in an implicit cast. 5227 From = ImplicitCastExpr::Create(Context, Result.get()->getType(), 5228 CK_UserDefinedConversion, 5229 Result.get(), 0, 5230 Result.get()->getValueKind()); 5231 } 5232 5233 // We'll complain below about a non-integral condition type. 5234 break; 5235 5236 case 1: { 5237 // Apply this conversion. 5238 DeclAccessPair Found = ViableConversions[0]; 5239 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 5240 5241 CXXConversionDecl *Conversion 5242 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 5243 QualType ConvTy 5244 = Conversion->getConversionType().getNonReferenceType(); 5245 if (!Diagnoser.SuppressConversion) { 5246 if (isSFINAEContext()) 5247 return ExprError(); 5248 5249 Diagnoser.diagnoseConversion(*this, Loc, T, ConvTy) 5250 << From->getSourceRange(); 5251 } 5252 5253 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion, 5254 HadMultipleCandidates); 5255 if (Result.isInvalid()) 5256 return ExprError(); 5257 // Record usage of conversion in an implicit cast. 5258 From = ImplicitCastExpr::Create(Context, Result.get()->getType(), 5259 CK_UserDefinedConversion, 5260 Result.get(), 0, 5261 Result.get()->getValueKind()); 5262 break; 5263 } 5264 5265 default: 5266 if (Diagnoser.Suppress) 5267 return ExprError(); 5268 5269 Diagnoser.diagnoseAmbiguous(*this, Loc, T) << From->getSourceRange(); 5270 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 5271 CXXConversionDecl *Conv 5272 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 5273 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 5274 Diagnoser.noteAmbiguous(*this, Conv, ConvTy); 5275 } 5276 return Owned(From); 5277 } 5278 5279 if (!isIntegralOrEnumerationType(From->getType(), AllowScopedEnumerations) && 5280 !Diagnoser.Suppress) { 5281 Diagnoser.diagnoseNotInt(*this, Loc, From->getType()) 5282 << From->getSourceRange(); 5283 } 5284 5285 return DefaultLvalueConversion(From); 5286} 5287 5288/// AddOverloadCandidate - Adds the given function to the set of 5289/// candidate functions, using the given function call arguments. If 5290/// @p SuppressUserConversions, then don't allow user-defined 5291/// conversions via constructors or conversion operators. 5292/// 5293/// \param PartialOverloading true if we are performing "partial" overloading 5294/// based on an incomplete set of function arguments. This feature is used by 5295/// code completion. 5296void 5297Sema::AddOverloadCandidate(FunctionDecl *Function, 5298 DeclAccessPair FoundDecl, 5299 ArrayRef<Expr *> Args, 5300 OverloadCandidateSet& CandidateSet, 5301 bool SuppressUserConversions, 5302 bool PartialOverloading, 5303 bool AllowExplicit) { 5304 const FunctionProtoType* Proto 5305 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 5306 assert(Proto && "Functions without a prototype cannot be overloaded"); 5307 assert(!Function->getDescribedFunctionTemplate() && 5308 "Use AddTemplateOverloadCandidate for function templates"); 5309 5310 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 5311 if (!isa<CXXConstructorDecl>(Method)) { 5312 // If we get here, it's because we're calling a member function 5313 // that is named without a member access expression (e.g., 5314 // "this->f") that was either written explicitly or created 5315 // implicitly. This can happen with a qualified call to a member 5316 // function, e.g., X::f(). We use an empty type for the implied 5317 // object argument (C++ [over.call.func]p3), and the acting context 5318 // is irrelevant. 5319 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 5320 QualType(), Expr::Classification::makeSimpleLValue(), 5321 Args, CandidateSet, SuppressUserConversions); 5322 return; 5323 } 5324 // We treat a constructor like a non-member function, since its object 5325 // argument doesn't participate in overload resolution. 5326 } 5327 5328 if (!CandidateSet.isNewCandidate(Function)) 5329 return; 5330 5331 // Overload resolution is always an unevaluated context. 5332 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5333 5334 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 5335 // C++ [class.copy]p3: 5336 // A member function template is never instantiated to perform the copy 5337 // of a class object to an object of its class type. 5338 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 5339 if (Args.size() == 1 && 5340 Constructor->isSpecializationCopyingObject() && 5341 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 5342 IsDerivedFrom(Args[0]->getType(), ClassType))) 5343 return; 5344 } 5345 5346 // Add this candidate 5347 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size()); 5348 Candidate.FoundDecl = FoundDecl; 5349 Candidate.Function = Function; 5350 Candidate.Viable = true; 5351 Candidate.IsSurrogate = false; 5352 Candidate.IgnoreObjectArgument = false; 5353 Candidate.ExplicitCallArguments = Args.size(); 5354 5355 unsigned NumArgsInProto = Proto->getNumArgs(); 5356 5357 // (C++ 13.3.2p2): A candidate function having fewer than m 5358 // parameters is viable only if it has an ellipsis in its parameter 5359 // list (8.3.5). 5360 if ((Args.size() + (PartialOverloading && Args.size())) > NumArgsInProto && 5361 !Proto->isVariadic()) { 5362 Candidate.Viable = false; 5363 Candidate.FailureKind = ovl_fail_too_many_arguments; 5364 return; 5365 } 5366 5367 // (C++ 13.3.2p2): A candidate function having more than m parameters 5368 // is viable only if the (m+1)st parameter has a default argument 5369 // (8.3.6). For the purposes of overload resolution, the 5370 // parameter list is truncated on the right, so that there are 5371 // exactly m parameters. 5372 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 5373 if (Args.size() < MinRequiredArgs && !PartialOverloading) { 5374 // Not enough arguments. 5375 Candidate.Viable = false; 5376 Candidate.FailureKind = ovl_fail_too_few_arguments; 5377 return; 5378 } 5379 5380 // (CUDA B.1): Check for invalid calls between targets. 5381 if (getLangOpts().CUDA) 5382 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext)) 5383 if (CheckCUDATarget(Caller, Function)) { 5384 Candidate.Viable = false; 5385 Candidate.FailureKind = ovl_fail_bad_target; 5386 return; 5387 } 5388 5389 // Determine the implicit conversion sequences for each of the 5390 // arguments. 5391 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5392 if (ArgIdx < NumArgsInProto) { 5393 // (C++ 13.3.2p3): for F to be a viable function, there shall 5394 // exist for each argument an implicit conversion sequence 5395 // (13.3.3.1) that converts that argument to the corresponding 5396 // parameter of F. 5397 QualType ParamType = Proto->getArgType(ArgIdx); 5398 Candidate.Conversions[ArgIdx] 5399 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5400 SuppressUserConversions, 5401 /*InOverloadResolution=*/true, 5402 /*AllowObjCWritebackConversion=*/ 5403 getLangOpts().ObjCAutoRefCount, 5404 AllowExplicit); 5405 if (Candidate.Conversions[ArgIdx].isBad()) { 5406 Candidate.Viable = false; 5407 Candidate.FailureKind = ovl_fail_bad_conversion; 5408 break; 5409 } 5410 } else { 5411 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5412 // argument for which there is no corresponding parameter is 5413 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5414 Candidate.Conversions[ArgIdx].setEllipsis(); 5415 } 5416 } 5417} 5418 5419/// \brief Add all of the function declarations in the given function set to 5420/// the overload canddiate set. 5421void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 5422 ArrayRef<Expr *> Args, 5423 OverloadCandidateSet& CandidateSet, 5424 bool SuppressUserConversions, 5425 TemplateArgumentListInfo *ExplicitTemplateArgs) { 5426 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 5427 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 5428 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 5429 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 5430 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 5431 cast<CXXMethodDecl>(FD)->getParent(), 5432 Args[0]->getType(), Args[0]->Classify(Context), 5433 Args.slice(1), CandidateSet, 5434 SuppressUserConversions); 5435 else 5436 AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet, 5437 SuppressUserConversions); 5438 } else { 5439 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 5440 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 5441 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 5442 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 5443 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 5444 ExplicitTemplateArgs, 5445 Args[0]->getType(), 5446 Args[0]->Classify(Context), Args.slice(1), 5447 CandidateSet, SuppressUserConversions); 5448 else 5449 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 5450 ExplicitTemplateArgs, Args, 5451 CandidateSet, SuppressUserConversions); 5452 } 5453 } 5454} 5455 5456/// AddMethodCandidate - Adds a named decl (which is some kind of 5457/// method) as a method candidate to the given overload set. 5458void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 5459 QualType ObjectType, 5460 Expr::Classification ObjectClassification, 5461 Expr **Args, unsigned NumArgs, 5462 OverloadCandidateSet& CandidateSet, 5463 bool SuppressUserConversions) { 5464 NamedDecl *Decl = FoundDecl.getDecl(); 5465 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 5466 5467 if (isa<UsingShadowDecl>(Decl)) 5468 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 5469 5470 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 5471 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 5472 "Expected a member function template"); 5473 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 5474 /*ExplicitArgs*/ 0, 5475 ObjectType, ObjectClassification, 5476 llvm::makeArrayRef(Args, NumArgs), CandidateSet, 5477 SuppressUserConversions); 5478 } else { 5479 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 5480 ObjectType, ObjectClassification, 5481 llvm::makeArrayRef(Args, NumArgs), 5482 CandidateSet, SuppressUserConversions); 5483 } 5484} 5485 5486/// AddMethodCandidate - Adds the given C++ member function to the set 5487/// of candidate functions, using the given function call arguments 5488/// and the object argument (@c Object). For example, in a call 5489/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 5490/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 5491/// allow user-defined conversions via constructors or conversion 5492/// operators. 5493void 5494Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 5495 CXXRecordDecl *ActingContext, QualType ObjectType, 5496 Expr::Classification ObjectClassification, 5497 ArrayRef<Expr *> Args, 5498 OverloadCandidateSet& CandidateSet, 5499 bool SuppressUserConversions) { 5500 const FunctionProtoType* Proto 5501 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 5502 assert(Proto && "Methods without a prototype cannot be overloaded"); 5503 assert(!isa<CXXConstructorDecl>(Method) && 5504 "Use AddOverloadCandidate for constructors"); 5505 5506 if (!CandidateSet.isNewCandidate(Method)) 5507 return; 5508 5509 // Overload resolution is always an unevaluated context. 5510 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5511 5512 // Add this candidate 5513 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); 5514 Candidate.FoundDecl = FoundDecl; 5515 Candidate.Function = Method; 5516 Candidate.IsSurrogate = false; 5517 Candidate.IgnoreObjectArgument = false; 5518 Candidate.ExplicitCallArguments = Args.size(); 5519 5520 unsigned NumArgsInProto = Proto->getNumArgs(); 5521 5522 // (C++ 13.3.2p2): A candidate function having fewer than m 5523 // parameters is viable only if it has an ellipsis in its parameter 5524 // list (8.3.5). 5525 if (Args.size() > NumArgsInProto && !Proto->isVariadic()) { 5526 Candidate.Viable = false; 5527 Candidate.FailureKind = ovl_fail_too_many_arguments; 5528 return; 5529 } 5530 5531 // (C++ 13.3.2p2): A candidate function having more than m parameters 5532 // is viable only if the (m+1)st parameter has a default argument 5533 // (8.3.6). For the purposes of overload resolution, the 5534 // parameter list is truncated on the right, so that there are 5535 // exactly m parameters. 5536 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 5537 if (Args.size() < MinRequiredArgs) { 5538 // Not enough arguments. 5539 Candidate.Viable = false; 5540 Candidate.FailureKind = ovl_fail_too_few_arguments; 5541 return; 5542 } 5543 5544 Candidate.Viable = true; 5545 5546 if (Method->isStatic() || ObjectType.isNull()) 5547 // The implicit object argument is ignored. 5548 Candidate.IgnoreObjectArgument = true; 5549 else { 5550 // Determine the implicit conversion sequence for the object 5551 // parameter. 5552 Candidate.Conversions[0] 5553 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 5554 Method, ActingContext); 5555 if (Candidate.Conversions[0].isBad()) { 5556 Candidate.Viable = false; 5557 Candidate.FailureKind = ovl_fail_bad_conversion; 5558 return; 5559 } 5560 } 5561 5562 // Determine the implicit conversion sequences for each of the 5563 // arguments. 5564 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5565 if (ArgIdx < NumArgsInProto) { 5566 // (C++ 13.3.2p3): for F to be a viable function, there shall 5567 // exist for each argument an implicit conversion sequence 5568 // (13.3.3.1) that converts that argument to the corresponding 5569 // parameter of F. 5570 QualType ParamType = Proto->getArgType(ArgIdx); 5571 Candidate.Conversions[ArgIdx + 1] 5572 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5573 SuppressUserConversions, 5574 /*InOverloadResolution=*/true, 5575 /*AllowObjCWritebackConversion=*/ 5576 getLangOpts().ObjCAutoRefCount); 5577 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 5578 Candidate.Viable = false; 5579 Candidate.FailureKind = ovl_fail_bad_conversion; 5580 break; 5581 } 5582 } else { 5583 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5584 // argument for which there is no corresponding parameter is 5585 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5586 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 5587 } 5588 } 5589} 5590 5591/// \brief Add a C++ member function template as a candidate to the candidate 5592/// set, using template argument deduction to produce an appropriate member 5593/// function template specialization. 5594void 5595Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 5596 DeclAccessPair FoundDecl, 5597 CXXRecordDecl *ActingContext, 5598 TemplateArgumentListInfo *ExplicitTemplateArgs, 5599 QualType ObjectType, 5600 Expr::Classification ObjectClassification, 5601 ArrayRef<Expr *> Args, 5602 OverloadCandidateSet& CandidateSet, 5603 bool SuppressUserConversions) { 5604 if (!CandidateSet.isNewCandidate(MethodTmpl)) 5605 return; 5606 5607 // C++ [over.match.funcs]p7: 5608 // In each case where a candidate is a function template, candidate 5609 // function template specializations are generated using template argument 5610 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 5611 // candidate functions in the usual way.113) A given name can refer to one 5612 // or more function templates and also to a set of overloaded non-template 5613 // functions. In such a case, the candidate functions generated from each 5614 // function template are combined with the set of non-template candidate 5615 // functions. 5616 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5617 FunctionDecl *Specialization = 0; 5618 if (TemplateDeductionResult Result 5619 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, Args, 5620 Specialization, Info)) { 5621 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5622 Candidate.FoundDecl = FoundDecl; 5623 Candidate.Function = MethodTmpl->getTemplatedDecl(); 5624 Candidate.Viable = false; 5625 Candidate.FailureKind = ovl_fail_bad_deduction; 5626 Candidate.IsSurrogate = false; 5627 Candidate.IgnoreObjectArgument = false; 5628 Candidate.ExplicitCallArguments = Args.size(); 5629 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5630 Info); 5631 return; 5632 } 5633 5634 // Add the function template specialization produced by template argument 5635 // deduction as a candidate. 5636 assert(Specialization && "Missing member function template specialization?"); 5637 assert(isa<CXXMethodDecl>(Specialization) && 5638 "Specialization is not a member function?"); 5639 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 5640 ActingContext, ObjectType, ObjectClassification, Args, 5641 CandidateSet, SuppressUserConversions); 5642} 5643 5644/// \brief Add a C++ function template specialization as a candidate 5645/// in the candidate set, using template argument deduction to produce 5646/// an appropriate function template specialization. 5647void 5648Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 5649 DeclAccessPair FoundDecl, 5650 TemplateArgumentListInfo *ExplicitTemplateArgs, 5651 ArrayRef<Expr *> Args, 5652 OverloadCandidateSet& CandidateSet, 5653 bool SuppressUserConversions) { 5654 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 5655 return; 5656 5657 // C++ [over.match.funcs]p7: 5658 // In each case where a candidate is a function template, candidate 5659 // function template specializations are generated using template argument 5660 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 5661 // candidate functions in the usual way.113) A given name can refer to one 5662 // or more function templates and also to a set of overloaded non-template 5663 // functions. In such a case, the candidate functions generated from each 5664 // function template are combined with the set of non-template candidate 5665 // functions. 5666 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5667 FunctionDecl *Specialization = 0; 5668 if (TemplateDeductionResult Result 5669 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, Args, 5670 Specialization, Info)) { 5671 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5672 Candidate.FoundDecl = FoundDecl; 5673 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 5674 Candidate.Viable = false; 5675 Candidate.FailureKind = ovl_fail_bad_deduction; 5676 Candidate.IsSurrogate = false; 5677 Candidate.IgnoreObjectArgument = false; 5678 Candidate.ExplicitCallArguments = Args.size(); 5679 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5680 Info); 5681 return; 5682 } 5683 5684 // Add the function template specialization produced by template argument 5685 // deduction as a candidate. 5686 assert(Specialization && "Missing function template specialization?"); 5687 AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet, 5688 SuppressUserConversions); 5689} 5690 5691/// AddConversionCandidate - Add a C++ conversion function as a 5692/// candidate in the candidate set (C++ [over.match.conv], 5693/// C++ [over.match.copy]). From is the expression we're converting from, 5694/// and ToType is the type that we're eventually trying to convert to 5695/// (which may or may not be the same type as the type that the 5696/// conversion function produces). 5697void 5698Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 5699 DeclAccessPair FoundDecl, 5700 CXXRecordDecl *ActingContext, 5701 Expr *From, QualType ToType, 5702 OverloadCandidateSet& CandidateSet) { 5703 assert(!Conversion->getDescribedFunctionTemplate() && 5704 "Conversion function templates use AddTemplateConversionCandidate"); 5705 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 5706 if (!CandidateSet.isNewCandidate(Conversion)) 5707 return; 5708 5709 // Overload resolution is always an unevaluated context. 5710 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5711 5712 // Add this candidate 5713 OverloadCandidate &Candidate = CandidateSet.addCandidate(1); 5714 Candidate.FoundDecl = FoundDecl; 5715 Candidate.Function = Conversion; 5716 Candidate.IsSurrogate = false; 5717 Candidate.IgnoreObjectArgument = false; 5718 Candidate.FinalConversion.setAsIdentityConversion(); 5719 Candidate.FinalConversion.setFromType(ConvType); 5720 Candidate.FinalConversion.setAllToTypes(ToType); 5721 Candidate.Viable = true; 5722 Candidate.ExplicitCallArguments = 1; 5723 5724 // C++ [over.match.funcs]p4: 5725 // For conversion functions, the function is considered to be a member of 5726 // the class of the implicit implied object argument for the purpose of 5727 // defining the type of the implicit object parameter. 5728 // 5729 // Determine the implicit conversion sequence for the implicit 5730 // object parameter. 5731 QualType ImplicitParamType = From->getType(); 5732 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 5733 ImplicitParamType = FromPtrType->getPointeeType(); 5734 CXXRecordDecl *ConversionContext 5735 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 5736 5737 Candidate.Conversions[0] 5738 = TryObjectArgumentInitialization(*this, From->getType(), 5739 From->Classify(Context), 5740 Conversion, ConversionContext); 5741 5742 if (Candidate.Conversions[0].isBad()) { 5743 Candidate.Viable = false; 5744 Candidate.FailureKind = ovl_fail_bad_conversion; 5745 return; 5746 } 5747 5748 // We won't go through a user-define type conversion function to convert a 5749 // derived to base as such conversions are given Conversion Rank. They only 5750 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 5751 QualType FromCanon 5752 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 5753 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 5754 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 5755 Candidate.Viable = false; 5756 Candidate.FailureKind = ovl_fail_trivial_conversion; 5757 return; 5758 } 5759 5760 // To determine what the conversion from the result of calling the 5761 // conversion function to the type we're eventually trying to 5762 // convert to (ToType), we need to synthesize a call to the 5763 // conversion function and attempt copy initialization from it. This 5764 // makes sure that we get the right semantics with respect to 5765 // lvalues/rvalues and the type. Fortunately, we can allocate this 5766 // call on the stack and we don't need its arguments to be 5767 // well-formed. 5768 DeclRefExpr ConversionRef(Conversion, false, Conversion->getType(), 5769 VK_LValue, From->getLocStart()); 5770 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 5771 Context.getPointerType(Conversion->getType()), 5772 CK_FunctionToPointerDecay, 5773 &ConversionRef, VK_RValue); 5774 5775 QualType ConversionType = Conversion->getConversionType(); 5776 if (RequireCompleteType(From->getLocStart(), ConversionType, 0)) { 5777 Candidate.Viable = false; 5778 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5779 return; 5780 } 5781 5782 ExprValueKind VK = Expr::getValueKindForType(ConversionType); 5783 5784 // Note that it is safe to allocate CallExpr on the stack here because 5785 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 5786 // allocator). 5787 QualType CallResultType = ConversionType.getNonLValueExprType(Context); 5788 CallExpr Call(Context, &ConversionFn, MultiExprArg(), CallResultType, VK, 5789 From->getLocStart()); 5790 ImplicitConversionSequence ICS = 5791 TryCopyInitialization(*this, &Call, ToType, 5792 /*SuppressUserConversions=*/true, 5793 /*InOverloadResolution=*/false, 5794 /*AllowObjCWritebackConversion=*/false); 5795 5796 switch (ICS.getKind()) { 5797 case ImplicitConversionSequence::StandardConversion: 5798 Candidate.FinalConversion = ICS.Standard; 5799 5800 // C++ [over.ics.user]p3: 5801 // If the user-defined conversion is specified by a specialization of a 5802 // conversion function template, the second standard conversion sequence 5803 // shall have exact match rank. 5804 if (Conversion->getPrimaryTemplate() && 5805 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 5806 Candidate.Viable = false; 5807 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 5808 } 5809 5810 // C++0x [dcl.init.ref]p5: 5811 // In the second case, if the reference is an rvalue reference and 5812 // the second standard conversion sequence of the user-defined 5813 // conversion sequence includes an lvalue-to-rvalue conversion, the 5814 // program is ill-formed. 5815 if (ToType->isRValueReferenceType() && 5816 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 5817 Candidate.Viable = false; 5818 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5819 } 5820 break; 5821 5822 case ImplicitConversionSequence::BadConversion: 5823 Candidate.Viable = false; 5824 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5825 break; 5826 5827 default: 5828 llvm_unreachable( 5829 "Can only end up with a standard conversion sequence or failure"); 5830 } 5831} 5832 5833/// \brief Adds a conversion function template specialization 5834/// candidate to the overload set, using template argument deduction 5835/// to deduce the template arguments of the conversion function 5836/// template from the type that we are converting to (C++ 5837/// [temp.deduct.conv]). 5838void 5839Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 5840 DeclAccessPair FoundDecl, 5841 CXXRecordDecl *ActingDC, 5842 Expr *From, QualType ToType, 5843 OverloadCandidateSet &CandidateSet) { 5844 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 5845 "Only conversion function templates permitted here"); 5846 5847 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 5848 return; 5849 5850 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5851 CXXConversionDecl *Specialization = 0; 5852 if (TemplateDeductionResult Result 5853 = DeduceTemplateArguments(FunctionTemplate, ToType, 5854 Specialization, Info)) { 5855 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5856 Candidate.FoundDecl = FoundDecl; 5857 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 5858 Candidate.Viable = false; 5859 Candidate.FailureKind = ovl_fail_bad_deduction; 5860 Candidate.IsSurrogate = false; 5861 Candidate.IgnoreObjectArgument = false; 5862 Candidate.ExplicitCallArguments = 1; 5863 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5864 Info); 5865 return; 5866 } 5867 5868 // Add the conversion function template specialization produced by 5869 // template argument deduction as a candidate. 5870 assert(Specialization && "Missing function template specialization?"); 5871 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 5872 CandidateSet); 5873} 5874 5875/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 5876/// converts the given @c Object to a function pointer via the 5877/// conversion function @c Conversion, and then attempts to call it 5878/// with the given arguments (C++ [over.call.object]p2-4). Proto is 5879/// the type of function that we'll eventually be calling. 5880void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 5881 DeclAccessPair FoundDecl, 5882 CXXRecordDecl *ActingContext, 5883 const FunctionProtoType *Proto, 5884 Expr *Object, 5885 ArrayRef<Expr *> Args, 5886 OverloadCandidateSet& CandidateSet) { 5887 if (!CandidateSet.isNewCandidate(Conversion)) 5888 return; 5889 5890 // Overload resolution is always an unevaluated context. 5891 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5892 5893 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); 5894 Candidate.FoundDecl = FoundDecl; 5895 Candidate.Function = 0; 5896 Candidate.Surrogate = Conversion; 5897 Candidate.Viable = true; 5898 Candidate.IsSurrogate = true; 5899 Candidate.IgnoreObjectArgument = false; 5900 Candidate.ExplicitCallArguments = Args.size(); 5901 5902 // Determine the implicit conversion sequence for the implicit 5903 // object parameter. 5904 ImplicitConversionSequence ObjectInit 5905 = TryObjectArgumentInitialization(*this, Object->getType(), 5906 Object->Classify(Context), 5907 Conversion, ActingContext); 5908 if (ObjectInit.isBad()) { 5909 Candidate.Viable = false; 5910 Candidate.FailureKind = ovl_fail_bad_conversion; 5911 Candidate.Conversions[0] = ObjectInit; 5912 return; 5913 } 5914 5915 // The first conversion is actually a user-defined conversion whose 5916 // first conversion is ObjectInit's standard conversion (which is 5917 // effectively a reference binding). Record it as such. 5918 Candidate.Conversions[0].setUserDefined(); 5919 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 5920 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 5921 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false; 5922 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 5923 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl; 5924 Candidate.Conversions[0].UserDefined.After 5925 = Candidate.Conversions[0].UserDefined.Before; 5926 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 5927 5928 // Find the 5929 unsigned NumArgsInProto = Proto->getNumArgs(); 5930 5931 // (C++ 13.3.2p2): A candidate function having fewer than m 5932 // parameters is viable only if it has an ellipsis in its parameter 5933 // list (8.3.5). 5934 if (Args.size() > NumArgsInProto && !Proto->isVariadic()) { 5935 Candidate.Viable = false; 5936 Candidate.FailureKind = ovl_fail_too_many_arguments; 5937 return; 5938 } 5939 5940 // Function types don't have any default arguments, so just check if 5941 // we have enough arguments. 5942 if (Args.size() < NumArgsInProto) { 5943 // Not enough arguments. 5944 Candidate.Viable = false; 5945 Candidate.FailureKind = ovl_fail_too_few_arguments; 5946 return; 5947 } 5948 5949 // Determine the implicit conversion sequences for each of the 5950 // arguments. 5951 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5952 if (ArgIdx < NumArgsInProto) { 5953 // (C++ 13.3.2p3): for F to be a viable function, there shall 5954 // exist for each argument an implicit conversion sequence 5955 // (13.3.3.1) that converts that argument to the corresponding 5956 // parameter of F. 5957 QualType ParamType = Proto->getArgType(ArgIdx); 5958 Candidate.Conversions[ArgIdx + 1] 5959 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5960 /*SuppressUserConversions=*/false, 5961 /*InOverloadResolution=*/false, 5962 /*AllowObjCWritebackConversion=*/ 5963 getLangOpts().ObjCAutoRefCount); 5964 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 5965 Candidate.Viable = false; 5966 Candidate.FailureKind = ovl_fail_bad_conversion; 5967 break; 5968 } 5969 } else { 5970 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5971 // argument for which there is no corresponding parameter is 5972 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5973 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 5974 } 5975 } 5976} 5977 5978/// \brief Add overload candidates for overloaded operators that are 5979/// member functions. 5980/// 5981/// Add the overloaded operator candidates that are member functions 5982/// for the operator Op that was used in an operator expression such 5983/// as "x Op y". , Args/NumArgs provides the operator arguments, and 5984/// CandidateSet will store the added overload candidates. (C++ 5985/// [over.match.oper]). 5986void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 5987 SourceLocation OpLoc, 5988 Expr **Args, unsigned NumArgs, 5989 OverloadCandidateSet& CandidateSet, 5990 SourceRange OpRange) { 5991 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5992 5993 // C++ [over.match.oper]p3: 5994 // For a unary operator @ with an operand of a type whose 5995 // cv-unqualified version is T1, and for a binary operator @ with 5996 // a left operand of a type whose cv-unqualified version is T1 and 5997 // a right operand of a type whose cv-unqualified version is T2, 5998 // three sets of candidate functions, designated member 5999 // candidates, non-member candidates and built-in candidates, are 6000 // constructed as follows: 6001 QualType T1 = Args[0]->getType(); 6002 6003 // -- If T1 is a class type, the set of member candidates is the 6004 // result of the qualified lookup of T1::operator@ 6005 // (13.3.1.1.1); otherwise, the set of member candidates is 6006 // empty. 6007 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 6008 // Complete the type if it can be completed. Otherwise, we're done. 6009 if (RequireCompleteType(OpLoc, T1, 0)) 6010 return; 6011 6012 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 6013 LookupQualifiedName(Operators, T1Rec->getDecl()); 6014 Operators.suppressDiagnostics(); 6015 6016 for (LookupResult::iterator Oper = Operators.begin(), 6017 OperEnd = Operators.end(); 6018 Oper != OperEnd; 6019 ++Oper) 6020 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 6021 Args[0]->Classify(Context), Args + 1, NumArgs - 1, 6022 CandidateSet, 6023 /* SuppressUserConversions = */ false); 6024 } 6025} 6026 6027/// AddBuiltinCandidate - Add a candidate for a built-in 6028/// operator. ResultTy and ParamTys are the result and parameter types 6029/// of the built-in candidate, respectively. Args and NumArgs are the 6030/// arguments being passed to the candidate. IsAssignmentOperator 6031/// should be true when this built-in candidate is an assignment 6032/// operator. NumContextualBoolArguments is the number of arguments 6033/// (at the beginning of the argument list) that will be contextually 6034/// converted to bool. 6035void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 6036 Expr **Args, unsigned NumArgs, 6037 OverloadCandidateSet& CandidateSet, 6038 bool IsAssignmentOperator, 6039 unsigned NumContextualBoolArguments) { 6040 // Overload resolution is always an unevaluated context. 6041 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 6042 6043 // Add this candidate 6044 OverloadCandidate &Candidate = CandidateSet.addCandidate(NumArgs); 6045 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 6046 Candidate.Function = 0; 6047 Candidate.IsSurrogate = false; 6048 Candidate.IgnoreObjectArgument = false; 6049 Candidate.BuiltinTypes.ResultTy = ResultTy; 6050 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6051 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 6052 6053 // Determine the implicit conversion sequences for each of the 6054 // arguments. 6055 Candidate.Viable = true; 6056 Candidate.ExplicitCallArguments = NumArgs; 6057 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6058 // C++ [over.match.oper]p4: 6059 // For the built-in assignment operators, conversions of the 6060 // left operand are restricted as follows: 6061 // -- no temporaries are introduced to hold the left operand, and 6062 // -- no user-defined conversions are applied to the left 6063 // operand to achieve a type match with the left-most 6064 // parameter of a built-in candidate. 6065 // 6066 // We block these conversions by turning off user-defined 6067 // conversions, since that is the only way that initialization of 6068 // a reference to a non-class type can occur from something that 6069 // is not of the same type. 6070 if (ArgIdx < NumContextualBoolArguments) { 6071 assert(ParamTys[ArgIdx] == Context.BoolTy && 6072 "Contextual conversion to bool requires bool type"); 6073 Candidate.Conversions[ArgIdx] 6074 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 6075 } else { 6076 Candidate.Conversions[ArgIdx] 6077 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 6078 ArgIdx == 0 && IsAssignmentOperator, 6079 /*InOverloadResolution=*/false, 6080 /*AllowObjCWritebackConversion=*/ 6081 getLangOpts().ObjCAutoRefCount); 6082 } 6083 if (Candidate.Conversions[ArgIdx].isBad()) { 6084 Candidate.Viable = false; 6085 Candidate.FailureKind = ovl_fail_bad_conversion; 6086 break; 6087 } 6088 } 6089} 6090 6091/// BuiltinCandidateTypeSet - A set of types that will be used for the 6092/// candidate operator functions for built-in operators (C++ 6093/// [over.built]). The types are separated into pointer types and 6094/// enumeration types. 6095class BuiltinCandidateTypeSet { 6096 /// TypeSet - A set of types. 6097 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 6098 6099 /// PointerTypes - The set of pointer types that will be used in the 6100 /// built-in candidates. 6101 TypeSet PointerTypes; 6102 6103 /// MemberPointerTypes - The set of member pointer types that will be 6104 /// used in the built-in candidates. 6105 TypeSet MemberPointerTypes; 6106 6107 /// EnumerationTypes - The set of enumeration types that will be 6108 /// used in the built-in candidates. 6109 TypeSet EnumerationTypes; 6110 6111 /// \brief The set of vector types that will be used in the built-in 6112 /// candidates. 6113 TypeSet VectorTypes; 6114 6115 /// \brief A flag indicating non-record types are viable candidates 6116 bool HasNonRecordTypes; 6117 6118 /// \brief A flag indicating whether either arithmetic or enumeration types 6119 /// were present in the candidate set. 6120 bool HasArithmeticOrEnumeralTypes; 6121 6122 /// \brief A flag indicating whether the nullptr type was present in the 6123 /// candidate set. 6124 bool HasNullPtrType; 6125 6126 /// Sema - The semantic analysis instance where we are building the 6127 /// candidate type set. 6128 Sema &SemaRef; 6129 6130 /// Context - The AST context in which we will build the type sets. 6131 ASTContext &Context; 6132 6133 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 6134 const Qualifiers &VisibleQuals); 6135 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 6136 6137public: 6138 /// iterator - Iterates through the types that are part of the set. 6139 typedef TypeSet::iterator iterator; 6140 6141 BuiltinCandidateTypeSet(Sema &SemaRef) 6142 : HasNonRecordTypes(false), 6143 HasArithmeticOrEnumeralTypes(false), 6144 HasNullPtrType(false), 6145 SemaRef(SemaRef), 6146 Context(SemaRef.Context) { } 6147 6148 void AddTypesConvertedFrom(QualType Ty, 6149 SourceLocation Loc, 6150 bool AllowUserConversions, 6151 bool AllowExplicitConversions, 6152 const Qualifiers &VisibleTypeConversionsQuals); 6153 6154 /// pointer_begin - First pointer type found; 6155 iterator pointer_begin() { return PointerTypes.begin(); } 6156 6157 /// pointer_end - Past the last pointer type found; 6158 iterator pointer_end() { return PointerTypes.end(); } 6159 6160 /// member_pointer_begin - First member pointer type found; 6161 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 6162 6163 /// member_pointer_end - Past the last member pointer type found; 6164 iterator member_pointer_end() { return MemberPointerTypes.end(); } 6165 6166 /// enumeration_begin - First enumeration type found; 6167 iterator enumeration_begin() { return EnumerationTypes.begin(); } 6168 6169 /// enumeration_end - Past the last enumeration type found; 6170 iterator enumeration_end() { return EnumerationTypes.end(); } 6171 6172 iterator vector_begin() { return VectorTypes.begin(); } 6173 iterator vector_end() { return VectorTypes.end(); } 6174 6175 bool hasNonRecordTypes() { return HasNonRecordTypes; } 6176 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 6177 bool hasNullPtrType() const { return HasNullPtrType; } 6178}; 6179 6180/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 6181/// the set of pointer types along with any more-qualified variants of 6182/// that type. For example, if @p Ty is "int const *", this routine 6183/// will add "int const *", "int const volatile *", "int const 6184/// restrict *", and "int const volatile restrict *" to the set of 6185/// pointer types. Returns true if the add of @p Ty itself succeeded, 6186/// false otherwise. 6187/// 6188/// FIXME: what to do about extended qualifiers? 6189bool 6190BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 6191 const Qualifiers &VisibleQuals) { 6192 6193 // Insert this type. 6194 if (!PointerTypes.insert(Ty)) 6195 return false; 6196 6197 QualType PointeeTy; 6198 const PointerType *PointerTy = Ty->getAs<PointerType>(); 6199 bool buildObjCPtr = false; 6200 if (!PointerTy) { 6201 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>(); 6202 PointeeTy = PTy->getPointeeType(); 6203 buildObjCPtr = true; 6204 } else { 6205 PointeeTy = PointerTy->getPointeeType(); 6206 } 6207 6208 // Don't add qualified variants of arrays. For one, they're not allowed 6209 // (the qualifier would sink to the element type), and for another, the 6210 // only overload situation where it matters is subscript or pointer +- int, 6211 // and those shouldn't have qualifier variants anyway. 6212 if (PointeeTy->isArrayType()) 6213 return true; 6214 6215 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 6216 bool hasVolatile = VisibleQuals.hasVolatile(); 6217 bool hasRestrict = VisibleQuals.hasRestrict(); 6218 6219 // Iterate through all strict supersets of BaseCVR. 6220 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 6221 if ((CVR | BaseCVR) != CVR) continue; 6222 // Skip over volatile if no volatile found anywhere in the types. 6223 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 6224 6225 // Skip over restrict if no restrict found anywhere in the types, or if 6226 // the type cannot be restrict-qualified. 6227 if ((CVR & Qualifiers::Restrict) && 6228 (!hasRestrict || 6229 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType())))) 6230 continue; 6231 6232 // Build qualified pointee type. 6233 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 6234 6235 // Build qualified pointer type. 6236 QualType QPointerTy; 6237 if (!buildObjCPtr) 6238 QPointerTy = Context.getPointerType(QPointeeTy); 6239 else 6240 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy); 6241 6242 // Insert qualified pointer type. 6243 PointerTypes.insert(QPointerTy); 6244 } 6245 6246 return true; 6247} 6248 6249/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 6250/// to the set of pointer types along with any more-qualified variants of 6251/// that type. For example, if @p Ty is "int const *", this routine 6252/// will add "int const *", "int const volatile *", "int const 6253/// restrict *", and "int const volatile restrict *" to the set of 6254/// pointer types. Returns true if the add of @p Ty itself succeeded, 6255/// false otherwise. 6256/// 6257/// FIXME: what to do about extended qualifiers? 6258bool 6259BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 6260 QualType Ty) { 6261 // Insert this type. 6262 if (!MemberPointerTypes.insert(Ty)) 6263 return false; 6264 6265 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 6266 assert(PointerTy && "type was not a member pointer type!"); 6267 6268 QualType PointeeTy = PointerTy->getPointeeType(); 6269 // Don't add qualified variants of arrays. For one, they're not allowed 6270 // (the qualifier would sink to the element type), and for another, the 6271 // only overload situation where it matters is subscript or pointer +- int, 6272 // and those shouldn't have qualifier variants anyway. 6273 if (PointeeTy->isArrayType()) 6274 return true; 6275 const Type *ClassTy = PointerTy->getClass(); 6276 6277 // Iterate through all strict supersets of the pointee type's CVR 6278 // qualifiers. 6279 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 6280 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 6281 if ((CVR | BaseCVR) != CVR) continue; 6282 6283 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 6284 MemberPointerTypes.insert( 6285 Context.getMemberPointerType(QPointeeTy, ClassTy)); 6286 } 6287 6288 return true; 6289} 6290 6291/// AddTypesConvertedFrom - Add each of the types to which the type @p 6292/// Ty can be implicit converted to the given set of @p Types. We're 6293/// primarily interested in pointer types and enumeration types. We also 6294/// take member pointer types, for the conditional operator. 6295/// AllowUserConversions is true if we should look at the conversion 6296/// functions of a class type, and AllowExplicitConversions if we 6297/// should also include the explicit conversion functions of a class 6298/// type. 6299void 6300BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 6301 SourceLocation Loc, 6302 bool AllowUserConversions, 6303 bool AllowExplicitConversions, 6304 const Qualifiers &VisibleQuals) { 6305 // Only deal with canonical types. 6306 Ty = Context.getCanonicalType(Ty); 6307 6308 // Look through reference types; they aren't part of the type of an 6309 // expression for the purposes of conversions. 6310 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 6311 Ty = RefTy->getPointeeType(); 6312 6313 // If we're dealing with an array type, decay to the pointer. 6314 if (Ty->isArrayType()) 6315 Ty = SemaRef.Context.getArrayDecayedType(Ty); 6316 6317 // Otherwise, we don't care about qualifiers on the type. 6318 Ty = Ty.getLocalUnqualifiedType(); 6319 6320 // Flag if we ever add a non-record type. 6321 const RecordType *TyRec = Ty->getAs<RecordType>(); 6322 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 6323 6324 // Flag if we encounter an arithmetic type. 6325 HasArithmeticOrEnumeralTypes = 6326 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 6327 6328 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 6329 PointerTypes.insert(Ty); 6330 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 6331 // Insert our type, and its more-qualified variants, into the set 6332 // of types. 6333 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 6334 return; 6335 } else if (Ty->isMemberPointerType()) { 6336 // Member pointers are far easier, since the pointee can't be converted. 6337 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 6338 return; 6339 } else if (Ty->isEnumeralType()) { 6340 HasArithmeticOrEnumeralTypes = true; 6341 EnumerationTypes.insert(Ty); 6342 } else if (Ty->isVectorType()) { 6343 // We treat vector types as arithmetic types in many contexts as an 6344 // extension. 6345 HasArithmeticOrEnumeralTypes = true; 6346 VectorTypes.insert(Ty); 6347 } else if (Ty->isNullPtrType()) { 6348 HasNullPtrType = true; 6349 } else if (AllowUserConversions && TyRec) { 6350 // No conversion functions in incomplete types. 6351 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 6352 return; 6353 6354 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 6355 std::pair<CXXRecordDecl::conversion_iterator, 6356 CXXRecordDecl::conversion_iterator> 6357 Conversions = ClassDecl->getVisibleConversionFunctions(); 6358 for (CXXRecordDecl::conversion_iterator 6359 I = Conversions.first, E = Conversions.second; I != E; ++I) { 6360 NamedDecl *D = I.getDecl(); 6361 if (isa<UsingShadowDecl>(D)) 6362 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6363 6364 // Skip conversion function templates; they don't tell us anything 6365 // about which builtin types we can convert to. 6366 if (isa<FunctionTemplateDecl>(D)) 6367 continue; 6368 6369 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6370 if (AllowExplicitConversions || !Conv->isExplicit()) { 6371 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 6372 VisibleQuals); 6373 } 6374 } 6375 } 6376} 6377 6378/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 6379/// the volatile- and non-volatile-qualified assignment operators for the 6380/// given type to the candidate set. 6381static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 6382 QualType T, 6383 Expr **Args, 6384 unsigned NumArgs, 6385 OverloadCandidateSet &CandidateSet) { 6386 QualType ParamTypes[2]; 6387 6388 // T& operator=(T&, T) 6389 ParamTypes[0] = S.Context.getLValueReferenceType(T); 6390 ParamTypes[1] = T; 6391 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6392 /*IsAssignmentOperator=*/true); 6393 6394 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 6395 // volatile T& operator=(volatile T&, T) 6396 ParamTypes[0] 6397 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 6398 ParamTypes[1] = T; 6399 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6400 /*IsAssignmentOperator=*/true); 6401 } 6402} 6403 6404/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 6405/// if any, found in visible type conversion functions found in ArgExpr's type. 6406static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 6407 Qualifiers VRQuals; 6408 const RecordType *TyRec; 6409 if (const MemberPointerType *RHSMPType = 6410 ArgExpr->getType()->getAs<MemberPointerType>()) 6411 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 6412 else 6413 TyRec = ArgExpr->getType()->getAs<RecordType>(); 6414 if (!TyRec) { 6415 // Just to be safe, assume the worst case. 6416 VRQuals.addVolatile(); 6417 VRQuals.addRestrict(); 6418 return VRQuals; 6419 } 6420 6421 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 6422 if (!ClassDecl->hasDefinition()) 6423 return VRQuals; 6424 6425 std::pair<CXXRecordDecl::conversion_iterator, 6426 CXXRecordDecl::conversion_iterator> 6427 Conversions = ClassDecl->getVisibleConversionFunctions(); 6428 6429 for (CXXRecordDecl::conversion_iterator 6430 I = Conversions.first, E = Conversions.second; I != E; ++I) { 6431 NamedDecl *D = I.getDecl(); 6432 if (isa<UsingShadowDecl>(D)) 6433 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6434 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 6435 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 6436 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 6437 CanTy = ResTypeRef->getPointeeType(); 6438 // Need to go down the pointer/mempointer chain and add qualifiers 6439 // as see them. 6440 bool done = false; 6441 while (!done) { 6442 if (CanTy.isRestrictQualified()) 6443 VRQuals.addRestrict(); 6444 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 6445 CanTy = ResTypePtr->getPointeeType(); 6446 else if (const MemberPointerType *ResTypeMPtr = 6447 CanTy->getAs<MemberPointerType>()) 6448 CanTy = ResTypeMPtr->getPointeeType(); 6449 else 6450 done = true; 6451 if (CanTy.isVolatileQualified()) 6452 VRQuals.addVolatile(); 6453 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 6454 return VRQuals; 6455 } 6456 } 6457 } 6458 return VRQuals; 6459} 6460 6461namespace { 6462 6463/// \brief Helper class to manage the addition of builtin operator overload 6464/// candidates. It provides shared state and utility methods used throughout 6465/// the process, as well as a helper method to add each group of builtin 6466/// operator overloads from the standard to a candidate set. 6467class BuiltinOperatorOverloadBuilder { 6468 // Common instance state available to all overload candidate addition methods. 6469 Sema &S; 6470 Expr **Args; 6471 unsigned NumArgs; 6472 Qualifiers VisibleTypeConversionsQuals; 6473 bool HasArithmeticOrEnumeralCandidateType; 6474 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 6475 OverloadCandidateSet &CandidateSet; 6476 6477 // Define some constants used to index and iterate over the arithemetic types 6478 // provided via the getArithmeticType() method below. 6479 // The "promoted arithmetic types" are the arithmetic 6480 // types are that preserved by promotion (C++ [over.built]p2). 6481 static const unsigned FirstIntegralType = 3; 6482 static const unsigned LastIntegralType = 20; 6483 static const unsigned FirstPromotedIntegralType = 3, 6484 LastPromotedIntegralType = 11; 6485 static const unsigned FirstPromotedArithmeticType = 0, 6486 LastPromotedArithmeticType = 11; 6487 static const unsigned NumArithmeticTypes = 20; 6488 6489 /// \brief Get the canonical type for a given arithmetic type index. 6490 CanQualType getArithmeticType(unsigned index) { 6491 assert(index < NumArithmeticTypes); 6492 static CanQualType ASTContext::* const 6493 ArithmeticTypes[NumArithmeticTypes] = { 6494 // Start of promoted types. 6495 &ASTContext::FloatTy, 6496 &ASTContext::DoubleTy, 6497 &ASTContext::LongDoubleTy, 6498 6499 // Start of integral types. 6500 &ASTContext::IntTy, 6501 &ASTContext::LongTy, 6502 &ASTContext::LongLongTy, 6503 &ASTContext::Int128Ty, 6504 &ASTContext::UnsignedIntTy, 6505 &ASTContext::UnsignedLongTy, 6506 &ASTContext::UnsignedLongLongTy, 6507 &ASTContext::UnsignedInt128Ty, 6508 // End of promoted types. 6509 6510 &ASTContext::BoolTy, 6511 &ASTContext::CharTy, 6512 &ASTContext::WCharTy, 6513 &ASTContext::Char16Ty, 6514 &ASTContext::Char32Ty, 6515 &ASTContext::SignedCharTy, 6516 &ASTContext::ShortTy, 6517 &ASTContext::UnsignedCharTy, 6518 &ASTContext::UnsignedShortTy, 6519 // End of integral types. 6520 // FIXME: What about complex? What about half? 6521 }; 6522 return S.Context.*ArithmeticTypes[index]; 6523 } 6524 6525 /// \brief Gets the canonical type resulting from the usual arithemetic 6526 /// converions for the given arithmetic types. 6527 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 6528 // Accelerator table for performing the usual arithmetic conversions. 6529 // The rules are basically: 6530 // - if either is floating-point, use the wider floating-point 6531 // - if same signedness, use the higher rank 6532 // - if same size, use unsigned of the higher rank 6533 // - use the larger type 6534 // These rules, together with the axiom that higher ranks are 6535 // never smaller, are sufficient to precompute all of these results 6536 // *except* when dealing with signed types of higher rank. 6537 // (we could precompute SLL x UI for all known platforms, but it's 6538 // better not to make any assumptions). 6539 // We assume that int128 has a higher rank than long long on all platforms. 6540 enum PromotedType { 6541 Dep=-1, 6542 Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 6543 }; 6544 static const PromotedType ConversionsTable[LastPromotedArithmeticType] 6545 [LastPromotedArithmeticType] = { 6546/* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt, Flt, Flt }, 6547/* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 6548/*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 6549/* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 }, 6550/* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, S128, Dep, UL, ULL, U128 }, 6551/* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, S128, Dep, Dep, ULL, U128 }, 6552/*S128*/ { Flt, Dbl, LDbl, S128, S128, S128, S128, S128, S128, S128, U128 }, 6553/* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, S128, UI, UL, ULL, U128 }, 6554/* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, S128, UL, UL, ULL, U128 }, 6555/* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, S128, ULL, ULL, ULL, U128 }, 6556/*U128*/ { Flt, Dbl, LDbl, U128, U128, U128, U128, U128, U128, U128, U128 }, 6557 }; 6558 6559 assert(L < LastPromotedArithmeticType); 6560 assert(R < LastPromotedArithmeticType); 6561 int Idx = ConversionsTable[L][R]; 6562 6563 // Fast path: the table gives us a concrete answer. 6564 if (Idx != Dep) return getArithmeticType(Idx); 6565 6566 // Slow path: we need to compare widths. 6567 // An invariant is that the signed type has higher rank. 6568 CanQualType LT = getArithmeticType(L), 6569 RT = getArithmeticType(R); 6570 unsigned LW = S.Context.getIntWidth(LT), 6571 RW = S.Context.getIntWidth(RT); 6572 6573 // If they're different widths, use the signed type. 6574 if (LW > RW) return LT; 6575 else if (LW < RW) return RT; 6576 6577 // Otherwise, use the unsigned type of the signed type's rank. 6578 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 6579 assert(L == SLL || R == SLL); 6580 return S.Context.UnsignedLongLongTy; 6581 } 6582 6583 /// \brief Helper method to factor out the common pattern of adding overloads 6584 /// for '++' and '--' builtin operators. 6585 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 6586 bool HasVolatile, 6587 bool HasRestrict) { 6588 QualType ParamTypes[2] = { 6589 S.Context.getLValueReferenceType(CandidateTy), 6590 S.Context.IntTy 6591 }; 6592 6593 // Non-volatile version. 6594 if (NumArgs == 1) 6595 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 6596 else 6597 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 6598 6599 // Use a heuristic to reduce number of builtin candidates in the set: 6600 // add volatile version only if there are conversions to a volatile type. 6601 if (HasVolatile) { 6602 ParamTypes[0] = 6603 S.Context.getLValueReferenceType( 6604 S.Context.getVolatileType(CandidateTy)); 6605 if (NumArgs == 1) 6606 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 6607 else 6608 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 6609 } 6610 6611 // Add restrict version only if there are conversions to a restrict type 6612 // and our candidate type is a non-restrict-qualified pointer. 6613 if (HasRestrict && CandidateTy->isAnyPointerType() && 6614 !CandidateTy.isRestrictQualified()) { 6615 ParamTypes[0] 6616 = S.Context.getLValueReferenceType( 6617 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict)); 6618 if (NumArgs == 1) 6619 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 6620 else 6621 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 6622 6623 if (HasVolatile) { 6624 ParamTypes[0] 6625 = S.Context.getLValueReferenceType( 6626 S.Context.getCVRQualifiedType(CandidateTy, 6627 (Qualifiers::Volatile | 6628 Qualifiers::Restrict))); 6629 if (NumArgs == 1) 6630 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, 6631 CandidateSet); 6632 else 6633 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 6634 } 6635 } 6636 6637 } 6638 6639public: 6640 BuiltinOperatorOverloadBuilder( 6641 Sema &S, Expr **Args, unsigned NumArgs, 6642 Qualifiers VisibleTypeConversionsQuals, 6643 bool HasArithmeticOrEnumeralCandidateType, 6644 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 6645 OverloadCandidateSet &CandidateSet) 6646 : S(S), Args(Args), NumArgs(NumArgs), 6647 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 6648 HasArithmeticOrEnumeralCandidateType( 6649 HasArithmeticOrEnumeralCandidateType), 6650 CandidateTypes(CandidateTypes), 6651 CandidateSet(CandidateSet) { 6652 // Validate some of our static helper constants in debug builds. 6653 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 6654 "Invalid first promoted integral type"); 6655 assert(getArithmeticType(LastPromotedIntegralType - 1) 6656 == S.Context.UnsignedInt128Ty && 6657 "Invalid last promoted integral type"); 6658 assert(getArithmeticType(FirstPromotedArithmeticType) 6659 == S.Context.FloatTy && 6660 "Invalid first promoted arithmetic type"); 6661 assert(getArithmeticType(LastPromotedArithmeticType - 1) 6662 == S.Context.UnsignedInt128Ty && 6663 "Invalid last promoted arithmetic type"); 6664 } 6665 6666 // C++ [over.built]p3: 6667 // 6668 // For every pair (T, VQ), where T is an arithmetic type, and VQ 6669 // is either volatile or empty, there exist candidate operator 6670 // functions of the form 6671 // 6672 // VQ T& operator++(VQ T&); 6673 // T operator++(VQ T&, int); 6674 // 6675 // C++ [over.built]p4: 6676 // 6677 // For every pair (T, VQ), where T is an arithmetic type other 6678 // than bool, and VQ is either volatile or empty, there exist 6679 // candidate operator functions of the form 6680 // 6681 // VQ T& operator--(VQ T&); 6682 // T operator--(VQ T&, int); 6683 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 6684 if (!HasArithmeticOrEnumeralCandidateType) 6685 return; 6686 6687 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 6688 Arith < NumArithmeticTypes; ++Arith) { 6689 addPlusPlusMinusMinusStyleOverloads( 6690 getArithmeticType(Arith), 6691 VisibleTypeConversionsQuals.hasVolatile(), 6692 VisibleTypeConversionsQuals.hasRestrict()); 6693 } 6694 } 6695 6696 // C++ [over.built]p5: 6697 // 6698 // For every pair (T, VQ), where T is a cv-qualified or 6699 // cv-unqualified object type, and VQ is either volatile or 6700 // empty, there exist candidate operator functions of the form 6701 // 6702 // T*VQ& operator++(T*VQ&); 6703 // T*VQ& operator--(T*VQ&); 6704 // T* operator++(T*VQ&, int); 6705 // T* operator--(T*VQ&, int); 6706 void addPlusPlusMinusMinusPointerOverloads() { 6707 for (BuiltinCandidateTypeSet::iterator 6708 Ptr = CandidateTypes[0].pointer_begin(), 6709 PtrEnd = CandidateTypes[0].pointer_end(); 6710 Ptr != PtrEnd; ++Ptr) { 6711 // Skip pointer types that aren't pointers to object types. 6712 if (!(*Ptr)->getPointeeType()->isObjectType()) 6713 continue; 6714 6715 addPlusPlusMinusMinusStyleOverloads(*Ptr, 6716 (!(*Ptr).isVolatileQualified() && 6717 VisibleTypeConversionsQuals.hasVolatile()), 6718 (!(*Ptr).isRestrictQualified() && 6719 VisibleTypeConversionsQuals.hasRestrict())); 6720 } 6721 } 6722 6723 // C++ [over.built]p6: 6724 // For every cv-qualified or cv-unqualified object type T, there 6725 // exist candidate operator functions of the form 6726 // 6727 // T& operator*(T*); 6728 // 6729 // C++ [over.built]p7: 6730 // For every function type T that does not have cv-qualifiers or a 6731 // ref-qualifier, there exist candidate operator functions of the form 6732 // T& operator*(T*); 6733 void addUnaryStarPointerOverloads() { 6734 for (BuiltinCandidateTypeSet::iterator 6735 Ptr = CandidateTypes[0].pointer_begin(), 6736 PtrEnd = CandidateTypes[0].pointer_end(); 6737 Ptr != PtrEnd; ++Ptr) { 6738 QualType ParamTy = *Ptr; 6739 QualType PointeeTy = ParamTy->getPointeeType(); 6740 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 6741 continue; 6742 6743 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 6744 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 6745 continue; 6746 6747 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 6748 &ParamTy, Args, 1, CandidateSet); 6749 } 6750 } 6751 6752 // C++ [over.built]p9: 6753 // For every promoted arithmetic type T, there exist candidate 6754 // operator functions of the form 6755 // 6756 // T operator+(T); 6757 // T operator-(T); 6758 void addUnaryPlusOrMinusArithmeticOverloads() { 6759 if (!HasArithmeticOrEnumeralCandidateType) 6760 return; 6761 6762 for (unsigned Arith = FirstPromotedArithmeticType; 6763 Arith < LastPromotedArithmeticType; ++Arith) { 6764 QualType ArithTy = getArithmeticType(Arith); 6765 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 6766 } 6767 6768 // Extension: We also add these operators for vector types. 6769 for (BuiltinCandidateTypeSet::iterator 6770 Vec = CandidateTypes[0].vector_begin(), 6771 VecEnd = CandidateTypes[0].vector_end(); 6772 Vec != VecEnd; ++Vec) { 6773 QualType VecTy = *Vec; 6774 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 6775 } 6776 } 6777 6778 // C++ [over.built]p8: 6779 // For every type T, there exist candidate operator functions of 6780 // the form 6781 // 6782 // T* operator+(T*); 6783 void addUnaryPlusPointerOverloads() { 6784 for (BuiltinCandidateTypeSet::iterator 6785 Ptr = CandidateTypes[0].pointer_begin(), 6786 PtrEnd = CandidateTypes[0].pointer_end(); 6787 Ptr != PtrEnd; ++Ptr) { 6788 QualType ParamTy = *Ptr; 6789 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 6790 } 6791 } 6792 6793 // C++ [over.built]p10: 6794 // For every promoted integral type T, there exist candidate 6795 // operator functions of the form 6796 // 6797 // T operator~(T); 6798 void addUnaryTildePromotedIntegralOverloads() { 6799 if (!HasArithmeticOrEnumeralCandidateType) 6800 return; 6801 6802 for (unsigned Int = FirstPromotedIntegralType; 6803 Int < LastPromotedIntegralType; ++Int) { 6804 QualType IntTy = getArithmeticType(Int); 6805 S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 6806 } 6807 6808 // Extension: We also add this operator for vector types. 6809 for (BuiltinCandidateTypeSet::iterator 6810 Vec = CandidateTypes[0].vector_begin(), 6811 VecEnd = CandidateTypes[0].vector_end(); 6812 Vec != VecEnd; ++Vec) { 6813 QualType VecTy = *Vec; 6814 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 6815 } 6816 } 6817 6818 // C++ [over.match.oper]p16: 6819 // For every pointer to member type T, there exist candidate operator 6820 // functions of the form 6821 // 6822 // bool operator==(T,T); 6823 // bool operator!=(T,T); 6824 void addEqualEqualOrNotEqualMemberPointerOverloads() { 6825 /// Set of (canonical) types that we've already handled. 6826 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6827 6828 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6829 for (BuiltinCandidateTypeSet::iterator 6830 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 6831 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 6832 MemPtr != MemPtrEnd; 6833 ++MemPtr) { 6834 // Don't add the same builtin candidate twice. 6835 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 6836 continue; 6837 6838 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 6839 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6840 CandidateSet); 6841 } 6842 } 6843 } 6844 6845 // C++ [over.built]p15: 6846 // 6847 // For every T, where T is an enumeration type, a pointer type, or 6848 // std::nullptr_t, there exist candidate operator functions of the form 6849 // 6850 // bool operator<(T, T); 6851 // bool operator>(T, T); 6852 // bool operator<=(T, T); 6853 // bool operator>=(T, T); 6854 // bool operator==(T, T); 6855 // bool operator!=(T, T); 6856 void addRelationalPointerOrEnumeralOverloads() { 6857 // C++ [over.match.oper]p3: 6858 // [...]the built-in candidates include all of the candidate operator 6859 // functions defined in 13.6 that, compared to the given operator, [...] 6860 // do not have the same parameter-type-list as any non-template non-member 6861 // candidate. 6862 // 6863 // Note that in practice, this only affects enumeration types because there 6864 // aren't any built-in candidates of record type, and a user-defined operator 6865 // must have an operand of record or enumeration type. Also, the only other 6866 // overloaded operator with enumeration arguments, operator=, 6867 // cannot be overloaded for enumeration types, so this is the only place 6868 // where we must suppress candidates like this. 6869 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 6870 UserDefinedBinaryOperators; 6871 6872 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6873 if (CandidateTypes[ArgIdx].enumeration_begin() != 6874 CandidateTypes[ArgIdx].enumeration_end()) { 6875 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 6876 CEnd = CandidateSet.end(); 6877 C != CEnd; ++C) { 6878 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 6879 continue; 6880 6881 if (C->Function->isFunctionTemplateSpecialization()) 6882 continue; 6883 6884 QualType FirstParamType = 6885 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 6886 QualType SecondParamType = 6887 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 6888 6889 // Skip if either parameter isn't of enumeral type. 6890 if (!FirstParamType->isEnumeralType() || 6891 !SecondParamType->isEnumeralType()) 6892 continue; 6893 6894 // Add this operator to the set of known user-defined operators. 6895 UserDefinedBinaryOperators.insert( 6896 std::make_pair(S.Context.getCanonicalType(FirstParamType), 6897 S.Context.getCanonicalType(SecondParamType))); 6898 } 6899 } 6900 } 6901 6902 /// Set of (canonical) types that we've already handled. 6903 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6904 6905 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6906 for (BuiltinCandidateTypeSet::iterator 6907 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 6908 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 6909 Ptr != PtrEnd; ++Ptr) { 6910 // Don't add the same builtin candidate twice. 6911 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6912 continue; 6913 6914 QualType ParamTypes[2] = { *Ptr, *Ptr }; 6915 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6916 CandidateSet); 6917 } 6918 for (BuiltinCandidateTypeSet::iterator 6919 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 6920 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 6921 Enum != EnumEnd; ++Enum) { 6922 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 6923 6924 // Don't add the same builtin candidate twice, or if a user defined 6925 // candidate exists. 6926 if (!AddedTypes.insert(CanonType) || 6927 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 6928 CanonType))) 6929 continue; 6930 6931 QualType ParamTypes[2] = { *Enum, *Enum }; 6932 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6933 CandidateSet); 6934 } 6935 6936 if (CandidateTypes[ArgIdx].hasNullPtrType()) { 6937 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy); 6938 if (AddedTypes.insert(NullPtrTy) && 6939 !UserDefinedBinaryOperators.count(std::make_pair(NullPtrTy, 6940 NullPtrTy))) { 6941 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy }; 6942 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6943 CandidateSet); 6944 } 6945 } 6946 } 6947 } 6948 6949 // C++ [over.built]p13: 6950 // 6951 // For every cv-qualified or cv-unqualified object type T 6952 // there exist candidate operator functions of the form 6953 // 6954 // T* operator+(T*, ptrdiff_t); 6955 // T& operator[](T*, ptrdiff_t); [BELOW] 6956 // T* operator-(T*, ptrdiff_t); 6957 // T* operator+(ptrdiff_t, T*); 6958 // T& operator[](ptrdiff_t, T*); [BELOW] 6959 // 6960 // C++ [over.built]p14: 6961 // 6962 // For every T, where T is a pointer to object type, there 6963 // exist candidate operator functions of the form 6964 // 6965 // ptrdiff_t operator-(T, T); 6966 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 6967 /// Set of (canonical) types that we've already handled. 6968 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6969 6970 for (int Arg = 0; Arg < 2; ++Arg) { 6971 QualType AsymetricParamTypes[2] = { 6972 S.Context.getPointerDiffType(), 6973 S.Context.getPointerDiffType(), 6974 }; 6975 for (BuiltinCandidateTypeSet::iterator 6976 Ptr = CandidateTypes[Arg].pointer_begin(), 6977 PtrEnd = CandidateTypes[Arg].pointer_end(); 6978 Ptr != PtrEnd; ++Ptr) { 6979 QualType PointeeTy = (*Ptr)->getPointeeType(); 6980 if (!PointeeTy->isObjectType()) 6981 continue; 6982 6983 AsymetricParamTypes[Arg] = *Ptr; 6984 if (Arg == 0 || Op == OO_Plus) { 6985 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 6986 // T* operator+(ptrdiff_t, T*); 6987 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, 6988 CandidateSet); 6989 } 6990 if (Op == OO_Minus) { 6991 // ptrdiff_t operator-(T, T); 6992 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6993 continue; 6994 6995 QualType ParamTypes[2] = { *Ptr, *Ptr }; 6996 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 6997 Args, 2, CandidateSet); 6998 } 6999 } 7000 } 7001 } 7002 7003 // C++ [over.built]p12: 7004 // 7005 // For every pair of promoted arithmetic types L and R, there 7006 // exist candidate operator functions of the form 7007 // 7008 // LR operator*(L, R); 7009 // LR operator/(L, R); 7010 // LR operator+(L, R); 7011 // LR operator-(L, R); 7012 // bool operator<(L, R); 7013 // bool operator>(L, R); 7014 // bool operator<=(L, R); 7015 // bool operator>=(L, R); 7016 // bool operator==(L, R); 7017 // bool operator!=(L, R); 7018 // 7019 // where LR is the result of the usual arithmetic conversions 7020 // between types L and R. 7021 // 7022 // C++ [over.built]p24: 7023 // 7024 // For every pair of promoted arithmetic types L and R, there exist 7025 // candidate operator functions of the form 7026 // 7027 // LR operator?(bool, L, R); 7028 // 7029 // where LR is the result of the usual arithmetic conversions 7030 // between types L and R. 7031 // Our candidates ignore the first parameter. 7032 void addGenericBinaryArithmeticOverloads(bool isComparison) { 7033 if (!HasArithmeticOrEnumeralCandidateType) 7034 return; 7035 7036 for (unsigned Left = FirstPromotedArithmeticType; 7037 Left < LastPromotedArithmeticType; ++Left) { 7038 for (unsigned Right = FirstPromotedArithmeticType; 7039 Right < LastPromotedArithmeticType; ++Right) { 7040 QualType LandR[2] = { getArithmeticType(Left), 7041 getArithmeticType(Right) }; 7042 QualType Result = 7043 isComparison ? S.Context.BoolTy 7044 : getUsualArithmeticConversions(Left, Right); 7045 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 7046 } 7047 } 7048 7049 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 7050 // conditional operator for vector types. 7051 for (BuiltinCandidateTypeSet::iterator 7052 Vec1 = CandidateTypes[0].vector_begin(), 7053 Vec1End = CandidateTypes[0].vector_end(); 7054 Vec1 != Vec1End; ++Vec1) { 7055 for (BuiltinCandidateTypeSet::iterator 7056 Vec2 = CandidateTypes[1].vector_begin(), 7057 Vec2End = CandidateTypes[1].vector_end(); 7058 Vec2 != Vec2End; ++Vec2) { 7059 QualType LandR[2] = { *Vec1, *Vec2 }; 7060 QualType Result = S.Context.BoolTy; 7061 if (!isComparison) { 7062 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 7063 Result = *Vec1; 7064 else 7065 Result = *Vec2; 7066 } 7067 7068 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 7069 } 7070 } 7071 } 7072 7073 // C++ [over.built]p17: 7074 // 7075 // For every pair of promoted integral types L and R, there 7076 // exist candidate operator functions of the form 7077 // 7078 // LR operator%(L, R); 7079 // LR operator&(L, R); 7080 // LR operator^(L, R); 7081 // LR operator|(L, R); 7082 // L operator<<(L, R); 7083 // L operator>>(L, R); 7084 // 7085 // where LR is the result of the usual arithmetic conversions 7086 // between types L and R. 7087 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 7088 if (!HasArithmeticOrEnumeralCandidateType) 7089 return; 7090 7091 for (unsigned Left = FirstPromotedIntegralType; 7092 Left < LastPromotedIntegralType; ++Left) { 7093 for (unsigned Right = FirstPromotedIntegralType; 7094 Right < LastPromotedIntegralType; ++Right) { 7095 QualType LandR[2] = { getArithmeticType(Left), 7096 getArithmeticType(Right) }; 7097 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 7098 ? LandR[0] 7099 : getUsualArithmeticConversions(Left, Right); 7100 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 7101 } 7102 } 7103 } 7104 7105 // C++ [over.built]p20: 7106 // 7107 // For every pair (T, VQ), where T is an enumeration or 7108 // pointer to member type and VQ is either volatile or 7109 // empty, there exist candidate operator functions of the form 7110 // 7111 // VQ T& operator=(VQ T&, T); 7112 void addAssignmentMemberPointerOrEnumeralOverloads() { 7113 /// Set of (canonical) types that we've already handled. 7114 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7115 7116 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 7117 for (BuiltinCandidateTypeSet::iterator 7118 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 7119 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 7120 Enum != EnumEnd; ++Enum) { 7121 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 7122 continue; 7123 7124 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, 7125 CandidateSet); 7126 } 7127 7128 for (BuiltinCandidateTypeSet::iterator 7129 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 7130 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 7131 MemPtr != MemPtrEnd; ++MemPtr) { 7132 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 7133 continue; 7134 7135 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, 7136 CandidateSet); 7137 } 7138 } 7139 } 7140 7141 // C++ [over.built]p19: 7142 // 7143 // For every pair (T, VQ), where T is any type and VQ is either 7144 // volatile or empty, there exist candidate operator functions 7145 // of the form 7146 // 7147 // T*VQ& operator=(T*VQ&, T*); 7148 // 7149 // C++ [over.built]p21: 7150 // 7151 // For every pair (T, VQ), where T is a cv-qualified or 7152 // cv-unqualified object type and VQ is either volatile or 7153 // empty, there exist candidate operator functions of the form 7154 // 7155 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 7156 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 7157 void addAssignmentPointerOverloads(bool isEqualOp) { 7158 /// Set of (canonical) types that we've already handled. 7159 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7160 7161 for (BuiltinCandidateTypeSet::iterator 7162 Ptr = CandidateTypes[0].pointer_begin(), 7163 PtrEnd = CandidateTypes[0].pointer_end(); 7164 Ptr != PtrEnd; ++Ptr) { 7165 // If this is operator=, keep track of the builtin candidates we added. 7166 if (isEqualOp) 7167 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 7168 else if (!(*Ptr)->getPointeeType()->isObjectType()) 7169 continue; 7170 7171 // non-volatile version 7172 QualType ParamTypes[2] = { 7173 S.Context.getLValueReferenceType(*Ptr), 7174 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 7175 }; 7176 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7177 /*IsAssigmentOperator=*/ isEqualOp); 7178 7179 bool NeedVolatile = !(*Ptr).isVolatileQualified() && 7180 VisibleTypeConversionsQuals.hasVolatile(); 7181 if (NeedVolatile) { 7182 // volatile version 7183 ParamTypes[0] = 7184 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 7185 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7186 /*IsAssigmentOperator=*/isEqualOp); 7187 } 7188 7189 if (!(*Ptr).isRestrictQualified() && 7190 VisibleTypeConversionsQuals.hasRestrict()) { 7191 // restrict version 7192 ParamTypes[0] 7193 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr)); 7194 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7195 /*IsAssigmentOperator=*/isEqualOp); 7196 7197 if (NeedVolatile) { 7198 // volatile restrict version 7199 ParamTypes[0] 7200 = S.Context.getLValueReferenceType( 7201 S.Context.getCVRQualifiedType(*Ptr, 7202 (Qualifiers::Volatile | 7203 Qualifiers::Restrict))); 7204 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7205 CandidateSet, 7206 /*IsAssigmentOperator=*/isEqualOp); 7207 } 7208 } 7209 } 7210 7211 if (isEqualOp) { 7212 for (BuiltinCandidateTypeSet::iterator 7213 Ptr = CandidateTypes[1].pointer_begin(), 7214 PtrEnd = CandidateTypes[1].pointer_end(); 7215 Ptr != PtrEnd; ++Ptr) { 7216 // Make sure we don't add the same candidate twice. 7217 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7218 continue; 7219 7220 QualType ParamTypes[2] = { 7221 S.Context.getLValueReferenceType(*Ptr), 7222 *Ptr, 7223 }; 7224 7225 // non-volatile version 7226 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7227 /*IsAssigmentOperator=*/true); 7228 7229 bool NeedVolatile = !(*Ptr).isVolatileQualified() && 7230 VisibleTypeConversionsQuals.hasVolatile(); 7231 if (NeedVolatile) { 7232 // volatile version 7233 ParamTypes[0] = 7234 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 7235 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7236 CandidateSet, /*IsAssigmentOperator=*/true); 7237 } 7238 7239 if (!(*Ptr).isRestrictQualified() && 7240 VisibleTypeConversionsQuals.hasRestrict()) { 7241 // restrict version 7242 ParamTypes[0] 7243 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr)); 7244 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7245 CandidateSet, /*IsAssigmentOperator=*/true); 7246 7247 if (NeedVolatile) { 7248 // volatile restrict version 7249 ParamTypes[0] 7250 = S.Context.getLValueReferenceType( 7251 S.Context.getCVRQualifiedType(*Ptr, 7252 (Qualifiers::Volatile | 7253 Qualifiers::Restrict))); 7254 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7255 CandidateSet, /*IsAssigmentOperator=*/true); 7256 7257 } 7258 } 7259 } 7260 } 7261 } 7262 7263 // C++ [over.built]p18: 7264 // 7265 // For every triple (L, VQ, R), where L is an arithmetic type, 7266 // VQ is either volatile or empty, and R is a promoted 7267 // arithmetic type, there exist candidate operator functions of 7268 // the form 7269 // 7270 // VQ L& operator=(VQ L&, R); 7271 // VQ L& operator*=(VQ L&, R); 7272 // VQ L& operator/=(VQ L&, R); 7273 // VQ L& operator+=(VQ L&, R); 7274 // VQ L& operator-=(VQ L&, R); 7275 void addAssignmentArithmeticOverloads(bool isEqualOp) { 7276 if (!HasArithmeticOrEnumeralCandidateType) 7277 return; 7278 7279 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 7280 for (unsigned Right = FirstPromotedArithmeticType; 7281 Right < LastPromotedArithmeticType; ++Right) { 7282 QualType ParamTypes[2]; 7283 ParamTypes[1] = getArithmeticType(Right); 7284 7285 // Add this built-in operator as a candidate (VQ is empty). 7286 ParamTypes[0] = 7287 S.Context.getLValueReferenceType(getArithmeticType(Left)); 7288 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7289 /*IsAssigmentOperator=*/isEqualOp); 7290 7291 // Add this built-in operator as a candidate (VQ is 'volatile'). 7292 if (VisibleTypeConversionsQuals.hasVolatile()) { 7293 ParamTypes[0] = 7294 S.Context.getVolatileType(getArithmeticType(Left)); 7295 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7296 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7297 CandidateSet, 7298 /*IsAssigmentOperator=*/isEqualOp); 7299 } 7300 } 7301 } 7302 7303 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 7304 for (BuiltinCandidateTypeSet::iterator 7305 Vec1 = CandidateTypes[0].vector_begin(), 7306 Vec1End = CandidateTypes[0].vector_end(); 7307 Vec1 != Vec1End; ++Vec1) { 7308 for (BuiltinCandidateTypeSet::iterator 7309 Vec2 = CandidateTypes[1].vector_begin(), 7310 Vec2End = CandidateTypes[1].vector_end(); 7311 Vec2 != Vec2End; ++Vec2) { 7312 QualType ParamTypes[2]; 7313 ParamTypes[1] = *Vec2; 7314 // Add this built-in operator as a candidate (VQ is empty). 7315 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 7316 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7317 /*IsAssigmentOperator=*/isEqualOp); 7318 7319 // Add this built-in operator as a candidate (VQ is 'volatile'). 7320 if (VisibleTypeConversionsQuals.hasVolatile()) { 7321 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 7322 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7323 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7324 CandidateSet, 7325 /*IsAssigmentOperator=*/isEqualOp); 7326 } 7327 } 7328 } 7329 } 7330 7331 // C++ [over.built]p22: 7332 // 7333 // For every triple (L, VQ, R), where L is an integral type, VQ 7334 // is either volatile or empty, and R is a promoted integral 7335 // type, there exist candidate operator functions of the form 7336 // 7337 // VQ L& operator%=(VQ L&, R); 7338 // VQ L& operator<<=(VQ L&, R); 7339 // VQ L& operator>>=(VQ L&, R); 7340 // VQ L& operator&=(VQ L&, R); 7341 // VQ L& operator^=(VQ L&, R); 7342 // VQ L& operator|=(VQ L&, R); 7343 void addAssignmentIntegralOverloads() { 7344 if (!HasArithmeticOrEnumeralCandidateType) 7345 return; 7346 7347 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 7348 for (unsigned Right = FirstPromotedIntegralType; 7349 Right < LastPromotedIntegralType; ++Right) { 7350 QualType ParamTypes[2]; 7351 ParamTypes[1] = getArithmeticType(Right); 7352 7353 // Add this built-in operator as a candidate (VQ is empty). 7354 ParamTypes[0] = 7355 S.Context.getLValueReferenceType(getArithmeticType(Left)); 7356 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 7357 if (VisibleTypeConversionsQuals.hasVolatile()) { 7358 // Add this built-in operator as a candidate (VQ is 'volatile'). 7359 ParamTypes[0] = getArithmeticType(Left); 7360 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 7361 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7362 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7363 CandidateSet); 7364 } 7365 } 7366 } 7367 } 7368 7369 // C++ [over.operator]p23: 7370 // 7371 // There also exist candidate operator functions of the form 7372 // 7373 // bool operator!(bool); 7374 // bool operator&&(bool, bool); 7375 // bool operator||(bool, bool); 7376 void addExclaimOverload() { 7377 QualType ParamTy = S.Context.BoolTy; 7378 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 7379 /*IsAssignmentOperator=*/false, 7380 /*NumContextualBoolArguments=*/1); 7381 } 7382 void addAmpAmpOrPipePipeOverload() { 7383 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 7384 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 7385 /*IsAssignmentOperator=*/false, 7386 /*NumContextualBoolArguments=*/2); 7387 } 7388 7389 // C++ [over.built]p13: 7390 // 7391 // For every cv-qualified or cv-unqualified object type T there 7392 // exist candidate operator functions of the form 7393 // 7394 // T* operator+(T*, ptrdiff_t); [ABOVE] 7395 // T& operator[](T*, ptrdiff_t); 7396 // T* operator-(T*, ptrdiff_t); [ABOVE] 7397 // T* operator+(ptrdiff_t, T*); [ABOVE] 7398 // T& operator[](ptrdiff_t, T*); 7399 void addSubscriptOverloads() { 7400 for (BuiltinCandidateTypeSet::iterator 7401 Ptr = CandidateTypes[0].pointer_begin(), 7402 PtrEnd = CandidateTypes[0].pointer_end(); 7403 Ptr != PtrEnd; ++Ptr) { 7404 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 7405 QualType PointeeType = (*Ptr)->getPointeeType(); 7406 if (!PointeeType->isObjectType()) 7407 continue; 7408 7409 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 7410 7411 // T& operator[](T*, ptrdiff_t) 7412 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 7413 } 7414 7415 for (BuiltinCandidateTypeSet::iterator 7416 Ptr = CandidateTypes[1].pointer_begin(), 7417 PtrEnd = CandidateTypes[1].pointer_end(); 7418 Ptr != PtrEnd; ++Ptr) { 7419 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 7420 QualType PointeeType = (*Ptr)->getPointeeType(); 7421 if (!PointeeType->isObjectType()) 7422 continue; 7423 7424 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 7425 7426 // T& operator[](ptrdiff_t, T*) 7427 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 7428 } 7429 } 7430 7431 // C++ [over.built]p11: 7432 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 7433 // C1 is the same type as C2 or is a derived class of C2, T is an object 7434 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 7435 // there exist candidate operator functions of the form 7436 // 7437 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 7438 // 7439 // where CV12 is the union of CV1 and CV2. 7440 void addArrowStarOverloads() { 7441 for (BuiltinCandidateTypeSet::iterator 7442 Ptr = CandidateTypes[0].pointer_begin(), 7443 PtrEnd = CandidateTypes[0].pointer_end(); 7444 Ptr != PtrEnd; ++Ptr) { 7445 QualType C1Ty = (*Ptr); 7446 QualType C1; 7447 QualifierCollector Q1; 7448 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 7449 if (!isa<RecordType>(C1)) 7450 continue; 7451 // heuristic to reduce number of builtin candidates in the set. 7452 // Add volatile/restrict version only if there are conversions to a 7453 // volatile/restrict type. 7454 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 7455 continue; 7456 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 7457 continue; 7458 for (BuiltinCandidateTypeSet::iterator 7459 MemPtr = CandidateTypes[1].member_pointer_begin(), 7460 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 7461 MemPtr != MemPtrEnd; ++MemPtr) { 7462 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 7463 QualType C2 = QualType(mptr->getClass(), 0); 7464 C2 = C2.getUnqualifiedType(); 7465 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 7466 break; 7467 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 7468 // build CV12 T& 7469 QualType T = mptr->getPointeeType(); 7470 if (!VisibleTypeConversionsQuals.hasVolatile() && 7471 T.isVolatileQualified()) 7472 continue; 7473 if (!VisibleTypeConversionsQuals.hasRestrict() && 7474 T.isRestrictQualified()) 7475 continue; 7476 T = Q1.apply(S.Context, T); 7477 QualType ResultTy = S.Context.getLValueReferenceType(T); 7478 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 7479 } 7480 } 7481 } 7482 7483 // Note that we don't consider the first argument, since it has been 7484 // contextually converted to bool long ago. The candidates below are 7485 // therefore added as binary. 7486 // 7487 // C++ [over.built]p25: 7488 // For every type T, where T is a pointer, pointer-to-member, or scoped 7489 // enumeration type, there exist candidate operator functions of the form 7490 // 7491 // T operator?(bool, T, T); 7492 // 7493 void addConditionalOperatorOverloads() { 7494 /// Set of (canonical) types that we've already handled. 7495 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7496 7497 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 7498 for (BuiltinCandidateTypeSet::iterator 7499 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 7500 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 7501 Ptr != PtrEnd; ++Ptr) { 7502 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7503 continue; 7504 7505 QualType ParamTypes[2] = { *Ptr, *Ptr }; 7506 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 7507 } 7508 7509 for (BuiltinCandidateTypeSet::iterator 7510 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 7511 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 7512 MemPtr != MemPtrEnd; ++MemPtr) { 7513 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 7514 continue; 7515 7516 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 7517 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); 7518 } 7519 7520 if (S.getLangOpts().CPlusPlus11) { 7521 for (BuiltinCandidateTypeSet::iterator 7522 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 7523 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 7524 Enum != EnumEnd; ++Enum) { 7525 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 7526 continue; 7527 7528 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 7529 continue; 7530 7531 QualType ParamTypes[2] = { *Enum, *Enum }; 7532 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); 7533 } 7534 } 7535 } 7536 } 7537}; 7538 7539} // end anonymous namespace 7540 7541/// AddBuiltinOperatorCandidates - Add the appropriate built-in 7542/// operator overloads to the candidate set (C++ [over.built]), based 7543/// on the operator @p Op and the arguments given. For example, if the 7544/// operator is a binary '+', this routine might add "int 7545/// operator+(int, int)" to cover integer addition. 7546void 7547Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 7548 SourceLocation OpLoc, 7549 Expr **Args, unsigned NumArgs, 7550 OverloadCandidateSet& CandidateSet) { 7551 // Find all of the types that the arguments can convert to, but only 7552 // if the operator we're looking at has built-in operator candidates 7553 // that make use of these types. Also record whether we encounter non-record 7554 // candidate types or either arithmetic or enumeral candidate types. 7555 Qualifiers VisibleTypeConversionsQuals; 7556 VisibleTypeConversionsQuals.addConst(); 7557 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7558 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 7559 7560 bool HasNonRecordCandidateType = false; 7561 bool HasArithmeticOrEnumeralCandidateType = false; 7562 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 7563 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 7564 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 7565 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 7566 OpLoc, 7567 true, 7568 (Op == OO_Exclaim || 7569 Op == OO_AmpAmp || 7570 Op == OO_PipePipe), 7571 VisibleTypeConversionsQuals); 7572 HasNonRecordCandidateType = HasNonRecordCandidateType || 7573 CandidateTypes[ArgIdx].hasNonRecordTypes(); 7574 HasArithmeticOrEnumeralCandidateType = 7575 HasArithmeticOrEnumeralCandidateType || 7576 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 7577 } 7578 7579 // Exit early when no non-record types have been added to the candidate set 7580 // for any of the arguments to the operator. 7581 // 7582 // We can't exit early for !, ||, or &&, since there we have always have 7583 // 'bool' overloads. 7584 if (!HasNonRecordCandidateType && 7585 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe)) 7586 return; 7587 7588 // Setup an object to manage the common state for building overloads. 7589 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, 7590 VisibleTypeConversionsQuals, 7591 HasArithmeticOrEnumeralCandidateType, 7592 CandidateTypes, CandidateSet); 7593 7594 // Dispatch over the operation to add in only those overloads which apply. 7595 switch (Op) { 7596 case OO_None: 7597 case NUM_OVERLOADED_OPERATORS: 7598 llvm_unreachable("Expected an overloaded operator"); 7599 7600 case OO_New: 7601 case OO_Delete: 7602 case OO_Array_New: 7603 case OO_Array_Delete: 7604 case OO_Call: 7605 llvm_unreachable( 7606 "Special operators don't use AddBuiltinOperatorCandidates"); 7607 7608 case OO_Comma: 7609 case OO_Arrow: 7610 // C++ [over.match.oper]p3: 7611 // -- For the operator ',', the unary operator '&', or the 7612 // operator '->', the built-in candidates set is empty. 7613 break; 7614 7615 case OO_Plus: // '+' is either unary or binary 7616 if (NumArgs == 1) 7617 OpBuilder.addUnaryPlusPointerOverloads(); 7618 // Fall through. 7619 7620 case OO_Minus: // '-' is either unary or binary 7621 if (NumArgs == 1) { 7622 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 7623 } else { 7624 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 7625 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7626 } 7627 break; 7628 7629 case OO_Star: // '*' is either unary or binary 7630 if (NumArgs == 1) 7631 OpBuilder.addUnaryStarPointerOverloads(); 7632 else 7633 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7634 break; 7635 7636 case OO_Slash: 7637 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7638 break; 7639 7640 case OO_PlusPlus: 7641 case OO_MinusMinus: 7642 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 7643 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 7644 break; 7645 7646 case OO_EqualEqual: 7647 case OO_ExclaimEqual: 7648 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 7649 // Fall through. 7650 7651 case OO_Less: 7652 case OO_Greater: 7653 case OO_LessEqual: 7654 case OO_GreaterEqual: 7655 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 7656 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 7657 break; 7658 7659 case OO_Percent: 7660 case OO_Caret: 7661 case OO_Pipe: 7662 case OO_LessLess: 7663 case OO_GreaterGreater: 7664 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 7665 break; 7666 7667 case OO_Amp: // '&' is either unary or binary 7668 if (NumArgs == 1) 7669 // C++ [over.match.oper]p3: 7670 // -- For the operator ',', the unary operator '&', or the 7671 // operator '->', the built-in candidates set is empty. 7672 break; 7673 7674 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 7675 break; 7676 7677 case OO_Tilde: 7678 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 7679 break; 7680 7681 case OO_Equal: 7682 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 7683 // Fall through. 7684 7685 case OO_PlusEqual: 7686 case OO_MinusEqual: 7687 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 7688 // Fall through. 7689 7690 case OO_StarEqual: 7691 case OO_SlashEqual: 7692 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 7693 break; 7694 7695 case OO_PercentEqual: 7696 case OO_LessLessEqual: 7697 case OO_GreaterGreaterEqual: 7698 case OO_AmpEqual: 7699 case OO_CaretEqual: 7700 case OO_PipeEqual: 7701 OpBuilder.addAssignmentIntegralOverloads(); 7702 break; 7703 7704 case OO_Exclaim: 7705 OpBuilder.addExclaimOverload(); 7706 break; 7707 7708 case OO_AmpAmp: 7709 case OO_PipePipe: 7710 OpBuilder.addAmpAmpOrPipePipeOverload(); 7711 break; 7712 7713 case OO_Subscript: 7714 OpBuilder.addSubscriptOverloads(); 7715 break; 7716 7717 case OO_ArrowStar: 7718 OpBuilder.addArrowStarOverloads(); 7719 break; 7720 7721 case OO_Conditional: 7722 OpBuilder.addConditionalOperatorOverloads(); 7723 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7724 break; 7725 } 7726} 7727 7728/// \brief Add function candidates found via argument-dependent lookup 7729/// to the set of overloading candidates. 7730/// 7731/// This routine performs argument-dependent name lookup based on the 7732/// given function name (which may also be an operator name) and adds 7733/// all of the overload candidates found by ADL to the overload 7734/// candidate set (C++ [basic.lookup.argdep]). 7735void 7736Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 7737 bool Operator, SourceLocation Loc, 7738 ArrayRef<Expr *> Args, 7739 TemplateArgumentListInfo *ExplicitTemplateArgs, 7740 OverloadCandidateSet& CandidateSet, 7741 bool PartialOverloading) { 7742 ADLResult Fns; 7743 7744 // FIXME: This approach for uniquing ADL results (and removing 7745 // redundant candidates from the set) relies on pointer-equality, 7746 // which means we need to key off the canonical decl. However, 7747 // always going back to the canonical decl might not get us the 7748 // right set of default arguments. What default arguments are 7749 // we supposed to consider on ADL candidates, anyway? 7750 7751 // FIXME: Pass in the explicit template arguments? 7752 ArgumentDependentLookup(Name, Operator, Loc, Args, Fns); 7753 7754 // Erase all of the candidates we already knew about. 7755 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 7756 CandEnd = CandidateSet.end(); 7757 Cand != CandEnd; ++Cand) 7758 if (Cand->Function) { 7759 Fns.erase(Cand->Function); 7760 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 7761 Fns.erase(FunTmpl); 7762 } 7763 7764 // For each of the ADL candidates we found, add it to the overload 7765 // set. 7766 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 7767 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 7768 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 7769 if (ExplicitTemplateArgs) 7770 continue; 7771 7772 AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet, false, 7773 PartialOverloading); 7774 } else 7775 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 7776 FoundDecl, ExplicitTemplateArgs, 7777 Args, CandidateSet); 7778 } 7779} 7780 7781/// isBetterOverloadCandidate - Determines whether the first overload 7782/// candidate is a better candidate than the second (C++ 13.3.3p1). 7783bool 7784isBetterOverloadCandidate(Sema &S, 7785 const OverloadCandidate &Cand1, 7786 const OverloadCandidate &Cand2, 7787 SourceLocation Loc, 7788 bool UserDefinedConversion) { 7789 // Define viable functions to be better candidates than non-viable 7790 // functions. 7791 if (!Cand2.Viable) 7792 return Cand1.Viable; 7793 else if (!Cand1.Viable) 7794 return false; 7795 7796 // C++ [over.match.best]p1: 7797 // 7798 // -- if F is a static member function, ICS1(F) is defined such 7799 // that ICS1(F) is neither better nor worse than ICS1(G) for 7800 // any function G, and, symmetrically, ICS1(G) is neither 7801 // better nor worse than ICS1(F). 7802 unsigned StartArg = 0; 7803 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 7804 StartArg = 1; 7805 7806 // C++ [over.match.best]p1: 7807 // A viable function F1 is defined to be a better function than another 7808 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 7809 // conversion sequence than ICSi(F2), and then... 7810 unsigned NumArgs = Cand1.NumConversions; 7811 assert(Cand2.NumConversions == NumArgs && "Overload candidate mismatch"); 7812 bool HasBetterConversion = false; 7813 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 7814 switch (CompareImplicitConversionSequences(S, 7815 Cand1.Conversions[ArgIdx], 7816 Cand2.Conversions[ArgIdx])) { 7817 case ImplicitConversionSequence::Better: 7818 // Cand1 has a better conversion sequence. 7819 HasBetterConversion = true; 7820 break; 7821 7822 case ImplicitConversionSequence::Worse: 7823 // Cand1 can't be better than Cand2. 7824 return false; 7825 7826 case ImplicitConversionSequence::Indistinguishable: 7827 // Do nothing. 7828 break; 7829 } 7830 } 7831 7832 // -- for some argument j, ICSj(F1) is a better conversion sequence than 7833 // ICSj(F2), or, if not that, 7834 if (HasBetterConversion) 7835 return true; 7836 7837 // - F1 is a non-template function and F2 is a function template 7838 // specialization, or, if not that, 7839 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 7840 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 7841 return true; 7842 7843 // -- F1 and F2 are function template specializations, and the function 7844 // template for F1 is more specialized than the template for F2 7845 // according to the partial ordering rules described in 14.5.5.2, or, 7846 // if not that, 7847 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 7848 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 7849 if (FunctionTemplateDecl *BetterTemplate 7850 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 7851 Cand2.Function->getPrimaryTemplate(), 7852 Loc, 7853 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 7854 : TPOC_Call, 7855 Cand1.ExplicitCallArguments)) 7856 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 7857 } 7858 7859 // -- the context is an initialization by user-defined conversion 7860 // (see 8.5, 13.3.1.5) and the standard conversion sequence 7861 // from the return type of F1 to the destination type (i.e., 7862 // the type of the entity being initialized) is a better 7863 // conversion sequence than the standard conversion sequence 7864 // from the return type of F2 to the destination type. 7865 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 7866 isa<CXXConversionDecl>(Cand1.Function) && 7867 isa<CXXConversionDecl>(Cand2.Function)) { 7868 // First check whether we prefer one of the conversion functions over the 7869 // other. This only distinguishes the results in non-standard, extension 7870 // cases such as the conversion from a lambda closure type to a function 7871 // pointer or block. 7872 ImplicitConversionSequence::CompareKind FuncResult 7873 = compareConversionFunctions(S, Cand1.Function, Cand2.Function); 7874 if (FuncResult != ImplicitConversionSequence::Indistinguishable) 7875 return FuncResult; 7876 7877 switch (CompareStandardConversionSequences(S, 7878 Cand1.FinalConversion, 7879 Cand2.FinalConversion)) { 7880 case ImplicitConversionSequence::Better: 7881 // Cand1 has a better conversion sequence. 7882 return true; 7883 7884 case ImplicitConversionSequence::Worse: 7885 // Cand1 can't be better than Cand2. 7886 return false; 7887 7888 case ImplicitConversionSequence::Indistinguishable: 7889 // Do nothing 7890 break; 7891 } 7892 } 7893 7894 return false; 7895} 7896 7897/// \brief Computes the best viable function (C++ 13.3.3) 7898/// within an overload candidate set. 7899/// 7900/// \param Loc The location of the function name (or operator symbol) for 7901/// which overload resolution occurs. 7902/// 7903/// \param Best If overload resolution was successful or found a deleted 7904/// function, \p Best points to the candidate function found. 7905/// 7906/// \returns The result of overload resolution. 7907OverloadingResult 7908OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 7909 iterator &Best, 7910 bool UserDefinedConversion) { 7911 // Find the best viable function. 7912 Best = end(); 7913 for (iterator Cand = begin(); Cand != end(); ++Cand) { 7914 if (Cand->Viable) 7915 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 7916 UserDefinedConversion)) 7917 Best = Cand; 7918 } 7919 7920 // If we didn't find any viable functions, abort. 7921 if (Best == end()) 7922 return OR_No_Viable_Function; 7923 7924 // Make sure that this function is better than every other viable 7925 // function. If not, we have an ambiguity. 7926 for (iterator Cand = begin(); Cand != end(); ++Cand) { 7927 if (Cand->Viable && 7928 Cand != Best && 7929 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 7930 UserDefinedConversion)) { 7931 Best = end(); 7932 return OR_Ambiguous; 7933 } 7934 } 7935 7936 // Best is the best viable function. 7937 if (Best->Function && 7938 (Best->Function->isDeleted() || 7939 S.isFunctionConsideredUnavailable(Best->Function))) 7940 return OR_Deleted; 7941 7942 return OR_Success; 7943} 7944 7945namespace { 7946 7947enum OverloadCandidateKind { 7948 oc_function, 7949 oc_method, 7950 oc_constructor, 7951 oc_function_template, 7952 oc_method_template, 7953 oc_constructor_template, 7954 oc_implicit_default_constructor, 7955 oc_implicit_copy_constructor, 7956 oc_implicit_move_constructor, 7957 oc_implicit_copy_assignment, 7958 oc_implicit_move_assignment, 7959 oc_implicit_inherited_constructor 7960}; 7961 7962OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 7963 FunctionDecl *Fn, 7964 std::string &Description) { 7965 bool isTemplate = false; 7966 7967 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 7968 isTemplate = true; 7969 Description = S.getTemplateArgumentBindingsText( 7970 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 7971 } 7972 7973 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 7974 if (!Ctor->isImplicit()) 7975 return isTemplate ? oc_constructor_template : oc_constructor; 7976 7977 if (Ctor->getInheritedConstructor()) 7978 return oc_implicit_inherited_constructor; 7979 7980 if (Ctor->isDefaultConstructor()) 7981 return oc_implicit_default_constructor; 7982 7983 if (Ctor->isMoveConstructor()) 7984 return oc_implicit_move_constructor; 7985 7986 assert(Ctor->isCopyConstructor() && 7987 "unexpected sort of implicit constructor"); 7988 return oc_implicit_copy_constructor; 7989 } 7990 7991 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 7992 // This actually gets spelled 'candidate function' for now, but 7993 // it doesn't hurt to split it out. 7994 if (!Meth->isImplicit()) 7995 return isTemplate ? oc_method_template : oc_method; 7996 7997 if (Meth->isMoveAssignmentOperator()) 7998 return oc_implicit_move_assignment; 7999 8000 if (Meth->isCopyAssignmentOperator()) 8001 return oc_implicit_copy_assignment; 8002 8003 assert(isa<CXXConversionDecl>(Meth) && "expected conversion"); 8004 return oc_method; 8005 } 8006 8007 return isTemplate ? oc_function_template : oc_function; 8008} 8009 8010void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { 8011 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 8012 if (!Ctor) return; 8013 8014 Ctor = Ctor->getInheritedConstructor(); 8015 if (!Ctor) return; 8016 8017 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 8018} 8019 8020} // end anonymous namespace 8021 8022// Notes the location of an overload candidate. 8023void Sema::NoteOverloadCandidate(FunctionDecl *Fn, QualType DestType) { 8024 std::string FnDesc; 8025 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 8026 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate) 8027 << (unsigned) K << FnDesc; 8028 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType); 8029 Diag(Fn->getLocation(), PD); 8030 MaybeEmitInheritedConstructorNote(*this, Fn); 8031} 8032 8033//Notes the location of all overload candidates designated through 8034// OverloadedExpr 8035void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr, QualType DestType) { 8036 assert(OverloadedExpr->getType() == Context.OverloadTy); 8037 8038 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); 8039 OverloadExpr *OvlExpr = Ovl.Expression; 8040 8041 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 8042 IEnd = OvlExpr->decls_end(); 8043 I != IEnd; ++I) { 8044 if (FunctionTemplateDecl *FunTmpl = 8045 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) { 8046 NoteOverloadCandidate(FunTmpl->getTemplatedDecl(), DestType); 8047 } else if (FunctionDecl *Fun 8048 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) { 8049 NoteOverloadCandidate(Fun, DestType); 8050 } 8051 } 8052} 8053 8054/// Diagnoses an ambiguous conversion. The partial diagnostic is the 8055/// "lead" diagnostic; it will be given two arguments, the source and 8056/// target types of the conversion. 8057void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 8058 Sema &S, 8059 SourceLocation CaretLoc, 8060 const PartialDiagnostic &PDiag) const { 8061 S.Diag(CaretLoc, PDiag) 8062 << Ambiguous.getFromType() << Ambiguous.getToType(); 8063 // FIXME: The note limiting machinery is borrowed from 8064 // OverloadCandidateSet::NoteCandidates; there's an opportunity for 8065 // refactoring here. 8066 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 8067 unsigned CandsShown = 0; 8068 AmbiguousConversionSequence::const_iterator I, E; 8069 for (I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 8070 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) 8071 break; 8072 ++CandsShown; 8073 S.NoteOverloadCandidate(*I); 8074 } 8075 if (I != E) 8076 S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I); 8077} 8078 8079namespace { 8080 8081void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 8082 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 8083 assert(Conv.isBad()); 8084 assert(Cand->Function && "for now, candidate must be a function"); 8085 FunctionDecl *Fn = Cand->Function; 8086 8087 // There's a conversion slot for the object argument if this is a 8088 // non-constructor method. Note that 'I' corresponds the 8089 // conversion-slot index. 8090 bool isObjectArgument = false; 8091 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 8092 if (I == 0) 8093 isObjectArgument = true; 8094 else 8095 I--; 8096 } 8097 8098 std::string FnDesc; 8099 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 8100 8101 Expr *FromExpr = Conv.Bad.FromExpr; 8102 QualType FromTy = Conv.Bad.getFromType(); 8103 QualType ToTy = Conv.Bad.getToType(); 8104 8105 if (FromTy == S.Context.OverloadTy) { 8106 assert(FromExpr && "overload set argument came from implicit argument?"); 8107 Expr *E = FromExpr->IgnoreParens(); 8108 if (isa<UnaryOperator>(E)) 8109 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 8110 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 8111 8112 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 8113 << (unsigned) FnKind << FnDesc 8114 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8115 << ToTy << Name << I+1; 8116 MaybeEmitInheritedConstructorNote(S, Fn); 8117 return; 8118 } 8119 8120 // Do some hand-waving analysis to see if the non-viability is due 8121 // to a qualifier mismatch. 8122 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 8123 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 8124 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 8125 CToTy = RT->getPointeeType(); 8126 else { 8127 // TODO: detect and diagnose the full richness of const mismatches. 8128 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 8129 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 8130 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 8131 } 8132 8133 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 8134 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 8135 Qualifiers FromQs = CFromTy.getQualifiers(); 8136 Qualifiers ToQs = CToTy.getQualifiers(); 8137 8138 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 8139 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 8140 << (unsigned) FnKind << FnDesc 8141 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8142 << FromTy 8143 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 8144 << (unsigned) isObjectArgument << I+1; 8145 MaybeEmitInheritedConstructorNote(S, Fn); 8146 return; 8147 } 8148 8149 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 8150 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership) 8151 << (unsigned) FnKind << FnDesc 8152 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8153 << FromTy 8154 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime() 8155 << (unsigned) isObjectArgument << I+1; 8156 MaybeEmitInheritedConstructorNote(S, Fn); 8157 return; 8158 } 8159 8160 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) { 8161 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc) 8162 << (unsigned) FnKind << FnDesc 8163 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8164 << FromTy 8165 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr() 8166 << (unsigned) isObjectArgument << I+1; 8167 MaybeEmitInheritedConstructorNote(S, Fn); 8168 return; 8169 } 8170 8171 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 8172 assert(CVR && "unexpected qualifiers mismatch"); 8173 8174 if (isObjectArgument) { 8175 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 8176 << (unsigned) FnKind << FnDesc 8177 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8178 << FromTy << (CVR - 1); 8179 } else { 8180 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 8181 << (unsigned) FnKind << FnDesc 8182 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8183 << FromTy << (CVR - 1) << I+1; 8184 } 8185 MaybeEmitInheritedConstructorNote(S, Fn); 8186 return; 8187 } 8188 8189 // Special diagnostic for failure to convert an initializer list, since 8190 // telling the user that it has type void is not useful. 8191 if (FromExpr && isa<InitListExpr>(FromExpr)) { 8192 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument) 8193 << (unsigned) FnKind << FnDesc 8194 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8195 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8196 MaybeEmitInheritedConstructorNote(S, Fn); 8197 return; 8198 } 8199 8200 // Diagnose references or pointers to incomplete types differently, 8201 // since it's far from impossible that the incompleteness triggered 8202 // the failure. 8203 QualType TempFromTy = FromTy.getNonReferenceType(); 8204 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 8205 TempFromTy = PTy->getPointeeType(); 8206 if (TempFromTy->isIncompleteType()) { 8207 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 8208 << (unsigned) FnKind << FnDesc 8209 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8210 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8211 MaybeEmitInheritedConstructorNote(S, Fn); 8212 return; 8213 } 8214 8215 // Diagnose base -> derived pointer conversions. 8216 unsigned BaseToDerivedConversion = 0; 8217 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 8218 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 8219 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 8220 FromPtrTy->getPointeeType()) && 8221 !FromPtrTy->getPointeeType()->isIncompleteType() && 8222 !ToPtrTy->getPointeeType()->isIncompleteType() && 8223 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 8224 FromPtrTy->getPointeeType())) 8225 BaseToDerivedConversion = 1; 8226 } 8227 } else if (const ObjCObjectPointerType *FromPtrTy 8228 = FromTy->getAs<ObjCObjectPointerType>()) { 8229 if (const ObjCObjectPointerType *ToPtrTy 8230 = ToTy->getAs<ObjCObjectPointerType>()) 8231 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 8232 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 8233 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 8234 FromPtrTy->getPointeeType()) && 8235 FromIface->isSuperClassOf(ToIface)) 8236 BaseToDerivedConversion = 2; 8237 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 8238 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 8239 !FromTy->isIncompleteType() && 8240 !ToRefTy->getPointeeType()->isIncompleteType() && 8241 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) { 8242 BaseToDerivedConversion = 3; 8243 } else if (ToTy->isLValueReferenceType() && !FromExpr->isLValue() && 8244 ToTy.getNonReferenceType().getCanonicalType() == 8245 FromTy.getNonReferenceType().getCanonicalType()) { 8246 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_lvalue) 8247 << (unsigned) FnKind << FnDesc 8248 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8249 << (unsigned) isObjectArgument << I + 1; 8250 MaybeEmitInheritedConstructorNote(S, Fn); 8251 return; 8252 } 8253 } 8254 8255 if (BaseToDerivedConversion) { 8256 S.Diag(Fn->getLocation(), 8257 diag::note_ovl_candidate_bad_base_to_derived_conv) 8258 << (unsigned) FnKind << FnDesc 8259 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8260 << (BaseToDerivedConversion - 1) 8261 << FromTy << ToTy << I+1; 8262 MaybeEmitInheritedConstructorNote(S, Fn); 8263 return; 8264 } 8265 8266 if (isa<ObjCObjectPointerType>(CFromTy) && 8267 isa<PointerType>(CToTy)) { 8268 Qualifiers FromQs = CFromTy.getQualifiers(); 8269 Qualifiers ToQs = CToTy.getQualifiers(); 8270 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 8271 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv) 8272 << (unsigned) FnKind << FnDesc 8273 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8274 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8275 MaybeEmitInheritedConstructorNote(S, Fn); 8276 return; 8277 } 8278 } 8279 8280 // Emit the generic diagnostic and, optionally, add the hints to it. 8281 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv); 8282 FDiag << (unsigned) FnKind << FnDesc 8283 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8284 << FromTy << ToTy << (unsigned) isObjectArgument << I + 1 8285 << (unsigned) (Cand->Fix.Kind); 8286 8287 // If we can fix the conversion, suggest the FixIts. 8288 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(), 8289 HE = Cand->Fix.Hints.end(); HI != HE; ++HI) 8290 FDiag << *HI; 8291 S.Diag(Fn->getLocation(), FDiag); 8292 8293 MaybeEmitInheritedConstructorNote(S, Fn); 8294} 8295 8296void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 8297 unsigned NumFormalArgs) { 8298 // TODO: treat calls to a missing default constructor as a special case 8299 8300 FunctionDecl *Fn = Cand->Function; 8301 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 8302 8303 unsigned MinParams = Fn->getMinRequiredArguments(); 8304 8305 // With invalid overloaded operators, it's possible that we think we 8306 // have an arity mismatch when it fact it looks like we have the 8307 // right number of arguments, because only overloaded operators have 8308 // the weird behavior of overloading member and non-member functions. 8309 // Just don't report anything. 8310 if (Fn->isInvalidDecl() && 8311 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName) 8312 return; 8313 8314 // at least / at most / exactly 8315 unsigned mode, modeCount; 8316 if (NumFormalArgs < MinParams) { 8317 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 8318 (Cand->FailureKind == ovl_fail_bad_deduction && 8319 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 8320 if (MinParams != FnTy->getNumArgs() || 8321 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 8322 mode = 0; // "at least" 8323 else 8324 mode = 2; // "exactly" 8325 modeCount = MinParams; 8326 } else { 8327 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 8328 (Cand->FailureKind == ovl_fail_bad_deduction && 8329 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 8330 if (MinParams != FnTy->getNumArgs()) 8331 mode = 1; // "at most" 8332 else 8333 mode = 2; // "exactly" 8334 modeCount = FnTy->getNumArgs(); 8335 } 8336 8337 std::string Description; 8338 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 8339 8340 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName()) 8341 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one) 8342 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 8343 << Fn->getParamDecl(0) << NumFormalArgs; 8344 else 8345 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 8346 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 8347 << modeCount << NumFormalArgs; 8348 MaybeEmitInheritedConstructorNote(S, Fn); 8349} 8350 8351/// Diagnose a failed template-argument deduction. 8352void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 8353 unsigned NumArgs) { 8354 FunctionDecl *Fn = Cand->Function; // pattern 8355 8356 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 8357 NamedDecl *ParamD; 8358 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 8359 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 8360 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 8361 switch (Cand->DeductionFailure.Result) { 8362 case Sema::TDK_Success: 8363 llvm_unreachable("TDK_success while diagnosing bad deduction"); 8364 8365 case Sema::TDK_Incomplete: { 8366 assert(ParamD && "no parameter found for incomplete deduction result"); 8367 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 8368 << ParamD->getDeclName(); 8369 MaybeEmitInheritedConstructorNote(S, Fn); 8370 return; 8371 } 8372 8373 case Sema::TDK_Underqualified: { 8374 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 8375 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 8376 8377 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 8378 8379 // Param will have been canonicalized, but it should just be a 8380 // qualified version of ParamD, so move the qualifiers to that. 8381 QualifierCollector Qs; 8382 Qs.strip(Param); 8383 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 8384 assert(S.Context.hasSameType(Param, NonCanonParam)); 8385 8386 // Arg has also been canonicalized, but there's nothing we can do 8387 // about that. It also doesn't matter as much, because it won't 8388 // have any template parameters in it (because deduction isn't 8389 // done on dependent types). 8390 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 8391 8392 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 8393 << ParamD->getDeclName() << Arg << NonCanonParam; 8394 MaybeEmitInheritedConstructorNote(S, Fn); 8395 return; 8396 } 8397 8398 case Sema::TDK_Inconsistent: { 8399 assert(ParamD && "no parameter found for inconsistent deduction result"); 8400 int which = 0; 8401 if (isa<TemplateTypeParmDecl>(ParamD)) 8402 which = 0; 8403 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 8404 which = 1; 8405 else { 8406 which = 2; 8407 } 8408 8409 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 8410 << which << ParamD->getDeclName() 8411 << *Cand->DeductionFailure.getFirstArg() 8412 << *Cand->DeductionFailure.getSecondArg(); 8413 MaybeEmitInheritedConstructorNote(S, Fn); 8414 return; 8415 } 8416 8417 case Sema::TDK_InvalidExplicitArguments: 8418 assert(ParamD && "no parameter found for invalid explicit arguments"); 8419 if (ParamD->getDeclName()) 8420 S.Diag(Fn->getLocation(), 8421 diag::note_ovl_candidate_explicit_arg_mismatch_named) 8422 << ParamD->getDeclName(); 8423 else { 8424 int index = 0; 8425 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 8426 index = TTP->getIndex(); 8427 else if (NonTypeTemplateParmDecl *NTTP 8428 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 8429 index = NTTP->getIndex(); 8430 else 8431 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 8432 S.Diag(Fn->getLocation(), 8433 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 8434 << (index + 1); 8435 } 8436 MaybeEmitInheritedConstructorNote(S, Fn); 8437 return; 8438 8439 case Sema::TDK_TooManyArguments: 8440 case Sema::TDK_TooFewArguments: 8441 DiagnoseArityMismatch(S, Cand, NumArgs); 8442 return; 8443 8444 case Sema::TDK_InstantiationDepth: 8445 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 8446 MaybeEmitInheritedConstructorNote(S, Fn); 8447 return; 8448 8449 case Sema::TDK_SubstitutionFailure: { 8450 // Format the template argument list into the argument string. 8451 SmallString<128> TemplateArgString; 8452 if (TemplateArgumentList *Args = 8453 Cand->DeductionFailure.getTemplateArgumentList()) { 8454 TemplateArgString = " "; 8455 TemplateArgString += S.getTemplateArgumentBindingsText( 8456 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), *Args); 8457 } 8458 8459 // If this candidate was disabled by enable_if, say so. 8460 PartialDiagnosticAt *PDiag = Cand->DeductionFailure.getSFINAEDiagnostic(); 8461 if (PDiag && PDiag->second.getDiagID() == 8462 diag::err_typename_nested_not_found_enable_if) { 8463 // FIXME: Use the source range of the condition, and the fully-qualified 8464 // name of the enable_if template. These are both present in PDiag. 8465 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if) 8466 << "'enable_if'" << TemplateArgString; 8467 return; 8468 } 8469 8470 // Format the SFINAE diagnostic into the argument string. 8471 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s 8472 // formatted message in another diagnostic. 8473 SmallString<128> SFINAEArgString; 8474 SourceRange R; 8475 if (PDiag) { 8476 SFINAEArgString = ": "; 8477 R = SourceRange(PDiag->first, PDiag->first); 8478 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString); 8479 } 8480 8481 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 8482 << TemplateArgString << SFINAEArgString << R; 8483 MaybeEmitInheritedConstructorNote(S, Fn); 8484 return; 8485 } 8486 8487 case Sema::TDK_FailedOverloadResolution: { 8488 OverloadExpr::FindResult R = 8489 OverloadExpr::find(Cand->DeductionFailure.getExpr()); 8490 S.Diag(Fn->getLocation(), 8491 diag::note_ovl_candidate_failed_overload_resolution) 8492 << R.Expression->getName(); 8493 return; 8494 } 8495 8496 case Sema::TDK_NonDeducedMismatch: 8497 // FIXME: Provide a source location to indicate what we couldn't match. 8498 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_non_deduced_mismatch) 8499 << *Cand->DeductionFailure.getFirstArg() 8500 << *Cand->DeductionFailure.getSecondArg(); 8501 return; 8502 8503 // TODO: diagnose these individually, then kill off 8504 // note_ovl_candidate_bad_deduction, which is uselessly vague. 8505 case Sema::TDK_MiscellaneousDeductionFailure: 8506 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 8507 MaybeEmitInheritedConstructorNote(S, Fn); 8508 return; 8509 } 8510} 8511 8512/// CUDA: diagnose an invalid call across targets. 8513void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) { 8514 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext); 8515 FunctionDecl *Callee = Cand->Function; 8516 8517 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller), 8518 CalleeTarget = S.IdentifyCUDATarget(Callee); 8519 8520 std::string FnDesc; 8521 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Callee, FnDesc); 8522 8523 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target) 8524 << (unsigned) FnKind << CalleeTarget << CallerTarget; 8525} 8526 8527/// Generates a 'note' diagnostic for an overload candidate. We've 8528/// already generated a primary error at the call site. 8529/// 8530/// It really does need to be a single diagnostic with its caret 8531/// pointed at the candidate declaration. Yes, this creates some 8532/// major challenges of technical writing. Yes, this makes pointing 8533/// out problems with specific arguments quite awkward. It's still 8534/// better than generating twenty screens of text for every failed 8535/// overload. 8536/// 8537/// It would be great to be able to express per-candidate problems 8538/// more richly for those diagnostic clients that cared, but we'd 8539/// still have to be just as careful with the default diagnostics. 8540void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 8541 unsigned NumArgs) { 8542 FunctionDecl *Fn = Cand->Function; 8543 8544 // Note deleted candidates, but only if they're viable. 8545 if (Cand->Viable && (Fn->isDeleted() || 8546 S.isFunctionConsideredUnavailable(Fn))) { 8547 std::string FnDesc; 8548 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 8549 8550 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 8551 << FnKind << FnDesc 8552 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0); 8553 MaybeEmitInheritedConstructorNote(S, Fn); 8554 return; 8555 } 8556 8557 // We don't really have anything else to say about viable candidates. 8558 if (Cand->Viable) { 8559 S.NoteOverloadCandidate(Fn); 8560 return; 8561 } 8562 8563 switch (Cand->FailureKind) { 8564 case ovl_fail_too_many_arguments: 8565 case ovl_fail_too_few_arguments: 8566 return DiagnoseArityMismatch(S, Cand, NumArgs); 8567 8568 case ovl_fail_bad_deduction: 8569 return DiagnoseBadDeduction(S, Cand, NumArgs); 8570 8571 case ovl_fail_trivial_conversion: 8572 case ovl_fail_bad_final_conversion: 8573 case ovl_fail_final_conversion_not_exact: 8574 return S.NoteOverloadCandidate(Fn); 8575 8576 case ovl_fail_bad_conversion: { 8577 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 8578 for (unsigned N = Cand->NumConversions; I != N; ++I) 8579 if (Cand->Conversions[I].isBad()) 8580 return DiagnoseBadConversion(S, Cand, I); 8581 8582 // FIXME: this currently happens when we're called from SemaInit 8583 // when user-conversion overload fails. Figure out how to handle 8584 // those conditions and diagnose them well. 8585 return S.NoteOverloadCandidate(Fn); 8586 } 8587 8588 case ovl_fail_bad_target: 8589 return DiagnoseBadTarget(S, Cand); 8590 } 8591} 8592 8593void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 8594 // Desugar the type of the surrogate down to a function type, 8595 // retaining as many typedefs as possible while still showing 8596 // the function type (and, therefore, its parameter types). 8597 QualType FnType = Cand->Surrogate->getConversionType(); 8598 bool isLValueReference = false; 8599 bool isRValueReference = false; 8600 bool isPointer = false; 8601 if (const LValueReferenceType *FnTypeRef = 8602 FnType->getAs<LValueReferenceType>()) { 8603 FnType = FnTypeRef->getPointeeType(); 8604 isLValueReference = true; 8605 } else if (const RValueReferenceType *FnTypeRef = 8606 FnType->getAs<RValueReferenceType>()) { 8607 FnType = FnTypeRef->getPointeeType(); 8608 isRValueReference = true; 8609 } 8610 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 8611 FnType = FnTypePtr->getPointeeType(); 8612 isPointer = true; 8613 } 8614 // Desugar down to a function type. 8615 FnType = QualType(FnType->getAs<FunctionType>(), 0); 8616 // Reconstruct the pointer/reference as appropriate. 8617 if (isPointer) FnType = S.Context.getPointerType(FnType); 8618 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 8619 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 8620 8621 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 8622 << FnType; 8623 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 8624} 8625 8626void NoteBuiltinOperatorCandidate(Sema &S, 8627 StringRef Opc, 8628 SourceLocation OpLoc, 8629 OverloadCandidate *Cand) { 8630 assert(Cand->NumConversions <= 2 && "builtin operator is not binary"); 8631 std::string TypeStr("operator"); 8632 TypeStr += Opc; 8633 TypeStr += "("; 8634 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 8635 if (Cand->NumConversions == 1) { 8636 TypeStr += ")"; 8637 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 8638 } else { 8639 TypeStr += ", "; 8640 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 8641 TypeStr += ")"; 8642 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 8643 } 8644} 8645 8646void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 8647 OverloadCandidate *Cand) { 8648 unsigned NoOperands = Cand->NumConversions; 8649 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 8650 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 8651 if (ICS.isBad()) break; // all meaningless after first invalid 8652 if (!ICS.isAmbiguous()) continue; 8653 8654 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 8655 S.PDiag(diag::note_ambiguous_type_conversion)); 8656 } 8657} 8658 8659SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 8660 if (Cand->Function) 8661 return Cand->Function->getLocation(); 8662 if (Cand->IsSurrogate) 8663 return Cand->Surrogate->getLocation(); 8664 return SourceLocation(); 8665} 8666 8667static unsigned 8668RankDeductionFailure(const OverloadCandidate::DeductionFailureInfo &DFI) { 8669 switch ((Sema::TemplateDeductionResult)DFI.Result) { 8670 case Sema::TDK_Success: 8671 llvm_unreachable("TDK_success while diagnosing bad deduction"); 8672 8673 case Sema::TDK_Invalid: 8674 case Sema::TDK_Incomplete: 8675 return 1; 8676 8677 case Sema::TDK_Underqualified: 8678 case Sema::TDK_Inconsistent: 8679 return 2; 8680 8681 case Sema::TDK_SubstitutionFailure: 8682 case Sema::TDK_NonDeducedMismatch: 8683 case Sema::TDK_MiscellaneousDeductionFailure: 8684 return 3; 8685 8686 case Sema::TDK_InstantiationDepth: 8687 case Sema::TDK_FailedOverloadResolution: 8688 return 4; 8689 8690 case Sema::TDK_InvalidExplicitArguments: 8691 return 5; 8692 8693 case Sema::TDK_TooManyArguments: 8694 case Sema::TDK_TooFewArguments: 8695 return 6; 8696 } 8697 llvm_unreachable("Unhandled deduction result"); 8698} 8699 8700struct CompareOverloadCandidatesForDisplay { 8701 Sema &S; 8702 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 8703 8704 bool operator()(const OverloadCandidate *L, 8705 const OverloadCandidate *R) { 8706 // Fast-path this check. 8707 if (L == R) return false; 8708 8709 // Order first by viability. 8710 if (L->Viable) { 8711 if (!R->Viable) return true; 8712 8713 // TODO: introduce a tri-valued comparison for overload 8714 // candidates. Would be more worthwhile if we had a sort 8715 // that could exploit it. 8716 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 8717 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 8718 } else if (R->Viable) 8719 return false; 8720 8721 assert(L->Viable == R->Viable); 8722 8723 // Criteria by which we can sort non-viable candidates: 8724 if (!L->Viable) { 8725 // 1. Arity mismatches come after other candidates. 8726 if (L->FailureKind == ovl_fail_too_many_arguments || 8727 L->FailureKind == ovl_fail_too_few_arguments) 8728 return false; 8729 if (R->FailureKind == ovl_fail_too_many_arguments || 8730 R->FailureKind == ovl_fail_too_few_arguments) 8731 return true; 8732 8733 // 2. Bad conversions come first and are ordered by the number 8734 // of bad conversions and quality of good conversions. 8735 if (L->FailureKind == ovl_fail_bad_conversion) { 8736 if (R->FailureKind != ovl_fail_bad_conversion) 8737 return true; 8738 8739 // The conversion that can be fixed with a smaller number of changes, 8740 // comes first. 8741 unsigned numLFixes = L->Fix.NumConversionsFixed; 8742 unsigned numRFixes = R->Fix.NumConversionsFixed; 8743 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes; 8744 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes; 8745 if (numLFixes != numRFixes) { 8746 if (numLFixes < numRFixes) 8747 return true; 8748 else 8749 return false; 8750 } 8751 8752 // If there's any ordering between the defined conversions... 8753 // FIXME: this might not be transitive. 8754 assert(L->NumConversions == R->NumConversions); 8755 8756 int leftBetter = 0; 8757 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 8758 for (unsigned E = L->NumConversions; I != E; ++I) { 8759 switch (CompareImplicitConversionSequences(S, 8760 L->Conversions[I], 8761 R->Conversions[I])) { 8762 case ImplicitConversionSequence::Better: 8763 leftBetter++; 8764 break; 8765 8766 case ImplicitConversionSequence::Worse: 8767 leftBetter--; 8768 break; 8769 8770 case ImplicitConversionSequence::Indistinguishable: 8771 break; 8772 } 8773 } 8774 if (leftBetter > 0) return true; 8775 if (leftBetter < 0) return false; 8776 8777 } else if (R->FailureKind == ovl_fail_bad_conversion) 8778 return false; 8779 8780 if (L->FailureKind == ovl_fail_bad_deduction) { 8781 if (R->FailureKind != ovl_fail_bad_deduction) 8782 return true; 8783 8784 if (L->DeductionFailure.Result != R->DeductionFailure.Result) 8785 return RankDeductionFailure(L->DeductionFailure) 8786 < RankDeductionFailure(R->DeductionFailure); 8787 } else if (R->FailureKind == ovl_fail_bad_deduction) 8788 return false; 8789 8790 // TODO: others? 8791 } 8792 8793 // Sort everything else by location. 8794 SourceLocation LLoc = GetLocationForCandidate(L); 8795 SourceLocation RLoc = GetLocationForCandidate(R); 8796 8797 // Put candidates without locations (e.g. builtins) at the end. 8798 if (LLoc.isInvalid()) return false; 8799 if (RLoc.isInvalid()) return true; 8800 8801 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 8802 } 8803}; 8804 8805/// CompleteNonViableCandidate - Normally, overload resolution only 8806/// computes up to the first. Produces the FixIt set if possible. 8807void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 8808 ArrayRef<Expr *> Args) { 8809 assert(!Cand->Viable); 8810 8811 // Don't do anything on failures other than bad conversion. 8812 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 8813 8814 // We only want the FixIts if all the arguments can be corrected. 8815 bool Unfixable = false; 8816 // Use a implicit copy initialization to check conversion fixes. 8817 Cand->Fix.setConversionChecker(TryCopyInitialization); 8818 8819 // Skip forward to the first bad conversion. 8820 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 8821 unsigned ConvCount = Cand->NumConversions; 8822 while (true) { 8823 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 8824 ConvIdx++; 8825 if (Cand->Conversions[ConvIdx - 1].isBad()) { 8826 Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S); 8827 break; 8828 } 8829 } 8830 8831 if (ConvIdx == ConvCount) 8832 return; 8833 8834 assert(!Cand->Conversions[ConvIdx].isInitialized() && 8835 "remaining conversion is initialized?"); 8836 8837 // FIXME: this should probably be preserved from the overload 8838 // operation somehow. 8839 bool SuppressUserConversions = false; 8840 8841 const FunctionProtoType* Proto; 8842 unsigned ArgIdx = ConvIdx; 8843 8844 if (Cand->IsSurrogate) { 8845 QualType ConvType 8846 = Cand->Surrogate->getConversionType().getNonReferenceType(); 8847 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 8848 ConvType = ConvPtrType->getPointeeType(); 8849 Proto = ConvType->getAs<FunctionProtoType>(); 8850 ArgIdx--; 8851 } else if (Cand->Function) { 8852 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 8853 if (isa<CXXMethodDecl>(Cand->Function) && 8854 !isa<CXXConstructorDecl>(Cand->Function)) 8855 ArgIdx--; 8856 } else { 8857 // Builtin binary operator with a bad first conversion. 8858 assert(ConvCount <= 3); 8859 for (; ConvIdx != ConvCount; ++ConvIdx) 8860 Cand->Conversions[ConvIdx] 8861 = TryCopyInitialization(S, Args[ConvIdx], 8862 Cand->BuiltinTypes.ParamTypes[ConvIdx], 8863 SuppressUserConversions, 8864 /*InOverloadResolution*/ true, 8865 /*AllowObjCWritebackConversion=*/ 8866 S.getLangOpts().ObjCAutoRefCount); 8867 return; 8868 } 8869 8870 // Fill in the rest of the conversions. 8871 unsigned NumArgsInProto = Proto->getNumArgs(); 8872 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 8873 if (ArgIdx < NumArgsInProto) { 8874 Cand->Conversions[ConvIdx] 8875 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 8876 SuppressUserConversions, 8877 /*InOverloadResolution=*/true, 8878 /*AllowObjCWritebackConversion=*/ 8879 S.getLangOpts().ObjCAutoRefCount); 8880 // Store the FixIt in the candidate if it exists. 8881 if (!Unfixable && Cand->Conversions[ConvIdx].isBad()) 8882 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S); 8883 } 8884 else 8885 Cand->Conversions[ConvIdx].setEllipsis(); 8886 } 8887} 8888 8889} // end anonymous namespace 8890 8891/// PrintOverloadCandidates - When overload resolution fails, prints 8892/// diagnostic messages containing the candidates in the candidate 8893/// set. 8894void OverloadCandidateSet::NoteCandidates(Sema &S, 8895 OverloadCandidateDisplayKind OCD, 8896 ArrayRef<Expr *> Args, 8897 StringRef Opc, 8898 SourceLocation OpLoc) { 8899 // Sort the candidates by viability and position. Sorting directly would 8900 // be prohibitive, so we make a set of pointers and sort those. 8901 SmallVector<OverloadCandidate*, 32> Cands; 8902 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 8903 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 8904 if (Cand->Viable) 8905 Cands.push_back(Cand); 8906 else if (OCD == OCD_AllCandidates) { 8907 CompleteNonViableCandidate(S, Cand, Args); 8908 if (Cand->Function || Cand->IsSurrogate) 8909 Cands.push_back(Cand); 8910 // Otherwise, this a non-viable builtin candidate. We do not, in general, 8911 // want to list every possible builtin candidate. 8912 } 8913 } 8914 8915 std::sort(Cands.begin(), Cands.end(), 8916 CompareOverloadCandidatesForDisplay(S)); 8917 8918 bool ReportedAmbiguousConversions = false; 8919 8920 SmallVectorImpl<OverloadCandidate*>::iterator I, E; 8921 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 8922 unsigned CandsShown = 0; 8923 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 8924 OverloadCandidate *Cand = *I; 8925 8926 // Set an arbitrary limit on the number of candidate functions we'll spam 8927 // the user with. FIXME: This limit should depend on details of the 8928 // candidate list. 8929 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) { 8930 break; 8931 } 8932 ++CandsShown; 8933 8934 if (Cand->Function) 8935 NoteFunctionCandidate(S, Cand, Args.size()); 8936 else if (Cand->IsSurrogate) 8937 NoteSurrogateCandidate(S, Cand); 8938 else { 8939 assert(Cand->Viable && 8940 "Non-viable built-in candidates are not added to Cands."); 8941 // Generally we only see ambiguities including viable builtin 8942 // operators if overload resolution got screwed up by an 8943 // ambiguous user-defined conversion. 8944 // 8945 // FIXME: It's quite possible for different conversions to see 8946 // different ambiguities, though. 8947 if (!ReportedAmbiguousConversions) { 8948 NoteAmbiguousUserConversions(S, OpLoc, Cand); 8949 ReportedAmbiguousConversions = true; 8950 } 8951 8952 // If this is a viable builtin, print it. 8953 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 8954 } 8955 } 8956 8957 if (I != E) 8958 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 8959} 8960 8961// [PossiblyAFunctionType] --> [Return] 8962// NonFunctionType --> NonFunctionType 8963// R (A) --> R(A) 8964// R (*)(A) --> R (A) 8965// R (&)(A) --> R (A) 8966// R (S::*)(A) --> R (A) 8967QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { 8968 QualType Ret = PossiblyAFunctionType; 8969 if (const PointerType *ToTypePtr = 8970 PossiblyAFunctionType->getAs<PointerType>()) 8971 Ret = ToTypePtr->getPointeeType(); 8972 else if (const ReferenceType *ToTypeRef = 8973 PossiblyAFunctionType->getAs<ReferenceType>()) 8974 Ret = ToTypeRef->getPointeeType(); 8975 else if (const MemberPointerType *MemTypePtr = 8976 PossiblyAFunctionType->getAs<MemberPointerType>()) 8977 Ret = MemTypePtr->getPointeeType(); 8978 Ret = 8979 Context.getCanonicalType(Ret).getUnqualifiedType(); 8980 return Ret; 8981} 8982 8983// A helper class to help with address of function resolution 8984// - allows us to avoid passing around all those ugly parameters 8985class AddressOfFunctionResolver 8986{ 8987 Sema& S; 8988 Expr* SourceExpr; 8989 const QualType& TargetType; 8990 QualType TargetFunctionType; // Extracted function type from target type 8991 8992 bool Complain; 8993 //DeclAccessPair& ResultFunctionAccessPair; 8994 ASTContext& Context; 8995 8996 bool TargetTypeIsNonStaticMemberFunction; 8997 bool FoundNonTemplateFunction; 8998 8999 OverloadExpr::FindResult OvlExprInfo; 9000 OverloadExpr *OvlExpr; 9001 TemplateArgumentListInfo OvlExplicitTemplateArgs; 9002 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 9003 9004public: 9005 AddressOfFunctionResolver(Sema &S, Expr* SourceExpr, 9006 const QualType& TargetType, bool Complain) 9007 : S(S), SourceExpr(SourceExpr), TargetType(TargetType), 9008 Complain(Complain), Context(S.getASTContext()), 9009 TargetTypeIsNonStaticMemberFunction( 9010 !!TargetType->getAs<MemberPointerType>()), 9011 FoundNonTemplateFunction(false), 9012 OvlExprInfo(OverloadExpr::find(SourceExpr)), 9013 OvlExpr(OvlExprInfo.Expression) 9014 { 9015 ExtractUnqualifiedFunctionTypeFromTargetType(); 9016 9017 if (!TargetFunctionType->isFunctionType()) { 9018 if (OvlExpr->hasExplicitTemplateArgs()) { 9019 DeclAccessPair dap; 9020 if (FunctionDecl* Fn = S.ResolveSingleFunctionTemplateSpecialization( 9021 OvlExpr, false, &dap) ) { 9022 9023 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 9024 if (!Method->isStatic()) { 9025 // If the target type is a non-function type and the function 9026 // found is a non-static member function, pretend as if that was 9027 // the target, it's the only possible type to end up with. 9028 TargetTypeIsNonStaticMemberFunction = true; 9029 9030 // And skip adding the function if its not in the proper form. 9031 // We'll diagnose this due to an empty set of functions. 9032 if (!OvlExprInfo.HasFormOfMemberPointer) 9033 return; 9034 } 9035 } 9036 9037 Matches.push_back(std::make_pair(dap,Fn)); 9038 } 9039 } 9040 return; 9041 } 9042 9043 if (OvlExpr->hasExplicitTemplateArgs()) 9044 OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); 9045 9046 if (FindAllFunctionsThatMatchTargetTypeExactly()) { 9047 // C++ [over.over]p4: 9048 // If more than one function is selected, [...] 9049 if (Matches.size() > 1) { 9050 if (FoundNonTemplateFunction) 9051 EliminateAllTemplateMatches(); 9052 else 9053 EliminateAllExceptMostSpecializedTemplate(); 9054 } 9055 } 9056 } 9057 9058private: 9059 bool isTargetTypeAFunction() const { 9060 return TargetFunctionType->isFunctionType(); 9061 } 9062 9063 // [ToType] [Return] 9064 9065 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false 9066 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false 9067 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true 9068 void inline ExtractUnqualifiedFunctionTypeFromTargetType() { 9069 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); 9070 } 9071 9072 // return true if any matching specializations were found 9073 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, 9074 const DeclAccessPair& CurAccessFunPair) { 9075 if (CXXMethodDecl *Method 9076 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 9077 // Skip non-static function templates when converting to pointer, and 9078 // static when converting to member pointer. 9079 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 9080 return false; 9081 } 9082 else if (TargetTypeIsNonStaticMemberFunction) 9083 return false; 9084 9085 // C++ [over.over]p2: 9086 // If the name is a function template, template argument deduction is 9087 // done (14.8.2.2), and if the argument deduction succeeds, the 9088 // resulting template argument list is used to generate a single 9089 // function template specialization, which is added to the set of 9090 // overloaded functions considered. 9091 FunctionDecl *Specialization = 0; 9092 TemplateDeductionInfo Info(OvlExpr->getNameLoc()); 9093 if (Sema::TemplateDeductionResult Result 9094 = S.DeduceTemplateArguments(FunctionTemplate, 9095 &OvlExplicitTemplateArgs, 9096 TargetFunctionType, Specialization, 9097 Info)) { 9098 // FIXME: make a note of the failed deduction for diagnostics. 9099 (void)Result; 9100 return false; 9101 } 9102 9103 // Template argument deduction ensures that we have an exact match. 9104 // This function template specicalization works. 9105 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 9106 assert(TargetFunctionType 9107 == Context.getCanonicalType(Specialization->getType())); 9108 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); 9109 return true; 9110 } 9111 9112 bool AddMatchingNonTemplateFunction(NamedDecl* Fn, 9113 const DeclAccessPair& CurAccessFunPair) { 9114 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 9115 // Skip non-static functions when converting to pointer, and static 9116 // when converting to member pointer. 9117 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 9118 return false; 9119 } 9120 else if (TargetTypeIsNonStaticMemberFunction) 9121 return false; 9122 9123 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 9124 if (S.getLangOpts().CUDA) 9125 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext)) 9126 if (S.CheckCUDATarget(Caller, FunDecl)) 9127 return false; 9128 9129 QualType ResultTy; 9130 if (Context.hasSameUnqualifiedType(TargetFunctionType, 9131 FunDecl->getType()) || 9132 S.IsNoReturnConversion(FunDecl->getType(), TargetFunctionType, 9133 ResultTy)) { 9134 Matches.push_back(std::make_pair(CurAccessFunPair, 9135 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 9136 FoundNonTemplateFunction = true; 9137 return true; 9138 } 9139 } 9140 9141 return false; 9142 } 9143 9144 bool FindAllFunctionsThatMatchTargetTypeExactly() { 9145 bool Ret = false; 9146 9147 // If the overload expression doesn't have the form of a pointer to 9148 // member, don't try to convert it to a pointer-to-member type. 9149 if (IsInvalidFormOfPointerToMemberFunction()) 9150 return false; 9151 9152 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 9153 E = OvlExpr->decls_end(); 9154 I != E; ++I) { 9155 // Look through any using declarations to find the underlying function. 9156 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 9157 9158 // C++ [over.over]p3: 9159 // Non-member functions and static member functions match 9160 // targets of type "pointer-to-function" or "reference-to-function." 9161 // Nonstatic member functions match targets of 9162 // type "pointer-to-member-function." 9163 // Note that according to DR 247, the containing class does not matter. 9164 if (FunctionTemplateDecl *FunctionTemplate 9165 = dyn_cast<FunctionTemplateDecl>(Fn)) { 9166 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) 9167 Ret = true; 9168 } 9169 // If we have explicit template arguments supplied, skip non-templates. 9170 else if (!OvlExpr->hasExplicitTemplateArgs() && 9171 AddMatchingNonTemplateFunction(Fn, I.getPair())) 9172 Ret = true; 9173 } 9174 assert(Ret || Matches.empty()); 9175 return Ret; 9176 } 9177 9178 void EliminateAllExceptMostSpecializedTemplate() { 9179 // [...] and any given function template specialization F1 is 9180 // eliminated if the set contains a second function template 9181 // specialization whose function template is more specialized 9182 // than the function template of F1 according to the partial 9183 // ordering rules of 14.5.5.2. 9184 9185 // The algorithm specified above is quadratic. We instead use a 9186 // two-pass algorithm (similar to the one used to identify the 9187 // best viable function in an overload set) that identifies the 9188 // best function template (if it exists). 9189 9190 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 9191 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 9192 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 9193 9194 UnresolvedSetIterator Result = 9195 S.getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 9196 TPOC_Other, 0, SourceExpr->getLocStart(), 9197 S.PDiag(), 9198 S.PDiag(diag::err_addr_ovl_ambiguous) 9199 << Matches[0].second->getDeclName(), 9200 S.PDiag(diag::note_ovl_candidate) 9201 << (unsigned) oc_function_template, 9202 Complain, TargetFunctionType); 9203 9204 if (Result != MatchesCopy.end()) { 9205 // Make it the first and only element 9206 Matches[0].first = Matches[Result - MatchesCopy.begin()].first; 9207 Matches[0].second = cast<FunctionDecl>(*Result); 9208 Matches.resize(1); 9209 } 9210 } 9211 9212 void EliminateAllTemplateMatches() { 9213 // [...] any function template specializations in the set are 9214 // eliminated if the set also contains a non-template function, [...] 9215 for (unsigned I = 0, N = Matches.size(); I != N; ) { 9216 if (Matches[I].second->getPrimaryTemplate() == 0) 9217 ++I; 9218 else { 9219 Matches[I] = Matches[--N]; 9220 Matches.set_size(N); 9221 } 9222 } 9223 } 9224 9225public: 9226 void ComplainNoMatchesFound() const { 9227 assert(Matches.empty()); 9228 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) 9229 << OvlExpr->getName() << TargetFunctionType 9230 << OvlExpr->getSourceRange(); 9231 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); 9232 } 9233 9234 bool IsInvalidFormOfPointerToMemberFunction() const { 9235 return TargetTypeIsNonStaticMemberFunction && 9236 !OvlExprInfo.HasFormOfMemberPointer; 9237 } 9238 9239 void ComplainIsInvalidFormOfPointerToMemberFunction() const { 9240 // TODO: Should we condition this on whether any functions might 9241 // have matched, or is it more appropriate to do that in callers? 9242 // TODO: a fixit wouldn't hurt. 9243 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 9244 << TargetType << OvlExpr->getSourceRange(); 9245 } 9246 9247 void ComplainOfInvalidConversion() const { 9248 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 9249 << OvlExpr->getName() << TargetType; 9250 } 9251 9252 void ComplainMultipleMatchesFound() const { 9253 assert(Matches.size() > 1); 9254 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) 9255 << OvlExpr->getName() 9256 << OvlExpr->getSourceRange(); 9257 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); 9258 } 9259 9260 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); } 9261 9262 int getNumMatches() const { return Matches.size(); } 9263 9264 FunctionDecl* getMatchingFunctionDecl() const { 9265 if (Matches.size() != 1) return 0; 9266 return Matches[0].second; 9267 } 9268 9269 const DeclAccessPair* getMatchingFunctionAccessPair() const { 9270 if (Matches.size() != 1) return 0; 9271 return &Matches[0].first; 9272 } 9273}; 9274 9275/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 9276/// an overloaded function (C++ [over.over]), where @p From is an 9277/// expression with overloaded function type and @p ToType is the type 9278/// we're trying to resolve to. For example: 9279/// 9280/// @code 9281/// int f(double); 9282/// int f(int); 9283/// 9284/// int (*pfd)(double) = f; // selects f(double) 9285/// @endcode 9286/// 9287/// This routine returns the resulting FunctionDecl if it could be 9288/// resolved, and NULL otherwise. When @p Complain is true, this 9289/// routine will emit diagnostics if there is an error. 9290FunctionDecl * 9291Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, 9292 QualType TargetType, 9293 bool Complain, 9294 DeclAccessPair &FoundResult, 9295 bool *pHadMultipleCandidates) { 9296 assert(AddressOfExpr->getType() == Context.OverloadTy); 9297 9298 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, 9299 Complain); 9300 int NumMatches = Resolver.getNumMatches(); 9301 FunctionDecl* Fn = 0; 9302 if (NumMatches == 0 && Complain) { 9303 if (Resolver.IsInvalidFormOfPointerToMemberFunction()) 9304 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); 9305 else 9306 Resolver.ComplainNoMatchesFound(); 9307 } 9308 else if (NumMatches > 1 && Complain) 9309 Resolver.ComplainMultipleMatchesFound(); 9310 else if (NumMatches == 1) { 9311 Fn = Resolver.getMatchingFunctionDecl(); 9312 assert(Fn); 9313 FoundResult = *Resolver.getMatchingFunctionAccessPair(); 9314 if (Complain) 9315 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); 9316 } 9317 9318 if (pHadMultipleCandidates) 9319 *pHadMultipleCandidates = Resolver.hadMultipleCandidates(); 9320 return Fn; 9321} 9322 9323/// \brief Given an expression that refers to an overloaded function, try to 9324/// resolve that overloaded function expression down to a single function. 9325/// 9326/// This routine can only resolve template-ids that refer to a single function 9327/// template, where that template-id refers to a single template whose template 9328/// arguments are either provided by the template-id or have defaults, 9329/// as described in C++0x [temp.arg.explicit]p3. 9330FunctionDecl * 9331Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl, 9332 bool Complain, 9333 DeclAccessPair *FoundResult) { 9334 // C++ [over.over]p1: 9335 // [...] [Note: any redundant set of parentheses surrounding the 9336 // overloaded function name is ignored (5.1). ] 9337 // C++ [over.over]p1: 9338 // [...] The overloaded function name can be preceded by the & 9339 // operator. 9340 9341 // If we didn't actually find any template-ids, we're done. 9342 if (!ovl->hasExplicitTemplateArgs()) 9343 return 0; 9344 9345 TemplateArgumentListInfo ExplicitTemplateArgs; 9346 ovl->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 9347 9348 // Look through all of the overloaded functions, searching for one 9349 // whose type matches exactly. 9350 FunctionDecl *Matched = 0; 9351 for (UnresolvedSetIterator I = ovl->decls_begin(), 9352 E = ovl->decls_end(); I != E; ++I) { 9353 // C++0x [temp.arg.explicit]p3: 9354 // [...] In contexts where deduction is done and fails, or in contexts 9355 // where deduction is not done, if a template argument list is 9356 // specified and it, along with any default template arguments, 9357 // identifies a single function template specialization, then the 9358 // template-id is an lvalue for the function template specialization. 9359 FunctionTemplateDecl *FunctionTemplate 9360 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 9361 9362 // C++ [over.over]p2: 9363 // If the name is a function template, template argument deduction is 9364 // done (14.8.2.2), and if the argument deduction succeeds, the 9365 // resulting template argument list is used to generate a single 9366 // function template specialization, which is added to the set of 9367 // overloaded functions considered. 9368 FunctionDecl *Specialization = 0; 9369 TemplateDeductionInfo Info(ovl->getNameLoc()); 9370 if (TemplateDeductionResult Result 9371 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 9372 Specialization, Info)) { 9373 // FIXME: make a note of the failed deduction for diagnostics. 9374 (void)Result; 9375 continue; 9376 } 9377 9378 assert(Specialization && "no specialization and no error?"); 9379 9380 // Multiple matches; we can't resolve to a single declaration. 9381 if (Matched) { 9382 if (Complain) { 9383 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous) 9384 << ovl->getName(); 9385 NoteAllOverloadCandidates(ovl); 9386 } 9387 return 0; 9388 } 9389 9390 Matched = Specialization; 9391 if (FoundResult) *FoundResult = I.getPair(); 9392 } 9393 9394 return Matched; 9395} 9396 9397 9398 9399 9400// Resolve and fix an overloaded expression that can be resolved 9401// because it identifies a single function template specialization. 9402// 9403// Last three arguments should only be supplied if Complain = true 9404// 9405// Return true if it was logically possible to so resolve the 9406// expression, regardless of whether or not it succeeded. Always 9407// returns true if 'complain' is set. 9408bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization( 9409 ExprResult &SrcExpr, bool doFunctionPointerConverion, 9410 bool complain, const SourceRange& OpRangeForComplaining, 9411 QualType DestTypeForComplaining, 9412 unsigned DiagIDForComplaining) { 9413 assert(SrcExpr.get()->getType() == Context.OverloadTy); 9414 9415 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get()); 9416 9417 DeclAccessPair found; 9418 ExprResult SingleFunctionExpression; 9419 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization( 9420 ovl.Expression, /*complain*/ false, &found)) { 9421 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getLocStart())) { 9422 SrcExpr = ExprError(); 9423 return true; 9424 } 9425 9426 // It is only correct to resolve to an instance method if we're 9427 // resolving a form that's permitted to be a pointer to member. 9428 // Otherwise we'll end up making a bound member expression, which 9429 // is illegal in all the contexts we resolve like this. 9430 if (!ovl.HasFormOfMemberPointer && 9431 isa<CXXMethodDecl>(fn) && 9432 cast<CXXMethodDecl>(fn)->isInstance()) { 9433 if (!complain) return false; 9434 9435 Diag(ovl.Expression->getExprLoc(), 9436 diag::err_bound_member_function) 9437 << 0 << ovl.Expression->getSourceRange(); 9438 9439 // TODO: I believe we only end up here if there's a mix of 9440 // static and non-static candidates (otherwise the expression 9441 // would have 'bound member' type, not 'overload' type). 9442 // Ideally we would note which candidate was chosen and why 9443 // the static candidates were rejected. 9444 SrcExpr = ExprError(); 9445 return true; 9446 } 9447 9448 // Fix the expression to refer to 'fn'. 9449 SingleFunctionExpression = 9450 Owned(FixOverloadedFunctionReference(SrcExpr.take(), found, fn)); 9451 9452 // If desired, do function-to-pointer decay. 9453 if (doFunctionPointerConverion) { 9454 SingleFunctionExpression = 9455 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.take()); 9456 if (SingleFunctionExpression.isInvalid()) { 9457 SrcExpr = ExprError(); 9458 return true; 9459 } 9460 } 9461 } 9462 9463 if (!SingleFunctionExpression.isUsable()) { 9464 if (complain) { 9465 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) 9466 << ovl.Expression->getName() 9467 << DestTypeForComplaining 9468 << OpRangeForComplaining 9469 << ovl.Expression->getQualifierLoc().getSourceRange(); 9470 NoteAllOverloadCandidates(SrcExpr.get()); 9471 9472 SrcExpr = ExprError(); 9473 return true; 9474 } 9475 9476 return false; 9477 } 9478 9479 SrcExpr = SingleFunctionExpression; 9480 return true; 9481} 9482 9483/// \brief Add a single candidate to the overload set. 9484static void AddOverloadedCallCandidate(Sema &S, 9485 DeclAccessPair FoundDecl, 9486 TemplateArgumentListInfo *ExplicitTemplateArgs, 9487 ArrayRef<Expr *> Args, 9488 OverloadCandidateSet &CandidateSet, 9489 bool PartialOverloading, 9490 bool KnownValid) { 9491 NamedDecl *Callee = FoundDecl.getDecl(); 9492 if (isa<UsingShadowDecl>(Callee)) 9493 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 9494 9495 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 9496 if (ExplicitTemplateArgs) { 9497 assert(!KnownValid && "Explicit template arguments?"); 9498 return; 9499 } 9500 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet, false, 9501 PartialOverloading); 9502 return; 9503 } 9504 9505 if (FunctionTemplateDecl *FuncTemplate 9506 = dyn_cast<FunctionTemplateDecl>(Callee)) { 9507 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 9508 ExplicitTemplateArgs, Args, CandidateSet); 9509 return; 9510 } 9511 9512 assert(!KnownValid && "unhandled case in overloaded call candidate"); 9513} 9514 9515/// \brief Add the overload candidates named by callee and/or found by argument 9516/// dependent lookup to the given overload set. 9517void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 9518 ArrayRef<Expr *> Args, 9519 OverloadCandidateSet &CandidateSet, 9520 bool PartialOverloading) { 9521 9522#ifndef NDEBUG 9523 // Verify that ArgumentDependentLookup is consistent with the rules 9524 // in C++0x [basic.lookup.argdep]p3: 9525 // 9526 // Let X be the lookup set produced by unqualified lookup (3.4.1) 9527 // and let Y be the lookup set produced by argument dependent 9528 // lookup (defined as follows). If X contains 9529 // 9530 // -- a declaration of a class member, or 9531 // 9532 // -- a block-scope function declaration that is not a 9533 // using-declaration, or 9534 // 9535 // -- a declaration that is neither a function or a function 9536 // template 9537 // 9538 // then Y is empty. 9539 9540 if (ULE->requiresADL()) { 9541 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 9542 E = ULE->decls_end(); I != E; ++I) { 9543 assert(!(*I)->getDeclContext()->isRecord()); 9544 assert(isa<UsingShadowDecl>(*I) || 9545 !(*I)->getDeclContext()->isFunctionOrMethod()); 9546 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 9547 } 9548 } 9549#endif 9550 9551 // It would be nice to avoid this copy. 9552 TemplateArgumentListInfo TABuffer; 9553 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 9554 if (ULE->hasExplicitTemplateArgs()) { 9555 ULE->copyTemplateArgumentsInto(TABuffer); 9556 ExplicitTemplateArgs = &TABuffer; 9557 } 9558 9559 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 9560 E = ULE->decls_end(); I != E; ++I) 9561 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args, 9562 CandidateSet, PartialOverloading, 9563 /*KnownValid*/ true); 9564 9565 if (ULE->requiresADL()) 9566 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 9567 ULE->getExprLoc(), 9568 Args, ExplicitTemplateArgs, 9569 CandidateSet, PartialOverloading); 9570} 9571 9572/// Attempt to recover from an ill-formed use of a non-dependent name in a 9573/// template, where the non-dependent name was declared after the template 9574/// was defined. This is common in code written for a compilers which do not 9575/// correctly implement two-stage name lookup. 9576/// 9577/// Returns true if a viable candidate was found and a diagnostic was issued. 9578static bool 9579DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc, 9580 const CXXScopeSpec &SS, LookupResult &R, 9581 TemplateArgumentListInfo *ExplicitTemplateArgs, 9582 ArrayRef<Expr *> Args) { 9583 if (SemaRef.ActiveTemplateInstantiations.empty() || !SS.isEmpty()) 9584 return false; 9585 9586 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) { 9587 if (DC->isTransparentContext()) 9588 continue; 9589 9590 SemaRef.LookupQualifiedName(R, DC); 9591 9592 if (!R.empty()) { 9593 R.suppressDiagnostics(); 9594 9595 if (isa<CXXRecordDecl>(DC)) { 9596 // Don't diagnose names we find in classes; we get much better 9597 // diagnostics for these from DiagnoseEmptyLookup. 9598 R.clear(); 9599 return false; 9600 } 9601 9602 OverloadCandidateSet Candidates(FnLoc); 9603 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 9604 AddOverloadedCallCandidate(SemaRef, I.getPair(), 9605 ExplicitTemplateArgs, Args, 9606 Candidates, false, /*KnownValid*/ false); 9607 9608 OverloadCandidateSet::iterator Best; 9609 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) { 9610 // No viable functions. Don't bother the user with notes for functions 9611 // which don't work and shouldn't be found anyway. 9612 R.clear(); 9613 return false; 9614 } 9615 9616 // Find the namespaces where ADL would have looked, and suggest 9617 // declaring the function there instead. 9618 Sema::AssociatedNamespaceSet AssociatedNamespaces; 9619 Sema::AssociatedClassSet AssociatedClasses; 9620 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args, 9621 AssociatedNamespaces, 9622 AssociatedClasses); 9623 Sema::AssociatedNamespaceSet SuggestedNamespaces; 9624 DeclContext *Std = SemaRef.getStdNamespace(); 9625 for (Sema::AssociatedNamespaceSet::iterator 9626 it = AssociatedNamespaces.begin(), 9627 end = AssociatedNamespaces.end(); it != end; ++it) { 9628 // Never suggest declaring a function within namespace 'std'. 9629 if (Std && Std->Encloses(*it)) 9630 continue; 9631 9632 // Never suggest declaring a function within a namespace with a reserved 9633 // name, like __gnu_cxx. 9634 NamespaceDecl *NS = dyn_cast<NamespaceDecl>(*it); 9635 if (NS && 9636 NS->getQualifiedNameAsString().find("__") != std::string::npos) 9637 continue; 9638 9639 SuggestedNamespaces.insert(*it); 9640 } 9641 9642 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup) 9643 << R.getLookupName(); 9644 if (SuggestedNamespaces.empty()) { 9645 SemaRef.Diag(Best->Function->getLocation(), 9646 diag::note_not_found_by_two_phase_lookup) 9647 << R.getLookupName() << 0; 9648 } else if (SuggestedNamespaces.size() == 1) { 9649 SemaRef.Diag(Best->Function->getLocation(), 9650 diag::note_not_found_by_two_phase_lookup) 9651 << R.getLookupName() << 1 << *SuggestedNamespaces.begin(); 9652 } else { 9653 // FIXME: It would be useful to list the associated namespaces here, 9654 // but the diagnostics infrastructure doesn't provide a way to produce 9655 // a localized representation of a list of items. 9656 SemaRef.Diag(Best->Function->getLocation(), 9657 diag::note_not_found_by_two_phase_lookup) 9658 << R.getLookupName() << 2; 9659 } 9660 9661 // Try to recover by calling this function. 9662 return true; 9663 } 9664 9665 R.clear(); 9666 } 9667 9668 return false; 9669} 9670 9671/// Attempt to recover from ill-formed use of a non-dependent operator in a 9672/// template, where the non-dependent operator was declared after the template 9673/// was defined. 9674/// 9675/// Returns true if a viable candidate was found and a diagnostic was issued. 9676static bool 9677DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op, 9678 SourceLocation OpLoc, 9679 ArrayRef<Expr *> Args) { 9680 DeclarationName OpName = 9681 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op); 9682 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName); 9683 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R, 9684 /*ExplicitTemplateArgs=*/0, Args); 9685} 9686 9687namespace { 9688// Callback to limit the allowed keywords and to only accept typo corrections 9689// that are keywords or whose decls refer to functions (or template functions) 9690// that accept the given number of arguments. 9691class RecoveryCallCCC : public CorrectionCandidateCallback { 9692 public: 9693 RecoveryCallCCC(Sema &SemaRef, unsigned NumArgs, bool HasExplicitTemplateArgs) 9694 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs) { 9695 WantTypeSpecifiers = SemaRef.getLangOpts().CPlusPlus; 9696 WantRemainingKeywords = false; 9697 } 9698 9699 virtual bool ValidateCandidate(const TypoCorrection &candidate) { 9700 if (!candidate.getCorrectionDecl()) 9701 return candidate.isKeyword(); 9702 9703 for (TypoCorrection::const_decl_iterator DI = candidate.begin(), 9704 DIEnd = candidate.end(); DI != DIEnd; ++DI) { 9705 FunctionDecl *FD = 0; 9706 NamedDecl *ND = (*DI)->getUnderlyingDecl(); 9707 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 9708 FD = FTD->getTemplatedDecl(); 9709 if (!HasExplicitTemplateArgs && !FD) { 9710 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) { 9711 // If the Decl is neither a function nor a template function, 9712 // determine if it is a pointer or reference to a function. If so, 9713 // check against the number of arguments expected for the pointee. 9714 QualType ValType = cast<ValueDecl>(ND)->getType(); 9715 if (ValType->isAnyPointerType() || ValType->isReferenceType()) 9716 ValType = ValType->getPointeeType(); 9717 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>()) 9718 if (FPT->getNumArgs() == NumArgs) 9719 return true; 9720 } 9721 } 9722 if (FD && FD->getNumParams() >= NumArgs && 9723 FD->getMinRequiredArguments() <= NumArgs) 9724 return true; 9725 } 9726 return false; 9727 } 9728 9729 private: 9730 unsigned NumArgs; 9731 bool HasExplicitTemplateArgs; 9732}; 9733 9734// Callback that effectively disabled typo correction 9735class NoTypoCorrectionCCC : public CorrectionCandidateCallback { 9736 public: 9737 NoTypoCorrectionCCC() { 9738 WantTypeSpecifiers = false; 9739 WantExpressionKeywords = false; 9740 WantCXXNamedCasts = false; 9741 WantRemainingKeywords = false; 9742 } 9743 9744 virtual bool ValidateCandidate(const TypoCorrection &candidate) { 9745 return false; 9746 } 9747}; 9748 9749class BuildRecoveryCallExprRAII { 9750 Sema &SemaRef; 9751public: 9752 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) { 9753 assert(SemaRef.IsBuildingRecoveryCallExpr == false); 9754 SemaRef.IsBuildingRecoveryCallExpr = true; 9755 } 9756 9757 ~BuildRecoveryCallExprRAII() { 9758 SemaRef.IsBuildingRecoveryCallExpr = false; 9759 } 9760}; 9761 9762} 9763 9764/// Attempts to recover from a call where no functions were found. 9765/// 9766/// Returns true if new candidates were found. 9767static ExprResult 9768BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 9769 UnresolvedLookupExpr *ULE, 9770 SourceLocation LParenLoc, 9771 llvm::MutableArrayRef<Expr *> Args, 9772 SourceLocation RParenLoc, 9773 bool EmptyLookup, bool AllowTypoCorrection) { 9774 // Do not try to recover if it is already building a recovery call. 9775 // This stops infinite loops for template instantiations like 9776 // 9777 // template <typename T> auto foo(T t) -> decltype(foo(t)) {} 9778 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {} 9779 // 9780 if (SemaRef.IsBuildingRecoveryCallExpr) 9781 return ExprError(); 9782 BuildRecoveryCallExprRAII RCE(SemaRef); 9783 9784 CXXScopeSpec SS; 9785 SS.Adopt(ULE->getQualifierLoc()); 9786 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc(); 9787 9788 TemplateArgumentListInfo TABuffer; 9789 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 9790 if (ULE->hasExplicitTemplateArgs()) { 9791 ULE->copyTemplateArgumentsInto(TABuffer); 9792 ExplicitTemplateArgs = &TABuffer; 9793 } 9794 9795 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 9796 Sema::LookupOrdinaryName); 9797 RecoveryCallCCC Validator(SemaRef, Args.size(), ExplicitTemplateArgs != 0); 9798 NoTypoCorrectionCCC RejectAll; 9799 CorrectionCandidateCallback *CCC = AllowTypoCorrection ? 9800 (CorrectionCandidateCallback*)&Validator : 9801 (CorrectionCandidateCallback*)&RejectAll; 9802 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R, 9803 ExplicitTemplateArgs, Args) && 9804 (!EmptyLookup || 9805 SemaRef.DiagnoseEmptyLookup(S, SS, R, *CCC, 9806 ExplicitTemplateArgs, Args))) 9807 return ExprError(); 9808 9809 assert(!R.empty() && "lookup results empty despite recovery"); 9810 9811 // Build an implicit member call if appropriate. Just drop the 9812 // casts and such from the call, we don't really care. 9813 ExprResult NewFn = ExprError(); 9814 if ((*R.begin())->isCXXClassMember()) 9815 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, 9816 R, ExplicitTemplateArgs); 9817 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid()) 9818 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false, 9819 ExplicitTemplateArgs); 9820 else 9821 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 9822 9823 if (NewFn.isInvalid()) 9824 return ExprError(); 9825 9826 // This shouldn't cause an infinite loop because we're giving it 9827 // an expression with viable lookup results, which should never 9828 // end up here. 9829 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 9830 MultiExprArg(Args.data(), Args.size()), 9831 RParenLoc); 9832} 9833 9834/// \brief Constructs and populates an OverloadedCandidateSet from 9835/// the given function. 9836/// \returns true when an the ExprResult output parameter has been set. 9837bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn, 9838 UnresolvedLookupExpr *ULE, 9839 Expr **Args, unsigned NumArgs, 9840 SourceLocation RParenLoc, 9841 OverloadCandidateSet *CandidateSet, 9842 ExprResult *Result) { 9843#ifndef NDEBUG 9844 if (ULE->requiresADL()) { 9845 // To do ADL, we must have found an unqualified name. 9846 assert(!ULE->getQualifier() && "qualified name with ADL"); 9847 9848 // We don't perform ADL for implicit declarations of builtins. 9849 // Verify that this was correctly set up. 9850 FunctionDecl *F; 9851 if (ULE->decls_begin() + 1 == ULE->decls_end() && 9852 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 9853 F->getBuiltinID() && F->isImplicit()) 9854 llvm_unreachable("performing ADL for builtin"); 9855 9856 // We don't perform ADL in C. 9857 assert(getLangOpts().CPlusPlus && "ADL enabled in C"); 9858 } 9859#endif 9860 9861 UnbridgedCastsSet UnbridgedCasts; 9862 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) { 9863 *Result = ExprError(); 9864 return true; 9865 } 9866 9867 // Add the functions denoted by the callee to the set of candidate 9868 // functions, including those from argument-dependent lookup. 9869 AddOverloadedCallCandidates(ULE, llvm::makeArrayRef(Args, NumArgs), 9870 *CandidateSet); 9871 9872 // If we found nothing, try to recover. 9873 // BuildRecoveryCallExpr diagnoses the error itself, so we just bail 9874 // out if it fails. 9875 if (CandidateSet->empty()) { 9876 // In Microsoft mode, if we are inside a template class member function then 9877 // create a type dependent CallExpr. The goal is to postpone name lookup 9878 // to instantiation time to be able to search into type dependent base 9879 // classes. 9880 if (getLangOpts().MicrosoftMode && CurContext->isDependentContext() && 9881 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) { 9882 CallExpr *CE = new (Context) CallExpr(Context, Fn, 9883 llvm::makeArrayRef(Args, NumArgs), 9884 Context.DependentTy, VK_RValue, 9885 RParenLoc); 9886 CE->setTypeDependent(true); 9887 *Result = Owned(CE); 9888 return true; 9889 } 9890 return false; 9891 } 9892 9893 UnbridgedCasts.restore(); 9894 return false; 9895} 9896 9897/// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns 9898/// the completed call expression. If overload resolution fails, emits 9899/// diagnostics and returns ExprError() 9900static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 9901 UnresolvedLookupExpr *ULE, 9902 SourceLocation LParenLoc, 9903 Expr **Args, unsigned NumArgs, 9904 SourceLocation RParenLoc, 9905 Expr *ExecConfig, 9906 OverloadCandidateSet *CandidateSet, 9907 OverloadCandidateSet::iterator *Best, 9908 OverloadingResult OverloadResult, 9909 bool AllowTypoCorrection) { 9910 if (CandidateSet->empty()) 9911 return BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, 9912 llvm::MutableArrayRef<Expr *>(Args, NumArgs), 9913 RParenLoc, /*EmptyLookup=*/true, 9914 AllowTypoCorrection); 9915 9916 switch (OverloadResult) { 9917 case OR_Success: { 9918 FunctionDecl *FDecl = (*Best)->Function; 9919 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl); 9920 SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()); 9921 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl); 9922 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, 9923 RParenLoc, ExecConfig); 9924 } 9925 9926 case OR_No_Viable_Function: { 9927 // Try to recover by looking for viable functions which the user might 9928 // have meant to call. 9929 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, 9930 llvm::MutableArrayRef<Expr *>(Args, NumArgs), 9931 RParenLoc, 9932 /*EmptyLookup=*/false, 9933 AllowTypoCorrection); 9934 if (!Recovery.isInvalid()) 9935 return Recovery; 9936 9937 SemaRef.Diag(Fn->getLocStart(), 9938 diag::err_ovl_no_viable_function_in_call) 9939 << ULE->getName() << Fn->getSourceRange(); 9940 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, 9941 llvm::makeArrayRef(Args, NumArgs)); 9942 break; 9943 } 9944 9945 case OR_Ambiguous: 9946 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_ambiguous_call) 9947 << ULE->getName() << Fn->getSourceRange(); 9948 CandidateSet->NoteCandidates(SemaRef, OCD_ViableCandidates, 9949 llvm::makeArrayRef(Args, NumArgs)); 9950 break; 9951 9952 case OR_Deleted: { 9953 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_deleted_call) 9954 << (*Best)->Function->isDeleted() 9955 << ULE->getName() 9956 << SemaRef.getDeletedOrUnavailableSuffix((*Best)->Function) 9957 << Fn->getSourceRange(); 9958 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, 9959 llvm::makeArrayRef(Args, NumArgs)); 9960 9961 // We emitted an error for the unvailable/deleted function call but keep 9962 // the call in the AST. 9963 FunctionDecl *FDecl = (*Best)->Function; 9964 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl); 9965 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, 9966 RParenLoc, ExecConfig); 9967 } 9968 } 9969 9970 // Overload resolution failed. 9971 return ExprError(); 9972} 9973 9974/// BuildOverloadedCallExpr - Given the call expression that calls Fn 9975/// (which eventually refers to the declaration Func) and the call 9976/// arguments Args/NumArgs, attempt to resolve the function call down 9977/// to a specific function. If overload resolution succeeds, returns 9978/// the call expression produced by overload resolution. 9979/// Otherwise, emits diagnostics and returns ExprError. 9980ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, 9981 UnresolvedLookupExpr *ULE, 9982 SourceLocation LParenLoc, 9983 Expr **Args, unsigned NumArgs, 9984 SourceLocation RParenLoc, 9985 Expr *ExecConfig, 9986 bool AllowTypoCorrection) { 9987 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 9988 ExprResult result; 9989 9990 if (buildOverloadedCallSet(S, Fn, ULE, Args, NumArgs, LParenLoc, 9991 &CandidateSet, &result)) 9992 return result; 9993 9994 OverloadCandidateSet::iterator Best; 9995 OverloadingResult OverloadResult = 9996 CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best); 9997 9998 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 9999 RParenLoc, ExecConfig, &CandidateSet, 10000 &Best, OverloadResult, 10001 AllowTypoCorrection); 10002} 10003 10004static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 10005 return Functions.size() > 1 || 10006 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 10007} 10008 10009/// \brief Create a unary operation that may resolve to an overloaded 10010/// operator. 10011/// 10012/// \param OpLoc The location of the operator itself (e.g., '*'). 10013/// 10014/// \param OpcIn The UnaryOperator::Opcode that describes this 10015/// operator. 10016/// 10017/// \param Fns The set of non-member functions that will be 10018/// considered by overload resolution. The caller needs to build this 10019/// set based on the context using, e.g., 10020/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 10021/// set should not contain any member functions; those will be added 10022/// by CreateOverloadedUnaryOp(). 10023/// 10024/// \param Input The input argument. 10025ExprResult 10026Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 10027 const UnresolvedSetImpl &Fns, 10028 Expr *Input) { 10029 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 10030 10031 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 10032 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 10033 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 10034 // TODO: provide better source location info. 10035 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 10036 10037 if (checkPlaceholderForOverload(*this, Input)) 10038 return ExprError(); 10039 10040 Expr *Args[2] = { Input, 0 }; 10041 unsigned NumArgs = 1; 10042 10043 // For post-increment and post-decrement, add the implicit '0' as 10044 // the second argument, so that we know this is a post-increment or 10045 // post-decrement. 10046 if (Opc == UO_PostInc || Opc == UO_PostDec) { 10047 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 10048 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 10049 SourceLocation()); 10050 NumArgs = 2; 10051 } 10052 10053 if (Input->isTypeDependent()) { 10054 if (Fns.empty()) 10055 return Owned(new (Context) UnaryOperator(Input, 10056 Opc, 10057 Context.DependentTy, 10058 VK_RValue, OK_Ordinary, 10059 OpLoc)); 10060 10061 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10062 UnresolvedLookupExpr *Fn 10063 = UnresolvedLookupExpr::Create(Context, NamingClass, 10064 NestedNameSpecifierLoc(), OpNameInfo, 10065 /*ADL*/ true, IsOverloaded(Fns), 10066 Fns.begin(), Fns.end()); 10067 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 10068 llvm::makeArrayRef(Args, NumArgs), 10069 Context.DependentTy, 10070 VK_RValue, 10071 OpLoc, false)); 10072 } 10073 10074 // Build an empty overload set. 10075 OverloadCandidateSet CandidateSet(OpLoc); 10076 10077 // Add the candidates from the given function set. 10078 AddFunctionCandidates(Fns, llvm::makeArrayRef(Args, NumArgs), CandidateSet, 10079 false); 10080 10081 // Add operator candidates that are member functions. 10082 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 10083 10084 // Add candidates from ADL. 10085 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 10086 OpLoc, llvm::makeArrayRef(Args, NumArgs), 10087 /*ExplicitTemplateArgs*/ 0, 10088 CandidateSet); 10089 10090 // Add builtin operator candidates. 10091 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 10092 10093 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10094 10095 // Perform overload resolution. 10096 OverloadCandidateSet::iterator Best; 10097 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 10098 case OR_Success: { 10099 // We found a built-in operator or an overloaded operator. 10100 FunctionDecl *FnDecl = Best->Function; 10101 10102 if (FnDecl) { 10103 // We matched an overloaded operator. Build a call to that 10104 // operator. 10105 10106 // Convert the arguments. 10107 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 10108 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 10109 10110 ExprResult InputRes = 10111 PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 10112 Best->FoundDecl, Method); 10113 if (InputRes.isInvalid()) 10114 return ExprError(); 10115 Input = InputRes.take(); 10116 } else { 10117 // Convert the arguments. 10118 ExprResult InputInit 10119 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 10120 Context, 10121 FnDecl->getParamDecl(0)), 10122 SourceLocation(), 10123 Input); 10124 if (InputInit.isInvalid()) 10125 return ExprError(); 10126 Input = InputInit.take(); 10127 } 10128 10129 // Determine the result type. 10130 QualType ResultTy = FnDecl->getResultType(); 10131 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10132 ResultTy = ResultTy.getNonLValueExprType(Context); 10133 10134 // Build the actual expression node. 10135 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, Best->FoundDecl, 10136 HadMultipleCandidates, OpLoc); 10137 if (FnExpr.isInvalid()) 10138 return ExprError(); 10139 10140 Args[0] = Input; 10141 CallExpr *TheCall = 10142 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 10143 llvm::makeArrayRef(Args, NumArgs), 10144 ResultTy, VK, OpLoc, false); 10145 10146 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 10147 FnDecl)) 10148 return ExprError(); 10149 10150 return MaybeBindToTemporary(TheCall); 10151 } else { 10152 // We matched a built-in operator. Convert the arguments, then 10153 // break out so that we will build the appropriate built-in 10154 // operator node. 10155 ExprResult InputRes = 10156 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 10157 Best->Conversions[0], AA_Passing); 10158 if (InputRes.isInvalid()) 10159 return ExprError(); 10160 Input = InputRes.take(); 10161 break; 10162 } 10163 } 10164 10165 case OR_No_Viable_Function: 10166 // This is an erroneous use of an operator which can be overloaded by 10167 // a non-member function. Check for non-member operators which were 10168 // defined too late to be candidates. 10169 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, 10170 llvm::makeArrayRef(Args, NumArgs))) 10171 // FIXME: Recover by calling the found function. 10172 return ExprError(); 10173 10174 // No viable function; fall through to handling this as a 10175 // built-in operator, which will produce an error message for us. 10176 break; 10177 10178 case OR_Ambiguous: 10179 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 10180 << UnaryOperator::getOpcodeStr(Opc) 10181 << Input->getType() 10182 << Input->getSourceRange(); 10183 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 10184 llvm::makeArrayRef(Args, NumArgs), 10185 UnaryOperator::getOpcodeStr(Opc), OpLoc); 10186 return ExprError(); 10187 10188 case OR_Deleted: 10189 Diag(OpLoc, diag::err_ovl_deleted_oper) 10190 << Best->Function->isDeleted() 10191 << UnaryOperator::getOpcodeStr(Opc) 10192 << getDeletedOrUnavailableSuffix(Best->Function) 10193 << Input->getSourceRange(); 10194 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10195 llvm::makeArrayRef(Args, NumArgs), 10196 UnaryOperator::getOpcodeStr(Opc), OpLoc); 10197 return ExprError(); 10198 } 10199 10200 // Either we found no viable overloaded operator or we matched a 10201 // built-in operator. In either case, fall through to trying to 10202 // build a built-in operation. 10203 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 10204} 10205 10206/// \brief Create a binary operation that may resolve to an overloaded 10207/// operator. 10208/// 10209/// \param OpLoc The location of the operator itself (e.g., '+'). 10210/// 10211/// \param OpcIn The BinaryOperator::Opcode that describes this 10212/// operator. 10213/// 10214/// \param Fns The set of non-member functions that will be 10215/// considered by overload resolution. The caller needs to build this 10216/// set based on the context using, e.g., 10217/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 10218/// set should not contain any member functions; those will be added 10219/// by CreateOverloadedBinOp(). 10220/// 10221/// \param LHS Left-hand argument. 10222/// \param RHS Right-hand argument. 10223ExprResult 10224Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 10225 unsigned OpcIn, 10226 const UnresolvedSetImpl &Fns, 10227 Expr *LHS, Expr *RHS) { 10228 Expr *Args[2] = { LHS, RHS }; 10229 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 10230 10231 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 10232 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 10233 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 10234 10235 // If either side is type-dependent, create an appropriate dependent 10236 // expression. 10237 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 10238 if (Fns.empty()) { 10239 // If there are no functions to store, just build a dependent 10240 // BinaryOperator or CompoundAssignment. 10241 if (Opc <= BO_Assign || Opc > BO_OrAssign) 10242 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 10243 Context.DependentTy, 10244 VK_RValue, OK_Ordinary, 10245 OpLoc, 10246 FPFeatures.fp_contract)); 10247 10248 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 10249 Context.DependentTy, 10250 VK_LValue, 10251 OK_Ordinary, 10252 Context.DependentTy, 10253 Context.DependentTy, 10254 OpLoc, 10255 FPFeatures.fp_contract)); 10256 } 10257 10258 // FIXME: save results of ADL from here? 10259 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10260 // TODO: provide better source location info in DNLoc component. 10261 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 10262 UnresolvedLookupExpr *Fn 10263 = UnresolvedLookupExpr::Create(Context, NamingClass, 10264 NestedNameSpecifierLoc(), OpNameInfo, 10265 /*ADL*/ true, IsOverloaded(Fns), 10266 Fns.begin(), Fns.end()); 10267 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, Args, 10268 Context.DependentTy, VK_RValue, 10269 OpLoc, FPFeatures.fp_contract)); 10270 } 10271 10272 // Always do placeholder-like conversions on the RHS. 10273 if (checkPlaceholderForOverload(*this, Args[1])) 10274 return ExprError(); 10275 10276 // Do placeholder-like conversion on the LHS; note that we should 10277 // not get here with a PseudoObject LHS. 10278 assert(Args[0]->getObjectKind() != OK_ObjCProperty); 10279 if (checkPlaceholderForOverload(*this, Args[0])) 10280 return ExprError(); 10281 10282 // If this is the assignment operator, we only perform overload resolution 10283 // if the left-hand side is a class or enumeration type. This is actually 10284 // a hack. The standard requires that we do overload resolution between the 10285 // various built-in candidates, but as DR507 points out, this can lead to 10286 // problems. So we do it this way, which pretty much follows what GCC does. 10287 // Note that we go the traditional code path for compound assignment forms. 10288 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 10289 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10290 10291 // If this is the .* operator, which is not overloadable, just 10292 // create a built-in binary operator. 10293 if (Opc == BO_PtrMemD) 10294 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10295 10296 // Build an empty overload set. 10297 OverloadCandidateSet CandidateSet(OpLoc); 10298 10299 // Add the candidates from the given function set. 10300 AddFunctionCandidates(Fns, Args, CandidateSet, false); 10301 10302 // Add operator candidates that are member functions. 10303 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 10304 10305 // Add candidates from ADL. 10306 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 10307 OpLoc, Args, 10308 /*ExplicitTemplateArgs*/ 0, 10309 CandidateSet); 10310 10311 // Add builtin operator candidates. 10312 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 10313 10314 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10315 10316 // Perform overload resolution. 10317 OverloadCandidateSet::iterator Best; 10318 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 10319 case OR_Success: { 10320 // We found a built-in operator or an overloaded operator. 10321 FunctionDecl *FnDecl = Best->Function; 10322 10323 if (FnDecl) { 10324 // We matched an overloaded operator. Build a call to that 10325 // operator. 10326 10327 // Convert the arguments. 10328 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 10329 // Best->Access is only meaningful for class members. 10330 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 10331 10332 ExprResult Arg1 = 10333 PerformCopyInitialization( 10334 InitializedEntity::InitializeParameter(Context, 10335 FnDecl->getParamDecl(0)), 10336 SourceLocation(), Owned(Args[1])); 10337 if (Arg1.isInvalid()) 10338 return ExprError(); 10339 10340 ExprResult Arg0 = 10341 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 10342 Best->FoundDecl, Method); 10343 if (Arg0.isInvalid()) 10344 return ExprError(); 10345 Args[0] = Arg0.takeAs<Expr>(); 10346 Args[1] = RHS = Arg1.takeAs<Expr>(); 10347 } else { 10348 // Convert the arguments. 10349 ExprResult Arg0 = PerformCopyInitialization( 10350 InitializedEntity::InitializeParameter(Context, 10351 FnDecl->getParamDecl(0)), 10352 SourceLocation(), Owned(Args[0])); 10353 if (Arg0.isInvalid()) 10354 return ExprError(); 10355 10356 ExprResult Arg1 = 10357 PerformCopyInitialization( 10358 InitializedEntity::InitializeParameter(Context, 10359 FnDecl->getParamDecl(1)), 10360 SourceLocation(), Owned(Args[1])); 10361 if (Arg1.isInvalid()) 10362 return ExprError(); 10363 Args[0] = LHS = Arg0.takeAs<Expr>(); 10364 Args[1] = RHS = Arg1.takeAs<Expr>(); 10365 } 10366 10367 // Determine the result type. 10368 QualType ResultTy = FnDecl->getResultType(); 10369 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10370 ResultTy = ResultTy.getNonLValueExprType(Context); 10371 10372 // Build the actual expression node. 10373 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 10374 Best->FoundDecl, 10375 HadMultipleCandidates, OpLoc); 10376 if (FnExpr.isInvalid()) 10377 return ExprError(); 10378 10379 CXXOperatorCallExpr *TheCall = 10380 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 10381 Args, ResultTy, VK, OpLoc, 10382 FPFeatures.fp_contract); 10383 10384 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 10385 FnDecl)) 10386 return ExprError(); 10387 10388 ArrayRef<const Expr *> ArgsArray(Args, 2); 10389 // Cut off the implicit 'this'. 10390 if (isa<CXXMethodDecl>(FnDecl)) 10391 ArgsArray = ArgsArray.slice(1); 10392 checkCall(FnDecl, ArgsArray, 0, isa<CXXMethodDecl>(FnDecl), OpLoc, 10393 TheCall->getSourceRange(), VariadicDoesNotApply); 10394 10395 return MaybeBindToTemporary(TheCall); 10396 } else { 10397 // We matched a built-in operator. Convert the arguments, then 10398 // break out so that we will build the appropriate built-in 10399 // operator node. 10400 ExprResult ArgsRes0 = 10401 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 10402 Best->Conversions[0], AA_Passing); 10403 if (ArgsRes0.isInvalid()) 10404 return ExprError(); 10405 Args[0] = ArgsRes0.take(); 10406 10407 ExprResult ArgsRes1 = 10408 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 10409 Best->Conversions[1], AA_Passing); 10410 if (ArgsRes1.isInvalid()) 10411 return ExprError(); 10412 Args[1] = ArgsRes1.take(); 10413 break; 10414 } 10415 } 10416 10417 case OR_No_Viable_Function: { 10418 // C++ [over.match.oper]p9: 10419 // If the operator is the operator , [...] and there are no 10420 // viable functions, then the operator is assumed to be the 10421 // built-in operator and interpreted according to clause 5. 10422 if (Opc == BO_Comma) 10423 break; 10424 10425 // For class as left operand for assignment or compound assigment 10426 // operator do not fall through to handling in built-in, but report that 10427 // no overloaded assignment operator found 10428 ExprResult Result = ExprError(); 10429 if (Args[0]->getType()->isRecordType() && 10430 Opc >= BO_Assign && Opc <= BO_OrAssign) { 10431 Diag(OpLoc, diag::err_ovl_no_viable_oper) 10432 << BinaryOperator::getOpcodeStr(Opc) 10433 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10434 } else { 10435 // This is an erroneous use of an operator which can be overloaded by 10436 // a non-member function. Check for non-member operators which were 10437 // defined too late to be candidates. 10438 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args)) 10439 // FIXME: Recover by calling the found function. 10440 return ExprError(); 10441 10442 // No viable function; try to create a built-in operation, which will 10443 // produce an error. Then, show the non-viable candidates. 10444 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10445 } 10446 assert(Result.isInvalid() && 10447 "C++ binary operator overloading is missing candidates!"); 10448 if (Result.isInvalid()) 10449 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10450 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10451 return Result; 10452 } 10453 10454 case OR_Ambiguous: 10455 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 10456 << BinaryOperator::getOpcodeStr(Opc) 10457 << Args[0]->getType() << Args[1]->getType() 10458 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10459 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 10460 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10461 return ExprError(); 10462 10463 case OR_Deleted: 10464 if (isImplicitlyDeleted(Best->Function)) { 10465 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 10466 Diag(OpLoc, diag::err_ovl_deleted_special_oper) 10467 << Context.getRecordType(Method->getParent()) 10468 << getSpecialMember(Method); 10469 10470 // The user probably meant to call this special member. Just 10471 // explain why it's deleted. 10472 NoteDeletedFunction(Method); 10473 return ExprError(); 10474 } else { 10475 Diag(OpLoc, diag::err_ovl_deleted_oper) 10476 << Best->Function->isDeleted() 10477 << BinaryOperator::getOpcodeStr(Opc) 10478 << getDeletedOrUnavailableSuffix(Best->Function) 10479 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10480 } 10481 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10482 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10483 return ExprError(); 10484 } 10485 10486 // We matched a built-in operator; build it. 10487 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10488} 10489 10490ExprResult 10491Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 10492 SourceLocation RLoc, 10493 Expr *Base, Expr *Idx) { 10494 Expr *Args[2] = { Base, Idx }; 10495 DeclarationName OpName = 10496 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 10497 10498 // If either side is type-dependent, create an appropriate dependent 10499 // expression. 10500 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 10501 10502 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10503 // CHECKME: no 'operator' keyword? 10504 DeclarationNameInfo OpNameInfo(OpName, LLoc); 10505 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 10506 UnresolvedLookupExpr *Fn 10507 = UnresolvedLookupExpr::Create(Context, NamingClass, 10508 NestedNameSpecifierLoc(), OpNameInfo, 10509 /*ADL*/ true, /*Overloaded*/ false, 10510 UnresolvedSetIterator(), 10511 UnresolvedSetIterator()); 10512 // Can't add any actual overloads yet 10513 10514 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 10515 Args, 10516 Context.DependentTy, 10517 VK_RValue, 10518 RLoc, false)); 10519 } 10520 10521 // Handle placeholders on both operands. 10522 if (checkPlaceholderForOverload(*this, Args[0])) 10523 return ExprError(); 10524 if (checkPlaceholderForOverload(*this, Args[1])) 10525 return ExprError(); 10526 10527 // Build an empty overload set. 10528 OverloadCandidateSet CandidateSet(LLoc); 10529 10530 // Subscript can only be overloaded as a member function. 10531 10532 // Add operator candidates that are member functions. 10533 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 10534 10535 // Add builtin operator candidates. 10536 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 10537 10538 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10539 10540 // Perform overload resolution. 10541 OverloadCandidateSet::iterator Best; 10542 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 10543 case OR_Success: { 10544 // We found a built-in operator or an overloaded operator. 10545 FunctionDecl *FnDecl = Best->Function; 10546 10547 if (FnDecl) { 10548 // We matched an overloaded operator. Build a call to that 10549 // operator. 10550 10551 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 10552 10553 // Convert the arguments. 10554 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 10555 ExprResult Arg0 = 10556 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 10557 Best->FoundDecl, Method); 10558 if (Arg0.isInvalid()) 10559 return ExprError(); 10560 Args[0] = Arg0.take(); 10561 10562 // Convert the arguments. 10563 ExprResult InputInit 10564 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 10565 Context, 10566 FnDecl->getParamDecl(0)), 10567 SourceLocation(), 10568 Owned(Args[1])); 10569 if (InputInit.isInvalid()) 10570 return ExprError(); 10571 10572 Args[1] = InputInit.takeAs<Expr>(); 10573 10574 // Determine the result type 10575 QualType ResultTy = FnDecl->getResultType(); 10576 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10577 ResultTy = ResultTy.getNonLValueExprType(Context); 10578 10579 // Build the actual expression node. 10580 DeclarationNameInfo OpLocInfo(OpName, LLoc); 10581 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 10582 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 10583 Best->FoundDecl, 10584 HadMultipleCandidates, 10585 OpLocInfo.getLoc(), 10586 OpLocInfo.getInfo()); 10587 if (FnExpr.isInvalid()) 10588 return ExprError(); 10589 10590 CXXOperatorCallExpr *TheCall = 10591 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 10592 FnExpr.take(), Args, 10593 ResultTy, VK, RLoc, 10594 false); 10595 10596 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 10597 FnDecl)) 10598 return ExprError(); 10599 10600 return MaybeBindToTemporary(TheCall); 10601 } else { 10602 // We matched a built-in operator. Convert the arguments, then 10603 // break out so that we will build the appropriate built-in 10604 // operator node. 10605 ExprResult ArgsRes0 = 10606 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 10607 Best->Conversions[0], AA_Passing); 10608 if (ArgsRes0.isInvalid()) 10609 return ExprError(); 10610 Args[0] = ArgsRes0.take(); 10611 10612 ExprResult ArgsRes1 = 10613 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 10614 Best->Conversions[1], AA_Passing); 10615 if (ArgsRes1.isInvalid()) 10616 return ExprError(); 10617 Args[1] = ArgsRes1.take(); 10618 10619 break; 10620 } 10621 } 10622 10623 case OR_No_Viable_Function: { 10624 if (CandidateSet.empty()) 10625 Diag(LLoc, diag::err_ovl_no_oper) 10626 << Args[0]->getType() << /*subscript*/ 0 10627 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10628 else 10629 Diag(LLoc, diag::err_ovl_no_viable_subscript) 10630 << Args[0]->getType() 10631 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10632 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10633 "[]", LLoc); 10634 return ExprError(); 10635 } 10636 10637 case OR_Ambiguous: 10638 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 10639 << "[]" 10640 << Args[0]->getType() << Args[1]->getType() 10641 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10642 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 10643 "[]", LLoc); 10644 return ExprError(); 10645 10646 case OR_Deleted: 10647 Diag(LLoc, diag::err_ovl_deleted_oper) 10648 << Best->Function->isDeleted() << "[]" 10649 << getDeletedOrUnavailableSuffix(Best->Function) 10650 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10651 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10652 "[]", LLoc); 10653 return ExprError(); 10654 } 10655 10656 // We matched a built-in operator; build it. 10657 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 10658} 10659 10660/// BuildCallToMemberFunction - Build a call to a member 10661/// function. MemExpr is the expression that refers to the member 10662/// function (and includes the object parameter), Args/NumArgs are the 10663/// arguments to the function call (not including the object 10664/// parameter). The caller needs to validate that the member 10665/// expression refers to a non-static member function or an overloaded 10666/// member function. 10667ExprResult 10668Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 10669 SourceLocation LParenLoc, Expr **Args, 10670 unsigned NumArgs, SourceLocation RParenLoc) { 10671 assert(MemExprE->getType() == Context.BoundMemberTy || 10672 MemExprE->getType() == Context.OverloadTy); 10673 10674 // Dig out the member expression. This holds both the object 10675 // argument and the member function we're referring to. 10676 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 10677 10678 // Determine whether this is a call to a pointer-to-member function. 10679 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) { 10680 assert(op->getType() == Context.BoundMemberTy); 10681 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI); 10682 10683 QualType fnType = 10684 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType(); 10685 10686 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>(); 10687 QualType resultType = proto->getCallResultType(Context); 10688 ExprValueKind valueKind = Expr::getValueKindForType(proto->getResultType()); 10689 10690 // Check that the object type isn't more qualified than the 10691 // member function we're calling. 10692 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals()); 10693 10694 QualType objectType = op->getLHS()->getType(); 10695 if (op->getOpcode() == BO_PtrMemI) 10696 objectType = objectType->castAs<PointerType>()->getPointeeType(); 10697 Qualifiers objectQuals = objectType.getQualifiers(); 10698 10699 Qualifiers difference = objectQuals - funcQuals; 10700 difference.removeObjCGCAttr(); 10701 difference.removeAddressSpace(); 10702 if (difference) { 10703 std::string qualsString = difference.getAsString(); 10704 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals) 10705 << fnType.getUnqualifiedType() 10706 << qualsString 10707 << (qualsString.find(' ') == std::string::npos ? 1 : 2); 10708 } 10709 10710 CXXMemberCallExpr *call 10711 = new (Context) CXXMemberCallExpr(Context, MemExprE, 10712 llvm::makeArrayRef(Args, NumArgs), 10713 resultType, valueKind, RParenLoc); 10714 10715 if (CheckCallReturnType(proto->getResultType(), 10716 op->getRHS()->getLocStart(), 10717 call, 0)) 10718 return ExprError(); 10719 10720 if (ConvertArgumentsForCall(call, op, 0, proto, Args, NumArgs, RParenLoc)) 10721 return ExprError(); 10722 10723 return MaybeBindToTemporary(call); 10724 } 10725 10726 UnbridgedCastsSet UnbridgedCasts; 10727 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) 10728 return ExprError(); 10729 10730 MemberExpr *MemExpr; 10731 CXXMethodDecl *Method = 0; 10732 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 10733 NestedNameSpecifier *Qualifier = 0; 10734 if (isa<MemberExpr>(NakedMemExpr)) { 10735 MemExpr = cast<MemberExpr>(NakedMemExpr); 10736 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 10737 FoundDecl = MemExpr->getFoundDecl(); 10738 Qualifier = MemExpr->getQualifier(); 10739 UnbridgedCasts.restore(); 10740 } else { 10741 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 10742 Qualifier = UnresExpr->getQualifier(); 10743 10744 QualType ObjectType = UnresExpr->getBaseType(); 10745 Expr::Classification ObjectClassification 10746 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 10747 : UnresExpr->getBase()->Classify(Context); 10748 10749 // Add overload candidates 10750 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 10751 10752 // FIXME: avoid copy. 10753 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 10754 if (UnresExpr->hasExplicitTemplateArgs()) { 10755 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 10756 TemplateArgs = &TemplateArgsBuffer; 10757 } 10758 10759 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 10760 E = UnresExpr->decls_end(); I != E; ++I) { 10761 10762 NamedDecl *Func = *I; 10763 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 10764 if (isa<UsingShadowDecl>(Func)) 10765 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 10766 10767 10768 // Microsoft supports direct constructor calls. 10769 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) { 10770 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), 10771 llvm::makeArrayRef(Args, NumArgs), CandidateSet); 10772 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 10773 // If explicit template arguments were provided, we can't call a 10774 // non-template member function. 10775 if (TemplateArgs) 10776 continue; 10777 10778 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 10779 ObjectClassification, 10780 llvm::makeArrayRef(Args, NumArgs), CandidateSet, 10781 /*SuppressUserConversions=*/false); 10782 } else { 10783 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 10784 I.getPair(), ActingDC, TemplateArgs, 10785 ObjectType, ObjectClassification, 10786 llvm::makeArrayRef(Args, NumArgs), 10787 CandidateSet, 10788 /*SuppressUsedConversions=*/false); 10789 } 10790 } 10791 10792 DeclarationName DeclName = UnresExpr->getMemberName(); 10793 10794 UnbridgedCasts.restore(); 10795 10796 OverloadCandidateSet::iterator Best; 10797 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 10798 Best)) { 10799 case OR_Success: 10800 Method = cast<CXXMethodDecl>(Best->Function); 10801 FoundDecl = Best->FoundDecl; 10802 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 10803 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 10804 break; 10805 10806 case OR_No_Viable_Function: 10807 Diag(UnresExpr->getMemberLoc(), 10808 diag::err_ovl_no_viable_member_function_in_call) 10809 << DeclName << MemExprE->getSourceRange(); 10810 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10811 llvm::makeArrayRef(Args, NumArgs)); 10812 // FIXME: Leaking incoming expressions! 10813 return ExprError(); 10814 10815 case OR_Ambiguous: 10816 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 10817 << DeclName << MemExprE->getSourceRange(); 10818 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10819 llvm::makeArrayRef(Args, NumArgs)); 10820 // FIXME: Leaking incoming expressions! 10821 return ExprError(); 10822 10823 case OR_Deleted: 10824 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 10825 << Best->Function->isDeleted() 10826 << DeclName 10827 << getDeletedOrUnavailableSuffix(Best->Function) 10828 << MemExprE->getSourceRange(); 10829 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10830 llvm::makeArrayRef(Args, NumArgs)); 10831 // FIXME: Leaking incoming expressions! 10832 return ExprError(); 10833 } 10834 10835 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 10836 10837 // If overload resolution picked a static member, build a 10838 // non-member call based on that function. 10839 if (Method->isStatic()) { 10840 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 10841 Args, NumArgs, RParenLoc); 10842 } 10843 10844 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 10845 } 10846 10847 QualType ResultType = Method->getResultType(); 10848 ExprValueKind VK = Expr::getValueKindForType(ResultType); 10849 ResultType = ResultType.getNonLValueExprType(Context); 10850 10851 assert(Method && "Member call to something that isn't a method?"); 10852 CXXMemberCallExpr *TheCall = 10853 new (Context) CXXMemberCallExpr(Context, MemExprE, 10854 llvm::makeArrayRef(Args, NumArgs), 10855 ResultType, VK, RParenLoc); 10856 10857 // Check for a valid return type. 10858 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 10859 TheCall, Method)) 10860 return ExprError(); 10861 10862 // Convert the object argument (for a non-static member function call). 10863 // We only need to do this if there was actually an overload; otherwise 10864 // it was done at lookup. 10865 if (!Method->isStatic()) { 10866 ExprResult ObjectArg = 10867 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier, 10868 FoundDecl, Method); 10869 if (ObjectArg.isInvalid()) 10870 return ExprError(); 10871 MemExpr->setBase(ObjectArg.take()); 10872 } 10873 10874 // Convert the rest of the arguments 10875 const FunctionProtoType *Proto = 10876 Method->getType()->getAs<FunctionProtoType>(); 10877 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 10878 RParenLoc)) 10879 return ExprError(); 10880 10881 DiagnoseSentinelCalls(Method, LParenLoc, Args, NumArgs); 10882 10883 if (CheckFunctionCall(Method, TheCall, Proto)) 10884 return ExprError(); 10885 10886 if ((isa<CXXConstructorDecl>(CurContext) || 10887 isa<CXXDestructorDecl>(CurContext)) && 10888 TheCall->getMethodDecl()->isPure()) { 10889 const CXXMethodDecl *MD = TheCall->getMethodDecl(); 10890 10891 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts())) { 10892 Diag(MemExpr->getLocStart(), 10893 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor) 10894 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext) 10895 << MD->getParent()->getDeclName(); 10896 10897 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName(); 10898 } 10899 } 10900 return MaybeBindToTemporary(TheCall); 10901} 10902 10903/// BuildCallToObjectOfClassType - Build a call to an object of class 10904/// type (C++ [over.call.object]), which can end up invoking an 10905/// overloaded function call operator (@c operator()) or performing a 10906/// user-defined conversion on the object argument. 10907ExprResult 10908Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj, 10909 SourceLocation LParenLoc, 10910 Expr **Args, unsigned NumArgs, 10911 SourceLocation RParenLoc) { 10912 if (checkPlaceholderForOverload(*this, Obj)) 10913 return ExprError(); 10914 ExprResult Object = Owned(Obj); 10915 10916 UnbridgedCastsSet UnbridgedCasts; 10917 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) 10918 return ExprError(); 10919 10920 assert(Object.get()->getType()->isRecordType() && "Requires object type argument"); 10921 const RecordType *Record = Object.get()->getType()->getAs<RecordType>(); 10922 10923 // C++ [over.call.object]p1: 10924 // If the primary-expression E in the function call syntax 10925 // evaluates to a class object of type "cv T", then the set of 10926 // candidate functions includes at least the function call 10927 // operators of T. The function call operators of T are obtained by 10928 // ordinary lookup of the name operator() in the context of 10929 // (E).operator(). 10930 OverloadCandidateSet CandidateSet(LParenLoc); 10931 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 10932 10933 if (RequireCompleteType(LParenLoc, Object.get()->getType(), 10934 diag::err_incomplete_object_call, Object.get())) 10935 return true; 10936 10937 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 10938 LookupQualifiedName(R, Record->getDecl()); 10939 R.suppressDiagnostics(); 10940 10941 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 10942 Oper != OperEnd; ++Oper) { 10943 AddMethodCandidate(Oper.getPair(), Object.get()->getType(), 10944 Object.get()->Classify(Context), Args, NumArgs, CandidateSet, 10945 /*SuppressUserConversions=*/ false); 10946 } 10947 10948 // C++ [over.call.object]p2: 10949 // In addition, for each (non-explicit in C++0x) conversion function 10950 // declared in T of the form 10951 // 10952 // operator conversion-type-id () cv-qualifier; 10953 // 10954 // where cv-qualifier is the same cv-qualification as, or a 10955 // greater cv-qualification than, cv, and where conversion-type-id 10956 // denotes the type "pointer to function of (P1,...,Pn) returning 10957 // R", or the type "reference to pointer to function of 10958 // (P1,...,Pn) returning R", or the type "reference to function 10959 // of (P1,...,Pn) returning R", a surrogate call function [...] 10960 // is also considered as a candidate function. Similarly, 10961 // surrogate call functions are added to the set of candidate 10962 // functions for each conversion function declared in an 10963 // accessible base class provided the function is not hidden 10964 // within T by another intervening declaration. 10965 std::pair<CXXRecordDecl::conversion_iterator, 10966 CXXRecordDecl::conversion_iterator> Conversions 10967 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 10968 for (CXXRecordDecl::conversion_iterator 10969 I = Conversions.first, E = Conversions.second; I != E; ++I) { 10970 NamedDecl *D = *I; 10971 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 10972 if (isa<UsingShadowDecl>(D)) 10973 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 10974 10975 // Skip over templated conversion functions; they aren't 10976 // surrogates. 10977 if (isa<FunctionTemplateDecl>(D)) 10978 continue; 10979 10980 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 10981 if (!Conv->isExplicit()) { 10982 // Strip the reference type (if any) and then the pointer type (if 10983 // any) to get down to what might be a function type. 10984 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 10985 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 10986 ConvType = ConvPtrType->getPointeeType(); 10987 10988 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 10989 { 10990 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 10991 Object.get(), llvm::makeArrayRef(Args, NumArgs), 10992 CandidateSet); 10993 } 10994 } 10995 } 10996 10997 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10998 10999 // Perform overload resolution. 11000 OverloadCandidateSet::iterator Best; 11001 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(), 11002 Best)) { 11003 case OR_Success: 11004 // Overload resolution succeeded; we'll build the appropriate call 11005 // below. 11006 break; 11007 11008 case OR_No_Viable_Function: 11009 if (CandidateSet.empty()) 11010 Diag(Object.get()->getLocStart(), diag::err_ovl_no_oper) 11011 << Object.get()->getType() << /*call*/ 1 11012 << Object.get()->getSourceRange(); 11013 else 11014 Diag(Object.get()->getLocStart(), 11015 diag::err_ovl_no_viable_object_call) 11016 << Object.get()->getType() << Object.get()->getSourceRange(); 11017 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 11018 llvm::makeArrayRef(Args, NumArgs)); 11019 break; 11020 11021 case OR_Ambiguous: 11022 Diag(Object.get()->getLocStart(), 11023 diag::err_ovl_ambiguous_object_call) 11024 << Object.get()->getType() << Object.get()->getSourceRange(); 11025 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 11026 llvm::makeArrayRef(Args, NumArgs)); 11027 break; 11028 11029 case OR_Deleted: 11030 Diag(Object.get()->getLocStart(), 11031 diag::err_ovl_deleted_object_call) 11032 << Best->Function->isDeleted() 11033 << Object.get()->getType() 11034 << getDeletedOrUnavailableSuffix(Best->Function) 11035 << Object.get()->getSourceRange(); 11036 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 11037 llvm::makeArrayRef(Args, NumArgs)); 11038 break; 11039 } 11040 11041 if (Best == CandidateSet.end()) 11042 return true; 11043 11044 UnbridgedCasts.restore(); 11045 11046 if (Best->Function == 0) { 11047 // Since there is no function declaration, this is one of the 11048 // surrogate candidates. Dig out the conversion function. 11049 CXXConversionDecl *Conv 11050 = cast<CXXConversionDecl>( 11051 Best->Conversions[0].UserDefined.ConversionFunction); 11052 11053 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 11054 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 11055 11056 // We selected one of the surrogate functions that converts the 11057 // object parameter to a function pointer. Perform the conversion 11058 // on the object argument, then let ActOnCallExpr finish the job. 11059 11060 // Create an implicit member expr to refer to the conversion operator. 11061 // and then call it. 11062 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl, 11063 Conv, HadMultipleCandidates); 11064 if (Call.isInvalid()) 11065 return ExprError(); 11066 // Record usage of conversion in an implicit cast. 11067 Call = Owned(ImplicitCastExpr::Create(Context, Call.get()->getType(), 11068 CK_UserDefinedConversion, 11069 Call.get(), 0, VK_RValue)); 11070 11071 return ActOnCallExpr(S, Call.get(), LParenLoc, MultiExprArg(Args, NumArgs), 11072 RParenLoc); 11073 } 11074 11075 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 11076 11077 // We found an overloaded operator(). Build a CXXOperatorCallExpr 11078 // that calls this method, using Object for the implicit object 11079 // parameter and passing along the remaining arguments. 11080 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 11081 11082 // An error diagnostic has already been printed when parsing the declaration. 11083 if (Method->isInvalidDecl()) 11084 return ExprError(); 11085 11086 const FunctionProtoType *Proto = 11087 Method->getType()->getAs<FunctionProtoType>(); 11088 11089 unsigned NumArgsInProto = Proto->getNumArgs(); 11090 unsigned NumArgsToCheck = NumArgs; 11091 11092 // Build the full argument list for the method call (the 11093 // implicit object parameter is placed at the beginning of the 11094 // list). 11095 Expr **MethodArgs; 11096 if (NumArgs < NumArgsInProto) { 11097 NumArgsToCheck = NumArgsInProto; 11098 MethodArgs = new Expr*[NumArgsInProto + 1]; 11099 } else { 11100 MethodArgs = new Expr*[NumArgs + 1]; 11101 } 11102 MethodArgs[0] = Object.get(); 11103 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 11104 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 11105 11106 DeclarationNameInfo OpLocInfo( 11107 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc); 11108 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc)); 11109 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, Best->FoundDecl, 11110 HadMultipleCandidates, 11111 OpLocInfo.getLoc(), 11112 OpLocInfo.getInfo()); 11113 if (NewFn.isInvalid()) 11114 return true; 11115 11116 // Once we've built TheCall, all of the expressions are properly 11117 // owned. 11118 QualType ResultTy = Method->getResultType(); 11119 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11120 ResultTy = ResultTy.getNonLValueExprType(Context); 11121 11122 CXXOperatorCallExpr *TheCall = 11123 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn.take(), 11124 llvm::makeArrayRef(MethodArgs, NumArgs+1), 11125 ResultTy, VK, RParenLoc, false); 11126 delete [] MethodArgs; 11127 11128 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 11129 Method)) 11130 return true; 11131 11132 // We may have default arguments. If so, we need to allocate more 11133 // slots in the call for them. 11134 if (NumArgs < NumArgsInProto) 11135 TheCall->setNumArgs(Context, NumArgsInProto + 1); 11136 else if (NumArgs > NumArgsInProto) 11137 NumArgsToCheck = NumArgsInProto; 11138 11139 bool IsError = false; 11140 11141 // Initialize the implicit object parameter. 11142 ExprResult ObjRes = 11143 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/0, 11144 Best->FoundDecl, Method); 11145 if (ObjRes.isInvalid()) 11146 IsError = true; 11147 else 11148 Object = ObjRes; 11149 TheCall->setArg(0, Object.take()); 11150 11151 // Check the argument types. 11152 for (unsigned i = 0; i != NumArgsToCheck; i++) { 11153 Expr *Arg; 11154 if (i < NumArgs) { 11155 Arg = Args[i]; 11156 11157 // Pass the argument. 11158 11159 ExprResult InputInit 11160 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 11161 Context, 11162 Method->getParamDecl(i)), 11163 SourceLocation(), Arg); 11164 11165 IsError |= InputInit.isInvalid(); 11166 Arg = InputInit.takeAs<Expr>(); 11167 } else { 11168 ExprResult DefArg 11169 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 11170 if (DefArg.isInvalid()) { 11171 IsError = true; 11172 break; 11173 } 11174 11175 Arg = DefArg.takeAs<Expr>(); 11176 } 11177 11178 TheCall->setArg(i + 1, Arg); 11179 } 11180 11181 // If this is a variadic call, handle args passed through "...". 11182 if (Proto->isVariadic()) { 11183 // Promote the arguments (C99 6.5.2.2p7). 11184 for (unsigned i = NumArgsInProto; i < NumArgs; i++) { 11185 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod, 0); 11186 IsError |= Arg.isInvalid(); 11187 TheCall->setArg(i + 1, Arg.take()); 11188 } 11189 } 11190 11191 if (IsError) return true; 11192 11193 DiagnoseSentinelCalls(Method, LParenLoc, Args, NumArgs); 11194 11195 if (CheckFunctionCall(Method, TheCall, Proto)) 11196 return true; 11197 11198 return MaybeBindToTemporary(TheCall); 11199} 11200 11201/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 11202/// (if one exists), where @c Base is an expression of class type and 11203/// @c Member is the name of the member we're trying to find. 11204ExprResult 11205Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 11206 assert(Base->getType()->isRecordType() && 11207 "left-hand side must have class type"); 11208 11209 if (checkPlaceholderForOverload(*this, Base)) 11210 return ExprError(); 11211 11212 SourceLocation Loc = Base->getExprLoc(); 11213 11214 // C++ [over.ref]p1: 11215 // 11216 // [...] An expression x->m is interpreted as (x.operator->())->m 11217 // for a class object x of type T if T::operator->() exists and if 11218 // the operator is selected as the best match function by the 11219 // overload resolution mechanism (13.3). 11220 DeclarationName OpName = 11221 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 11222 OverloadCandidateSet CandidateSet(Loc); 11223 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 11224 11225 if (RequireCompleteType(Loc, Base->getType(), 11226 diag::err_typecheck_incomplete_tag, Base)) 11227 return ExprError(); 11228 11229 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 11230 LookupQualifiedName(R, BaseRecord->getDecl()); 11231 R.suppressDiagnostics(); 11232 11233 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 11234 Oper != OperEnd; ++Oper) { 11235 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 11236 0, 0, CandidateSet, /*SuppressUserConversions=*/false); 11237 } 11238 11239 bool HadMultipleCandidates = (CandidateSet.size() > 1); 11240 11241 // Perform overload resolution. 11242 OverloadCandidateSet::iterator Best; 11243 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 11244 case OR_Success: 11245 // Overload resolution succeeded; we'll build the call below. 11246 break; 11247 11248 case OR_No_Viable_Function: 11249 if (CandidateSet.empty()) 11250 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 11251 << Base->getType() << Base->getSourceRange(); 11252 else 11253 Diag(OpLoc, diag::err_ovl_no_viable_oper) 11254 << "operator->" << Base->getSourceRange(); 11255 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base); 11256 return ExprError(); 11257 11258 case OR_Ambiguous: 11259 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 11260 << "->" << Base->getType() << Base->getSourceRange(); 11261 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Base); 11262 return ExprError(); 11263 11264 case OR_Deleted: 11265 Diag(OpLoc, diag::err_ovl_deleted_oper) 11266 << Best->Function->isDeleted() 11267 << "->" 11268 << getDeletedOrUnavailableSuffix(Best->Function) 11269 << Base->getSourceRange(); 11270 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base); 11271 return ExprError(); 11272 } 11273 11274 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 11275 11276 // Convert the object parameter. 11277 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 11278 ExprResult BaseResult = 11279 PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 11280 Best->FoundDecl, Method); 11281 if (BaseResult.isInvalid()) 11282 return ExprError(); 11283 Base = BaseResult.take(); 11284 11285 // Build the operator call. 11286 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, Best->FoundDecl, 11287 HadMultipleCandidates, OpLoc); 11288 if (FnExpr.isInvalid()) 11289 return ExprError(); 11290 11291 QualType ResultTy = Method->getResultType(); 11292 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11293 ResultTy = ResultTy.getNonLValueExprType(Context); 11294 CXXOperatorCallExpr *TheCall = 11295 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.take(), 11296 Base, ResultTy, VK, OpLoc, false); 11297 11298 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 11299 Method)) 11300 return ExprError(); 11301 11302 return MaybeBindToTemporary(TheCall); 11303} 11304 11305/// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to 11306/// a literal operator described by the provided lookup results. 11307ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R, 11308 DeclarationNameInfo &SuffixInfo, 11309 ArrayRef<Expr*> Args, 11310 SourceLocation LitEndLoc, 11311 TemplateArgumentListInfo *TemplateArgs) { 11312 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc(); 11313 11314 OverloadCandidateSet CandidateSet(UDSuffixLoc); 11315 AddFunctionCandidates(R.asUnresolvedSet(), Args, CandidateSet, true, 11316 TemplateArgs); 11317 11318 bool HadMultipleCandidates = (CandidateSet.size() > 1); 11319 11320 // Perform overload resolution. This will usually be trivial, but might need 11321 // to perform substitutions for a literal operator template. 11322 OverloadCandidateSet::iterator Best; 11323 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) { 11324 case OR_Success: 11325 case OR_Deleted: 11326 break; 11327 11328 case OR_No_Viable_Function: 11329 Diag(UDSuffixLoc, diag::err_ovl_no_viable_function_in_call) 11330 << R.getLookupName(); 11331 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11332 return ExprError(); 11333 11334 case OR_Ambiguous: 11335 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName(); 11336 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args); 11337 return ExprError(); 11338 } 11339 11340 FunctionDecl *FD = Best->Function; 11341 ExprResult Fn = CreateFunctionRefExpr(*this, FD, Best->FoundDecl, 11342 HadMultipleCandidates, 11343 SuffixInfo.getLoc(), 11344 SuffixInfo.getInfo()); 11345 if (Fn.isInvalid()) 11346 return true; 11347 11348 // Check the argument types. This should almost always be a no-op, except 11349 // that array-to-pointer decay is applied to string literals. 11350 Expr *ConvArgs[2]; 11351 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) { 11352 ExprResult InputInit = PerformCopyInitialization( 11353 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)), 11354 SourceLocation(), Args[ArgIdx]); 11355 if (InputInit.isInvalid()) 11356 return true; 11357 ConvArgs[ArgIdx] = InputInit.take(); 11358 } 11359 11360 QualType ResultTy = FD->getResultType(); 11361 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11362 ResultTy = ResultTy.getNonLValueExprType(Context); 11363 11364 UserDefinedLiteral *UDL = 11365 new (Context) UserDefinedLiteral(Context, Fn.take(), 11366 llvm::makeArrayRef(ConvArgs, Args.size()), 11367 ResultTy, VK, LitEndLoc, UDSuffixLoc); 11368 11369 if (CheckCallReturnType(FD->getResultType(), UDSuffixLoc, UDL, FD)) 11370 return ExprError(); 11371 11372 if (CheckFunctionCall(FD, UDL, NULL)) 11373 return ExprError(); 11374 11375 return MaybeBindToTemporary(UDL); 11376} 11377 11378/// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the 11379/// given LookupResult is non-empty, it is assumed to describe a member which 11380/// will be invoked. Otherwise, the function will be found via argument 11381/// dependent lookup. 11382/// CallExpr is set to a valid expression and FRS_Success returned on success, 11383/// otherwise CallExpr is set to ExprError() and some non-success value 11384/// is returned. 11385Sema::ForRangeStatus 11386Sema::BuildForRangeBeginEndCall(Scope *S, SourceLocation Loc, 11387 SourceLocation RangeLoc, VarDecl *Decl, 11388 BeginEndFunction BEF, 11389 const DeclarationNameInfo &NameInfo, 11390 LookupResult &MemberLookup, 11391 OverloadCandidateSet *CandidateSet, 11392 Expr *Range, ExprResult *CallExpr) { 11393 CandidateSet->clear(); 11394 if (!MemberLookup.empty()) { 11395 ExprResult MemberRef = 11396 BuildMemberReferenceExpr(Range, Range->getType(), Loc, 11397 /*IsPtr=*/false, CXXScopeSpec(), 11398 /*TemplateKWLoc=*/SourceLocation(), 11399 /*FirstQualifierInScope=*/0, 11400 MemberLookup, 11401 /*TemplateArgs=*/0); 11402 if (MemberRef.isInvalid()) { 11403 *CallExpr = ExprError(); 11404 Diag(Range->getLocStart(), diag::note_in_for_range) 11405 << RangeLoc << BEF << Range->getType(); 11406 return FRS_DiagnosticIssued; 11407 } 11408 *CallExpr = ActOnCallExpr(S, MemberRef.get(), Loc, MultiExprArg(), Loc, 0); 11409 if (CallExpr->isInvalid()) { 11410 *CallExpr = ExprError(); 11411 Diag(Range->getLocStart(), diag::note_in_for_range) 11412 << RangeLoc << BEF << Range->getType(); 11413 return FRS_DiagnosticIssued; 11414 } 11415 } else { 11416 UnresolvedSet<0> FoundNames; 11417 UnresolvedLookupExpr *Fn = 11418 UnresolvedLookupExpr::Create(Context, /*NamingClass=*/0, 11419 NestedNameSpecifierLoc(), NameInfo, 11420 /*NeedsADL=*/true, /*Overloaded=*/false, 11421 FoundNames.begin(), FoundNames.end()); 11422 11423 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, &Range, 1, Loc, 11424 CandidateSet, CallExpr); 11425 if (CandidateSet->empty() || CandidateSetError) { 11426 *CallExpr = ExprError(); 11427 return FRS_NoViableFunction; 11428 } 11429 OverloadCandidateSet::iterator Best; 11430 OverloadingResult OverloadResult = 11431 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best); 11432 11433 if (OverloadResult == OR_No_Viable_Function) { 11434 *CallExpr = ExprError(); 11435 return FRS_NoViableFunction; 11436 } 11437 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, &Range, 1, 11438 Loc, 0, CandidateSet, &Best, 11439 OverloadResult, 11440 /*AllowTypoCorrection=*/false); 11441 if (CallExpr->isInvalid() || OverloadResult != OR_Success) { 11442 *CallExpr = ExprError(); 11443 Diag(Range->getLocStart(), diag::note_in_for_range) 11444 << RangeLoc << BEF << Range->getType(); 11445 return FRS_DiagnosticIssued; 11446 } 11447 } 11448 return FRS_Success; 11449} 11450 11451 11452/// FixOverloadedFunctionReference - E is an expression that refers to 11453/// a C++ overloaded function (possibly with some parentheses and 11454/// perhaps a '&' around it). We have resolved the overloaded function 11455/// to the function declaration Fn, so patch up the expression E to 11456/// refer (possibly indirectly) to Fn. Returns the new expr. 11457Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 11458 FunctionDecl *Fn) { 11459 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 11460 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 11461 Found, Fn); 11462 if (SubExpr == PE->getSubExpr()) 11463 return PE; 11464 11465 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 11466 } 11467 11468 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 11469 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 11470 Found, Fn); 11471 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 11472 SubExpr->getType()) && 11473 "Implicit cast type cannot be determined from overload"); 11474 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 11475 if (SubExpr == ICE->getSubExpr()) 11476 return ICE; 11477 11478 return ImplicitCastExpr::Create(Context, ICE->getType(), 11479 ICE->getCastKind(), 11480 SubExpr, 0, 11481 ICE->getValueKind()); 11482 } 11483 11484 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 11485 assert(UnOp->getOpcode() == UO_AddrOf && 11486 "Can only take the address of an overloaded function"); 11487 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 11488 if (Method->isStatic()) { 11489 // Do nothing: static member functions aren't any different 11490 // from non-member functions. 11491 } else { 11492 // Fix the sub expression, which really has to be an 11493 // UnresolvedLookupExpr holding an overloaded member function 11494 // or template. 11495 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 11496 Found, Fn); 11497 if (SubExpr == UnOp->getSubExpr()) 11498 return UnOp; 11499 11500 assert(isa<DeclRefExpr>(SubExpr) 11501 && "fixed to something other than a decl ref"); 11502 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 11503 && "fixed to a member ref with no nested name qualifier"); 11504 11505 // We have taken the address of a pointer to member 11506 // function. Perform the computation here so that we get the 11507 // appropriate pointer to member type. 11508 QualType ClassType 11509 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 11510 QualType MemPtrType 11511 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 11512 11513 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 11514 VK_RValue, OK_Ordinary, 11515 UnOp->getOperatorLoc()); 11516 } 11517 } 11518 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 11519 Found, Fn); 11520 if (SubExpr == UnOp->getSubExpr()) 11521 return UnOp; 11522 11523 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 11524 Context.getPointerType(SubExpr->getType()), 11525 VK_RValue, OK_Ordinary, 11526 UnOp->getOperatorLoc()); 11527 } 11528 11529 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 11530 // FIXME: avoid copy. 11531 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 11532 if (ULE->hasExplicitTemplateArgs()) { 11533 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 11534 TemplateArgs = &TemplateArgsBuffer; 11535 } 11536 11537 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 11538 ULE->getQualifierLoc(), 11539 ULE->getTemplateKeywordLoc(), 11540 Fn, 11541 /*enclosing*/ false, // FIXME? 11542 ULE->getNameLoc(), 11543 Fn->getType(), 11544 VK_LValue, 11545 Found.getDecl(), 11546 TemplateArgs); 11547 MarkDeclRefReferenced(DRE); 11548 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1); 11549 return DRE; 11550 } 11551 11552 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 11553 // FIXME: avoid copy. 11554 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 11555 if (MemExpr->hasExplicitTemplateArgs()) { 11556 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 11557 TemplateArgs = &TemplateArgsBuffer; 11558 } 11559 11560 Expr *Base; 11561 11562 // If we're filling in a static method where we used to have an 11563 // implicit member access, rewrite to a simple decl ref. 11564 if (MemExpr->isImplicitAccess()) { 11565 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 11566 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 11567 MemExpr->getQualifierLoc(), 11568 MemExpr->getTemplateKeywordLoc(), 11569 Fn, 11570 /*enclosing*/ false, 11571 MemExpr->getMemberLoc(), 11572 Fn->getType(), 11573 VK_LValue, 11574 Found.getDecl(), 11575 TemplateArgs); 11576 MarkDeclRefReferenced(DRE); 11577 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1); 11578 return DRE; 11579 } else { 11580 SourceLocation Loc = MemExpr->getMemberLoc(); 11581 if (MemExpr->getQualifier()) 11582 Loc = MemExpr->getQualifierLoc().getBeginLoc(); 11583 CheckCXXThisCapture(Loc); 11584 Base = new (Context) CXXThisExpr(Loc, 11585 MemExpr->getBaseType(), 11586 /*isImplicit=*/true); 11587 } 11588 } else 11589 Base = MemExpr->getBase(); 11590 11591 ExprValueKind valueKind; 11592 QualType type; 11593 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 11594 valueKind = VK_LValue; 11595 type = Fn->getType(); 11596 } else { 11597 valueKind = VK_RValue; 11598 type = Context.BoundMemberTy; 11599 } 11600 11601 MemberExpr *ME = MemberExpr::Create(Context, Base, 11602 MemExpr->isArrow(), 11603 MemExpr->getQualifierLoc(), 11604 MemExpr->getTemplateKeywordLoc(), 11605 Fn, 11606 Found, 11607 MemExpr->getMemberNameInfo(), 11608 TemplateArgs, 11609 type, valueKind, OK_Ordinary); 11610 ME->setHadMultipleCandidates(true); 11611 MarkMemberReferenced(ME); 11612 return ME; 11613 } 11614 11615 llvm_unreachable("Invalid reference to overloaded function"); 11616} 11617 11618ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 11619 DeclAccessPair Found, 11620 FunctionDecl *Fn) { 11621 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 11622} 11623 11624} // end namespace clang 11625