SemaOverload.cpp revision 7acc5a64822093ec746748efcdabb162bd1b8560
1//===--- SemaOverload.cpp - C++ Overloading -------------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Sema/Overload.h" 15#include "clang/AST/ASTContext.h" 16#include "clang/AST/CXXInheritance.h" 17#include "clang/AST/DeclObjC.h" 18#include "clang/AST/Expr.h" 19#include "clang/AST/ExprCXX.h" 20#include "clang/AST/ExprObjC.h" 21#include "clang/AST/TypeOrdering.h" 22#include "clang/Basic/Diagnostic.h" 23#include "clang/Basic/PartialDiagnostic.h" 24#include "clang/Lex/Preprocessor.h" 25#include "clang/Sema/Initialization.h" 26#include "clang/Sema/Lookup.h" 27#include "clang/Sema/SemaInternal.h" 28#include "clang/Sema/Template.h" 29#include "clang/Sema/TemplateDeduction.h" 30#include "llvm/ADT/DenseSet.h" 31#include "llvm/ADT/STLExtras.h" 32#include "llvm/ADT/SmallPtrSet.h" 33#include "llvm/ADT/SmallString.h" 34#include <algorithm> 35 36namespace clang { 37using namespace sema; 38 39/// A convenience routine for creating a decayed reference to a function. 40static ExprResult 41CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, NamedDecl *FoundDecl, 42 bool HadMultipleCandidates, 43 SourceLocation Loc = SourceLocation(), 44 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){ 45 if (S.DiagnoseUseOfDecl(FoundDecl, Loc)) 46 return ExprError(); 47 48 DeclRefExpr *DRE = new (S.Context) DeclRefExpr(Fn, false, Fn->getType(), 49 VK_LValue, Loc, LocInfo); 50 if (HadMultipleCandidates) 51 DRE->setHadMultipleCandidates(true); 52 53 S.MarkDeclRefReferenced(DRE); 54 55 ExprResult E = S.Owned(DRE); 56 E = S.DefaultFunctionArrayConversion(E.take()); 57 if (E.isInvalid()) 58 return ExprError(); 59 return E; 60} 61 62static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 63 bool InOverloadResolution, 64 StandardConversionSequence &SCS, 65 bool CStyle, 66 bool AllowObjCWritebackConversion); 67 68static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From, 69 QualType &ToType, 70 bool InOverloadResolution, 71 StandardConversionSequence &SCS, 72 bool CStyle); 73static OverloadingResult 74IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 75 UserDefinedConversionSequence& User, 76 OverloadCandidateSet& Conversions, 77 bool AllowExplicit); 78 79 80static ImplicitConversionSequence::CompareKind 81CompareStandardConversionSequences(Sema &S, 82 const StandardConversionSequence& SCS1, 83 const StandardConversionSequence& SCS2); 84 85static ImplicitConversionSequence::CompareKind 86CompareQualificationConversions(Sema &S, 87 const StandardConversionSequence& SCS1, 88 const StandardConversionSequence& SCS2); 89 90static ImplicitConversionSequence::CompareKind 91CompareDerivedToBaseConversions(Sema &S, 92 const StandardConversionSequence& SCS1, 93 const StandardConversionSequence& SCS2); 94 95 96 97/// GetConversionCategory - Retrieve the implicit conversion 98/// category corresponding to the given implicit conversion kind. 99ImplicitConversionCategory 100GetConversionCategory(ImplicitConversionKind Kind) { 101 static const ImplicitConversionCategory 102 Category[(int)ICK_Num_Conversion_Kinds] = { 103 ICC_Identity, 104 ICC_Lvalue_Transformation, 105 ICC_Lvalue_Transformation, 106 ICC_Lvalue_Transformation, 107 ICC_Identity, 108 ICC_Qualification_Adjustment, 109 ICC_Promotion, 110 ICC_Promotion, 111 ICC_Promotion, 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 ICC_Conversion, 124 ICC_Conversion 125 }; 126 return Category[(int)Kind]; 127} 128 129/// GetConversionRank - Retrieve the implicit conversion rank 130/// corresponding to the given implicit conversion kind. 131ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 132 static const ImplicitConversionRank 133 Rank[(int)ICK_Num_Conversion_Kinds] = { 134 ICR_Exact_Match, 135 ICR_Exact_Match, 136 ICR_Exact_Match, 137 ICR_Exact_Match, 138 ICR_Exact_Match, 139 ICR_Exact_Match, 140 ICR_Promotion, 141 ICR_Promotion, 142 ICR_Promotion, 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_Conversion, 153 ICR_Conversion, 154 ICR_Complex_Real_Conversion, 155 ICR_Conversion, 156 ICR_Conversion, 157 ICR_Writeback_Conversion 158 }; 159 return Rank[(int)Kind]; 160} 161 162/// GetImplicitConversionName - Return the name of this kind of 163/// implicit conversion. 164const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 165 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 166 "No conversion", 167 "Lvalue-to-rvalue", 168 "Array-to-pointer", 169 "Function-to-pointer", 170 "Noreturn adjustment", 171 "Qualification", 172 "Integral promotion", 173 "Floating point promotion", 174 "Complex promotion", 175 "Integral conversion", 176 "Floating conversion", 177 "Complex conversion", 178 "Floating-integral conversion", 179 "Pointer conversion", 180 "Pointer-to-member conversion", 181 "Boolean conversion", 182 "Compatible-types conversion", 183 "Derived-to-base conversion", 184 "Vector conversion", 185 "Vector splat", 186 "Complex-real conversion", 187 "Block Pointer conversion", 188 "Transparent Union Conversion" 189 "Writeback conversion" 190 }; 191 return Name[Kind]; 192} 193 194/// StandardConversionSequence - Set the standard conversion 195/// sequence to the identity conversion. 196void StandardConversionSequence::setAsIdentityConversion() { 197 First = ICK_Identity; 198 Second = ICK_Identity; 199 Third = ICK_Identity; 200 DeprecatedStringLiteralToCharPtr = false; 201 QualificationIncludesObjCLifetime = false; 202 ReferenceBinding = false; 203 DirectBinding = false; 204 IsLvalueReference = true; 205 BindsToFunctionLvalue = false; 206 BindsToRvalue = false; 207 BindsImplicitObjectArgumentWithoutRefQualifier = false; 208 ObjCLifetimeConversionBinding = false; 209 CopyConstructor = 0; 210} 211 212/// getRank - Retrieve the rank of this standard conversion sequence 213/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 214/// implicit conversions. 215ImplicitConversionRank StandardConversionSequence::getRank() const { 216 ImplicitConversionRank Rank = ICR_Exact_Match; 217 if (GetConversionRank(First) > Rank) 218 Rank = GetConversionRank(First); 219 if (GetConversionRank(Second) > Rank) 220 Rank = GetConversionRank(Second); 221 if (GetConversionRank(Third) > Rank) 222 Rank = GetConversionRank(Third); 223 return Rank; 224} 225 226/// isPointerConversionToBool - Determines whether this conversion is 227/// a conversion of a pointer or pointer-to-member to bool. This is 228/// used as part of the ranking of standard conversion sequences 229/// (C++ 13.3.3.2p4). 230bool StandardConversionSequence::isPointerConversionToBool() const { 231 // Note that FromType has not necessarily been transformed by the 232 // array-to-pointer or function-to-pointer implicit conversions, so 233 // check for their presence as well as checking whether FromType is 234 // a pointer. 235 if (getToType(1)->isBooleanType() && 236 (getFromType()->isPointerType() || 237 getFromType()->isObjCObjectPointerType() || 238 getFromType()->isBlockPointerType() || 239 getFromType()->isNullPtrType() || 240 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 241 return true; 242 243 return false; 244} 245 246/// isPointerConversionToVoidPointer - Determines whether this 247/// conversion is a conversion of a pointer to a void pointer. This is 248/// used as part of the ranking of standard conversion sequences (C++ 249/// 13.3.3.2p4). 250bool 251StandardConversionSequence:: 252isPointerConversionToVoidPointer(ASTContext& Context) const { 253 QualType FromType = getFromType(); 254 QualType ToType = getToType(1); 255 256 // Note that FromType has not necessarily been transformed by the 257 // array-to-pointer implicit conversion, so check for its presence 258 // and redo the conversion to get a pointer. 259 if (First == ICK_Array_To_Pointer) 260 FromType = Context.getArrayDecayedType(FromType); 261 262 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType()) 263 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 264 return ToPtrType->getPointeeType()->isVoidType(); 265 266 return false; 267} 268 269/// Skip any implicit casts which could be either part of a narrowing conversion 270/// or after one in an implicit conversion. 271static const Expr *IgnoreNarrowingConversion(const Expr *Converted) { 272 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) { 273 switch (ICE->getCastKind()) { 274 case CK_NoOp: 275 case CK_IntegralCast: 276 case CK_IntegralToBoolean: 277 case CK_IntegralToFloating: 278 case CK_FloatingToIntegral: 279 case CK_FloatingToBoolean: 280 case CK_FloatingCast: 281 Converted = ICE->getSubExpr(); 282 continue; 283 284 default: 285 return Converted; 286 } 287 } 288 289 return Converted; 290} 291 292/// Check if this standard conversion sequence represents a narrowing 293/// conversion, according to C++11 [dcl.init.list]p7. 294/// 295/// \param Ctx The AST context. 296/// \param Converted The result of applying this standard conversion sequence. 297/// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the 298/// value of the expression prior to the narrowing conversion. 299/// \param ConstantType If this is an NK_Constant_Narrowing conversion, the 300/// type of the expression prior to the narrowing conversion. 301NarrowingKind 302StandardConversionSequence::getNarrowingKind(ASTContext &Ctx, 303 const Expr *Converted, 304 APValue &ConstantValue, 305 QualType &ConstantType) const { 306 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++"); 307 308 // C++11 [dcl.init.list]p7: 309 // A narrowing conversion is an implicit conversion ... 310 QualType FromType = getToType(0); 311 QualType ToType = getToType(1); 312 switch (Second) { 313 // -- from a floating-point type to an integer type, or 314 // 315 // -- from an integer type or unscoped enumeration type to a floating-point 316 // type, except where the source is a constant expression and the actual 317 // value after conversion will fit into the target type and will produce 318 // the original value when converted back to the original type, or 319 case ICK_Floating_Integral: 320 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) { 321 return NK_Type_Narrowing; 322 } else if (FromType->isIntegralType(Ctx) && ToType->isRealFloatingType()) { 323 llvm::APSInt IntConstantValue; 324 const Expr *Initializer = IgnoreNarrowingConversion(Converted); 325 if (Initializer && 326 Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) { 327 // Convert the integer to the floating type. 328 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType)); 329 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(), 330 llvm::APFloat::rmNearestTiesToEven); 331 // And back. 332 llvm::APSInt ConvertedValue = IntConstantValue; 333 bool ignored; 334 Result.convertToInteger(ConvertedValue, 335 llvm::APFloat::rmTowardZero, &ignored); 336 // If the resulting value is different, this was a narrowing conversion. 337 if (IntConstantValue != ConvertedValue) { 338 ConstantValue = APValue(IntConstantValue); 339 ConstantType = Initializer->getType(); 340 return NK_Constant_Narrowing; 341 } 342 } else { 343 // Variables are always narrowings. 344 return NK_Variable_Narrowing; 345 } 346 } 347 return NK_Not_Narrowing; 348 349 // -- from long double to double or float, or from double to float, except 350 // where the source is a constant expression and the actual value after 351 // conversion is within the range of values that can be represented (even 352 // if it cannot be represented exactly), or 353 case ICK_Floating_Conversion: 354 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() && 355 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) { 356 // FromType is larger than ToType. 357 const Expr *Initializer = IgnoreNarrowingConversion(Converted); 358 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) { 359 // Constant! 360 assert(ConstantValue.isFloat()); 361 llvm::APFloat FloatVal = ConstantValue.getFloat(); 362 // Convert the source value into the target type. 363 bool ignored; 364 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert( 365 Ctx.getFloatTypeSemantics(ToType), 366 llvm::APFloat::rmNearestTiesToEven, &ignored); 367 // If there was no overflow, the source value is within the range of 368 // values that can be represented. 369 if (ConvertStatus & llvm::APFloat::opOverflow) { 370 ConstantType = Initializer->getType(); 371 return NK_Constant_Narrowing; 372 } 373 } else { 374 return NK_Variable_Narrowing; 375 } 376 } 377 return NK_Not_Narrowing; 378 379 // -- from an integer type or unscoped enumeration type to an integer type 380 // that cannot represent all the values of the original type, except where 381 // the source is a constant expression and the actual value after 382 // conversion will fit into the target type and will produce the original 383 // value when converted back to the original type. 384 case ICK_Boolean_Conversion: // Bools are integers too. 385 if (!FromType->isIntegralOrUnscopedEnumerationType()) { 386 // Boolean conversions can be from pointers and pointers to members 387 // [conv.bool], and those aren't considered narrowing conversions. 388 return NK_Not_Narrowing; 389 } // Otherwise, fall through to the integral case. 390 case ICK_Integral_Conversion: { 391 assert(FromType->isIntegralOrUnscopedEnumerationType()); 392 assert(ToType->isIntegralOrUnscopedEnumerationType()); 393 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType(); 394 const unsigned FromWidth = Ctx.getIntWidth(FromType); 395 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType(); 396 const unsigned ToWidth = Ctx.getIntWidth(ToType); 397 398 if (FromWidth > ToWidth || 399 (FromWidth == ToWidth && FromSigned != ToSigned) || 400 (FromSigned && !ToSigned)) { 401 // Not all values of FromType can be represented in ToType. 402 llvm::APSInt InitializerValue; 403 const Expr *Initializer = IgnoreNarrowingConversion(Converted); 404 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) { 405 // Such conversions on variables are always narrowing. 406 return NK_Variable_Narrowing; 407 } 408 bool Narrowing = false; 409 if (FromWidth < ToWidth) { 410 // Negative -> unsigned is narrowing. Otherwise, more bits is never 411 // narrowing. 412 if (InitializerValue.isSigned() && InitializerValue.isNegative()) 413 Narrowing = true; 414 } else { 415 // Add a bit to the InitializerValue so we don't have to worry about 416 // signed vs. unsigned comparisons. 417 InitializerValue = InitializerValue.extend( 418 InitializerValue.getBitWidth() + 1); 419 // Convert the initializer to and from the target width and signed-ness. 420 llvm::APSInt ConvertedValue = InitializerValue; 421 ConvertedValue = ConvertedValue.trunc(ToWidth); 422 ConvertedValue.setIsSigned(ToSigned); 423 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth()); 424 ConvertedValue.setIsSigned(InitializerValue.isSigned()); 425 // If the result is different, this was a narrowing conversion. 426 if (ConvertedValue != InitializerValue) 427 Narrowing = true; 428 } 429 if (Narrowing) { 430 ConstantType = Initializer->getType(); 431 ConstantValue = APValue(InitializerValue); 432 return NK_Constant_Narrowing; 433 } 434 } 435 return NK_Not_Narrowing; 436 } 437 438 default: 439 // Other kinds of conversions are not narrowings. 440 return NK_Not_Narrowing; 441 } 442} 443 444/// DebugPrint - Print this standard conversion sequence to standard 445/// error. Useful for debugging overloading issues. 446void StandardConversionSequence::DebugPrint() const { 447 raw_ostream &OS = llvm::errs(); 448 bool PrintedSomething = false; 449 if (First != ICK_Identity) { 450 OS << GetImplicitConversionName(First); 451 PrintedSomething = true; 452 } 453 454 if (Second != ICK_Identity) { 455 if (PrintedSomething) { 456 OS << " -> "; 457 } 458 OS << GetImplicitConversionName(Second); 459 460 if (CopyConstructor) { 461 OS << " (by copy constructor)"; 462 } else if (DirectBinding) { 463 OS << " (direct reference binding)"; 464 } else if (ReferenceBinding) { 465 OS << " (reference binding)"; 466 } 467 PrintedSomething = true; 468 } 469 470 if (Third != ICK_Identity) { 471 if (PrintedSomething) { 472 OS << " -> "; 473 } 474 OS << GetImplicitConversionName(Third); 475 PrintedSomething = true; 476 } 477 478 if (!PrintedSomething) { 479 OS << "No conversions required"; 480 } 481} 482 483/// DebugPrint - Print this user-defined conversion sequence to standard 484/// error. Useful for debugging overloading issues. 485void UserDefinedConversionSequence::DebugPrint() const { 486 raw_ostream &OS = llvm::errs(); 487 if (Before.First || Before.Second || Before.Third) { 488 Before.DebugPrint(); 489 OS << " -> "; 490 } 491 if (ConversionFunction) 492 OS << '\'' << *ConversionFunction << '\''; 493 else 494 OS << "aggregate initialization"; 495 if (After.First || After.Second || After.Third) { 496 OS << " -> "; 497 After.DebugPrint(); 498 } 499} 500 501/// DebugPrint - Print this implicit conversion sequence to standard 502/// error. Useful for debugging overloading issues. 503void ImplicitConversionSequence::DebugPrint() const { 504 raw_ostream &OS = llvm::errs(); 505 switch (ConversionKind) { 506 case StandardConversion: 507 OS << "Standard conversion: "; 508 Standard.DebugPrint(); 509 break; 510 case UserDefinedConversion: 511 OS << "User-defined conversion: "; 512 UserDefined.DebugPrint(); 513 break; 514 case EllipsisConversion: 515 OS << "Ellipsis conversion"; 516 break; 517 case AmbiguousConversion: 518 OS << "Ambiguous conversion"; 519 break; 520 case BadConversion: 521 OS << "Bad conversion"; 522 break; 523 } 524 525 OS << "\n"; 526} 527 528void AmbiguousConversionSequence::construct() { 529 new (&conversions()) ConversionSet(); 530} 531 532void AmbiguousConversionSequence::destruct() { 533 conversions().~ConversionSet(); 534} 535 536void 537AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 538 FromTypePtr = O.FromTypePtr; 539 ToTypePtr = O.ToTypePtr; 540 new (&conversions()) ConversionSet(O.conversions()); 541} 542 543namespace { 544 // Structure used by OverloadCandidate::DeductionFailureInfo to store 545 // template argument information. 546 struct DFIArguments { 547 TemplateArgument FirstArg; 548 TemplateArgument SecondArg; 549 }; 550 // Structure used by OverloadCandidate::DeductionFailureInfo to store 551 // template parameter and template argument information. 552 struct DFIParamWithArguments : DFIArguments { 553 TemplateParameter Param; 554 }; 555} 556 557/// \brief Convert from Sema's representation of template deduction information 558/// to the form used in overload-candidate information. 559OverloadCandidate::DeductionFailureInfo 560static MakeDeductionFailureInfo(ASTContext &Context, 561 Sema::TemplateDeductionResult TDK, 562 TemplateDeductionInfo &Info) { 563 OverloadCandidate::DeductionFailureInfo Result; 564 Result.Result = static_cast<unsigned>(TDK); 565 Result.HasDiagnostic = false; 566 Result.Data = 0; 567 switch (TDK) { 568 case Sema::TDK_Success: 569 case Sema::TDK_Invalid: 570 case Sema::TDK_InstantiationDepth: 571 case Sema::TDK_TooManyArguments: 572 case Sema::TDK_TooFewArguments: 573 break; 574 575 case Sema::TDK_Incomplete: 576 case Sema::TDK_InvalidExplicitArguments: 577 Result.Data = Info.Param.getOpaqueValue(); 578 break; 579 580 case Sema::TDK_NonDeducedMismatch: { 581 // FIXME: Should allocate from normal heap so that we can free this later. 582 DFIArguments *Saved = new (Context) DFIArguments; 583 Saved->FirstArg = Info.FirstArg; 584 Saved->SecondArg = Info.SecondArg; 585 Result.Data = Saved; 586 break; 587 } 588 589 case Sema::TDK_Inconsistent: 590 case Sema::TDK_Underqualified: { 591 // FIXME: Should allocate from normal heap so that we can free this later. 592 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 593 Saved->Param = Info.Param; 594 Saved->FirstArg = Info.FirstArg; 595 Saved->SecondArg = Info.SecondArg; 596 Result.Data = Saved; 597 break; 598 } 599 600 case Sema::TDK_SubstitutionFailure: 601 Result.Data = Info.take(); 602 if (Info.hasSFINAEDiagnostic()) { 603 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt( 604 SourceLocation(), PartialDiagnostic::NullDiagnostic()); 605 Info.takeSFINAEDiagnostic(*Diag); 606 Result.HasDiagnostic = true; 607 } 608 break; 609 610 case Sema::TDK_FailedOverloadResolution: 611 Result.Data = Info.Expression; 612 break; 613 614 case Sema::TDK_MiscellaneousDeductionFailure: 615 break; 616 } 617 618 return Result; 619} 620 621void OverloadCandidate::DeductionFailureInfo::Destroy() { 622 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 623 case Sema::TDK_Success: 624 case Sema::TDK_Invalid: 625 case Sema::TDK_InstantiationDepth: 626 case Sema::TDK_Incomplete: 627 case Sema::TDK_TooManyArguments: 628 case Sema::TDK_TooFewArguments: 629 case Sema::TDK_InvalidExplicitArguments: 630 case Sema::TDK_FailedOverloadResolution: 631 break; 632 633 case Sema::TDK_Inconsistent: 634 case Sema::TDK_Underqualified: 635 case Sema::TDK_NonDeducedMismatch: 636 // FIXME: Destroy the data? 637 Data = 0; 638 break; 639 640 case Sema::TDK_SubstitutionFailure: 641 // FIXME: Destroy the template argument list? 642 Data = 0; 643 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) { 644 Diag->~PartialDiagnosticAt(); 645 HasDiagnostic = false; 646 } 647 break; 648 649 // Unhandled 650 case Sema::TDK_MiscellaneousDeductionFailure: 651 break; 652 } 653} 654 655PartialDiagnosticAt * 656OverloadCandidate::DeductionFailureInfo::getSFINAEDiagnostic() { 657 if (HasDiagnostic) 658 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic)); 659 return 0; 660} 661 662TemplateParameter 663OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 664 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 665 case Sema::TDK_Success: 666 case Sema::TDK_Invalid: 667 case Sema::TDK_InstantiationDepth: 668 case Sema::TDK_TooManyArguments: 669 case Sema::TDK_TooFewArguments: 670 case Sema::TDK_SubstitutionFailure: 671 case Sema::TDK_NonDeducedMismatch: 672 case Sema::TDK_FailedOverloadResolution: 673 return TemplateParameter(); 674 675 case Sema::TDK_Incomplete: 676 case Sema::TDK_InvalidExplicitArguments: 677 return TemplateParameter::getFromOpaqueValue(Data); 678 679 case Sema::TDK_Inconsistent: 680 case Sema::TDK_Underqualified: 681 return static_cast<DFIParamWithArguments*>(Data)->Param; 682 683 // Unhandled 684 case Sema::TDK_MiscellaneousDeductionFailure: 685 break; 686 } 687 688 return TemplateParameter(); 689} 690 691TemplateArgumentList * 692OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 693 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 694 case Sema::TDK_Success: 695 case Sema::TDK_Invalid: 696 case Sema::TDK_InstantiationDepth: 697 case Sema::TDK_TooManyArguments: 698 case Sema::TDK_TooFewArguments: 699 case Sema::TDK_Incomplete: 700 case Sema::TDK_InvalidExplicitArguments: 701 case Sema::TDK_Inconsistent: 702 case Sema::TDK_Underqualified: 703 case Sema::TDK_NonDeducedMismatch: 704 case Sema::TDK_FailedOverloadResolution: 705 return 0; 706 707 case Sema::TDK_SubstitutionFailure: 708 return static_cast<TemplateArgumentList*>(Data); 709 710 // Unhandled 711 case Sema::TDK_MiscellaneousDeductionFailure: 712 break; 713 } 714 715 return 0; 716} 717 718const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 719 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 720 case Sema::TDK_Success: 721 case Sema::TDK_Invalid: 722 case Sema::TDK_InstantiationDepth: 723 case Sema::TDK_Incomplete: 724 case Sema::TDK_TooManyArguments: 725 case Sema::TDK_TooFewArguments: 726 case Sema::TDK_InvalidExplicitArguments: 727 case Sema::TDK_SubstitutionFailure: 728 case Sema::TDK_FailedOverloadResolution: 729 return 0; 730 731 case Sema::TDK_Inconsistent: 732 case Sema::TDK_Underqualified: 733 case Sema::TDK_NonDeducedMismatch: 734 return &static_cast<DFIArguments*>(Data)->FirstArg; 735 736 // Unhandled 737 case Sema::TDK_MiscellaneousDeductionFailure: 738 break; 739 } 740 741 return 0; 742} 743 744const TemplateArgument * 745OverloadCandidate::DeductionFailureInfo::getSecondArg() { 746 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 747 case Sema::TDK_Success: 748 case Sema::TDK_Invalid: 749 case Sema::TDK_InstantiationDepth: 750 case Sema::TDK_Incomplete: 751 case Sema::TDK_TooManyArguments: 752 case Sema::TDK_TooFewArguments: 753 case Sema::TDK_InvalidExplicitArguments: 754 case Sema::TDK_SubstitutionFailure: 755 case Sema::TDK_FailedOverloadResolution: 756 return 0; 757 758 case Sema::TDK_Inconsistent: 759 case Sema::TDK_Underqualified: 760 case Sema::TDK_NonDeducedMismatch: 761 return &static_cast<DFIArguments*>(Data)->SecondArg; 762 763 // Unhandled 764 case Sema::TDK_MiscellaneousDeductionFailure: 765 break; 766 } 767 768 return 0; 769} 770 771Expr * 772OverloadCandidate::DeductionFailureInfo::getExpr() { 773 if (static_cast<Sema::TemplateDeductionResult>(Result) == 774 Sema::TDK_FailedOverloadResolution) 775 return static_cast<Expr*>(Data); 776 777 return 0; 778} 779 780void OverloadCandidateSet::destroyCandidates() { 781 for (iterator i = begin(), e = end(); i != e; ++i) { 782 for (unsigned ii = 0, ie = i->NumConversions; ii != ie; ++ii) 783 i->Conversions[ii].~ImplicitConversionSequence(); 784 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction) 785 i->DeductionFailure.Destroy(); 786 } 787} 788 789void OverloadCandidateSet::clear() { 790 destroyCandidates(); 791 NumInlineSequences = 0; 792 Candidates.clear(); 793 Functions.clear(); 794} 795 796namespace { 797 class UnbridgedCastsSet { 798 struct Entry { 799 Expr **Addr; 800 Expr *Saved; 801 }; 802 SmallVector<Entry, 2> Entries; 803 804 public: 805 void save(Sema &S, Expr *&E) { 806 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)); 807 Entry entry = { &E, E }; 808 Entries.push_back(entry); 809 E = S.stripARCUnbridgedCast(E); 810 } 811 812 void restore() { 813 for (SmallVectorImpl<Entry>::iterator 814 i = Entries.begin(), e = Entries.end(); i != e; ++i) 815 *i->Addr = i->Saved; 816 } 817 }; 818} 819 820/// checkPlaceholderForOverload - Do any interesting placeholder-like 821/// preprocessing on the given expression. 822/// 823/// \param unbridgedCasts a collection to which to add unbridged casts; 824/// without this, they will be immediately diagnosed as errors 825/// 826/// Return true on unrecoverable error. 827static bool checkPlaceholderForOverload(Sema &S, Expr *&E, 828 UnbridgedCastsSet *unbridgedCasts = 0) { 829 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) { 830 // We can't handle overloaded expressions here because overload 831 // resolution might reasonably tweak them. 832 if (placeholder->getKind() == BuiltinType::Overload) return false; 833 834 // If the context potentially accepts unbridged ARC casts, strip 835 // the unbridged cast and add it to the collection for later restoration. 836 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast && 837 unbridgedCasts) { 838 unbridgedCasts->save(S, E); 839 return false; 840 } 841 842 // Go ahead and check everything else. 843 ExprResult result = S.CheckPlaceholderExpr(E); 844 if (result.isInvalid()) 845 return true; 846 847 E = result.take(); 848 return false; 849 } 850 851 // Nothing to do. 852 return false; 853} 854 855/// checkArgPlaceholdersForOverload - Check a set of call operands for 856/// placeholders. 857static bool checkArgPlaceholdersForOverload(Sema &S, 858 MultiExprArg Args, 859 UnbridgedCastsSet &unbridged) { 860 for (unsigned i = 0, e = Args.size(); i != e; ++i) 861 if (checkPlaceholderForOverload(S, Args[i], &unbridged)) 862 return true; 863 864 return false; 865} 866 867// IsOverload - Determine whether the given New declaration is an 868// overload of the declarations in Old. This routine returns false if 869// New and Old cannot be overloaded, e.g., if New has the same 870// signature as some function in Old (C++ 1.3.10) or if the Old 871// declarations aren't functions (or function templates) at all. When 872// it does return false, MatchedDecl will point to the decl that New 873// cannot be overloaded with. This decl may be a UsingShadowDecl on 874// top of the underlying declaration. 875// 876// Example: Given the following input: 877// 878// void f(int, float); // #1 879// void f(int, int); // #2 880// int f(int, int); // #3 881// 882// When we process #1, there is no previous declaration of "f", 883// so IsOverload will not be used. 884// 885// When we process #2, Old contains only the FunctionDecl for #1. By 886// comparing the parameter types, we see that #1 and #2 are overloaded 887// (since they have different signatures), so this routine returns 888// false; MatchedDecl is unchanged. 889// 890// When we process #3, Old is an overload set containing #1 and #2. We 891// compare the signatures of #3 to #1 (they're overloaded, so we do 892// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 893// identical (return types of functions are not part of the 894// signature), IsOverload returns false and MatchedDecl will be set to 895// point to the FunctionDecl for #2. 896// 897// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 898// into a class by a using declaration. The rules for whether to hide 899// shadow declarations ignore some properties which otherwise figure 900// into a function template's signature. 901Sema::OverloadKind 902Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 903 NamedDecl *&Match, bool NewIsUsingDecl) { 904 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 905 I != E; ++I) { 906 NamedDecl *OldD = *I; 907 908 bool OldIsUsingDecl = false; 909 if (isa<UsingShadowDecl>(OldD)) { 910 OldIsUsingDecl = true; 911 912 // We can always introduce two using declarations into the same 913 // context, even if they have identical signatures. 914 if (NewIsUsingDecl) continue; 915 916 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 917 } 918 919 // If either declaration was introduced by a using declaration, 920 // we'll need to use slightly different rules for matching. 921 // Essentially, these rules are the normal rules, except that 922 // function templates hide function templates with different 923 // return types or template parameter lists. 924 bool UseMemberUsingDeclRules = 925 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord() && 926 !New->getFriendObjectKind(); 927 928 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 929 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 930 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 931 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 932 continue; 933 } 934 935 Match = *I; 936 return Ovl_Match; 937 } 938 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 939 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 940 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 941 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 942 continue; 943 } 944 945 if (!shouldLinkPossiblyHiddenDecl(*I, New)) 946 continue; 947 948 Match = *I; 949 return Ovl_Match; 950 } 951 } else if (isa<UsingDecl>(OldD)) { 952 // We can overload with these, which can show up when doing 953 // redeclaration checks for UsingDecls. 954 assert(Old.getLookupKind() == LookupUsingDeclName); 955 } else if (isa<TagDecl>(OldD)) { 956 // We can always overload with tags by hiding them. 957 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 958 // Optimistically assume that an unresolved using decl will 959 // overload; if it doesn't, we'll have to diagnose during 960 // template instantiation. 961 } else { 962 // (C++ 13p1): 963 // Only function declarations can be overloaded; object and type 964 // declarations cannot be overloaded. 965 Match = *I; 966 return Ovl_NonFunction; 967 } 968 } 969 970 return Ovl_Overload; 971} 972 973static bool canBeOverloaded(const FunctionDecl &D) { 974 if (D.getAttr<OverloadableAttr>()) 975 return true; 976 if (D.isExternC()) 977 return false; 978 979 // Main cannot be overloaded (basic.start.main). 980 if (D.isMain()) 981 return false; 982 983 return true; 984} 985 986static bool shouldTryToOverload(Sema &S, FunctionDecl *New, FunctionDecl *Old, 987 bool UseUsingDeclRules) { 988 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 989 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 990 991 // C++ [temp.fct]p2: 992 // A function template can be overloaded with other function templates 993 // and with normal (non-template) functions. 994 if ((OldTemplate == 0) != (NewTemplate == 0)) 995 return true; 996 997 // Is the function New an overload of the function Old? 998 QualType OldQType = S.Context.getCanonicalType(Old->getType()); 999 QualType NewQType = S.Context.getCanonicalType(New->getType()); 1000 1001 // Compare the signatures (C++ 1.3.10) of the two functions to 1002 // determine whether they are overloads. If we find any mismatch 1003 // in the signature, they are overloads. 1004 1005 // If either of these functions is a K&R-style function (no 1006 // prototype), then we consider them to have matching signatures. 1007 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 1008 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 1009 return false; 1010 1011 const FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 1012 const FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 1013 1014 // The signature of a function includes the types of its 1015 // parameters (C++ 1.3.10), which includes the presence or absence 1016 // of the ellipsis; see C++ DR 357). 1017 if (OldQType != NewQType && 1018 (OldType->getNumArgs() != NewType->getNumArgs() || 1019 OldType->isVariadic() != NewType->isVariadic() || 1020 !S.FunctionArgTypesAreEqual(OldType, NewType))) 1021 return true; 1022 1023 // C++ [temp.over.link]p4: 1024 // The signature of a function template consists of its function 1025 // signature, its return type and its template parameter list. The names 1026 // of the template parameters are significant only for establishing the 1027 // relationship between the template parameters and the rest of the 1028 // signature. 1029 // 1030 // We check the return type and template parameter lists for function 1031 // templates first; the remaining checks follow. 1032 // 1033 // However, we don't consider either of these when deciding whether 1034 // a member introduced by a shadow declaration is hidden. 1035 if (!UseUsingDeclRules && NewTemplate && 1036 (!S.TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 1037 OldTemplate->getTemplateParameters(), 1038 false, S.TPL_TemplateMatch) || 1039 OldType->getResultType() != NewType->getResultType())) 1040 return true; 1041 1042 // If the function is a class member, its signature includes the 1043 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. 1044 // 1045 // As part of this, also check whether one of the member functions 1046 // is static, in which case they are not overloads (C++ 1047 // 13.1p2). While not part of the definition of the signature, 1048 // this check is important to determine whether these functions 1049 // can be overloaded. 1050 CXXMethodDecl *OldMethod = dyn_cast<CXXMethodDecl>(Old); 1051 CXXMethodDecl *NewMethod = dyn_cast<CXXMethodDecl>(New); 1052 if (OldMethod && NewMethod && 1053 !OldMethod->isStatic() && !NewMethod->isStatic()) { 1054 if (OldMethod->getRefQualifier() != NewMethod->getRefQualifier()) { 1055 if (!UseUsingDeclRules && 1056 (OldMethod->getRefQualifier() == RQ_None || 1057 NewMethod->getRefQualifier() == RQ_None)) { 1058 // C++0x [over.load]p2: 1059 // - Member function declarations with the same name and the same 1060 // parameter-type-list as well as member function template 1061 // declarations with the same name, the same parameter-type-list, and 1062 // the same template parameter lists cannot be overloaded if any of 1063 // them, but not all, have a ref-qualifier (8.3.5). 1064 S.Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) 1065 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); 1066 S.Diag(OldMethod->getLocation(), diag::note_previous_declaration); 1067 } 1068 return true; 1069 } 1070 1071 // We may not have applied the implicit const for a constexpr member 1072 // function yet (because we haven't yet resolved whether this is a static 1073 // or non-static member function). Add it now, on the assumption that this 1074 // is a redeclaration of OldMethod. 1075 unsigned NewQuals = NewMethod->getTypeQualifiers(); 1076 if (NewMethod->isConstexpr() && !isa<CXXConstructorDecl>(NewMethod)) 1077 NewQuals |= Qualifiers::Const; 1078 if (OldMethod->getTypeQualifiers() != NewQuals) 1079 return true; 1080 } 1081 1082 // The signatures match; this is not an overload. 1083 return false; 1084} 1085 1086bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 1087 bool UseUsingDeclRules) { 1088 if (!shouldTryToOverload(*this, New, Old, UseUsingDeclRules)) 1089 return false; 1090 1091 // If both of the functions are extern "C", then they are not 1092 // overloads. 1093 if (!canBeOverloaded(*Old) && !canBeOverloaded(*New)) 1094 return false; 1095 1096 return true; 1097} 1098 1099/// \brief Checks availability of the function depending on the current 1100/// function context. Inside an unavailable function, unavailability is ignored. 1101/// 1102/// \returns true if \arg FD is unavailable and current context is inside 1103/// an available function, false otherwise. 1104bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) { 1105 return FD->isUnavailable() && !cast<Decl>(CurContext)->isUnavailable(); 1106} 1107 1108/// \brief Tries a user-defined conversion from From to ToType. 1109/// 1110/// Produces an implicit conversion sequence for when a standard conversion 1111/// is not an option. See TryImplicitConversion for more information. 1112static ImplicitConversionSequence 1113TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 1114 bool SuppressUserConversions, 1115 bool AllowExplicit, 1116 bool InOverloadResolution, 1117 bool CStyle, 1118 bool AllowObjCWritebackConversion) { 1119 ImplicitConversionSequence ICS; 1120 1121 if (SuppressUserConversions) { 1122 // We're not in the case above, so there is no conversion that 1123 // we can perform. 1124 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 1125 return ICS; 1126 } 1127 1128 // Attempt user-defined conversion. 1129 OverloadCandidateSet Conversions(From->getExprLoc()); 1130 OverloadingResult UserDefResult 1131 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 1132 AllowExplicit); 1133 1134 if (UserDefResult == OR_Success) { 1135 ICS.setUserDefined(); 1136 // C++ [over.ics.user]p4: 1137 // A conversion of an expression of class type to the same class 1138 // type is given Exact Match rank, and a conversion of an 1139 // expression of class type to a base class of that type is 1140 // given Conversion rank, in spite of the fact that a copy 1141 // constructor (i.e., a user-defined conversion function) is 1142 // called for those cases. 1143 if (CXXConstructorDecl *Constructor 1144 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 1145 QualType FromCanon 1146 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 1147 QualType ToCanon 1148 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 1149 if (Constructor->isCopyConstructor() && 1150 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 1151 // Turn this into a "standard" conversion sequence, so that it 1152 // gets ranked with standard conversion sequences. 1153 ICS.setStandard(); 1154 ICS.Standard.setAsIdentityConversion(); 1155 ICS.Standard.setFromType(From->getType()); 1156 ICS.Standard.setAllToTypes(ToType); 1157 ICS.Standard.CopyConstructor = Constructor; 1158 if (ToCanon != FromCanon) 1159 ICS.Standard.Second = ICK_Derived_To_Base; 1160 } 1161 } 1162 1163 // C++ [over.best.ics]p4: 1164 // However, when considering the argument of a user-defined 1165 // conversion function that is a candidate by 13.3.1.3 when 1166 // invoked for the copying of the temporary in the second step 1167 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 1168 // 13.3.1.6 in all cases, only standard conversion sequences and 1169 // ellipsis conversion sequences are allowed. 1170 if (SuppressUserConversions && ICS.isUserDefined()) { 1171 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 1172 } 1173 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 1174 ICS.setAmbiguous(); 1175 ICS.Ambiguous.setFromType(From->getType()); 1176 ICS.Ambiguous.setToType(ToType); 1177 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 1178 Cand != Conversions.end(); ++Cand) 1179 if (Cand->Viable) 1180 ICS.Ambiguous.addConversion(Cand->Function); 1181 } else { 1182 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 1183 } 1184 1185 return ICS; 1186} 1187 1188/// TryImplicitConversion - Attempt to perform an implicit conversion 1189/// from the given expression (Expr) to the given type (ToType). This 1190/// function returns an implicit conversion sequence that can be used 1191/// to perform the initialization. Given 1192/// 1193/// void f(float f); 1194/// void g(int i) { f(i); } 1195/// 1196/// this routine would produce an implicit conversion sequence to 1197/// describe the initialization of f from i, which will be a standard 1198/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 1199/// 4.1) followed by a floating-integral conversion (C++ 4.9). 1200// 1201/// Note that this routine only determines how the conversion can be 1202/// performed; it does not actually perform the conversion. As such, 1203/// it will not produce any diagnostics if no conversion is available, 1204/// but will instead return an implicit conversion sequence of kind 1205/// "BadConversion". 1206/// 1207/// If @p SuppressUserConversions, then user-defined conversions are 1208/// not permitted. 1209/// If @p AllowExplicit, then explicit user-defined conversions are 1210/// permitted. 1211/// 1212/// \param AllowObjCWritebackConversion Whether we allow the Objective-C 1213/// writeback conversion, which allows __autoreleasing id* parameters to 1214/// be initialized with __strong id* or __weak id* arguments. 1215static ImplicitConversionSequence 1216TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 1217 bool SuppressUserConversions, 1218 bool AllowExplicit, 1219 bool InOverloadResolution, 1220 bool CStyle, 1221 bool AllowObjCWritebackConversion) { 1222 ImplicitConversionSequence ICS; 1223 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 1224 ICS.Standard, CStyle, AllowObjCWritebackConversion)){ 1225 ICS.setStandard(); 1226 return ICS; 1227 } 1228 1229 if (!S.getLangOpts().CPlusPlus) { 1230 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 1231 return ICS; 1232 } 1233 1234 // C++ [over.ics.user]p4: 1235 // A conversion of an expression of class type to the same class 1236 // type is given Exact Match rank, and a conversion of an 1237 // expression of class type to a base class of that type is 1238 // given Conversion rank, in spite of the fact that a copy/move 1239 // constructor (i.e., a user-defined conversion function) is 1240 // called for those cases. 1241 QualType FromType = From->getType(); 1242 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 1243 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 1244 S.IsDerivedFrom(FromType, ToType))) { 1245 ICS.setStandard(); 1246 ICS.Standard.setAsIdentityConversion(); 1247 ICS.Standard.setFromType(FromType); 1248 ICS.Standard.setAllToTypes(ToType); 1249 1250 // We don't actually check at this point whether there is a valid 1251 // copy/move constructor, since overloading just assumes that it 1252 // exists. When we actually perform initialization, we'll find the 1253 // appropriate constructor to copy the returned object, if needed. 1254 ICS.Standard.CopyConstructor = 0; 1255 1256 // Determine whether this is considered a derived-to-base conversion. 1257 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 1258 ICS.Standard.Second = ICK_Derived_To_Base; 1259 1260 return ICS; 1261 } 1262 1263 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, 1264 AllowExplicit, InOverloadResolution, CStyle, 1265 AllowObjCWritebackConversion); 1266} 1267 1268ImplicitConversionSequence 1269Sema::TryImplicitConversion(Expr *From, QualType ToType, 1270 bool SuppressUserConversions, 1271 bool AllowExplicit, 1272 bool InOverloadResolution, 1273 bool CStyle, 1274 bool AllowObjCWritebackConversion) { 1275 return clang::TryImplicitConversion(*this, From, ToType, 1276 SuppressUserConversions, AllowExplicit, 1277 InOverloadResolution, CStyle, 1278 AllowObjCWritebackConversion); 1279} 1280 1281/// PerformImplicitConversion - Perform an implicit conversion of the 1282/// expression From to the type ToType. Returns the 1283/// converted expression. Flavor is the kind of conversion we're 1284/// performing, used in the error message. If @p AllowExplicit, 1285/// explicit user-defined conversions are permitted. 1286ExprResult 1287Sema::PerformImplicitConversion(Expr *From, QualType ToType, 1288 AssignmentAction Action, bool AllowExplicit) { 1289 ImplicitConversionSequence ICS; 1290 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 1291} 1292 1293ExprResult 1294Sema::PerformImplicitConversion(Expr *From, QualType ToType, 1295 AssignmentAction Action, bool AllowExplicit, 1296 ImplicitConversionSequence& ICS) { 1297 if (checkPlaceholderForOverload(*this, From)) 1298 return ExprError(); 1299 1300 // Objective-C ARC: Determine whether we will allow the writeback conversion. 1301 bool AllowObjCWritebackConversion 1302 = getLangOpts().ObjCAutoRefCount && 1303 (Action == AA_Passing || Action == AA_Sending); 1304 1305 ICS = clang::TryImplicitConversion(*this, From, ToType, 1306 /*SuppressUserConversions=*/false, 1307 AllowExplicit, 1308 /*InOverloadResolution=*/false, 1309 /*CStyle=*/false, 1310 AllowObjCWritebackConversion); 1311 return PerformImplicitConversion(From, ToType, ICS, Action); 1312} 1313 1314/// \brief Determine whether the conversion from FromType to ToType is a valid 1315/// conversion that strips "noreturn" off the nested function type. 1316bool Sema::IsNoReturnConversion(QualType FromType, QualType ToType, 1317 QualType &ResultTy) { 1318 if (Context.hasSameUnqualifiedType(FromType, ToType)) 1319 return false; 1320 1321 // Permit the conversion F(t __attribute__((noreturn))) -> F(t) 1322 // where F adds one of the following at most once: 1323 // - a pointer 1324 // - a member pointer 1325 // - a block pointer 1326 CanQualType CanTo = Context.getCanonicalType(ToType); 1327 CanQualType CanFrom = Context.getCanonicalType(FromType); 1328 Type::TypeClass TyClass = CanTo->getTypeClass(); 1329 if (TyClass != CanFrom->getTypeClass()) return false; 1330 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { 1331 if (TyClass == Type::Pointer) { 1332 CanTo = CanTo.getAs<PointerType>()->getPointeeType(); 1333 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType(); 1334 } else if (TyClass == Type::BlockPointer) { 1335 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType(); 1336 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType(); 1337 } else if (TyClass == Type::MemberPointer) { 1338 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType(); 1339 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType(); 1340 } else { 1341 return false; 1342 } 1343 1344 TyClass = CanTo->getTypeClass(); 1345 if (TyClass != CanFrom->getTypeClass()) return false; 1346 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) 1347 return false; 1348 } 1349 1350 const FunctionType *FromFn = cast<FunctionType>(CanFrom); 1351 FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); 1352 if (!EInfo.getNoReturn()) return false; 1353 1354 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); 1355 assert(QualType(FromFn, 0).isCanonical()); 1356 if (QualType(FromFn, 0) != CanTo) return false; 1357 1358 ResultTy = ToType; 1359 return true; 1360} 1361 1362/// \brief Determine whether the conversion from FromType to ToType is a valid 1363/// vector conversion. 1364/// 1365/// \param ICK Will be set to the vector conversion kind, if this is a vector 1366/// conversion. 1367static bool IsVectorConversion(ASTContext &Context, QualType FromType, 1368 QualType ToType, ImplicitConversionKind &ICK) { 1369 // We need at least one of these types to be a vector type to have a vector 1370 // conversion. 1371 if (!ToType->isVectorType() && !FromType->isVectorType()) 1372 return false; 1373 1374 // Identical types require no conversions. 1375 if (Context.hasSameUnqualifiedType(FromType, ToType)) 1376 return false; 1377 1378 // There are no conversions between extended vector types, only identity. 1379 if (ToType->isExtVectorType()) { 1380 // There are no conversions between extended vector types other than the 1381 // identity conversion. 1382 if (FromType->isExtVectorType()) 1383 return false; 1384 1385 // Vector splat from any arithmetic type to a vector. 1386 if (FromType->isArithmeticType()) { 1387 ICK = ICK_Vector_Splat; 1388 return true; 1389 } 1390 } 1391 1392 // We can perform the conversion between vector types in the following cases: 1393 // 1)vector types are equivalent AltiVec and GCC vector types 1394 // 2)lax vector conversions are permitted and the vector types are of the 1395 // same size 1396 if (ToType->isVectorType() && FromType->isVectorType()) { 1397 if (Context.areCompatibleVectorTypes(FromType, ToType) || 1398 (Context.getLangOpts().LaxVectorConversions && 1399 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 1400 ICK = ICK_Vector_Conversion; 1401 return true; 1402 } 1403 } 1404 1405 return false; 1406} 1407 1408static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType, 1409 bool InOverloadResolution, 1410 StandardConversionSequence &SCS, 1411 bool CStyle); 1412 1413/// IsStandardConversion - Determines whether there is a standard 1414/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 1415/// expression From to the type ToType. Standard conversion sequences 1416/// only consider non-class types; for conversions that involve class 1417/// types, use TryImplicitConversion. If a conversion exists, SCS will 1418/// contain the standard conversion sequence required to perform this 1419/// conversion and this routine will return true. Otherwise, this 1420/// routine will return false and the value of SCS is unspecified. 1421static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 1422 bool InOverloadResolution, 1423 StandardConversionSequence &SCS, 1424 bool CStyle, 1425 bool AllowObjCWritebackConversion) { 1426 QualType FromType = From->getType(); 1427 1428 // Standard conversions (C++ [conv]) 1429 SCS.setAsIdentityConversion(); 1430 SCS.DeprecatedStringLiteralToCharPtr = false; 1431 SCS.IncompatibleObjC = false; 1432 SCS.setFromType(FromType); 1433 SCS.CopyConstructor = 0; 1434 1435 // There are no standard conversions for class types in C++, so 1436 // abort early. When overloading in C, however, we do permit 1437 if (FromType->isRecordType() || ToType->isRecordType()) { 1438 if (S.getLangOpts().CPlusPlus) 1439 return false; 1440 1441 // When we're overloading in C, we allow, as standard conversions, 1442 } 1443 1444 // The first conversion can be an lvalue-to-rvalue conversion, 1445 // array-to-pointer conversion, or function-to-pointer conversion 1446 // (C++ 4p1). 1447 1448 if (FromType == S.Context.OverloadTy) { 1449 DeclAccessPair AccessPair; 1450 if (FunctionDecl *Fn 1451 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 1452 AccessPair)) { 1453 // We were able to resolve the address of the overloaded function, 1454 // so we can convert to the type of that function. 1455 FromType = Fn->getType(); 1456 1457 // we can sometimes resolve &foo<int> regardless of ToType, so check 1458 // if the type matches (identity) or we are converting to bool 1459 if (!S.Context.hasSameUnqualifiedType( 1460 S.ExtractUnqualifiedFunctionType(ToType), FromType)) { 1461 QualType resultTy; 1462 // if the function type matches except for [[noreturn]], it's ok 1463 if (!S.IsNoReturnConversion(FromType, 1464 S.ExtractUnqualifiedFunctionType(ToType), resultTy)) 1465 // otherwise, only a boolean conversion is standard 1466 if (!ToType->isBooleanType()) 1467 return false; 1468 } 1469 1470 // Check if the "from" expression is taking the address of an overloaded 1471 // function and recompute the FromType accordingly. Take advantage of the 1472 // fact that non-static member functions *must* have such an address-of 1473 // expression. 1474 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn); 1475 if (Method && !Method->isStatic()) { 1476 assert(isa<UnaryOperator>(From->IgnoreParens()) && 1477 "Non-unary operator on non-static member address"); 1478 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() 1479 == UO_AddrOf && 1480 "Non-address-of operator on non-static member address"); 1481 const Type *ClassType 1482 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1483 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1484 } else if (isa<UnaryOperator>(From->IgnoreParens())) { 1485 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == 1486 UO_AddrOf && 1487 "Non-address-of operator for overloaded function expression"); 1488 FromType = S.Context.getPointerType(FromType); 1489 } 1490 1491 // Check that we've computed the proper type after overload resolution. 1492 assert(S.Context.hasSameType( 1493 FromType, 1494 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1495 } else { 1496 return false; 1497 } 1498 } 1499 // Lvalue-to-rvalue conversion (C++11 4.1): 1500 // A glvalue (3.10) of a non-function, non-array type T can 1501 // be converted to a prvalue. 1502 bool argIsLValue = From->isGLValue(); 1503 if (argIsLValue && 1504 !FromType->isFunctionType() && !FromType->isArrayType() && 1505 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1506 SCS.First = ICK_Lvalue_To_Rvalue; 1507 1508 // C11 6.3.2.1p2: 1509 // ... if the lvalue has atomic type, the value has the non-atomic version 1510 // of the type of the lvalue ... 1511 if (const AtomicType *Atomic = FromType->getAs<AtomicType>()) 1512 FromType = Atomic->getValueType(); 1513 1514 // If T is a non-class type, the type of the rvalue is the 1515 // cv-unqualified version of T. Otherwise, the type of the rvalue 1516 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1517 // just strip the qualifiers because they don't matter. 1518 FromType = FromType.getUnqualifiedType(); 1519 } else if (FromType->isArrayType()) { 1520 // Array-to-pointer conversion (C++ 4.2) 1521 SCS.First = ICK_Array_To_Pointer; 1522 1523 // An lvalue or rvalue of type "array of N T" or "array of unknown 1524 // bound of T" can be converted to an rvalue of type "pointer to 1525 // T" (C++ 4.2p1). 1526 FromType = S.Context.getArrayDecayedType(FromType); 1527 1528 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1529 // This conversion is deprecated. (C++ D.4). 1530 SCS.DeprecatedStringLiteralToCharPtr = true; 1531 1532 // For the purpose of ranking in overload resolution 1533 // (13.3.3.1.1), this conversion is considered an 1534 // array-to-pointer conversion followed by a qualification 1535 // conversion (4.4). (C++ 4.2p2) 1536 SCS.Second = ICK_Identity; 1537 SCS.Third = ICK_Qualification; 1538 SCS.QualificationIncludesObjCLifetime = false; 1539 SCS.setAllToTypes(FromType); 1540 return true; 1541 } 1542 } else if (FromType->isFunctionType() && argIsLValue) { 1543 // Function-to-pointer conversion (C++ 4.3). 1544 SCS.First = ICK_Function_To_Pointer; 1545 1546 // An lvalue of function type T can be converted to an rvalue of 1547 // type "pointer to T." The result is a pointer to the 1548 // function. (C++ 4.3p1). 1549 FromType = S.Context.getPointerType(FromType); 1550 } else { 1551 // We don't require any conversions for the first step. 1552 SCS.First = ICK_Identity; 1553 } 1554 SCS.setToType(0, FromType); 1555 1556 // The second conversion can be an integral promotion, floating 1557 // point promotion, integral conversion, floating point conversion, 1558 // floating-integral conversion, pointer conversion, 1559 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1560 // For overloading in C, this can also be a "compatible-type" 1561 // conversion. 1562 bool IncompatibleObjC = false; 1563 ImplicitConversionKind SecondICK = ICK_Identity; 1564 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1565 // The unqualified versions of the types are the same: there's no 1566 // conversion to do. 1567 SCS.Second = ICK_Identity; 1568 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1569 // Integral promotion (C++ 4.5). 1570 SCS.Second = ICK_Integral_Promotion; 1571 FromType = ToType.getUnqualifiedType(); 1572 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1573 // Floating point promotion (C++ 4.6). 1574 SCS.Second = ICK_Floating_Promotion; 1575 FromType = ToType.getUnqualifiedType(); 1576 } else if (S.IsComplexPromotion(FromType, ToType)) { 1577 // Complex promotion (Clang extension) 1578 SCS.Second = ICK_Complex_Promotion; 1579 FromType = ToType.getUnqualifiedType(); 1580 } else if (ToType->isBooleanType() && 1581 (FromType->isArithmeticType() || 1582 FromType->isAnyPointerType() || 1583 FromType->isBlockPointerType() || 1584 FromType->isMemberPointerType() || 1585 FromType->isNullPtrType())) { 1586 // Boolean conversions (C++ 4.12). 1587 SCS.Second = ICK_Boolean_Conversion; 1588 FromType = S.Context.BoolTy; 1589 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1590 ToType->isIntegralType(S.Context)) { 1591 // Integral conversions (C++ 4.7). 1592 SCS.Second = ICK_Integral_Conversion; 1593 FromType = ToType.getUnqualifiedType(); 1594 } else if (FromType->isAnyComplexType() && ToType->isAnyComplexType()) { 1595 // Complex conversions (C99 6.3.1.6) 1596 SCS.Second = ICK_Complex_Conversion; 1597 FromType = ToType.getUnqualifiedType(); 1598 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1599 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1600 // Complex-real conversions (C99 6.3.1.7) 1601 SCS.Second = ICK_Complex_Real; 1602 FromType = ToType.getUnqualifiedType(); 1603 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1604 // Floating point conversions (C++ 4.8). 1605 SCS.Second = ICK_Floating_Conversion; 1606 FromType = ToType.getUnqualifiedType(); 1607 } else if ((FromType->isRealFloatingType() && 1608 ToType->isIntegralType(S.Context)) || 1609 (FromType->isIntegralOrUnscopedEnumerationType() && 1610 ToType->isRealFloatingType())) { 1611 // Floating-integral conversions (C++ 4.9). 1612 SCS.Second = ICK_Floating_Integral; 1613 FromType = ToType.getUnqualifiedType(); 1614 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { 1615 SCS.Second = ICK_Block_Pointer_Conversion; 1616 } else if (AllowObjCWritebackConversion && 1617 S.isObjCWritebackConversion(FromType, ToType, FromType)) { 1618 SCS.Second = ICK_Writeback_Conversion; 1619 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1620 FromType, IncompatibleObjC)) { 1621 // Pointer conversions (C++ 4.10). 1622 SCS.Second = ICK_Pointer_Conversion; 1623 SCS.IncompatibleObjC = IncompatibleObjC; 1624 FromType = FromType.getUnqualifiedType(); 1625 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1626 InOverloadResolution, FromType)) { 1627 // Pointer to member conversions (4.11). 1628 SCS.Second = ICK_Pointer_Member; 1629 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1630 SCS.Second = SecondICK; 1631 FromType = ToType.getUnqualifiedType(); 1632 } else if (!S.getLangOpts().CPlusPlus && 1633 S.Context.typesAreCompatible(ToType, FromType)) { 1634 // Compatible conversions (Clang extension for C function overloading) 1635 SCS.Second = ICK_Compatible_Conversion; 1636 FromType = ToType.getUnqualifiedType(); 1637 } else if (S.IsNoReturnConversion(FromType, ToType, FromType)) { 1638 // Treat a conversion that strips "noreturn" as an identity conversion. 1639 SCS.Second = ICK_NoReturn_Adjustment; 1640 } else if (IsTransparentUnionStandardConversion(S, From, ToType, 1641 InOverloadResolution, 1642 SCS, CStyle)) { 1643 SCS.Second = ICK_TransparentUnionConversion; 1644 FromType = ToType; 1645 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS, 1646 CStyle)) { 1647 // tryAtomicConversion has updated the standard conversion sequence 1648 // appropriately. 1649 return true; 1650 } else if (ToType->isEventT() && 1651 From->isIntegerConstantExpr(S.getASTContext()) && 1652 (From->EvaluateKnownConstInt(S.getASTContext()) == 0)) { 1653 SCS.Second = ICK_Zero_Event_Conversion; 1654 FromType = ToType; 1655 } else { 1656 // No second conversion required. 1657 SCS.Second = ICK_Identity; 1658 } 1659 SCS.setToType(1, FromType); 1660 1661 QualType CanonFrom; 1662 QualType CanonTo; 1663 // The third conversion can be a qualification conversion (C++ 4p1). 1664 bool ObjCLifetimeConversion; 1665 if (S.IsQualificationConversion(FromType, ToType, CStyle, 1666 ObjCLifetimeConversion)) { 1667 SCS.Third = ICK_Qualification; 1668 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion; 1669 FromType = ToType; 1670 CanonFrom = S.Context.getCanonicalType(FromType); 1671 CanonTo = S.Context.getCanonicalType(ToType); 1672 } else { 1673 // No conversion required 1674 SCS.Third = ICK_Identity; 1675 1676 // C++ [over.best.ics]p6: 1677 // [...] Any difference in top-level cv-qualification is 1678 // subsumed by the initialization itself and does not constitute 1679 // a conversion. [...] 1680 CanonFrom = S.Context.getCanonicalType(FromType); 1681 CanonTo = S.Context.getCanonicalType(ToType); 1682 if (CanonFrom.getLocalUnqualifiedType() 1683 == CanonTo.getLocalUnqualifiedType() && 1684 CanonFrom.getLocalQualifiers() != CanonTo.getLocalQualifiers()) { 1685 FromType = ToType; 1686 CanonFrom = CanonTo; 1687 } 1688 } 1689 SCS.setToType(2, FromType); 1690 1691 // If we have not converted the argument type to the parameter type, 1692 // this is a bad conversion sequence. 1693 if (CanonFrom != CanonTo) 1694 return false; 1695 1696 return true; 1697} 1698 1699static bool 1700IsTransparentUnionStandardConversion(Sema &S, Expr* From, 1701 QualType &ToType, 1702 bool InOverloadResolution, 1703 StandardConversionSequence &SCS, 1704 bool CStyle) { 1705 1706 const RecordType *UT = ToType->getAsUnionType(); 1707 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 1708 return false; 1709 // The field to initialize within the transparent union. 1710 RecordDecl *UD = UT->getDecl(); 1711 // It's compatible if the expression matches any of the fields. 1712 for (RecordDecl::field_iterator it = UD->field_begin(), 1713 itend = UD->field_end(); 1714 it != itend; ++it) { 1715 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, 1716 CStyle, /*ObjCWritebackConversion=*/false)) { 1717 ToType = it->getType(); 1718 return true; 1719 } 1720 } 1721 return false; 1722} 1723 1724/// IsIntegralPromotion - Determines whether the conversion from the 1725/// expression From (whose potentially-adjusted type is FromType) to 1726/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1727/// sets PromotedType to the promoted type. 1728bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1729 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1730 // All integers are built-in. 1731 if (!To) { 1732 return false; 1733 } 1734 1735 // An rvalue of type char, signed char, unsigned char, short int, or 1736 // unsigned short int can be converted to an rvalue of type int if 1737 // int can represent all the values of the source type; otherwise, 1738 // the source rvalue can be converted to an rvalue of type unsigned 1739 // int (C++ 4.5p1). 1740 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1741 !FromType->isEnumeralType()) { 1742 if (// We can promote any signed, promotable integer type to an int 1743 (FromType->isSignedIntegerType() || 1744 // We can promote any unsigned integer type whose size is 1745 // less than int to an int. 1746 (!FromType->isSignedIntegerType() && 1747 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1748 return To->getKind() == BuiltinType::Int; 1749 } 1750 1751 return To->getKind() == BuiltinType::UInt; 1752 } 1753 1754 // C++11 [conv.prom]p3: 1755 // A prvalue of an unscoped enumeration type whose underlying type is not 1756 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1757 // following types that can represent all the values of the enumeration 1758 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1759 // unsigned int, long int, unsigned long int, long long int, or unsigned 1760 // long long int. If none of the types in that list can represent all the 1761 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1762 // type can be converted to an rvalue a prvalue of the extended integer type 1763 // with lowest integer conversion rank (4.13) greater than the rank of long 1764 // long in which all the values of the enumeration can be represented. If 1765 // there are two such extended types, the signed one is chosen. 1766 // C++11 [conv.prom]p4: 1767 // A prvalue of an unscoped enumeration type whose underlying type is fixed 1768 // can be converted to a prvalue of its underlying type. Moreover, if 1769 // integral promotion can be applied to its underlying type, a prvalue of an 1770 // unscoped enumeration type whose underlying type is fixed can also be 1771 // converted to a prvalue of the promoted underlying type. 1772 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1773 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1774 // provided for a scoped enumeration. 1775 if (FromEnumType->getDecl()->isScoped()) 1776 return false; 1777 1778 // We can perform an integral promotion to the underlying type of the enum, 1779 // even if that's not the promoted type. 1780 if (FromEnumType->getDecl()->isFixed()) { 1781 QualType Underlying = FromEnumType->getDecl()->getIntegerType(); 1782 return Context.hasSameUnqualifiedType(Underlying, ToType) || 1783 IsIntegralPromotion(From, Underlying, ToType); 1784 } 1785 1786 // We have already pre-calculated the promotion type, so this is trivial. 1787 if (ToType->isIntegerType() && 1788 !RequireCompleteType(From->getLocStart(), FromType, 0)) 1789 return Context.hasSameUnqualifiedType(ToType, 1790 FromEnumType->getDecl()->getPromotionType()); 1791 } 1792 1793 // C++0x [conv.prom]p2: 1794 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1795 // to an rvalue a prvalue of the first of the following types that can 1796 // represent all the values of its underlying type: int, unsigned int, 1797 // long int, unsigned long int, long long int, or unsigned long long int. 1798 // If none of the types in that list can represent all the values of its 1799 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1800 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1801 // type. 1802 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1803 ToType->isIntegerType()) { 1804 // Determine whether the type we're converting from is signed or 1805 // unsigned. 1806 bool FromIsSigned = FromType->isSignedIntegerType(); 1807 uint64_t FromSize = Context.getTypeSize(FromType); 1808 1809 // The types we'll try to promote to, in the appropriate 1810 // order. Try each of these types. 1811 QualType PromoteTypes[6] = { 1812 Context.IntTy, Context.UnsignedIntTy, 1813 Context.LongTy, Context.UnsignedLongTy , 1814 Context.LongLongTy, Context.UnsignedLongLongTy 1815 }; 1816 for (int Idx = 0; Idx < 6; ++Idx) { 1817 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1818 if (FromSize < ToSize || 1819 (FromSize == ToSize && 1820 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1821 // We found the type that we can promote to. If this is the 1822 // type we wanted, we have a promotion. Otherwise, no 1823 // promotion. 1824 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1825 } 1826 } 1827 } 1828 1829 // An rvalue for an integral bit-field (9.6) can be converted to an 1830 // rvalue of type int if int can represent all the values of the 1831 // bit-field; otherwise, it can be converted to unsigned int if 1832 // unsigned int can represent all the values of the bit-field. If 1833 // the bit-field is larger yet, no integral promotion applies to 1834 // it. If the bit-field has an enumerated type, it is treated as any 1835 // other value of that type for promotion purposes (C++ 4.5p3). 1836 // FIXME: We should delay checking of bit-fields until we actually perform the 1837 // conversion. 1838 using llvm::APSInt; 1839 if (From) 1840 if (FieldDecl *MemberDecl = From->getSourceBitField()) { 1841 APSInt BitWidth; 1842 if (FromType->isIntegralType(Context) && 1843 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1844 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1845 ToSize = Context.getTypeSize(ToType); 1846 1847 // Are we promoting to an int from a bitfield that fits in an int? 1848 if (BitWidth < ToSize || 1849 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1850 return To->getKind() == BuiltinType::Int; 1851 } 1852 1853 // Are we promoting to an unsigned int from an unsigned bitfield 1854 // that fits into an unsigned int? 1855 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1856 return To->getKind() == BuiltinType::UInt; 1857 } 1858 1859 return false; 1860 } 1861 } 1862 1863 // An rvalue of type bool can be converted to an rvalue of type int, 1864 // with false becoming zero and true becoming one (C++ 4.5p4). 1865 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1866 return true; 1867 } 1868 1869 return false; 1870} 1871 1872/// IsFloatingPointPromotion - Determines whether the conversion from 1873/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1874/// returns true and sets PromotedType to the promoted type. 1875bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1876 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1877 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1878 /// An rvalue of type float can be converted to an rvalue of type 1879 /// double. (C++ 4.6p1). 1880 if (FromBuiltin->getKind() == BuiltinType::Float && 1881 ToBuiltin->getKind() == BuiltinType::Double) 1882 return true; 1883 1884 // C99 6.3.1.5p1: 1885 // When a float is promoted to double or long double, or a 1886 // double is promoted to long double [...]. 1887 if (!getLangOpts().CPlusPlus && 1888 (FromBuiltin->getKind() == BuiltinType::Float || 1889 FromBuiltin->getKind() == BuiltinType::Double) && 1890 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1891 return true; 1892 1893 // Half can be promoted to float. 1894 if (!getLangOpts().NativeHalfType && 1895 FromBuiltin->getKind() == BuiltinType::Half && 1896 ToBuiltin->getKind() == BuiltinType::Float) 1897 return true; 1898 } 1899 1900 return false; 1901} 1902 1903/// \brief Determine if a conversion is a complex promotion. 1904/// 1905/// A complex promotion is defined as a complex -> complex conversion 1906/// where the conversion between the underlying real types is a 1907/// floating-point or integral promotion. 1908bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1909 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1910 if (!FromComplex) 1911 return false; 1912 1913 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1914 if (!ToComplex) 1915 return false; 1916 1917 return IsFloatingPointPromotion(FromComplex->getElementType(), 1918 ToComplex->getElementType()) || 1919 IsIntegralPromotion(0, FromComplex->getElementType(), 1920 ToComplex->getElementType()); 1921} 1922 1923/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1924/// the pointer type FromPtr to a pointer to type ToPointee, with the 1925/// same type qualifiers as FromPtr has on its pointee type. ToType, 1926/// if non-empty, will be a pointer to ToType that may or may not have 1927/// the right set of qualifiers on its pointee. 1928/// 1929static QualType 1930BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1931 QualType ToPointee, QualType ToType, 1932 ASTContext &Context, 1933 bool StripObjCLifetime = false) { 1934 assert((FromPtr->getTypeClass() == Type::Pointer || 1935 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1936 "Invalid similarly-qualified pointer type"); 1937 1938 /// Conversions to 'id' subsume cv-qualifier conversions. 1939 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1940 return ToType.getUnqualifiedType(); 1941 1942 QualType CanonFromPointee 1943 = Context.getCanonicalType(FromPtr->getPointeeType()); 1944 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1945 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1946 1947 if (StripObjCLifetime) 1948 Quals.removeObjCLifetime(); 1949 1950 // Exact qualifier match -> return the pointer type we're converting to. 1951 if (CanonToPointee.getLocalQualifiers() == Quals) { 1952 // ToType is exactly what we need. Return it. 1953 if (!ToType.isNull()) 1954 return ToType.getUnqualifiedType(); 1955 1956 // Build a pointer to ToPointee. It has the right qualifiers 1957 // already. 1958 if (isa<ObjCObjectPointerType>(ToType)) 1959 return Context.getObjCObjectPointerType(ToPointee); 1960 return Context.getPointerType(ToPointee); 1961 } 1962 1963 // Just build a canonical type that has the right qualifiers. 1964 QualType QualifiedCanonToPointee 1965 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1966 1967 if (isa<ObjCObjectPointerType>(ToType)) 1968 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1969 return Context.getPointerType(QualifiedCanonToPointee); 1970} 1971 1972static bool isNullPointerConstantForConversion(Expr *Expr, 1973 bool InOverloadResolution, 1974 ASTContext &Context) { 1975 // Handle value-dependent integral null pointer constants correctly. 1976 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1977 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1978 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1979 return !InOverloadResolution; 1980 1981 return Expr->isNullPointerConstant(Context, 1982 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1983 : Expr::NPC_ValueDependentIsNull); 1984} 1985 1986/// IsPointerConversion - Determines whether the conversion of the 1987/// expression From, which has the (possibly adjusted) type FromType, 1988/// can be converted to the type ToType via a pointer conversion (C++ 1989/// 4.10). If so, returns true and places the converted type (that 1990/// might differ from ToType in its cv-qualifiers at some level) into 1991/// ConvertedType. 1992/// 1993/// This routine also supports conversions to and from block pointers 1994/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1995/// pointers to interfaces. FIXME: Once we've determined the 1996/// appropriate overloading rules for Objective-C, we may want to 1997/// split the Objective-C checks into a different routine; however, 1998/// GCC seems to consider all of these conversions to be pointer 1999/// conversions, so for now they live here. IncompatibleObjC will be 2000/// set if the conversion is an allowed Objective-C conversion that 2001/// should result in a warning. 2002bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 2003 bool InOverloadResolution, 2004 QualType& ConvertedType, 2005 bool &IncompatibleObjC) { 2006 IncompatibleObjC = false; 2007 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 2008 IncompatibleObjC)) 2009 return true; 2010 2011 // Conversion from a null pointer constant to any Objective-C pointer type. 2012 if (ToType->isObjCObjectPointerType() && 2013 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 2014 ConvertedType = ToType; 2015 return true; 2016 } 2017 2018 // Blocks: Block pointers can be converted to void*. 2019 if (FromType->isBlockPointerType() && ToType->isPointerType() && 2020 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 2021 ConvertedType = ToType; 2022 return true; 2023 } 2024 // Blocks: A null pointer constant can be converted to a block 2025 // pointer type. 2026 if (ToType->isBlockPointerType() && 2027 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 2028 ConvertedType = ToType; 2029 return true; 2030 } 2031 2032 // If the left-hand-side is nullptr_t, the right side can be a null 2033 // pointer constant. 2034 if (ToType->isNullPtrType() && 2035 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 2036 ConvertedType = ToType; 2037 return true; 2038 } 2039 2040 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 2041 if (!ToTypePtr) 2042 return false; 2043 2044 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 2045 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 2046 ConvertedType = ToType; 2047 return true; 2048 } 2049 2050 // Beyond this point, both types need to be pointers 2051 // , including objective-c pointers. 2052 QualType ToPointeeType = ToTypePtr->getPointeeType(); 2053 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() && 2054 !getLangOpts().ObjCAutoRefCount) { 2055 ConvertedType = BuildSimilarlyQualifiedPointerType( 2056 FromType->getAs<ObjCObjectPointerType>(), 2057 ToPointeeType, 2058 ToType, Context); 2059 return true; 2060 } 2061 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 2062 if (!FromTypePtr) 2063 return false; 2064 2065 QualType FromPointeeType = FromTypePtr->getPointeeType(); 2066 2067 // If the unqualified pointee types are the same, this can't be a 2068 // pointer conversion, so don't do all of the work below. 2069 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 2070 return false; 2071 2072 // An rvalue of type "pointer to cv T," where T is an object type, 2073 // can be converted to an rvalue of type "pointer to cv void" (C++ 2074 // 4.10p2). 2075 if (FromPointeeType->isIncompleteOrObjectType() && 2076 ToPointeeType->isVoidType()) { 2077 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2078 ToPointeeType, 2079 ToType, Context, 2080 /*StripObjCLifetime=*/true); 2081 return true; 2082 } 2083 2084 // MSVC allows implicit function to void* type conversion. 2085 if (getLangOpts().MicrosoftExt && FromPointeeType->isFunctionType() && 2086 ToPointeeType->isVoidType()) { 2087 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2088 ToPointeeType, 2089 ToType, Context); 2090 return true; 2091 } 2092 2093 // When we're overloading in C, we allow a special kind of pointer 2094 // conversion for compatible-but-not-identical pointee types. 2095 if (!getLangOpts().CPlusPlus && 2096 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 2097 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2098 ToPointeeType, 2099 ToType, Context); 2100 return true; 2101 } 2102 2103 // C++ [conv.ptr]p3: 2104 // 2105 // An rvalue of type "pointer to cv D," where D is a class type, 2106 // can be converted to an rvalue of type "pointer to cv B," where 2107 // B is a base class (clause 10) of D. If B is an inaccessible 2108 // (clause 11) or ambiguous (10.2) base class of D, a program that 2109 // necessitates this conversion is ill-formed. The result of the 2110 // conversion is a pointer to the base class sub-object of the 2111 // derived class object. The null pointer value is converted to 2112 // the null pointer value of the destination type. 2113 // 2114 // Note that we do not check for ambiguity or inaccessibility 2115 // here. That is handled by CheckPointerConversion. 2116 if (getLangOpts().CPlusPlus && 2117 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 2118 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 2119 !RequireCompleteType(From->getLocStart(), FromPointeeType, 0) && 2120 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 2121 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2122 ToPointeeType, 2123 ToType, Context); 2124 return true; 2125 } 2126 2127 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() && 2128 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) { 2129 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2130 ToPointeeType, 2131 ToType, Context); 2132 return true; 2133 } 2134 2135 return false; 2136} 2137 2138/// \brief Adopt the given qualifiers for the given type. 2139static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){ 2140 Qualifiers TQs = T.getQualifiers(); 2141 2142 // Check whether qualifiers already match. 2143 if (TQs == Qs) 2144 return T; 2145 2146 if (Qs.compatiblyIncludes(TQs)) 2147 return Context.getQualifiedType(T, Qs); 2148 2149 return Context.getQualifiedType(T.getUnqualifiedType(), Qs); 2150} 2151 2152/// isObjCPointerConversion - Determines whether this is an 2153/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 2154/// with the same arguments and return values. 2155bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 2156 QualType& ConvertedType, 2157 bool &IncompatibleObjC) { 2158 if (!getLangOpts().ObjC1) 2159 return false; 2160 2161 // The set of qualifiers on the type we're converting from. 2162 Qualifiers FromQualifiers = FromType.getQualifiers(); 2163 2164 // First, we handle all conversions on ObjC object pointer types. 2165 const ObjCObjectPointerType* ToObjCPtr = 2166 ToType->getAs<ObjCObjectPointerType>(); 2167 const ObjCObjectPointerType *FromObjCPtr = 2168 FromType->getAs<ObjCObjectPointerType>(); 2169 2170 if (ToObjCPtr && FromObjCPtr) { 2171 // If the pointee types are the same (ignoring qualifications), 2172 // then this is not a pointer conversion. 2173 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 2174 FromObjCPtr->getPointeeType())) 2175 return false; 2176 2177 // Check for compatible 2178 // Objective C++: We're able to convert between "id" or "Class" and a 2179 // pointer to any interface (in both directions). 2180 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 2181 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2182 return true; 2183 } 2184 // Conversions with Objective-C's id<...>. 2185 if ((FromObjCPtr->isObjCQualifiedIdType() || 2186 ToObjCPtr->isObjCQualifiedIdType()) && 2187 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 2188 /*compare=*/false)) { 2189 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2190 return true; 2191 } 2192 // Objective C++: We're able to convert from a pointer to an 2193 // interface to a pointer to a different interface. 2194 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 2195 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 2196 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 2197 if (getLangOpts().CPlusPlus && LHS && RHS && 2198 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 2199 FromObjCPtr->getPointeeType())) 2200 return false; 2201 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 2202 ToObjCPtr->getPointeeType(), 2203 ToType, Context); 2204 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2205 return true; 2206 } 2207 2208 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 2209 // Okay: this is some kind of implicit downcast of Objective-C 2210 // interfaces, which is permitted. However, we're going to 2211 // complain about it. 2212 IncompatibleObjC = true; 2213 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 2214 ToObjCPtr->getPointeeType(), 2215 ToType, Context); 2216 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2217 return true; 2218 } 2219 } 2220 // Beyond this point, both types need to be C pointers or block pointers. 2221 QualType ToPointeeType; 2222 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 2223 ToPointeeType = ToCPtr->getPointeeType(); 2224 else if (const BlockPointerType *ToBlockPtr = 2225 ToType->getAs<BlockPointerType>()) { 2226 // Objective C++: We're able to convert from a pointer to any object 2227 // to a block pointer type. 2228 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 2229 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2230 return true; 2231 } 2232 ToPointeeType = ToBlockPtr->getPointeeType(); 2233 } 2234 else if (FromType->getAs<BlockPointerType>() && 2235 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 2236 // Objective C++: We're able to convert from a block pointer type to a 2237 // pointer to any object. 2238 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2239 return true; 2240 } 2241 else 2242 return false; 2243 2244 QualType FromPointeeType; 2245 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 2246 FromPointeeType = FromCPtr->getPointeeType(); 2247 else if (const BlockPointerType *FromBlockPtr = 2248 FromType->getAs<BlockPointerType>()) 2249 FromPointeeType = FromBlockPtr->getPointeeType(); 2250 else 2251 return false; 2252 2253 // If we have pointers to pointers, recursively check whether this 2254 // is an Objective-C conversion. 2255 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 2256 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 2257 IncompatibleObjC)) { 2258 // We always complain about this conversion. 2259 IncompatibleObjC = true; 2260 ConvertedType = Context.getPointerType(ConvertedType); 2261 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2262 return true; 2263 } 2264 // Allow conversion of pointee being objective-c pointer to another one; 2265 // as in I* to id. 2266 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 2267 ToPointeeType->getAs<ObjCObjectPointerType>() && 2268 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 2269 IncompatibleObjC)) { 2270 2271 ConvertedType = Context.getPointerType(ConvertedType); 2272 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2273 return true; 2274 } 2275 2276 // If we have pointers to functions or blocks, check whether the only 2277 // differences in the argument and result types are in Objective-C 2278 // pointer conversions. If so, we permit the conversion (but 2279 // complain about it). 2280 const FunctionProtoType *FromFunctionType 2281 = FromPointeeType->getAs<FunctionProtoType>(); 2282 const FunctionProtoType *ToFunctionType 2283 = ToPointeeType->getAs<FunctionProtoType>(); 2284 if (FromFunctionType && ToFunctionType) { 2285 // If the function types are exactly the same, this isn't an 2286 // Objective-C pointer conversion. 2287 if (Context.getCanonicalType(FromPointeeType) 2288 == Context.getCanonicalType(ToPointeeType)) 2289 return false; 2290 2291 // Perform the quick checks that will tell us whether these 2292 // function types are obviously different. 2293 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 2294 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 2295 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 2296 return false; 2297 2298 bool HasObjCConversion = false; 2299 if (Context.getCanonicalType(FromFunctionType->getResultType()) 2300 == Context.getCanonicalType(ToFunctionType->getResultType())) { 2301 // Okay, the types match exactly. Nothing to do. 2302 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 2303 ToFunctionType->getResultType(), 2304 ConvertedType, IncompatibleObjC)) { 2305 // Okay, we have an Objective-C pointer conversion. 2306 HasObjCConversion = true; 2307 } else { 2308 // Function types are too different. Abort. 2309 return false; 2310 } 2311 2312 // Check argument types. 2313 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 2314 ArgIdx != NumArgs; ++ArgIdx) { 2315 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 2316 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 2317 if (Context.getCanonicalType(FromArgType) 2318 == Context.getCanonicalType(ToArgType)) { 2319 // Okay, the types match exactly. Nothing to do. 2320 } else if (isObjCPointerConversion(FromArgType, ToArgType, 2321 ConvertedType, IncompatibleObjC)) { 2322 // Okay, we have an Objective-C pointer conversion. 2323 HasObjCConversion = true; 2324 } else { 2325 // Argument types are too different. Abort. 2326 return false; 2327 } 2328 } 2329 2330 if (HasObjCConversion) { 2331 // We had an Objective-C conversion. Allow this pointer 2332 // conversion, but complain about it. 2333 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2334 IncompatibleObjC = true; 2335 return true; 2336 } 2337 } 2338 2339 return false; 2340} 2341 2342/// \brief Determine whether this is an Objective-C writeback conversion, 2343/// used for parameter passing when performing automatic reference counting. 2344/// 2345/// \param FromType The type we're converting form. 2346/// 2347/// \param ToType The type we're converting to. 2348/// 2349/// \param ConvertedType The type that will be produced after applying 2350/// this conversion. 2351bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType, 2352 QualType &ConvertedType) { 2353 if (!getLangOpts().ObjCAutoRefCount || 2354 Context.hasSameUnqualifiedType(FromType, ToType)) 2355 return false; 2356 2357 // Parameter must be a pointer to __autoreleasing (with no other qualifiers). 2358 QualType ToPointee; 2359 if (const PointerType *ToPointer = ToType->getAs<PointerType>()) 2360 ToPointee = ToPointer->getPointeeType(); 2361 else 2362 return false; 2363 2364 Qualifiers ToQuals = ToPointee.getQualifiers(); 2365 if (!ToPointee->isObjCLifetimeType() || 2366 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing || 2367 !ToQuals.withoutObjCLifetime().empty()) 2368 return false; 2369 2370 // Argument must be a pointer to __strong to __weak. 2371 QualType FromPointee; 2372 if (const PointerType *FromPointer = FromType->getAs<PointerType>()) 2373 FromPointee = FromPointer->getPointeeType(); 2374 else 2375 return false; 2376 2377 Qualifiers FromQuals = FromPointee.getQualifiers(); 2378 if (!FromPointee->isObjCLifetimeType() || 2379 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong && 2380 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak)) 2381 return false; 2382 2383 // Make sure that we have compatible qualifiers. 2384 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing); 2385 if (!ToQuals.compatiblyIncludes(FromQuals)) 2386 return false; 2387 2388 // Remove qualifiers from the pointee type we're converting from; they 2389 // aren't used in the compatibility check belong, and we'll be adding back 2390 // qualifiers (with __autoreleasing) if the compatibility check succeeds. 2391 FromPointee = FromPointee.getUnqualifiedType(); 2392 2393 // The unqualified form of the pointee types must be compatible. 2394 ToPointee = ToPointee.getUnqualifiedType(); 2395 bool IncompatibleObjC; 2396 if (Context.typesAreCompatible(FromPointee, ToPointee)) 2397 FromPointee = ToPointee; 2398 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee, 2399 IncompatibleObjC)) 2400 return false; 2401 2402 /// \brief Construct the type we're converting to, which is a pointer to 2403 /// __autoreleasing pointee. 2404 FromPointee = Context.getQualifiedType(FromPointee, FromQuals); 2405 ConvertedType = Context.getPointerType(FromPointee); 2406 return true; 2407} 2408 2409bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, 2410 QualType& ConvertedType) { 2411 QualType ToPointeeType; 2412 if (const BlockPointerType *ToBlockPtr = 2413 ToType->getAs<BlockPointerType>()) 2414 ToPointeeType = ToBlockPtr->getPointeeType(); 2415 else 2416 return false; 2417 2418 QualType FromPointeeType; 2419 if (const BlockPointerType *FromBlockPtr = 2420 FromType->getAs<BlockPointerType>()) 2421 FromPointeeType = FromBlockPtr->getPointeeType(); 2422 else 2423 return false; 2424 // We have pointer to blocks, check whether the only 2425 // differences in the argument and result types are in Objective-C 2426 // pointer conversions. If so, we permit the conversion. 2427 2428 const FunctionProtoType *FromFunctionType 2429 = FromPointeeType->getAs<FunctionProtoType>(); 2430 const FunctionProtoType *ToFunctionType 2431 = ToPointeeType->getAs<FunctionProtoType>(); 2432 2433 if (!FromFunctionType || !ToFunctionType) 2434 return false; 2435 2436 if (Context.hasSameType(FromPointeeType, ToPointeeType)) 2437 return true; 2438 2439 // Perform the quick checks that will tell us whether these 2440 // function types are obviously different. 2441 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 2442 FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) 2443 return false; 2444 2445 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); 2446 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); 2447 if (FromEInfo != ToEInfo) 2448 return false; 2449 2450 bool IncompatibleObjC = false; 2451 if (Context.hasSameType(FromFunctionType->getResultType(), 2452 ToFunctionType->getResultType())) { 2453 // Okay, the types match exactly. Nothing to do. 2454 } else { 2455 QualType RHS = FromFunctionType->getResultType(); 2456 QualType LHS = ToFunctionType->getResultType(); 2457 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) && 2458 !RHS.hasQualifiers() && LHS.hasQualifiers()) 2459 LHS = LHS.getUnqualifiedType(); 2460 2461 if (Context.hasSameType(RHS,LHS)) { 2462 // OK exact match. 2463 } else if (isObjCPointerConversion(RHS, LHS, 2464 ConvertedType, IncompatibleObjC)) { 2465 if (IncompatibleObjC) 2466 return false; 2467 // Okay, we have an Objective-C pointer conversion. 2468 } 2469 else 2470 return false; 2471 } 2472 2473 // Check argument types. 2474 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 2475 ArgIdx != NumArgs; ++ArgIdx) { 2476 IncompatibleObjC = false; 2477 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 2478 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 2479 if (Context.hasSameType(FromArgType, ToArgType)) { 2480 // Okay, the types match exactly. Nothing to do. 2481 } else if (isObjCPointerConversion(ToArgType, FromArgType, 2482 ConvertedType, IncompatibleObjC)) { 2483 if (IncompatibleObjC) 2484 return false; 2485 // Okay, we have an Objective-C pointer conversion. 2486 } else 2487 // Argument types are too different. Abort. 2488 return false; 2489 } 2490 if (LangOpts.ObjCAutoRefCount && 2491 !Context.FunctionTypesMatchOnNSConsumedAttrs(FromFunctionType, 2492 ToFunctionType)) 2493 return false; 2494 2495 ConvertedType = ToType; 2496 return true; 2497} 2498 2499enum { 2500 ft_default, 2501 ft_different_class, 2502 ft_parameter_arity, 2503 ft_parameter_mismatch, 2504 ft_return_type, 2505 ft_qualifer_mismatch 2506}; 2507 2508/// HandleFunctionTypeMismatch - Gives diagnostic information for differeing 2509/// function types. Catches different number of parameter, mismatch in 2510/// parameter types, and different return types. 2511void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag, 2512 QualType FromType, QualType ToType) { 2513 // If either type is not valid, include no extra info. 2514 if (FromType.isNull() || ToType.isNull()) { 2515 PDiag << ft_default; 2516 return; 2517 } 2518 2519 // Get the function type from the pointers. 2520 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) { 2521 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(), 2522 *ToMember = ToType->getAs<MemberPointerType>(); 2523 if (FromMember->getClass() != ToMember->getClass()) { 2524 PDiag << ft_different_class << QualType(ToMember->getClass(), 0) 2525 << QualType(FromMember->getClass(), 0); 2526 return; 2527 } 2528 FromType = FromMember->getPointeeType(); 2529 ToType = ToMember->getPointeeType(); 2530 } 2531 2532 if (FromType->isPointerType()) 2533 FromType = FromType->getPointeeType(); 2534 if (ToType->isPointerType()) 2535 ToType = ToType->getPointeeType(); 2536 2537 // Remove references. 2538 FromType = FromType.getNonReferenceType(); 2539 ToType = ToType.getNonReferenceType(); 2540 2541 // Don't print extra info for non-specialized template functions. 2542 if (FromType->isInstantiationDependentType() && 2543 !FromType->getAs<TemplateSpecializationType>()) { 2544 PDiag << ft_default; 2545 return; 2546 } 2547 2548 // No extra info for same types. 2549 if (Context.hasSameType(FromType, ToType)) { 2550 PDiag << ft_default; 2551 return; 2552 } 2553 2554 const FunctionProtoType *FromFunction = FromType->getAs<FunctionProtoType>(), 2555 *ToFunction = ToType->getAs<FunctionProtoType>(); 2556 2557 // Both types need to be function types. 2558 if (!FromFunction || !ToFunction) { 2559 PDiag << ft_default; 2560 return; 2561 } 2562 2563 if (FromFunction->getNumArgs() != ToFunction->getNumArgs()) { 2564 PDiag << ft_parameter_arity << ToFunction->getNumArgs() 2565 << FromFunction->getNumArgs(); 2566 return; 2567 } 2568 2569 // Handle different parameter types. 2570 unsigned ArgPos; 2571 if (!FunctionArgTypesAreEqual(FromFunction, ToFunction, &ArgPos)) { 2572 PDiag << ft_parameter_mismatch << ArgPos + 1 2573 << ToFunction->getArgType(ArgPos) 2574 << FromFunction->getArgType(ArgPos); 2575 return; 2576 } 2577 2578 // Handle different return type. 2579 if (!Context.hasSameType(FromFunction->getResultType(), 2580 ToFunction->getResultType())) { 2581 PDiag << ft_return_type << ToFunction->getResultType() 2582 << FromFunction->getResultType(); 2583 return; 2584 } 2585 2586 unsigned FromQuals = FromFunction->getTypeQuals(), 2587 ToQuals = ToFunction->getTypeQuals(); 2588 if (FromQuals != ToQuals) { 2589 PDiag << ft_qualifer_mismatch << ToQuals << FromQuals; 2590 return; 2591 } 2592 2593 // Unable to find a difference, so add no extra info. 2594 PDiag << ft_default; 2595} 2596 2597/// FunctionArgTypesAreEqual - This routine checks two function proto types 2598/// for equality of their argument types. Caller has already checked that 2599/// they have same number of arguments. This routine assumes that Objective-C 2600/// pointer types which only differ in their protocol qualifiers are equal. 2601/// If the parameters are different, ArgPos will have the parameter index 2602/// of the first different parameter. 2603bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, 2604 const FunctionProtoType *NewType, 2605 unsigned *ArgPos) { 2606 if (!getLangOpts().ObjC1) { 2607 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 2608 N = NewType->arg_type_begin(), 2609 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 2610 if (!Context.hasSameType(*O, *N)) { 2611 if (ArgPos) *ArgPos = O - OldType->arg_type_begin(); 2612 return false; 2613 } 2614 } 2615 return true; 2616 } 2617 2618 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 2619 N = NewType->arg_type_begin(), 2620 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 2621 QualType ToType = (*O); 2622 QualType FromType = (*N); 2623 if (!Context.hasSameType(ToType, FromType)) { 2624 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 2625 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 2626 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 2627 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 2628 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 2629 PTFr->getPointeeType()->isObjCQualifiedClassType())) 2630 continue; 2631 } 2632 else if (const ObjCObjectPointerType *PTTo = 2633 ToType->getAs<ObjCObjectPointerType>()) { 2634 if (const ObjCObjectPointerType *PTFr = 2635 FromType->getAs<ObjCObjectPointerType>()) 2636 if (Context.hasSameUnqualifiedType( 2637 PTTo->getObjectType()->getBaseType(), 2638 PTFr->getObjectType()->getBaseType())) 2639 continue; 2640 } 2641 if (ArgPos) *ArgPos = O - OldType->arg_type_begin(); 2642 return false; 2643 } 2644 } 2645 return true; 2646} 2647 2648/// CheckPointerConversion - Check the pointer conversion from the 2649/// expression From to the type ToType. This routine checks for 2650/// ambiguous or inaccessible derived-to-base pointer 2651/// conversions for which IsPointerConversion has already returned 2652/// true. It returns true and produces a diagnostic if there was an 2653/// error, or returns false otherwise. 2654bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 2655 CastKind &Kind, 2656 CXXCastPath& BasePath, 2657 bool IgnoreBaseAccess) { 2658 QualType FromType = From->getType(); 2659 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 2660 2661 Kind = CK_BitCast; 2662 2663 if (!IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() && 2664 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) == 2665 Expr::NPCK_ZeroExpression) { 2666 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy)) 2667 DiagRuntimeBehavior(From->getExprLoc(), From, 2668 PDiag(diag::warn_impcast_bool_to_null_pointer) 2669 << ToType << From->getSourceRange()); 2670 else if (!isUnevaluatedContext()) 2671 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer) 2672 << ToType << From->getSourceRange(); 2673 } 2674 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 2675 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) { 2676 QualType FromPointeeType = FromPtrType->getPointeeType(), 2677 ToPointeeType = ToPtrType->getPointeeType(); 2678 2679 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 2680 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 2681 // We must have a derived-to-base conversion. Check an 2682 // ambiguous or inaccessible conversion. 2683 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 2684 From->getExprLoc(), 2685 From->getSourceRange(), &BasePath, 2686 IgnoreBaseAccess)) 2687 return true; 2688 2689 // The conversion was successful. 2690 Kind = CK_DerivedToBase; 2691 } 2692 } 2693 } else if (const ObjCObjectPointerType *ToPtrType = 2694 ToType->getAs<ObjCObjectPointerType>()) { 2695 if (const ObjCObjectPointerType *FromPtrType = 2696 FromType->getAs<ObjCObjectPointerType>()) { 2697 // Objective-C++ conversions are always okay. 2698 // FIXME: We should have a different class of conversions for the 2699 // Objective-C++ implicit conversions. 2700 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 2701 return false; 2702 } else if (FromType->isBlockPointerType()) { 2703 Kind = CK_BlockPointerToObjCPointerCast; 2704 } else { 2705 Kind = CK_CPointerToObjCPointerCast; 2706 } 2707 } else if (ToType->isBlockPointerType()) { 2708 if (!FromType->isBlockPointerType()) 2709 Kind = CK_AnyPointerToBlockPointerCast; 2710 } 2711 2712 // We shouldn't fall into this case unless it's valid for other 2713 // reasons. 2714 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 2715 Kind = CK_NullToPointer; 2716 2717 return false; 2718} 2719 2720/// IsMemberPointerConversion - Determines whether the conversion of the 2721/// expression From, which has the (possibly adjusted) type FromType, can be 2722/// converted to the type ToType via a member pointer conversion (C++ 4.11). 2723/// If so, returns true and places the converted type (that might differ from 2724/// ToType in its cv-qualifiers at some level) into ConvertedType. 2725bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 2726 QualType ToType, 2727 bool InOverloadResolution, 2728 QualType &ConvertedType) { 2729 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 2730 if (!ToTypePtr) 2731 return false; 2732 2733 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 2734 if (From->isNullPointerConstant(Context, 2735 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 2736 : Expr::NPC_ValueDependentIsNull)) { 2737 ConvertedType = ToType; 2738 return true; 2739 } 2740 2741 // Otherwise, both types have to be member pointers. 2742 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 2743 if (!FromTypePtr) 2744 return false; 2745 2746 // A pointer to member of B can be converted to a pointer to member of D, 2747 // where D is derived from B (C++ 4.11p2). 2748 QualType FromClass(FromTypePtr->getClass(), 0); 2749 QualType ToClass(ToTypePtr->getClass(), 0); 2750 2751 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && 2752 !RequireCompleteType(From->getLocStart(), ToClass, 0) && 2753 IsDerivedFrom(ToClass, FromClass)) { 2754 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 2755 ToClass.getTypePtr()); 2756 return true; 2757 } 2758 2759 return false; 2760} 2761 2762/// CheckMemberPointerConversion - Check the member pointer conversion from the 2763/// expression From to the type ToType. This routine checks for ambiguous or 2764/// virtual or inaccessible base-to-derived member pointer conversions 2765/// for which IsMemberPointerConversion has already returned true. It returns 2766/// true and produces a diagnostic if there was an error, or returns false 2767/// otherwise. 2768bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 2769 CastKind &Kind, 2770 CXXCastPath &BasePath, 2771 bool IgnoreBaseAccess) { 2772 QualType FromType = From->getType(); 2773 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 2774 if (!FromPtrType) { 2775 // This must be a null pointer to member pointer conversion 2776 assert(From->isNullPointerConstant(Context, 2777 Expr::NPC_ValueDependentIsNull) && 2778 "Expr must be null pointer constant!"); 2779 Kind = CK_NullToMemberPointer; 2780 return false; 2781 } 2782 2783 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 2784 assert(ToPtrType && "No member pointer cast has a target type " 2785 "that is not a member pointer."); 2786 2787 QualType FromClass = QualType(FromPtrType->getClass(), 0); 2788 QualType ToClass = QualType(ToPtrType->getClass(), 0); 2789 2790 // FIXME: What about dependent types? 2791 assert(FromClass->isRecordType() && "Pointer into non-class."); 2792 assert(ToClass->isRecordType() && "Pointer into non-class."); 2793 2794 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 2795 /*DetectVirtual=*/true); 2796 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 2797 assert(DerivationOkay && 2798 "Should not have been called if derivation isn't OK."); 2799 (void)DerivationOkay; 2800 2801 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 2802 getUnqualifiedType())) { 2803 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 2804 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 2805 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 2806 return true; 2807 } 2808 2809 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 2810 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 2811 << FromClass << ToClass << QualType(VBase, 0) 2812 << From->getSourceRange(); 2813 return true; 2814 } 2815 2816 if (!IgnoreBaseAccess) 2817 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 2818 Paths.front(), 2819 diag::err_downcast_from_inaccessible_base); 2820 2821 // Must be a base to derived member conversion. 2822 BuildBasePathArray(Paths, BasePath); 2823 Kind = CK_BaseToDerivedMemberPointer; 2824 return false; 2825} 2826 2827/// IsQualificationConversion - Determines whether the conversion from 2828/// an rvalue of type FromType to ToType is a qualification conversion 2829/// (C++ 4.4). 2830/// 2831/// \param ObjCLifetimeConversion Output parameter that will be set to indicate 2832/// when the qualification conversion involves a change in the Objective-C 2833/// object lifetime. 2834bool 2835Sema::IsQualificationConversion(QualType FromType, QualType ToType, 2836 bool CStyle, bool &ObjCLifetimeConversion) { 2837 FromType = Context.getCanonicalType(FromType); 2838 ToType = Context.getCanonicalType(ToType); 2839 ObjCLifetimeConversion = false; 2840 2841 // If FromType and ToType are the same type, this is not a 2842 // qualification conversion. 2843 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 2844 return false; 2845 2846 // (C++ 4.4p4): 2847 // A conversion can add cv-qualifiers at levels other than the first 2848 // in multi-level pointers, subject to the following rules: [...] 2849 bool PreviousToQualsIncludeConst = true; 2850 bool UnwrappedAnyPointer = false; 2851 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 2852 // Within each iteration of the loop, we check the qualifiers to 2853 // determine if this still looks like a qualification 2854 // conversion. Then, if all is well, we unwrap one more level of 2855 // pointers or pointers-to-members and do it all again 2856 // until there are no more pointers or pointers-to-members left to 2857 // unwrap. 2858 UnwrappedAnyPointer = true; 2859 2860 Qualifiers FromQuals = FromType.getQualifiers(); 2861 Qualifiers ToQuals = ToType.getQualifiers(); 2862 2863 // Objective-C ARC: 2864 // Check Objective-C lifetime conversions. 2865 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() && 2866 UnwrappedAnyPointer) { 2867 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) { 2868 ObjCLifetimeConversion = true; 2869 FromQuals.removeObjCLifetime(); 2870 ToQuals.removeObjCLifetime(); 2871 } else { 2872 // Qualification conversions cannot cast between different 2873 // Objective-C lifetime qualifiers. 2874 return false; 2875 } 2876 } 2877 2878 // Allow addition/removal of GC attributes but not changing GC attributes. 2879 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() && 2880 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) { 2881 FromQuals.removeObjCGCAttr(); 2882 ToQuals.removeObjCGCAttr(); 2883 } 2884 2885 // -- for every j > 0, if const is in cv 1,j then const is in cv 2886 // 2,j, and similarly for volatile. 2887 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals)) 2888 return false; 2889 2890 // -- if the cv 1,j and cv 2,j are different, then const is in 2891 // every cv for 0 < k < j. 2892 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers() 2893 && !PreviousToQualsIncludeConst) 2894 return false; 2895 2896 // Keep track of whether all prior cv-qualifiers in the "to" type 2897 // include const. 2898 PreviousToQualsIncludeConst 2899 = PreviousToQualsIncludeConst && ToQuals.hasConst(); 2900 } 2901 2902 // We are left with FromType and ToType being the pointee types 2903 // after unwrapping the original FromType and ToType the same number 2904 // of types. If we unwrapped any pointers, and if FromType and 2905 // ToType have the same unqualified type (since we checked 2906 // qualifiers above), then this is a qualification conversion. 2907 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2908} 2909 2910/// \brief - Determine whether this is a conversion from a scalar type to an 2911/// atomic type. 2912/// 2913/// If successful, updates \c SCS's second and third steps in the conversion 2914/// sequence to finish the conversion. 2915static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType, 2916 bool InOverloadResolution, 2917 StandardConversionSequence &SCS, 2918 bool CStyle) { 2919 const AtomicType *ToAtomic = ToType->getAs<AtomicType>(); 2920 if (!ToAtomic) 2921 return false; 2922 2923 StandardConversionSequence InnerSCS; 2924 if (!IsStandardConversion(S, From, ToAtomic->getValueType(), 2925 InOverloadResolution, InnerSCS, 2926 CStyle, /*AllowObjCWritebackConversion=*/false)) 2927 return false; 2928 2929 SCS.Second = InnerSCS.Second; 2930 SCS.setToType(1, InnerSCS.getToType(1)); 2931 SCS.Third = InnerSCS.Third; 2932 SCS.QualificationIncludesObjCLifetime 2933 = InnerSCS.QualificationIncludesObjCLifetime; 2934 SCS.setToType(2, InnerSCS.getToType(2)); 2935 return true; 2936} 2937 2938static bool isFirstArgumentCompatibleWithType(ASTContext &Context, 2939 CXXConstructorDecl *Constructor, 2940 QualType Type) { 2941 const FunctionProtoType *CtorType = 2942 Constructor->getType()->getAs<FunctionProtoType>(); 2943 if (CtorType->getNumArgs() > 0) { 2944 QualType FirstArg = CtorType->getArgType(0); 2945 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType())) 2946 return true; 2947 } 2948 return false; 2949} 2950 2951static OverloadingResult 2952IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType, 2953 CXXRecordDecl *To, 2954 UserDefinedConversionSequence &User, 2955 OverloadCandidateSet &CandidateSet, 2956 bool AllowExplicit) { 2957 DeclContext::lookup_result R = S.LookupConstructors(To); 2958 for (DeclContext::lookup_iterator Con = R.begin(), ConEnd = R.end(); 2959 Con != ConEnd; ++Con) { 2960 NamedDecl *D = *Con; 2961 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2962 2963 // Find the constructor (which may be a template). 2964 CXXConstructorDecl *Constructor = 0; 2965 FunctionTemplateDecl *ConstructorTmpl 2966 = dyn_cast<FunctionTemplateDecl>(D); 2967 if (ConstructorTmpl) 2968 Constructor 2969 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2970 else 2971 Constructor = cast<CXXConstructorDecl>(D); 2972 2973 bool Usable = !Constructor->isInvalidDecl() && 2974 S.isInitListConstructor(Constructor) && 2975 (AllowExplicit || !Constructor->isExplicit()); 2976 if (Usable) { 2977 // If the first argument is (a reference to) the target type, 2978 // suppress conversions. 2979 bool SuppressUserConversions = 2980 isFirstArgumentCompatibleWithType(S.Context, Constructor, ToType); 2981 if (ConstructorTmpl) 2982 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2983 /*ExplicitArgs*/ 0, 2984 From, CandidateSet, 2985 SuppressUserConversions); 2986 else 2987 S.AddOverloadCandidate(Constructor, FoundDecl, 2988 From, CandidateSet, 2989 SuppressUserConversions); 2990 } 2991 } 2992 2993 bool HadMultipleCandidates = (CandidateSet.size() > 1); 2994 2995 OverloadCandidateSet::iterator Best; 2996 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2997 case OR_Success: { 2998 // Record the standard conversion we used and the conversion function. 2999 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function); 3000 QualType ThisType = Constructor->getThisType(S.Context); 3001 // Initializer lists don't have conversions as such. 3002 User.Before.setAsIdentityConversion(); 3003 User.HadMultipleCandidates = HadMultipleCandidates; 3004 User.ConversionFunction = Constructor; 3005 User.FoundConversionFunction = Best->FoundDecl; 3006 User.After.setAsIdentityConversion(); 3007 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 3008 User.After.setAllToTypes(ToType); 3009 return OR_Success; 3010 } 3011 3012 case OR_No_Viable_Function: 3013 return OR_No_Viable_Function; 3014 case OR_Deleted: 3015 return OR_Deleted; 3016 case OR_Ambiguous: 3017 return OR_Ambiguous; 3018 } 3019 3020 llvm_unreachable("Invalid OverloadResult!"); 3021} 3022 3023/// Determines whether there is a user-defined conversion sequence 3024/// (C++ [over.ics.user]) that converts expression From to the type 3025/// ToType. If such a conversion exists, User will contain the 3026/// user-defined conversion sequence that performs such a conversion 3027/// and this routine will return true. Otherwise, this routine returns 3028/// false and User is unspecified. 3029/// 3030/// \param AllowExplicit true if the conversion should consider C++0x 3031/// "explicit" conversion functions as well as non-explicit conversion 3032/// functions (C++0x [class.conv.fct]p2). 3033static OverloadingResult 3034IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 3035 UserDefinedConversionSequence &User, 3036 OverloadCandidateSet &CandidateSet, 3037 bool AllowExplicit) { 3038 // Whether we will only visit constructors. 3039 bool ConstructorsOnly = false; 3040 3041 // If the type we are conversion to is a class type, enumerate its 3042 // constructors. 3043 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 3044 // C++ [over.match.ctor]p1: 3045 // When objects of class type are direct-initialized (8.5), or 3046 // copy-initialized from an expression of the same or a 3047 // derived class type (8.5), overload resolution selects the 3048 // constructor. [...] For copy-initialization, the candidate 3049 // functions are all the converting constructors (12.3.1) of 3050 // that class. The argument list is the expression-list within 3051 // the parentheses of the initializer. 3052 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 3053 (From->getType()->getAs<RecordType>() && 3054 S.IsDerivedFrom(From->getType(), ToType))) 3055 ConstructorsOnly = true; 3056 3057 S.RequireCompleteType(From->getExprLoc(), ToType, 0); 3058 // RequireCompleteType may have returned true due to some invalid decl 3059 // during template instantiation, but ToType may be complete enough now 3060 // to try to recover. 3061 if (ToType->isIncompleteType()) { 3062 // We're not going to find any constructors. 3063 } else if (CXXRecordDecl *ToRecordDecl 3064 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 3065 3066 Expr **Args = &From; 3067 unsigned NumArgs = 1; 3068 bool ListInitializing = false; 3069 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) { 3070 // But first, see if there is an init-list-contructor that will work. 3071 OverloadingResult Result = IsInitializerListConstructorConversion( 3072 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit); 3073 if (Result != OR_No_Viable_Function) 3074 return Result; 3075 // Never mind. 3076 CandidateSet.clear(); 3077 3078 // If we're list-initializing, we pass the individual elements as 3079 // arguments, not the entire list. 3080 Args = InitList->getInits(); 3081 NumArgs = InitList->getNumInits(); 3082 ListInitializing = true; 3083 } 3084 3085 DeclContext::lookup_result R = S.LookupConstructors(ToRecordDecl); 3086 for (DeclContext::lookup_iterator Con = R.begin(), ConEnd = R.end(); 3087 Con != ConEnd; ++Con) { 3088 NamedDecl *D = *Con; 3089 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 3090 3091 // Find the constructor (which may be a template). 3092 CXXConstructorDecl *Constructor = 0; 3093 FunctionTemplateDecl *ConstructorTmpl 3094 = dyn_cast<FunctionTemplateDecl>(D); 3095 if (ConstructorTmpl) 3096 Constructor 3097 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 3098 else 3099 Constructor = cast<CXXConstructorDecl>(D); 3100 3101 bool Usable = !Constructor->isInvalidDecl(); 3102 if (ListInitializing) 3103 Usable = Usable && (AllowExplicit || !Constructor->isExplicit()); 3104 else 3105 Usable = Usable &&Constructor->isConvertingConstructor(AllowExplicit); 3106 if (Usable) { 3107 bool SuppressUserConversions = !ConstructorsOnly; 3108 if (SuppressUserConversions && ListInitializing) { 3109 SuppressUserConversions = false; 3110 if (NumArgs == 1) { 3111 // If the first argument is (a reference to) the target type, 3112 // suppress conversions. 3113 SuppressUserConversions = isFirstArgumentCompatibleWithType( 3114 S.Context, Constructor, ToType); 3115 } 3116 } 3117 if (ConstructorTmpl) 3118 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 3119 /*ExplicitArgs*/ 0, 3120 llvm::makeArrayRef(Args, NumArgs), 3121 CandidateSet, SuppressUserConversions); 3122 else 3123 // Allow one user-defined conversion when user specifies a 3124 // From->ToType conversion via an static cast (c-style, etc). 3125 S.AddOverloadCandidate(Constructor, FoundDecl, 3126 llvm::makeArrayRef(Args, NumArgs), 3127 CandidateSet, SuppressUserConversions); 3128 } 3129 } 3130 } 3131 } 3132 3133 // Enumerate conversion functions, if we're allowed to. 3134 if (ConstructorsOnly || isa<InitListExpr>(From)) { 3135 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 0)) { 3136 // No conversion functions from incomplete types. 3137 } else if (const RecordType *FromRecordType 3138 = From->getType()->getAs<RecordType>()) { 3139 if (CXXRecordDecl *FromRecordDecl 3140 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 3141 // Add all of the conversion functions as candidates. 3142 std::pair<CXXRecordDecl::conversion_iterator, 3143 CXXRecordDecl::conversion_iterator> 3144 Conversions = FromRecordDecl->getVisibleConversionFunctions(); 3145 for (CXXRecordDecl::conversion_iterator 3146 I = Conversions.first, E = Conversions.second; I != E; ++I) { 3147 DeclAccessPair FoundDecl = I.getPair(); 3148 NamedDecl *D = FoundDecl.getDecl(); 3149 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 3150 if (isa<UsingShadowDecl>(D)) 3151 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3152 3153 CXXConversionDecl *Conv; 3154 FunctionTemplateDecl *ConvTemplate; 3155 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 3156 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3157 else 3158 Conv = cast<CXXConversionDecl>(D); 3159 3160 if (AllowExplicit || !Conv->isExplicit()) { 3161 if (ConvTemplate) 3162 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 3163 ActingContext, From, ToType, 3164 CandidateSet); 3165 else 3166 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 3167 From, ToType, CandidateSet); 3168 } 3169 } 3170 } 3171 } 3172 3173 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3174 3175 OverloadCandidateSet::iterator Best; 3176 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 3177 case OR_Success: 3178 // Record the standard conversion we used and the conversion function. 3179 if (CXXConstructorDecl *Constructor 3180 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 3181 // C++ [over.ics.user]p1: 3182 // If the user-defined conversion is specified by a 3183 // constructor (12.3.1), the initial standard conversion 3184 // sequence converts the source type to the type required by 3185 // the argument of the constructor. 3186 // 3187 QualType ThisType = Constructor->getThisType(S.Context); 3188 if (isa<InitListExpr>(From)) { 3189 // Initializer lists don't have conversions as such. 3190 User.Before.setAsIdentityConversion(); 3191 } else { 3192 if (Best->Conversions[0].isEllipsis()) 3193 User.EllipsisConversion = true; 3194 else { 3195 User.Before = Best->Conversions[0].Standard; 3196 User.EllipsisConversion = false; 3197 } 3198 } 3199 User.HadMultipleCandidates = HadMultipleCandidates; 3200 User.ConversionFunction = Constructor; 3201 User.FoundConversionFunction = Best->FoundDecl; 3202 User.After.setAsIdentityConversion(); 3203 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 3204 User.After.setAllToTypes(ToType); 3205 return OR_Success; 3206 } 3207 if (CXXConversionDecl *Conversion 3208 = dyn_cast<CXXConversionDecl>(Best->Function)) { 3209 // C++ [over.ics.user]p1: 3210 // 3211 // [...] If the user-defined conversion is specified by a 3212 // conversion function (12.3.2), the initial standard 3213 // conversion sequence converts the source type to the 3214 // implicit object parameter of the conversion function. 3215 User.Before = Best->Conversions[0].Standard; 3216 User.HadMultipleCandidates = HadMultipleCandidates; 3217 User.ConversionFunction = Conversion; 3218 User.FoundConversionFunction = Best->FoundDecl; 3219 User.EllipsisConversion = false; 3220 3221 // C++ [over.ics.user]p2: 3222 // The second standard conversion sequence converts the 3223 // result of the user-defined conversion to the target type 3224 // for the sequence. Since an implicit conversion sequence 3225 // is an initialization, the special rules for 3226 // initialization by user-defined conversion apply when 3227 // selecting the best user-defined conversion for a 3228 // user-defined conversion sequence (see 13.3.3 and 3229 // 13.3.3.1). 3230 User.After = Best->FinalConversion; 3231 return OR_Success; 3232 } 3233 llvm_unreachable("Not a constructor or conversion function?"); 3234 3235 case OR_No_Viable_Function: 3236 return OR_No_Viable_Function; 3237 case OR_Deleted: 3238 // No conversion here! We're done. 3239 return OR_Deleted; 3240 3241 case OR_Ambiguous: 3242 return OR_Ambiguous; 3243 } 3244 3245 llvm_unreachable("Invalid OverloadResult!"); 3246} 3247 3248bool 3249Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 3250 ImplicitConversionSequence ICS; 3251 OverloadCandidateSet CandidateSet(From->getExprLoc()); 3252 OverloadingResult OvResult = 3253 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 3254 CandidateSet, false); 3255 if (OvResult == OR_Ambiguous) 3256 Diag(From->getLocStart(), 3257 diag::err_typecheck_ambiguous_condition) 3258 << From->getType() << ToType << From->getSourceRange(); 3259 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 3260 Diag(From->getLocStart(), 3261 diag::err_typecheck_nonviable_condition) 3262 << From->getType() << ToType << From->getSourceRange(); 3263 else 3264 return false; 3265 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From); 3266 return true; 3267} 3268 3269/// \brief Compare the user-defined conversion functions or constructors 3270/// of two user-defined conversion sequences to determine whether any ordering 3271/// is possible. 3272static ImplicitConversionSequence::CompareKind 3273compareConversionFunctions(Sema &S, 3274 FunctionDecl *Function1, 3275 FunctionDecl *Function2) { 3276 if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus11) 3277 return ImplicitConversionSequence::Indistinguishable; 3278 3279 // Objective-C++: 3280 // If both conversion functions are implicitly-declared conversions from 3281 // a lambda closure type to a function pointer and a block pointer, 3282 // respectively, always prefer the conversion to a function pointer, 3283 // because the function pointer is more lightweight and is more likely 3284 // to keep code working. 3285 CXXConversionDecl *Conv1 = dyn_cast<CXXConversionDecl>(Function1); 3286 if (!Conv1) 3287 return ImplicitConversionSequence::Indistinguishable; 3288 3289 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2); 3290 if (!Conv2) 3291 return ImplicitConversionSequence::Indistinguishable; 3292 3293 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) { 3294 bool Block1 = Conv1->getConversionType()->isBlockPointerType(); 3295 bool Block2 = Conv2->getConversionType()->isBlockPointerType(); 3296 if (Block1 != Block2) 3297 return Block1? ImplicitConversionSequence::Worse 3298 : ImplicitConversionSequence::Better; 3299 } 3300 3301 return ImplicitConversionSequence::Indistinguishable; 3302} 3303 3304/// CompareImplicitConversionSequences - Compare two implicit 3305/// conversion sequences to determine whether one is better than the 3306/// other or if they are indistinguishable (C++ 13.3.3.2). 3307static ImplicitConversionSequence::CompareKind 3308CompareImplicitConversionSequences(Sema &S, 3309 const ImplicitConversionSequence& ICS1, 3310 const ImplicitConversionSequence& ICS2) 3311{ 3312 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 3313 // conversion sequences (as defined in 13.3.3.1) 3314 // -- a standard conversion sequence (13.3.3.1.1) is a better 3315 // conversion sequence than a user-defined conversion sequence or 3316 // an ellipsis conversion sequence, and 3317 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 3318 // conversion sequence than an ellipsis conversion sequence 3319 // (13.3.3.1.3). 3320 // 3321 // C++0x [over.best.ics]p10: 3322 // For the purpose of ranking implicit conversion sequences as 3323 // described in 13.3.3.2, the ambiguous conversion sequence is 3324 // treated as a user-defined sequence that is indistinguishable 3325 // from any other user-defined conversion sequence. 3326 if (ICS1.getKindRank() < ICS2.getKindRank()) 3327 return ImplicitConversionSequence::Better; 3328 if (ICS2.getKindRank() < ICS1.getKindRank()) 3329 return ImplicitConversionSequence::Worse; 3330 3331 // The following checks require both conversion sequences to be of 3332 // the same kind. 3333 if (ICS1.getKind() != ICS2.getKind()) 3334 return ImplicitConversionSequence::Indistinguishable; 3335 3336 ImplicitConversionSequence::CompareKind Result = 3337 ImplicitConversionSequence::Indistinguishable; 3338 3339 // Two implicit conversion sequences of the same form are 3340 // indistinguishable conversion sequences unless one of the 3341 // following rules apply: (C++ 13.3.3.2p3): 3342 if (ICS1.isStandard()) 3343 Result = CompareStandardConversionSequences(S, 3344 ICS1.Standard, ICS2.Standard); 3345 else if (ICS1.isUserDefined()) { 3346 // User-defined conversion sequence U1 is a better conversion 3347 // sequence than another user-defined conversion sequence U2 if 3348 // they contain the same user-defined conversion function or 3349 // constructor and if the second standard conversion sequence of 3350 // U1 is better than the second standard conversion sequence of 3351 // U2 (C++ 13.3.3.2p3). 3352 if (ICS1.UserDefined.ConversionFunction == 3353 ICS2.UserDefined.ConversionFunction) 3354 Result = CompareStandardConversionSequences(S, 3355 ICS1.UserDefined.After, 3356 ICS2.UserDefined.After); 3357 else 3358 Result = compareConversionFunctions(S, 3359 ICS1.UserDefined.ConversionFunction, 3360 ICS2.UserDefined.ConversionFunction); 3361 } 3362 3363 // List-initialization sequence L1 is a better conversion sequence than 3364 // list-initialization sequence L2 if L1 converts to std::initializer_list<X> 3365 // for some X and L2 does not. 3366 if (Result == ImplicitConversionSequence::Indistinguishable && 3367 !ICS1.isBad() && 3368 ICS1.isListInitializationSequence() && 3369 ICS2.isListInitializationSequence()) { 3370 if (ICS1.isStdInitializerListElement() && 3371 !ICS2.isStdInitializerListElement()) 3372 return ImplicitConversionSequence::Better; 3373 if (!ICS1.isStdInitializerListElement() && 3374 ICS2.isStdInitializerListElement()) 3375 return ImplicitConversionSequence::Worse; 3376 } 3377 3378 return Result; 3379} 3380 3381static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 3382 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 3383 Qualifiers Quals; 3384 T1 = Context.getUnqualifiedArrayType(T1, Quals); 3385 T2 = Context.getUnqualifiedArrayType(T2, Quals); 3386 } 3387 3388 return Context.hasSameUnqualifiedType(T1, T2); 3389} 3390 3391// Per 13.3.3.2p3, compare the given standard conversion sequences to 3392// determine if one is a proper subset of the other. 3393static ImplicitConversionSequence::CompareKind 3394compareStandardConversionSubsets(ASTContext &Context, 3395 const StandardConversionSequence& SCS1, 3396 const StandardConversionSequence& SCS2) { 3397 ImplicitConversionSequence::CompareKind Result 3398 = ImplicitConversionSequence::Indistinguishable; 3399 3400 // the identity conversion sequence is considered to be a subsequence of 3401 // any non-identity conversion sequence 3402 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 3403 return ImplicitConversionSequence::Better; 3404 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 3405 return ImplicitConversionSequence::Worse; 3406 3407 if (SCS1.Second != SCS2.Second) { 3408 if (SCS1.Second == ICK_Identity) 3409 Result = ImplicitConversionSequence::Better; 3410 else if (SCS2.Second == ICK_Identity) 3411 Result = ImplicitConversionSequence::Worse; 3412 else 3413 return ImplicitConversionSequence::Indistinguishable; 3414 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 3415 return ImplicitConversionSequence::Indistinguishable; 3416 3417 if (SCS1.Third == SCS2.Third) { 3418 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 3419 : ImplicitConversionSequence::Indistinguishable; 3420 } 3421 3422 if (SCS1.Third == ICK_Identity) 3423 return Result == ImplicitConversionSequence::Worse 3424 ? ImplicitConversionSequence::Indistinguishable 3425 : ImplicitConversionSequence::Better; 3426 3427 if (SCS2.Third == ICK_Identity) 3428 return Result == ImplicitConversionSequence::Better 3429 ? ImplicitConversionSequence::Indistinguishable 3430 : ImplicitConversionSequence::Worse; 3431 3432 return ImplicitConversionSequence::Indistinguishable; 3433} 3434 3435/// \brief Determine whether one of the given reference bindings is better 3436/// than the other based on what kind of bindings they are. 3437static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 3438 const StandardConversionSequence &SCS2) { 3439 // C++0x [over.ics.rank]p3b4: 3440 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 3441 // implicit object parameter of a non-static member function declared 3442 // without a ref-qualifier, and *either* S1 binds an rvalue reference 3443 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 3444 // lvalue reference to a function lvalue and S2 binds an rvalue 3445 // reference*. 3446 // 3447 // FIXME: Rvalue references. We're going rogue with the above edits, 3448 // because the semantics in the current C++0x working paper (N3225 at the 3449 // time of this writing) break the standard definition of std::forward 3450 // and std::reference_wrapper when dealing with references to functions. 3451 // Proposed wording changes submitted to CWG for consideration. 3452 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 3453 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 3454 return false; 3455 3456 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 3457 SCS2.IsLvalueReference) || 3458 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 3459 !SCS2.IsLvalueReference); 3460} 3461 3462/// CompareStandardConversionSequences - Compare two standard 3463/// conversion sequences to determine whether one is better than the 3464/// other or if they are indistinguishable (C++ 13.3.3.2p3). 3465static ImplicitConversionSequence::CompareKind 3466CompareStandardConversionSequences(Sema &S, 3467 const StandardConversionSequence& SCS1, 3468 const StandardConversionSequence& SCS2) 3469{ 3470 // Standard conversion sequence S1 is a better conversion sequence 3471 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 3472 3473 // -- S1 is a proper subsequence of S2 (comparing the conversion 3474 // sequences in the canonical form defined by 13.3.3.1.1, 3475 // excluding any Lvalue Transformation; the identity conversion 3476 // sequence is considered to be a subsequence of any 3477 // non-identity conversion sequence) or, if not that, 3478 if (ImplicitConversionSequence::CompareKind CK 3479 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 3480 return CK; 3481 3482 // -- the rank of S1 is better than the rank of S2 (by the rules 3483 // defined below), or, if not that, 3484 ImplicitConversionRank Rank1 = SCS1.getRank(); 3485 ImplicitConversionRank Rank2 = SCS2.getRank(); 3486 if (Rank1 < Rank2) 3487 return ImplicitConversionSequence::Better; 3488 else if (Rank2 < Rank1) 3489 return ImplicitConversionSequence::Worse; 3490 3491 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 3492 // are indistinguishable unless one of the following rules 3493 // applies: 3494 3495 // A conversion that is not a conversion of a pointer, or 3496 // pointer to member, to bool is better than another conversion 3497 // that is such a conversion. 3498 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 3499 return SCS2.isPointerConversionToBool() 3500 ? ImplicitConversionSequence::Better 3501 : ImplicitConversionSequence::Worse; 3502 3503 // C++ [over.ics.rank]p4b2: 3504 // 3505 // If class B is derived directly or indirectly from class A, 3506 // conversion of B* to A* is better than conversion of B* to 3507 // void*, and conversion of A* to void* is better than conversion 3508 // of B* to void*. 3509 bool SCS1ConvertsToVoid 3510 = SCS1.isPointerConversionToVoidPointer(S.Context); 3511 bool SCS2ConvertsToVoid 3512 = SCS2.isPointerConversionToVoidPointer(S.Context); 3513 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 3514 // Exactly one of the conversion sequences is a conversion to 3515 // a void pointer; it's the worse conversion. 3516 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 3517 : ImplicitConversionSequence::Worse; 3518 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 3519 // Neither conversion sequence converts to a void pointer; compare 3520 // their derived-to-base conversions. 3521 if (ImplicitConversionSequence::CompareKind DerivedCK 3522 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 3523 return DerivedCK; 3524 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid && 3525 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) { 3526 // Both conversion sequences are conversions to void 3527 // pointers. Compare the source types to determine if there's an 3528 // inheritance relationship in their sources. 3529 QualType FromType1 = SCS1.getFromType(); 3530 QualType FromType2 = SCS2.getFromType(); 3531 3532 // Adjust the types we're converting from via the array-to-pointer 3533 // conversion, if we need to. 3534 if (SCS1.First == ICK_Array_To_Pointer) 3535 FromType1 = S.Context.getArrayDecayedType(FromType1); 3536 if (SCS2.First == ICK_Array_To_Pointer) 3537 FromType2 = S.Context.getArrayDecayedType(FromType2); 3538 3539 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType(); 3540 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType(); 3541 3542 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3543 return ImplicitConversionSequence::Better; 3544 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3545 return ImplicitConversionSequence::Worse; 3546 3547 // Objective-C++: If one interface is more specific than the 3548 // other, it is the better one. 3549 const ObjCObjectPointerType* FromObjCPtr1 3550 = FromType1->getAs<ObjCObjectPointerType>(); 3551 const ObjCObjectPointerType* FromObjCPtr2 3552 = FromType2->getAs<ObjCObjectPointerType>(); 3553 if (FromObjCPtr1 && FromObjCPtr2) { 3554 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1, 3555 FromObjCPtr2); 3556 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2, 3557 FromObjCPtr1); 3558 if (AssignLeft != AssignRight) { 3559 return AssignLeft? ImplicitConversionSequence::Better 3560 : ImplicitConversionSequence::Worse; 3561 } 3562 } 3563 } 3564 3565 // Compare based on qualification conversions (C++ 13.3.3.2p3, 3566 // bullet 3). 3567 if (ImplicitConversionSequence::CompareKind QualCK 3568 = CompareQualificationConversions(S, SCS1, SCS2)) 3569 return QualCK; 3570 3571 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 3572 // Check for a better reference binding based on the kind of bindings. 3573 if (isBetterReferenceBindingKind(SCS1, SCS2)) 3574 return ImplicitConversionSequence::Better; 3575 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 3576 return ImplicitConversionSequence::Worse; 3577 3578 // C++ [over.ics.rank]p3b4: 3579 // -- S1 and S2 are reference bindings (8.5.3), and the types to 3580 // which the references refer are the same type except for 3581 // top-level cv-qualifiers, and the type to which the reference 3582 // initialized by S2 refers is more cv-qualified than the type 3583 // to which the reference initialized by S1 refers. 3584 QualType T1 = SCS1.getToType(2); 3585 QualType T2 = SCS2.getToType(2); 3586 T1 = S.Context.getCanonicalType(T1); 3587 T2 = S.Context.getCanonicalType(T2); 3588 Qualifiers T1Quals, T2Quals; 3589 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3590 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3591 if (UnqualT1 == UnqualT2) { 3592 // Objective-C++ ARC: If the references refer to objects with different 3593 // lifetimes, prefer bindings that don't change lifetime. 3594 if (SCS1.ObjCLifetimeConversionBinding != 3595 SCS2.ObjCLifetimeConversionBinding) { 3596 return SCS1.ObjCLifetimeConversionBinding 3597 ? ImplicitConversionSequence::Worse 3598 : ImplicitConversionSequence::Better; 3599 } 3600 3601 // If the type is an array type, promote the element qualifiers to the 3602 // type for comparison. 3603 if (isa<ArrayType>(T1) && T1Quals) 3604 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3605 if (isa<ArrayType>(T2) && T2Quals) 3606 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3607 if (T2.isMoreQualifiedThan(T1)) 3608 return ImplicitConversionSequence::Better; 3609 else if (T1.isMoreQualifiedThan(T2)) 3610 return ImplicitConversionSequence::Worse; 3611 } 3612 } 3613 3614 // In Microsoft mode, prefer an integral conversion to a 3615 // floating-to-integral conversion if the integral conversion 3616 // is between types of the same size. 3617 // For example: 3618 // void f(float); 3619 // void f(int); 3620 // int main { 3621 // long a; 3622 // f(a); 3623 // } 3624 // Here, MSVC will call f(int) instead of generating a compile error 3625 // as clang will do in standard mode. 3626 if (S.getLangOpts().MicrosoftMode && 3627 SCS1.Second == ICK_Integral_Conversion && 3628 SCS2.Second == ICK_Floating_Integral && 3629 S.Context.getTypeSize(SCS1.getFromType()) == 3630 S.Context.getTypeSize(SCS1.getToType(2))) 3631 return ImplicitConversionSequence::Better; 3632 3633 return ImplicitConversionSequence::Indistinguishable; 3634} 3635 3636/// CompareQualificationConversions - Compares two standard conversion 3637/// sequences to determine whether they can be ranked based on their 3638/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 3639ImplicitConversionSequence::CompareKind 3640CompareQualificationConversions(Sema &S, 3641 const StandardConversionSequence& SCS1, 3642 const StandardConversionSequence& SCS2) { 3643 // C++ 13.3.3.2p3: 3644 // -- S1 and S2 differ only in their qualification conversion and 3645 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 3646 // cv-qualification signature of type T1 is a proper subset of 3647 // the cv-qualification signature of type T2, and S1 is not the 3648 // deprecated string literal array-to-pointer conversion (4.2). 3649 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 3650 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 3651 return ImplicitConversionSequence::Indistinguishable; 3652 3653 // FIXME: the example in the standard doesn't use a qualification 3654 // conversion (!) 3655 QualType T1 = SCS1.getToType(2); 3656 QualType T2 = SCS2.getToType(2); 3657 T1 = S.Context.getCanonicalType(T1); 3658 T2 = S.Context.getCanonicalType(T2); 3659 Qualifiers T1Quals, T2Quals; 3660 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3661 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3662 3663 // If the types are the same, we won't learn anything by unwrapped 3664 // them. 3665 if (UnqualT1 == UnqualT2) 3666 return ImplicitConversionSequence::Indistinguishable; 3667 3668 // If the type is an array type, promote the element qualifiers to the type 3669 // for comparison. 3670 if (isa<ArrayType>(T1) && T1Quals) 3671 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3672 if (isa<ArrayType>(T2) && T2Quals) 3673 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3674 3675 ImplicitConversionSequence::CompareKind Result 3676 = ImplicitConversionSequence::Indistinguishable; 3677 3678 // Objective-C++ ARC: 3679 // Prefer qualification conversions not involving a change in lifetime 3680 // to qualification conversions that do not change lifetime. 3681 if (SCS1.QualificationIncludesObjCLifetime != 3682 SCS2.QualificationIncludesObjCLifetime) { 3683 Result = SCS1.QualificationIncludesObjCLifetime 3684 ? ImplicitConversionSequence::Worse 3685 : ImplicitConversionSequence::Better; 3686 } 3687 3688 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 3689 // Within each iteration of the loop, we check the qualifiers to 3690 // determine if this still looks like a qualification 3691 // conversion. Then, if all is well, we unwrap one more level of 3692 // pointers or pointers-to-members and do it all again 3693 // until there are no more pointers or pointers-to-members left 3694 // to unwrap. This essentially mimics what 3695 // IsQualificationConversion does, but here we're checking for a 3696 // strict subset of qualifiers. 3697 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 3698 // The qualifiers are the same, so this doesn't tell us anything 3699 // about how the sequences rank. 3700 ; 3701 else if (T2.isMoreQualifiedThan(T1)) { 3702 // T1 has fewer qualifiers, so it could be the better sequence. 3703 if (Result == ImplicitConversionSequence::Worse) 3704 // Neither has qualifiers that are a subset of the other's 3705 // qualifiers. 3706 return ImplicitConversionSequence::Indistinguishable; 3707 3708 Result = ImplicitConversionSequence::Better; 3709 } else if (T1.isMoreQualifiedThan(T2)) { 3710 // T2 has fewer qualifiers, so it could be the better sequence. 3711 if (Result == ImplicitConversionSequence::Better) 3712 // Neither has qualifiers that are a subset of the other's 3713 // qualifiers. 3714 return ImplicitConversionSequence::Indistinguishable; 3715 3716 Result = ImplicitConversionSequence::Worse; 3717 } else { 3718 // Qualifiers are disjoint. 3719 return ImplicitConversionSequence::Indistinguishable; 3720 } 3721 3722 // If the types after this point are equivalent, we're done. 3723 if (S.Context.hasSameUnqualifiedType(T1, T2)) 3724 break; 3725 } 3726 3727 // Check that the winning standard conversion sequence isn't using 3728 // the deprecated string literal array to pointer conversion. 3729 switch (Result) { 3730 case ImplicitConversionSequence::Better: 3731 if (SCS1.DeprecatedStringLiteralToCharPtr) 3732 Result = ImplicitConversionSequence::Indistinguishable; 3733 break; 3734 3735 case ImplicitConversionSequence::Indistinguishable: 3736 break; 3737 3738 case ImplicitConversionSequence::Worse: 3739 if (SCS2.DeprecatedStringLiteralToCharPtr) 3740 Result = ImplicitConversionSequence::Indistinguishable; 3741 break; 3742 } 3743 3744 return Result; 3745} 3746 3747/// CompareDerivedToBaseConversions - Compares two standard conversion 3748/// sequences to determine whether they can be ranked based on their 3749/// various kinds of derived-to-base conversions (C++ 3750/// [over.ics.rank]p4b3). As part of these checks, we also look at 3751/// conversions between Objective-C interface types. 3752ImplicitConversionSequence::CompareKind 3753CompareDerivedToBaseConversions(Sema &S, 3754 const StandardConversionSequence& SCS1, 3755 const StandardConversionSequence& SCS2) { 3756 QualType FromType1 = SCS1.getFromType(); 3757 QualType ToType1 = SCS1.getToType(1); 3758 QualType FromType2 = SCS2.getFromType(); 3759 QualType ToType2 = SCS2.getToType(1); 3760 3761 // Adjust the types we're converting from via the array-to-pointer 3762 // conversion, if we need to. 3763 if (SCS1.First == ICK_Array_To_Pointer) 3764 FromType1 = S.Context.getArrayDecayedType(FromType1); 3765 if (SCS2.First == ICK_Array_To_Pointer) 3766 FromType2 = S.Context.getArrayDecayedType(FromType2); 3767 3768 // Canonicalize all of the types. 3769 FromType1 = S.Context.getCanonicalType(FromType1); 3770 ToType1 = S.Context.getCanonicalType(ToType1); 3771 FromType2 = S.Context.getCanonicalType(FromType2); 3772 ToType2 = S.Context.getCanonicalType(ToType2); 3773 3774 // C++ [over.ics.rank]p4b3: 3775 // 3776 // If class B is derived directly or indirectly from class A and 3777 // class C is derived directly or indirectly from B, 3778 // 3779 // Compare based on pointer conversions. 3780 if (SCS1.Second == ICK_Pointer_Conversion && 3781 SCS2.Second == ICK_Pointer_Conversion && 3782 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 3783 FromType1->isPointerType() && FromType2->isPointerType() && 3784 ToType1->isPointerType() && ToType2->isPointerType()) { 3785 QualType FromPointee1 3786 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3787 QualType ToPointee1 3788 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3789 QualType FromPointee2 3790 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3791 QualType ToPointee2 3792 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3793 3794 // -- conversion of C* to B* is better than conversion of C* to A*, 3795 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3796 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3797 return ImplicitConversionSequence::Better; 3798 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3799 return ImplicitConversionSequence::Worse; 3800 } 3801 3802 // -- conversion of B* to A* is better than conversion of C* to A*, 3803 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 3804 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3805 return ImplicitConversionSequence::Better; 3806 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3807 return ImplicitConversionSequence::Worse; 3808 } 3809 } else if (SCS1.Second == ICK_Pointer_Conversion && 3810 SCS2.Second == ICK_Pointer_Conversion) { 3811 const ObjCObjectPointerType *FromPtr1 3812 = FromType1->getAs<ObjCObjectPointerType>(); 3813 const ObjCObjectPointerType *FromPtr2 3814 = FromType2->getAs<ObjCObjectPointerType>(); 3815 const ObjCObjectPointerType *ToPtr1 3816 = ToType1->getAs<ObjCObjectPointerType>(); 3817 const ObjCObjectPointerType *ToPtr2 3818 = ToType2->getAs<ObjCObjectPointerType>(); 3819 3820 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 3821 // Apply the same conversion ranking rules for Objective-C pointer types 3822 // that we do for C++ pointers to class types. However, we employ the 3823 // Objective-C pseudo-subtyping relationship used for assignment of 3824 // Objective-C pointer types. 3825 bool FromAssignLeft 3826 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 3827 bool FromAssignRight 3828 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 3829 bool ToAssignLeft 3830 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 3831 bool ToAssignRight 3832 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 3833 3834 // A conversion to an a non-id object pointer type or qualified 'id' 3835 // type is better than a conversion to 'id'. 3836 if (ToPtr1->isObjCIdType() && 3837 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 3838 return ImplicitConversionSequence::Worse; 3839 if (ToPtr2->isObjCIdType() && 3840 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 3841 return ImplicitConversionSequence::Better; 3842 3843 // A conversion to a non-id object pointer type is better than a 3844 // conversion to a qualified 'id' type 3845 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 3846 return ImplicitConversionSequence::Worse; 3847 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 3848 return ImplicitConversionSequence::Better; 3849 3850 // A conversion to an a non-Class object pointer type or qualified 'Class' 3851 // type is better than a conversion to 'Class'. 3852 if (ToPtr1->isObjCClassType() && 3853 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 3854 return ImplicitConversionSequence::Worse; 3855 if (ToPtr2->isObjCClassType() && 3856 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 3857 return ImplicitConversionSequence::Better; 3858 3859 // A conversion to a non-Class object pointer type is better than a 3860 // conversion to a qualified 'Class' type. 3861 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 3862 return ImplicitConversionSequence::Worse; 3863 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 3864 return ImplicitConversionSequence::Better; 3865 3866 // -- "conversion of C* to B* is better than conversion of C* to A*," 3867 if (S.Context.hasSameType(FromType1, FromType2) && 3868 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 3869 (ToAssignLeft != ToAssignRight)) 3870 return ToAssignLeft? ImplicitConversionSequence::Worse 3871 : ImplicitConversionSequence::Better; 3872 3873 // -- "conversion of B* to A* is better than conversion of C* to A*," 3874 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 3875 (FromAssignLeft != FromAssignRight)) 3876 return FromAssignLeft? ImplicitConversionSequence::Better 3877 : ImplicitConversionSequence::Worse; 3878 } 3879 } 3880 3881 // Ranking of member-pointer types. 3882 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 3883 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 3884 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 3885 const MemberPointerType * FromMemPointer1 = 3886 FromType1->getAs<MemberPointerType>(); 3887 const MemberPointerType * ToMemPointer1 = 3888 ToType1->getAs<MemberPointerType>(); 3889 const MemberPointerType * FromMemPointer2 = 3890 FromType2->getAs<MemberPointerType>(); 3891 const MemberPointerType * ToMemPointer2 = 3892 ToType2->getAs<MemberPointerType>(); 3893 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 3894 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 3895 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 3896 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 3897 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 3898 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 3899 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 3900 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 3901 // conversion of A::* to B::* is better than conversion of A::* to C::*, 3902 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3903 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3904 return ImplicitConversionSequence::Worse; 3905 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3906 return ImplicitConversionSequence::Better; 3907 } 3908 // conversion of B::* to C::* is better than conversion of A::* to C::* 3909 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 3910 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3911 return ImplicitConversionSequence::Better; 3912 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3913 return ImplicitConversionSequence::Worse; 3914 } 3915 } 3916 3917 if (SCS1.Second == ICK_Derived_To_Base) { 3918 // -- conversion of C to B is better than conversion of C to A, 3919 // -- binding of an expression of type C to a reference of type 3920 // B& is better than binding an expression of type C to a 3921 // reference of type A&, 3922 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3923 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3924 if (S.IsDerivedFrom(ToType1, ToType2)) 3925 return ImplicitConversionSequence::Better; 3926 else if (S.IsDerivedFrom(ToType2, ToType1)) 3927 return ImplicitConversionSequence::Worse; 3928 } 3929 3930 // -- conversion of B to A is better than conversion of C to A. 3931 // -- binding of an expression of type B to a reference of type 3932 // A& is better than binding an expression of type C to a 3933 // reference of type A&, 3934 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3935 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3936 if (S.IsDerivedFrom(FromType2, FromType1)) 3937 return ImplicitConversionSequence::Better; 3938 else if (S.IsDerivedFrom(FromType1, FromType2)) 3939 return ImplicitConversionSequence::Worse; 3940 } 3941 } 3942 3943 return ImplicitConversionSequence::Indistinguishable; 3944} 3945 3946/// \brief Determine whether the given type is valid, e.g., it is not an invalid 3947/// C++ class. 3948static bool isTypeValid(QualType T) { 3949 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) 3950 return !Record->isInvalidDecl(); 3951 3952 return true; 3953} 3954 3955/// CompareReferenceRelationship - Compare the two types T1 and T2 to 3956/// determine whether they are reference-related, 3957/// reference-compatible, reference-compatible with added 3958/// qualification, or incompatible, for use in C++ initialization by 3959/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 3960/// type, and the first type (T1) is the pointee type of the reference 3961/// type being initialized. 3962Sema::ReferenceCompareResult 3963Sema::CompareReferenceRelationship(SourceLocation Loc, 3964 QualType OrigT1, QualType OrigT2, 3965 bool &DerivedToBase, 3966 bool &ObjCConversion, 3967 bool &ObjCLifetimeConversion) { 3968 assert(!OrigT1->isReferenceType() && 3969 "T1 must be the pointee type of the reference type"); 3970 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 3971 3972 QualType T1 = Context.getCanonicalType(OrigT1); 3973 QualType T2 = Context.getCanonicalType(OrigT2); 3974 Qualifiers T1Quals, T2Quals; 3975 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 3976 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 3977 3978 // C++ [dcl.init.ref]p4: 3979 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 3980 // reference-related to "cv2 T2" if T1 is the same type as T2, or 3981 // T1 is a base class of T2. 3982 DerivedToBase = false; 3983 ObjCConversion = false; 3984 ObjCLifetimeConversion = false; 3985 if (UnqualT1 == UnqualT2) { 3986 // Nothing to do. 3987 } else if (!RequireCompleteType(Loc, OrigT2, 0) && 3988 isTypeValid(UnqualT1) && isTypeValid(UnqualT2) && 3989 IsDerivedFrom(UnqualT2, UnqualT1)) 3990 DerivedToBase = true; 3991 else if (UnqualT1->isObjCObjectOrInterfaceType() && 3992 UnqualT2->isObjCObjectOrInterfaceType() && 3993 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 3994 ObjCConversion = true; 3995 else 3996 return Ref_Incompatible; 3997 3998 // At this point, we know that T1 and T2 are reference-related (at 3999 // least). 4000 4001 // If the type is an array type, promote the element qualifiers to the type 4002 // for comparison. 4003 if (isa<ArrayType>(T1) && T1Quals) 4004 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 4005 if (isa<ArrayType>(T2) && T2Quals) 4006 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 4007 4008 // C++ [dcl.init.ref]p4: 4009 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 4010 // reference-related to T2 and cv1 is the same cv-qualification 4011 // as, or greater cv-qualification than, cv2. For purposes of 4012 // overload resolution, cases for which cv1 is greater 4013 // cv-qualification than cv2 are identified as 4014 // reference-compatible with added qualification (see 13.3.3.2). 4015 // 4016 // Note that we also require equivalence of Objective-C GC and address-space 4017 // qualifiers when performing these computations, so that e.g., an int in 4018 // address space 1 is not reference-compatible with an int in address 4019 // space 2. 4020 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() && 4021 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) { 4022 T1Quals.removeObjCLifetime(); 4023 T2Quals.removeObjCLifetime(); 4024 ObjCLifetimeConversion = true; 4025 } 4026 4027 if (T1Quals == T2Quals) 4028 return Ref_Compatible; 4029 else if (T1Quals.compatiblyIncludes(T2Quals)) 4030 return Ref_Compatible_With_Added_Qualification; 4031 else 4032 return Ref_Related; 4033} 4034 4035/// \brief Look for a user-defined conversion to an value reference-compatible 4036/// with DeclType. Return true if something definite is found. 4037static bool 4038FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 4039 QualType DeclType, SourceLocation DeclLoc, 4040 Expr *Init, QualType T2, bool AllowRvalues, 4041 bool AllowExplicit) { 4042 assert(T2->isRecordType() && "Can only find conversions of record types."); 4043 CXXRecordDecl *T2RecordDecl 4044 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 4045 4046 OverloadCandidateSet CandidateSet(DeclLoc); 4047 std::pair<CXXRecordDecl::conversion_iterator, 4048 CXXRecordDecl::conversion_iterator> 4049 Conversions = T2RecordDecl->getVisibleConversionFunctions(); 4050 for (CXXRecordDecl::conversion_iterator 4051 I = Conversions.first, E = Conversions.second; I != E; ++I) { 4052 NamedDecl *D = *I; 4053 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 4054 if (isa<UsingShadowDecl>(D)) 4055 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4056 4057 FunctionTemplateDecl *ConvTemplate 4058 = dyn_cast<FunctionTemplateDecl>(D); 4059 CXXConversionDecl *Conv; 4060 if (ConvTemplate) 4061 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 4062 else 4063 Conv = cast<CXXConversionDecl>(D); 4064 4065 // If this is an explicit conversion, and we're not allowed to consider 4066 // explicit conversions, skip it. 4067 if (!AllowExplicit && Conv->isExplicit()) 4068 continue; 4069 4070 if (AllowRvalues) { 4071 bool DerivedToBase = false; 4072 bool ObjCConversion = false; 4073 bool ObjCLifetimeConversion = false; 4074 4075 // If we are initializing an rvalue reference, don't permit conversion 4076 // functions that return lvalues. 4077 if (!ConvTemplate && DeclType->isRValueReferenceType()) { 4078 const ReferenceType *RefType 4079 = Conv->getConversionType()->getAs<LValueReferenceType>(); 4080 if (RefType && !RefType->getPointeeType()->isFunctionType()) 4081 continue; 4082 } 4083 4084 if (!ConvTemplate && 4085 S.CompareReferenceRelationship( 4086 DeclLoc, 4087 Conv->getConversionType().getNonReferenceType() 4088 .getUnqualifiedType(), 4089 DeclType.getNonReferenceType().getUnqualifiedType(), 4090 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) == 4091 Sema::Ref_Incompatible) 4092 continue; 4093 } else { 4094 // If the conversion function doesn't return a reference type, 4095 // it can't be considered for this conversion. An rvalue reference 4096 // is only acceptable if its referencee is a function type. 4097 4098 const ReferenceType *RefType = 4099 Conv->getConversionType()->getAs<ReferenceType>(); 4100 if (!RefType || 4101 (!RefType->isLValueReferenceType() && 4102 !RefType->getPointeeType()->isFunctionType())) 4103 continue; 4104 } 4105 4106 if (ConvTemplate) 4107 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 4108 Init, DeclType, CandidateSet); 4109 else 4110 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 4111 DeclType, CandidateSet); 4112 } 4113 4114 bool HadMultipleCandidates = (CandidateSet.size() > 1); 4115 4116 OverloadCandidateSet::iterator Best; 4117 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 4118 case OR_Success: 4119 // C++ [over.ics.ref]p1: 4120 // 4121 // [...] If the parameter binds directly to the result of 4122 // applying a conversion function to the argument 4123 // expression, the implicit conversion sequence is a 4124 // user-defined conversion sequence (13.3.3.1.2), with the 4125 // second standard conversion sequence either an identity 4126 // conversion or, if the conversion function returns an 4127 // entity of a type that is a derived class of the parameter 4128 // type, a derived-to-base Conversion. 4129 if (!Best->FinalConversion.DirectBinding) 4130 return false; 4131 4132 ICS.setUserDefined(); 4133 ICS.UserDefined.Before = Best->Conversions[0].Standard; 4134 ICS.UserDefined.After = Best->FinalConversion; 4135 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates; 4136 ICS.UserDefined.ConversionFunction = Best->Function; 4137 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl; 4138 ICS.UserDefined.EllipsisConversion = false; 4139 assert(ICS.UserDefined.After.ReferenceBinding && 4140 ICS.UserDefined.After.DirectBinding && 4141 "Expected a direct reference binding!"); 4142 return true; 4143 4144 case OR_Ambiguous: 4145 ICS.setAmbiguous(); 4146 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4147 Cand != CandidateSet.end(); ++Cand) 4148 if (Cand->Viable) 4149 ICS.Ambiguous.addConversion(Cand->Function); 4150 return true; 4151 4152 case OR_No_Viable_Function: 4153 case OR_Deleted: 4154 // There was no suitable conversion, or we found a deleted 4155 // conversion; continue with other checks. 4156 return false; 4157 } 4158 4159 llvm_unreachable("Invalid OverloadResult!"); 4160} 4161 4162/// \brief Compute an implicit conversion sequence for reference 4163/// initialization. 4164static ImplicitConversionSequence 4165TryReferenceInit(Sema &S, Expr *Init, QualType DeclType, 4166 SourceLocation DeclLoc, 4167 bool SuppressUserConversions, 4168 bool AllowExplicit) { 4169 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 4170 4171 // Most paths end in a failed conversion. 4172 ImplicitConversionSequence ICS; 4173 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 4174 4175 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 4176 QualType T2 = Init->getType(); 4177 4178 // If the initializer is the address of an overloaded function, try 4179 // to resolve the overloaded function. If all goes well, T2 is the 4180 // type of the resulting function. 4181 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 4182 DeclAccessPair Found; 4183 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 4184 false, Found)) 4185 T2 = Fn->getType(); 4186 } 4187 4188 // Compute some basic properties of the types and the initializer. 4189 bool isRValRef = DeclType->isRValueReferenceType(); 4190 bool DerivedToBase = false; 4191 bool ObjCConversion = false; 4192 bool ObjCLifetimeConversion = false; 4193 Expr::Classification InitCategory = Init->Classify(S.Context); 4194 Sema::ReferenceCompareResult RefRelationship 4195 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 4196 ObjCConversion, ObjCLifetimeConversion); 4197 4198 4199 // C++0x [dcl.init.ref]p5: 4200 // A reference to type "cv1 T1" is initialized by an expression 4201 // of type "cv2 T2" as follows: 4202 4203 // -- If reference is an lvalue reference and the initializer expression 4204 if (!isRValRef) { 4205 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 4206 // reference-compatible with "cv2 T2," or 4207 // 4208 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 4209 if (InitCategory.isLValue() && 4210 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 4211 // C++ [over.ics.ref]p1: 4212 // When a parameter of reference type binds directly (8.5.3) 4213 // to an argument expression, the implicit conversion sequence 4214 // is the identity conversion, unless the argument expression 4215 // has a type that is a derived class of the parameter type, 4216 // in which case the implicit conversion sequence is a 4217 // derived-to-base Conversion (13.3.3.1). 4218 ICS.setStandard(); 4219 ICS.Standard.First = ICK_Identity; 4220 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 4221 : ObjCConversion? ICK_Compatible_Conversion 4222 : ICK_Identity; 4223 ICS.Standard.Third = ICK_Identity; 4224 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 4225 ICS.Standard.setToType(0, T2); 4226 ICS.Standard.setToType(1, T1); 4227 ICS.Standard.setToType(2, T1); 4228 ICS.Standard.ReferenceBinding = true; 4229 ICS.Standard.DirectBinding = true; 4230 ICS.Standard.IsLvalueReference = !isRValRef; 4231 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4232 ICS.Standard.BindsToRvalue = false; 4233 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4234 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 4235 ICS.Standard.CopyConstructor = 0; 4236 4237 // Nothing more to do: the inaccessibility/ambiguity check for 4238 // derived-to-base conversions is suppressed when we're 4239 // computing the implicit conversion sequence (C++ 4240 // [over.best.ics]p2). 4241 return ICS; 4242 } 4243 4244 // -- has a class type (i.e., T2 is a class type), where T1 is 4245 // not reference-related to T2, and can be implicitly 4246 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 4247 // is reference-compatible with "cv3 T3" 92) (this 4248 // conversion is selected by enumerating the applicable 4249 // conversion functions (13.3.1.6) and choosing the best 4250 // one through overload resolution (13.3)), 4251 if (!SuppressUserConversions && T2->isRecordType() && 4252 !S.RequireCompleteType(DeclLoc, T2, 0) && 4253 RefRelationship == Sema::Ref_Incompatible) { 4254 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 4255 Init, T2, /*AllowRvalues=*/false, 4256 AllowExplicit)) 4257 return ICS; 4258 } 4259 } 4260 4261 // -- Otherwise, the reference shall be an lvalue reference to a 4262 // non-volatile const type (i.e., cv1 shall be const), or the reference 4263 // shall be an rvalue reference. 4264 // 4265 // We actually handle one oddity of C++ [over.ics.ref] at this 4266 // point, which is that, due to p2 (which short-circuits reference 4267 // binding by only attempting a simple conversion for non-direct 4268 // bindings) and p3's strange wording, we allow a const volatile 4269 // reference to bind to an rvalue. Hence the check for the presence 4270 // of "const" rather than checking for "const" being the only 4271 // qualifier. 4272 // This is also the point where rvalue references and lvalue inits no longer 4273 // go together. 4274 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified())) 4275 return ICS; 4276 4277 // -- If the initializer expression 4278 // 4279 // -- is an xvalue, class prvalue, array prvalue or function 4280 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or 4281 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 4282 (InitCategory.isXValue() || 4283 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 4284 (InitCategory.isLValue() && T2->isFunctionType()))) { 4285 ICS.setStandard(); 4286 ICS.Standard.First = ICK_Identity; 4287 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 4288 : ObjCConversion? ICK_Compatible_Conversion 4289 : ICK_Identity; 4290 ICS.Standard.Third = ICK_Identity; 4291 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 4292 ICS.Standard.setToType(0, T2); 4293 ICS.Standard.setToType(1, T1); 4294 ICS.Standard.setToType(2, T1); 4295 ICS.Standard.ReferenceBinding = true; 4296 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 4297 // binding unless we're binding to a class prvalue. 4298 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 4299 // allow the use of rvalue references in C++98/03 for the benefit of 4300 // standard library implementors; therefore, we need the xvalue check here. 4301 ICS.Standard.DirectBinding = 4302 S.getLangOpts().CPlusPlus11 || 4303 (InitCategory.isPRValue() && !T2->isRecordType()); 4304 ICS.Standard.IsLvalueReference = !isRValRef; 4305 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4306 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 4307 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4308 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 4309 ICS.Standard.CopyConstructor = 0; 4310 return ICS; 4311 } 4312 4313 // -- has a class type (i.e., T2 is a class type), where T1 is not 4314 // reference-related to T2, and can be implicitly converted to 4315 // an xvalue, class prvalue, or function lvalue of type 4316 // "cv3 T3", where "cv1 T1" is reference-compatible with 4317 // "cv3 T3", 4318 // 4319 // then the reference is bound to the value of the initializer 4320 // expression in the first case and to the result of the conversion 4321 // in the second case (or, in either case, to an appropriate base 4322 // class subobject). 4323 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 4324 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 4325 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 4326 Init, T2, /*AllowRvalues=*/true, 4327 AllowExplicit)) { 4328 // In the second case, if the reference is an rvalue reference 4329 // and the second standard conversion sequence of the 4330 // user-defined conversion sequence includes an lvalue-to-rvalue 4331 // conversion, the program is ill-formed. 4332 if (ICS.isUserDefined() && isRValRef && 4333 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 4334 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 4335 4336 return ICS; 4337 } 4338 4339 // -- Otherwise, a temporary of type "cv1 T1" is created and 4340 // initialized from the initializer expression using the 4341 // rules for a non-reference copy initialization (8.5). The 4342 // reference is then bound to the temporary. If T1 is 4343 // reference-related to T2, cv1 must be the same 4344 // cv-qualification as, or greater cv-qualification than, 4345 // cv2; otherwise, the program is ill-formed. 4346 if (RefRelationship == Sema::Ref_Related) { 4347 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 4348 // we would be reference-compatible or reference-compatible with 4349 // added qualification. But that wasn't the case, so the reference 4350 // initialization fails. 4351 // 4352 // Note that we only want to check address spaces and cvr-qualifiers here. 4353 // ObjC GC and lifetime qualifiers aren't important. 4354 Qualifiers T1Quals = T1.getQualifiers(); 4355 Qualifiers T2Quals = T2.getQualifiers(); 4356 T1Quals.removeObjCGCAttr(); 4357 T1Quals.removeObjCLifetime(); 4358 T2Quals.removeObjCGCAttr(); 4359 T2Quals.removeObjCLifetime(); 4360 if (!T1Quals.compatiblyIncludes(T2Quals)) 4361 return ICS; 4362 } 4363 4364 // If at least one of the types is a class type, the types are not 4365 // related, and we aren't allowed any user conversions, the 4366 // reference binding fails. This case is important for breaking 4367 // recursion, since TryImplicitConversion below will attempt to 4368 // create a temporary through the use of a copy constructor. 4369 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 4370 (T1->isRecordType() || T2->isRecordType())) 4371 return ICS; 4372 4373 // If T1 is reference-related to T2 and the reference is an rvalue 4374 // reference, the initializer expression shall not be an lvalue. 4375 if (RefRelationship >= Sema::Ref_Related && 4376 isRValRef && Init->Classify(S.Context).isLValue()) 4377 return ICS; 4378 4379 // C++ [over.ics.ref]p2: 4380 // When a parameter of reference type is not bound directly to 4381 // an argument expression, the conversion sequence is the one 4382 // required to convert the argument expression to the 4383 // underlying type of the reference according to 4384 // 13.3.3.1. Conceptually, this conversion sequence corresponds 4385 // to copy-initializing a temporary of the underlying type with 4386 // the argument expression. Any difference in top-level 4387 // cv-qualification is subsumed by the initialization itself 4388 // and does not constitute a conversion. 4389 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 4390 /*AllowExplicit=*/false, 4391 /*InOverloadResolution=*/false, 4392 /*CStyle=*/false, 4393 /*AllowObjCWritebackConversion=*/false); 4394 4395 // Of course, that's still a reference binding. 4396 if (ICS.isStandard()) { 4397 ICS.Standard.ReferenceBinding = true; 4398 ICS.Standard.IsLvalueReference = !isRValRef; 4399 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4400 ICS.Standard.BindsToRvalue = true; 4401 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4402 ICS.Standard.ObjCLifetimeConversionBinding = false; 4403 } else if (ICS.isUserDefined()) { 4404 // Don't allow rvalue references to bind to lvalues. 4405 if (DeclType->isRValueReferenceType()) { 4406 if (const ReferenceType *RefType 4407 = ICS.UserDefined.ConversionFunction->getResultType() 4408 ->getAs<LValueReferenceType>()) { 4409 if (!RefType->getPointeeType()->isFunctionType()) { 4410 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, 4411 DeclType); 4412 return ICS; 4413 } 4414 } 4415 } 4416 4417 ICS.UserDefined.After.ReferenceBinding = true; 4418 ICS.UserDefined.After.IsLvalueReference = !isRValRef; 4419 ICS.UserDefined.After.BindsToFunctionLvalue = T2->isFunctionType(); 4420 ICS.UserDefined.After.BindsToRvalue = true; 4421 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4422 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false; 4423 } 4424 4425 return ICS; 4426} 4427 4428static ImplicitConversionSequence 4429TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 4430 bool SuppressUserConversions, 4431 bool InOverloadResolution, 4432 bool AllowObjCWritebackConversion, 4433 bool AllowExplicit = false); 4434 4435/// TryListConversion - Try to copy-initialize a value of type ToType from the 4436/// initializer list From. 4437static ImplicitConversionSequence 4438TryListConversion(Sema &S, InitListExpr *From, QualType ToType, 4439 bool SuppressUserConversions, 4440 bool InOverloadResolution, 4441 bool AllowObjCWritebackConversion) { 4442 // C++11 [over.ics.list]p1: 4443 // When an argument is an initializer list, it is not an expression and 4444 // special rules apply for converting it to a parameter type. 4445 4446 ImplicitConversionSequence Result; 4447 Result.setBad(BadConversionSequence::no_conversion, From, ToType); 4448 Result.setListInitializationSequence(); 4449 4450 // We need a complete type for what follows. Incomplete types can never be 4451 // initialized from init lists. 4452 if (S.RequireCompleteType(From->getLocStart(), ToType, 0)) 4453 return Result; 4454 4455 // C++11 [over.ics.list]p2: 4456 // If the parameter type is std::initializer_list<X> or "array of X" and 4457 // all the elements can be implicitly converted to X, the implicit 4458 // conversion sequence is the worst conversion necessary to convert an 4459 // element of the list to X. 4460 bool toStdInitializerList = false; 4461 QualType X; 4462 if (ToType->isArrayType()) 4463 X = S.Context.getAsArrayType(ToType)->getElementType(); 4464 else 4465 toStdInitializerList = S.isStdInitializerList(ToType, &X); 4466 if (!X.isNull()) { 4467 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) { 4468 Expr *Init = From->getInit(i); 4469 ImplicitConversionSequence ICS = 4470 TryCopyInitialization(S, Init, X, SuppressUserConversions, 4471 InOverloadResolution, 4472 AllowObjCWritebackConversion); 4473 // If a single element isn't convertible, fail. 4474 if (ICS.isBad()) { 4475 Result = ICS; 4476 break; 4477 } 4478 // Otherwise, look for the worst conversion. 4479 if (Result.isBad() || 4480 CompareImplicitConversionSequences(S, ICS, Result) == 4481 ImplicitConversionSequence::Worse) 4482 Result = ICS; 4483 } 4484 4485 // For an empty list, we won't have computed any conversion sequence. 4486 // Introduce the identity conversion sequence. 4487 if (From->getNumInits() == 0) { 4488 Result.setStandard(); 4489 Result.Standard.setAsIdentityConversion(); 4490 Result.Standard.setFromType(ToType); 4491 Result.Standard.setAllToTypes(ToType); 4492 } 4493 4494 Result.setListInitializationSequence(); 4495 Result.setStdInitializerListElement(toStdInitializerList); 4496 return Result; 4497 } 4498 4499 // C++11 [over.ics.list]p3: 4500 // Otherwise, if the parameter is a non-aggregate class X and overload 4501 // resolution chooses a single best constructor [...] the implicit 4502 // conversion sequence is a user-defined conversion sequence. If multiple 4503 // constructors are viable but none is better than the others, the 4504 // implicit conversion sequence is a user-defined conversion sequence. 4505 if (ToType->isRecordType() && !ToType->isAggregateType()) { 4506 // This function can deal with initializer lists. 4507 Result = TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, 4508 /*AllowExplicit=*/false, 4509 InOverloadResolution, /*CStyle=*/false, 4510 AllowObjCWritebackConversion); 4511 Result.setListInitializationSequence(); 4512 return Result; 4513 } 4514 4515 // C++11 [over.ics.list]p4: 4516 // Otherwise, if the parameter has an aggregate type which can be 4517 // initialized from the initializer list [...] the implicit conversion 4518 // sequence is a user-defined conversion sequence. 4519 if (ToType->isAggregateType()) { 4520 // Type is an aggregate, argument is an init list. At this point it comes 4521 // down to checking whether the initialization works. 4522 // FIXME: Find out whether this parameter is consumed or not. 4523 InitializedEntity Entity = 4524 InitializedEntity::InitializeParameter(S.Context, ToType, 4525 /*Consumed=*/false); 4526 if (S.CanPerformCopyInitialization(Entity, S.Owned(From))) { 4527 Result.setUserDefined(); 4528 Result.UserDefined.Before.setAsIdentityConversion(); 4529 // Initializer lists don't have a type. 4530 Result.UserDefined.Before.setFromType(QualType()); 4531 Result.UserDefined.Before.setAllToTypes(QualType()); 4532 4533 Result.UserDefined.After.setAsIdentityConversion(); 4534 Result.UserDefined.After.setFromType(ToType); 4535 Result.UserDefined.After.setAllToTypes(ToType); 4536 Result.UserDefined.ConversionFunction = 0; 4537 } 4538 return Result; 4539 } 4540 4541 // C++11 [over.ics.list]p5: 4542 // Otherwise, if the parameter is a reference, see 13.3.3.1.4. 4543 if (ToType->isReferenceType()) { 4544 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't 4545 // mention initializer lists in any way. So we go by what list- 4546 // initialization would do and try to extrapolate from that. 4547 4548 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType(); 4549 4550 // If the initializer list has a single element that is reference-related 4551 // to the parameter type, we initialize the reference from that. 4552 if (From->getNumInits() == 1) { 4553 Expr *Init = From->getInit(0); 4554 4555 QualType T2 = Init->getType(); 4556 4557 // If the initializer is the address of an overloaded function, try 4558 // to resolve the overloaded function. If all goes well, T2 is the 4559 // type of the resulting function. 4560 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 4561 DeclAccessPair Found; 4562 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction( 4563 Init, ToType, false, Found)) 4564 T2 = Fn->getType(); 4565 } 4566 4567 // Compute some basic properties of the types and the initializer. 4568 bool dummy1 = false; 4569 bool dummy2 = false; 4570 bool dummy3 = false; 4571 Sema::ReferenceCompareResult RefRelationship 4572 = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1, 4573 dummy2, dummy3); 4574 4575 if (RefRelationship >= Sema::Ref_Related) 4576 return TryReferenceInit(S, Init, ToType, 4577 /*FIXME:*/From->getLocStart(), 4578 SuppressUserConversions, 4579 /*AllowExplicit=*/false); 4580 } 4581 4582 // Otherwise, we bind the reference to a temporary created from the 4583 // initializer list. 4584 Result = TryListConversion(S, From, T1, SuppressUserConversions, 4585 InOverloadResolution, 4586 AllowObjCWritebackConversion); 4587 if (Result.isFailure()) 4588 return Result; 4589 assert(!Result.isEllipsis() && 4590 "Sub-initialization cannot result in ellipsis conversion."); 4591 4592 // Can we even bind to a temporary? 4593 if (ToType->isRValueReferenceType() || 4594 (T1.isConstQualified() && !T1.isVolatileQualified())) { 4595 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard : 4596 Result.UserDefined.After; 4597 SCS.ReferenceBinding = true; 4598 SCS.IsLvalueReference = ToType->isLValueReferenceType(); 4599 SCS.BindsToRvalue = true; 4600 SCS.BindsToFunctionLvalue = false; 4601 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4602 SCS.ObjCLifetimeConversionBinding = false; 4603 } else 4604 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue, 4605 From, ToType); 4606 return Result; 4607 } 4608 4609 // C++11 [over.ics.list]p6: 4610 // Otherwise, if the parameter type is not a class: 4611 if (!ToType->isRecordType()) { 4612 // - if the initializer list has one element, the implicit conversion 4613 // sequence is the one required to convert the element to the 4614 // parameter type. 4615 unsigned NumInits = From->getNumInits(); 4616 if (NumInits == 1) 4617 Result = TryCopyInitialization(S, From->getInit(0), ToType, 4618 SuppressUserConversions, 4619 InOverloadResolution, 4620 AllowObjCWritebackConversion); 4621 // - if the initializer list has no elements, the implicit conversion 4622 // sequence is the identity conversion. 4623 else if (NumInits == 0) { 4624 Result.setStandard(); 4625 Result.Standard.setAsIdentityConversion(); 4626 Result.Standard.setFromType(ToType); 4627 Result.Standard.setAllToTypes(ToType); 4628 } 4629 Result.setListInitializationSequence(); 4630 return Result; 4631 } 4632 4633 // C++11 [over.ics.list]p7: 4634 // In all cases other than those enumerated above, no conversion is possible 4635 return Result; 4636} 4637 4638/// TryCopyInitialization - Try to copy-initialize a value of type 4639/// ToType from the expression From. Return the implicit conversion 4640/// sequence required to pass this argument, which may be a bad 4641/// conversion sequence (meaning that the argument cannot be passed to 4642/// a parameter of this type). If @p SuppressUserConversions, then we 4643/// do not permit any user-defined conversion sequences. 4644static ImplicitConversionSequence 4645TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 4646 bool SuppressUserConversions, 4647 bool InOverloadResolution, 4648 bool AllowObjCWritebackConversion, 4649 bool AllowExplicit) { 4650 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From)) 4651 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions, 4652 InOverloadResolution,AllowObjCWritebackConversion); 4653 4654 if (ToType->isReferenceType()) 4655 return TryReferenceInit(S, From, ToType, 4656 /*FIXME:*/From->getLocStart(), 4657 SuppressUserConversions, 4658 AllowExplicit); 4659 4660 return TryImplicitConversion(S, From, ToType, 4661 SuppressUserConversions, 4662 /*AllowExplicit=*/false, 4663 InOverloadResolution, 4664 /*CStyle=*/false, 4665 AllowObjCWritebackConversion); 4666} 4667 4668static bool TryCopyInitialization(const CanQualType FromQTy, 4669 const CanQualType ToQTy, 4670 Sema &S, 4671 SourceLocation Loc, 4672 ExprValueKind FromVK) { 4673 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK); 4674 ImplicitConversionSequence ICS = 4675 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false); 4676 4677 return !ICS.isBad(); 4678} 4679 4680/// TryObjectArgumentInitialization - Try to initialize the object 4681/// parameter of the given member function (@c Method) from the 4682/// expression @p From. 4683static ImplicitConversionSequence 4684TryObjectArgumentInitialization(Sema &S, QualType FromType, 4685 Expr::Classification FromClassification, 4686 CXXMethodDecl *Method, 4687 CXXRecordDecl *ActingContext) { 4688 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 4689 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 4690 // const volatile object. 4691 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 4692 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 4693 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 4694 4695 // Set up the conversion sequence as a "bad" conversion, to allow us 4696 // to exit early. 4697 ImplicitConversionSequence ICS; 4698 4699 // We need to have an object of class type. 4700 if (const PointerType *PT = FromType->getAs<PointerType>()) { 4701 FromType = PT->getPointeeType(); 4702 4703 // When we had a pointer, it's implicitly dereferenced, so we 4704 // better have an lvalue. 4705 assert(FromClassification.isLValue()); 4706 } 4707 4708 assert(FromType->isRecordType()); 4709 4710 // C++0x [over.match.funcs]p4: 4711 // For non-static member functions, the type of the implicit object 4712 // parameter is 4713 // 4714 // - "lvalue reference to cv X" for functions declared without a 4715 // ref-qualifier or with the & ref-qualifier 4716 // - "rvalue reference to cv X" for functions declared with the && 4717 // ref-qualifier 4718 // 4719 // where X is the class of which the function is a member and cv is the 4720 // cv-qualification on the member function declaration. 4721 // 4722 // However, when finding an implicit conversion sequence for the argument, we 4723 // are not allowed to create temporaries or perform user-defined conversions 4724 // (C++ [over.match.funcs]p5). We perform a simplified version of 4725 // reference binding here, that allows class rvalues to bind to 4726 // non-constant references. 4727 4728 // First check the qualifiers. 4729 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 4730 if (ImplicitParamType.getCVRQualifiers() 4731 != FromTypeCanon.getLocalCVRQualifiers() && 4732 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 4733 ICS.setBad(BadConversionSequence::bad_qualifiers, 4734 FromType, ImplicitParamType); 4735 return ICS; 4736 } 4737 4738 // Check that we have either the same type or a derived type. It 4739 // affects the conversion rank. 4740 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 4741 ImplicitConversionKind SecondKind; 4742 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 4743 SecondKind = ICK_Identity; 4744 } else if (S.IsDerivedFrom(FromType, ClassType)) 4745 SecondKind = ICK_Derived_To_Base; 4746 else { 4747 ICS.setBad(BadConversionSequence::unrelated_class, 4748 FromType, ImplicitParamType); 4749 return ICS; 4750 } 4751 4752 // Check the ref-qualifier. 4753 switch (Method->getRefQualifier()) { 4754 case RQ_None: 4755 // Do nothing; we don't care about lvalueness or rvalueness. 4756 break; 4757 4758 case RQ_LValue: 4759 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 4760 // non-const lvalue reference cannot bind to an rvalue 4761 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 4762 ImplicitParamType); 4763 return ICS; 4764 } 4765 break; 4766 4767 case RQ_RValue: 4768 if (!FromClassification.isRValue()) { 4769 // rvalue reference cannot bind to an lvalue 4770 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 4771 ImplicitParamType); 4772 return ICS; 4773 } 4774 break; 4775 } 4776 4777 // Success. Mark this as a reference binding. 4778 ICS.setStandard(); 4779 ICS.Standard.setAsIdentityConversion(); 4780 ICS.Standard.Second = SecondKind; 4781 ICS.Standard.setFromType(FromType); 4782 ICS.Standard.setAllToTypes(ImplicitParamType); 4783 ICS.Standard.ReferenceBinding = true; 4784 ICS.Standard.DirectBinding = true; 4785 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 4786 ICS.Standard.BindsToFunctionLvalue = false; 4787 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 4788 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 4789 = (Method->getRefQualifier() == RQ_None); 4790 return ICS; 4791} 4792 4793/// PerformObjectArgumentInitialization - Perform initialization of 4794/// the implicit object parameter for the given Method with the given 4795/// expression. 4796ExprResult 4797Sema::PerformObjectArgumentInitialization(Expr *From, 4798 NestedNameSpecifier *Qualifier, 4799 NamedDecl *FoundDecl, 4800 CXXMethodDecl *Method) { 4801 QualType FromRecordType, DestType; 4802 QualType ImplicitParamRecordType = 4803 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 4804 4805 Expr::Classification FromClassification; 4806 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 4807 FromRecordType = PT->getPointeeType(); 4808 DestType = Method->getThisType(Context); 4809 FromClassification = Expr::Classification::makeSimpleLValue(); 4810 } else { 4811 FromRecordType = From->getType(); 4812 DestType = ImplicitParamRecordType; 4813 FromClassification = From->Classify(Context); 4814 } 4815 4816 // Note that we always use the true parent context when performing 4817 // the actual argument initialization. 4818 ImplicitConversionSequence ICS 4819 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 4820 Method, Method->getParent()); 4821 if (ICS.isBad()) { 4822 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 4823 Qualifiers FromQs = FromRecordType.getQualifiers(); 4824 Qualifiers ToQs = DestType.getQualifiers(); 4825 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4826 if (CVR) { 4827 Diag(From->getLocStart(), 4828 diag::err_member_function_call_bad_cvr) 4829 << Method->getDeclName() << FromRecordType << (CVR - 1) 4830 << From->getSourceRange(); 4831 Diag(Method->getLocation(), diag::note_previous_decl) 4832 << Method->getDeclName(); 4833 return ExprError(); 4834 } 4835 } 4836 4837 return Diag(From->getLocStart(), 4838 diag::err_implicit_object_parameter_init) 4839 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 4840 } 4841 4842 if (ICS.Standard.Second == ICK_Derived_To_Base) { 4843 ExprResult FromRes = 4844 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 4845 if (FromRes.isInvalid()) 4846 return ExprError(); 4847 From = FromRes.take(); 4848 } 4849 4850 if (!Context.hasSameType(From->getType(), DestType)) 4851 From = ImpCastExprToType(From, DestType, CK_NoOp, 4852 From->getValueKind()).take(); 4853 return Owned(From); 4854} 4855 4856/// TryContextuallyConvertToBool - Attempt to contextually convert the 4857/// expression From to bool (C++0x [conv]p3). 4858static ImplicitConversionSequence 4859TryContextuallyConvertToBool(Sema &S, Expr *From) { 4860 // FIXME: This is pretty broken. 4861 return TryImplicitConversion(S, From, S.Context.BoolTy, 4862 // FIXME: Are these flags correct? 4863 /*SuppressUserConversions=*/false, 4864 /*AllowExplicit=*/true, 4865 /*InOverloadResolution=*/false, 4866 /*CStyle=*/false, 4867 /*AllowObjCWritebackConversion=*/false); 4868} 4869 4870/// PerformContextuallyConvertToBool - Perform a contextual conversion 4871/// of the expression From to bool (C++0x [conv]p3). 4872ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) { 4873 if (checkPlaceholderForOverload(*this, From)) 4874 return ExprError(); 4875 4876 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 4877 if (!ICS.isBad()) 4878 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 4879 4880 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 4881 return Diag(From->getLocStart(), 4882 diag::err_typecheck_bool_condition) 4883 << From->getType() << From->getSourceRange(); 4884 return ExprError(); 4885} 4886 4887/// Check that the specified conversion is permitted in a converted constant 4888/// expression, according to C++11 [expr.const]p3. Return true if the conversion 4889/// is acceptable. 4890static bool CheckConvertedConstantConversions(Sema &S, 4891 StandardConversionSequence &SCS) { 4892 // Since we know that the target type is an integral or unscoped enumeration 4893 // type, most conversion kinds are impossible. All possible First and Third 4894 // conversions are fine. 4895 switch (SCS.Second) { 4896 case ICK_Identity: 4897 case ICK_Integral_Promotion: 4898 case ICK_Integral_Conversion: 4899 case ICK_Zero_Event_Conversion: 4900 return true; 4901 4902 case ICK_Boolean_Conversion: 4903 // Conversion from an integral or unscoped enumeration type to bool is 4904 // classified as ICK_Boolean_Conversion, but it's also an integral 4905 // conversion, so it's permitted in a converted constant expression. 4906 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() && 4907 SCS.getToType(2)->isBooleanType(); 4908 4909 case ICK_Floating_Integral: 4910 case ICK_Complex_Real: 4911 return false; 4912 4913 case ICK_Lvalue_To_Rvalue: 4914 case ICK_Array_To_Pointer: 4915 case ICK_Function_To_Pointer: 4916 case ICK_NoReturn_Adjustment: 4917 case ICK_Qualification: 4918 case ICK_Compatible_Conversion: 4919 case ICK_Vector_Conversion: 4920 case ICK_Vector_Splat: 4921 case ICK_Derived_To_Base: 4922 case ICK_Pointer_Conversion: 4923 case ICK_Pointer_Member: 4924 case ICK_Block_Pointer_Conversion: 4925 case ICK_Writeback_Conversion: 4926 case ICK_Floating_Promotion: 4927 case ICK_Complex_Promotion: 4928 case ICK_Complex_Conversion: 4929 case ICK_Floating_Conversion: 4930 case ICK_TransparentUnionConversion: 4931 llvm_unreachable("unexpected second conversion kind"); 4932 4933 case ICK_Num_Conversion_Kinds: 4934 break; 4935 } 4936 4937 llvm_unreachable("unknown conversion kind"); 4938} 4939 4940/// CheckConvertedConstantExpression - Check that the expression From is a 4941/// converted constant expression of type T, perform the conversion and produce 4942/// the converted expression, per C++11 [expr.const]p3. 4943ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T, 4944 llvm::APSInt &Value, 4945 CCEKind CCE) { 4946 assert(LangOpts.CPlusPlus11 && "converted constant expression outside C++11"); 4947 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type"); 4948 4949 if (checkPlaceholderForOverload(*this, From)) 4950 return ExprError(); 4951 4952 // C++11 [expr.const]p3 with proposed wording fixes: 4953 // A converted constant expression of type T is a core constant expression, 4954 // implicitly converted to a prvalue of type T, where the converted 4955 // expression is a literal constant expression and the implicit conversion 4956 // sequence contains only user-defined conversions, lvalue-to-rvalue 4957 // conversions, integral promotions, and integral conversions other than 4958 // narrowing conversions. 4959 ImplicitConversionSequence ICS = 4960 TryImplicitConversion(From, T, 4961 /*SuppressUserConversions=*/false, 4962 /*AllowExplicit=*/false, 4963 /*InOverloadResolution=*/false, 4964 /*CStyle=*/false, 4965 /*AllowObjcWritebackConversion=*/false); 4966 StandardConversionSequence *SCS = 0; 4967 switch (ICS.getKind()) { 4968 case ImplicitConversionSequence::StandardConversion: 4969 if (!CheckConvertedConstantConversions(*this, ICS.Standard)) 4970 return Diag(From->getLocStart(), 4971 diag::err_typecheck_converted_constant_expression_disallowed) 4972 << From->getType() << From->getSourceRange() << T; 4973 SCS = &ICS.Standard; 4974 break; 4975 case ImplicitConversionSequence::UserDefinedConversion: 4976 // We are converting from class type to an integral or enumeration type, so 4977 // the Before sequence must be trivial. 4978 if (!CheckConvertedConstantConversions(*this, ICS.UserDefined.After)) 4979 return Diag(From->getLocStart(), 4980 diag::err_typecheck_converted_constant_expression_disallowed) 4981 << From->getType() << From->getSourceRange() << T; 4982 SCS = &ICS.UserDefined.After; 4983 break; 4984 case ImplicitConversionSequence::AmbiguousConversion: 4985 case ImplicitConversionSequence::BadConversion: 4986 if (!DiagnoseMultipleUserDefinedConversion(From, T)) 4987 return Diag(From->getLocStart(), 4988 diag::err_typecheck_converted_constant_expression) 4989 << From->getType() << From->getSourceRange() << T; 4990 return ExprError(); 4991 4992 case ImplicitConversionSequence::EllipsisConversion: 4993 llvm_unreachable("ellipsis conversion in converted constant expression"); 4994 } 4995 4996 ExprResult Result = PerformImplicitConversion(From, T, ICS, AA_Converting); 4997 if (Result.isInvalid()) 4998 return Result; 4999 5000 // Check for a narrowing implicit conversion. 5001 APValue PreNarrowingValue; 5002 QualType PreNarrowingType; 5003 switch (SCS->getNarrowingKind(Context, Result.get(), PreNarrowingValue, 5004 PreNarrowingType)) { 5005 case NK_Variable_Narrowing: 5006 // Implicit conversion to a narrower type, and the value is not a constant 5007 // expression. We'll diagnose this in a moment. 5008 case NK_Not_Narrowing: 5009 break; 5010 5011 case NK_Constant_Narrowing: 5012 Diag(From->getLocStart(), 5013 isSFINAEContext() ? diag::err_cce_narrowing_sfinae : 5014 diag::err_cce_narrowing) 5015 << CCE << /*Constant*/1 5016 << PreNarrowingValue.getAsString(Context, PreNarrowingType) << T; 5017 break; 5018 5019 case NK_Type_Narrowing: 5020 Diag(From->getLocStart(), 5021 isSFINAEContext() ? diag::err_cce_narrowing_sfinae : 5022 diag::err_cce_narrowing) 5023 << CCE << /*Constant*/0 << From->getType() << T; 5024 break; 5025 } 5026 5027 // Check the expression is a constant expression. 5028 SmallVector<PartialDiagnosticAt, 8> Notes; 5029 Expr::EvalResult Eval; 5030 Eval.Diag = &Notes; 5031 5032 if (!Result.get()->EvaluateAsRValue(Eval, Context) || !Eval.Val.isInt()) { 5033 // The expression can't be folded, so we can't keep it at this position in 5034 // the AST. 5035 Result = ExprError(); 5036 } else { 5037 Value = Eval.Val.getInt(); 5038 5039 if (Notes.empty()) { 5040 // It's a constant expression. 5041 return Result; 5042 } 5043 } 5044 5045 // It's not a constant expression. Produce an appropriate diagnostic. 5046 if (Notes.size() == 1 && 5047 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr) 5048 Diag(Notes[0].first, diag::err_expr_not_cce) << CCE; 5049 else { 5050 Diag(From->getLocStart(), diag::err_expr_not_cce) 5051 << CCE << From->getSourceRange(); 5052 for (unsigned I = 0; I < Notes.size(); ++I) 5053 Diag(Notes[I].first, Notes[I].second); 5054 } 5055 return Result; 5056} 5057 5058/// dropPointerConversions - If the given standard conversion sequence 5059/// involves any pointer conversions, remove them. This may change 5060/// the result type of the conversion sequence. 5061static void dropPointerConversion(StandardConversionSequence &SCS) { 5062 if (SCS.Second == ICK_Pointer_Conversion) { 5063 SCS.Second = ICK_Identity; 5064 SCS.Third = ICK_Identity; 5065 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0]; 5066 } 5067} 5068 5069/// TryContextuallyConvertToObjCPointer - Attempt to contextually 5070/// convert the expression From to an Objective-C pointer type. 5071static ImplicitConversionSequence 5072TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) { 5073 // Do an implicit conversion to 'id'. 5074 QualType Ty = S.Context.getObjCIdType(); 5075 ImplicitConversionSequence ICS 5076 = TryImplicitConversion(S, From, Ty, 5077 // FIXME: Are these flags correct? 5078 /*SuppressUserConversions=*/false, 5079 /*AllowExplicit=*/true, 5080 /*InOverloadResolution=*/false, 5081 /*CStyle=*/false, 5082 /*AllowObjCWritebackConversion=*/false); 5083 5084 // Strip off any final conversions to 'id'. 5085 switch (ICS.getKind()) { 5086 case ImplicitConversionSequence::BadConversion: 5087 case ImplicitConversionSequence::AmbiguousConversion: 5088 case ImplicitConversionSequence::EllipsisConversion: 5089 break; 5090 5091 case ImplicitConversionSequence::UserDefinedConversion: 5092 dropPointerConversion(ICS.UserDefined.After); 5093 break; 5094 5095 case ImplicitConversionSequence::StandardConversion: 5096 dropPointerConversion(ICS.Standard); 5097 break; 5098 } 5099 5100 return ICS; 5101} 5102 5103/// PerformContextuallyConvertToObjCPointer - Perform a contextual 5104/// conversion of the expression From to an Objective-C pointer type. 5105ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) { 5106 if (checkPlaceholderForOverload(*this, From)) 5107 return ExprError(); 5108 5109 QualType Ty = Context.getObjCIdType(); 5110 ImplicitConversionSequence ICS = 5111 TryContextuallyConvertToObjCPointer(*this, From); 5112 if (!ICS.isBad()) 5113 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 5114 return ExprError(); 5115} 5116 5117/// Determine whether the provided type is an integral type, or an enumeration 5118/// type of a permitted flavor. 5119bool Sema::ICEConvertDiagnoser::match(QualType T) { 5120 return AllowScopedEnumerations ? T->isIntegralOrEnumerationType() 5121 : T->isIntegralOrUnscopedEnumerationType(); 5122} 5123 5124static ExprResult 5125diagnoseAmbiguousConversion(Sema &SemaRef, SourceLocation Loc, Expr *From, 5126 Sema::ContextualImplicitConverter &Converter, 5127 QualType T, UnresolvedSetImpl &ViableConversions) { 5128 5129 if (Converter.Suppress) 5130 return ExprError(); 5131 5132 Converter.diagnoseAmbiguous(SemaRef, Loc, T) << From->getSourceRange(); 5133 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 5134 CXXConversionDecl *Conv = 5135 cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 5136 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 5137 Converter.noteAmbiguous(SemaRef, Conv, ConvTy); 5138 } 5139 return SemaRef.Owned(From); 5140} 5141 5142static bool 5143diagnoseNoViableConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From, 5144 Sema::ContextualImplicitConverter &Converter, 5145 QualType T, bool HadMultipleCandidates, 5146 UnresolvedSetImpl &ExplicitConversions) { 5147 if (ExplicitConversions.size() == 1 && !Converter.Suppress) { 5148 DeclAccessPair Found = ExplicitConversions[0]; 5149 CXXConversionDecl *Conversion = 5150 cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 5151 5152 // The user probably meant to invoke the given explicit 5153 // conversion; use it. 5154 QualType ConvTy = Conversion->getConversionType().getNonReferenceType(); 5155 std::string TypeStr; 5156 ConvTy.getAsStringInternal(TypeStr, SemaRef.getPrintingPolicy()); 5157 5158 Converter.diagnoseExplicitConv(SemaRef, Loc, T, ConvTy) 5159 << FixItHint::CreateInsertion(From->getLocStart(), 5160 "static_cast<" + TypeStr + ">(") 5161 << FixItHint::CreateInsertion( 5162 SemaRef.PP.getLocForEndOfToken(From->getLocEnd()), ")"); 5163 Converter.noteExplicitConv(SemaRef, Conversion, ConvTy); 5164 5165 // If we aren't in a SFINAE context, build a call to the 5166 // explicit conversion function. 5167 if (SemaRef.isSFINAEContext()) 5168 return true; 5169 5170 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 5171 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion, 5172 HadMultipleCandidates); 5173 if (Result.isInvalid()) 5174 return true; 5175 // Record usage of conversion in an implicit cast. 5176 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(), 5177 CK_UserDefinedConversion, Result.get(), 0, 5178 Result.get()->getValueKind()); 5179 } 5180 return false; 5181} 5182 5183static bool recordConversion(Sema &SemaRef, SourceLocation Loc, Expr *&From, 5184 Sema::ContextualImplicitConverter &Converter, 5185 QualType T, bool HadMultipleCandidates, 5186 DeclAccessPair &Found) { 5187 CXXConversionDecl *Conversion = 5188 cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 5189 SemaRef.CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 5190 5191 QualType ToType = Conversion->getConversionType().getNonReferenceType(); 5192 if (!Converter.SuppressConversion) { 5193 if (SemaRef.isSFINAEContext()) 5194 return true; 5195 5196 Converter.diagnoseConversion(SemaRef, Loc, T, ToType) 5197 << From->getSourceRange(); 5198 } 5199 5200 ExprResult Result = SemaRef.BuildCXXMemberCallExpr(From, Found, Conversion, 5201 HadMultipleCandidates); 5202 if (Result.isInvalid()) 5203 return true; 5204 // Record usage of conversion in an implicit cast. 5205 From = ImplicitCastExpr::Create(SemaRef.Context, Result.get()->getType(), 5206 CK_UserDefinedConversion, Result.get(), 0, 5207 Result.get()->getValueKind()); 5208 return false; 5209} 5210 5211static ExprResult finishContextualImplicitConversion( 5212 Sema &SemaRef, SourceLocation Loc, Expr *From, 5213 Sema::ContextualImplicitConverter &Converter) { 5214 if (!Converter.match(From->getType()) && !Converter.Suppress) 5215 Converter.diagnoseNoMatch(SemaRef, Loc, From->getType()) 5216 << From->getSourceRange(); 5217 5218 return SemaRef.DefaultLvalueConversion(From); 5219} 5220 5221static void 5222collectViableConversionCandidates(Sema &SemaRef, Expr *From, QualType ToType, 5223 UnresolvedSetImpl &ViableConversions, 5224 OverloadCandidateSet &CandidateSet) { 5225 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 5226 DeclAccessPair FoundDecl = ViableConversions[I]; 5227 NamedDecl *D = FoundDecl.getDecl(); 5228 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 5229 if (isa<UsingShadowDecl>(D)) 5230 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 5231 5232 CXXConversionDecl *Conv; 5233 FunctionTemplateDecl *ConvTemplate; 5234 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 5235 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 5236 else 5237 Conv = cast<CXXConversionDecl>(D); 5238 5239 if (ConvTemplate) 5240 SemaRef.AddTemplateConversionCandidate( 5241 ConvTemplate, FoundDecl, ActingContext, From, ToType, CandidateSet); 5242 else 5243 SemaRef.AddConversionCandidate(Conv, FoundDecl, ActingContext, From, 5244 ToType, CandidateSet); 5245 } 5246} 5247 5248/// \brief Attempt to convert the given expression to a type which is accepted 5249/// by the given converter. 5250/// 5251/// This routine will attempt to convert an expression of class type to a 5252/// type accepted by the specified converter. In C++11 and before, the class 5253/// must have a single non-explicit conversion function converting to a matching 5254/// type. In C++1y, there can be multiple such conversion functions, but only 5255/// one target type. 5256/// 5257/// \param Loc The source location of the construct that requires the 5258/// conversion. 5259/// 5260/// \param From The expression we're converting from. 5261/// 5262/// \param Converter Used to control and diagnose the conversion process. 5263/// 5264/// \returns The expression, converted to an integral or enumeration type if 5265/// successful. 5266ExprResult Sema::PerformContextualImplicitConversion( 5267 SourceLocation Loc, Expr *From, ContextualImplicitConverter &Converter) { 5268 // We can't perform any more checking for type-dependent expressions. 5269 if (From->isTypeDependent()) 5270 return Owned(From); 5271 5272 // Process placeholders immediately. 5273 if (From->hasPlaceholderType()) { 5274 ExprResult result = CheckPlaceholderExpr(From); 5275 if (result.isInvalid()) 5276 return result; 5277 From = result.take(); 5278 } 5279 5280 // If the expression already has a matching type, we're golden. 5281 QualType T = From->getType(); 5282 if (Converter.match(T)) 5283 return DefaultLvalueConversion(From); 5284 5285 // FIXME: Check for missing '()' if T is a function type? 5286 5287 // We can only perform contextual implicit conversions on objects of class 5288 // type. 5289 const RecordType *RecordTy = T->getAs<RecordType>(); 5290 if (!RecordTy || !getLangOpts().CPlusPlus) { 5291 if (!Converter.Suppress) 5292 Converter.diagnoseNoMatch(*this, Loc, T) << From->getSourceRange(); 5293 return Owned(From); 5294 } 5295 5296 // We must have a complete class type. 5297 struct TypeDiagnoserPartialDiag : TypeDiagnoser { 5298 ContextualImplicitConverter &Converter; 5299 Expr *From; 5300 5301 TypeDiagnoserPartialDiag(ContextualImplicitConverter &Converter, Expr *From) 5302 : TypeDiagnoser(Converter.Suppress), Converter(Converter), From(From) {} 5303 5304 virtual void diagnose(Sema &S, SourceLocation Loc, QualType T) { 5305 Converter.diagnoseIncomplete(S, Loc, T) << From->getSourceRange(); 5306 } 5307 } IncompleteDiagnoser(Converter, From); 5308 5309 if (RequireCompleteType(Loc, T, IncompleteDiagnoser)) 5310 return Owned(From); 5311 5312 // Look for a conversion to an integral or enumeration type. 5313 UnresolvedSet<4> 5314 ViableConversions; // These are *potentially* viable in C++1y. 5315 UnresolvedSet<4> ExplicitConversions; 5316 std::pair<CXXRecordDecl::conversion_iterator, 5317 CXXRecordDecl::conversion_iterator> Conversions = 5318 cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 5319 5320 bool HadMultipleCandidates = 5321 (std::distance(Conversions.first, Conversions.second) > 1); 5322 5323 // To check that there is only one target type, in C++1y: 5324 QualType ToType; 5325 bool HasUniqueTargetType = true; 5326 5327 // Collect explicit or viable (potentially in C++1y) conversions. 5328 for (CXXRecordDecl::conversion_iterator I = Conversions.first, 5329 E = Conversions.second; 5330 I != E; ++I) { 5331 NamedDecl *D = (*I)->getUnderlyingDecl(); 5332 CXXConversionDecl *Conversion; 5333 FunctionTemplateDecl *ConvTemplate = dyn_cast<FunctionTemplateDecl>(D); 5334 if (ConvTemplate) { 5335 if (getLangOpts().CPlusPlus1y) 5336 Conversion = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 5337 else 5338 continue; // C++11 does not consider conversion operator templates(?). 5339 } else 5340 Conversion = cast<CXXConversionDecl>(D); 5341 5342 assert((!ConvTemplate || getLangOpts().CPlusPlus1y) && 5343 "Conversion operator templates are considered potentially " 5344 "viable in C++1y"); 5345 5346 QualType CurToType = Conversion->getConversionType().getNonReferenceType(); 5347 if (Converter.match(CurToType) || ConvTemplate) { 5348 5349 if (Conversion->isExplicit()) { 5350 // FIXME: For C++1y, do we need this restriction? 5351 // cf. diagnoseNoViableConversion() 5352 if (!ConvTemplate) 5353 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 5354 } else { 5355 if (!ConvTemplate && getLangOpts().CPlusPlus1y) { 5356 if (ToType.isNull()) 5357 ToType = CurToType.getUnqualifiedType(); 5358 else if (HasUniqueTargetType && 5359 (CurToType.getUnqualifiedType() != ToType)) 5360 HasUniqueTargetType = false; 5361 } 5362 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 5363 } 5364 } 5365 } 5366 5367 if (getLangOpts().CPlusPlus1y) { 5368 // C++1y [conv]p6: 5369 // ... An expression e of class type E appearing in such a context 5370 // is said to be contextually implicitly converted to a specified 5371 // type T and is well-formed if and only if e can be implicitly 5372 // converted to a type T that is determined as follows: E is searched 5373 // for conversion functions whose return type is cv T or reference to 5374 // cv T such that T is allowed by the context. There shall be 5375 // exactly one such T. 5376 5377 // If no unique T is found: 5378 if (ToType.isNull()) { 5379 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T, 5380 HadMultipleCandidates, 5381 ExplicitConversions)) 5382 return ExprError(); 5383 return finishContextualImplicitConversion(*this, Loc, From, Converter); 5384 } 5385 5386 // If more than one unique Ts are found: 5387 if (!HasUniqueTargetType) 5388 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T, 5389 ViableConversions); 5390 5391 // If one unique T is found: 5392 // First, build a candidate set from the previously recorded 5393 // potentially viable conversions. 5394 OverloadCandidateSet CandidateSet(Loc); 5395 collectViableConversionCandidates(*this, From, ToType, ViableConversions, 5396 CandidateSet); 5397 5398 // Then, perform overload resolution over the candidate set. 5399 OverloadCandidateSet::iterator Best; 5400 switch (CandidateSet.BestViableFunction(*this, Loc, Best)) { 5401 case OR_Success: { 5402 // Apply this conversion. 5403 DeclAccessPair Found = 5404 DeclAccessPair::make(Best->Function, Best->FoundDecl.getAccess()); 5405 if (recordConversion(*this, Loc, From, Converter, T, 5406 HadMultipleCandidates, Found)) 5407 return ExprError(); 5408 break; 5409 } 5410 case OR_Ambiguous: 5411 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T, 5412 ViableConversions); 5413 case OR_No_Viable_Function: 5414 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T, 5415 HadMultipleCandidates, 5416 ExplicitConversions)) 5417 return ExprError(); 5418 // fall through 'OR_Deleted' case. 5419 case OR_Deleted: 5420 // We'll complain below about a non-integral condition type. 5421 break; 5422 } 5423 } else { 5424 switch (ViableConversions.size()) { 5425 case 0: { 5426 if (diagnoseNoViableConversion(*this, Loc, From, Converter, T, 5427 HadMultipleCandidates, 5428 ExplicitConversions)) 5429 return ExprError(); 5430 5431 // We'll complain below about a non-integral condition type. 5432 break; 5433 } 5434 case 1: { 5435 // Apply this conversion. 5436 DeclAccessPair Found = ViableConversions[0]; 5437 if (recordConversion(*this, Loc, From, Converter, T, 5438 HadMultipleCandidates, Found)) 5439 return ExprError(); 5440 break; 5441 } 5442 default: 5443 return diagnoseAmbiguousConversion(*this, Loc, From, Converter, T, 5444 ViableConversions); 5445 } 5446 } 5447 5448 return finishContextualImplicitConversion(*this, Loc, From, Converter); 5449} 5450 5451/// AddOverloadCandidate - Adds the given function to the set of 5452/// candidate functions, using the given function call arguments. If 5453/// @p SuppressUserConversions, then don't allow user-defined 5454/// conversions via constructors or conversion operators. 5455/// 5456/// \param PartialOverloading true if we are performing "partial" overloading 5457/// based on an incomplete set of function arguments. This feature is used by 5458/// code completion. 5459void 5460Sema::AddOverloadCandidate(FunctionDecl *Function, 5461 DeclAccessPair FoundDecl, 5462 ArrayRef<Expr *> Args, 5463 OverloadCandidateSet& CandidateSet, 5464 bool SuppressUserConversions, 5465 bool PartialOverloading, 5466 bool AllowExplicit) { 5467 const FunctionProtoType* Proto 5468 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 5469 assert(Proto && "Functions without a prototype cannot be overloaded"); 5470 assert(!Function->getDescribedFunctionTemplate() && 5471 "Use AddTemplateOverloadCandidate for function templates"); 5472 5473 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 5474 if (!isa<CXXConstructorDecl>(Method)) { 5475 // If we get here, it's because we're calling a member function 5476 // that is named without a member access expression (e.g., 5477 // "this->f") that was either written explicitly or created 5478 // implicitly. This can happen with a qualified call to a member 5479 // function, e.g., X::f(). We use an empty type for the implied 5480 // object argument (C++ [over.call.func]p3), and the acting context 5481 // is irrelevant. 5482 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 5483 QualType(), Expr::Classification::makeSimpleLValue(), 5484 Args, CandidateSet, SuppressUserConversions); 5485 return; 5486 } 5487 // We treat a constructor like a non-member function, since its object 5488 // argument doesn't participate in overload resolution. 5489 } 5490 5491 if (!CandidateSet.isNewCandidate(Function)) 5492 return; 5493 5494 // Overload resolution is always an unevaluated context. 5495 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5496 5497 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 5498 // C++ [class.copy]p3: 5499 // A member function template is never instantiated to perform the copy 5500 // of a class object to an object of its class type. 5501 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 5502 if (Args.size() == 1 && 5503 Constructor->isSpecializationCopyingObject() && 5504 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 5505 IsDerivedFrom(Args[0]->getType(), ClassType))) 5506 return; 5507 } 5508 5509 // Add this candidate 5510 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size()); 5511 Candidate.FoundDecl = FoundDecl; 5512 Candidate.Function = Function; 5513 Candidate.Viable = true; 5514 Candidate.IsSurrogate = false; 5515 Candidate.IgnoreObjectArgument = false; 5516 Candidate.ExplicitCallArguments = Args.size(); 5517 5518 unsigned NumArgsInProto = Proto->getNumArgs(); 5519 5520 // (C++ 13.3.2p2): A candidate function having fewer than m 5521 // parameters is viable only if it has an ellipsis in its parameter 5522 // list (8.3.5). 5523 if ((Args.size() + (PartialOverloading && Args.size())) > NumArgsInProto && 5524 !Proto->isVariadic()) { 5525 Candidate.Viable = false; 5526 Candidate.FailureKind = ovl_fail_too_many_arguments; 5527 return; 5528 } 5529 5530 // (C++ 13.3.2p2): A candidate function having more than m parameters 5531 // is viable only if the (m+1)st parameter has a default argument 5532 // (8.3.6). For the purposes of overload resolution, the 5533 // parameter list is truncated on the right, so that there are 5534 // exactly m parameters. 5535 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 5536 if (Args.size() < MinRequiredArgs && !PartialOverloading) { 5537 // Not enough arguments. 5538 Candidate.Viable = false; 5539 Candidate.FailureKind = ovl_fail_too_few_arguments; 5540 return; 5541 } 5542 5543 // (CUDA B.1): Check for invalid calls between targets. 5544 if (getLangOpts().CUDA) 5545 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext)) 5546 if (CheckCUDATarget(Caller, Function)) { 5547 Candidate.Viable = false; 5548 Candidate.FailureKind = ovl_fail_bad_target; 5549 return; 5550 } 5551 5552 // Determine the implicit conversion sequences for each of the 5553 // arguments. 5554 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5555 if (ArgIdx < NumArgsInProto) { 5556 // (C++ 13.3.2p3): for F to be a viable function, there shall 5557 // exist for each argument an implicit conversion sequence 5558 // (13.3.3.1) that converts that argument to the corresponding 5559 // parameter of F. 5560 QualType ParamType = Proto->getArgType(ArgIdx); 5561 Candidate.Conversions[ArgIdx] 5562 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5563 SuppressUserConversions, 5564 /*InOverloadResolution=*/true, 5565 /*AllowObjCWritebackConversion=*/ 5566 getLangOpts().ObjCAutoRefCount, 5567 AllowExplicit); 5568 if (Candidate.Conversions[ArgIdx].isBad()) { 5569 Candidate.Viable = false; 5570 Candidate.FailureKind = ovl_fail_bad_conversion; 5571 break; 5572 } 5573 } else { 5574 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5575 // argument for which there is no corresponding parameter is 5576 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5577 Candidate.Conversions[ArgIdx].setEllipsis(); 5578 } 5579 } 5580} 5581 5582/// \brief Add all of the function declarations in the given function set to 5583/// the overload canddiate set. 5584void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 5585 ArrayRef<Expr *> Args, 5586 OverloadCandidateSet& CandidateSet, 5587 bool SuppressUserConversions, 5588 TemplateArgumentListInfo *ExplicitTemplateArgs) { 5589 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 5590 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 5591 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 5592 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 5593 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 5594 cast<CXXMethodDecl>(FD)->getParent(), 5595 Args[0]->getType(), Args[0]->Classify(Context), 5596 Args.slice(1), CandidateSet, 5597 SuppressUserConversions); 5598 else 5599 AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet, 5600 SuppressUserConversions); 5601 } else { 5602 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 5603 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 5604 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 5605 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 5606 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 5607 ExplicitTemplateArgs, 5608 Args[0]->getType(), 5609 Args[0]->Classify(Context), Args.slice(1), 5610 CandidateSet, SuppressUserConversions); 5611 else 5612 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 5613 ExplicitTemplateArgs, Args, 5614 CandidateSet, SuppressUserConversions); 5615 } 5616 } 5617} 5618 5619/// AddMethodCandidate - Adds a named decl (which is some kind of 5620/// method) as a method candidate to the given overload set. 5621void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 5622 QualType ObjectType, 5623 Expr::Classification ObjectClassification, 5624 ArrayRef<Expr *> Args, 5625 OverloadCandidateSet& CandidateSet, 5626 bool SuppressUserConversions) { 5627 NamedDecl *Decl = FoundDecl.getDecl(); 5628 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 5629 5630 if (isa<UsingShadowDecl>(Decl)) 5631 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 5632 5633 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 5634 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 5635 "Expected a member function template"); 5636 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 5637 /*ExplicitArgs*/ 0, 5638 ObjectType, ObjectClassification, 5639 Args, CandidateSet, 5640 SuppressUserConversions); 5641 } else { 5642 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 5643 ObjectType, ObjectClassification, 5644 Args, 5645 CandidateSet, SuppressUserConversions); 5646 } 5647} 5648 5649/// AddMethodCandidate - Adds the given C++ member function to the set 5650/// of candidate functions, using the given function call arguments 5651/// and the object argument (@c Object). For example, in a call 5652/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 5653/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 5654/// allow user-defined conversions via constructors or conversion 5655/// operators. 5656void 5657Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 5658 CXXRecordDecl *ActingContext, QualType ObjectType, 5659 Expr::Classification ObjectClassification, 5660 ArrayRef<Expr *> Args, 5661 OverloadCandidateSet& CandidateSet, 5662 bool SuppressUserConversions) { 5663 const FunctionProtoType* Proto 5664 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 5665 assert(Proto && "Methods without a prototype cannot be overloaded"); 5666 assert(!isa<CXXConstructorDecl>(Method) && 5667 "Use AddOverloadCandidate for constructors"); 5668 5669 if (!CandidateSet.isNewCandidate(Method)) 5670 return; 5671 5672 // Overload resolution is always an unevaluated context. 5673 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5674 5675 // Add this candidate 5676 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); 5677 Candidate.FoundDecl = FoundDecl; 5678 Candidate.Function = Method; 5679 Candidate.IsSurrogate = false; 5680 Candidate.IgnoreObjectArgument = false; 5681 Candidate.ExplicitCallArguments = Args.size(); 5682 5683 unsigned NumArgsInProto = Proto->getNumArgs(); 5684 5685 // (C++ 13.3.2p2): A candidate function having fewer than m 5686 // parameters is viable only if it has an ellipsis in its parameter 5687 // list (8.3.5). 5688 if (Args.size() > NumArgsInProto && !Proto->isVariadic()) { 5689 Candidate.Viable = false; 5690 Candidate.FailureKind = ovl_fail_too_many_arguments; 5691 return; 5692 } 5693 5694 // (C++ 13.3.2p2): A candidate function having more than m parameters 5695 // is viable only if the (m+1)st parameter has a default argument 5696 // (8.3.6). For the purposes of overload resolution, the 5697 // parameter list is truncated on the right, so that there are 5698 // exactly m parameters. 5699 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 5700 if (Args.size() < MinRequiredArgs) { 5701 // Not enough arguments. 5702 Candidate.Viable = false; 5703 Candidate.FailureKind = ovl_fail_too_few_arguments; 5704 return; 5705 } 5706 5707 Candidate.Viable = true; 5708 5709 if (Method->isStatic() || ObjectType.isNull()) 5710 // The implicit object argument is ignored. 5711 Candidate.IgnoreObjectArgument = true; 5712 else { 5713 // Determine the implicit conversion sequence for the object 5714 // parameter. 5715 Candidate.Conversions[0] 5716 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 5717 Method, ActingContext); 5718 if (Candidate.Conversions[0].isBad()) { 5719 Candidate.Viable = false; 5720 Candidate.FailureKind = ovl_fail_bad_conversion; 5721 return; 5722 } 5723 } 5724 5725 // Determine the implicit conversion sequences for each of the 5726 // arguments. 5727 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5728 if (ArgIdx < NumArgsInProto) { 5729 // (C++ 13.3.2p3): for F to be a viable function, there shall 5730 // exist for each argument an implicit conversion sequence 5731 // (13.3.3.1) that converts that argument to the corresponding 5732 // parameter of F. 5733 QualType ParamType = Proto->getArgType(ArgIdx); 5734 Candidate.Conversions[ArgIdx + 1] 5735 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5736 SuppressUserConversions, 5737 /*InOverloadResolution=*/true, 5738 /*AllowObjCWritebackConversion=*/ 5739 getLangOpts().ObjCAutoRefCount); 5740 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 5741 Candidate.Viable = false; 5742 Candidate.FailureKind = ovl_fail_bad_conversion; 5743 break; 5744 } 5745 } else { 5746 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5747 // argument for which there is no corresponding parameter is 5748 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5749 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 5750 } 5751 } 5752} 5753 5754/// \brief Add a C++ member function template as a candidate to the candidate 5755/// set, using template argument deduction to produce an appropriate member 5756/// function template specialization. 5757void 5758Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 5759 DeclAccessPair FoundDecl, 5760 CXXRecordDecl *ActingContext, 5761 TemplateArgumentListInfo *ExplicitTemplateArgs, 5762 QualType ObjectType, 5763 Expr::Classification ObjectClassification, 5764 ArrayRef<Expr *> Args, 5765 OverloadCandidateSet& CandidateSet, 5766 bool SuppressUserConversions) { 5767 if (!CandidateSet.isNewCandidate(MethodTmpl)) 5768 return; 5769 5770 // C++ [over.match.funcs]p7: 5771 // In each case where a candidate is a function template, candidate 5772 // function template specializations are generated using template argument 5773 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 5774 // candidate functions in the usual way.113) A given name can refer to one 5775 // or more function templates and also to a set of overloaded non-template 5776 // functions. In such a case, the candidate functions generated from each 5777 // function template are combined with the set of non-template candidate 5778 // functions. 5779 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5780 FunctionDecl *Specialization = 0; 5781 if (TemplateDeductionResult Result 5782 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, Args, 5783 Specialization, Info)) { 5784 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5785 Candidate.FoundDecl = FoundDecl; 5786 Candidate.Function = MethodTmpl->getTemplatedDecl(); 5787 Candidate.Viable = false; 5788 Candidate.FailureKind = ovl_fail_bad_deduction; 5789 Candidate.IsSurrogate = false; 5790 Candidate.IgnoreObjectArgument = false; 5791 Candidate.ExplicitCallArguments = Args.size(); 5792 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5793 Info); 5794 return; 5795 } 5796 5797 // Add the function template specialization produced by template argument 5798 // deduction as a candidate. 5799 assert(Specialization && "Missing member function template specialization?"); 5800 assert(isa<CXXMethodDecl>(Specialization) && 5801 "Specialization is not a member function?"); 5802 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 5803 ActingContext, ObjectType, ObjectClassification, Args, 5804 CandidateSet, SuppressUserConversions); 5805} 5806 5807/// \brief Add a C++ function template specialization as a candidate 5808/// in the candidate set, using template argument deduction to produce 5809/// an appropriate function template specialization. 5810void 5811Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 5812 DeclAccessPair FoundDecl, 5813 TemplateArgumentListInfo *ExplicitTemplateArgs, 5814 ArrayRef<Expr *> Args, 5815 OverloadCandidateSet& CandidateSet, 5816 bool SuppressUserConversions) { 5817 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 5818 return; 5819 5820 // C++ [over.match.funcs]p7: 5821 // In each case where a candidate is a function template, candidate 5822 // function template specializations are generated using template argument 5823 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 5824 // candidate functions in the usual way.113) A given name can refer to one 5825 // or more function templates and also to a set of overloaded non-template 5826 // functions. In such a case, the candidate functions generated from each 5827 // function template are combined with the set of non-template candidate 5828 // functions. 5829 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5830 FunctionDecl *Specialization = 0; 5831 if (TemplateDeductionResult Result 5832 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, Args, 5833 Specialization, Info)) { 5834 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5835 Candidate.FoundDecl = FoundDecl; 5836 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 5837 Candidate.Viable = false; 5838 Candidate.FailureKind = ovl_fail_bad_deduction; 5839 Candidate.IsSurrogate = false; 5840 Candidate.IgnoreObjectArgument = false; 5841 Candidate.ExplicitCallArguments = Args.size(); 5842 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5843 Info); 5844 return; 5845 } 5846 5847 // Add the function template specialization produced by template argument 5848 // deduction as a candidate. 5849 assert(Specialization && "Missing function template specialization?"); 5850 AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet, 5851 SuppressUserConversions); 5852} 5853 5854/// AddConversionCandidate - Add a C++ conversion function as a 5855/// candidate in the candidate set (C++ [over.match.conv], 5856/// C++ [over.match.copy]). From is the expression we're converting from, 5857/// and ToType is the type that we're eventually trying to convert to 5858/// (which may or may not be the same type as the type that the 5859/// conversion function produces). 5860void 5861Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 5862 DeclAccessPair FoundDecl, 5863 CXXRecordDecl *ActingContext, 5864 Expr *From, QualType ToType, 5865 OverloadCandidateSet& CandidateSet) { 5866 assert(!Conversion->getDescribedFunctionTemplate() && 5867 "Conversion function templates use AddTemplateConversionCandidate"); 5868 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 5869 if (!CandidateSet.isNewCandidate(Conversion)) 5870 return; 5871 5872 // If the conversion function has an undeduced return type, trigger its 5873 // deduction now. 5874 if (getLangOpts().CPlusPlus1y && ConvType->isUndeducedType()) { 5875 if (DeduceReturnType(Conversion, From->getExprLoc())) 5876 return; 5877 ConvType = Conversion->getConversionType().getNonReferenceType(); 5878 } 5879 5880 // Overload resolution is always an unevaluated context. 5881 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5882 5883 // Add this candidate 5884 OverloadCandidate &Candidate = CandidateSet.addCandidate(1); 5885 Candidate.FoundDecl = FoundDecl; 5886 Candidate.Function = Conversion; 5887 Candidate.IsSurrogate = false; 5888 Candidate.IgnoreObjectArgument = false; 5889 Candidate.FinalConversion.setAsIdentityConversion(); 5890 Candidate.FinalConversion.setFromType(ConvType); 5891 Candidate.FinalConversion.setAllToTypes(ToType); 5892 Candidate.Viable = true; 5893 Candidate.ExplicitCallArguments = 1; 5894 5895 // C++ [over.match.funcs]p4: 5896 // For conversion functions, the function is considered to be a member of 5897 // the class of the implicit implied object argument for the purpose of 5898 // defining the type of the implicit object parameter. 5899 // 5900 // Determine the implicit conversion sequence for the implicit 5901 // object parameter. 5902 QualType ImplicitParamType = From->getType(); 5903 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 5904 ImplicitParamType = FromPtrType->getPointeeType(); 5905 CXXRecordDecl *ConversionContext 5906 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 5907 5908 Candidate.Conversions[0] 5909 = TryObjectArgumentInitialization(*this, From->getType(), 5910 From->Classify(Context), 5911 Conversion, ConversionContext); 5912 5913 if (Candidate.Conversions[0].isBad()) { 5914 Candidate.Viable = false; 5915 Candidate.FailureKind = ovl_fail_bad_conversion; 5916 return; 5917 } 5918 5919 // We won't go through a user-define type conversion function to convert a 5920 // derived to base as such conversions are given Conversion Rank. They only 5921 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 5922 QualType FromCanon 5923 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 5924 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 5925 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 5926 Candidate.Viable = false; 5927 Candidate.FailureKind = ovl_fail_trivial_conversion; 5928 return; 5929 } 5930 5931 // To determine what the conversion from the result of calling the 5932 // conversion function to the type we're eventually trying to 5933 // convert to (ToType), we need to synthesize a call to the 5934 // conversion function and attempt copy initialization from it. This 5935 // makes sure that we get the right semantics with respect to 5936 // lvalues/rvalues and the type. Fortunately, we can allocate this 5937 // call on the stack and we don't need its arguments to be 5938 // well-formed. 5939 DeclRefExpr ConversionRef(Conversion, false, Conversion->getType(), 5940 VK_LValue, From->getLocStart()); 5941 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 5942 Context.getPointerType(Conversion->getType()), 5943 CK_FunctionToPointerDecay, 5944 &ConversionRef, VK_RValue); 5945 5946 QualType ConversionType = Conversion->getConversionType(); 5947 if (RequireCompleteType(From->getLocStart(), ConversionType, 0)) { 5948 Candidate.Viable = false; 5949 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5950 return; 5951 } 5952 5953 ExprValueKind VK = Expr::getValueKindForType(ConversionType); 5954 5955 // Note that it is safe to allocate CallExpr on the stack here because 5956 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 5957 // allocator). 5958 QualType CallResultType = ConversionType.getNonLValueExprType(Context); 5959 CallExpr Call(Context, &ConversionFn, None, CallResultType, VK, 5960 From->getLocStart()); 5961 ImplicitConversionSequence ICS = 5962 TryCopyInitialization(*this, &Call, ToType, 5963 /*SuppressUserConversions=*/true, 5964 /*InOverloadResolution=*/false, 5965 /*AllowObjCWritebackConversion=*/false); 5966 5967 switch (ICS.getKind()) { 5968 case ImplicitConversionSequence::StandardConversion: 5969 Candidate.FinalConversion = ICS.Standard; 5970 5971 // C++ [over.ics.user]p3: 5972 // If the user-defined conversion is specified by a specialization of a 5973 // conversion function template, the second standard conversion sequence 5974 // shall have exact match rank. 5975 if (Conversion->getPrimaryTemplate() && 5976 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 5977 Candidate.Viable = false; 5978 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 5979 } 5980 5981 // C++0x [dcl.init.ref]p5: 5982 // In the second case, if the reference is an rvalue reference and 5983 // the second standard conversion sequence of the user-defined 5984 // conversion sequence includes an lvalue-to-rvalue conversion, the 5985 // program is ill-formed. 5986 if (ToType->isRValueReferenceType() && 5987 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 5988 Candidate.Viable = false; 5989 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5990 } 5991 break; 5992 5993 case ImplicitConversionSequence::BadConversion: 5994 Candidate.Viable = false; 5995 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5996 break; 5997 5998 default: 5999 llvm_unreachable( 6000 "Can only end up with a standard conversion sequence or failure"); 6001 } 6002} 6003 6004/// \brief Adds a conversion function template specialization 6005/// candidate to the overload set, using template argument deduction 6006/// to deduce the template arguments of the conversion function 6007/// template from the type that we are converting to (C++ 6008/// [temp.deduct.conv]). 6009void 6010Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 6011 DeclAccessPair FoundDecl, 6012 CXXRecordDecl *ActingDC, 6013 Expr *From, QualType ToType, 6014 OverloadCandidateSet &CandidateSet) { 6015 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 6016 "Only conversion function templates permitted here"); 6017 6018 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 6019 return; 6020 6021 TemplateDeductionInfo Info(CandidateSet.getLocation()); 6022 CXXConversionDecl *Specialization = 0; 6023 if (TemplateDeductionResult Result 6024 = DeduceTemplateArguments(FunctionTemplate, ToType, 6025 Specialization, Info)) { 6026 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 6027 Candidate.FoundDecl = FoundDecl; 6028 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 6029 Candidate.Viable = false; 6030 Candidate.FailureKind = ovl_fail_bad_deduction; 6031 Candidate.IsSurrogate = false; 6032 Candidate.IgnoreObjectArgument = false; 6033 Candidate.ExplicitCallArguments = 1; 6034 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 6035 Info); 6036 return; 6037 } 6038 6039 // Add the conversion function template specialization produced by 6040 // template argument deduction as a candidate. 6041 assert(Specialization && "Missing function template specialization?"); 6042 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 6043 CandidateSet); 6044} 6045 6046/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 6047/// converts the given @c Object to a function pointer via the 6048/// conversion function @c Conversion, and then attempts to call it 6049/// with the given arguments (C++ [over.call.object]p2-4). Proto is 6050/// the type of function that we'll eventually be calling. 6051void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 6052 DeclAccessPair FoundDecl, 6053 CXXRecordDecl *ActingContext, 6054 const FunctionProtoType *Proto, 6055 Expr *Object, 6056 ArrayRef<Expr *> Args, 6057 OverloadCandidateSet& CandidateSet) { 6058 if (!CandidateSet.isNewCandidate(Conversion)) 6059 return; 6060 6061 // Overload resolution is always an unevaluated context. 6062 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 6063 6064 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); 6065 Candidate.FoundDecl = FoundDecl; 6066 Candidate.Function = 0; 6067 Candidate.Surrogate = Conversion; 6068 Candidate.Viable = true; 6069 Candidate.IsSurrogate = true; 6070 Candidate.IgnoreObjectArgument = false; 6071 Candidate.ExplicitCallArguments = Args.size(); 6072 6073 // Determine the implicit conversion sequence for the implicit 6074 // object parameter. 6075 ImplicitConversionSequence ObjectInit 6076 = TryObjectArgumentInitialization(*this, Object->getType(), 6077 Object->Classify(Context), 6078 Conversion, ActingContext); 6079 if (ObjectInit.isBad()) { 6080 Candidate.Viable = false; 6081 Candidate.FailureKind = ovl_fail_bad_conversion; 6082 Candidate.Conversions[0] = ObjectInit; 6083 return; 6084 } 6085 6086 // The first conversion is actually a user-defined conversion whose 6087 // first conversion is ObjectInit's standard conversion (which is 6088 // effectively a reference binding). Record it as such. 6089 Candidate.Conversions[0].setUserDefined(); 6090 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 6091 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 6092 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false; 6093 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 6094 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl; 6095 Candidate.Conversions[0].UserDefined.After 6096 = Candidate.Conversions[0].UserDefined.Before; 6097 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 6098 6099 // Find the 6100 unsigned NumArgsInProto = Proto->getNumArgs(); 6101 6102 // (C++ 13.3.2p2): A candidate function having fewer than m 6103 // parameters is viable only if it has an ellipsis in its parameter 6104 // list (8.3.5). 6105 if (Args.size() > NumArgsInProto && !Proto->isVariadic()) { 6106 Candidate.Viable = false; 6107 Candidate.FailureKind = ovl_fail_too_many_arguments; 6108 return; 6109 } 6110 6111 // Function types don't have any default arguments, so just check if 6112 // we have enough arguments. 6113 if (Args.size() < NumArgsInProto) { 6114 // Not enough arguments. 6115 Candidate.Viable = false; 6116 Candidate.FailureKind = ovl_fail_too_few_arguments; 6117 return; 6118 } 6119 6120 // Determine the implicit conversion sequences for each of the 6121 // arguments. 6122 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 6123 if (ArgIdx < NumArgsInProto) { 6124 // (C++ 13.3.2p3): for F to be a viable function, there shall 6125 // exist for each argument an implicit conversion sequence 6126 // (13.3.3.1) that converts that argument to the corresponding 6127 // parameter of F. 6128 QualType ParamType = Proto->getArgType(ArgIdx); 6129 Candidate.Conversions[ArgIdx + 1] 6130 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 6131 /*SuppressUserConversions=*/false, 6132 /*InOverloadResolution=*/false, 6133 /*AllowObjCWritebackConversion=*/ 6134 getLangOpts().ObjCAutoRefCount); 6135 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 6136 Candidate.Viable = false; 6137 Candidate.FailureKind = ovl_fail_bad_conversion; 6138 break; 6139 } 6140 } else { 6141 // (C++ 13.3.2p2): For the purposes of overload resolution, any 6142 // argument for which there is no corresponding parameter is 6143 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 6144 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 6145 } 6146 } 6147} 6148 6149/// \brief Add overload candidates for overloaded operators that are 6150/// member functions. 6151/// 6152/// Add the overloaded operator candidates that are member functions 6153/// for the operator Op that was used in an operator expression such 6154/// as "x Op y". , Args/NumArgs provides the operator arguments, and 6155/// CandidateSet will store the added overload candidates. (C++ 6156/// [over.match.oper]). 6157void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 6158 SourceLocation OpLoc, 6159 ArrayRef<Expr *> Args, 6160 OverloadCandidateSet& CandidateSet, 6161 SourceRange OpRange) { 6162 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6163 6164 // C++ [over.match.oper]p3: 6165 // For a unary operator @ with an operand of a type whose 6166 // cv-unqualified version is T1, and for a binary operator @ with 6167 // a left operand of a type whose cv-unqualified version is T1 and 6168 // a right operand of a type whose cv-unqualified version is T2, 6169 // three sets of candidate functions, designated member 6170 // candidates, non-member candidates and built-in candidates, are 6171 // constructed as follows: 6172 QualType T1 = Args[0]->getType(); 6173 6174 // -- If T1 is a complete class type or a class currently being 6175 // defined, the set of member candidates is the result of the 6176 // qualified lookup of T1::operator@ (13.3.1.1.1); otherwise, 6177 // the set of member candidates is empty. 6178 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 6179 // Complete the type if it can be completed. 6180 RequireCompleteType(OpLoc, T1, 0); 6181 // If the type is neither complete nor being defined, bail out now. 6182 if (!T1Rec->getDecl()->getDefinition()) 6183 return; 6184 6185 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 6186 LookupQualifiedName(Operators, T1Rec->getDecl()); 6187 Operators.suppressDiagnostics(); 6188 6189 for (LookupResult::iterator Oper = Operators.begin(), 6190 OperEnd = Operators.end(); 6191 Oper != OperEnd; 6192 ++Oper) 6193 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 6194 Args[0]->Classify(Context), 6195 Args.slice(1), 6196 CandidateSet, 6197 /* SuppressUserConversions = */ false); 6198 } 6199} 6200 6201/// AddBuiltinCandidate - Add a candidate for a built-in 6202/// operator. ResultTy and ParamTys are the result and parameter types 6203/// of the built-in candidate, respectively. Args and NumArgs are the 6204/// arguments being passed to the candidate. IsAssignmentOperator 6205/// should be true when this built-in candidate is an assignment 6206/// operator. NumContextualBoolArguments is the number of arguments 6207/// (at the beginning of the argument list) that will be contextually 6208/// converted to bool. 6209void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 6210 ArrayRef<Expr *> Args, 6211 OverloadCandidateSet& CandidateSet, 6212 bool IsAssignmentOperator, 6213 unsigned NumContextualBoolArguments) { 6214 // Overload resolution is always an unevaluated context. 6215 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 6216 6217 // Add this candidate 6218 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size()); 6219 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 6220 Candidate.Function = 0; 6221 Candidate.IsSurrogate = false; 6222 Candidate.IgnoreObjectArgument = false; 6223 Candidate.BuiltinTypes.ResultTy = ResultTy; 6224 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) 6225 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 6226 6227 // Determine the implicit conversion sequences for each of the 6228 // arguments. 6229 Candidate.Viable = true; 6230 Candidate.ExplicitCallArguments = Args.size(); 6231 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 6232 // C++ [over.match.oper]p4: 6233 // For the built-in assignment operators, conversions of the 6234 // left operand are restricted as follows: 6235 // -- no temporaries are introduced to hold the left operand, and 6236 // -- no user-defined conversions are applied to the left 6237 // operand to achieve a type match with the left-most 6238 // parameter of a built-in candidate. 6239 // 6240 // We block these conversions by turning off user-defined 6241 // conversions, since that is the only way that initialization of 6242 // a reference to a non-class type can occur from something that 6243 // is not of the same type. 6244 if (ArgIdx < NumContextualBoolArguments) { 6245 assert(ParamTys[ArgIdx] == Context.BoolTy && 6246 "Contextual conversion to bool requires bool type"); 6247 Candidate.Conversions[ArgIdx] 6248 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 6249 } else { 6250 Candidate.Conversions[ArgIdx] 6251 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 6252 ArgIdx == 0 && IsAssignmentOperator, 6253 /*InOverloadResolution=*/false, 6254 /*AllowObjCWritebackConversion=*/ 6255 getLangOpts().ObjCAutoRefCount); 6256 } 6257 if (Candidate.Conversions[ArgIdx].isBad()) { 6258 Candidate.Viable = false; 6259 Candidate.FailureKind = ovl_fail_bad_conversion; 6260 break; 6261 } 6262 } 6263} 6264 6265/// BuiltinCandidateTypeSet - A set of types that will be used for the 6266/// candidate operator functions for built-in operators (C++ 6267/// [over.built]). The types are separated into pointer types and 6268/// enumeration types. 6269class BuiltinCandidateTypeSet { 6270 /// TypeSet - A set of types. 6271 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 6272 6273 /// PointerTypes - The set of pointer types that will be used in the 6274 /// built-in candidates. 6275 TypeSet PointerTypes; 6276 6277 /// MemberPointerTypes - The set of member pointer types that will be 6278 /// used in the built-in candidates. 6279 TypeSet MemberPointerTypes; 6280 6281 /// EnumerationTypes - The set of enumeration types that will be 6282 /// used in the built-in candidates. 6283 TypeSet EnumerationTypes; 6284 6285 /// \brief The set of vector types that will be used in the built-in 6286 /// candidates. 6287 TypeSet VectorTypes; 6288 6289 /// \brief A flag indicating non-record types are viable candidates 6290 bool HasNonRecordTypes; 6291 6292 /// \brief A flag indicating whether either arithmetic or enumeration types 6293 /// were present in the candidate set. 6294 bool HasArithmeticOrEnumeralTypes; 6295 6296 /// \brief A flag indicating whether the nullptr type was present in the 6297 /// candidate set. 6298 bool HasNullPtrType; 6299 6300 /// Sema - The semantic analysis instance where we are building the 6301 /// candidate type set. 6302 Sema &SemaRef; 6303 6304 /// Context - The AST context in which we will build the type sets. 6305 ASTContext &Context; 6306 6307 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 6308 const Qualifiers &VisibleQuals); 6309 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 6310 6311public: 6312 /// iterator - Iterates through the types that are part of the set. 6313 typedef TypeSet::iterator iterator; 6314 6315 BuiltinCandidateTypeSet(Sema &SemaRef) 6316 : HasNonRecordTypes(false), 6317 HasArithmeticOrEnumeralTypes(false), 6318 HasNullPtrType(false), 6319 SemaRef(SemaRef), 6320 Context(SemaRef.Context) { } 6321 6322 void AddTypesConvertedFrom(QualType Ty, 6323 SourceLocation Loc, 6324 bool AllowUserConversions, 6325 bool AllowExplicitConversions, 6326 const Qualifiers &VisibleTypeConversionsQuals); 6327 6328 /// pointer_begin - First pointer type found; 6329 iterator pointer_begin() { return PointerTypes.begin(); } 6330 6331 /// pointer_end - Past the last pointer type found; 6332 iterator pointer_end() { return PointerTypes.end(); } 6333 6334 /// member_pointer_begin - First member pointer type found; 6335 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 6336 6337 /// member_pointer_end - Past the last member pointer type found; 6338 iterator member_pointer_end() { return MemberPointerTypes.end(); } 6339 6340 /// enumeration_begin - First enumeration type found; 6341 iterator enumeration_begin() { return EnumerationTypes.begin(); } 6342 6343 /// enumeration_end - Past the last enumeration type found; 6344 iterator enumeration_end() { return EnumerationTypes.end(); } 6345 6346 iterator vector_begin() { return VectorTypes.begin(); } 6347 iterator vector_end() { return VectorTypes.end(); } 6348 6349 bool hasNonRecordTypes() { return HasNonRecordTypes; } 6350 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 6351 bool hasNullPtrType() const { return HasNullPtrType; } 6352}; 6353 6354/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 6355/// the set of pointer types along with any more-qualified variants of 6356/// that type. For example, if @p Ty is "int const *", this routine 6357/// will add "int const *", "int const volatile *", "int const 6358/// restrict *", and "int const volatile restrict *" to the set of 6359/// pointer types. Returns true if the add of @p Ty itself succeeded, 6360/// false otherwise. 6361/// 6362/// FIXME: what to do about extended qualifiers? 6363bool 6364BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 6365 const Qualifiers &VisibleQuals) { 6366 6367 // Insert this type. 6368 if (!PointerTypes.insert(Ty)) 6369 return false; 6370 6371 QualType PointeeTy; 6372 const PointerType *PointerTy = Ty->getAs<PointerType>(); 6373 bool buildObjCPtr = false; 6374 if (!PointerTy) { 6375 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>(); 6376 PointeeTy = PTy->getPointeeType(); 6377 buildObjCPtr = true; 6378 } else { 6379 PointeeTy = PointerTy->getPointeeType(); 6380 } 6381 6382 // Don't add qualified variants of arrays. For one, they're not allowed 6383 // (the qualifier would sink to the element type), and for another, the 6384 // only overload situation where it matters is subscript or pointer +- int, 6385 // and those shouldn't have qualifier variants anyway. 6386 if (PointeeTy->isArrayType()) 6387 return true; 6388 6389 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 6390 bool hasVolatile = VisibleQuals.hasVolatile(); 6391 bool hasRestrict = VisibleQuals.hasRestrict(); 6392 6393 // Iterate through all strict supersets of BaseCVR. 6394 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 6395 if ((CVR | BaseCVR) != CVR) continue; 6396 // Skip over volatile if no volatile found anywhere in the types. 6397 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 6398 6399 // Skip over restrict if no restrict found anywhere in the types, or if 6400 // the type cannot be restrict-qualified. 6401 if ((CVR & Qualifiers::Restrict) && 6402 (!hasRestrict || 6403 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType())))) 6404 continue; 6405 6406 // Build qualified pointee type. 6407 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 6408 6409 // Build qualified pointer type. 6410 QualType QPointerTy; 6411 if (!buildObjCPtr) 6412 QPointerTy = Context.getPointerType(QPointeeTy); 6413 else 6414 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy); 6415 6416 // Insert qualified pointer type. 6417 PointerTypes.insert(QPointerTy); 6418 } 6419 6420 return true; 6421} 6422 6423/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 6424/// to the set of pointer types along with any more-qualified variants of 6425/// that type. For example, if @p Ty is "int const *", this routine 6426/// will add "int const *", "int const volatile *", "int const 6427/// restrict *", and "int const volatile restrict *" to the set of 6428/// pointer types. Returns true if the add of @p Ty itself succeeded, 6429/// false otherwise. 6430/// 6431/// FIXME: what to do about extended qualifiers? 6432bool 6433BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 6434 QualType Ty) { 6435 // Insert this type. 6436 if (!MemberPointerTypes.insert(Ty)) 6437 return false; 6438 6439 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 6440 assert(PointerTy && "type was not a member pointer type!"); 6441 6442 QualType PointeeTy = PointerTy->getPointeeType(); 6443 // Don't add qualified variants of arrays. For one, they're not allowed 6444 // (the qualifier would sink to the element type), and for another, the 6445 // only overload situation where it matters is subscript or pointer +- int, 6446 // and those shouldn't have qualifier variants anyway. 6447 if (PointeeTy->isArrayType()) 6448 return true; 6449 const Type *ClassTy = PointerTy->getClass(); 6450 6451 // Iterate through all strict supersets of the pointee type's CVR 6452 // qualifiers. 6453 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 6454 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 6455 if ((CVR | BaseCVR) != CVR) continue; 6456 6457 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 6458 MemberPointerTypes.insert( 6459 Context.getMemberPointerType(QPointeeTy, ClassTy)); 6460 } 6461 6462 return true; 6463} 6464 6465/// AddTypesConvertedFrom - Add each of the types to which the type @p 6466/// Ty can be implicit converted to the given set of @p Types. We're 6467/// primarily interested in pointer types and enumeration types. We also 6468/// take member pointer types, for the conditional operator. 6469/// AllowUserConversions is true if we should look at the conversion 6470/// functions of a class type, and AllowExplicitConversions if we 6471/// should also include the explicit conversion functions of a class 6472/// type. 6473void 6474BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 6475 SourceLocation Loc, 6476 bool AllowUserConversions, 6477 bool AllowExplicitConversions, 6478 const Qualifiers &VisibleQuals) { 6479 // Only deal with canonical types. 6480 Ty = Context.getCanonicalType(Ty); 6481 6482 // Look through reference types; they aren't part of the type of an 6483 // expression for the purposes of conversions. 6484 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 6485 Ty = RefTy->getPointeeType(); 6486 6487 // If we're dealing with an array type, decay to the pointer. 6488 if (Ty->isArrayType()) 6489 Ty = SemaRef.Context.getArrayDecayedType(Ty); 6490 6491 // Otherwise, we don't care about qualifiers on the type. 6492 Ty = Ty.getLocalUnqualifiedType(); 6493 6494 // Flag if we ever add a non-record type. 6495 const RecordType *TyRec = Ty->getAs<RecordType>(); 6496 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 6497 6498 // Flag if we encounter an arithmetic type. 6499 HasArithmeticOrEnumeralTypes = 6500 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 6501 6502 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 6503 PointerTypes.insert(Ty); 6504 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 6505 // Insert our type, and its more-qualified variants, into the set 6506 // of types. 6507 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 6508 return; 6509 } else if (Ty->isMemberPointerType()) { 6510 // Member pointers are far easier, since the pointee can't be converted. 6511 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 6512 return; 6513 } else if (Ty->isEnumeralType()) { 6514 HasArithmeticOrEnumeralTypes = true; 6515 EnumerationTypes.insert(Ty); 6516 } else if (Ty->isVectorType()) { 6517 // We treat vector types as arithmetic types in many contexts as an 6518 // extension. 6519 HasArithmeticOrEnumeralTypes = true; 6520 VectorTypes.insert(Ty); 6521 } else if (Ty->isNullPtrType()) { 6522 HasNullPtrType = true; 6523 } else if (AllowUserConversions && TyRec) { 6524 // No conversion functions in incomplete types. 6525 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 6526 return; 6527 6528 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 6529 std::pair<CXXRecordDecl::conversion_iterator, 6530 CXXRecordDecl::conversion_iterator> 6531 Conversions = ClassDecl->getVisibleConversionFunctions(); 6532 for (CXXRecordDecl::conversion_iterator 6533 I = Conversions.first, E = Conversions.second; I != E; ++I) { 6534 NamedDecl *D = I.getDecl(); 6535 if (isa<UsingShadowDecl>(D)) 6536 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6537 6538 // Skip conversion function templates; they don't tell us anything 6539 // about which builtin types we can convert to. 6540 if (isa<FunctionTemplateDecl>(D)) 6541 continue; 6542 6543 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6544 if (AllowExplicitConversions || !Conv->isExplicit()) { 6545 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 6546 VisibleQuals); 6547 } 6548 } 6549 } 6550} 6551 6552/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 6553/// the volatile- and non-volatile-qualified assignment operators for the 6554/// given type to the candidate set. 6555static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 6556 QualType T, 6557 ArrayRef<Expr *> Args, 6558 OverloadCandidateSet &CandidateSet) { 6559 QualType ParamTypes[2]; 6560 6561 // T& operator=(T&, T) 6562 ParamTypes[0] = S.Context.getLValueReferenceType(T); 6563 ParamTypes[1] = T; 6564 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 6565 /*IsAssignmentOperator=*/true); 6566 6567 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 6568 // volatile T& operator=(volatile T&, T) 6569 ParamTypes[0] 6570 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 6571 ParamTypes[1] = T; 6572 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 6573 /*IsAssignmentOperator=*/true); 6574 } 6575} 6576 6577/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 6578/// if any, found in visible type conversion functions found in ArgExpr's type. 6579static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 6580 Qualifiers VRQuals; 6581 const RecordType *TyRec; 6582 if (const MemberPointerType *RHSMPType = 6583 ArgExpr->getType()->getAs<MemberPointerType>()) 6584 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 6585 else 6586 TyRec = ArgExpr->getType()->getAs<RecordType>(); 6587 if (!TyRec) { 6588 // Just to be safe, assume the worst case. 6589 VRQuals.addVolatile(); 6590 VRQuals.addRestrict(); 6591 return VRQuals; 6592 } 6593 6594 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 6595 if (!ClassDecl->hasDefinition()) 6596 return VRQuals; 6597 6598 std::pair<CXXRecordDecl::conversion_iterator, 6599 CXXRecordDecl::conversion_iterator> 6600 Conversions = ClassDecl->getVisibleConversionFunctions(); 6601 6602 for (CXXRecordDecl::conversion_iterator 6603 I = Conversions.first, E = Conversions.second; I != E; ++I) { 6604 NamedDecl *D = I.getDecl(); 6605 if (isa<UsingShadowDecl>(D)) 6606 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6607 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 6608 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 6609 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 6610 CanTy = ResTypeRef->getPointeeType(); 6611 // Need to go down the pointer/mempointer chain and add qualifiers 6612 // as see them. 6613 bool done = false; 6614 while (!done) { 6615 if (CanTy.isRestrictQualified()) 6616 VRQuals.addRestrict(); 6617 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 6618 CanTy = ResTypePtr->getPointeeType(); 6619 else if (const MemberPointerType *ResTypeMPtr = 6620 CanTy->getAs<MemberPointerType>()) 6621 CanTy = ResTypeMPtr->getPointeeType(); 6622 else 6623 done = true; 6624 if (CanTy.isVolatileQualified()) 6625 VRQuals.addVolatile(); 6626 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 6627 return VRQuals; 6628 } 6629 } 6630 } 6631 return VRQuals; 6632} 6633 6634namespace { 6635 6636/// \brief Helper class to manage the addition of builtin operator overload 6637/// candidates. It provides shared state and utility methods used throughout 6638/// the process, as well as a helper method to add each group of builtin 6639/// operator overloads from the standard to a candidate set. 6640class BuiltinOperatorOverloadBuilder { 6641 // Common instance state available to all overload candidate addition methods. 6642 Sema &S; 6643 ArrayRef<Expr *> Args; 6644 Qualifiers VisibleTypeConversionsQuals; 6645 bool HasArithmeticOrEnumeralCandidateType; 6646 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 6647 OverloadCandidateSet &CandidateSet; 6648 6649 // Define some constants used to index and iterate over the arithemetic types 6650 // provided via the getArithmeticType() method below. 6651 // The "promoted arithmetic types" are the arithmetic 6652 // types are that preserved by promotion (C++ [over.built]p2). 6653 static const unsigned FirstIntegralType = 3; 6654 static const unsigned LastIntegralType = 20; 6655 static const unsigned FirstPromotedIntegralType = 3, 6656 LastPromotedIntegralType = 11; 6657 static const unsigned FirstPromotedArithmeticType = 0, 6658 LastPromotedArithmeticType = 11; 6659 static const unsigned NumArithmeticTypes = 20; 6660 6661 /// \brief Get the canonical type for a given arithmetic type index. 6662 CanQualType getArithmeticType(unsigned index) { 6663 assert(index < NumArithmeticTypes); 6664 static CanQualType ASTContext::* const 6665 ArithmeticTypes[NumArithmeticTypes] = { 6666 // Start of promoted types. 6667 &ASTContext::FloatTy, 6668 &ASTContext::DoubleTy, 6669 &ASTContext::LongDoubleTy, 6670 6671 // Start of integral types. 6672 &ASTContext::IntTy, 6673 &ASTContext::LongTy, 6674 &ASTContext::LongLongTy, 6675 &ASTContext::Int128Ty, 6676 &ASTContext::UnsignedIntTy, 6677 &ASTContext::UnsignedLongTy, 6678 &ASTContext::UnsignedLongLongTy, 6679 &ASTContext::UnsignedInt128Ty, 6680 // End of promoted types. 6681 6682 &ASTContext::BoolTy, 6683 &ASTContext::CharTy, 6684 &ASTContext::WCharTy, 6685 &ASTContext::Char16Ty, 6686 &ASTContext::Char32Ty, 6687 &ASTContext::SignedCharTy, 6688 &ASTContext::ShortTy, 6689 &ASTContext::UnsignedCharTy, 6690 &ASTContext::UnsignedShortTy, 6691 // End of integral types. 6692 // FIXME: What about complex? What about half? 6693 }; 6694 return S.Context.*ArithmeticTypes[index]; 6695 } 6696 6697 /// \brief Gets the canonical type resulting from the usual arithemetic 6698 /// converions for the given arithmetic types. 6699 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 6700 // Accelerator table for performing the usual arithmetic conversions. 6701 // The rules are basically: 6702 // - if either is floating-point, use the wider floating-point 6703 // - if same signedness, use the higher rank 6704 // - if same size, use unsigned of the higher rank 6705 // - use the larger type 6706 // These rules, together with the axiom that higher ranks are 6707 // never smaller, are sufficient to precompute all of these results 6708 // *except* when dealing with signed types of higher rank. 6709 // (we could precompute SLL x UI for all known platforms, but it's 6710 // better not to make any assumptions). 6711 // We assume that int128 has a higher rank than long long on all platforms. 6712 enum PromotedType { 6713 Dep=-1, 6714 Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 6715 }; 6716 static const PromotedType ConversionsTable[LastPromotedArithmeticType] 6717 [LastPromotedArithmeticType] = { 6718/* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt, Flt, Flt }, 6719/* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 6720/*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 6721/* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 }, 6722/* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, S128, Dep, UL, ULL, U128 }, 6723/* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, S128, Dep, Dep, ULL, U128 }, 6724/*S128*/ { Flt, Dbl, LDbl, S128, S128, S128, S128, S128, S128, S128, U128 }, 6725/* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, S128, UI, UL, ULL, U128 }, 6726/* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, S128, UL, UL, ULL, U128 }, 6727/* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, S128, ULL, ULL, ULL, U128 }, 6728/*U128*/ { Flt, Dbl, LDbl, U128, U128, U128, U128, U128, U128, U128, U128 }, 6729 }; 6730 6731 assert(L < LastPromotedArithmeticType); 6732 assert(R < LastPromotedArithmeticType); 6733 int Idx = ConversionsTable[L][R]; 6734 6735 // Fast path: the table gives us a concrete answer. 6736 if (Idx != Dep) return getArithmeticType(Idx); 6737 6738 // Slow path: we need to compare widths. 6739 // An invariant is that the signed type has higher rank. 6740 CanQualType LT = getArithmeticType(L), 6741 RT = getArithmeticType(R); 6742 unsigned LW = S.Context.getIntWidth(LT), 6743 RW = S.Context.getIntWidth(RT); 6744 6745 // If they're different widths, use the signed type. 6746 if (LW > RW) return LT; 6747 else if (LW < RW) return RT; 6748 6749 // Otherwise, use the unsigned type of the signed type's rank. 6750 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 6751 assert(L == SLL || R == SLL); 6752 return S.Context.UnsignedLongLongTy; 6753 } 6754 6755 /// \brief Helper method to factor out the common pattern of adding overloads 6756 /// for '++' and '--' builtin operators. 6757 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 6758 bool HasVolatile, 6759 bool HasRestrict) { 6760 QualType ParamTypes[2] = { 6761 S.Context.getLValueReferenceType(CandidateTy), 6762 S.Context.IntTy 6763 }; 6764 6765 // Non-volatile version. 6766 if (Args.size() == 1) 6767 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet); 6768 else 6769 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet); 6770 6771 // Use a heuristic to reduce number of builtin candidates in the set: 6772 // add volatile version only if there are conversions to a volatile type. 6773 if (HasVolatile) { 6774 ParamTypes[0] = 6775 S.Context.getLValueReferenceType( 6776 S.Context.getVolatileType(CandidateTy)); 6777 if (Args.size() == 1) 6778 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet); 6779 else 6780 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet); 6781 } 6782 6783 // Add restrict version only if there are conversions to a restrict type 6784 // and our candidate type is a non-restrict-qualified pointer. 6785 if (HasRestrict && CandidateTy->isAnyPointerType() && 6786 !CandidateTy.isRestrictQualified()) { 6787 ParamTypes[0] 6788 = S.Context.getLValueReferenceType( 6789 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict)); 6790 if (Args.size() == 1) 6791 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet); 6792 else 6793 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet); 6794 6795 if (HasVolatile) { 6796 ParamTypes[0] 6797 = S.Context.getLValueReferenceType( 6798 S.Context.getCVRQualifiedType(CandidateTy, 6799 (Qualifiers::Volatile | 6800 Qualifiers::Restrict))); 6801 if (Args.size() == 1) 6802 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet); 6803 else 6804 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, CandidateSet); 6805 } 6806 } 6807 6808 } 6809 6810public: 6811 BuiltinOperatorOverloadBuilder( 6812 Sema &S, ArrayRef<Expr *> Args, 6813 Qualifiers VisibleTypeConversionsQuals, 6814 bool HasArithmeticOrEnumeralCandidateType, 6815 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 6816 OverloadCandidateSet &CandidateSet) 6817 : S(S), Args(Args), 6818 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 6819 HasArithmeticOrEnumeralCandidateType( 6820 HasArithmeticOrEnumeralCandidateType), 6821 CandidateTypes(CandidateTypes), 6822 CandidateSet(CandidateSet) { 6823 // Validate some of our static helper constants in debug builds. 6824 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 6825 "Invalid first promoted integral type"); 6826 assert(getArithmeticType(LastPromotedIntegralType - 1) 6827 == S.Context.UnsignedInt128Ty && 6828 "Invalid last promoted integral type"); 6829 assert(getArithmeticType(FirstPromotedArithmeticType) 6830 == S.Context.FloatTy && 6831 "Invalid first promoted arithmetic type"); 6832 assert(getArithmeticType(LastPromotedArithmeticType - 1) 6833 == S.Context.UnsignedInt128Ty && 6834 "Invalid last promoted arithmetic type"); 6835 } 6836 6837 // C++ [over.built]p3: 6838 // 6839 // For every pair (T, VQ), where T is an arithmetic type, and VQ 6840 // is either volatile or empty, there exist candidate operator 6841 // functions of the form 6842 // 6843 // VQ T& operator++(VQ T&); 6844 // T operator++(VQ T&, int); 6845 // 6846 // C++ [over.built]p4: 6847 // 6848 // For every pair (T, VQ), where T is an arithmetic type other 6849 // than bool, and VQ is either volatile or empty, there exist 6850 // candidate operator functions of the form 6851 // 6852 // VQ T& operator--(VQ T&); 6853 // T operator--(VQ T&, int); 6854 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 6855 if (!HasArithmeticOrEnumeralCandidateType) 6856 return; 6857 6858 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 6859 Arith < NumArithmeticTypes; ++Arith) { 6860 addPlusPlusMinusMinusStyleOverloads( 6861 getArithmeticType(Arith), 6862 VisibleTypeConversionsQuals.hasVolatile(), 6863 VisibleTypeConversionsQuals.hasRestrict()); 6864 } 6865 } 6866 6867 // C++ [over.built]p5: 6868 // 6869 // For every pair (T, VQ), where T is a cv-qualified or 6870 // cv-unqualified object type, and VQ is either volatile or 6871 // empty, there exist candidate operator functions of the form 6872 // 6873 // T*VQ& operator++(T*VQ&); 6874 // T*VQ& operator--(T*VQ&); 6875 // T* operator++(T*VQ&, int); 6876 // T* operator--(T*VQ&, int); 6877 void addPlusPlusMinusMinusPointerOverloads() { 6878 for (BuiltinCandidateTypeSet::iterator 6879 Ptr = CandidateTypes[0].pointer_begin(), 6880 PtrEnd = CandidateTypes[0].pointer_end(); 6881 Ptr != PtrEnd; ++Ptr) { 6882 // Skip pointer types that aren't pointers to object types. 6883 if (!(*Ptr)->getPointeeType()->isObjectType()) 6884 continue; 6885 6886 addPlusPlusMinusMinusStyleOverloads(*Ptr, 6887 (!(*Ptr).isVolatileQualified() && 6888 VisibleTypeConversionsQuals.hasVolatile()), 6889 (!(*Ptr).isRestrictQualified() && 6890 VisibleTypeConversionsQuals.hasRestrict())); 6891 } 6892 } 6893 6894 // C++ [over.built]p6: 6895 // For every cv-qualified or cv-unqualified object type T, there 6896 // exist candidate operator functions of the form 6897 // 6898 // T& operator*(T*); 6899 // 6900 // C++ [over.built]p7: 6901 // For every function type T that does not have cv-qualifiers or a 6902 // ref-qualifier, there exist candidate operator functions of the form 6903 // T& operator*(T*); 6904 void addUnaryStarPointerOverloads() { 6905 for (BuiltinCandidateTypeSet::iterator 6906 Ptr = CandidateTypes[0].pointer_begin(), 6907 PtrEnd = CandidateTypes[0].pointer_end(); 6908 Ptr != PtrEnd; ++Ptr) { 6909 QualType ParamTy = *Ptr; 6910 QualType PointeeTy = ParamTy->getPointeeType(); 6911 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 6912 continue; 6913 6914 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 6915 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 6916 continue; 6917 6918 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 6919 &ParamTy, Args, CandidateSet); 6920 } 6921 } 6922 6923 // C++ [over.built]p9: 6924 // For every promoted arithmetic type T, there exist candidate 6925 // operator functions of the form 6926 // 6927 // T operator+(T); 6928 // T operator-(T); 6929 void addUnaryPlusOrMinusArithmeticOverloads() { 6930 if (!HasArithmeticOrEnumeralCandidateType) 6931 return; 6932 6933 for (unsigned Arith = FirstPromotedArithmeticType; 6934 Arith < LastPromotedArithmeticType; ++Arith) { 6935 QualType ArithTy = getArithmeticType(Arith); 6936 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, CandidateSet); 6937 } 6938 6939 // Extension: We also add these operators for vector types. 6940 for (BuiltinCandidateTypeSet::iterator 6941 Vec = CandidateTypes[0].vector_begin(), 6942 VecEnd = CandidateTypes[0].vector_end(); 6943 Vec != VecEnd; ++Vec) { 6944 QualType VecTy = *Vec; 6945 S.AddBuiltinCandidate(VecTy, &VecTy, Args, CandidateSet); 6946 } 6947 } 6948 6949 // C++ [over.built]p8: 6950 // For every type T, there exist candidate operator functions of 6951 // the form 6952 // 6953 // T* operator+(T*); 6954 void addUnaryPlusPointerOverloads() { 6955 for (BuiltinCandidateTypeSet::iterator 6956 Ptr = CandidateTypes[0].pointer_begin(), 6957 PtrEnd = CandidateTypes[0].pointer_end(); 6958 Ptr != PtrEnd; ++Ptr) { 6959 QualType ParamTy = *Ptr; 6960 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, CandidateSet); 6961 } 6962 } 6963 6964 // C++ [over.built]p10: 6965 // For every promoted integral type T, there exist candidate 6966 // operator functions of the form 6967 // 6968 // T operator~(T); 6969 void addUnaryTildePromotedIntegralOverloads() { 6970 if (!HasArithmeticOrEnumeralCandidateType) 6971 return; 6972 6973 for (unsigned Int = FirstPromotedIntegralType; 6974 Int < LastPromotedIntegralType; ++Int) { 6975 QualType IntTy = getArithmeticType(Int); 6976 S.AddBuiltinCandidate(IntTy, &IntTy, Args, CandidateSet); 6977 } 6978 6979 // Extension: We also add this operator for vector types. 6980 for (BuiltinCandidateTypeSet::iterator 6981 Vec = CandidateTypes[0].vector_begin(), 6982 VecEnd = CandidateTypes[0].vector_end(); 6983 Vec != VecEnd; ++Vec) { 6984 QualType VecTy = *Vec; 6985 S.AddBuiltinCandidate(VecTy, &VecTy, Args, CandidateSet); 6986 } 6987 } 6988 6989 // C++ [over.match.oper]p16: 6990 // For every pointer to member type T, there exist candidate operator 6991 // functions of the form 6992 // 6993 // bool operator==(T,T); 6994 // bool operator!=(T,T); 6995 void addEqualEqualOrNotEqualMemberPointerOverloads() { 6996 /// Set of (canonical) types that we've already handled. 6997 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6998 6999 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 7000 for (BuiltinCandidateTypeSet::iterator 7001 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 7002 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 7003 MemPtr != MemPtrEnd; 7004 ++MemPtr) { 7005 // Don't add the same builtin candidate twice. 7006 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 7007 continue; 7008 7009 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 7010 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet); 7011 } 7012 } 7013 } 7014 7015 // C++ [over.built]p15: 7016 // 7017 // For every T, where T is an enumeration type, a pointer type, or 7018 // std::nullptr_t, there exist candidate operator functions of the form 7019 // 7020 // bool operator<(T, T); 7021 // bool operator>(T, T); 7022 // bool operator<=(T, T); 7023 // bool operator>=(T, T); 7024 // bool operator==(T, T); 7025 // bool operator!=(T, T); 7026 void addRelationalPointerOrEnumeralOverloads() { 7027 // C++ [over.match.oper]p3: 7028 // [...]the built-in candidates include all of the candidate operator 7029 // functions defined in 13.6 that, compared to the given operator, [...] 7030 // do not have the same parameter-type-list as any non-template non-member 7031 // candidate. 7032 // 7033 // Note that in practice, this only affects enumeration types because there 7034 // aren't any built-in candidates of record type, and a user-defined operator 7035 // must have an operand of record or enumeration type. Also, the only other 7036 // overloaded operator with enumeration arguments, operator=, 7037 // cannot be overloaded for enumeration types, so this is the only place 7038 // where we must suppress candidates like this. 7039 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 7040 UserDefinedBinaryOperators; 7041 7042 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 7043 if (CandidateTypes[ArgIdx].enumeration_begin() != 7044 CandidateTypes[ArgIdx].enumeration_end()) { 7045 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 7046 CEnd = CandidateSet.end(); 7047 C != CEnd; ++C) { 7048 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 7049 continue; 7050 7051 if (C->Function->isFunctionTemplateSpecialization()) 7052 continue; 7053 7054 QualType FirstParamType = 7055 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 7056 QualType SecondParamType = 7057 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 7058 7059 // Skip if either parameter isn't of enumeral type. 7060 if (!FirstParamType->isEnumeralType() || 7061 !SecondParamType->isEnumeralType()) 7062 continue; 7063 7064 // Add this operator to the set of known user-defined operators. 7065 UserDefinedBinaryOperators.insert( 7066 std::make_pair(S.Context.getCanonicalType(FirstParamType), 7067 S.Context.getCanonicalType(SecondParamType))); 7068 } 7069 } 7070 } 7071 7072 /// Set of (canonical) types that we've already handled. 7073 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7074 7075 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 7076 for (BuiltinCandidateTypeSet::iterator 7077 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 7078 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 7079 Ptr != PtrEnd; ++Ptr) { 7080 // Don't add the same builtin candidate twice. 7081 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7082 continue; 7083 7084 QualType ParamTypes[2] = { *Ptr, *Ptr }; 7085 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet); 7086 } 7087 for (BuiltinCandidateTypeSet::iterator 7088 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 7089 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 7090 Enum != EnumEnd; ++Enum) { 7091 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 7092 7093 // Don't add the same builtin candidate twice, or if a user defined 7094 // candidate exists. 7095 if (!AddedTypes.insert(CanonType) || 7096 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 7097 CanonType))) 7098 continue; 7099 7100 QualType ParamTypes[2] = { *Enum, *Enum }; 7101 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet); 7102 } 7103 7104 if (CandidateTypes[ArgIdx].hasNullPtrType()) { 7105 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy); 7106 if (AddedTypes.insert(NullPtrTy) && 7107 !UserDefinedBinaryOperators.count(std::make_pair(NullPtrTy, 7108 NullPtrTy))) { 7109 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy }; 7110 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 7111 CandidateSet); 7112 } 7113 } 7114 } 7115 } 7116 7117 // C++ [over.built]p13: 7118 // 7119 // For every cv-qualified or cv-unqualified object type T 7120 // there exist candidate operator functions of the form 7121 // 7122 // T* operator+(T*, ptrdiff_t); 7123 // T& operator[](T*, ptrdiff_t); [BELOW] 7124 // T* operator-(T*, ptrdiff_t); 7125 // T* operator+(ptrdiff_t, T*); 7126 // T& operator[](ptrdiff_t, T*); [BELOW] 7127 // 7128 // C++ [over.built]p14: 7129 // 7130 // For every T, where T is a pointer to object type, there 7131 // exist candidate operator functions of the form 7132 // 7133 // ptrdiff_t operator-(T, T); 7134 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 7135 /// Set of (canonical) types that we've already handled. 7136 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7137 7138 for (int Arg = 0; Arg < 2; ++Arg) { 7139 QualType AsymetricParamTypes[2] = { 7140 S.Context.getPointerDiffType(), 7141 S.Context.getPointerDiffType(), 7142 }; 7143 for (BuiltinCandidateTypeSet::iterator 7144 Ptr = CandidateTypes[Arg].pointer_begin(), 7145 PtrEnd = CandidateTypes[Arg].pointer_end(); 7146 Ptr != PtrEnd; ++Ptr) { 7147 QualType PointeeTy = (*Ptr)->getPointeeType(); 7148 if (!PointeeTy->isObjectType()) 7149 continue; 7150 7151 AsymetricParamTypes[Arg] = *Ptr; 7152 if (Arg == 0 || Op == OO_Plus) { 7153 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 7154 // T* operator+(ptrdiff_t, T*); 7155 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, CandidateSet); 7156 } 7157 if (Op == OO_Minus) { 7158 // ptrdiff_t operator-(T, T); 7159 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7160 continue; 7161 7162 QualType ParamTypes[2] = { *Ptr, *Ptr }; 7163 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 7164 Args, CandidateSet); 7165 } 7166 } 7167 } 7168 } 7169 7170 // C++ [over.built]p12: 7171 // 7172 // For every pair of promoted arithmetic types L and R, there 7173 // exist candidate operator functions of the form 7174 // 7175 // LR operator*(L, R); 7176 // LR operator/(L, R); 7177 // LR operator+(L, R); 7178 // LR operator-(L, R); 7179 // bool operator<(L, R); 7180 // bool operator>(L, R); 7181 // bool operator<=(L, R); 7182 // bool operator>=(L, R); 7183 // bool operator==(L, R); 7184 // bool operator!=(L, R); 7185 // 7186 // where LR is the result of the usual arithmetic conversions 7187 // between types L and R. 7188 // 7189 // C++ [over.built]p24: 7190 // 7191 // For every pair of promoted arithmetic types L and R, there exist 7192 // candidate operator functions of the form 7193 // 7194 // LR operator?(bool, L, R); 7195 // 7196 // where LR is the result of the usual arithmetic conversions 7197 // between types L and R. 7198 // Our candidates ignore the first parameter. 7199 void addGenericBinaryArithmeticOverloads(bool isComparison) { 7200 if (!HasArithmeticOrEnumeralCandidateType) 7201 return; 7202 7203 for (unsigned Left = FirstPromotedArithmeticType; 7204 Left < LastPromotedArithmeticType; ++Left) { 7205 for (unsigned Right = FirstPromotedArithmeticType; 7206 Right < LastPromotedArithmeticType; ++Right) { 7207 QualType LandR[2] = { getArithmeticType(Left), 7208 getArithmeticType(Right) }; 7209 QualType Result = 7210 isComparison ? S.Context.BoolTy 7211 : getUsualArithmeticConversions(Left, Right); 7212 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet); 7213 } 7214 } 7215 7216 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 7217 // conditional operator for vector types. 7218 for (BuiltinCandidateTypeSet::iterator 7219 Vec1 = CandidateTypes[0].vector_begin(), 7220 Vec1End = CandidateTypes[0].vector_end(); 7221 Vec1 != Vec1End; ++Vec1) { 7222 for (BuiltinCandidateTypeSet::iterator 7223 Vec2 = CandidateTypes[1].vector_begin(), 7224 Vec2End = CandidateTypes[1].vector_end(); 7225 Vec2 != Vec2End; ++Vec2) { 7226 QualType LandR[2] = { *Vec1, *Vec2 }; 7227 QualType Result = S.Context.BoolTy; 7228 if (!isComparison) { 7229 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 7230 Result = *Vec1; 7231 else 7232 Result = *Vec2; 7233 } 7234 7235 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet); 7236 } 7237 } 7238 } 7239 7240 // C++ [over.built]p17: 7241 // 7242 // For every pair of promoted integral types L and R, there 7243 // exist candidate operator functions of the form 7244 // 7245 // LR operator%(L, R); 7246 // LR operator&(L, R); 7247 // LR operator^(L, R); 7248 // LR operator|(L, R); 7249 // L operator<<(L, R); 7250 // L operator>>(L, R); 7251 // 7252 // where LR is the result of the usual arithmetic conversions 7253 // between types L and R. 7254 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 7255 if (!HasArithmeticOrEnumeralCandidateType) 7256 return; 7257 7258 for (unsigned Left = FirstPromotedIntegralType; 7259 Left < LastPromotedIntegralType; ++Left) { 7260 for (unsigned Right = FirstPromotedIntegralType; 7261 Right < LastPromotedIntegralType; ++Right) { 7262 QualType LandR[2] = { getArithmeticType(Left), 7263 getArithmeticType(Right) }; 7264 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 7265 ? LandR[0] 7266 : getUsualArithmeticConversions(Left, Right); 7267 S.AddBuiltinCandidate(Result, LandR, Args, CandidateSet); 7268 } 7269 } 7270 } 7271 7272 // C++ [over.built]p20: 7273 // 7274 // For every pair (T, VQ), where T is an enumeration or 7275 // pointer to member type and VQ is either volatile or 7276 // empty, there exist candidate operator functions of the form 7277 // 7278 // VQ T& operator=(VQ T&, T); 7279 void addAssignmentMemberPointerOrEnumeralOverloads() { 7280 /// Set of (canonical) types that we've already handled. 7281 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7282 7283 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 7284 for (BuiltinCandidateTypeSet::iterator 7285 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 7286 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 7287 Enum != EnumEnd; ++Enum) { 7288 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 7289 continue; 7290 7291 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, CandidateSet); 7292 } 7293 7294 for (BuiltinCandidateTypeSet::iterator 7295 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 7296 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 7297 MemPtr != MemPtrEnd; ++MemPtr) { 7298 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 7299 continue; 7300 7301 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, CandidateSet); 7302 } 7303 } 7304 } 7305 7306 // C++ [over.built]p19: 7307 // 7308 // For every pair (T, VQ), where T is any type and VQ is either 7309 // volatile or empty, there exist candidate operator functions 7310 // of the form 7311 // 7312 // T*VQ& operator=(T*VQ&, T*); 7313 // 7314 // C++ [over.built]p21: 7315 // 7316 // For every pair (T, VQ), where T is a cv-qualified or 7317 // cv-unqualified object type and VQ is either volatile or 7318 // empty, there exist candidate operator functions of the form 7319 // 7320 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 7321 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 7322 void addAssignmentPointerOverloads(bool isEqualOp) { 7323 /// Set of (canonical) types that we've already handled. 7324 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7325 7326 for (BuiltinCandidateTypeSet::iterator 7327 Ptr = CandidateTypes[0].pointer_begin(), 7328 PtrEnd = CandidateTypes[0].pointer_end(); 7329 Ptr != PtrEnd; ++Ptr) { 7330 // If this is operator=, keep track of the builtin candidates we added. 7331 if (isEqualOp) 7332 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 7333 else if (!(*Ptr)->getPointeeType()->isObjectType()) 7334 continue; 7335 7336 // non-volatile version 7337 QualType ParamTypes[2] = { 7338 S.Context.getLValueReferenceType(*Ptr), 7339 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 7340 }; 7341 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7342 /*IsAssigmentOperator=*/ isEqualOp); 7343 7344 bool NeedVolatile = !(*Ptr).isVolatileQualified() && 7345 VisibleTypeConversionsQuals.hasVolatile(); 7346 if (NeedVolatile) { 7347 // volatile version 7348 ParamTypes[0] = 7349 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 7350 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7351 /*IsAssigmentOperator=*/isEqualOp); 7352 } 7353 7354 if (!(*Ptr).isRestrictQualified() && 7355 VisibleTypeConversionsQuals.hasRestrict()) { 7356 // restrict version 7357 ParamTypes[0] 7358 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr)); 7359 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7360 /*IsAssigmentOperator=*/isEqualOp); 7361 7362 if (NeedVolatile) { 7363 // volatile restrict version 7364 ParamTypes[0] 7365 = S.Context.getLValueReferenceType( 7366 S.Context.getCVRQualifiedType(*Ptr, 7367 (Qualifiers::Volatile | 7368 Qualifiers::Restrict))); 7369 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7370 /*IsAssigmentOperator=*/isEqualOp); 7371 } 7372 } 7373 } 7374 7375 if (isEqualOp) { 7376 for (BuiltinCandidateTypeSet::iterator 7377 Ptr = CandidateTypes[1].pointer_begin(), 7378 PtrEnd = CandidateTypes[1].pointer_end(); 7379 Ptr != PtrEnd; ++Ptr) { 7380 // Make sure we don't add the same candidate twice. 7381 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7382 continue; 7383 7384 QualType ParamTypes[2] = { 7385 S.Context.getLValueReferenceType(*Ptr), 7386 *Ptr, 7387 }; 7388 7389 // non-volatile version 7390 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7391 /*IsAssigmentOperator=*/true); 7392 7393 bool NeedVolatile = !(*Ptr).isVolatileQualified() && 7394 VisibleTypeConversionsQuals.hasVolatile(); 7395 if (NeedVolatile) { 7396 // volatile version 7397 ParamTypes[0] = 7398 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 7399 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7400 /*IsAssigmentOperator=*/true); 7401 } 7402 7403 if (!(*Ptr).isRestrictQualified() && 7404 VisibleTypeConversionsQuals.hasRestrict()) { 7405 // restrict version 7406 ParamTypes[0] 7407 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr)); 7408 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7409 /*IsAssigmentOperator=*/true); 7410 7411 if (NeedVolatile) { 7412 // volatile restrict version 7413 ParamTypes[0] 7414 = S.Context.getLValueReferenceType( 7415 S.Context.getCVRQualifiedType(*Ptr, 7416 (Qualifiers::Volatile | 7417 Qualifiers::Restrict))); 7418 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7419 /*IsAssigmentOperator=*/true); 7420 } 7421 } 7422 } 7423 } 7424 } 7425 7426 // C++ [over.built]p18: 7427 // 7428 // For every triple (L, VQ, R), where L is an arithmetic type, 7429 // VQ is either volatile or empty, and R is a promoted 7430 // arithmetic type, there exist candidate operator functions of 7431 // the form 7432 // 7433 // VQ L& operator=(VQ L&, R); 7434 // VQ L& operator*=(VQ L&, R); 7435 // VQ L& operator/=(VQ L&, R); 7436 // VQ L& operator+=(VQ L&, R); 7437 // VQ L& operator-=(VQ L&, R); 7438 void addAssignmentArithmeticOverloads(bool isEqualOp) { 7439 if (!HasArithmeticOrEnumeralCandidateType) 7440 return; 7441 7442 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 7443 for (unsigned Right = FirstPromotedArithmeticType; 7444 Right < LastPromotedArithmeticType; ++Right) { 7445 QualType ParamTypes[2]; 7446 ParamTypes[1] = getArithmeticType(Right); 7447 7448 // Add this built-in operator as a candidate (VQ is empty). 7449 ParamTypes[0] = 7450 S.Context.getLValueReferenceType(getArithmeticType(Left)); 7451 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7452 /*IsAssigmentOperator=*/isEqualOp); 7453 7454 // Add this built-in operator as a candidate (VQ is 'volatile'). 7455 if (VisibleTypeConversionsQuals.hasVolatile()) { 7456 ParamTypes[0] = 7457 S.Context.getVolatileType(getArithmeticType(Left)); 7458 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7459 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7460 /*IsAssigmentOperator=*/isEqualOp); 7461 } 7462 } 7463 } 7464 7465 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 7466 for (BuiltinCandidateTypeSet::iterator 7467 Vec1 = CandidateTypes[0].vector_begin(), 7468 Vec1End = CandidateTypes[0].vector_end(); 7469 Vec1 != Vec1End; ++Vec1) { 7470 for (BuiltinCandidateTypeSet::iterator 7471 Vec2 = CandidateTypes[1].vector_begin(), 7472 Vec2End = CandidateTypes[1].vector_end(); 7473 Vec2 != Vec2End; ++Vec2) { 7474 QualType ParamTypes[2]; 7475 ParamTypes[1] = *Vec2; 7476 // Add this built-in operator as a candidate (VQ is empty). 7477 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 7478 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7479 /*IsAssigmentOperator=*/isEqualOp); 7480 7481 // Add this built-in operator as a candidate (VQ is 'volatile'). 7482 if (VisibleTypeConversionsQuals.hasVolatile()) { 7483 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 7484 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7485 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet, 7486 /*IsAssigmentOperator=*/isEqualOp); 7487 } 7488 } 7489 } 7490 } 7491 7492 // C++ [over.built]p22: 7493 // 7494 // For every triple (L, VQ, R), where L is an integral type, VQ 7495 // is either volatile or empty, and R is a promoted integral 7496 // type, there exist candidate operator functions of the form 7497 // 7498 // VQ L& operator%=(VQ L&, R); 7499 // VQ L& operator<<=(VQ L&, R); 7500 // VQ L& operator>>=(VQ L&, R); 7501 // VQ L& operator&=(VQ L&, R); 7502 // VQ L& operator^=(VQ L&, R); 7503 // VQ L& operator|=(VQ L&, R); 7504 void addAssignmentIntegralOverloads() { 7505 if (!HasArithmeticOrEnumeralCandidateType) 7506 return; 7507 7508 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 7509 for (unsigned Right = FirstPromotedIntegralType; 7510 Right < LastPromotedIntegralType; ++Right) { 7511 QualType ParamTypes[2]; 7512 ParamTypes[1] = getArithmeticType(Right); 7513 7514 // Add this built-in operator as a candidate (VQ is empty). 7515 ParamTypes[0] = 7516 S.Context.getLValueReferenceType(getArithmeticType(Left)); 7517 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet); 7518 if (VisibleTypeConversionsQuals.hasVolatile()) { 7519 // Add this built-in operator as a candidate (VQ is 'volatile'). 7520 ParamTypes[0] = getArithmeticType(Left); 7521 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 7522 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7523 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, CandidateSet); 7524 } 7525 } 7526 } 7527 } 7528 7529 // C++ [over.operator]p23: 7530 // 7531 // There also exist candidate operator functions of the form 7532 // 7533 // bool operator!(bool); 7534 // bool operator&&(bool, bool); 7535 // bool operator||(bool, bool); 7536 void addExclaimOverload() { 7537 QualType ParamTy = S.Context.BoolTy; 7538 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, CandidateSet, 7539 /*IsAssignmentOperator=*/false, 7540 /*NumContextualBoolArguments=*/1); 7541 } 7542 void addAmpAmpOrPipePipeOverload() { 7543 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 7544 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, CandidateSet, 7545 /*IsAssignmentOperator=*/false, 7546 /*NumContextualBoolArguments=*/2); 7547 } 7548 7549 // C++ [over.built]p13: 7550 // 7551 // For every cv-qualified or cv-unqualified object type T there 7552 // exist candidate operator functions of the form 7553 // 7554 // T* operator+(T*, ptrdiff_t); [ABOVE] 7555 // T& operator[](T*, ptrdiff_t); 7556 // T* operator-(T*, ptrdiff_t); [ABOVE] 7557 // T* operator+(ptrdiff_t, T*); [ABOVE] 7558 // T& operator[](ptrdiff_t, T*); 7559 void addSubscriptOverloads() { 7560 for (BuiltinCandidateTypeSet::iterator 7561 Ptr = CandidateTypes[0].pointer_begin(), 7562 PtrEnd = CandidateTypes[0].pointer_end(); 7563 Ptr != PtrEnd; ++Ptr) { 7564 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 7565 QualType PointeeType = (*Ptr)->getPointeeType(); 7566 if (!PointeeType->isObjectType()) 7567 continue; 7568 7569 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 7570 7571 // T& operator[](T*, ptrdiff_t) 7572 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet); 7573 } 7574 7575 for (BuiltinCandidateTypeSet::iterator 7576 Ptr = CandidateTypes[1].pointer_begin(), 7577 PtrEnd = CandidateTypes[1].pointer_end(); 7578 Ptr != PtrEnd; ++Ptr) { 7579 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 7580 QualType PointeeType = (*Ptr)->getPointeeType(); 7581 if (!PointeeType->isObjectType()) 7582 continue; 7583 7584 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 7585 7586 // T& operator[](ptrdiff_t, T*) 7587 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet); 7588 } 7589 } 7590 7591 // C++ [over.built]p11: 7592 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 7593 // C1 is the same type as C2 or is a derived class of C2, T is an object 7594 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 7595 // there exist candidate operator functions of the form 7596 // 7597 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 7598 // 7599 // where CV12 is the union of CV1 and CV2. 7600 void addArrowStarOverloads() { 7601 for (BuiltinCandidateTypeSet::iterator 7602 Ptr = CandidateTypes[0].pointer_begin(), 7603 PtrEnd = CandidateTypes[0].pointer_end(); 7604 Ptr != PtrEnd; ++Ptr) { 7605 QualType C1Ty = (*Ptr); 7606 QualType C1; 7607 QualifierCollector Q1; 7608 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 7609 if (!isa<RecordType>(C1)) 7610 continue; 7611 // heuristic to reduce number of builtin candidates in the set. 7612 // Add volatile/restrict version only if there are conversions to a 7613 // volatile/restrict type. 7614 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 7615 continue; 7616 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 7617 continue; 7618 for (BuiltinCandidateTypeSet::iterator 7619 MemPtr = CandidateTypes[1].member_pointer_begin(), 7620 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 7621 MemPtr != MemPtrEnd; ++MemPtr) { 7622 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 7623 QualType C2 = QualType(mptr->getClass(), 0); 7624 C2 = C2.getUnqualifiedType(); 7625 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 7626 break; 7627 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 7628 // build CV12 T& 7629 QualType T = mptr->getPointeeType(); 7630 if (!VisibleTypeConversionsQuals.hasVolatile() && 7631 T.isVolatileQualified()) 7632 continue; 7633 if (!VisibleTypeConversionsQuals.hasRestrict() && 7634 T.isRestrictQualified()) 7635 continue; 7636 T = Q1.apply(S.Context, T); 7637 QualType ResultTy = S.Context.getLValueReferenceType(T); 7638 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, CandidateSet); 7639 } 7640 } 7641 } 7642 7643 // Note that we don't consider the first argument, since it has been 7644 // contextually converted to bool long ago. The candidates below are 7645 // therefore added as binary. 7646 // 7647 // C++ [over.built]p25: 7648 // For every type T, where T is a pointer, pointer-to-member, or scoped 7649 // enumeration type, there exist candidate operator functions of the form 7650 // 7651 // T operator?(bool, T, T); 7652 // 7653 void addConditionalOperatorOverloads() { 7654 /// Set of (canonical) types that we've already handled. 7655 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7656 7657 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 7658 for (BuiltinCandidateTypeSet::iterator 7659 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 7660 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 7661 Ptr != PtrEnd; ++Ptr) { 7662 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7663 continue; 7664 7665 QualType ParamTypes[2] = { *Ptr, *Ptr }; 7666 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, CandidateSet); 7667 } 7668 7669 for (BuiltinCandidateTypeSet::iterator 7670 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 7671 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 7672 MemPtr != MemPtrEnd; ++MemPtr) { 7673 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 7674 continue; 7675 7676 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 7677 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, CandidateSet); 7678 } 7679 7680 if (S.getLangOpts().CPlusPlus11) { 7681 for (BuiltinCandidateTypeSet::iterator 7682 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 7683 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 7684 Enum != EnumEnd; ++Enum) { 7685 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 7686 continue; 7687 7688 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 7689 continue; 7690 7691 QualType ParamTypes[2] = { *Enum, *Enum }; 7692 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, CandidateSet); 7693 } 7694 } 7695 } 7696 } 7697}; 7698 7699} // end anonymous namespace 7700 7701/// AddBuiltinOperatorCandidates - Add the appropriate built-in 7702/// operator overloads to the candidate set (C++ [over.built]), based 7703/// on the operator @p Op and the arguments given. For example, if the 7704/// operator is a binary '+', this routine might add "int 7705/// operator+(int, int)" to cover integer addition. 7706void 7707Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 7708 SourceLocation OpLoc, 7709 llvm::ArrayRef<Expr *> Args, 7710 OverloadCandidateSet& CandidateSet) { 7711 // Find all of the types that the arguments can convert to, but only 7712 // if the operator we're looking at has built-in operator candidates 7713 // that make use of these types. Also record whether we encounter non-record 7714 // candidate types or either arithmetic or enumeral candidate types. 7715 Qualifiers VisibleTypeConversionsQuals; 7716 VisibleTypeConversionsQuals.addConst(); 7717 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) 7718 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 7719 7720 bool HasNonRecordCandidateType = false; 7721 bool HasArithmeticOrEnumeralCandidateType = false; 7722 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 7723 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 7724 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 7725 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 7726 OpLoc, 7727 true, 7728 (Op == OO_Exclaim || 7729 Op == OO_AmpAmp || 7730 Op == OO_PipePipe), 7731 VisibleTypeConversionsQuals); 7732 HasNonRecordCandidateType = HasNonRecordCandidateType || 7733 CandidateTypes[ArgIdx].hasNonRecordTypes(); 7734 HasArithmeticOrEnumeralCandidateType = 7735 HasArithmeticOrEnumeralCandidateType || 7736 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 7737 } 7738 7739 // Exit early when no non-record types have been added to the candidate set 7740 // for any of the arguments to the operator. 7741 // 7742 // We can't exit early for !, ||, or &&, since there we have always have 7743 // 'bool' overloads. 7744 if (!HasNonRecordCandidateType && 7745 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe)) 7746 return; 7747 7748 // Setup an object to manage the common state for building overloads. 7749 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, 7750 VisibleTypeConversionsQuals, 7751 HasArithmeticOrEnumeralCandidateType, 7752 CandidateTypes, CandidateSet); 7753 7754 // Dispatch over the operation to add in only those overloads which apply. 7755 switch (Op) { 7756 case OO_None: 7757 case NUM_OVERLOADED_OPERATORS: 7758 llvm_unreachable("Expected an overloaded operator"); 7759 7760 case OO_New: 7761 case OO_Delete: 7762 case OO_Array_New: 7763 case OO_Array_Delete: 7764 case OO_Call: 7765 llvm_unreachable( 7766 "Special operators don't use AddBuiltinOperatorCandidates"); 7767 7768 case OO_Comma: 7769 case OO_Arrow: 7770 // C++ [over.match.oper]p3: 7771 // -- For the operator ',', the unary operator '&', or the 7772 // operator '->', the built-in candidates set is empty. 7773 break; 7774 7775 case OO_Plus: // '+' is either unary or binary 7776 if (Args.size() == 1) 7777 OpBuilder.addUnaryPlusPointerOverloads(); 7778 // Fall through. 7779 7780 case OO_Minus: // '-' is either unary or binary 7781 if (Args.size() == 1) { 7782 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 7783 } else { 7784 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 7785 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7786 } 7787 break; 7788 7789 case OO_Star: // '*' is either unary or binary 7790 if (Args.size() == 1) 7791 OpBuilder.addUnaryStarPointerOverloads(); 7792 else 7793 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7794 break; 7795 7796 case OO_Slash: 7797 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7798 break; 7799 7800 case OO_PlusPlus: 7801 case OO_MinusMinus: 7802 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 7803 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 7804 break; 7805 7806 case OO_EqualEqual: 7807 case OO_ExclaimEqual: 7808 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 7809 // Fall through. 7810 7811 case OO_Less: 7812 case OO_Greater: 7813 case OO_LessEqual: 7814 case OO_GreaterEqual: 7815 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 7816 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 7817 break; 7818 7819 case OO_Percent: 7820 case OO_Caret: 7821 case OO_Pipe: 7822 case OO_LessLess: 7823 case OO_GreaterGreater: 7824 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 7825 break; 7826 7827 case OO_Amp: // '&' is either unary or binary 7828 if (Args.size() == 1) 7829 // C++ [over.match.oper]p3: 7830 // -- For the operator ',', the unary operator '&', or the 7831 // operator '->', the built-in candidates set is empty. 7832 break; 7833 7834 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 7835 break; 7836 7837 case OO_Tilde: 7838 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 7839 break; 7840 7841 case OO_Equal: 7842 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 7843 // Fall through. 7844 7845 case OO_PlusEqual: 7846 case OO_MinusEqual: 7847 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 7848 // Fall through. 7849 7850 case OO_StarEqual: 7851 case OO_SlashEqual: 7852 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 7853 break; 7854 7855 case OO_PercentEqual: 7856 case OO_LessLessEqual: 7857 case OO_GreaterGreaterEqual: 7858 case OO_AmpEqual: 7859 case OO_CaretEqual: 7860 case OO_PipeEqual: 7861 OpBuilder.addAssignmentIntegralOverloads(); 7862 break; 7863 7864 case OO_Exclaim: 7865 OpBuilder.addExclaimOverload(); 7866 break; 7867 7868 case OO_AmpAmp: 7869 case OO_PipePipe: 7870 OpBuilder.addAmpAmpOrPipePipeOverload(); 7871 break; 7872 7873 case OO_Subscript: 7874 OpBuilder.addSubscriptOverloads(); 7875 break; 7876 7877 case OO_ArrowStar: 7878 OpBuilder.addArrowStarOverloads(); 7879 break; 7880 7881 case OO_Conditional: 7882 OpBuilder.addConditionalOperatorOverloads(); 7883 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7884 break; 7885 } 7886} 7887 7888/// \brief Add function candidates found via argument-dependent lookup 7889/// to the set of overloading candidates. 7890/// 7891/// This routine performs argument-dependent name lookup based on the 7892/// given function name (which may also be an operator name) and adds 7893/// all of the overload candidates found by ADL to the overload 7894/// candidate set (C++ [basic.lookup.argdep]). 7895void 7896Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 7897 bool Operator, SourceLocation Loc, 7898 ArrayRef<Expr *> Args, 7899 TemplateArgumentListInfo *ExplicitTemplateArgs, 7900 OverloadCandidateSet& CandidateSet, 7901 bool PartialOverloading) { 7902 ADLResult Fns; 7903 7904 // FIXME: This approach for uniquing ADL results (and removing 7905 // redundant candidates from the set) relies on pointer-equality, 7906 // which means we need to key off the canonical decl. However, 7907 // always going back to the canonical decl might not get us the 7908 // right set of default arguments. What default arguments are 7909 // we supposed to consider on ADL candidates, anyway? 7910 7911 // FIXME: Pass in the explicit template arguments? 7912 ArgumentDependentLookup(Name, Operator, Loc, Args, Fns); 7913 7914 // Erase all of the candidates we already knew about. 7915 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 7916 CandEnd = CandidateSet.end(); 7917 Cand != CandEnd; ++Cand) 7918 if (Cand->Function) { 7919 Fns.erase(Cand->Function); 7920 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 7921 Fns.erase(FunTmpl); 7922 } 7923 7924 // For each of the ADL candidates we found, add it to the overload 7925 // set. 7926 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 7927 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 7928 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 7929 if (ExplicitTemplateArgs) 7930 continue; 7931 7932 AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet, false, 7933 PartialOverloading); 7934 } else 7935 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 7936 FoundDecl, ExplicitTemplateArgs, 7937 Args, CandidateSet); 7938 } 7939} 7940 7941/// isBetterOverloadCandidate - Determines whether the first overload 7942/// candidate is a better candidate than the second (C++ 13.3.3p1). 7943bool 7944isBetterOverloadCandidate(Sema &S, 7945 const OverloadCandidate &Cand1, 7946 const OverloadCandidate &Cand2, 7947 SourceLocation Loc, 7948 bool UserDefinedConversion) { 7949 // Define viable functions to be better candidates than non-viable 7950 // functions. 7951 if (!Cand2.Viable) 7952 return Cand1.Viable; 7953 else if (!Cand1.Viable) 7954 return false; 7955 7956 // C++ [over.match.best]p1: 7957 // 7958 // -- if F is a static member function, ICS1(F) is defined such 7959 // that ICS1(F) is neither better nor worse than ICS1(G) for 7960 // any function G, and, symmetrically, ICS1(G) is neither 7961 // better nor worse than ICS1(F). 7962 unsigned StartArg = 0; 7963 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 7964 StartArg = 1; 7965 7966 // C++ [over.match.best]p1: 7967 // A viable function F1 is defined to be a better function than another 7968 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 7969 // conversion sequence than ICSi(F2), and then... 7970 unsigned NumArgs = Cand1.NumConversions; 7971 assert(Cand2.NumConversions == NumArgs && "Overload candidate mismatch"); 7972 bool HasBetterConversion = false; 7973 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 7974 switch (CompareImplicitConversionSequences(S, 7975 Cand1.Conversions[ArgIdx], 7976 Cand2.Conversions[ArgIdx])) { 7977 case ImplicitConversionSequence::Better: 7978 // Cand1 has a better conversion sequence. 7979 HasBetterConversion = true; 7980 break; 7981 7982 case ImplicitConversionSequence::Worse: 7983 // Cand1 can't be better than Cand2. 7984 return false; 7985 7986 case ImplicitConversionSequence::Indistinguishable: 7987 // Do nothing. 7988 break; 7989 } 7990 } 7991 7992 // -- for some argument j, ICSj(F1) is a better conversion sequence than 7993 // ICSj(F2), or, if not that, 7994 if (HasBetterConversion) 7995 return true; 7996 7997 // - F1 is a non-template function and F2 is a function template 7998 // specialization, or, if not that, 7999 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 8000 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 8001 return true; 8002 8003 // -- F1 and F2 are function template specializations, and the function 8004 // template for F1 is more specialized than the template for F2 8005 // according to the partial ordering rules described in 14.5.5.2, or, 8006 // if not that, 8007 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 8008 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 8009 if (FunctionTemplateDecl *BetterTemplate 8010 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 8011 Cand2.Function->getPrimaryTemplate(), 8012 Loc, 8013 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 8014 : TPOC_Call, 8015 Cand1.ExplicitCallArguments)) 8016 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 8017 } 8018 8019 // -- the context is an initialization by user-defined conversion 8020 // (see 8.5, 13.3.1.5) and the standard conversion sequence 8021 // from the return type of F1 to the destination type (i.e., 8022 // the type of the entity being initialized) is a better 8023 // conversion sequence than the standard conversion sequence 8024 // from the return type of F2 to the destination type. 8025 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 8026 isa<CXXConversionDecl>(Cand1.Function) && 8027 isa<CXXConversionDecl>(Cand2.Function)) { 8028 // First check whether we prefer one of the conversion functions over the 8029 // other. This only distinguishes the results in non-standard, extension 8030 // cases such as the conversion from a lambda closure type to a function 8031 // pointer or block. 8032 ImplicitConversionSequence::CompareKind FuncResult 8033 = compareConversionFunctions(S, Cand1.Function, Cand2.Function); 8034 if (FuncResult != ImplicitConversionSequence::Indistinguishable) 8035 return FuncResult; 8036 8037 switch (CompareStandardConversionSequences(S, 8038 Cand1.FinalConversion, 8039 Cand2.FinalConversion)) { 8040 case ImplicitConversionSequence::Better: 8041 // Cand1 has a better conversion sequence. 8042 return true; 8043 8044 case ImplicitConversionSequence::Worse: 8045 // Cand1 can't be better than Cand2. 8046 return false; 8047 8048 case ImplicitConversionSequence::Indistinguishable: 8049 // Do nothing 8050 break; 8051 } 8052 } 8053 8054 return false; 8055} 8056 8057/// \brief Computes the best viable function (C++ 13.3.3) 8058/// within an overload candidate set. 8059/// 8060/// \param Loc The location of the function name (or operator symbol) for 8061/// which overload resolution occurs. 8062/// 8063/// \param Best If overload resolution was successful or found a deleted 8064/// function, \p Best points to the candidate function found. 8065/// 8066/// \returns The result of overload resolution. 8067OverloadingResult 8068OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 8069 iterator &Best, 8070 bool UserDefinedConversion) { 8071 // Find the best viable function. 8072 Best = end(); 8073 for (iterator Cand = begin(); Cand != end(); ++Cand) { 8074 if (Cand->Viable) 8075 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 8076 UserDefinedConversion)) 8077 Best = Cand; 8078 } 8079 8080 // If we didn't find any viable functions, abort. 8081 if (Best == end()) 8082 return OR_No_Viable_Function; 8083 8084 // Make sure that this function is better than every other viable 8085 // function. If not, we have an ambiguity. 8086 for (iterator Cand = begin(); Cand != end(); ++Cand) { 8087 if (Cand->Viable && 8088 Cand != Best && 8089 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 8090 UserDefinedConversion)) { 8091 Best = end(); 8092 return OR_Ambiguous; 8093 } 8094 } 8095 8096 // Best is the best viable function. 8097 if (Best->Function && 8098 (Best->Function->isDeleted() || 8099 S.isFunctionConsideredUnavailable(Best->Function))) 8100 return OR_Deleted; 8101 8102 return OR_Success; 8103} 8104 8105namespace { 8106 8107enum OverloadCandidateKind { 8108 oc_function, 8109 oc_method, 8110 oc_constructor, 8111 oc_function_template, 8112 oc_method_template, 8113 oc_constructor_template, 8114 oc_implicit_default_constructor, 8115 oc_implicit_copy_constructor, 8116 oc_implicit_move_constructor, 8117 oc_implicit_copy_assignment, 8118 oc_implicit_move_assignment, 8119 oc_implicit_inherited_constructor 8120}; 8121 8122OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 8123 FunctionDecl *Fn, 8124 std::string &Description) { 8125 bool isTemplate = false; 8126 8127 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 8128 isTemplate = true; 8129 Description = S.getTemplateArgumentBindingsText( 8130 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 8131 } 8132 8133 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 8134 if (!Ctor->isImplicit()) 8135 return isTemplate ? oc_constructor_template : oc_constructor; 8136 8137 if (Ctor->getInheritedConstructor()) 8138 return oc_implicit_inherited_constructor; 8139 8140 if (Ctor->isDefaultConstructor()) 8141 return oc_implicit_default_constructor; 8142 8143 if (Ctor->isMoveConstructor()) 8144 return oc_implicit_move_constructor; 8145 8146 assert(Ctor->isCopyConstructor() && 8147 "unexpected sort of implicit constructor"); 8148 return oc_implicit_copy_constructor; 8149 } 8150 8151 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 8152 // This actually gets spelled 'candidate function' for now, but 8153 // it doesn't hurt to split it out. 8154 if (!Meth->isImplicit()) 8155 return isTemplate ? oc_method_template : oc_method; 8156 8157 if (Meth->isMoveAssignmentOperator()) 8158 return oc_implicit_move_assignment; 8159 8160 if (Meth->isCopyAssignmentOperator()) 8161 return oc_implicit_copy_assignment; 8162 8163 assert(isa<CXXConversionDecl>(Meth) && "expected conversion"); 8164 return oc_method; 8165 } 8166 8167 return isTemplate ? oc_function_template : oc_function; 8168} 8169 8170void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { 8171 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 8172 if (!Ctor) return; 8173 8174 Ctor = Ctor->getInheritedConstructor(); 8175 if (!Ctor) return; 8176 8177 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 8178} 8179 8180} // end anonymous namespace 8181 8182// Notes the location of an overload candidate. 8183void Sema::NoteOverloadCandidate(FunctionDecl *Fn, QualType DestType) { 8184 std::string FnDesc; 8185 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 8186 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate) 8187 << (unsigned) K << FnDesc; 8188 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType); 8189 Diag(Fn->getLocation(), PD); 8190 MaybeEmitInheritedConstructorNote(*this, Fn); 8191} 8192 8193//Notes the location of all overload candidates designated through 8194// OverloadedExpr 8195void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr, QualType DestType) { 8196 assert(OverloadedExpr->getType() == Context.OverloadTy); 8197 8198 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); 8199 OverloadExpr *OvlExpr = Ovl.Expression; 8200 8201 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 8202 IEnd = OvlExpr->decls_end(); 8203 I != IEnd; ++I) { 8204 if (FunctionTemplateDecl *FunTmpl = 8205 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) { 8206 NoteOverloadCandidate(FunTmpl->getTemplatedDecl(), DestType); 8207 } else if (FunctionDecl *Fun 8208 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) { 8209 NoteOverloadCandidate(Fun, DestType); 8210 } 8211 } 8212} 8213 8214/// Diagnoses an ambiguous conversion. The partial diagnostic is the 8215/// "lead" diagnostic; it will be given two arguments, the source and 8216/// target types of the conversion. 8217void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 8218 Sema &S, 8219 SourceLocation CaretLoc, 8220 const PartialDiagnostic &PDiag) const { 8221 S.Diag(CaretLoc, PDiag) 8222 << Ambiguous.getFromType() << Ambiguous.getToType(); 8223 // FIXME: The note limiting machinery is borrowed from 8224 // OverloadCandidateSet::NoteCandidates; there's an opportunity for 8225 // refactoring here. 8226 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 8227 unsigned CandsShown = 0; 8228 AmbiguousConversionSequence::const_iterator I, E; 8229 for (I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 8230 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) 8231 break; 8232 ++CandsShown; 8233 S.NoteOverloadCandidate(*I); 8234 } 8235 if (I != E) 8236 S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I); 8237} 8238 8239namespace { 8240 8241void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 8242 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 8243 assert(Conv.isBad()); 8244 assert(Cand->Function && "for now, candidate must be a function"); 8245 FunctionDecl *Fn = Cand->Function; 8246 8247 // There's a conversion slot for the object argument if this is a 8248 // non-constructor method. Note that 'I' corresponds the 8249 // conversion-slot index. 8250 bool isObjectArgument = false; 8251 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 8252 if (I == 0) 8253 isObjectArgument = true; 8254 else 8255 I--; 8256 } 8257 8258 std::string FnDesc; 8259 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 8260 8261 Expr *FromExpr = Conv.Bad.FromExpr; 8262 QualType FromTy = Conv.Bad.getFromType(); 8263 QualType ToTy = Conv.Bad.getToType(); 8264 8265 if (FromTy == S.Context.OverloadTy) { 8266 assert(FromExpr && "overload set argument came from implicit argument?"); 8267 Expr *E = FromExpr->IgnoreParens(); 8268 if (isa<UnaryOperator>(E)) 8269 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 8270 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 8271 8272 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 8273 << (unsigned) FnKind << FnDesc 8274 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8275 << ToTy << Name << I+1; 8276 MaybeEmitInheritedConstructorNote(S, Fn); 8277 return; 8278 } 8279 8280 // Do some hand-waving analysis to see if the non-viability is due 8281 // to a qualifier mismatch. 8282 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 8283 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 8284 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 8285 CToTy = RT->getPointeeType(); 8286 else { 8287 // TODO: detect and diagnose the full richness of const mismatches. 8288 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 8289 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 8290 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 8291 } 8292 8293 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 8294 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 8295 Qualifiers FromQs = CFromTy.getQualifiers(); 8296 Qualifiers ToQs = CToTy.getQualifiers(); 8297 8298 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 8299 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 8300 << (unsigned) FnKind << FnDesc 8301 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8302 << FromTy 8303 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 8304 << (unsigned) isObjectArgument << I+1; 8305 MaybeEmitInheritedConstructorNote(S, Fn); 8306 return; 8307 } 8308 8309 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 8310 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership) 8311 << (unsigned) FnKind << FnDesc 8312 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8313 << FromTy 8314 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime() 8315 << (unsigned) isObjectArgument << I+1; 8316 MaybeEmitInheritedConstructorNote(S, Fn); 8317 return; 8318 } 8319 8320 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) { 8321 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc) 8322 << (unsigned) FnKind << FnDesc 8323 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8324 << FromTy 8325 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr() 8326 << (unsigned) isObjectArgument << I+1; 8327 MaybeEmitInheritedConstructorNote(S, Fn); 8328 return; 8329 } 8330 8331 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 8332 assert(CVR && "unexpected qualifiers mismatch"); 8333 8334 if (isObjectArgument) { 8335 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 8336 << (unsigned) FnKind << FnDesc 8337 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8338 << FromTy << (CVR - 1); 8339 } else { 8340 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 8341 << (unsigned) FnKind << FnDesc 8342 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8343 << FromTy << (CVR - 1) << I+1; 8344 } 8345 MaybeEmitInheritedConstructorNote(S, Fn); 8346 return; 8347 } 8348 8349 // Special diagnostic for failure to convert an initializer list, since 8350 // telling the user that it has type void is not useful. 8351 if (FromExpr && isa<InitListExpr>(FromExpr)) { 8352 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument) 8353 << (unsigned) FnKind << FnDesc 8354 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8355 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8356 MaybeEmitInheritedConstructorNote(S, Fn); 8357 return; 8358 } 8359 8360 // Diagnose references or pointers to incomplete types differently, 8361 // since it's far from impossible that the incompleteness triggered 8362 // the failure. 8363 QualType TempFromTy = FromTy.getNonReferenceType(); 8364 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 8365 TempFromTy = PTy->getPointeeType(); 8366 if (TempFromTy->isIncompleteType()) { 8367 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 8368 << (unsigned) FnKind << FnDesc 8369 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8370 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8371 MaybeEmitInheritedConstructorNote(S, Fn); 8372 return; 8373 } 8374 8375 // Diagnose base -> derived pointer conversions. 8376 unsigned BaseToDerivedConversion = 0; 8377 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 8378 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 8379 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 8380 FromPtrTy->getPointeeType()) && 8381 !FromPtrTy->getPointeeType()->isIncompleteType() && 8382 !ToPtrTy->getPointeeType()->isIncompleteType() && 8383 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 8384 FromPtrTy->getPointeeType())) 8385 BaseToDerivedConversion = 1; 8386 } 8387 } else if (const ObjCObjectPointerType *FromPtrTy 8388 = FromTy->getAs<ObjCObjectPointerType>()) { 8389 if (const ObjCObjectPointerType *ToPtrTy 8390 = ToTy->getAs<ObjCObjectPointerType>()) 8391 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 8392 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 8393 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 8394 FromPtrTy->getPointeeType()) && 8395 FromIface->isSuperClassOf(ToIface)) 8396 BaseToDerivedConversion = 2; 8397 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 8398 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 8399 !FromTy->isIncompleteType() && 8400 !ToRefTy->getPointeeType()->isIncompleteType() && 8401 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) { 8402 BaseToDerivedConversion = 3; 8403 } else if (ToTy->isLValueReferenceType() && !FromExpr->isLValue() && 8404 ToTy.getNonReferenceType().getCanonicalType() == 8405 FromTy.getNonReferenceType().getCanonicalType()) { 8406 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_lvalue) 8407 << (unsigned) FnKind << FnDesc 8408 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8409 << (unsigned) isObjectArgument << I + 1; 8410 MaybeEmitInheritedConstructorNote(S, Fn); 8411 return; 8412 } 8413 } 8414 8415 if (BaseToDerivedConversion) { 8416 S.Diag(Fn->getLocation(), 8417 diag::note_ovl_candidate_bad_base_to_derived_conv) 8418 << (unsigned) FnKind << FnDesc 8419 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8420 << (BaseToDerivedConversion - 1) 8421 << FromTy << ToTy << I+1; 8422 MaybeEmitInheritedConstructorNote(S, Fn); 8423 return; 8424 } 8425 8426 if (isa<ObjCObjectPointerType>(CFromTy) && 8427 isa<PointerType>(CToTy)) { 8428 Qualifiers FromQs = CFromTy.getQualifiers(); 8429 Qualifiers ToQs = CToTy.getQualifiers(); 8430 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 8431 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv) 8432 << (unsigned) FnKind << FnDesc 8433 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8434 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8435 MaybeEmitInheritedConstructorNote(S, Fn); 8436 return; 8437 } 8438 } 8439 8440 // Emit the generic diagnostic and, optionally, add the hints to it. 8441 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv); 8442 FDiag << (unsigned) FnKind << FnDesc 8443 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8444 << FromTy << ToTy << (unsigned) isObjectArgument << I + 1 8445 << (unsigned) (Cand->Fix.Kind); 8446 8447 // If we can fix the conversion, suggest the FixIts. 8448 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(), 8449 HE = Cand->Fix.Hints.end(); HI != HE; ++HI) 8450 FDiag << *HI; 8451 S.Diag(Fn->getLocation(), FDiag); 8452 8453 MaybeEmitInheritedConstructorNote(S, Fn); 8454} 8455 8456void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 8457 unsigned NumFormalArgs) { 8458 // TODO: treat calls to a missing default constructor as a special case 8459 8460 FunctionDecl *Fn = Cand->Function; 8461 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 8462 8463 unsigned MinParams = Fn->getMinRequiredArguments(); 8464 8465 // With invalid overloaded operators, it's possible that we think we 8466 // have an arity mismatch when it fact it looks like we have the 8467 // right number of arguments, because only overloaded operators have 8468 // the weird behavior of overloading member and non-member functions. 8469 // Just don't report anything. 8470 if (Fn->isInvalidDecl() && 8471 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName) 8472 return; 8473 8474 // at least / at most / exactly 8475 unsigned mode, modeCount; 8476 if (NumFormalArgs < MinParams) { 8477 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 8478 (Cand->FailureKind == ovl_fail_bad_deduction && 8479 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 8480 if (MinParams != FnTy->getNumArgs() || 8481 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 8482 mode = 0; // "at least" 8483 else 8484 mode = 2; // "exactly" 8485 modeCount = MinParams; 8486 } else { 8487 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 8488 (Cand->FailureKind == ovl_fail_bad_deduction && 8489 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 8490 if (MinParams != FnTy->getNumArgs()) 8491 mode = 1; // "at most" 8492 else 8493 mode = 2; // "exactly" 8494 modeCount = FnTy->getNumArgs(); 8495 } 8496 8497 std::string Description; 8498 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 8499 8500 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName()) 8501 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one) 8502 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 8503 << Fn->getParamDecl(0) << NumFormalArgs; 8504 else 8505 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 8506 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 8507 << modeCount << NumFormalArgs; 8508 MaybeEmitInheritedConstructorNote(S, Fn); 8509} 8510 8511/// Diagnose a failed template-argument deduction. 8512void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 8513 unsigned NumArgs) { 8514 FunctionDecl *Fn = Cand->Function; // pattern 8515 8516 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 8517 NamedDecl *ParamD; 8518 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 8519 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 8520 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 8521 switch (Cand->DeductionFailure.Result) { 8522 case Sema::TDK_Success: 8523 llvm_unreachable("TDK_success while diagnosing bad deduction"); 8524 8525 case Sema::TDK_Incomplete: { 8526 assert(ParamD && "no parameter found for incomplete deduction result"); 8527 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 8528 << ParamD->getDeclName(); 8529 MaybeEmitInheritedConstructorNote(S, Fn); 8530 return; 8531 } 8532 8533 case Sema::TDK_Underqualified: { 8534 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 8535 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 8536 8537 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 8538 8539 // Param will have been canonicalized, but it should just be a 8540 // qualified version of ParamD, so move the qualifiers to that. 8541 QualifierCollector Qs; 8542 Qs.strip(Param); 8543 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 8544 assert(S.Context.hasSameType(Param, NonCanonParam)); 8545 8546 // Arg has also been canonicalized, but there's nothing we can do 8547 // about that. It also doesn't matter as much, because it won't 8548 // have any template parameters in it (because deduction isn't 8549 // done on dependent types). 8550 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 8551 8552 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 8553 << ParamD->getDeclName() << Arg << NonCanonParam; 8554 MaybeEmitInheritedConstructorNote(S, Fn); 8555 return; 8556 } 8557 8558 case Sema::TDK_Inconsistent: { 8559 assert(ParamD && "no parameter found for inconsistent deduction result"); 8560 int which = 0; 8561 if (isa<TemplateTypeParmDecl>(ParamD)) 8562 which = 0; 8563 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 8564 which = 1; 8565 else { 8566 which = 2; 8567 } 8568 8569 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 8570 << which << ParamD->getDeclName() 8571 << *Cand->DeductionFailure.getFirstArg() 8572 << *Cand->DeductionFailure.getSecondArg(); 8573 MaybeEmitInheritedConstructorNote(S, Fn); 8574 return; 8575 } 8576 8577 case Sema::TDK_InvalidExplicitArguments: 8578 assert(ParamD && "no parameter found for invalid explicit arguments"); 8579 if (ParamD->getDeclName()) 8580 S.Diag(Fn->getLocation(), 8581 diag::note_ovl_candidate_explicit_arg_mismatch_named) 8582 << ParamD->getDeclName(); 8583 else { 8584 int index = 0; 8585 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 8586 index = TTP->getIndex(); 8587 else if (NonTypeTemplateParmDecl *NTTP 8588 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 8589 index = NTTP->getIndex(); 8590 else 8591 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 8592 S.Diag(Fn->getLocation(), 8593 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 8594 << (index + 1); 8595 } 8596 MaybeEmitInheritedConstructorNote(S, Fn); 8597 return; 8598 8599 case Sema::TDK_TooManyArguments: 8600 case Sema::TDK_TooFewArguments: 8601 DiagnoseArityMismatch(S, Cand, NumArgs); 8602 return; 8603 8604 case Sema::TDK_InstantiationDepth: 8605 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 8606 MaybeEmitInheritedConstructorNote(S, Fn); 8607 return; 8608 8609 case Sema::TDK_SubstitutionFailure: { 8610 // Format the template argument list into the argument string. 8611 SmallString<128> TemplateArgString; 8612 if (TemplateArgumentList *Args = 8613 Cand->DeductionFailure.getTemplateArgumentList()) { 8614 TemplateArgString = " "; 8615 TemplateArgString += S.getTemplateArgumentBindingsText( 8616 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), *Args); 8617 } 8618 8619 // If this candidate was disabled by enable_if, say so. 8620 PartialDiagnosticAt *PDiag = Cand->DeductionFailure.getSFINAEDiagnostic(); 8621 if (PDiag && PDiag->second.getDiagID() == 8622 diag::err_typename_nested_not_found_enable_if) { 8623 // FIXME: Use the source range of the condition, and the fully-qualified 8624 // name of the enable_if template. These are both present in PDiag. 8625 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if) 8626 << "'enable_if'" << TemplateArgString; 8627 return; 8628 } 8629 8630 // Format the SFINAE diagnostic into the argument string. 8631 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s 8632 // formatted message in another diagnostic. 8633 SmallString<128> SFINAEArgString; 8634 SourceRange R; 8635 if (PDiag) { 8636 SFINAEArgString = ": "; 8637 R = SourceRange(PDiag->first, PDiag->first); 8638 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString); 8639 } 8640 8641 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 8642 << TemplateArgString << SFINAEArgString << R; 8643 MaybeEmitInheritedConstructorNote(S, Fn); 8644 return; 8645 } 8646 8647 case Sema::TDK_FailedOverloadResolution: { 8648 OverloadExpr::FindResult R = 8649 OverloadExpr::find(Cand->DeductionFailure.getExpr()); 8650 S.Diag(Fn->getLocation(), 8651 diag::note_ovl_candidate_failed_overload_resolution) 8652 << R.Expression->getName(); 8653 return; 8654 } 8655 8656 case Sema::TDK_NonDeducedMismatch: { 8657 // FIXME: Provide a source location to indicate what we couldn't match. 8658 TemplateArgument FirstTA = *Cand->DeductionFailure.getFirstArg(); 8659 TemplateArgument SecondTA = *Cand->DeductionFailure.getSecondArg(); 8660 if (FirstTA.getKind() == TemplateArgument::Template && 8661 SecondTA.getKind() == TemplateArgument::Template) { 8662 TemplateName FirstTN = FirstTA.getAsTemplate(); 8663 TemplateName SecondTN = SecondTA.getAsTemplate(); 8664 if (FirstTN.getKind() == TemplateName::Template && 8665 SecondTN.getKind() == TemplateName::Template) { 8666 if (FirstTN.getAsTemplateDecl()->getName() == 8667 SecondTN.getAsTemplateDecl()->getName()) { 8668 // FIXME: This fixes a bad diagnostic where both templates are named 8669 // the same. This particular case is a bit difficult since: 8670 // 1) It is passed as a string to the diagnostic printer. 8671 // 2) The diagnostic printer only attempts to find a better 8672 // name for types, not decls. 8673 // Ideally, this should folded into the diagnostic printer. 8674 S.Diag(Fn->getLocation(), 8675 diag::note_ovl_candidate_non_deduced_mismatch_qualified) 8676 << FirstTN.getAsTemplateDecl() << SecondTN.getAsTemplateDecl(); 8677 return; 8678 } 8679 } 8680 } 8681 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_non_deduced_mismatch) 8682 << FirstTA << SecondTA; 8683 return; 8684 } 8685 // TODO: diagnose these individually, then kill off 8686 // note_ovl_candidate_bad_deduction, which is uselessly vague. 8687 case Sema::TDK_MiscellaneousDeductionFailure: 8688 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 8689 MaybeEmitInheritedConstructorNote(S, Fn); 8690 return; 8691 } 8692} 8693 8694/// CUDA: diagnose an invalid call across targets. 8695void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) { 8696 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext); 8697 FunctionDecl *Callee = Cand->Function; 8698 8699 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller), 8700 CalleeTarget = S.IdentifyCUDATarget(Callee); 8701 8702 std::string FnDesc; 8703 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Callee, FnDesc); 8704 8705 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target) 8706 << (unsigned) FnKind << CalleeTarget << CallerTarget; 8707} 8708 8709/// Generates a 'note' diagnostic for an overload candidate. We've 8710/// already generated a primary error at the call site. 8711/// 8712/// It really does need to be a single diagnostic with its caret 8713/// pointed at the candidate declaration. Yes, this creates some 8714/// major challenges of technical writing. Yes, this makes pointing 8715/// out problems with specific arguments quite awkward. It's still 8716/// better than generating twenty screens of text for every failed 8717/// overload. 8718/// 8719/// It would be great to be able to express per-candidate problems 8720/// more richly for those diagnostic clients that cared, but we'd 8721/// still have to be just as careful with the default diagnostics. 8722void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 8723 unsigned NumArgs) { 8724 FunctionDecl *Fn = Cand->Function; 8725 8726 // Note deleted candidates, but only if they're viable. 8727 if (Cand->Viable && (Fn->isDeleted() || 8728 S.isFunctionConsideredUnavailable(Fn))) { 8729 std::string FnDesc; 8730 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 8731 8732 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 8733 << FnKind << FnDesc 8734 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0); 8735 MaybeEmitInheritedConstructorNote(S, Fn); 8736 return; 8737 } 8738 8739 // We don't really have anything else to say about viable candidates. 8740 if (Cand->Viable) { 8741 S.NoteOverloadCandidate(Fn); 8742 return; 8743 } 8744 8745 switch (Cand->FailureKind) { 8746 case ovl_fail_too_many_arguments: 8747 case ovl_fail_too_few_arguments: 8748 return DiagnoseArityMismatch(S, Cand, NumArgs); 8749 8750 case ovl_fail_bad_deduction: 8751 return DiagnoseBadDeduction(S, Cand, NumArgs); 8752 8753 case ovl_fail_trivial_conversion: 8754 case ovl_fail_bad_final_conversion: 8755 case ovl_fail_final_conversion_not_exact: 8756 return S.NoteOverloadCandidate(Fn); 8757 8758 case ovl_fail_bad_conversion: { 8759 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 8760 for (unsigned N = Cand->NumConversions; I != N; ++I) 8761 if (Cand->Conversions[I].isBad()) 8762 return DiagnoseBadConversion(S, Cand, I); 8763 8764 // FIXME: this currently happens when we're called from SemaInit 8765 // when user-conversion overload fails. Figure out how to handle 8766 // those conditions and diagnose them well. 8767 return S.NoteOverloadCandidate(Fn); 8768 } 8769 8770 case ovl_fail_bad_target: 8771 return DiagnoseBadTarget(S, Cand); 8772 } 8773} 8774 8775void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 8776 // Desugar the type of the surrogate down to a function type, 8777 // retaining as many typedefs as possible while still showing 8778 // the function type (and, therefore, its parameter types). 8779 QualType FnType = Cand->Surrogate->getConversionType(); 8780 bool isLValueReference = false; 8781 bool isRValueReference = false; 8782 bool isPointer = false; 8783 if (const LValueReferenceType *FnTypeRef = 8784 FnType->getAs<LValueReferenceType>()) { 8785 FnType = FnTypeRef->getPointeeType(); 8786 isLValueReference = true; 8787 } else if (const RValueReferenceType *FnTypeRef = 8788 FnType->getAs<RValueReferenceType>()) { 8789 FnType = FnTypeRef->getPointeeType(); 8790 isRValueReference = true; 8791 } 8792 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 8793 FnType = FnTypePtr->getPointeeType(); 8794 isPointer = true; 8795 } 8796 // Desugar down to a function type. 8797 FnType = QualType(FnType->getAs<FunctionType>(), 0); 8798 // Reconstruct the pointer/reference as appropriate. 8799 if (isPointer) FnType = S.Context.getPointerType(FnType); 8800 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 8801 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 8802 8803 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 8804 << FnType; 8805 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 8806} 8807 8808void NoteBuiltinOperatorCandidate(Sema &S, 8809 StringRef Opc, 8810 SourceLocation OpLoc, 8811 OverloadCandidate *Cand) { 8812 assert(Cand->NumConversions <= 2 && "builtin operator is not binary"); 8813 std::string TypeStr("operator"); 8814 TypeStr += Opc; 8815 TypeStr += "("; 8816 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 8817 if (Cand->NumConversions == 1) { 8818 TypeStr += ")"; 8819 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 8820 } else { 8821 TypeStr += ", "; 8822 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 8823 TypeStr += ")"; 8824 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 8825 } 8826} 8827 8828void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 8829 OverloadCandidate *Cand) { 8830 unsigned NoOperands = Cand->NumConversions; 8831 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 8832 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 8833 if (ICS.isBad()) break; // all meaningless after first invalid 8834 if (!ICS.isAmbiguous()) continue; 8835 8836 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 8837 S.PDiag(diag::note_ambiguous_type_conversion)); 8838 } 8839} 8840 8841SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 8842 if (Cand->Function) 8843 return Cand->Function->getLocation(); 8844 if (Cand->IsSurrogate) 8845 return Cand->Surrogate->getLocation(); 8846 return SourceLocation(); 8847} 8848 8849static unsigned 8850RankDeductionFailure(const OverloadCandidate::DeductionFailureInfo &DFI) { 8851 switch ((Sema::TemplateDeductionResult)DFI.Result) { 8852 case Sema::TDK_Success: 8853 llvm_unreachable("TDK_success while diagnosing bad deduction"); 8854 8855 case Sema::TDK_Invalid: 8856 case Sema::TDK_Incomplete: 8857 return 1; 8858 8859 case Sema::TDK_Underqualified: 8860 case Sema::TDK_Inconsistent: 8861 return 2; 8862 8863 case Sema::TDK_SubstitutionFailure: 8864 case Sema::TDK_NonDeducedMismatch: 8865 case Sema::TDK_MiscellaneousDeductionFailure: 8866 return 3; 8867 8868 case Sema::TDK_InstantiationDepth: 8869 case Sema::TDK_FailedOverloadResolution: 8870 return 4; 8871 8872 case Sema::TDK_InvalidExplicitArguments: 8873 return 5; 8874 8875 case Sema::TDK_TooManyArguments: 8876 case Sema::TDK_TooFewArguments: 8877 return 6; 8878 } 8879 llvm_unreachable("Unhandled deduction result"); 8880} 8881 8882struct CompareOverloadCandidatesForDisplay { 8883 Sema &S; 8884 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 8885 8886 bool operator()(const OverloadCandidate *L, 8887 const OverloadCandidate *R) { 8888 // Fast-path this check. 8889 if (L == R) return false; 8890 8891 // Order first by viability. 8892 if (L->Viable) { 8893 if (!R->Viable) return true; 8894 8895 // TODO: introduce a tri-valued comparison for overload 8896 // candidates. Would be more worthwhile if we had a sort 8897 // that could exploit it. 8898 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 8899 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 8900 } else if (R->Viable) 8901 return false; 8902 8903 assert(L->Viable == R->Viable); 8904 8905 // Criteria by which we can sort non-viable candidates: 8906 if (!L->Viable) { 8907 // 1. Arity mismatches come after other candidates. 8908 if (L->FailureKind == ovl_fail_too_many_arguments || 8909 L->FailureKind == ovl_fail_too_few_arguments) 8910 return false; 8911 if (R->FailureKind == ovl_fail_too_many_arguments || 8912 R->FailureKind == ovl_fail_too_few_arguments) 8913 return true; 8914 8915 // 2. Bad conversions come first and are ordered by the number 8916 // of bad conversions and quality of good conversions. 8917 if (L->FailureKind == ovl_fail_bad_conversion) { 8918 if (R->FailureKind != ovl_fail_bad_conversion) 8919 return true; 8920 8921 // The conversion that can be fixed with a smaller number of changes, 8922 // comes first. 8923 unsigned numLFixes = L->Fix.NumConversionsFixed; 8924 unsigned numRFixes = R->Fix.NumConversionsFixed; 8925 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes; 8926 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes; 8927 if (numLFixes != numRFixes) { 8928 if (numLFixes < numRFixes) 8929 return true; 8930 else 8931 return false; 8932 } 8933 8934 // If there's any ordering between the defined conversions... 8935 // FIXME: this might not be transitive. 8936 assert(L->NumConversions == R->NumConversions); 8937 8938 int leftBetter = 0; 8939 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 8940 for (unsigned E = L->NumConversions; I != E; ++I) { 8941 switch (CompareImplicitConversionSequences(S, 8942 L->Conversions[I], 8943 R->Conversions[I])) { 8944 case ImplicitConversionSequence::Better: 8945 leftBetter++; 8946 break; 8947 8948 case ImplicitConversionSequence::Worse: 8949 leftBetter--; 8950 break; 8951 8952 case ImplicitConversionSequence::Indistinguishable: 8953 break; 8954 } 8955 } 8956 if (leftBetter > 0) return true; 8957 if (leftBetter < 0) return false; 8958 8959 } else if (R->FailureKind == ovl_fail_bad_conversion) 8960 return false; 8961 8962 if (L->FailureKind == ovl_fail_bad_deduction) { 8963 if (R->FailureKind != ovl_fail_bad_deduction) 8964 return true; 8965 8966 if (L->DeductionFailure.Result != R->DeductionFailure.Result) 8967 return RankDeductionFailure(L->DeductionFailure) 8968 < RankDeductionFailure(R->DeductionFailure); 8969 } else if (R->FailureKind == ovl_fail_bad_deduction) 8970 return false; 8971 8972 // TODO: others? 8973 } 8974 8975 // Sort everything else by location. 8976 SourceLocation LLoc = GetLocationForCandidate(L); 8977 SourceLocation RLoc = GetLocationForCandidate(R); 8978 8979 // Put candidates without locations (e.g. builtins) at the end. 8980 if (LLoc.isInvalid()) return false; 8981 if (RLoc.isInvalid()) return true; 8982 8983 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 8984 } 8985}; 8986 8987/// CompleteNonViableCandidate - Normally, overload resolution only 8988/// computes up to the first. Produces the FixIt set if possible. 8989void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 8990 ArrayRef<Expr *> Args) { 8991 assert(!Cand->Viable); 8992 8993 // Don't do anything on failures other than bad conversion. 8994 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 8995 8996 // We only want the FixIts if all the arguments can be corrected. 8997 bool Unfixable = false; 8998 // Use a implicit copy initialization to check conversion fixes. 8999 Cand->Fix.setConversionChecker(TryCopyInitialization); 9000 9001 // Skip forward to the first bad conversion. 9002 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 9003 unsigned ConvCount = Cand->NumConversions; 9004 while (true) { 9005 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 9006 ConvIdx++; 9007 if (Cand->Conversions[ConvIdx - 1].isBad()) { 9008 Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S); 9009 break; 9010 } 9011 } 9012 9013 if (ConvIdx == ConvCount) 9014 return; 9015 9016 assert(!Cand->Conversions[ConvIdx].isInitialized() && 9017 "remaining conversion is initialized?"); 9018 9019 // FIXME: this should probably be preserved from the overload 9020 // operation somehow. 9021 bool SuppressUserConversions = false; 9022 9023 const FunctionProtoType* Proto; 9024 unsigned ArgIdx = ConvIdx; 9025 9026 if (Cand->IsSurrogate) { 9027 QualType ConvType 9028 = Cand->Surrogate->getConversionType().getNonReferenceType(); 9029 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 9030 ConvType = ConvPtrType->getPointeeType(); 9031 Proto = ConvType->getAs<FunctionProtoType>(); 9032 ArgIdx--; 9033 } else if (Cand->Function) { 9034 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 9035 if (isa<CXXMethodDecl>(Cand->Function) && 9036 !isa<CXXConstructorDecl>(Cand->Function)) 9037 ArgIdx--; 9038 } else { 9039 // Builtin binary operator with a bad first conversion. 9040 assert(ConvCount <= 3); 9041 for (; ConvIdx != ConvCount; ++ConvIdx) 9042 Cand->Conversions[ConvIdx] 9043 = TryCopyInitialization(S, Args[ConvIdx], 9044 Cand->BuiltinTypes.ParamTypes[ConvIdx], 9045 SuppressUserConversions, 9046 /*InOverloadResolution*/ true, 9047 /*AllowObjCWritebackConversion=*/ 9048 S.getLangOpts().ObjCAutoRefCount); 9049 return; 9050 } 9051 9052 // Fill in the rest of the conversions. 9053 unsigned NumArgsInProto = Proto->getNumArgs(); 9054 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 9055 if (ArgIdx < NumArgsInProto) { 9056 Cand->Conversions[ConvIdx] 9057 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 9058 SuppressUserConversions, 9059 /*InOverloadResolution=*/true, 9060 /*AllowObjCWritebackConversion=*/ 9061 S.getLangOpts().ObjCAutoRefCount); 9062 // Store the FixIt in the candidate if it exists. 9063 if (!Unfixable && Cand->Conversions[ConvIdx].isBad()) 9064 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S); 9065 } 9066 else 9067 Cand->Conversions[ConvIdx].setEllipsis(); 9068 } 9069} 9070 9071} // end anonymous namespace 9072 9073/// PrintOverloadCandidates - When overload resolution fails, prints 9074/// diagnostic messages containing the candidates in the candidate 9075/// set. 9076void OverloadCandidateSet::NoteCandidates(Sema &S, 9077 OverloadCandidateDisplayKind OCD, 9078 ArrayRef<Expr *> Args, 9079 StringRef Opc, 9080 SourceLocation OpLoc) { 9081 // Sort the candidates by viability and position. Sorting directly would 9082 // be prohibitive, so we make a set of pointers and sort those. 9083 SmallVector<OverloadCandidate*, 32> Cands; 9084 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 9085 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 9086 if (Cand->Viable) 9087 Cands.push_back(Cand); 9088 else if (OCD == OCD_AllCandidates) { 9089 CompleteNonViableCandidate(S, Cand, Args); 9090 if (Cand->Function || Cand->IsSurrogate) 9091 Cands.push_back(Cand); 9092 // Otherwise, this a non-viable builtin candidate. We do not, in general, 9093 // want to list every possible builtin candidate. 9094 } 9095 } 9096 9097 std::sort(Cands.begin(), Cands.end(), 9098 CompareOverloadCandidatesForDisplay(S)); 9099 9100 bool ReportedAmbiguousConversions = false; 9101 9102 SmallVectorImpl<OverloadCandidate*>::iterator I, E; 9103 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 9104 unsigned CandsShown = 0; 9105 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 9106 OverloadCandidate *Cand = *I; 9107 9108 // Set an arbitrary limit on the number of candidate functions we'll spam 9109 // the user with. FIXME: This limit should depend on details of the 9110 // candidate list. 9111 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) { 9112 break; 9113 } 9114 ++CandsShown; 9115 9116 if (Cand->Function) 9117 NoteFunctionCandidate(S, Cand, Args.size()); 9118 else if (Cand->IsSurrogate) 9119 NoteSurrogateCandidate(S, Cand); 9120 else { 9121 assert(Cand->Viable && 9122 "Non-viable built-in candidates are not added to Cands."); 9123 // Generally we only see ambiguities including viable builtin 9124 // operators if overload resolution got screwed up by an 9125 // ambiguous user-defined conversion. 9126 // 9127 // FIXME: It's quite possible for different conversions to see 9128 // different ambiguities, though. 9129 if (!ReportedAmbiguousConversions) { 9130 NoteAmbiguousUserConversions(S, OpLoc, Cand); 9131 ReportedAmbiguousConversions = true; 9132 } 9133 9134 // If this is a viable builtin, print it. 9135 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 9136 } 9137 } 9138 9139 if (I != E) 9140 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 9141} 9142 9143// [PossiblyAFunctionType] --> [Return] 9144// NonFunctionType --> NonFunctionType 9145// R (A) --> R(A) 9146// R (*)(A) --> R (A) 9147// R (&)(A) --> R (A) 9148// R (S::*)(A) --> R (A) 9149QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { 9150 QualType Ret = PossiblyAFunctionType; 9151 if (const PointerType *ToTypePtr = 9152 PossiblyAFunctionType->getAs<PointerType>()) 9153 Ret = ToTypePtr->getPointeeType(); 9154 else if (const ReferenceType *ToTypeRef = 9155 PossiblyAFunctionType->getAs<ReferenceType>()) 9156 Ret = ToTypeRef->getPointeeType(); 9157 else if (const MemberPointerType *MemTypePtr = 9158 PossiblyAFunctionType->getAs<MemberPointerType>()) 9159 Ret = MemTypePtr->getPointeeType(); 9160 Ret = 9161 Context.getCanonicalType(Ret).getUnqualifiedType(); 9162 return Ret; 9163} 9164 9165// A helper class to help with address of function resolution 9166// - allows us to avoid passing around all those ugly parameters 9167class AddressOfFunctionResolver 9168{ 9169 Sema& S; 9170 Expr* SourceExpr; 9171 const QualType& TargetType; 9172 QualType TargetFunctionType; // Extracted function type from target type 9173 9174 bool Complain; 9175 //DeclAccessPair& ResultFunctionAccessPair; 9176 ASTContext& Context; 9177 9178 bool TargetTypeIsNonStaticMemberFunction; 9179 bool FoundNonTemplateFunction; 9180 9181 OverloadExpr::FindResult OvlExprInfo; 9182 OverloadExpr *OvlExpr; 9183 TemplateArgumentListInfo OvlExplicitTemplateArgs; 9184 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 9185 9186public: 9187 AddressOfFunctionResolver(Sema &S, Expr* SourceExpr, 9188 const QualType& TargetType, bool Complain) 9189 : S(S), SourceExpr(SourceExpr), TargetType(TargetType), 9190 Complain(Complain), Context(S.getASTContext()), 9191 TargetTypeIsNonStaticMemberFunction( 9192 !!TargetType->getAs<MemberPointerType>()), 9193 FoundNonTemplateFunction(false), 9194 OvlExprInfo(OverloadExpr::find(SourceExpr)), 9195 OvlExpr(OvlExprInfo.Expression) 9196 { 9197 ExtractUnqualifiedFunctionTypeFromTargetType(); 9198 9199 if (!TargetFunctionType->isFunctionType()) { 9200 if (OvlExpr->hasExplicitTemplateArgs()) { 9201 DeclAccessPair dap; 9202 if (FunctionDecl* Fn = S.ResolveSingleFunctionTemplateSpecialization( 9203 OvlExpr, false, &dap) ) { 9204 9205 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 9206 if (!Method->isStatic()) { 9207 // If the target type is a non-function type and the function 9208 // found is a non-static member function, pretend as if that was 9209 // the target, it's the only possible type to end up with. 9210 TargetTypeIsNonStaticMemberFunction = true; 9211 9212 // And skip adding the function if its not in the proper form. 9213 // We'll diagnose this due to an empty set of functions. 9214 if (!OvlExprInfo.HasFormOfMemberPointer) 9215 return; 9216 } 9217 } 9218 9219 Matches.push_back(std::make_pair(dap,Fn)); 9220 } 9221 } 9222 return; 9223 } 9224 9225 if (OvlExpr->hasExplicitTemplateArgs()) 9226 OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); 9227 9228 if (FindAllFunctionsThatMatchTargetTypeExactly()) { 9229 // C++ [over.over]p4: 9230 // If more than one function is selected, [...] 9231 if (Matches.size() > 1) { 9232 if (FoundNonTemplateFunction) 9233 EliminateAllTemplateMatches(); 9234 else 9235 EliminateAllExceptMostSpecializedTemplate(); 9236 } 9237 } 9238 } 9239 9240private: 9241 bool isTargetTypeAFunction() const { 9242 return TargetFunctionType->isFunctionType(); 9243 } 9244 9245 // [ToType] [Return] 9246 9247 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false 9248 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false 9249 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true 9250 void inline ExtractUnqualifiedFunctionTypeFromTargetType() { 9251 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); 9252 } 9253 9254 // return true if any matching specializations were found 9255 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, 9256 const DeclAccessPair& CurAccessFunPair) { 9257 if (CXXMethodDecl *Method 9258 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 9259 // Skip non-static function templates when converting to pointer, and 9260 // static when converting to member pointer. 9261 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 9262 return false; 9263 } 9264 else if (TargetTypeIsNonStaticMemberFunction) 9265 return false; 9266 9267 // C++ [over.over]p2: 9268 // If the name is a function template, template argument deduction is 9269 // done (14.8.2.2), and if the argument deduction succeeds, the 9270 // resulting template argument list is used to generate a single 9271 // function template specialization, which is added to the set of 9272 // overloaded functions considered. 9273 FunctionDecl *Specialization = 0; 9274 TemplateDeductionInfo Info(OvlExpr->getNameLoc()); 9275 if (Sema::TemplateDeductionResult Result 9276 = S.DeduceTemplateArguments(FunctionTemplate, 9277 &OvlExplicitTemplateArgs, 9278 TargetFunctionType, Specialization, 9279 Info, /*InOverloadResolution=*/true)) { 9280 // FIXME: make a note of the failed deduction for diagnostics. 9281 (void)Result; 9282 return false; 9283 } 9284 9285 // Template argument deduction ensures that we have an exact match or 9286 // compatible pointer-to-function arguments that would be adjusted by ICS. 9287 // This function template specicalization works. 9288 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 9289 assert(S.isSameOrCompatibleFunctionType( 9290 Context.getCanonicalType(Specialization->getType()), 9291 Context.getCanonicalType(TargetFunctionType))); 9292 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); 9293 return true; 9294 } 9295 9296 bool AddMatchingNonTemplateFunction(NamedDecl* Fn, 9297 const DeclAccessPair& CurAccessFunPair) { 9298 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 9299 // Skip non-static functions when converting to pointer, and static 9300 // when converting to member pointer. 9301 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 9302 return false; 9303 } 9304 else if (TargetTypeIsNonStaticMemberFunction) 9305 return false; 9306 9307 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 9308 if (S.getLangOpts().CUDA) 9309 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext)) 9310 if (S.CheckCUDATarget(Caller, FunDecl)) 9311 return false; 9312 9313 // If any candidate has a placeholder return type, trigger its deduction 9314 // now. 9315 if (S.getLangOpts().CPlusPlus1y && 9316 FunDecl->getResultType()->isUndeducedType() && 9317 S.DeduceReturnType(FunDecl, SourceExpr->getLocStart(), Complain)) 9318 return false; 9319 9320 QualType ResultTy; 9321 if (Context.hasSameUnqualifiedType(TargetFunctionType, 9322 FunDecl->getType()) || 9323 S.IsNoReturnConversion(FunDecl->getType(), TargetFunctionType, 9324 ResultTy)) { 9325 Matches.push_back(std::make_pair(CurAccessFunPair, 9326 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 9327 FoundNonTemplateFunction = true; 9328 return true; 9329 } 9330 } 9331 9332 return false; 9333 } 9334 9335 bool FindAllFunctionsThatMatchTargetTypeExactly() { 9336 bool Ret = false; 9337 9338 // If the overload expression doesn't have the form of a pointer to 9339 // member, don't try to convert it to a pointer-to-member type. 9340 if (IsInvalidFormOfPointerToMemberFunction()) 9341 return false; 9342 9343 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 9344 E = OvlExpr->decls_end(); 9345 I != E; ++I) { 9346 // Look through any using declarations to find the underlying function. 9347 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 9348 9349 // C++ [over.over]p3: 9350 // Non-member functions and static member functions match 9351 // targets of type "pointer-to-function" or "reference-to-function." 9352 // Nonstatic member functions match targets of 9353 // type "pointer-to-member-function." 9354 // Note that according to DR 247, the containing class does not matter. 9355 if (FunctionTemplateDecl *FunctionTemplate 9356 = dyn_cast<FunctionTemplateDecl>(Fn)) { 9357 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) 9358 Ret = true; 9359 } 9360 // If we have explicit template arguments supplied, skip non-templates. 9361 else if (!OvlExpr->hasExplicitTemplateArgs() && 9362 AddMatchingNonTemplateFunction(Fn, I.getPair())) 9363 Ret = true; 9364 } 9365 assert(Ret || Matches.empty()); 9366 return Ret; 9367 } 9368 9369 void EliminateAllExceptMostSpecializedTemplate() { 9370 // [...] and any given function template specialization F1 is 9371 // eliminated if the set contains a second function template 9372 // specialization whose function template is more specialized 9373 // than the function template of F1 according to the partial 9374 // ordering rules of 14.5.5.2. 9375 9376 // The algorithm specified above is quadratic. We instead use a 9377 // two-pass algorithm (similar to the one used to identify the 9378 // best viable function in an overload set) that identifies the 9379 // best function template (if it exists). 9380 9381 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 9382 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 9383 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 9384 9385 UnresolvedSetIterator Result = 9386 S.getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 9387 TPOC_Other, 0, SourceExpr->getLocStart(), 9388 S.PDiag(), 9389 S.PDiag(diag::err_addr_ovl_ambiguous) 9390 << Matches[0].second->getDeclName(), 9391 S.PDiag(diag::note_ovl_candidate) 9392 << (unsigned) oc_function_template, 9393 Complain, TargetFunctionType); 9394 9395 if (Result != MatchesCopy.end()) { 9396 // Make it the first and only element 9397 Matches[0].first = Matches[Result - MatchesCopy.begin()].first; 9398 Matches[0].second = cast<FunctionDecl>(*Result); 9399 Matches.resize(1); 9400 } 9401 } 9402 9403 void EliminateAllTemplateMatches() { 9404 // [...] any function template specializations in the set are 9405 // eliminated if the set also contains a non-template function, [...] 9406 for (unsigned I = 0, N = Matches.size(); I != N; ) { 9407 if (Matches[I].second->getPrimaryTemplate() == 0) 9408 ++I; 9409 else { 9410 Matches[I] = Matches[--N]; 9411 Matches.set_size(N); 9412 } 9413 } 9414 } 9415 9416public: 9417 void ComplainNoMatchesFound() const { 9418 assert(Matches.empty()); 9419 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) 9420 << OvlExpr->getName() << TargetFunctionType 9421 << OvlExpr->getSourceRange(); 9422 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); 9423 } 9424 9425 bool IsInvalidFormOfPointerToMemberFunction() const { 9426 return TargetTypeIsNonStaticMemberFunction && 9427 !OvlExprInfo.HasFormOfMemberPointer; 9428 } 9429 9430 void ComplainIsInvalidFormOfPointerToMemberFunction() const { 9431 // TODO: Should we condition this on whether any functions might 9432 // have matched, or is it more appropriate to do that in callers? 9433 // TODO: a fixit wouldn't hurt. 9434 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 9435 << TargetType << OvlExpr->getSourceRange(); 9436 } 9437 9438 void ComplainOfInvalidConversion() const { 9439 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 9440 << OvlExpr->getName() << TargetType; 9441 } 9442 9443 void ComplainMultipleMatchesFound() const { 9444 assert(Matches.size() > 1); 9445 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) 9446 << OvlExpr->getName() 9447 << OvlExpr->getSourceRange(); 9448 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); 9449 } 9450 9451 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); } 9452 9453 int getNumMatches() const { return Matches.size(); } 9454 9455 FunctionDecl* getMatchingFunctionDecl() const { 9456 if (Matches.size() != 1) return 0; 9457 return Matches[0].second; 9458 } 9459 9460 const DeclAccessPair* getMatchingFunctionAccessPair() const { 9461 if (Matches.size() != 1) return 0; 9462 return &Matches[0].first; 9463 } 9464}; 9465 9466/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 9467/// an overloaded function (C++ [over.over]), where @p From is an 9468/// expression with overloaded function type and @p ToType is the type 9469/// we're trying to resolve to. For example: 9470/// 9471/// @code 9472/// int f(double); 9473/// int f(int); 9474/// 9475/// int (*pfd)(double) = f; // selects f(double) 9476/// @endcode 9477/// 9478/// This routine returns the resulting FunctionDecl if it could be 9479/// resolved, and NULL otherwise. When @p Complain is true, this 9480/// routine will emit diagnostics if there is an error. 9481FunctionDecl * 9482Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, 9483 QualType TargetType, 9484 bool Complain, 9485 DeclAccessPair &FoundResult, 9486 bool *pHadMultipleCandidates) { 9487 assert(AddressOfExpr->getType() == Context.OverloadTy); 9488 9489 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, 9490 Complain); 9491 int NumMatches = Resolver.getNumMatches(); 9492 FunctionDecl* Fn = 0; 9493 if (NumMatches == 0 && Complain) { 9494 if (Resolver.IsInvalidFormOfPointerToMemberFunction()) 9495 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); 9496 else 9497 Resolver.ComplainNoMatchesFound(); 9498 } 9499 else if (NumMatches > 1 && Complain) 9500 Resolver.ComplainMultipleMatchesFound(); 9501 else if (NumMatches == 1) { 9502 Fn = Resolver.getMatchingFunctionDecl(); 9503 assert(Fn); 9504 FoundResult = *Resolver.getMatchingFunctionAccessPair(); 9505 if (Complain) 9506 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); 9507 } 9508 9509 if (pHadMultipleCandidates) 9510 *pHadMultipleCandidates = Resolver.hadMultipleCandidates(); 9511 return Fn; 9512} 9513 9514/// \brief Given an expression that refers to an overloaded function, try to 9515/// resolve that overloaded function expression down to a single function. 9516/// 9517/// This routine can only resolve template-ids that refer to a single function 9518/// template, where that template-id refers to a single template whose template 9519/// arguments are either provided by the template-id or have defaults, 9520/// as described in C++0x [temp.arg.explicit]p3. 9521FunctionDecl * 9522Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl, 9523 bool Complain, 9524 DeclAccessPair *FoundResult) { 9525 // C++ [over.over]p1: 9526 // [...] [Note: any redundant set of parentheses surrounding the 9527 // overloaded function name is ignored (5.1). ] 9528 // C++ [over.over]p1: 9529 // [...] The overloaded function name can be preceded by the & 9530 // operator. 9531 9532 // If we didn't actually find any template-ids, we're done. 9533 if (!ovl->hasExplicitTemplateArgs()) 9534 return 0; 9535 9536 TemplateArgumentListInfo ExplicitTemplateArgs; 9537 ovl->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 9538 9539 // Look through all of the overloaded functions, searching for one 9540 // whose type matches exactly. 9541 FunctionDecl *Matched = 0; 9542 for (UnresolvedSetIterator I = ovl->decls_begin(), 9543 E = ovl->decls_end(); I != E; ++I) { 9544 // C++0x [temp.arg.explicit]p3: 9545 // [...] In contexts where deduction is done and fails, or in contexts 9546 // where deduction is not done, if a template argument list is 9547 // specified and it, along with any default template arguments, 9548 // identifies a single function template specialization, then the 9549 // template-id is an lvalue for the function template specialization. 9550 FunctionTemplateDecl *FunctionTemplate 9551 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 9552 9553 // C++ [over.over]p2: 9554 // If the name is a function template, template argument deduction is 9555 // done (14.8.2.2), and if the argument deduction succeeds, the 9556 // resulting template argument list is used to generate a single 9557 // function template specialization, which is added to the set of 9558 // overloaded functions considered. 9559 FunctionDecl *Specialization = 0; 9560 TemplateDeductionInfo Info(ovl->getNameLoc()); 9561 if (TemplateDeductionResult Result 9562 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 9563 Specialization, Info, 9564 /*InOverloadResolution=*/true)) { 9565 // FIXME: make a note of the failed deduction for diagnostics. 9566 (void)Result; 9567 continue; 9568 } 9569 9570 assert(Specialization && "no specialization and no error?"); 9571 9572 // Multiple matches; we can't resolve to a single declaration. 9573 if (Matched) { 9574 if (Complain) { 9575 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous) 9576 << ovl->getName(); 9577 NoteAllOverloadCandidates(ovl); 9578 } 9579 return 0; 9580 } 9581 9582 Matched = Specialization; 9583 if (FoundResult) *FoundResult = I.getPair(); 9584 } 9585 9586 if (Matched && getLangOpts().CPlusPlus1y && 9587 Matched->getResultType()->isUndeducedType() && 9588 DeduceReturnType(Matched, ovl->getExprLoc(), Complain)) 9589 return 0; 9590 9591 return Matched; 9592} 9593 9594 9595 9596 9597// Resolve and fix an overloaded expression that can be resolved 9598// because it identifies a single function template specialization. 9599// 9600// Last three arguments should only be supplied if Complain = true 9601// 9602// Return true if it was logically possible to so resolve the 9603// expression, regardless of whether or not it succeeded. Always 9604// returns true if 'complain' is set. 9605bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization( 9606 ExprResult &SrcExpr, bool doFunctionPointerConverion, 9607 bool complain, const SourceRange& OpRangeForComplaining, 9608 QualType DestTypeForComplaining, 9609 unsigned DiagIDForComplaining) { 9610 assert(SrcExpr.get()->getType() == Context.OverloadTy); 9611 9612 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get()); 9613 9614 DeclAccessPair found; 9615 ExprResult SingleFunctionExpression; 9616 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization( 9617 ovl.Expression, /*complain*/ false, &found)) { 9618 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getLocStart())) { 9619 SrcExpr = ExprError(); 9620 return true; 9621 } 9622 9623 // It is only correct to resolve to an instance method if we're 9624 // resolving a form that's permitted to be a pointer to member. 9625 // Otherwise we'll end up making a bound member expression, which 9626 // is illegal in all the contexts we resolve like this. 9627 if (!ovl.HasFormOfMemberPointer && 9628 isa<CXXMethodDecl>(fn) && 9629 cast<CXXMethodDecl>(fn)->isInstance()) { 9630 if (!complain) return false; 9631 9632 Diag(ovl.Expression->getExprLoc(), 9633 diag::err_bound_member_function) 9634 << 0 << ovl.Expression->getSourceRange(); 9635 9636 // TODO: I believe we only end up here if there's a mix of 9637 // static and non-static candidates (otherwise the expression 9638 // would have 'bound member' type, not 'overload' type). 9639 // Ideally we would note which candidate was chosen and why 9640 // the static candidates were rejected. 9641 SrcExpr = ExprError(); 9642 return true; 9643 } 9644 9645 // Fix the expression to refer to 'fn'. 9646 SingleFunctionExpression = 9647 Owned(FixOverloadedFunctionReference(SrcExpr.take(), found, fn)); 9648 9649 // If desired, do function-to-pointer decay. 9650 if (doFunctionPointerConverion) { 9651 SingleFunctionExpression = 9652 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.take()); 9653 if (SingleFunctionExpression.isInvalid()) { 9654 SrcExpr = ExprError(); 9655 return true; 9656 } 9657 } 9658 } 9659 9660 if (!SingleFunctionExpression.isUsable()) { 9661 if (complain) { 9662 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) 9663 << ovl.Expression->getName() 9664 << DestTypeForComplaining 9665 << OpRangeForComplaining 9666 << ovl.Expression->getQualifierLoc().getSourceRange(); 9667 NoteAllOverloadCandidates(SrcExpr.get()); 9668 9669 SrcExpr = ExprError(); 9670 return true; 9671 } 9672 9673 return false; 9674 } 9675 9676 SrcExpr = SingleFunctionExpression; 9677 return true; 9678} 9679 9680/// \brief Add a single candidate to the overload set. 9681static void AddOverloadedCallCandidate(Sema &S, 9682 DeclAccessPair FoundDecl, 9683 TemplateArgumentListInfo *ExplicitTemplateArgs, 9684 ArrayRef<Expr *> Args, 9685 OverloadCandidateSet &CandidateSet, 9686 bool PartialOverloading, 9687 bool KnownValid) { 9688 NamedDecl *Callee = FoundDecl.getDecl(); 9689 if (isa<UsingShadowDecl>(Callee)) 9690 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 9691 9692 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 9693 if (ExplicitTemplateArgs) { 9694 assert(!KnownValid && "Explicit template arguments?"); 9695 return; 9696 } 9697 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet, false, 9698 PartialOverloading); 9699 return; 9700 } 9701 9702 if (FunctionTemplateDecl *FuncTemplate 9703 = dyn_cast<FunctionTemplateDecl>(Callee)) { 9704 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 9705 ExplicitTemplateArgs, Args, CandidateSet); 9706 return; 9707 } 9708 9709 assert(!KnownValid && "unhandled case in overloaded call candidate"); 9710} 9711 9712/// \brief Add the overload candidates named by callee and/or found by argument 9713/// dependent lookup to the given overload set. 9714void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 9715 ArrayRef<Expr *> Args, 9716 OverloadCandidateSet &CandidateSet, 9717 bool PartialOverloading) { 9718 9719#ifndef NDEBUG 9720 // Verify that ArgumentDependentLookup is consistent with the rules 9721 // in C++0x [basic.lookup.argdep]p3: 9722 // 9723 // Let X be the lookup set produced by unqualified lookup (3.4.1) 9724 // and let Y be the lookup set produced by argument dependent 9725 // lookup (defined as follows). If X contains 9726 // 9727 // -- a declaration of a class member, or 9728 // 9729 // -- a block-scope function declaration that is not a 9730 // using-declaration, or 9731 // 9732 // -- a declaration that is neither a function or a function 9733 // template 9734 // 9735 // then Y is empty. 9736 9737 if (ULE->requiresADL()) { 9738 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 9739 E = ULE->decls_end(); I != E; ++I) { 9740 assert(!(*I)->getDeclContext()->isRecord()); 9741 assert(isa<UsingShadowDecl>(*I) || 9742 !(*I)->getDeclContext()->isFunctionOrMethod()); 9743 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 9744 } 9745 } 9746#endif 9747 9748 // It would be nice to avoid this copy. 9749 TemplateArgumentListInfo TABuffer; 9750 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 9751 if (ULE->hasExplicitTemplateArgs()) { 9752 ULE->copyTemplateArgumentsInto(TABuffer); 9753 ExplicitTemplateArgs = &TABuffer; 9754 } 9755 9756 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 9757 E = ULE->decls_end(); I != E; ++I) 9758 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args, 9759 CandidateSet, PartialOverloading, 9760 /*KnownValid*/ true); 9761 9762 if (ULE->requiresADL()) 9763 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 9764 ULE->getExprLoc(), 9765 Args, ExplicitTemplateArgs, 9766 CandidateSet, PartialOverloading); 9767} 9768 9769/// Attempt to recover from an ill-formed use of a non-dependent name in a 9770/// template, where the non-dependent name was declared after the template 9771/// was defined. This is common in code written for a compilers which do not 9772/// correctly implement two-stage name lookup. 9773/// 9774/// Returns true if a viable candidate was found and a diagnostic was issued. 9775static bool 9776DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc, 9777 const CXXScopeSpec &SS, LookupResult &R, 9778 TemplateArgumentListInfo *ExplicitTemplateArgs, 9779 ArrayRef<Expr *> Args) { 9780 if (SemaRef.ActiveTemplateInstantiations.empty() || !SS.isEmpty()) 9781 return false; 9782 9783 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) { 9784 if (DC->isTransparentContext()) 9785 continue; 9786 9787 SemaRef.LookupQualifiedName(R, DC); 9788 9789 if (!R.empty()) { 9790 R.suppressDiagnostics(); 9791 9792 if (isa<CXXRecordDecl>(DC)) { 9793 // Don't diagnose names we find in classes; we get much better 9794 // diagnostics for these from DiagnoseEmptyLookup. 9795 R.clear(); 9796 return false; 9797 } 9798 9799 OverloadCandidateSet Candidates(FnLoc); 9800 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 9801 AddOverloadedCallCandidate(SemaRef, I.getPair(), 9802 ExplicitTemplateArgs, Args, 9803 Candidates, false, /*KnownValid*/ false); 9804 9805 OverloadCandidateSet::iterator Best; 9806 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) { 9807 // No viable functions. Don't bother the user with notes for functions 9808 // which don't work and shouldn't be found anyway. 9809 R.clear(); 9810 return false; 9811 } 9812 9813 // Find the namespaces where ADL would have looked, and suggest 9814 // declaring the function there instead. 9815 Sema::AssociatedNamespaceSet AssociatedNamespaces; 9816 Sema::AssociatedClassSet AssociatedClasses; 9817 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args, 9818 AssociatedNamespaces, 9819 AssociatedClasses); 9820 Sema::AssociatedNamespaceSet SuggestedNamespaces; 9821 DeclContext *Std = SemaRef.getStdNamespace(); 9822 for (Sema::AssociatedNamespaceSet::iterator 9823 it = AssociatedNamespaces.begin(), 9824 end = AssociatedNamespaces.end(); it != end; ++it) { 9825 // Never suggest declaring a function within namespace 'std'. 9826 if (Std && Std->Encloses(*it)) 9827 continue; 9828 9829 // Never suggest declaring a function within a namespace with a reserved 9830 // name, like __gnu_cxx. 9831 NamespaceDecl *NS = dyn_cast<NamespaceDecl>(*it); 9832 if (NS && 9833 NS->getQualifiedNameAsString().find("__") != std::string::npos) 9834 continue; 9835 9836 SuggestedNamespaces.insert(*it); 9837 } 9838 9839 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup) 9840 << R.getLookupName(); 9841 if (SuggestedNamespaces.empty()) { 9842 SemaRef.Diag(Best->Function->getLocation(), 9843 diag::note_not_found_by_two_phase_lookup) 9844 << R.getLookupName() << 0; 9845 } else if (SuggestedNamespaces.size() == 1) { 9846 SemaRef.Diag(Best->Function->getLocation(), 9847 diag::note_not_found_by_two_phase_lookup) 9848 << R.getLookupName() << 1 << *SuggestedNamespaces.begin(); 9849 } else { 9850 // FIXME: It would be useful to list the associated namespaces here, 9851 // but the diagnostics infrastructure doesn't provide a way to produce 9852 // a localized representation of a list of items. 9853 SemaRef.Diag(Best->Function->getLocation(), 9854 diag::note_not_found_by_two_phase_lookup) 9855 << R.getLookupName() << 2; 9856 } 9857 9858 // Try to recover by calling this function. 9859 return true; 9860 } 9861 9862 R.clear(); 9863 } 9864 9865 return false; 9866} 9867 9868/// Attempt to recover from ill-formed use of a non-dependent operator in a 9869/// template, where the non-dependent operator was declared after the template 9870/// was defined. 9871/// 9872/// Returns true if a viable candidate was found and a diagnostic was issued. 9873static bool 9874DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op, 9875 SourceLocation OpLoc, 9876 ArrayRef<Expr *> Args) { 9877 DeclarationName OpName = 9878 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op); 9879 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName); 9880 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R, 9881 /*ExplicitTemplateArgs=*/0, Args); 9882} 9883 9884namespace { 9885// Callback to limit the allowed keywords and to only accept typo corrections 9886// that are keywords or whose decls refer to functions (or template functions) 9887// that accept the given number of arguments. 9888class RecoveryCallCCC : public CorrectionCandidateCallback { 9889 public: 9890 RecoveryCallCCC(Sema &SemaRef, unsigned NumArgs, bool HasExplicitTemplateArgs) 9891 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs) { 9892 WantTypeSpecifiers = SemaRef.getLangOpts().CPlusPlus; 9893 WantRemainingKeywords = false; 9894 } 9895 9896 virtual bool ValidateCandidate(const TypoCorrection &candidate) { 9897 if (!candidate.getCorrectionDecl()) 9898 return candidate.isKeyword(); 9899 9900 for (TypoCorrection::const_decl_iterator DI = candidate.begin(), 9901 DIEnd = candidate.end(); DI != DIEnd; ++DI) { 9902 FunctionDecl *FD = 0; 9903 NamedDecl *ND = (*DI)->getUnderlyingDecl(); 9904 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 9905 FD = FTD->getTemplatedDecl(); 9906 if (!HasExplicitTemplateArgs && !FD) { 9907 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) { 9908 // If the Decl is neither a function nor a template function, 9909 // determine if it is a pointer or reference to a function. If so, 9910 // check against the number of arguments expected for the pointee. 9911 QualType ValType = cast<ValueDecl>(ND)->getType(); 9912 if (ValType->isAnyPointerType() || ValType->isReferenceType()) 9913 ValType = ValType->getPointeeType(); 9914 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>()) 9915 if (FPT->getNumArgs() == NumArgs) 9916 return true; 9917 } 9918 } 9919 if (FD && FD->getNumParams() >= NumArgs && 9920 FD->getMinRequiredArguments() <= NumArgs) 9921 return true; 9922 } 9923 return false; 9924 } 9925 9926 private: 9927 unsigned NumArgs; 9928 bool HasExplicitTemplateArgs; 9929}; 9930 9931// Callback that effectively disabled typo correction 9932class NoTypoCorrectionCCC : public CorrectionCandidateCallback { 9933 public: 9934 NoTypoCorrectionCCC() { 9935 WantTypeSpecifiers = false; 9936 WantExpressionKeywords = false; 9937 WantCXXNamedCasts = false; 9938 WantRemainingKeywords = false; 9939 } 9940 9941 virtual bool ValidateCandidate(const TypoCorrection &candidate) { 9942 return false; 9943 } 9944}; 9945 9946class BuildRecoveryCallExprRAII { 9947 Sema &SemaRef; 9948public: 9949 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) { 9950 assert(SemaRef.IsBuildingRecoveryCallExpr == false); 9951 SemaRef.IsBuildingRecoveryCallExpr = true; 9952 } 9953 9954 ~BuildRecoveryCallExprRAII() { 9955 SemaRef.IsBuildingRecoveryCallExpr = false; 9956 } 9957}; 9958 9959} 9960 9961/// Attempts to recover from a call where no functions were found. 9962/// 9963/// Returns true if new candidates were found. 9964static ExprResult 9965BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 9966 UnresolvedLookupExpr *ULE, 9967 SourceLocation LParenLoc, 9968 llvm::MutableArrayRef<Expr *> Args, 9969 SourceLocation RParenLoc, 9970 bool EmptyLookup, bool AllowTypoCorrection) { 9971 // Do not try to recover if it is already building a recovery call. 9972 // This stops infinite loops for template instantiations like 9973 // 9974 // template <typename T> auto foo(T t) -> decltype(foo(t)) {} 9975 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {} 9976 // 9977 if (SemaRef.IsBuildingRecoveryCallExpr) 9978 return ExprError(); 9979 BuildRecoveryCallExprRAII RCE(SemaRef); 9980 9981 CXXScopeSpec SS; 9982 SS.Adopt(ULE->getQualifierLoc()); 9983 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc(); 9984 9985 TemplateArgumentListInfo TABuffer; 9986 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 9987 if (ULE->hasExplicitTemplateArgs()) { 9988 ULE->copyTemplateArgumentsInto(TABuffer); 9989 ExplicitTemplateArgs = &TABuffer; 9990 } 9991 9992 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 9993 Sema::LookupOrdinaryName); 9994 RecoveryCallCCC Validator(SemaRef, Args.size(), ExplicitTemplateArgs != 0); 9995 NoTypoCorrectionCCC RejectAll; 9996 CorrectionCandidateCallback *CCC = AllowTypoCorrection ? 9997 (CorrectionCandidateCallback*)&Validator : 9998 (CorrectionCandidateCallback*)&RejectAll; 9999 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R, 10000 ExplicitTemplateArgs, Args) && 10001 (!EmptyLookup || 10002 SemaRef.DiagnoseEmptyLookup(S, SS, R, *CCC, 10003 ExplicitTemplateArgs, Args))) 10004 return ExprError(); 10005 10006 assert(!R.empty() && "lookup results empty despite recovery"); 10007 10008 // Build an implicit member call if appropriate. Just drop the 10009 // casts and such from the call, we don't really care. 10010 ExprResult NewFn = ExprError(); 10011 if ((*R.begin())->isCXXClassMember()) 10012 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, 10013 R, ExplicitTemplateArgs); 10014 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid()) 10015 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false, 10016 ExplicitTemplateArgs); 10017 else 10018 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 10019 10020 if (NewFn.isInvalid()) 10021 return ExprError(); 10022 10023 // This shouldn't cause an infinite loop because we're giving it 10024 // an expression with viable lookup results, which should never 10025 // end up here. 10026 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 10027 MultiExprArg(Args.data(), Args.size()), 10028 RParenLoc); 10029} 10030 10031/// \brief Constructs and populates an OverloadedCandidateSet from 10032/// the given function. 10033/// \returns true when an the ExprResult output parameter has been set. 10034bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn, 10035 UnresolvedLookupExpr *ULE, 10036 MultiExprArg Args, 10037 SourceLocation RParenLoc, 10038 OverloadCandidateSet *CandidateSet, 10039 ExprResult *Result) { 10040#ifndef NDEBUG 10041 if (ULE->requiresADL()) { 10042 // To do ADL, we must have found an unqualified name. 10043 assert(!ULE->getQualifier() && "qualified name with ADL"); 10044 10045 // We don't perform ADL for implicit declarations of builtins. 10046 // Verify that this was correctly set up. 10047 FunctionDecl *F; 10048 if (ULE->decls_begin() + 1 == ULE->decls_end() && 10049 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 10050 F->getBuiltinID() && F->isImplicit()) 10051 llvm_unreachable("performing ADL for builtin"); 10052 10053 // We don't perform ADL in C. 10054 assert(getLangOpts().CPlusPlus && "ADL enabled in C"); 10055 } 10056#endif 10057 10058 UnbridgedCastsSet UnbridgedCasts; 10059 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) { 10060 *Result = ExprError(); 10061 return true; 10062 } 10063 10064 // Add the functions denoted by the callee to the set of candidate 10065 // functions, including those from argument-dependent lookup. 10066 AddOverloadedCallCandidates(ULE, Args, *CandidateSet); 10067 10068 // If we found nothing, try to recover. 10069 // BuildRecoveryCallExpr diagnoses the error itself, so we just bail 10070 // out if it fails. 10071 if (CandidateSet->empty()) { 10072 // In Microsoft mode, if we are inside a template class member function then 10073 // create a type dependent CallExpr. The goal is to postpone name lookup 10074 // to instantiation time to be able to search into type dependent base 10075 // classes. 10076 if (getLangOpts().MicrosoftMode && CurContext->isDependentContext() && 10077 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) { 10078 CallExpr *CE = new (Context) CallExpr(Context, Fn, Args, 10079 Context.DependentTy, VK_RValue, 10080 RParenLoc); 10081 CE->setTypeDependent(true); 10082 *Result = Owned(CE); 10083 return true; 10084 } 10085 return false; 10086 } 10087 10088 UnbridgedCasts.restore(); 10089 return false; 10090} 10091 10092/// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns 10093/// the completed call expression. If overload resolution fails, emits 10094/// diagnostics and returns ExprError() 10095static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 10096 UnresolvedLookupExpr *ULE, 10097 SourceLocation LParenLoc, 10098 MultiExprArg Args, 10099 SourceLocation RParenLoc, 10100 Expr *ExecConfig, 10101 OverloadCandidateSet *CandidateSet, 10102 OverloadCandidateSet::iterator *Best, 10103 OverloadingResult OverloadResult, 10104 bool AllowTypoCorrection) { 10105 if (CandidateSet->empty()) 10106 return BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, Args, 10107 RParenLoc, /*EmptyLookup=*/true, 10108 AllowTypoCorrection); 10109 10110 switch (OverloadResult) { 10111 case OR_Success: { 10112 FunctionDecl *FDecl = (*Best)->Function; 10113 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl); 10114 if (SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc())) 10115 return ExprError(); 10116 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl); 10117 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc, 10118 ExecConfig); 10119 } 10120 10121 case OR_No_Viable_Function: { 10122 // Try to recover by looking for viable functions which the user might 10123 // have meant to call. 10124 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, 10125 Args, RParenLoc, 10126 /*EmptyLookup=*/false, 10127 AllowTypoCorrection); 10128 if (!Recovery.isInvalid()) 10129 return Recovery; 10130 10131 SemaRef.Diag(Fn->getLocStart(), 10132 diag::err_ovl_no_viable_function_in_call) 10133 << ULE->getName() << Fn->getSourceRange(); 10134 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args); 10135 break; 10136 } 10137 10138 case OR_Ambiguous: 10139 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_ambiguous_call) 10140 << ULE->getName() << Fn->getSourceRange(); 10141 CandidateSet->NoteCandidates(SemaRef, OCD_ViableCandidates, Args); 10142 break; 10143 10144 case OR_Deleted: { 10145 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_deleted_call) 10146 << (*Best)->Function->isDeleted() 10147 << ULE->getName() 10148 << SemaRef.getDeletedOrUnavailableSuffix((*Best)->Function) 10149 << Fn->getSourceRange(); 10150 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, Args); 10151 10152 // We emitted an error for the unvailable/deleted function call but keep 10153 // the call in the AST. 10154 FunctionDecl *FDecl = (*Best)->Function; 10155 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl); 10156 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, RParenLoc, 10157 ExecConfig); 10158 } 10159 } 10160 10161 // Overload resolution failed. 10162 return ExprError(); 10163} 10164 10165/// BuildOverloadedCallExpr - Given the call expression that calls Fn 10166/// (which eventually refers to the declaration Func) and the call 10167/// arguments Args/NumArgs, attempt to resolve the function call down 10168/// to a specific function. If overload resolution succeeds, returns 10169/// the call expression produced by overload resolution. 10170/// Otherwise, emits diagnostics and returns ExprError. 10171ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, 10172 UnresolvedLookupExpr *ULE, 10173 SourceLocation LParenLoc, 10174 MultiExprArg Args, 10175 SourceLocation RParenLoc, 10176 Expr *ExecConfig, 10177 bool AllowTypoCorrection) { 10178 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 10179 ExprResult result; 10180 10181 if (buildOverloadedCallSet(S, Fn, ULE, Args, LParenLoc, &CandidateSet, 10182 &result)) 10183 return result; 10184 10185 OverloadCandidateSet::iterator Best; 10186 OverloadingResult OverloadResult = 10187 CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best); 10188 10189 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args, 10190 RParenLoc, ExecConfig, &CandidateSet, 10191 &Best, OverloadResult, 10192 AllowTypoCorrection); 10193} 10194 10195static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 10196 return Functions.size() > 1 || 10197 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 10198} 10199 10200/// \brief Create a unary operation that may resolve to an overloaded 10201/// operator. 10202/// 10203/// \param OpLoc The location of the operator itself (e.g., '*'). 10204/// 10205/// \param OpcIn The UnaryOperator::Opcode that describes this 10206/// operator. 10207/// 10208/// \param Fns The set of non-member functions that will be 10209/// considered by overload resolution. The caller needs to build this 10210/// set based on the context using, e.g., 10211/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 10212/// set should not contain any member functions; those will be added 10213/// by CreateOverloadedUnaryOp(). 10214/// 10215/// \param Input The input argument. 10216ExprResult 10217Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 10218 const UnresolvedSetImpl &Fns, 10219 Expr *Input) { 10220 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 10221 10222 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 10223 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 10224 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 10225 // TODO: provide better source location info. 10226 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 10227 10228 if (checkPlaceholderForOverload(*this, Input)) 10229 return ExprError(); 10230 10231 Expr *Args[2] = { Input, 0 }; 10232 unsigned NumArgs = 1; 10233 10234 // For post-increment and post-decrement, add the implicit '0' as 10235 // the second argument, so that we know this is a post-increment or 10236 // post-decrement. 10237 if (Opc == UO_PostInc || Opc == UO_PostDec) { 10238 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 10239 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 10240 SourceLocation()); 10241 NumArgs = 2; 10242 } 10243 10244 ArrayRef<Expr *> ArgsArray(Args, NumArgs); 10245 10246 if (Input->isTypeDependent()) { 10247 if (Fns.empty()) 10248 return Owned(new (Context) UnaryOperator(Input, 10249 Opc, 10250 Context.DependentTy, 10251 VK_RValue, OK_Ordinary, 10252 OpLoc)); 10253 10254 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10255 UnresolvedLookupExpr *Fn 10256 = UnresolvedLookupExpr::Create(Context, NamingClass, 10257 NestedNameSpecifierLoc(), OpNameInfo, 10258 /*ADL*/ true, IsOverloaded(Fns), 10259 Fns.begin(), Fns.end()); 10260 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, ArgsArray, 10261 Context.DependentTy, 10262 VK_RValue, 10263 OpLoc, false)); 10264 } 10265 10266 // Build an empty overload set. 10267 OverloadCandidateSet CandidateSet(OpLoc); 10268 10269 // Add the candidates from the given function set. 10270 AddFunctionCandidates(Fns, ArgsArray, CandidateSet, false); 10271 10272 // Add operator candidates that are member functions. 10273 AddMemberOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet); 10274 10275 // Add candidates from ADL. 10276 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, OpLoc, 10277 ArgsArray, /*ExplicitTemplateArgs*/ 0, 10278 CandidateSet); 10279 10280 // Add builtin operator candidates. 10281 AddBuiltinOperatorCandidates(Op, OpLoc, ArgsArray, CandidateSet); 10282 10283 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10284 10285 // Perform overload resolution. 10286 OverloadCandidateSet::iterator Best; 10287 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 10288 case OR_Success: { 10289 // We found a built-in operator or an overloaded operator. 10290 FunctionDecl *FnDecl = Best->Function; 10291 10292 if (FnDecl) { 10293 // We matched an overloaded operator. Build a call to that 10294 // operator. 10295 10296 // Convert the arguments. 10297 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 10298 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 10299 10300 ExprResult InputRes = 10301 PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 10302 Best->FoundDecl, Method); 10303 if (InputRes.isInvalid()) 10304 return ExprError(); 10305 Input = InputRes.take(); 10306 } else { 10307 // Convert the arguments. 10308 ExprResult InputInit 10309 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 10310 Context, 10311 FnDecl->getParamDecl(0)), 10312 SourceLocation(), 10313 Input); 10314 if (InputInit.isInvalid()) 10315 return ExprError(); 10316 Input = InputInit.take(); 10317 } 10318 10319 // Determine the result type. 10320 QualType ResultTy = FnDecl->getResultType(); 10321 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10322 ResultTy = ResultTy.getNonLValueExprType(Context); 10323 10324 // Build the actual expression node. 10325 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, Best->FoundDecl, 10326 HadMultipleCandidates, OpLoc); 10327 if (FnExpr.isInvalid()) 10328 return ExprError(); 10329 10330 Args[0] = Input; 10331 CallExpr *TheCall = 10332 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), ArgsArray, 10333 ResultTy, VK, OpLoc, false); 10334 10335 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 10336 FnDecl)) 10337 return ExprError(); 10338 10339 return MaybeBindToTemporary(TheCall); 10340 } else { 10341 // We matched a built-in operator. Convert the arguments, then 10342 // break out so that we will build the appropriate built-in 10343 // operator node. 10344 ExprResult InputRes = 10345 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 10346 Best->Conversions[0], AA_Passing); 10347 if (InputRes.isInvalid()) 10348 return ExprError(); 10349 Input = InputRes.take(); 10350 break; 10351 } 10352 } 10353 10354 case OR_No_Viable_Function: 10355 // This is an erroneous use of an operator which can be overloaded by 10356 // a non-member function. Check for non-member operators which were 10357 // defined too late to be candidates. 10358 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, ArgsArray)) 10359 // FIXME: Recover by calling the found function. 10360 return ExprError(); 10361 10362 // No viable function; fall through to handling this as a 10363 // built-in operator, which will produce an error message for us. 10364 break; 10365 10366 case OR_Ambiguous: 10367 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 10368 << UnaryOperator::getOpcodeStr(Opc) 10369 << Input->getType() 10370 << Input->getSourceRange(); 10371 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, ArgsArray, 10372 UnaryOperator::getOpcodeStr(Opc), OpLoc); 10373 return ExprError(); 10374 10375 case OR_Deleted: 10376 Diag(OpLoc, diag::err_ovl_deleted_oper) 10377 << Best->Function->isDeleted() 10378 << UnaryOperator::getOpcodeStr(Opc) 10379 << getDeletedOrUnavailableSuffix(Best->Function) 10380 << Input->getSourceRange(); 10381 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, ArgsArray, 10382 UnaryOperator::getOpcodeStr(Opc), OpLoc); 10383 return ExprError(); 10384 } 10385 10386 // Either we found no viable overloaded operator or we matched a 10387 // built-in operator. In either case, fall through to trying to 10388 // build a built-in operation. 10389 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 10390} 10391 10392/// \brief Create a binary operation that may resolve to an overloaded 10393/// operator. 10394/// 10395/// \param OpLoc The location of the operator itself (e.g., '+'). 10396/// 10397/// \param OpcIn The BinaryOperator::Opcode that describes this 10398/// operator. 10399/// 10400/// \param Fns The set of non-member functions that will be 10401/// considered by overload resolution. The caller needs to build this 10402/// set based on the context using, e.g., 10403/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 10404/// set should not contain any member functions; those will be added 10405/// by CreateOverloadedBinOp(). 10406/// 10407/// \param LHS Left-hand argument. 10408/// \param RHS Right-hand argument. 10409ExprResult 10410Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 10411 unsigned OpcIn, 10412 const UnresolvedSetImpl &Fns, 10413 Expr *LHS, Expr *RHS) { 10414 Expr *Args[2] = { LHS, RHS }; 10415 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 10416 10417 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 10418 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 10419 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 10420 10421 // If either side is type-dependent, create an appropriate dependent 10422 // expression. 10423 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 10424 if (Fns.empty()) { 10425 // If there are no functions to store, just build a dependent 10426 // BinaryOperator or CompoundAssignment. 10427 if (Opc <= BO_Assign || Opc > BO_OrAssign) 10428 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 10429 Context.DependentTy, 10430 VK_RValue, OK_Ordinary, 10431 OpLoc, 10432 FPFeatures.fp_contract)); 10433 10434 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 10435 Context.DependentTy, 10436 VK_LValue, 10437 OK_Ordinary, 10438 Context.DependentTy, 10439 Context.DependentTy, 10440 OpLoc, 10441 FPFeatures.fp_contract)); 10442 } 10443 10444 // FIXME: save results of ADL from here? 10445 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10446 // TODO: provide better source location info in DNLoc component. 10447 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 10448 UnresolvedLookupExpr *Fn 10449 = UnresolvedLookupExpr::Create(Context, NamingClass, 10450 NestedNameSpecifierLoc(), OpNameInfo, 10451 /*ADL*/ true, IsOverloaded(Fns), 10452 Fns.begin(), Fns.end()); 10453 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, Args, 10454 Context.DependentTy, VK_RValue, 10455 OpLoc, FPFeatures.fp_contract)); 10456 } 10457 10458 // Always do placeholder-like conversions on the RHS. 10459 if (checkPlaceholderForOverload(*this, Args[1])) 10460 return ExprError(); 10461 10462 // Do placeholder-like conversion on the LHS; note that we should 10463 // not get here with a PseudoObject LHS. 10464 assert(Args[0]->getObjectKind() != OK_ObjCProperty); 10465 if (checkPlaceholderForOverload(*this, Args[0])) 10466 return ExprError(); 10467 10468 // If this is the assignment operator, we only perform overload resolution 10469 // if the left-hand side is a class or enumeration type. This is actually 10470 // a hack. The standard requires that we do overload resolution between the 10471 // various built-in candidates, but as DR507 points out, this can lead to 10472 // problems. So we do it this way, which pretty much follows what GCC does. 10473 // Note that we go the traditional code path for compound assignment forms. 10474 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 10475 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10476 10477 // If this is the .* operator, which is not overloadable, just 10478 // create a built-in binary operator. 10479 if (Opc == BO_PtrMemD) 10480 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10481 10482 // Build an empty overload set. 10483 OverloadCandidateSet CandidateSet(OpLoc); 10484 10485 // Add the candidates from the given function set. 10486 AddFunctionCandidates(Fns, Args, CandidateSet, false); 10487 10488 // Add operator candidates that are member functions. 10489 AddMemberOperatorCandidates(Op, OpLoc, Args, CandidateSet); 10490 10491 // Add candidates from ADL. 10492 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 10493 OpLoc, Args, 10494 /*ExplicitTemplateArgs*/ 0, 10495 CandidateSet); 10496 10497 // Add builtin operator candidates. 10498 AddBuiltinOperatorCandidates(Op, OpLoc, Args, CandidateSet); 10499 10500 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10501 10502 // Perform overload resolution. 10503 OverloadCandidateSet::iterator Best; 10504 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 10505 case OR_Success: { 10506 // We found a built-in operator or an overloaded operator. 10507 FunctionDecl *FnDecl = Best->Function; 10508 10509 if (FnDecl) { 10510 // We matched an overloaded operator. Build a call to that 10511 // operator. 10512 10513 // Convert the arguments. 10514 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 10515 // Best->Access is only meaningful for class members. 10516 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 10517 10518 ExprResult Arg1 = 10519 PerformCopyInitialization( 10520 InitializedEntity::InitializeParameter(Context, 10521 FnDecl->getParamDecl(0)), 10522 SourceLocation(), Owned(Args[1])); 10523 if (Arg1.isInvalid()) 10524 return ExprError(); 10525 10526 ExprResult Arg0 = 10527 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 10528 Best->FoundDecl, Method); 10529 if (Arg0.isInvalid()) 10530 return ExprError(); 10531 Args[0] = Arg0.takeAs<Expr>(); 10532 Args[1] = RHS = Arg1.takeAs<Expr>(); 10533 } else { 10534 // Convert the arguments. 10535 ExprResult Arg0 = PerformCopyInitialization( 10536 InitializedEntity::InitializeParameter(Context, 10537 FnDecl->getParamDecl(0)), 10538 SourceLocation(), Owned(Args[0])); 10539 if (Arg0.isInvalid()) 10540 return ExprError(); 10541 10542 ExprResult Arg1 = 10543 PerformCopyInitialization( 10544 InitializedEntity::InitializeParameter(Context, 10545 FnDecl->getParamDecl(1)), 10546 SourceLocation(), Owned(Args[1])); 10547 if (Arg1.isInvalid()) 10548 return ExprError(); 10549 Args[0] = LHS = Arg0.takeAs<Expr>(); 10550 Args[1] = RHS = Arg1.takeAs<Expr>(); 10551 } 10552 10553 // Determine the result type. 10554 QualType ResultTy = FnDecl->getResultType(); 10555 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10556 ResultTy = ResultTy.getNonLValueExprType(Context); 10557 10558 // Build the actual expression node. 10559 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 10560 Best->FoundDecl, 10561 HadMultipleCandidates, OpLoc); 10562 if (FnExpr.isInvalid()) 10563 return ExprError(); 10564 10565 CXXOperatorCallExpr *TheCall = 10566 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 10567 Args, ResultTy, VK, OpLoc, 10568 FPFeatures.fp_contract); 10569 10570 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 10571 FnDecl)) 10572 return ExprError(); 10573 10574 ArrayRef<const Expr *> ArgsArray(Args, 2); 10575 // Cut off the implicit 'this'. 10576 if (isa<CXXMethodDecl>(FnDecl)) 10577 ArgsArray = ArgsArray.slice(1); 10578 checkCall(FnDecl, ArgsArray, 0, isa<CXXMethodDecl>(FnDecl), OpLoc, 10579 TheCall->getSourceRange(), VariadicDoesNotApply); 10580 10581 return MaybeBindToTemporary(TheCall); 10582 } else { 10583 // We matched a built-in operator. Convert the arguments, then 10584 // break out so that we will build the appropriate built-in 10585 // operator node. 10586 ExprResult ArgsRes0 = 10587 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 10588 Best->Conversions[0], AA_Passing); 10589 if (ArgsRes0.isInvalid()) 10590 return ExprError(); 10591 Args[0] = ArgsRes0.take(); 10592 10593 ExprResult ArgsRes1 = 10594 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 10595 Best->Conversions[1], AA_Passing); 10596 if (ArgsRes1.isInvalid()) 10597 return ExprError(); 10598 Args[1] = ArgsRes1.take(); 10599 break; 10600 } 10601 } 10602 10603 case OR_No_Viable_Function: { 10604 // C++ [over.match.oper]p9: 10605 // If the operator is the operator , [...] and there are no 10606 // viable functions, then the operator is assumed to be the 10607 // built-in operator and interpreted according to clause 5. 10608 if (Opc == BO_Comma) 10609 break; 10610 10611 // For class as left operand for assignment or compound assigment 10612 // operator do not fall through to handling in built-in, but report that 10613 // no overloaded assignment operator found 10614 ExprResult Result = ExprError(); 10615 if (Args[0]->getType()->isRecordType() && 10616 Opc >= BO_Assign && Opc <= BO_OrAssign) { 10617 Diag(OpLoc, diag::err_ovl_no_viable_oper) 10618 << BinaryOperator::getOpcodeStr(Opc) 10619 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10620 } else { 10621 // This is an erroneous use of an operator which can be overloaded by 10622 // a non-member function. Check for non-member operators which were 10623 // defined too late to be candidates. 10624 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args)) 10625 // FIXME: Recover by calling the found function. 10626 return ExprError(); 10627 10628 // No viable function; try to create a built-in operation, which will 10629 // produce an error. Then, show the non-viable candidates. 10630 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10631 } 10632 assert(Result.isInvalid() && 10633 "C++ binary operator overloading is missing candidates!"); 10634 if (Result.isInvalid()) 10635 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10636 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10637 return Result; 10638 } 10639 10640 case OR_Ambiguous: 10641 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 10642 << BinaryOperator::getOpcodeStr(Opc) 10643 << Args[0]->getType() << Args[1]->getType() 10644 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10645 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 10646 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10647 return ExprError(); 10648 10649 case OR_Deleted: 10650 if (isImplicitlyDeleted(Best->Function)) { 10651 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 10652 Diag(OpLoc, diag::err_ovl_deleted_special_oper) 10653 << Context.getRecordType(Method->getParent()) 10654 << getSpecialMember(Method); 10655 10656 // The user probably meant to call this special member. Just 10657 // explain why it's deleted. 10658 NoteDeletedFunction(Method); 10659 return ExprError(); 10660 } else { 10661 Diag(OpLoc, diag::err_ovl_deleted_oper) 10662 << Best->Function->isDeleted() 10663 << BinaryOperator::getOpcodeStr(Opc) 10664 << getDeletedOrUnavailableSuffix(Best->Function) 10665 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10666 } 10667 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10668 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10669 return ExprError(); 10670 } 10671 10672 // We matched a built-in operator; build it. 10673 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10674} 10675 10676ExprResult 10677Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 10678 SourceLocation RLoc, 10679 Expr *Base, Expr *Idx) { 10680 Expr *Args[2] = { Base, Idx }; 10681 DeclarationName OpName = 10682 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 10683 10684 // If either side is type-dependent, create an appropriate dependent 10685 // expression. 10686 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 10687 10688 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10689 // CHECKME: no 'operator' keyword? 10690 DeclarationNameInfo OpNameInfo(OpName, LLoc); 10691 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 10692 UnresolvedLookupExpr *Fn 10693 = UnresolvedLookupExpr::Create(Context, NamingClass, 10694 NestedNameSpecifierLoc(), OpNameInfo, 10695 /*ADL*/ true, /*Overloaded*/ false, 10696 UnresolvedSetIterator(), 10697 UnresolvedSetIterator()); 10698 // Can't add any actual overloads yet 10699 10700 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 10701 Args, 10702 Context.DependentTy, 10703 VK_RValue, 10704 RLoc, false)); 10705 } 10706 10707 // Handle placeholders on both operands. 10708 if (checkPlaceholderForOverload(*this, Args[0])) 10709 return ExprError(); 10710 if (checkPlaceholderForOverload(*this, Args[1])) 10711 return ExprError(); 10712 10713 // Build an empty overload set. 10714 OverloadCandidateSet CandidateSet(LLoc); 10715 10716 // Subscript can only be overloaded as a member function. 10717 10718 // Add operator candidates that are member functions. 10719 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet); 10720 10721 // Add builtin operator candidates. 10722 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, CandidateSet); 10723 10724 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10725 10726 // Perform overload resolution. 10727 OverloadCandidateSet::iterator Best; 10728 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 10729 case OR_Success: { 10730 // We found a built-in operator or an overloaded operator. 10731 FunctionDecl *FnDecl = Best->Function; 10732 10733 if (FnDecl) { 10734 // We matched an overloaded operator. Build a call to that 10735 // operator. 10736 10737 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 10738 10739 // Convert the arguments. 10740 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 10741 ExprResult Arg0 = 10742 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 10743 Best->FoundDecl, Method); 10744 if (Arg0.isInvalid()) 10745 return ExprError(); 10746 Args[0] = Arg0.take(); 10747 10748 // Convert the arguments. 10749 ExprResult InputInit 10750 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 10751 Context, 10752 FnDecl->getParamDecl(0)), 10753 SourceLocation(), 10754 Owned(Args[1])); 10755 if (InputInit.isInvalid()) 10756 return ExprError(); 10757 10758 Args[1] = InputInit.takeAs<Expr>(); 10759 10760 // Determine the result type 10761 QualType ResultTy = FnDecl->getResultType(); 10762 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10763 ResultTy = ResultTy.getNonLValueExprType(Context); 10764 10765 // Build the actual expression node. 10766 DeclarationNameInfo OpLocInfo(OpName, LLoc); 10767 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 10768 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 10769 Best->FoundDecl, 10770 HadMultipleCandidates, 10771 OpLocInfo.getLoc(), 10772 OpLocInfo.getInfo()); 10773 if (FnExpr.isInvalid()) 10774 return ExprError(); 10775 10776 CXXOperatorCallExpr *TheCall = 10777 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 10778 FnExpr.take(), Args, 10779 ResultTy, VK, RLoc, 10780 false); 10781 10782 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 10783 FnDecl)) 10784 return ExprError(); 10785 10786 return MaybeBindToTemporary(TheCall); 10787 } else { 10788 // We matched a built-in operator. Convert the arguments, then 10789 // break out so that we will build the appropriate built-in 10790 // operator node. 10791 ExprResult ArgsRes0 = 10792 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 10793 Best->Conversions[0], AA_Passing); 10794 if (ArgsRes0.isInvalid()) 10795 return ExprError(); 10796 Args[0] = ArgsRes0.take(); 10797 10798 ExprResult ArgsRes1 = 10799 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 10800 Best->Conversions[1], AA_Passing); 10801 if (ArgsRes1.isInvalid()) 10802 return ExprError(); 10803 Args[1] = ArgsRes1.take(); 10804 10805 break; 10806 } 10807 } 10808 10809 case OR_No_Viable_Function: { 10810 if (CandidateSet.empty()) 10811 Diag(LLoc, diag::err_ovl_no_oper) 10812 << Args[0]->getType() << /*subscript*/ 0 10813 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10814 else 10815 Diag(LLoc, diag::err_ovl_no_viable_subscript) 10816 << Args[0]->getType() 10817 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10818 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10819 "[]", LLoc); 10820 return ExprError(); 10821 } 10822 10823 case OR_Ambiguous: 10824 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 10825 << "[]" 10826 << Args[0]->getType() << Args[1]->getType() 10827 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10828 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 10829 "[]", LLoc); 10830 return ExprError(); 10831 10832 case OR_Deleted: 10833 Diag(LLoc, diag::err_ovl_deleted_oper) 10834 << Best->Function->isDeleted() << "[]" 10835 << getDeletedOrUnavailableSuffix(Best->Function) 10836 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10837 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10838 "[]", LLoc); 10839 return ExprError(); 10840 } 10841 10842 // We matched a built-in operator; build it. 10843 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 10844} 10845 10846/// BuildCallToMemberFunction - Build a call to a member 10847/// function. MemExpr is the expression that refers to the member 10848/// function (and includes the object parameter), Args/NumArgs are the 10849/// arguments to the function call (not including the object 10850/// parameter). The caller needs to validate that the member 10851/// expression refers to a non-static member function or an overloaded 10852/// member function. 10853ExprResult 10854Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 10855 SourceLocation LParenLoc, 10856 MultiExprArg Args, 10857 SourceLocation RParenLoc) { 10858 assert(MemExprE->getType() == Context.BoundMemberTy || 10859 MemExprE->getType() == Context.OverloadTy); 10860 10861 // Dig out the member expression. This holds both the object 10862 // argument and the member function we're referring to. 10863 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 10864 10865 // Determine whether this is a call to a pointer-to-member function. 10866 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) { 10867 assert(op->getType() == Context.BoundMemberTy); 10868 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI); 10869 10870 QualType fnType = 10871 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType(); 10872 10873 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>(); 10874 QualType resultType = proto->getCallResultType(Context); 10875 ExprValueKind valueKind = Expr::getValueKindForType(proto->getResultType()); 10876 10877 // Check that the object type isn't more qualified than the 10878 // member function we're calling. 10879 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals()); 10880 10881 QualType objectType = op->getLHS()->getType(); 10882 if (op->getOpcode() == BO_PtrMemI) 10883 objectType = objectType->castAs<PointerType>()->getPointeeType(); 10884 Qualifiers objectQuals = objectType.getQualifiers(); 10885 10886 Qualifiers difference = objectQuals - funcQuals; 10887 difference.removeObjCGCAttr(); 10888 difference.removeAddressSpace(); 10889 if (difference) { 10890 std::string qualsString = difference.getAsString(); 10891 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals) 10892 << fnType.getUnqualifiedType() 10893 << qualsString 10894 << (qualsString.find(' ') == std::string::npos ? 1 : 2); 10895 } 10896 10897 CXXMemberCallExpr *call 10898 = new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 10899 resultType, valueKind, RParenLoc); 10900 10901 if (CheckCallReturnType(proto->getResultType(), 10902 op->getRHS()->getLocStart(), 10903 call, 0)) 10904 return ExprError(); 10905 10906 if (ConvertArgumentsForCall(call, op, 0, proto, Args, RParenLoc)) 10907 return ExprError(); 10908 10909 return MaybeBindToTemporary(call); 10910 } 10911 10912 UnbridgedCastsSet UnbridgedCasts; 10913 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) 10914 return ExprError(); 10915 10916 MemberExpr *MemExpr; 10917 CXXMethodDecl *Method = 0; 10918 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 10919 NestedNameSpecifier *Qualifier = 0; 10920 if (isa<MemberExpr>(NakedMemExpr)) { 10921 MemExpr = cast<MemberExpr>(NakedMemExpr); 10922 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 10923 FoundDecl = MemExpr->getFoundDecl(); 10924 Qualifier = MemExpr->getQualifier(); 10925 UnbridgedCasts.restore(); 10926 } else { 10927 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 10928 Qualifier = UnresExpr->getQualifier(); 10929 10930 QualType ObjectType = UnresExpr->getBaseType(); 10931 Expr::Classification ObjectClassification 10932 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 10933 : UnresExpr->getBase()->Classify(Context); 10934 10935 // Add overload candidates 10936 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 10937 10938 // FIXME: avoid copy. 10939 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 10940 if (UnresExpr->hasExplicitTemplateArgs()) { 10941 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 10942 TemplateArgs = &TemplateArgsBuffer; 10943 } 10944 10945 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 10946 E = UnresExpr->decls_end(); I != E; ++I) { 10947 10948 NamedDecl *Func = *I; 10949 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 10950 if (isa<UsingShadowDecl>(Func)) 10951 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 10952 10953 10954 // Microsoft supports direct constructor calls. 10955 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) { 10956 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), 10957 Args, CandidateSet); 10958 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 10959 // If explicit template arguments were provided, we can't call a 10960 // non-template member function. 10961 if (TemplateArgs) 10962 continue; 10963 10964 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 10965 ObjectClassification, Args, CandidateSet, 10966 /*SuppressUserConversions=*/false); 10967 } else { 10968 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 10969 I.getPair(), ActingDC, TemplateArgs, 10970 ObjectType, ObjectClassification, 10971 Args, CandidateSet, 10972 /*SuppressUsedConversions=*/false); 10973 } 10974 } 10975 10976 DeclarationName DeclName = UnresExpr->getMemberName(); 10977 10978 UnbridgedCasts.restore(); 10979 10980 OverloadCandidateSet::iterator Best; 10981 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 10982 Best)) { 10983 case OR_Success: 10984 Method = cast<CXXMethodDecl>(Best->Function); 10985 FoundDecl = Best->FoundDecl; 10986 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 10987 if (DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc())) 10988 return ExprError(); 10989 break; 10990 10991 case OR_No_Viable_Function: 10992 Diag(UnresExpr->getMemberLoc(), 10993 diag::err_ovl_no_viable_member_function_in_call) 10994 << DeclName << MemExprE->getSourceRange(); 10995 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 10996 // FIXME: Leaking incoming expressions! 10997 return ExprError(); 10998 10999 case OR_Ambiguous: 11000 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 11001 << DeclName << MemExprE->getSourceRange(); 11002 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11003 // FIXME: Leaking incoming expressions! 11004 return ExprError(); 11005 11006 case OR_Deleted: 11007 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 11008 << Best->Function->isDeleted() 11009 << DeclName 11010 << getDeletedOrUnavailableSuffix(Best->Function) 11011 << MemExprE->getSourceRange(); 11012 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11013 // FIXME: Leaking incoming expressions! 11014 return ExprError(); 11015 } 11016 11017 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 11018 11019 // If overload resolution picked a static member, build a 11020 // non-member call based on that function. 11021 if (Method->isStatic()) { 11022 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, Args, 11023 RParenLoc); 11024 } 11025 11026 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 11027 } 11028 11029 QualType ResultType = Method->getResultType(); 11030 ExprValueKind VK = Expr::getValueKindForType(ResultType); 11031 ResultType = ResultType.getNonLValueExprType(Context); 11032 11033 assert(Method && "Member call to something that isn't a method?"); 11034 CXXMemberCallExpr *TheCall = 11035 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 11036 ResultType, VK, RParenLoc); 11037 11038 // Check for a valid return type. 11039 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 11040 TheCall, Method)) 11041 return ExprError(); 11042 11043 // Convert the object argument (for a non-static member function call). 11044 // We only need to do this if there was actually an overload; otherwise 11045 // it was done at lookup. 11046 if (!Method->isStatic()) { 11047 ExprResult ObjectArg = 11048 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier, 11049 FoundDecl, Method); 11050 if (ObjectArg.isInvalid()) 11051 return ExprError(); 11052 MemExpr->setBase(ObjectArg.take()); 11053 } 11054 11055 // Convert the rest of the arguments 11056 const FunctionProtoType *Proto = 11057 Method->getType()->getAs<FunctionProtoType>(); 11058 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, 11059 RParenLoc)) 11060 return ExprError(); 11061 11062 DiagnoseSentinelCalls(Method, LParenLoc, Args); 11063 11064 if (CheckFunctionCall(Method, TheCall, Proto)) 11065 return ExprError(); 11066 11067 if ((isa<CXXConstructorDecl>(CurContext) || 11068 isa<CXXDestructorDecl>(CurContext)) && 11069 TheCall->getMethodDecl()->isPure()) { 11070 const CXXMethodDecl *MD = TheCall->getMethodDecl(); 11071 11072 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts())) { 11073 Diag(MemExpr->getLocStart(), 11074 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor) 11075 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext) 11076 << MD->getParent()->getDeclName(); 11077 11078 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName(); 11079 } 11080 } 11081 return MaybeBindToTemporary(TheCall); 11082} 11083 11084/// BuildCallToObjectOfClassType - Build a call to an object of class 11085/// type (C++ [over.call.object]), which can end up invoking an 11086/// overloaded function call operator (@c operator()) or performing a 11087/// user-defined conversion on the object argument. 11088ExprResult 11089Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj, 11090 SourceLocation LParenLoc, 11091 MultiExprArg Args, 11092 SourceLocation RParenLoc) { 11093 if (checkPlaceholderForOverload(*this, Obj)) 11094 return ExprError(); 11095 ExprResult Object = Owned(Obj); 11096 11097 UnbridgedCastsSet UnbridgedCasts; 11098 if (checkArgPlaceholdersForOverload(*this, Args, UnbridgedCasts)) 11099 return ExprError(); 11100 11101 assert(Object.get()->getType()->isRecordType() && "Requires object type argument"); 11102 const RecordType *Record = Object.get()->getType()->getAs<RecordType>(); 11103 11104 // C++ [over.call.object]p1: 11105 // If the primary-expression E in the function call syntax 11106 // evaluates to a class object of type "cv T", then the set of 11107 // candidate functions includes at least the function call 11108 // operators of T. The function call operators of T are obtained by 11109 // ordinary lookup of the name operator() in the context of 11110 // (E).operator(). 11111 OverloadCandidateSet CandidateSet(LParenLoc); 11112 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 11113 11114 if (RequireCompleteType(LParenLoc, Object.get()->getType(), 11115 diag::err_incomplete_object_call, Object.get())) 11116 return true; 11117 11118 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 11119 LookupQualifiedName(R, Record->getDecl()); 11120 R.suppressDiagnostics(); 11121 11122 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 11123 Oper != OperEnd; ++Oper) { 11124 AddMethodCandidate(Oper.getPair(), Object.get()->getType(), 11125 Object.get()->Classify(Context), 11126 Args, CandidateSet, 11127 /*SuppressUserConversions=*/ false); 11128 } 11129 11130 // C++ [over.call.object]p2: 11131 // In addition, for each (non-explicit in C++0x) conversion function 11132 // declared in T of the form 11133 // 11134 // operator conversion-type-id () cv-qualifier; 11135 // 11136 // where cv-qualifier is the same cv-qualification as, or a 11137 // greater cv-qualification than, cv, and where conversion-type-id 11138 // denotes the type "pointer to function of (P1,...,Pn) returning 11139 // R", or the type "reference to pointer to function of 11140 // (P1,...,Pn) returning R", or the type "reference to function 11141 // of (P1,...,Pn) returning R", a surrogate call function [...] 11142 // is also considered as a candidate function. Similarly, 11143 // surrogate call functions are added to the set of candidate 11144 // functions for each conversion function declared in an 11145 // accessible base class provided the function is not hidden 11146 // within T by another intervening declaration. 11147 std::pair<CXXRecordDecl::conversion_iterator, 11148 CXXRecordDecl::conversion_iterator> Conversions 11149 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 11150 for (CXXRecordDecl::conversion_iterator 11151 I = Conversions.first, E = Conversions.second; I != E; ++I) { 11152 NamedDecl *D = *I; 11153 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 11154 if (isa<UsingShadowDecl>(D)) 11155 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 11156 11157 // Skip over templated conversion functions; they aren't 11158 // surrogates. 11159 if (isa<FunctionTemplateDecl>(D)) 11160 continue; 11161 11162 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 11163 if (!Conv->isExplicit()) { 11164 // Strip the reference type (if any) and then the pointer type (if 11165 // any) to get down to what might be a function type. 11166 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 11167 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 11168 ConvType = ConvPtrType->getPointeeType(); 11169 11170 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 11171 { 11172 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 11173 Object.get(), Args, CandidateSet); 11174 } 11175 } 11176 } 11177 11178 bool HadMultipleCandidates = (CandidateSet.size() > 1); 11179 11180 // Perform overload resolution. 11181 OverloadCandidateSet::iterator Best; 11182 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(), 11183 Best)) { 11184 case OR_Success: 11185 // Overload resolution succeeded; we'll build the appropriate call 11186 // below. 11187 break; 11188 11189 case OR_No_Viable_Function: 11190 if (CandidateSet.empty()) 11191 Diag(Object.get()->getLocStart(), diag::err_ovl_no_oper) 11192 << Object.get()->getType() << /*call*/ 1 11193 << Object.get()->getSourceRange(); 11194 else 11195 Diag(Object.get()->getLocStart(), 11196 diag::err_ovl_no_viable_object_call) 11197 << Object.get()->getType() << Object.get()->getSourceRange(); 11198 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11199 break; 11200 11201 case OR_Ambiguous: 11202 Diag(Object.get()->getLocStart(), 11203 diag::err_ovl_ambiguous_object_call) 11204 << Object.get()->getType() << Object.get()->getSourceRange(); 11205 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args); 11206 break; 11207 11208 case OR_Deleted: 11209 Diag(Object.get()->getLocStart(), 11210 diag::err_ovl_deleted_object_call) 11211 << Best->Function->isDeleted() 11212 << Object.get()->getType() 11213 << getDeletedOrUnavailableSuffix(Best->Function) 11214 << Object.get()->getSourceRange(); 11215 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11216 break; 11217 } 11218 11219 if (Best == CandidateSet.end()) 11220 return true; 11221 11222 UnbridgedCasts.restore(); 11223 11224 if (Best->Function == 0) { 11225 // Since there is no function declaration, this is one of the 11226 // surrogate candidates. Dig out the conversion function. 11227 CXXConversionDecl *Conv 11228 = cast<CXXConversionDecl>( 11229 Best->Conversions[0].UserDefined.ConversionFunction); 11230 11231 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 11232 if (DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc)) 11233 return ExprError(); 11234 11235 // We selected one of the surrogate functions that converts the 11236 // object parameter to a function pointer. Perform the conversion 11237 // on the object argument, then let ActOnCallExpr finish the job. 11238 11239 // Create an implicit member expr to refer to the conversion operator. 11240 // and then call it. 11241 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl, 11242 Conv, HadMultipleCandidates); 11243 if (Call.isInvalid()) 11244 return ExprError(); 11245 // Record usage of conversion in an implicit cast. 11246 Call = Owned(ImplicitCastExpr::Create(Context, Call.get()->getType(), 11247 CK_UserDefinedConversion, 11248 Call.get(), 0, VK_RValue)); 11249 11250 return ActOnCallExpr(S, Call.get(), LParenLoc, Args, RParenLoc); 11251 } 11252 11253 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 11254 11255 // We found an overloaded operator(). Build a CXXOperatorCallExpr 11256 // that calls this method, using Object for the implicit object 11257 // parameter and passing along the remaining arguments. 11258 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 11259 11260 // An error diagnostic has already been printed when parsing the declaration. 11261 if (Method->isInvalidDecl()) 11262 return ExprError(); 11263 11264 const FunctionProtoType *Proto = 11265 Method->getType()->getAs<FunctionProtoType>(); 11266 11267 unsigned NumArgsInProto = Proto->getNumArgs(); 11268 unsigned NumArgsToCheck = Args.size(); 11269 11270 // Build the full argument list for the method call (the 11271 // implicit object parameter is placed at the beginning of the 11272 // list). 11273 Expr **MethodArgs; 11274 if (Args.size() < NumArgsInProto) { 11275 NumArgsToCheck = NumArgsInProto; 11276 MethodArgs = new Expr*[NumArgsInProto + 1]; 11277 } else { 11278 MethodArgs = new Expr*[Args.size() + 1]; 11279 } 11280 MethodArgs[0] = Object.get(); 11281 for (unsigned ArgIdx = 0, e = Args.size(); ArgIdx != e; ++ArgIdx) 11282 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 11283 11284 DeclarationNameInfo OpLocInfo( 11285 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc); 11286 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc)); 11287 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, Best->FoundDecl, 11288 HadMultipleCandidates, 11289 OpLocInfo.getLoc(), 11290 OpLocInfo.getInfo()); 11291 if (NewFn.isInvalid()) 11292 return true; 11293 11294 // Once we've built TheCall, all of the expressions are properly 11295 // owned. 11296 QualType ResultTy = Method->getResultType(); 11297 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11298 ResultTy = ResultTy.getNonLValueExprType(Context); 11299 11300 CXXOperatorCallExpr *TheCall = 11301 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn.take(), 11302 llvm::makeArrayRef(MethodArgs, Args.size()+1), 11303 ResultTy, VK, RParenLoc, false); 11304 delete [] MethodArgs; 11305 11306 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 11307 Method)) 11308 return true; 11309 11310 // We may have default arguments. If so, we need to allocate more 11311 // slots in the call for them. 11312 if (Args.size() < NumArgsInProto) 11313 TheCall->setNumArgs(Context, NumArgsInProto + 1); 11314 else if (Args.size() > NumArgsInProto) 11315 NumArgsToCheck = NumArgsInProto; 11316 11317 bool IsError = false; 11318 11319 // Initialize the implicit object parameter. 11320 ExprResult ObjRes = 11321 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/0, 11322 Best->FoundDecl, Method); 11323 if (ObjRes.isInvalid()) 11324 IsError = true; 11325 else 11326 Object = ObjRes; 11327 TheCall->setArg(0, Object.take()); 11328 11329 // Check the argument types. 11330 for (unsigned i = 0; i != NumArgsToCheck; i++) { 11331 Expr *Arg; 11332 if (i < Args.size()) { 11333 Arg = Args[i]; 11334 11335 // Pass the argument. 11336 11337 ExprResult InputInit 11338 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 11339 Context, 11340 Method->getParamDecl(i)), 11341 SourceLocation(), Arg); 11342 11343 IsError |= InputInit.isInvalid(); 11344 Arg = InputInit.takeAs<Expr>(); 11345 } else { 11346 ExprResult DefArg 11347 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 11348 if (DefArg.isInvalid()) { 11349 IsError = true; 11350 break; 11351 } 11352 11353 Arg = DefArg.takeAs<Expr>(); 11354 } 11355 11356 TheCall->setArg(i + 1, Arg); 11357 } 11358 11359 // If this is a variadic call, handle args passed through "...". 11360 if (Proto->isVariadic()) { 11361 // Promote the arguments (C99 6.5.2.2p7). 11362 for (unsigned i = NumArgsInProto, e = Args.size(); i < e; i++) { 11363 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod, 0); 11364 IsError |= Arg.isInvalid(); 11365 TheCall->setArg(i + 1, Arg.take()); 11366 } 11367 } 11368 11369 if (IsError) return true; 11370 11371 DiagnoseSentinelCalls(Method, LParenLoc, Args); 11372 11373 if (CheckFunctionCall(Method, TheCall, Proto)) 11374 return true; 11375 11376 return MaybeBindToTemporary(TheCall); 11377} 11378 11379/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 11380/// (if one exists), where @c Base is an expression of class type and 11381/// @c Member is the name of the member we're trying to find. 11382ExprResult 11383Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 11384 assert(Base->getType()->isRecordType() && 11385 "left-hand side must have class type"); 11386 11387 if (checkPlaceholderForOverload(*this, Base)) 11388 return ExprError(); 11389 11390 SourceLocation Loc = Base->getExprLoc(); 11391 11392 // C++ [over.ref]p1: 11393 // 11394 // [...] An expression x->m is interpreted as (x.operator->())->m 11395 // for a class object x of type T if T::operator->() exists and if 11396 // the operator is selected as the best match function by the 11397 // overload resolution mechanism (13.3). 11398 DeclarationName OpName = 11399 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 11400 OverloadCandidateSet CandidateSet(Loc); 11401 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 11402 11403 if (RequireCompleteType(Loc, Base->getType(), 11404 diag::err_typecheck_incomplete_tag, Base)) 11405 return ExprError(); 11406 11407 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 11408 LookupQualifiedName(R, BaseRecord->getDecl()); 11409 R.suppressDiagnostics(); 11410 11411 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 11412 Oper != OperEnd; ++Oper) { 11413 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 11414 None, CandidateSet, /*SuppressUserConversions=*/false); 11415 } 11416 11417 bool HadMultipleCandidates = (CandidateSet.size() > 1); 11418 11419 // Perform overload resolution. 11420 OverloadCandidateSet::iterator Best; 11421 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 11422 case OR_Success: 11423 // Overload resolution succeeded; we'll build the call below. 11424 break; 11425 11426 case OR_No_Viable_Function: 11427 if (CandidateSet.empty()) 11428 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 11429 << Base->getType() << Base->getSourceRange(); 11430 else 11431 Diag(OpLoc, diag::err_ovl_no_viable_oper) 11432 << "operator->" << Base->getSourceRange(); 11433 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base); 11434 return ExprError(); 11435 11436 case OR_Ambiguous: 11437 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 11438 << "->" << Base->getType() << Base->getSourceRange(); 11439 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Base); 11440 return ExprError(); 11441 11442 case OR_Deleted: 11443 Diag(OpLoc, diag::err_ovl_deleted_oper) 11444 << Best->Function->isDeleted() 11445 << "->" 11446 << getDeletedOrUnavailableSuffix(Best->Function) 11447 << Base->getSourceRange(); 11448 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base); 11449 return ExprError(); 11450 } 11451 11452 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 11453 11454 // Convert the object parameter. 11455 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 11456 ExprResult BaseResult = 11457 PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 11458 Best->FoundDecl, Method); 11459 if (BaseResult.isInvalid()) 11460 return ExprError(); 11461 Base = BaseResult.take(); 11462 11463 // Build the operator call. 11464 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, Best->FoundDecl, 11465 HadMultipleCandidates, OpLoc); 11466 if (FnExpr.isInvalid()) 11467 return ExprError(); 11468 11469 QualType ResultTy = Method->getResultType(); 11470 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11471 ResultTy = ResultTy.getNonLValueExprType(Context); 11472 CXXOperatorCallExpr *TheCall = 11473 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.take(), 11474 Base, ResultTy, VK, OpLoc, false); 11475 11476 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 11477 Method)) 11478 return ExprError(); 11479 11480 return MaybeBindToTemporary(TheCall); 11481} 11482 11483/// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to 11484/// a literal operator described by the provided lookup results. 11485ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R, 11486 DeclarationNameInfo &SuffixInfo, 11487 ArrayRef<Expr*> Args, 11488 SourceLocation LitEndLoc, 11489 TemplateArgumentListInfo *TemplateArgs) { 11490 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc(); 11491 11492 OverloadCandidateSet CandidateSet(UDSuffixLoc); 11493 AddFunctionCandidates(R.asUnresolvedSet(), Args, CandidateSet, true, 11494 TemplateArgs); 11495 11496 bool HadMultipleCandidates = (CandidateSet.size() > 1); 11497 11498 // Perform overload resolution. This will usually be trivial, but might need 11499 // to perform substitutions for a literal operator template. 11500 OverloadCandidateSet::iterator Best; 11501 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) { 11502 case OR_Success: 11503 case OR_Deleted: 11504 break; 11505 11506 case OR_No_Viable_Function: 11507 Diag(UDSuffixLoc, diag::err_ovl_no_viable_function_in_call) 11508 << R.getLookupName(); 11509 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11510 return ExprError(); 11511 11512 case OR_Ambiguous: 11513 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName(); 11514 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args); 11515 return ExprError(); 11516 } 11517 11518 FunctionDecl *FD = Best->Function; 11519 ExprResult Fn = CreateFunctionRefExpr(*this, FD, Best->FoundDecl, 11520 HadMultipleCandidates, 11521 SuffixInfo.getLoc(), 11522 SuffixInfo.getInfo()); 11523 if (Fn.isInvalid()) 11524 return true; 11525 11526 // Check the argument types. This should almost always be a no-op, except 11527 // that array-to-pointer decay is applied to string literals. 11528 Expr *ConvArgs[2]; 11529 for (unsigned ArgIdx = 0, N = Args.size(); ArgIdx != N; ++ArgIdx) { 11530 ExprResult InputInit = PerformCopyInitialization( 11531 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)), 11532 SourceLocation(), Args[ArgIdx]); 11533 if (InputInit.isInvalid()) 11534 return true; 11535 ConvArgs[ArgIdx] = InputInit.take(); 11536 } 11537 11538 QualType ResultTy = FD->getResultType(); 11539 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11540 ResultTy = ResultTy.getNonLValueExprType(Context); 11541 11542 UserDefinedLiteral *UDL = 11543 new (Context) UserDefinedLiteral(Context, Fn.take(), 11544 llvm::makeArrayRef(ConvArgs, Args.size()), 11545 ResultTy, VK, LitEndLoc, UDSuffixLoc); 11546 11547 if (CheckCallReturnType(FD->getResultType(), UDSuffixLoc, UDL, FD)) 11548 return ExprError(); 11549 11550 if (CheckFunctionCall(FD, UDL, NULL)) 11551 return ExprError(); 11552 11553 return MaybeBindToTemporary(UDL); 11554} 11555 11556/// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the 11557/// given LookupResult is non-empty, it is assumed to describe a member which 11558/// will be invoked. Otherwise, the function will be found via argument 11559/// dependent lookup. 11560/// CallExpr is set to a valid expression and FRS_Success returned on success, 11561/// otherwise CallExpr is set to ExprError() and some non-success value 11562/// is returned. 11563Sema::ForRangeStatus 11564Sema::BuildForRangeBeginEndCall(Scope *S, SourceLocation Loc, 11565 SourceLocation RangeLoc, VarDecl *Decl, 11566 BeginEndFunction BEF, 11567 const DeclarationNameInfo &NameInfo, 11568 LookupResult &MemberLookup, 11569 OverloadCandidateSet *CandidateSet, 11570 Expr *Range, ExprResult *CallExpr) { 11571 CandidateSet->clear(); 11572 if (!MemberLookup.empty()) { 11573 ExprResult MemberRef = 11574 BuildMemberReferenceExpr(Range, Range->getType(), Loc, 11575 /*IsPtr=*/false, CXXScopeSpec(), 11576 /*TemplateKWLoc=*/SourceLocation(), 11577 /*FirstQualifierInScope=*/0, 11578 MemberLookup, 11579 /*TemplateArgs=*/0); 11580 if (MemberRef.isInvalid()) { 11581 *CallExpr = ExprError(); 11582 Diag(Range->getLocStart(), diag::note_in_for_range) 11583 << RangeLoc << BEF << Range->getType(); 11584 return FRS_DiagnosticIssued; 11585 } 11586 *CallExpr = ActOnCallExpr(S, MemberRef.get(), Loc, None, Loc, 0); 11587 if (CallExpr->isInvalid()) { 11588 *CallExpr = ExprError(); 11589 Diag(Range->getLocStart(), diag::note_in_for_range) 11590 << RangeLoc << BEF << Range->getType(); 11591 return FRS_DiagnosticIssued; 11592 } 11593 } else { 11594 UnresolvedSet<0> FoundNames; 11595 UnresolvedLookupExpr *Fn = 11596 UnresolvedLookupExpr::Create(Context, /*NamingClass=*/0, 11597 NestedNameSpecifierLoc(), NameInfo, 11598 /*NeedsADL=*/true, /*Overloaded=*/false, 11599 FoundNames.begin(), FoundNames.end()); 11600 11601 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, Range, Loc, 11602 CandidateSet, CallExpr); 11603 if (CandidateSet->empty() || CandidateSetError) { 11604 *CallExpr = ExprError(); 11605 return FRS_NoViableFunction; 11606 } 11607 OverloadCandidateSet::iterator Best; 11608 OverloadingResult OverloadResult = 11609 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best); 11610 11611 if (OverloadResult == OR_No_Viable_Function) { 11612 *CallExpr = ExprError(); 11613 return FRS_NoViableFunction; 11614 } 11615 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, Range, 11616 Loc, 0, CandidateSet, &Best, 11617 OverloadResult, 11618 /*AllowTypoCorrection=*/false); 11619 if (CallExpr->isInvalid() || OverloadResult != OR_Success) { 11620 *CallExpr = ExprError(); 11621 Diag(Range->getLocStart(), diag::note_in_for_range) 11622 << RangeLoc << BEF << Range->getType(); 11623 return FRS_DiagnosticIssued; 11624 } 11625 } 11626 return FRS_Success; 11627} 11628 11629 11630/// FixOverloadedFunctionReference - E is an expression that refers to 11631/// a C++ overloaded function (possibly with some parentheses and 11632/// perhaps a '&' around it). We have resolved the overloaded function 11633/// to the function declaration Fn, so patch up the expression E to 11634/// refer (possibly indirectly) to Fn. Returns the new expr. 11635Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 11636 FunctionDecl *Fn) { 11637 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 11638 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 11639 Found, Fn); 11640 if (SubExpr == PE->getSubExpr()) 11641 return PE; 11642 11643 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 11644 } 11645 11646 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 11647 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 11648 Found, Fn); 11649 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 11650 SubExpr->getType()) && 11651 "Implicit cast type cannot be determined from overload"); 11652 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 11653 if (SubExpr == ICE->getSubExpr()) 11654 return ICE; 11655 11656 return ImplicitCastExpr::Create(Context, ICE->getType(), 11657 ICE->getCastKind(), 11658 SubExpr, 0, 11659 ICE->getValueKind()); 11660 } 11661 11662 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 11663 assert(UnOp->getOpcode() == UO_AddrOf && 11664 "Can only take the address of an overloaded function"); 11665 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 11666 if (Method->isStatic()) { 11667 // Do nothing: static member functions aren't any different 11668 // from non-member functions. 11669 } else { 11670 // Fix the sub expression, which really has to be an 11671 // UnresolvedLookupExpr holding an overloaded member function 11672 // or template. 11673 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 11674 Found, Fn); 11675 if (SubExpr == UnOp->getSubExpr()) 11676 return UnOp; 11677 11678 assert(isa<DeclRefExpr>(SubExpr) 11679 && "fixed to something other than a decl ref"); 11680 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 11681 && "fixed to a member ref with no nested name qualifier"); 11682 11683 // We have taken the address of a pointer to member 11684 // function. Perform the computation here so that we get the 11685 // appropriate pointer to member type. 11686 QualType ClassType 11687 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 11688 QualType MemPtrType 11689 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 11690 11691 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 11692 VK_RValue, OK_Ordinary, 11693 UnOp->getOperatorLoc()); 11694 } 11695 } 11696 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 11697 Found, Fn); 11698 if (SubExpr == UnOp->getSubExpr()) 11699 return UnOp; 11700 11701 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 11702 Context.getPointerType(SubExpr->getType()), 11703 VK_RValue, OK_Ordinary, 11704 UnOp->getOperatorLoc()); 11705 } 11706 11707 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 11708 // FIXME: avoid copy. 11709 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 11710 if (ULE->hasExplicitTemplateArgs()) { 11711 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 11712 TemplateArgs = &TemplateArgsBuffer; 11713 } 11714 11715 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 11716 ULE->getQualifierLoc(), 11717 ULE->getTemplateKeywordLoc(), 11718 Fn, 11719 /*enclosing*/ false, // FIXME? 11720 ULE->getNameLoc(), 11721 Fn->getType(), 11722 VK_LValue, 11723 Found.getDecl(), 11724 TemplateArgs); 11725 MarkDeclRefReferenced(DRE); 11726 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1); 11727 return DRE; 11728 } 11729 11730 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 11731 // FIXME: avoid copy. 11732 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 11733 if (MemExpr->hasExplicitTemplateArgs()) { 11734 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 11735 TemplateArgs = &TemplateArgsBuffer; 11736 } 11737 11738 Expr *Base; 11739 11740 // If we're filling in a static method where we used to have an 11741 // implicit member access, rewrite to a simple decl ref. 11742 if (MemExpr->isImplicitAccess()) { 11743 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 11744 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 11745 MemExpr->getQualifierLoc(), 11746 MemExpr->getTemplateKeywordLoc(), 11747 Fn, 11748 /*enclosing*/ false, 11749 MemExpr->getMemberLoc(), 11750 Fn->getType(), 11751 VK_LValue, 11752 Found.getDecl(), 11753 TemplateArgs); 11754 MarkDeclRefReferenced(DRE); 11755 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1); 11756 return DRE; 11757 } else { 11758 SourceLocation Loc = MemExpr->getMemberLoc(); 11759 if (MemExpr->getQualifier()) 11760 Loc = MemExpr->getQualifierLoc().getBeginLoc(); 11761 CheckCXXThisCapture(Loc); 11762 Base = new (Context) CXXThisExpr(Loc, 11763 MemExpr->getBaseType(), 11764 /*isImplicit=*/true); 11765 } 11766 } else 11767 Base = MemExpr->getBase(); 11768 11769 ExprValueKind valueKind; 11770 QualType type; 11771 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 11772 valueKind = VK_LValue; 11773 type = Fn->getType(); 11774 } else { 11775 valueKind = VK_RValue; 11776 type = Context.BoundMemberTy; 11777 } 11778 11779 MemberExpr *ME = MemberExpr::Create(Context, Base, 11780 MemExpr->isArrow(), 11781 MemExpr->getQualifierLoc(), 11782 MemExpr->getTemplateKeywordLoc(), 11783 Fn, 11784 Found, 11785 MemExpr->getMemberNameInfo(), 11786 TemplateArgs, 11787 type, valueKind, OK_Ordinary); 11788 ME->setHadMultipleCandidates(true); 11789 MarkMemberReferenced(ME); 11790 return ME; 11791 } 11792 11793 llvm_unreachable("Invalid reference to overloaded function"); 11794} 11795 11796ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 11797 DeclAccessPair Found, 11798 FunctionDecl *Fn) { 11799 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 11800} 11801 11802} // end namespace clang 11803