SemaOverload.cpp revision dc7b641574a733624489bd87fc7061771edf2113
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 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/SemaInternal.h" 15#include "clang/Sema/Lookup.h" 16#include "clang/Sema/Initialization.h" 17#include "clang/Sema/Template.h" 18#include "clang/Sema/TemplateDeduction.h" 19#include "clang/Basic/Diagnostic.h" 20#include "clang/Lex/Preprocessor.h" 21#include "clang/AST/ASTContext.h" 22#include "clang/AST/CXXInheritance.h" 23#include "clang/AST/DeclObjC.h" 24#include "clang/AST/Expr.h" 25#include "clang/AST/ExprCXX.h" 26#include "clang/AST/ExprObjC.h" 27#include "clang/AST/TypeOrdering.h" 28#include "clang/Basic/PartialDiagnostic.h" 29#include "llvm/ADT/DenseSet.h" 30#include "llvm/ADT/SmallPtrSet.h" 31#include "llvm/ADT/SmallString.h" 32#include "llvm/ADT/STLExtras.h" 33#include <algorithm> 34 35namespace clang { 36using namespace sema; 37 38/// A convenience routine for creating a decayed reference to a 39/// function. 40static ExprResult 41CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, bool HadMultipleCandidates, 42 SourceLocation Loc = SourceLocation(), 43 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){ 44 DeclRefExpr *DRE = new (S.Context) DeclRefExpr(Fn, false, Fn->getType(), 45 VK_LValue, Loc, LocInfo); 46 if (HadMultipleCandidates) 47 DRE->setHadMultipleCandidates(true); 48 ExprResult E = S.Owned(DRE); 49 E = S.DefaultFunctionArrayConversion(E.take()); 50 if (E.isInvalid()) 51 return ExprError(); 52 return E; 53} 54 55static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 56 bool InOverloadResolution, 57 StandardConversionSequence &SCS, 58 bool CStyle, 59 bool AllowObjCWritebackConversion); 60 61static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From, 62 QualType &ToType, 63 bool InOverloadResolution, 64 StandardConversionSequence &SCS, 65 bool CStyle); 66static OverloadingResult 67IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 68 UserDefinedConversionSequence& User, 69 OverloadCandidateSet& Conversions, 70 bool AllowExplicit); 71 72 73static ImplicitConversionSequence::CompareKind 74CompareStandardConversionSequences(Sema &S, 75 const StandardConversionSequence& SCS1, 76 const StandardConversionSequence& SCS2); 77 78static ImplicitConversionSequence::CompareKind 79CompareQualificationConversions(Sema &S, 80 const StandardConversionSequence& SCS1, 81 const StandardConversionSequence& SCS2); 82 83static ImplicitConversionSequence::CompareKind 84CompareDerivedToBaseConversions(Sema &S, 85 const StandardConversionSequence& SCS1, 86 const StandardConversionSequence& SCS2); 87 88 89 90/// GetConversionCategory - Retrieve the implicit conversion 91/// category corresponding to the given implicit conversion kind. 92ImplicitConversionCategory 93GetConversionCategory(ImplicitConversionKind Kind) { 94 static const ImplicitConversionCategory 95 Category[(int)ICK_Num_Conversion_Kinds] = { 96 ICC_Identity, 97 ICC_Lvalue_Transformation, 98 ICC_Lvalue_Transformation, 99 ICC_Lvalue_Transformation, 100 ICC_Identity, 101 ICC_Qualification_Adjustment, 102 ICC_Promotion, 103 ICC_Promotion, 104 ICC_Promotion, 105 ICC_Conversion, 106 ICC_Conversion, 107 ICC_Conversion, 108 ICC_Conversion, 109 ICC_Conversion, 110 ICC_Conversion, 111 ICC_Conversion, 112 ICC_Conversion, 113 ICC_Conversion, 114 ICC_Conversion, 115 ICC_Conversion, 116 ICC_Conversion, 117 ICC_Conversion 118 }; 119 return Category[(int)Kind]; 120} 121 122/// GetConversionRank - Retrieve the implicit conversion rank 123/// corresponding to the given implicit conversion kind. 124ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 125 static const ImplicitConversionRank 126 Rank[(int)ICK_Num_Conversion_Kinds] = { 127 ICR_Exact_Match, 128 ICR_Exact_Match, 129 ICR_Exact_Match, 130 ICR_Exact_Match, 131 ICR_Exact_Match, 132 ICR_Exact_Match, 133 ICR_Promotion, 134 ICR_Promotion, 135 ICR_Promotion, 136 ICR_Conversion, 137 ICR_Conversion, 138 ICR_Conversion, 139 ICR_Conversion, 140 ICR_Conversion, 141 ICR_Conversion, 142 ICR_Conversion, 143 ICR_Conversion, 144 ICR_Conversion, 145 ICR_Conversion, 146 ICR_Conversion, 147 ICR_Complex_Real_Conversion, 148 ICR_Conversion, 149 ICR_Conversion, 150 ICR_Writeback_Conversion 151 }; 152 return Rank[(int)Kind]; 153} 154 155/// GetImplicitConversionName - Return the name of this kind of 156/// implicit conversion. 157const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 158 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 159 "No conversion", 160 "Lvalue-to-rvalue", 161 "Array-to-pointer", 162 "Function-to-pointer", 163 "Noreturn adjustment", 164 "Qualification", 165 "Integral promotion", 166 "Floating point promotion", 167 "Complex promotion", 168 "Integral conversion", 169 "Floating conversion", 170 "Complex conversion", 171 "Floating-integral conversion", 172 "Pointer conversion", 173 "Pointer-to-member conversion", 174 "Boolean conversion", 175 "Compatible-types conversion", 176 "Derived-to-base conversion", 177 "Vector conversion", 178 "Vector splat", 179 "Complex-real conversion", 180 "Block Pointer conversion", 181 "Transparent Union Conversion" 182 "Writeback conversion" 183 }; 184 return Name[Kind]; 185} 186 187/// StandardConversionSequence - Set the standard conversion 188/// sequence to the identity conversion. 189void StandardConversionSequence::setAsIdentityConversion() { 190 First = ICK_Identity; 191 Second = ICK_Identity; 192 Third = ICK_Identity; 193 DeprecatedStringLiteralToCharPtr = false; 194 QualificationIncludesObjCLifetime = false; 195 ReferenceBinding = false; 196 DirectBinding = false; 197 IsLvalueReference = true; 198 BindsToFunctionLvalue = false; 199 BindsToRvalue = false; 200 BindsImplicitObjectArgumentWithoutRefQualifier = false; 201 ObjCLifetimeConversionBinding = false; 202 CopyConstructor = 0; 203} 204 205/// getRank - Retrieve the rank of this standard conversion sequence 206/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 207/// implicit conversions. 208ImplicitConversionRank StandardConversionSequence::getRank() const { 209 ImplicitConversionRank Rank = ICR_Exact_Match; 210 if (GetConversionRank(First) > Rank) 211 Rank = GetConversionRank(First); 212 if (GetConversionRank(Second) > Rank) 213 Rank = GetConversionRank(Second); 214 if (GetConversionRank(Third) > Rank) 215 Rank = GetConversionRank(Third); 216 return Rank; 217} 218 219/// isPointerConversionToBool - Determines whether this conversion is 220/// a conversion of a pointer or pointer-to-member to bool. This is 221/// used as part of the ranking of standard conversion sequences 222/// (C++ 13.3.3.2p4). 223bool StandardConversionSequence::isPointerConversionToBool() const { 224 // Note that FromType has not necessarily been transformed by the 225 // array-to-pointer or function-to-pointer implicit conversions, so 226 // check for their presence as well as checking whether FromType is 227 // a pointer. 228 if (getToType(1)->isBooleanType() && 229 (getFromType()->isPointerType() || 230 getFromType()->isObjCObjectPointerType() || 231 getFromType()->isBlockPointerType() || 232 getFromType()->isNullPtrType() || 233 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 234 return true; 235 236 return false; 237} 238 239/// isPointerConversionToVoidPointer - Determines whether this 240/// conversion is a conversion of a pointer to a void pointer. This is 241/// used as part of the ranking of standard conversion sequences (C++ 242/// 13.3.3.2p4). 243bool 244StandardConversionSequence:: 245isPointerConversionToVoidPointer(ASTContext& Context) const { 246 QualType FromType = getFromType(); 247 QualType ToType = getToType(1); 248 249 // Note that FromType has not necessarily been transformed by the 250 // array-to-pointer implicit conversion, so check for its presence 251 // and redo the conversion to get a pointer. 252 if (First == ICK_Array_To_Pointer) 253 FromType = Context.getArrayDecayedType(FromType); 254 255 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType()) 256 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 257 return ToPtrType->getPointeeType()->isVoidType(); 258 259 return false; 260} 261 262/// Skip any implicit casts which could be either part of a narrowing conversion 263/// or after one in an implicit conversion. 264static const Expr *IgnoreNarrowingConversion(const Expr *Converted) { 265 while (const ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(Converted)) { 266 switch (ICE->getCastKind()) { 267 case CK_NoOp: 268 case CK_IntegralCast: 269 case CK_IntegralToBoolean: 270 case CK_IntegralToFloating: 271 case CK_FloatingToIntegral: 272 case CK_FloatingToBoolean: 273 case CK_FloatingCast: 274 Converted = ICE->getSubExpr(); 275 continue; 276 277 default: 278 return Converted; 279 } 280 } 281 282 return Converted; 283} 284 285/// Check if this standard conversion sequence represents a narrowing 286/// conversion, according to C++11 [dcl.init.list]p7. 287/// 288/// \param Ctx The AST context. 289/// \param Converted The result of applying this standard conversion sequence. 290/// \param ConstantValue If this is an NK_Constant_Narrowing conversion, the 291/// value of the expression prior to the narrowing conversion. 292/// \param ConstantType If this is an NK_Constant_Narrowing conversion, the 293/// type of the expression prior to the narrowing conversion. 294NarrowingKind 295StandardConversionSequence::getNarrowingKind(ASTContext &Ctx, 296 const Expr *Converted, 297 APValue &ConstantValue, 298 QualType &ConstantType) const { 299 assert(Ctx.getLangOpts().CPlusPlus && "narrowing check outside C++"); 300 301 // C++11 [dcl.init.list]p7: 302 // A narrowing conversion is an implicit conversion ... 303 QualType FromType = getToType(0); 304 QualType ToType = getToType(1); 305 switch (Second) { 306 // -- from a floating-point type to an integer type, or 307 // 308 // -- from an integer type or unscoped enumeration type to a floating-point 309 // type, except where the source is a constant expression and the actual 310 // value after conversion will fit into the target type and will produce 311 // the original value when converted back to the original type, or 312 case ICK_Floating_Integral: 313 if (FromType->isRealFloatingType() && ToType->isIntegralType(Ctx)) { 314 return NK_Type_Narrowing; 315 } else if (FromType->isIntegralType(Ctx) && ToType->isRealFloatingType()) { 316 llvm::APSInt IntConstantValue; 317 const Expr *Initializer = IgnoreNarrowingConversion(Converted); 318 if (Initializer && 319 Initializer->isIntegerConstantExpr(IntConstantValue, Ctx)) { 320 // Convert the integer to the floating type. 321 llvm::APFloat Result(Ctx.getFloatTypeSemantics(ToType)); 322 Result.convertFromAPInt(IntConstantValue, IntConstantValue.isSigned(), 323 llvm::APFloat::rmNearestTiesToEven); 324 // And back. 325 llvm::APSInt ConvertedValue = IntConstantValue; 326 bool ignored; 327 Result.convertToInteger(ConvertedValue, 328 llvm::APFloat::rmTowardZero, &ignored); 329 // If the resulting value is different, this was a narrowing conversion. 330 if (IntConstantValue != ConvertedValue) { 331 ConstantValue = APValue(IntConstantValue); 332 ConstantType = Initializer->getType(); 333 return NK_Constant_Narrowing; 334 } 335 } else { 336 // Variables are always narrowings. 337 return NK_Variable_Narrowing; 338 } 339 } 340 return NK_Not_Narrowing; 341 342 // -- from long double to double or float, or from double to float, except 343 // where the source is a constant expression and the actual value after 344 // conversion is within the range of values that can be represented (even 345 // if it cannot be represented exactly), or 346 case ICK_Floating_Conversion: 347 if (FromType->isRealFloatingType() && ToType->isRealFloatingType() && 348 Ctx.getFloatingTypeOrder(FromType, ToType) == 1) { 349 // FromType is larger than ToType. 350 const Expr *Initializer = IgnoreNarrowingConversion(Converted); 351 if (Initializer->isCXX11ConstantExpr(Ctx, &ConstantValue)) { 352 // Constant! 353 assert(ConstantValue.isFloat()); 354 llvm::APFloat FloatVal = ConstantValue.getFloat(); 355 // Convert the source value into the target type. 356 bool ignored; 357 llvm::APFloat::opStatus ConvertStatus = FloatVal.convert( 358 Ctx.getFloatTypeSemantics(ToType), 359 llvm::APFloat::rmNearestTiesToEven, &ignored); 360 // If there was no overflow, the source value is within the range of 361 // values that can be represented. 362 if (ConvertStatus & llvm::APFloat::opOverflow) { 363 ConstantType = Initializer->getType(); 364 return NK_Constant_Narrowing; 365 } 366 } else { 367 return NK_Variable_Narrowing; 368 } 369 } 370 return NK_Not_Narrowing; 371 372 // -- from an integer type or unscoped enumeration type to an integer type 373 // that cannot represent all the values of the original type, except where 374 // the source is a constant expression and the actual value after 375 // conversion will fit into the target type and will produce the original 376 // value when converted back to the original type. 377 case ICK_Boolean_Conversion: // Bools are integers too. 378 if (!FromType->isIntegralOrUnscopedEnumerationType()) { 379 // Boolean conversions can be from pointers and pointers to members 380 // [conv.bool], and those aren't considered narrowing conversions. 381 return NK_Not_Narrowing; 382 } // Otherwise, fall through to the integral case. 383 case ICK_Integral_Conversion: { 384 assert(FromType->isIntegralOrUnscopedEnumerationType()); 385 assert(ToType->isIntegralOrUnscopedEnumerationType()); 386 const bool FromSigned = FromType->isSignedIntegerOrEnumerationType(); 387 const unsigned FromWidth = Ctx.getIntWidth(FromType); 388 const bool ToSigned = ToType->isSignedIntegerOrEnumerationType(); 389 const unsigned ToWidth = Ctx.getIntWidth(ToType); 390 391 if (FromWidth > ToWidth || 392 (FromWidth == ToWidth && FromSigned != ToSigned) || 393 (FromSigned && !ToSigned)) { 394 // Not all values of FromType can be represented in ToType. 395 llvm::APSInt InitializerValue; 396 const Expr *Initializer = IgnoreNarrowingConversion(Converted); 397 if (!Initializer->isIntegerConstantExpr(InitializerValue, Ctx)) { 398 // Such conversions on variables are always narrowing. 399 return NK_Variable_Narrowing; 400 } 401 bool Narrowing = false; 402 if (FromWidth < ToWidth) { 403 // Negative -> unsigned is narrowing. Otherwise, more bits is never 404 // narrowing. 405 if (InitializerValue.isSigned() && InitializerValue.isNegative()) 406 Narrowing = true; 407 } else { 408 // Add a bit to the InitializerValue so we don't have to worry about 409 // signed vs. unsigned comparisons. 410 InitializerValue = InitializerValue.extend( 411 InitializerValue.getBitWidth() + 1); 412 // Convert the initializer to and from the target width and signed-ness. 413 llvm::APSInt ConvertedValue = InitializerValue; 414 ConvertedValue = ConvertedValue.trunc(ToWidth); 415 ConvertedValue.setIsSigned(ToSigned); 416 ConvertedValue = ConvertedValue.extend(InitializerValue.getBitWidth()); 417 ConvertedValue.setIsSigned(InitializerValue.isSigned()); 418 // If the result is different, this was a narrowing conversion. 419 if (ConvertedValue != InitializerValue) 420 Narrowing = true; 421 } 422 if (Narrowing) { 423 ConstantType = Initializer->getType(); 424 ConstantValue = APValue(InitializerValue); 425 return NK_Constant_Narrowing; 426 } 427 } 428 return NK_Not_Narrowing; 429 } 430 431 default: 432 // Other kinds of conversions are not narrowings. 433 return NK_Not_Narrowing; 434 } 435} 436 437/// DebugPrint - Print this standard conversion sequence to standard 438/// error. Useful for debugging overloading issues. 439void StandardConversionSequence::DebugPrint() const { 440 raw_ostream &OS = llvm::errs(); 441 bool PrintedSomething = false; 442 if (First != ICK_Identity) { 443 OS << GetImplicitConversionName(First); 444 PrintedSomething = true; 445 } 446 447 if (Second != ICK_Identity) { 448 if (PrintedSomething) { 449 OS << " -> "; 450 } 451 OS << GetImplicitConversionName(Second); 452 453 if (CopyConstructor) { 454 OS << " (by copy constructor)"; 455 } else if (DirectBinding) { 456 OS << " (direct reference binding)"; 457 } else if (ReferenceBinding) { 458 OS << " (reference binding)"; 459 } 460 PrintedSomething = true; 461 } 462 463 if (Third != ICK_Identity) { 464 if (PrintedSomething) { 465 OS << " -> "; 466 } 467 OS << GetImplicitConversionName(Third); 468 PrintedSomething = true; 469 } 470 471 if (!PrintedSomething) { 472 OS << "No conversions required"; 473 } 474} 475 476/// DebugPrint - Print this user-defined conversion sequence to standard 477/// error. Useful for debugging overloading issues. 478void UserDefinedConversionSequence::DebugPrint() const { 479 raw_ostream &OS = llvm::errs(); 480 if (Before.First || Before.Second || Before.Third) { 481 Before.DebugPrint(); 482 OS << " -> "; 483 } 484 if (ConversionFunction) 485 OS << '\'' << *ConversionFunction << '\''; 486 else 487 OS << "aggregate initialization"; 488 if (After.First || After.Second || After.Third) { 489 OS << " -> "; 490 After.DebugPrint(); 491 } 492} 493 494/// DebugPrint - Print this implicit conversion sequence to standard 495/// error. Useful for debugging overloading issues. 496void ImplicitConversionSequence::DebugPrint() const { 497 raw_ostream &OS = llvm::errs(); 498 switch (ConversionKind) { 499 case StandardConversion: 500 OS << "Standard conversion: "; 501 Standard.DebugPrint(); 502 break; 503 case UserDefinedConversion: 504 OS << "User-defined conversion: "; 505 UserDefined.DebugPrint(); 506 break; 507 case EllipsisConversion: 508 OS << "Ellipsis conversion"; 509 break; 510 case AmbiguousConversion: 511 OS << "Ambiguous conversion"; 512 break; 513 case BadConversion: 514 OS << "Bad conversion"; 515 break; 516 } 517 518 OS << "\n"; 519} 520 521void AmbiguousConversionSequence::construct() { 522 new (&conversions()) ConversionSet(); 523} 524 525void AmbiguousConversionSequence::destruct() { 526 conversions().~ConversionSet(); 527} 528 529void 530AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 531 FromTypePtr = O.FromTypePtr; 532 ToTypePtr = O.ToTypePtr; 533 new (&conversions()) ConversionSet(O.conversions()); 534} 535 536namespace { 537 // Structure used by OverloadCandidate::DeductionFailureInfo to store 538 // template parameter and template argument information. 539 struct DFIParamWithArguments { 540 TemplateParameter Param; 541 TemplateArgument FirstArg; 542 TemplateArgument SecondArg; 543 }; 544} 545 546/// \brief Convert from Sema's representation of template deduction information 547/// to the form used in overload-candidate information. 548OverloadCandidate::DeductionFailureInfo 549static MakeDeductionFailureInfo(ASTContext &Context, 550 Sema::TemplateDeductionResult TDK, 551 TemplateDeductionInfo &Info) { 552 OverloadCandidate::DeductionFailureInfo Result; 553 Result.Result = static_cast<unsigned>(TDK); 554 Result.HasDiagnostic = false; 555 Result.Data = 0; 556 switch (TDK) { 557 case Sema::TDK_Success: 558 case Sema::TDK_Invalid: 559 case Sema::TDK_InstantiationDepth: 560 case Sema::TDK_TooManyArguments: 561 case Sema::TDK_TooFewArguments: 562 break; 563 564 case Sema::TDK_Incomplete: 565 case Sema::TDK_InvalidExplicitArguments: 566 Result.Data = Info.Param.getOpaqueValue(); 567 break; 568 569 case Sema::TDK_Inconsistent: 570 case Sema::TDK_Underqualified: { 571 // FIXME: Should allocate from normal heap so that we can free this later. 572 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 573 Saved->Param = Info.Param; 574 Saved->FirstArg = Info.FirstArg; 575 Saved->SecondArg = Info.SecondArg; 576 Result.Data = Saved; 577 break; 578 } 579 580 case Sema::TDK_SubstitutionFailure: 581 Result.Data = Info.take(); 582 if (Info.hasSFINAEDiagnostic()) { 583 PartialDiagnosticAt *Diag = new (Result.Diagnostic) PartialDiagnosticAt( 584 SourceLocation(), PartialDiagnostic::NullDiagnostic()); 585 Info.takeSFINAEDiagnostic(*Diag); 586 Result.HasDiagnostic = true; 587 } 588 break; 589 590 case Sema::TDK_NonDeducedMismatch: 591 case Sema::TDK_FailedOverloadResolution: 592 break; 593 } 594 595 return Result; 596} 597 598void OverloadCandidate::DeductionFailureInfo::Destroy() { 599 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 600 case Sema::TDK_Success: 601 case Sema::TDK_Invalid: 602 case Sema::TDK_InstantiationDepth: 603 case Sema::TDK_Incomplete: 604 case Sema::TDK_TooManyArguments: 605 case Sema::TDK_TooFewArguments: 606 case Sema::TDK_InvalidExplicitArguments: 607 break; 608 609 case Sema::TDK_Inconsistent: 610 case Sema::TDK_Underqualified: 611 // FIXME: Destroy the data? 612 Data = 0; 613 break; 614 615 case Sema::TDK_SubstitutionFailure: 616 // FIXME: Destroy the template argument list? 617 Data = 0; 618 if (PartialDiagnosticAt *Diag = getSFINAEDiagnostic()) { 619 Diag->~PartialDiagnosticAt(); 620 HasDiagnostic = false; 621 } 622 break; 623 624 // Unhandled 625 case Sema::TDK_NonDeducedMismatch: 626 case Sema::TDK_FailedOverloadResolution: 627 break; 628 } 629} 630 631PartialDiagnosticAt * 632OverloadCandidate::DeductionFailureInfo::getSFINAEDiagnostic() { 633 if (HasDiagnostic) 634 return static_cast<PartialDiagnosticAt*>(static_cast<void*>(Diagnostic)); 635 return 0; 636} 637 638TemplateParameter 639OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 640 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 641 case Sema::TDK_Success: 642 case Sema::TDK_Invalid: 643 case Sema::TDK_InstantiationDepth: 644 case Sema::TDK_TooManyArguments: 645 case Sema::TDK_TooFewArguments: 646 case Sema::TDK_SubstitutionFailure: 647 return TemplateParameter(); 648 649 case Sema::TDK_Incomplete: 650 case Sema::TDK_InvalidExplicitArguments: 651 return TemplateParameter::getFromOpaqueValue(Data); 652 653 case Sema::TDK_Inconsistent: 654 case Sema::TDK_Underqualified: 655 return static_cast<DFIParamWithArguments*>(Data)->Param; 656 657 // Unhandled 658 case Sema::TDK_NonDeducedMismatch: 659 case Sema::TDK_FailedOverloadResolution: 660 break; 661 } 662 663 return TemplateParameter(); 664} 665 666TemplateArgumentList * 667OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 668 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 669 case Sema::TDK_Success: 670 case Sema::TDK_Invalid: 671 case Sema::TDK_InstantiationDepth: 672 case Sema::TDK_TooManyArguments: 673 case Sema::TDK_TooFewArguments: 674 case Sema::TDK_Incomplete: 675 case Sema::TDK_InvalidExplicitArguments: 676 case Sema::TDK_Inconsistent: 677 case Sema::TDK_Underqualified: 678 return 0; 679 680 case Sema::TDK_SubstitutionFailure: 681 return static_cast<TemplateArgumentList*>(Data); 682 683 // Unhandled 684 case Sema::TDK_NonDeducedMismatch: 685 case Sema::TDK_FailedOverloadResolution: 686 break; 687 } 688 689 return 0; 690} 691 692const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 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_Incomplete: 698 case Sema::TDK_TooManyArguments: 699 case Sema::TDK_TooFewArguments: 700 case Sema::TDK_InvalidExplicitArguments: 701 case Sema::TDK_SubstitutionFailure: 702 return 0; 703 704 case Sema::TDK_Inconsistent: 705 case Sema::TDK_Underqualified: 706 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 707 708 // Unhandled 709 case Sema::TDK_NonDeducedMismatch: 710 case Sema::TDK_FailedOverloadResolution: 711 break; 712 } 713 714 return 0; 715} 716 717const TemplateArgument * 718OverloadCandidate::DeductionFailureInfo::getSecondArg() { 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 return 0; 729 730 case Sema::TDK_Inconsistent: 731 case Sema::TDK_Underqualified: 732 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 733 734 // Unhandled 735 case Sema::TDK_NonDeducedMismatch: 736 case Sema::TDK_FailedOverloadResolution: 737 break; 738 } 739 740 return 0; 741} 742 743void OverloadCandidateSet::destroyCandidates() { 744 for (iterator i = begin(), e = end(); i != e; ++i) { 745 for (unsigned ii = 0, ie = i->NumConversions; ii != ie; ++ii) 746 i->Conversions[ii].~ImplicitConversionSequence(); 747 if (!i->Viable && i->FailureKind == ovl_fail_bad_deduction) 748 i->DeductionFailure.Destroy(); 749 } 750} 751 752void OverloadCandidateSet::clear() { 753 destroyCandidates(); 754 NumInlineSequences = 0; 755 Candidates.clear(); 756 Functions.clear(); 757} 758 759namespace { 760 class UnbridgedCastsSet { 761 struct Entry { 762 Expr **Addr; 763 Expr *Saved; 764 }; 765 SmallVector<Entry, 2> Entries; 766 767 public: 768 void save(Sema &S, Expr *&E) { 769 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)); 770 Entry entry = { &E, E }; 771 Entries.push_back(entry); 772 E = S.stripARCUnbridgedCast(E); 773 } 774 775 void restore() { 776 for (SmallVectorImpl<Entry>::iterator 777 i = Entries.begin(), e = Entries.end(); i != e; ++i) 778 *i->Addr = i->Saved; 779 } 780 }; 781} 782 783/// checkPlaceholderForOverload - Do any interesting placeholder-like 784/// preprocessing on the given expression. 785/// 786/// \param unbridgedCasts a collection to which to add unbridged casts; 787/// without this, they will be immediately diagnosed as errors 788/// 789/// Return true on unrecoverable error. 790static bool checkPlaceholderForOverload(Sema &S, Expr *&E, 791 UnbridgedCastsSet *unbridgedCasts = 0) { 792 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) { 793 // We can't handle overloaded expressions here because overload 794 // resolution might reasonably tweak them. 795 if (placeholder->getKind() == BuiltinType::Overload) return false; 796 797 // If the context potentially accepts unbridged ARC casts, strip 798 // the unbridged cast and add it to the collection for later restoration. 799 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast && 800 unbridgedCasts) { 801 unbridgedCasts->save(S, E); 802 return false; 803 } 804 805 // Go ahead and check everything else. 806 ExprResult result = S.CheckPlaceholderExpr(E); 807 if (result.isInvalid()) 808 return true; 809 810 E = result.take(); 811 return false; 812 } 813 814 // Nothing to do. 815 return false; 816} 817 818/// checkArgPlaceholdersForOverload - Check a set of call operands for 819/// placeholders. 820static bool checkArgPlaceholdersForOverload(Sema &S, Expr **args, 821 unsigned numArgs, 822 UnbridgedCastsSet &unbridged) { 823 for (unsigned i = 0; i != numArgs; ++i) 824 if (checkPlaceholderForOverload(S, args[i], &unbridged)) 825 return true; 826 827 return false; 828} 829 830// IsOverload - Determine whether the given New declaration is an 831// overload of the declarations in Old. This routine returns false if 832// New and Old cannot be overloaded, e.g., if New has the same 833// signature as some function in Old (C++ 1.3.10) or if the Old 834// declarations aren't functions (or function templates) at all. When 835// it does return false, MatchedDecl will point to the decl that New 836// cannot be overloaded with. This decl may be a UsingShadowDecl on 837// top of the underlying declaration. 838// 839// Example: Given the following input: 840// 841// void f(int, float); // #1 842// void f(int, int); // #2 843// int f(int, int); // #3 844// 845// When we process #1, there is no previous declaration of "f", 846// so IsOverload will not be used. 847// 848// When we process #2, Old contains only the FunctionDecl for #1. By 849// comparing the parameter types, we see that #1 and #2 are overloaded 850// (since they have different signatures), so this routine returns 851// false; MatchedDecl is unchanged. 852// 853// When we process #3, Old is an overload set containing #1 and #2. We 854// compare the signatures of #3 to #1 (they're overloaded, so we do 855// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 856// identical (return types of functions are not part of the 857// signature), IsOverload returns false and MatchedDecl will be set to 858// point to the FunctionDecl for #2. 859// 860// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 861// into a class by a using declaration. The rules for whether to hide 862// shadow declarations ignore some properties which otherwise figure 863// into a function template's signature. 864Sema::OverloadKind 865Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 866 NamedDecl *&Match, bool NewIsUsingDecl) { 867 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 868 I != E; ++I) { 869 NamedDecl *OldD = *I; 870 871 bool OldIsUsingDecl = false; 872 if (isa<UsingShadowDecl>(OldD)) { 873 OldIsUsingDecl = true; 874 875 // We can always introduce two using declarations into the same 876 // context, even if they have identical signatures. 877 if (NewIsUsingDecl) continue; 878 879 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 880 } 881 882 // If either declaration was introduced by a using declaration, 883 // we'll need to use slightly different rules for matching. 884 // Essentially, these rules are the normal rules, except that 885 // function templates hide function templates with different 886 // return types or template parameter lists. 887 bool UseMemberUsingDeclRules = 888 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 889 890 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 891 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 892 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 893 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 894 continue; 895 } 896 897 Match = *I; 898 return Ovl_Match; 899 } 900 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 901 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 902 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 903 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 904 continue; 905 } 906 907 Match = *I; 908 return Ovl_Match; 909 } 910 } else if (isa<UsingDecl>(OldD)) { 911 // We can overload with these, which can show up when doing 912 // redeclaration checks for UsingDecls. 913 assert(Old.getLookupKind() == LookupUsingDeclName); 914 } else if (isa<TagDecl>(OldD)) { 915 // We can always overload with tags by hiding them. 916 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 917 // Optimistically assume that an unresolved using decl will 918 // overload; if it doesn't, we'll have to diagnose during 919 // template instantiation. 920 } else { 921 // (C++ 13p1): 922 // Only function declarations can be overloaded; object and type 923 // declarations cannot be overloaded. 924 Match = *I; 925 return Ovl_NonFunction; 926 } 927 } 928 929 return Ovl_Overload; 930} 931 932bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 933 bool UseUsingDeclRules) { 934 // If both of the functions are extern "C", then they are not 935 // overloads. 936 if (Old->isExternC() && New->isExternC()) 937 return false; 938 939 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 940 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 941 942 // C++ [temp.fct]p2: 943 // A function template can be overloaded with other function templates 944 // and with normal (non-template) functions. 945 if ((OldTemplate == 0) != (NewTemplate == 0)) 946 return true; 947 948 // Is the function New an overload of the function Old? 949 QualType OldQType = Context.getCanonicalType(Old->getType()); 950 QualType NewQType = Context.getCanonicalType(New->getType()); 951 952 // Compare the signatures (C++ 1.3.10) of the two functions to 953 // determine whether they are overloads. If we find any mismatch 954 // in the signature, they are overloads. 955 956 // If either of these functions is a K&R-style function (no 957 // prototype), then we consider them to have matching signatures. 958 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 959 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 960 return false; 961 962 const FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 963 const FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 964 965 // The signature of a function includes the types of its 966 // parameters (C++ 1.3.10), which includes the presence or absence 967 // of the ellipsis; see C++ DR 357). 968 if (OldQType != NewQType && 969 (OldType->getNumArgs() != NewType->getNumArgs() || 970 OldType->isVariadic() != NewType->isVariadic() || 971 !FunctionArgTypesAreEqual(OldType, NewType))) 972 return true; 973 974 // C++ [temp.over.link]p4: 975 // The signature of a function template consists of its function 976 // signature, its return type and its template parameter list. The names 977 // of the template parameters are significant only for establishing the 978 // relationship between the template parameters and the rest of the 979 // signature. 980 // 981 // We check the return type and template parameter lists for function 982 // templates first; the remaining checks follow. 983 // 984 // However, we don't consider either of these when deciding whether 985 // a member introduced by a shadow declaration is hidden. 986 if (!UseUsingDeclRules && NewTemplate && 987 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 988 OldTemplate->getTemplateParameters(), 989 false, TPL_TemplateMatch) || 990 OldType->getResultType() != NewType->getResultType())) 991 return true; 992 993 // If the function is a class member, its signature includes the 994 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. 995 // 996 // As part of this, also check whether one of the member functions 997 // is static, in which case they are not overloads (C++ 998 // 13.1p2). While not part of the definition of the signature, 999 // this check is important to determine whether these functions 1000 // can be overloaded. 1001 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 1002 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 1003 if (OldMethod && NewMethod && 1004 !OldMethod->isStatic() && !NewMethod->isStatic() && 1005 (OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers() || 1006 OldMethod->getRefQualifier() != NewMethod->getRefQualifier())) { 1007 if (!UseUsingDeclRules && 1008 OldMethod->getRefQualifier() != NewMethod->getRefQualifier() && 1009 (OldMethod->getRefQualifier() == RQ_None || 1010 NewMethod->getRefQualifier() == RQ_None)) { 1011 // C++0x [over.load]p2: 1012 // - Member function declarations with the same name and the same 1013 // parameter-type-list as well as member function template 1014 // declarations with the same name, the same parameter-type-list, and 1015 // the same template parameter lists cannot be overloaded if any of 1016 // them, but not all, have a ref-qualifier (8.3.5). 1017 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) 1018 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); 1019 Diag(OldMethod->getLocation(), diag::note_previous_declaration); 1020 } 1021 1022 return true; 1023 } 1024 1025 // The signatures match; this is not an overload. 1026 return false; 1027} 1028 1029/// \brief Checks availability of the function depending on the current 1030/// function context. Inside an unavailable function, unavailability is ignored. 1031/// 1032/// \returns true if \arg FD is unavailable and current context is inside 1033/// an available function, false otherwise. 1034bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) { 1035 return FD->isUnavailable() && !cast<Decl>(CurContext)->isUnavailable(); 1036} 1037 1038/// \brief Tries a user-defined conversion from From to ToType. 1039/// 1040/// Produces an implicit conversion sequence for when a standard conversion 1041/// is not an option. See TryImplicitConversion for more information. 1042static ImplicitConversionSequence 1043TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 1044 bool SuppressUserConversions, 1045 bool AllowExplicit, 1046 bool InOverloadResolution, 1047 bool CStyle, 1048 bool AllowObjCWritebackConversion) { 1049 ImplicitConversionSequence ICS; 1050 1051 if (SuppressUserConversions) { 1052 // We're not in the case above, so there is no conversion that 1053 // we can perform. 1054 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 1055 return ICS; 1056 } 1057 1058 // Attempt user-defined conversion. 1059 OverloadCandidateSet Conversions(From->getExprLoc()); 1060 OverloadingResult UserDefResult 1061 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 1062 AllowExplicit); 1063 1064 if (UserDefResult == OR_Success) { 1065 ICS.setUserDefined(); 1066 // C++ [over.ics.user]p4: 1067 // A conversion of an expression of class type to the same class 1068 // type is given Exact Match rank, and a conversion of an 1069 // expression of class type to a base class of that type is 1070 // given Conversion rank, in spite of the fact that a copy 1071 // constructor (i.e., a user-defined conversion function) is 1072 // called for those cases. 1073 if (CXXConstructorDecl *Constructor 1074 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 1075 QualType FromCanon 1076 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 1077 QualType ToCanon 1078 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 1079 if (Constructor->isCopyConstructor() && 1080 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 1081 // Turn this into a "standard" conversion sequence, so that it 1082 // gets ranked with standard conversion sequences. 1083 ICS.setStandard(); 1084 ICS.Standard.setAsIdentityConversion(); 1085 ICS.Standard.setFromType(From->getType()); 1086 ICS.Standard.setAllToTypes(ToType); 1087 ICS.Standard.CopyConstructor = Constructor; 1088 if (ToCanon != FromCanon) 1089 ICS.Standard.Second = ICK_Derived_To_Base; 1090 } 1091 } 1092 1093 // C++ [over.best.ics]p4: 1094 // However, when considering the argument of a user-defined 1095 // conversion function that is a candidate by 13.3.1.3 when 1096 // invoked for the copying of the temporary in the second step 1097 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 1098 // 13.3.1.6 in all cases, only standard conversion sequences and 1099 // ellipsis conversion sequences are allowed. 1100 if (SuppressUserConversions && ICS.isUserDefined()) { 1101 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 1102 } 1103 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 1104 ICS.setAmbiguous(); 1105 ICS.Ambiguous.setFromType(From->getType()); 1106 ICS.Ambiguous.setToType(ToType); 1107 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 1108 Cand != Conversions.end(); ++Cand) 1109 if (Cand->Viable) 1110 ICS.Ambiguous.addConversion(Cand->Function); 1111 } else { 1112 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 1113 } 1114 1115 return ICS; 1116} 1117 1118/// TryImplicitConversion - Attempt to perform an implicit conversion 1119/// from the given expression (Expr) to the given type (ToType). This 1120/// function returns an implicit conversion sequence that can be used 1121/// to perform the initialization. Given 1122/// 1123/// void f(float f); 1124/// void g(int i) { f(i); } 1125/// 1126/// this routine would produce an implicit conversion sequence to 1127/// describe the initialization of f from i, which will be a standard 1128/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 1129/// 4.1) followed by a floating-integral conversion (C++ 4.9). 1130// 1131/// Note that this routine only determines how the conversion can be 1132/// performed; it does not actually perform the conversion. As such, 1133/// it will not produce any diagnostics if no conversion is available, 1134/// but will instead return an implicit conversion sequence of kind 1135/// "BadConversion". 1136/// 1137/// If @p SuppressUserConversions, then user-defined conversions are 1138/// not permitted. 1139/// If @p AllowExplicit, then explicit user-defined conversions are 1140/// permitted. 1141/// 1142/// \param AllowObjCWritebackConversion Whether we allow the Objective-C 1143/// writeback conversion, which allows __autoreleasing id* parameters to 1144/// be initialized with __strong id* or __weak id* arguments. 1145static ImplicitConversionSequence 1146TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 1147 bool SuppressUserConversions, 1148 bool AllowExplicit, 1149 bool InOverloadResolution, 1150 bool CStyle, 1151 bool AllowObjCWritebackConversion) { 1152 ImplicitConversionSequence ICS; 1153 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 1154 ICS.Standard, CStyle, AllowObjCWritebackConversion)){ 1155 ICS.setStandard(); 1156 return ICS; 1157 } 1158 1159 if (!S.getLangOpts().CPlusPlus) { 1160 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 1161 return ICS; 1162 } 1163 1164 // C++ [over.ics.user]p4: 1165 // A conversion of an expression of class type to the same class 1166 // type is given Exact Match rank, and a conversion of an 1167 // expression of class type to a base class of that type is 1168 // given Conversion rank, in spite of the fact that a copy/move 1169 // constructor (i.e., a user-defined conversion function) is 1170 // called for those cases. 1171 QualType FromType = From->getType(); 1172 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 1173 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 1174 S.IsDerivedFrom(FromType, ToType))) { 1175 ICS.setStandard(); 1176 ICS.Standard.setAsIdentityConversion(); 1177 ICS.Standard.setFromType(FromType); 1178 ICS.Standard.setAllToTypes(ToType); 1179 1180 // We don't actually check at this point whether there is a valid 1181 // copy/move constructor, since overloading just assumes that it 1182 // exists. When we actually perform initialization, we'll find the 1183 // appropriate constructor to copy the returned object, if needed. 1184 ICS.Standard.CopyConstructor = 0; 1185 1186 // Determine whether this is considered a derived-to-base conversion. 1187 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 1188 ICS.Standard.Second = ICK_Derived_To_Base; 1189 1190 return ICS; 1191 } 1192 1193 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, 1194 AllowExplicit, InOverloadResolution, CStyle, 1195 AllowObjCWritebackConversion); 1196} 1197 1198ImplicitConversionSequence 1199Sema::TryImplicitConversion(Expr *From, QualType ToType, 1200 bool SuppressUserConversions, 1201 bool AllowExplicit, 1202 bool InOverloadResolution, 1203 bool CStyle, 1204 bool AllowObjCWritebackConversion) { 1205 return clang::TryImplicitConversion(*this, From, ToType, 1206 SuppressUserConversions, AllowExplicit, 1207 InOverloadResolution, CStyle, 1208 AllowObjCWritebackConversion); 1209} 1210 1211/// PerformImplicitConversion - Perform an implicit conversion of the 1212/// expression From to the type ToType. Returns the 1213/// converted expression. Flavor is the kind of conversion we're 1214/// performing, used in the error message. If @p AllowExplicit, 1215/// explicit user-defined conversions are permitted. 1216ExprResult 1217Sema::PerformImplicitConversion(Expr *From, QualType ToType, 1218 AssignmentAction Action, bool AllowExplicit) { 1219 ImplicitConversionSequence ICS; 1220 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 1221} 1222 1223ExprResult 1224Sema::PerformImplicitConversion(Expr *From, QualType ToType, 1225 AssignmentAction Action, bool AllowExplicit, 1226 ImplicitConversionSequence& ICS) { 1227 if (checkPlaceholderForOverload(*this, From)) 1228 return ExprError(); 1229 1230 // Objective-C ARC: Determine whether we will allow the writeback conversion. 1231 bool AllowObjCWritebackConversion 1232 = getLangOpts().ObjCAutoRefCount && 1233 (Action == AA_Passing || Action == AA_Sending); 1234 1235 ICS = clang::TryImplicitConversion(*this, From, ToType, 1236 /*SuppressUserConversions=*/false, 1237 AllowExplicit, 1238 /*InOverloadResolution=*/false, 1239 /*CStyle=*/false, 1240 AllowObjCWritebackConversion); 1241 return PerformImplicitConversion(From, ToType, ICS, Action); 1242} 1243 1244/// \brief Determine whether the conversion from FromType to ToType is a valid 1245/// conversion that strips "noreturn" off the nested function type. 1246bool Sema::IsNoReturnConversion(QualType FromType, QualType ToType, 1247 QualType &ResultTy) { 1248 if (Context.hasSameUnqualifiedType(FromType, ToType)) 1249 return false; 1250 1251 // Permit the conversion F(t __attribute__((noreturn))) -> F(t) 1252 // where F adds one of the following at most once: 1253 // - a pointer 1254 // - a member pointer 1255 // - a block pointer 1256 CanQualType CanTo = Context.getCanonicalType(ToType); 1257 CanQualType CanFrom = Context.getCanonicalType(FromType); 1258 Type::TypeClass TyClass = CanTo->getTypeClass(); 1259 if (TyClass != CanFrom->getTypeClass()) return false; 1260 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { 1261 if (TyClass == Type::Pointer) { 1262 CanTo = CanTo.getAs<PointerType>()->getPointeeType(); 1263 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType(); 1264 } else if (TyClass == Type::BlockPointer) { 1265 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType(); 1266 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType(); 1267 } else if (TyClass == Type::MemberPointer) { 1268 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType(); 1269 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType(); 1270 } else { 1271 return false; 1272 } 1273 1274 TyClass = CanTo->getTypeClass(); 1275 if (TyClass != CanFrom->getTypeClass()) return false; 1276 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) 1277 return false; 1278 } 1279 1280 const FunctionType *FromFn = cast<FunctionType>(CanFrom); 1281 FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); 1282 if (!EInfo.getNoReturn()) return false; 1283 1284 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); 1285 assert(QualType(FromFn, 0).isCanonical()); 1286 if (QualType(FromFn, 0) != CanTo) return false; 1287 1288 ResultTy = ToType; 1289 return true; 1290} 1291 1292/// \brief Determine whether the conversion from FromType to ToType is a valid 1293/// vector conversion. 1294/// 1295/// \param ICK Will be set to the vector conversion kind, if this is a vector 1296/// conversion. 1297static bool IsVectorConversion(ASTContext &Context, QualType FromType, 1298 QualType ToType, ImplicitConversionKind &ICK) { 1299 // We need at least one of these types to be a vector type to have a vector 1300 // conversion. 1301 if (!ToType->isVectorType() && !FromType->isVectorType()) 1302 return false; 1303 1304 // Identical types require no conversions. 1305 if (Context.hasSameUnqualifiedType(FromType, ToType)) 1306 return false; 1307 1308 // There are no conversions between extended vector types, only identity. 1309 if (ToType->isExtVectorType()) { 1310 // There are no conversions between extended vector types other than the 1311 // identity conversion. 1312 if (FromType->isExtVectorType()) 1313 return false; 1314 1315 // Vector splat from any arithmetic type to a vector. 1316 if (FromType->isArithmeticType()) { 1317 ICK = ICK_Vector_Splat; 1318 return true; 1319 } 1320 } 1321 1322 // We can perform the conversion between vector types in the following cases: 1323 // 1)vector types are equivalent AltiVec and GCC vector types 1324 // 2)lax vector conversions are permitted and the vector types are of the 1325 // same size 1326 if (ToType->isVectorType() && FromType->isVectorType()) { 1327 if (Context.areCompatibleVectorTypes(FromType, ToType) || 1328 (Context.getLangOpts().LaxVectorConversions && 1329 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 1330 ICK = ICK_Vector_Conversion; 1331 return true; 1332 } 1333 } 1334 1335 return false; 1336} 1337 1338static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType, 1339 bool InOverloadResolution, 1340 StandardConversionSequence &SCS, 1341 bool CStyle); 1342 1343/// IsStandardConversion - Determines whether there is a standard 1344/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 1345/// expression From to the type ToType. Standard conversion sequences 1346/// only consider non-class types; for conversions that involve class 1347/// types, use TryImplicitConversion. If a conversion exists, SCS will 1348/// contain the standard conversion sequence required to perform this 1349/// conversion and this routine will return true. Otherwise, this 1350/// routine will return false and the value of SCS is unspecified. 1351static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 1352 bool InOverloadResolution, 1353 StandardConversionSequence &SCS, 1354 bool CStyle, 1355 bool AllowObjCWritebackConversion) { 1356 QualType FromType = From->getType(); 1357 1358 // Standard conversions (C++ [conv]) 1359 SCS.setAsIdentityConversion(); 1360 SCS.DeprecatedStringLiteralToCharPtr = false; 1361 SCS.IncompatibleObjC = false; 1362 SCS.setFromType(FromType); 1363 SCS.CopyConstructor = 0; 1364 1365 // There are no standard conversions for class types in C++, so 1366 // abort early. When overloading in C, however, we do permit 1367 if (FromType->isRecordType() || ToType->isRecordType()) { 1368 if (S.getLangOpts().CPlusPlus) 1369 return false; 1370 1371 // When we're overloading in C, we allow, as standard conversions, 1372 } 1373 1374 // The first conversion can be an lvalue-to-rvalue conversion, 1375 // array-to-pointer conversion, or function-to-pointer conversion 1376 // (C++ 4p1). 1377 1378 if (FromType == S.Context.OverloadTy) { 1379 DeclAccessPair AccessPair; 1380 if (FunctionDecl *Fn 1381 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 1382 AccessPair)) { 1383 // We were able to resolve the address of the overloaded function, 1384 // so we can convert to the type of that function. 1385 FromType = Fn->getType(); 1386 1387 // we can sometimes resolve &foo<int> regardless of ToType, so check 1388 // if the type matches (identity) or we are converting to bool 1389 if (!S.Context.hasSameUnqualifiedType( 1390 S.ExtractUnqualifiedFunctionType(ToType), FromType)) { 1391 QualType resultTy; 1392 // if the function type matches except for [[noreturn]], it's ok 1393 if (!S.IsNoReturnConversion(FromType, 1394 S.ExtractUnqualifiedFunctionType(ToType), resultTy)) 1395 // otherwise, only a boolean conversion is standard 1396 if (!ToType->isBooleanType()) 1397 return false; 1398 } 1399 1400 // Check if the "from" expression is taking the address of an overloaded 1401 // function and recompute the FromType accordingly. Take advantage of the 1402 // fact that non-static member functions *must* have such an address-of 1403 // expression. 1404 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn); 1405 if (Method && !Method->isStatic()) { 1406 assert(isa<UnaryOperator>(From->IgnoreParens()) && 1407 "Non-unary operator on non-static member address"); 1408 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() 1409 == UO_AddrOf && 1410 "Non-address-of operator on non-static member address"); 1411 const Type *ClassType 1412 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1413 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1414 } else if (isa<UnaryOperator>(From->IgnoreParens())) { 1415 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == 1416 UO_AddrOf && 1417 "Non-address-of operator for overloaded function expression"); 1418 FromType = S.Context.getPointerType(FromType); 1419 } 1420 1421 // Check that we've computed the proper type after overload resolution. 1422 assert(S.Context.hasSameType( 1423 FromType, 1424 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1425 } else { 1426 return false; 1427 } 1428 } 1429 // Lvalue-to-rvalue conversion (C++11 4.1): 1430 // A glvalue (3.10) of a non-function, non-array type T can 1431 // be converted to a prvalue. 1432 bool argIsLValue = From->isGLValue(); 1433 if (argIsLValue && 1434 !FromType->isFunctionType() && !FromType->isArrayType() && 1435 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1436 SCS.First = ICK_Lvalue_To_Rvalue; 1437 1438 // C11 6.3.2.1p2: 1439 // ... if the lvalue has atomic type, the value has the non-atomic version 1440 // of the type of the lvalue ... 1441 if (const AtomicType *Atomic = FromType->getAs<AtomicType>()) 1442 FromType = Atomic->getValueType(); 1443 1444 // If T is a non-class type, the type of the rvalue is the 1445 // cv-unqualified version of T. Otherwise, the type of the rvalue 1446 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1447 // just strip the qualifiers because they don't matter. 1448 FromType = FromType.getUnqualifiedType(); 1449 } else if (FromType->isArrayType()) { 1450 // Array-to-pointer conversion (C++ 4.2) 1451 SCS.First = ICK_Array_To_Pointer; 1452 1453 // An lvalue or rvalue of type "array of N T" or "array of unknown 1454 // bound of T" can be converted to an rvalue of type "pointer to 1455 // T" (C++ 4.2p1). 1456 FromType = S.Context.getArrayDecayedType(FromType); 1457 1458 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1459 // This conversion is deprecated. (C++ D.4). 1460 SCS.DeprecatedStringLiteralToCharPtr = true; 1461 1462 // For the purpose of ranking in overload resolution 1463 // (13.3.3.1.1), this conversion is considered an 1464 // array-to-pointer conversion followed by a qualification 1465 // conversion (4.4). (C++ 4.2p2) 1466 SCS.Second = ICK_Identity; 1467 SCS.Third = ICK_Qualification; 1468 SCS.QualificationIncludesObjCLifetime = false; 1469 SCS.setAllToTypes(FromType); 1470 return true; 1471 } 1472 } else if (FromType->isFunctionType() && argIsLValue) { 1473 // Function-to-pointer conversion (C++ 4.3). 1474 SCS.First = ICK_Function_To_Pointer; 1475 1476 // An lvalue of function type T can be converted to an rvalue of 1477 // type "pointer to T." The result is a pointer to the 1478 // function. (C++ 4.3p1). 1479 FromType = S.Context.getPointerType(FromType); 1480 } else { 1481 // We don't require any conversions for the first step. 1482 SCS.First = ICK_Identity; 1483 } 1484 SCS.setToType(0, FromType); 1485 1486 // The second conversion can be an integral promotion, floating 1487 // point promotion, integral conversion, floating point conversion, 1488 // floating-integral conversion, pointer conversion, 1489 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1490 // For overloading in C, this can also be a "compatible-type" 1491 // conversion. 1492 bool IncompatibleObjC = false; 1493 ImplicitConversionKind SecondICK = ICK_Identity; 1494 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1495 // The unqualified versions of the types are the same: there's no 1496 // conversion to do. 1497 SCS.Second = ICK_Identity; 1498 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1499 // Integral promotion (C++ 4.5). 1500 SCS.Second = ICK_Integral_Promotion; 1501 FromType = ToType.getUnqualifiedType(); 1502 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1503 // Floating point promotion (C++ 4.6). 1504 SCS.Second = ICK_Floating_Promotion; 1505 FromType = ToType.getUnqualifiedType(); 1506 } else if (S.IsComplexPromotion(FromType, ToType)) { 1507 // Complex promotion (Clang extension) 1508 SCS.Second = ICK_Complex_Promotion; 1509 FromType = ToType.getUnqualifiedType(); 1510 } else if (ToType->isBooleanType() && 1511 (FromType->isArithmeticType() || 1512 FromType->isAnyPointerType() || 1513 FromType->isBlockPointerType() || 1514 FromType->isMemberPointerType() || 1515 FromType->isNullPtrType())) { 1516 // Boolean conversions (C++ 4.12). 1517 SCS.Second = ICK_Boolean_Conversion; 1518 FromType = S.Context.BoolTy; 1519 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1520 ToType->isIntegralType(S.Context)) { 1521 // Integral conversions (C++ 4.7). 1522 SCS.Second = ICK_Integral_Conversion; 1523 FromType = ToType.getUnqualifiedType(); 1524 } else if (FromType->isAnyComplexType() && ToType->isComplexType()) { 1525 // Complex conversions (C99 6.3.1.6) 1526 SCS.Second = ICK_Complex_Conversion; 1527 FromType = ToType.getUnqualifiedType(); 1528 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1529 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1530 // Complex-real conversions (C99 6.3.1.7) 1531 SCS.Second = ICK_Complex_Real; 1532 FromType = ToType.getUnqualifiedType(); 1533 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1534 // Floating point conversions (C++ 4.8). 1535 SCS.Second = ICK_Floating_Conversion; 1536 FromType = ToType.getUnqualifiedType(); 1537 } else if ((FromType->isRealFloatingType() && 1538 ToType->isIntegralType(S.Context)) || 1539 (FromType->isIntegralOrUnscopedEnumerationType() && 1540 ToType->isRealFloatingType())) { 1541 // Floating-integral conversions (C++ 4.9). 1542 SCS.Second = ICK_Floating_Integral; 1543 FromType = ToType.getUnqualifiedType(); 1544 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { 1545 SCS.Second = ICK_Block_Pointer_Conversion; 1546 } else if (AllowObjCWritebackConversion && 1547 S.isObjCWritebackConversion(FromType, ToType, FromType)) { 1548 SCS.Second = ICK_Writeback_Conversion; 1549 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1550 FromType, IncompatibleObjC)) { 1551 // Pointer conversions (C++ 4.10). 1552 SCS.Second = ICK_Pointer_Conversion; 1553 SCS.IncompatibleObjC = IncompatibleObjC; 1554 FromType = FromType.getUnqualifiedType(); 1555 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1556 InOverloadResolution, FromType)) { 1557 // Pointer to member conversions (4.11). 1558 SCS.Second = ICK_Pointer_Member; 1559 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1560 SCS.Second = SecondICK; 1561 FromType = ToType.getUnqualifiedType(); 1562 } else if (!S.getLangOpts().CPlusPlus && 1563 S.Context.typesAreCompatible(ToType, FromType)) { 1564 // Compatible conversions (Clang extension for C function overloading) 1565 SCS.Second = ICK_Compatible_Conversion; 1566 FromType = ToType.getUnqualifiedType(); 1567 } else if (S.IsNoReturnConversion(FromType, ToType, FromType)) { 1568 // Treat a conversion that strips "noreturn" as an identity conversion. 1569 SCS.Second = ICK_NoReturn_Adjustment; 1570 } else if (IsTransparentUnionStandardConversion(S, From, ToType, 1571 InOverloadResolution, 1572 SCS, CStyle)) { 1573 SCS.Second = ICK_TransparentUnionConversion; 1574 FromType = ToType; 1575 } else if (tryAtomicConversion(S, From, ToType, InOverloadResolution, SCS, 1576 CStyle)) { 1577 // tryAtomicConversion has updated the standard conversion sequence 1578 // appropriately. 1579 return true; 1580 } else { 1581 // No second conversion required. 1582 SCS.Second = ICK_Identity; 1583 } 1584 SCS.setToType(1, FromType); 1585 1586 QualType CanonFrom; 1587 QualType CanonTo; 1588 // The third conversion can be a qualification conversion (C++ 4p1). 1589 bool ObjCLifetimeConversion; 1590 if (S.IsQualificationConversion(FromType, ToType, CStyle, 1591 ObjCLifetimeConversion)) { 1592 SCS.Third = ICK_Qualification; 1593 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion; 1594 FromType = ToType; 1595 CanonFrom = S.Context.getCanonicalType(FromType); 1596 CanonTo = S.Context.getCanonicalType(ToType); 1597 } else { 1598 // No conversion required 1599 SCS.Third = ICK_Identity; 1600 1601 // C++ [over.best.ics]p6: 1602 // [...] Any difference in top-level cv-qualification is 1603 // subsumed by the initialization itself and does not constitute 1604 // a conversion. [...] 1605 CanonFrom = S.Context.getCanonicalType(FromType); 1606 CanonTo = S.Context.getCanonicalType(ToType); 1607 if (CanonFrom.getLocalUnqualifiedType() 1608 == CanonTo.getLocalUnqualifiedType() && 1609 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1610 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr() 1611 || CanonFrom.getObjCLifetime() != CanonTo.getObjCLifetime())) { 1612 FromType = ToType; 1613 CanonFrom = CanonTo; 1614 } 1615 } 1616 SCS.setToType(2, FromType); 1617 1618 // If we have not converted the argument type to the parameter type, 1619 // this is a bad conversion sequence. 1620 if (CanonFrom != CanonTo) 1621 return false; 1622 1623 return true; 1624} 1625 1626static bool 1627IsTransparentUnionStandardConversion(Sema &S, Expr* From, 1628 QualType &ToType, 1629 bool InOverloadResolution, 1630 StandardConversionSequence &SCS, 1631 bool CStyle) { 1632 1633 const RecordType *UT = ToType->getAsUnionType(); 1634 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 1635 return false; 1636 // The field to initialize within the transparent union. 1637 RecordDecl *UD = UT->getDecl(); 1638 // It's compatible if the expression matches any of the fields. 1639 for (RecordDecl::field_iterator it = UD->field_begin(), 1640 itend = UD->field_end(); 1641 it != itend; ++it) { 1642 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, 1643 CStyle, /*ObjCWritebackConversion=*/false)) { 1644 ToType = it->getType(); 1645 return true; 1646 } 1647 } 1648 return false; 1649} 1650 1651/// IsIntegralPromotion - Determines whether the conversion from the 1652/// expression From (whose potentially-adjusted type is FromType) to 1653/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1654/// sets PromotedType to the promoted type. 1655bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1656 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1657 // All integers are built-in. 1658 if (!To) { 1659 return false; 1660 } 1661 1662 // An rvalue of type char, signed char, unsigned char, short int, or 1663 // unsigned short int can be converted to an rvalue of type int if 1664 // int can represent all the values of the source type; otherwise, 1665 // the source rvalue can be converted to an rvalue of type unsigned 1666 // int (C++ 4.5p1). 1667 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1668 !FromType->isEnumeralType()) { 1669 if (// We can promote any signed, promotable integer type to an int 1670 (FromType->isSignedIntegerType() || 1671 // We can promote any unsigned integer type whose size is 1672 // less than int to an int. 1673 (!FromType->isSignedIntegerType() && 1674 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1675 return To->getKind() == BuiltinType::Int; 1676 } 1677 1678 return To->getKind() == BuiltinType::UInt; 1679 } 1680 1681 // C++11 [conv.prom]p3: 1682 // A prvalue of an unscoped enumeration type whose underlying type is not 1683 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1684 // following types that can represent all the values of the enumeration 1685 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1686 // unsigned int, long int, unsigned long int, long long int, or unsigned 1687 // long long int. If none of the types in that list can represent all the 1688 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1689 // type can be converted to an rvalue a prvalue of the extended integer type 1690 // with lowest integer conversion rank (4.13) greater than the rank of long 1691 // long in which all the values of the enumeration can be represented. If 1692 // there are two such extended types, the signed one is chosen. 1693 // C++11 [conv.prom]p4: 1694 // A prvalue of an unscoped enumeration type whose underlying type is fixed 1695 // can be converted to a prvalue of its underlying type. Moreover, if 1696 // integral promotion can be applied to its underlying type, a prvalue of an 1697 // unscoped enumeration type whose underlying type is fixed can also be 1698 // converted to a prvalue of the promoted underlying type. 1699 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1700 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1701 // provided for a scoped enumeration. 1702 if (FromEnumType->getDecl()->isScoped()) 1703 return false; 1704 1705 // We can perform an integral promotion to the underlying type of the enum, 1706 // even if that's not the promoted type. 1707 if (FromEnumType->getDecl()->isFixed()) { 1708 QualType Underlying = FromEnumType->getDecl()->getIntegerType(); 1709 return Context.hasSameUnqualifiedType(Underlying, ToType) || 1710 IsIntegralPromotion(From, Underlying, ToType); 1711 } 1712 1713 // We have already pre-calculated the promotion type, so this is trivial. 1714 if (ToType->isIntegerType() && 1715 !RequireCompleteType(From->getLocStart(), FromType, 0)) 1716 return Context.hasSameUnqualifiedType(ToType, 1717 FromEnumType->getDecl()->getPromotionType()); 1718 } 1719 1720 // C++0x [conv.prom]p2: 1721 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1722 // to an rvalue a prvalue of the first of the following types that can 1723 // represent all the values of its underlying type: int, unsigned int, 1724 // long int, unsigned long int, long long int, or unsigned long long int. 1725 // If none of the types in that list can represent all the values of its 1726 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1727 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1728 // type. 1729 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1730 ToType->isIntegerType()) { 1731 // Determine whether the type we're converting from is signed or 1732 // unsigned. 1733 bool FromIsSigned = FromType->isSignedIntegerType(); 1734 uint64_t FromSize = Context.getTypeSize(FromType); 1735 1736 // The types we'll try to promote to, in the appropriate 1737 // order. Try each of these types. 1738 QualType PromoteTypes[6] = { 1739 Context.IntTy, Context.UnsignedIntTy, 1740 Context.LongTy, Context.UnsignedLongTy , 1741 Context.LongLongTy, Context.UnsignedLongLongTy 1742 }; 1743 for (int Idx = 0; Idx < 6; ++Idx) { 1744 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1745 if (FromSize < ToSize || 1746 (FromSize == ToSize && 1747 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1748 // We found the type that we can promote to. If this is the 1749 // type we wanted, we have a promotion. Otherwise, no 1750 // promotion. 1751 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1752 } 1753 } 1754 } 1755 1756 // An rvalue for an integral bit-field (9.6) can be converted to an 1757 // rvalue of type int if int can represent all the values of the 1758 // bit-field; otherwise, it can be converted to unsigned int if 1759 // unsigned int can represent all the values of the bit-field. If 1760 // the bit-field is larger yet, no integral promotion applies to 1761 // it. If the bit-field has an enumerated type, it is treated as any 1762 // other value of that type for promotion purposes (C++ 4.5p3). 1763 // FIXME: We should delay checking of bit-fields until we actually perform the 1764 // conversion. 1765 using llvm::APSInt; 1766 if (From) 1767 if (FieldDecl *MemberDecl = From->getBitField()) { 1768 APSInt BitWidth; 1769 if (FromType->isIntegralType(Context) && 1770 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1771 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1772 ToSize = Context.getTypeSize(ToType); 1773 1774 // Are we promoting to an int from a bitfield that fits in an int? 1775 if (BitWidth < ToSize || 1776 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1777 return To->getKind() == BuiltinType::Int; 1778 } 1779 1780 // Are we promoting to an unsigned int from an unsigned bitfield 1781 // that fits into an unsigned int? 1782 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1783 return To->getKind() == BuiltinType::UInt; 1784 } 1785 1786 return false; 1787 } 1788 } 1789 1790 // An rvalue of type bool can be converted to an rvalue of type int, 1791 // with false becoming zero and true becoming one (C++ 4.5p4). 1792 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1793 return true; 1794 } 1795 1796 return false; 1797} 1798 1799/// IsFloatingPointPromotion - Determines whether the conversion from 1800/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1801/// returns true and sets PromotedType to the promoted type. 1802bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1803 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1804 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1805 /// An rvalue of type float can be converted to an rvalue of type 1806 /// double. (C++ 4.6p1). 1807 if (FromBuiltin->getKind() == BuiltinType::Float && 1808 ToBuiltin->getKind() == BuiltinType::Double) 1809 return true; 1810 1811 // C99 6.3.1.5p1: 1812 // When a float is promoted to double or long double, or a 1813 // double is promoted to long double [...]. 1814 if (!getLangOpts().CPlusPlus && 1815 (FromBuiltin->getKind() == BuiltinType::Float || 1816 FromBuiltin->getKind() == BuiltinType::Double) && 1817 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1818 return true; 1819 1820 // Half can be promoted to float. 1821 if (FromBuiltin->getKind() == BuiltinType::Half && 1822 ToBuiltin->getKind() == BuiltinType::Float) 1823 return true; 1824 } 1825 1826 return false; 1827} 1828 1829/// \brief Determine if a conversion is a complex promotion. 1830/// 1831/// A complex promotion is defined as a complex -> complex conversion 1832/// where the conversion between the underlying real types is a 1833/// floating-point or integral promotion. 1834bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1835 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1836 if (!FromComplex) 1837 return false; 1838 1839 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1840 if (!ToComplex) 1841 return false; 1842 1843 return IsFloatingPointPromotion(FromComplex->getElementType(), 1844 ToComplex->getElementType()) || 1845 IsIntegralPromotion(0, FromComplex->getElementType(), 1846 ToComplex->getElementType()); 1847} 1848 1849/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1850/// the pointer type FromPtr to a pointer to type ToPointee, with the 1851/// same type qualifiers as FromPtr has on its pointee type. ToType, 1852/// if non-empty, will be a pointer to ToType that may or may not have 1853/// the right set of qualifiers on its pointee. 1854/// 1855static QualType 1856BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1857 QualType ToPointee, QualType ToType, 1858 ASTContext &Context, 1859 bool StripObjCLifetime = false) { 1860 assert((FromPtr->getTypeClass() == Type::Pointer || 1861 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1862 "Invalid similarly-qualified pointer type"); 1863 1864 /// Conversions to 'id' subsume cv-qualifier conversions. 1865 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1866 return ToType.getUnqualifiedType(); 1867 1868 QualType CanonFromPointee 1869 = Context.getCanonicalType(FromPtr->getPointeeType()); 1870 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1871 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1872 1873 if (StripObjCLifetime) 1874 Quals.removeObjCLifetime(); 1875 1876 // Exact qualifier match -> return the pointer type we're converting to. 1877 if (CanonToPointee.getLocalQualifiers() == Quals) { 1878 // ToType is exactly what we need. Return it. 1879 if (!ToType.isNull()) 1880 return ToType.getUnqualifiedType(); 1881 1882 // Build a pointer to ToPointee. It has the right qualifiers 1883 // already. 1884 if (isa<ObjCObjectPointerType>(ToType)) 1885 return Context.getObjCObjectPointerType(ToPointee); 1886 return Context.getPointerType(ToPointee); 1887 } 1888 1889 // Just build a canonical type that has the right qualifiers. 1890 QualType QualifiedCanonToPointee 1891 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1892 1893 if (isa<ObjCObjectPointerType>(ToType)) 1894 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1895 return Context.getPointerType(QualifiedCanonToPointee); 1896} 1897 1898static bool isNullPointerConstantForConversion(Expr *Expr, 1899 bool InOverloadResolution, 1900 ASTContext &Context) { 1901 // Handle value-dependent integral null pointer constants correctly. 1902 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1903 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1904 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1905 return !InOverloadResolution; 1906 1907 return Expr->isNullPointerConstant(Context, 1908 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1909 : Expr::NPC_ValueDependentIsNull); 1910} 1911 1912/// IsPointerConversion - Determines whether the conversion of the 1913/// expression From, which has the (possibly adjusted) type FromType, 1914/// can be converted to the type ToType via a pointer conversion (C++ 1915/// 4.10). If so, returns true and places the converted type (that 1916/// might differ from ToType in its cv-qualifiers at some level) into 1917/// ConvertedType. 1918/// 1919/// This routine also supports conversions to and from block pointers 1920/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1921/// pointers to interfaces. FIXME: Once we've determined the 1922/// appropriate overloading rules for Objective-C, we may want to 1923/// split the Objective-C checks into a different routine; however, 1924/// GCC seems to consider all of these conversions to be pointer 1925/// conversions, so for now they live here. IncompatibleObjC will be 1926/// set if the conversion is an allowed Objective-C conversion that 1927/// should result in a warning. 1928bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1929 bool InOverloadResolution, 1930 QualType& ConvertedType, 1931 bool &IncompatibleObjC) { 1932 IncompatibleObjC = false; 1933 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 1934 IncompatibleObjC)) 1935 return true; 1936 1937 // Conversion from a null pointer constant to any Objective-C pointer type. 1938 if (ToType->isObjCObjectPointerType() && 1939 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1940 ConvertedType = ToType; 1941 return true; 1942 } 1943 1944 // Blocks: Block pointers can be converted to void*. 1945 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1946 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1947 ConvertedType = ToType; 1948 return true; 1949 } 1950 // Blocks: A null pointer constant can be converted to a block 1951 // pointer type. 1952 if (ToType->isBlockPointerType() && 1953 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1954 ConvertedType = ToType; 1955 return true; 1956 } 1957 1958 // If the left-hand-side is nullptr_t, the right side can be a null 1959 // pointer constant. 1960 if (ToType->isNullPtrType() && 1961 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1962 ConvertedType = ToType; 1963 return true; 1964 } 1965 1966 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1967 if (!ToTypePtr) 1968 return false; 1969 1970 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1971 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1972 ConvertedType = ToType; 1973 return true; 1974 } 1975 1976 // Beyond this point, both types need to be pointers 1977 // , including objective-c pointers. 1978 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1979 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() && 1980 !getLangOpts().ObjCAutoRefCount) { 1981 ConvertedType = BuildSimilarlyQualifiedPointerType( 1982 FromType->getAs<ObjCObjectPointerType>(), 1983 ToPointeeType, 1984 ToType, Context); 1985 return true; 1986 } 1987 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1988 if (!FromTypePtr) 1989 return false; 1990 1991 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1992 1993 // If the unqualified pointee types are the same, this can't be a 1994 // pointer conversion, so don't do all of the work below. 1995 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1996 return false; 1997 1998 // An rvalue of type "pointer to cv T," where T is an object type, 1999 // can be converted to an rvalue of type "pointer to cv void" (C++ 2000 // 4.10p2). 2001 if (FromPointeeType->isIncompleteOrObjectType() && 2002 ToPointeeType->isVoidType()) { 2003 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2004 ToPointeeType, 2005 ToType, Context, 2006 /*StripObjCLifetime=*/true); 2007 return true; 2008 } 2009 2010 // MSVC allows implicit function to void* type conversion. 2011 if (getLangOpts().MicrosoftExt && FromPointeeType->isFunctionType() && 2012 ToPointeeType->isVoidType()) { 2013 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2014 ToPointeeType, 2015 ToType, Context); 2016 return true; 2017 } 2018 2019 // When we're overloading in C, we allow a special kind of pointer 2020 // conversion for compatible-but-not-identical pointee types. 2021 if (!getLangOpts().CPlusPlus && 2022 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 2023 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2024 ToPointeeType, 2025 ToType, Context); 2026 return true; 2027 } 2028 2029 // C++ [conv.ptr]p3: 2030 // 2031 // An rvalue of type "pointer to cv D," where D is a class type, 2032 // can be converted to an rvalue of type "pointer to cv B," where 2033 // B is a base class (clause 10) of D. If B is an inaccessible 2034 // (clause 11) or ambiguous (10.2) base class of D, a program that 2035 // necessitates this conversion is ill-formed. The result of the 2036 // conversion is a pointer to the base class sub-object of the 2037 // derived class object. The null pointer value is converted to 2038 // the null pointer value of the destination type. 2039 // 2040 // Note that we do not check for ambiguity or inaccessibility 2041 // here. That is handled by CheckPointerConversion. 2042 if (getLangOpts().CPlusPlus && 2043 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 2044 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 2045 !RequireCompleteType(From->getLocStart(), FromPointeeType, 0) && 2046 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 2047 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2048 ToPointeeType, 2049 ToType, Context); 2050 return true; 2051 } 2052 2053 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() && 2054 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) { 2055 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 2056 ToPointeeType, 2057 ToType, Context); 2058 return true; 2059 } 2060 2061 return false; 2062} 2063 2064/// \brief Adopt the given qualifiers for the given type. 2065static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){ 2066 Qualifiers TQs = T.getQualifiers(); 2067 2068 // Check whether qualifiers already match. 2069 if (TQs == Qs) 2070 return T; 2071 2072 if (Qs.compatiblyIncludes(TQs)) 2073 return Context.getQualifiedType(T, Qs); 2074 2075 return Context.getQualifiedType(T.getUnqualifiedType(), Qs); 2076} 2077 2078/// isObjCPointerConversion - Determines whether this is an 2079/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 2080/// with the same arguments and return values. 2081bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 2082 QualType& ConvertedType, 2083 bool &IncompatibleObjC) { 2084 if (!getLangOpts().ObjC1) 2085 return false; 2086 2087 // The set of qualifiers on the type we're converting from. 2088 Qualifiers FromQualifiers = FromType.getQualifiers(); 2089 2090 // First, we handle all conversions on ObjC object pointer types. 2091 const ObjCObjectPointerType* ToObjCPtr = 2092 ToType->getAs<ObjCObjectPointerType>(); 2093 const ObjCObjectPointerType *FromObjCPtr = 2094 FromType->getAs<ObjCObjectPointerType>(); 2095 2096 if (ToObjCPtr && FromObjCPtr) { 2097 // If the pointee types are the same (ignoring qualifications), 2098 // then this is not a pointer conversion. 2099 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 2100 FromObjCPtr->getPointeeType())) 2101 return false; 2102 2103 // Check for compatible 2104 // Objective C++: We're able to convert between "id" or "Class" and a 2105 // pointer to any interface (in both directions). 2106 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 2107 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2108 return true; 2109 } 2110 // Conversions with Objective-C's id<...>. 2111 if ((FromObjCPtr->isObjCQualifiedIdType() || 2112 ToObjCPtr->isObjCQualifiedIdType()) && 2113 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 2114 /*compare=*/false)) { 2115 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2116 return true; 2117 } 2118 // Objective C++: We're able to convert from a pointer to an 2119 // interface to a pointer to a different interface. 2120 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 2121 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 2122 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 2123 if (getLangOpts().CPlusPlus && LHS && RHS && 2124 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 2125 FromObjCPtr->getPointeeType())) 2126 return false; 2127 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 2128 ToObjCPtr->getPointeeType(), 2129 ToType, Context); 2130 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2131 return true; 2132 } 2133 2134 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 2135 // Okay: this is some kind of implicit downcast of Objective-C 2136 // interfaces, which is permitted. However, we're going to 2137 // complain about it. 2138 IncompatibleObjC = true; 2139 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 2140 ToObjCPtr->getPointeeType(), 2141 ToType, Context); 2142 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2143 return true; 2144 } 2145 } 2146 // Beyond this point, both types need to be C pointers or block pointers. 2147 QualType ToPointeeType; 2148 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 2149 ToPointeeType = ToCPtr->getPointeeType(); 2150 else if (const BlockPointerType *ToBlockPtr = 2151 ToType->getAs<BlockPointerType>()) { 2152 // Objective C++: We're able to convert from a pointer to any object 2153 // to a block pointer type. 2154 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 2155 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2156 return true; 2157 } 2158 ToPointeeType = ToBlockPtr->getPointeeType(); 2159 } 2160 else if (FromType->getAs<BlockPointerType>() && 2161 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 2162 // Objective C++: We're able to convert from a block pointer type to a 2163 // pointer to any object. 2164 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2165 return true; 2166 } 2167 else 2168 return false; 2169 2170 QualType FromPointeeType; 2171 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 2172 FromPointeeType = FromCPtr->getPointeeType(); 2173 else if (const BlockPointerType *FromBlockPtr = 2174 FromType->getAs<BlockPointerType>()) 2175 FromPointeeType = FromBlockPtr->getPointeeType(); 2176 else 2177 return false; 2178 2179 // If we have pointers to pointers, recursively check whether this 2180 // is an Objective-C conversion. 2181 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 2182 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 2183 IncompatibleObjC)) { 2184 // We always complain about this conversion. 2185 IncompatibleObjC = true; 2186 ConvertedType = Context.getPointerType(ConvertedType); 2187 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2188 return true; 2189 } 2190 // Allow conversion of pointee being objective-c pointer to another one; 2191 // as in I* to id. 2192 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 2193 ToPointeeType->getAs<ObjCObjectPointerType>() && 2194 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 2195 IncompatibleObjC)) { 2196 2197 ConvertedType = Context.getPointerType(ConvertedType); 2198 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 2199 return true; 2200 } 2201 2202 // If we have pointers to functions or blocks, check whether the only 2203 // differences in the argument and result types are in Objective-C 2204 // pointer conversions. If so, we permit the conversion (but 2205 // complain about it). 2206 const FunctionProtoType *FromFunctionType 2207 = FromPointeeType->getAs<FunctionProtoType>(); 2208 const FunctionProtoType *ToFunctionType 2209 = ToPointeeType->getAs<FunctionProtoType>(); 2210 if (FromFunctionType && ToFunctionType) { 2211 // If the function types are exactly the same, this isn't an 2212 // Objective-C pointer conversion. 2213 if (Context.getCanonicalType(FromPointeeType) 2214 == Context.getCanonicalType(ToPointeeType)) 2215 return false; 2216 2217 // Perform the quick checks that will tell us whether these 2218 // function types are obviously different. 2219 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 2220 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 2221 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 2222 return false; 2223 2224 bool HasObjCConversion = false; 2225 if (Context.getCanonicalType(FromFunctionType->getResultType()) 2226 == Context.getCanonicalType(ToFunctionType->getResultType())) { 2227 // Okay, the types match exactly. Nothing to do. 2228 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 2229 ToFunctionType->getResultType(), 2230 ConvertedType, IncompatibleObjC)) { 2231 // Okay, we have an Objective-C pointer conversion. 2232 HasObjCConversion = true; 2233 } else { 2234 // Function types are too different. Abort. 2235 return false; 2236 } 2237 2238 // Check argument types. 2239 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 2240 ArgIdx != NumArgs; ++ArgIdx) { 2241 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 2242 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 2243 if (Context.getCanonicalType(FromArgType) 2244 == Context.getCanonicalType(ToArgType)) { 2245 // Okay, the types match exactly. Nothing to do. 2246 } else if (isObjCPointerConversion(FromArgType, ToArgType, 2247 ConvertedType, IncompatibleObjC)) { 2248 // Okay, we have an Objective-C pointer conversion. 2249 HasObjCConversion = true; 2250 } else { 2251 // Argument types are too different. Abort. 2252 return false; 2253 } 2254 } 2255 2256 if (HasObjCConversion) { 2257 // We had an Objective-C conversion. Allow this pointer 2258 // conversion, but complain about it. 2259 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2260 IncompatibleObjC = true; 2261 return true; 2262 } 2263 } 2264 2265 return false; 2266} 2267 2268/// \brief Determine whether this is an Objective-C writeback conversion, 2269/// used for parameter passing when performing automatic reference counting. 2270/// 2271/// \param FromType The type we're converting form. 2272/// 2273/// \param ToType The type we're converting to. 2274/// 2275/// \param ConvertedType The type that will be produced after applying 2276/// this conversion. 2277bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType, 2278 QualType &ConvertedType) { 2279 if (!getLangOpts().ObjCAutoRefCount || 2280 Context.hasSameUnqualifiedType(FromType, ToType)) 2281 return false; 2282 2283 // Parameter must be a pointer to __autoreleasing (with no other qualifiers). 2284 QualType ToPointee; 2285 if (const PointerType *ToPointer = ToType->getAs<PointerType>()) 2286 ToPointee = ToPointer->getPointeeType(); 2287 else 2288 return false; 2289 2290 Qualifiers ToQuals = ToPointee.getQualifiers(); 2291 if (!ToPointee->isObjCLifetimeType() || 2292 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing || 2293 !ToQuals.withoutObjCLifetime().empty()) 2294 return false; 2295 2296 // Argument must be a pointer to __strong to __weak. 2297 QualType FromPointee; 2298 if (const PointerType *FromPointer = FromType->getAs<PointerType>()) 2299 FromPointee = FromPointer->getPointeeType(); 2300 else 2301 return false; 2302 2303 Qualifiers FromQuals = FromPointee.getQualifiers(); 2304 if (!FromPointee->isObjCLifetimeType() || 2305 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong && 2306 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak)) 2307 return false; 2308 2309 // Make sure that we have compatible qualifiers. 2310 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing); 2311 if (!ToQuals.compatiblyIncludes(FromQuals)) 2312 return false; 2313 2314 // Remove qualifiers from the pointee type we're converting from; they 2315 // aren't used in the compatibility check belong, and we'll be adding back 2316 // qualifiers (with __autoreleasing) if the compatibility check succeeds. 2317 FromPointee = FromPointee.getUnqualifiedType(); 2318 2319 // The unqualified form of the pointee types must be compatible. 2320 ToPointee = ToPointee.getUnqualifiedType(); 2321 bool IncompatibleObjC; 2322 if (Context.typesAreCompatible(FromPointee, ToPointee)) 2323 FromPointee = ToPointee; 2324 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee, 2325 IncompatibleObjC)) 2326 return false; 2327 2328 /// \brief Construct the type we're converting to, which is a pointer to 2329 /// __autoreleasing pointee. 2330 FromPointee = Context.getQualifiedType(FromPointee, FromQuals); 2331 ConvertedType = Context.getPointerType(FromPointee); 2332 return true; 2333} 2334 2335bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, 2336 QualType& ConvertedType) { 2337 QualType ToPointeeType; 2338 if (const BlockPointerType *ToBlockPtr = 2339 ToType->getAs<BlockPointerType>()) 2340 ToPointeeType = ToBlockPtr->getPointeeType(); 2341 else 2342 return false; 2343 2344 QualType FromPointeeType; 2345 if (const BlockPointerType *FromBlockPtr = 2346 FromType->getAs<BlockPointerType>()) 2347 FromPointeeType = FromBlockPtr->getPointeeType(); 2348 else 2349 return false; 2350 // We have pointer to blocks, check whether the only 2351 // differences in the argument and result types are in Objective-C 2352 // pointer conversions. If so, we permit the conversion. 2353 2354 const FunctionProtoType *FromFunctionType 2355 = FromPointeeType->getAs<FunctionProtoType>(); 2356 const FunctionProtoType *ToFunctionType 2357 = ToPointeeType->getAs<FunctionProtoType>(); 2358 2359 if (!FromFunctionType || !ToFunctionType) 2360 return false; 2361 2362 if (Context.hasSameType(FromPointeeType, ToPointeeType)) 2363 return true; 2364 2365 // Perform the quick checks that will tell us whether these 2366 // function types are obviously different. 2367 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 2368 FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) 2369 return false; 2370 2371 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); 2372 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); 2373 if (FromEInfo != ToEInfo) 2374 return false; 2375 2376 bool IncompatibleObjC = false; 2377 if (Context.hasSameType(FromFunctionType->getResultType(), 2378 ToFunctionType->getResultType())) { 2379 // Okay, the types match exactly. Nothing to do. 2380 } else { 2381 QualType RHS = FromFunctionType->getResultType(); 2382 QualType LHS = ToFunctionType->getResultType(); 2383 if ((!getLangOpts().CPlusPlus || !RHS->isRecordType()) && 2384 !RHS.hasQualifiers() && LHS.hasQualifiers()) 2385 LHS = LHS.getUnqualifiedType(); 2386 2387 if (Context.hasSameType(RHS,LHS)) { 2388 // OK exact match. 2389 } else if (isObjCPointerConversion(RHS, LHS, 2390 ConvertedType, IncompatibleObjC)) { 2391 if (IncompatibleObjC) 2392 return false; 2393 // Okay, we have an Objective-C pointer conversion. 2394 } 2395 else 2396 return false; 2397 } 2398 2399 // Check argument types. 2400 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 2401 ArgIdx != NumArgs; ++ArgIdx) { 2402 IncompatibleObjC = false; 2403 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 2404 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 2405 if (Context.hasSameType(FromArgType, ToArgType)) { 2406 // Okay, the types match exactly. Nothing to do. 2407 } else if (isObjCPointerConversion(ToArgType, FromArgType, 2408 ConvertedType, IncompatibleObjC)) { 2409 if (IncompatibleObjC) 2410 return false; 2411 // Okay, we have an Objective-C pointer conversion. 2412 } else 2413 // Argument types are too different. Abort. 2414 return false; 2415 } 2416 if (LangOpts.ObjCAutoRefCount && 2417 !Context.FunctionTypesMatchOnNSConsumedAttrs(FromFunctionType, 2418 ToFunctionType)) 2419 return false; 2420 2421 ConvertedType = ToType; 2422 return true; 2423} 2424 2425enum { 2426 ft_default, 2427 ft_different_class, 2428 ft_parameter_arity, 2429 ft_parameter_mismatch, 2430 ft_return_type, 2431 ft_qualifer_mismatch 2432}; 2433 2434/// HandleFunctionTypeMismatch - Gives diagnostic information for differeing 2435/// function types. Catches different number of parameter, mismatch in 2436/// parameter types, and different return types. 2437void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag, 2438 QualType FromType, QualType ToType) { 2439 // If either type is not valid, include no extra info. 2440 if (FromType.isNull() || ToType.isNull()) { 2441 PDiag << ft_default; 2442 return; 2443 } 2444 2445 // Get the function type from the pointers. 2446 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) { 2447 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(), 2448 *ToMember = ToType->getAs<MemberPointerType>(); 2449 if (FromMember->getClass() != ToMember->getClass()) { 2450 PDiag << ft_different_class << QualType(ToMember->getClass(), 0) 2451 << QualType(FromMember->getClass(), 0); 2452 return; 2453 } 2454 FromType = FromMember->getPointeeType(); 2455 ToType = ToMember->getPointeeType(); 2456 } 2457 2458 if (FromType->isPointerType()) 2459 FromType = FromType->getPointeeType(); 2460 if (ToType->isPointerType()) 2461 ToType = ToType->getPointeeType(); 2462 2463 // Remove references. 2464 FromType = FromType.getNonReferenceType(); 2465 ToType = ToType.getNonReferenceType(); 2466 2467 // Don't print extra info for non-specialized template functions. 2468 if (FromType->isInstantiationDependentType() && 2469 !FromType->getAs<TemplateSpecializationType>()) { 2470 PDiag << ft_default; 2471 return; 2472 } 2473 2474 // No extra info for same types. 2475 if (Context.hasSameType(FromType, ToType)) { 2476 PDiag << ft_default; 2477 return; 2478 } 2479 2480 const FunctionProtoType *FromFunction = FromType->getAs<FunctionProtoType>(), 2481 *ToFunction = ToType->getAs<FunctionProtoType>(); 2482 2483 // Both types need to be function types. 2484 if (!FromFunction || !ToFunction) { 2485 PDiag << ft_default; 2486 return; 2487 } 2488 2489 if (FromFunction->getNumArgs() != ToFunction->getNumArgs()) { 2490 PDiag << ft_parameter_arity << ToFunction->getNumArgs() 2491 << FromFunction->getNumArgs(); 2492 return; 2493 } 2494 2495 // Handle different parameter types. 2496 unsigned ArgPos; 2497 if (!FunctionArgTypesAreEqual(FromFunction, ToFunction, &ArgPos)) { 2498 PDiag << ft_parameter_mismatch << ArgPos + 1 2499 << ToFunction->getArgType(ArgPos) 2500 << FromFunction->getArgType(ArgPos); 2501 return; 2502 } 2503 2504 // Handle different return type. 2505 if (!Context.hasSameType(FromFunction->getResultType(), 2506 ToFunction->getResultType())) { 2507 PDiag << ft_return_type << ToFunction->getResultType() 2508 << FromFunction->getResultType(); 2509 return; 2510 } 2511 2512 unsigned FromQuals = FromFunction->getTypeQuals(), 2513 ToQuals = ToFunction->getTypeQuals(); 2514 if (FromQuals != ToQuals) { 2515 PDiag << ft_qualifer_mismatch << ToQuals << FromQuals; 2516 return; 2517 } 2518 2519 // Unable to find a difference, so add no extra info. 2520 PDiag << ft_default; 2521} 2522 2523/// FunctionArgTypesAreEqual - This routine checks two function proto types 2524/// for equality of their argument types. Caller has already checked that 2525/// they have same number of arguments. This routine assumes that Objective-C 2526/// pointer types which only differ in their protocol qualifiers are equal. 2527/// If the parameters are different, ArgPos will have the parameter index 2528/// of the first different parameter. 2529bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, 2530 const FunctionProtoType *NewType, 2531 unsigned *ArgPos) { 2532 if (!getLangOpts().ObjC1) { 2533 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 2534 N = NewType->arg_type_begin(), 2535 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 2536 if (!Context.hasSameType(*O, *N)) { 2537 if (ArgPos) *ArgPos = O - OldType->arg_type_begin(); 2538 return false; 2539 } 2540 } 2541 return true; 2542 } 2543 2544 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 2545 N = NewType->arg_type_begin(), 2546 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 2547 QualType ToType = (*O); 2548 QualType FromType = (*N); 2549 if (!Context.hasSameType(ToType, FromType)) { 2550 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 2551 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 2552 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 2553 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 2554 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 2555 PTFr->getPointeeType()->isObjCQualifiedClassType())) 2556 continue; 2557 } 2558 else if (const ObjCObjectPointerType *PTTo = 2559 ToType->getAs<ObjCObjectPointerType>()) { 2560 if (const ObjCObjectPointerType *PTFr = 2561 FromType->getAs<ObjCObjectPointerType>()) 2562 if (Context.hasSameUnqualifiedType( 2563 PTTo->getObjectType()->getBaseType(), 2564 PTFr->getObjectType()->getBaseType())) 2565 continue; 2566 } 2567 if (ArgPos) *ArgPos = O - OldType->arg_type_begin(); 2568 return false; 2569 } 2570 } 2571 return true; 2572} 2573 2574/// CheckPointerConversion - Check the pointer conversion from the 2575/// expression From to the type ToType. This routine checks for 2576/// ambiguous or inaccessible derived-to-base pointer 2577/// conversions for which IsPointerConversion has already returned 2578/// true. It returns true and produces a diagnostic if there was an 2579/// error, or returns false otherwise. 2580bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 2581 CastKind &Kind, 2582 CXXCastPath& BasePath, 2583 bool IgnoreBaseAccess) { 2584 QualType FromType = From->getType(); 2585 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 2586 2587 Kind = CK_BitCast; 2588 2589 if (!IsCStyleOrFunctionalCast && !FromType->isAnyPointerType() && 2590 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull) == 2591 Expr::NPCK_ZeroExpression) { 2592 if (Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy)) 2593 DiagRuntimeBehavior(From->getExprLoc(), From, 2594 PDiag(diag::warn_impcast_bool_to_null_pointer) 2595 << ToType << From->getSourceRange()); 2596 else if (!isUnevaluatedContext()) 2597 Diag(From->getExprLoc(), diag::warn_non_literal_null_pointer) 2598 << ToType << From->getSourceRange(); 2599 } 2600 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 2601 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) { 2602 QualType FromPointeeType = FromPtrType->getPointeeType(), 2603 ToPointeeType = ToPtrType->getPointeeType(); 2604 2605 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 2606 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 2607 // We must have a derived-to-base conversion. Check an 2608 // ambiguous or inaccessible conversion. 2609 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 2610 From->getExprLoc(), 2611 From->getSourceRange(), &BasePath, 2612 IgnoreBaseAccess)) 2613 return true; 2614 2615 // The conversion was successful. 2616 Kind = CK_DerivedToBase; 2617 } 2618 } 2619 } else if (const ObjCObjectPointerType *ToPtrType = 2620 ToType->getAs<ObjCObjectPointerType>()) { 2621 if (const ObjCObjectPointerType *FromPtrType = 2622 FromType->getAs<ObjCObjectPointerType>()) { 2623 // Objective-C++ conversions are always okay. 2624 // FIXME: We should have a different class of conversions for the 2625 // Objective-C++ implicit conversions. 2626 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 2627 return false; 2628 } else if (FromType->isBlockPointerType()) { 2629 Kind = CK_BlockPointerToObjCPointerCast; 2630 } else { 2631 Kind = CK_CPointerToObjCPointerCast; 2632 } 2633 } else if (ToType->isBlockPointerType()) { 2634 if (!FromType->isBlockPointerType()) 2635 Kind = CK_AnyPointerToBlockPointerCast; 2636 } 2637 2638 // We shouldn't fall into this case unless it's valid for other 2639 // reasons. 2640 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 2641 Kind = CK_NullToPointer; 2642 2643 return false; 2644} 2645 2646/// IsMemberPointerConversion - Determines whether the conversion of the 2647/// expression From, which has the (possibly adjusted) type FromType, can be 2648/// converted to the type ToType via a member pointer conversion (C++ 4.11). 2649/// If so, returns true and places the converted type (that might differ from 2650/// ToType in its cv-qualifiers at some level) into ConvertedType. 2651bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 2652 QualType ToType, 2653 bool InOverloadResolution, 2654 QualType &ConvertedType) { 2655 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 2656 if (!ToTypePtr) 2657 return false; 2658 2659 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 2660 if (From->isNullPointerConstant(Context, 2661 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 2662 : Expr::NPC_ValueDependentIsNull)) { 2663 ConvertedType = ToType; 2664 return true; 2665 } 2666 2667 // Otherwise, both types have to be member pointers. 2668 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 2669 if (!FromTypePtr) 2670 return false; 2671 2672 // A pointer to member of B can be converted to a pointer to member of D, 2673 // where D is derived from B (C++ 4.11p2). 2674 QualType FromClass(FromTypePtr->getClass(), 0); 2675 QualType ToClass(ToTypePtr->getClass(), 0); 2676 2677 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && 2678 !RequireCompleteType(From->getLocStart(), ToClass, 0) && 2679 IsDerivedFrom(ToClass, FromClass)) { 2680 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 2681 ToClass.getTypePtr()); 2682 return true; 2683 } 2684 2685 return false; 2686} 2687 2688/// CheckMemberPointerConversion - Check the member pointer conversion from the 2689/// expression From to the type ToType. This routine checks for ambiguous or 2690/// virtual or inaccessible base-to-derived member pointer conversions 2691/// for which IsMemberPointerConversion has already returned true. It returns 2692/// true and produces a diagnostic if there was an error, or returns false 2693/// otherwise. 2694bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 2695 CastKind &Kind, 2696 CXXCastPath &BasePath, 2697 bool IgnoreBaseAccess) { 2698 QualType FromType = From->getType(); 2699 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 2700 if (!FromPtrType) { 2701 // This must be a null pointer to member pointer conversion 2702 assert(From->isNullPointerConstant(Context, 2703 Expr::NPC_ValueDependentIsNull) && 2704 "Expr must be null pointer constant!"); 2705 Kind = CK_NullToMemberPointer; 2706 return false; 2707 } 2708 2709 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 2710 assert(ToPtrType && "No member pointer cast has a target type " 2711 "that is not a member pointer."); 2712 2713 QualType FromClass = QualType(FromPtrType->getClass(), 0); 2714 QualType ToClass = QualType(ToPtrType->getClass(), 0); 2715 2716 // FIXME: What about dependent types? 2717 assert(FromClass->isRecordType() && "Pointer into non-class."); 2718 assert(ToClass->isRecordType() && "Pointer into non-class."); 2719 2720 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 2721 /*DetectVirtual=*/true); 2722 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 2723 assert(DerivationOkay && 2724 "Should not have been called if derivation isn't OK."); 2725 (void)DerivationOkay; 2726 2727 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 2728 getUnqualifiedType())) { 2729 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 2730 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 2731 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 2732 return true; 2733 } 2734 2735 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 2736 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 2737 << FromClass << ToClass << QualType(VBase, 0) 2738 << From->getSourceRange(); 2739 return true; 2740 } 2741 2742 if (!IgnoreBaseAccess) 2743 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 2744 Paths.front(), 2745 diag::err_downcast_from_inaccessible_base); 2746 2747 // Must be a base to derived member conversion. 2748 BuildBasePathArray(Paths, BasePath); 2749 Kind = CK_BaseToDerivedMemberPointer; 2750 return false; 2751} 2752 2753/// IsQualificationConversion - Determines whether the conversion from 2754/// an rvalue of type FromType to ToType is a qualification conversion 2755/// (C++ 4.4). 2756/// 2757/// \param ObjCLifetimeConversion Output parameter that will be set to indicate 2758/// when the qualification conversion involves a change in the Objective-C 2759/// object lifetime. 2760bool 2761Sema::IsQualificationConversion(QualType FromType, QualType ToType, 2762 bool CStyle, bool &ObjCLifetimeConversion) { 2763 FromType = Context.getCanonicalType(FromType); 2764 ToType = Context.getCanonicalType(ToType); 2765 ObjCLifetimeConversion = false; 2766 2767 // If FromType and ToType are the same type, this is not a 2768 // qualification conversion. 2769 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 2770 return false; 2771 2772 // (C++ 4.4p4): 2773 // A conversion can add cv-qualifiers at levels other than the first 2774 // in multi-level pointers, subject to the following rules: [...] 2775 bool PreviousToQualsIncludeConst = true; 2776 bool UnwrappedAnyPointer = false; 2777 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 2778 // Within each iteration of the loop, we check the qualifiers to 2779 // determine if this still looks like a qualification 2780 // conversion. Then, if all is well, we unwrap one more level of 2781 // pointers or pointers-to-members and do it all again 2782 // until there are no more pointers or pointers-to-members left to 2783 // unwrap. 2784 UnwrappedAnyPointer = true; 2785 2786 Qualifiers FromQuals = FromType.getQualifiers(); 2787 Qualifiers ToQuals = ToType.getQualifiers(); 2788 2789 // Objective-C ARC: 2790 // Check Objective-C lifetime conversions. 2791 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() && 2792 UnwrappedAnyPointer) { 2793 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) { 2794 ObjCLifetimeConversion = true; 2795 FromQuals.removeObjCLifetime(); 2796 ToQuals.removeObjCLifetime(); 2797 } else { 2798 // Qualification conversions cannot cast between different 2799 // Objective-C lifetime qualifiers. 2800 return false; 2801 } 2802 } 2803 2804 // Allow addition/removal of GC attributes but not changing GC attributes. 2805 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() && 2806 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) { 2807 FromQuals.removeObjCGCAttr(); 2808 ToQuals.removeObjCGCAttr(); 2809 } 2810 2811 // -- for every j > 0, if const is in cv 1,j then const is in cv 2812 // 2,j, and similarly for volatile. 2813 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals)) 2814 return false; 2815 2816 // -- if the cv 1,j and cv 2,j are different, then const is in 2817 // every cv for 0 < k < j. 2818 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers() 2819 && !PreviousToQualsIncludeConst) 2820 return false; 2821 2822 // Keep track of whether all prior cv-qualifiers in the "to" type 2823 // include const. 2824 PreviousToQualsIncludeConst 2825 = PreviousToQualsIncludeConst && ToQuals.hasConst(); 2826 } 2827 2828 // We are left with FromType and ToType being the pointee types 2829 // after unwrapping the original FromType and ToType the same number 2830 // of types. If we unwrapped any pointers, and if FromType and 2831 // ToType have the same unqualified type (since we checked 2832 // qualifiers above), then this is a qualification conversion. 2833 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2834} 2835 2836/// \brief - Determine whether this is a conversion from a scalar type to an 2837/// atomic type. 2838/// 2839/// If successful, updates \c SCS's second and third steps in the conversion 2840/// sequence to finish the conversion. 2841static bool tryAtomicConversion(Sema &S, Expr *From, QualType ToType, 2842 bool InOverloadResolution, 2843 StandardConversionSequence &SCS, 2844 bool CStyle) { 2845 const AtomicType *ToAtomic = ToType->getAs<AtomicType>(); 2846 if (!ToAtomic) 2847 return false; 2848 2849 StandardConversionSequence InnerSCS; 2850 if (!IsStandardConversion(S, From, ToAtomic->getValueType(), 2851 InOverloadResolution, InnerSCS, 2852 CStyle, /*AllowObjCWritebackConversion=*/false)) 2853 return false; 2854 2855 SCS.Second = InnerSCS.Second; 2856 SCS.setToType(1, InnerSCS.getToType(1)); 2857 SCS.Third = InnerSCS.Third; 2858 SCS.QualificationIncludesObjCLifetime 2859 = InnerSCS.QualificationIncludesObjCLifetime; 2860 SCS.setToType(2, InnerSCS.getToType(2)); 2861 return true; 2862} 2863 2864static bool isFirstArgumentCompatibleWithType(ASTContext &Context, 2865 CXXConstructorDecl *Constructor, 2866 QualType Type) { 2867 const FunctionProtoType *CtorType = 2868 Constructor->getType()->getAs<FunctionProtoType>(); 2869 if (CtorType->getNumArgs() > 0) { 2870 QualType FirstArg = CtorType->getArgType(0); 2871 if (Context.hasSameUnqualifiedType(Type, FirstArg.getNonReferenceType())) 2872 return true; 2873 } 2874 return false; 2875} 2876 2877static OverloadingResult 2878IsInitializerListConstructorConversion(Sema &S, Expr *From, QualType ToType, 2879 CXXRecordDecl *To, 2880 UserDefinedConversionSequence &User, 2881 OverloadCandidateSet &CandidateSet, 2882 bool AllowExplicit) { 2883 DeclContext::lookup_iterator Con, ConEnd; 2884 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(To); 2885 Con != ConEnd; ++Con) { 2886 NamedDecl *D = *Con; 2887 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2888 2889 // Find the constructor (which may be a template). 2890 CXXConstructorDecl *Constructor = 0; 2891 FunctionTemplateDecl *ConstructorTmpl 2892 = dyn_cast<FunctionTemplateDecl>(D); 2893 if (ConstructorTmpl) 2894 Constructor 2895 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2896 else 2897 Constructor = cast<CXXConstructorDecl>(D); 2898 2899 bool Usable = !Constructor->isInvalidDecl() && 2900 S.isInitListConstructor(Constructor) && 2901 (AllowExplicit || !Constructor->isExplicit()); 2902 if (Usable) { 2903 // If the first argument is (a reference to) the target type, 2904 // suppress conversions. 2905 bool SuppressUserConversions = 2906 isFirstArgumentCompatibleWithType(S.Context, Constructor, ToType); 2907 if (ConstructorTmpl) 2908 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2909 /*ExplicitArgs*/ 0, 2910 From, CandidateSet, 2911 SuppressUserConversions); 2912 else 2913 S.AddOverloadCandidate(Constructor, FoundDecl, 2914 From, CandidateSet, 2915 SuppressUserConversions); 2916 } 2917 } 2918 2919 bool HadMultipleCandidates = (CandidateSet.size() > 1); 2920 2921 OverloadCandidateSet::iterator Best; 2922 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2923 case OR_Success: { 2924 // Record the standard conversion we used and the conversion function. 2925 CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(Best->Function); 2926 S.MarkFunctionReferenced(From->getLocStart(), Constructor); 2927 2928 QualType ThisType = Constructor->getThisType(S.Context); 2929 // Initializer lists don't have conversions as such. 2930 User.Before.setAsIdentityConversion(); 2931 User.HadMultipleCandidates = HadMultipleCandidates; 2932 User.ConversionFunction = Constructor; 2933 User.FoundConversionFunction = Best->FoundDecl; 2934 User.After.setAsIdentityConversion(); 2935 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2936 User.After.setAllToTypes(ToType); 2937 return OR_Success; 2938 } 2939 2940 case OR_No_Viable_Function: 2941 return OR_No_Viable_Function; 2942 case OR_Deleted: 2943 return OR_Deleted; 2944 case OR_Ambiguous: 2945 return OR_Ambiguous; 2946 } 2947 2948 llvm_unreachable("Invalid OverloadResult!"); 2949} 2950 2951/// Determines whether there is a user-defined conversion sequence 2952/// (C++ [over.ics.user]) that converts expression From to the type 2953/// ToType. If such a conversion exists, User will contain the 2954/// user-defined conversion sequence that performs such a conversion 2955/// and this routine will return true. Otherwise, this routine returns 2956/// false and User is unspecified. 2957/// 2958/// \param AllowExplicit true if the conversion should consider C++0x 2959/// "explicit" conversion functions as well as non-explicit conversion 2960/// functions (C++0x [class.conv.fct]p2). 2961static OverloadingResult 2962IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 2963 UserDefinedConversionSequence &User, 2964 OverloadCandidateSet &CandidateSet, 2965 bool AllowExplicit) { 2966 // Whether we will only visit constructors. 2967 bool ConstructorsOnly = false; 2968 2969 // If the type we are conversion to is a class type, enumerate its 2970 // constructors. 2971 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 2972 // C++ [over.match.ctor]p1: 2973 // When objects of class type are direct-initialized (8.5), or 2974 // copy-initialized from an expression of the same or a 2975 // derived class type (8.5), overload resolution selects the 2976 // constructor. [...] For copy-initialization, the candidate 2977 // functions are all the converting constructors (12.3.1) of 2978 // that class. The argument list is the expression-list within 2979 // the parentheses of the initializer. 2980 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 2981 (From->getType()->getAs<RecordType>() && 2982 S.IsDerivedFrom(From->getType(), ToType))) 2983 ConstructorsOnly = true; 2984 2985 S.RequireCompleteType(From->getLocStart(), ToType, 0); 2986 // RequireCompleteType may have returned true due to some invalid decl 2987 // during template instantiation, but ToType may be complete enough now 2988 // to try to recover. 2989 if (ToType->isIncompleteType()) { 2990 // We're not going to find any constructors. 2991 } else if (CXXRecordDecl *ToRecordDecl 2992 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 2993 2994 Expr **Args = &From; 2995 unsigned NumArgs = 1; 2996 bool ListInitializing = false; 2997 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) { 2998 // But first, see if there is an init-list-contructor that will work. 2999 OverloadingResult Result = IsInitializerListConstructorConversion( 3000 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit); 3001 if (Result != OR_No_Viable_Function) 3002 return Result; 3003 // Never mind. 3004 CandidateSet.clear(); 3005 3006 // If we're list-initializing, we pass the individual elements as 3007 // arguments, not the entire list. 3008 Args = InitList->getInits(); 3009 NumArgs = InitList->getNumInits(); 3010 ListInitializing = true; 3011 } 3012 3013 DeclContext::lookup_iterator Con, ConEnd; 3014 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 3015 Con != ConEnd; ++Con) { 3016 NamedDecl *D = *Con; 3017 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 3018 3019 // Find the constructor (which may be a template). 3020 CXXConstructorDecl *Constructor = 0; 3021 FunctionTemplateDecl *ConstructorTmpl 3022 = dyn_cast<FunctionTemplateDecl>(D); 3023 if (ConstructorTmpl) 3024 Constructor 3025 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 3026 else 3027 Constructor = cast<CXXConstructorDecl>(D); 3028 3029 bool Usable = !Constructor->isInvalidDecl(); 3030 if (ListInitializing) 3031 Usable = Usable && (AllowExplicit || !Constructor->isExplicit()); 3032 else 3033 Usable = Usable &&Constructor->isConvertingConstructor(AllowExplicit); 3034 if (Usable) { 3035 bool SuppressUserConversions = !ConstructorsOnly; 3036 if (SuppressUserConversions && ListInitializing) { 3037 SuppressUserConversions = false; 3038 if (NumArgs == 1) { 3039 // If the first argument is (a reference to) the target type, 3040 // suppress conversions. 3041 SuppressUserConversions = isFirstArgumentCompatibleWithType( 3042 S.Context, Constructor, ToType); 3043 } 3044 } 3045 if (ConstructorTmpl) 3046 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 3047 /*ExplicitArgs*/ 0, 3048 llvm::makeArrayRef(Args, NumArgs), 3049 CandidateSet, SuppressUserConversions); 3050 else 3051 // Allow one user-defined conversion when user specifies a 3052 // From->ToType conversion via an static cast (c-style, etc). 3053 S.AddOverloadCandidate(Constructor, FoundDecl, 3054 llvm::makeArrayRef(Args, NumArgs), 3055 CandidateSet, SuppressUserConversions); 3056 } 3057 } 3058 } 3059 } 3060 3061 // Enumerate conversion functions, if we're allowed to. 3062 if (ConstructorsOnly || isa<InitListExpr>(From)) { 3063 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 0)) { 3064 // No conversion functions from incomplete types. 3065 } else if (const RecordType *FromRecordType 3066 = From->getType()->getAs<RecordType>()) { 3067 if (CXXRecordDecl *FromRecordDecl 3068 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 3069 // Add all of the conversion functions as candidates. 3070 const UnresolvedSetImpl *Conversions 3071 = FromRecordDecl->getVisibleConversionFunctions(); 3072 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3073 E = Conversions->end(); I != E; ++I) { 3074 DeclAccessPair FoundDecl = I.getPair(); 3075 NamedDecl *D = FoundDecl.getDecl(); 3076 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 3077 if (isa<UsingShadowDecl>(D)) 3078 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3079 3080 CXXConversionDecl *Conv; 3081 FunctionTemplateDecl *ConvTemplate; 3082 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 3083 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3084 else 3085 Conv = cast<CXXConversionDecl>(D); 3086 3087 if (AllowExplicit || !Conv->isExplicit()) { 3088 if (ConvTemplate) 3089 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 3090 ActingContext, From, ToType, 3091 CandidateSet); 3092 else 3093 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 3094 From, ToType, CandidateSet); 3095 } 3096 } 3097 } 3098 } 3099 3100 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3101 3102 OverloadCandidateSet::iterator Best; 3103 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 3104 case OR_Success: 3105 // Record the standard conversion we used and the conversion function. 3106 if (CXXConstructorDecl *Constructor 3107 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 3108 S.MarkFunctionReferenced(From->getLocStart(), Constructor); 3109 3110 // C++ [over.ics.user]p1: 3111 // If the user-defined conversion is specified by a 3112 // constructor (12.3.1), the initial standard conversion 3113 // sequence converts the source type to the type required by 3114 // the argument of the constructor. 3115 // 3116 QualType ThisType = Constructor->getThisType(S.Context); 3117 if (isa<InitListExpr>(From)) { 3118 // Initializer lists don't have conversions as such. 3119 User.Before.setAsIdentityConversion(); 3120 } else { 3121 if (Best->Conversions[0].isEllipsis()) 3122 User.EllipsisConversion = true; 3123 else { 3124 User.Before = Best->Conversions[0].Standard; 3125 User.EllipsisConversion = false; 3126 } 3127 } 3128 User.HadMultipleCandidates = HadMultipleCandidates; 3129 User.ConversionFunction = Constructor; 3130 User.FoundConversionFunction = Best->FoundDecl; 3131 User.After.setAsIdentityConversion(); 3132 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 3133 User.After.setAllToTypes(ToType); 3134 return OR_Success; 3135 } 3136 if (CXXConversionDecl *Conversion 3137 = dyn_cast<CXXConversionDecl>(Best->Function)) { 3138 S.MarkFunctionReferenced(From->getLocStart(), Conversion); 3139 3140 // C++ [over.ics.user]p1: 3141 // 3142 // [...] If the user-defined conversion is specified by a 3143 // conversion function (12.3.2), the initial standard 3144 // conversion sequence converts the source type to the 3145 // implicit object parameter of the conversion function. 3146 User.Before = Best->Conversions[0].Standard; 3147 User.HadMultipleCandidates = HadMultipleCandidates; 3148 User.ConversionFunction = Conversion; 3149 User.FoundConversionFunction = Best->FoundDecl; 3150 User.EllipsisConversion = false; 3151 3152 // C++ [over.ics.user]p2: 3153 // The second standard conversion sequence converts the 3154 // result of the user-defined conversion to the target type 3155 // for the sequence. Since an implicit conversion sequence 3156 // is an initialization, the special rules for 3157 // initialization by user-defined conversion apply when 3158 // selecting the best user-defined conversion for a 3159 // user-defined conversion sequence (see 13.3.3 and 3160 // 13.3.3.1). 3161 User.After = Best->FinalConversion; 3162 return OR_Success; 3163 } 3164 llvm_unreachable("Not a constructor or conversion function?"); 3165 3166 case OR_No_Viable_Function: 3167 return OR_No_Viable_Function; 3168 case OR_Deleted: 3169 // No conversion here! We're done. 3170 return OR_Deleted; 3171 3172 case OR_Ambiguous: 3173 return OR_Ambiguous; 3174 } 3175 3176 llvm_unreachable("Invalid OverloadResult!"); 3177} 3178 3179bool 3180Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 3181 ImplicitConversionSequence ICS; 3182 OverloadCandidateSet CandidateSet(From->getExprLoc()); 3183 OverloadingResult OvResult = 3184 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 3185 CandidateSet, false); 3186 if (OvResult == OR_Ambiguous) 3187 Diag(From->getLocStart(), 3188 diag::err_typecheck_ambiguous_condition) 3189 << From->getType() << ToType << From->getSourceRange(); 3190 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 3191 Diag(From->getLocStart(), 3192 diag::err_typecheck_nonviable_condition) 3193 << From->getType() << ToType << From->getSourceRange(); 3194 else 3195 return false; 3196 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From); 3197 return true; 3198} 3199 3200/// \brief Compare the user-defined conversion functions or constructors 3201/// of two user-defined conversion sequences to determine whether any ordering 3202/// is possible. 3203static ImplicitConversionSequence::CompareKind 3204compareConversionFunctions(Sema &S, 3205 FunctionDecl *Function1, 3206 FunctionDecl *Function2) { 3207 if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus0x) 3208 return ImplicitConversionSequence::Indistinguishable; 3209 3210 // Objective-C++: 3211 // If both conversion functions are implicitly-declared conversions from 3212 // a lambda closure type to a function pointer and a block pointer, 3213 // respectively, always prefer the conversion to a function pointer, 3214 // because the function pointer is more lightweight and is more likely 3215 // to keep code working. 3216 CXXConversionDecl *Conv1 = dyn_cast<CXXConversionDecl>(Function1); 3217 if (!Conv1) 3218 return ImplicitConversionSequence::Indistinguishable; 3219 3220 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2); 3221 if (!Conv2) 3222 return ImplicitConversionSequence::Indistinguishable; 3223 3224 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) { 3225 bool Block1 = Conv1->getConversionType()->isBlockPointerType(); 3226 bool Block2 = Conv2->getConversionType()->isBlockPointerType(); 3227 if (Block1 != Block2) 3228 return Block1? ImplicitConversionSequence::Worse 3229 : ImplicitConversionSequence::Better; 3230 } 3231 3232 return ImplicitConversionSequence::Indistinguishable; 3233} 3234 3235/// CompareImplicitConversionSequences - Compare two implicit 3236/// conversion sequences to determine whether one is better than the 3237/// other or if they are indistinguishable (C++ 13.3.3.2). 3238static ImplicitConversionSequence::CompareKind 3239CompareImplicitConversionSequences(Sema &S, 3240 const ImplicitConversionSequence& ICS1, 3241 const ImplicitConversionSequence& ICS2) 3242{ 3243 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 3244 // conversion sequences (as defined in 13.3.3.1) 3245 // -- a standard conversion sequence (13.3.3.1.1) is a better 3246 // conversion sequence than a user-defined conversion sequence or 3247 // an ellipsis conversion sequence, and 3248 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 3249 // conversion sequence than an ellipsis conversion sequence 3250 // (13.3.3.1.3). 3251 // 3252 // C++0x [over.best.ics]p10: 3253 // For the purpose of ranking implicit conversion sequences as 3254 // described in 13.3.3.2, the ambiguous conversion sequence is 3255 // treated as a user-defined sequence that is indistinguishable 3256 // from any other user-defined conversion sequence. 3257 if (ICS1.getKindRank() < ICS2.getKindRank()) 3258 return ImplicitConversionSequence::Better; 3259 if (ICS2.getKindRank() < ICS1.getKindRank()) 3260 return ImplicitConversionSequence::Worse; 3261 3262 // The following checks require both conversion sequences to be of 3263 // the same kind. 3264 if (ICS1.getKind() != ICS2.getKind()) 3265 return ImplicitConversionSequence::Indistinguishable; 3266 3267 ImplicitConversionSequence::CompareKind Result = 3268 ImplicitConversionSequence::Indistinguishable; 3269 3270 // Two implicit conversion sequences of the same form are 3271 // indistinguishable conversion sequences unless one of the 3272 // following rules apply: (C++ 13.3.3.2p3): 3273 if (ICS1.isStandard()) 3274 Result = CompareStandardConversionSequences(S, 3275 ICS1.Standard, ICS2.Standard); 3276 else if (ICS1.isUserDefined()) { 3277 // User-defined conversion sequence U1 is a better conversion 3278 // sequence than another user-defined conversion sequence U2 if 3279 // they contain the same user-defined conversion function or 3280 // constructor and if the second standard conversion sequence of 3281 // U1 is better than the second standard conversion sequence of 3282 // U2 (C++ 13.3.3.2p3). 3283 if (ICS1.UserDefined.ConversionFunction == 3284 ICS2.UserDefined.ConversionFunction) 3285 Result = CompareStandardConversionSequences(S, 3286 ICS1.UserDefined.After, 3287 ICS2.UserDefined.After); 3288 else 3289 Result = compareConversionFunctions(S, 3290 ICS1.UserDefined.ConversionFunction, 3291 ICS2.UserDefined.ConversionFunction); 3292 } 3293 3294 // List-initialization sequence L1 is a better conversion sequence than 3295 // list-initialization sequence L2 if L1 converts to std::initializer_list<X> 3296 // for some X and L2 does not. 3297 if (Result == ImplicitConversionSequence::Indistinguishable && 3298 !ICS1.isBad() && 3299 ICS1.isListInitializationSequence() && 3300 ICS2.isListInitializationSequence()) { 3301 if (ICS1.isStdInitializerListElement() && 3302 !ICS2.isStdInitializerListElement()) 3303 return ImplicitConversionSequence::Better; 3304 if (!ICS1.isStdInitializerListElement() && 3305 ICS2.isStdInitializerListElement()) 3306 return ImplicitConversionSequence::Worse; 3307 } 3308 3309 return Result; 3310} 3311 3312static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 3313 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 3314 Qualifiers Quals; 3315 T1 = Context.getUnqualifiedArrayType(T1, Quals); 3316 T2 = Context.getUnqualifiedArrayType(T2, Quals); 3317 } 3318 3319 return Context.hasSameUnqualifiedType(T1, T2); 3320} 3321 3322// Per 13.3.3.2p3, compare the given standard conversion sequences to 3323// determine if one is a proper subset of the other. 3324static ImplicitConversionSequence::CompareKind 3325compareStandardConversionSubsets(ASTContext &Context, 3326 const StandardConversionSequence& SCS1, 3327 const StandardConversionSequence& SCS2) { 3328 ImplicitConversionSequence::CompareKind Result 3329 = ImplicitConversionSequence::Indistinguishable; 3330 3331 // the identity conversion sequence is considered to be a subsequence of 3332 // any non-identity conversion sequence 3333 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 3334 return ImplicitConversionSequence::Better; 3335 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 3336 return ImplicitConversionSequence::Worse; 3337 3338 if (SCS1.Second != SCS2.Second) { 3339 if (SCS1.Second == ICK_Identity) 3340 Result = ImplicitConversionSequence::Better; 3341 else if (SCS2.Second == ICK_Identity) 3342 Result = ImplicitConversionSequence::Worse; 3343 else 3344 return ImplicitConversionSequence::Indistinguishable; 3345 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 3346 return ImplicitConversionSequence::Indistinguishable; 3347 3348 if (SCS1.Third == SCS2.Third) { 3349 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 3350 : ImplicitConversionSequence::Indistinguishable; 3351 } 3352 3353 if (SCS1.Third == ICK_Identity) 3354 return Result == ImplicitConversionSequence::Worse 3355 ? ImplicitConversionSequence::Indistinguishable 3356 : ImplicitConversionSequence::Better; 3357 3358 if (SCS2.Third == ICK_Identity) 3359 return Result == ImplicitConversionSequence::Better 3360 ? ImplicitConversionSequence::Indistinguishable 3361 : ImplicitConversionSequence::Worse; 3362 3363 return ImplicitConversionSequence::Indistinguishable; 3364} 3365 3366/// \brief Determine whether one of the given reference bindings is better 3367/// than the other based on what kind of bindings they are. 3368static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 3369 const StandardConversionSequence &SCS2) { 3370 // C++0x [over.ics.rank]p3b4: 3371 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 3372 // implicit object parameter of a non-static member function declared 3373 // without a ref-qualifier, and *either* S1 binds an rvalue reference 3374 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 3375 // lvalue reference to a function lvalue and S2 binds an rvalue 3376 // reference*. 3377 // 3378 // FIXME: Rvalue references. We're going rogue with the above edits, 3379 // because the semantics in the current C++0x working paper (N3225 at the 3380 // time of this writing) break the standard definition of std::forward 3381 // and std::reference_wrapper when dealing with references to functions. 3382 // Proposed wording changes submitted to CWG for consideration. 3383 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 3384 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 3385 return false; 3386 3387 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 3388 SCS2.IsLvalueReference) || 3389 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 3390 !SCS2.IsLvalueReference); 3391} 3392 3393/// CompareStandardConversionSequences - Compare two standard 3394/// conversion sequences to determine whether one is better than the 3395/// other or if they are indistinguishable (C++ 13.3.3.2p3). 3396static ImplicitConversionSequence::CompareKind 3397CompareStandardConversionSequences(Sema &S, 3398 const StandardConversionSequence& SCS1, 3399 const StandardConversionSequence& SCS2) 3400{ 3401 // Standard conversion sequence S1 is a better conversion sequence 3402 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 3403 3404 // -- S1 is a proper subsequence of S2 (comparing the conversion 3405 // sequences in the canonical form defined by 13.3.3.1.1, 3406 // excluding any Lvalue Transformation; the identity conversion 3407 // sequence is considered to be a subsequence of any 3408 // non-identity conversion sequence) or, if not that, 3409 if (ImplicitConversionSequence::CompareKind CK 3410 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 3411 return CK; 3412 3413 // -- the rank of S1 is better than the rank of S2 (by the rules 3414 // defined below), or, if not that, 3415 ImplicitConversionRank Rank1 = SCS1.getRank(); 3416 ImplicitConversionRank Rank2 = SCS2.getRank(); 3417 if (Rank1 < Rank2) 3418 return ImplicitConversionSequence::Better; 3419 else if (Rank2 < Rank1) 3420 return ImplicitConversionSequence::Worse; 3421 3422 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 3423 // are indistinguishable unless one of the following rules 3424 // applies: 3425 3426 // A conversion that is not a conversion of a pointer, or 3427 // pointer to member, to bool is better than another conversion 3428 // that is such a conversion. 3429 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 3430 return SCS2.isPointerConversionToBool() 3431 ? ImplicitConversionSequence::Better 3432 : ImplicitConversionSequence::Worse; 3433 3434 // C++ [over.ics.rank]p4b2: 3435 // 3436 // If class B is derived directly or indirectly from class A, 3437 // conversion of B* to A* is better than conversion of B* to 3438 // void*, and conversion of A* to void* is better than conversion 3439 // of B* to void*. 3440 bool SCS1ConvertsToVoid 3441 = SCS1.isPointerConversionToVoidPointer(S.Context); 3442 bool SCS2ConvertsToVoid 3443 = SCS2.isPointerConversionToVoidPointer(S.Context); 3444 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 3445 // Exactly one of the conversion sequences is a conversion to 3446 // a void pointer; it's the worse conversion. 3447 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 3448 : ImplicitConversionSequence::Worse; 3449 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 3450 // Neither conversion sequence converts to a void pointer; compare 3451 // their derived-to-base conversions. 3452 if (ImplicitConversionSequence::CompareKind DerivedCK 3453 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 3454 return DerivedCK; 3455 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid && 3456 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) { 3457 // Both conversion sequences are conversions to void 3458 // pointers. Compare the source types to determine if there's an 3459 // inheritance relationship in their sources. 3460 QualType FromType1 = SCS1.getFromType(); 3461 QualType FromType2 = SCS2.getFromType(); 3462 3463 // Adjust the types we're converting from via the array-to-pointer 3464 // conversion, if we need to. 3465 if (SCS1.First == ICK_Array_To_Pointer) 3466 FromType1 = S.Context.getArrayDecayedType(FromType1); 3467 if (SCS2.First == ICK_Array_To_Pointer) 3468 FromType2 = S.Context.getArrayDecayedType(FromType2); 3469 3470 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType(); 3471 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType(); 3472 3473 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3474 return ImplicitConversionSequence::Better; 3475 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3476 return ImplicitConversionSequence::Worse; 3477 3478 // Objective-C++: If one interface is more specific than the 3479 // other, it is the better one. 3480 const ObjCObjectPointerType* FromObjCPtr1 3481 = FromType1->getAs<ObjCObjectPointerType>(); 3482 const ObjCObjectPointerType* FromObjCPtr2 3483 = FromType2->getAs<ObjCObjectPointerType>(); 3484 if (FromObjCPtr1 && FromObjCPtr2) { 3485 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1, 3486 FromObjCPtr2); 3487 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2, 3488 FromObjCPtr1); 3489 if (AssignLeft != AssignRight) { 3490 return AssignLeft? ImplicitConversionSequence::Better 3491 : ImplicitConversionSequence::Worse; 3492 } 3493 } 3494 } 3495 3496 // Compare based on qualification conversions (C++ 13.3.3.2p3, 3497 // bullet 3). 3498 if (ImplicitConversionSequence::CompareKind QualCK 3499 = CompareQualificationConversions(S, SCS1, SCS2)) 3500 return QualCK; 3501 3502 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 3503 // Check for a better reference binding based on the kind of bindings. 3504 if (isBetterReferenceBindingKind(SCS1, SCS2)) 3505 return ImplicitConversionSequence::Better; 3506 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 3507 return ImplicitConversionSequence::Worse; 3508 3509 // C++ [over.ics.rank]p3b4: 3510 // -- S1 and S2 are reference bindings (8.5.3), and the types to 3511 // which the references refer are the same type except for 3512 // top-level cv-qualifiers, and the type to which the reference 3513 // initialized by S2 refers is more cv-qualified than the type 3514 // to which the reference initialized by S1 refers. 3515 QualType T1 = SCS1.getToType(2); 3516 QualType T2 = SCS2.getToType(2); 3517 T1 = S.Context.getCanonicalType(T1); 3518 T2 = S.Context.getCanonicalType(T2); 3519 Qualifiers T1Quals, T2Quals; 3520 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3521 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3522 if (UnqualT1 == UnqualT2) { 3523 // Objective-C++ ARC: If the references refer to objects with different 3524 // lifetimes, prefer bindings that don't change lifetime. 3525 if (SCS1.ObjCLifetimeConversionBinding != 3526 SCS2.ObjCLifetimeConversionBinding) { 3527 return SCS1.ObjCLifetimeConversionBinding 3528 ? ImplicitConversionSequence::Worse 3529 : ImplicitConversionSequence::Better; 3530 } 3531 3532 // If the type is an array type, promote the element qualifiers to the 3533 // type for comparison. 3534 if (isa<ArrayType>(T1) && T1Quals) 3535 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3536 if (isa<ArrayType>(T2) && T2Quals) 3537 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3538 if (T2.isMoreQualifiedThan(T1)) 3539 return ImplicitConversionSequence::Better; 3540 else if (T1.isMoreQualifiedThan(T2)) 3541 return ImplicitConversionSequence::Worse; 3542 } 3543 } 3544 3545 // In Microsoft mode, prefer an integral conversion to a 3546 // floating-to-integral conversion if the integral conversion 3547 // is between types of the same size. 3548 // For example: 3549 // void f(float); 3550 // void f(int); 3551 // int main { 3552 // long a; 3553 // f(a); 3554 // } 3555 // Here, MSVC will call f(int) instead of generating a compile error 3556 // as clang will do in standard mode. 3557 if (S.getLangOpts().MicrosoftMode && 3558 SCS1.Second == ICK_Integral_Conversion && 3559 SCS2.Second == ICK_Floating_Integral && 3560 S.Context.getTypeSize(SCS1.getFromType()) == 3561 S.Context.getTypeSize(SCS1.getToType(2))) 3562 return ImplicitConversionSequence::Better; 3563 3564 return ImplicitConversionSequence::Indistinguishable; 3565} 3566 3567/// CompareQualificationConversions - Compares two standard conversion 3568/// sequences to determine whether they can be ranked based on their 3569/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 3570ImplicitConversionSequence::CompareKind 3571CompareQualificationConversions(Sema &S, 3572 const StandardConversionSequence& SCS1, 3573 const StandardConversionSequence& SCS2) { 3574 // C++ 13.3.3.2p3: 3575 // -- S1 and S2 differ only in their qualification conversion and 3576 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 3577 // cv-qualification signature of type T1 is a proper subset of 3578 // the cv-qualification signature of type T2, and S1 is not the 3579 // deprecated string literal array-to-pointer conversion (4.2). 3580 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 3581 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 3582 return ImplicitConversionSequence::Indistinguishable; 3583 3584 // FIXME: the example in the standard doesn't use a qualification 3585 // conversion (!) 3586 QualType T1 = SCS1.getToType(2); 3587 QualType T2 = SCS2.getToType(2); 3588 T1 = S.Context.getCanonicalType(T1); 3589 T2 = S.Context.getCanonicalType(T2); 3590 Qualifiers T1Quals, T2Quals; 3591 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3592 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3593 3594 // If the types are the same, we won't learn anything by unwrapped 3595 // them. 3596 if (UnqualT1 == UnqualT2) 3597 return ImplicitConversionSequence::Indistinguishable; 3598 3599 // If the type is an array type, promote the element qualifiers to the type 3600 // for comparison. 3601 if (isa<ArrayType>(T1) && T1Quals) 3602 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3603 if (isa<ArrayType>(T2) && T2Quals) 3604 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3605 3606 ImplicitConversionSequence::CompareKind Result 3607 = ImplicitConversionSequence::Indistinguishable; 3608 3609 // Objective-C++ ARC: 3610 // Prefer qualification conversions not involving a change in lifetime 3611 // to qualification conversions that do not change lifetime. 3612 if (SCS1.QualificationIncludesObjCLifetime != 3613 SCS2.QualificationIncludesObjCLifetime) { 3614 Result = SCS1.QualificationIncludesObjCLifetime 3615 ? ImplicitConversionSequence::Worse 3616 : ImplicitConversionSequence::Better; 3617 } 3618 3619 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 3620 // Within each iteration of the loop, we check the qualifiers to 3621 // determine if this still looks like a qualification 3622 // conversion. Then, if all is well, we unwrap one more level of 3623 // pointers or pointers-to-members and do it all again 3624 // until there are no more pointers or pointers-to-members left 3625 // to unwrap. This essentially mimics what 3626 // IsQualificationConversion does, but here we're checking for a 3627 // strict subset of qualifiers. 3628 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 3629 // The qualifiers are the same, so this doesn't tell us anything 3630 // about how the sequences rank. 3631 ; 3632 else if (T2.isMoreQualifiedThan(T1)) { 3633 // T1 has fewer qualifiers, so it could be the better sequence. 3634 if (Result == ImplicitConversionSequence::Worse) 3635 // Neither has qualifiers that are a subset of the other's 3636 // qualifiers. 3637 return ImplicitConversionSequence::Indistinguishable; 3638 3639 Result = ImplicitConversionSequence::Better; 3640 } else if (T1.isMoreQualifiedThan(T2)) { 3641 // T2 has fewer qualifiers, so it could be the better sequence. 3642 if (Result == ImplicitConversionSequence::Better) 3643 // Neither has qualifiers that are a subset of the other's 3644 // qualifiers. 3645 return ImplicitConversionSequence::Indistinguishable; 3646 3647 Result = ImplicitConversionSequence::Worse; 3648 } else { 3649 // Qualifiers are disjoint. 3650 return ImplicitConversionSequence::Indistinguishable; 3651 } 3652 3653 // If the types after this point are equivalent, we're done. 3654 if (S.Context.hasSameUnqualifiedType(T1, T2)) 3655 break; 3656 } 3657 3658 // Check that the winning standard conversion sequence isn't using 3659 // the deprecated string literal array to pointer conversion. 3660 switch (Result) { 3661 case ImplicitConversionSequence::Better: 3662 if (SCS1.DeprecatedStringLiteralToCharPtr) 3663 Result = ImplicitConversionSequence::Indistinguishable; 3664 break; 3665 3666 case ImplicitConversionSequence::Indistinguishable: 3667 break; 3668 3669 case ImplicitConversionSequence::Worse: 3670 if (SCS2.DeprecatedStringLiteralToCharPtr) 3671 Result = ImplicitConversionSequence::Indistinguishable; 3672 break; 3673 } 3674 3675 return Result; 3676} 3677 3678/// CompareDerivedToBaseConversions - Compares two standard conversion 3679/// sequences to determine whether they can be ranked based on their 3680/// various kinds of derived-to-base conversions (C++ 3681/// [over.ics.rank]p4b3). As part of these checks, we also look at 3682/// conversions between Objective-C interface types. 3683ImplicitConversionSequence::CompareKind 3684CompareDerivedToBaseConversions(Sema &S, 3685 const StandardConversionSequence& SCS1, 3686 const StandardConversionSequence& SCS2) { 3687 QualType FromType1 = SCS1.getFromType(); 3688 QualType ToType1 = SCS1.getToType(1); 3689 QualType FromType2 = SCS2.getFromType(); 3690 QualType ToType2 = SCS2.getToType(1); 3691 3692 // Adjust the types we're converting from via the array-to-pointer 3693 // conversion, if we need to. 3694 if (SCS1.First == ICK_Array_To_Pointer) 3695 FromType1 = S.Context.getArrayDecayedType(FromType1); 3696 if (SCS2.First == ICK_Array_To_Pointer) 3697 FromType2 = S.Context.getArrayDecayedType(FromType2); 3698 3699 // Canonicalize all of the types. 3700 FromType1 = S.Context.getCanonicalType(FromType1); 3701 ToType1 = S.Context.getCanonicalType(ToType1); 3702 FromType2 = S.Context.getCanonicalType(FromType2); 3703 ToType2 = S.Context.getCanonicalType(ToType2); 3704 3705 // C++ [over.ics.rank]p4b3: 3706 // 3707 // If class B is derived directly or indirectly from class A and 3708 // class C is derived directly or indirectly from B, 3709 // 3710 // Compare based on pointer conversions. 3711 if (SCS1.Second == ICK_Pointer_Conversion && 3712 SCS2.Second == ICK_Pointer_Conversion && 3713 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 3714 FromType1->isPointerType() && FromType2->isPointerType() && 3715 ToType1->isPointerType() && ToType2->isPointerType()) { 3716 QualType FromPointee1 3717 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3718 QualType ToPointee1 3719 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3720 QualType FromPointee2 3721 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3722 QualType ToPointee2 3723 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3724 3725 // -- conversion of C* to B* is better than conversion of C* to A*, 3726 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3727 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3728 return ImplicitConversionSequence::Better; 3729 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3730 return ImplicitConversionSequence::Worse; 3731 } 3732 3733 // -- conversion of B* to A* is better than conversion of C* to A*, 3734 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 3735 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3736 return ImplicitConversionSequence::Better; 3737 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3738 return ImplicitConversionSequence::Worse; 3739 } 3740 } else if (SCS1.Second == ICK_Pointer_Conversion && 3741 SCS2.Second == ICK_Pointer_Conversion) { 3742 const ObjCObjectPointerType *FromPtr1 3743 = FromType1->getAs<ObjCObjectPointerType>(); 3744 const ObjCObjectPointerType *FromPtr2 3745 = FromType2->getAs<ObjCObjectPointerType>(); 3746 const ObjCObjectPointerType *ToPtr1 3747 = ToType1->getAs<ObjCObjectPointerType>(); 3748 const ObjCObjectPointerType *ToPtr2 3749 = ToType2->getAs<ObjCObjectPointerType>(); 3750 3751 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 3752 // Apply the same conversion ranking rules for Objective-C pointer types 3753 // that we do for C++ pointers to class types. However, we employ the 3754 // Objective-C pseudo-subtyping relationship used for assignment of 3755 // Objective-C pointer types. 3756 bool FromAssignLeft 3757 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 3758 bool FromAssignRight 3759 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 3760 bool ToAssignLeft 3761 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 3762 bool ToAssignRight 3763 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 3764 3765 // A conversion to an a non-id object pointer type or qualified 'id' 3766 // type is better than a conversion to 'id'. 3767 if (ToPtr1->isObjCIdType() && 3768 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 3769 return ImplicitConversionSequence::Worse; 3770 if (ToPtr2->isObjCIdType() && 3771 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 3772 return ImplicitConversionSequence::Better; 3773 3774 // A conversion to a non-id object pointer type is better than a 3775 // conversion to a qualified 'id' type 3776 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 3777 return ImplicitConversionSequence::Worse; 3778 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 3779 return ImplicitConversionSequence::Better; 3780 3781 // A conversion to an a non-Class object pointer type or qualified 'Class' 3782 // type is better than a conversion to 'Class'. 3783 if (ToPtr1->isObjCClassType() && 3784 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 3785 return ImplicitConversionSequence::Worse; 3786 if (ToPtr2->isObjCClassType() && 3787 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 3788 return ImplicitConversionSequence::Better; 3789 3790 // A conversion to a non-Class object pointer type is better than a 3791 // conversion to a qualified 'Class' type. 3792 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 3793 return ImplicitConversionSequence::Worse; 3794 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 3795 return ImplicitConversionSequence::Better; 3796 3797 // -- "conversion of C* to B* is better than conversion of C* to A*," 3798 if (S.Context.hasSameType(FromType1, FromType2) && 3799 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 3800 (ToAssignLeft != ToAssignRight)) 3801 return ToAssignLeft? ImplicitConversionSequence::Worse 3802 : ImplicitConversionSequence::Better; 3803 3804 // -- "conversion of B* to A* is better than conversion of C* to A*," 3805 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 3806 (FromAssignLeft != FromAssignRight)) 3807 return FromAssignLeft? ImplicitConversionSequence::Better 3808 : ImplicitConversionSequence::Worse; 3809 } 3810 } 3811 3812 // Ranking of member-pointer types. 3813 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 3814 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 3815 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 3816 const MemberPointerType * FromMemPointer1 = 3817 FromType1->getAs<MemberPointerType>(); 3818 const MemberPointerType * ToMemPointer1 = 3819 ToType1->getAs<MemberPointerType>(); 3820 const MemberPointerType * FromMemPointer2 = 3821 FromType2->getAs<MemberPointerType>(); 3822 const MemberPointerType * ToMemPointer2 = 3823 ToType2->getAs<MemberPointerType>(); 3824 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 3825 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 3826 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 3827 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 3828 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 3829 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 3830 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 3831 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 3832 // conversion of A::* to B::* is better than conversion of A::* to C::*, 3833 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3834 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3835 return ImplicitConversionSequence::Worse; 3836 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3837 return ImplicitConversionSequence::Better; 3838 } 3839 // conversion of B::* to C::* is better than conversion of A::* to C::* 3840 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 3841 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3842 return ImplicitConversionSequence::Better; 3843 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3844 return ImplicitConversionSequence::Worse; 3845 } 3846 } 3847 3848 if (SCS1.Second == ICK_Derived_To_Base) { 3849 // -- conversion of C to B is better than conversion of C to A, 3850 // -- binding of an expression of type C to a reference of type 3851 // B& is better than binding an expression of type C to a 3852 // reference of type A&, 3853 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3854 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3855 if (S.IsDerivedFrom(ToType1, ToType2)) 3856 return ImplicitConversionSequence::Better; 3857 else if (S.IsDerivedFrom(ToType2, ToType1)) 3858 return ImplicitConversionSequence::Worse; 3859 } 3860 3861 // -- conversion of B to A is better than conversion of C to A. 3862 // -- binding of an expression of type B to a reference of type 3863 // A& is better than binding an expression of type C to a 3864 // reference of type A&, 3865 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3866 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3867 if (S.IsDerivedFrom(FromType2, FromType1)) 3868 return ImplicitConversionSequence::Better; 3869 else if (S.IsDerivedFrom(FromType1, FromType2)) 3870 return ImplicitConversionSequence::Worse; 3871 } 3872 } 3873 3874 return ImplicitConversionSequence::Indistinguishable; 3875} 3876 3877/// CompareReferenceRelationship - Compare the two types T1 and T2 to 3878/// determine whether they are reference-related, 3879/// reference-compatible, reference-compatible with added 3880/// qualification, or incompatible, for use in C++ initialization by 3881/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 3882/// type, and the first type (T1) is the pointee type of the reference 3883/// type being initialized. 3884Sema::ReferenceCompareResult 3885Sema::CompareReferenceRelationship(SourceLocation Loc, 3886 QualType OrigT1, QualType OrigT2, 3887 bool &DerivedToBase, 3888 bool &ObjCConversion, 3889 bool &ObjCLifetimeConversion) { 3890 assert(!OrigT1->isReferenceType() && 3891 "T1 must be the pointee type of the reference type"); 3892 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 3893 3894 QualType T1 = Context.getCanonicalType(OrigT1); 3895 QualType T2 = Context.getCanonicalType(OrigT2); 3896 Qualifiers T1Quals, T2Quals; 3897 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 3898 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 3899 3900 // C++ [dcl.init.ref]p4: 3901 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 3902 // reference-related to "cv2 T2" if T1 is the same type as T2, or 3903 // T1 is a base class of T2. 3904 DerivedToBase = false; 3905 ObjCConversion = false; 3906 ObjCLifetimeConversion = false; 3907 if (UnqualT1 == UnqualT2) { 3908 // Nothing to do. 3909 } else if (!RequireCompleteType(Loc, OrigT2, 0) && 3910 IsDerivedFrom(UnqualT2, UnqualT1)) 3911 DerivedToBase = true; 3912 else if (UnqualT1->isObjCObjectOrInterfaceType() && 3913 UnqualT2->isObjCObjectOrInterfaceType() && 3914 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 3915 ObjCConversion = true; 3916 else 3917 return Ref_Incompatible; 3918 3919 // At this point, we know that T1 and T2 are reference-related (at 3920 // least). 3921 3922 // If the type is an array type, promote the element qualifiers to the type 3923 // for comparison. 3924 if (isa<ArrayType>(T1) && T1Quals) 3925 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 3926 if (isa<ArrayType>(T2) && T2Quals) 3927 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 3928 3929 // C++ [dcl.init.ref]p4: 3930 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 3931 // reference-related to T2 and cv1 is the same cv-qualification 3932 // as, or greater cv-qualification than, cv2. For purposes of 3933 // overload resolution, cases for which cv1 is greater 3934 // cv-qualification than cv2 are identified as 3935 // reference-compatible with added qualification (see 13.3.3.2). 3936 // 3937 // Note that we also require equivalence of Objective-C GC and address-space 3938 // qualifiers when performing these computations, so that e.g., an int in 3939 // address space 1 is not reference-compatible with an int in address 3940 // space 2. 3941 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() && 3942 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) { 3943 T1Quals.removeObjCLifetime(); 3944 T2Quals.removeObjCLifetime(); 3945 ObjCLifetimeConversion = true; 3946 } 3947 3948 if (T1Quals == T2Quals) 3949 return Ref_Compatible; 3950 else if (T1Quals.compatiblyIncludes(T2Quals)) 3951 return Ref_Compatible_With_Added_Qualification; 3952 else 3953 return Ref_Related; 3954} 3955 3956/// \brief Look for a user-defined conversion to an value reference-compatible 3957/// with DeclType. Return true if something definite is found. 3958static bool 3959FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 3960 QualType DeclType, SourceLocation DeclLoc, 3961 Expr *Init, QualType T2, bool AllowRvalues, 3962 bool AllowExplicit) { 3963 assert(T2->isRecordType() && "Can only find conversions of record types."); 3964 CXXRecordDecl *T2RecordDecl 3965 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 3966 3967 OverloadCandidateSet CandidateSet(DeclLoc); 3968 const UnresolvedSetImpl *Conversions 3969 = T2RecordDecl->getVisibleConversionFunctions(); 3970 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3971 E = Conversions->end(); I != E; ++I) { 3972 NamedDecl *D = *I; 3973 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3974 if (isa<UsingShadowDecl>(D)) 3975 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3976 3977 FunctionTemplateDecl *ConvTemplate 3978 = dyn_cast<FunctionTemplateDecl>(D); 3979 CXXConversionDecl *Conv; 3980 if (ConvTemplate) 3981 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3982 else 3983 Conv = cast<CXXConversionDecl>(D); 3984 3985 // If this is an explicit conversion, and we're not allowed to consider 3986 // explicit conversions, skip it. 3987 if (!AllowExplicit && Conv->isExplicit()) 3988 continue; 3989 3990 if (AllowRvalues) { 3991 bool DerivedToBase = false; 3992 bool ObjCConversion = false; 3993 bool ObjCLifetimeConversion = false; 3994 3995 // If we are initializing an rvalue reference, don't permit conversion 3996 // functions that return lvalues. 3997 if (!ConvTemplate && DeclType->isRValueReferenceType()) { 3998 const ReferenceType *RefType 3999 = Conv->getConversionType()->getAs<LValueReferenceType>(); 4000 if (RefType && !RefType->getPointeeType()->isFunctionType()) 4001 continue; 4002 } 4003 4004 if (!ConvTemplate && 4005 S.CompareReferenceRelationship( 4006 DeclLoc, 4007 Conv->getConversionType().getNonReferenceType() 4008 .getUnqualifiedType(), 4009 DeclType.getNonReferenceType().getUnqualifiedType(), 4010 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) == 4011 Sema::Ref_Incompatible) 4012 continue; 4013 } else { 4014 // If the conversion function doesn't return a reference type, 4015 // it can't be considered for this conversion. An rvalue reference 4016 // is only acceptable if its referencee is a function type. 4017 4018 const ReferenceType *RefType = 4019 Conv->getConversionType()->getAs<ReferenceType>(); 4020 if (!RefType || 4021 (!RefType->isLValueReferenceType() && 4022 !RefType->getPointeeType()->isFunctionType())) 4023 continue; 4024 } 4025 4026 if (ConvTemplate) 4027 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 4028 Init, DeclType, CandidateSet); 4029 else 4030 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 4031 DeclType, CandidateSet); 4032 } 4033 4034 bool HadMultipleCandidates = (CandidateSet.size() > 1); 4035 4036 OverloadCandidateSet::iterator Best; 4037 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 4038 case OR_Success: 4039 // C++ [over.ics.ref]p1: 4040 // 4041 // [...] If the parameter binds directly to the result of 4042 // applying a conversion function to the argument 4043 // expression, the implicit conversion sequence is a 4044 // user-defined conversion sequence (13.3.3.1.2), with the 4045 // second standard conversion sequence either an identity 4046 // conversion or, if the conversion function returns an 4047 // entity of a type that is a derived class of the parameter 4048 // type, a derived-to-base Conversion. 4049 if (!Best->FinalConversion.DirectBinding) 4050 return false; 4051 4052 if (Best->Function) 4053 S.MarkFunctionReferenced(DeclLoc, Best->Function); 4054 ICS.setUserDefined(); 4055 ICS.UserDefined.Before = Best->Conversions[0].Standard; 4056 ICS.UserDefined.After = Best->FinalConversion; 4057 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates; 4058 ICS.UserDefined.ConversionFunction = Best->Function; 4059 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl; 4060 ICS.UserDefined.EllipsisConversion = false; 4061 assert(ICS.UserDefined.After.ReferenceBinding && 4062 ICS.UserDefined.After.DirectBinding && 4063 "Expected a direct reference binding!"); 4064 return true; 4065 4066 case OR_Ambiguous: 4067 ICS.setAmbiguous(); 4068 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4069 Cand != CandidateSet.end(); ++Cand) 4070 if (Cand->Viable) 4071 ICS.Ambiguous.addConversion(Cand->Function); 4072 return true; 4073 4074 case OR_No_Viable_Function: 4075 case OR_Deleted: 4076 // There was no suitable conversion, or we found a deleted 4077 // conversion; continue with other checks. 4078 return false; 4079 } 4080 4081 llvm_unreachable("Invalid OverloadResult!"); 4082} 4083 4084/// \brief Compute an implicit conversion sequence for reference 4085/// initialization. 4086static ImplicitConversionSequence 4087TryReferenceInit(Sema &S, Expr *Init, QualType DeclType, 4088 SourceLocation DeclLoc, 4089 bool SuppressUserConversions, 4090 bool AllowExplicit) { 4091 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 4092 4093 // Most paths end in a failed conversion. 4094 ImplicitConversionSequence ICS; 4095 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 4096 4097 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 4098 QualType T2 = Init->getType(); 4099 4100 // If the initializer is the address of an overloaded function, try 4101 // to resolve the overloaded function. If all goes well, T2 is the 4102 // type of the resulting function. 4103 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 4104 DeclAccessPair Found; 4105 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 4106 false, Found)) 4107 T2 = Fn->getType(); 4108 } 4109 4110 // Compute some basic properties of the types and the initializer. 4111 bool isRValRef = DeclType->isRValueReferenceType(); 4112 bool DerivedToBase = false; 4113 bool ObjCConversion = false; 4114 bool ObjCLifetimeConversion = false; 4115 Expr::Classification InitCategory = Init->Classify(S.Context); 4116 Sema::ReferenceCompareResult RefRelationship 4117 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 4118 ObjCConversion, ObjCLifetimeConversion); 4119 4120 4121 // C++0x [dcl.init.ref]p5: 4122 // A reference to type "cv1 T1" is initialized by an expression 4123 // of type "cv2 T2" as follows: 4124 4125 // -- If reference is an lvalue reference and the initializer expression 4126 if (!isRValRef) { 4127 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 4128 // reference-compatible with "cv2 T2," or 4129 // 4130 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 4131 if (InitCategory.isLValue() && 4132 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 4133 // C++ [over.ics.ref]p1: 4134 // When a parameter of reference type binds directly (8.5.3) 4135 // to an argument expression, the implicit conversion sequence 4136 // is the identity conversion, unless the argument expression 4137 // has a type that is a derived class of the parameter type, 4138 // in which case the implicit conversion sequence is a 4139 // derived-to-base Conversion (13.3.3.1). 4140 ICS.setStandard(); 4141 ICS.Standard.First = ICK_Identity; 4142 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 4143 : ObjCConversion? ICK_Compatible_Conversion 4144 : ICK_Identity; 4145 ICS.Standard.Third = ICK_Identity; 4146 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 4147 ICS.Standard.setToType(0, T2); 4148 ICS.Standard.setToType(1, T1); 4149 ICS.Standard.setToType(2, T1); 4150 ICS.Standard.ReferenceBinding = true; 4151 ICS.Standard.DirectBinding = true; 4152 ICS.Standard.IsLvalueReference = !isRValRef; 4153 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4154 ICS.Standard.BindsToRvalue = false; 4155 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4156 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 4157 ICS.Standard.CopyConstructor = 0; 4158 4159 // Nothing more to do: the inaccessibility/ambiguity check for 4160 // derived-to-base conversions is suppressed when we're 4161 // computing the implicit conversion sequence (C++ 4162 // [over.best.ics]p2). 4163 return ICS; 4164 } 4165 4166 // -- has a class type (i.e., T2 is a class type), where T1 is 4167 // not reference-related to T2, and can be implicitly 4168 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 4169 // is reference-compatible with "cv3 T3" 92) (this 4170 // conversion is selected by enumerating the applicable 4171 // conversion functions (13.3.1.6) and choosing the best 4172 // one through overload resolution (13.3)), 4173 if (!SuppressUserConversions && T2->isRecordType() && 4174 !S.RequireCompleteType(DeclLoc, T2, 0) && 4175 RefRelationship == Sema::Ref_Incompatible) { 4176 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 4177 Init, T2, /*AllowRvalues=*/false, 4178 AllowExplicit)) 4179 return ICS; 4180 } 4181 } 4182 4183 // -- Otherwise, the reference shall be an lvalue reference to a 4184 // non-volatile const type (i.e., cv1 shall be const), or the reference 4185 // shall be an rvalue reference. 4186 // 4187 // We actually handle one oddity of C++ [over.ics.ref] at this 4188 // point, which is that, due to p2 (which short-circuits reference 4189 // binding by only attempting a simple conversion for non-direct 4190 // bindings) and p3's strange wording, we allow a const volatile 4191 // reference to bind to an rvalue. Hence the check for the presence 4192 // of "const" rather than checking for "const" being the only 4193 // qualifier. 4194 // This is also the point where rvalue references and lvalue inits no longer 4195 // go together. 4196 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified())) 4197 return ICS; 4198 4199 // -- If the initializer expression 4200 // 4201 // -- is an xvalue, class prvalue, array prvalue or function 4202 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or 4203 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 4204 (InitCategory.isXValue() || 4205 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 4206 (InitCategory.isLValue() && T2->isFunctionType()))) { 4207 ICS.setStandard(); 4208 ICS.Standard.First = ICK_Identity; 4209 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 4210 : ObjCConversion? ICK_Compatible_Conversion 4211 : ICK_Identity; 4212 ICS.Standard.Third = ICK_Identity; 4213 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 4214 ICS.Standard.setToType(0, T2); 4215 ICS.Standard.setToType(1, T1); 4216 ICS.Standard.setToType(2, T1); 4217 ICS.Standard.ReferenceBinding = true; 4218 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 4219 // binding unless we're binding to a class prvalue. 4220 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 4221 // allow the use of rvalue references in C++98/03 for the benefit of 4222 // standard library implementors; therefore, we need the xvalue check here. 4223 ICS.Standard.DirectBinding = 4224 S.getLangOpts().CPlusPlus0x || 4225 (InitCategory.isPRValue() && !T2->isRecordType()); 4226 ICS.Standard.IsLvalueReference = !isRValRef; 4227 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4228 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 4229 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4230 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 4231 ICS.Standard.CopyConstructor = 0; 4232 return ICS; 4233 } 4234 4235 // -- has a class type (i.e., T2 is a class type), where T1 is not 4236 // reference-related to T2, and can be implicitly converted to 4237 // an xvalue, class prvalue, or function lvalue of type 4238 // "cv3 T3", where "cv1 T1" is reference-compatible with 4239 // "cv3 T3", 4240 // 4241 // then the reference is bound to the value of the initializer 4242 // expression in the first case and to the result of the conversion 4243 // in the second case (or, in either case, to an appropriate base 4244 // class subobject). 4245 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 4246 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 4247 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 4248 Init, T2, /*AllowRvalues=*/true, 4249 AllowExplicit)) { 4250 // In the second case, if the reference is an rvalue reference 4251 // and the second standard conversion sequence of the 4252 // user-defined conversion sequence includes an lvalue-to-rvalue 4253 // conversion, the program is ill-formed. 4254 if (ICS.isUserDefined() && isRValRef && 4255 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 4256 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 4257 4258 return ICS; 4259 } 4260 4261 // -- Otherwise, a temporary of type "cv1 T1" is created and 4262 // initialized from the initializer expression using the 4263 // rules for a non-reference copy initialization (8.5). The 4264 // reference is then bound to the temporary. If T1 is 4265 // reference-related to T2, cv1 must be the same 4266 // cv-qualification as, or greater cv-qualification than, 4267 // cv2; otherwise, the program is ill-formed. 4268 if (RefRelationship == Sema::Ref_Related) { 4269 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 4270 // we would be reference-compatible or reference-compatible with 4271 // added qualification. But that wasn't the case, so the reference 4272 // initialization fails. 4273 // 4274 // Note that we only want to check address spaces and cvr-qualifiers here. 4275 // ObjC GC and lifetime qualifiers aren't important. 4276 Qualifiers T1Quals = T1.getQualifiers(); 4277 Qualifiers T2Quals = T2.getQualifiers(); 4278 T1Quals.removeObjCGCAttr(); 4279 T1Quals.removeObjCLifetime(); 4280 T2Quals.removeObjCGCAttr(); 4281 T2Quals.removeObjCLifetime(); 4282 if (!T1Quals.compatiblyIncludes(T2Quals)) 4283 return ICS; 4284 } 4285 4286 // If at least one of the types is a class type, the types are not 4287 // related, and we aren't allowed any user conversions, the 4288 // reference binding fails. This case is important for breaking 4289 // recursion, since TryImplicitConversion below will attempt to 4290 // create a temporary through the use of a copy constructor. 4291 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 4292 (T1->isRecordType() || T2->isRecordType())) 4293 return ICS; 4294 4295 // If T1 is reference-related to T2 and the reference is an rvalue 4296 // reference, the initializer expression shall not be an lvalue. 4297 if (RefRelationship >= Sema::Ref_Related && 4298 isRValRef && Init->Classify(S.Context).isLValue()) 4299 return ICS; 4300 4301 // C++ [over.ics.ref]p2: 4302 // When a parameter of reference type is not bound directly to 4303 // an argument expression, the conversion sequence is the one 4304 // required to convert the argument expression to the 4305 // underlying type of the reference according to 4306 // 13.3.3.1. Conceptually, this conversion sequence corresponds 4307 // to copy-initializing a temporary of the underlying type with 4308 // the argument expression. Any difference in top-level 4309 // cv-qualification is subsumed by the initialization itself 4310 // and does not constitute a conversion. 4311 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 4312 /*AllowExplicit=*/false, 4313 /*InOverloadResolution=*/false, 4314 /*CStyle=*/false, 4315 /*AllowObjCWritebackConversion=*/false); 4316 4317 // Of course, that's still a reference binding. 4318 if (ICS.isStandard()) { 4319 ICS.Standard.ReferenceBinding = true; 4320 ICS.Standard.IsLvalueReference = !isRValRef; 4321 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4322 ICS.Standard.BindsToRvalue = true; 4323 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4324 ICS.Standard.ObjCLifetimeConversionBinding = false; 4325 } else if (ICS.isUserDefined()) { 4326 // Don't allow rvalue references to bind to lvalues. 4327 if (DeclType->isRValueReferenceType()) { 4328 if (const ReferenceType *RefType 4329 = ICS.UserDefined.ConversionFunction->getResultType() 4330 ->getAs<LValueReferenceType>()) { 4331 if (!RefType->getPointeeType()->isFunctionType()) { 4332 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, 4333 DeclType); 4334 return ICS; 4335 } 4336 } 4337 } 4338 4339 ICS.UserDefined.After.ReferenceBinding = true; 4340 ICS.UserDefined.After.IsLvalueReference = !isRValRef; 4341 ICS.UserDefined.After.BindsToFunctionLvalue = T2->isFunctionType(); 4342 ICS.UserDefined.After.BindsToRvalue = true; 4343 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4344 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false; 4345 } 4346 4347 return ICS; 4348} 4349 4350static ImplicitConversionSequence 4351TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 4352 bool SuppressUserConversions, 4353 bool InOverloadResolution, 4354 bool AllowObjCWritebackConversion, 4355 bool AllowExplicit = false); 4356 4357/// TryListConversion - Try to copy-initialize a value of type ToType from the 4358/// initializer list From. 4359static ImplicitConversionSequence 4360TryListConversion(Sema &S, InitListExpr *From, QualType ToType, 4361 bool SuppressUserConversions, 4362 bool InOverloadResolution, 4363 bool AllowObjCWritebackConversion) { 4364 // C++11 [over.ics.list]p1: 4365 // When an argument is an initializer list, it is not an expression and 4366 // special rules apply for converting it to a parameter type. 4367 4368 ImplicitConversionSequence Result; 4369 Result.setBad(BadConversionSequence::no_conversion, From, ToType); 4370 Result.setListInitializationSequence(); 4371 4372 // We need a complete type for what follows. Incomplete types can never be 4373 // initialized from init lists. 4374 if (S.RequireCompleteType(From->getLocStart(), ToType, 0)) 4375 return Result; 4376 4377 // C++11 [over.ics.list]p2: 4378 // If the parameter type is std::initializer_list<X> or "array of X" and 4379 // all the elements can be implicitly converted to X, the implicit 4380 // conversion sequence is the worst conversion necessary to convert an 4381 // element of the list to X. 4382 bool toStdInitializerList = false; 4383 QualType X; 4384 if (ToType->isArrayType()) 4385 X = S.Context.getBaseElementType(ToType); 4386 else 4387 toStdInitializerList = S.isStdInitializerList(ToType, &X); 4388 if (!X.isNull()) { 4389 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) { 4390 Expr *Init = From->getInit(i); 4391 ImplicitConversionSequence ICS = 4392 TryCopyInitialization(S, Init, X, SuppressUserConversions, 4393 InOverloadResolution, 4394 AllowObjCWritebackConversion); 4395 // If a single element isn't convertible, fail. 4396 if (ICS.isBad()) { 4397 Result = ICS; 4398 break; 4399 } 4400 // Otherwise, look for the worst conversion. 4401 if (Result.isBad() || 4402 CompareImplicitConversionSequences(S, ICS, Result) == 4403 ImplicitConversionSequence::Worse) 4404 Result = ICS; 4405 } 4406 4407 // For an empty list, we won't have computed any conversion sequence. 4408 // Introduce the identity conversion sequence. 4409 if (From->getNumInits() == 0) { 4410 Result.setStandard(); 4411 Result.Standard.setAsIdentityConversion(); 4412 Result.Standard.setFromType(ToType); 4413 Result.Standard.setAllToTypes(ToType); 4414 } 4415 4416 Result.setListInitializationSequence(); 4417 Result.setStdInitializerListElement(toStdInitializerList); 4418 return Result; 4419 } 4420 4421 // C++11 [over.ics.list]p3: 4422 // Otherwise, if the parameter is a non-aggregate class X and overload 4423 // resolution chooses a single best constructor [...] the implicit 4424 // conversion sequence is a user-defined conversion sequence. If multiple 4425 // constructors are viable but none is better than the others, the 4426 // implicit conversion sequence is a user-defined conversion sequence. 4427 if (ToType->isRecordType() && !ToType->isAggregateType()) { 4428 // This function can deal with initializer lists. 4429 Result = TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, 4430 /*AllowExplicit=*/false, 4431 InOverloadResolution, /*CStyle=*/false, 4432 AllowObjCWritebackConversion); 4433 Result.setListInitializationSequence(); 4434 return Result; 4435 } 4436 4437 // C++11 [over.ics.list]p4: 4438 // Otherwise, if the parameter has an aggregate type which can be 4439 // initialized from the initializer list [...] the implicit conversion 4440 // sequence is a user-defined conversion sequence. 4441 if (ToType->isAggregateType()) { 4442 // Type is an aggregate, argument is an init list. At this point it comes 4443 // down to checking whether the initialization works. 4444 // FIXME: Find out whether this parameter is consumed or not. 4445 InitializedEntity Entity = 4446 InitializedEntity::InitializeParameter(S.Context, ToType, 4447 /*Consumed=*/false); 4448 if (S.CanPerformCopyInitialization(Entity, S.Owned(From))) { 4449 Result.setUserDefined(); 4450 Result.UserDefined.Before.setAsIdentityConversion(); 4451 // Initializer lists don't have a type. 4452 Result.UserDefined.Before.setFromType(QualType()); 4453 Result.UserDefined.Before.setAllToTypes(QualType()); 4454 4455 Result.UserDefined.After.setAsIdentityConversion(); 4456 Result.UserDefined.After.setFromType(ToType); 4457 Result.UserDefined.After.setAllToTypes(ToType); 4458 Result.UserDefined.ConversionFunction = 0; 4459 } 4460 return Result; 4461 } 4462 4463 // C++11 [over.ics.list]p5: 4464 // Otherwise, if the parameter is a reference, see 13.3.3.1.4. 4465 if (ToType->isReferenceType()) { 4466 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't 4467 // mention initializer lists in any way. So we go by what list- 4468 // initialization would do and try to extrapolate from that. 4469 4470 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType(); 4471 4472 // If the initializer list has a single element that is reference-related 4473 // to the parameter type, we initialize the reference from that. 4474 if (From->getNumInits() == 1) { 4475 Expr *Init = From->getInit(0); 4476 4477 QualType T2 = Init->getType(); 4478 4479 // If the initializer is the address of an overloaded function, try 4480 // to resolve the overloaded function. If all goes well, T2 is the 4481 // type of the resulting function. 4482 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 4483 DeclAccessPair Found; 4484 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction( 4485 Init, ToType, false, Found)) 4486 T2 = Fn->getType(); 4487 } 4488 4489 // Compute some basic properties of the types and the initializer. 4490 bool dummy1 = false; 4491 bool dummy2 = false; 4492 bool dummy3 = false; 4493 Sema::ReferenceCompareResult RefRelationship 4494 = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1, 4495 dummy2, dummy3); 4496 4497 if (RefRelationship >= Sema::Ref_Related) 4498 return TryReferenceInit(S, Init, ToType, 4499 /*FIXME:*/From->getLocStart(), 4500 SuppressUserConversions, 4501 /*AllowExplicit=*/false); 4502 } 4503 4504 // Otherwise, we bind the reference to a temporary created from the 4505 // initializer list. 4506 Result = TryListConversion(S, From, T1, SuppressUserConversions, 4507 InOverloadResolution, 4508 AllowObjCWritebackConversion); 4509 if (Result.isFailure()) 4510 return Result; 4511 assert(!Result.isEllipsis() && 4512 "Sub-initialization cannot result in ellipsis conversion."); 4513 4514 // Can we even bind to a temporary? 4515 if (ToType->isRValueReferenceType() || 4516 (T1.isConstQualified() && !T1.isVolatileQualified())) { 4517 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard : 4518 Result.UserDefined.After; 4519 SCS.ReferenceBinding = true; 4520 SCS.IsLvalueReference = ToType->isLValueReferenceType(); 4521 SCS.BindsToRvalue = true; 4522 SCS.BindsToFunctionLvalue = false; 4523 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4524 SCS.ObjCLifetimeConversionBinding = false; 4525 } else 4526 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue, 4527 From, ToType); 4528 return Result; 4529 } 4530 4531 // C++11 [over.ics.list]p6: 4532 // Otherwise, if the parameter type is not a class: 4533 if (!ToType->isRecordType()) { 4534 // - if the initializer list has one element, the implicit conversion 4535 // sequence is the one required to convert the element to the 4536 // parameter type. 4537 unsigned NumInits = From->getNumInits(); 4538 if (NumInits == 1) 4539 Result = TryCopyInitialization(S, From->getInit(0), ToType, 4540 SuppressUserConversions, 4541 InOverloadResolution, 4542 AllowObjCWritebackConversion); 4543 // - if the initializer list has no elements, the implicit conversion 4544 // sequence is the identity conversion. 4545 else if (NumInits == 0) { 4546 Result.setStandard(); 4547 Result.Standard.setAsIdentityConversion(); 4548 Result.Standard.setFromType(ToType); 4549 Result.Standard.setAllToTypes(ToType); 4550 } 4551 Result.setListInitializationSequence(); 4552 return Result; 4553 } 4554 4555 // C++11 [over.ics.list]p7: 4556 // In all cases other than those enumerated above, no conversion is possible 4557 return Result; 4558} 4559 4560/// TryCopyInitialization - Try to copy-initialize a value of type 4561/// ToType from the expression From. Return the implicit conversion 4562/// sequence required to pass this argument, which may be a bad 4563/// conversion sequence (meaning that the argument cannot be passed to 4564/// a parameter of this type). If @p SuppressUserConversions, then we 4565/// do not permit any user-defined conversion sequences. 4566static ImplicitConversionSequence 4567TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 4568 bool SuppressUserConversions, 4569 bool InOverloadResolution, 4570 bool AllowObjCWritebackConversion, 4571 bool AllowExplicit) { 4572 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From)) 4573 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions, 4574 InOverloadResolution,AllowObjCWritebackConversion); 4575 4576 if (ToType->isReferenceType()) 4577 return TryReferenceInit(S, From, ToType, 4578 /*FIXME:*/From->getLocStart(), 4579 SuppressUserConversions, 4580 AllowExplicit); 4581 4582 return TryImplicitConversion(S, From, ToType, 4583 SuppressUserConversions, 4584 /*AllowExplicit=*/false, 4585 InOverloadResolution, 4586 /*CStyle=*/false, 4587 AllowObjCWritebackConversion); 4588} 4589 4590static bool TryCopyInitialization(const CanQualType FromQTy, 4591 const CanQualType ToQTy, 4592 Sema &S, 4593 SourceLocation Loc, 4594 ExprValueKind FromVK) { 4595 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK); 4596 ImplicitConversionSequence ICS = 4597 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false); 4598 4599 return !ICS.isBad(); 4600} 4601 4602/// TryObjectArgumentInitialization - Try to initialize the object 4603/// parameter of the given member function (@c Method) from the 4604/// expression @p From. 4605static ImplicitConversionSequence 4606TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 4607 Expr::Classification FromClassification, 4608 CXXMethodDecl *Method, 4609 CXXRecordDecl *ActingContext) { 4610 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 4611 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 4612 // const volatile object. 4613 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 4614 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 4615 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 4616 4617 // Set up the conversion sequence as a "bad" conversion, to allow us 4618 // to exit early. 4619 ImplicitConversionSequence ICS; 4620 4621 // We need to have an object of class type. 4622 QualType FromType = OrigFromType; 4623 if (const PointerType *PT = FromType->getAs<PointerType>()) { 4624 FromType = PT->getPointeeType(); 4625 4626 // When we had a pointer, it's implicitly dereferenced, so we 4627 // better have an lvalue. 4628 assert(FromClassification.isLValue()); 4629 } 4630 4631 assert(FromType->isRecordType()); 4632 4633 // C++0x [over.match.funcs]p4: 4634 // For non-static member functions, the type of the implicit object 4635 // parameter is 4636 // 4637 // - "lvalue reference to cv X" for functions declared without a 4638 // ref-qualifier or with the & ref-qualifier 4639 // - "rvalue reference to cv X" for functions declared with the && 4640 // ref-qualifier 4641 // 4642 // where X is the class of which the function is a member and cv is the 4643 // cv-qualification on the member function declaration. 4644 // 4645 // However, when finding an implicit conversion sequence for the argument, we 4646 // are not allowed to create temporaries or perform user-defined conversions 4647 // (C++ [over.match.funcs]p5). We perform a simplified version of 4648 // reference binding here, that allows class rvalues to bind to 4649 // non-constant references. 4650 4651 // First check the qualifiers. 4652 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 4653 if (ImplicitParamType.getCVRQualifiers() 4654 != FromTypeCanon.getLocalCVRQualifiers() && 4655 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 4656 ICS.setBad(BadConversionSequence::bad_qualifiers, 4657 OrigFromType, ImplicitParamType); 4658 return ICS; 4659 } 4660 4661 // Check that we have either the same type or a derived type. It 4662 // affects the conversion rank. 4663 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 4664 ImplicitConversionKind SecondKind; 4665 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 4666 SecondKind = ICK_Identity; 4667 } else if (S.IsDerivedFrom(FromType, ClassType)) 4668 SecondKind = ICK_Derived_To_Base; 4669 else { 4670 ICS.setBad(BadConversionSequence::unrelated_class, 4671 FromType, ImplicitParamType); 4672 return ICS; 4673 } 4674 4675 // Check the ref-qualifier. 4676 switch (Method->getRefQualifier()) { 4677 case RQ_None: 4678 // Do nothing; we don't care about lvalueness or rvalueness. 4679 break; 4680 4681 case RQ_LValue: 4682 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 4683 // non-const lvalue reference cannot bind to an rvalue 4684 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 4685 ImplicitParamType); 4686 return ICS; 4687 } 4688 break; 4689 4690 case RQ_RValue: 4691 if (!FromClassification.isRValue()) { 4692 // rvalue reference cannot bind to an lvalue 4693 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 4694 ImplicitParamType); 4695 return ICS; 4696 } 4697 break; 4698 } 4699 4700 // Success. Mark this as a reference binding. 4701 ICS.setStandard(); 4702 ICS.Standard.setAsIdentityConversion(); 4703 ICS.Standard.Second = SecondKind; 4704 ICS.Standard.setFromType(FromType); 4705 ICS.Standard.setAllToTypes(ImplicitParamType); 4706 ICS.Standard.ReferenceBinding = true; 4707 ICS.Standard.DirectBinding = true; 4708 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 4709 ICS.Standard.BindsToFunctionLvalue = false; 4710 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 4711 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 4712 = (Method->getRefQualifier() == RQ_None); 4713 return ICS; 4714} 4715 4716/// PerformObjectArgumentInitialization - Perform initialization of 4717/// the implicit object parameter for the given Method with the given 4718/// expression. 4719ExprResult 4720Sema::PerformObjectArgumentInitialization(Expr *From, 4721 NestedNameSpecifier *Qualifier, 4722 NamedDecl *FoundDecl, 4723 CXXMethodDecl *Method) { 4724 QualType FromRecordType, DestType; 4725 QualType ImplicitParamRecordType = 4726 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 4727 4728 Expr::Classification FromClassification; 4729 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 4730 FromRecordType = PT->getPointeeType(); 4731 DestType = Method->getThisType(Context); 4732 FromClassification = Expr::Classification::makeSimpleLValue(); 4733 } else { 4734 FromRecordType = From->getType(); 4735 DestType = ImplicitParamRecordType; 4736 FromClassification = From->Classify(Context); 4737 } 4738 4739 // Note that we always use the true parent context when performing 4740 // the actual argument initialization. 4741 ImplicitConversionSequence ICS 4742 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 4743 Method, Method->getParent()); 4744 if (ICS.isBad()) { 4745 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 4746 Qualifiers FromQs = FromRecordType.getQualifiers(); 4747 Qualifiers ToQs = DestType.getQualifiers(); 4748 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4749 if (CVR) { 4750 Diag(From->getLocStart(), 4751 diag::err_member_function_call_bad_cvr) 4752 << Method->getDeclName() << FromRecordType << (CVR - 1) 4753 << From->getSourceRange(); 4754 Diag(Method->getLocation(), diag::note_previous_decl) 4755 << Method->getDeclName(); 4756 return ExprError(); 4757 } 4758 } 4759 4760 return Diag(From->getLocStart(), 4761 diag::err_implicit_object_parameter_init) 4762 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 4763 } 4764 4765 if (ICS.Standard.Second == ICK_Derived_To_Base) { 4766 ExprResult FromRes = 4767 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 4768 if (FromRes.isInvalid()) 4769 return ExprError(); 4770 From = FromRes.take(); 4771 } 4772 4773 if (!Context.hasSameType(From->getType(), DestType)) 4774 From = ImpCastExprToType(From, DestType, CK_NoOp, 4775 From->getValueKind()).take(); 4776 return Owned(From); 4777} 4778 4779/// TryContextuallyConvertToBool - Attempt to contextually convert the 4780/// expression From to bool (C++0x [conv]p3). 4781static ImplicitConversionSequence 4782TryContextuallyConvertToBool(Sema &S, Expr *From) { 4783 // FIXME: This is pretty broken. 4784 return TryImplicitConversion(S, From, S.Context.BoolTy, 4785 // FIXME: Are these flags correct? 4786 /*SuppressUserConversions=*/false, 4787 /*AllowExplicit=*/true, 4788 /*InOverloadResolution=*/false, 4789 /*CStyle=*/false, 4790 /*AllowObjCWritebackConversion=*/false); 4791} 4792 4793/// PerformContextuallyConvertToBool - Perform a contextual conversion 4794/// of the expression From to bool (C++0x [conv]p3). 4795ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) { 4796 if (checkPlaceholderForOverload(*this, From)) 4797 return ExprError(); 4798 4799 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 4800 if (!ICS.isBad()) 4801 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 4802 4803 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 4804 return Diag(From->getLocStart(), 4805 diag::err_typecheck_bool_condition) 4806 << From->getType() << From->getSourceRange(); 4807 return ExprError(); 4808} 4809 4810/// Check that the specified conversion is permitted in a converted constant 4811/// expression, according to C++11 [expr.const]p3. Return true if the conversion 4812/// is acceptable. 4813static bool CheckConvertedConstantConversions(Sema &S, 4814 StandardConversionSequence &SCS) { 4815 // Since we know that the target type is an integral or unscoped enumeration 4816 // type, most conversion kinds are impossible. All possible First and Third 4817 // conversions are fine. 4818 switch (SCS.Second) { 4819 case ICK_Identity: 4820 case ICK_Integral_Promotion: 4821 case ICK_Integral_Conversion: 4822 return true; 4823 4824 case ICK_Boolean_Conversion: 4825 // Conversion from an integral or unscoped enumeration type to bool is 4826 // classified as ICK_Boolean_Conversion, but it's also an integral 4827 // conversion, so it's permitted in a converted constant expression. 4828 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() && 4829 SCS.getToType(2)->isBooleanType(); 4830 4831 case ICK_Floating_Integral: 4832 case ICK_Complex_Real: 4833 return false; 4834 4835 case ICK_Lvalue_To_Rvalue: 4836 case ICK_Array_To_Pointer: 4837 case ICK_Function_To_Pointer: 4838 case ICK_NoReturn_Adjustment: 4839 case ICK_Qualification: 4840 case ICK_Compatible_Conversion: 4841 case ICK_Vector_Conversion: 4842 case ICK_Vector_Splat: 4843 case ICK_Derived_To_Base: 4844 case ICK_Pointer_Conversion: 4845 case ICK_Pointer_Member: 4846 case ICK_Block_Pointer_Conversion: 4847 case ICK_Writeback_Conversion: 4848 case ICK_Floating_Promotion: 4849 case ICK_Complex_Promotion: 4850 case ICK_Complex_Conversion: 4851 case ICK_Floating_Conversion: 4852 case ICK_TransparentUnionConversion: 4853 llvm_unreachable("unexpected second conversion kind"); 4854 4855 case ICK_Num_Conversion_Kinds: 4856 break; 4857 } 4858 4859 llvm_unreachable("unknown conversion kind"); 4860} 4861 4862/// CheckConvertedConstantExpression - Check that the expression From is a 4863/// converted constant expression of type T, perform the conversion and produce 4864/// the converted expression, per C++11 [expr.const]p3. 4865ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T, 4866 llvm::APSInt &Value, 4867 CCEKind CCE) { 4868 assert(LangOpts.CPlusPlus0x && "converted constant expression outside C++11"); 4869 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type"); 4870 4871 if (checkPlaceholderForOverload(*this, From)) 4872 return ExprError(); 4873 4874 // C++11 [expr.const]p3 with proposed wording fixes: 4875 // A converted constant expression of type T is a core constant expression, 4876 // implicitly converted to a prvalue of type T, where the converted 4877 // expression is a literal constant expression and the implicit conversion 4878 // sequence contains only user-defined conversions, lvalue-to-rvalue 4879 // conversions, integral promotions, and integral conversions other than 4880 // narrowing conversions. 4881 ImplicitConversionSequence ICS = 4882 TryImplicitConversion(From, T, 4883 /*SuppressUserConversions=*/false, 4884 /*AllowExplicit=*/false, 4885 /*InOverloadResolution=*/false, 4886 /*CStyle=*/false, 4887 /*AllowObjcWritebackConversion=*/false); 4888 StandardConversionSequence *SCS = 0; 4889 switch (ICS.getKind()) { 4890 case ImplicitConversionSequence::StandardConversion: 4891 if (!CheckConvertedConstantConversions(*this, ICS.Standard)) 4892 return Diag(From->getLocStart(), 4893 diag::err_typecheck_converted_constant_expression_disallowed) 4894 << From->getType() << From->getSourceRange() << T; 4895 SCS = &ICS.Standard; 4896 break; 4897 case ImplicitConversionSequence::UserDefinedConversion: 4898 // We are converting from class type to an integral or enumeration type, so 4899 // the Before sequence must be trivial. 4900 if (!CheckConvertedConstantConversions(*this, ICS.UserDefined.After)) 4901 return Diag(From->getLocStart(), 4902 diag::err_typecheck_converted_constant_expression_disallowed) 4903 << From->getType() << From->getSourceRange() << T; 4904 SCS = &ICS.UserDefined.After; 4905 break; 4906 case ImplicitConversionSequence::AmbiguousConversion: 4907 case ImplicitConversionSequence::BadConversion: 4908 if (!DiagnoseMultipleUserDefinedConversion(From, T)) 4909 return Diag(From->getLocStart(), 4910 diag::err_typecheck_converted_constant_expression) 4911 << From->getType() << From->getSourceRange() << T; 4912 return ExprError(); 4913 4914 case ImplicitConversionSequence::EllipsisConversion: 4915 llvm_unreachable("ellipsis conversion in converted constant expression"); 4916 } 4917 4918 ExprResult Result = PerformImplicitConversion(From, T, ICS, AA_Converting); 4919 if (Result.isInvalid()) 4920 return Result; 4921 4922 // Check for a narrowing implicit conversion. 4923 APValue PreNarrowingValue; 4924 QualType PreNarrowingType; 4925 switch (SCS->getNarrowingKind(Context, Result.get(), PreNarrowingValue, 4926 PreNarrowingType)) { 4927 case NK_Variable_Narrowing: 4928 // Implicit conversion to a narrower type, and the value is not a constant 4929 // expression. We'll diagnose this in a moment. 4930 case NK_Not_Narrowing: 4931 break; 4932 4933 case NK_Constant_Narrowing: 4934 Diag(From->getLocStart(), 4935 isSFINAEContext() ? diag::err_cce_narrowing_sfinae : 4936 diag::err_cce_narrowing) 4937 << CCE << /*Constant*/1 4938 << PreNarrowingValue.getAsString(Context, PreNarrowingType) << T; 4939 break; 4940 4941 case NK_Type_Narrowing: 4942 Diag(From->getLocStart(), 4943 isSFINAEContext() ? diag::err_cce_narrowing_sfinae : 4944 diag::err_cce_narrowing) 4945 << CCE << /*Constant*/0 << From->getType() << T; 4946 break; 4947 } 4948 4949 // Check the expression is a constant expression. 4950 llvm::SmallVector<PartialDiagnosticAt, 8> Notes; 4951 Expr::EvalResult Eval; 4952 Eval.Diag = &Notes; 4953 4954 if (!Result.get()->EvaluateAsRValue(Eval, Context)) { 4955 // The expression can't be folded, so we can't keep it at this position in 4956 // the AST. 4957 Result = ExprError(); 4958 } else { 4959 Value = Eval.Val.getInt(); 4960 4961 if (Notes.empty()) { 4962 // It's a constant expression. 4963 return Result; 4964 } 4965 } 4966 4967 // It's not a constant expression. Produce an appropriate diagnostic. 4968 if (Notes.size() == 1 && 4969 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr) 4970 Diag(Notes[0].first, diag::err_expr_not_cce) << CCE; 4971 else { 4972 Diag(From->getLocStart(), diag::err_expr_not_cce) 4973 << CCE << From->getSourceRange(); 4974 for (unsigned I = 0; I < Notes.size(); ++I) 4975 Diag(Notes[I].first, Notes[I].second); 4976 } 4977 return Result; 4978} 4979 4980/// dropPointerConversions - If the given standard conversion sequence 4981/// involves any pointer conversions, remove them. This may change 4982/// the result type of the conversion sequence. 4983static void dropPointerConversion(StandardConversionSequence &SCS) { 4984 if (SCS.Second == ICK_Pointer_Conversion) { 4985 SCS.Second = ICK_Identity; 4986 SCS.Third = ICK_Identity; 4987 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0]; 4988 } 4989} 4990 4991/// TryContextuallyConvertToObjCPointer - Attempt to contextually 4992/// convert the expression From to an Objective-C pointer type. 4993static ImplicitConversionSequence 4994TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) { 4995 // Do an implicit conversion to 'id'. 4996 QualType Ty = S.Context.getObjCIdType(); 4997 ImplicitConversionSequence ICS 4998 = TryImplicitConversion(S, From, Ty, 4999 // FIXME: Are these flags correct? 5000 /*SuppressUserConversions=*/false, 5001 /*AllowExplicit=*/true, 5002 /*InOverloadResolution=*/false, 5003 /*CStyle=*/false, 5004 /*AllowObjCWritebackConversion=*/false); 5005 5006 // Strip off any final conversions to 'id'. 5007 switch (ICS.getKind()) { 5008 case ImplicitConversionSequence::BadConversion: 5009 case ImplicitConversionSequence::AmbiguousConversion: 5010 case ImplicitConversionSequence::EllipsisConversion: 5011 break; 5012 5013 case ImplicitConversionSequence::UserDefinedConversion: 5014 dropPointerConversion(ICS.UserDefined.After); 5015 break; 5016 5017 case ImplicitConversionSequence::StandardConversion: 5018 dropPointerConversion(ICS.Standard); 5019 break; 5020 } 5021 5022 return ICS; 5023} 5024 5025/// PerformContextuallyConvertToObjCPointer - Perform a contextual 5026/// conversion of the expression From to an Objective-C pointer type. 5027ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) { 5028 if (checkPlaceholderForOverload(*this, From)) 5029 return ExprError(); 5030 5031 QualType Ty = Context.getObjCIdType(); 5032 ImplicitConversionSequence ICS = 5033 TryContextuallyConvertToObjCPointer(*this, From); 5034 if (!ICS.isBad()) 5035 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 5036 return ExprError(); 5037} 5038 5039/// Determine whether the provided type is an integral type, or an enumeration 5040/// type of a permitted flavor. 5041static bool isIntegralOrEnumerationType(QualType T, bool AllowScopedEnum) { 5042 return AllowScopedEnum ? T->isIntegralOrEnumerationType() 5043 : T->isIntegralOrUnscopedEnumerationType(); 5044} 5045 5046/// \brief Attempt to convert the given expression to an integral or 5047/// enumeration type. 5048/// 5049/// This routine will attempt to convert an expression of class type to an 5050/// integral or enumeration type, if that class type only has a single 5051/// conversion to an integral or enumeration type. 5052/// 5053/// \param Loc The source location of the construct that requires the 5054/// conversion. 5055/// 5056/// \param From The expression we're converting from. 5057/// 5058/// \param Diagnoser Used to output any diagnostics. 5059/// 5060/// \param AllowScopedEnumerations Specifies whether conversions to scoped 5061/// enumerations should be considered. 5062/// 5063/// \returns The expression, converted to an integral or enumeration type if 5064/// successful. 5065ExprResult 5066Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 5067 ICEConvertDiagnoser &Diagnoser, 5068 bool AllowScopedEnumerations) { 5069 // We can't perform any more checking for type-dependent expressions. 5070 if (From->isTypeDependent()) 5071 return Owned(From); 5072 5073 // Process placeholders immediately. 5074 if (From->hasPlaceholderType()) { 5075 ExprResult result = CheckPlaceholderExpr(From); 5076 if (result.isInvalid()) return result; 5077 From = result.take(); 5078 } 5079 5080 // If the expression already has integral or enumeration type, we're golden. 5081 QualType T = From->getType(); 5082 if (isIntegralOrEnumerationType(T, AllowScopedEnumerations)) 5083 return DefaultLvalueConversion(From); 5084 5085 // FIXME: Check for missing '()' if T is a function type? 5086 5087 // If we don't have a class type in C++, there's no way we can get an 5088 // expression of integral or enumeration type. 5089 const RecordType *RecordTy = T->getAs<RecordType>(); 5090 if (!RecordTy || !getLangOpts().CPlusPlus) { 5091 if (!Diagnoser.Suppress) 5092 Diagnoser.diagnoseNotInt(*this, Loc, T) << From->getSourceRange(); 5093 return Owned(From); 5094 } 5095 5096 // We must have a complete class type. 5097 struct TypeDiagnoserPartialDiag : TypeDiagnoser { 5098 ICEConvertDiagnoser &Diagnoser; 5099 Expr *From; 5100 5101 TypeDiagnoserPartialDiag(ICEConvertDiagnoser &Diagnoser, Expr *From) 5102 : TypeDiagnoser(Diagnoser.Suppress), Diagnoser(Diagnoser), From(From) {} 5103 5104 virtual void diagnose(Sema &S, SourceLocation Loc, QualType T) { 5105 Diagnoser.diagnoseIncomplete(S, Loc, T) << From->getSourceRange(); 5106 } 5107 } IncompleteDiagnoser(Diagnoser, From); 5108 5109 if (RequireCompleteType(Loc, T, IncompleteDiagnoser)) 5110 return Owned(From); 5111 5112 // Look for a conversion to an integral or enumeration type. 5113 UnresolvedSet<4> ViableConversions; 5114 UnresolvedSet<4> ExplicitConversions; 5115 const UnresolvedSetImpl *Conversions 5116 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 5117 5118 bool HadMultipleCandidates = (Conversions->size() > 1); 5119 5120 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 5121 E = Conversions->end(); 5122 I != E; 5123 ++I) { 5124 if (CXXConversionDecl *Conversion 5125 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) { 5126 if (isIntegralOrEnumerationType( 5127 Conversion->getConversionType().getNonReferenceType(), 5128 AllowScopedEnumerations)) { 5129 if (Conversion->isExplicit()) 5130 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 5131 else 5132 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 5133 } 5134 } 5135 } 5136 5137 switch (ViableConversions.size()) { 5138 case 0: 5139 if (ExplicitConversions.size() == 1 && !Diagnoser.Suppress) { 5140 DeclAccessPair Found = ExplicitConversions[0]; 5141 CXXConversionDecl *Conversion 5142 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 5143 5144 // The user probably meant to invoke the given explicit 5145 // conversion; use it. 5146 QualType ConvTy 5147 = Conversion->getConversionType().getNonReferenceType(); 5148 std::string TypeStr; 5149 ConvTy.getAsStringInternal(TypeStr, getPrintingPolicy()); 5150 5151 Diagnoser.diagnoseExplicitConv(*this, Loc, T, ConvTy) 5152 << FixItHint::CreateInsertion(From->getLocStart(), 5153 "static_cast<" + TypeStr + ">(") 5154 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 5155 ")"); 5156 Diagnoser.noteExplicitConv(*this, Conversion, ConvTy); 5157 5158 // If we aren't in a SFINAE context, build a call to the 5159 // explicit conversion function. 5160 if (isSFINAEContext()) 5161 return ExprError(); 5162 5163 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 5164 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion, 5165 HadMultipleCandidates); 5166 if (Result.isInvalid()) 5167 return ExprError(); 5168 // Record usage of conversion in an implicit cast. 5169 From = ImplicitCastExpr::Create(Context, Result.get()->getType(), 5170 CK_UserDefinedConversion, 5171 Result.get(), 0, 5172 Result.get()->getValueKind()); 5173 } 5174 5175 // We'll complain below about a non-integral condition type. 5176 break; 5177 5178 case 1: { 5179 // Apply this conversion. 5180 DeclAccessPair Found = ViableConversions[0]; 5181 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 5182 5183 CXXConversionDecl *Conversion 5184 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 5185 QualType ConvTy 5186 = Conversion->getConversionType().getNonReferenceType(); 5187 if (!Diagnoser.SuppressConversion) { 5188 if (isSFINAEContext()) 5189 return ExprError(); 5190 5191 Diagnoser.diagnoseConversion(*this, Loc, T, ConvTy) 5192 << From->getSourceRange(); 5193 } 5194 5195 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion, 5196 HadMultipleCandidates); 5197 if (Result.isInvalid()) 5198 return ExprError(); 5199 // Record usage of conversion in an implicit cast. 5200 From = ImplicitCastExpr::Create(Context, Result.get()->getType(), 5201 CK_UserDefinedConversion, 5202 Result.get(), 0, 5203 Result.get()->getValueKind()); 5204 break; 5205 } 5206 5207 default: 5208 if (Diagnoser.Suppress) 5209 return ExprError(); 5210 5211 Diagnoser.diagnoseAmbiguous(*this, Loc, T) << From->getSourceRange(); 5212 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 5213 CXXConversionDecl *Conv 5214 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 5215 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 5216 Diagnoser.noteAmbiguous(*this, Conv, ConvTy); 5217 } 5218 return Owned(From); 5219 } 5220 5221 if (!isIntegralOrEnumerationType(From->getType(), AllowScopedEnumerations) && 5222 !Diagnoser.Suppress) { 5223 Diagnoser.diagnoseNotInt(*this, Loc, From->getType()) 5224 << From->getSourceRange(); 5225 } 5226 5227 return DefaultLvalueConversion(From); 5228} 5229 5230/// AddOverloadCandidate - Adds the given function to the set of 5231/// candidate functions, using the given function call arguments. If 5232/// @p SuppressUserConversions, then don't allow user-defined 5233/// conversions via constructors or conversion operators. 5234/// 5235/// \param PartialOverloading true if we are performing "partial" overloading 5236/// based on an incomplete set of function arguments. This feature is used by 5237/// code completion. 5238void 5239Sema::AddOverloadCandidate(FunctionDecl *Function, 5240 DeclAccessPair FoundDecl, 5241 llvm::ArrayRef<Expr *> Args, 5242 OverloadCandidateSet& CandidateSet, 5243 bool SuppressUserConversions, 5244 bool PartialOverloading, 5245 bool AllowExplicit) { 5246 const FunctionProtoType* Proto 5247 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 5248 assert(Proto && "Functions without a prototype cannot be overloaded"); 5249 assert(!Function->getDescribedFunctionTemplate() && 5250 "Use AddTemplateOverloadCandidate for function templates"); 5251 5252 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 5253 if (!isa<CXXConstructorDecl>(Method)) { 5254 // If we get here, it's because we're calling a member function 5255 // that is named without a member access expression (e.g., 5256 // "this->f") that was either written explicitly or created 5257 // implicitly. This can happen with a qualified call to a member 5258 // function, e.g., X::f(). We use an empty type for the implied 5259 // object argument (C++ [over.call.func]p3), and the acting context 5260 // is irrelevant. 5261 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 5262 QualType(), Expr::Classification::makeSimpleLValue(), 5263 Args, CandidateSet, SuppressUserConversions); 5264 return; 5265 } 5266 // We treat a constructor like a non-member function, since its object 5267 // argument doesn't participate in overload resolution. 5268 } 5269 5270 if (!CandidateSet.isNewCandidate(Function)) 5271 return; 5272 5273 // Overload resolution is always an unevaluated context. 5274 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5275 5276 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 5277 // C++ [class.copy]p3: 5278 // A member function template is never instantiated to perform the copy 5279 // of a class object to an object of its class type. 5280 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 5281 if (Args.size() == 1 && 5282 Constructor->isSpecializationCopyingObject() && 5283 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 5284 IsDerivedFrom(Args[0]->getType(), ClassType))) 5285 return; 5286 } 5287 5288 // Add this candidate 5289 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size()); 5290 Candidate.FoundDecl = FoundDecl; 5291 Candidate.Function = Function; 5292 Candidate.Viable = true; 5293 Candidate.IsSurrogate = false; 5294 Candidate.IgnoreObjectArgument = false; 5295 Candidate.ExplicitCallArguments = Args.size(); 5296 5297 unsigned NumArgsInProto = Proto->getNumArgs(); 5298 5299 // (C++ 13.3.2p2): A candidate function having fewer than m 5300 // parameters is viable only if it has an ellipsis in its parameter 5301 // list (8.3.5). 5302 if ((Args.size() + (PartialOverloading && Args.size())) > NumArgsInProto && 5303 !Proto->isVariadic()) { 5304 Candidate.Viable = false; 5305 Candidate.FailureKind = ovl_fail_too_many_arguments; 5306 return; 5307 } 5308 5309 // (C++ 13.3.2p2): A candidate function having more than m parameters 5310 // is viable only if the (m+1)st parameter has a default argument 5311 // (8.3.6). For the purposes of overload resolution, the 5312 // parameter list is truncated on the right, so that there are 5313 // exactly m parameters. 5314 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 5315 if (Args.size() < MinRequiredArgs && !PartialOverloading) { 5316 // Not enough arguments. 5317 Candidate.Viable = false; 5318 Candidate.FailureKind = ovl_fail_too_few_arguments; 5319 return; 5320 } 5321 5322 // (CUDA B.1): Check for invalid calls between targets. 5323 if (getLangOpts().CUDA) 5324 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext)) 5325 if (CheckCUDATarget(Caller, Function)) { 5326 Candidate.Viable = false; 5327 Candidate.FailureKind = ovl_fail_bad_target; 5328 return; 5329 } 5330 5331 // Determine the implicit conversion sequences for each of the 5332 // arguments. 5333 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5334 if (ArgIdx < NumArgsInProto) { 5335 // (C++ 13.3.2p3): for F to be a viable function, there shall 5336 // exist for each argument an implicit conversion sequence 5337 // (13.3.3.1) that converts that argument to the corresponding 5338 // parameter of F. 5339 QualType ParamType = Proto->getArgType(ArgIdx); 5340 Candidate.Conversions[ArgIdx] 5341 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5342 SuppressUserConversions, 5343 /*InOverloadResolution=*/true, 5344 /*AllowObjCWritebackConversion=*/ 5345 getLangOpts().ObjCAutoRefCount, 5346 AllowExplicit); 5347 if (Candidate.Conversions[ArgIdx].isBad()) { 5348 Candidate.Viable = false; 5349 Candidate.FailureKind = ovl_fail_bad_conversion; 5350 break; 5351 } 5352 } else { 5353 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5354 // argument for which there is no corresponding parameter is 5355 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5356 Candidate.Conversions[ArgIdx].setEllipsis(); 5357 } 5358 } 5359} 5360 5361/// \brief Add all of the function declarations in the given function set to 5362/// the overload canddiate set. 5363void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 5364 llvm::ArrayRef<Expr *> Args, 5365 OverloadCandidateSet& CandidateSet, 5366 bool SuppressUserConversions, 5367 TemplateArgumentListInfo *ExplicitTemplateArgs) { 5368 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 5369 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 5370 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 5371 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 5372 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 5373 cast<CXXMethodDecl>(FD)->getParent(), 5374 Args[0]->getType(), Args[0]->Classify(Context), 5375 Args.slice(1), CandidateSet, 5376 SuppressUserConversions); 5377 else 5378 AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet, 5379 SuppressUserConversions); 5380 } else { 5381 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 5382 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 5383 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 5384 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 5385 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 5386 ExplicitTemplateArgs, 5387 Args[0]->getType(), 5388 Args[0]->Classify(Context), Args.slice(1), 5389 CandidateSet, SuppressUserConversions); 5390 else 5391 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 5392 ExplicitTemplateArgs, Args, 5393 CandidateSet, SuppressUserConversions); 5394 } 5395 } 5396} 5397 5398/// AddMethodCandidate - Adds a named decl (which is some kind of 5399/// method) as a method candidate to the given overload set. 5400void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 5401 QualType ObjectType, 5402 Expr::Classification ObjectClassification, 5403 Expr **Args, unsigned NumArgs, 5404 OverloadCandidateSet& CandidateSet, 5405 bool SuppressUserConversions) { 5406 NamedDecl *Decl = FoundDecl.getDecl(); 5407 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 5408 5409 if (isa<UsingShadowDecl>(Decl)) 5410 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 5411 5412 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 5413 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 5414 "Expected a member function template"); 5415 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 5416 /*ExplicitArgs*/ 0, 5417 ObjectType, ObjectClassification, 5418 llvm::makeArrayRef(Args, NumArgs), CandidateSet, 5419 SuppressUserConversions); 5420 } else { 5421 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 5422 ObjectType, ObjectClassification, 5423 llvm::makeArrayRef(Args, NumArgs), 5424 CandidateSet, SuppressUserConversions); 5425 } 5426} 5427 5428/// AddMethodCandidate - Adds the given C++ member function to the set 5429/// of candidate functions, using the given function call arguments 5430/// and the object argument (@c Object). For example, in a call 5431/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 5432/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 5433/// allow user-defined conversions via constructors or conversion 5434/// operators. 5435void 5436Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 5437 CXXRecordDecl *ActingContext, QualType ObjectType, 5438 Expr::Classification ObjectClassification, 5439 llvm::ArrayRef<Expr *> Args, 5440 OverloadCandidateSet& CandidateSet, 5441 bool SuppressUserConversions) { 5442 const FunctionProtoType* Proto 5443 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 5444 assert(Proto && "Methods without a prototype cannot be overloaded"); 5445 assert(!isa<CXXConstructorDecl>(Method) && 5446 "Use AddOverloadCandidate for constructors"); 5447 5448 if (!CandidateSet.isNewCandidate(Method)) 5449 return; 5450 5451 // Overload resolution is always an unevaluated context. 5452 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5453 5454 // Add this candidate 5455 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); 5456 Candidate.FoundDecl = FoundDecl; 5457 Candidate.Function = Method; 5458 Candidate.IsSurrogate = false; 5459 Candidate.IgnoreObjectArgument = false; 5460 Candidate.ExplicitCallArguments = Args.size(); 5461 5462 unsigned NumArgsInProto = Proto->getNumArgs(); 5463 5464 // (C++ 13.3.2p2): A candidate function having fewer than m 5465 // parameters is viable only if it has an ellipsis in its parameter 5466 // list (8.3.5). 5467 if (Args.size() > NumArgsInProto && !Proto->isVariadic()) { 5468 Candidate.Viable = false; 5469 Candidate.FailureKind = ovl_fail_too_many_arguments; 5470 return; 5471 } 5472 5473 // (C++ 13.3.2p2): A candidate function having more than m parameters 5474 // is viable only if the (m+1)st parameter has a default argument 5475 // (8.3.6). For the purposes of overload resolution, the 5476 // parameter list is truncated on the right, so that there are 5477 // exactly m parameters. 5478 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 5479 if (Args.size() < MinRequiredArgs) { 5480 // Not enough arguments. 5481 Candidate.Viable = false; 5482 Candidate.FailureKind = ovl_fail_too_few_arguments; 5483 return; 5484 } 5485 5486 Candidate.Viable = true; 5487 5488 if (Method->isStatic() || ObjectType.isNull()) 5489 // The implicit object argument is ignored. 5490 Candidate.IgnoreObjectArgument = true; 5491 else { 5492 // Determine the implicit conversion sequence for the object 5493 // parameter. 5494 Candidate.Conversions[0] 5495 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 5496 Method, ActingContext); 5497 if (Candidate.Conversions[0].isBad()) { 5498 Candidate.Viable = false; 5499 Candidate.FailureKind = ovl_fail_bad_conversion; 5500 return; 5501 } 5502 } 5503 5504 // Determine the implicit conversion sequences for each of the 5505 // arguments. 5506 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5507 if (ArgIdx < NumArgsInProto) { 5508 // (C++ 13.3.2p3): for F to be a viable function, there shall 5509 // exist for each argument an implicit conversion sequence 5510 // (13.3.3.1) that converts that argument to the corresponding 5511 // parameter of F. 5512 QualType ParamType = Proto->getArgType(ArgIdx); 5513 Candidate.Conversions[ArgIdx + 1] 5514 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5515 SuppressUserConversions, 5516 /*InOverloadResolution=*/true, 5517 /*AllowObjCWritebackConversion=*/ 5518 getLangOpts().ObjCAutoRefCount); 5519 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 5520 Candidate.Viable = false; 5521 Candidate.FailureKind = ovl_fail_bad_conversion; 5522 break; 5523 } 5524 } else { 5525 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5526 // argument for which there is no corresponding parameter is 5527 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5528 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 5529 } 5530 } 5531} 5532 5533/// \brief Add a C++ member function template as a candidate to the candidate 5534/// set, using template argument deduction to produce an appropriate member 5535/// function template specialization. 5536void 5537Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 5538 DeclAccessPair FoundDecl, 5539 CXXRecordDecl *ActingContext, 5540 TemplateArgumentListInfo *ExplicitTemplateArgs, 5541 QualType ObjectType, 5542 Expr::Classification ObjectClassification, 5543 llvm::ArrayRef<Expr *> Args, 5544 OverloadCandidateSet& CandidateSet, 5545 bool SuppressUserConversions) { 5546 if (!CandidateSet.isNewCandidate(MethodTmpl)) 5547 return; 5548 5549 // C++ [over.match.funcs]p7: 5550 // In each case where a candidate is a function template, candidate 5551 // function template specializations are generated using template argument 5552 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 5553 // candidate functions in the usual way.113) A given name can refer to one 5554 // or more function templates and also to a set of overloaded non-template 5555 // functions. In such a case, the candidate functions generated from each 5556 // function template are combined with the set of non-template candidate 5557 // functions. 5558 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5559 FunctionDecl *Specialization = 0; 5560 if (TemplateDeductionResult Result 5561 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, Args, 5562 Specialization, Info)) { 5563 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5564 Candidate.FoundDecl = FoundDecl; 5565 Candidate.Function = MethodTmpl->getTemplatedDecl(); 5566 Candidate.Viable = false; 5567 Candidate.FailureKind = ovl_fail_bad_deduction; 5568 Candidate.IsSurrogate = false; 5569 Candidate.IgnoreObjectArgument = false; 5570 Candidate.ExplicitCallArguments = Args.size(); 5571 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5572 Info); 5573 return; 5574 } 5575 5576 // Add the function template specialization produced by template argument 5577 // deduction as a candidate. 5578 assert(Specialization && "Missing member function template specialization?"); 5579 assert(isa<CXXMethodDecl>(Specialization) && 5580 "Specialization is not a member function?"); 5581 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 5582 ActingContext, ObjectType, ObjectClassification, Args, 5583 CandidateSet, SuppressUserConversions); 5584} 5585 5586/// \brief Add a C++ function template specialization as a candidate 5587/// in the candidate set, using template argument deduction to produce 5588/// an appropriate function template specialization. 5589void 5590Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 5591 DeclAccessPair FoundDecl, 5592 TemplateArgumentListInfo *ExplicitTemplateArgs, 5593 llvm::ArrayRef<Expr *> Args, 5594 OverloadCandidateSet& CandidateSet, 5595 bool SuppressUserConversions) { 5596 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 5597 return; 5598 5599 // C++ [over.match.funcs]p7: 5600 // In each case where a candidate is a function template, candidate 5601 // function template specializations are generated using template argument 5602 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 5603 // candidate functions in the usual way.113) A given name can refer to one 5604 // or more function templates and also to a set of overloaded non-template 5605 // functions. In such a case, the candidate functions generated from each 5606 // function template are combined with the set of non-template candidate 5607 // functions. 5608 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5609 FunctionDecl *Specialization = 0; 5610 if (TemplateDeductionResult Result 5611 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, Args, 5612 Specialization, Info)) { 5613 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5614 Candidate.FoundDecl = FoundDecl; 5615 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 5616 Candidate.Viable = false; 5617 Candidate.FailureKind = ovl_fail_bad_deduction; 5618 Candidate.IsSurrogate = false; 5619 Candidate.IgnoreObjectArgument = false; 5620 Candidate.ExplicitCallArguments = Args.size(); 5621 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5622 Info); 5623 return; 5624 } 5625 5626 // Add the function template specialization produced by template argument 5627 // deduction as a candidate. 5628 assert(Specialization && "Missing function template specialization?"); 5629 AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet, 5630 SuppressUserConversions); 5631} 5632 5633/// AddConversionCandidate - Add a C++ conversion function as a 5634/// candidate in the candidate set (C++ [over.match.conv], 5635/// C++ [over.match.copy]). From is the expression we're converting from, 5636/// and ToType is the type that we're eventually trying to convert to 5637/// (which may or may not be the same type as the type that the 5638/// conversion function produces). 5639void 5640Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 5641 DeclAccessPair FoundDecl, 5642 CXXRecordDecl *ActingContext, 5643 Expr *From, QualType ToType, 5644 OverloadCandidateSet& CandidateSet) { 5645 assert(!Conversion->getDescribedFunctionTemplate() && 5646 "Conversion function templates use AddTemplateConversionCandidate"); 5647 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 5648 if (!CandidateSet.isNewCandidate(Conversion)) 5649 return; 5650 5651 // Overload resolution is always an unevaluated context. 5652 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5653 5654 // Add this candidate 5655 OverloadCandidate &Candidate = CandidateSet.addCandidate(1); 5656 Candidate.FoundDecl = FoundDecl; 5657 Candidate.Function = Conversion; 5658 Candidate.IsSurrogate = false; 5659 Candidate.IgnoreObjectArgument = false; 5660 Candidate.FinalConversion.setAsIdentityConversion(); 5661 Candidate.FinalConversion.setFromType(ConvType); 5662 Candidate.FinalConversion.setAllToTypes(ToType); 5663 Candidate.Viable = true; 5664 Candidate.ExplicitCallArguments = 1; 5665 5666 // C++ [over.match.funcs]p4: 5667 // For conversion functions, the function is considered to be a member of 5668 // the class of the implicit implied object argument for the purpose of 5669 // defining the type of the implicit object parameter. 5670 // 5671 // Determine the implicit conversion sequence for the implicit 5672 // object parameter. 5673 QualType ImplicitParamType = From->getType(); 5674 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 5675 ImplicitParamType = FromPtrType->getPointeeType(); 5676 CXXRecordDecl *ConversionContext 5677 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 5678 5679 Candidate.Conversions[0] 5680 = TryObjectArgumentInitialization(*this, From->getType(), 5681 From->Classify(Context), 5682 Conversion, ConversionContext); 5683 5684 if (Candidate.Conversions[0].isBad()) { 5685 Candidate.Viable = false; 5686 Candidate.FailureKind = ovl_fail_bad_conversion; 5687 return; 5688 } 5689 5690 // We won't go through a user-define type conversion function to convert a 5691 // derived to base as such conversions are given Conversion Rank. They only 5692 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 5693 QualType FromCanon 5694 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 5695 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 5696 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 5697 Candidate.Viable = false; 5698 Candidate.FailureKind = ovl_fail_trivial_conversion; 5699 return; 5700 } 5701 5702 // To determine what the conversion from the result of calling the 5703 // conversion function to the type we're eventually trying to 5704 // convert to (ToType), we need to synthesize a call to the 5705 // conversion function and attempt copy initialization from it. This 5706 // makes sure that we get the right semantics with respect to 5707 // lvalues/rvalues and the type. Fortunately, we can allocate this 5708 // call on the stack and we don't need its arguments to be 5709 // well-formed. 5710 DeclRefExpr ConversionRef(Conversion, false, Conversion->getType(), 5711 VK_LValue, From->getLocStart()); 5712 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 5713 Context.getPointerType(Conversion->getType()), 5714 CK_FunctionToPointerDecay, 5715 &ConversionRef, VK_RValue); 5716 5717 QualType ConversionType = Conversion->getConversionType(); 5718 if (RequireCompleteType(From->getLocStart(), ConversionType, 0)) { 5719 Candidate.Viable = false; 5720 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5721 return; 5722 } 5723 5724 ExprValueKind VK = Expr::getValueKindForType(ConversionType); 5725 5726 // Note that it is safe to allocate CallExpr on the stack here because 5727 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 5728 // allocator). 5729 QualType CallResultType = ConversionType.getNonLValueExprType(Context); 5730 CallExpr Call(Context, &ConversionFn, MultiExprArg(), CallResultType, VK, 5731 From->getLocStart()); 5732 ImplicitConversionSequence ICS = 5733 TryCopyInitialization(*this, &Call, ToType, 5734 /*SuppressUserConversions=*/true, 5735 /*InOverloadResolution=*/false, 5736 /*AllowObjCWritebackConversion=*/false); 5737 5738 switch (ICS.getKind()) { 5739 case ImplicitConversionSequence::StandardConversion: 5740 Candidate.FinalConversion = ICS.Standard; 5741 5742 // C++ [over.ics.user]p3: 5743 // If the user-defined conversion is specified by a specialization of a 5744 // conversion function template, the second standard conversion sequence 5745 // shall have exact match rank. 5746 if (Conversion->getPrimaryTemplate() && 5747 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 5748 Candidate.Viable = false; 5749 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 5750 } 5751 5752 // C++0x [dcl.init.ref]p5: 5753 // In the second case, if the reference is an rvalue reference and 5754 // the second standard conversion sequence of the user-defined 5755 // conversion sequence includes an lvalue-to-rvalue conversion, the 5756 // program is ill-formed. 5757 if (ToType->isRValueReferenceType() && 5758 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 5759 Candidate.Viable = false; 5760 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5761 } 5762 break; 5763 5764 case ImplicitConversionSequence::BadConversion: 5765 Candidate.Viable = false; 5766 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5767 break; 5768 5769 default: 5770 llvm_unreachable( 5771 "Can only end up with a standard conversion sequence or failure"); 5772 } 5773} 5774 5775/// \brief Adds a conversion function template specialization 5776/// candidate to the overload set, using template argument deduction 5777/// to deduce the template arguments of the conversion function 5778/// template from the type that we are converting to (C++ 5779/// [temp.deduct.conv]). 5780void 5781Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 5782 DeclAccessPair FoundDecl, 5783 CXXRecordDecl *ActingDC, 5784 Expr *From, QualType ToType, 5785 OverloadCandidateSet &CandidateSet) { 5786 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 5787 "Only conversion function templates permitted here"); 5788 5789 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 5790 return; 5791 5792 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5793 CXXConversionDecl *Specialization = 0; 5794 if (TemplateDeductionResult Result 5795 = DeduceTemplateArguments(FunctionTemplate, ToType, 5796 Specialization, Info)) { 5797 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5798 Candidate.FoundDecl = FoundDecl; 5799 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 5800 Candidate.Viable = false; 5801 Candidate.FailureKind = ovl_fail_bad_deduction; 5802 Candidate.IsSurrogate = false; 5803 Candidate.IgnoreObjectArgument = false; 5804 Candidate.ExplicitCallArguments = 1; 5805 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5806 Info); 5807 return; 5808 } 5809 5810 // Add the conversion function template specialization produced by 5811 // template argument deduction as a candidate. 5812 assert(Specialization && "Missing function template specialization?"); 5813 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 5814 CandidateSet); 5815} 5816 5817/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 5818/// converts the given @c Object to a function pointer via the 5819/// conversion function @c Conversion, and then attempts to call it 5820/// with the given arguments (C++ [over.call.object]p2-4). Proto is 5821/// the type of function that we'll eventually be calling. 5822void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 5823 DeclAccessPair FoundDecl, 5824 CXXRecordDecl *ActingContext, 5825 const FunctionProtoType *Proto, 5826 Expr *Object, 5827 llvm::ArrayRef<Expr *> Args, 5828 OverloadCandidateSet& CandidateSet) { 5829 if (!CandidateSet.isNewCandidate(Conversion)) 5830 return; 5831 5832 // Overload resolution is always an unevaluated context. 5833 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5834 5835 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); 5836 Candidate.FoundDecl = FoundDecl; 5837 Candidate.Function = 0; 5838 Candidate.Surrogate = Conversion; 5839 Candidate.Viable = true; 5840 Candidate.IsSurrogate = true; 5841 Candidate.IgnoreObjectArgument = false; 5842 Candidate.ExplicitCallArguments = Args.size(); 5843 5844 // Determine the implicit conversion sequence for the implicit 5845 // object parameter. 5846 ImplicitConversionSequence ObjectInit 5847 = TryObjectArgumentInitialization(*this, Object->getType(), 5848 Object->Classify(Context), 5849 Conversion, ActingContext); 5850 if (ObjectInit.isBad()) { 5851 Candidate.Viable = false; 5852 Candidate.FailureKind = ovl_fail_bad_conversion; 5853 Candidate.Conversions[0] = ObjectInit; 5854 return; 5855 } 5856 5857 // The first conversion is actually a user-defined conversion whose 5858 // first conversion is ObjectInit's standard conversion (which is 5859 // effectively a reference binding). Record it as such. 5860 Candidate.Conversions[0].setUserDefined(); 5861 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 5862 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 5863 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false; 5864 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 5865 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl; 5866 Candidate.Conversions[0].UserDefined.After 5867 = Candidate.Conversions[0].UserDefined.Before; 5868 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 5869 5870 // Find the 5871 unsigned NumArgsInProto = Proto->getNumArgs(); 5872 5873 // (C++ 13.3.2p2): A candidate function having fewer than m 5874 // parameters is viable only if it has an ellipsis in its parameter 5875 // list (8.3.5). 5876 if (Args.size() > NumArgsInProto && !Proto->isVariadic()) { 5877 Candidate.Viable = false; 5878 Candidate.FailureKind = ovl_fail_too_many_arguments; 5879 return; 5880 } 5881 5882 // Function types don't have any default arguments, so just check if 5883 // we have enough arguments. 5884 if (Args.size() < NumArgsInProto) { 5885 // Not enough arguments. 5886 Candidate.Viable = false; 5887 Candidate.FailureKind = ovl_fail_too_few_arguments; 5888 return; 5889 } 5890 5891 // Determine the implicit conversion sequences for each of the 5892 // arguments. 5893 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5894 if (ArgIdx < NumArgsInProto) { 5895 // (C++ 13.3.2p3): for F to be a viable function, there shall 5896 // exist for each argument an implicit conversion sequence 5897 // (13.3.3.1) that converts that argument to the corresponding 5898 // parameter of F. 5899 QualType ParamType = Proto->getArgType(ArgIdx); 5900 Candidate.Conversions[ArgIdx + 1] 5901 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5902 /*SuppressUserConversions=*/false, 5903 /*InOverloadResolution=*/false, 5904 /*AllowObjCWritebackConversion=*/ 5905 getLangOpts().ObjCAutoRefCount); 5906 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 5907 Candidate.Viable = false; 5908 Candidate.FailureKind = ovl_fail_bad_conversion; 5909 break; 5910 } 5911 } else { 5912 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5913 // argument for which there is no corresponding parameter is 5914 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5915 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 5916 } 5917 } 5918} 5919 5920/// \brief Add overload candidates for overloaded operators that are 5921/// member functions. 5922/// 5923/// Add the overloaded operator candidates that are member functions 5924/// for the operator Op that was used in an operator expression such 5925/// as "x Op y". , Args/NumArgs provides the operator arguments, and 5926/// CandidateSet will store the added overload candidates. (C++ 5927/// [over.match.oper]). 5928void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 5929 SourceLocation OpLoc, 5930 Expr **Args, unsigned NumArgs, 5931 OverloadCandidateSet& CandidateSet, 5932 SourceRange OpRange) { 5933 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5934 5935 // C++ [over.match.oper]p3: 5936 // For a unary operator @ with an operand of a type whose 5937 // cv-unqualified version is T1, and for a binary operator @ with 5938 // a left operand of a type whose cv-unqualified version is T1 and 5939 // a right operand of a type whose cv-unqualified version is T2, 5940 // three sets of candidate functions, designated member 5941 // candidates, non-member candidates and built-in candidates, are 5942 // constructed as follows: 5943 QualType T1 = Args[0]->getType(); 5944 5945 // -- If T1 is a class type, the set of member candidates is the 5946 // result of the qualified lookup of T1::operator@ 5947 // (13.3.1.1.1); otherwise, the set of member candidates is 5948 // empty. 5949 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 5950 // Complete the type if it can be completed. Otherwise, we're done. 5951 if (RequireCompleteType(OpLoc, T1, 0)) 5952 return; 5953 5954 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 5955 LookupQualifiedName(Operators, T1Rec->getDecl()); 5956 Operators.suppressDiagnostics(); 5957 5958 for (LookupResult::iterator Oper = Operators.begin(), 5959 OperEnd = Operators.end(); 5960 Oper != OperEnd; 5961 ++Oper) 5962 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 5963 Args[0]->Classify(Context), Args + 1, NumArgs - 1, 5964 CandidateSet, 5965 /* SuppressUserConversions = */ false); 5966 } 5967} 5968 5969/// AddBuiltinCandidate - Add a candidate for a built-in 5970/// operator. ResultTy and ParamTys are the result and parameter types 5971/// of the built-in candidate, respectively. Args and NumArgs are the 5972/// arguments being passed to the candidate. IsAssignmentOperator 5973/// should be true when this built-in candidate is an assignment 5974/// operator. NumContextualBoolArguments is the number of arguments 5975/// (at the beginning of the argument list) that will be contextually 5976/// converted to bool. 5977void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 5978 Expr **Args, unsigned NumArgs, 5979 OverloadCandidateSet& CandidateSet, 5980 bool IsAssignmentOperator, 5981 unsigned NumContextualBoolArguments) { 5982 // Overload resolution is always an unevaluated context. 5983 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5984 5985 // Add this candidate 5986 OverloadCandidate &Candidate = CandidateSet.addCandidate(NumArgs); 5987 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 5988 Candidate.Function = 0; 5989 Candidate.IsSurrogate = false; 5990 Candidate.IgnoreObjectArgument = false; 5991 Candidate.BuiltinTypes.ResultTy = ResultTy; 5992 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5993 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 5994 5995 // Determine the implicit conversion sequences for each of the 5996 // arguments. 5997 Candidate.Viable = true; 5998 Candidate.ExplicitCallArguments = NumArgs; 5999 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6000 // C++ [over.match.oper]p4: 6001 // For the built-in assignment operators, conversions of the 6002 // left operand are restricted as follows: 6003 // -- no temporaries are introduced to hold the left operand, and 6004 // -- no user-defined conversions are applied to the left 6005 // operand to achieve a type match with the left-most 6006 // parameter of a built-in candidate. 6007 // 6008 // We block these conversions by turning off user-defined 6009 // conversions, since that is the only way that initialization of 6010 // a reference to a non-class type can occur from something that 6011 // is not of the same type. 6012 if (ArgIdx < NumContextualBoolArguments) { 6013 assert(ParamTys[ArgIdx] == Context.BoolTy && 6014 "Contextual conversion to bool requires bool type"); 6015 Candidate.Conversions[ArgIdx] 6016 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 6017 } else { 6018 Candidate.Conversions[ArgIdx] 6019 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 6020 ArgIdx == 0 && IsAssignmentOperator, 6021 /*InOverloadResolution=*/false, 6022 /*AllowObjCWritebackConversion=*/ 6023 getLangOpts().ObjCAutoRefCount); 6024 } 6025 if (Candidate.Conversions[ArgIdx].isBad()) { 6026 Candidate.Viable = false; 6027 Candidate.FailureKind = ovl_fail_bad_conversion; 6028 break; 6029 } 6030 } 6031} 6032 6033/// BuiltinCandidateTypeSet - A set of types that will be used for the 6034/// candidate operator functions for built-in operators (C++ 6035/// [over.built]). The types are separated into pointer types and 6036/// enumeration types. 6037class BuiltinCandidateTypeSet { 6038 /// TypeSet - A set of types. 6039 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 6040 6041 /// PointerTypes - The set of pointer types that will be used in the 6042 /// built-in candidates. 6043 TypeSet PointerTypes; 6044 6045 /// MemberPointerTypes - The set of member pointer types that will be 6046 /// used in the built-in candidates. 6047 TypeSet MemberPointerTypes; 6048 6049 /// EnumerationTypes - The set of enumeration types that will be 6050 /// used in the built-in candidates. 6051 TypeSet EnumerationTypes; 6052 6053 /// \brief The set of vector types that will be used in the built-in 6054 /// candidates. 6055 TypeSet VectorTypes; 6056 6057 /// \brief A flag indicating non-record types are viable candidates 6058 bool HasNonRecordTypes; 6059 6060 /// \brief A flag indicating whether either arithmetic or enumeration types 6061 /// were present in the candidate set. 6062 bool HasArithmeticOrEnumeralTypes; 6063 6064 /// \brief A flag indicating whether the nullptr type was present in the 6065 /// candidate set. 6066 bool HasNullPtrType; 6067 6068 /// Sema - The semantic analysis instance where we are building the 6069 /// candidate type set. 6070 Sema &SemaRef; 6071 6072 /// Context - The AST context in which we will build the type sets. 6073 ASTContext &Context; 6074 6075 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 6076 const Qualifiers &VisibleQuals); 6077 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 6078 6079public: 6080 /// iterator - Iterates through the types that are part of the set. 6081 typedef TypeSet::iterator iterator; 6082 6083 BuiltinCandidateTypeSet(Sema &SemaRef) 6084 : HasNonRecordTypes(false), 6085 HasArithmeticOrEnumeralTypes(false), 6086 HasNullPtrType(false), 6087 SemaRef(SemaRef), 6088 Context(SemaRef.Context) { } 6089 6090 void AddTypesConvertedFrom(QualType Ty, 6091 SourceLocation Loc, 6092 bool AllowUserConversions, 6093 bool AllowExplicitConversions, 6094 const Qualifiers &VisibleTypeConversionsQuals); 6095 6096 /// pointer_begin - First pointer type found; 6097 iterator pointer_begin() { return PointerTypes.begin(); } 6098 6099 /// pointer_end - Past the last pointer type found; 6100 iterator pointer_end() { return PointerTypes.end(); } 6101 6102 /// member_pointer_begin - First member pointer type found; 6103 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 6104 6105 /// member_pointer_end - Past the last member pointer type found; 6106 iterator member_pointer_end() { return MemberPointerTypes.end(); } 6107 6108 /// enumeration_begin - First enumeration type found; 6109 iterator enumeration_begin() { return EnumerationTypes.begin(); } 6110 6111 /// enumeration_end - Past the last enumeration type found; 6112 iterator enumeration_end() { return EnumerationTypes.end(); } 6113 6114 iterator vector_begin() { return VectorTypes.begin(); } 6115 iterator vector_end() { return VectorTypes.end(); } 6116 6117 bool hasNonRecordTypes() { return HasNonRecordTypes; } 6118 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 6119 bool hasNullPtrType() const { return HasNullPtrType; } 6120}; 6121 6122/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 6123/// the set of pointer types along with any more-qualified variants of 6124/// that type. For example, if @p Ty is "int const *", this routine 6125/// will add "int const *", "int const volatile *", "int const 6126/// restrict *", and "int const volatile restrict *" to the set of 6127/// pointer types. Returns true if the add of @p Ty itself succeeded, 6128/// false otherwise. 6129/// 6130/// FIXME: what to do about extended qualifiers? 6131bool 6132BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 6133 const Qualifiers &VisibleQuals) { 6134 6135 // Insert this type. 6136 if (!PointerTypes.insert(Ty)) 6137 return false; 6138 6139 QualType PointeeTy; 6140 const PointerType *PointerTy = Ty->getAs<PointerType>(); 6141 bool buildObjCPtr = false; 6142 if (!PointerTy) { 6143 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>(); 6144 PointeeTy = PTy->getPointeeType(); 6145 buildObjCPtr = true; 6146 } else { 6147 PointeeTy = PointerTy->getPointeeType(); 6148 } 6149 6150 // Don't add qualified variants of arrays. For one, they're not allowed 6151 // (the qualifier would sink to the element type), and for another, the 6152 // only overload situation where it matters is subscript or pointer +- int, 6153 // and those shouldn't have qualifier variants anyway. 6154 if (PointeeTy->isArrayType()) 6155 return true; 6156 6157 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 6158 bool hasVolatile = VisibleQuals.hasVolatile(); 6159 bool hasRestrict = VisibleQuals.hasRestrict(); 6160 6161 // Iterate through all strict supersets of BaseCVR. 6162 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 6163 if ((CVR | BaseCVR) != CVR) continue; 6164 // Skip over volatile if no volatile found anywhere in the types. 6165 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 6166 6167 // Skip over restrict if no restrict found anywhere in the types, or if 6168 // the type cannot be restrict-qualified. 6169 if ((CVR & Qualifiers::Restrict) && 6170 (!hasRestrict || 6171 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType())))) 6172 continue; 6173 6174 // Build qualified pointee type. 6175 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 6176 6177 // Build qualified pointer type. 6178 QualType QPointerTy; 6179 if (!buildObjCPtr) 6180 QPointerTy = Context.getPointerType(QPointeeTy); 6181 else 6182 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy); 6183 6184 // Insert qualified pointer type. 6185 PointerTypes.insert(QPointerTy); 6186 } 6187 6188 return true; 6189} 6190 6191/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 6192/// to the set of pointer types along with any more-qualified variants of 6193/// that type. For example, if @p Ty is "int const *", this routine 6194/// will add "int const *", "int const volatile *", "int const 6195/// restrict *", and "int const volatile restrict *" to the set of 6196/// pointer types. Returns true if the add of @p Ty itself succeeded, 6197/// false otherwise. 6198/// 6199/// FIXME: what to do about extended qualifiers? 6200bool 6201BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 6202 QualType Ty) { 6203 // Insert this type. 6204 if (!MemberPointerTypes.insert(Ty)) 6205 return false; 6206 6207 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 6208 assert(PointerTy && "type was not a member pointer type!"); 6209 6210 QualType PointeeTy = PointerTy->getPointeeType(); 6211 // Don't add qualified variants of arrays. For one, they're not allowed 6212 // (the qualifier would sink to the element type), and for another, the 6213 // only overload situation where it matters is subscript or pointer +- int, 6214 // and those shouldn't have qualifier variants anyway. 6215 if (PointeeTy->isArrayType()) 6216 return true; 6217 const Type *ClassTy = PointerTy->getClass(); 6218 6219 // Iterate through all strict supersets of the pointee type's CVR 6220 // qualifiers. 6221 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 6222 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 6223 if ((CVR | BaseCVR) != CVR) continue; 6224 6225 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 6226 MemberPointerTypes.insert( 6227 Context.getMemberPointerType(QPointeeTy, ClassTy)); 6228 } 6229 6230 return true; 6231} 6232 6233/// AddTypesConvertedFrom - Add each of the types to which the type @p 6234/// Ty can be implicit converted to the given set of @p Types. We're 6235/// primarily interested in pointer types and enumeration types. We also 6236/// take member pointer types, for the conditional operator. 6237/// AllowUserConversions is true if we should look at the conversion 6238/// functions of a class type, and AllowExplicitConversions if we 6239/// should also include the explicit conversion functions of a class 6240/// type. 6241void 6242BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 6243 SourceLocation Loc, 6244 bool AllowUserConversions, 6245 bool AllowExplicitConversions, 6246 const Qualifiers &VisibleQuals) { 6247 // Only deal with canonical types. 6248 Ty = Context.getCanonicalType(Ty); 6249 6250 // Look through reference types; they aren't part of the type of an 6251 // expression for the purposes of conversions. 6252 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 6253 Ty = RefTy->getPointeeType(); 6254 6255 // If we're dealing with an array type, decay to the pointer. 6256 if (Ty->isArrayType()) 6257 Ty = SemaRef.Context.getArrayDecayedType(Ty); 6258 6259 // Otherwise, we don't care about qualifiers on the type. 6260 Ty = Ty.getLocalUnqualifiedType(); 6261 6262 // Flag if we ever add a non-record type. 6263 const RecordType *TyRec = Ty->getAs<RecordType>(); 6264 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 6265 6266 // Flag if we encounter an arithmetic type. 6267 HasArithmeticOrEnumeralTypes = 6268 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 6269 6270 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 6271 PointerTypes.insert(Ty); 6272 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 6273 // Insert our type, and its more-qualified variants, into the set 6274 // of types. 6275 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 6276 return; 6277 } else if (Ty->isMemberPointerType()) { 6278 // Member pointers are far easier, since the pointee can't be converted. 6279 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 6280 return; 6281 } else if (Ty->isEnumeralType()) { 6282 HasArithmeticOrEnumeralTypes = true; 6283 EnumerationTypes.insert(Ty); 6284 } else if (Ty->isVectorType()) { 6285 // We treat vector types as arithmetic types in many contexts as an 6286 // extension. 6287 HasArithmeticOrEnumeralTypes = true; 6288 VectorTypes.insert(Ty); 6289 } else if (Ty->isNullPtrType()) { 6290 HasNullPtrType = true; 6291 } else if (AllowUserConversions && TyRec) { 6292 // No conversion functions in incomplete types. 6293 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 6294 return; 6295 6296 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 6297 const UnresolvedSetImpl *Conversions 6298 = ClassDecl->getVisibleConversionFunctions(); 6299 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6300 E = Conversions->end(); I != E; ++I) { 6301 NamedDecl *D = I.getDecl(); 6302 if (isa<UsingShadowDecl>(D)) 6303 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6304 6305 // Skip conversion function templates; they don't tell us anything 6306 // about which builtin types we can convert to. 6307 if (isa<FunctionTemplateDecl>(D)) 6308 continue; 6309 6310 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6311 if (AllowExplicitConversions || !Conv->isExplicit()) { 6312 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 6313 VisibleQuals); 6314 } 6315 } 6316 } 6317} 6318 6319/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 6320/// the volatile- and non-volatile-qualified assignment operators for the 6321/// given type to the candidate set. 6322static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 6323 QualType T, 6324 Expr **Args, 6325 unsigned NumArgs, 6326 OverloadCandidateSet &CandidateSet) { 6327 QualType ParamTypes[2]; 6328 6329 // T& operator=(T&, T) 6330 ParamTypes[0] = S.Context.getLValueReferenceType(T); 6331 ParamTypes[1] = T; 6332 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6333 /*IsAssignmentOperator=*/true); 6334 6335 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 6336 // volatile T& operator=(volatile T&, T) 6337 ParamTypes[0] 6338 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 6339 ParamTypes[1] = T; 6340 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6341 /*IsAssignmentOperator=*/true); 6342 } 6343} 6344 6345/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 6346/// if any, found in visible type conversion functions found in ArgExpr's type. 6347static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 6348 Qualifiers VRQuals; 6349 const RecordType *TyRec; 6350 if (const MemberPointerType *RHSMPType = 6351 ArgExpr->getType()->getAs<MemberPointerType>()) 6352 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 6353 else 6354 TyRec = ArgExpr->getType()->getAs<RecordType>(); 6355 if (!TyRec) { 6356 // Just to be safe, assume the worst case. 6357 VRQuals.addVolatile(); 6358 VRQuals.addRestrict(); 6359 return VRQuals; 6360 } 6361 6362 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 6363 if (!ClassDecl->hasDefinition()) 6364 return VRQuals; 6365 6366 const UnresolvedSetImpl *Conversions = 6367 ClassDecl->getVisibleConversionFunctions(); 6368 6369 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6370 E = Conversions->end(); I != E; ++I) { 6371 NamedDecl *D = I.getDecl(); 6372 if (isa<UsingShadowDecl>(D)) 6373 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6374 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 6375 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 6376 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 6377 CanTy = ResTypeRef->getPointeeType(); 6378 // Need to go down the pointer/mempointer chain and add qualifiers 6379 // as see them. 6380 bool done = false; 6381 while (!done) { 6382 if (CanTy.isRestrictQualified()) 6383 VRQuals.addRestrict(); 6384 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 6385 CanTy = ResTypePtr->getPointeeType(); 6386 else if (const MemberPointerType *ResTypeMPtr = 6387 CanTy->getAs<MemberPointerType>()) 6388 CanTy = ResTypeMPtr->getPointeeType(); 6389 else 6390 done = true; 6391 if (CanTy.isVolatileQualified()) 6392 VRQuals.addVolatile(); 6393 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 6394 return VRQuals; 6395 } 6396 } 6397 } 6398 return VRQuals; 6399} 6400 6401namespace { 6402 6403/// \brief Helper class to manage the addition of builtin operator overload 6404/// candidates. It provides shared state and utility methods used throughout 6405/// the process, as well as a helper method to add each group of builtin 6406/// operator overloads from the standard to a candidate set. 6407class BuiltinOperatorOverloadBuilder { 6408 // Common instance state available to all overload candidate addition methods. 6409 Sema &S; 6410 Expr **Args; 6411 unsigned NumArgs; 6412 Qualifiers VisibleTypeConversionsQuals; 6413 bool HasArithmeticOrEnumeralCandidateType; 6414 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 6415 OverloadCandidateSet &CandidateSet; 6416 6417 // Define some constants used to index and iterate over the arithemetic types 6418 // provided via the getArithmeticType() method below. 6419 // The "promoted arithmetic types" are the arithmetic 6420 // types are that preserved by promotion (C++ [over.built]p2). 6421 static const unsigned FirstIntegralType = 3; 6422 static const unsigned LastIntegralType = 20; 6423 static const unsigned FirstPromotedIntegralType = 3, 6424 LastPromotedIntegralType = 11; 6425 static const unsigned FirstPromotedArithmeticType = 0, 6426 LastPromotedArithmeticType = 11; 6427 static const unsigned NumArithmeticTypes = 20; 6428 6429 /// \brief Get the canonical type for a given arithmetic type index. 6430 CanQualType getArithmeticType(unsigned index) { 6431 assert(index < NumArithmeticTypes); 6432 static CanQualType ASTContext::* const 6433 ArithmeticTypes[NumArithmeticTypes] = { 6434 // Start of promoted types. 6435 &ASTContext::FloatTy, 6436 &ASTContext::DoubleTy, 6437 &ASTContext::LongDoubleTy, 6438 6439 // Start of integral types. 6440 &ASTContext::IntTy, 6441 &ASTContext::LongTy, 6442 &ASTContext::LongLongTy, 6443 &ASTContext::Int128Ty, 6444 &ASTContext::UnsignedIntTy, 6445 &ASTContext::UnsignedLongTy, 6446 &ASTContext::UnsignedLongLongTy, 6447 &ASTContext::UnsignedInt128Ty, 6448 // End of promoted types. 6449 6450 &ASTContext::BoolTy, 6451 &ASTContext::CharTy, 6452 &ASTContext::WCharTy, 6453 &ASTContext::Char16Ty, 6454 &ASTContext::Char32Ty, 6455 &ASTContext::SignedCharTy, 6456 &ASTContext::ShortTy, 6457 &ASTContext::UnsignedCharTy, 6458 &ASTContext::UnsignedShortTy, 6459 // End of integral types. 6460 // FIXME: What about complex? What about half? 6461 }; 6462 return S.Context.*ArithmeticTypes[index]; 6463 } 6464 6465 /// \brief Gets the canonical type resulting from the usual arithemetic 6466 /// converions for the given arithmetic types. 6467 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 6468 // Accelerator table for performing the usual arithmetic conversions. 6469 // The rules are basically: 6470 // - if either is floating-point, use the wider floating-point 6471 // - if same signedness, use the higher rank 6472 // - if same size, use unsigned of the higher rank 6473 // - use the larger type 6474 // These rules, together with the axiom that higher ranks are 6475 // never smaller, are sufficient to precompute all of these results 6476 // *except* when dealing with signed types of higher rank. 6477 // (we could precompute SLL x UI for all known platforms, but it's 6478 // better not to make any assumptions). 6479 // We assume that int128 has a higher rank than long long on all platforms. 6480 enum PromotedType { 6481 Dep=-1, 6482 Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 6483 }; 6484 static const PromotedType ConversionsTable[LastPromotedArithmeticType] 6485 [LastPromotedArithmeticType] = { 6486/* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt, Flt, Flt }, 6487/* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 6488/*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 6489/* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 }, 6490/* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, S128, Dep, UL, ULL, U128 }, 6491/* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, S128, Dep, Dep, ULL, U128 }, 6492/*S128*/ { Flt, Dbl, LDbl, S128, S128, S128, S128, S128, S128, S128, U128 }, 6493/* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, S128, UI, UL, ULL, U128 }, 6494/* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, S128, UL, UL, ULL, U128 }, 6495/* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, S128, ULL, ULL, ULL, U128 }, 6496/*U128*/ { Flt, Dbl, LDbl, U128, U128, U128, U128, U128, U128, U128, U128 }, 6497 }; 6498 6499 assert(L < LastPromotedArithmeticType); 6500 assert(R < LastPromotedArithmeticType); 6501 int Idx = ConversionsTable[L][R]; 6502 6503 // Fast path: the table gives us a concrete answer. 6504 if (Idx != Dep) return getArithmeticType(Idx); 6505 6506 // Slow path: we need to compare widths. 6507 // An invariant is that the signed type has higher rank. 6508 CanQualType LT = getArithmeticType(L), 6509 RT = getArithmeticType(R); 6510 unsigned LW = S.Context.getIntWidth(LT), 6511 RW = S.Context.getIntWidth(RT); 6512 6513 // If they're different widths, use the signed type. 6514 if (LW > RW) return LT; 6515 else if (LW < RW) return RT; 6516 6517 // Otherwise, use the unsigned type of the signed type's rank. 6518 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 6519 assert(L == SLL || R == SLL); 6520 return S.Context.UnsignedLongLongTy; 6521 } 6522 6523 /// \brief Helper method to factor out the common pattern of adding overloads 6524 /// for '++' and '--' builtin operators. 6525 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 6526 bool HasVolatile, 6527 bool HasRestrict) { 6528 QualType ParamTypes[2] = { 6529 S.Context.getLValueReferenceType(CandidateTy), 6530 S.Context.IntTy 6531 }; 6532 6533 // Non-volatile version. 6534 if (NumArgs == 1) 6535 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 6536 else 6537 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 6538 6539 // Use a heuristic to reduce number of builtin candidates in the set: 6540 // add volatile version only if there are conversions to a volatile type. 6541 if (HasVolatile) { 6542 ParamTypes[0] = 6543 S.Context.getLValueReferenceType( 6544 S.Context.getVolatileType(CandidateTy)); 6545 if (NumArgs == 1) 6546 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 6547 else 6548 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 6549 } 6550 6551 // Add restrict version only if there are conversions to a restrict type 6552 // and our candidate type is a non-restrict-qualified pointer. 6553 if (HasRestrict && CandidateTy->isAnyPointerType() && 6554 !CandidateTy.isRestrictQualified()) { 6555 ParamTypes[0] 6556 = S.Context.getLValueReferenceType( 6557 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict)); 6558 if (NumArgs == 1) 6559 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 6560 else 6561 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 6562 6563 if (HasVolatile) { 6564 ParamTypes[0] 6565 = S.Context.getLValueReferenceType( 6566 S.Context.getCVRQualifiedType(CandidateTy, 6567 (Qualifiers::Volatile | 6568 Qualifiers::Restrict))); 6569 if (NumArgs == 1) 6570 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, 6571 CandidateSet); 6572 else 6573 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 6574 } 6575 } 6576 6577 } 6578 6579public: 6580 BuiltinOperatorOverloadBuilder( 6581 Sema &S, Expr **Args, unsigned NumArgs, 6582 Qualifiers VisibleTypeConversionsQuals, 6583 bool HasArithmeticOrEnumeralCandidateType, 6584 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 6585 OverloadCandidateSet &CandidateSet) 6586 : S(S), Args(Args), NumArgs(NumArgs), 6587 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 6588 HasArithmeticOrEnumeralCandidateType( 6589 HasArithmeticOrEnumeralCandidateType), 6590 CandidateTypes(CandidateTypes), 6591 CandidateSet(CandidateSet) { 6592 // Validate some of our static helper constants in debug builds. 6593 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 6594 "Invalid first promoted integral type"); 6595 assert(getArithmeticType(LastPromotedIntegralType - 1) 6596 == S.Context.UnsignedInt128Ty && 6597 "Invalid last promoted integral type"); 6598 assert(getArithmeticType(FirstPromotedArithmeticType) 6599 == S.Context.FloatTy && 6600 "Invalid first promoted arithmetic type"); 6601 assert(getArithmeticType(LastPromotedArithmeticType - 1) 6602 == S.Context.UnsignedInt128Ty && 6603 "Invalid last promoted arithmetic type"); 6604 } 6605 6606 // C++ [over.built]p3: 6607 // 6608 // For every pair (T, VQ), where T is an arithmetic type, and VQ 6609 // is either volatile or empty, there exist candidate operator 6610 // functions of the form 6611 // 6612 // VQ T& operator++(VQ T&); 6613 // T operator++(VQ T&, int); 6614 // 6615 // C++ [over.built]p4: 6616 // 6617 // For every pair (T, VQ), where T is an arithmetic type other 6618 // than bool, and VQ is either volatile or empty, there exist 6619 // candidate operator functions of the form 6620 // 6621 // VQ T& operator--(VQ T&); 6622 // T operator--(VQ T&, int); 6623 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 6624 if (!HasArithmeticOrEnumeralCandidateType) 6625 return; 6626 6627 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 6628 Arith < NumArithmeticTypes; ++Arith) { 6629 addPlusPlusMinusMinusStyleOverloads( 6630 getArithmeticType(Arith), 6631 VisibleTypeConversionsQuals.hasVolatile(), 6632 VisibleTypeConversionsQuals.hasRestrict()); 6633 } 6634 } 6635 6636 // C++ [over.built]p5: 6637 // 6638 // For every pair (T, VQ), where T is a cv-qualified or 6639 // cv-unqualified object type, and VQ is either volatile or 6640 // empty, there exist candidate operator functions of the form 6641 // 6642 // T*VQ& operator++(T*VQ&); 6643 // T*VQ& operator--(T*VQ&); 6644 // T* operator++(T*VQ&, int); 6645 // T* operator--(T*VQ&, int); 6646 void addPlusPlusMinusMinusPointerOverloads() { 6647 for (BuiltinCandidateTypeSet::iterator 6648 Ptr = CandidateTypes[0].pointer_begin(), 6649 PtrEnd = CandidateTypes[0].pointer_end(); 6650 Ptr != PtrEnd; ++Ptr) { 6651 // Skip pointer types that aren't pointers to object types. 6652 if (!(*Ptr)->getPointeeType()->isObjectType()) 6653 continue; 6654 6655 addPlusPlusMinusMinusStyleOverloads(*Ptr, 6656 (!(*Ptr).isVolatileQualified() && 6657 VisibleTypeConversionsQuals.hasVolatile()), 6658 (!(*Ptr).isRestrictQualified() && 6659 VisibleTypeConversionsQuals.hasRestrict())); 6660 } 6661 } 6662 6663 // C++ [over.built]p6: 6664 // For every cv-qualified or cv-unqualified object type T, there 6665 // exist candidate operator functions of the form 6666 // 6667 // T& operator*(T*); 6668 // 6669 // C++ [over.built]p7: 6670 // For every function type T that does not have cv-qualifiers or a 6671 // ref-qualifier, there exist candidate operator functions of the form 6672 // T& operator*(T*); 6673 void addUnaryStarPointerOverloads() { 6674 for (BuiltinCandidateTypeSet::iterator 6675 Ptr = CandidateTypes[0].pointer_begin(), 6676 PtrEnd = CandidateTypes[0].pointer_end(); 6677 Ptr != PtrEnd; ++Ptr) { 6678 QualType ParamTy = *Ptr; 6679 QualType PointeeTy = ParamTy->getPointeeType(); 6680 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 6681 continue; 6682 6683 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 6684 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 6685 continue; 6686 6687 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 6688 &ParamTy, Args, 1, CandidateSet); 6689 } 6690 } 6691 6692 // C++ [over.built]p9: 6693 // For every promoted arithmetic type T, there exist candidate 6694 // operator functions of the form 6695 // 6696 // T operator+(T); 6697 // T operator-(T); 6698 void addUnaryPlusOrMinusArithmeticOverloads() { 6699 if (!HasArithmeticOrEnumeralCandidateType) 6700 return; 6701 6702 for (unsigned Arith = FirstPromotedArithmeticType; 6703 Arith < LastPromotedArithmeticType; ++Arith) { 6704 QualType ArithTy = getArithmeticType(Arith); 6705 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 6706 } 6707 6708 // Extension: We also add these operators for vector types. 6709 for (BuiltinCandidateTypeSet::iterator 6710 Vec = CandidateTypes[0].vector_begin(), 6711 VecEnd = CandidateTypes[0].vector_end(); 6712 Vec != VecEnd; ++Vec) { 6713 QualType VecTy = *Vec; 6714 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 6715 } 6716 } 6717 6718 // C++ [over.built]p8: 6719 // For every type T, there exist candidate operator functions of 6720 // the form 6721 // 6722 // T* operator+(T*); 6723 void addUnaryPlusPointerOverloads() { 6724 for (BuiltinCandidateTypeSet::iterator 6725 Ptr = CandidateTypes[0].pointer_begin(), 6726 PtrEnd = CandidateTypes[0].pointer_end(); 6727 Ptr != PtrEnd; ++Ptr) { 6728 QualType ParamTy = *Ptr; 6729 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 6730 } 6731 } 6732 6733 // C++ [over.built]p10: 6734 // For every promoted integral type T, there exist candidate 6735 // operator functions of the form 6736 // 6737 // T operator~(T); 6738 void addUnaryTildePromotedIntegralOverloads() { 6739 if (!HasArithmeticOrEnumeralCandidateType) 6740 return; 6741 6742 for (unsigned Int = FirstPromotedIntegralType; 6743 Int < LastPromotedIntegralType; ++Int) { 6744 QualType IntTy = getArithmeticType(Int); 6745 S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 6746 } 6747 6748 // Extension: We also add this operator for vector types. 6749 for (BuiltinCandidateTypeSet::iterator 6750 Vec = CandidateTypes[0].vector_begin(), 6751 VecEnd = CandidateTypes[0].vector_end(); 6752 Vec != VecEnd; ++Vec) { 6753 QualType VecTy = *Vec; 6754 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 6755 } 6756 } 6757 6758 // C++ [over.match.oper]p16: 6759 // For every pointer to member type T, there exist candidate operator 6760 // functions of the form 6761 // 6762 // bool operator==(T,T); 6763 // bool operator!=(T,T); 6764 void addEqualEqualOrNotEqualMemberPointerOverloads() { 6765 /// Set of (canonical) types that we've already handled. 6766 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6767 6768 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6769 for (BuiltinCandidateTypeSet::iterator 6770 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 6771 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 6772 MemPtr != MemPtrEnd; 6773 ++MemPtr) { 6774 // Don't add the same builtin candidate twice. 6775 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 6776 continue; 6777 6778 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 6779 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6780 CandidateSet); 6781 } 6782 } 6783 } 6784 6785 // C++ [over.built]p15: 6786 // 6787 // For every T, where T is an enumeration type, a pointer type, or 6788 // std::nullptr_t, there exist candidate operator functions of the form 6789 // 6790 // bool operator<(T, T); 6791 // bool operator>(T, T); 6792 // bool operator<=(T, T); 6793 // bool operator>=(T, T); 6794 // bool operator==(T, T); 6795 // bool operator!=(T, T); 6796 void addRelationalPointerOrEnumeralOverloads() { 6797 // C++ [over.match.oper]p3: 6798 // [...]the built-in candidates include all of the candidate operator 6799 // functions defined in 13.6 that, compared to the given operator, [...] 6800 // do not have the same parameter-type-list as any non-template non-member 6801 // candidate. 6802 // 6803 // Note that in practice, this only affects enumeration types because there 6804 // aren't any built-in candidates of record type, and a user-defined operator 6805 // must have an operand of record or enumeration type. Also, the only other 6806 // overloaded operator with enumeration arguments, operator=, 6807 // cannot be overloaded for enumeration types, so this is the only place 6808 // where we must suppress candidates like this. 6809 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 6810 UserDefinedBinaryOperators; 6811 6812 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6813 if (CandidateTypes[ArgIdx].enumeration_begin() != 6814 CandidateTypes[ArgIdx].enumeration_end()) { 6815 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 6816 CEnd = CandidateSet.end(); 6817 C != CEnd; ++C) { 6818 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 6819 continue; 6820 6821 if (C->Function->isFunctionTemplateSpecialization()) 6822 continue; 6823 6824 QualType FirstParamType = 6825 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 6826 QualType SecondParamType = 6827 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 6828 6829 // Skip if either parameter isn't of enumeral type. 6830 if (!FirstParamType->isEnumeralType() || 6831 !SecondParamType->isEnumeralType()) 6832 continue; 6833 6834 // Add this operator to the set of known user-defined operators. 6835 UserDefinedBinaryOperators.insert( 6836 std::make_pair(S.Context.getCanonicalType(FirstParamType), 6837 S.Context.getCanonicalType(SecondParamType))); 6838 } 6839 } 6840 } 6841 6842 /// Set of (canonical) types that we've already handled. 6843 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6844 6845 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6846 for (BuiltinCandidateTypeSet::iterator 6847 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 6848 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 6849 Ptr != PtrEnd; ++Ptr) { 6850 // Don't add the same builtin candidate twice. 6851 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6852 continue; 6853 6854 QualType ParamTypes[2] = { *Ptr, *Ptr }; 6855 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6856 CandidateSet); 6857 } 6858 for (BuiltinCandidateTypeSet::iterator 6859 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 6860 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 6861 Enum != EnumEnd; ++Enum) { 6862 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 6863 6864 // Don't add the same builtin candidate twice, or if a user defined 6865 // candidate exists. 6866 if (!AddedTypes.insert(CanonType) || 6867 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 6868 CanonType))) 6869 continue; 6870 6871 QualType ParamTypes[2] = { *Enum, *Enum }; 6872 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6873 CandidateSet); 6874 } 6875 6876 if (CandidateTypes[ArgIdx].hasNullPtrType()) { 6877 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy); 6878 if (AddedTypes.insert(NullPtrTy) && 6879 !UserDefinedBinaryOperators.count(std::make_pair(NullPtrTy, 6880 NullPtrTy))) { 6881 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy }; 6882 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6883 CandidateSet); 6884 } 6885 } 6886 } 6887 } 6888 6889 // C++ [over.built]p13: 6890 // 6891 // For every cv-qualified or cv-unqualified object type T 6892 // there exist candidate operator functions of the form 6893 // 6894 // T* operator+(T*, ptrdiff_t); 6895 // T& operator[](T*, ptrdiff_t); [BELOW] 6896 // T* operator-(T*, ptrdiff_t); 6897 // T* operator+(ptrdiff_t, T*); 6898 // T& operator[](ptrdiff_t, T*); [BELOW] 6899 // 6900 // C++ [over.built]p14: 6901 // 6902 // For every T, where T is a pointer to object type, there 6903 // exist candidate operator functions of the form 6904 // 6905 // ptrdiff_t operator-(T, T); 6906 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 6907 /// Set of (canonical) types that we've already handled. 6908 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6909 6910 for (int Arg = 0; Arg < 2; ++Arg) { 6911 QualType AsymetricParamTypes[2] = { 6912 S.Context.getPointerDiffType(), 6913 S.Context.getPointerDiffType(), 6914 }; 6915 for (BuiltinCandidateTypeSet::iterator 6916 Ptr = CandidateTypes[Arg].pointer_begin(), 6917 PtrEnd = CandidateTypes[Arg].pointer_end(); 6918 Ptr != PtrEnd; ++Ptr) { 6919 QualType PointeeTy = (*Ptr)->getPointeeType(); 6920 if (!PointeeTy->isObjectType()) 6921 continue; 6922 6923 AsymetricParamTypes[Arg] = *Ptr; 6924 if (Arg == 0 || Op == OO_Plus) { 6925 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 6926 // T* operator+(ptrdiff_t, T*); 6927 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, 6928 CandidateSet); 6929 } 6930 if (Op == OO_Minus) { 6931 // ptrdiff_t operator-(T, T); 6932 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6933 continue; 6934 6935 QualType ParamTypes[2] = { *Ptr, *Ptr }; 6936 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 6937 Args, 2, CandidateSet); 6938 } 6939 } 6940 } 6941 } 6942 6943 // C++ [over.built]p12: 6944 // 6945 // For every pair of promoted arithmetic types L and R, there 6946 // exist candidate operator functions of the form 6947 // 6948 // LR operator*(L, R); 6949 // LR operator/(L, R); 6950 // LR operator+(L, R); 6951 // LR operator-(L, R); 6952 // bool operator<(L, R); 6953 // bool operator>(L, R); 6954 // bool operator<=(L, R); 6955 // bool operator>=(L, R); 6956 // bool operator==(L, R); 6957 // bool operator!=(L, R); 6958 // 6959 // where LR is the result of the usual arithmetic conversions 6960 // between types L and R. 6961 // 6962 // C++ [over.built]p24: 6963 // 6964 // For every pair of promoted arithmetic types L and R, there exist 6965 // candidate operator functions of the form 6966 // 6967 // LR operator?(bool, L, R); 6968 // 6969 // where LR is the result of the usual arithmetic conversions 6970 // between types L and R. 6971 // Our candidates ignore the first parameter. 6972 void addGenericBinaryArithmeticOverloads(bool isComparison) { 6973 if (!HasArithmeticOrEnumeralCandidateType) 6974 return; 6975 6976 for (unsigned Left = FirstPromotedArithmeticType; 6977 Left < LastPromotedArithmeticType; ++Left) { 6978 for (unsigned Right = FirstPromotedArithmeticType; 6979 Right < LastPromotedArithmeticType; ++Right) { 6980 QualType LandR[2] = { getArithmeticType(Left), 6981 getArithmeticType(Right) }; 6982 QualType Result = 6983 isComparison ? S.Context.BoolTy 6984 : getUsualArithmeticConversions(Left, Right); 6985 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 6986 } 6987 } 6988 6989 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 6990 // conditional operator for vector types. 6991 for (BuiltinCandidateTypeSet::iterator 6992 Vec1 = CandidateTypes[0].vector_begin(), 6993 Vec1End = CandidateTypes[0].vector_end(); 6994 Vec1 != Vec1End; ++Vec1) { 6995 for (BuiltinCandidateTypeSet::iterator 6996 Vec2 = CandidateTypes[1].vector_begin(), 6997 Vec2End = CandidateTypes[1].vector_end(); 6998 Vec2 != Vec2End; ++Vec2) { 6999 QualType LandR[2] = { *Vec1, *Vec2 }; 7000 QualType Result = S.Context.BoolTy; 7001 if (!isComparison) { 7002 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 7003 Result = *Vec1; 7004 else 7005 Result = *Vec2; 7006 } 7007 7008 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 7009 } 7010 } 7011 } 7012 7013 // C++ [over.built]p17: 7014 // 7015 // For every pair of promoted integral types L and R, there 7016 // exist candidate operator functions of the form 7017 // 7018 // LR operator%(L, R); 7019 // LR operator&(L, R); 7020 // LR operator^(L, R); 7021 // LR operator|(L, R); 7022 // L operator<<(L, R); 7023 // L operator>>(L, R); 7024 // 7025 // where LR is the result of the usual arithmetic conversions 7026 // between types L and R. 7027 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 7028 if (!HasArithmeticOrEnumeralCandidateType) 7029 return; 7030 7031 for (unsigned Left = FirstPromotedIntegralType; 7032 Left < LastPromotedIntegralType; ++Left) { 7033 for (unsigned Right = FirstPromotedIntegralType; 7034 Right < LastPromotedIntegralType; ++Right) { 7035 QualType LandR[2] = { getArithmeticType(Left), 7036 getArithmeticType(Right) }; 7037 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 7038 ? LandR[0] 7039 : getUsualArithmeticConversions(Left, Right); 7040 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 7041 } 7042 } 7043 } 7044 7045 // C++ [over.built]p20: 7046 // 7047 // For every pair (T, VQ), where T is an enumeration or 7048 // pointer to member type and VQ is either volatile or 7049 // empty, there exist candidate operator functions of the form 7050 // 7051 // VQ T& operator=(VQ T&, T); 7052 void addAssignmentMemberPointerOrEnumeralOverloads() { 7053 /// Set of (canonical) types that we've already handled. 7054 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7055 7056 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 7057 for (BuiltinCandidateTypeSet::iterator 7058 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 7059 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 7060 Enum != EnumEnd; ++Enum) { 7061 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 7062 continue; 7063 7064 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, 7065 CandidateSet); 7066 } 7067 7068 for (BuiltinCandidateTypeSet::iterator 7069 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 7070 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 7071 MemPtr != MemPtrEnd; ++MemPtr) { 7072 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 7073 continue; 7074 7075 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, 7076 CandidateSet); 7077 } 7078 } 7079 } 7080 7081 // C++ [over.built]p19: 7082 // 7083 // For every pair (T, VQ), where T is any type and VQ is either 7084 // volatile or empty, there exist candidate operator functions 7085 // of the form 7086 // 7087 // T*VQ& operator=(T*VQ&, T*); 7088 // 7089 // C++ [over.built]p21: 7090 // 7091 // For every pair (T, VQ), where T is a cv-qualified or 7092 // cv-unqualified object type and VQ is either volatile or 7093 // empty, there exist candidate operator functions of the form 7094 // 7095 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 7096 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 7097 void addAssignmentPointerOverloads(bool isEqualOp) { 7098 /// Set of (canonical) types that we've already handled. 7099 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7100 7101 for (BuiltinCandidateTypeSet::iterator 7102 Ptr = CandidateTypes[0].pointer_begin(), 7103 PtrEnd = CandidateTypes[0].pointer_end(); 7104 Ptr != PtrEnd; ++Ptr) { 7105 // If this is operator=, keep track of the builtin candidates we added. 7106 if (isEqualOp) 7107 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 7108 else if (!(*Ptr)->getPointeeType()->isObjectType()) 7109 continue; 7110 7111 // non-volatile version 7112 QualType ParamTypes[2] = { 7113 S.Context.getLValueReferenceType(*Ptr), 7114 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 7115 }; 7116 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7117 /*IsAssigmentOperator=*/ isEqualOp); 7118 7119 bool NeedVolatile = !(*Ptr).isVolatileQualified() && 7120 VisibleTypeConversionsQuals.hasVolatile(); 7121 if (NeedVolatile) { 7122 // volatile version 7123 ParamTypes[0] = 7124 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 7125 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7126 /*IsAssigmentOperator=*/isEqualOp); 7127 } 7128 7129 if (!(*Ptr).isRestrictQualified() && 7130 VisibleTypeConversionsQuals.hasRestrict()) { 7131 // restrict version 7132 ParamTypes[0] 7133 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr)); 7134 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7135 /*IsAssigmentOperator=*/isEqualOp); 7136 7137 if (NeedVolatile) { 7138 // volatile restrict version 7139 ParamTypes[0] 7140 = S.Context.getLValueReferenceType( 7141 S.Context.getCVRQualifiedType(*Ptr, 7142 (Qualifiers::Volatile | 7143 Qualifiers::Restrict))); 7144 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7145 CandidateSet, 7146 /*IsAssigmentOperator=*/isEqualOp); 7147 } 7148 } 7149 } 7150 7151 if (isEqualOp) { 7152 for (BuiltinCandidateTypeSet::iterator 7153 Ptr = CandidateTypes[1].pointer_begin(), 7154 PtrEnd = CandidateTypes[1].pointer_end(); 7155 Ptr != PtrEnd; ++Ptr) { 7156 // Make sure we don't add the same candidate twice. 7157 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7158 continue; 7159 7160 QualType ParamTypes[2] = { 7161 S.Context.getLValueReferenceType(*Ptr), 7162 *Ptr, 7163 }; 7164 7165 // non-volatile version 7166 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7167 /*IsAssigmentOperator=*/true); 7168 7169 bool NeedVolatile = !(*Ptr).isVolatileQualified() && 7170 VisibleTypeConversionsQuals.hasVolatile(); 7171 if (NeedVolatile) { 7172 // volatile version 7173 ParamTypes[0] = 7174 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 7175 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7176 CandidateSet, /*IsAssigmentOperator=*/true); 7177 } 7178 7179 if (!(*Ptr).isRestrictQualified() && 7180 VisibleTypeConversionsQuals.hasRestrict()) { 7181 // restrict version 7182 ParamTypes[0] 7183 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr)); 7184 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7185 CandidateSet, /*IsAssigmentOperator=*/true); 7186 7187 if (NeedVolatile) { 7188 // volatile restrict version 7189 ParamTypes[0] 7190 = S.Context.getLValueReferenceType( 7191 S.Context.getCVRQualifiedType(*Ptr, 7192 (Qualifiers::Volatile | 7193 Qualifiers::Restrict))); 7194 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7195 CandidateSet, /*IsAssigmentOperator=*/true); 7196 7197 } 7198 } 7199 } 7200 } 7201 } 7202 7203 // C++ [over.built]p18: 7204 // 7205 // For every triple (L, VQ, R), where L is an arithmetic type, 7206 // VQ is either volatile or empty, and R is a promoted 7207 // arithmetic type, there exist candidate operator functions of 7208 // the form 7209 // 7210 // VQ L& operator=(VQ L&, R); 7211 // VQ L& operator*=(VQ L&, R); 7212 // VQ L& operator/=(VQ L&, R); 7213 // VQ L& operator+=(VQ L&, R); 7214 // VQ L& operator-=(VQ L&, R); 7215 void addAssignmentArithmeticOverloads(bool isEqualOp) { 7216 if (!HasArithmeticOrEnumeralCandidateType) 7217 return; 7218 7219 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 7220 for (unsigned Right = FirstPromotedArithmeticType; 7221 Right < LastPromotedArithmeticType; ++Right) { 7222 QualType ParamTypes[2]; 7223 ParamTypes[1] = getArithmeticType(Right); 7224 7225 // Add this built-in operator as a candidate (VQ is empty). 7226 ParamTypes[0] = 7227 S.Context.getLValueReferenceType(getArithmeticType(Left)); 7228 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7229 /*IsAssigmentOperator=*/isEqualOp); 7230 7231 // Add this built-in operator as a candidate (VQ is 'volatile'). 7232 if (VisibleTypeConversionsQuals.hasVolatile()) { 7233 ParamTypes[0] = 7234 S.Context.getVolatileType(getArithmeticType(Left)); 7235 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7236 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7237 CandidateSet, 7238 /*IsAssigmentOperator=*/isEqualOp); 7239 } 7240 } 7241 } 7242 7243 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 7244 for (BuiltinCandidateTypeSet::iterator 7245 Vec1 = CandidateTypes[0].vector_begin(), 7246 Vec1End = CandidateTypes[0].vector_end(); 7247 Vec1 != Vec1End; ++Vec1) { 7248 for (BuiltinCandidateTypeSet::iterator 7249 Vec2 = CandidateTypes[1].vector_begin(), 7250 Vec2End = CandidateTypes[1].vector_end(); 7251 Vec2 != Vec2End; ++Vec2) { 7252 QualType ParamTypes[2]; 7253 ParamTypes[1] = *Vec2; 7254 // Add this built-in operator as a candidate (VQ is empty). 7255 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 7256 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7257 /*IsAssigmentOperator=*/isEqualOp); 7258 7259 // Add this built-in operator as a candidate (VQ is 'volatile'). 7260 if (VisibleTypeConversionsQuals.hasVolatile()) { 7261 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 7262 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7263 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7264 CandidateSet, 7265 /*IsAssigmentOperator=*/isEqualOp); 7266 } 7267 } 7268 } 7269 } 7270 7271 // C++ [over.built]p22: 7272 // 7273 // For every triple (L, VQ, R), where L is an integral type, VQ 7274 // is either volatile or empty, and R is a promoted integral 7275 // type, there exist candidate operator functions of the form 7276 // 7277 // VQ L& operator%=(VQ L&, R); 7278 // VQ L& operator<<=(VQ L&, R); 7279 // VQ L& operator>>=(VQ L&, R); 7280 // VQ L& operator&=(VQ L&, R); 7281 // VQ L& operator^=(VQ L&, R); 7282 // VQ L& operator|=(VQ L&, R); 7283 void addAssignmentIntegralOverloads() { 7284 if (!HasArithmeticOrEnumeralCandidateType) 7285 return; 7286 7287 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 7288 for (unsigned Right = FirstPromotedIntegralType; 7289 Right < LastPromotedIntegralType; ++Right) { 7290 QualType ParamTypes[2]; 7291 ParamTypes[1] = getArithmeticType(Right); 7292 7293 // Add this built-in operator as a candidate (VQ is empty). 7294 ParamTypes[0] = 7295 S.Context.getLValueReferenceType(getArithmeticType(Left)); 7296 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 7297 if (VisibleTypeConversionsQuals.hasVolatile()) { 7298 // Add this built-in operator as a candidate (VQ is 'volatile'). 7299 ParamTypes[0] = getArithmeticType(Left); 7300 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 7301 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7302 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7303 CandidateSet); 7304 } 7305 } 7306 } 7307 } 7308 7309 // C++ [over.operator]p23: 7310 // 7311 // There also exist candidate operator functions of the form 7312 // 7313 // bool operator!(bool); 7314 // bool operator&&(bool, bool); 7315 // bool operator||(bool, bool); 7316 void addExclaimOverload() { 7317 QualType ParamTy = S.Context.BoolTy; 7318 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 7319 /*IsAssignmentOperator=*/false, 7320 /*NumContextualBoolArguments=*/1); 7321 } 7322 void addAmpAmpOrPipePipeOverload() { 7323 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 7324 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 7325 /*IsAssignmentOperator=*/false, 7326 /*NumContextualBoolArguments=*/2); 7327 } 7328 7329 // C++ [over.built]p13: 7330 // 7331 // For every cv-qualified or cv-unqualified object type T there 7332 // exist candidate operator functions of the form 7333 // 7334 // T* operator+(T*, ptrdiff_t); [ABOVE] 7335 // T& operator[](T*, ptrdiff_t); 7336 // T* operator-(T*, ptrdiff_t); [ABOVE] 7337 // T* operator+(ptrdiff_t, T*); [ABOVE] 7338 // T& operator[](ptrdiff_t, T*); 7339 void addSubscriptOverloads() { 7340 for (BuiltinCandidateTypeSet::iterator 7341 Ptr = CandidateTypes[0].pointer_begin(), 7342 PtrEnd = CandidateTypes[0].pointer_end(); 7343 Ptr != PtrEnd; ++Ptr) { 7344 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 7345 QualType PointeeType = (*Ptr)->getPointeeType(); 7346 if (!PointeeType->isObjectType()) 7347 continue; 7348 7349 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 7350 7351 // T& operator[](T*, ptrdiff_t) 7352 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 7353 } 7354 7355 for (BuiltinCandidateTypeSet::iterator 7356 Ptr = CandidateTypes[1].pointer_begin(), 7357 PtrEnd = CandidateTypes[1].pointer_end(); 7358 Ptr != PtrEnd; ++Ptr) { 7359 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 7360 QualType PointeeType = (*Ptr)->getPointeeType(); 7361 if (!PointeeType->isObjectType()) 7362 continue; 7363 7364 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 7365 7366 // T& operator[](ptrdiff_t, T*) 7367 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 7368 } 7369 } 7370 7371 // C++ [over.built]p11: 7372 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 7373 // C1 is the same type as C2 or is a derived class of C2, T is an object 7374 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 7375 // there exist candidate operator functions of the form 7376 // 7377 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 7378 // 7379 // where CV12 is the union of CV1 and CV2. 7380 void addArrowStarOverloads() { 7381 for (BuiltinCandidateTypeSet::iterator 7382 Ptr = CandidateTypes[0].pointer_begin(), 7383 PtrEnd = CandidateTypes[0].pointer_end(); 7384 Ptr != PtrEnd; ++Ptr) { 7385 QualType C1Ty = (*Ptr); 7386 QualType C1; 7387 QualifierCollector Q1; 7388 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 7389 if (!isa<RecordType>(C1)) 7390 continue; 7391 // heuristic to reduce number of builtin candidates in the set. 7392 // Add volatile/restrict version only if there are conversions to a 7393 // volatile/restrict type. 7394 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 7395 continue; 7396 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 7397 continue; 7398 for (BuiltinCandidateTypeSet::iterator 7399 MemPtr = CandidateTypes[1].member_pointer_begin(), 7400 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 7401 MemPtr != MemPtrEnd; ++MemPtr) { 7402 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 7403 QualType C2 = QualType(mptr->getClass(), 0); 7404 C2 = C2.getUnqualifiedType(); 7405 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 7406 break; 7407 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 7408 // build CV12 T& 7409 QualType T = mptr->getPointeeType(); 7410 if (!VisibleTypeConversionsQuals.hasVolatile() && 7411 T.isVolatileQualified()) 7412 continue; 7413 if (!VisibleTypeConversionsQuals.hasRestrict() && 7414 T.isRestrictQualified()) 7415 continue; 7416 T = Q1.apply(S.Context, T); 7417 QualType ResultTy = S.Context.getLValueReferenceType(T); 7418 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 7419 } 7420 } 7421 } 7422 7423 // Note that we don't consider the first argument, since it has been 7424 // contextually converted to bool long ago. The candidates below are 7425 // therefore added as binary. 7426 // 7427 // C++ [over.built]p25: 7428 // For every type T, where T is a pointer, pointer-to-member, or scoped 7429 // enumeration type, there exist candidate operator functions of the form 7430 // 7431 // T operator?(bool, T, T); 7432 // 7433 void addConditionalOperatorOverloads() { 7434 /// Set of (canonical) types that we've already handled. 7435 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7436 7437 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 7438 for (BuiltinCandidateTypeSet::iterator 7439 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 7440 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 7441 Ptr != PtrEnd; ++Ptr) { 7442 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7443 continue; 7444 7445 QualType ParamTypes[2] = { *Ptr, *Ptr }; 7446 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 7447 } 7448 7449 for (BuiltinCandidateTypeSet::iterator 7450 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 7451 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 7452 MemPtr != MemPtrEnd; ++MemPtr) { 7453 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 7454 continue; 7455 7456 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 7457 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); 7458 } 7459 7460 if (S.getLangOpts().CPlusPlus0x) { 7461 for (BuiltinCandidateTypeSet::iterator 7462 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 7463 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 7464 Enum != EnumEnd; ++Enum) { 7465 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 7466 continue; 7467 7468 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 7469 continue; 7470 7471 QualType ParamTypes[2] = { *Enum, *Enum }; 7472 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); 7473 } 7474 } 7475 } 7476 } 7477}; 7478 7479} // end anonymous namespace 7480 7481/// AddBuiltinOperatorCandidates - Add the appropriate built-in 7482/// operator overloads to the candidate set (C++ [over.built]), based 7483/// on the operator @p Op and the arguments given. For example, if the 7484/// operator is a binary '+', this routine might add "int 7485/// operator+(int, int)" to cover integer addition. 7486void 7487Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 7488 SourceLocation OpLoc, 7489 Expr **Args, unsigned NumArgs, 7490 OverloadCandidateSet& CandidateSet) { 7491 // Find all of the types that the arguments can convert to, but only 7492 // if the operator we're looking at has built-in operator candidates 7493 // that make use of these types. Also record whether we encounter non-record 7494 // candidate types or either arithmetic or enumeral candidate types. 7495 Qualifiers VisibleTypeConversionsQuals; 7496 VisibleTypeConversionsQuals.addConst(); 7497 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7498 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 7499 7500 bool HasNonRecordCandidateType = false; 7501 bool HasArithmeticOrEnumeralCandidateType = false; 7502 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 7503 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 7504 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 7505 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 7506 OpLoc, 7507 true, 7508 (Op == OO_Exclaim || 7509 Op == OO_AmpAmp || 7510 Op == OO_PipePipe), 7511 VisibleTypeConversionsQuals); 7512 HasNonRecordCandidateType = HasNonRecordCandidateType || 7513 CandidateTypes[ArgIdx].hasNonRecordTypes(); 7514 HasArithmeticOrEnumeralCandidateType = 7515 HasArithmeticOrEnumeralCandidateType || 7516 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 7517 } 7518 7519 // Exit early when no non-record types have been added to the candidate set 7520 // for any of the arguments to the operator. 7521 // 7522 // We can't exit early for !, ||, or &&, since there we have always have 7523 // 'bool' overloads. 7524 if (!HasNonRecordCandidateType && 7525 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe)) 7526 return; 7527 7528 // Setup an object to manage the common state for building overloads. 7529 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, 7530 VisibleTypeConversionsQuals, 7531 HasArithmeticOrEnumeralCandidateType, 7532 CandidateTypes, CandidateSet); 7533 7534 // Dispatch over the operation to add in only those overloads which apply. 7535 switch (Op) { 7536 case OO_None: 7537 case NUM_OVERLOADED_OPERATORS: 7538 llvm_unreachable("Expected an overloaded operator"); 7539 7540 case OO_New: 7541 case OO_Delete: 7542 case OO_Array_New: 7543 case OO_Array_Delete: 7544 case OO_Call: 7545 llvm_unreachable( 7546 "Special operators don't use AddBuiltinOperatorCandidates"); 7547 7548 case OO_Comma: 7549 case OO_Arrow: 7550 // C++ [over.match.oper]p3: 7551 // -- For the operator ',', the unary operator '&', or the 7552 // operator '->', the built-in candidates set is empty. 7553 break; 7554 7555 case OO_Plus: // '+' is either unary or binary 7556 if (NumArgs == 1) 7557 OpBuilder.addUnaryPlusPointerOverloads(); 7558 // Fall through. 7559 7560 case OO_Minus: // '-' is either unary or binary 7561 if (NumArgs == 1) { 7562 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 7563 } else { 7564 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 7565 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7566 } 7567 break; 7568 7569 case OO_Star: // '*' is either unary or binary 7570 if (NumArgs == 1) 7571 OpBuilder.addUnaryStarPointerOverloads(); 7572 else 7573 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7574 break; 7575 7576 case OO_Slash: 7577 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7578 break; 7579 7580 case OO_PlusPlus: 7581 case OO_MinusMinus: 7582 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 7583 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 7584 break; 7585 7586 case OO_EqualEqual: 7587 case OO_ExclaimEqual: 7588 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 7589 // Fall through. 7590 7591 case OO_Less: 7592 case OO_Greater: 7593 case OO_LessEqual: 7594 case OO_GreaterEqual: 7595 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 7596 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 7597 break; 7598 7599 case OO_Percent: 7600 case OO_Caret: 7601 case OO_Pipe: 7602 case OO_LessLess: 7603 case OO_GreaterGreater: 7604 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 7605 break; 7606 7607 case OO_Amp: // '&' is either unary or binary 7608 if (NumArgs == 1) 7609 // C++ [over.match.oper]p3: 7610 // -- For the operator ',', the unary operator '&', or the 7611 // operator '->', the built-in candidates set is empty. 7612 break; 7613 7614 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 7615 break; 7616 7617 case OO_Tilde: 7618 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 7619 break; 7620 7621 case OO_Equal: 7622 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 7623 // Fall through. 7624 7625 case OO_PlusEqual: 7626 case OO_MinusEqual: 7627 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 7628 // Fall through. 7629 7630 case OO_StarEqual: 7631 case OO_SlashEqual: 7632 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 7633 break; 7634 7635 case OO_PercentEqual: 7636 case OO_LessLessEqual: 7637 case OO_GreaterGreaterEqual: 7638 case OO_AmpEqual: 7639 case OO_CaretEqual: 7640 case OO_PipeEqual: 7641 OpBuilder.addAssignmentIntegralOverloads(); 7642 break; 7643 7644 case OO_Exclaim: 7645 OpBuilder.addExclaimOverload(); 7646 break; 7647 7648 case OO_AmpAmp: 7649 case OO_PipePipe: 7650 OpBuilder.addAmpAmpOrPipePipeOverload(); 7651 break; 7652 7653 case OO_Subscript: 7654 OpBuilder.addSubscriptOverloads(); 7655 break; 7656 7657 case OO_ArrowStar: 7658 OpBuilder.addArrowStarOverloads(); 7659 break; 7660 7661 case OO_Conditional: 7662 OpBuilder.addConditionalOperatorOverloads(); 7663 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7664 break; 7665 } 7666} 7667 7668/// \brief Add function candidates found via argument-dependent lookup 7669/// to the set of overloading candidates. 7670/// 7671/// This routine performs argument-dependent name lookup based on the 7672/// given function name (which may also be an operator name) and adds 7673/// all of the overload candidates found by ADL to the overload 7674/// candidate set (C++ [basic.lookup.argdep]). 7675void 7676Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 7677 bool Operator, SourceLocation Loc, 7678 llvm::ArrayRef<Expr *> Args, 7679 TemplateArgumentListInfo *ExplicitTemplateArgs, 7680 OverloadCandidateSet& CandidateSet, 7681 bool PartialOverloading) { 7682 ADLResult Fns; 7683 7684 // FIXME: This approach for uniquing ADL results (and removing 7685 // redundant candidates from the set) relies on pointer-equality, 7686 // which means we need to key off the canonical decl. However, 7687 // always going back to the canonical decl might not get us the 7688 // right set of default arguments. What default arguments are 7689 // we supposed to consider on ADL candidates, anyway? 7690 7691 // FIXME: Pass in the explicit template arguments? 7692 ArgumentDependentLookup(Name, Operator, Loc, Args, Fns); 7693 7694 // Erase all of the candidates we already knew about. 7695 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 7696 CandEnd = CandidateSet.end(); 7697 Cand != CandEnd; ++Cand) 7698 if (Cand->Function) { 7699 Fns.erase(Cand->Function); 7700 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 7701 Fns.erase(FunTmpl); 7702 } 7703 7704 // For each of the ADL candidates we found, add it to the overload 7705 // set. 7706 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 7707 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 7708 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 7709 if (ExplicitTemplateArgs) 7710 continue; 7711 7712 AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet, false, 7713 PartialOverloading); 7714 } else 7715 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 7716 FoundDecl, ExplicitTemplateArgs, 7717 Args, CandidateSet); 7718 } 7719} 7720 7721/// isBetterOverloadCandidate - Determines whether the first overload 7722/// candidate is a better candidate than the second (C++ 13.3.3p1). 7723bool 7724isBetterOverloadCandidate(Sema &S, 7725 const OverloadCandidate &Cand1, 7726 const OverloadCandidate &Cand2, 7727 SourceLocation Loc, 7728 bool UserDefinedConversion) { 7729 // Define viable functions to be better candidates than non-viable 7730 // functions. 7731 if (!Cand2.Viable) 7732 return Cand1.Viable; 7733 else if (!Cand1.Viable) 7734 return false; 7735 7736 // C++ [over.match.best]p1: 7737 // 7738 // -- if F is a static member function, ICS1(F) is defined such 7739 // that ICS1(F) is neither better nor worse than ICS1(G) for 7740 // any function G, and, symmetrically, ICS1(G) is neither 7741 // better nor worse than ICS1(F). 7742 unsigned StartArg = 0; 7743 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 7744 StartArg = 1; 7745 7746 // C++ [over.match.best]p1: 7747 // A viable function F1 is defined to be a better function than another 7748 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 7749 // conversion sequence than ICSi(F2), and then... 7750 unsigned NumArgs = Cand1.NumConversions; 7751 assert(Cand2.NumConversions == NumArgs && "Overload candidate mismatch"); 7752 bool HasBetterConversion = false; 7753 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 7754 switch (CompareImplicitConversionSequences(S, 7755 Cand1.Conversions[ArgIdx], 7756 Cand2.Conversions[ArgIdx])) { 7757 case ImplicitConversionSequence::Better: 7758 // Cand1 has a better conversion sequence. 7759 HasBetterConversion = true; 7760 break; 7761 7762 case ImplicitConversionSequence::Worse: 7763 // Cand1 can't be better than Cand2. 7764 return false; 7765 7766 case ImplicitConversionSequence::Indistinguishable: 7767 // Do nothing. 7768 break; 7769 } 7770 } 7771 7772 // -- for some argument j, ICSj(F1) is a better conversion sequence than 7773 // ICSj(F2), or, if not that, 7774 if (HasBetterConversion) 7775 return true; 7776 7777 // - F1 is a non-template function and F2 is a function template 7778 // specialization, or, if not that, 7779 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 7780 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 7781 return true; 7782 7783 // -- F1 and F2 are function template specializations, and the function 7784 // template for F1 is more specialized than the template for F2 7785 // according to the partial ordering rules described in 14.5.5.2, or, 7786 // if not that, 7787 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 7788 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 7789 if (FunctionTemplateDecl *BetterTemplate 7790 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 7791 Cand2.Function->getPrimaryTemplate(), 7792 Loc, 7793 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 7794 : TPOC_Call, 7795 Cand1.ExplicitCallArguments)) 7796 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 7797 } 7798 7799 // -- the context is an initialization by user-defined conversion 7800 // (see 8.5, 13.3.1.5) and the standard conversion sequence 7801 // from the return type of F1 to the destination type (i.e., 7802 // the type of the entity being initialized) is a better 7803 // conversion sequence than the standard conversion sequence 7804 // from the return type of F2 to the destination type. 7805 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 7806 isa<CXXConversionDecl>(Cand1.Function) && 7807 isa<CXXConversionDecl>(Cand2.Function)) { 7808 // First check whether we prefer one of the conversion functions over the 7809 // other. This only distinguishes the results in non-standard, extension 7810 // cases such as the conversion from a lambda closure type to a function 7811 // pointer or block. 7812 ImplicitConversionSequence::CompareKind FuncResult 7813 = compareConversionFunctions(S, Cand1.Function, Cand2.Function); 7814 if (FuncResult != ImplicitConversionSequence::Indistinguishable) 7815 return FuncResult; 7816 7817 switch (CompareStandardConversionSequences(S, 7818 Cand1.FinalConversion, 7819 Cand2.FinalConversion)) { 7820 case ImplicitConversionSequence::Better: 7821 // Cand1 has a better conversion sequence. 7822 return true; 7823 7824 case ImplicitConversionSequence::Worse: 7825 // Cand1 can't be better than Cand2. 7826 return false; 7827 7828 case ImplicitConversionSequence::Indistinguishable: 7829 // Do nothing 7830 break; 7831 } 7832 } 7833 7834 return false; 7835} 7836 7837/// \brief Computes the best viable function (C++ 13.3.3) 7838/// within an overload candidate set. 7839/// 7840/// \param Loc The location of the function name (or operator symbol) for 7841/// which overload resolution occurs. 7842/// 7843/// \param Best If overload resolution was successful or found a deleted 7844/// function, \p Best points to the candidate function found. 7845/// 7846/// \returns The result of overload resolution. 7847OverloadingResult 7848OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 7849 iterator &Best, 7850 bool UserDefinedConversion) { 7851 // Find the best viable function. 7852 Best = end(); 7853 for (iterator Cand = begin(); Cand != end(); ++Cand) { 7854 if (Cand->Viable) 7855 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 7856 UserDefinedConversion)) 7857 Best = Cand; 7858 } 7859 7860 // If we didn't find any viable functions, abort. 7861 if (Best == end()) 7862 return OR_No_Viable_Function; 7863 7864 // Make sure that this function is better than every other viable 7865 // function. If not, we have an ambiguity. 7866 for (iterator Cand = begin(); Cand != end(); ++Cand) { 7867 if (Cand->Viable && 7868 Cand != Best && 7869 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 7870 UserDefinedConversion)) { 7871 Best = end(); 7872 return OR_Ambiguous; 7873 } 7874 } 7875 7876 // Best is the best viable function. 7877 if (Best->Function && 7878 (Best->Function->isDeleted() || 7879 S.isFunctionConsideredUnavailable(Best->Function))) 7880 return OR_Deleted; 7881 7882 return OR_Success; 7883} 7884 7885namespace { 7886 7887enum OverloadCandidateKind { 7888 oc_function, 7889 oc_method, 7890 oc_constructor, 7891 oc_function_template, 7892 oc_method_template, 7893 oc_constructor_template, 7894 oc_implicit_default_constructor, 7895 oc_implicit_copy_constructor, 7896 oc_implicit_move_constructor, 7897 oc_implicit_copy_assignment, 7898 oc_implicit_move_assignment, 7899 oc_implicit_inherited_constructor 7900}; 7901 7902OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 7903 FunctionDecl *Fn, 7904 std::string &Description) { 7905 bool isTemplate = false; 7906 7907 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 7908 isTemplate = true; 7909 Description = S.getTemplateArgumentBindingsText( 7910 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 7911 } 7912 7913 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 7914 if (!Ctor->isImplicit()) 7915 return isTemplate ? oc_constructor_template : oc_constructor; 7916 7917 if (Ctor->getInheritedConstructor()) 7918 return oc_implicit_inherited_constructor; 7919 7920 if (Ctor->isDefaultConstructor()) 7921 return oc_implicit_default_constructor; 7922 7923 if (Ctor->isMoveConstructor()) 7924 return oc_implicit_move_constructor; 7925 7926 assert(Ctor->isCopyConstructor() && 7927 "unexpected sort of implicit constructor"); 7928 return oc_implicit_copy_constructor; 7929 } 7930 7931 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 7932 // This actually gets spelled 'candidate function' for now, but 7933 // it doesn't hurt to split it out. 7934 if (!Meth->isImplicit()) 7935 return isTemplate ? oc_method_template : oc_method; 7936 7937 if (Meth->isMoveAssignmentOperator()) 7938 return oc_implicit_move_assignment; 7939 7940 if (Meth->isCopyAssignmentOperator()) 7941 return oc_implicit_copy_assignment; 7942 7943 assert(isa<CXXConversionDecl>(Meth) && "expected conversion"); 7944 return oc_method; 7945 } 7946 7947 return isTemplate ? oc_function_template : oc_function; 7948} 7949 7950void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { 7951 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 7952 if (!Ctor) return; 7953 7954 Ctor = Ctor->getInheritedConstructor(); 7955 if (!Ctor) return; 7956 7957 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 7958} 7959 7960} // end anonymous namespace 7961 7962// Notes the location of an overload candidate. 7963void Sema::NoteOverloadCandidate(FunctionDecl *Fn, QualType DestType) { 7964 std::string FnDesc; 7965 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 7966 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate) 7967 << (unsigned) K << FnDesc; 7968 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType); 7969 Diag(Fn->getLocation(), PD); 7970 MaybeEmitInheritedConstructorNote(*this, Fn); 7971} 7972 7973//Notes the location of all overload candidates designated through 7974// OverloadedExpr 7975void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr, QualType DestType) { 7976 assert(OverloadedExpr->getType() == Context.OverloadTy); 7977 7978 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); 7979 OverloadExpr *OvlExpr = Ovl.Expression; 7980 7981 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7982 IEnd = OvlExpr->decls_end(); 7983 I != IEnd; ++I) { 7984 if (FunctionTemplateDecl *FunTmpl = 7985 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) { 7986 NoteOverloadCandidate(FunTmpl->getTemplatedDecl(), DestType); 7987 } else if (FunctionDecl *Fun 7988 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) { 7989 NoteOverloadCandidate(Fun, DestType); 7990 } 7991 } 7992} 7993 7994/// Diagnoses an ambiguous conversion. The partial diagnostic is the 7995/// "lead" diagnostic; it will be given two arguments, the source and 7996/// target types of the conversion. 7997void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 7998 Sema &S, 7999 SourceLocation CaretLoc, 8000 const PartialDiagnostic &PDiag) const { 8001 S.Diag(CaretLoc, PDiag) 8002 << Ambiguous.getFromType() << Ambiguous.getToType(); 8003 for (AmbiguousConversionSequence::const_iterator 8004 I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 8005 S.NoteOverloadCandidate(*I); 8006 } 8007} 8008 8009namespace { 8010 8011void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 8012 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 8013 assert(Conv.isBad()); 8014 assert(Cand->Function && "for now, candidate must be a function"); 8015 FunctionDecl *Fn = Cand->Function; 8016 8017 // There's a conversion slot for the object argument if this is a 8018 // non-constructor method. Note that 'I' corresponds the 8019 // conversion-slot index. 8020 bool isObjectArgument = false; 8021 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 8022 if (I == 0) 8023 isObjectArgument = true; 8024 else 8025 I--; 8026 } 8027 8028 std::string FnDesc; 8029 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 8030 8031 Expr *FromExpr = Conv.Bad.FromExpr; 8032 QualType FromTy = Conv.Bad.getFromType(); 8033 QualType ToTy = Conv.Bad.getToType(); 8034 8035 if (FromTy == S.Context.OverloadTy) { 8036 assert(FromExpr && "overload set argument came from implicit argument?"); 8037 Expr *E = FromExpr->IgnoreParens(); 8038 if (isa<UnaryOperator>(E)) 8039 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 8040 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 8041 8042 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 8043 << (unsigned) FnKind << FnDesc 8044 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8045 << ToTy << Name << I+1; 8046 MaybeEmitInheritedConstructorNote(S, Fn); 8047 return; 8048 } 8049 8050 // Do some hand-waving analysis to see if the non-viability is due 8051 // to a qualifier mismatch. 8052 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 8053 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 8054 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 8055 CToTy = RT->getPointeeType(); 8056 else { 8057 // TODO: detect and diagnose the full richness of const mismatches. 8058 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 8059 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 8060 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 8061 } 8062 8063 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 8064 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 8065 Qualifiers FromQs = CFromTy.getQualifiers(); 8066 Qualifiers ToQs = CToTy.getQualifiers(); 8067 8068 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 8069 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 8070 << (unsigned) FnKind << FnDesc 8071 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8072 << FromTy 8073 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 8074 << (unsigned) isObjectArgument << I+1; 8075 MaybeEmitInheritedConstructorNote(S, Fn); 8076 return; 8077 } 8078 8079 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 8080 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership) 8081 << (unsigned) FnKind << FnDesc 8082 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8083 << FromTy 8084 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime() 8085 << (unsigned) isObjectArgument << I+1; 8086 MaybeEmitInheritedConstructorNote(S, Fn); 8087 return; 8088 } 8089 8090 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) { 8091 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc) 8092 << (unsigned) FnKind << FnDesc 8093 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8094 << FromTy 8095 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr() 8096 << (unsigned) isObjectArgument << I+1; 8097 MaybeEmitInheritedConstructorNote(S, Fn); 8098 return; 8099 } 8100 8101 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 8102 assert(CVR && "unexpected qualifiers mismatch"); 8103 8104 if (isObjectArgument) { 8105 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 8106 << (unsigned) FnKind << FnDesc 8107 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8108 << FromTy << (CVR - 1); 8109 } else { 8110 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 8111 << (unsigned) FnKind << FnDesc 8112 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8113 << FromTy << (CVR - 1) << I+1; 8114 } 8115 MaybeEmitInheritedConstructorNote(S, Fn); 8116 return; 8117 } 8118 8119 // Special diagnostic for failure to convert an initializer list, since 8120 // telling the user that it has type void is not useful. 8121 if (FromExpr && isa<InitListExpr>(FromExpr)) { 8122 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument) 8123 << (unsigned) FnKind << FnDesc 8124 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8125 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8126 MaybeEmitInheritedConstructorNote(S, Fn); 8127 return; 8128 } 8129 8130 // Diagnose references or pointers to incomplete types differently, 8131 // since it's far from impossible that the incompleteness triggered 8132 // the failure. 8133 QualType TempFromTy = FromTy.getNonReferenceType(); 8134 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 8135 TempFromTy = PTy->getPointeeType(); 8136 if (TempFromTy->isIncompleteType()) { 8137 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 8138 << (unsigned) FnKind << FnDesc 8139 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8140 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8141 MaybeEmitInheritedConstructorNote(S, Fn); 8142 return; 8143 } 8144 8145 // Diagnose base -> derived pointer conversions. 8146 unsigned BaseToDerivedConversion = 0; 8147 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 8148 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 8149 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 8150 FromPtrTy->getPointeeType()) && 8151 !FromPtrTy->getPointeeType()->isIncompleteType() && 8152 !ToPtrTy->getPointeeType()->isIncompleteType() && 8153 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 8154 FromPtrTy->getPointeeType())) 8155 BaseToDerivedConversion = 1; 8156 } 8157 } else if (const ObjCObjectPointerType *FromPtrTy 8158 = FromTy->getAs<ObjCObjectPointerType>()) { 8159 if (const ObjCObjectPointerType *ToPtrTy 8160 = ToTy->getAs<ObjCObjectPointerType>()) 8161 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 8162 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 8163 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 8164 FromPtrTy->getPointeeType()) && 8165 FromIface->isSuperClassOf(ToIface)) 8166 BaseToDerivedConversion = 2; 8167 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 8168 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 8169 !FromTy->isIncompleteType() && 8170 !ToRefTy->getPointeeType()->isIncompleteType() && 8171 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) { 8172 BaseToDerivedConversion = 3; 8173 } else if (ToTy->isLValueReferenceType() && !FromExpr->isLValue() && 8174 ToTy.getNonReferenceType().getCanonicalType() == 8175 FromTy.getNonReferenceType().getCanonicalType()) { 8176 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_lvalue) 8177 << (unsigned) FnKind << FnDesc 8178 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8179 << (unsigned) isObjectArgument << I + 1; 8180 MaybeEmitInheritedConstructorNote(S, Fn); 8181 return; 8182 } 8183 } 8184 8185 if (BaseToDerivedConversion) { 8186 S.Diag(Fn->getLocation(), 8187 diag::note_ovl_candidate_bad_base_to_derived_conv) 8188 << (unsigned) FnKind << FnDesc 8189 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8190 << (BaseToDerivedConversion - 1) 8191 << FromTy << ToTy << I+1; 8192 MaybeEmitInheritedConstructorNote(S, Fn); 8193 return; 8194 } 8195 8196 if (isa<ObjCObjectPointerType>(CFromTy) && 8197 isa<PointerType>(CToTy)) { 8198 Qualifiers FromQs = CFromTy.getQualifiers(); 8199 Qualifiers ToQs = CToTy.getQualifiers(); 8200 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 8201 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv) 8202 << (unsigned) FnKind << FnDesc 8203 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8204 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8205 MaybeEmitInheritedConstructorNote(S, Fn); 8206 return; 8207 } 8208 } 8209 8210 // Emit the generic diagnostic and, optionally, add the hints to it. 8211 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv); 8212 FDiag << (unsigned) FnKind << FnDesc 8213 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8214 << FromTy << ToTy << (unsigned) isObjectArgument << I + 1 8215 << (unsigned) (Cand->Fix.Kind); 8216 8217 // If we can fix the conversion, suggest the FixIts. 8218 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(), 8219 HE = Cand->Fix.Hints.end(); HI != HE; ++HI) 8220 FDiag << *HI; 8221 S.Diag(Fn->getLocation(), FDiag); 8222 8223 MaybeEmitInheritedConstructorNote(S, Fn); 8224} 8225 8226void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 8227 unsigned NumFormalArgs) { 8228 // TODO: treat calls to a missing default constructor as a special case 8229 8230 FunctionDecl *Fn = Cand->Function; 8231 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 8232 8233 unsigned MinParams = Fn->getMinRequiredArguments(); 8234 8235 // With invalid overloaded operators, it's possible that we think we 8236 // have an arity mismatch when it fact it looks like we have the 8237 // right number of arguments, because only overloaded operators have 8238 // the weird behavior of overloading member and non-member functions. 8239 // Just don't report anything. 8240 if (Fn->isInvalidDecl() && 8241 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName) 8242 return; 8243 8244 // at least / at most / exactly 8245 unsigned mode, modeCount; 8246 if (NumFormalArgs < MinParams) { 8247 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 8248 (Cand->FailureKind == ovl_fail_bad_deduction && 8249 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 8250 if (MinParams != FnTy->getNumArgs() || 8251 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 8252 mode = 0; // "at least" 8253 else 8254 mode = 2; // "exactly" 8255 modeCount = MinParams; 8256 } else { 8257 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 8258 (Cand->FailureKind == ovl_fail_bad_deduction && 8259 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 8260 if (MinParams != FnTy->getNumArgs()) 8261 mode = 1; // "at most" 8262 else 8263 mode = 2; // "exactly" 8264 modeCount = FnTy->getNumArgs(); 8265 } 8266 8267 std::string Description; 8268 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 8269 8270 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName()) 8271 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one) 8272 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 8273 << Fn->getParamDecl(0) << NumFormalArgs; 8274 else 8275 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 8276 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 8277 << modeCount << NumFormalArgs; 8278 MaybeEmitInheritedConstructorNote(S, Fn); 8279} 8280 8281/// Diagnose a failed template-argument deduction. 8282void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 8283 unsigned NumArgs) { 8284 FunctionDecl *Fn = Cand->Function; // pattern 8285 8286 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 8287 NamedDecl *ParamD; 8288 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 8289 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 8290 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 8291 switch (Cand->DeductionFailure.Result) { 8292 case Sema::TDK_Success: 8293 llvm_unreachable("TDK_success while diagnosing bad deduction"); 8294 8295 case Sema::TDK_Incomplete: { 8296 assert(ParamD && "no parameter found for incomplete deduction result"); 8297 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 8298 << ParamD->getDeclName(); 8299 MaybeEmitInheritedConstructorNote(S, Fn); 8300 return; 8301 } 8302 8303 case Sema::TDK_Underqualified: { 8304 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 8305 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 8306 8307 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 8308 8309 // Param will have been canonicalized, but it should just be a 8310 // qualified version of ParamD, so move the qualifiers to that. 8311 QualifierCollector Qs; 8312 Qs.strip(Param); 8313 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 8314 assert(S.Context.hasSameType(Param, NonCanonParam)); 8315 8316 // Arg has also been canonicalized, but there's nothing we can do 8317 // about that. It also doesn't matter as much, because it won't 8318 // have any template parameters in it (because deduction isn't 8319 // done on dependent types). 8320 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 8321 8322 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 8323 << ParamD->getDeclName() << Arg << NonCanonParam; 8324 MaybeEmitInheritedConstructorNote(S, Fn); 8325 return; 8326 } 8327 8328 case Sema::TDK_Inconsistent: { 8329 assert(ParamD && "no parameter found for inconsistent deduction result"); 8330 int which = 0; 8331 if (isa<TemplateTypeParmDecl>(ParamD)) 8332 which = 0; 8333 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 8334 which = 1; 8335 else { 8336 which = 2; 8337 } 8338 8339 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 8340 << which << ParamD->getDeclName() 8341 << *Cand->DeductionFailure.getFirstArg() 8342 << *Cand->DeductionFailure.getSecondArg(); 8343 MaybeEmitInheritedConstructorNote(S, Fn); 8344 return; 8345 } 8346 8347 case Sema::TDK_InvalidExplicitArguments: 8348 assert(ParamD && "no parameter found for invalid explicit arguments"); 8349 if (ParamD->getDeclName()) 8350 S.Diag(Fn->getLocation(), 8351 diag::note_ovl_candidate_explicit_arg_mismatch_named) 8352 << ParamD->getDeclName(); 8353 else { 8354 int index = 0; 8355 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 8356 index = TTP->getIndex(); 8357 else if (NonTypeTemplateParmDecl *NTTP 8358 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 8359 index = NTTP->getIndex(); 8360 else 8361 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 8362 S.Diag(Fn->getLocation(), 8363 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 8364 << (index + 1); 8365 } 8366 MaybeEmitInheritedConstructorNote(S, Fn); 8367 return; 8368 8369 case Sema::TDK_TooManyArguments: 8370 case Sema::TDK_TooFewArguments: 8371 DiagnoseArityMismatch(S, Cand, NumArgs); 8372 return; 8373 8374 case Sema::TDK_InstantiationDepth: 8375 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 8376 MaybeEmitInheritedConstructorNote(S, Fn); 8377 return; 8378 8379 case Sema::TDK_SubstitutionFailure: { 8380 // Format the template argument list into the argument string. 8381 llvm::SmallString<128> TemplateArgString; 8382 if (TemplateArgumentList *Args = 8383 Cand->DeductionFailure.getTemplateArgumentList()) { 8384 TemplateArgString = " "; 8385 TemplateArgString += S.getTemplateArgumentBindingsText( 8386 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), *Args); 8387 } 8388 8389 // If this candidate was disabled by enable_if, say so. 8390 PartialDiagnosticAt *PDiag = Cand->DeductionFailure.getSFINAEDiagnostic(); 8391 if (PDiag && PDiag->second.getDiagID() == 8392 diag::err_typename_nested_not_found_enable_if) { 8393 // FIXME: Use the source range of the condition, and the fully-qualified 8394 // name of the enable_if template. These are both present in PDiag. 8395 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if) 8396 << "'enable_if'" << TemplateArgString; 8397 return; 8398 } 8399 8400 // Format the SFINAE diagnostic into the argument string. 8401 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s 8402 // formatted message in another diagnostic. 8403 llvm::SmallString<128> SFINAEArgString; 8404 SourceRange R; 8405 if (PDiag) { 8406 SFINAEArgString = ": "; 8407 R = SourceRange(PDiag->first, PDiag->first); 8408 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString); 8409 } 8410 8411 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 8412 << TemplateArgString << SFINAEArgString << R; 8413 MaybeEmitInheritedConstructorNote(S, Fn); 8414 return; 8415 } 8416 8417 // TODO: diagnose these individually, then kill off 8418 // note_ovl_candidate_bad_deduction, which is uselessly vague. 8419 case Sema::TDK_NonDeducedMismatch: 8420 case Sema::TDK_FailedOverloadResolution: 8421 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 8422 MaybeEmitInheritedConstructorNote(S, Fn); 8423 return; 8424 } 8425} 8426 8427/// CUDA: diagnose an invalid call across targets. 8428void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) { 8429 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext); 8430 FunctionDecl *Callee = Cand->Function; 8431 8432 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller), 8433 CalleeTarget = S.IdentifyCUDATarget(Callee); 8434 8435 std::string FnDesc; 8436 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Callee, FnDesc); 8437 8438 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target) 8439 << (unsigned) FnKind << CalleeTarget << CallerTarget; 8440} 8441 8442/// Generates a 'note' diagnostic for an overload candidate. We've 8443/// already generated a primary error at the call site. 8444/// 8445/// It really does need to be a single diagnostic with its caret 8446/// pointed at the candidate declaration. Yes, this creates some 8447/// major challenges of technical writing. Yes, this makes pointing 8448/// out problems with specific arguments quite awkward. It's still 8449/// better than generating twenty screens of text for every failed 8450/// overload. 8451/// 8452/// It would be great to be able to express per-candidate problems 8453/// more richly for those diagnostic clients that cared, but we'd 8454/// still have to be just as careful with the default diagnostics. 8455void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 8456 unsigned NumArgs) { 8457 FunctionDecl *Fn = Cand->Function; 8458 8459 // Note deleted candidates, but only if they're viable. 8460 if (Cand->Viable && (Fn->isDeleted() || 8461 S.isFunctionConsideredUnavailable(Fn))) { 8462 std::string FnDesc; 8463 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 8464 8465 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 8466 << FnKind << FnDesc 8467 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0); 8468 MaybeEmitInheritedConstructorNote(S, Fn); 8469 return; 8470 } 8471 8472 // We don't really have anything else to say about viable candidates. 8473 if (Cand->Viable) { 8474 S.NoteOverloadCandidate(Fn); 8475 return; 8476 } 8477 8478 switch (Cand->FailureKind) { 8479 case ovl_fail_too_many_arguments: 8480 case ovl_fail_too_few_arguments: 8481 return DiagnoseArityMismatch(S, Cand, NumArgs); 8482 8483 case ovl_fail_bad_deduction: 8484 return DiagnoseBadDeduction(S, Cand, NumArgs); 8485 8486 case ovl_fail_trivial_conversion: 8487 case ovl_fail_bad_final_conversion: 8488 case ovl_fail_final_conversion_not_exact: 8489 return S.NoteOverloadCandidate(Fn); 8490 8491 case ovl_fail_bad_conversion: { 8492 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 8493 for (unsigned N = Cand->NumConversions; I != N; ++I) 8494 if (Cand->Conversions[I].isBad()) 8495 return DiagnoseBadConversion(S, Cand, I); 8496 8497 // FIXME: this currently happens when we're called from SemaInit 8498 // when user-conversion overload fails. Figure out how to handle 8499 // those conditions and diagnose them well. 8500 return S.NoteOverloadCandidate(Fn); 8501 } 8502 8503 case ovl_fail_bad_target: 8504 return DiagnoseBadTarget(S, Cand); 8505 } 8506} 8507 8508void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 8509 // Desugar the type of the surrogate down to a function type, 8510 // retaining as many typedefs as possible while still showing 8511 // the function type (and, therefore, its parameter types). 8512 QualType FnType = Cand->Surrogate->getConversionType(); 8513 bool isLValueReference = false; 8514 bool isRValueReference = false; 8515 bool isPointer = false; 8516 if (const LValueReferenceType *FnTypeRef = 8517 FnType->getAs<LValueReferenceType>()) { 8518 FnType = FnTypeRef->getPointeeType(); 8519 isLValueReference = true; 8520 } else if (const RValueReferenceType *FnTypeRef = 8521 FnType->getAs<RValueReferenceType>()) { 8522 FnType = FnTypeRef->getPointeeType(); 8523 isRValueReference = true; 8524 } 8525 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 8526 FnType = FnTypePtr->getPointeeType(); 8527 isPointer = true; 8528 } 8529 // Desugar down to a function type. 8530 FnType = QualType(FnType->getAs<FunctionType>(), 0); 8531 // Reconstruct the pointer/reference as appropriate. 8532 if (isPointer) FnType = S.Context.getPointerType(FnType); 8533 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 8534 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 8535 8536 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 8537 << FnType; 8538 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 8539} 8540 8541void NoteBuiltinOperatorCandidate(Sema &S, 8542 StringRef Opc, 8543 SourceLocation OpLoc, 8544 OverloadCandidate *Cand) { 8545 assert(Cand->NumConversions <= 2 && "builtin operator is not binary"); 8546 std::string TypeStr("operator"); 8547 TypeStr += Opc; 8548 TypeStr += "("; 8549 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 8550 if (Cand->NumConversions == 1) { 8551 TypeStr += ")"; 8552 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 8553 } else { 8554 TypeStr += ", "; 8555 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 8556 TypeStr += ")"; 8557 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 8558 } 8559} 8560 8561void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 8562 OverloadCandidate *Cand) { 8563 unsigned NoOperands = Cand->NumConversions; 8564 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 8565 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 8566 if (ICS.isBad()) break; // all meaningless after first invalid 8567 if (!ICS.isAmbiguous()) continue; 8568 8569 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 8570 S.PDiag(diag::note_ambiguous_type_conversion)); 8571 } 8572} 8573 8574SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 8575 if (Cand->Function) 8576 return Cand->Function->getLocation(); 8577 if (Cand->IsSurrogate) 8578 return Cand->Surrogate->getLocation(); 8579 return SourceLocation(); 8580} 8581 8582static unsigned 8583RankDeductionFailure(const OverloadCandidate::DeductionFailureInfo &DFI) { 8584 switch ((Sema::TemplateDeductionResult)DFI.Result) { 8585 case Sema::TDK_Success: 8586 llvm_unreachable("TDK_success while diagnosing bad deduction"); 8587 8588 case Sema::TDK_Invalid: 8589 case Sema::TDK_Incomplete: 8590 return 1; 8591 8592 case Sema::TDK_Underqualified: 8593 case Sema::TDK_Inconsistent: 8594 return 2; 8595 8596 case Sema::TDK_SubstitutionFailure: 8597 case Sema::TDK_NonDeducedMismatch: 8598 return 3; 8599 8600 case Sema::TDK_InstantiationDepth: 8601 case Sema::TDK_FailedOverloadResolution: 8602 return 4; 8603 8604 case Sema::TDK_InvalidExplicitArguments: 8605 return 5; 8606 8607 case Sema::TDK_TooManyArguments: 8608 case Sema::TDK_TooFewArguments: 8609 return 6; 8610 } 8611 llvm_unreachable("Unhandled deduction result"); 8612} 8613 8614struct CompareOverloadCandidatesForDisplay { 8615 Sema &S; 8616 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 8617 8618 bool operator()(const OverloadCandidate *L, 8619 const OverloadCandidate *R) { 8620 // Fast-path this check. 8621 if (L == R) return false; 8622 8623 // Order first by viability. 8624 if (L->Viable) { 8625 if (!R->Viable) return true; 8626 8627 // TODO: introduce a tri-valued comparison for overload 8628 // candidates. Would be more worthwhile if we had a sort 8629 // that could exploit it. 8630 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 8631 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 8632 } else if (R->Viable) 8633 return false; 8634 8635 assert(L->Viable == R->Viable); 8636 8637 // Criteria by which we can sort non-viable candidates: 8638 if (!L->Viable) { 8639 // 1. Arity mismatches come after other candidates. 8640 if (L->FailureKind == ovl_fail_too_many_arguments || 8641 L->FailureKind == ovl_fail_too_few_arguments) 8642 return false; 8643 if (R->FailureKind == ovl_fail_too_many_arguments || 8644 R->FailureKind == ovl_fail_too_few_arguments) 8645 return true; 8646 8647 // 2. Bad conversions come first and are ordered by the number 8648 // of bad conversions and quality of good conversions. 8649 if (L->FailureKind == ovl_fail_bad_conversion) { 8650 if (R->FailureKind != ovl_fail_bad_conversion) 8651 return true; 8652 8653 // The conversion that can be fixed with a smaller number of changes, 8654 // comes first. 8655 unsigned numLFixes = L->Fix.NumConversionsFixed; 8656 unsigned numRFixes = R->Fix.NumConversionsFixed; 8657 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes; 8658 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes; 8659 if (numLFixes != numRFixes) { 8660 if (numLFixes < numRFixes) 8661 return true; 8662 else 8663 return false; 8664 } 8665 8666 // If there's any ordering between the defined conversions... 8667 // FIXME: this might not be transitive. 8668 assert(L->NumConversions == R->NumConversions); 8669 8670 int leftBetter = 0; 8671 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 8672 for (unsigned E = L->NumConversions; I != E; ++I) { 8673 switch (CompareImplicitConversionSequences(S, 8674 L->Conversions[I], 8675 R->Conversions[I])) { 8676 case ImplicitConversionSequence::Better: 8677 leftBetter++; 8678 break; 8679 8680 case ImplicitConversionSequence::Worse: 8681 leftBetter--; 8682 break; 8683 8684 case ImplicitConversionSequence::Indistinguishable: 8685 break; 8686 } 8687 } 8688 if (leftBetter > 0) return true; 8689 if (leftBetter < 0) return false; 8690 8691 } else if (R->FailureKind == ovl_fail_bad_conversion) 8692 return false; 8693 8694 if (L->FailureKind == ovl_fail_bad_deduction) { 8695 if (R->FailureKind != ovl_fail_bad_deduction) 8696 return true; 8697 8698 if (L->DeductionFailure.Result != R->DeductionFailure.Result) 8699 return RankDeductionFailure(L->DeductionFailure) 8700 < RankDeductionFailure(R->DeductionFailure); 8701 } else if (R->FailureKind == ovl_fail_bad_deduction) 8702 return false; 8703 8704 // TODO: others? 8705 } 8706 8707 // Sort everything else by location. 8708 SourceLocation LLoc = GetLocationForCandidate(L); 8709 SourceLocation RLoc = GetLocationForCandidate(R); 8710 8711 // Put candidates without locations (e.g. builtins) at the end. 8712 if (LLoc.isInvalid()) return false; 8713 if (RLoc.isInvalid()) return true; 8714 8715 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 8716 } 8717}; 8718 8719/// CompleteNonViableCandidate - Normally, overload resolution only 8720/// computes up to the first. Produces the FixIt set if possible. 8721void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 8722 llvm::ArrayRef<Expr *> Args) { 8723 assert(!Cand->Viable); 8724 8725 // Don't do anything on failures other than bad conversion. 8726 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 8727 8728 // We only want the FixIts if all the arguments can be corrected. 8729 bool Unfixable = false; 8730 // Use a implicit copy initialization to check conversion fixes. 8731 Cand->Fix.setConversionChecker(TryCopyInitialization); 8732 8733 // Skip forward to the first bad conversion. 8734 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 8735 unsigned ConvCount = Cand->NumConversions; 8736 while (true) { 8737 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 8738 ConvIdx++; 8739 if (Cand->Conversions[ConvIdx - 1].isBad()) { 8740 Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S); 8741 break; 8742 } 8743 } 8744 8745 if (ConvIdx == ConvCount) 8746 return; 8747 8748 assert(!Cand->Conversions[ConvIdx].isInitialized() && 8749 "remaining conversion is initialized?"); 8750 8751 // FIXME: this should probably be preserved from the overload 8752 // operation somehow. 8753 bool SuppressUserConversions = false; 8754 8755 const FunctionProtoType* Proto; 8756 unsigned ArgIdx = ConvIdx; 8757 8758 if (Cand->IsSurrogate) { 8759 QualType ConvType 8760 = Cand->Surrogate->getConversionType().getNonReferenceType(); 8761 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 8762 ConvType = ConvPtrType->getPointeeType(); 8763 Proto = ConvType->getAs<FunctionProtoType>(); 8764 ArgIdx--; 8765 } else if (Cand->Function) { 8766 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 8767 if (isa<CXXMethodDecl>(Cand->Function) && 8768 !isa<CXXConstructorDecl>(Cand->Function)) 8769 ArgIdx--; 8770 } else { 8771 // Builtin binary operator with a bad first conversion. 8772 assert(ConvCount <= 3); 8773 for (; ConvIdx != ConvCount; ++ConvIdx) 8774 Cand->Conversions[ConvIdx] 8775 = TryCopyInitialization(S, Args[ConvIdx], 8776 Cand->BuiltinTypes.ParamTypes[ConvIdx], 8777 SuppressUserConversions, 8778 /*InOverloadResolution*/ true, 8779 /*AllowObjCWritebackConversion=*/ 8780 S.getLangOpts().ObjCAutoRefCount); 8781 return; 8782 } 8783 8784 // Fill in the rest of the conversions. 8785 unsigned NumArgsInProto = Proto->getNumArgs(); 8786 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 8787 if (ArgIdx < NumArgsInProto) { 8788 Cand->Conversions[ConvIdx] 8789 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 8790 SuppressUserConversions, 8791 /*InOverloadResolution=*/true, 8792 /*AllowObjCWritebackConversion=*/ 8793 S.getLangOpts().ObjCAutoRefCount); 8794 // Store the FixIt in the candidate if it exists. 8795 if (!Unfixable && Cand->Conversions[ConvIdx].isBad()) 8796 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S); 8797 } 8798 else 8799 Cand->Conversions[ConvIdx].setEllipsis(); 8800 } 8801} 8802 8803} // end anonymous namespace 8804 8805/// PrintOverloadCandidates - When overload resolution fails, prints 8806/// diagnostic messages containing the candidates in the candidate 8807/// set. 8808void OverloadCandidateSet::NoteCandidates(Sema &S, 8809 OverloadCandidateDisplayKind OCD, 8810 llvm::ArrayRef<Expr *> Args, 8811 StringRef Opc, 8812 SourceLocation OpLoc) { 8813 // Sort the candidates by viability and position. Sorting directly would 8814 // be prohibitive, so we make a set of pointers and sort those. 8815 SmallVector<OverloadCandidate*, 32> Cands; 8816 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 8817 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 8818 if (Cand->Viable) 8819 Cands.push_back(Cand); 8820 else if (OCD == OCD_AllCandidates) { 8821 CompleteNonViableCandidate(S, Cand, Args); 8822 if (Cand->Function || Cand->IsSurrogate) 8823 Cands.push_back(Cand); 8824 // Otherwise, this a non-viable builtin candidate. We do not, in general, 8825 // want to list every possible builtin candidate. 8826 } 8827 } 8828 8829 std::sort(Cands.begin(), Cands.end(), 8830 CompareOverloadCandidatesForDisplay(S)); 8831 8832 bool ReportedAmbiguousConversions = false; 8833 8834 SmallVectorImpl<OverloadCandidate*>::iterator I, E; 8835 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 8836 unsigned CandsShown = 0; 8837 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 8838 OverloadCandidate *Cand = *I; 8839 8840 // Set an arbitrary limit on the number of candidate functions we'll spam 8841 // the user with. FIXME: This limit should depend on details of the 8842 // candidate list. 8843 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) { 8844 break; 8845 } 8846 ++CandsShown; 8847 8848 if (Cand->Function) 8849 NoteFunctionCandidate(S, Cand, Args.size()); 8850 else if (Cand->IsSurrogate) 8851 NoteSurrogateCandidate(S, Cand); 8852 else { 8853 assert(Cand->Viable && 8854 "Non-viable built-in candidates are not added to Cands."); 8855 // Generally we only see ambiguities including viable builtin 8856 // operators if overload resolution got screwed up by an 8857 // ambiguous user-defined conversion. 8858 // 8859 // FIXME: It's quite possible for different conversions to see 8860 // different ambiguities, though. 8861 if (!ReportedAmbiguousConversions) { 8862 NoteAmbiguousUserConversions(S, OpLoc, Cand); 8863 ReportedAmbiguousConversions = true; 8864 } 8865 8866 // If this is a viable builtin, print it. 8867 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 8868 } 8869 } 8870 8871 if (I != E) 8872 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 8873} 8874 8875// [PossiblyAFunctionType] --> [Return] 8876// NonFunctionType --> NonFunctionType 8877// R (A) --> R(A) 8878// R (*)(A) --> R (A) 8879// R (&)(A) --> R (A) 8880// R (S::*)(A) --> R (A) 8881QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { 8882 QualType Ret = PossiblyAFunctionType; 8883 if (const PointerType *ToTypePtr = 8884 PossiblyAFunctionType->getAs<PointerType>()) 8885 Ret = ToTypePtr->getPointeeType(); 8886 else if (const ReferenceType *ToTypeRef = 8887 PossiblyAFunctionType->getAs<ReferenceType>()) 8888 Ret = ToTypeRef->getPointeeType(); 8889 else if (const MemberPointerType *MemTypePtr = 8890 PossiblyAFunctionType->getAs<MemberPointerType>()) 8891 Ret = MemTypePtr->getPointeeType(); 8892 Ret = 8893 Context.getCanonicalType(Ret).getUnqualifiedType(); 8894 return Ret; 8895} 8896 8897// A helper class to help with address of function resolution 8898// - allows us to avoid passing around all those ugly parameters 8899class AddressOfFunctionResolver 8900{ 8901 Sema& S; 8902 Expr* SourceExpr; 8903 const QualType& TargetType; 8904 QualType TargetFunctionType; // Extracted function type from target type 8905 8906 bool Complain; 8907 //DeclAccessPair& ResultFunctionAccessPair; 8908 ASTContext& Context; 8909 8910 bool TargetTypeIsNonStaticMemberFunction; 8911 bool FoundNonTemplateFunction; 8912 8913 OverloadExpr::FindResult OvlExprInfo; 8914 OverloadExpr *OvlExpr; 8915 TemplateArgumentListInfo OvlExplicitTemplateArgs; 8916 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 8917 8918public: 8919 AddressOfFunctionResolver(Sema &S, Expr* SourceExpr, 8920 const QualType& TargetType, bool Complain) 8921 : S(S), SourceExpr(SourceExpr), TargetType(TargetType), 8922 Complain(Complain), Context(S.getASTContext()), 8923 TargetTypeIsNonStaticMemberFunction( 8924 !!TargetType->getAs<MemberPointerType>()), 8925 FoundNonTemplateFunction(false), 8926 OvlExprInfo(OverloadExpr::find(SourceExpr)), 8927 OvlExpr(OvlExprInfo.Expression) 8928 { 8929 ExtractUnqualifiedFunctionTypeFromTargetType(); 8930 8931 if (!TargetFunctionType->isFunctionType()) { 8932 if (OvlExpr->hasExplicitTemplateArgs()) { 8933 DeclAccessPair dap; 8934 if (FunctionDecl* Fn = S.ResolveSingleFunctionTemplateSpecialization( 8935 OvlExpr, false, &dap) ) { 8936 8937 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 8938 if (!Method->isStatic()) { 8939 // If the target type is a non-function type and the function 8940 // found is a non-static member function, pretend as if that was 8941 // the target, it's the only possible type to end up with. 8942 TargetTypeIsNonStaticMemberFunction = true; 8943 8944 // And skip adding the function if its not in the proper form. 8945 // We'll diagnose this due to an empty set of functions. 8946 if (!OvlExprInfo.HasFormOfMemberPointer) 8947 return; 8948 } 8949 } 8950 8951 Matches.push_back(std::make_pair(dap,Fn)); 8952 } 8953 } 8954 return; 8955 } 8956 8957 if (OvlExpr->hasExplicitTemplateArgs()) 8958 OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); 8959 8960 if (FindAllFunctionsThatMatchTargetTypeExactly()) { 8961 // C++ [over.over]p4: 8962 // If more than one function is selected, [...] 8963 if (Matches.size() > 1) { 8964 if (FoundNonTemplateFunction) 8965 EliminateAllTemplateMatches(); 8966 else 8967 EliminateAllExceptMostSpecializedTemplate(); 8968 } 8969 } 8970 } 8971 8972private: 8973 bool isTargetTypeAFunction() const { 8974 return TargetFunctionType->isFunctionType(); 8975 } 8976 8977 // [ToType] [Return] 8978 8979 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false 8980 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false 8981 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true 8982 void inline ExtractUnqualifiedFunctionTypeFromTargetType() { 8983 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); 8984 } 8985 8986 // return true if any matching specializations were found 8987 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, 8988 const DeclAccessPair& CurAccessFunPair) { 8989 if (CXXMethodDecl *Method 8990 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 8991 // Skip non-static function templates when converting to pointer, and 8992 // static when converting to member pointer. 8993 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 8994 return false; 8995 } 8996 else if (TargetTypeIsNonStaticMemberFunction) 8997 return false; 8998 8999 // C++ [over.over]p2: 9000 // If the name is a function template, template argument deduction is 9001 // done (14.8.2.2), and if the argument deduction succeeds, the 9002 // resulting template argument list is used to generate a single 9003 // function template specialization, which is added to the set of 9004 // overloaded functions considered. 9005 FunctionDecl *Specialization = 0; 9006 TemplateDeductionInfo Info(OvlExpr->getNameLoc()); 9007 if (Sema::TemplateDeductionResult Result 9008 = S.DeduceTemplateArguments(FunctionTemplate, 9009 &OvlExplicitTemplateArgs, 9010 TargetFunctionType, Specialization, 9011 Info)) { 9012 // FIXME: make a note of the failed deduction for diagnostics. 9013 (void)Result; 9014 return false; 9015 } 9016 9017 // Template argument deduction ensures that we have an exact match. 9018 // This function template specicalization works. 9019 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 9020 assert(TargetFunctionType 9021 == Context.getCanonicalType(Specialization->getType())); 9022 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); 9023 return true; 9024 } 9025 9026 bool AddMatchingNonTemplateFunction(NamedDecl* Fn, 9027 const DeclAccessPair& CurAccessFunPair) { 9028 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 9029 // Skip non-static functions when converting to pointer, and static 9030 // when converting to member pointer. 9031 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 9032 return false; 9033 } 9034 else if (TargetTypeIsNonStaticMemberFunction) 9035 return false; 9036 9037 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 9038 if (S.getLangOpts().CUDA) 9039 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext)) 9040 if (S.CheckCUDATarget(Caller, FunDecl)) 9041 return false; 9042 9043 QualType ResultTy; 9044 if (Context.hasSameUnqualifiedType(TargetFunctionType, 9045 FunDecl->getType()) || 9046 S.IsNoReturnConversion(FunDecl->getType(), TargetFunctionType, 9047 ResultTy)) { 9048 Matches.push_back(std::make_pair(CurAccessFunPair, 9049 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 9050 FoundNonTemplateFunction = true; 9051 return true; 9052 } 9053 } 9054 9055 return false; 9056 } 9057 9058 bool FindAllFunctionsThatMatchTargetTypeExactly() { 9059 bool Ret = false; 9060 9061 // If the overload expression doesn't have the form of a pointer to 9062 // member, don't try to convert it to a pointer-to-member type. 9063 if (IsInvalidFormOfPointerToMemberFunction()) 9064 return false; 9065 9066 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 9067 E = OvlExpr->decls_end(); 9068 I != E; ++I) { 9069 // Look through any using declarations to find the underlying function. 9070 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 9071 9072 // C++ [over.over]p3: 9073 // Non-member functions and static member functions match 9074 // targets of type "pointer-to-function" or "reference-to-function." 9075 // Nonstatic member functions match targets of 9076 // type "pointer-to-member-function." 9077 // Note that according to DR 247, the containing class does not matter. 9078 if (FunctionTemplateDecl *FunctionTemplate 9079 = dyn_cast<FunctionTemplateDecl>(Fn)) { 9080 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) 9081 Ret = true; 9082 } 9083 // If we have explicit template arguments supplied, skip non-templates. 9084 else if (!OvlExpr->hasExplicitTemplateArgs() && 9085 AddMatchingNonTemplateFunction(Fn, I.getPair())) 9086 Ret = true; 9087 } 9088 assert(Ret || Matches.empty()); 9089 return Ret; 9090 } 9091 9092 void EliminateAllExceptMostSpecializedTemplate() { 9093 // [...] and any given function template specialization F1 is 9094 // eliminated if the set contains a second function template 9095 // specialization whose function template is more specialized 9096 // than the function template of F1 according to the partial 9097 // ordering rules of 14.5.5.2. 9098 9099 // The algorithm specified above is quadratic. We instead use a 9100 // two-pass algorithm (similar to the one used to identify the 9101 // best viable function in an overload set) that identifies the 9102 // best function template (if it exists). 9103 9104 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 9105 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 9106 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 9107 9108 UnresolvedSetIterator Result = 9109 S.getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 9110 TPOC_Other, 0, SourceExpr->getLocStart(), 9111 S.PDiag(), 9112 S.PDiag(diag::err_addr_ovl_ambiguous) 9113 << Matches[0].second->getDeclName(), 9114 S.PDiag(diag::note_ovl_candidate) 9115 << (unsigned) oc_function_template, 9116 Complain, TargetFunctionType); 9117 9118 if (Result != MatchesCopy.end()) { 9119 // Make it the first and only element 9120 Matches[0].first = Matches[Result - MatchesCopy.begin()].first; 9121 Matches[0].second = cast<FunctionDecl>(*Result); 9122 Matches.resize(1); 9123 } 9124 } 9125 9126 void EliminateAllTemplateMatches() { 9127 // [...] any function template specializations in the set are 9128 // eliminated if the set also contains a non-template function, [...] 9129 for (unsigned I = 0, N = Matches.size(); I != N; ) { 9130 if (Matches[I].second->getPrimaryTemplate() == 0) 9131 ++I; 9132 else { 9133 Matches[I] = Matches[--N]; 9134 Matches.set_size(N); 9135 } 9136 } 9137 } 9138 9139public: 9140 void ComplainNoMatchesFound() const { 9141 assert(Matches.empty()); 9142 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) 9143 << OvlExpr->getName() << TargetFunctionType 9144 << OvlExpr->getSourceRange(); 9145 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); 9146 } 9147 9148 bool IsInvalidFormOfPointerToMemberFunction() const { 9149 return TargetTypeIsNonStaticMemberFunction && 9150 !OvlExprInfo.HasFormOfMemberPointer; 9151 } 9152 9153 void ComplainIsInvalidFormOfPointerToMemberFunction() const { 9154 // TODO: Should we condition this on whether any functions might 9155 // have matched, or is it more appropriate to do that in callers? 9156 // TODO: a fixit wouldn't hurt. 9157 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 9158 << TargetType << OvlExpr->getSourceRange(); 9159 } 9160 9161 void ComplainOfInvalidConversion() const { 9162 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 9163 << OvlExpr->getName() << TargetType; 9164 } 9165 9166 void ComplainMultipleMatchesFound() const { 9167 assert(Matches.size() > 1); 9168 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) 9169 << OvlExpr->getName() 9170 << OvlExpr->getSourceRange(); 9171 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); 9172 } 9173 9174 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); } 9175 9176 int getNumMatches() const { return Matches.size(); } 9177 9178 FunctionDecl* getMatchingFunctionDecl() const { 9179 if (Matches.size() != 1) return 0; 9180 return Matches[0].second; 9181 } 9182 9183 const DeclAccessPair* getMatchingFunctionAccessPair() const { 9184 if (Matches.size() != 1) return 0; 9185 return &Matches[0].first; 9186 } 9187}; 9188 9189/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 9190/// an overloaded function (C++ [over.over]), where @p From is an 9191/// expression with overloaded function type and @p ToType is the type 9192/// we're trying to resolve to. For example: 9193/// 9194/// @code 9195/// int f(double); 9196/// int f(int); 9197/// 9198/// int (*pfd)(double) = f; // selects f(double) 9199/// @endcode 9200/// 9201/// This routine returns the resulting FunctionDecl if it could be 9202/// resolved, and NULL otherwise. When @p Complain is true, this 9203/// routine will emit diagnostics if there is an error. 9204FunctionDecl * 9205Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, 9206 QualType TargetType, 9207 bool Complain, 9208 DeclAccessPair &FoundResult, 9209 bool *pHadMultipleCandidates) { 9210 assert(AddressOfExpr->getType() == Context.OverloadTy); 9211 9212 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, 9213 Complain); 9214 int NumMatches = Resolver.getNumMatches(); 9215 FunctionDecl* Fn = 0; 9216 if (NumMatches == 0 && Complain) { 9217 if (Resolver.IsInvalidFormOfPointerToMemberFunction()) 9218 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); 9219 else 9220 Resolver.ComplainNoMatchesFound(); 9221 } 9222 else if (NumMatches > 1 && Complain) 9223 Resolver.ComplainMultipleMatchesFound(); 9224 else if (NumMatches == 1) { 9225 Fn = Resolver.getMatchingFunctionDecl(); 9226 assert(Fn); 9227 FoundResult = *Resolver.getMatchingFunctionAccessPair(); 9228 MarkFunctionReferenced(AddressOfExpr->getLocStart(), Fn); 9229 if (Complain) 9230 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); 9231 } 9232 9233 if (pHadMultipleCandidates) 9234 *pHadMultipleCandidates = Resolver.hadMultipleCandidates(); 9235 return Fn; 9236} 9237 9238/// \brief Given an expression that refers to an overloaded function, try to 9239/// resolve that overloaded function expression down to a single function. 9240/// 9241/// This routine can only resolve template-ids that refer to a single function 9242/// template, where that template-id refers to a single template whose template 9243/// arguments are either provided by the template-id or have defaults, 9244/// as described in C++0x [temp.arg.explicit]p3. 9245FunctionDecl * 9246Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl, 9247 bool Complain, 9248 DeclAccessPair *FoundResult) { 9249 // C++ [over.over]p1: 9250 // [...] [Note: any redundant set of parentheses surrounding the 9251 // overloaded function name is ignored (5.1). ] 9252 // C++ [over.over]p1: 9253 // [...] The overloaded function name can be preceded by the & 9254 // operator. 9255 9256 // If we didn't actually find any template-ids, we're done. 9257 if (!ovl->hasExplicitTemplateArgs()) 9258 return 0; 9259 9260 TemplateArgumentListInfo ExplicitTemplateArgs; 9261 ovl->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 9262 9263 // Look through all of the overloaded functions, searching for one 9264 // whose type matches exactly. 9265 FunctionDecl *Matched = 0; 9266 for (UnresolvedSetIterator I = ovl->decls_begin(), 9267 E = ovl->decls_end(); I != E; ++I) { 9268 // C++0x [temp.arg.explicit]p3: 9269 // [...] In contexts where deduction is done and fails, or in contexts 9270 // where deduction is not done, if a template argument list is 9271 // specified and it, along with any default template arguments, 9272 // identifies a single function template specialization, then the 9273 // template-id is an lvalue for the function template specialization. 9274 FunctionTemplateDecl *FunctionTemplate 9275 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 9276 9277 // C++ [over.over]p2: 9278 // If the name is a function template, template argument deduction is 9279 // done (14.8.2.2), and if the argument deduction succeeds, the 9280 // resulting template argument list is used to generate a single 9281 // function template specialization, which is added to the set of 9282 // overloaded functions considered. 9283 FunctionDecl *Specialization = 0; 9284 TemplateDeductionInfo Info(ovl->getNameLoc()); 9285 if (TemplateDeductionResult Result 9286 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 9287 Specialization, Info)) { 9288 // FIXME: make a note of the failed deduction for diagnostics. 9289 (void)Result; 9290 continue; 9291 } 9292 9293 assert(Specialization && "no specialization and no error?"); 9294 9295 // Multiple matches; we can't resolve to a single declaration. 9296 if (Matched) { 9297 if (Complain) { 9298 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous) 9299 << ovl->getName(); 9300 NoteAllOverloadCandidates(ovl); 9301 } 9302 return 0; 9303 } 9304 9305 Matched = Specialization; 9306 if (FoundResult) *FoundResult = I.getPair(); 9307 } 9308 9309 return Matched; 9310} 9311 9312 9313 9314 9315// Resolve and fix an overloaded expression that can be resolved 9316// because it identifies a single function template specialization. 9317// 9318// Last three arguments should only be supplied if Complain = true 9319// 9320// Return true if it was logically possible to so resolve the 9321// expression, regardless of whether or not it succeeded. Always 9322// returns true if 'complain' is set. 9323bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization( 9324 ExprResult &SrcExpr, bool doFunctionPointerConverion, 9325 bool complain, const SourceRange& OpRangeForComplaining, 9326 QualType DestTypeForComplaining, 9327 unsigned DiagIDForComplaining) { 9328 assert(SrcExpr.get()->getType() == Context.OverloadTy); 9329 9330 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get()); 9331 9332 DeclAccessPair found; 9333 ExprResult SingleFunctionExpression; 9334 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization( 9335 ovl.Expression, /*complain*/ false, &found)) { 9336 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getLocStart())) { 9337 SrcExpr = ExprError(); 9338 return true; 9339 } 9340 9341 // It is only correct to resolve to an instance method if we're 9342 // resolving a form that's permitted to be a pointer to member. 9343 // Otherwise we'll end up making a bound member expression, which 9344 // is illegal in all the contexts we resolve like this. 9345 if (!ovl.HasFormOfMemberPointer && 9346 isa<CXXMethodDecl>(fn) && 9347 cast<CXXMethodDecl>(fn)->isInstance()) { 9348 if (!complain) return false; 9349 9350 Diag(ovl.Expression->getExprLoc(), 9351 diag::err_bound_member_function) 9352 << 0 << ovl.Expression->getSourceRange(); 9353 9354 // TODO: I believe we only end up here if there's a mix of 9355 // static and non-static candidates (otherwise the expression 9356 // would have 'bound member' type, not 'overload' type). 9357 // Ideally we would note which candidate was chosen and why 9358 // the static candidates were rejected. 9359 SrcExpr = ExprError(); 9360 return true; 9361 } 9362 9363 // Fix the expression to refer to 'fn'. 9364 SingleFunctionExpression = 9365 Owned(FixOverloadedFunctionReference(SrcExpr.take(), found, fn)); 9366 9367 // If desired, do function-to-pointer decay. 9368 if (doFunctionPointerConverion) { 9369 SingleFunctionExpression = 9370 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.take()); 9371 if (SingleFunctionExpression.isInvalid()) { 9372 SrcExpr = ExprError(); 9373 return true; 9374 } 9375 } 9376 } 9377 9378 if (!SingleFunctionExpression.isUsable()) { 9379 if (complain) { 9380 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) 9381 << ovl.Expression->getName() 9382 << DestTypeForComplaining 9383 << OpRangeForComplaining 9384 << ovl.Expression->getQualifierLoc().getSourceRange(); 9385 NoteAllOverloadCandidates(SrcExpr.get()); 9386 9387 SrcExpr = ExprError(); 9388 return true; 9389 } 9390 9391 return false; 9392 } 9393 9394 SrcExpr = SingleFunctionExpression; 9395 return true; 9396} 9397 9398/// \brief Add a single candidate to the overload set. 9399static void AddOverloadedCallCandidate(Sema &S, 9400 DeclAccessPair FoundDecl, 9401 TemplateArgumentListInfo *ExplicitTemplateArgs, 9402 llvm::ArrayRef<Expr *> Args, 9403 OverloadCandidateSet &CandidateSet, 9404 bool PartialOverloading, 9405 bool KnownValid) { 9406 NamedDecl *Callee = FoundDecl.getDecl(); 9407 if (isa<UsingShadowDecl>(Callee)) 9408 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 9409 9410 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 9411 if (ExplicitTemplateArgs) { 9412 assert(!KnownValid && "Explicit template arguments?"); 9413 return; 9414 } 9415 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet, false, 9416 PartialOverloading); 9417 return; 9418 } 9419 9420 if (FunctionTemplateDecl *FuncTemplate 9421 = dyn_cast<FunctionTemplateDecl>(Callee)) { 9422 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 9423 ExplicitTemplateArgs, Args, CandidateSet); 9424 return; 9425 } 9426 9427 assert(!KnownValid && "unhandled case in overloaded call candidate"); 9428} 9429 9430/// \brief Add the overload candidates named by callee and/or found by argument 9431/// dependent lookup to the given overload set. 9432void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 9433 llvm::ArrayRef<Expr *> Args, 9434 OverloadCandidateSet &CandidateSet, 9435 bool PartialOverloading) { 9436 9437#ifndef NDEBUG 9438 // Verify that ArgumentDependentLookup is consistent with the rules 9439 // in C++0x [basic.lookup.argdep]p3: 9440 // 9441 // Let X be the lookup set produced by unqualified lookup (3.4.1) 9442 // and let Y be the lookup set produced by argument dependent 9443 // lookup (defined as follows). If X contains 9444 // 9445 // -- a declaration of a class member, or 9446 // 9447 // -- a block-scope function declaration that is not a 9448 // using-declaration, or 9449 // 9450 // -- a declaration that is neither a function or a function 9451 // template 9452 // 9453 // then Y is empty. 9454 9455 if (ULE->requiresADL()) { 9456 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 9457 E = ULE->decls_end(); I != E; ++I) { 9458 assert(!(*I)->getDeclContext()->isRecord()); 9459 assert(isa<UsingShadowDecl>(*I) || 9460 !(*I)->getDeclContext()->isFunctionOrMethod()); 9461 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 9462 } 9463 } 9464#endif 9465 9466 // It would be nice to avoid this copy. 9467 TemplateArgumentListInfo TABuffer; 9468 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 9469 if (ULE->hasExplicitTemplateArgs()) { 9470 ULE->copyTemplateArgumentsInto(TABuffer); 9471 ExplicitTemplateArgs = &TABuffer; 9472 } 9473 9474 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 9475 E = ULE->decls_end(); I != E; ++I) 9476 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args, 9477 CandidateSet, PartialOverloading, 9478 /*KnownValid*/ true); 9479 9480 if (ULE->requiresADL()) 9481 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 9482 ULE->getExprLoc(), 9483 Args, ExplicitTemplateArgs, 9484 CandidateSet, PartialOverloading); 9485} 9486 9487/// Attempt to recover from an ill-formed use of a non-dependent name in a 9488/// template, where the non-dependent name was declared after the template 9489/// was defined. This is common in code written for a compilers which do not 9490/// correctly implement two-stage name lookup. 9491/// 9492/// Returns true if a viable candidate was found and a diagnostic was issued. 9493static bool 9494DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc, 9495 const CXXScopeSpec &SS, LookupResult &R, 9496 TemplateArgumentListInfo *ExplicitTemplateArgs, 9497 llvm::ArrayRef<Expr *> Args) { 9498 if (SemaRef.ActiveTemplateInstantiations.empty() || !SS.isEmpty()) 9499 return false; 9500 9501 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) { 9502 if (DC->isTransparentContext()) 9503 continue; 9504 9505 SemaRef.LookupQualifiedName(R, DC); 9506 9507 if (!R.empty()) { 9508 R.suppressDiagnostics(); 9509 9510 if (isa<CXXRecordDecl>(DC)) { 9511 // Don't diagnose names we find in classes; we get much better 9512 // diagnostics for these from DiagnoseEmptyLookup. 9513 R.clear(); 9514 return false; 9515 } 9516 9517 OverloadCandidateSet Candidates(FnLoc); 9518 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 9519 AddOverloadedCallCandidate(SemaRef, I.getPair(), 9520 ExplicitTemplateArgs, Args, 9521 Candidates, false, /*KnownValid*/ false); 9522 9523 OverloadCandidateSet::iterator Best; 9524 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) { 9525 // No viable functions. Don't bother the user with notes for functions 9526 // which don't work and shouldn't be found anyway. 9527 R.clear(); 9528 return false; 9529 } 9530 9531 // Find the namespaces where ADL would have looked, and suggest 9532 // declaring the function there instead. 9533 Sema::AssociatedNamespaceSet AssociatedNamespaces; 9534 Sema::AssociatedClassSet AssociatedClasses; 9535 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args, 9536 AssociatedNamespaces, 9537 AssociatedClasses); 9538 // Never suggest declaring a function within namespace 'std'. 9539 Sema::AssociatedNamespaceSet SuggestedNamespaces; 9540 if (DeclContext *Std = SemaRef.getStdNamespace()) { 9541 for (Sema::AssociatedNamespaceSet::iterator 9542 it = AssociatedNamespaces.begin(), 9543 end = AssociatedNamespaces.end(); it != end; ++it) { 9544 if (!Std->Encloses(*it)) 9545 SuggestedNamespaces.insert(*it); 9546 } 9547 } else { 9548 // Lacking the 'std::' namespace, use all of the associated namespaces. 9549 SuggestedNamespaces = AssociatedNamespaces; 9550 } 9551 9552 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup) 9553 << R.getLookupName(); 9554 if (SuggestedNamespaces.empty()) { 9555 SemaRef.Diag(Best->Function->getLocation(), 9556 diag::note_not_found_by_two_phase_lookup) 9557 << R.getLookupName() << 0; 9558 } else if (SuggestedNamespaces.size() == 1) { 9559 SemaRef.Diag(Best->Function->getLocation(), 9560 diag::note_not_found_by_two_phase_lookup) 9561 << R.getLookupName() << 1 << *SuggestedNamespaces.begin(); 9562 } else { 9563 // FIXME: It would be useful to list the associated namespaces here, 9564 // but the diagnostics infrastructure doesn't provide a way to produce 9565 // a localized representation of a list of items. 9566 SemaRef.Diag(Best->Function->getLocation(), 9567 diag::note_not_found_by_two_phase_lookup) 9568 << R.getLookupName() << 2; 9569 } 9570 9571 // Try to recover by calling this function. 9572 return true; 9573 } 9574 9575 R.clear(); 9576 } 9577 9578 return false; 9579} 9580 9581/// Attempt to recover from ill-formed use of a non-dependent operator in a 9582/// template, where the non-dependent operator was declared after the template 9583/// was defined. 9584/// 9585/// Returns true if a viable candidate was found and a diagnostic was issued. 9586static bool 9587DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op, 9588 SourceLocation OpLoc, 9589 llvm::ArrayRef<Expr *> Args) { 9590 DeclarationName OpName = 9591 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op); 9592 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName); 9593 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R, 9594 /*ExplicitTemplateArgs=*/0, Args); 9595} 9596 9597namespace { 9598// Callback to limit the allowed keywords and to only accept typo corrections 9599// that are keywords or whose decls refer to functions (or template functions) 9600// that accept the given number of arguments. 9601class RecoveryCallCCC : public CorrectionCandidateCallback { 9602 public: 9603 RecoveryCallCCC(Sema &SemaRef, unsigned NumArgs, bool HasExplicitTemplateArgs) 9604 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs) { 9605 WantTypeSpecifiers = SemaRef.getLangOpts().CPlusPlus; 9606 WantRemainingKeywords = false; 9607 } 9608 9609 virtual bool ValidateCandidate(const TypoCorrection &candidate) { 9610 if (!candidate.getCorrectionDecl()) 9611 return candidate.isKeyword(); 9612 9613 for (TypoCorrection::const_decl_iterator DI = candidate.begin(), 9614 DIEnd = candidate.end(); DI != DIEnd; ++DI) { 9615 FunctionDecl *FD = 0; 9616 NamedDecl *ND = (*DI)->getUnderlyingDecl(); 9617 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 9618 FD = FTD->getTemplatedDecl(); 9619 if (!HasExplicitTemplateArgs && !FD) { 9620 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) { 9621 // If the Decl is neither a function nor a template function, 9622 // determine if it is a pointer or reference to a function. If so, 9623 // check against the number of arguments expected for the pointee. 9624 QualType ValType = cast<ValueDecl>(ND)->getType(); 9625 if (ValType->isAnyPointerType() || ValType->isReferenceType()) 9626 ValType = ValType->getPointeeType(); 9627 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>()) 9628 if (FPT->getNumArgs() == NumArgs) 9629 return true; 9630 } 9631 } 9632 if (FD && FD->getNumParams() >= NumArgs && 9633 FD->getMinRequiredArguments() <= NumArgs) 9634 return true; 9635 } 9636 return false; 9637 } 9638 9639 private: 9640 unsigned NumArgs; 9641 bool HasExplicitTemplateArgs; 9642}; 9643 9644// Callback that effectively disabled typo correction 9645class NoTypoCorrectionCCC : public CorrectionCandidateCallback { 9646 public: 9647 NoTypoCorrectionCCC() { 9648 WantTypeSpecifiers = false; 9649 WantExpressionKeywords = false; 9650 WantCXXNamedCasts = false; 9651 WantRemainingKeywords = false; 9652 } 9653 9654 virtual bool ValidateCandidate(const TypoCorrection &candidate) { 9655 return false; 9656 } 9657}; 9658 9659class BuildRecoveryCallExprRAII { 9660 Sema &SemaRef; 9661public: 9662 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) { 9663 assert(SemaRef.IsBuildingRecoveryCallExpr == false); 9664 SemaRef.IsBuildingRecoveryCallExpr = true; 9665 } 9666 9667 ~BuildRecoveryCallExprRAII() { 9668 SemaRef.IsBuildingRecoveryCallExpr = false; 9669 } 9670}; 9671 9672} 9673 9674/// Attempts to recover from a call where no functions were found. 9675/// 9676/// Returns true if new candidates were found. 9677static ExprResult 9678BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 9679 UnresolvedLookupExpr *ULE, 9680 SourceLocation LParenLoc, 9681 llvm::MutableArrayRef<Expr *> Args, 9682 SourceLocation RParenLoc, 9683 bool EmptyLookup, bool AllowTypoCorrection) { 9684 // Do not try to recover if it is already building a recovery call. 9685 // This stops infinite loops for template instantiations like 9686 // 9687 // template <typename T> auto foo(T t) -> decltype(foo(t)) {} 9688 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {} 9689 // 9690 if (SemaRef.IsBuildingRecoveryCallExpr) 9691 return ExprError(); 9692 BuildRecoveryCallExprRAII RCE(SemaRef); 9693 9694 CXXScopeSpec SS; 9695 SS.Adopt(ULE->getQualifierLoc()); 9696 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc(); 9697 9698 TemplateArgumentListInfo TABuffer; 9699 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 9700 if (ULE->hasExplicitTemplateArgs()) { 9701 ULE->copyTemplateArgumentsInto(TABuffer); 9702 ExplicitTemplateArgs = &TABuffer; 9703 } 9704 9705 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 9706 Sema::LookupOrdinaryName); 9707 RecoveryCallCCC Validator(SemaRef, Args.size(), ExplicitTemplateArgs != 0); 9708 NoTypoCorrectionCCC RejectAll; 9709 CorrectionCandidateCallback *CCC = AllowTypoCorrection ? 9710 (CorrectionCandidateCallback*)&Validator : 9711 (CorrectionCandidateCallback*)&RejectAll; 9712 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R, 9713 ExplicitTemplateArgs, Args) && 9714 (!EmptyLookup || 9715 SemaRef.DiagnoseEmptyLookup(S, SS, R, *CCC, 9716 ExplicitTemplateArgs, Args))) 9717 return ExprError(); 9718 9719 assert(!R.empty() && "lookup results empty despite recovery"); 9720 9721 // Build an implicit member call if appropriate. Just drop the 9722 // casts and such from the call, we don't really care. 9723 ExprResult NewFn = ExprError(); 9724 if ((*R.begin())->isCXXClassMember()) 9725 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, 9726 R, ExplicitTemplateArgs); 9727 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid()) 9728 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false, 9729 ExplicitTemplateArgs); 9730 else 9731 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 9732 9733 if (NewFn.isInvalid()) 9734 return ExprError(); 9735 9736 // This shouldn't cause an infinite loop because we're giving it 9737 // an expression with viable lookup results, which should never 9738 // end up here. 9739 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 9740 MultiExprArg(Args.data(), Args.size()), 9741 RParenLoc); 9742} 9743 9744/// \brief Constructs and populates an OverloadedCandidateSet from 9745/// the given function. 9746/// \returns true when an the ExprResult output parameter has been set. 9747bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn, 9748 UnresolvedLookupExpr *ULE, 9749 Expr **Args, unsigned NumArgs, 9750 SourceLocation RParenLoc, 9751 OverloadCandidateSet *CandidateSet, 9752 ExprResult *Result) { 9753#ifndef NDEBUG 9754 if (ULE->requiresADL()) { 9755 // To do ADL, we must have found an unqualified name. 9756 assert(!ULE->getQualifier() && "qualified name with ADL"); 9757 9758 // We don't perform ADL for implicit declarations of builtins. 9759 // Verify that this was correctly set up. 9760 FunctionDecl *F; 9761 if (ULE->decls_begin() + 1 == ULE->decls_end() && 9762 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 9763 F->getBuiltinID() && F->isImplicit()) 9764 llvm_unreachable("performing ADL for builtin"); 9765 9766 // We don't perform ADL in C. 9767 assert(getLangOpts().CPlusPlus && "ADL enabled in C"); 9768 } 9769#endif 9770 9771 UnbridgedCastsSet UnbridgedCasts; 9772 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) { 9773 *Result = ExprError(); 9774 return true; 9775 } 9776 9777 // Add the functions denoted by the callee to the set of candidate 9778 // functions, including those from argument-dependent lookup. 9779 AddOverloadedCallCandidates(ULE, llvm::makeArrayRef(Args, NumArgs), 9780 *CandidateSet); 9781 9782 // If we found nothing, try to recover. 9783 // BuildRecoveryCallExpr diagnoses the error itself, so we just bail 9784 // out if it fails. 9785 if (CandidateSet->empty()) { 9786 // In Microsoft mode, if we are inside a template class member function then 9787 // create a type dependent CallExpr. The goal is to postpone name lookup 9788 // to instantiation time to be able to search into type dependent base 9789 // classes. 9790 if (getLangOpts().MicrosoftMode && CurContext->isDependentContext() && 9791 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) { 9792 CallExpr *CE = new (Context) CallExpr(Context, Fn, 9793 llvm::makeArrayRef(Args, NumArgs), 9794 Context.DependentTy, VK_RValue, 9795 RParenLoc); 9796 CE->setTypeDependent(true); 9797 *Result = Owned(CE); 9798 return true; 9799 } 9800 return false; 9801 } 9802 9803 UnbridgedCasts.restore(); 9804 return false; 9805} 9806 9807/// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns 9808/// the completed call expression. If overload resolution fails, emits 9809/// diagnostics and returns ExprError() 9810static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 9811 UnresolvedLookupExpr *ULE, 9812 SourceLocation LParenLoc, 9813 Expr **Args, unsigned NumArgs, 9814 SourceLocation RParenLoc, 9815 Expr *ExecConfig, 9816 OverloadCandidateSet *CandidateSet, 9817 OverloadCandidateSet::iterator *Best, 9818 OverloadingResult OverloadResult, 9819 bool AllowTypoCorrection) { 9820 if (CandidateSet->empty()) 9821 return BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, 9822 llvm::MutableArrayRef<Expr *>(Args, NumArgs), 9823 RParenLoc, /*EmptyLookup=*/true, 9824 AllowTypoCorrection); 9825 9826 switch (OverloadResult) { 9827 case OR_Success: { 9828 FunctionDecl *FDecl = (*Best)->Function; 9829 SemaRef.MarkFunctionReferenced(Fn->getExprLoc(), FDecl); 9830 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl); 9831 SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()); 9832 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl); 9833 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, 9834 RParenLoc, ExecConfig); 9835 } 9836 9837 case OR_No_Viable_Function: { 9838 // Try to recover by looking for viable functions which the user might 9839 // have meant to call. 9840 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, 9841 llvm::MutableArrayRef<Expr *>(Args, NumArgs), 9842 RParenLoc, 9843 /*EmptyLookup=*/false, 9844 AllowTypoCorrection); 9845 if (!Recovery.isInvalid()) 9846 return Recovery; 9847 9848 SemaRef.Diag(Fn->getLocStart(), 9849 diag::err_ovl_no_viable_function_in_call) 9850 << ULE->getName() << Fn->getSourceRange(); 9851 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, 9852 llvm::makeArrayRef(Args, NumArgs)); 9853 break; 9854 } 9855 9856 case OR_Ambiguous: 9857 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_ambiguous_call) 9858 << ULE->getName() << Fn->getSourceRange(); 9859 CandidateSet->NoteCandidates(SemaRef, OCD_ViableCandidates, 9860 llvm::makeArrayRef(Args, NumArgs)); 9861 break; 9862 9863 case OR_Deleted: { 9864 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_deleted_call) 9865 << (*Best)->Function->isDeleted() 9866 << ULE->getName() 9867 << SemaRef.getDeletedOrUnavailableSuffix((*Best)->Function) 9868 << Fn->getSourceRange(); 9869 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, 9870 llvm::makeArrayRef(Args, NumArgs)); 9871 9872 // We emitted an error for the unvailable/deleted function call but keep 9873 // the call in the AST. 9874 FunctionDecl *FDecl = (*Best)->Function; 9875 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl); 9876 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, 9877 RParenLoc, ExecConfig); 9878 } 9879 } 9880 9881 // Overload resolution failed. 9882 return ExprError(); 9883} 9884 9885/// BuildOverloadedCallExpr - Given the call expression that calls Fn 9886/// (which eventually refers to the declaration Func) and the call 9887/// arguments Args/NumArgs, attempt to resolve the function call down 9888/// to a specific function. If overload resolution succeeds, returns 9889/// the call expression produced by overload resolution. 9890/// Otherwise, emits diagnostics and returns ExprError. 9891ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, 9892 UnresolvedLookupExpr *ULE, 9893 SourceLocation LParenLoc, 9894 Expr **Args, unsigned NumArgs, 9895 SourceLocation RParenLoc, 9896 Expr *ExecConfig, 9897 bool AllowTypoCorrection) { 9898 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 9899 ExprResult result; 9900 9901 if (buildOverloadedCallSet(S, Fn, ULE, Args, NumArgs, LParenLoc, 9902 &CandidateSet, &result)) 9903 return result; 9904 9905 OverloadCandidateSet::iterator Best; 9906 OverloadingResult OverloadResult = 9907 CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best); 9908 9909 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 9910 RParenLoc, ExecConfig, &CandidateSet, 9911 &Best, OverloadResult, 9912 AllowTypoCorrection); 9913} 9914 9915static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 9916 return Functions.size() > 1 || 9917 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 9918} 9919 9920/// \brief Create a unary operation that may resolve to an overloaded 9921/// operator. 9922/// 9923/// \param OpLoc The location of the operator itself (e.g., '*'). 9924/// 9925/// \param OpcIn The UnaryOperator::Opcode that describes this 9926/// operator. 9927/// 9928/// \param Fns The set of non-member functions that will be 9929/// considered by overload resolution. The caller needs to build this 9930/// set based on the context using, e.g., 9931/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 9932/// set should not contain any member functions; those will be added 9933/// by CreateOverloadedUnaryOp(). 9934/// 9935/// \param Input The input argument. 9936ExprResult 9937Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 9938 const UnresolvedSetImpl &Fns, 9939 Expr *Input) { 9940 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 9941 9942 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 9943 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 9944 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 9945 // TODO: provide better source location info. 9946 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 9947 9948 if (checkPlaceholderForOverload(*this, Input)) 9949 return ExprError(); 9950 9951 Expr *Args[2] = { Input, 0 }; 9952 unsigned NumArgs = 1; 9953 9954 // For post-increment and post-decrement, add the implicit '0' as 9955 // the second argument, so that we know this is a post-increment or 9956 // post-decrement. 9957 if (Opc == UO_PostInc || Opc == UO_PostDec) { 9958 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 9959 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 9960 SourceLocation()); 9961 NumArgs = 2; 9962 } 9963 9964 if (Input->isTypeDependent()) { 9965 if (Fns.empty()) 9966 return Owned(new (Context) UnaryOperator(Input, 9967 Opc, 9968 Context.DependentTy, 9969 VK_RValue, OK_Ordinary, 9970 OpLoc)); 9971 9972 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 9973 UnresolvedLookupExpr *Fn 9974 = UnresolvedLookupExpr::Create(Context, NamingClass, 9975 NestedNameSpecifierLoc(), OpNameInfo, 9976 /*ADL*/ true, IsOverloaded(Fns), 9977 Fns.begin(), Fns.end()); 9978 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 9979 llvm::makeArrayRef(Args, NumArgs), 9980 Context.DependentTy, 9981 VK_RValue, 9982 OpLoc, false)); 9983 } 9984 9985 // Build an empty overload set. 9986 OverloadCandidateSet CandidateSet(OpLoc); 9987 9988 // Add the candidates from the given function set. 9989 AddFunctionCandidates(Fns, llvm::makeArrayRef(Args, NumArgs), CandidateSet, 9990 false); 9991 9992 // Add operator candidates that are member functions. 9993 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 9994 9995 // Add candidates from ADL. 9996 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 9997 OpLoc, llvm::makeArrayRef(Args, NumArgs), 9998 /*ExplicitTemplateArgs*/ 0, 9999 CandidateSet); 10000 10001 // Add builtin operator candidates. 10002 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 10003 10004 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10005 10006 // Perform overload resolution. 10007 OverloadCandidateSet::iterator Best; 10008 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 10009 case OR_Success: { 10010 // We found a built-in operator or an overloaded operator. 10011 FunctionDecl *FnDecl = Best->Function; 10012 10013 if (FnDecl) { 10014 // We matched an overloaded operator. Build a call to that 10015 // operator. 10016 10017 MarkFunctionReferenced(OpLoc, FnDecl); 10018 10019 // Convert the arguments. 10020 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 10021 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 10022 10023 ExprResult InputRes = 10024 PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 10025 Best->FoundDecl, Method); 10026 if (InputRes.isInvalid()) 10027 return ExprError(); 10028 Input = InputRes.take(); 10029 } else { 10030 // Convert the arguments. 10031 ExprResult InputInit 10032 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 10033 Context, 10034 FnDecl->getParamDecl(0)), 10035 SourceLocation(), 10036 Input); 10037 if (InputInit.isInvalid()) 10038 return ExprError(); 10039 Input = InputInit.take(); 10040 } 10041 10042 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 10043 10044 // Determine the result type. 10045 QualType ResultTy = FnDecl->getResultType(); 10046 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10047 ResultTy = ResultTy.getNonLValueExprType(Context); 10048 10049 // Build the actual expression node. 10050 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 10051 HadMultipleCandidates, OpLoc); 10052 if (FnExpr.isInvalid()) 10053 return ExprError(); 10054 10055 Args[0] = Input; 10056 CallExpr *TheCall = 10057 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 10058 llvm::makeArrayRef(Args, NumArgs), 10059 ResultTy, VK, OpLoc, false); 10060 10061 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 10062 FnDecl)) 10063 return ExprError(); 10064 10065 return MaybeBindToTemporary(TheCall); 10066 } else { 10067 // We matched a built-in operator. Convert the arguments, then 10068 // break out so that we will build the appropriate built-in 10069 // operator node. 10070 ExprResult InputRes = 10071 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 10072 Best->Conversions[0], AA_Passing); 10073 if (InputRes.isInvalid()) 10074 return ExprError(); 10075 Input = InputRes.take(); 10076 break; 10077 } 10078 } 10079 10080 case OR_No_Viable_Function: 10081 // This is an erroneous use of an operator which can be overloaded by 10082 // a non-member function. Check for non-member operators which were 10083 // defined too late to be candidates. 10084 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, 10085 llvm::makeArrayRef(Args, NumArgs))) 10086 // FIXME: Recover by calling the found function. 10087 return ExprError(); 10088 10089 // No viable function; fall through to handling this as a 10090 // built-in operator, which will produce an error message for us. 10091 break; 10092 10093 case OR_Ambiguous: 10094 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 10095 << UnaryOperator::getOpcodeStr(Opc) 10096 << Input->getType() 10097 << Input->getSourceRange(); 10098 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 10099 llvm::makeArrayRef(Args, NumArgs), 10100 UnaryOperator::getOpcodeStr(Opc), OpLoc); 10101 return ExprError(); 10102 10103 case OR_Deleted: 10104 Diag(OpLoc, diag::err_ovl_deleted_oper) 10105 << Best->Function->isDeleted() 10106 << UnaryOperator::getOpcodeStr(Opc) 10107 << getDeletedOrUnavailableSuffix(Best->Function) 10108 << Input->getSourceRange(); 10109 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10110 llvm::makeArrayRef(Args, NumArgs), 10111 UnaryOperator::getOpcodeStr(Opc), OpLoc); 10112 return ExprError(); 10113 } 10114 10115 // Either we found no viable overloaded operator or we matched a 10116 // built-in operator. In either case, fall through to trying to 10117 // build a built-in operation. 10118 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 10119} 10120 10121/// \brief Create a binary operation that may resolve to an overloaded 10122/// operator. 10123/// 10124/// \param OpLoc The location of the operator itself (e.g., '+'). 10125/// 10126/// \param OpcIn The BinaryOperator::Opcode that describes this 10127/// operator. 10128/// 10129/// \param Fns The set of non-member functions that will be 10130/// considered by overload resolution. The caller needs to build this 10131/// set based on the context using, e.g., 10132/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 10133/// set should not contain any member functions; those will be added 10134/// by CreateOverloadedBinOp(). 10135/// 10136/// \param LHS Left-hand argument. 10137/// \param RHS Right-hand argument. 10138ExprResult 10139Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 10140 unsigned OpcIn, 10141 const UnresolvedSetImpl &Fns, 10142 Expr *LHS, Expr *RHS) { 10143 Expr *Args[2] = { LHS, RHS }; 10144 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 10145 10146 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 10147 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 10148 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 10149 10150 // If either side is type-dependent, create an appropriate dependent 10151 // expression. 10152 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 10153 if (Fns.empty()) { 10154 // If there are no functions to store, just build a dependent 10155 // BinaryOperator or CompoundAssignment. 10156 if (Opc <= BO_Assign || Opc > BO_OrAssign) 10157 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 10158 Context.DependentTy, 10159 VK_RValue, OK_Ordinary, 10160 OpLoc, 10161 FPFeatures.fp_contract)); 10162 10163 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 10164 Context.DependentTy, 10165 VK_LValue, 10166 OK_Ordinary, 10167 Context.DependentTy, 10168 Context.DependentTy, 10169 OpLoc, 10170 FPFeatures.fp_contract)); 10171 } 10172 10173 // FIXME: save results of ADL from here? 10174 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10175 // TODO: provide better source location info in DNLoc component. 10176 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 10177 UnresolvedLookupExpr *Fn 10178 = UnresolvedLookupExpr::Create(Context, NamingClass, 10179 NestedNameSpecifierLoc(), OpNameInfo, 10180 /*ADL*/ true, IsOverloaded(Fns), 10181 Fns.begin(), Fns.end()); 10182 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, Args, 10183 Context.DependentTy, VK_RValue, 10184 OpLoc, FPFeatures.fp_contract)); 10185 } 10186 10187 // Always do placeholder-like conversions on the RHS. 10188 if (checkPlaceholderForOverload(*this, Args[1])) 10189 return ExprError(); 10190 10191 // Do placeholder-like conversion on the LHS; note that we should 10192 // not get here with a PseudoObject LHS. 10193 assert(Args[0]->getObjectKind() != OK_ObjCProperty); 10194 if (checkPlaceholderForOverload(*this, Args[0])) 10195 return ExprError(); 10196 10197 // If this is the assignment operator, we only perform overload resolution 10198 // if the left-hand side is a class or enumeration type. This is actually 10199 // a hack. The standard requires that we do overload resolution between the 10200 // various built-in candidates, but as DR507 points out, this can lead to 10201 // problems. So we do it this way, which pretty much follows what GCC does. 10202 // Note that we go the traditional code path for compound assignment forms. 10203 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 10204 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10205 10206 // If this is the .* operator, which is not overloadable, just 10207 // create a built-in binary operator. 10208 if (Opc == BO_PtrMemD) 10209 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10210 10211 // Build an empty overload set. 10212 OverloadCandidateSet CandidateSet(OpLoc); 10213 10214 // Add the candidates from the given function set. 10215 AddFunctionCandidates(Fns, Args, CandidateSet, false); 10216 10217 // Add operator candidates that are member functions. 10218 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 10219 10220 // Add candidates from ADL. 10221 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 10222 OpLoc, Args, 10223 /*ExplicitTemplateArgs*/ 0, 10224 CandidateSet); 10225 10226 // Add builtin operator candidates. 10227 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 10228 10229 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10230 10231 // Perform overload resolution. 10232 OverloadCandidateSet::iterator Best; 10233 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 10234 case OR_Success: { 10235 // We found a built-in operator or an overloaded operator. 10236 FunctionDecl *FnDecl = Best->Function; 10237 10238 if (FnDecl) { 10239 // We matched an overloaded operator. Build a call to that 10240 // operator. 10241 10242 MarkFunctionReferenced(OpLoc, FnDecl); 10243 10244 // Convert the arguments. 10245 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 10246 // Best->Access is only meaningful for class members. 10247 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 10248 10249 ExprResult Arg1 = 10250 PerformCopyInitialization( 10251 InitializedEntity::InitializeParameter(Context, 10252 FnDecl->getParamDecl(0)), 10253 SourceLocation(), Owned(Args[1])); 10254 if (Arg1.isInvalid()) 10255 return ExprError(); 10256 10257 ExprResult Arg0 = 10258 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 10259 Best->FoundDecl, Method); 10260 if (Arg0.isInvalid()) 10261 return ExprError(); 10262 Args[0] = Arg0.takeAs<Expr>(); 10263 Args[1] = RHS = Arg1.takeAs<Expr>(); 10264 } else { 10265 // Convert the arguments. 10266 ExprResult Arg0 = PerformCopyInitialization( 10267 InitializedEntity::InitializeParameter(Context, 10268 FnDecl->getParamDecl(0)), 10269 SourceLocation(), Owned(Args[0])); 10270 if (Arg0.isInvalid()) 10271 return ExprError(); 10272 10273 ExprResult Arg1 = 10274 PerformCopyInitialization( 10275 InitializedEntity::InitializeParameter(Context, 10276 FnDecl->getParamDecl(1)), 10277 SourceLocation(), Owned(Args[1])); 10278 if (Arg1.isInvalid()) 10279 return ExprError(); 10280 Args[0] = LHS = Arg0.takeAs<Expr>(); 10281 Args[1] = RHS = Arg1.takeAs<Expr>(); 10282 } 10283 10284 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 10285 10286 // Determine the result type. 10287 QualType ResultTy = FnDecl->getResultType(); 10288 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10289 ResultTy = ResultTy.getNonLValueExprType(Context); 10290 10291 // Build the actual expression node. 10292 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 10293 HadMultipleCandidates, OpLoc); 10294 if (FnExpr.isInvalid()) 10295 return ExprError(); 10296 10297 CXXOperatorCallExpr *TheCall = 10298 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 10299 Args, ResultTy, VK, OpLoc, 10300 FPFeatures.fp_contract); 10301 10302 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 10303 FnDecl)) 10304 return ExprError(); 10305 10306 return MaybeBindToTemporary(TheCall); 10307 } else { 10308 // We matched a built-in operator. Convert the arguments, then 10309 // break out so that we will build the appropriate built-in 10310 // operator node. 10311 ExprResult ArgsRes0 = 10312 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 10313 Best->Conversions[0], AA_Passing); 10314 if (ArgsRes0.isInvalid()) 10315 return ExprError(); 10316 Args[0] = ArgsRes0.take(); 10317 10318 ExprResult ArgsRes1 = 10319 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 10320 Best->Conversions[1], AA_Passing); 10321 if (ArgsRes1.isInvalid()) 10322 return ExprError(); 10323 Args[1] = ArgsRes1.take(); 10324 break; 10325 } 10326 } 10327 10328 case OR_No_Viable_Function: { 10329 // C++ [over.match.oper]p9: 10330 // If the operator is the operator , [...] and there are no 10331 // viable functions, then the operator is assumed to be the 10332 // built-in operator and interpreted according to clause 5. 10333 if (Opc == BO_Comma) 10334 break; 10335 10336 // For class as left operand for assignment or compound assigment 10337 // operator do not fall through to handling in built-in, but report that 10338 // no overloaded assignment operator found 10339 ExprResult Result = ExprError(); 10340 if (Args[0]->getType()->isRecordType() && 10341 Opc >= BO_Assign && Opc <= BO_OrAssign) { 10342 Diag(OpLoc, diag::err_ovl_no_viable_oper) 10343 << BinaryOperator::getOpcodeStr(Opc) 10344 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10345 } else { 10346 // This is an erroneous use of an operator which can be overloaded by 10347 // a non-member function. Check for non-member operators which were 10348 // defined too late to be candidates. 10349 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args)) 10350 // FIXME: Recover by calling the found function. 10351 return ExprError(); 10352 10353 // No viable function; try to create a built-in operation, which will 10354 // produce an error. Then, show the non-viable candidates. 10355 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10356 } 10357 assert(Result.isInvalid() && 10358 "C++ binary operator overloading is missing candidates!"); 10359 if (Result.isInvalid()) 10360 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10361 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10362 return Result; 10363 } 10364 10365 case OR_Ambiguous: 10366 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 10367 << BinaryOperator::getOpcodeStr(Opc) 10368 << Args[0]->getType() << Args[1]->getType() 10369 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10370 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 10371 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10372 return ExprError(); 10373 10374 case OR_Deleted: 10375 if (isImplicitlyDeleted(Best->Function)) { 10376 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 10377 Diag(OpLoc, diag::err_ovl_deleted_special_oper) 10378 << getSpecialMember(Method) 10379 << BinaryOperator::getOpcodeStr(Opc) 10380 << getDeletedOrUnavailableSuffix(Best->Function); 10381 10382 if (getSpecialMember(Method) != CXXInvalid) { 10383 // The user probably meant to call this special member. Just 10384 // explain why it's deleted. 10385 NoteDeletedFunction(Method); 10386 return ExprError(); 10387 } 10388 } else { 10389 Diag(OpLoc, diag::err_ovl_deleted_oper) 10390 << Best->Function->isDeleted() 10391 << BinaryOperator::getOpcodeStr(Opc) 10392 << getDeletedOrUnavailableSuffix(Best->Function) 10393 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10394 } 10395 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10396 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10397 return ExprError(); 10398 } 10399 10400 // We matched a built-in operator; build it. 10401 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10402} 10403 10404ExprResult 10405Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 10406 SourceLocation RLoc, 10407 Expr *Base, Expr *Idx) { 10408 Expr *Args[2] = { Base, Idx }; 10409 DeclarationName OpName = 10410 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 10411 10412 // If either side is type-dependent, create an appropriate dependent 10413 // expression. 10414 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 10415 10416 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10417 // CHECKME: no 'operator' keyword? 10418 DeclarationNameInfo OpNameInfo(OpName, LLoc); 10419 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 10420 UnresolvedLookupExpr *Fn 10421 = UnresolvedLookupExpr::Create(Context, NamingClass, 10422 NestedNameSpecifierLoc(), OpNameInfo, 10423 /*ADL*/ true, /*Overloaded*/ false, 10424 UnresolvedSetIterator(), 10425 UnresolvedSetIterator()); 10426 // Can't add any actual overloads yet 10427 10428 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 10429 Args, 10430 Context.DependentTy, 10431 VK_RValue, 10432 RLoc, false)); 10433 } 10434 10435 // Handle placeholders on both operands. 10436 if (checkPlaceholderForOverload(*this, Args[0])) 10437 return ExprError(); 10438 if (checkPlaceholderForOverload(*this, Args[1])) 10439 return ExprError(); 10440 10441 // Build an empty overload set. 10442 OverloadCandidateSet CandidateSet(LLoc); 10443 10444 // Subscript can only be overloaded as a member function. 10445 10446 // Add operator candidates that are member functions. 10447 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 10448 10449 // Add builtin operator candidates. 10450 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 10451 10452 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10453 10454 // Perform overload resolution. 10455 OverloadCandidateSet::iterator Best; 10456 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 10457 case OR_Success: { 10458 // We found a built-in operator or an overloaded operator. 10459 FunctionDecl *FnDecl = Best->Function; 10460 10461 if (FnDecl) { 10462 // We matched an overloaded operator. Build a call to that 10463 // operator. 10464 10465 MarkFunctionReferenced(LLoc, FnDecl); 10466 10467 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 10468 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 10469 10470 // Convert the arguments. 10471 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 10472 ExprResult Arg0 = 10473 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 10474 Best->FoundDecl, Method); 10475 if (Arg0.isInvalid()) 10476 return ExprError(); 10477 Args[0] = Arg0.take(); 10478 10479 // Convert the arguments. 10480 ExprResult InputInit 10481 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 10482 Context, 10483 FnDecl->getParamDecl(0)), 10484 SourceLocation(), 10485 Owned(Args[1])); 10486 if (InputInit.isInvalid()) 10487 return ExprError(); 10488 10489 Args[1] = InputInit.takeAs<Expr>(); 10490 10491 // Determine the result type 10492 QualType ResultTy = FnDecl->getResultType(); 10493 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10494 ResultTy = ResultTy.getNonLValueExprType(Context); 10495 10496 // Build the actual expression node. 10497 DeclarationNameInfo OpLocInfo(OpName, LLoc); 10498 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 10499 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 10500 HadMultipleCandidates, 10501 OpLocInfo.getLoc(), 10502 OpLocInfo.getInfo()); 10503 if (FnExpr.isInvalid()) 10504 return ExprError(); 10505 10506 CXXOperatorCallExpr *TheCall = 10507 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 10508 FnExpr.take(), Args, 10509 ResultTy, VK, RLoc, 10510 false); 10511 10512 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 10513 FnDecl)) 10514 return ExprError(); 10515 10516 return MaybeBindToTemporary(TheCall); 10517 } else { 10518 // We matched a built-in operator. Convert the arguments, then 10519 // break out so that we will build the appropriate built-in 10520 // operator node. 10521 ExprResult ArgsRes0 = 10522 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 10523 Best->Conversions[0], AA_Passing); 10524 if (ArgsRes0.isInvalid()) 10525 return ExprError(); 10526 Args[0] = ArgsRes0.take(); 10527 10528 ExprResult ArgsRes1 = 10529 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 10530 Best->Conversions[1], AA_Passing); 10531 if (ArgsRes1.isInvalid()) 10532 return ExprError(); 10533 Args[1] = ArgsRes1.take(); 10534 10535 break; 10536 } 10537 } 10538 10539 case OR_No_Viable_Function: { 10540 if (CandidateSet.empty()) 10541 Diag(LLoc, diag::err_ovl_no_oper) 10542 << Args[0]->getType() << /*subscript*/ 0 10543 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10544 else 10545 Diag(LLoc, diag::err_ovl_no_viable_subscript) 10546 << Args[0]->getType() 10547 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10548 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10549 "[]", LLoc); 10550 return ExprError(); 10551 } 10552 10553 case OR_Ambiguous: 10554 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 10555 << "[]" 10556 << Args[0]->getType() << Args[1]->getType() 10557 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10558 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 10559 "[]", LLoc); 10560 return ExprError(); 10561 10562 case OR_Deleted: 10563 Diag(LLoc, diag::err_ovl_deleted_oper) 10564 << Best->Function->isDeleted() << "[]" 10565 << getDeletedOrUnavailableSuffix(Best->Function) 10566 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10567 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10568 "[]", LLoc); 10569 return ExprError(); 10570 } 10571 10572 // We matched a built-in operator; build it. 10573 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 10574} 10575 10576/// BuildCallToMemberFunction - Build a call to a member 10577/// function. MemExpr is the expression that refers to the member 10578/// function (and includes the object parameter), Args/NumArgs are the 10579/// arguments to the function call (not including the object 10580/// parameter). The caller needs to validate that the member 10581/// expression refers to a non-static member function or an overloaded 10582/// member function. 10583ExprResult 10584Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 10585 SourceLocation LParenLoc, Expr **Args, 10586 unsigned NumArgs, SourceLocation RParenLoc) { 10587 assert(MemExprE->getType() == Context.BoundMemberTy || 10588 MemExprE->getType() == Context.OverloadTy); 10589 10590 // Dig out the member expression. This holds both the object 10591 // argument and the member function we're referring to. 10592 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 10593 10594 // Determine whether this is a call to a pointer-to-member function. 10595 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) { 10596 assert(op->getType() == Context.BoundMemberTy); 10597 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI); 10598 10599 QualType fnType = 10600 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType(); 10601 10602 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>(); 10603 QualType resultType = proto->getCallResultType(Context); 10604 ExprValueKind valueKind = Expr::getValueKindForType(proto->getResultType()); 10605 10606 // Check that the object type isn't more qualified than the 10607 // member function we're calling. 10608 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals()); 10609 10610 QualType objectType = op->getLHS()->getType(); 10611 if (op->getOpcode() == BO_PtrMemI) 10612 objectType = objectType->castAs<PointerType>()->getPointeeType(); 10613 Qualifiers objectQuals = objectType.getQualifiers(); 10614 10615 Qualifiers difference = objectQuals - funcQuals; 10616 difference.removeObjCGCAttr(); 10617 difference.removeAddressSpace(); 10618 if (difference) { 10619 std::string qualsString = difference.getAsString(); 10620 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals) 10621 << fnType.getUnqualifiedType() 10622 << qualsString 10623 << (qualsString.find(' ') == std::string::npos ? 1 : 2); 10624 } 10625 10626 CXXMemberCallExpr *call 10627 = new (Context) CXXMemberCallExpr(Context, MemExprE, 10628 llvm::makeArrayRef(Args, NumArgs), 10629 resultType, valueKind, RParenLoc); 10630 10631 if (CheckCallReturnType(proto->getResultType(), 10632 op->getRHS()->getLocStart(), 10633 call, 0)) 10634 return ExprError(); 10635 10636 if (ConvertArgumentsForCall(call, op, 0, proto, Args, NumArgs, RParenLoc)) 10637 return ExprError(); 10638 10639 return MaybeBindToTemporary(call); 10640 } 10641 10642 UnbridgedCastsSet UnbridgedCasts; 10643 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) 10644 return ExprError(); 10645 10646 MemberExpr *MemExpr; 10647 CXXMethodDecl *Method = 0; 10648 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 10649 NestedNameSpecifier *Qualifier = 0; 10650 if (isa<MemberExpr>(NakedMemExpr)) { 10651 MemExpr = cast<MemberExpr>(NakedMemExpr); 10652 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 10653 FoundDecl = MemExpr->getFoundDecl(); 10654 Qualifier = MemExpr->getQualifier(); 10655 UnbridgedCasts.restore(); 10656 } else { 10657 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 10658 Qualifier = UnresExpr->getQualifier(); 10659 10660 QualType ObjectType = UnresExpr->getBaseType(); 10661 Expr::Classification ObjectClassification 10662 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 10663 : UnresExpr->getBase()->Classify(Context); 10664 10665 // Add overload candidates 10666 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 10667 10668 // FIXME: avoid copy. 10669 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 10670 if (UnresExpr->hasExplicitTemplateArgs()) { 10671 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 10672 TemplateArgs = &TemplateArgsBuffer; 10673 } 10674 10675 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 10676 E = UnresExpr->decls_end(); I != E; ++I) { 10677 10678 NamedDecl *Func = *I; 10679 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 10680 if (isa<UsingShadowDecl>(Func)) 10681 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 10682 10683 10684 // Microsoft supports direct constructor calls. 10685 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) { 10686 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), 10687 llvm::makeArrayRef(Args, NumArgs), CandidateSet); 10688 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 10689 // If explicit template arguments were provided, we can't call a 10690 // non-template member function. 10691 if (TemplateArgs) 10692 continue; 10693 10694 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 10695 ObjectClassification, 10696 llvm::makeArrayRef(Args, NumArgs), CandidateSet, 10697 /*SuppressUserConversions=*/false); 10698 } else { 10699 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 10700 I.getPair(), ActingDC, TemplateArgs, 10701 ObjectType, ObjectClassification, 10702 llvm::makeArrayRef(Args, NumArgs), 10703 CandidateSet, 10704 /*SuppressUsedConversions=*/false); 10705 } 10706 } 10707 10708 DeclarationName DeclName = UnresExpr->getMemberName(); 10709 10710 UnbridgedCasts.restore(); 10711 10712 OverloadCandidateSet::iterator Best; 10713 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 10714 Best)) { 10715 case OR_Success: 10716 Method = cast<CXXMethodDecl>(Best->Function); 10717 MarkFunctionReferenced(UnresExpr->getMemberLoc(), Method); 10718 FoundDecl = Best->FoundDecl; 10719 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 10720 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 10721 break; 10722 10723 case OR_No_Viable_Function: 10724 Diag(UnresExpr->getMemberLoc(), 10725 diag::err_ovl_no_viable_member_function_in_call) 10726 << DeclName << MemExprE->getSourceRange(); 10727 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10728 llvm::makeArrayRef(Args, NumArgs)); 10729 // FIXME: Leaking incoming expressions! 10730 return ExprError(); 10731 10732 case OR_Ambiguous: 10733 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 10734 << DeclName << MemExprE->getSourceRange(); 10735 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10736 llvm::makeArrayRef(Args, NumArgs)); 10737 // FIXME: Leaking incoming expressions! 10738 return ExprError(); 10739 10740 case OR_Deleted: 10741 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 10742 << Best->Function->isDeleted() 10743 << DeclName 10744 << getDeletedOrUnavailableSuffix(Best->Function) 10745 << MemExprE->getSourceRange(); 10746 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10747 llvm::makeArrayRef(Args, NumArgs)); 10748 // FIXME: Leaking incoming expressions! 10749 return ExprError(); 10750 } 10751 10752 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 10753 10754 // If overload resolution picked a static member, build a 10755 // non-member call based on that function. 10756 if (Method->isStatic()) { 10757 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 10758 Args, NumArgs, RParenLoc); 10759 } 10760 10761 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 10762 } 10763 10764 QualType ResultType = Method->getResultType(); 10765 ExprValueKind VK = Expr::getValueKindForType(ResultType); 10766 ResultType = ResultType.getNonLValueExprType(Context); 10767 10768 assert(Method && "Member call to something that isn't a method?"); 10769 CXXMemberCallExpr *TheCall = 10770 new (Context) CXXMemberCallExpr(Context, MemExprE, 10771 llvm::makeArrayRef(Args, NumArgs), 10772 ResultType, VK, RParenLoc); 10773 10774 // Check for a valid return type. 10775 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 10776 TheCall, Method)) 10777 return ExprError(); 10778 10779 // Convert the object argument (for a non-static member function call). 10780 // We only need to do this if there was actually an overload; otherwise 10781 // it was done at lookup. 10782 if (!Method->isStatic()) { 10783 ExprResult ObjectArg = 10784 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier, 10785 FoundDecl, Method); 10786 if (ObjectArg.isInvalid()) 10787 return ExprError(); 10788 MemExpr->setBase(ObjectArg.take()); 10789 } 10790 10791 // Convert the rest of the arguments 10792 const FunctionProtoType *Proto = 10793 Method->getType()->getAs<FunctionProtoType>(); 10794 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 10795 RParenLoc)) 10796 return ExprError(); 10797 10798 DiagnoseSentinelCalls(Method, LParenLoc, Args, NumArgs); 10799 10800 if (CheckFunctionCall(Method, TheCall, Proto)) 10801 return ExprError(); 10802 10803 if ((isa<CXXConstructorDecl>(CurContext) || 10804 isa<CXXDestructorDecl>(CurContext)) && 10805 TheCall->getMethodDecl()->isPure()) { 10806 const CXXMethodDecl *MD = TheCall->getMethodDecl(); 10807 10808 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts())) { 10809 Diag(MemExpr->getLocStart(), 10810 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor) 10811 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext) 10812 << MD->getParent()->getDeclName(); 10813 10814 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName(); 10815 } 10816 } 10817 return MaybeBindToTemporary(TheCall); 10818} 10819 10820/// BuildCallToObjectOfClassType - Build a call to an object of class 10821/// type (C++ [over.call.object]), which can end up invoking an 10822/// overloaded function call operator (@c operator()) or performing a 10823/// user-defined conversion on the object argument. 10824ExprResult 10825Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj, 10826 SourceLocation LParenLoc, 10827 Expr **Args, unsigned NumArgs, 10828 SourceLocation RParenLoc) { 10829 if (checkPlaceholderForOverload(*this, Obj)) 10830 return ExprError(); 10831 ExprResult Object = Owned(Obj); 10832 10833 UnbridgedCastsSet UnbridgedCasts; 10834 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) 10835 return ExprError(); 10836 10837 assert(Object.get()->getType()->isRecordType() && "Requires object type argument"); 10838 const RecordType *Record = Object.get()->getType()->getAs<RecordType>(); 10839 10840 // C++ [over.call.object]p1: 10841 // If the primary-expression E in the function call syntax 10842 // evaluates to a class object of type "cv T", then the set of 10843 // candidate functions includes at least the function call 10844 // operators of T. The function call operators of T are obtained by 10845 // ordinary lookup of the name operator() in the context of 10846 // (E).operator(). 10847 OverloadCandidateSet CandidateSet(LParenLoc); 10848 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 10849 10850 if (RequireCompleteType(LParenLoc, Object.get()->getType(), 10851 diag::err_incomplete_object_call, Object.get())) 10852 return true; 10853 10854 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 10855 LookupQualifiedName(R, Record->getDecl()); 10856 R.suppressDiagnostics(); 10857 10858 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 10859 Oper != OperEnd; ++Oper) { 10860 AddMethodCandidate(Oper.getPair(), Object.get()->getType(), 10861 Object.get()->Classify(Context), Args, NumArgs, CandidateSet, 10862 /*SuppressUserConversions=*/ false); 10863 } 10864 10865 // C++ [over.call.object]p2: 10866 // In addition, for each (non-explicit in C++0x) conversion function 10867 // declared in T of the form 10868 // 10869 // operator conversion-type-id () cv-qualifier; 10870 // 10871 // where cv-qualifier is the same cv-qualification as, or a 10872 // greater cv-qualification than, cv, and where conversion-type-id 10873 // denotes the type "pointer to function of (P1,...,Pn) returning 10874 // R", or the type "reference to pointer to function of 10875 // (P1,...,Pn) returning R", or the type "reference to function 10876 // of (P1,...,Pn) returning R", a surrogate call function [...] 10877 // is also considered as a candidate function. Similarly, 10878 // surrogate call functions are added to the set of candidate 10879 // functions for each conversion function declared in an 10880 // accessible base class provided the function is not hidden 10881 // within T by another intervening declaration. 10882 const UnresolvedSetImpl *Conversions 10883 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 10884 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 10885 E = Conversions->end(); I != E; ++I) { 10886 NamedDecl *D = *I; 10887 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 10888 if (isa<UsingShadowDecl>(D)) 10889 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 10890 10891 // Skip over templated conversion functions; they aren't 10892 // surrogates. 10893 if (isa<FunctionTemplateDecl>(D)) 10894 continue; 10895 10896 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 10897 if (!Conv->isExplicit()) { 10898 // Strip the reference type (if any) and then the pointer type (if 10899 // any) to get down to what might be a function type. 10900 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 10901 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 10902 ConvType = ConvPtrType->getPointeeType(); 10903 10904 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 10905 { 10906 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 10907 Object.get(), llvm::makeArrayRef(Args, NumArgs), 10908 CandidateSet); 10909 } 10910 } 10911 } 10912 10913 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10914 10915 // Perform overload resolution. 10916 OverloadCandidateSet::iterator Best; 10917 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(), 10918 Best)) { 10919 case OR_Success: 10920 // Overload resolution succeeded; we'll build the appropriate call 10921 // below. 10922 break; 10923 10924 case OR_No_Viable_Function: 10925 if (CandidateSet.empty()) 10926 Diag(Object.get()->getLocStart(), diag::err_ovl_no_oper) 10927 << Object.get()->getType() << /*call*/ 1 10928 << Object.get()->getSourceRange(); 10929 else 10930 Diag(Object.get()->getLocStart(), 10931 diag::err_ovl_no_viable_object_call) 10932 << Object.get()->getType() << Object.get()->getSourceRange(); 10933 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10934 llvm::makeArrayRef(Args, NumArgs)); 10935 break; 10936 10937 case OR_Ambiguous: 10938 Diag(Object.get()->getLocStart(), 10939 diag::err_ovl_ambiguous_object_call) 10940 << Object.get()->getType() << Object.get()->getSourceRange(); 10941 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 10942 llvm::makeArrayRef(Args, NumArgs)); 10943 break; 10944 10945 case OR_Deleted: 10946 Diag(Object.get()->getLocStart(), 10947 diag::err_ovl_deleted_object_call) 10948 << Best->Function->isDeleted() 10949 << Object.get()->getType() 10950 << getDeletedOrUnavailableSuffix(Best->Function) 10951 << Object.get()->getSourceRange(); 10952 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10953 llvm::makeArrayRef(Args, NumArgs)); 10954 break; 10955 } 10956 10957 if (Best == CandidateSet.end()) 10958 return true; 10959 10960 UnbridgedCasts.restore(); 10961 10962 if (Best->Function == 0) { 10963 // Since there is no function declaration, this is one of the 10964 // surrogate candidates. Dig out the conversion function. 10965 CXXConversionDecl *Conv 10966 = cast<CXXConversionDecl>( 10967 Best->Conversions[0].UserDefined.ConversionFunction); 10968 10969 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 10970 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 10971 10972 // We selected one of the surrogate functions that converts the 10973 // object parameter to a function pointer. Perform the conversion 10974 // on the object argument, then let ActOnCallExpr finish the job. 10975 10976 // Create an implicit member expr to refer to the conversion operator. 10977 // and then call it. 10978 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl, 10979 Conv, HadMultipleCandidates); 10980 if (Call.isInvalid()) 10981 return ExprError(); 10982 // Record usage of conversion in an implicit cast. 10983 Call = Owned(ImplicitCastExpr::Create(Context, Call.get()->getType(), 10984 CK_UserDefinedConversion, 10985 Call.get(), 0, VK_RValue)); 10986 10987 return ActOnCallExpr(S, Call.get(), LParenLoc, MultiExprArg(Args, NumArgs), 10988 RParenLoc); 10989 } 10990 10991 MarkFunctionReferenced(LParenLoc, Best->Function); 10992 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 10993 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 10994 10995 // We found an overloaded operator(). Build a CXXOperatorCallExpr 10996 // that calls this method, using Object for the implicit object 10997 // parameter and passing along the remaining arguments. 10998 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 10999 const FunctionProtoType *Proto = 11000 Method->getType()->getAs<FunctionProtoType>(); 11001 11002 unsigned NumArgsInProto = Proto->getNumArgs(); 11003 unsigned NumArgsToCheck = NumArgs; 11004 11005 // Build the full argument list for the method call (the 11006 // implicit object parameter is placed at the beginning of the 11007 // list). 11008 Expr **MethodArgs; 11009 if (NumArgs < NumArgsInProto) { 11010 NumArgsToCheck = NumArgsInProto; 11011 MethodArgs = new Expr*[NumArgsInProto + 1]; 11012 } else { 11013 MethodArgs = new Expr*[NumArgs + 1]; 11014 } 11015 MethodArgs[0] = Object.get(); 11016 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 11017 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 11018 11019 DeclarationNameInfo OpLocInfo( 11020 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc); 11021 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc)); 11022 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, 11023 HadMultipleCandidates, 11024 OpLocInfo.getLoc(), 11025 OpLocInfo.getInfo()); 11026 if (NewFn.isInvalid()) 11027 return true; 11028 11029 // Once we've built TheCall, all of the expressions are properly 11030 // owned. 11031 QualType ResultTy = Method->getResultType(); 11032 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11033 ResultTy = ResultTy.getNonLValueExprType(Context); 11034 11035 CXXOperatorCallExpr *TheCall = 11036 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn.take(), 11037 llvm::makeArrayRef(MethodArgs, NumArgs+1), 11038 ResultTy, VK, RParenLoc, false); 11039 delete [] MethodArgs; 11040 11041 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 11042 Method)) 11043 return true; 11044 11045 // We may have default arguments. If so, we need to allocate more 11046 // slots in the call for them. 11047 if (NumArgs < NumArgsInProto) 11048 TheCall->setNumArgs(Context, NumArgsInProto + 1); 11049 else if (NumArgs > NumArgsInProto) 11050 NumArgsToCheck = NumArgsInProto; 11051 11052 bool IsError = false; 11053 11054 // Initialize the implicit object parameter. 11055 ExprResult ObjRes = 11056 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/0, 11057 Best->FoundDecl, Method); 11058 if (ObjRes.isInvalid()) 11059 IsError = true; 11060 else 11061 Object = ObjRes; 11062 TheCall->setArg(0, Object.take()); 11063 11064 // Check the argument types. 11065 for (unsigned i = 0; i != NumArgsToCheck; i++) { 11066 Expr *Arg; 11067 if (i < NumArgs) { 11068 Arg = Args[i]; 11069 11070 // Pass the argument. 11071 11072 ExprResult InputInit 11073 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 11074 Context, 11075 Method->getParamDecl(i)), 11076 SourceLocation(), Arg); 11077 11078 IsError |= InputInit.isInvalid(); 11079 Arg = InputInit.takeAs<Expr>(); 11080 } else { 11081 ExprResult DefArg 11082 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 11083 if (DefArg.isInvalid()) { 11084 IsError = true; 11085 break; 11086 } 11087 11088 Arg = DefArg.takeAs<Expr>(); 11089 } 11090 11091 TheCall->setArg(i + 1, Arg); 11092 } 11093 11094 // If this is a variadic call, handle args passed through "...". 11095 if (Proto->isVariadic()) { 11096 // Promote the arguments (C99 6.5.2.2p7). 11097 for (unsigned i = NumArgsInProto; i < NumArgs; i++) { 11098 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod, 0); 11099 IsError |= Arg.isInvalid(); 11100 TheCall->setArg(i + 1, Arg.take()); 11101 } 11102 } 11103 11104 if (IsError) return true; 11105 11106 DiagnoseSentinelCalls(Method, LParenLoc, Args, NumArgs); 11107 11108 if (CheckFunctionCall(Method, TheCall, Proto)) 11109 return true; 11110 11111 return MaybeBindToTemporary(TheCall); 11112} 11113 11114/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 11115/// (if one exists), where @c Base is an expression of class type and 11116/// @c Member is the name of the member we're trying to find. 11117ExprResult 11118Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 11119 assert(Base->getType()->isRecordType() && 11120 "left-hand side must have class type"); 11121 11122 if (checkPlaceholderForOverload(*this, Base)) 11123 return ExprError(); 11124 11125 SourceLocation Loc = Base->getExprLoc(); 11126 11127 // C++ [over.ref]p1: 11128 // 11129 // [...] An expression x->m is interpreted as (x.operator->())->m 11130 // for a class object x of type T if T::operator->() exists and if 11131 // the operator is selected as the best match function by the 11132 // overload resolution mechanism (13.3). 11133 DeclarationName OpName = 11134 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 11135 OverloadCandidateSet CandidateSet(Loc); 11136 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 11137 11138 if (RequireCompleteType(Loc, Base->getType(), 11139 diag::err_typecheck_incomplete_tag, Base)) 11140 return ExprError(); 11141 11142 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 11143 LookupQualifiedName(R, BaseRecord->getDecl()); 11144 R.suppressDiagnostics(); 11145 11146 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 11147 Oper != OperEnd; ++Oper) { 11148 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 11149 0, 0, CandidateSet, /*SuppressUserConversions=*/false); 11150 } 11151 11152 bool HadMultipleCandidates = (CandidateSet.size() > 1); 11153 11154 // Perform overload resolution. 11155 OverloadCandidateSet::iterator Best; 11156 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 11157 case OR_Success: 11158 // Overload resolution succeeded; we'll build the call below. 11159 break; 11160 11161 case OR_No_Viable_Function: 11162 if (CandidateSet.empty()) 11163 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 11164 << Base->getType() << Base->getSourceRange(); 11165 else 11166 Diag(OpLoc, diag::err_ovl_no_viable_oper) 11167 << "operator->" << Base->getSourceRange(); 11168 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base); 11169 return ExprError(); 11170 11171 case OR_Ambiguous: 11172 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 11173 << "->" << Base->getType() << Base->getSourceRange(); 11174 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Base); 11175 return ExprError(); 11176 11177 case OR_Deleted: 11178 Diag(OpLoc, diag::err_ovl_deleted_oper) 11179 << Best->Function->isDeleted() 11180 << "->" 11181 << getDeletedOrUnavailableSuffix(Best->Function) 11182 << Base->getSourceRange(); 11183 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base); 11184 return ExprError(); 11185 } 11186 11187 MarkFunctionReferenced(OpLoc, Best->Function); 11188 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 11189 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 11190 11191 // Convert the object parameter. 11192 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 11193 ExprResult BaseResult = 11194 PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 11195 Best->FoundDecl, Method); 11196 if (BaseResult.isInvalid()) 11197 return ExprError(); 11198 Base = BaseResult.take(); 11199 11200 // Build the operator call. 11201 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, 11202 HadMultipleCandidates, OpLoc); 11203 if (FnExpr.isInvalid()) 11204 return ExprError(); 11205 11206 QualType ResultTy = Method->getResultType(); 11207 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11208 ResultTy = ResultTy.getNonLValueExprType(Context); 11209 CXXOperatorCallExpr *TheCall = 11210 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.take(), 11211 Base, ResultTy, VK, OpLoc, false); 11212 11213 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 11214 Method)) 11215 return ExprError(); 11216 11217 return MaybeBindToTemporary(TheCall); 11218} 11219 11220/// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to 11221/// a literal operator described by the provided lookup results. 11222ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R, 11223 DeclarationNameInfo &SuffixInfo, 11224 ArrayRef<Expr*> Args, 11225 SourceLocation LitEndLoc, 11226 TemplateArgumentListInfo *TemplateArgs) { 11227 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc(); 11228 11229 OverloadCandidateSet CandidateSet(UDSuffixLoc); 11230 AddFunctionCandidates(R.asUnresolvedSet(), Args, CandidateSet, true, 11231 TemplateArgs); 11232 11233 bool HadMultipleCandidates = (CandidateSet.size() > 1); 11234 11235 // Perform overload resolution. This will usually be trivial, but might need 11236 // to perform substitutions for a literal operator template. 11237 OverloadCandidateSet::iterator Best; 11238 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) { 11239 case OR_Success: 11240 case OR_Deleted: 11241 break; 11242 11243 case OR_No_Viable_Function: 11244 Diag(UDSuffixLoc, diag::err_ovl_no_viable_function_in_call) 11245 << R.getLookupName(); 11246 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11247 return ExprError(); 11248 11249 case OR_Ambiguous: 11250 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName(); 11251 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args); 11252 return ExprError(); 11253 } 11254 11255 FunctionDecl *FD = Best->Function; 11256 MarkFunctionReferenced(UDSuffixLoc, FD); 11257 DiagnoseUseOfDecl(Best->FoundDecl, UDSuffixLoc); 11258 11259 ExprResult Fn = CreateFunctionRefExpr(*this, FD, HadMultipleCandidates, 11260 SuffixInfo.getLoc(), 11261 SuffixInfo.getInfo()); 11262 if (Fn.isInvalid()) 11263 return true; 11264 11265 // Check the argument types. This should almost always be a no-op, except 11266 // that array-to-pointer decay is applied to string literals. 11267 Expr *ConvArgs[2]; 11268 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) { 11269 ExprResult InputInit = PerformCopyInitialization( 11270 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)), 11271 SourceLocation(), Args[ArgIdx]); 11272 if (InputInit.isInvalid()) 11273 return true; 11274 ConvArgs[ArgIdx] = InputInit.take(); 11275 } 11276 11277 QualType ResultTy = FD->getResultType(); 11278 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11279 ResultTy = ResultTy.getNonLValueExprType(Context); 11280 11281 UserDefinedLiteral *UDL = 11282 new (Context) UserDefinedLiteral(Context, Fn.take(), 11283 llvm::makeArrayRef(ConvArgs, Args.size()), 11284 ResultTy, VK, LitEndLoc, UDSuffixLoc); 11285 11286 if (CheckCallReturnType(FD->getResultType(), UDSuffixLoc, UDL, FD)) 11287 return ExprError(); 11288 11289 if (CheckFunctionCall(FD, UDL, NULL)) 11290 return ExprError(); 11291 11292 return MaybeBindToTemporary(UDL); 11293} 11294 11295/// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the 11296/// given LookupResult is non-empty, it is assumed to describe a member which 11297/// will be invoked. Otherwise, the function will be found via argument 11298/// dependent lookup. 11299/// CallExpr is set to a valid expression and FRS_Success returned on success, 11300/// otherwise CallExpr is set to ExprError() and some non-success value 11301/// is returned. 11302Sema::ForRangeStatus 11303Sema::BuildForRangeBeginEndCall(Scope *S, SourceLocation Loc, 11304 SourceLocation RangeLoc, VarDecl *Decl, 11305 BeginEndFunction BEF, 11306 const DeclarationNameInfo &NameInfo, 11307 LookupResult &MemberLookup, 11308 OverloadCandidateSet *CandidateSet, 11309 Expr *Range, ExprResult *CallExpr) { 11310 CandidateSet->clear(); 11311 if (!MemberLookup.empty()) { 11312 ExprResult MemberRef = 11313 BuildMemberReferenceExpr(Range, Range->getType(), Loc, 11314 /*IsPtr=*/false, CXXScopeSpec(), 11315 /*TemplateKWLoc=*/SourceLocation(), 11316 /*FirstQualifierInScope=*/0, 11317 MemberLookup, 11318 /*TemplateArgs=*/0); 11319 if (MemberRef.isInvalid()) { 11320 *CallExpr = ExprError(); 11321 Diag(Range->getLocStart(), diag::note_in_for_range) 11322 << RangeLoc << BEF << Range->getType(); 11323 return FRS_DiagnosticIssued; 11324 } 11325 *CallExpr = ActOnCallExpr(S, MemberRef.get(), Loc, MultiExprArg(), Loc, 0); 11326 if (CallExpr->isInvalid()) { 11327 *CallExpr = ExprError(); 11328 Diag(Range->getLocStart(), diag::note_in_for_range) 11329 << RangeLoc << BEF << Range->getType(); 11330 return FRS_DiagnosticIssued; 11331 } 11332 } else { 11333 UnresolvedSet<0> FoundNames; 11334 UnresolvedLookupExpr *Fn = 11335 UnresolvedLookupExpr::Create(Context, /*NamingClass=*/0, 11336 NestedNameSpecifierLoc(), NameInfo, 11337 /*NeedsADL=*/true, /*Overloaded=*/false, 11338 FoundNames.begin(), FoundNames.end()); 11339 11340 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, &Range, 1, Loc, 11341 CandidateSet, CallExpr); 11342 if (CandidateSet->empty() || CandidateSetError) { 11343 *CallExpr = ExprError(); 11344 return FRS_NoViableFunction; 11345 } 11346 OverloadCandidateSet::iterator Best; 11347 OverloadingResult OverloadResult = 11348 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best); 11349 11350 if (OverloadResult == OR_No_Viable_Function) { 11351 *CallExpr = ExprError(); 11352 return FRS_NoViableFunction; 11353 } 11354 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, &Range, 1, 11355 Loc, 0, CandidateSet, &Best, 11356 OverloadResult, 11357 /*AllowTypoCorrection=*/false); 11358 if (CallExpr->isInvalid() || OverloadResult != OR_Success) { 11359 *CallExpr = ExprError(); 11360 Diag(Range->getLocStart(), diag::note_in_for_range) 11361 << RangeLoc << BEF << Range->getType(); 11362 return FRS_DiagnosticIssued; 11363 } 11364 } 11365 return FRS_Success; 11366} 11367 11368 11369/// FixOverloadedFunctionReference - E is an expression that refers to 11370/// a C++ overloaded function (possibly with some parentheses and 11371/// perhaps a '&' around it). We have resolved the overloaded function 11372/// to the function declaration Fn, so patch up the expression E to 11373/// refer (possibly indirectly) to Fn. Returns the new expr. 11374Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 11375 FunctionDecl *Fn) { 11376 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 11377 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 11378 Found, Fn); 11379 if (SubExpr == PE->getSubExpr()) 11380 return PE; 11381 11382 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 11383 } 11384 11385 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 11386 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 11387 Found, Fn); 11388 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 11389 SubExpr->getType()) && 11390 "Implicit cast type cannot be determined from overload"); 11391 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 11392 if (SubExpr == ICE->getSubExpr()) 11393 return ICE; 11394 11395 return ImplicitCastExpr::Create(Context, ICE->getType(), 11396 ICE->getCastKind(), 11397 SubExpr, 0, 11398 ICE->getValueKind()); 11399 } 11400 11401 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 11402 assert(UnOp->getOpcode() == UO_AddrOf && 11403 "Can only take the address of an overloaded function"); 11404 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 11405 if (Method->isStatic()) { 11406 // Do nothing: static member functions aren't any different 11407 // from non-member functions. 11408 } else { 11409 // Fix the sub expression, which really has to be an 11410 // UnresolvedLookupExpr holding an overloaded member function 11411 // or template. 11412 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 11413 Found, Fn); 11414 if (SubExpr == UnOp->getSubExpr()) 11415 return UnOp; 11416 11417 assert(isa<DeclRefExpr>(SubExpr) 11418 && "fixed to something other than a decl ref"); 11419 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 11420 && "fixed to a member ref with no nested name qualifier"); 11421 11422 // We have taken the address of a pointer to member 11423 // function. Perform the computation here so that we get the 11424 // appropriate pointer to member type. 11425 QualType ClassType 11426 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 11427 QualType MemPtrType 11428 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 11429 11430 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 11431 VK_RValue, OK_Ordinary, 11432 UnOp->getOperatorLoc()); 11433 } 11434 } 11435 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 11436 Found, Fn); 11437 if (SubExpr == UnOp->getSubExpr()) 11438 return UnOp; 11439 11440 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 11441 Context.getPointerType(SubExpr->getType()), 11442 VK_RValue, OK_Ordinary, 11443 UnOp->getOperatorLoc()); 11444 } 11445 11446 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 11447 // FIXME: avoid copy. 11448 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 11449 if (ULE->hasExplicitTemplateArgs()) { 11450 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 11451 TemplateArgs = &TemplateArgsBuffer; 11452 } 11453 11454 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 11455 ULE->getQualifierLoc(), 11456 ULE->getTemplateKeywordLoc(), 11457 Fn, 11458 /*enclosing*/ false, // FIXME? 11459 ULE->getNameLoc(), 11460 Fn->getType(), 11461 VK_LValue, 11462 Found.getDecl(), 11463 TemplateArgs); 11464 MarkDeclRefReferenced(DRE); 11465 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1); 11466 return DRE; 11467 } 11468 11469 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 11470 // FIXME: avoid copy. 11471 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 11472 if (MemExpr->hasExplicitTemplateArgs()) { 11473 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 11474 TemplateArgs = &TemplateArgsBuffer; 11475 } 11476 11477 Expr *Base; 11478 11479 // If we're filling in a static method where we used to have an 11480 // implicit member access, rewrite to a simple decl ref. 11481 if (MemExpr->isImplicitAccess()) { 11482 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 11483 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 11484 MemExpr->getQualifierLoc(), 11485 MemExpr->getTemplateKeywordLoc(), 11486 Fn, 11487 /*enclosing*/ false, 11488 MemExpr->getMemberLoc(), 11489 Fn->getType(), 11490 VK_LValue, 11491 Found.getDecl(), 11492 TemplateArgs); 11493 MarkDeclRefReferenced(DRE); 11494 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1); 11495 return DRE; 11496 } else { 11497 SourceLocation Loc = MemExpr->getMemberLoc(); 11498 if (MemExpr->getQualifier()) 11499 Loc = MemExpr->getQualifierLoc().getBeginLoc(); 11500 CheckCXXThisCapture(Loc); 11501 Base = new (Context) CXXThisExpr(Loc, 11502 MemExpr->getBaseType(), 11503 /*isImplicit=*/true); 11504 } 11505 } else 11506 Base = MemExpr->getBase(); 11507 11508 ExprValueKind valueKind; 11509 QualType type; 11510 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 11511 valueKind = VK_LValue; 11512 type = Fn->getType(); 11513 } else { 11514 valueKind = VK_RValue; 11515 type = Context.BoundMemberTy; 11516 } 11517 11518 MemberExpr *ME = MemberExpr::Create(Context, Base, 11519 MemExpr->isArrow(), 11520 MemExpr->getQualifierLoc(), 11521 MemExpr->getTemplateKeywordLoc(), 11522 Fn, 11523 Found, 11524 MemExpr->getMemberNameInfo(), 11525 TemplateArgs, 11526 type, valueKind, OK_Ordinary); 11527 ME->setHadMultipleCandidates(true); 11528 return ME; 11529 } 11530 11531 llvm_unreachable("Invalid reference to overloaded function"); 11532} 11533 11534ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 11535 DeclAccessPair Found, 11536 FunctionDecl *Fn) { 11537 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 11538} 11539 11540} // end namespace clang 11541