SemaOverload.cpp revision 45a37da030be06bb7babf5e65a64d62cd0def7e6
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 QualType ThisType = Constructor->getThisType(S.Context); 2927 // Initializer lists don't have conversions as such. 2928 User.Before.setAsIdentityConversion(); 2929 User.HadMultipleCandidates = HadMultipleCandidates; 2930 User.ConversionFunction = Constructor; 2931 User.FoundConversionFunction = Best->FoundDecl; 2932 User.After.setAsIdentityConversion(); 2933 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2934 User.After.setAllToTypes(ToType); 2935 return OR_Success; 2936 } 2937 2938 case OR_No_Viable_Function: 2939 return OR_No_Viable_Function; 2940 case OR_Deleted: 2941 return OR_Deleted; 2942 case OR_Ambiguous: 2943 return OR_Ambiguous; 2944 } 2945 2946 llvm_unreachable("Invalid OverloadResult!"); 2947} 2948 2949/// Determines whether there is a user-defined conversion sequence 2950/// (C++ [over.ics.user]) that converts expression From to the type 2951/// ToType. If such a conversion exists, User will contain the 2952/// user-defined conversion sequence that performs such a conversion 2953/// and this routine will return true. Otherwise, this routine returns 2954/// false and User is unspecified. 2955/// 2956/// \param AllowExplicit true if the conversion should consider C++0x 2957/// "explicit" conversion functions as well as non-explicit conversion 2958/// functions (C++0x [class.conv.fct]p2). 2959static OverloadingResult 2960IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 2961 UserDefinedConversionSequence &User, 2962 OverloadCandidateSet &CandidateSet, 2963 bool AllowExplicit) { 2964 // Whether we will only visit constructors. 2965 bool ConstructorsOnly = false; 2966 2967 // If the type we are conversion to is a class type, enumerate its 2968 // constructors. 2969 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 2970 // C++ [over.match.ctor]p1: 2971 // When objects of class type are direct-initialized (8.5), or 2972 // copy-initialized from an expression of the same or a 2973 // derived class type (8.5), overload resolution selects the 2974 // constructor. [...] For copy-initialization, the candidate 2975 // functions are all the converting constructors (12.3.1) of 2976 // that class. The argument list is the expression-list within 2977 // the parentheses of the initializer. 2978 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 2979 (From->getType()->getAs<RecordType>() && 2980 S.IsDerivedFrom(From->getType(), ToType))) 2981 ConstructorsOnly = true; 2982 2983 S.RequireCompleteType(From->getLocStart(), ToType, 0); 2984 // RequireCompleteType may have returned true due to some invalid decl 2985 // during template instantiation, but ToType may be complete enough now 2986 // to try to recover. 2987 if (ToType->isIncompleteType()) { 2988 // We're not going to find any constructors. 2989 } else if (CXXRecordDecl *ToRecordDecl 2990 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 2991 2992 Expr **Args = &From; 2993 unsigned NumArgs = 1; 2994 bool ListInitializing = false; 2995 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) { 2996 // But first, see if there is an init-list-contructor that will work. 2997 OverloadingResult Result = IsInitializerListConstructorConversion( 2998 S, From, ToType, ToRecordDecl, User, CandidateSet, AllowExplicit); 2999 if (Result != OR_No_Viable_Function) 3000 return Result; 3001 // Never mind. 3002 CandidateSet.clear(); 3003 3004 // If we're list-initializing, we pass the individual elements as 3005 // arguments, not the entire list. 3006 Args = InitList->getInits(); 3007 NumArgs = InitList->getNumInits(); 3008 ListInitializing = true; 3009 } 3010 3011 DeclContext::lookup_iterator Con, ConEnd; 3012 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 3013 Con != ConEnd; ++Con) { 3014 NamedDecl *D = *Con; 3015 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 3016 3017 // Find the constructor (which may be a template). 3018 CXXConstructorDecl *Constructor = 0; 3019 FunctionTemplateDecl *ConstructorTmpl 3020 = dyn_cast<FunctionTemplateDecl>(D); 3021 if (ConstructorTmpl) 3022 Constructor 3023 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 3024 else 3025 Constructor = cast<CXXConstructorDecl>(D); 3026 3027 bool Usable = !Constructor->isInvalidDecl(); 3028 if (ListInitializing) 3029 Usable = Usable && (AllowExplicit || !Constructor->isExplicit()); 3030 else 3031 Usable = Usable &&Constructor->isConvertingConstructor(AllowExplicit); 3032 if (Usable) { 3033 bool SuppressUserConversions = !ConstructorsOnly; 3034 if (SuppressUserConversions && ListInitializing) { 3035 SuppressUserConversions = false; 3036 if (NumArgs == 1) { 3037 // If the first argument is (a reference to) the target type, 3038 // suppress conversions. 3039 SuppressUserConversions = isFirstArgumentCompatibleWithType( 3040 S.Context, Constructor, ToType); 3041 } 3042 } 3043 if (ConstructorTmpl) 3044 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 3045 /*ExplicitArgs*/ 0, 3046 llvm::makeArrayRef(Args, NumArgs), 3047 CandidateSet, SuppressUserConversions); 3048 else 3049 // Allow one user-defined conversion when user specifies a 3050 // From->ToType conversion via an static cast (c-style, etc). 3051 S.AddOverloadCandidate(Constructor, FoundDecl, 3052 llvm::makeArrayRef(Args, NumArgs), 3053 CandidateSet, SuppressUserConversions); 3054 } 3055 } 3056 } 3057 } 3058 3059 // Enumerate conversion functions, if we're allowed to. 3060 if (ConstructorsOnly || isa<InitListExpr>(From)) { 3061 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 0)) { 3062 // No conversion functions from incomplete types. 3063 } else if (const RecordType *FromRecordType 3064 = From->getType()->getAs<RecordType>()) { 3065 if (CXXRecordDecl *FromRecordDecl 3066 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 3067 // Add all of the conversion functions as candidates. 3068 const UnresolvedSetImpl *Conversions 3069 = FromRecordDecl->getVisibleConversionFunctions(); 3070 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3071 E = Conversions->end(); I != E; ++I) { 3072 DeclAccessPair FoundDecl = I.getPair(); 3073 NamedDecl *D = FoundDecl.getDecl(); 3074 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 3075 if (isa<UsingShadowDecl>(D)) 3076 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3077 3078 CXXConversionDecl *Conv; 3079 FunctionTemplateDecl *ConvTemplate; 3080 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 3081 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3082 else 3083 Conv = cast<CXXConversionDecl>(D); 3084 3085 if (AllowExplicit || !Conv->isExplicit()) { 3086 if (ConvTemplate) 3087 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 3088 ActingContext, From, ToType, 3089 CandidateSet); 3090 else 3091 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 3092 From, ToType, CandidateSet); 3093 } 3094 } 3095 } 3096 } 3097 3098 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3099 3100 OverloadCandidateSet::iterator Best; 3101 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 3102 case OR_Success: 3103 // Record the standard conversion we used and the conversion function. 3104 if (CXXConstructorDecl *Constructor 3105 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 3106 // C++ [over.ics.user]p1: 3107 // If the user-defined conversion is specified by a 3108 // constructor (12.3.1), the initial standard conversion 3109 // sequence converts the source type to the type required by 3110 // the argument of the constructor. 3111 // 3112 QualType ThisType = Constructor->getThisType(S.Context); 3113 if (isa<InitListExpr>(From)) { 3114 // Initializer lists don't have conversions as such. 3115 User.Before.setAsIdentityConversion(); 3116 } else { 3117 if (Best->Conversions[0].isEllipsis()) 3118 User.EllipsisConversion = true; 3119 else { 3120 User.Before = Best->Conversions[0].Standard; 3121 User.EllipsisConversion = false; 3122 } 3123 } 3124 User.HadMultipleCandidates = HadMultipleCandidates; 3125 User.ConversionFunction = Constructor; 3126 User.FoundConversionFunction = Best->FoundDecl; 3127 User.After.setAsIdentityConversion(); 3128 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 3129 User.After.setAllToTypes(ToType); 3130 return OR_Success; 3131 } 3132 if (CXXConversionDecl *Conversion 3133 = dyn_cast<CXXConversionDecl>(Best->Function)) { 3134 // C++ [over.ics.user]p1: 3135 // 3136 // [...] If the user-defined conversion is specified by a 3137 // conversion function (12.3.2), the initial standard 3138 // conversion sequence converts the source type to the 3139 // implicit object parameter of the conversion function. 3140 User.Before = Best->Conversions[0].Standard; 3141 User.HadMultipleCandidates = HadMultipleCandidates; 3142 User.ConversionFunction = Conversion; 3143 User.FoundConversionFunction = Best->FoundDecl; 3144 User.EllipsisConversion = false; 3145 3146 // C++ [over.ics.user]p2: 3147 // The second standard conversion sequence converts the 3148 // result of the user-defined conversion to the target type 3149 // for the sequence. Since an implicit conversion sequence 3150 // is an initialization, the special rules for 3151 // initialization by user-defined conversion apply when 3152 // selecting the best user-defined conversion for a 3153 // user-defined conversion sequence (see 13.3.3 and 3154 // 13.3.3.1). 3155 User.After = Best->FinalConversion; 3156 return OR_Success; 3157 } 3158 llvm_unreachable("Not a constructor or conversion function?"); 3159 3160 case OR_No_Viable_Function: 3161 return OR_No_Viable_Function; 3162 case OR_Deleted: 3163 // No conversion here! We're done. 3164 return OR_Deleted; 3165 3166 case OR_Ambiguous: 3167 return OR_Ambiguous; 3168 } 3169 3170 llvm_unreachable("Invalid OverloadResult!"); 3171} 3172 3173bool 3174Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 3175 ImplicitConversionSequence ICS; 3176 OverloadCandidateSet CandidateSet(From->getExprLoc()); 3177 OverloadingResult OvResult = 3178 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 3179 CandidateSet, false); 3180 if (OvResult == OR_Ambiguous) 3181 Diag(From->getLocStart(), 3182 diag::err_typecheck_ambiguous_condition) 3183 << From->getType() << ToType << From->getSourceRange(); 3184 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 3185 Diag(From->getLocStart(), 3186 diag::err_typecheck_nonviable_condition) 3187 << From->getType() << ToType << From->getSourceRange(); 3188 else 3189 return false; 3190 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, From); 3191 return true; 3192} 3193 3194/// \brief Compare the user-defined conversion functions or constructors 3195/// of two user-defined conversion sequences to determine whether any ordering 3196/// is possible. 3197static ImplicitConversionSequence::CompareKind 3198compareConversionFunctions(Sema &S, 3199 FunctionDecl *Function1, 3200 FunctionDecl *Function2) { 3201 if (!S.getLangOpts().ObjC1 || !S.getLangOpts().CPlusPlus0x) 3202 return ImplicitConversionSequence::Indistinguishable; 3203 3204 // Objective-C++: 3205 // If both conversion functions are implicitly-declared conversions from 3206 // a lambda closure type to a function pointer and a block pointer, 3207 // respectively, always prefer the conversion to a function pointer, 3208 // because the function pointer is more lightweight and is more likely 3209 // to keep code working. 3210 CXXConversionDecl *Conv1 = dyn_cast<CXXConversionDecl>(Function1); 3211 if (!Conv1) 3212 return ImplicitConversionSequence::Indistinguishable; 3213 3214 CXXConversionDecl *Conv2 = dyn_cast<CXXConversionDecl>(Function2); 3215 if (!Conv2) 3216 return ImplicitConversionSequence::Indistinguishable; 3217 3218 if (Conv1->getParent()->isLambda() && Conv2->getParent()->isLambda()) { 3219 bool Block1 = Conv1->getConversionType()->isBlockPointerType(); 3220 bool Block2 = Conv2->getConversionType()->isBlockPointerType(); 3221 if (Block1 != Block2) 3222 return Block1? ImplicitConversionSequence::Worse 3223 : ImplicitConversionSequence::Better; 3224 } 3225 3226 return ImplicitConversionSequence::Indistinguishable; 3227} 3228 3229/// CompareImplicitConversionSequences - Compare two implicit 3230/// conversion sequences to determine whether one is better than the 3231/// other or if they are indistinguishable (C++ 13.3.3.2). 3232static ImplicitConversionSequence::CompareKind 3233CompareImplicitConversionSequences(Sema &S, 3234 const ImplicitConversionSequence& ICS1, 3235 const ImplicitConversionSequence& ICS2) 3236{ 3237 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 3238 // conversion sequences (as defined in 13.3.3.1) 3239 // -- a standard conversion sequence (13.3.3.1.1) is a better 3240 // conversion sequence than a user-defined conversion sequence or 3241 // an ellipsis conversion sequence, and 3242 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 3243 // conversion sequence than an ellipsis conversion sequence 3244 // (13.3.3.1.3). 3245 // 3246 // C++0x [over.best.ics]p10: 3247 // For the purpose of ranking implicit conversion sequences as 3248 // described in 13.3.3.2, the ambiguous conversion sequence is 3249 // treated as a user-defined sequence that is indistinguishable 3250 // from any other user-defined conversion sequence. 3251 if (ICS1.getKindRank() < ICS2.getKindRank()) 3252 return ImplicitConversionSequence::Better; 3253 if (ICS2.getKindRank() < ICS1.getKindRank()) 3254 return ImplicitConversionSequence::Worse; 3255 3256 // The following checks require both conversion sequences to be of 3257 // the same kind. 3258 if (ICS1.getKind() != ICS2.getKind()) 3259 return ImplicitConversionSequence::Indistinguishable; 3260 3261 ImplicitConversionSequence::CompareKind Result = 3262 ImplicitConversionSequence::Indistinguishable; 3263 3264 // Two implicit conversion sequences of the same form are 3265 // indistinguishable conversion sequences unless one of the 3266 // following rules apply: (C++ 13.3.3.2p3): 3267 if (ICS1.isStandard()) 3268 Result = CompareStandardConversionSequences(S, 3269 ICS1.Standard, ICS2.Standard); 3270 else if (ICS1.isUserDefined()) { 3271 // User-defined conversion sequence U1 is a better conversion 3272 // sequence than another user-defined conversion sequence U2 if 3273 // they contain the same user-defined conversion function or 3274 // constructor and if the second standard conversion sequence of 3275 // U1 is better than the second standard conversion sequence of 3276 // U2 (C++ 13.3.3.2p3). 3277 if (ICS1.UserDefined.ConversionFunction == 3278 ICS2.UserDefined.ConversionFunction) 3279 Result = CompareStandardConversionSequences(S, 3280 ICS1.UserDefined.After, 3281 ICS2.UserDefined.After); 3282 else 3283 Result = compareConversionFunctions(S, 3284 ICS1.UserDefined.ConversionFunction, 3285 ICS2.UserDefined.ConversionFunction); 3286 } 3287 3288 // List-initialization sequence L1 is a better conversion sequence than 3289 // list-initialization sequence L2 if L1 converts to std::initializer_list<X> 3290 // for some X and L2 does not. 3291 if (Result == ImplicitConversionSequence::Indistinguishable && 3292 !ICS1.isBad() && 3293 ICS1.isListInitializationSequence() && 3294 ICS2.isListInitializationSequence()) { 3295 if (ICS1.isStdInitializerListElement() && 3296 !ICS2.isStdInitializerListElement()) 3297 return ImplicitConversionSequence::Better; 3298 if (!ICS1.isStdInitializerListElement() && 3299 ICS2.isStdInitializerListElement()) 3300 return ImplicitConversionSequence::Worse; 3301 } 3302 3303 return Result; 3304} 3305 3306static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 3307 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 3308 Qualifiers Quals; 3309 T1 = Context.getUnqualifiedArrayType(T1, Quals); 3310 T2 = Context.getUnqualifiedArrayType(T2, Quals); 3311 } 3312 3313 return Context.hasSameUnqualifiedType(T1, T2); 3314} 3315 3316// Per 13.3.3.2p3, compare the given standard conversion sequences to 3317// determine if one is a proper subset of the other. 3318static ImplicitConversionSequence::CompareKind 3319compareStandardConversionSubsets(ASTContext &Context, 3320 const StandardConversionSequence& SCS1, 3321 const StandardConversionSequence& SCS2) { 3322 ImplicitConversionSequence::CompareKind Result 3323 = ImplicitConversionSequence::Indistinguishable; 3324 3325 // the identity conversion sequence is considered to be a subsequence of 3326 // any non-identity conversion sequence 3327 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 3328 return ImplicitConversionSequence::Better; 3329 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 3330 return ImplicitConversionSequence::Worse; 3331 3332 if (SCS1.Second != SCS2.Second) { 3333 if (SCS1.Second == ICK_Identity) 3334 Result = ImplicitConversionSequence::Better; 3335 else if (SCS2.Second == ICK_Identity) 3336 Result = ImplicitConversionSequence::Worse; 3337 else 3338 return ImplicitConversionSequence::Indistinguishable; 3339 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 3340 return ImplicitConversionSequence::Indistinguishable; 3341 3342 if (SCS1.Third == SCS2.Third) { 3343 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 3344 : ImplicitConversionSequence::Indistinguishable; 3345 } 3346 3347 if (SCS1.Third == ICK_Identity) 3348 return Result == ImplicitConversionSequence::Worse 3349 ? ImplicitConversionSequence::Indistinguishable 3350 : ImplicitConversionSequence::Better; 3351 3352 if (SCS2.Third == ICK_Identity) 3353 return Result == ImplicitConversionSequence::Better 3354 ? ImplicitConversionSequence::Indistinguishable 3355 : ImplicitConversionSequence::Worse; 3356 3357 return ImplicitConversionSequence::Indistinguishable; 3358} 3359 3360/// \brief Determine whether one of the given reference bindings is better 3361/// than the other based on what kind of bindings they are. 3362static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 3363 const StandardConversionSequence &SCS2) { 3364 // C++0x [over.ics.rank]p3b4: 3365 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 3366 // implicit object parameter of a non-static member function declared 3367 // without a ref-qualifier, and *either* S1 binds an rvalue reference 3368 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 3369 // lvalue reference to a function lvalue and S2 binds an rvalue 3370 // reference*. 3371 // 3372 // FIXME: Rvalue references. We're going rogue with the above edits, 3373 // because the semantics in the current C++0x working paper (N3225 at the 3374 // time of this writing) break the standard definition of std::forward 3375 // and std::reference_wrapper when dealing with references to functions. 3376 // Proposed wording changes submitted to CWG for consideration. 3377 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 3378 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 3379 return false; 3380 3381 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 3382 SCS2.IsLvalueReference) || 3383 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 3384 !SCS2.IsLvalueReference); 3385} 3386 3387/// CompareStandardConversionSequences - Compare two standard 3388/// conversion sequences to determine whether one is better than the 3389/// other or if they are indistinguishable (C++ 13.3.3.2p3). 3390static ImplicitConversionSequence::CompareKind 3391CompareStandardConversionSequences(Sema &S, 3392 const StandardConversionSequence& SCS1, 3393 const StandardConversionSequence& SCS2) 3394{ 3395 // Standard conversion sequence S1 is a better conversion sequence 3396 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 3397 3398 // -- S1 is a proper subsequence of S2 (comparing the conversion 3399 // sequences in the canonical form defined by 13.3.3.1.1, 3400 // excluding any Lvalue Transformation; the identity conversion 3401 // sequence is considered to be a subsequence of any 3402 // non-identity conversion sequence) or, if not that, 3403 if (ImplicitConversionSequence::CompareKind CK 3404 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 3405 return CK; 3406 3407 // -- the rank of S1 is better than the rank of S2 (by the rules 3408 // defined below), or, if not that, 3409 ImplicitConversionRank Rank1 = SCS1.getRank(); 3410 ImplicitConversionRank Rank2 = SCS2.getRank(); 3411 if (Rank1 < Rank2) 3412 return ImplicitConversionSequence::Better; 3413 else if (Rank2 < Rank1) 3414 return ImplicitConversionSequence::Worse; 3415 3416 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 3417 // are indistinguishable unless one of the following rules 3418 // applies: 3419 3420 // A conversion that is not a conversion of a pointer, or 3421 // pointer to member, to bool is better than another conversion 3422 // that is such a conversion. 3423 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 3424 return SCS2.isPointerConversionToBool() 3425 ? ImplicitConversionSequence::Better 3426 : ImplicitConversionSequence::Worse; 3427 3428 // C++ [over.ics.rank]p4b2: 3429 // 3430 // If class B is derived directly or indirectly from class A, 3431 // conversion of B* to A* is better than conversion of B* to 3432 // void*, and conversion of A* to void* is better than conversion 3433 // of B* to void*. 3434 bool SCS1ConvertsToVoid 3435 = SCS1.isPointerConversionToVoidPointer(S.Context); 3436 bool SCS2ConvertsToVoid 3437 = SCS2.isPointerConversionToVoidPointer(S.Context); 3438 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 3439 // Exactly one of the conversion sequences is a conversion to 3440 // a void pointer; it's the worse conversion. 3441 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 3442 : ImplicitConversionSequence::Worse; 3443 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 3444 // Neither conversion sequence converts to a void pointer; compare 3445 // their derived-to-base conversions. 3446 if (ImplicitConversionSequence::CompareKind DerivedCK 3447 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 3448 return DerivedCK; 3449 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid && 3450 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) { 3451 // Both conversion sequences are conversions to void 3452 // pointers. Compare the source types to determine if there's an 3453 // inheritance relationship in their sources. 3454 QualType FromType1 = SCS1.getFromType(); 3455 QualType FromType2 = SCS2.getFromType(); 3456 3457 // Adjust the types we're converting from via the array-to-pointer 3458 // conversion, if we need to. 3459 if (SCS1.First == ICK_Array_To_Pointer) 3460 FromType1 = S.Context.getArrayDecayedType(FromType1); 3461 if (SCS2.First == ICK_Array_To_Pointer) 3462 FromType2 = S.Context.getArrayDecayedType(FromType2); 3463 3464 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType(); 3465 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType(); 3466 3467 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3468 return ImplicitConversionSequence::Better; 3469 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3470 return ImplicitConversionSequence::Worse; 3471 3472 // Objective-C++: If one interface is more specific than the 3473 // other, it is the better one. 3474 const ObjCObjectPointerType* FromObjCPtr1 3475 = FromType1->getAs<ObjCObjectPointerType>(); 3476 const ObjCObjectPointerType* FromObjCPtr2 3477 = FromType2->getAs<ObjCObjectPointerType>(); 3478 if (FromObjCPtr1 && FromObjCPtr2) { 3479 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1, 3480 FromObjCPtr2); 3481 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2, 3482 FromObjCPtr1); 3483 if (AssignLeft != AssignRight) { 3484 return AssignLeft? ImplicitConversionSequence::Better 3485 : ImplicitConversionSequence::Worse; 3486 } 3487 } 3488 } 3489 3490 // Compare based on qualification conversions (C++ 13.3.3.2p3, 3491 // bullet 3). 3492 if (ImplicitConversionSequence::CompareKind QualCK 3493 = CompareQualificationConversions(S, SCS1, SCS2)) 3494 return QualCK; 3495 3496 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 3497 // Check for a better reference binding based on the kind of bindings. 3498 if (isBetterReferenceBindingKind(SCS1, SCS2)) 3499 return ImplicitConversionSequence::Better; 3500 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 3501 return ImplicitConversionSequence::Worse; 3502 3503 // C++ [over.ics.rank]p3b4: 3504 // -- S1 and S2 are reference bindings (8.5.3), and the types to 3505 // which the references refer are the same type except for 3506 // top-level cv-qualifiers, and the type to which the reference 3507 // initialized by S2 refers is more cv-qualified than the type 3508 // to which the reference initialized by S1 refers. 3509 QualType T1 = SCS1.getToType(2); 3510 QualType T2 = SCS2.getToType(2); 3511 T1 = S.Context.getCanonicalType(T1); 3512 T2 = S.Context.getCanonicalType(T2); 3513 Qualifiers T1Quals, T2Quals; 3514 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3515 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3516 if (UnqualT1 == UnqualT2) { 3517 // Objective-C++ ARC: If the references refer to objects with different 3518 // lifetimes, prefer bindings that don't change lifetime. 3519 if (SCS1.ObjCLifetimeConversionBinding != 3520 SCS2.ObjCLifetimeConversionBinding) { 3521 return SCS1.ObjCLifetimeConversionBinding 3522 ? ImplicitConversionSequence::Worse 3523 : ImplicitConversionSequence::Better; 3524 } 3525 3526 // If the type is an array type, promote the element qualifiers to the 3527 // type for comparison. 3528 if (isa<ArrayType>(T1) && T1Quals) 3529 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3530 if (isa<ArrayType>(T2) && T2Quals) 3531 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3532 if (T2.isMoreQualifiedThan(T1)) 3533 return ImplicitConversionSequence::Better; 3534 else if (T1.isMoreQualifiedThan(T2)) 3535 return ImplicitConversionSequence::Worse; 3536 } 3537 } 3538 3539 // In Microsoft mode, prefer an integral conversion to a 3540 // floating-to-integral conversion if the integral conversion 3541 // is between types of the same size. 3542 // For example: 3543 // void f(float); 3544 // void f(int); 3545 // int main { 3546 // long a; 3547 // f(a); 3548 // } 3549 // Here, MSVC will call f(int) instead of generating a compile error 3550 // as clang will do in standard mode. 3551 if (S.getLangOpts().MicrosoftMode && 3552 SCS1.Second == ICK_Integral_Conversion && 3553 SCS2.Second == ICK_Floating_Integral && 3554 S.Context.getTypeSize(SCS1.getFromType()) == 3555 S.Context.getTypeSize(SCS1.getToType(2))) 3556 return ImplicitConversionSequence::Better; 3557 3558 return ImplicitConversionSequence::Indistinguishable; 3559} 3560 3561/// CompareQualificationConversions - Compares two standard conversion 3562/// sequences to determine whether they can be ranked based on their 3563/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 3564ImplicitConversionSequence::CompareKind 3565CompareQualificationConversions(Sema &S, 3566 const StandardConversionSequence& SCS1, 3567 const StandardConversionSequence& SCS2) { 3568 // C++ 13.3.3.2p3: 3569 // -- S1 and S2 differ only in their qualification conversion and 3570 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 3571 // cv-qualification signature of type T1 is a proper subset of 3572 // the cv-qualification signature of type T2, and S1 is not the 3573 // deprecated string literal array-to-pointer conversion (4.2). 3574 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 3575 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 3576 return ImplicitConversionSequence::Indistinguishable; 3577 3578 // FIXME: the example in the standard doesn't use a qualification 3579 // conversion (!) 3580 QualType T1 = SCS1.getToType(2); 3581 QualType T2 = SCS2.getToType(2); 3582 T1 = S.Context.getCanonicalType(T1); 3583 T2 = S.Context.getCanonicalType(T2); 3584 Qualifiers T1Quals, T2Quals; 3585 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3586 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3587 3588 // If the types are the same, we won't learn anything by unwrapped 3589 // them. 3590 if (UnqualT1 == UnqualT2) 3591 return ImplicitConversionSequence::Indistinguishable; 3592 3593 // If the type is an array type, promote the element qualifiers to the type 3594 // for comparison. 3595 if (isa<ArrayType>(T1) && T1Quals) 3596 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3597 if (isa<ArrayType>(T2) && T2Quals) 3598 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3599 3600 ImplicitConversionSequence::CompareKind Result 3601 = ImplicitConversionSequence::Indistinguishable; 3602 3603 // Objective-C++ ARC: 3604 // Prefer qualification conversions not involving a change in lifetime 3605 // to qualification conversions that do not change lifetime. 3606 if (SCS1.QualificationIncludesObjCLifetime != 3607 SCS2.QualificationIncludesObjCLifetime) { 3608 Result = SCS1.QualificationIncludesObjCLifetime 3609 ? ImplicitConversionSequence::Worse 3610 : ImplicitConversionSequence::Better; 3611 } 3612 3613 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 3614 // Within each iteration of the loop, we check the qualifiers to 3615 // determine if this still looks like a qualification 3616 // conversion. Then, if all is well, we unwrap one more level of 3617 // pointers or pointers-to-members and do it all again 3618 // until there are no more pointers or pointers-to-members left 3619 // to unwrap. This essentially mimics what 3620 // IsQualificationConversion does, but here we're checking for a 3621 // strict subset of qualifiers. 3622 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 3623 // The qualifiers are the same, so this doesn't tell us anything 3624 // about how the sequences rank. 3625 ; 3626 else if (T2.isMoreQualifiedThan(T1)) { 3627 // T1 has fewer qualifiers, so it could be the better sequence. 3628 if (Result == ImplicitConversionSequence::Worse) 3629 // Neither has qualifiers that are a subset of the other's 3630 // qualifiers. 3631 return ImplicitConversionSequence::Indistinguishable; 3632 3633 Result = ImplicitConversionSequence::Better; 3634 } else if (T1.isMoreQualifiedThan(T2)) { 3635 // T2 has fewer qualifiers, so it could be the better sequence. 3636 if (Result == ImplicitConversionSequence::Better) 3637 // Neither has qualifiers that are a subset of the other's 3638 // qualifiers. 3639 return ImplicitConversionSequence::Indistinguishable; 3640 3641 Result = ImplicitConversionSequence::Worse; 3642 } else { 3643 // Qualifiers are disjoint. 3644 return ImplicitConversionSequence::Indistinguishable; 3645 } 3646 3647 // If the types after this point are equivalent, we're done. 3648 if (S.Context.hasSameUnqualifiedType(T1, T2)) 3649 break; 3650 } 3651 3652 // Check that the winning standard conversion sequence isn't using 3653 // the deprecated string literal array to pointer conversion. 3654 switch (Result) { 3655 case ImplicitConversionSequence::Better: 3656 if (SCS1.DeprecatedStringLiteralToCharPtr) 3657 Result = ImplicitConversionSequence::Indistinguishable; 3658 break; 3659 3660 case ImplicitConversionSequence::Indistinguishable: 3661 break; 3662 3663 case ImplicitConversionSequence::Worse: 3664 if (SCS2.DeprecatedStringLiteralToCharPtr) 3665 Result = ImplicitConversionSequence::Indistinguishable; 3666 break; 3667 } 3668 3669 return Result; 3670} 3671 3672/// CompareDerivedToBaseConversions - Compares two standard conversion 3673/// sequences to determine whether they can be ranked based on their 3674/// various kinds of derived-to-base conversions (C++ 3675/// [over.ics.rank]p4b3). As part of these checks, we also look at 3676/// conversions between Objective-C interface types. 3677ImplicitConversionSequence::CompareKind 3678CompareDerivedToBaseConversions(Sema &S, 3679 const StandardConversionSequence& SCS1, 3680 const StandardConversionSequence& SCS2) { 3681 QualType FromType1 = SCS1.getFromType(); 3682 QualType ToType1 = SCS1.getToType(1); 3683 QualType FromType2 = SCS2.getFromType(); 3684 QualType ToType2 = SCS2.getToType(1); 3685 3686 // Adjust the types we're converting from via the array-to-pointer 3687 // conversion, if we need to. 3688 if (SCS1.First == ICK_Array_To_Pointer) 3689 FromType1 = S.Context.getArrayDecayedType(FromType1); 3690 if (SCS2.First == ICK_Array_To_Pointer) 3691 FromType2 = S.Context.getArrayDecayedType(FromType2); 3692 3693 // Canonicalize all of the types. 3694 FromType1 = S.Context.getCanonicalType(FromType1); 3695 ToType1 = S.Context.getCanonicalType(ToType1); 3696 FromType2 = S.Context.getCanonicalType(FromType2); 3697 ToType2 = S.Context.getCanonicalType(ToType2); 3698 3699 // C++ [over.ics.rank]p4b3: 3700 // 3701 // If class B is derived directly or indirectly from class A and 3702 // class C is derived directly or indirectly from B, 3703 // 3704 // Compare based on pointer conversions. 3705 if (SCS1.Second == ICK_Pointer_Conversion && 3706 SCS2.Second == ICK_Pointer_Conversion && 3707 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 3708 FromType1->isPointerType() && FromType2->isPointerType() && 3709 ToType1->isPointerType() && ToType2->isPointerType()) { 3710 QualType FromPointee1 3711 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3712 QualType ToPointee1 3713 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3714 QualType FromPointee2 3715 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3716 QualType ToPointee2 3717 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3718 3719 // -- conversion of C* to B* is better than conversion of C* to A*, 3720 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3721 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3722 return ImplicitConversionSequence::Better; 3723 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3724 return ImplicitConversionSequence::Worse; 3725 } 3726 3727 // -- conversion of B* to A* is better than conversion of C* to A*, 3728 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 3729 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3730 return ImplicitConversionSequence::Better; 3731 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3732 return ImplicitConversionSequence::Worse; 3733 } 3734 } else if (SCS1.Second == ICK_Pointer_Conversion && 3735 SCS2.Second == ICK_Pointer_Conversion) { 3736 const ObjCObjectPointerType *FromPtr1 3737 = FromType1->getAs<ObjCObjectPointerType>(); 3738 const ObjCObjectPointerType *FromPtr2 3739 = FromType2->getAs<ObjCObjectPointerType>(); 3740 const ObjCObjectPointerType *ToPtr1 3741 = ToType1->getAs<ObjCObjectPointerType>(); 3742 const ObjCObjectPointerType *ToPtr2 3743 = ToType2->getAs<ObjCObjectPointerType>(); 3744 3745 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 3746 // Apply the same conversion ranking rules for Objective-C pointer types 3747 // that we do for C++ pointers to class types. However, we employ the 3748 // Objective-C pseudo-subtyping relationship used for assignment of 3749 // Objective-C pointer types. 3750 bool FromAssignLeft 3751 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 3752 bool FromAssignRight 3753 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 3754 bool ToAssignLeft 3755 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 3756 bool ToAssignRight 3757 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 3758 3759 // A conversion to an a non-id object pointer type or qualified 'id' 3760 // type is better than a conversion to 'id'. 3761 if (ToPtr1->isObjCIdType() && 3762 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 3763 return ImplicitConversionSequence::Worse; 3764 if (ToPtr2->isObjCIdType() && 3765 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 3766 return ImplicitConversionSequence::Better; 3767 3768 // A conversion to a non-id object pointer type is better than a 3769 // conversion to a qualified 'id' type 3770 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 3771 return ImplicitConversionSequence::Worse; 3772 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 3773 return ImplicitConversionSequence::Better; 3774 3775 // A conversion to an a non-Class object pointer type or qualified 'Class' 3776 // type is better than a conversion to 'Class'. 3777 if (ToPtr1->isObjCClassType() && 3778 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 3779 return ImplicitConversionSequence::Worse; 3780 if (ToPtr2->isObjCClassType() && 3781 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 3782 return ImplicitConversionSequence::Better; 3783 3784 // A conversion to a non-Class object pointer type is better than a 3785 // conversion to a qualified 'Class' type. 3786 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 3787 return ImplicitConversionSequence::Worse; 3788 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 3789 return ImplicitConversionSequence::Better; 3790 3791 // -- "conversion of C* to B* is better than conversion of C* to A*," 3792 if (S.Context.hasSameType(FromType1, FromType2) && 3793 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 3794 (ToAssignLeft != ToAssignRight)) 3795 return ToAssignLeft? ImplicitConversionSequence::Worse 3796 : ImplicitConversionSequence::Better; 3797 3798 // -- "conversion of B* to A* is better than conversion of C* to A*," 3799 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 3800 (FromAssignLeft != FromAssignRight)) 3801 return FromAssignLeft? ImplicitConversionSequence::Better 3802 : ImplicitConversionSequence::Worse; 3803 } 3804 } 3805 3806 // Ranking of member-pointer types. 3807 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 3808 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 3809 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 3810 const MemberPointerType * FromMemPointer1 = 3811 FromType1->getAs<MemberPointerType>(); 3812 const MemberPointerType * ToMemPointer1 = 3813 ToType1->getAs<MemberPointerType>(); 3814 const MemberPointerType * FromMemPointer2 = 3815 FromType2->getAs<MemberPointerType>(); 3816 const MemberPointerType * ToMemPointer2 = 3817 ToType2->getAs<MemberPointerType>(); 3818 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 3819 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 3820 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 3821 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 3822 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 3823 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 3824 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 3825 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 3826 // conversion of A::* to B::* is better than conversion of A::* to C::*, 3827 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3828 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3829 return ImplicitConversionSequence::Worse; 3830 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3831 return ImplicitConversionSequence::Better; 3832 } 3833 // conversion of B::* to C::* is better than conversion of A::* to C::* 3834 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 3835 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3836 return ImplicitConversionSequence::Better; 3837 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3838 return ImplicitConversionSequence::Worse; 3839 } 3840 } 3841 3842 if (SCS1.Second == ICK_Derived_To_Base) { 3843 // -- conversion of C to B is better than conversion of C to A, 3844 // -- binding of an expression of type C to a reference of type 3845 // B& is better than binding an expression of type C to a 3846 // reference of type A&, 3847 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3848 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3849 if (S.IsDerivedFrom(ToType1, ToType2)) 3850 return ImplicitConversionSequence::Better; 3851 else if (S.IsDerivedFrom(ToType2, ToType1)) 3852 return ImplicitConversionSequence::Worse; 3853 } 3854 3855 // -- conversion of B to A is better than conversion of C to A. 3856 // -- binding of an expression of type B to a reference of type 3857 // A& is better than binding an expression of type C to a 3858 // reference of type A&, 3859 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3860 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3861 if (S.IsDerivedFrom(FromType2, FromType1)) 3862 return ImplicitConversionSequence::Better; 3863 else if (S.IsDerivedFrom(FromType1, FromType2)) 3864 return ImplicitConversionSequence::Worse; 3865 } 3866 } 3867 3868 return ImplicitConversionSequence::Indistinguishable; 3869} 3870 3871/// CompareReferenceRelationship - Compare the two types T1 and T2 to 3872/// determine whether they are reference-related, 3873/// reference-compatible, reference-compatible with added 3874/// qualification, or incompatible, for use in C++ initialization by 3875/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 3876/// type, and the first type (T1) is the pointee type of the reference 3877/// type being initialized. 3878Sema::ReferenceCompareResult 3879Sema::CompareReferenceRelationship(SourceLocation Loc, 3880 QualType OrigT1, QualType OrigT2, 3881 bool &DerivedToBase, 3882 bool &ObjCConversion, 3883 bool &ObjCLifetimeConversion) { 3884 assert(!OrigT1->isReferenceType() && 3885 "T1 must be the pointee type of the reference type"); 3886 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 3887 3888 QualType T1 = Context.getCanonicalType(OrigT1); 3889 QualType T2 = Context.getCanonicalType(OrigT2); 3890 Qualifiers T1Quals, T2Quals; 3891 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 3892 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 3893 3894 // C++ [dcl.init.ref]p4: 3895 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 3896 // reference-related to "cv2 T2" if T1 is the same type as T2, or 3897 // T1 is a base class of T2. 3898 DerivedToBase = false; 3899 ObjCConversion = false; 3900 ObjCLifetimeConversion = false; 3901 if (UnqualT1 == UnqualT2) { 3902 // Nothing to do. 3903 } else if (!RequireCompleteType(Loc, OrigT2, 0) && 3904 IsDerivedFrom(UnqualT2, UnqualT1)) 3905 DerivedToBase = true; 3906 else if (UnqualT1->isObjCObjectOrInterfaceType() && 3907 UnqualT2->isObjCObjectOrInterfaceType() && 3908 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 3909 ObjCConversion = true; 3910 else 3911 return Ref_Incompatible; 3912 3913 // At this point, we know that T1 and T2 are reference-related (at 3914 // least). 3915 3916 // If the type is an array type, promote the element qualifiers to the type 3917 // for comparison. 3918 if (isa<ArrayType>(T1) && T1Quals) 3919 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 3920 if (isa<ArrayType>(T2) && T2Quals) 3921 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 3922 3923 // C++ [dcl.init.ref]p4: 3924 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 3925 // reference-related to T2 and cv1 is the same cv-qualification 3926 // as, or greater cv-qualification than, cv2. For purposes of 3927 // overload resolution, cases for which cv1 is greater 3928 // cv-qualification than cv2 are identified as 3929 // reference-compatible with added qualification (see 13.3.3.2). 3930 // 3931 // Note that we also require equivalence of Objective-C GC and address-space 3932 // qualifiers when performing these computations, so that e.g., an int in 3933 // address space 1 is not reference-compatible with an int in address 3934 // space 2. 3935 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() && 3936 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) { 3937 T1Quals.removeObjCLifetime(); 3938 T2Quals.removeObjCLifetime(); 3939 ObjCLifetimeConversion = true; 3940 } 3941 3942 if (T1Quals == T2Quals) 3943 return Ref_Compatible; 3944 else if (T1Quals.compatiblyIncludes(T2Quals)) 3945 return Ref_Compatible_With_Added_Qualification; 3946 else 3947 return Ref_Related; 3948} 3949 3950/// \brief Look for a user-defined conversion to an value reference-compatible 3951/// with DeclType. Return true if something definite is found. 3952static bool 3953FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 3954 QualType DeclType, SourceLocation DeclLoc, 3955 Expr *Init, QualType T2, bool AllowRvalues, 3956 bool AllowExplicit) { 3957 assert(T2->isRecordType() && "Can only find conversions of record types."); 3958 CXXRecordDecl *T2RecordDecl 3959 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 3960 3961 OverloadCandidateSet CandidateSet(DeclLoc); 3962 const UnresolvedSetImpl *Conversions 3963 = T2RecordDecl->getVisibleConversionFunctions(); 3964 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3965 E = Conversions->end(); I != E; ++I) { 3966 NamedDecl *D = *I; 3967 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3968 if (isa<UsingShadowDecl>(D)) 3969 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3970 3971 FunctionTemplateDecl *ConvTemplate 3972 = dyn_cast<FunctionTemplateDecl>(D); 3973 CXXConversionDecl *Conv; 3974 if (ConvTemplate) 3975 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3976 else 3977 Conv = cast<CXXConversionDecl>(D); 3978 3979 // If this is an explicit conversion, and we're not allowed to consider 3980 // explicit conversions, skip it. 3981 if (!AllowExplicit && Conv->isExplicit()) 3982 continue; 3983 3984 if (AllowRvalues) { 3985 bool DerivedToBase = false; 3986 bool ObjCConversion = false; 3987 bool ObjCLifetimeConversion = false; 3988 3989 // If we are initializing an rvalue reference, don't permit conversion 3990 // functions that return lvalues. 3991 if (!ConvTemplate && DeclType->isRValueReferenceType()) { 3992 const ReferenceType *RefType 3993 = Conv->getConversionType()->getAs<LValueReferenceType>(); 3994 if (RefType && !RefType->getPointeeType()->isFunctionType()) 3995 continue; 3996 } 3997 3998 if (!ConvTemplate && 3999 S.CompareReferenceRelationship( 4000 DeclLoc, 4001 Conv->getConversionType().getNonReferenceType() 4002 .getUnqualifiedType(), 4003 DeclType.getNonReferenceType().getUnqualifiedType(), 4004 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) == 4005 Sema::Ref_Incompatible) 4006 continue; 4007 } else { 4008 // If the conversion function doesn't return a reference type, 4009 // it can't be considered for this conversion. An rvalue reference 4010 // is only acceptable if its referencee is a function type. 4011 4012 const ReferenceType *RefType = 4013 Conv->getConversionType()->getAs<ReferenceType>(); 4014 if (!RefType || 4015 (!RefType->isLValueReferenceType() && 4016 !RefType->getPointeeType()->isFunctionType())) 4017 continue; 4018 } 4019 4020 if (ConvTemplate) 4021 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 4022 Init, DeclType, CandidateSet); 4023 else 4024 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 4025 DeclType, CandidateSet); 4026 } 4027 4028 bool HadMultipleCandidates = (CandidateSet.size() > 1); 4029 4030 OverloadCandidateSet::iterator Best; 4031 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 4032 case OR_Success: 4033 // C++ [over.ics.ref]p1: 4034 // 4035 // [...] If the parameter binds directly to the result of 4036 // applying a conversion function to the argument 4037 // expression, the implicit conversion sequence is a 4038 // user-defined conversion sequence (13.3.3.1.2), with the 4039 // second standard conversion sequence either an identity 4040 // conversion or, if the conversion function returns an 4041 // entity of a type that is a derived class of the parameter 4042 // type, a derived-to-base Conversion. 4043 if (!Best->FinalConversion.DirectBinding) 4044 return false; 4045 4046 ICS.setUserDefined(); 4047 ICS.UserDefined.Before = Best->Conversions[0].Standard; 4048 ICS.UserDefined.After = Best->FinalConversion; 4049 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates; 4050 ICS.UserDefined.ConversionFunction = Best->Function; 4051 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl; 4052 ICS.UserDefined.EllipsisConversion = false; 4053 assert(ICS.UserDefined.After.ReferenceBinding && 4054 ICS.UserDefined.After.DirectBinding && 4055 "Expected a direct reference binding!"); 4056 return true; 4057 4058 case OR_Ambiguous: 4059 ICS.setAmbiguous(); 4060 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 4061 Cand != CandidateSet.end(); ++Cand) 4062 if (Cand->Viable) 4063 ICS.Ambiguous.addConversion(Cand->Function); 4064 return true; 4065 4066 case OR_No_Viable_Function: 4067 case OR_Deleted: 4068 // There was no suitable conversion, or we found a deleted 4069 // conversion; continue with other checks. 4070 return false; 4071 } 4072 4073 llvm_unreachable("Invalid OverloadResult!"); 4074} 4075 4076/// \brief Compute an implicit conversion sequence for reference 4077/// initialization. 4078static ImplicitConversionSequence 4079TryReferenceInit(Sema &S, Expr *Init, QualType DeclType, 4080 SourceLocation DeclLoc, 4081 bool SuppressUserConversions, 4082 bool AllowExplicit) { 4083 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 4084 4085 // Most paths end in a failed conversion. 4086 ImplicitConversionSequence ICS; 4087 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 4088 4089 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 4090 QualType T2 = Init->getType(); 4091 4092 // If the initializer is the address of an overloaded function, try 4093 // to resolve the overloaded function. If all goes well, T2 is the 4094 // type of the resulting function. 4095 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 4096 DeclAccessPair Found; 4097 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 4098 false, Found)) 4099 T2 = Fn->getType(); 4100 } 4101 4102 // Compute some basic properties of the types and the initializer. 4103 bool isRValRef = DeclType->isRValueReferenceType(); 4104 bool DerivedToBase = false; 4105 bool ObjCConversion = false; 4106 bool ObjCLifetimeConversion = false; 4107 Expr::Classification InitCategory = Init->Classify(S.Context); 4108 Sema::ReferenceCompareResult RefRelationship 4109 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 4110 ObjCConversion, ObjCLifetimeConversion); 4111 4112 4113 // C++0x [dcl.init.ref]p5: 4114 // A reference to type "cv1 T1" is initialized by an expression 4115 // of type "cv2 T2" as follows: 4116 4117 // -- If reference is an lvalue reference and the initializer expression 4118 if (!isRValRef) { 4119 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 4120 // reference-compatible with "cv2 T2," or 4121 // 4122 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 4123 if (InitCategory.isLValue() && 4124 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 4125 // C++ [over.ics.ref]p1: 4126 // When a parameter of reference type binds directly (8.5.3) 4127 // to an argument expression, the implicit conversion sequence 4128 // is the identity conversion, unless the argument expression 4129 // has a type that is a derived class of the parameter type, 4130 // in which case the implicit conversion sequence is a 4131 // derived-to-base Conversion (13.3.3.1). 4132 ICS.setStandard(); 4133 ICS.Standard.First = ICK_Identity; 4134 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 4135 : ObjCConversion? ICK_Compatible_Conversion 4136 : ICK_Identity; 4137 ICS.Standard.Third = ICK_Identity; 4138 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 4139 ICS.Standard.setToType(0, T2); 4140 ICS.Standard.setToType(1, T1); 4141 ICS.Standard.setToType(2, T1); 4142 ICS.Standard.ReferenceBinding = true; 4143 ICS.Standard.DirectBinding = true; 4144 ICS.Standard.IsLvalueReference = !isRValRef; 4145 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4146 ICS.Standard.BindsToRvalue = false; 4147 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4148 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 4149 ICS.Standard.CopyConstructor = 0; 4150 4151 // Nothing more to do: the inaccessibility/ambiguity check for 4152 // derived-to-base conversions is suppressed when we're 4153 // computing the implicit conversion sequence (C++ 4154 // [over.best.ics]p2). 4155 return ICS; 4156 } 4157 4158 // -- has a class type (i.e., T2 is a class type), where T1 is 4159 // not reference-related to T2, and can be implicitly 4160 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 4161 // is reference-compatible with "cv3 T3" 92) (this 4162 // conversion is selected by enumerating the applicable 4163 // conversion functions (13.3.1.6) and choosing the best 4164 // one through overload resolution (13.3)), 4165 if (!SuppressUserConversions && T2->isRecordType() && 4166 !S.RequireCompleteType(DeclLoc, T2, 0) && 4167 RefRelationship == Sema::Ref_Incompatible) { 4168 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 4169 Init, T2, /*AllowRvalues=*/false, 4170 AllowExplicit)) 4171 return ICS; 4172 } 4173 } 4174 4175 // -- Otherwise, the reference shall be an lvalue reference to a 4176 // non-volatile const type (i.e., cv1 shall be const), or the reference 4177 // shall be an rvalue reference. 4178 // 4179 // We actually handle one oddity of C++ [over.ics.ref] at this 4180 // point, which is that, due to p2 (which short-circuits reference 4181 // binding by only attempting a simple conversion for non-direct 4182 // bindings) and p3's strange wording, we allow a const volatile 4183 // reference to bind to an rvalue. Hence the check for the presence 4184 // of "const" rather than checking for "const" being the only 4185 // qualifier. 4186 // This is also the point where rvalue references and lvalue inits no longer 4187 // go together. 4188 if (!isRValRef && (!T1.isConstQualified() || T1.isVolatileQualified())) 4189 return ICS; 4190 4191 // -- If the initializer expression 4192 // 4193 // -- is an xvalue, class prvalue, array prvalue or function 4194 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or 4195 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 4196 (InitCategory.isXValue() || 4197 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 4198 (InitCategory.isLValue() && T2->isFunctionType()))) { 4199 ICS.setStandard(); 4200 ICS.Standard.First = ICK_Identity; 4201 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 4202 : ObjCConversion? ICK_Compatible_Conversion 4203 : ICK_Identity; 4204 ICS.Standard.Third = ICK_Identity; 4205 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 4206 ICS.Standard.setToType(0, T2); 4207 ICS.Standard.setToType(1, T1); 4208 ICS.Standard.setToType(2, T1); 4209 ICS.Standard.ReferenceBinding = true; 4210 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 4211 // binding unless we're binding to a class prvalue. 4212 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 4213 // allow the use of rvalue references in C++98/03 for the benefit of 4214 // standard library implementors; therefore, we need the xvalue check here. 4215 ICS.Standard.DirectBinding = 4216 S.getLangOpts().CPlusPlus0x || 4217 (InitCategory.isPRValue() && !T2->isRecordType()); 4218 ICS.Standard.IsLvalueReference = !isRValRef; 4219 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4220 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 4221 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4222 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 4223 ICS.Standard.CopyConstructor = 0; 4224 return ICS; 4225 } 4226 4227 // -- has a class type (i.e., T2 is a class type), where T1 is not 4228 // reference-related to T2, and can be implicitly converted to 4229 // an xvalue, class prvalue, or function lvalue of type 4230 // "cv3 T3", where "cv1 T1" is reference-compatible with 4231 // "cv3 T3", 4232 // 4233 // then the reference is bound to the value of the initializer 4234 // expression in the first case and to the result of the conversion 4235 // in the second case (or, in either case, to an appropriate base 4236 // class subobject). 4237 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 4238 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 4239 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 4240 Init, T2, /*AllowRvalues=*/true, 4241 AllowExplicit)) { 4242 // In the second case, if the reference is an rvalue reference 4243 // and the second standard conversion sequence of the 4244 // user-defined conversion sequence includes an lvalue-to-rvalue 4245 // conversion, the program is ill-formed. 4246 if (ICS.isUserDefined() && isRValRef && 4247 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 4248 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 4249 4250 return ICS; 4251 } 4252 4253 // -- Otherwise, a temporary of type "cv1 T1" is created and 4254 // initialized from the initializer expression using the 4255 // rules for a non-reference copy initialization (8.5). The 4256 // reference is then bound to the temporary. If T1 is 4257 // reference-related to T2, cv1 must be the same 4258 // cv-qualification as, or greater cv-qualification than, 4259 // cv2; otherwise, the program is ill-formed. 4260 if (RefRelationship == Sema::Ref_Related) { 4261 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 4262 // we would be reference-compatible or reference-compatible with 4263 // added qualification. But that wasn't the case, so the reference 4264 // initialization fails. 4265 // 4266 // Note that we only want to check address spaces and cvr-qualifiers here. 4267 // ObjC GC and lifetime qualifiers aren't important. 4268 Qualifiers T1Quals = T1.getQualifiers(); 4269 Qualifiers T2Quals = T2.getQualifiers(); 4270 T1Quals.removeObjCGCAttr(); 4271 T1Quals.removeObjCLifetime(); 4272 T2Quals.removeObjCGCAttr(); 4273 T2Quals.removeObjCLifetime(); 4274 if (!T1Quals.compatiblyIncludes(T2Quals)) 4275 return ICS; 4276 } 4277 4278 // If at least one of the types is a class type, the types are not 4279 // related, and we aren't allowed any user conversions, the 4280 // reference binding fails. This case is important for breaking 4281 // recursion, since TryImplicitConversion below will attempt to 4282 // create a temporary through the use of a copy constructor. 4283 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 4284 (T1->isRecordType() || T2->isRecordType())) 4285 return ICS; 4286 4287 // If T1 is reference-related to T2 and the reference is an rvalue 4288 // reference, the initializer expression shall not be an lvalue. 4289 if (RefRelationship >= Sema::Ref_Related && 4290 isRValRef && Init->Classify(S.Context).isLValue()) 4291 return ICS; 4292 4293 // C++ [over.ics.ref]p2: 4294 // When a parameter of reference type is not bound directly to 4295 // an argument expression, the conversion sequence is the one 4296 // required to convert the argument expression to the 4297 // underlying type of the reference according to 4298 // 13.3.3.1. Conceptually, this conversion sequence corresponds 4299 // to copy-initializing a temporary of the underlying type with 4300 // the argument expression. Any difference in top-level 4301 // cv-qualification is subsumed by the initialization itself 4302 // and does not constitute a conversion. 4303 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 4304 /*AllowExplicit=*/false, 4305 /*InOverloadResolution=*/false, 4306 /*CStyle=*/false, 4307 /*AllowObjCWritebackConversion=*/false); 4308 4309 // Of course, that's still a reference binding. 4310 if (ICS.isStandard()) { 4311 ICS.Standard.ReferenceBinding = true; 4312 ICS.Standard.IsLvalueReference = !isRValRef; 4313 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 4314 ICS.Standard.BindsToRvalue = true; 4315 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4316 ICS.Standard.ObjCLifetimeConversionBinding = false; 4317 } else if (ICS.isUserDefined()) { 4318 // Don't allow rvalue references to bind to lvalues. 4319 if (DeclType->isRValueReferenceType()) { 4320 if (const ReferenceType *RefType 4321 = ICS.UserDefined.ConversionFunction->getResultType() 4322 ->getAs<LValueReferenceType>()) { 4323 if (!RefType->getPointeeType()->isFunctionType()) { 4324 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, 4325 DeclType); 4326 return ICS; 4327 } 4328 } 4329 } 4330 4331 ICS.UserDefined.After.ReferenceBinding = true; 4332 ICS.UserDefined.After.IsLvalueReference = !isRValRef; 4333 ICS.UserDefined.After.BindsToFunctionLvalue = T2->isFunctionType(); 4334 ICS.UserDefined.After.BindsToRvalue = true; 4335 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4336 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false; 4337 } 4338 4339 return ICS; 4340} 4341 4342static ImplicitConversionSequence 4343TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 4344 bool SuppressUserConversions, 4345 bool InOverloadResolution, 4346 bool AllowObjCWritebackConversion, 4347 bool AllowExplicit = false); 4348 4349/// TryListConversion - Try to copy-initialize a value of type ToType from the 4350/// initializer list From. 4351static ImplicitConversionSequence 4352TryListConversion(Sema &S, InitListExpr *From, QualType ToType, 4353 bool SuppressUserConversions, 4354 bool InOverloadResolution, 4355 bool AllowObjCWritebackConversion) { 4356 // C++11 [over.ics.list]p1: 4357 // When an argument is an initializer list, it is not an expression and 4358 // special rules apply for converting it to a parameter type. 4359 4360 ImplicitConversionSequence Result; 4361 Result.setBad(BadConversionSequence::no_conversion, From, ToType); 4362 Result.setListInitializationSequence(); 4363 4364 // We need a complete type for what follows. Incomplete types can never be 4365 // initialized from init lists. 4366 if (S.RequireCompleteType(From->getLocStart(), ToType, 0)) 4367 return Result; 4368 4369 // C++11 [over.ics.list]p2: 4370 // If the parameter type is std::initializer_list<X> or "array of X" and 4371 // all the elements can be implicitly converted to X, the implicit 4372 // conversion sequence is the worst conversion necessary to convert an 4373 // element of the list to X. 4374 bool toStdInitializerList = false; 4375 QualType X; 4376 if (ToType->isArrayType()) 4377 X = S.Context.getBaseElementType(ToType); 4378 else 4379 toStdInitializerList = S.isStdInitializerList(ToType, &X); 4380 if (!X.isNull()) { 4381 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) { 4382 Expr *Init = From->getInit(i); 4383 ImplicitConversionSequence ICS = 4384 TryCopyInitialization(S, Init, X, SuppressUserConversions, 4385 InOverloadResolution, 4386 AllowObjCWritebackConversion); 4387 // If a single element isn't convertible, fail. 4388 if (ICS.isBad()) { 4389 Result = ICS; 4390 break; 4391 } 4392 // Otherwise, look for the worst conversion. 4393 if (Result.isBad() || 4394 CompareImplicitConversionSequences(S, ICS, Result) == 4395 ImplicitConversionSequence::Worse) 4396 Result = ICS; 4397 } 4398 4399 // For an empty list, we won't have computed any conversion sequence. 4400 // Introduce the identity conversion sequence. 4401 if (From->getNumInits() == 0) { 4402 Result.setStandard(); 4403 Result.Standard.setAsIdentityConversion(); 4404 Result.Standard.setFromType(ToType); 4405 Result.Standard.setAllToTypes(ToType); 4406 } 4407 4408 Result.setListInitializationSequence(); 4409 Result.setStdInitializerListElement(toStdInitializerList); 4410 return Result; 4411 } 4412 4413 // C++11 [over.ics.list]p3: 4414 // Otherwise, if the parameter is a non-aggregate class X and overload 4415 // resolution chooses a single best constructor [...] the implicit 4416 // conversion sequence is a user-defined conversion sequence. If multiple 4417 // constructors are viable but none is better than the others, the 4418 // implicit conversion sequence is a user-defined conversion sequence. 4419 if (ToType->isRecordType() && !ToType->isAggregateType()) { 4420 // This function can deal with initializer lists. 4421 Result = TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, 4422 /*AllowExplicit=*/false, 4423 InOverloadResolution, /*CStyle=*/false, 4424 AllowObjCWritebackConversion); 4425 Result.setListInitializationSequence(); 4426 return Result; 4427 } 4428 4429 // C++11 [over.ics.list]p4: 4430 // Otherwise, if the parameter has an aggregate type which can be 4431 // initialized from the initializer list [...] the implicit conversion 4432 // sequence is a user-defined conversion sequence. 4433 if (ToType->isAggregateType()) { 4434 // Type is an aggregate, argument is an init list. At this point it comes 4435 // down to checking whether the initialization works. 4436 // FIXME: Find out whether this parameter is consumed or not. 4437 InitializedEntity Entity = 4438 InitializedEntity::InitializeParameter(S.Context, ToType, 4439 /*Consumed=*/false); 4440 if (S.CanPerformCopyInitialization(Entity, S.Owned(From))) { 4441 Result.setUserDefined(); 4442 Result.UserDefined.Before.setAsIdentityConversion(); 4443 // Initializer lists don't have a type. 4444 Result.UserDefined.Before.setFromType(QualType()); 4445 Result.UserDefined.Before.setAllToTypes(QualType()); 4446 4447 Result.UserDefined.After.setAsIdentityConversion(); 4448 Result.UserDefined.After.setFromType(ToType); 4449 Result.UserDefined.After.setAllToTypes(ToType); 4450 Result.UserDefined.ConversionFunction = 0; 4451 } 4452 return Result; 4453 } 4454 4455 // C++11 [over.ics.list]p5: 4456 // Otherwise, if the parameter is a reference, see 13.3.3.1.4. 4457 if (ToType->isReferenceType()) { 4458 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't 4459 // mention initializer lists in any way. So we go by what list- 4460 // initialization would do and try to extrapolate from that. 4461 4462 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType(); 4463 4464 // If the initializer list has a single element that is reference-related 4465 // to the parameter type, we initialize the reference from that. 4466 if (From->getNumInits() == 1) { 4467 Expr *Init = From->getInit(0); 4468 4469 QualType T2 = Init->getType(); 4470 4471 // If the initializer is the address of an overloaded function, try 4472 // to resolve the overloaded function. If all goes well, T2 is the 4473 // type of the resulting function. 4474 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 4475 DeclAccessPair Found; 4476 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction( 4477 Init, ToType, false, Found)) 4478 T2 = Fn->getType(); 4479 } 4480 4481 // Compute some basic properties of the types and the initializer. 4482 bool dummy1 = false; 4483 bool dummy2 = false; 4484 bool dummy3 = false; 4485 Sema::ReferenceCompareResult RefRelationship 4486 = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1, 4487 dummy2, dummy3); 4488 4489 if (RefRelationship >= Sema::Ref_Related) 4490 return TryReferenceInit(S, Init, ToType, 4491 /*FIXME:*/From->getLocStart(), 4492 SuppressUserConversions, 4493 /*AllowExplicit=*/false); 4494 } 4495 4496 // Otherwise, we bind the reference to a temporary created from the 4497 // initializer list. 4498 Result = TryListConversion(S, From, T1, SuppressUserConversions, 4499 InOverloadResolution, 4500 AllowObjCWritebackConversion); 4501 if (Result.isFailure()) 4502 return Result; 4503 assert(!Result.isEllipsis() && 4504 "Sub-initialization cannot result in ellipsis conversion."); 4505 4506 // Can we even bind to a temporary? 4507 if (ToType->isRValueReferenceType() || 4508 (T1.isConstQualified() && !T1.isVolatileQualified())) { 4509 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard : 4510 Result.UserDefined.After; 4511 SCS.ReferenceBinding = true; 4512 SCS.IsLvalueReference = ToType->isLValueReferenceType(); 4513 SCS.BindsToRvalue = true; 4514 SCS.BindsToFunctionLvalue = false; 4515 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4516 SCS.ObjCLifetimeConversionBinding = false; 4517 } else 4518 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue, 4519 From, ToType); 4520 return Result; 4521 } 4522 4523 // C++11 [over.ics.list]p6: 4524 // Otherwise, if the parameter type is not a class: 4525 if (!ToType->isRecordType()) { 4526 // - if the initializer list has one element, the implicit conversion 4527 // sequence is the one required to convert the element to the 4528 // parameter type. 4529 unsigned NumInits = From->getNumInits(); 4530 if (NumInits == 1) 4531 Result = TryCopyInitialization(S, From->getInit(0), ToType, 4532 SuppressUserConversions, 4533 InOverloadResolution, 4534 AllowObjCWritebackConversion); 4535 // - if the initializer list has no elements, the implicit conversion 4536 // sequence is the identity conversion. 4537 else if (NumInits == 0) { 4538 Result.setStandard(); 4539 Result.Standard.setAsIdentityConversion(); 4540 Result.Standard.setFromType(ToType); 4541 Result.Standard.setAllToTypes(ToType); 4542 } 4543 Result.setListInitializationSequence(); 4544 return Result; 4545 } 4546 4547 // C++11 [over.ics.list]p7: 4548 // In all cases other than those enumerated above, no conversion is possible 4549 return Result; 4550} 4551 4552/// TryCopyInitialization - Try to copy-initialize a value of type 4553/// ToType from the expression From. Return the implicit conversion 4554/// sequence required to pass this argument, which may be a bad 4555/// conversion sequence (meaning that the argument cannot be passed to 4556/// a parameter of this type). If @p SuppressUserConversions, then we 4557/// do not permit any user-defined conversion sequences. 4558static ImplicitConversionSequence 4559TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 4560 bool SuppressUserConversions, 4561 bool InOverloadResolution, 4562 bool AllowObjCWritebackConversion, 4563 bool AllowExplicit) { 4564 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From)) 4565 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions, 4566 InOverloadResolution,AllowObjCWritebackConversion); 4567 4568 if (ToType->isReferenceType()) 4569 return TryReferenceInit(S, From, ToType, 4570 /*FIXME:*/From->getLocStart(), 4571 SuppressUserConversions, 4572 AllowExplicit); 4573 4574 return TryImplicitConversion(S, From, ToType, 4575 SuppressUserConversions, 4576 /*AllowExplicit=*/false, 4577 InOverloadResolution, 4578 /*CStyle=*/false, 4579 AllowObjCWritebackConversion); 4580} 4581 4582static bool TryCopyInitialization(const CanQualType FromQTy, 4583 const CanQualType ToQTy, 4584 Sema &S, 4585 SourceLocation Loc, 4586 ExprValueKind FromVK) { 4587 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK); 4588 ImplicitConversionSequence ICS = 4589 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false); 4590 4591 return !ICS.isBad(); 4592} 4593 4594/// TryObjectArgumentInitialization - Try to initialize the object 4595/// parameter of the given member function (@c Method) from the 4596/// expression @p From. 4597static ImplicitConversionSequence 4598TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 4599 Expr::Classification FromClassification, 4600 CXXMethodDecl *Method, 4601 CXXRecordDecl *ActingContext) { 4602 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 4603 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 4604 // const volatile object. 4605 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 4606 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 4607 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 4608 4609 // Set up the conversion sequence as a "bad" conversion, to allow us 4610 // to exit early. 4611 ImplicitConversionSequence ICS; 4612 4613 // We need to have an object of class type. 4614 QualType FromType = OrigFromType; 4615 if (const PointerType *PT = FromType->getAs<PointerType>()) { 4616 FromType = PT->getPointeeType(); 4617 4618 // When we had a pointer, it's implicitly dereferenced, so we 4619 // better have an lvalue. 4620 assert(FromClassification.isLValue()); 4621 } 4622 4623 assert(FromType->isRecordType()); 4624 4625 // C++0x [over.match.funcs]p4: 4626 // For non-static member functions, the type of the implicit object 4627 // parameter is 4628 // 4629 // - "lvalue reference to cv X" for functions declared without a 4630 // ref-qualifier or with the & ref-qualifier 4631 // - "rvalue reference to cv X" for functions declared with the && 4632 // ref-qualifier 4633 // 4634 // where X is the class of which the function is a member and cv is the 4635 // cv-qualification on the member function declaration. 4636 // 4637 // However, when finding an implicit conversion sequence for the argument, we 4638 // are not allowed to create temporaries or perform user-defined conversions 4639 // (C++ [over.match.funcs]p5). We perform a simplified version of 4640 // reference binding here, that allows class rvalues to bind to 4641 // non-constant references. 4642 4643 // First check the qualifiers. 4644 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 4645 if (ImplicitParamType.getCVRQualifiers() 4646 != FromTypeCanon.getLocalCVRQualifiers() && 4647 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 4648 ICS.setBad(BadConversionSequence::bad_qualifiers, 4649 OrigFromType, ImplicitParamType); 4650 return ICS; 4651 } 4652 4653 // Check that we have either the same type or a derived type. It 4654 // affects the conversion rank. 4655 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 4656 ImplicitConversionKind SecondKind; 4657 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 4658 SecondKind = ICK_Identity; 4659 } else if (S.IsDerivedFrom(FromType, ClassType)) 4660 SecondKind = ICK_Derived_To_Base; 4661 else { 4662 ICS.setBad(BadConversionSequence::unrelated_class, 4663 FromType, ImplicitParamType); 4664 return ICS; 4665 } 4666 4667 // Check the ref-qualifier. 4668 switch (Method->getRefQualifier()) { 4669 case RQ_None: 4670 // Do nothing; we don't care about lvalueness or rvalueness. 4671 break; 4672 4673 case RQ_LValue: 4674 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 4675 // non-const lvalue reference cannot bind to an rvalue 4676 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 4677 ImplicitParamType); 4678 return ICS; 4679 } 4680 break; 4681 4682 case RQ_RValue: 4683 if (!FromClassification.isRValue()) { 4684 // rvalue reference cannot bind to an lvalue 4685 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 4686 ImplicitParamType); 4687 return ICS; 4688 } 4689 break; 4690 } 4691 4692 // Success. Mark this as a reference binding. 4693 ICS.setStandard(); 4694 ICS.Standard.setAsIdentityConversion(); 4695 ICS.Standard.Second = SecondKind; 4696 ICS.Standard.setFromType(FromType); 4697 ICS.Standard.setAllToTypes(ImplicitParamType); 4698 ICS.Standard.ReferenceBinding = true; 4699 ICS.Standard.DirectBinding = true; 4700 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 4701 ICS.Standard.BindsToFunctionLvalue = false; 4702 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 4703 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 4704 = (Method->getRefQualifier() == RQ_None); 4705 return ICS; 4706} 4707 4708/// PerformObjectArgumentInitialization - Perform initialization of 4709/// the implicit object parameter for the given Method with the given 4710/// expression. 4711ExprResult 4712Sema::PerformObjectArgumentInitialization(Expr *From, 4713 NestedNameSpecifier *Qualifier, 4714 NamedDecl *FoundDecl, 4715 CXXMethodDecl *Method) { 4716 QualType FromRecordType, DestType; 4717 QualType ImplicitParamRecordType = 4718 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 4719 4720 Expr::Classification FromClassification; 4721 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 4722 FromRecordType = PT->getPointeeType(); 4723 DestType = Method->getThisType(Context); 4724 FromClassification = Expr::Classification::makeSimpleLValue(); 4725 } else { 4726 FromRecordType = From->getType(); 4727 DestType = ImplicitParamRecordType; 4728 FromClassification = From->Classify(Context); 4729 } 4730 4731 // Note that we always use the true parent context when performing 4732 // the actual argument initialization. 4733 ImplicitConversionSequence ICS 4734 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 4735 Method, Method->getParent()); 4736 if (ICS.isBad()) { 4737 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 4738 Qualifiers FromQs = FromRecordType.getQualifiers(); 4739 Qualifiers ToQs = DestType.getQualifiers(); 4740 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4741 if (CVR) { 4742 Diag(From->getLocStart(), 4743 diag::err_member_function_call_bad_cvr) 4744 << Method->getDeclName() << FromRecordType << (CVR - 1) 4745 << From->getSourceRange(); 4746 Diag(Method->getLocation(), diag::note_previous_decl) 4747 << Method->getDeclName(); 4748 return ExprError(); 4749 } 4750 } 4751 4752 return Diag(From->getLocStart(), 4753 diag::err_implicit_object_parameter_init) 4754 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 4755 } 4756 4757 if (ICS.Standard.Second == ICK_Derived_To_Base) { 4758 ExprResult FromRes = 4759 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 4760 if (FromRes.isInvalid()) 4761 return ExprError(); 4762 From = FromRes.take(); 4763 } 4764 4765 if (!Context.hasSameType(From->getType(), DestType)) 4766 From = ImpCastExprToType(From, DestType, CK_NoOp, 4767 From->getValueKind()).take(); 4768 return Owned(From); 4769} 4770 4771/// TryContextuallyConvertToBool - Attempt to contextually convert the 4772/// expression From to bool (C++0x [conv]p3). 4773static ImplicitConversionSequence 4774TryContextuallyConvertToBool(Sema &S, Expr *From) { 4775 // FIXME: This is pretty broken. 4776 return TryImplicitConversion(S, From, S.Context.BoolTy, 4777 // FIXME: Are these flags correct? 4778 /*SuppressUserConversions=*/false, 4779 /*AllowExplicit=*/true, 4780 /*InOverloadResolution=*/false, 4781 /*CStyle=*/false, 4782 /*AllowObjCWritebackConversion=*/false); 4783} 4784 4785/// PerformContextuallyConvertToBool - Perform a contextual conversion 4786/// of the expression From to bool (C++0x [conv]p3). 4787ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) { 4788 if (checkPlaceholderForOverload(*this, From)) 4789 return ExprError(); 4790 4791 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 4792 if (!ICS.isBad()) 4793 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 4794 4795 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 4796 return Diag(From->getLocStart(), 4797 diag::err_typecheck_bool_condition) 4798 << From->getType() << From->getSourceRange(); 4799 return ExprError(); 4800} 4801 4802/// Check that the specified conversion is permitted in a converted constant 4803/// expression, according to C++11 [expr.const]p3. Return true if the conversion 4804/// is acceptable. 4805static bool CheckConvertedConstantConversions(Sema &S, 4806 StandardConversionSequence &SCS) { 4807 // Since we know that the target type is an integral or unscoped enumeration 4808 // type, most conversion kinds are impossible. All possible First and Third 4809 // conversions are fine. 4810 switch (SCS.Second) { 4811 case ICK_Identity: 4812 case ICK_Integral_Promotion: 4813 case ICK_Integral_Conversion: 4814 return true; 4815 4816 case ICK_Boolean_Conversion: 4817 // Conversion from an integral or unscoped enumeration type to bool is 4818 // classified as ICK_Boolean_Conversion, but it's also an integral 4819 // conversion, so it's permitted in a converted constant expression. 4820 return SCS.getFromType()->isIntegralOrUnscopedEnumerationType() && 4821 SCS.getToType(2)->isBooleanType(); 4822 4823 case ICK_Floating_Integral: 4824 case ICK_Complex_Real: 4825 return false; 4826 4827 case ICK_Lvalue_To_Rvalue: 4828 case ICK_Array_To_Pointer: 4829 case ICK_Function_To_Pointer: 4830 case ICK_NoReturn_Adjustment: 4831 case ICK_Qualification: 4832 case ICK_Compatible_Conversion: 4833 case ICK_Vector_Conversion: 4834 case ICK_Vector_Splat: 4835 case ICK_Derived_To_Base: 4836 case ICK_Pointer_Conversion: 4837 case ICK_Pointer_Member: 4838 case ICK_Block_Pointer_Conversion: 4839 case ICK_Writeback_Conversion: 4840 case ICK_Floating_Promotion: 4841 case ICK_Complex_Promotion: 4842 case ICK_Complex_Conversion: 4843 case ICK_Floating_Conversion: 4844 case ICK_TransparentUnionConversion: 4845 llvm_unreachable("unexpected second conversion kind"); 4846 4847 case ICK_Num_Conversion_Kinds: 4848 break; 4849 } 4850 4851 llvm_unreachable("unknown conversion kind"); 4852} 4853 4854/// CheckConvertedConstantExpression - Check that the expression From is a 4855/// converted constant expression of type T, perform the conversion and produce 4856/// the converted expression, per C++11 [expr.const]p3. 4857ExprResult Sema::CheckConvertedConstantExpression(Expr *From, QualType T, 4858 llvm::APSInt &Value, 4859 CCEKind CCE) { 4860 assert(LangOpts.CPlusPlus0x && "converted constant expression outside C++11"); 4861 assert(T->isIntegralOrEnumerationType() && "unexpected converted const type"); 4862 4863 if (checkPlaceholderForOverload(*this, From)) 4864 return ExprError(); 4865 4866 // C++11 [expr.const]p3 with proposed wording fixes: 4867 // A converted constant expression of type T is a core constant expression, 4868 // implicitly converted to a prvalue of type T, where the converted 4869 // expression is a literal constant expression and the implicit conversion 4870 // sequence contains only user-defined conversions, lvalue-to-rvalue 4871 // conversions, integral promotions, and integral conversions other than 4872 // narrowing conversions. 4873 ImplicitConversionSequence ICS = 4874 TryImplicitConversion(From, T, 4875 /*SuppressUserConversions=*/false, 4876 /*AllowExplicit=*/false, 4877 /*InOverloadResolution=*/false, 4878 /*CStyle=*/false, 4879 /*AllowObjcWritebackConversion=*/false); 4880 StandardConversionSequence *SCS = 0; 4881 switch (ICS.getKind()) { 4882 case ImplicitConversionSequence::StandardConversion: 4883 if (!CheckConvertedConstantConversions(*this, ICS.Standard)) 4884 return Diag(From->getLocStart(), 4885 diag::err_typecheck_converted_constant_expression_disallowed) 4886 << From->getType() << From->getSourceRange() << T; 4887 SCS = &ICS.Standard; 4888 break; 4889 case ImplicitConversionSequence::UserDefinedConversion: 4890 // We are converting from class type to an integral or enumeration type, so 4891 // the Before sequence must be trivial. 4892 if (!CheckConvertedConstantConversions(*this, ICS.UserDefined.After)) 4893 return Diag(From->getLocStart(), 4894 diag::err_typecheck_converted_constant_expression_disallowed) 4895 << From->getType() << From->getSourceRange() << T; 4896 SCS = &ICS.UserDefined.After; 4897 break; 4898 case ImplicitConversionSequence::AmbiguousConversion: 4899 case ImplicitConversionSequence::BadConversion: 4900 if (!DiagnoseMultipleUserDefinedConversion(From, T)) 4901 return Diag(From->getLocStart(), 4902 diag::err_typecheck_converted_constant_expression) 4903 << From->getType() << From->getSourceRange() << T; 4904 return ExprError(); 4905 4906 case ImplicitConversionSequence::EllipsisConversion: 4907 llvm_unreachable("ellipsis conversion in converted constant expression"); 4908 } 4909 4910 ExprResult Result = PerformImplicitConversion(From, T, ICS, AA_Converting); 4911 if (Result.isInvalid()) 4912 return Result; 4913 4914 // Check for a narrowing implicit conversion. 4915 APValue PreNarrowingValue; 4916 QualType PreNarrowingType; 4917 switch (SCS->getNarrowingKind(Context, Result.get(), PreNarrowingValue, 4918 PreNarrowingType)) { 4919 case NK_Variable_Narrowing: 4920 // Implicit conversion to a narrower type, and the value is not a constant 4921 // expression. We'll diagnose this in a moment. 4922 case NK_Not_Narrowing: 4923 break; 4924 4925 case NK_Constant_Narrowing: 4926 Diag(From->getLocStart(), 4927 isSFINAEContext() ? diag::err_cce_narrowing_sfinae : 4928 diag::err_cce_narrowing) 4929 << CCE << /*Constant*/1 4930 << PreNarrowingValue.getAsString(Context, PreNarrowingType) << T; 4931 break; 4932 4933 case NK_Type_Narrowing: 4934 Diag(From->getLocStart(), 4935 isSFINAEContext() ? diag::err_cce_narrowing_sfinae : 4936 diag::err_cce_narrowing) 4937 << CCE << /*Constant*/0 << From->getType() << T; 4938 break; 4939 } 4940 4941 // Check the expression is a constant expression. 4942 llvm::SmallVector<PartialDiagnosticAt, 8> Notes; 4943 Expr::EvalResult Eval; 4944 Eval.Diag = &Notes; 4945 4946 if (!Result.get()->EvaluateAsRValue(Eval, Context)) { 4947 // The expression can't be folded, so we can't keep it at this position in 4948 // the AST. 4949 Result = ExprError(); 4950 } else { 4951 Value = Eval.Val.getInt(); 4952 4953 if (Notes.empty()) { 4954 // It's a constant expression. 4955 return Result; 4956 } 4957 } 4958 4959 // It's not a constant expression. Produce an appropriate diagnostic. 4960 if (Notes.size() == 1 && 4961 Notes[0].second.getDiagID() == diag::note_invalid_subexpr_in_const_expr) 4962 Diag(Notes[0].first, diag::err_expr_not_cce) << CCE; 4963 else { 4964 Diag(From->getLocStart(), diag::err_expr_not_cce) 4965 << CCE << From->getSourceRange(); 4966 for (unsigned I = 0; I < Notes.size(); ++I) 4967 Diag(Notes[I].first, Notes[I].second); 4968 } 4969 return Result; 4970} 4971 4972/// dropPointerConversions - If the given standard conversion sequence 4973/// involves any pointer conversions, remove them. This may change 4974/// the result type of the conversion sequence. 4975static void dropPointerConversion(StandardConversionSequence &SCS) { 4976 if (SCS.Second == ICK_Pointer_Conversion) { 4977 SCS.Second = ICK_Identity; 4978 SCS.Third = ICK_Identity; 4979 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0]; 4980 } 4981} 4982 4983/// TryContextuallyConvertToObjCPointer - Attempt to contextually 4984/// convert the expression From to an Objective-C pointer type. 4985static ImplicitConversionSequence 4986TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) { 4987 // Do an implicit conversion to 'id'. 4988 QualType Ty = S.Context.getObjCIdType(); 4989 ImplicitConversionSequence ICS 4990 = TryImplicitConversion(S, From, Ty, 4991 // FIXME: Are these flags correct? 4992 /*SuppressUserConversions=*/false, 4993 /*AllowExplicit=*/true, 4994 /*InOverloadResolution=*/false, 4995 /*CStyle=*/false, 4996 /*AllowObjCWritebackConversion=*/false); 4997 4998 // Strip off any final conversions to 'id'. 4999 switch (ICS.getKind()) { 5000 case ImplicitConversionSequence::BadConversion: 5001 case ImplicitConversionSequence::AmbiguousConversion: 5002 case ImplicitConversionSequence::EllipsisConversion: 5003 break; 5004 5005 case ImplicitConversionSequence::UserDefinedConversion: 5006 dropPointerConversion(ICS.UserDefined.After); 5007 break; 5008 5009 case ImplicitConversionSequence::StandardConversion: 5010 dropPointerConversion(ICS.Standard); 5011 break; 5012 } 5013 5014 return ICS; 5015} 5016 5017/// PerformContextuallyConvertToObjCPointer - Perform a contextual 5018/// conversion of the expression From to an Objective-C pointer type. 5019ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) { 5020 if (checkPlaceholderForOverload(*this, From)) 5021 return ExprError(); 5022 5023 QualType Ty = Context.getObjCIdType(); 5024 ImplicitConversionSequence ICS = 5025 TryContextuallyConvertToObjCPointer(*this, From); 5026 if (!ICS.isBad()) 5027 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 5028 return ExprError(); 5029} 5030 5031/// Determine whether the provided type is an integral type, or an enumeration 5032/// type of a permitted flavor. 5033static bool isIntegralOrEnumerationType(QualType T, bool AllowScopedEnum) { 5034 return AllowScopedEnum ? T->isIntegralOrEnumerationType() 5035 : T->isIntegralOrUnscopedEnumerationType(); 5036} 5037 5038/// \brief Attempt to convert the given expression to an integral or 5039/// enumeration type. 5040/// 5041/// This routine will attempt to convert an expression of class type to an 5042/// integral or enumeration type, if that class type only has a single 5043/// conversion to an integral or enumeration type. 5044/// 5045/// \param Loc The source location of the construct that requires the 5046/// conversion. 5047/// 5048/// \param From The expression we're converting from. 5049/// 5050/// \param Diagnoser Used to output any diagnostics. 5051/// 5052/// \param AllowScopedEnumerations Specifies whether conversions to scoped 5053/// enumerations should be considered. 5054/// 5055/// \returns The expression, converted to an integral or enumeration type if 5056/// successful. 5057ExprResult 5058Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 5059 ICEConvertDiagnoser &Diagnoser, 5060 bool AllowScopedEnumerations) { 5061 // We can't perform any more checking for type-dependent expressions. 5062 if (From->isTypeDependent()) 5063 return Owned(From); 5064 5065 // Process placeholders immediately. 5066 if (From->hasPlaceholderType()) { 5067 ExprResult result = CheckPlaceholderExpr(From); 5068 if (result.isInvalid()) return result; 5069 From = result.take(); 5070 } 5071 5072 // If the expression already has integral or enumeration type, we're golden. 5073 QualType T = From->getType(); 5074 if (isIntegralOrEnumerationType(T, AllowScopedEnumerations)) 5075 return DefaultLvalueConversion(From); 5076 5077 // FIXME: Check for missing '()' if T is a function type? 5078 5079 // If we don't have a class type in C++, there's no way we can get an 5080 // expression of integral or enumeration type. 5081 const RecordType *RecordTy = T->getAs<RecordType>(); 5082 if (!RecordTy || !getLangOpts().CPlusPlus) { 5083 if (!Diagnoser.Suppress) 5084 Diagnoser.diagnoseNotInt(*this, Loc, T) << From->getSourceRange(); 5085 return Owned(From); 5086 } 5087 5088 // We must have a complete class type. 5089 struct TypeDiagnoserPartialDiag : TypeDiagnoser { 5090 ICEConvertDiagnoser &Diagnoser; 5091 Expr *From; 5092 5093 TypeDiagnoserPartialDiag(ICEConvertDiagnoser &Diagnoser, Expr *From) 5094 : TypeDiagnoser(Diagnoser.Suppress), Diagnoser(Diagnoser), From(From) {} 5095 5096 virtual void diagnose(Sema &S, SourceLocation Loc, QualType T) { 5097 Diagnoser.diagnoseIncomplete(S, Loc, T) << From->getSourceRange(); 5098 } 5099 } IncompleteDiagnoser(Diagnoser, From); 5100 5101 if (RequireCompleteType(Loc, T, IncompleteDiagnoser)) 5102 return Owned(From); 5103 5104 // Look for a conversion to an integral or enumeration type. 5105 UnresolvedSet<4> ViableConversions; 5106 UnresolvedSet<4> ExplicitConversions; 5107 const UnresolvedSetImpl *Conversions 5108 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 5109 5110 bool HadMultipleCandidates = (Conversions->size() > 1); 5111 5112 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 5113 E = Conversions->end(); 5114 I != E; 5115 ++I) { 5116 if (CXXConversionDecl *Conversion 5117 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) { 5118 if (isIntegralOrEnumerationType( 5119 Conversion->getConversionType().getNonReferenceType(), 5120 AllowScopedEnumerations)) { 5121 if (Conversion->isExplicit()) 5122 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 5123 else 5124 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 5125 } 5126 } 5127 } 5128 5129 switch (ViableConversions.size()) { 5130 case 0: 5131 if (ExplicitConversions.size() == 1 && !Diagnoser.Suppress) { 5132 DeclAccessPair Found = ExplicitConversions[0]; 5133 CXXConversionDecl *Conversion 5134 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 5135 5136 // The user probably meant to invoke the given explicit 5137 // conversion; use it. 5138 QualType ConvTy 5139 = Conversion->getConversionType().getNonReferenceType(); 5140 std::string TypeStr; 5141 ConvTy.getAsStringInternal(TypeStr, getPrintingPolicy()); 5142 5143 Diagnoser.diagnoseExplicitConv(*this, Loc, T, ConvTy) 5144 << FixItHint::CreateInsertion(From->getLocStart(), 5145 "static_cast<" + TypeStr + ">(") 5146 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 5147 ")"); 5148 Diagnoser.noteExplicitConv(*this, Conversion, ConvTy); 5149 5150 // If we aren't in a SFINAE context, build a call to the 5151 // explicit conversion function. 5152 if (isSFINAEContext()) 5153 return ExprError(); 5154 5155 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 5156 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion, 5157 HadMultipleCandidates); 5158 if (Result.isInvalid()) 5159 return ExprError(); 5160 // Record usage of conversion in an implicit cast. 5161 From = ImplicitCastExpr::Create(Context, Result.get()->getType(), 5162 CK_UserDefinedConversion, 5163 Result.get(), 0, 5164 Result.get()->getValueKind()); 5165 } 5166 5167 // We'll complain below about a non-integral condition type. 5168 break; 5169 5170 case 1: { 5171 // Apply this conversion. 5172 DeclAccessPair Found = ViableConversions[0]; 5173 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 5174 5175 CXXConversionDecl *Conversion 5176 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 5177 QualType ConvTy 5178 = Conversion->getConversionType().getNonReferenceType(); 5179 if (!Diagnoser.SuppressConversion) { 5180 if (isSFINAEContext()) 5181 return ExprError(); 5182 5183 Diagnoser.diagnoseConversion(*this, Loc, T, ConvTy) 5184 << From->getSourceRange(); 5185 } 5186 5187 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion, 5188 HadMultipleCandidates); 5189 if (Result.isInvalid()) 5190 return ExprError(); 5191 // Record usage of conversion in an implicit cast. 5192 From = ImplicitCastExpr::Create(Context, Result.get()->getType(), 5193 CK_UserDefinedConversion, 5194 Result.get(), 0, 5195 Result.get()->getValueKind()); 5196 break; 5197 } 5198 5199 default: 5200 if (Diagnoser.Suppress) 5201 return ExprError(); 5202 5203 Diagnoser.diagnoseAmbiguous(*this, Loc, T) << From->getSourceRange(); 5204 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 5205 CXXConversionDecl *Conv 5206 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 5207 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 5208 Diagnoser.noteAmbiguous(*this, Conv, ConvTy); 5209 } 5210 return Owned(From); 5211 } 5212 5213 if (!isIntegralOrEnumerationType(From->getType(), AllowScopedEnumerations) && 5214 !Diagnoser.Suppress) { 5215 Diagnoser.diagnoseNotInt(*this, Loc, From->getType()) 5216 << From->getSourceRange(); 5217 } 5218 5219 return DefaultLvalueConversion(From); 5220} 5221 5222/// AddOverloadCandidate - Adds the given function to the set of 5223/// candidate functions, using the given function call arguments. If 5224/// @p SuppressUserConversions, then don't allow user-defined 5225/// conversions via constructors or conversion operators. 5226/// 5227/// \param PartialOverloading true if we are performing "partial" overloading 5228/// based on an incomplete set of function arguments. This feature is used by 5229/// code completion. 5230void 5231Sema::AddOverloadCandidate(FunctionDecl *Function, 5232 DeclAccessPair FoundDecl, 5233 llvm::ArrayRef<Expr *> Args, 5234 OverloadCandidateSet& CandidateSet, 5235 bool SuppressUserConversions, 5236 bool PartialOverloading, 5237 bool AllowExplicit) { 5238 const FunctionProtoType* Proto 5239 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 5240 assert(Proto && "Functions without a prototype cannot be overloaded"); 5241 assert(!Function->getDescribedFunctionTemplate() && 5242 "Use AddTemplateOverloadCandidate for function templates"); 5243 5244 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 5245 if (!isa<CXXConstructorDecl>(Method)) { 5246 // If we get here, it's because we're calling a member function 5247 // that is named without a member access expression (e.g., 5248 // "this->f") that was either written explicitly or created 5249 // implicitly. This can happen with a qualified call to a member 5250 // function, e.g., X::f(). We use an empty type for the implied 5251 // object argument (C++ [over.call.func]p3), and the acting context 5252 // is irrelevant. 5253 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 5254 QualType(), Expr::Classification::makeSimpleLValue(), 5255 Args, CandidateSet, SuppressUserConversions); 5256 return; 5257 } 5258 // We treat a constructor like a non-member function, since its object 5259 // argument doesn't participate in overload resolution. 5260 } 5261 5262 if (!CandidateSet.isNewCandidate(Function)) 5263 return; 5264 5265 // Overload resolution is always an unevaluated context. 5266 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5267 5268 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 5269 // C++ [class.copy]p3: 5270 // A member function template is never instantiated to perform the copy 5271 // of a class object to an object of its class type. 5272 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 5273 if (Args.size() == 1 && 5274 Constructor->isSpecializationCopyingObject() && 5275 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 5276 IsDerivedFrom(Args[0]->getType(), ClassType))) 5277 return; 5278 } 5279 5280 // Add this candidate 5281 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size()); 5282 Candidate.FoundDecl = FoundDecl; 5283 Candidate.Function = Function; 5284 Candidate.Viable = true; 5285 Candidate.IsSurrogate = false; 5286 Candidate.IgnoreObjectArgument = false; 5287 Candidate.ExplicitCallArguments = Args.size(); 5288 5289 unsigned NumArgsInProto = Proto->getNumArgs(); 5290 5291 // (C++ 13.3.2p2): A candidate function having fewer than m 5292 // parameters is viable only if it has an ellipsis in its parameter 5293 // list (8.3.5). 5294 if ((Args.size() + (PartialOverloading && Args.size())) > NumArgsInProto && 5295 !Proto->isVariadic()) { 5296 Candidate.Viable = false; 5297 Candidate.FailureKind = ovl_fail_too_many_arguments; 5298 return; 5299 } 5300 5301 // (C++ 13.3.2p2): A candidate function having more than m parameters 5302 // is viable only if the (m+1)st parameter has a default argument 5303 // (8.3.6). For the purposes of overload resolution, the 5304 // parameter list is truncated on the right, so that there are 5305 // exactly m parameters. 5306 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 5307 if (Args.size() < MinRequiredArgs && !PartialOverloading) { 5308 // Not enough arguments. 5309 Candidate.Viable = false; 5310 Candidate.FailureKind = ovl_fail_too_few_arguments; 5311 return; 5312 } 5313 5314 // (CUDA B.1): Check for invalid calls between targets. 5315 if (getLangOpts().CUDA) 5316 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext)) 5317 if (CheckCUDATarget(Caller, Function)) { 5318 Candidate.Viable = false; 5319 Candidate.FailureKind = ovl_fail_bad_target; 5320 return; 5321 } 5322 5323 // Determine the implicit conversion sequences for each of the 5324 // arguments. 5325 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5326 if (ArgIdx < NumArgsInProto) { 5327 // (C++ 13.3.2p3): for F to be a viable function, there shall 5328 // exist for each argument an implicit conversion sequence 5329 // (13.3.3.1) that converts that argument to the corresponding 5330 // parameter of F. 5331 QualType ParamType = Proto->getArgType(ArgIdx); 5332 Candidate.Conversions[ArgIdx] 5333 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5334 SuppressUserConversions, 5335 /*InOverloadResolution=*/true, 5336 /*AllowObjCWritebackConversion=*/ 5337 getLangOpts().ObjCAutoRefCount, 5338 AllowExplicit); 5339 if (Candidate.Conversions[ArgIdx].isBad()) { 5340 Candidate.Viable = false; 5341 Candidate.FailureKind = ovl_fail_bad_conversion; 5342 break; 5343 } 5344 } else { 5345 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5346 // argument for which there is no corresponding parameter is 5347 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5348 Candidate.Conversions[ArgIdx].setEllipsis(); 5349 } 5350 } 5351} 5352 5353/// \brief Add all of the function declarations in the given function set to 5354/// the overload canddiate set. 5355void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 5356 llvm::ArrayRef<Expr *> Args, 5357 OverloadCandidateSet& CandidateSet, 5358 bool SuppressUserConversions, 5359 TemplateArgumentListInfo *ExplicitTemplateArgs) { 5360 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 5361 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 5362 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 5363 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 5364 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 5365 cast<CXXMethodDecl>(FD)->getParent(), 5366 Args[0]->getType(), Args[0]->Classify(Context), 5367 Args.slice(1), CandidateSet, 5368 SuppressUserConversions); 5369 else 5370 AddOverloadCandidate(FD, F.getPair(), Args, CandidateSet, 5371 SuppressUserConversions); 5372 } else { 5373 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 5374 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 5375 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 5376 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 5377 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 5378 ExplicitTemplateArgs, 5379 Args[0]->getType(), 5380 Args[0]->Classify(Context), Args.slice(1), 5381 CandidateSet, SuppressUserConversions); 5382 else 5383 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 5384 ExplicitTemplateArgs, Args, 5385 CandidateSet, SuppressUserConversions); 5386 } 5387 } 5388} 5389 5390/// AddMethodCandidate - Adds a named decl (which is some kind of 5391/// method) as a method candidate to the given overload set. 5392void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 5393 QualType ObjectType, 5394 Expr::Classification ObjectClassification, 5395 Expr **Args, unsigned NumArgs, 5396 OverloadCandidateSet& CandidateSet, 5397 bool SuppressUserConversions) { 5398 NamedDecl *Decl = FoundDecl.getDecl(); 5399 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 5400 5401 if (isa<UsingShadowDecl>(Decl)) 5402 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 5403 5404 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 5405 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 5406 "Expected a member function template"); 5407 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 5408 /*ExplicitArgs*/ 0, 5409 ObjectType, ObjectClassification, 5410 llvm::makeArrayRef(Args, NumArgs), CandidateSet, 5411 SuppressUserConversions); 5412 } else { 5413 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 5414 ObjectType, ObjectClassification, 5415 llvm::makeArrayRef(Args, NumArgs), 5416 CandidateSet, SuppressUserConversions); 5417 } 5418} 5419 5420/// AddMethodCandidate - Adds the given C++ member function to the set 5421/// of candidate functions, using the given function call arguments 5422/// and the object argument (@c Object). For example, in a call 5423/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 5424/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 5425/// allow user-defined conversions via constructors or conversion 5426/// operators. 5427void 5428Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 5429 CXXRecordDecl *ActingContext, QualType ObjectType, 5430 Expr::Classification ObjectClassification, 5431 llvm::ArrayRef<Expr *> Args, 5432 OverloadCandidateSet& CandidateSet, 5433 bool SuppressUserConversions) { 5434 const FunctionProtoType* Proto 5435 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 5436 assert(Proto && "Methods without a prototype cannot be overloaded"); 5437 assert(!isa<CXXConstructorDecl>(Method) && 5438 "Use AddOverloadCandidate for constructors"); 5439 5440 if (!CandidateSet.isNewCandidate(Method)) 5441 return; 5442 5443 // Overload resolution is always an unevaluated context. 5444 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5445 5446 // Add this candidate 5447 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); 5448 Candidate.FoundDecl = FoundDecl; 5449 Candidate.Function = Method; 5450 Candidate.IsSurrogate = false; 5451 Candidate.IgnoreObjectArgument = false; 5452 Candidate.ExplicitCallArguments = Args.size(); 5453 5454 unsigned NumArgsInProto = Proto->getNumArgs(); 5455 5456 // (C++ 13.3.2p2): A candidate function having fewer than m 5457 // parameters is viable only if it has an ellipsis in its parameter 5458 // list (8.3.5). 5459 if (Args.size() > NumArgsInProto && !Proto->isVariadic()) { 5460 Candidate.Viable = false; 5461 Candidate.FailureKind = ovl_fail_too_many_arguments; 5462 return; 5463 } 5464 5465 // (C++ 13.3.2p2): A candidate function having more than m parameters 5466 // is viable only if the (m+1)st parameter has a default argument 5467 // (8.3.6). For the purposes of overload resolution, the 5468 // parameter list is truncated on the right, so that there are 5469 // exactly m parameters. 5470 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 5471 if (Args.size() < MinRequiredArgs) { 5472 // Not enough arguments. 5473 Candidate.Viable = false; 5474 Candidate.FailureKind = ovl_fail_too_few_arguments; 5475 return; 5476 } 5477 5478 Candidate.Viable = true; 5479 5480 if (Method->isStatic() || ObjectType.isNull()) 5481 // The implicit object argument is ignored. 5482 Candidate.IgnoreObjectArgument = true; 5483 else { 5484 // Determine the implicit conversion sequence for the object 5485 // parameter. 5486 Candidate.Conversions[0] 5487 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 5488 Method, ActingContext); 5489 if (Candidate.Conversions[0].isBad()) { 5490 Candidate.Viable = false; 5491 Candidate.FailureKind = ovl_fail_bad_conversion; 5492 return; 5493 } 5494 } 5495 5496 // Determine the implicit conversion sequences for each of the 5497 // arguments. 5498 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5499 if (ArgIdx < NumArgsInProto) { 5500 // (C++ 13.3.2p3): for F to be a viable function, there shall 5501 // exist for each argument an implicit conversion sequence 5502 // (13.3.3.1) that converts that argument to the corresponding 5503 // parameter of F. 5504 QualType ParamType = Proto->getArgType(ArgIdx); 5505 Candidate.Conversions[ArgIdx + 1] 5506 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5507 SuppressUserConversions, 5508 /*InOverloadResolution=*/true, 5509 /*AllowObjCWritebackConversion=*/ 5510 getLangOpts().ObjCAutoRefCount); 5511 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 5512 Candidate.Viable = false; 5513 Candidate.FailureKind = ovl_fail_bad_conversion; 5514 break; 5515 } 5516 } else { 5517 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5518 // argument for which there is no corresponding parameter is 5519 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5520 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 5521 } 5522 } 5523} 5524 5525/// \brief Add a C++ member function template as a candidate to the candidate 5526/// set, using template argument deduction to produce an appropriate member 5527/// function template specialization. 5528void 5529Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 5530 DeclAccessPair FoundDecl, 5531 CXXRecordDecl *ActingContext, 5532 TemplateArgumentListInfo *ExplicitTemplateArgs, 5533 QualType ObjectType, 5534 Expr::Classification ObjectClassification, 5535 llvm::ArrayRef<Expr *> Args, 5536 OverloadCandidateSet& CandidateSet, 5537 bool SuppressUserConversions) { 5538 if (!CandidateSet.isNewCandidate(MethodTmpl)) 5539 return; 5540 5541 // C++ [over.match.funcs]p7: 5542 // In each case where a candidate is a function template, candidate 5543 // function template specializations are generated using template argument 5544 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 5545 // candidate functions in the usual way.113) A given name can refer to one 5546 // or more function templates and also to a set of overloaded non-template 5547 // functions. In such a case, the candidate functions generated from each 5548 // function template are combined with the set of non-template candidate 5549 // functions. 5550 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5551 FunctionDecl *Specialization = 0; 5552 if (TemplateDeductionResult Result 5553 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, Args, 5554 Specialization, Info)) { 5555 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5556 Candidate.FoundDecl = FoundDecl; 5557 Candidate.Function = MethodTmpl->getTemplatedDecl(); 5558 Candidate.Viable = false; 5559 Candidate.FailureKind = ovl_fail_bad_deduction; 5560 Candidate.IsSurrogate = false; 5561 Candidate.IgnoreObjectArgument = false; 5562 Candidate.ExplicitCallArguments = Args.size(); 5563 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5564 Info); 5565 return; 5566 } 5567 5568 // Add the function template specialization produced by template argument 5569 // deduction as a candidate. 5570 assert(Specialization && "Missing member function template specialization?"); 5571 assert(isa<CXXMethodDecl>(Specialization) && 5572 "Specialization is not a member function?"); 5573 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 5574 ActingContext, ObjectType, ObjectClassification, Args, 5575 CandidateSet, SuppressUserConversions); 5576} 5577 5578/// \brief Add a C++ function template specialization as a candidate 5579/// in the candidate set, using template argument deduction to produce 5580/// an appropriate function template specialization. 5581void 5582Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 5583 DeclAccessPair FoundDecl, 5584 TemplateArgumentListInfo *ExplicitTemplateArgs, 5585 llvm::ArrayRef<Expr *> Args, 5586 OverloadCandidateSet& CandidateSet, 5587 bool SuppressUserConversions) { 5588 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 5589 return; 5590 5591 // C++ [over.match.funcs]p7: 5592 // In each case where a candidate is a function template, candidate 5593 // function template specializations are generated using template argument 5594 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 5595 // candidate functions in the usual way.113) A given name can refer to one 5596 // or more function templates and also to a set of overloaded non-template 5597 // functions. In such a case, the candidate functions generated from each 5598 // function template are combined with the set of non-template candidate 5599 // functions. 5600 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5601 FunctionDecl *Specialization = 0; 5602 if (TemplateDeductionResult Result 5603 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, Args, 5604 Specialization, Info)) { 5605 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5606 Candidate.FoundDecl = FoundDecl; 5607 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 5608 Candidate.Viable = false; 5609 Candidate.FailureKind = ovl_fail_bad_deduction; 5610 Candidate.IsSurrogate = false; 5611 Candidate.IgnoreObjectArgument = false; 5612 Candidate.ExplicitCallArguments = Args.size(); 5613 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5614 Info); 5615 return; 5616 } 5617 5618 // Add the function template specialization produced by template argument 5619 // deduction as a candidate. 5620 assert(Specialization && "Missing function template specialization?"); 5621 AddOverloadCandidate(Specialization, FoundDecl, Args, CandidateSet, 5622 SuppressUserConversions); 5623} 5624 5625/// AddConversionCandidate - Add a C++ conversion function as a 5626/// candidate in the candidate set (C++ [over.match.conv], 5627/// C++ [over.match.copy]). From is the expression we're converting from, 5628/// and ToType is the type that we're eventually trying to convert to 5629/// (which may or may not be the same type as the type that the 5630/// conversion function produces). 5631void 5632Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 5633 DeclAccessPair FoundDecl, 5634 CXXRecordDecl *ActingContext, 5635 Expr *From, QualType ToType, 5636 OverloadCandidateSet& CandidateSet) { 5637 assert(!Conversion->getDescribedFunctionTemplate() && 5638 "Conversion function templates use AddTemplateConversionCandidate"); 5639 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 5640 if (!CandidateSet.isNewCandidate(Conversion)) 5641 return; 5642 5643 // Overload resolution is always an unevaluated context. 5644 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5645 5646 // Add this candidate 5647 OverloadCandidate &Candidate = CandidateSet.addCandidate(1); 5648 Candidate.FoundDecl = FoundDecl; 5649 Candidate.Function = Conversion; 5650 Candidate.IsSurrogate = false; 5651 Candidate.IgnoreObjectArgument = false; 5652 Candidate.FinalConversion.setAsIdentityConversion(); 5653 Candidate.FinalConversion.setFromType(ConvType); 5654 Candidate.FinalConversion.setAllToTypes(ToType); 5655 Candidate.Viable = true; 5656 Candidate.ExplicitCallArguments = 1; 5657 5658 // C++ [over.match.funcs]p4: 5659 // For conversion functions, the function is considered to be a member of 5660 // the class of the implicit implied object argument for the purpose of 5661 // defining the type of the implicit object parameter. 5662 // 5663 // Determine the implicit conversion sequence for the implicit 5664 // object parameter. 5665 QualType ImplicitParamType = From->getType(); 5666 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 5667 ImplicitParamType = FromPtrType->getPointeeType(); 5668 CXXRecordDecl *ConversionContext 5669 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 5670 5671 Candidate.Conversions[0] 5672 = TryObjectArgumentInitialization(*this, From->getType(), 5673 From->Classify(Context), 5674 Conversion, ConversionContext); 5675 5676 if (Candidate.Conversions[0].isBad()) { 5677 Candidate.Viable = false; 5678 Candidate.FailureKind = ovl_fail_bad_conversion; 5679 return; 5680 } 5681 5682 // We won't go through a user-define type conversion function to convert a 5683 // derived to base as such conversions are given Conversion Rank. They only 5684 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 5685 QualType FromCanon 5686 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 5687 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 5688 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 5689 Candidate.Viable = false; 5690 Candidate.FailureKind = ovl_fail_trivial_conversion; 5691 return; 5692 } 5693 5694 // To determine what the conversion from the result of calling the 5695 // conversion function to the type we're eventually trying to 5696 // convert to (ToType), we need to synthesize a call to the 5697 // conversion function and attempt copy initialization from it. This 5698 // makes sure that we get the right semantics with respect to 5699 // lvalues/rvalues and the type. Fortunately, we can allocate this 5700 // call on the stack and we don't need its arguments to be 5701 // well-formed. 5702 DeclRefExpr ConversionRef(Conversion, false, Conversion->getType(), 5703 VK_LValue, From->getLocStart()); 5704 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 5705 Context.getPointerType(Conversion->getType()), 5706 CK_FunctionToPointerDecay, 5707 &ConversionRef, VK_RValue); 5708 5709 QualType ConversionType = Conversion->getConversionType(); 5710 if (RequireCompleteType(From->getLocStart(), ConversionType, 0)) { 5711 Candidate.Viable = false; 5712 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5713 return; 5714 } 5715 5716 ExprValueKind VK = Expr::getValueKindForType(ConversionType); 5717 5718 // Note that it is safe to allocate CallExpr on the stack here because 5719 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 5720 // allocator). 5721 QualType CallResultType = ConversionType.getNonLValueExprType(Context); 5722 CallExpr Call(Context, &ConversionFn, MultiExprArg(), CallResultType, VK, 5723 From->getLocStart()); 5724 ImplicitConversionSequence ICS = 5725 TryCopyInitialization(*this, &Call, ToType, 5726 /*SuppressUserConversions=*/true, 5727 /*InOverloadResolution=*/false, 5728 /*AllowObjCWritebackConversion=*/false); 5729 5730 switch (ICS.getKind()) { 5731 case ImplicitConversionSequence::StandardConversion: 5732 Candidate.FinalConversion = ICS.Standard; 5733 5734 // C++ [over.ics.user]p3: 5735 // If the user-defined conversion is specified by a specialization of a 5736 // conversion function template, the second standard conversion sequence 5737 // shall have exact match rank. 5738 if (Conversion->getPrimaryTemplate() && 5739 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 5740 Candidate.Viable = false; 5741 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 5742 } 5743 5744 // C++0x [dcl.init.ref]p5: 5745 // In the second case, if the reference is an rvalue reference and 5746 // the second standard conversion sequence of the user-defined 5747 // conversion sequence includes an lvalue-to-rvalue conversion, the 5748 // program is ill-formed. 5749 if (ToType->isRValueReferenceType() && 5750 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 5751 Candidate.Viable = false; 5752 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5753 } 5754 break; 5755 5756 case ImplicitConversionSequence::BadConversion: 5757 Candidate.Viable = false; 5758 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5759 break; 5760 5761 default: 5762 llvm_unreachable( 5763 "Can only end up with a standard conversion sequence or failure"); 5764 } 5765} 5766 5767/// \brief Adds a conversion function template specialization 5768/// candidate to the overload set, using template argument deduction 5769/// to deduce the template arguments of the conversion function 5770/// template from the type that we are converting to (C++ 5771/// [temp.deduct.conv]). 5772void 5773Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 5774 DeclAccessPair FoundDecl, 5775 CXXRecordDecl *ActingDC, 5776 Expr *From, QualType ToType, 5777 OverloadCandidateSet &CandidateSet) { 5778 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 5779 "Only conversion function templates permitted here"); 5780 5781 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 5782 return; 5783 5784 TemplateDeductionInfo Info(CandidateSet.getLocation()); 5785 CXXConversionDecl *Specialization = 0; 5786 if (TemplateDeductionResult Result 5787 = DeduceTemplateArguments(FunctionTemplate, ToType, 5788 Specialization, Info)) { 5789 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5790 Candidate.FoundDecl = FoundDecl; 5791 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 5792 Candidate.Viable = false; 5793 Candidate.FailureKind = ovl_fail_bad_deduction; 5794 Candidate.IsSurrogate = false; 5795 Candidate.IgnoreObjectArgument = false; 5796 Candidate.ExplicitCallArguments = 1; 5797 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5798 Info); 5799 return; 5800 } 5801 5802 // Add the conversion function template specialization produced by 5803 // template argument deduction as a candidate. 5804 assert(Specialization && "Missing function template specialization?"); 5805 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 5806 CandidateSet); 5807} 5808 5809/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 5810/// converts the given @c Object to a function pointer via the 5811/// conversion function @c Conversion, and then attempts to call it 5812/// with the given arguments (C++ [over.call.object]p2-4). Proto is 5813/// the type of function that we'll eventually be calling. 5814void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 5815 DeclAccessPair FoundDecl, 5816 CXXRecordDecl *ActingContext, 5817 const FunctionProtoType *Proto, 5818 Expr *Object, 5819 llvm::ArrayRef<Expr *> Args, 5820 OverloadCandidateSet& CandidateSet) { 5821 if (!CandidateSet.isNewCandidate(Conversion)) 5822 return; 5823 5824 // Overload resolution is always an unevaluated context. 5825 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5826 5827 OverloadCandidate &Candidate = CandidateSet.addCandidate(Args.size() + 1); 5828 Candidate.FoundDecl = FoundDecl; 5829 Candidate.Function = 0; 5830 Candidate.Surrogate = Conversion; 5831 Candidate.Viable = true; 5832 Candidate.IsSurrogate = true; 5833 Candidate.IgnoreObjectArgument = false; 5834 Candidate.ExplicitCallArguments = Args.size(); 5835 5836 // Determine the implicit conversion sequence for the implicit 5837 // object parameter. 5838 ImplicitConversionSequence ObjectInit 5839 = TryObjectArgumentInitialization(*this, Object->getType(), 5840 Object->Classify(Context), 5841 Conversion, ActingContext); 5842 if (ObjectInit.isBad()) { 5843 Candidate.Viable = false; 5844 Candidate.FailureKind = ovl_fail_bad_conversion; 5845 Candidate.Conversions[0] = ObjectInit; 5846 return; 5847 } 5848 5849 // The first conversion is actually a user-defined conversion whose 5850 // first conversion is ObjectInit's standard conversion (which is 5851 // effectively a reference binding). Record it as such. 5852 Candidate.Conversions[0].setUserDefined(); 5853 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 5854 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 5855 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false; 5856 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 5857 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl; 5858 Candidate.Conversions[0].UserDefined.After 5859 = Candidate.Conversions[0].UserDefined.Before; 5860 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 5861 5862 // Find the 5863 unsigned NumArgsInProto = Proto->getNumArgs(); 5864 5865 // (C++ 13.3.2p2): A candidate function having fewer than m 5866 // parameters is viable only if it has an ellipsis in its parameter 5867 // list (8.3.5). 5868 if (Args.size() > NumArgsInProto && !Proto->isVariadic()) { 5869 Candidate.Viable = false; 5870 Candidate.FailureKind = ovl_fail_too_many_arguments; 5871 return; 5872 } 5873 5874 // Function types don't have any default arguments, so just check if 5875 // we have enough arguments. 5876 if (Args.size() < NumArgsInProto) { 5877 // Not enough arguments. 5878 Candidate.Viable = false; 5879 Candidate.FailureKind = ovl_fail_too_few_arguments; 5880 return; 5881 } 5882 5883 // Determine the implicit conversion sequences for each of the 5884 // arguments. 5885 for (unsigned ArgIdx = 0; ArgIdx < Args.size(); ++ArgIdx) { 5886 if (ArgIdx < NumArgsInProto) { 5887 // (C++ 13.3.2p3): for F to be a viable function, there shall 5888 // exist for each argument an implicit conversion sequence 5889 // (13.3.3.1) that converts that argument to the corresponding 5890 // parameter of F. 5891 QualType ParamType = Proto->getArgType(ArgIdx); 5892 Candidate.Conversions[ArgIdx + 1] 5893 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5894 /*SuppressUserConversions=*/false, 5895 /*InOverloadResolution=*/false, 5896 /*AllowObjCWritebackConversion=*/ 5897 getLangOpts().ObjCAutoRefCount); 5898 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 5899 Candidate.Viable = false; 5900 Candidate.FailureKind = ovl_fail_bad_conversion; 5901 break; 5902 } 5903 } else { 5904 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5905 // argument for which there is no corresponding parameter is 5906 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5907 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 5908 } 5909 } 5910} 5911 5912/// \brief Add overload candidates for overloaded operators that are 5913/// member functions. 5914/// 5915/// Add the overloaded operator candidates that are member functions 5916/// for the operator Op that was used in an operator expression such 5917/// as "x Op y". , Args/NumArgs provides the operator arguments, and 5918/// CandidateSet will store the added overload candidates. (C++ 5919/// [over.match.oper]). 5920void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 5921 SourceLocation OpLoc, 5922 Expr **Args, unsigned NumArgs, 5923 OverloadCandidateSet& CandidateSet, 5924 SourceRange OpRange) { 5925 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5926 5927 // C++ [over.match.oper]p3: 5928 // For a unary operator @ with an operand of a type whose 5929 // cv-unqualified version is T1, and for a binary operator @ with 5930 // a left operand of a type whose cv-unqualified version is T1 and 5931 // a right operand of a type whose cv-unqualified version is T2, 5932 // three sets of candidate functions, designated member 5933 // candidates, non-member candidates and built-in candidates, are 5934 // constructed as follows: 5935 QualType T1 = Args[0]->getType(); 5936 5937 // -- If T1 is a class type, the set of member candidates is the 5938 // result of the qualified lookup of T1::operator@ 5939 // (13.3.1.1.1); otherwise, the set of member candidates is 5940 // empty. 5941 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 5942 // Complete the type if it can be completed. Otherwise, we're done. 5943 if (RequireCompleteType(OpLoc, T1, 0)) 5944 return; 5945 5946 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 5947 LookupQualifiedName(Operators, T1Rec->getDecl()); 5948 Operators.suppressDiagnostics(); 5949 5950 for (LookupResult::iterator Oper = Operators.begin(), 5951 OperEnd = Operators.end(); 5952 Oper != OperEnd; 5953 ++Oper) 5954 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 5955 Args[0]->Classify(Context), Args + 1, NumArgs - 1, 5956 CandidateSet, 5957 /* SuppressUserConversions = */ false); 5958 } 5959} 5960 5961/// AddBuiltinCandidate - Add a candidate for a built-in 5962/// operator. ResultTy and ParamTys are the result and parameter types 5963/// of the built-in candidate, respectively. Args and NumArgs are the 5964/// arguments being passed to the candidate. IsAssignmentOperator 5965/// should be true when this built-in candidate is an assignment 5966/// operator. NumContextualBoolArguments is the number of arguments 5967/// (at the beginning of the argument list) that will be contextually 5968/// converted to bool. 5969void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 5970 Expr **Args, unsigned NumArgs, 5971 OverloadCandidateSet& CandidateSet, 5972 bool IsAssignmentOperator, 5973 unsigned NumContextualBoolArguments) { 5974 // Overload resolution is always an unevaluated context. 5975 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5976 5977 // Add this candidate 5978 OverloadCandidate &Candidate = CandidateSet.addCandidate(NumArgs); 5979 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 5980 Candidate.Function = 0; 5981 Candidate.IsSurrogate = false; 5982 Candidate.IgnoreObjectArgument = false; 5983 Candidate.BuiltinTypes.ResultTy = ResultTy; 5984 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5985 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 5986 5987 // Determine the implicit conversion sequences for each of the 5988 // arguments. 5989 Candidate.Viable = true; 5990 Candidate.ExplicitCallArguments = NumArgs; 5991 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5992 // C++ [over.match.oper]p4: 5993 // For the built-in assignment operators, conversions of the 5994 // left operand are restricted as follows: 5995 // -- no temporaries are introduced to hold the left operand, and 5996 // -- no user-defined conversions are applied to the left 5997 // operand to achieve a type match with the left-most 5998 // parameter of a built-in candidate. 5999 // 6000 // We block these conversions by turning off user-defined 6001 // conversions, since that is the only way that initialization of 6002 // a reference to a non-class type can occur from something that 6003 // is not of the same type. 6004 if (ArgIdx < NumContextualBoolArguments) { 6005 assert(ParamTys[ArgIdx] == Context.BoolTy && 6006 "Contextual conversion to bool requires bool type"); 6007 Candidate.Conversions[ArgIdx] 6008 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 6009 } else { 6010 Candidate.Conversions[ArgIdx] 6011 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 6012 ArgIdx == 0 && IsAssignmentOperator, 6013 /*InOverloadResolution=*/false, 6014 /*AllowObjCWritebackConversion=*/ 6015 getLangOpts().ObjCAutoRefCount); 6016 } 6017 if (Candidate.Conversions[ArgIdx].isBad()) { 6018 Candidate.Viable = false; 6019 Candidate.FailureKind = ovl_fail_bad_conversion; 6020 break; 6021 } 6022 } 6023} 6024 6025/// BuiltinCandidateTypeSet - A set of types that will be used for the 6026/// candidate operator functions for built-in operators (C++ 6027/// [over.built]). The types are separated into pointer types and 6028/// enumeration types. 6029class BuiltinCandidateTypeSet { 6030 /// TypeSet - A set of types. 6031 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 6032 6033 /// PointerTypes - The set of pointer types that will be used in the 6034 /// built-in candidates. 6035 TypeSet PointerTypes; 6036 6037 /// MemberPointerTypes - The set of member pointer types that will be 6038 /// used in the built-in candidates. 6039 TypeSet MemberPointerTypes; 6040 6041 /// EnumerationTypes - The set of enumeration types that will be 6042 /// used in the built-in candidates. 6043 TypeSet EnumerationTypes; 6044 6045 /// \brief The set of vector types that will be used in the built-in 6046 /// candidates. 6047 TypeSet VectorTypes; 6048 6049 /// \brief A flag indicating non-record types are viable candidates 6050 bool HasNonRecordTypes; 6051 6052 /// \brief A flag indicating whether either arithmetic or enumeration types 6053 /// were present in the candidate set. 6054 bool HasArithmeticOrEnumeralTypes; 6055 6056 /// \brief A flag indicating whether the nullptr type was present in the 6057 /// candidate set. 6058 bool HasNullPtrType; 6059 6060 /// Sema - The semantic analysis instance where we are building the 6061 /// candidate type set. 6062 Sema &SemaRef; 6063 6064 /// Context - The AST context in which we will build the type sets. 6065 ASTContext &Context; 6066 6067 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 6068 const Qualifiers &VisibleQuals); 6069 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 6070 6071public: 6072 /// iterator - Iterates through the types that are part of the set. 6073 typedef TypeSet::iterator iterator; 6074 6075 BuiltinCandidateTypeSet(Sema &SemaRef) 6076 : HasNonRecordTypes(false), 6077 HasArithmeticOrEnumeralTypes(false), 6078 HasNullPtrType(false), 6079 SemaRef(SemaRef), 6080 Context(SemaRef.Context) { } 6081 6082 void AddTypesConvertedFrom(QualType Ty, 6083 SourceLocation Loc, 6084 bool AllowUserConversions, 6085 bool AllowExplicitConversions, 6086 const Qualifiers &VisibleTypeConversionsQuals); 6087 6088 /// pointer_begin - First pointer type found; 6089 iterator pointer_begin() { return PointerTypes.begin(); } 6090 6091 /// pointer_end - Past the last pointer type found; 6092 iterator pointer_end() { return PointerTypes.end(); } 6093 6094 /// member_pointer_begin - First member pointer type found; 6095 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 6096 6097 /// member_pointer_end - Past the last member pointer type found; 6098 iterator member_pointer_end() { return MemberPointerTypes.end(); } 6099 6100 /// enumeration_begin - First enumeration type found; 6101 iterator enumeration_begin() { return EnumerationTypes.begin(); } 6102 6103 /// enumeration_end - Past the last enumeration type found; 6104 iterator enumeration_end() { return EnumerationTypes.end(); } 6105 6106 iterator vector_begin() { return VectorTypes.begin(); } 6107 iterator vector_end() { return VectorTypes.end(); } 6108 6109 bool hasNonRecordTypes() { return HasNonRecordTypes; } 6110 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 6111 bool hasNullPtrType() const { return HasNullPtrType; } 6112}; 6113 6114/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 6115/// the set of pointer types along with any more-qualified variants of 6116/// that type. For example, if @p Ty is "int const *", this routine 6117/// will add "int const *", "int const volatile *", "int const 6118/// restrict *", and "int const volatile restrict *" to the set of 6119/// pointer types. Returns true if the add of @p Ty itself succeeded, 6120/// false otherwise. 6121/// 6122/// FIXME: what to do about extended qualifiers? 6123bool 6124BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 6125 const Qualifiers &VisibleQuals) { 6126 6127 // Insert this type. 6128 if (!PointerTypes.insert(Ty)) 6129 return false; 6130 6131 QualType PointeeTy; 6132 const PointerType *PointerTy = Ty->getAs<PointerType>(); 6133 bool buildObjCPtr = false; 6134 if (!PointerTy) { 6135 const ObjCObjectPointerType *PTy = Ty->castAs<ObjCObjectPointerType>(); 6136 PointeeTy = PTy->getPointeeType(); 6137 buildObjCPtr = true; 6138 } else { 6139 PointeeTy = PointerTy->getPointeeType(); 6140 } 6141 6142 // Don't add qualified variants of arrays. For one, they're not allowed 6143 // (the qualifier would sink to the element type), and for another, the 6144 // only overload situation where it matters is subscript or pointer +- int, 6145 // and those shouldn't have qualifier variants anyway. 6146 if (PointeeTy->isArrayType()) 6147 return true; 6148 6149 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 6150 bool hasVolatile = VisibleQuals.hasVolatile(); 6151 bool hasRestrict = VisibleQuals.hasRestrict(); 6152 6153 // Iterate through all strict supersets of BaseCVR. 6154 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 6155 if ((CVR | BaseCVR) != CVR) continue; 6156 // Skip over volatile if no volatile found anywhere in the types. 6157 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 6158 6159 // Skip over restrict if no restrict found anywhere in the types, or if 6160 // the type cannot be restrict-qualified. 6161 if ((CVR & Qualifiers::Restrict) && 6162 (!hasRestrict || 6163 (!(PointeeTy->isAnyPointerType() || PointeeTy->isReferenceType())))) 6164 continue; 6165 6166 // Build qualified pointee type. 6167 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 6168 6169 // Build qualified pointer type. 6170 QualType QPointerTy; 6171 if (!buildObjCPtr) 6172 QPointerTy = Context.getPointerType(QPointeeTy); 6173 else 6174 QPointerTy = Context.getObjCObjectPointerType(QPointeeTy); 6175 6176 // Insert qualified pointer type. 6177 PointerTypes.insert(QPointerTy); 6178 } 6179 6180 return true; 6181} 6182 6183/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 6184/// to the set of pointer types along with any more-qualified variants of 6185/// that type. For example, if @p Ty is "int const *", this routine 6186/// will add "int const *", "int const volatile *", "int const 6187/// restrict *", and "int const volatile restrict *" to the set of 6188/// pointer types. Returns true if the add of @p Ty itself succeeded, 6189/// false otherwise. 6190/// 6191/// FIXME: what to do about extended qualifiers? 6192bool 6193BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 6194 QualType Ty) { 6195 // Insert this type. 6196 if (!MemberPointerTypes.insert(Ty)) 6197 return false; 6198 6199 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 6200 assert(PointerTy && "type was not a member pointer type!"); 6201 6202 QualType PointeeTy = PointerTy->getPointeeType(); 6203 // Don't add qualified variants of arrays. For one, they're not allowed 6204 // (the qualifier would sink to the element type), and for another, the 6205 // only overload situation where it matters is subscript or pointer +- int, 6206 // and those shouldn't have qualifier variants anyway. 6207 if (PointeeTy->isArrayType()) 6208 return true; 6209 const Type *ClassTy = PointerTy->getClass(); 6210 6211 // Iterate through all strict supersets of the pointee type's CVR 6212 // qualifiers. 6213 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 6214 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 6215 if ((CVR | BaseCVR) != CVR) continue; 6216 6217 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 6218 MemberPointerTypes.insert( 6219 Context.getMemberPointerType(QPointeeTy, ClassTy)); 6220 } 6221 6222 return true; 6223} 6224 6225/// AddTypesConvertedFrom - Add each of the types to which the type @p 6226/// Ty can be implicit converted to the given set of @p Types. We're 6227/// primarily interested in pointer types and enumeration types. We also 6228/// take member pointer types, for the conditional operator. 6229/// AllowUserConversions is true if we should look at the conversion 6230/// functions of a class type, and AllowExplicitConversions if we 6231/// should also include the explicit conversion functions of a class 6232/// type. 6233void 6234BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 6235 SourceLocation Loc, 6236 bool AllowUserConversions, 6237 bool AllowExplicitConversions, 6238 const Qualifiers &VisibleQuals) { 6239 // Only deal with canonical types. 6240 Ty = Context.getCanonicalType(Ty); 6241 6242 // Look through reference types; they aren't part of the type of an 6243 // expression for the purposes of conversions. 6244 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 6245 Ty = RefTy->getPointeeType(); 6246 6247 // If we're dealing with an array type, decay to the pointer. 6248 if (Ty->isArrayType()) 6249 Ty = SemaRef.Context.getArrayDecayedType(Ty); 6250 6251 // Otherwise, we don't care about qualifiers on the type. 6252 Ty = Ty.getLocalUnqualifiedType(); 6253 6254 // Flag if we ever add a non-record type. 6255 const RecordType *TyRec = Ty->getAs<RecordType>(); 6256 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 6257 6258 // Flag if we encounter an arithmetic type. 6259 HasArithmeticOrEnumeralTypes = 6260 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 6261 6262 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 6263 PointerTypes.insert(Ty); 6264 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 6265 // Insert our type, and its more-qualified variants, into the set 6266 // of types. 6267 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 6268 return; 6269 } else if (Ty->isMemberPointerType()) { 6270 // Member pointers are far easier, since the pointee can't be converted. 6271 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 6272 return; 6273 } else if (Ty->isEnumeralType()) { 6274 HasArithmeticOrEnumeralTypes = true; 6275 EnumerationTypes.insert(Ty); 6276 } else if (Ty->isVectorType()) { 6277 // We treat vector types as arithmetic types in many contexts as an 6278 // extension. 6279 HasArithmeticOrEnumeralTypes = true; 6280 VectorTypes.insert(Ty); 6281 } else if (Ty->isNullPtrType()) { 6282 HasNullPtrType = true; 6283 } else if (AllowUserConversions && TyRec) { 6284 // No conversion functions in incomplete types. 6285 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 6286 return; 6287 6288 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 6289 const UnresolvedSetImpl *Conversions 6290 = ClassDecl->getVisibleConversionFunctions(); 6291 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6292 E = Conversions->end(); I != E; ++I) { 6293 NamedDecl *D = I.getDecl(); 6294 if (isa<UsingShadowDecl>(D)) 6295 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6296 6297 // Skip conversion function templates; they don't tell us anything 6298 // about which builtin types we can convert to. 6299 if (isa<FunctionTemplateDecl>(D)) 6300 continue; 6301 6302 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 6303 if (AllowExplicitConversions || !Conv->isExplicit()) { 6304 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 6305 VisibleQuals); 6306 } 6307 } 6308 } 6309} 6310 6311/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 6312/// the volatile- and non-volatile-qualified assignment operators for the 6313/// given type to the candidate set. 6314static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 6315 QualType T, 6316 Expr **Args, 6317 unsigned NumArgs, 6318 OverloadCandidateSet &CandidateSet) { 6319 QualType ParamTypes[2]; 6320 6321 // T& operator=(T&, T) 6322 ParamTypes[0] = S.Context.getLValueReferenceType(T); 6323 ParamTypes[1] = T; 6324 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6325 /*IsAssignmentOperator=*/true); 6326 6327 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 6328 // volatile T& operator=(volatile T&, T) 6329 ParamTypes[0] 6330 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 6331 ParamTypes[1] = T; 6332 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6333 /*IsAssignmentOperator=*/true); 6334 } 6335} 6336 6337/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 6338/// if any, found in visible type conversion functions found in ArgExpr's type. 6339static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 6340 Qualifiers VRQuals; 6341 const RecordType *TyRec; 6342 if (const MemberPointerType *RHSMPType = 6343 ArgExpr->getType()->getAs<MemberPointerType>()) 6344 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 6345 else 6346 TyRec = ArgExpr->getType()->getAs<RecordType>(); 6347 if (!TyRec) { 6348 // Just to be safe, assume the worst case. 6349 VRQuals.addVolatile(); 6350 VRQuals.addRestrict(); 6351 return VRQuals; 6352 } 6353 6354 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 6355 if (!ClassDecl->hasDefinition()) 6356 return VRQuals; 6357 6358 const UnresolvedSetImpl *Conversions = 6359 ClassDecl->getVisibleConversionFunctions(); 6360 6361 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 6362 E = Conversions->end(); I != E; ++I) { 6363 NamedDecl *D = I.getDecl(); 6364 if (isa<UsingShadowDecl>(D)) 6365 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 6366 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 6367 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 6368 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 6369 CanTy = ResTypeRef->getPointeeType(); 6370 // Need to go down the pointer/mempointer chain and add qualifiers 6371 // as see them. 6372 bool done = false; 6373 while (!done) { 6374 if (CanTy.isRestrictQualified()) 6375 VRQuals.addRestrict(); 6376 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 6377 CanTy = ResTypePtr->getPointeeType(); 6378 else if (const MemberPointerType *ResTypeMPtr = 6379 CanTy->getAs<MemberPointerType>()) 6380 CanTy = ResTypeMPtr->getPointeeType(); 6381 else 6382 done = true; 6383 if (CanTy.isVolatileQualified()) 6384 VRQuals.addVolatile(); 6385 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 6386 return VRQuals; 6387 } 6388 } 6389 } 6390 return VRQuals; 6391} 6392 6393namespace { 6394 6395/// \brief Helper class to manage the addition of builtin operator overload 6396/// candidates. It provides shared state and utility methods used throughout 6397/// the process, as well as a helper method to add each group of builtin 6398/// operator overloads from the standard to a candidate set. 6399class BuiltinOperatorOverloadBuilder { 6400 // Common instance state available to all overload candidate addition methods. 6401 Sema &S; 6402 Expr **Args; 6403 unsigned NumArgs; 6404 Qualifiers VisibleTypeConversionsQuals; 6405 bool HasArithmeticOrEnumeralCandidateType; 6406 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 6407 OverloadCandidateSet &CandidateSet; 6408 6409 // Define some constants used to index and iterate over the arithemetic types 6410 // provided via the getArithmeticType() method below. 6411 // The "promoted arithmetic types" are the arithmetic 6412 // types are that preserved by promotion (C++ [over.built]p2). 6413 static const unsigned FirstIntegralType = 3; 6414 static const unsigned LastIntegralType = 20; 6415 static const unsigned FirstPromotedIntegralType = 3, 6416 LastPromotedIntegralType = 11; 6417 static const unsigned FirstPromotedArithmeticType = 0, 6418 LastPromotedArithmeticType = 11; 6419 static const unsigned NumArithmeticTypes = 20; 6420 6421 /// \brief Get the canonical type for a given arithmetic type index. 6422 CanQualType getArithmeticType(unsigned index) { 6423 assert(index < NumArithmeticTypes); 6424 static CanQualType ASTContext::* const 6425 ArithmeticTypes[NumArithmeticTypes] = { 6426 // Start of promoted types. 6427 &ASTContext::FloatTy, 6428 &ASTContext::DoubleTy, 6429 &ASTContext::LongDoubleTy, 6430 6431 // Start of integral types. 6432 &ASTContext::IntTy, 6433 &ASTContext::LongTy, 6434 &ASTContext::LongLongTy, 6435 &ASTContext::Int128Ty, 6436 &ASTContext::UnsignedIntTy, 6437 &ASTContext::UnsignedLongTy, 6438 &ASTContext::UnsignedLongLongTy, 6439 &ASTContext::UnsignedInt128Ty, 6440 // End of promoted types. 6441 6442 &ASTContext::BoolTy, 6443 &ASTContext::CharTy, 6444 &ASTContext::WCharTy, 6445 &ASTContext::Char16Ty, 6446 &ASTContext::Char32Ty, 6447 &ASTContext::SignedCharTy, 6448 &ASTContext::ShortTy, 6449 &ASTContext::UnsignedCharTy, 6450 &ASTContext::UnsignedShortTy, 6451 // End of integral types. 6452 // FIXME: What about complex? What about half? 6453 }; 6454 return S.Context.*ArithmeticTypes[index]; 6455 } 6456 6457 /// \brief Gets the canonical type resulting from the usual arithemetic 6458 /// converions for the given arithmetic types. 6459 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 6460 // Accelerator table for performing the usual arithmetic conversions. 6461 // The rules are basically: 6462 // - if either is floating-point, use the wider floating-point 6463 // - if same signedness, use the higher rank 6464 // - if same size, use unsigned of the higher rank 6465 // - use the larger type 6466 // These rules, together with the axiom that higher ranks are 6467 // never smaller, are sufficient to precompute all of these results 6468 // *except* when dealing with signed types of higher rank. 6469 // (we could precompute SLL x UI for all known platforms, but it's 6470 // better not to make any assumptions). 6471 // We assume that int128 has a higher rank than long long on all platforms. 6472 enum PromotedType { 6473 Dep=-1, 6474 Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 6475 }; 6476 static const PromotedType ConversionsTable[LastPromotedArithmeticType] 6477 [LastPromotedArithmeticType] = { 6478/* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt, Flt, Flt }, 6479/* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 6480/*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 6481/* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, S128, UI, UL, ULL, U128 }, 6482/* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, S128, Dep, UL, ULL, U128 }, 6483/* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, S128, Dep, Dep, ULL, U128 }, 6484/*S128*/ { Flt, Dbl, LDbl, S128, S128, S128, S128, S128, S128, S128, U128 }, 6485/* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, S128, UI, UL, ULL, U128 }, 6486/* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, S128, UL, UL, ULL, U128 }, 6487/* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, S128, ULL, ULL, ULL, U128 }, 6488/*U128*/ { Flt, Dbl, LDbl, U128, U128, U128, U128, U128, U128, U128, U128 }, 6489 }; 6490 6491 assert(L < LastPromotedArithmeticType); 6492 assert(R < LastPromotedArithmeticType); 6493 int Idx = ConversionsTable[L][R]; 6494 6495 // Fast path: the table gives us a concrete answer. 6496 if (Idx != Dep) return getArithmeticType(Idx); 6497 6498 // Slow path: we need to compare widths. 6499 // An invariant is that the signed type has higher rank. 6500 CanQualType LT = getArithmeticType(L), 6501 RT = getArithmeticType(R); 6502 unsigned LW = S.Context.getIntWidth(LT), 6503 RW = S.Context.getIntWidth(RT); 6504 6505 // If they're different widths, use the signed type. 6506 if (LW > RW) return LT; 6507 else if (LW < RW) return RT; 6508 6509 // Otherwise, use the unsigned type of the signed type's rank. 6510 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 6511 assert(L == SLL || R == SLL); 6512 return S.Context.UnsignedLongLongTy; 6513 } 6514 6515 /// \brief Helper method to factor out the common pattern of adding overloads 6516 /// for '++' and '--' builtin operators. 6517 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 6518 bool HasVolatile, 6519 bool HasRestrict) { 6520 QualType ParamTypes[2] = { 6521 S.Context.getLValueReferenceType(CandidateTy), 6522 S.Context.IntTy 6523 }; 6524 6525 // Non-volatile version. 6526 if (NumArgs == 1) 6527 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 6528 else 6529 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 6530 6531 // Use a heuristic to reduce number of builtin candidates in the set: 6532 // add volatile version only if there are conversions to a volatile type. 6533 if (HasVolatile) { 6534 ParamTypes[0] = 6535 S.Context.getLValueReferenceType( 6536 S.Context.getVolatileType(CandidateTy)); 6537 if (NumArgs == 1) 6538 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 6539 else 6540 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 6541 } 6542 6543 // Add restrict version only if there are conversions to a restrict type 6544 // and our candidate type is a non-restrict-qualified pointer. 6545 if (HasRestrict && CandidateTy->isAnyPointerType() && 6546 !CandidateTy.isRestrictQualified()) { 6547 ParamTypes[0] 6548 = S.Context.getLValueReferenceType( 6549 S.Context.getCVRQualifiedType(CandidateTy, Qualifiers::Restrict)); 6550 if (NumArgs == 1) 6551 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 6552 else 6553 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 6554 6555 if (HasVolatile) { 6556 ParamTypes[0] 6557 = S.Context.getLValueReferenceType( 6558 S.Context.getCVRQualifiedType(CandidateTy, 6559 (Qualifiers::Volatile | 6560 Qualifiers::Restrict))); 6561 if (NumArgs == 1) 6562 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, 6563 CandidateSet); 6564 else 6565 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 6566 } 6567 } 6568 6569 } 6570 6571public: 6572 BuiltinOperatorOverloadBuilder( 6573 Sema &S, Expr **Args, unsigned NumArgs, 6574 Qualifiers VisibleTypeConversionsQuals, 6575 bool HasArithmeticOrEnumeralCandidateType, 6576 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 6577 OverloadCandidateSet &CandidateSet) 6578 : S(S), Args(Args), NumArgs(NumArgs), 6579 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 6580 HasArithmeticOrEnumeralCandidateType( 6581 HasArithmeticOrEnumeralCandidateType), 6582 CandidateTypes(CandidateTypes), 6583 CandidateSet(CandidateSet) { 6584 // Validate some of our static helper constants in debug builds. 6585 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 6586 "Invalid first promoted integral type"); 6587 assert(getArithmeticType(LastPromotedIntegralType - 1) 6588 == S.Context.UnsignedInt128Ty && 6589 "Invalid last promoted integral type"); 6590 assert(getArithmeticType(FirstPromotedArithmeticType) 6591 == S.Context.FloatTy && 6592 "Invalid first promoted arithmetic type"); 6593 assert(getArithmeticType(LastPromotedArithmeticType - 1) 6594 == S.Context.UnsignedInt128Ty && 6595 "Invalid last promoted arithmetic type"); 6596 } 6597 6598 // C++ [over.built]p3: 6599 // 6600 // For every pair (T, VQ), where T is an arithmetic type, and VQ 6601 // is either volatile or empty, there exist candidate operator 6602 // functions of the form 6603 // 6604 // VQ T& operator++(VQ T&); 6605 // T operator++(VQ T&, int); 6606 // 6607 // C++ [over.built]p4: 6608 // 6609 // For every pair (T, VQ), where T is an arithmetic type other 6610 // than bool, and VQ is either volatile or empty, there exist 6611 // candidate operator functions of the form 6612 // 6613 // VQ T& operator--(VQ T&); 6614 // T operator--(VQ T&, int); 6615 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 6616 if (!HasArithmeticOrEnumeralCandidateType) 6617 return; 6618 6619 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 6620 Arith < NumArithmeticTypes; ++Arith) { 6621 addPlusPlusMinusMinusStyleOverloads( 6622 getArithmeticType(Arith), 6623 VisibleTypeConversionsQuals.hasVolatile(), 6624 VisibleTypeConversionsQuals.hasRestrict()); 6625 } 6626 } 6627 6628 // C++ [over.built]p5: 6629 // 6630 // For every pair (T, VQ), where T is a cv-qualified or 6631 // cv-unqualified object type, and VQ is either volatile or 6632 // empty, there exist candidate operator functions of the form 6633 // 6634 // T*VQ& operator++(T*VQ&); 6635 // T*VQ& operator--(T*VQ&); 6636 // T* operator++(T*VQ&, int); 6637 // T* operator--(T*VQ&, int); 6638 void addPlusPlusMinusMinusPointerOverloads() { 6639 for (BuiltinCandidateTypeSet::iterator 6640 Ptr = CandidateTypes[0].pointer_begin(), 6641 PtrEnd = CandidateTypes[0].pointer_end(); 6642 Ptr != PtrEnd; ++Ptr) { 6643 // Skip pointer types that aren't pointers to object types. 6644 if (!(*Ptr)->getPointeeType()->isObjectType()) 6645 continue; 6646 6647 addPlusPlusMinusMinusStyleOverloads(*Ptr, 6648 (!(*Ptr).isVolatileQualified() && 6649 VisibleTypeConversionsQuals.hasVolatile()), 6650 (!(*Ptr).isRestrictQualified() && 6651 VisibleTypeConversionsQuals.hasRestrict())); 6652 } 6653 } 6654 6655 // C++ [over.built]p6: 6656 // For every cv-qualified or cv-unqualified object type T, there 6657 // exist candidate operator functions of the form 6658 // 6659 // T& operator*(T*); 6660 // 6661 // C++ [over.built]p7: 6662 // For every function type T that does not have cv-qualifiers or a 6663 // ref-qualifier, there exist candidate operator functions of the form 6664 // T& operator*(T*); 6665 void addUnaryStarPointerOverloads() { 6666 for (BuiltinCandidateTypeSet::iterator 6667 Ptr = CandidateTypes[0].pointer_begin(), 6668 PtrEnd = CandidateTypes[0].pointer_end(); 6669 Ptr != PtrEnd; ++Ptr) { 6670 QualType ParamTy = *Ptr; 6671 QualType PointeeTy = ParamTy->getPointeeType(); 6672 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 6673 continue; 6674 6675 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 6676 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 6677 continue; 6678 6679 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 6680 &ParamTy, Args, 1, CandidateSet); 6681 } 6682 } 6683 6684 // C++ [over.built]p9: 6685 // For every promoted arithmetic type T, there exist candidate 6686 // operator functions of the form 6687 // 6688 // T operator+(T); 6689 // T operator-(T); 6690 void addUnaryPlusOrMinusArithmeticOverloads() { 6691 if (!HasArithmeticOrEnumeralCandidateType) 6692 return; 6693 6694 for (unsigned Arith = FirstPromotedArithmeticType; 6695 Arith < LastPromotedArithmeticType; ++Arith) { 6696 QualType ArithTy = getArithmeticType(Arith); 6697 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 6698 } 6699 6700 // Extension: We also add these operators for vector types. 6701 for (BuiltinCandidateTypeSet::iterator 6702 Vec = CandidateTypes[0].vector_begin(), 6703 VecEnd = CandidateTypes[0].vector_end(); 6704 Vec != VecEnd; ++Vec) { 6705 QualType VecTy = *Vec; 6706 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 6707 } 6708 } 6709 6710 // C++ [over.built]p8: 6711 // For every type T, there exist candidate operator functions of 6712 // the form 6713 // 6714 // T* operator+(T*); 6715 void addUnaryPlusPointerOverloads() { 6716 for (BuiltinCandidateTypeSet::iterator 6717 Ptr = CandidateTypes[0].pointer_begin(), 6718 PtrEnd = CandidateTypes[0].pointer_end(); 6719 Ptr != PtrEnd; ++Ptr) { 6720 QualType ParamTy = *Ptr; 6721 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 6722 } 6723 } 6724 6725 // C++ [over.built]p10: 6726 // For every promoted integral type T, there exist candidate 6727 // operator functions of the form 6728 // 6729 // T operator~(T); 6730 void addUnaryTildePromotedIntegralOverloads() { 6731 if (!HasArithmeticOrEnumeralCandidateType) 6732 return; 6733 6734 for (unsigned Int = FirstPromotedIntegralType; 6735 Int < LastPromotedIntegralType; ++Int) { 6736 QualType IntTy = getArithmeticType(Int); 6737 S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 6738 } 6739 6740 // Extension: We also add this operator for vector types. 6741 for (BuiltinCandidateTypeSet::iterator 6742 Vec = CandidateTypes[0].vector_begin(), 6743 VecEnd = CandidateTypes[0].vector_end(); 6744 Vec != VecEnd; ++Vec) { 6745 QualType VecTy = *Vec; 6746 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 6747 } 6748 } 6749 6750 // C++ [over.match.oper]p16: 6751 // For every pointer to member type T, there exist candidate operator 6752 // functions of the form 6753 // 6754 // bool operator==(T,T); 6755 // bool operator!=(T,T); 6756 void addEqualEqualOrNotEqualMemberPointerOverloads() { 6757 /// Set of (canonical) types that we've already handled. 6758 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6759 6760 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6761 for (BuiltinCandidateTypeSet::iterator 6762 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 6763 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 6764 MemPtr != MemPtrEnd; 6765 ++MemPtr) { 6766 // Don't add the same builtin candidate twice. 6767 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 6768 continue; 6769 6770 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 6771 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6772 CandidateSet); 6773 } 6774 } 6775 } 6776 6777 // C++ [over.built]p15: 6778 // 6779 // For every T, where T is an enumeration type, a pointer type, or 6780 // std::nullptr_t, there exist candidate operator functions of the form 6781 // 6782 // bool operator<(T, T); 6783 // bool operator>(T, T); 6784 // bool operator<=(T, T); 6785 // bool operator>=(T, T); 6786 // bool operator==(T, T); 6787 // bool operator!=(T, T); 6788 void addRelationalPointerOrEnumeralOverloads() { 6789 // C++ [over.match.oper]p3: 6790 // [...]the built-in candidates include all of the candidate operator 6791 // functions defined in 13.6 that, compared to the given operator, [...] 6792 // do not have the same parameter-type-list as any non-template non-member 6793 // candidate. 6794 // 6795 // Note that in practice, this only affects enumeration types because there 6796 // aren't any built-in candidates of record type, and a user-defined operator 6797 // must have an operand of record or enumeration type. Also, the only other 6798 // overloaded operator with enumeration arguments, operator=, 6799 // cannot be overloaded for enumeration types, so this is the only place 6800 // where we must suppress candidates like this. 6801 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 6802 UserDefinedBinaryOperators; 6803 6804 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6805 if (CandidateTypes[ArgIdx].enumeration_begin() != 6806 CandidateTypes[ArgIdx].enumeration_end()) { 6807 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 6808 CEnd = CandidateSet.end(); 6809 C != CEnd; ++C) { 6810 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 6811 continue; 6812 6813 if (C->Function->isFunctionTemplateSpecialization()) 6814 continue; 6815 6816 QualType FirstParamType = 6817 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 6818 QualType SecondParamType = 6819 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 6820 6821 // Skip if either parameter isn't of enumeral type. 6822 if (!FirstParamType->isEnumeralType() || 6823 !SecondParamType->isEnumeralType()) 6824 continue; 6825 6826 // Add this operator to the set of known user-defined operators. 6827 UserDefinedBinaryOperators.insert( 6828 std::make_pair(S.Context.getCanonicalType(FirstParamType), 6829 S.Context.getCanonicalType(SecondParamType))); 6830 } 6831 } 6832 } 6833 6834 /// Set of (canonical) types that we've already handled. 6835 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6836 6837 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6838 for (BuiltinCandidateTypeSet::iterator 6839 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 6840 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 6841 Ptr != PtrEnd; ++Ptr) { 6842 // Don't add the same builtin candidate twice. 6843 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6844 continue; 6845 6846 QualType ParamTypes[2] = { *Ptr, *Ptr }; 6847 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6848 CandidateSet); 6849 } 6850 for (BuiltinCandidateTypeSet::iterator 6851 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 6852 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 6853 Enum != EnumEnd; ++Enum) { 6854 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 6855 6856 // Don't add the same builtin candidate twice, or if a user defined 6857 // candidate exists. 6858 if (!AddedTypes.insert(CanonType) || 6859 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 6860 CanonType))) 6861 continue; 6862 6863 QualType ParamTypes[2] = { *Enum, *Enum }; 6864 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6865 CandidateSet); 6866 } 6867 6868 if (CandidateTypes[ArgIdx].hasNullPtrType()) { 6869 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy); 6870 if (AddedTypes.insert(NullPtrTy) && 6871 !UserDefinedBinaryOperators.count(std::make_pair(NullPtrTy, 6872 NullPtrTy))) { 6873 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy }; 6874 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6875 CandidateSet); 6876 } 6877 } 6878 } 6879 } 6880 6881 // C++ [over.built]p13: 6882 // 6883 // For every cv-qualified or cv-unqualified object type T 6884 // there exist candidate operator functions of the form 6885 // 6886 // T* operator+(T*, ptrdiff_t); 6887 // T& operator[](T*, ptrdiff_t); [BELOW] 6888 // T* operator-(T*, ptrdiff_t); 6889 // T* operator+(ptrdiff_t, T*); 6890 // T& operator[](ptrdiff_t, T*); [BELOW] 6891 // 6892 // C++ [over.built]p14: 6893 // 6894 // For every T, where T is a pointer to object type, there 6895 // exist candidate operator functions of the form 6896 // 6897 // ptrdiff_t operator-(T, T); 6898 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 6899 /// Set of (canonical) types that we've already handled. 6900 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6901 6902 for (int Arg = 0; Arg < 2; ++Arg) { 6903 QualType AsymetricParamTypes[2] = { 6904 S.Context.getPointerDiffType(), 6905 S.Context.getPointerDiffType(), 6906 }; 6907 for (BuiltinCandidateTypeSet::iterator 6908 Ptr = CandidateTypes[Arg].pointer_begin(), 6909 PtrEnd = CandidateTypes[Arg].pointer_end(); 6910 Ptr != PtrEnd; ++Ptr) { 6911 QualType PointeeTy = (*Ptr)->getPointeeType(); 6912 if (!PointeeTy->isObjectType()) 6913 continue; 6914 6915 AsymetricParamTypes[Arg] = *Ptr; 6916 if (Arg == 0 || Op == OO_Plus) { 6917 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 6918 // T* operator+(ptrdiff_t, T*); 6919 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, 6920 CandidateSet); 6921 } 6922 if (Op == OO_Minus) { 6923 // ptrdiff_t operator-(T, T); 6924 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6925 continue; 6926 6927 QualType ParamTypes[2] = { *Ptr, *Ptr }; 6928 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 6929 Args, 2, CandidateSet); 6930 } 6931 } 6932 } 6933 } 6934 6935 // C++ [over.built]p12: 6936 // 6937 // For every pair of promoted arithmetic types L and R, there 6938 // exist candidate operator functions of the form 6939 // 6940 // LR operator*(L, R); 6941 // LR operator/(L, R); 6942 // LR operator+(L, R); 6943 // LR operator-(L, R); 6944 // bool operator<(L, R); 6945 // bool operator>(L, R); 6946 // bool operator<=(L, R); 6947 // bool operator>=(L, R); 6948 // bool operator==(L, R); 6949 // bool operator!=(L, R); 6950 // 6951 // where LR is the result of the usual arithmetic conversions 6952 // between types L and R. 6953 // 6954 // C++ [over.built]p24: 6955 // 6956 // For every pair of promoted arithmetic types L and R, there exist 6957 // candidate operator functions of the form 6958 // 6959 // LR operator?(bool, L, R); 6960 // 6961 // where LR is the result of the usual arithmetic conversions 6962 // between types L and R. 6963 // Our candidates ignore the first parameter. 6964 void addGenericBinaryArithmeticOverloads(bool isComparison) { 6965 if (!HasArithmeticOrEnumeralCandidateType) 6966 return; 6967 6968 for (unsigned Left = FirstPromotedArithmeticType; 6969 Left < LastPromotedArithmeticType; ++Left) { 6970 for (unsigned Right = FirstPromotedArithmeticType; 6971 Right < LastPromotedArithmeticType; ++Right) { 6972 QualType LandR[2] = { getArithmeticType(Left), 6973 getArithmeticType(Right) }; 6974 QualType Result = 6975 isComparison ? S.Context.BoolTy 6976 : getUsualArithmeticConversions(Left, Right); 6977 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 6978 } 6979 } 6980 6981 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 6982 // conditional operator for vector types. 6983 for (BuiltinCandidateTypeSet::iterator 6984 Vec1 = CandidateTypes[0].vector_begin(), 6985 Vec1End = CandidateTypes[0].vector_end(); 6986 Vec1 != Vec1End; ++Vec1) { 6987 for (BuiltinCandidateTypeSet::iterator 6988 Vec2 = CandidateTypes[1].vector_begin(), 6989 Vec2End = CandidateTypes[1].vector_end(); 6990 Vec2 != Vec2End; ++Vec2) { 6991 QualType LandR[2] = { *Vec1, *Vec2 }; 6992 QualType Result = S.Context.BoolTy; 6993 if (!isComparison) { 6994 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 6995 Result = *Vec1; 6996 else 6997 Result = *Vec2; 6998 } 6999 7000 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 7001 } 7002 } 7003 } 7004 7005 // C++ [over.built]p17: 7006 // 7007 // For every pair of promoted integral types L and R, there 7008 // exist candidate operator functions of the form 7009 // 7010 // LR operator%(L, R); 7011 // LR operator&(L, R); 7012 // LR operator^(L, R); 7013 // LR operator|(L, R); 7014 // L operator<<(L, R); 7015 // L operator>>(L, R); 7016 // 7017 // where LR is the result of the usual arithmetic conversions 7018 // between types L and R. 7019 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 7020 if (!HasArithmeticOrEnumeralCandidateType) 7021 return; 7022 7023 for (unsigned Left = FirstPromotedIntegralType; 7024 Left < LastPromotedIntegralType; ++Left) { 7025 for (unsigned Right = FirstPromotedIntegralType; 7026 Right < LastPromotedIntegralType; ++Right) { 7027 QualType LandR[2] = { getArithmeticType(Left), 7028 getArithmeticType(Right) }; 7029 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 7030 ? LandR[0] 7031 : getUsualArithmeticConversions(Left, Right); 7032 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 7033 } 7034 } 7035 } 7036 7037 // C++ [over.built]p20: 7038 // 7039 // For every pair (T, VQ), where T is an enumeration or 7040 // pointer to member type and VQ is either volatile or 7041 // empty, there exist candidate operator functions of the form 7042 // 7043 // VQ T& operator=(VQ T&, T); 7044 void addAssignmentMemberPointerOrEnumeralOverloads() { 7045 /// Set of (canonical) types that we've already handled. 7046 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7047 7048 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 7049 for (BuiltinCandidateTypeSet::iterator 7050 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 7051 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 7052 Enum != EnumEnd; ++Enum) { 7053 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 7054 continue; 7055 7056 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, 7057 CandidateSet); 7058 } 7059 7060 for (BuiltinCandidateTypeSet::iterator 7061 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 7062 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 7063 MemPtr != MemPtrEnd; ++MemPtr) { 7064 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 7065 continue; 7066 7067 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, 7068 CandidateSet); 7069 } 7070 } 7071 } 7072 7073 // C++ [over.built]p19: 7074 // 7075 // For every pair (T, VQ), where T is any type and VQ is either 7076 // volatile or empty, there exist candidate operator functions 7077 // of the form 7078 // 7079 // T*VQ& operator=(T*VQ&, T*); 7080 // 7081 // C++ [over.built]p21: 7082 // 7083 // For every pair (T, VQ), where T is a cv-qualified or 7084 // cv-unqualified object type and VQ is either volatile or 7085 // empty, there exist candidate operator functions of the form 7086 // 7087 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 7088 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 7089 void addAssignmentPointerOverloads(bool isEqualOp) { 7090 /// Set of (canonical) types that we've already handled. 7091 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7092 7093 for (BuiltinCandidateTypeSet::iterator 7094 Ptr = CandidateTypes[0].pointer_begin(), 7095 PtrEnd = CandidateTypes[0].pointer_end(); 7096 Ptr != PtrEnd; ++Ptr) { 7097 // If this is operator=, keep track of the builtin candidates we added. 7098 if (isEqualOp) 7099 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 7100 else if (!(*Ptr)->getPointeeType()->isObjectType()) 7101 continue; 7102 7103 // non-volatile version 7104 QualType ParamTypes[2] = { 7105 S.Context.getLValueReferenceType(*Ptr), 7106 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 7107 }; 7108 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7109 /*IsAssigmentOperator=*/ isEqualOp); 7110 7111 bool NeedVolatile = !(*Ptr).isVolatileQualified() && 7112 VisibleTypeConversionsQuals.hasVolatile(); 7113 if (NeedVolatile) { 7114 // volatile version 7115 ParamTypes[0] = 7116 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 7117 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7118 /*IsAssigmentOperator=*/isEqualOp); 7119 } 7120 7121 if (!(*Ptr).isRestrictQualified() && 7122 VisibleTypeConversionsQuals.hasRestrict()) { 7123 // restrict version 7124 ParamTypes[0] 7125 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr)); 7126 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7127 /*IsAssigmentOperator=*/isEqualOp); 7128 7129 if (NeedVolatile) { 7130 // volatile restrict version 7131 ParamTypes[0] 7132 = S.Context.getLValueReferenceType( 7133 S.Context.getCVRQualifiedType(*Ptr, 7134 (Qualifiers::Volatile | 7135 Qualifiers::Restrict))); 7136 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7137 CandidateSet, 7138 /*IsAssigmentOperator=*/isEqualOp); 7139 } 7140 } 7141 } 7142 7143 if (isEqualOp) { 7144 for (BuiltinCandidateTypeSet::iterator 7145 Ptr = CandidateTypes[1].pointer_begin(), 7146 PtrEnd = CandidateTypes[1].pointer_end(); 7147 Ptr != PtrEnd; ++Ptr) { 7148 // Make sure we don't add the same candidate twice. 7149 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7150 continue; 7151 7152 QualType ParamTypes[2] = { 7153 S.Context.getLValueReferenceType(*Ptr), 7154 *Ptr, 7155 }; 7156 7157 // non-volatile version 7158 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7159 /*IsAssigmentOperator=*/true); 7160 7161 bool NeedVolatile = !(*Ptr).isVolatileQualified() && 7162 VisibleTypeConversionsQuals.hasVolatile(); 7163 if (NeedVolatile) { 7164 // volatile version 7165 ParamTypes[0] = 7166 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 7167 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7168 CandidateSet, /*IsAssigmentOperator=*/true); 7169 } 7170 7171 if (!(*Ptr).isRestrictQualified() && 7172 VisibleTypeConversionsQuals.hasRestrict()) { 7173 // restrict version 7174 ParamTypes[0] 7175 = S.Context.getLValueReferenceType(S.Context.getRestrictType(*Ptr)); 7176 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7177 CandidateSet, /*IsAssigmentOperator=*/true); 7178 7179 if (NeedVolatile) { 7180 // volatile restrict version 7181 ParamTypes[0] 7182 = S.Context.getLValueReferenceType( 7183 S.Context.getCVRQualifiedType(*Ptr, 7184 (Qualifiers::Volatile | 7185 Qualifiers::Restrict))); 7186 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7187 CandidateSet, /*IsAssigmentOperator=*/true); 7188 7189 } 7190 } 7191 } 7192 } 7193 } 7194 7195 // C++ [over.built]p18: 7196 // 7197 // For every triple (L, VQ, R), where L is an arithmetic type, 7198 // VQ is either volatile or empty, and R is a promoted 7199 // arithmetic type, there exist candidate operator functions of 7200 // the form 7201 // 7202 // VQ L& operator=(VQ L&, R); 7203 // VQ L& operator*=(VQ L&, R); 7204 // VQ L& operator/=(VQ L&, R); 7205 // VQ L& operator+=(VQ L&, R); 7206 // VQ L& operator-=(VQ L&, R); 7207 void addAssignmentArithmeticOverloads(bool isEqualOp) { 7208 if (!HasArithmeticOrEnumeralCandidateType) 7209 return; 7210 7211 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 7212 for (unsigned Right = FirstPromotedArithmeticType; 7213 Right < LastPromotedArithmeticType; ++Right) { 7214 QualType ParamTypes[2]; 7215 ParamTypes[1] = getArithmeticType(Right); 7216 7217 // Add this built-in operator as a candidate (VQ is empty). 7218 ParamTypes[0] = 7219 S.Context.getLValueReferenceType(getArithmeticType(Left)); 7220 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7221 /*IsAssigmentOperator=*/isEqualOp); 7222 7223 // Add this built-in operator as a candidate (VQ is 'volatile'). 7224 if (VisibleTypeConversionsQuals.hasVolatile()) { 7225 ParamTypes[0] = 7226 S.Context.getVolatileType(getArithmeticType(Left)); 7227 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7228 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7229 CandidateSet, 7230 /*IsAssigmentOperator=*/isEqualOp); 7231 } 7232 } 7233 } 7234 7235 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 7236 for (BuiltinCandidateTypeSet::iterator 7237 Vec1 = CandidateTypes[0].vector_begin(), 7238 Vec1End = CandidateTypes[0].vector_end(); 7239 Vec1 != Vec1End; ++Vec1) { 7240 for (BuiltinCandidateTypeSet::iterator 7241 Vec2 = CandidateTypes[1].vector_begin(), 7242 Vec2End = CandidateTypes[1].vector_end(); 7243 Vec2 != Vec2End; ++Vec2) { 7244 QualType ParamTypes[2]; 7245 ParamTypes[1] = *Vec2; 7246 // Add this built-in operator as a candidate (VQ is empty). 7247 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 7248 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 7249 /*IsAssigmentOperator=*/isEqualOp); 7250 7251 // Add this built-in operator as a candidate (VQ is 'volatile'). 7252 if (VisibleTypeConversionsQuals.hasVolatile()) { 7253 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 7254 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7255 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7256 CandidateSet, 7257 /*IsAssigmentOperator=*/isEqualOp); 7258 } 7259 } 7260 } 7261 } 7262 7263 // C++ [over.built]p22: 7264 // 7265 // For every triple (L, VQ, R), where L is an integral type, VQ 7266 // is either volatile or empty, and R is a promoted integral 7267 // type, there exist candidate operator functions of the form 7268 // 7269 // VQ L& operator%=(VQ L&, R); 7270 // VQ L& operator<<=(VQ L&, R); 7271 // VQ L& operator>>=(VQ L&, R); 7272 // VQ L& operator&=(VQ L&, R); 7273 // VQ L& operator^=(VQ L&, R); 7274 // VQ L& operator|=(VQ L&, R); 7275 void addAssignmentIntegralOverloads() { 7276 if (!HasArithmeticOrEnumeralCandidateType) 7277 return; 7278 7279 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 7280 for (unsigned Right = FirstPromotedIntegralType; 7281 Right < LastPromotedIntegralType; ++Right) { 7282 QualType ParamTypes[2]; 7283 ParamTypes[1] = getArithmeticType(Right); 7284 7285 // Add this built-in operator as a candidate (VQ is empty). 7286 ParamTypes[0] = 7287 S.Context.getLValueReferenceType(getArithmeticType(Left)); 7288 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 7289 if (VisibleTypeConversionsQuals.hasVolatile()) { 7290 // Add this built-in operator as a candidate (VQ is 'volatile'). 7291 ParamTypes[0] = getArithmeticType(Left); 7292 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 7293 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 7294 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 7295 CandidateSet); 7296 } 7297 } 7298 } 7299 } 7300 7301 // C++ [over.operator]p23: 7302 // 7303 // There also exist candidate operator functions of the form 7304 // 7305 // bool operator!(bool); 7306 // bool operator&&(bool, bool); 7307 // bool operator||(bool, bool); 7308 void addExclaimOverload() { 7309 QualType ParamTy = S.Context.BoolTy; 7310 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 7311 /*IsAssignmentOperator=*/false, 7312 /*NumContextualBoolArguments=*/1); 7313 } 7314 void addAmpAmpOrPipePipeOverload() { 7315 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 7316 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 7317 /*IsAssignmentOperator=*/false, 7318 /*NumContextualBoolArguments=*/2); 7319 } 7320 7321 // C++ [over.built]p13: 7322 // 7323 // For every cv-qualified or cv-unqualified object type T there 7324 // exist candidate operator functions of the form 7325 // 7326 // T* operator+(T*, ptrdiff_t); [ABOVE] 7327 // T& operator[](T*, ptrdiff_t); 7328 // T* operator-(T*, ptrdiff_t); [ABOVE] 7329 // T* operator+(ptrdiff_t, T*); [ABOVE] 7330 // T& operator[](ptrdiff_t, T*); 7331 void addSubscriptOverloads() { 7332 for (BuiltinCandidateTypeSet::iterator 7333 Ptr = CandidateTypes[0].pointer_begin(), 7334 PtrEnd = CandidateTypes[0].pointer_end(); 7335 Ptr != PtrEnd; ++Ptr) { 7336 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 7337 QualType PointeeType = (*Ptr)->getPointeeType(); 7338 if (!PointeeType->isObjectType()) 7339 continue; 7340 7341 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 7342 7343 // T& operator[](T*, ptrdiff_t) 7344 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 7345 } 7346 7347 for (BuiltinCandidateTypeSet::iterator 7348 Ptr = CandidateTypes[1].pointer_begin(), 7349 PtrEnd = CandidateTypes[1].pointer_end(); 7350 Ptr != PtrEnd; ++Ptr) { 7351 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 7352 QualType PointeeType = (*Ptr)->getPointeeType(); 7353 if (!PointeeType->isObjectType()) 7354 continue; 7355 7356 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 7357 7358 // T& operator[](ptrdiff_t, T*) 7359 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 7360 } 7361 } 7362 7363 // C++ [over.built]p11: 7364 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 7365 // C1 is the same type as C2 or is a derived class of C2, T is an object 7366 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 7367 // there exist candidate operator functions of the form 7368 // 7369 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 7370 // 7371 // where CV12 is the union of CV1 and CV2. 7372 void addArrowStarOverloads() { 7373 for (BuiltinCandidateTypeSet::iterator 7374 Ptr = CandidateTypes[0].pointer_begin(), 7375 PtrEnd = CandidateTypes[0].pointer_end(); 7376 Ptr != PtrEnd; ++Ptr) { 7377 QualType C1Ty = (*Ptr); 7378 QualType C1; 7379 QualifierCollector Q1; 7380 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 7381 if (!isa<RecordType>(C1)) 7382 continue; 7383 // heuristic to reduce number of builtin candidates in the set. 7384 // Add volatile/restrict version only if there are conversions to a 7385 // volatile/restrict type. 7386 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 7387 continue; 7388 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 7389 continue; 7390 for (BuiltinCandidateTypeSet::iterator 7391 MemPtr = CandidateTypes[1].member_pointer_begin(), 7392 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 7393 MemPtr != MemPtrEnd; ++MemPtr) { 7394 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 7395 QualType C2 = QualType(mptr->getClass(), 0); 7396 C2 = C2.getUnqualifiedType(); 7397 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 7398 break; 7399 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 7400 // build CV12 T& 7401 QualType T = mptr->getPointeeType(); 7402 if (!VisibleTypeConversionsQuals.hasVolatile() && 7403 T.isVolatileQualified()) 7404 continue; 7405 if (!VisibleTypeConversionsQuals.hasRestrict() && 7406 T.isRestrictQualified()) 7407 continue; 7408 T = Q1.apply(S.Context, T); 7409 QualType ResultTy = S.Context.getLValueReferenceType(T); 7410 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 7411 } 7412 } 7413 } 7414 7415 // Note that we don't consider the first argument, since it has been 7416 // contextually converted to bool long ago. The candidates below are 7417 // therefore added as binary. 7418 // 7419 // C++ [over.built]p25: 7420 // For every type T, where T is a pointer, pointer-to-member, or scoped 7421 // enumeration type, there exist candidate operator functions of the form 7422 // 7423 // T operator?(bool, T, T); 7424 // 7425 void addConditionalOperatorOverloads() { 7426 /// Set of (canonical) types that we've already handled. 7427 llvm::SmallPtrSet<QualType, 8> AddedTypes; 7428 7429 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 7430 for (BuiltinCandidateTypeSet::iterator 7431 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 7432 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 7433 Ptr != PtrEnd; ++Ptr) { 7434 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 7435 continue; 7436 7437 QualType ParamTypes[2] = { *Ptr, *Ptr }; 7438 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 7439 } 7440 7441 for (BuiltinCandidateTypeSet::iterator 7442 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 7443 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 7444 MemPtr != MemPtrEnd; ++MemPtr) { 7445 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 7446 continue; 7447 7448 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 7449 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); 7450 } 7451 7452 if (S.getLangOpts().CPlusPlus0x) { 7453 for (BuiltinCandidateTypeSet::iterator 7454 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 7455 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 7456 Enum != EnumEnd; ++Enum) { 7457 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 7458 continue; 7459 7460 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 7461 continue; 7462 7463 QualType ParamTypes[2] = { *Enum, *Enum }; 7464 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); 7465 } 7466 } 7467 } 7468 } 7469}; 7470 7471} // end anonymous namespace 7472 7473/// AddBuiltinOperatorCandidates - Add the appropriate built-in 7474/// operator overloads to the candidate set (C++ [over.built]), based 7475/// on the operator @p Op and the arguments given. For example, if the 7476/// operator is a binary '+', this routine might add "int 7477/// operator+(int, int)" to cover integer addition. 7478void 7479Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 7480 SourceLocation OpLoc, 7481 Expr **Args, unsigned NumArgs, 7482 OverloadCandidateSet& CandidateSet) { 7483 // Find all of the types that the arguments can convert to, but only 7484 // if the operator we're looking at has built-in operator candidates 7485 // that make use of these types. Also record whether we encounter non-record 7486 // candidate types or either arithmetic or enumeral candidate types. 7487 Qualifiers VisibleTypeConversionsQuals; 7488 VisibleTypeConversionsQuals.addConst(); 7489 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7490 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 7491 7492 bool HasNonRecordCandidateType = false; 7493 bool HasArithmeticOrEnumeralCandidateType = false; 7494 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 7495 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 7496 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 7497 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 7498 OpLoc, 7499 true, 7500 (Op == OO_Exclaim || 7501 Op == OO_AmpAmp || 7502 Op == OO_PipePipe), 7503 VisibleTypeConversionsQuals); 7504 HasNonRecordCandidateType = HasNonRecordCandidateType || 7505 CandidateTypes[ArgIdx].hasNonRecordTypes(); 7506 HasArithmeticOrEnumeralCandidateType = 7507 HasArithmeticOrEnumeralCandidateType || 7508 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 7509 } 7510 7511 // Exit early when no non-record types have been added to the candidate set 7512 // for any of the arguments to the operator. 7513 // 7514 // We can't exit early for !, ||, or &&, since there we have always have 7515 // 'bool' overloads. 7516 if (!HasNonRecordCandidateType && 7517 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe)) 7518 return; 7519 7520 // Setup an object to manage the common state for building overloads. 7521 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, 7522 VisibleTypeConversionsQuals, 7523 HasArithmeticOrEnumeralCandidateType, 7524 CandidateTypes, CandidateSet); 7525 7526 // Dispatch over the operation to add in only those overloads which apply. 7527 switch (Op) { 7528 case OO_None: 7529 case NUM_OVERLOADED_OPERATORS: 7530 llvm_unreachable("Expected an overloaded operator"); 7531 7532 case OO_New: 7533 case OO_Delete: 7534 case OO_Array_New: 7535 case OO_Array_Delete: 7536 case OO_Call: 7537 llvm_unreachable( 7538 "Special operators don't use AddBuiltinOperatorCandidates"); 7539 7540 case OO_Comma: 7541 case OO_Arrow: 7542 // C++ [over.match.oper]p3: 7543 // -- For the operator ',', the unary operator '&', or the 7544 // operator '->', the built-in candidates set is empty. 7545 break; 7546 7547 case OO_Plus: // '+' is either unary or binary 7548 if (NumArgs == 1) 7549 OpBuilder.addUnaryPlusPointerOverloads(); 7550 // Fall through. 7551 7552 case OO_Minus: // '-' is either unary or binary 7553 if (NumArgs == 1) { 7554 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 7555 } else { 7556 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 7557 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7558 } 7559 break; 7560 7561 case OO_Star: // '*' is either unary or binary 7562 if (NumArgs == 1) 7563 OpBuilder.addUnaryStarPointerOverloads(); 7564 else 7565 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7566 break; 7567 7568 case OO_Slash: 7569 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7570 break; 7571 7572 case OO_PlusPlus: 7573 case OO_MinusMinus: 7574 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 7575 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 7576 break; 7577 7578 case OO_EqualEqual: 7579 case OO_ExclaimEqual: 7580 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 7581 // Fall through. 7582 7583 case OO_Less: 7584 case OO_Greater: 7585 case OO_LessEqual: 7586 case OO_GreaterEqual: 7587 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 7588 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 7589 break; 7590 7591 case OO_Percent: 7592 case OO_Caret: 7593 case OO_Pipe: 7594 case OO_LessLess: 7595 case OO_GreaterGreater: 7596 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 7597 break; 7598 7599 case OO_Amp: // '&' is either unary or binary 7600 if (NumArgs == 1) 7601 // C++ [over.match.oper]p3: 7602 // -- For the operator ',', the unary operator '&', or the 7603 // operator '->', the built-in candidates set is empty. 7604 break; 7605 7606 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 7607 break; 7608 7609 case OO_Tilde: 7610 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 7611 break; 7612 7613 case OO_Equal: 7614 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 7615 // Fall through. 7616 7617 case OO_PlusEqual: 7618 case OO_MinusEqual: 7619 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 7620 // Fall through. 7621 7622 case OO_StarEqual: 7623 case OO_SlashEqual: 7624 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 7625 break; 7626 7627 case OO_PercentEqual: 7628 case OO_LessLessEqual: 7629 case OO_GreaterGreaterEqual: 7630 case OO_AmpEqual: 7631 case OO_CaretEqual: 7632 case OO_PipeEqual: 7633 OpBuilder.addAssignmentIntegralOverloads(); 7634 break; 7635 7636 case OO_Exclaim: 7637 OpBuilder.addExclaimOverload(); 7638 break; 7639 7640 case OO_AmpAmp: 7641 case OO_PipePipe: 7642 OpBuilder.addAmpAmpOrPipePipeOverload(); 7643 break; 7644 7645 case OO_Subscript: 7646 OpBuilder.addSubscriptOverloads(); 7647 break; 7648 7649 case OO_ArrowStar: 7650 OpBuilder.addArrowStarOverloads(); 7651 break; 7652 7653 case OO_Conditional: 7654 OpBuilder.addConditionalOperatorOverloads(); 7655 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 7656 break; 7657 } 7658} 7659 7660/// \brief Add function candidates found via argument-dependent lookup 7661/// to the set of overloading candidates. 7662/// 7663/// This routine performs argument-dependent name lookup based on the 7664/// given function name (which may also be an operator name) and adds 7665/// all of the overload candidates found by ADL to the overload 7666/// candidate set (C++ [basic.lookup.argdep]). 7667void 7668Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 7669 bool Operator, SourceLocation Loc, 7670 llvm::ArrayRef<Expr *> Args, 7671 TemplateArgumentListInfo *ExplicitTemplateArgs, 7672 OverloadCandidateSet& CandidateSet, 7673 bool PartialOverloading) { 7674 ADLResult Fns; 7675 7676 // FIXME: This approach for uniquing ADL results (and removing 7677 // redundant candidates from the set) relies on pointer-equality, 7678 // which means we need to key off the canonical decl. However, 7679 // always going back to the canonical decl might not get us the 7680 // right set of default arguments. What default arguments are 7681 // we supposed to consider on ADL candidates, anyway? 7682 7683 // FIXME: Pass in the explicit template arguments? 7684 ArgumentDependentLookup(Name, Operator, Loc, Args, Fns); 7685 7686 // Erase all of the candidates we already knew about. 7687 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 7688 CandEnd = CandidateSet.end(); 7689 Cand != CandEnd; ++Cand) 7690 if (Cand->Function) { 7691 Fns.erase(Cand->Function); 7692 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 7693 Fns.erase(FunTmpl); 7694 } 7695 7696 // For each of the ADL candidates we found, add it to the overload 7697 // set. 7698 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 7699 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 7700 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 7701 if (ExplicitTemplateArgs) 7702 continue; 7703 7704 AddOverloadCandidate(FD, FoundDecl, Args, CandidateSet, false, 7705 PartialOverloading); 7706 } else 7707 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 7708 FoundDecl, ExplicitTemplateArgs, 7709 Args, CandidateSet); 7710 } 7711} 7712 7713/// isBetterOverloadCandidate - Determines whether the first overload 7714/// candidate is a better candidate than the second (C++ 13.3.3p1). 7715bool 7716isBetterOverloadCandidate(Sema &S, 7717 const OverloadCandidate &Cand1, 7718 const OverloadCandidate &Cand2, 7719 SourceLocation Loc, 7720 bool UserDefinedConversion) { 7721 // Define viable functions to be better candidates than non-viable 7722 // functions. 7723 if (!Cand2.Viable) 7724 return Cand1.Viable; 7725 else if (!Cand1.Viable) 7726 return false; 7727 7728 // C++ [over.match.best]p1: 7729 // 7730 // -- if F is a static member function, ICS1(F) is defined such 7731 // that ICS1(F) is neither better nor worse than ICS1(G) for 7732 // any function G, and, symmetrically, ICS1(G) is neither 7733 // better nor worse than ICS1(F). 7734 unsigned StartArg = 0; 7735 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 7736 StartArg = 1; 7737 7738 // C++ [over.match.best]p1: 7739 // A viable function F1 is defined to be a better function than another 7740 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 7741 // conversion sequence than ICSi(F2), and then... 7742 unsigned NumArgs = Cand1.NumConversions; 7743 assert(Cand2.NumConversions == NumArgs && "Overload candidate mismatch"); 7744 bool HasBetterConversion = false; 7745 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 7746 switch (CompareImplicitConversionSequences(S, 7747 Cand1.Conversions[ArgIdx], 7748 Cand2.Conversions[ArgIdx])) { 7749 case ImplicitConversionSequence::Better: 7750 // Cand1 has a better conversion sequence. 7751 HasBetterConversion = true; 7752 break; 7753 7754 case ImplicitConversionSequence::Worse: 7755 // Cand1 can't be better than Cand2. 7756 return false; 7757 7758 case ImplicitConversionSequence::Indistinguishable: 7759 // Do nothing. 7760 break; 7761 } 7762 } 7763 7764 // -- for some argument j, ICSj(F1) is a better conversion sequence than 7765 // ICSj(F2), or, if not that, 7766 if (HasBetterConversion) 7767 return true; 7768 7769 // - F1 is a non-template function and F2 is a function template 7770 // specialization, or, if not that, 7771 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 7772 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 7773 return true; 7774 7775 // -- F1 and F2 are function template specializations, and the function 7776 // template for F1 is more specialized than the template for F2 7777 // according to the partial ordering rules described in 14.5.5.2, or, 7778 // if not that, 7779 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 7780 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 7781 if (FunctionTemplateDecl *BetterTemplate 7782 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 7783 Cand2.Function->getPrimaryTemplate(), 7784 Loc, 7785 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 7786 : TPOC_Call, 7787 Cand1.ExplicitCallArguments)) 7788 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 7789 } 7790 7791 // -- the context is an initialization by user-defined conversion 7792 // (see 8.5, 13.3.1.5) and the standard conversion sequence 7793 // from the return type of F1 to the destination type (i.e., 7794 // the type of the entity being initialized) is a better 7795 // conversion sequence than the standard conversion sequence 7796 // from the return type of F2 to the destination type. 7797 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 7798 isa<CXXConversionDecl>(Cand1.Function) && 7799 isa<CXXConversionDecl>(Cand2.Function)) { 7800 // First check whether we prefer one of the conversion functions over the 7801 // other. This only distinguishes the results in non-standard, extension 7802 // cases such as the conversion from a lambda closure type to a function 7803 // pointer or block. 7804 ImplicitConversionSequence::CompareKind FuncResult 7805 = compareConversionFunctions(S, Cand1.Function, Cand2.Function); 7806 if (FuncResult != ImplicitConversionSequence::Indistinguishable) 7807 return FuncResult; 7808 7809 switch (CompareStandardConversionSequences(S, 7810 Cand1.FinalConversion, 7811 Cand2.FinalConversion)) { 7812 case ImplicitConversionSequence::Better: 7813 // Cand1 has a better conversion sequence. 7814 return true; 7815 7816 case ImplicitConversionSequence::Worse: 7817 // Cand1 can't be better than Cand2. 7818 return false; 7819 7820 case ImplicitConversionSequence::Indistinguishable: 7821 // Do nothing 7822 break; 7823 } 7824 } 7825 7826 return false; 7827} 7828 7829/// \brief Computes the best viable function (C++ 13.3.3) 7830/// within an overload candidate set. 7831/// 7832/// \param Loc The location of the function name (or operator symbol) for 7833/// which overload resolution occurs. 7834/// 7835/// \param Best If overload resolution was successful or found a deleted 7836/// function, \p Best points to the candidate function found. 7837/// 7838/// \returns The result of overload resolution. 7839OverloadingResult 7840OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 7841 iterator &Best, 7842 bool UserDefinedConversion) { 7843 // Find the best viable function. 7844 Best = end(); 7845 for (iterator Cand = begin(); Cand != end(); ++Cand) { 7846 if (Cand->Viable) 7847 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 7848 UserDefinedConversion)) 7849 Best = Cand; 7850 } 7851 7852 // If we didn't find any viable functions, abort. 7853 if (Best == end()) 7854 return OR_No_Viable_Function; 7855 7856 // Make sure that this function is better than every other viable 7857 // function. If not, we have an ambiguity. 7858 for (iterator Cand = begin(); Cand != end(); ++Cand) { 7859 if (Cand->Viable && 7860 Cand != Best && 7861 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 7862 UserDefinedConversion)) { 7863 Best = end(); 7864 return OR_Ambiguous; 7865 } 7866 } 7867 7868 // Best is the best viable function. 7869 if (Best->Function && 7870 (Best->Function->isDeleted() || 7871 S.isFunctionConsideredUnavailable(Best->Function))) 7872 return OR_Deleted; 7873 7874 return OR_Success; 7875} 7876 7877namespace { 7878 7879enum OverloadCandidateKind { 7880 oc_function, 7881 oc_method, 7882 oc_constructor, 7883 oc_function_template, 7884 oc_method_template, 7885 oc_constructor_template, 7886 oc_implicit_default_constructor, 7887 oc_implicit_copy_constructor, 7888 oc_implicit_move_constructor, 7889 oc_implicit_copy_assignment, 7890 oc_implicit_move_assignment, 7891 oc_implicit_inherited_constructor 7892}; 7893 7894OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 7895 FunctionDecl *Fn, 7896 std::string &Description) { 7897 bool isTemplate = false; 7898 7899 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 7900 isTemplate = true; 7901 Description = S.getTemplateArgumentBindingsText( 7902 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 7903 } 7904 7905 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 7906 if (!Ctor->isImplicit()) 7907 return isTemplate ? oc_constructor_template : oc_constructor; 7908 7909 if (Ctor->getInheritedConstructor()) 7910 return oc_implicit_inherited_constructor; 7911 7912 if (Ctor->isDefaultConstructor()) 7913 return oc_implicit_default_constructor; 7914 7915 if (Ctor->isMoveConstructor()) 7916 return oc_implicit_move_constructor; 7917 7918 assert(Ctor->isCopyConstructor() && 7919 "unexpected sort of implicit constructor"); 7920 return oc_implicit_copy_constructor; 7921 } 7922 7923 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 7924 // This actually gets spelled 'candidate function' for now, but 7925 // it doesn't hurt to split it out. 7926 if (!Meth->isImplicit()) 7927 return isTemplate ? oc_method_template : oc_method; 7928 7929 if (Meth->isMoveAssignmentOperator()) 7930 return oc_implicit_move_assignment; 7931 7932 if (Meth->isCopyAssignmentOperator()) 7933 return oc_implicit_copy_assignment; 7934 7935 assert(isa<CXXConversionDecl>(Meth) && "expected conversion"); 7936 return oc_method; 7937 } 7938 7939 return isTemplate ? oc_function_template : oc_function; 7940} 7941 7942void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { 7943 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 7944 if (!Ctor) return; 7945 7946 Ctor = Ctor->getInheritedConstructor(); 7947 if (!Ctor) return; 7948 7949 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 7950} 7951 7952} // end anonymous namespace 7953 7954// Notes the location of an overload candidate. 7955void Sema::NoteOverloadCandidate(FunctionDecl *Fn, QualType DestType) { 7956 std::string FnDesc; 7957 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 7958 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate) 7959 << (unsigned) K << FnDesc; 7960 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType); 7961 Diag(Fn->getLocation(), PD); 7962 MaybeEmitInheritedConstructorNote(*this, Fn); 7963} 7964 7965//Notes the location of all overload candidates designated through 7966// OverloadedExpr 7967void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr, QualType DestType) { 7968 assert(OverloadedExpr->getType() == Context.OverloadTy); 7969 7970 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); 7971 OverloadExpr *OvlExpr = Ovl.Expression; 7972 7973 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7974 IEnd = OvlExpr->decls_end(); 7975 I != IEnd; ++I) { 7976 if (FunctionTemplateDecl *FunTmpl = 7977 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) { 7978 NoteOverloadCandidate(FunTmpl->getTemplatedDecl(), DestType); 7979 } else if (FunctionDecl *Fun 7980 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) { 7981 NoteOverloadCandidate(Fun, DestType); 7982 } 7983 } 7984} 7985 7986/// Diagnoses an ambiguous conversion. The partial diagnostic is the 7987/// "lead" diagnostic; it will be given two arguments, the source and 7988/// target types of the conversion. 7989void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 7990 Sema &S, 7991 SourceLocation CaretLoc, 7992 const PartialDiagnostic &PDiag) const { 7993 S.Diag(CaretLoc, PDiag) 7994 << Ambiguous.getFromType() << Ambiguous.getToType(); 7995 // FIXME: The note limiting machinery is borrowed from 7996 // OverloadCandidateSet::NoteCandidates; there's an opportunity for 7997 // refactoring here. 7998 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 7999 unsigned CandsShown = 0; 8000 AmbiguousConversionSequence::const_iterator I, E; 8001 for (I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 8002 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) 8003 break; 8004 ++CandsShown; 8005 S.NoteOverloadCandidate(*I); 8006 } 8007 if (I != E) 8008 S.Diag(SourceLocation(), diag::note_ovl_too_many_candidates) << int(E - I); 8009} 8010 8011namespace { 8012 8013void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 8014 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 8015 assert(Conv.isBad()); 8016 assert(Cand->Function && "for now, candidate must be a function"); 8017 FunctionDecl *Fn = Cand->Function; 8018 8019 // There's a conversion slot for the object argument if this is a 8020 // non-constructor method. Note that 'I' corresponds the 8021 // conversion-slot index. 8022 bool isObjectArgument = false; 8023 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 8024 if (I == 0) 8025 isObjectArgument = true; 8026 else 8027 I--; 8028 } 8029 8030 std::string FnDesc; 8031 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 8032 8033 Expr *FromExpr = Conv.Bad.FromExpr; 8034 QualType FromTy = Conv.Bad.getFromType(); 8035 QualType ToTy = Conv.Bad.getToType(); 8036 8037 if (FromTy == S.Context.OverloadTy) { 8038 assert(FromExpr && "overload set argument came from implicit argument?"); 8039 Expr *E = FromExpr->IgnoreParens(); 8040 if (isa<UnaryOperator>(E)) 8041 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 8042 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 8043 8044 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 8045 << (unsigned) FnKind << FnDesc 8046 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8047 << ToTy << Name << I+1; 8048 MaybeEmitInheritedConstructorNote(S, Fn); 8049 return; 8050 } 8051 8052 // Do some hand-waving analysis to see if the non-viability is due 8053 // to a qualifier mismatch. 8054 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 8055 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 8056 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 8057 CToTy = RT->getPointeeType(); 8058 else { 8059 // TODO: detect and diagnose the full richness of const mismatches. 8060 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 8061 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 8062 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 8063 } 8064 8065 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 8066 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 8067 Qualifiers FromQs = CFromTy.getQualifiers(); 8068 Qualifiers ToQs = CToTy.getQualifiers(); 8069 8070 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 8071 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 8072 << (unsigned) FnKind << FnDesc 8073 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8074 << FromTy 8075 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 8076 << (unsigned) isObjectArgument << I+1; 8077 MaybeEmitInheritedConstructorNote(S, Fn); 8078 return; 8079 } 8080 8081 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 8082 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership) 8083 << (unsigned) FnKind << FnDesc 8084 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8085 << FromTy 8086 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime() 8087 << (unsigned) isObjectArgument << I+1; 8088 MaybeEmitInheritedConstructorNote(S, Fn); 8089 return; 8090 } 8091 8092 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) { 8093 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc) 8094 << (unsigned) FnKind << FnDesc 8095 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8096 << FromTy 8097 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr() 8098 << (unsigned) isObjectArgument << I+1; 8099 MaybeEmitInheritedConstructorNote(S, Fn); 8100 return; 8101 } 8102 8103 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 8104 assert(CVR && "unexpected qualifiers mismatch"); 8105 8106 if (isObjectArgument) { 8107 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 8108 << (unsigned) FnKind << FnDesc 8109 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8110 << FromTy << (CVR - 1); 8111 } else { 8112 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 8113 << (unsigned) FnKind << FnDesc 8114 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8115 << FromTy << (CVR - 1) << I+1; 8116 } 8117 MaybeEmitInheritedConstructorNote(S, Fn); 8118 return; 8119 } 8120 8121 // Special diagnostic for failure to convert an initializer list, since 8122 // telling the user that it has type void is not useful. 8123 if (FromExpr && isa<InitListExpr>(FromExpr)) { 8124 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument) 8125 << (unsigned) FnKind << FnDesc 8126 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8127 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8128 MaybeEmitInheritedConstructorNote(S, Fn); 8129 return; 8130 } 8131 8132 // Diagnose references or pointers to incomplete types differently, 8133 // since it's far from impossible that the incompleteness triggered 8134 // the failure. 8135 QualType TempFromTy = FromTy.getNonReferenceType(); 8136 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 8137 TempFromTy = PTy->getPointeeType(); 8138 if (TempFromTy->isIncompleteType()) { 8139 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 8140 << (unsigned) FnKind << FnDesc 8141 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8142 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8143 MaybeEmitInheritedConstructorNote(S, Fn); 8144 return; 8145 } 8146 8147 // Diagnose base -> derived pointer conversions. 8148 unsigned BaseToDerivedConversion = 0; 8149 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 8150 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 8151 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 8152 FromPtrTy->getPointeeType()) && 8153 !FromPtrTy->getPointeeType()->isIncompleteType() && 8154 !ToPtrTy->getPointeeType()->isIncompleteType() && 8155 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 8156 FromPtrTy->getPointeeType())) 8157 BaseToDerivedConversion = 1; 8158 } 8159 } else if (const ObjCObjectPointerType *FromPtrTy 8160 = FromTy->getAs<ObjCObjectPointerType>()) { 8161 if (const ObjCObjectPointerType *ToPtrTy 8162 = ToTy->getAs<ObjCObjectPointerType>()) 8163 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 8164 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 8165 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 8166 FromPtrTy->getPointeeType()) && 8167 FromIface->isSuperClassOf(ToIface)) 8168 BaseToDerivedConversion = 2; 8169 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 8170 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 8171 !FromTy->isIncompleteType() && 8172 !ToRefTy->getPointeeType()->isIncompleteType() && 8173 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) { 8174 BaseToDerivedConversion = 3; 8175 } else if (ToTy->isLValueReferenceType() && !FromExpr->isLValue() && 8176 ToTy.getNonReferenceType().getCanonicalType() == 8177 FromTy.getNonReferenceType().getCanonicalType()) { 8178 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_lvalue) 8179 << (unsigned) FnKind << FnDesc 8180 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8181 << (unsigned) isObjectArgument << I + 1; 8182 MaybeEmitInheritedConstructorNote(S, Fn); 8183 return; 8184 } 8185 } 8186 8187 if (BaseToDerivedConversion) { 8188 S.Diag(Fn->getLocation(), 8189 diag::note_ovl_candidate_bad_base_to_derived_conv) 8190 << (unsigned) FnKind << FnDesc 8191 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8192 << (BaseToDerivedConversion - 1) 8193 << FromTy << ToTy << I+1; 8194 MaybeEmitInheritedConstructorNote(S, Fn); 8195 return; 8196 } 8197 8198 if (isa<ObjCObjectPointerType>(CFromTy) && 8199 isa<PointerType>(CToTy)) { 8200 Qualifiers FromQs = CFromTy.getQualifiers(); 8201 Qualifiers ToQs = CToTy.getQualifiers(); 8202 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 8203 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv) 8204 << (unsigned) FnKind << FnDesc 8205 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8206 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 8207 MaybeEmitInheritedConstructorNote(S, Fn); 8208 return; 8209 } 8210 } 8211 8212 // Emit the generic diagnostic and, optionally, add the hints to it. 8213 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv); 8214 FDiag << (unsigned) FnKind << FnDesc 8215 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 8216 << FromTy << ToTy << (unsigned) isObjectArgument << I + 1 8217 << (unsigned) (Cand->Fix.Kind); 8218 8219 // If we can fix the conversion, suggest the FixIts. 8220 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(), 8221 HE = Cand->Fix.Hints.end(); HI != HE; ++HI) 8222 FDiag << *HI; 8223 S.Diag(Fn->getLocation(), FDiag); 8224 8225 MaybeEmitInheritedConstructorNote(S, Fn); 8226} 8227 8228void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 8229 unsigned NumFormalArgs) { 8230 // TODO: treat calls to a missing default constructor as a special case 8231 8232 FunctionDecl *Fn = Cand->Function; 8233 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 8234 8235 unsigned MinParams = Fn->getMinRequiredArguments(); 8236 8237 // With invalid overloaded operators, it's possible that we think we 8238 // have an arity mismatch when it fact it looks like we have the 8239 // right number of arguments, because only overloaded operators have 8240 // the weird behavior of overloading member and non-member functions. 8241 // Just don't report anything. 8242 if (Fn->isInvalidDecl() && 8243 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName) 8244 return; 8245 8246 // at least / at most / exactly 8247 unsigned mode, modeCount; 8248 if (NumFormalArgs < MinParams) { 8249 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 8250 (Cand->FailureKind == ovl_fail_bad_deduction && 8251 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 8252 if (MinParams != FnTy->getNumArgs() || 8253 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 8254 mode = 0; // "at least" 8255 else 8256 mode = 2; // "exactly" 8257 modeCount = MinParams; 8258 } else { 8259 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 8260 (Cand->FailureKind == ovl_fail_bad_deduction && 8261 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 8262 if (MinParams != FnTy->getNumArgs()) 8263 mode = 1; // "at most" 8264 else 8265 mode = 2; // "exactly" 8266 modeCount = FnTy->getNumArgs(); 8267 } 8268 8269 std::string Description; 8270 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 8271 8272 if (modeCount == 1 && Fn->getParamDecl(0)->getDeclName()) 8273 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity_one) 8274 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 8275 << Fn->getParamDecl(0) << NumFormalArgs; 8276 else 8277 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 8278 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 8279 << modeCount << NumFormalArgs; 8280 MaybeEmitInheritedConstructorNote(S, Fn); 8281} 8282 8283/// Diagnose a failed template-argument deduction. 8284void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 8285 unsigned NumArgs) { 8286 FunctionDecl *Fn = Cand->Function; // pattern 8287 8288 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 8289 NamedDecl *ParamD; 8290 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 8291 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 8292 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 8293 switch (Cand->DeductionFailure.Result) { 8294 case Sema::TDK_Success: 8295 llvm_unreachable("TDK_success while diagnosing bad deduction"); 8296 8297 case Sema::TDK_Incomplete: { 8298 assert(ParamD && "no parameter found for incomplete deduction result"); 8299 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 8300 << ParamD->getDeclName(); 8301 MaybeEmitInheritedConstructorNote(S, Fn); 8302 return; 8303 } 8304 8305 case Sema::TDK_Underqualified: { 8306 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 8307 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 8308 8309 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 8310 8311 // Param will have been canonicalized, but it should just be a 8312 // qualified version of ParamD, so move the qualifiers to that. 8313 QualifierCollector Qs; 8314 Qs.strip(Param); 8315 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 8316 assert(S.Context.hasSameType(Param, NonCanonParam)); 8317 8318 // Arg has also been canonicalized, but there's nothing we can do 8319 // about that. It also doesn't matter as much, because it won't 8320 // have any template parameters in it (because deduction isn't 8321 // done on dependent types). 8322 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 8323 8324 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 8325 << ParamD->getDeclName() << Arg << NonCanonParam; 8326 MaybeEmitInheritedConstructorNote(S, Fn); 8327 return; 8328 } 8329 8330 case Sema::TDK_Inconsistent: { 8331 assert(ParamD && "no parameter found for inconsistent deduction result"); 8332 int which = 0; 8333 if (isa<TemplateTypeParmDecl>(ParamD)) 8334 which = 0; 8335 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 8336 which = 1; 8337 else { 8338 which = 2; 8339 } 8340 8341 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 8342 << which << ParamD->getDeclName() 8343 << *Cand->DeductionFailure.getFirstArg() 8344 << *Cand->DeductionFailure.getSecondArg(); 8345 MaybeEmitInheritedConstructorNote(S, Fn); 8346 return; 8347 } 8348 8349 case Sema::TDK_InvalidExplicitArguments: 8350 assert(ParamD && "no parameter found for invalid explicit arguments"); 8351 if (ParamD->getDeclName()) 8352 S.Diag(Fn->getLocation(), 8353 diag::note_ovl_candidate_explicit_arg_mismatch_named) 8354 << ParamD->getDeclName(); 8355 else { 8356 int index = 0; 8357 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 8358 index = TTP->getIndex(); 8359 else if (NonTypeTemplateParmDecl *NTTP 8360 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 8361 index = NTTP->getIndex(); 8362 else 8363 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 8364 S.Diag(Fn->getLocation(), 8365 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 8366 << (index + 1); 8367 } 8368 MaybeEmitInheritedConstructorNote(S, Fn); 8369 return; 8370 8371 case Sema::TDK_TooManyArguments: 8372 case Sema::TDK_TooFewArguments: 8373 DiagnoseArityMismatch(S, Cand, NumArgs); 8374 return; 8375 8376 case Sema::TDK_InstantiationDepth: 8377 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 8378 MaybeEmitInheritedConstructorNote(S, Fn); 8379 return; 8380 8381 case Sema::TDK_SubstitutionFailure: { 8382 // Format the template argument list into the argument string. 8383 llvm::SmallString<128> TemplateArgString; 8384 if (TemplateArgumentList *Args = 8385 Cand->DeductionFailure.getTemplateArgumentList()) { 8386 TemplateArgString = " "; 8387 TemplateArgString += S.getTemplateArgumentBindingsText( 8388 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), *Args); 8389 } 8390 8391 // If this candidate was disabled by enable_if, say so. 8392 PartialDiagnosticAt *PDiag = Cand->DeductionFailure.getSFINAEDiagnostic(); 8393 if (PDiag && PDiag->second.getDiagID() == 8394 diag::err_typename_nested_not_found_enable_if) { 8395 // FIXME: Use the source range of the condition, and the fully-qualified 8396 // name of the enable_if template. These are both present in PDiag. 8397 S.Diag(PDiag->first, diag::note_ovl_candidate_disabled_by_enable_if) 8398 << "'enable_if'" << TemplateArgString; 8399 return; 8400 } 8401 8402 // Format the SFINAE diagnostic into the argument string. 8403 // FIXME: Add a general mechanism to include a PartialDiagnostic *'s 8404 // formatted message in another diagnostic. 8405 llvm::SmallString<128> SFINAEArgString; 8406 SourceRange R; 8407 if (PDiag) { 8408 SFINAEArgString = ": "; 8409 R = SourceRange(PDiag->first, PDiag->first); 8410 PDiag->second.EmitToString(S.getDiagnostics(), SFINAEArgString); 8411 } 8412 8413 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 8414 << TemplateArgString << SFINAEArgString << R; 8415 MaybeEmitInheritedConstructorNote(S, Fn); 8416 return; 8417 } 8418 8419 // TODO: diagnose these individually, then kill off 8420 // note_ovl_candidate_bad_deduction, which is uselessly vague. 8421 case Sema::TDK_NonDeducedMismatch: 8422 case Sema::TDK_FailedOverloadResolution: 8423 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 8424 MaybeEmitInheritedConstructorNote(S, Fn); 8425 return; 8426 } 8427} 8428 8429/// CUDA: diagnose an invalid call across targets. 8430void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) { 8431 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext); 8432 FunctionDecl *Callee = Cand->Function; 8433 8434 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller), 8435 CalleeTarget = S.IdentifyCUDATarget(Callee); 8436 8437 std::string FnDesc; 8438 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Callee, FnDesc); 8439 8440 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target) 8441 << (unsigned) FnKind << CalleeTarget << CallerTarget; 8442} 8443 8444/// Generates a 'note' diagnostic for an overload candidate. We've 8445/// already generated a primary error at the call site. 8446/// 8447/// It really does need to be a single diagnostic with its caret 8448/// pointed at the candidate declaration. Yes, this creates some 8449/// major challenges of technical writing. Yes, this makes pointing 8450/// out problems with specific arguments quite awkward. It's still 8451/// better than generating twenty screens of text for every failed 8452/// overload. 8453/// 8454/// It would be great to be able to express per-candidate problems 8455/// more richly for those diagnostic clients that cared, but we'd 8456/// still have to be just as careful with the default diagnostics. 8457void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 8458 unsigned NumArgs) { 8459 FunctionDecl *Fn = Cand->Function; 8460 8461 // Note deleted candidates, but only if they're viable. 8462 if (Cand->Viable && (Fn->isDeleted() || 8463 S.isFunctionConsideredUnavailable(Fn))) { 8464 std::string FnDesc; 8465 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 8466 8467 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 8468 << FnKind << FnDesc 8469 << (Fn->isDeleted() ? (Fn->isDeletedAsWritten() ? 1 : 2) : 0); 8470 MaybeEmitInheritedConstructorNote(S, Fn); 8471 return; 8472 } 8473 8474 // We don't really have anything else to say about viable candidates. 8475 if (Cand->Viable) { 8476 S.NoteOverloadCandidate(Fn); 8477 return; 8478 } 8479 8480 switch (Cand->FailureKind) { 8481 case ovl_fail_too_many_arguments: 8482 case ovl_fail_too_few_arguments: 8483 return DiagnoseArityMismatch(S, Cand, NumArgs); 8484 8485 case ovl_fail_bad_deduction: 8486 return DiagnoseBadDeduction(S, Cand, NumArgs); 8487 8488 case ovl_fail_trivial_conversion: 8489 case ovl_fail_bad_final_conversion: 8490 case ovl_fail_final_conversion_not_exact: 8491 return S.NoteOverloadCandidate(Fn); 8492 8493 case ovl_fail_bad_conversion: { 8494 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 8495 for (unsigned N = Cand->NumConversions; I != N; ++I) 8496 if (Cand->Conversions[I].isBad()) 8497 return DiagnoseBadConversion(S, Cand, I); 8498 8499 // FIXME: this currently happens when we're called from SemaInit 8500 // when user-conversion overload fails. Figure out how to handle 8501 // those conditions and diagnose them well. 8502 return S.NoteOverloadCandidate(Fn); 8503 } 8504 8505 case ovl_fail_bad_target: 8506 return DiagnoseBadTarget(S, Cand); 8507 } 8508} 8509 8510void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 8511 // Desugar the type of the surrogate down to a function type, 8512 // retaining as many typedefs as possible while still showing 8513 // the function type (and, therefore, its parameter types). 8514 QualType FnType = Cand->Surrogate->getConversionType(); 8515 bool isLValueReference = false; 8516 bool isRValueReference = false; 8517 bool isPointer = false; 8518 if (const LValueReferenceType *FnTypeRef = 8519 FnType->getAs<LValueReferenceType>()) { 8520 FnType = FnTypeRef->getPointeeType(); 8521 isLValueReference = true; 8522 } else if (const RValueReferenceType *FnTypeRef = 8523 FnType->getAs<RValueReferenceType>()) { 8524 FnType = FnTypeRef->getPointeeType(); 8525 isRValueReference = true; 8526 } 8527 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 8528 FnType = FnTypePtr->getPointeeType(); 8529 isPointer = true; 8530 } 8531 // Desugar down to a function type. 8532 FnType = QualType(FnType->getAs<FunctionType>(), 0); 8533 // Reconstruct the pointer/reference as appropriate. 8534 if (isPointer) FnType = S.Context.getPointerType(FnType); 8535 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 8536 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 8537 8538 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 8539 << FnType; 8540 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 8541} 8542 8543void NoteBuiltinOperatorCandidate(Sema &S, 8544 StringRef Opc, 8545 SourceLocation OpLoc, 8546 OverloadCandidate *Cand) { 8547 assert(Cand->NumConversions <= 2 && "builtin operator is not binary"); 8548 std::string TypeStr("operator"); 8549 TypeStr += Opc; 8550 TypeStr += "("; 8551 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 8552 if (Cand->NumConversions == 1) { 8553 TypeStr += ")"; 8554 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 8555 } else { 8556 TypeStr += ", "; 8557 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 8558 TypeStr += ")"; 8559 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 8560 } 8561} 8562 8563void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 8564 OverloadCandidate *Cand) { 8565 unsigned NoOperands = Cand->NumConversions; 8566 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 8567 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 8568 if (ICS.isBad()) break; // all meaningless after first invalid 8569 if (!ICS.isAmbiguous()) continue; 8570 8571 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 8572 S.PDiag(diag::note_ambiguous_type_conversion)); 8573 } 8574} 8575 8576SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 8577 if (Cand->Function) 8578 return Cand->Function->getLocation(); 8579 if (Cand->IsSurrogate) 8580 return Cand->Surrogate->getLocation(); 8581 return SourceLocation(); 8582} 8583 8584static unsigned 8585RankDeductionFailure(const OverloadCandidate::DeductionFailureInfo &DFI) { 8586 switch ((Sema::TemplateDeductionResult)DFI.Result) { 8587 case Sema::TDK_Success: 8588 llvm_unreachable("TDK_success while diagnosing bad deduction"); 8589 8590 case Sema::TDK_Invalid: 8591 case Sema::TDK_Incomplete: 8592 return 1; 8593 8594 case Sema::TDK_Underqualified: 8595 case Sema::TDK_Inconsistent: 8596 return 2; 8597 8598 case Sema::TDK_SubstitutionFailure: 8599 case Sema::TDK_NonDeducedMismatch: 8600 return 3; 8601 8602 case Sema::TDK_InstantiationDepth: 8603 case Sema::TDK_FailedOverloadResolution: 8604 return 4; 8605 8606 case Sema::TDK_InvalidExplicitArguments: 8607 return 5; 8608 8609 case Sema::TDK_TooManyArguments: 8610 case Sema::TDK_TooFewArguments: 8611 return 6; 8612 } 8613 llvm_unreachable("Unhandled deduction result"); 8614} 8615 8616struct CompareOverloadCandidatesForDisplay { 8617 Sema &S; 8618 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 8619 8620 bool operator()(const OverloadCandidate *L, 8621 const OverloadCandidate *R) { 8622 // Fast-path this check. 8623 if (L == R) return false; 8624 8625 // Order first by viability. 8626 if (L->Viable) { 8627 if (!R->Viable) return true; 8628 8629 // TODO: introduce a tri-valued comparison for overload 8630 // candidates. Would be more worthwhile if we had a sort 8631 // that could exploit it. 8632 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 8633 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 8634 } else if (R->Viable) 8635 return false; 8636 8637 assert(L->Viable == R->Viable); 8638 8639 // Criteria by which we can sort non-viable candidates: 8640 if (!L->Viable) { 8641 // 1. Arity mismatches come after other candidates. 8642 if (L->FailureKind == ovl_fail_too_many_arguments || 8643 L->FailureKind == ovl_fail_too_few_arguments) 8644 return false; 8645 if (R->FailureKind == ovl_fail_too_many_arguments || 8646 R->FailureKind == ovl_fail_too_few_arguments) 8647 return true; 8648 8649 // 2. Bad conversions come first and are ordered by the number 8650 // of bad conversions and quality of good conversions. 8651 if (L->FailureKind == ovl_fail_bad_conversion) { 8652 if (R->FailureKind != ovl_fail_bad_conversion) 8653 return true; 8654 8655 // The conversion that can be fixed with a smaller number of changes, 8656 // comes first. 8657 unsigned numLFixes = L->Fix.NumConversionsFixed; 8658 unsigned numRFixes = R->Fix.NumConversionsFixed; 8659 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes; 8660 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes; 8661 if (numLFixes != numRFixes) { 8662 if (numLFixes < numRFixes) 8663 return true; 8664 else 8665 return false; 8666 } 8667 8668 // If there's any ordering between the defined conversions... 8669 // FIXME: this might not be transitive. 8670 assert(L->NumConversions == R->NumConversions); 8671 8672 int leftBetter = 0; 8673 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 8674 for (unsigned E = L->NumConversions; I != E; ++I) { 8675 switch (CompareImplicitConversionSequences(S, 8676 L->Conversions[I], 8677 R->Conversions[I])) { 8678 case ImplicitConversionSequence::Better: 8679 leftBetter++; 8680 break; 8681 8682 case ImplicitConversionSequence::Worse: 8683 leftBetter--; 8684 break; 8685 8686 case ImplicitConversionSequence::Indistinguishable: 8687 break; 8688 } 8689 } 8690 if (leftBetter > 0) return true; 8691 if (leftBetter < 0) return false; 8692 8693 } else if (R->FailureKind == ovl_fail_bad_conversion) 8694 return false; 8695 8696 if (L->FailureKind == ovl_fail_bad_deduction) { 8697 if (R->FailureKind != ovl_fail_bad_deduction) 8698 return true; 8699 8700 if (L->DeductionFailure.Result != R->DeductionFailure.Result) 8701 return RankDeductionFailure(L->DeductionFailure) 8702 < RankDeductionFailure(R->DeductionFailure); 8703 } else if (R->FailureKind == ovl_fail_bad_deduction) 8704 return false; 8705 8706 // TODO: others? 8707 } 8708 8709 // Sort everything else by location. 8710 SourceLocation LLoc = GetLocationForCandidate(L); 8711 SourceLocation RLoc = GetLocationForCandidate(R); 8712 8713 // Put candidates without locations (e.g. builtins) at the end. 8714 if (LLoc.isInvalid()) return false; 8715 if (RLoc.isInvalid()) return true; 8716 8717 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 8718 } 8719}; 8720 8721/// CompleteNonViableCandidate - Normally, overload resolution only 8722/// computes up to the first. Produces the FixIt set if possible. 8723void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 8724 llvm::ArrayRef<Expr *> Args) { 8725 assert(!Cand->Viable); 8726 8727 // Don't do anything on failures other than bad conversion. 8728 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 8729 8730 // We only want the FixIts if all the arguments can be corrected. 8731 bool Unfixable = false; 8732 // Use a implicit copy initialization to check conversion fixes. 8733 Cand->Fix.setConversionChecker(TryCopyInitialization); 8734 8735 // Skip forward to the first bad conversion. 8736 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 8737 unsigned ConvCount = Cand->NumConversions; 8738 while (true) { 8739 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 8740 ConvIdx++; 8741 if (Cand->Conversions[ConvIdx - 1].isBad()) { 8742 Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S); 8743 break; 8744 } 8745 } 8746 8747 if (ConvIdx == ConvCount) 8748 return; 8749 8750 assert(!Cand->Conversions[ConvIdx].isInitialized() && 8751 "remaining conversion is initialized?"); 8752 8753 // FIXME: this should probably be preserved from the overload 8754 // operation somehow. 8755 bool SuppressUserConversions = false; 8756 8757 const FunctionProtoType* Proto; 8758 unsigned ArgIdx = ConvIdx; 8759 8760 if (Cand->IsSurrogate) { 8761 QualType ConvType 8762 = Cand->Surrogate->getConversionType().getNonReferenceType(); 8763 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 8764 ConvType = ConvPtrType->getPointeeType(); 8765 Proto = ConvType->getAs<FunctionProtoType>(); 8766 ArgIdx--; 8767 } else if (Cand->Function) { 8768 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 8769 if (isa<CXXMethodDecl>(Cand->Function) && 8770 !isa<CXXConstructorDecl>(Cand->Function)) 8771 ArgIdx--; 8772 } else { 8773 // Builtin binary operator with a bad first conversion. 8774 assert(ConvCount <= 3); 8775 for (; ConvIdx != ConvCount; ++ConvIdx) 8776 Cand->Conversions[ConvIdx] 8777 = TryCopyInitialization(S, Args[ConvIdx], 8778 Cand->BuiltinTypes.ParamTypes[ConvIdx], 8779 SuppressUserConversions, 8780 /*InOverloadResolution*/ true, 8781 /*AllowObjCWritebackConversion=*/ 8782 S.getLangOpts().ObjCAutoRefCount); 8783 return; 8784 } 8785 8786 // Fill in the rest of the conversions. 8787 unsigned NumArgsInProto = Proto->getNumArgs(); 8788 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 8789 if (ArgIdx < NumArgsInProto) { 8790 Cand->Conversions[ConvIdx] 8791 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 8792 SuppressUserConversions, 8793 /*InOverloadResolution=*/true, 8794 /*AllowObjCWritebackConversion=*/ 8795 S.getLangOpts().ObjCAutoRefCount); 8796 // Store the FixIt in the candidate if it exists. 8797 if (!Unfixable && Cand->Conversions[ConvIdx].isBad()) 8798 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S); 8799 } 8800 else 8801 Cand->Conversions[ConvIdx].setEllipsis(); 8802 } 8803} 8804 8805} // end anonymous namespace 8806 8807/// PrintOverloadCandidates - When overload resolution fails, prints 8808/// diagnostic messages containing the candidates in the candidate 8809/// set. 8810void OverloadCandidateSet::NoteCandidates(Sema &S, 8811 OverloadCandidateDisplayKind OCD, 8812 llvm::ArrayRef<Expr *> Args, 8813 StringRef Opc, 8814 SourceLocation OpLoc) { 8815 // Sort the candidates by viability and position. Sorting directly would 8816 // be prohibitive, so we make a set of pointers and sort those. 8817 SmallVector<OverloadCandidate*, 32> Cands; 8818 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 8819 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 8820 if (Cand->Viable) 8821 Cands.push_back(Cand); 8822 else if (OCD == OCD_AllCandidates) { 8823 CompleteNonViableCandidate(S, Cand, Args); 8824 if (Cand->Function || Cand->IsSurrogate) 8825 Cands.push_back(Cand); 8826 // Otherwise, this a non-viable builtin candidate. We do not, in general, 8827 // want to list every possible builtin candidate. 8828 } 8829 } 8830 8831 std::sort(Cands.begin(), Cands.end(), 8832 CompareOverloadCandidatesForDisplay(S)); 8833 8834 bool ReportedAmbiguousConversions = false; 8835 8836 SmallVectorImpl<OverloadCandidate*>::iterator I, E; 8837 const OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 8838 unsigned CandsShown = 0; 8839 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 8840 OverloadCandidate *Cand = *I; 8841 8842 // Set an arbitrary limit on the number of candidate functions we'll spam 8843 // the user with. FIXME: This limit should depend on details of the 8844 // candidate list. 8845 if (CandsShown >= 4 && ShowOverloads == Ovl_Best) { 8846 break; 8847 } 8848 ++CandsShown; 8849 8850 if (Cand->Function) 8851 NoteFunctionCandidate(S, Cand, Args.size()); 8852 else if (Cand->IsSurrogate) 8853 NoteSurrogateCandidate(S, Cand); 8854 else { 8855 assert(Cand->Viable && 8856 "Non-viable built-in candidates are not added to Cands."); 8857 // Generally we only see ambiguities including viable builtin 8858 // operators if overload resolution got screwed up by an 8859 // ambiguous user-defined conversion. 8860 // 8861 // FIXME: It's quite possible for different conversions to see 8862 // different ambiguities, though. 8863 if (!ReportedAmbiguousConversions) { 8864 NoteAmbiguousUserConversions(S, OpLoc, Cand); 8865 ReportedAmbiguousConversions = true; 8866 } 8867 8868 // If this is a viable builtin, print it. 8869 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 8870 } 8871 } 8872 8873 if (I != E) 8874 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 8875} 8876 8877// [PossiblyAFunctionType] --> [Return] 8878// NonFunctionType --> NonFunctionType 8879// R (A) --> R(A) 8880// R (*)(A) --> R (A) 8881// R (&)(A) --> R (A) 8882// R (S::*)(A) --> R (A) 8883QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { 8884 QualType Ret = PossiblyAFunctionType; 8885 if (const PointerType *ToTypePtr = 8886 PossiblyAFunctionType->getAs<PointerType>()) 8887 Ret = ToTypePtr->getPointeeType(); 8888 else if (const ReferenceType *ToTypeRef = 8889 PossiblyAFunctionType->getAs<ReferenceType>()) 8890 Ret = ToTypeRef->getPointeeType(); 8891 else if (const MemberPointerType *MemTypePtr = 8892 PossiblyAFunctionType->getAs<MemberPointerType>()) 8893 Ret = MemTypePtr->getPointeeType(); 8894 Ret = 8895 Context.getCanonicalType(Ret).getUnqualifiedType(); 8896 return Ret; 8897} 8898 8899// A helper class to help with address of function resolution 8900// - allows us to avoid passing around all those ugly parameters 8901class AddressOfFunctionResolver 8902{ 8903 Sema& S; 8904 Expr* SourceExpr; 8905 const QualType& TargetType; 8906 QualType TargetFunctionType; // Extracted function type from target type 8907 8908 bool Complain; 8909 //DeclAccessPair& ResultFunctionAccessPair; 8910 ASTContext& Context; 8911 8912 bool TargetTypeIsNonStaticMemberFunction; 8913 bool FoundNonTemplateFunction; 8914 8915 OverloadExpr::FindResult OvlExprInfo; 8916 OverloadExpr *OvlExpr; 8917 TemplateArgumentListInfo OvlExplicitTemplateArgs; 8918 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 8919 8920public: 8921 AddressOfFunctionResolver(Sema &S, Expr* SourceExpr, 8922 const QualType& TargetType, bool Complain) 8923 : S(S), SourceExpr(SourceExpr), TargetType(TargetType), 8924 Complain(Complain), Context(S.getASTContext()), 8925 TargetTypeIsNonStaticMemberFunction( 8926 !!TargetType->getAs<MemberPointerType>()), 8927 FoundNonTemplateFunction(false), 8928 OvlExprInfo(OverloadExpr::find(SourceExpr)), 8929 OvlExpr(OvlExprInfo.Expression) 8930 { 8931 ExtractUnqualifiedFunctionTypeFromTargetType(); 8932 8933 if (!TargetFunctionType->isFunctionType()) { 8934 if (OvlExpr->hasExplicitTemplateArgs()) { 8935 DeclAccessPair dap; 8936 if (FunctionDecl* Fn = S.ResolveSingleFunctionTemplateSpecialization( 8937 OvlExpr, false, &dap) ) { 8938 8939 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 8940 if (!Method->isStatic()) { 8941 // If the target type is a non-function type and the function 8942 // found is a non-static member function, pretend as if that was 8943 // the target, it's the only possible type to end up with. 8944 TargetTypeIsNonStaticMemberFunction = true; 8945 8946 // And skip adding the function if its not in the proper form. 8947 // We'll diagnose this due to an empty set of functions. 8948 if (!OvlExprInfo.HasFormOfMemberPointer) 8949 return; 8950 } 8951 } 8952 8953 Matches.push_back(std::make_pair(dap,Fn)); 8954 } 8955 } 8956 return; 8957 } 8958 8959 if (OvlExpr->hasExplicitTemplateArgs()) 8960 OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); 8961 8962 if (FindAllFunctionsThatMatchTargetTypeExactly()) { 8963 // C++ [over.over]p4: 8964 // If more than one function is selected, [...] 8965 if (Matches.size() > 1) { 8966 if (FoundNonTemplateFunction) 8967 EliminateAllTemplateMatches(); 8968 else 8969 EliminateAllExceptMostSpecializedTemplate(); 8970 } 8971 } 8972 } 8973 8974private: 8975 bool isTargetTypeAFunction() const { 8976 return TargetFunctionType->isFunctionType(); 8977 } 8978 8979 // [ToType] [Return] 8980 8981 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false 8982 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false 8983 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true 8984 void inline ExtractUnqualifiedFunctionTypeFromTargetType() { 8985 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); 8986 } 8987 8988 // return true if any matching specializations were found 8989 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, 8990 const DeclAccessPair& CurAccessFunPair) { 8991 if (CXXMethodDecl *Method 8992 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 8993 // Skip non-static function templates when converting to pointer, and 8994 // static when converting to member pointer. 8995 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 8996 return false; 8997 } 8998 else if (TargetTypeIsNonStaticMemberFunction) 8999 return false; 9000 9001 // C++ [over.over]p2: 9002 // If the name is a function template, template argument deduction is 9003 // done (14.8.2.2), and if the argument deduction succeeds, the 9004 // resulting template argument list is used to generate a single 9005 // function template specialization, which is added to the set of 9006 // overloaded functions considered. 9007 FunctionDecl *Specialization = 0; 9008 TemplateDeductionInfo Info(OvlExpr->getNameLoc()); 9009 if (Sema::TemplateDeductionResult Result 9010 = S.DeduceTemplateArguments(FunctionTemplate, 9011 &OvlExplicitTemplateArgs, 9012 TargetFunctionType, Specialization, 9013 Info)) { 9014 // FIXME: make a note of the failed deduction for diagnostics. 9015 (void)Result; 9016 return false; 9017 } 9018 9019 // Template argument deduction ensures that we have an exact match. 9020 // This function template specicalization works. 9021 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 9022 assert(TargetFunctionType 9023 == Context.getCanonicalType(Specialization->getType())); 9024 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); 9025 return true; 9026 } 9027 9028 bool AddMatchingNonTemplateFunction(NamedDecl* Fn, 9029 const DeclAccessPair& CurAccessFunPair) { 9030 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 9031 // Skip non-static functions when converting to pointer, and static 9032 // when converting to member pointer. 9033 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 9034 return false; 9035 } 9036 else if (TargetTypeIsNonStaticMemberFunction) 9037 return false; 9038 9039 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 9040 if (S.getLangOpts().CUDA) 9041 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext)) 9042 if (S.CheckCUDATarget(Caller, FunDecl)) 9043 return false; 9044 9045 QualType ResultTy; 9046 if (Context.hasSameUnqualifiedType(TargetFunctionType, 9047 FunDecl->getType()) || 9048 S.IsNoReturnConversion(FunDecl->getType(), TargetFunctionType, 9049 ResultTy)) { 9050 Matches.push_back(std::make_pair(CurAccessFunPair, 9051 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 9052 FoundNonTemplateFunction = true; 9053 return true; 9054 } 9055 } 9056 9057 return false; 9058 } 9059 9060 bool FindAllFunctionsThatMatchTargetTypeExactly() { 9061 bool Ret = false; 9062 9063 // If the overload expression doesn't have the form of a pointer to 9064 // member, don't try to convert it to a pointer-to-member type. 9065 if (IsInvalidFormOfPointerToMemberFunction()) 9066 return false; 9067 9068 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 9069 E = OvlExpr->decls_end(); 9070 I != E; ++I) { 9071 // Look through any using declarations to find the underlying function. 9072 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 9073 9074 // C++ [over.over]p3: 9075 // Non-member functions and static member functions match 9076 // targets of type "pointer-to-function" or "reference-to-function." 9077 // Nonstatic member functions match targets of 9078 // type "pointer-to-member-function." 9079 // Note that according to DR 247, the containing class does not matter. 9080 if (FunctionTemplateDecl *FunctionTemplate 9081 = dyn_cast<FunctionTemplateDecl>(Fn)) { 9082 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) 9083 Ret = true; 9084 } 9085 // If we have explicit template arguments supplied, skip non-templates. 9086 else if (!OvlExpr->hasExplicitTemplateArgs() && 9087 AddMatchingNonTemplateFunction(Fn, I.getPair())) 9088 Ret = true; 9089 } 9090 assert(Ret || Matches.empty()); 9091 return Ret; 9092 } 9093 9094 void EliminateAllExceptMostSpecializedTemplate() { 9095 // [...] and any given function template specialization F1 is 9096 // eliminated if the set contains a second function template 9097 // specialization whose function template is more specialized 9098 // than the function template of F1 according to the partial 9099 // ordering rules of 14.5.5.2. 9100 9101 // The algorithm specified above is quadratic. We instead use a 9102 // two-pass algorithm (similar to the one used to identify the 9103 // best viable function in an overload set) that identifies the 9104 // best function template (if it exists). 9105 9106 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 9107 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 9108 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 9109 9110 UnresolvedSetIterator Result = 9111 S.getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 9112 TPOC_Other, 0, SourceExpr->getLocStart(), 9113 S.PDiag(), 9114 S.PDiag(diag::err_addr_ovl_ambiguous) 9115 << Matches[0].second->getDeclName(), 9116 S.PDiag(diag::note_ovl_candidate) 9117 << (unsigned) oc_function_template, 9118 Complain, TargetFunctionType); 9119 9120 if (Result != MatchesCopy.end()) { 9121 // Make it the first and only element 9122 Matches[0].first = Matches[Result - MatchesCopy.begin()].first; 9123 Matches[0].second = cast<FunctionDecl>(*Result); 9124 Matches.resize(1); 9125 } 9126 } 9127 9128 void EliminateAllTemplateMatches() { 9129 // [...] any function template specializations in the set are 9130 // eliminated if the set also contains a non-template function, [...] 9131 for (unsigned I = 0, N = Matches.size(); I != N; ) { 9132 if (Matches[I].second->getPrimaryTemplate() == 0) 9133 ++I; 9134 else { 9135 Matches[I] = Matches[--N]; 9136 Matches.set_size(N); 9137 } 9138 } 9139 } 9140 9141public: 9142 void ComplainNoMatchesFound() const { 9143 assert(Matches.empty()); 9144 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) 9145 << OvlExpr->getName() << TargetFunctionType 9146 << OvlExpr->getSourceRange(); 9147 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); 9148 } 9149 9150 bool IsInvalidFormOfPointerToMemberFunction() const { 9151 return TargetTypeIsNonStaticMemberFunction && 9152 !OvlExprInfo.HasFormOfMemberPointer; 9153 } 9154 9155 void ComplainIsInvalidFormOfPointerToMemberFunction() const { 9156 // TODO: Should we condition this on whether any functions might 9157 // have matched, or is it more appropriate to do that in callers? 9158 // TODO: a fixit wouldn't hurt. 9159 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 9160 << TargetType << OvlExpr->getSourceRange(); 9161 } 9162 9163 void ComplainOfInvalidConversion() const { 9164 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 9165 << OvlExpr->getName() << TargetType; 9166 } 9167 9168 void ComplainMultipleMatchesFound() const { 9169 assert(Matches.size() > 1); 9170 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) 9171 << OvlExpr->getName() 9172 << OvlExpr->getSourceRange(); 9173 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); 9174 } 9175 9176 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); } 9177 9178 int getNumMatches() const { return Matches.size(); } 9179 9180 FunctionDecl* getMatchingFunctionDecl() const { 9181 if (Matches.size() != 1) return 0; 9182 return Matches[0].second; 9183 } 9184 9185 const DeclAccessPair* getMatchingFunctionAccessPair() const { 9186 if (Matches.size() != 1) return 0; 9187 return &Matches[0].first; 9188 } 9189}; 9190 9191/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 9192/// an overloaded function (C++ [over.over]), where @p From is an 9193/// expression with overloaded function type and @p ToType is the type 9194/// we're trying to resolve to. For example: 9195/// 9196/// @code 9197/// int f(double); 9198/// int f(int); 9199/// 9200/// int (*pfd)(double) = f; // selects f(double) 9201/// @endcode 9202/// 9203/// This routine returns the resulting FunctionDecl if it could be 9204/// resolved, and NULL otherwise. When @p Complain is true, this 9205/// routine will emit diagnostics if there is an error. 9206FunctionDecl * 9207Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, 9208 QualType TargetType, 9209 bool Complain, 9210 DeclAccessPair &FoundResult, 9211 bool *pHadMultipleCandidates) { 9212 assert(AddressOfExpr->getType() == Context.OverloadTy); 9213 9214 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, 9215 Complain); 9216 int NumMatches = Resolver.getNumMatches(); 9217 FunctionDecl* Fn = 0; 9218 if (NumMatches == 0 && Complain) { 9219 if (Resolver.IsInvalidFormOfPointerToMemberFunction()) 9220 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); 9221 else 9222 Resolver.ComplainNoMatchesFound(); 9223 } 9224 else if (NumMatches > 1 && Complain) 9225 Resolver.ComplainMultipleMatchesFound(); 9226 else if (NumMatches == 1) { 9227 Fn = Resolver.getMatchingFunctionDecl(); 9228 assert(Fn); 9229 FoundResult = *Resolver.getMatchingFunctionAccessPair(); 9230 if (Complain) 9231 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); 9232 } 9233 9234 if (pHadMultipleCandidates) 9235 *pHadMultipleCandidates = Resolver.hadMultipleCandidates(); 9236 return Fn; 9237} 9238 9239/// \brief Given an expression that refers to an overloaded function, try to 9240/// resolve that overloaded function expression down to a single function. 9241/// 9242/// This routine can only resolve template-ids that refer to a single function 9243/// template, where that template-id refers to a single template whose template 9244/// arguments are either provided by the template-id or have defaults, 9245/// as described in C++0x [temp.arg.explicit]p3. 9246FunctionDecl * 9247Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl, 9248 bool Complain, 9249 DeclAccessPair *FoundResult) { 9250 // C++ [over.over]p1: 9251 // [...] [Note: any redundant set of parentheses surrounding the 9252 // overloaded function name is ignored (5.1). ] 9253 // C++ [over.over]p1: 9254 // [...] The overloaded function name can be preceded by the & 9255 // operator. 9256 9257 // If we didn't actually find any template-ids, we're done. 9258 if (!ovl->hasExplicitTemplateArgs()) 9259 return 0; 9260 9261 TemplateArgumentListInfo ExplicitTemplateArgs; 9262 ovl->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 9263 9264 // Look through all of the overloaded functions, searching for one 9265 // whose type matches exactly. 9266 FunctionDecl *Matched = 0; 9267 for (UnresolvedSetIterator I = ovl->decls_begin(), 9268 E = ovl->decls_end(); I != E; ++I) { 9269 // C++0x [temp.arg.explicit]p3: 9270 // [...] In contexts where deduction is done and fails, or in contexts 9271 // where deduction is not done, if a template argument list is 9272 // specified and it, along with any default template arguments, 9273 // identifies a single function template specialization, then the 9274 // template-id is an lvalue for the function template specialization. 9275 FunctionTemplateDecl *FunctionTemplate 9276 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 9277 9278 // C++ [over.over]p2: 9279 // If the name is a function template, template argument deduction is 9280 // done (14.8.2.2), and if the argument deduction succeeds, the 9281 // resulting template argument list is used to generate a single 9282 // function template specialization, which is added to the set of 9283 // overloaded functions considered. 9284 FunctionDecl *Specialization = 0; 9285 TemplateDeductionInfo Info(ovl->getNameLoc()); 9286 if (TemplateDeductionResult Result 9287 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 9288 Specialization, Info)) { 9289 // FIXME: make a note of the failed deduction for diagnostics. 9290 (void)Result; 9291 continue; 9292 } 9293 9294 assert(Specialization && "no specialization and no error?"); 9295 9296 // Multiple matches; we can't resolve to a single declaration. 9297 if (Matched) { 9298 if (Complain) { 9299 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous) 9300 << ovl->getName(); 9301 NoteAllOverloadCandidates(ovl); 9302 } 9303 return 0; 9304 } 9305 9306 Matched = Specialization; 9307 if (FoundResult) *FoundResult = I.getPair(); 9308 } 9309 9310 return Matched; 9311} 9312 9313 9314 9315 9316// Resolve and fix an overloaded expression that can be resolved 9317// because it identifies a single function template specialization. 9318// 9319// Last three arguments should only be supplied if Complain = true 9320// 9321// Return true if it was logically possible to so resolve the 9322// expression, regardless of whether or not it succeeded. Always 9323// returns true if 'complain' is set. 9324bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization( 9325 ExprResult &SrcExpr, bool doFunctionPointerConverion, 9326 bool complain, const SourceRange& OpRangeForComplaining, 9327 QualType DestTypeForComplaining, 9328 unsigned DiagIDForComplaining) { 9329 assert(SrcExpr.get()->getType() == Context.OverloadTy); 9330 9331 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get()); 9332 9333 DeclAccessPair found; 9334 ExprResult SingleFunctionExpression; 9335 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization( 9336 ovl.Expression, /*complain*/ false, &found)) { 9337 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getLocStart())) { 9338 SrcExpr = ExprError(); 9339 return true; 9340 } 9341 9342 // It is only correct to resolve to an instance method if we're 9343 // resolving a form that's permitted to be a pointer to member. 9344 // Otherwise we'll end up making a bound member expression, which 9345 // is illegal in all the contexts we resolve like this. 9346 if (!ovl.HasFormOfMemberPointer && 9347 isa<CXXMethodDecl>(fn) && 9348 cast<CXXMethodDecl>(fn)->isInstance()) { 9349 if (!complain) return false; 9350 9351 Diag(ovl.Expression->getExprLoc(), 9352 diag::err_bound_member_function) 9353 << 0 << ovl.Expression->getSourceRange(); 9354 9355 // TODO: I believe we only end up here if there's a mix of 9356 // static and non-static candidates (otherwise the expression 9357 // would have 'bound member' type, not 'overload' type). 9358 // Ideally we would note which candidate was chosen and why 9359 // the static candidates were rejected. 9360 SrcExpr = ExprError(); 9361 return true; 9362 } 9363 9364 // Fix the expression to refer to 'fn'. 9365 SingleFunctionExpression = 9366 Owned(FixOverloadedFunctionReference(SrcExpr.take(), found, fn)); 9367 9368 // If desired, do function-to-pointer decay. 9369 if (doFunctionPointerConverion) { 9370 SingleFunctionExpression = 9371 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.take()); 9372 if (SingleFunctionExpression.isInvalid()) { 9373 SrcExpr = ExprError(); 9374 return true; 9375 } 9376 } 9377 } 9378 9379 if (!SingleFunctionExpression.isUsable()) { 9380 if (complain) { 9381 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) 9382 << ovl.Expression->getName() 9383 << DestTypeForComplaining 9384 << OpRangeForComplaining 9385 << ovl.Expression->getQualifierLoc().getSourceRange(); 9386 NoteAllOverloadCandidates(SrcExpr.get()); 9387 9388 SrcExpr = ExprError(); 9389 return true; 9390 } 9391 9392 return false; 9393 } 9394 9395 SrcExpr = SingleFunctionExpression; 9396 return true; 9397} 9398 9399/// \brief Add a single candidate to the overload set. 9400static void AddOverloadedCallCandidate(Sema &S, 9401 DeclAccessPair FoundDecl, 9402 TemplateArgumentListInfo *ExplicitTemplateArgs, 9403 llvm::ArrayRef<Expr *> Args, 9404 OverloadCandidateSet &CandidateSet, 9405 bool PartialOverloading, 9406 bool KnownValid) { 9407 NamedDecl *Callee = FoundDecl.getDecl(); 9408 if (isa<UsingShadowDecl>(Callee)) 9409 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 9410 9411 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 9412 if (ExplicitTemplateArgs) { 9413 assert(!KnownValid && "Explicit template arguments?"); 9414 return; 9415 } 9416 S.AddOverloadCandidate(Func, FoundDecl, Args, CandidateSet, false, 9417 PartialOverloading); 9418 return; 9419 } 9420 9421 if (FunctionTemplateDecl *FuncTemplate 9422 = dyn_cast<FunctionTemplateDecl>(Callee)) { 9423 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 9424 ExplicitTemplateArgs, Args, CandidateSet); 9425 return; 9426 } 9427 9428 assert(!KnownValid && "unhandled case in overloaded call candidate"); 9429} 9430 9431/// \brief Add the overload candidates named by callee and/or found by argument 9432/// dependent lookup to the given overload set. 9433void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 9434 llvm::ArrayRef<Expr *> Args, 9435 OverloadCandidateSet &CandidateSet, 9436 bool PartialOverloading) { 9437 9438#ifndef NDEBUG 9439 // Verify that ArgumentDependentLookup is consistent with the rules 9440 // in C++0x [basic.lookup.argdep]p3: 9441 // 9442 // Let X be the lookup set produced by unqualified lookup (3.4.1) 9443 // and let Y be the lookup set produced by argument dependent 9444 // lookup (defined as follows). If X contains 9445 // 9446 // -- a declaration of a class member, or 9447 // 9448 // -- a block-scope function declaration that is not a 9449 // using-declaration, or 9450 // 9451 // -- a declaration that is neither a function or a function 9452 // template 9453 // 9454 // then Y is empty. 9455 9456 if (ULE->requiresADL()) { 9457 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 9458 E = ULE->decls_end(); I != E; ++I) { 9459 assert(!(*I)->getDeclContext()->isRecord()); 9460 assert(isa<UsingShadowDecl>(*I) || 9461 !(*I)->getDeclContext()->isFunctionOrMethod()); 9462 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 9463 } 9464 } 9465#endif 9466 9467 // It would be nice to avoid this copy. 9468 TemplateArgumentListInfo TABuffer; 9469 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 9470 if (ULE->hasExplicitTemplateArgs()) { 9471 ULE->copyTemplateArgumentsInto(TABuffer); 9472 ExplicitTemplateArgs = &TABuffer; 9473 } 9474 9475 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 9476 E = ULE->decls_end(); I != E; ++I) 9477 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, Args, 9478 CandidateSet, PartialOverloading, 9479 /*KnownValid*/ true); 9480 9481 if (ULE->requiresADL()) 9482 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 9483 ULE->getExprLoc(), 9484 Args, ExplicitTemplateArgs, 9485 CandidateSet, PartialOverloading); 9486} 9487 9488/// Attempt to recover from an ill-formed use of a non-dependent name in a 9489/// template, where the non-dependent name was declared after the template 9490/// was defined. This is common in code written for a compilers which do not 9491/// correctly implement two-stage name lookup. 9492/// 9493/// Returns true if a viable candidate was found and a diagnostic was issued. 9494static bool 9495DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc, 9496 const CXXScopeSpec &SS, LookupResult &R, 9497 TemplateArgumentListInfo *ExplicitTemplateArgs, 9498 llvm::ArrayRef<Expr *> Args) { 9499 if (SemaRef.ActiveTemplateInstantiations.empty() || !SS.isEmpty()) 9500 return false; 9501 9502 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) { 9503 if (DC->isTransparentContext()) 9504 continue; 9505 9506 SemaRef.LookupQualifiedName(R, DC); 9507 9508 if (!R.empty()) { 9509 R.suppressDiagnostics(); 9510 9511 if (isa<CXXRecordDecl>(DC)) { 9512 // Don't diagnose names we find in classes; we get much better 9513 // diagnostics for these from DiagnoseEmptyLookup. 9514 R.clear(); 9515 return false; 9516 } 9517 9518 OverloadCandidateSet Candidates(FnLoc); 9519 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 9520 AddOverloadedCallCandidate(SemaRef, I.getPair(), 9521 ExplicitTemplateArgs, Args, 9522 Candidates, false, /*KnownValid*/ false); 9523 9524 OverloadCandidateSet::iterator Best; 9525 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) { 9526 // No viable functions. Don't bother the user with notes for functions 9527 // which don't work and shouldn't be found anyway. 9528 R.clear(); 9529 return false; 9530 } 9531 9532 // Find the namespaces where ADL would have looked, and suggest 9533 // declaring the function there instead. 9534 Sema::AssociatedNamespaceSet AssociatedNamespaces; 9535 Sema::AssociatedClassSet AssociatedClasses; 9536 SemaRef.FindAssociatedClassesAndNamespaces(FnLoc, Args, 9537 AssociatedNamespaces, 9538 AssociatedClasses); 9539 // Never suggest declaring a function within namespace 'std'. 9540 Sema::AssociatedNamespaceSet SuggestedNamespaces; 9541 if (DeclContext *Std = SemaRef.getStdNamespace()) { 9542 for (Sema::AssociatedNamespaceSet::iterator 9543 it = AssociatedNamespaces.begin(), 9544 end = AssociatedNamespaces.end(); it != end; ++it) { 9545 if (!Std->Encloses(*it)) 9546 SuggestedNamespaces.insert(*it); 9547 } 9548 } else { 9549 // Lacking the 'std::' namespace, use all of the associated namespaces. 9550 SuggestedNamespaces = AssociatedNamespaces; 9551 } 9552 9553 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup) 9554 << R.getLookupName(); 9555 if (SuggestedNamespaces.empty()) { 9556 SemaRef.Diag(Best->Function->getLocation(), 9557 diag::note_not_found_by_two_phase_lookup) 9558 << R.getLookupName() << 0; 9559 } else if (SuggestedNamespaces.size() == 1) { 9560 SemaRef.Diag(Best->Function->getLocation(), 9561 diag::note_not_found_by_two_phase_lookup) 9562 << R.getLookupName() << 1 << *SuggestedNamespaces.begin(); 9563 } else { 9564 // FIXME: It would be useful to list the associated namespaces here, 9565 // but the diagnostics infrastructure doesn't provide a way to produce 9566 // a localized representation of a list of items. 9567 SemaRef.Diag(Best->Function->getLocation(), 9568 diag::note_not_found_by_two_phase_lookup) 9569 << R.getLookupName() << 2; 9570 } 9571 9572 // Try to recover by calling this function. 9573 return true; 9574 } 9575 9576 R.clear(); 9577 } 9578 9579 return false; 9580} 9581 9582/// Attempt to recover from ill-formed use of a non-dependent operator in a 9583/// template, where the non-dependent operator was declared after the template 9584/// was defined. 9585/// 9586/// Returns true if a viable candidate was found and a diagnostic was issued. 9587static bool 9588DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op, 9589 SourceLocation OpLoc, 9590 llvm::ArrayRef<Expr *> Args) { 9591 DeclarationName OpName = 9592 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op); 9593 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName); 9594 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R, 9595 /*ExplicitTemplateArgs=*/0, Args); 9596} 9597 9598namespace { 9599// Callback to limit the allowed keywords and to only accept typo corrections 9600// that are keywords or whose decls refer to functions (or template functions) 9601// that accept the given number of arguments. 9602class RecoveryCallCCC : public CorrectionCandidateCallback { 9603 public: 9604 RecoveryCallCCC(Sema &SemaRef, unsigned NumArgs, bool HasExplicitTemplateArgs) 9605 : NumArgs(NumArgs), HasExplicitTemplateArgs(HasExplicitTemplateArgs) { 9606 WantTypeSpecifiers = SemaRef.getLangOpts().CPlusPlus; 9607 WantRemainingKeywords = false; 9608 } 9609 9610 virtual bool ValidateCandidate(const TypoCorrection &candidate) { 9611 if (!candidate.getCorrectionDecl()) 9612 return candidate.isKeyword(); 9613 9614 for (TypoCorrection::const_decl_iterator DI = candidate.begin(), 9615 DIEnd = candidate.end(); DI != DIEnd; ++DI) { 9616 FunctionDecl *FD = 0; 9617 NamedDecl *ND = (*DI)->getUnderlyingDecl(); 9618 if (FunctionTemplateDecl *FTD = dyn_cast<FunctionTemplateDecl>(ND)) 9619 FD = FTD->getTemplatedDecl(); 9620 if (!HasExplicitTemplateArgs && !FD) { 9621 if (!(FD = dyn_cast<FunctionDecl>(ND)) && isa<ValueDecl>(ND)) { 9622 // If the Decl is neither a function nor a template function, 9623 // determine if it is a pointer or reference to a function. If so, 9624 // check against the number of arguments expected for the pointee. 9625 QualType ValType = cast<ValueDecl>(ND)->getType(); 9626 if (ValType->isAnyPointerType() || ValType->isReferenceType()) 9627 ValType = ValType->getPointeeType(); 9628 if (const FunctionProtoType *FPT = ValType->getAs<FunctionProtoType>()) 9629 if (FPT->getNumArgs() == NumArgs) 9630 return true; 9631 } 9632 } 9633 if (FD && FD->getNumParams() >= NumArgs && 9634 FD->getMinRequiredArguments() <= NumArgs) 9635 return true; 9636 } 9637 return false; 9638 } 9639 9640 private: 9641 unsigned NumArgs; 9642 bool HasExplicitTemplateArgs; 9643}; 9644 9645// Callback that effectively disabled typo correction 9646class NoTypoCorrectionCCC : public CorrectionCandidateCallback { 9647 public: 9648 NoTypoCorrectionCCC() { 9649 WantTypeSpecifiers = false; 9650 WantExpressionKeywords = false; 9651 WantCXXNamedCasts = false; 9652 WantRemainingKeywords = false; 9653 } 9654 9655 virtual bool ValidateCandidate(const TypoCorrection &candidate) { 9656 return false; 9657 } 9658}; 9659 9660class BuildRecoveryCallExprRAII { 9661 Sema &SemaRef; 9662public: 9663 BuildRecoveryCallExprRAII(Sema &S) : SemaRef(S) { 9664 assert(SemaRef.IsBuildingRecoveryCallExpr == false); 9665 SemaRef.IsBuildingRecoveryCallExpr = true; 9666 } 9667 9668 ~BuildRecoveryCallExprRAII() { 9669 SemaRef.IsBuildingRecoveryCallExpr = false; 9670 } 9671}; 9672 9673} 9674 9675/// Attempts to recover from a call where no functions were found. 9676/// 9677/// Returns true if new candidates were found. 9678static ExprResult 9679BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 9680 UnresolvedLookupExpr *ULE, 9681 SourceLocation LParenLoc, 9682 llvm::MutableArrayRef<Expr *> Args, 9683 SourceLocation RParenLoc, 9684 bool EmptyLookup, bool AllowTypoCorrection) { 9685 // Do not try to recover if it is already building a recovery call. 9686 // This stops infinite loops for template instantiations like 9687 // 9688 // template <typename T> auto foo(T t) -> decltype(foo(t)) {} 9689 // template <typename T> auto foo(T t) -> decltype(foo(&t)) {} 9690 // 9691 if (SemaRef.IsBuildingRecoveryCallExpr) 9692 return ExprError(); 9693 BuildRecoveryCallExprRAII RCE(SemaRef); 9694 9695 CXXScopeSpec SS; 9696 SS.Adopt(ULE->getQualifierLoc()); 9697 SourceLocation TemplateKWLoc = ULE->getTemplateKeywordLoc(); 9698 9699 TemplateArgumentListInfo TABuffer; 9700 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 9701 if (ULE->hasExplicitTemplateArgs()) { 9702 ULE->copyTemplateArgumentsInto(TABuffer); 9703 ExplicitTemplateArgs = &TABuffer; 9704 } 9705 9706 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 9707 Sema::LookupOrdinaryName); 9708 RecoveryCallCCC Validator(SemaRef, Args.size(), ExplicitTemplateArgs != 0); 9709 NoTypoCorrectionCCC RejectAll; 9710 CorrectionCandidateCallback *CCC = AllowTypoCorrection ? 9711 (CorrectionCandidateCallback*)&Validator : 9712 (CorrectionCandidateCallback*)&RejectAll; 9713 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R, 9714 ExplicitTemplateArgs, Args) && 9715 (!EmptyLookup || 9716 SemaRef.DiagnoseEmptyLookup(S, SS, R, *CCC, 9717 ExplicitTemplateArgs, Args))) 9718 return ExprError(); 9719 9720 assert(!R.empty() && "lookup results empty despite recovery"); 9721 9722 // Build an implicit member call if appropriate. Just drop the 9723 // casts and such from the call, we don't really care. 9724 ExprResult NewFn = ExprError(); 9725 if ((*R.begin())->isCXXClassMember()) 9726 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, TemplateKWLoc, 9727 R, ExplicitTemplateArgs); 9728 else if (ExplicitTemplateArgs || TemplateKWLoc.isValid()) 9729 NewFn = SemaRef.BuildTemplateIdExpr(SS, TemplateKWLoc, R, false, 9730 ExplicitTemplateArgs); 9731 else 9732 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 9733 9734 if (NewFn.isInvalid()) 9735 return ExprError(); 9736 9737 // This shouldn't cause an infinite loop because we're giving it 9738 // an expression with viable lookup results, which should never 9739 // end up here. 9740 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 9741 MultiExprArg(Args.data(), Args.size()), 9742 RParenLoc); 9743} 9744 9745/// \brief Constructs and populates an OverloadedCandidateSet from 9746/// the given function. 9747/// \returns true when an the ExprResult output parameter has been set. 9748bool Sema::buildOverloadedCallSet(Scope *S, Expr *Fn, 9749 UnresolvedLookupExpr *ULE, 9750 Expr **Args, unsigned NumArgs, 9751 SourceLocation RParenLoc, 9752 OverloadCandidateSet *CandidateSet, 9753 ExprResult *Result) { 9754#ifndef NDEBUG 9755 if (ULE->requiresADL()) { 9756 // To do ADL, we must have found an unqualified name. 9757 assert(!ULE->getQualifier() && "qualified name with ADL"); 9758 9759 // We don't perform ADL for implicit declarations of builtins. 9760 // Verify that this was correctly set up. 9761 FunctionDecl *F; 9762 if (ULE->decls_begin() + 1 == ULE->decls_end() && 9763 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 9764 F->getBuiltinID() && F->isImplicit()) 9765 llvm_unreachable("performing ADL for builtin"); 9766 9767 // We don't perform ADL in C. 9768 assert(getLangOpts().CPlusPlus && "ADL enabled in C"); 9769 } 9770#endif 9771 9772 UnbridgedCastsSet UnbridgedCasts; 9773 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) { 9774 *Result = ExprError(); 9775 return true; 9776 } 9777 9778 // Add the functions denoted by the callee to the set of candidate 9779 // functions, including those from argument-dependent lookup. 9780 AddOverloadedCallCandidates(ULE, llvm::makeArrayRef(Args, NumArgs), 9781 *CandidateSet); 9782 9783 // If we found nothing, try to recover. 9784 // BuildRecoveryCallExpr diagnoses the error itself, so we just bail 9785 // out if it fails. 9786 if (CandidateSet->empty()) { 9787 // In Microsoft mode, if we are inside a template class member function then 9788 // create a type dependent CallExpr. The goal is to postpone name lookup 9789 // to instantiation time to be able to search into type dependent base 9790 // classes. 9791 if (getLangOpts().MicrosoftMode && CurContext->isDependentContext() && 9792 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) { 9793 CallExpr *CE = new (Context) CallExpr(Context, Fn, 9794 llvm::makeArrayRef(Args, NumArgs), 9795 Context.DependentTy, VK_RValue, 9796 RParenLoc); 9797 CE->setTypeDependent(true); 9798 *Result = Owned(CE); 9799 return true; 9800 } 9801 return false; 9802 } 9803 9804 UnbridgedCasts.restore(); 9805 return false; 9806} 9807 9808/// FinishOverloadedCallExpr - given an OverloadCandidateSet, builds and returns 9809/// the completed call expression. If overload resolution fails, emits 9810/// diagnostics and returns ExprError() 9811static ExprResult FinishOverloadedCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 9812 UnresolvedLookupExpr *ULE, 9813 SourceLocation LParenLoc, 9814 Expr **Args, unsigned NumArgs, 9815 SourceLocation RParenLoc, 9816 Expr *ExecConfig, 9817 OverloadCandidateSet *CandidateSet, 9818 OverloadCandidateSet::iterator *Best, 9819 OverloadingResult OverloadResult, 9820 bool AllowTypoCorrection) { 9821 if (CandidateSet->empty()) 9822 return BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, 9823 llvm::MutableArrayRef<Expr *>(Args, NumArgs), 9824 RParenLoc, /*EmptyLookup=*/true, 9825 AllowTypoCorrection); 9826 9827 switch (OverloadResult) { 9828 case OR_Success: { 9829 FunctionDecl *FDecl = (*Best)->Function; 9830 SemaRef.MarkFunctionReferenced(Fn->getExprLoc(), FDecl); 9831 SemaRef.CheckUnresolvedLookupAccess(ULE, (*Best)->FoundDecl); 9832 SemaRef.DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()); 9833 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl); 9834 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, 9835 RParenLoc, ExecConfig); 9836 } 9837 9838 case OR_No_Viable_Function: { 9839 // Try to recover by looking for viable functions which the user might 9840 // have meant to call. 9841 ExprResult Recovery = BuildRecoveryCallExpr(SemaRef, S, Fn, ULE, LParenLoc, 9842 llvm::MutableArrayRef<Expr *>(Args, NumArgs), 9843 RParenLoc, 9844 /*EmptyLookup=*/false, 9845 AllowTypoCorrection); 9846 if (!Recovery.isInvalid()) 9847 return Recovery; 9848 9849 SemaRef.Diag(Fn->getLocStart(), 9850 diag::err_ovl_no_viable_function_in_call) 9851 << ULE->getName() << Fn->getSourceRange(); 9852 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, 9853 llvm::makeArrayRef(Args, NumArgs)); 9854 break; 9855 } 9856 9857 case OR_Ambiguous: 9858 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_ambiguous_call) 9859 << ULE->getName() << Fn->getSourceRange(); 9860 CandidateSet->NoteCandidates(SemaRef, OCD_ViableCandidates, 9861 llvm::makeArrayRef(Args, NumArgs)); 9862 break; 9863 9864 case OR_Deleted: { 9865 SemaRef.Diag(Fn->getLocStart(), diag::err_ovl_deleted_call) 9866 << (*Best)->Function->isDeleted() 9867 << ULE->getName() 9868 << SemaRef.getDeletedOrUnavailableSuffix((*Best)->Function) 9869 << Fn->getSourceRange(); 9870 CandidateSet->NoteCandidates(SemaRef, OCD_AllCandidates, 9871 llvm::makeArrayRef(Args, NumArgs)); 9872 9873 // We emitted an error for the unvailable/deleted function call but keep 9874 // the call in the AST. 9875 FunctionDecl *FDecl = (*Best)->Function; 9876 Fn = SemaRef.FixOverloadedFunctionReference(Fn, (*Best)->FoundDecl, FDecl); 9877 return SemaRef.BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, 9878 RParenLoc, ExecConfig); 9879 } 9880 } 9881 9882 // Overload resolution failed. 9883 return ExprError(); 9884} 9885 9886/// BuildOverloadedCallExpr - Given the call expression that calls Fn 9887/// (which eventually refers to the declaration Func) and the call 9888/// arguments Args/NumArgs, attempt to resolve the function call down 9889/// to a specific function. If overload resolution succeeds, returns 9890/// the call expression produced by overload resolution. 9891/// Otherwise, emits diagnostics and returns ExprError. 9892ExprResult Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, 9893 UnresolvedLookupExpr *ULE, 9894 SourceLocation LParenLoc, 9895 Expr **Args, unsigned NumArgs, 9896 SourceLocation RParenLoc, 9897 Expr *ExecConfig, 9898 bool AllowTypoCorrection) { 9899 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 9900 ExprResult result; 9901 9902 if (buildOverloadedCallSet(S, Fn, ULE, Args, NumArgs, LParenLoc, 9903 &CandidateSet, &result)) 9904 return result; 9905 9906 OverloadCandidateSet::iterator Best; 9907 OverloadingResult OverloadResult = 9908 CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best); 9909 9910 return FinishOverloadedCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 9911 RParenLoc, ExecConfig, &CandidateSet, 9912 &Best, OverloadResult, 9913 AllowTypoCorrection); 9914} 9915 9916static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 9917 return Functions.size() > 1 || 9918 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 9919} 9920 9921/// \brief Create a unary operation that may resolve to an overloaded 9922/// operator. 9923/// 9924/// \param OpLoc The location of the operator itself (e.g., '*'). 9925/// 9926/// \param OpcIn The UnaryOperator::Opcode that describes this 9927/// operator. 9928/// 9929/// \param Fns The set of non-member functions that will be 9930/// considered by overload resolution. The caller needs to build this 9931/// set based on the context using, e.g., 9932/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 9933/// set should not contain any member functions; those will be added 9934/// by CreateOverloadedUnaryOp(). 9935/// 9936/// \param Input The input argument. 9937ExprResult 9938Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 9939 const UnresolvedSetImpl &Fns, 9940 Expr *Input) { 9941 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 9942 9943 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 9944 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 9945 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 9946 // TODO: provide better source location info. 9947 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 9948 9949 if (checkPlaceholderForOverload(*this, Input)) 9950 return ExprError(); 9951 9952 Expr *Args[2] = { Input, 0 }; 9953 unsigned NumArgs = 1; 9954 9955 // For post-increment and post-decrement, add the implicit '0' as 9956 // the second argument, so that we know this is a post-increment or 9957 // post-decrement. 9958 if (Opc == UO_PostInc || Opc == UO_PostDec) { 9959 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 9960 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 9961 SourceLocation()); 9962 NumArgs = 2; 9963 } 9964 9965 if (Input->isTypeDependent()) { 9966 if (Fns.empty()) 9967 return Owned(new (Context) UnaryOperator(Input, 9968 Opc, 9969 Context.DependentTy, 9970 VK_RValue, OK_Ordinary, 9971 OpLoc)); 9972 9973 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 9974 UnresolvedLookupExpr *Fn 9975 = UnresolvedLookupExpr::Create(Context, NamingClass, 9976 NestedNameSpecifierLoc(), OpNameInfo, 9977 /*ADL*/ true, IsOverloaded(Fns), 9978 Fns.begin(), Fns.end()); 9979 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 9980 llvm::makeArrayRef(Args, NumArgs), 9981 Context.DependentTy, 9982 VK_RValue, 9983 OpLoc, false)); 9984 } 9985 9986 // Build an empty overload set. 9987 OverloadCandidateSet CandidateSet(OpLoc); 9988 9989 // Add the candidates from the given function set. 9990 AddFunctionCandidates(Fns, llvm::makeArrayRef(Args, NumArgs), CandidateSet, 9991 false); 9992 9993 // Add operator candidates that are member functions. 9994 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 9995 9996 // Add candidates from ADL. 9997 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 9998 OpLoc, llvm::makeArrayRef(Args, NumArgs), 9999 /*ExplicitTemplateArgs*/ 0, 10000 CandidateSet); 10001 10002 // Add builtin operator candidates. 10003 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 10004 10005 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10006 10007 // Perform overload resolution. 10008 OverloadCandidateSet::iterator Best; 10009 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 10010 case OR_Success: { 10011 // We found a built-in operator or an overloaded operator. 10012 FunctionDecl *FnDecl = Best->Function; 10013 10014 if (FnDecl) { 10015 // We matched an overloaded operator. Build a call to that 10016 // operator. 10017 10018 MarkFunctionReferenced(OpLoc, FnDecl); 10019 10020 // Convert the arguments. 10021 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 10022 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 10023 10024 ExprResult InputRes = 10025 PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 10026 Best->FoundDecl, Method); 10027 if (InputRes.isInvalid()) 10028 return ExprError(); 10029 Input = InputRes.take(); 10030 } else { 10031 // Convert the arguments. 10032 ExprResult InputInit 10033 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 10034 Context, 10035 FnDecl->getParamDecl(0)), 10036 SourceLocation(), 10037 Input); 10038 if (InputInit.isInvalid()) 10039 return ExprError(); 10040 Input = InputInit.take(); 10041 } 10042 10043 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 10044 10045 // Determine the result type. 10046 QualType ResultTy = FnDecl->getResultType(); 10047 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10048 ResultTy = ResultTy.getNonLValueExprType(Context); 10049 10050 // Build the actual expression node. 10051 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 10052 HadMultipleCandidates, OpLoc); 10053 if (FnExpr.isInvalid()) 10054 return ExprError(); 10055 10056 Args[0] = Input; 10057 CallExpr *TheCall = 10058 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 10059 llvm::makeArrayRef(Args, NumArgs), 10060 ResultTy, VK, OpLoc, false); 10061 10062 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 10063 FnDecl)) 10064 return ExprError(); 10065 10066 return MaybeBindToTemporary(TheCall); 10067 } else { 10068 // We matched a built-in operator. Convert the arguments, then 10069 // break out so that we will build the appropriate built-in 10070 // operator node. 10071 ExprResult InputRes = 10072 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 10073 Best->Conversions[0], AA_Passing); 10074 if (InputRes.isInvalid()) 10075 return ExprError(); 10076 Input = InputRes.take(); 10077 break; 10078 } 10079 } 10080 10081 case OR_No_Viable_Function: 10082 // This is an erroneous use of an operator which can be overloaded by 10083 // a non-member function. Check for non-member operators which were 10084 // defined too late to be candidates. 10085 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, 10086 llvm::makeArrayRef(Args, NumArgs))) 10087 // FIXME: Recover by calling the found function. 10088 return ExprError(); 10089 10090 // No viable function; fall through to handling this as a 10091 // built-in operator, which will produce an error message for us. 10092 break; 10093 10094 case OR_Ambiguous: 10095 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 10096 << UnaryOperator::getOpcodeStr(Opc) 10097 << Input->getType() 10098 << Input->getSourceRange(); 10099 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 10100 llvm::makeArrayRef(Args, NumArgs), 10101 UnaryOperator::getOpcodeStr(Opc), OpLoc); 10102 return ExprError(); 10103 10104 case OR_Deleted: 10105 Diag(OpLoc, diag::err_ovl_deleted_oper) 10106 << Best->Function->isDeleted() 10107 << UnaryOperator::getOpcodeStr(Opc) 10108 << getDeletedOrUnavailableSuffix(Best->Function) 10109 << Input->getSourceRange(); 10110 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10111 llvm::makeArrayRef(Args, NumArgs), 10112 UnaryOperator::getOpcodeStr(Opc), OpLoc); 10113 return ExprError(); 10114 } 10115 10116 // Either we found no viable overloaded operator or we matched a 10117 // built-in operator. In either case, fall through to trying to 10118 // build a built-in operation. 10119 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 10120} 10121 10122/// \brief Create a binary operation that may resolve to an overloaded 10123/// operator. 10124/// 10125/// \param OpLoc The location of the operator itself (e.g., '+'). 10126/// 10127/// \param OpcIn The BinaryOperator::Opcode that describes this 10128/// operator. 10129/// 10130/// \param Fns The set of non-member functions that will be 10131/// considered by overload resolution. The caller needs to build this 10132/// set based on the context using, e.g., 10133/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 10134/// set should not contain any member functions; those will be added 10135/// by CreateOverloadedBinOp(). 10136/// 10137/// \param LHS Left-hand argument. 10138/// \param RHS Right-hand argument. 10139ExprResult 10140Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 10141 unsigned OpcIn, 10142 const UnresolvedSetImpl &Fns, 10143 Expr *LHS, Expr *RHS) { 10144 Expr *Args[2] = { LHS, RHS }; 10145 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 10146 10147 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 10148 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 10149 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 10150 10151 // If either side is type-dependent, create an appropriate dependent 10152 // expression. 10153 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 10154 if (Fns.empty()) { 10155 // If there are no functions to store, just build a dependent 10156 // BinaryOperator or CompoundAssignment. 10157 if (Opc <= BO_Assign || Opc > BO_OrAssign) 10158 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 10159 Context.DependentTy, 10160 VK_RValue, OK_Ordinary, 10161 OpLoc, 10162 FPFeatures.fp_contract)); 10163 10164 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 10165 Context.DependentTy, 10166 VK_LValue, 10167 OK_Ordinary, 10168 Context.DependentTy, 10169 Context.DependentTy, 10170 OpLoc, 10171 FPFeatures.fp_contract)); 10172 } 10173 10174 // FIXME: save results of ADL from here? 10175 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10176 // TODO: provide better source location info in DNLoc component. 10177 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 10178 UnresolvedLookupExpr *Fn 10179 = UnresolvedLookupExpr::Create(Context, NamingClass, 10180 NestedNameSpecifierLoc(), OpNameInfo, 10181 /*ADL*/ true, IsOverloaded(Fns), 10182 Fns.begin(), Fns.end()); 10183 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, Args, 10184 Context.DependentTy, VK_RValue, 10185 OpLoc, FPFeatures.fp_contract)); 10186 } 10187 10188 // Always do placeholder-like conversions on the RHS. 10189 if (checkPlaceholderForOverload(*this, Args[1])) 10190 return ExprError(); 10191 10192 // Do placeholder-like conversion on the LHS; note that we should 10193 // not get here with a PseudoObject LHS. 10194 assert(Args[0]->getObjectKind() != OK_ObjCProperty); 10195 if (checkPlaceholderForOverload(*this, Args[0])) 10196 return ExprError(); 10197 10198 // If this is the assignment operator, we only perform overload resolution 10199 // if the left-hand side is a class or enumeration type. This is actually 10200 // a hack. The standard requires that we do overload resolution between the 10201 // various built-in candidates, but as DR507 points out, this can lead to 10202 // problems. So we do it this way, which pretty much follows what GCC does. 10203 // Note that we go the traditional code path for compound assignment forms. 10204 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 10205 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10206 10207 // If this is the .* operator, which is not overloadable, just 10208 // create a built-in binary operator. 10209 if (Opc == BO_PtrMemD) 10210 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10211 10212 // Build an empty overload set. 10213 OverloadCandidateSet CandidateSet(OpLoc); 10214 10215 // Add the candidates from the given function set. 10216 AddFunctionCandidates(Fns, Args, CandidateSet, false); 10217 10218 // Add operator candidates that are member functions. 10219 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 10220 10221 // Add candidates from ADL. 10222 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 10223 OpLoc, Args, 10224 /*ExplicitTemplateArgs*/ 0, 10225 CandidateSet); 10226 10227 // Add builtin operator candidates. 10228 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 10229 10230 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10231 10232 // Perform overload resolution. 10233 OverloadCandidateSet::iterator Best; 10234 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 10235 case OR_Success: { 10236 // We found a built-in operator or an overloaded operator. 10237 FunctionDecl *FnDecl = Best->Function; 10238 10239 if (FnDecl) { 10240 // We matched an overloaded operator. Build a call to that 10241 // operator. 10242 10243 MarkFunctionReferenced(OpLoc, FnDecl); 10244 10245 // Convert the arguments. 10246 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 10247 // Best->Access is only meaningful for class members. 10248 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 10249 10250 ExprResult Arg1 = 10251 PerformCopyInitialization( 10252 InitializedEntity::InitializeParameter(Context, 10253 FnDecl->getParamDecl(0)), 10254 SourceLocation(), Owned(Args[1])); 10255 if (Arg1.isInvalid()) 10256 return ExprError(); 10257 10258 ExprResult Arg0 = 10259 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 10260 Best->FoundDecl, Method); 10261 if (Arg0.isInvalid()) 10262 return ExprError(); 10263 Args[0] = Arg0.takeAs<Expr>(); 10264 Args[1] = RHS = Arg1.takeAs<Expr>(); 10265 } else { 10266 // Convert the arguments. 10267 ExprResult Arg0 = PerformCopyInitialization( 10268 InitializedEntity::InitializeParameter(Context, 10269 FnDecl->getParamDecl(0)), 10270 SourceLocation(), Owned(Args[0])); 10271 if (Arg0.isInvalid()) 10272 return ExprError(); 10273 10274 ExprResult Arg1 = 10275 PerformCopyInitialization( 10276 InitializedEntity::InitializeParameter(Context, 10277 FnDecl->getParamDecl(1)), 10278 SourceLocation(), Owned(Args[1])); 10279 if (Arg1.isInvalid()) 10280 return ExprError(); 10281 Args[0] = LHS = Arg0.takeAs<Expr>(); 10282 Args[1] = RHS = Arg1.takeAs<Expr>(); 10283 } 10284 10285 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 10286 10287 // Determine the result type. 10288 QualType ResultTy = FnDecl->getResultType(); 10289 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10290 ResultTy = ResultTy.getNonLValueExprType(Context); 10291 10292 // Build the actual expression node. 10293 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 10294 HadMultipleCandidates, OpLoc); 10295 if (FnExpr.isInvalid()) 10296 return ExprError(); 10297 10298 CXXOperatorCallExpr *TheCall = 10299 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 10300 Args, ResultTy, VK, OpLoc, 10301 FPFeatures.fp_contract); 10302 10303 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 10304 FnDecl)) 10305 return ExprError(); 10306 10307 return MaybeBindToTemporary(TheCall); 10308 } else { 10309 // We matched a built-in operator. Convert the arguments, then 10310 // break out so that we will build the appropriate built-in 10311 // operator node. 10312 ExprResult ArgsRes0 = 10313 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 10314 Best->Conversions[0], AA_Passing); 10315 if (ArgsRes0.isInvalid()) 10316 return ExprError(); 10317 Args[0] = ArgsRes0.take(); 10318 10319 ExprResult ArgsRes1 = 10320 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 10321 Best->Conversions[1], AA_Passing); 10322 if (ArgsRes1.isInvalid()) 10323 return ExprError(); 10324 Args[1] = ArgsRes1.take(); 10325 break; 10326 } 10327 } 10328 10329 case OR_No_Viable_Function: { 10330 // C++ [over.match.oper]p9: 10331 // If the operator is the operator , [...] and there are no 10332 // viable functions, then the operator is assumed to be the 10333 // built-in operator and interpreted according to clause 5. 10334 if (Opc == BO_Comma) 10335 break; 10336 10337 // For class as left operand for assignment or compound assigment 10338 // operator do not fall through to handling in built-in, but report that 10339 // no overloaded assignment operator found 10340 ExprResult Result = ExprError(); 10341 if (Args[0]->getType()->isRecordType() && 10342 Opc >= BO_Assign && Opc <= BO_OrAssign) { 10343 Diag(OpLoc, diag::err_ovl_no_viable_oper) 10344 << BinaryOperator::getOpcodeStr(Opc) 10345 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10346 } else { 10347 // This is an erroneous use of an operator which can be overloaded by 10348 // a non-member function. Check for non-member operators which were 10349 // defined too late to be candidates. 10350 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args)) 10351 // FIXME: Recover by calling the found function. 10352 return ExprError(); 10353 10354 // No viable function; try to create a built-in operation, which will 10355 // produce an error. Then, show the non-viable candidates. 10356 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10357 } 10358 assert(Result.isInvalid() && 10359 "C++ binary operator overloading is missing candidates!"); 10360 if (Result.isInvalid()) 10361 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10362 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10363 return Result; 10364 } 10365 10366 case OR_Ambiguous: 10367 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 10368 << BinaryOperator::getOpcodeStr(Opc) 10369 << Args[0]->getType() << Args[1]->getType() 10370 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10371 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 10372 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10373 return ExprError(); 10374 10375 case OR_Deleted: 10376 if (isImplicitlyDeleted(Best->Function)) { 10377 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 10378 Diag(OpLoc, diag::err_ovl_deleted_special_oper) 10379 << getSpecialMember(Method) 10380 << BinaryOperator::getOpcodeStr(Opc) 10381 << getDeletedOrUnavailableSuffix(Best->Function); 10382 10383 if (getSpecialMember(Method) != CXXInvalid) { 10384 // The user probably meant to call this special member. Just 10385 // explain why it's deleted. 10386 NoteDeletedFunction(Method); 10387 return ExprError(); 10388 } 10389 } else { 10390 Diag(OpLoc, diag::err_ovl_deleted_oper) 10391 << Best->Function->isDeleted() 10392 << BinaryOperator::getOpcodeStr(Opc) 10393 << getDeletedOrUnavailableSuffix(Best->Function) 10394 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10395 } 10396 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10397 BinaryOperator::getOpcodeStr(Opc), OpLoc); 10398 return ExprError(); 10399 } 10400 10401 // We matched a built-in operator; build it. 10402 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 10403} 10404 10405ExprResult 10406Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 10407 SourceLocation RLoc, 10408 Expr *Base, Expr *Idx) { 10409 Expr *Args[2] = { Base, Idx }; 10410 DeclarationName OpName = 10411 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 10412 10413 // If either side is type-dependent, create an appropriate dependent 10414 // expression. 10415 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 10416 10417 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 10418 // CHECKME: no 'operator' keyword? 10419 DeclarationNameInfo OpNameInfo(OpName, LLoc); 10420 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 10421 UnresolvedLookupExpr *Fn 10422 = UnresolvedLookupExpr::Create(Context, NamingClass, 10423 NestedNameSpecifierLoc(), OpNameInfo, 10424 /*ADL*/ true, /*Overloaded*/ false, 10425 UnresolvedSetIterator(), 10426 UnresolvedSetIterator()); 10427 // Can't add any actual overloads yet 10428 10429 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 10430 Args, 10431 Context.DependentTy, 10432 VK_RValue, 10433 RLoc, false)); 10434 } 10435 10436 // Handle placeholders on both operands. 10437 if (checkPlaceholderForOverload(*this, Args[0])) 10438 return ExprError(); 10439 if (checkPlaceholderForOverload(*this, Args[1])) 10440 return ExprError(); 10441 10442 // Build an empty overload set. 10443 OverloadCandidateSet CandidateSet(LLoc); 10444 10445 // Subscript can only be overloaded as a member function. 10446 10447 // Add operator candidates that are member functions. 10448 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 10449 10450 // Add builtin operator candidates. 10451 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 10452 10453 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10454 10455 // Perform overload resolution. 10456 OverloadCandidateSet::iterator Best; 10457 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 10458 case OR_Success: { 10459 // We found a built-in operator or an overloaded operator. 10460 FunctionDecl *FnDecl = Best->Function; 10461 10462 if (FnDecl) { 10463 // We matched an overloaded operator. Build a call to that 10464 // operator. 10465 10466 MarkFunctionReferenced(LLoc, FnDecl); 10467 10468 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 10469 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 10470 10471 // Convert the arguments. 10472 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 10473 ExprResult Arg0 = 10474 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 10475 Best->FoundDecl, Method); 10476 if (Arg0.isInvalid()) 10477 return ExprError(); 10478 Args[0] = Arg0.take(); 10479 10480 // Convert the arguments. 10481 ExprResult InputInit 10482 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 10483 Context, 10484 FnDecl->getParamDecl(0)), 10485 SourceLocation(), 10486 Owned(Args[1])); 10487 if (InputInit.isInvalid()) 10488 return ExprError(); 10489 10490 Args[1] = InputInit.takeAs<Expr>(); 10491 10492 // Determine the result type 10493 QualType ResultTy = FnDecl->getResultType(); 10494 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10495 ResultTy = ResultTy.getNonLValueExprType(Context); 10496 10497 // Build the actual expression node. 10498 DeclarationNameInfo OpLocInfo(OpName, LLoc); 10499 OpLocInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 10500 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 10501 HadMultipleCandidates, 10502 OpLocInfo.getLoc(), 10503 OpLocInfo.getInfo()); 10504 if (FnExpr.isInvalid()) 10505 return ExprError(); 10506 10507 CXXOperatorCallExpr *TheCall = 10508 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 10509 FnExpr.take(), Args, 10510 ResultTy, VK, RLoc, 10511 false); 10512 10513 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 10514 FnDecl)) 10515 return ExprError(); 10516 10517 return MaybeBindToTemporary(TheCall); 10518 } else { 10519 // We matched a built-in operator. Convert the arguments, then 10520 // break out so that we will build the appropriate built-in 10521 // operator node. 10522 ExprResult ArgsRes0 = 10523 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 10524 Best->Conversions[0], AA_Passing); 10525 if (ArgsRes0.isInvalid()) 10526 return ExprError(); 10527 Args[0] = ArgsRes0.take(); 10528 10529 ExprResult ArgsRes1 = 10530 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 10531 Best->Conversions[1], AA_Passing); 10532 if (ArgsRes1.isInvalid()) 10533 return ExprError(); 10534 Args[1] = ArgsRes1.take(); 10535 10536 break; 10537 } 10538 } 10539 10540 case OR_No_Viable_Function: { 10541 if (CandidateSet.empty()) 10542 Diag(LLoc, diag::err_ovl_no_oper) 10543 << Args[0]->getType() << /*subscript*/ 0 10544 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10545 else 10546 Diag(LLoc, diag::err_ovl_no_viable_subscript) 10547 << Args[0]->getType() 10548 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10549 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10550 "[]", LLoc); 10551 return ExprError(); 10552 } 10553 10554 case OR_Ambiguous: 10555 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 10556 << "[]" 10557 << Args[0]->getType() << Args[1]->getType() 10558 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10559 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 10560 "[]", LLoc); 10561 return ExprError(); 10562 10563 case OR_Deleted: 10564 Diag(LLoc, diag::err_ovl_deleted_oper) 10565 << Best->Function->isDeleted() << "[]" 10566 << getDeletedOrUnavailableSuffix(Best->Function) 10567 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 10568 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 10569 "[]", LLoc); 10570 return ExprError(); 10571 } 10572 10573 // We matched a built-in operator; build it. 10574 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 10575} 10576 10577/// BuildCallToMemberFunction - Build a call to a member 10578/// function. MemExpr is the expression that refers to the member 10579/// function (and includes the object parameter), Args/NumArgs are the 10580/// arguments to the function call (not including the object 10581/// parameter). The caller needs to validate that the member 10582/// expression refers to a non-static member function or an overloaded 10583/// member function. 10584ExprResult 10585Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 10586 SourceLocation LParenLoc, Expr **Args, 10587 unsigned NumArgs, SourceLocation RParenLoc) { 10588 assert(MemExprE->getType() == Context.BoundMemberTy || 10589 MemExprE->getType() == Context.OverloadTy); 10590 10591 // Dig out the member expression. This holds both the object 10592 // argument and the member function we're referring to. 10593 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 10594 10595 // Determine whether this is a call to a pointer-to-member function. 10596 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) { 10597 assert(op->getType() == Context.BoundMemberTy); 10598 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI); 10599 10600 QualType fnType = 10601 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType(); 10602 10603 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>(); 10604 QualType resultType = proto->getCallResultType(Context); 10605 ExprValueKind valueKind = Expr::getValueKindForType(proto->getResultType()); 10606 10607 // Check that the object type isn't more qualified than the 10608 // member function we're calling. 10609 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals()); 10610 10611 QualType objectType = op->getLHS()->getType(); 10612 if (op->getOpcode() == BO_PtrMemI) 10613 objectType = objectType->castAs<PointerType>()->getPointeeType(); 10614 Qualifiers objectQuals = objectType.getQualifiers(); 10615 10616 Qualifiers difference = objectQuals - funcQuals; 10617 difference.removeObjCGCAttr(); 10618 difference.removeAddressSpace(); 10619 if (difference) { 10620 std::string qualsString = difference.getAsString(); 10621 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals) 10622 << fnType.getUnqualifiedType() 10623 << qualsString 10624 << (qualsString.find(' ') == std::string::npos ? 1 : 2); 10625 } 10626 10627 CXXMemberCallExpr *call 10628 = new (Context) CXXMemberCallExpr(Context, MemExprE, 10629 llvm::makeArrayRef(Args, NumArgs), 10630 resultType, valueKind, RParenLoc); 10631 10632 if (CheckCallReturnType(proto->getResultType(), 10633 op->getRHS()->getLocStart(), 10634 call, 0)) 10635 return ExprError(); 10636 10637 if (ConvertArgumentsForCall(call, op, 0, proto, Args, NumArgs, RParenLoc)) 10638 return ExprError(); 10639 10640 return MaybeBindToTemporary(call); 10641 } 10642 10643 UnbridgedCastsSet UnbridgedCasts; 10644 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) 10645 return ExprError(); 10646 10647 MemberExpr *MemExpr; 10648 CXXMethodDecl *Method = 0; 10649 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 10650 NestedNameSpecifier *Qualifier = 0; 10651 if (isa<MemberExpr>(NakedMemExpr)) { 10652 MemExpr = cast<MemberExpr>(NakedMemExpr); 10653 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 10654 FoundDecl = MemExpr->getFoundDecl(); 10655 Qualifier = MemExpr->getQualifier(); 10656 UnbridgedCasts.restore(); 10657 } else { 10658 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 10659 Qualifier = UnresExpr->getQualifier(); 10660 10661 QualType ObjectType = UnresExpr->getBaseType(); 10662 Expr::Classification ObjectClassification 10663 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 10664 : UnresExpr->getBase()->Classify(Context); 10665 10666 // Add overload candidates 10667 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 10668 10669 // FIXME: avoid copy. 10670 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 10671 if (UnresExpr->hasExplicitTemplateArgs()) { 10672 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 10673 TemplateArgs = &TemplateArgsBuffer; 10674 } 10675 10676 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 10677 E = UnresExpr->decls_end(); I != E; ++I) { 10678 10679 NamedDecl *Func = *I; 10680 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 10681 if (isa<UsingShadowDecl>(Func)) 10682 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 10683 10684 10685 // Microsoft supports direct constructor calls. 10686 if (getLangOpts().MicrosoftExt && isa<CXXConstructorDecl>(Func)) { 10687 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), 10688 llvm::makeArrayRef(Args, NumArgs), CandidateSet); 10689 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 10690 // If explicit template arguments were provided, we can't call a 10691 // non-template member function. 10692 if (TemplateArgs) 10693 continue; 10694 10695 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 10696 ObjectClassification, 10697 llvm::makeArrayRef(Args, NumArgs), CandidateSet, 10698 /*SuppressUserConversions=*/false); 10699 } else { 10700 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 10701 I.getPair(), ActingDC, TemplateArgs, 10702 ObjectType, ObjectClassification, 10703 llvm::makeArrayRef(Args, NumArgs), 10704 CandidateSet, 10705 /*SuppressUsedConversions=*/false); 10706 } 10707 } 10708 10709 DeclarationName DeclName = UnresExpr->getMemberName(); 10710 10711 UnbridgedCasts.restore(); 10712 10713 OverloadCandidateSet::iterator Best; 10714 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 10715 Best)) { 10716 case OR_Success: 10717 Method = cast<CXXMethodDecl>(Best->Function); 10718 MarkFunctionReferenced(UnresExpr->getMemberLoc(), Method); 10719 FoundDecl = Best->FoundDecl; 10720 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 10721 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 10722 break; 10723 10724 case OR_No_Viable_Function: 10725 Diag(UnresExpr->getMemberLoc(), 10726 diag::err_ovl_no_viable_member_function_in_call) 10727 << DeclName << MemExprE->getSourceRange(); 10728 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10729 llvm::makeArrayRef(Args, NumArgs)); 10730 // FIXME: Leaking incoming expressions! 10731 return ExprError(); 10732 10733 case OR_Ambiguous: 10734 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 10735 << DeclName << MemExprE->getSourceRange(); 10736 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10737 llvm::makeArrayRef(Args, NumArgs)); 10738 // FIXME: Leaking incoming expressions! 10739 return ExprError(); 10740 10741 case OR_Deleted: 10742 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 10743 << Best->Function->isDeleted() 10744 << DeclName 10745 << getDeletedOrUnavailableSuffix(Best->Function) 10746 << MemExprE->getSourceRange(); 10747 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10748 llvm::makeArrayRef(Args, NumArgs)); 10749 // FIXME: Leaking incoming expressions! 10750 return ExprError(); 10751 } 10752 10753 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 10754 10755 // If overload resolution picked a static member, build a 10756 // non-member call based on that function. 10757 if (Method->isStatic()) { 10758 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 10759 Args, NumArgs, RParenLoc); 10760 } 10761 10762 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 10763 } 10764 10765 QualType ResultType = Method->getResultType(); 10766 ExprValueKind VK = Expr::getValueKindForType(ResultType); 10767 ResultType = ResultType.getNonLValueExprType(Context); 10768 10769 assert(Method && "Member call to something that isn't a method?"); 10770 CXXMemberCallExpr *TheCall = 10771 new (Context) CXXMemberCallExpr(Context, MemExprE, 10772 llvm::makeArrayRef(Args, NumArgs), 10773 ResultType, VK, RParenLoc); 10774 10775 // Check for a valid return type. 10776 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 10777 TheCall, Method)) 10778 return ExprError(); 10779 10780 // Convert the object argument (for a non-static member function call). 10781 // We only need to do this if there was actually an overload; otherwise 10782 // it was done at lookup. 10783 if (!Method->isStatic()) { 10784 ExprResult ObjectArg = 10785 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier, 10786 FoundDecl, Method); 10787 if (ObjectArg.isInvalid()) 10788 return ExprError(); 10789 MemExpr->setBase(ObjectArg.take()); 10790 } 10791 10792 // Convert the rest of the arguments 10793 const FunctionProtoType *Proto = 10794 Method->getType()->getAs<FunctionProtoType>(); 10795 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 10796 RParenLoc)) 10797 return ExprError(); 10798 10799 DiagnoseSentinelCalls(Method, LParenLoc, Args, NumArgs); 10800 10801 if (CheckFunctionCall(Method, TheCall, Proto)) 10802 return ExprError(); 10803 10804 if ((isa<CXXConstructorDecl>(CurContext) || 10805 isa<CXXDestructorDecl>(CurContext)) && 10806 TheCall->getMethodDecl()->isPure()) { 10807 const CXXMethodDecl *MD = TheCall->getMethodDecl(); 10808 10809 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts())) { 10810 Diag(MemExpr->getLocStart(), 10811 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor) 10812 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext) 10813 << MD->getParent()->getDeclName(); 10814 10815 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName(); 10816 } 10817 } 10818 return MaybeBindToTemporary(TheCall); 10819} 10820 10821/// BuildCallToObjectOfClassType - Build a call to an object of class 10822/// type (C++ [over.call.object]), which can end up invoking an 10823/// overloaded function call operator (@c operator()) or performing a 10824/// user-defined conversion on the object argument. 10825ExprResult 10826Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj, 10827 SourceLocation LParenLoc, 10828 Expr **Args, unsigned NumArgs, 10829 SourceLocation RParenLoc) { 10830 if (checkPlaceholderForOverload(*this, Obj)) 10831 return ExprError(); 10832 ExprResult Object = Owned(Obj); 10833 10834 UnbridgedCastsSet UnbridgedCasts; 10835 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) 10836 return ExprError(); 10837 10838 assert(Object.get()->getType()->isRecordType() && "Requires object type argument"); 10839 const RecordType *Record = Object.get()->getType()->getAs<RecordType>(); 10840 10841 // C++ [over.call.object]p1: 10842 // If the primary-expression E in the function call syntax 10843 // evaluates to a class object of type "cv T", then the set of 10844 // candidate functions includes at least the function call 10845 // operators of T. The function call operators of T are obtained by 10846 // ordinary lookup of the name operator() in the context of 10847 // (E).operator(). 10848 OverloadCandidateSet CandidateSet(LParenLoc); 10849 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 10850 10851 if (RequireCompleteType(LParenLoc, Object.get()->getType(), 10852 diag::err_incomplete_object_call, Object.get())) 10853 return true; 10854 10855 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 10856 LookupQualifiedName(R, Record->getDecl()); 10857 R.suppressDiagnostics(); 10858 10859 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 10860 Oper != OperEnd; ++Oper) { 10861 AddMethodCandidate(Oper.getPair(), Object.get()->getType(), 10862 Object.get()->Classify(Context), Args, NumArgs, CandidateSet, 10863 /*SuppressUserConversions=*/ false); 10864 } 10865 10866 // C++ [over.call.object]p2: 10867 // In addition, for each (non-explicit in C++0x) conversion function 10868 // declared in T of the form 10869 // 10870 // operator conversion-type-id () cv-qualifier; 10871 // 10872 // where cv-qualifier is the same cv-qualification as, or a 10873 // greater cv-qualification than, cv, and where conversion-type-id 10874 // denotes the type "pointer to function of (P1,...,Pn) returning 10875 // R", or the type "reference to pointer to function of 10876 // (P1,...,Pn) returning R", or the type "reference to function 10877 // of (P1,...,Pn) returning R", a surrogate call function [...] 10878 // is also considered as a candidate function. Similarly, 10879 // surrogate call functions are added to the set of candidate 10880 // functions for each conversion function declared in an 10881 // accessible base class provided the function is not hidden 10882 // within T by another intervening declaration. 10883 const UnresolvedSetImpl *Conversions 10884 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 10885 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 10886 E = Conversions->end(); I != E; ++I) { 10887 NamedDecl *D = *I; 10888 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 10889 if (isa<UsingShadowDecl>(D)) 10890 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 10891 10892 // Skip over templated conversion functions; they aren't 10893 // surrogates. 10894 if (isa<FunctionTemplateDecl>(D)) 10895 continue; 10896 10897 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 10898 if (!Conv->isExplicit()) { 10899 // Strip the reference type (if any) and then the pointer type (if 10900 // any) to get down to what might be a function type. 10901 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 10902 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 10903 ConvType = ConvPtrType->getPointeeType(); 10904 10905 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 10906 { 10907 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 10908 Object.get(), llvm::makeArrayRef(Args, NumArgs), 10909 CandidateSet); 10910 } 10911 } 10912 } 10913 10914 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10915 10916 // Perform overload resolution. 10917 OverloadCandidateSet::iterator Best; 10918 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(), 10919 Best)) { 10920 case OR_Success: 10921 // Overload resolution succeeded; we'll build the appropriate call 10922 // below. 10923 break; 10924 10925 case OR_No_Viable_Function: 10926 if (CandidateSet.empty()) 10927 Diag(Object.get()->getLocStart(), diag::err_ovl_no_oper) 10928 << Object.get()->getType() << /*call*/ 1 10929 << Object.get()->getSourceRange(); 10930 else 10931 Diag(Object.get()->getLocStart(), 10932 diag::err_ovl_no_viable_object_call) 10933 << Object.get()->getType() << Object.get()->getSourceRange(); 10934 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10935 llvm::makeArrayRef(Args, NumArgs)); 10936 break; 10937 10938 case OR_Ambiguous: 10939 Diag(Object.get()->getLocStart(), 10940 diag::err_ovl_ambiguous_object_call) 10941 << Object.get()->getType() << Object.get()->getSourceRange(); 10942 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 10943 llvm::makeArrayRef(Args, NumArgs)); 10944 break; 10945 10946 case OR_Deleted: 10947 Diag(Object.get()->getLocStart(), 10948 diag::err_ovl_deleted_object_call) 10949 << Best->Function->isDeleted() 10950 << Object.get()->getType() 10951 << getDeletedOrUnavailableSuffix(Best->Function) 10952 << Object.get()->getSourceRange(); 10953 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, 10954 llvm::makeArrayRef(Args, NumArgs)); 10955 break; 10956 } 10957 10958 if (Best == CandidateSet.end()) 10959 return true; 10960 10961 UnbridgedCasts.restore(); 10962 10963 if (Best->Function == 0) { 10964 // Since there is no function declaration, this is one of the 10965 // surrogate candidates. Dig out the conversion function. 10966 CXXConversionDecl *Conv 10967 = cast<CXXConversionDecl>( 10968 Best->Conversions[0].UserDefined.ConversionFunction); 10969 10970 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 10971 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 10972 10973 // We selected one of the surrogate functions that converts the 10974 // object parameter to a function pointer. Perform the conversion 10975 // on the object argument, then let ActOnCallExpr finish the job. 10976 10977 // Create an implicit member expr to refer to the conversion operator. 10978 // and then call it. 10979 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl, 10980 Conv, HadMultipleCandidates); 10981 if (Call.isInvalid()) 10982 return ExprError(); 10983 // Record usage of conversion in an implicit cast. 10984 Call = Owned(ImplicitCastExpr::Create(Context, Call.get()->getType(), 10985 CK_UserDefinedConversion, 10986 Call.get(), 0, VK_RValue)); 10987 10988 return ActOnCallExpr(S, Call.get(), LParenLoc, MultiExprArg(Args, NumArgs), 10989 RParenLoc); 10990 } 10991 10992 MarkFunctionReferenced(LParenLoc, Best->Function); 10993 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 10994 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 10995 10996 // We found an overloaded operator(). Build a CXXOperatorCallExpr 10997 // that calls this method, using Object for the implicit object 10998 // parameter and passing along the remaining arguments. 10999 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 11000 const FunctionProtoType *Proto = 11001 Method->getType()->getAs<FunctionProtoType>(); 11002 11003 unsigned NumArgsInProto = Proto->getNumArgs(); 11004 unsigned NumArgsToCheck = NumArgs; 11005 11006 // Build the full argument list for the method call (the 11007 // implicit object parameter is placed at the beginning of the 11008 // list). 11009 Expr **MethodArgs; 11010 if (NumArgs < NumArgsInProto) { 11011 NumArgsToCheck = NumArgsInProto; 11012 MethodArgs = new Expr*[NumArgsInProto + 1]; 11013 } else { 11014 MethodArgs = new Expr*[NumArgs + 1]; 11015 } 11016 MethodArgs[0] = Object.get(); 11017 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 11018 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 11019 11020 DeclarationNameInfo OpLocInfo( 11021 Context.DeclarationNames.getCXXOperatorName(OO_Call), LParenLoc); 11022 OpLocInfo.setCXXOperatorNameRange(SourceRange(LParenLoc, RParenLoc)); 11023 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, 11024 HadMultipleCandidates, 11025 OpLocInfo.getLoc(), 11026 OpLocInfo.getInfo()); 11027 if (NewFn.isInvalid()) 11028 return true; 11029 11030 // Once we've built TheCall, all of the expressions are properly 11031 // owned. 11032 QualType ResultTy = Method->getResultType(); 11033 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11034 ResultTy = ResultTy.getNonLValueExprType(Context); 11035 11036 CXXOperatorCallExpr *TheCall = 11037 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn.take(), 11038 llvm::makeArrayRef(MethodArgs, NumArgs+1), 11039 ResultTy, VK, RParenLoc, false); 11040 delete [] MethodArgs; 11041 11042 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 11043 Method)) 11044 return true; 11045 11046 // We may have default arguments. If so, we need to allocate more 11047 // slots in the call for them. 11048 if (NumArgs < NumArgsInProto) 11049 TheCall->setNumArgs(Context, NumArgsInProto + 1); 11050 else if (NumArgs > NumArgsInProto) 11051 NumArgsToCheck = NumArgsInProto; 11052 11053 bool IsError = false; 11054 11055 // Initialize the implicit object parameter. 11056 ExprResult ObjRes = 11057 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/0, 11058 Best->FoundDecl, Method); 11059 if (ObjRes.isInvalid()) 11060 IsError = true; 11061 else 11062 Object = ObjRes; 11063 TheCall->setArg(0, Object.take()); 11064 11065 // Check the argument types. 11066 for (unsigned i = 0; i != NumArgsToCheck; i++) { 11067 Expr *Arg; 11068 if (i < NumArgs) { 11069 Arg = Args[i]; 11070 11071 // Pass the argument. 11072 11073 ExprResult InputInit 11074 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 11075 Context, 11076 Method->getParamDecl(i)), 11077 SourceLocation(), Arg); 11078 11079 IsError |= InputInit.isInvalid(); 11080 Arg = InputInit.takeAs<Expr>(); 11081 } else { 11082 ExprResult DefArg 11083 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 11084 if (DefArg.isInvalid()) { 11085 IsError = true; 11086 break; 11087 } 11088 11089 Arg = DefArg.takeAs<Expr>(); 11090 } 11091 11092 TheCall->setArg(i + 1, Arg); 11093 } 11094 11095 // If this is a variadic call, handle args passed through "...". 11096 if (Proto->isVariadic()) { 11097 // Promote the arguments (C99 6.5.2.2p7). 11098 for (unsigned i = NumArgsInProto; i < NumArgs; i++) { 11099 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod, 0); 11100 IsError |= Arg.isInvalid(); 11101 TheCall->setArg(i + 1, Arg.take()); 11102 } 11103 } 11104 11105 if (IsError) return true; 11106 11107 DiagnoseSentinelCalls(Method, LParenLoc, Args, NumArgs); 11108 11109 if (CheckFunctionCall(Method, TheCall, Proto)) 11110 return true; 11111 11112 return MaybeBindToTemporary(TheCall); 11113} 11114 11115/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 11116/// (if one exists), where @c Base is an expression of class type and 11117/// @c Member is the name of the member we're trying to find. 11118ExprResult 11119Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 11120 assert(Base->getType()->isRecordType() && 11121 "left-hand side must have class type"); 11122 11123 if (checkPlaceholderForOverload(*this, Base)) 11124 return ExprError(); 11125 11126 SourceLocation Loc = Base->getExprLoc(); 11127 11128 // C++ [over.ref]p1: 11129 // 11130 // [...] An expression x->m is interpreted as (x.operator->())->m 11131 // for a class object x of type T if T::operator->() exists and if 11132 // the operator is selected as the best match function by the 11133 // overload resolution mechanism (13.3). 11134 DeclarationName OpName = 11135 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 11136 OverloadCandidateSet CandidateSet(Loc); 11137 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 11138 11139 if (RequireCompleteType(Loc, Base->getType(), 11140 diag::err_typecheck_incomplete_tag, Base)) 11141 return ExprError(); 11142 11143 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 11144 LookupQualifiedName(R, BaseRecord->getDecl()); 11145 R.suppressDiagnostics(); 11146 11147 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 11148 Oper != OperEnd; ++Oper) { 11149 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 11150 0, 0, CandidateSet, /*SuppressUserConversions=*/false); 11151 } 11152 11153 bool HadMultipleCandidates = (CandidateSet.size() > 1); 11154 11155 // Perform overload resolution. 11156 OverloadCandidateSet::iterator Best; 11157 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 11158 case OR_Success: 11159 // Overload resolution succeeded; we'll build the call below. 11160 break; 11161 11162 case OR_No_Viable_Function: 11163 if (CandidateSet.empty()) 11164 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 11165 << Base->getType() << Base->getSourceRange(); 11166 else 11167 Diag(OpLoc, diag::err_ovl_no_viable_oper) 11168 << "operator->" << Base->getSourceRange(); 11169 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base); 11170 return ExprError(); 11171 11172 case OR_Ambiguous: 11173 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 11174 << "->" << Base->getType() << Base->getSourceRange(); 11175 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Base); 11176 return ExprError(); 11177 11178 case OR_Deleted: 11179 Diag(OpLoc, diag::err_ovl_deleted_oper) 11180 << Best->Function->isDeleted() 11181 << "->" 11182 << getDeletedOrUnavailableSuffix(Best->Function) 11183 << Base->getSourceRange(); 11184 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Base); 11185 return ExprError(); 11186 } 11187 11188 MarkFunctionReferenced(OpLoc, Best->Function); 11189 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 11190 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 11191 11192 // Convert the object parameter. 11193 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 11194 ExprResult BaseResult = 11195 PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 11196 Best->FoundDecl, Method); 11197 if (BaseResult.isInvalid()) 11198 return ExprError(); 11199 Base = BaseResult.take(); 11200 11201 // Build the operator call. 11202 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, 11203 HadMultipleCandidates, OpLoc); 11204 if (FnExpr.isInvalid()) 11205 return ExprError(); 11206 11207 QualType ResultTy = Method->getResultType(); 11208 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11209 ResultTy = ResultTy.getNonLValueExprType(Context); 11210 CXXOperatorCallExpr *TheCall = 11211 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.take(), 11212 Base, ResultTy, VK, OpLoc, false); 11213 11214 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 11215 Method)) 11216 return ExprError(); 11217 11218 return MaybeBindToTemporary(TheCall); 11219} 11220 11221/// BuildLiteralOperatorCall - Build a UserDefinedLiteral by creating a call to 11222/// a literal operator described by the provided lookup results. 11223ExprResult Sema::BuildLiteralOperatorCall(LookupResult &R, 11224 DeclarationNameInfo &SuffixInfo, 11225 ArrayRef<Expr*> Args, 11226 SourceLocation LitEndLoc, 11227 TemplateArgumentListInfo *TemplateArgs) { 11228 SourceLocation UDSuffixLoc = SuffixInfo.getCXXLiteralOperatorNameLoc(); 11229 11230 OverloadCandidateSet CandidateSet(UDSuffixLoc); 11231 AddFunctionCandidates(R.asUnresolvedSet(), Args, CandidateSet, true, 11232 TemplateArgs); 11233 11234 bool HadMultipleCandidates = (CandidateSet.size() > 1); 11235 11236 // Perform overload resolution. This will usually be trivial, but might need 11237 // to perform substitutions for a literal operator template. 11238 OverloadCandidateSet::iterator Best; 11239 switch (CandidateSet.BestViableFunction(*this, UDSuffixLoc, Best)) { 11240 case OR_Success: 11241 case OR_Deleted: 11242 break; 11243 11244 case OR_No_Viable_Function: 11245 Diag(UDSuffixLoc, diag::err_ovl_no_viable_function_in_call) 11246 << R.getLookupName(); 11247 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args); 11248 return ExprError(); 11249 11250 case OR_Ambiguous: 11251 Diag(R.getNameLoc(), diag::err_ovl_ambiguous_call) << R.getLookupName(); 11252 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args); 11253 return ExprError(); 11254 } 11255 11256 FunctionDecl *FD = Best->Function; 11257 MarkFunctionReferenced(UDSuffixLoc, FD); 11258 DiagnoseUseOfDecl(Best->FoundDecl, UDSuffixLoc); 11259 11260 ExprResult Fn = CreateFunctionRefExpr(*this, FD, HadMultipleCandidates, 11261 SuffixInfo.getLoc(), 11262 SuffixInfo.getInfo()); 11263 if (Fn.isInvalid()) 11264 return true; 11265 11266 // Check the argument types. This should almost always be a no-op, except 11267 // that array-to-pointer decay is applied to string literals. 11268 Expr *ConvArgs[2]; 11269 for (unsigned ArgIdx = 0; ArgIdx != Args.size(); ++ArgIdx) { 11270 ExprResult InputInit = PerformCopyInitialization( 11271 InitializedEntity::InitializeParameter(Context, FD->getParamDecl(ArgIdx)), 11272 SourceLocation(), Args[ArgIdx]); 11273 if (InputInit.isInvalid()) 11274 return true; 11275 ConvArgs[ArgIdx] = InputInit.take(); 11276 } 11277 11278 QualType ResultTy = FD->getResultType(); 11279 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 11280 ResultTy = ResultTy.getNonLValueExprType(Context); 11281 11282 UserDefinedLiteral *UDL = 11283 new (Context) UserDefinedLiteral(Context, Fn.take(), 11284 llvm::makeArrayRef(ConvArgs, Args.size()), 11285 ResultTy, VK, LitEndLoc, UDSuffixLoc); 11286 11287 if (CheckCallReturnType(FD->getResultType(), UDSuffixLoc, UDL, FD)) 11288 return ExprError(); 11289 11290 if (CheckFunctionCall(FD, UDL, NULL)) 11291 return ExprError(); 11292 11293 return MaybeBindToTemporary(UDL); 11294} 11295 11296/// Build a call to 'begin' or 'end' for a C++11 for-range statement. If the 11297/// given LookupResult is non-empty, it is assumed to describe a member which 11298/// will be invoked. Otherwise, the function will be found via argument 11299/// dependent lookup. 11300/// CallExpr is set to a valid expression and FRS_Success returned on success, 11301/// otherwise CallExpr is set to ExprError() and some non-success value 11302/// is returned. 11303Sema::ForRangeStatus 11304Sema::BuildForRangeBeginEndCall(Scope *S, SourceLocation Loc, 11305 SourceLocation RangeLoc, VarDecl *Decl, 11306 BeginEndFunction BEF, 11307 const DeclarationNameInfo &NameInfo, 11308 LookupResult &MemberLookup, 11309 OverloadCandidateSet *CandidateSet, 11310 Expr *Range, ExprResult *CallExpr) { 11311 CandidateSet->clear(); 11312 if (!MemberLookup.empty()) { 11313 ExprResult MemberRef = 11314 BuildMemberReferenceExpr(Range, Range->getType(), Loc, 11315 /*IsPtr=*/false, CXXScopeSpec(), 11316 /*TemplateKWLoc=*/SourceLocation(), 11317 /*FirstQualifierInScope=*/0, 11318 MemberLookup, 11319 /*TemplateArgs=*/0); 11320 if (MemberRef.isInvalid()) { 11321 *CallExpr = ExprError(); 11322 Diag(Range->getLocStart(), diag::note_in_for_range) 11323 << RangeLoc << BEF << Range->getType(); 11324 return FRS_DiagnosticIssued; 11325 } 11326 *CallExpr = ActOnCallExpr(S, MemberRef.get(), Loc, MultiExprArg(), Loc, 0); 11327 if (CallExpr->isInvalid()) { 11328 *CallExpr = ExprError(); 11329 Diag(Range->getLocStart(), diag::note_in_for_range) 11330 << RangeLoc << BEF << Range->getType(); 11331 return FRS_DiagnosticIssued; 11332 } 11333 } else { 11334 UnresolvedSet<0> FoundNames; 11335 UnresolvedLookupExpr *Fn = 11336 UnresolvedLookupExpr::Create(Context, /*NamingClass=*/0, 11337 NestedNameSpecifierLoc(), NameInfo, 11338 /*NeedsADL=*/true, /*Overloaded=*/false, 11339 FoundNames.begin(), FoundNames.end()); 11340 11341 bool CandidateSetError = buildOverloadedCallSet(S, Fn, Fn, &Range, 1, Loc, 11342 CandidateSet, CallExpr); 11343 if (CandidateSet->empty() || CandidateSetError) { 11344 *CallExpr = ExprError(); 11345 return FRS_NoViableFunction; 11346 } 11347 OverloadCandidateSet::iterator Best; 11348 OverloadingResult OverloadResult = 11349 CandidateSet->BestViableFunction(*this, Fn->getLocStart(), Best); 11350 11351 if (OverloadResult == OR_No_Viable_Function) { 11352 *CallExpr = ExprError(); 11353 return FRS_NoViableFunction; 11354 } 11355 *CallExpr = FinishOverloadedCallExpr(*this, S, Fn, Fn, Loc, &Range, 1, 11356 Loc, 0, CandidateSet, &Best, 11357 OverloadResult, 11358 /*AllowTypoCorrection=*/false); 11359 if (CallExpr->isInvalid() || OverloadResult != OR_Success) { 11360 *CallExpr = ExprError(); 11361 Diag(Range->getLocStart(), diag::note_in_for_range) 11362 << RangeLoc << BEF << Range->getType(); 11363 return FRS_DiagnosticIssued; 11364 } 11365 } 11366 return FRS_Success; 11367} 11368 11369 11370/// FixOverloadedFunctionReference - E is an expression that refers to 11371/// a C++ overloaded function (possibly with some parentheses and 11372/// perhaps a '&' around it). We have resolved the overloaded function 11373/// to the function declaration Fn, so patch up the expression E to 11374/// refer (possibly indirectly) to Fn. Returns the new expr. 11375Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 11376 FunctionDecl *Fn) { 11377 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 11378 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 11379 Found, Fn); 11380 if (SubExpr == PE->getSubExpr()) 11381 return PE; 11382 11383 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 11384 } 11385 11386 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 11387 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 11388 Found, Fn); 11389 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 11390 SubExpr->getType()) && 11391 "Implicit cast type cannot be determined from overload"); 11392 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 11393 if (SubExpr == ICE->getSubExpr()) 11394 return ICE; 11395 11396 return ImplicitCastExpr::Create(Context, ICE->getType(), 11397 ICE->getCastKind(), 11398 SubExpr, 0, 11399 ICE->getValueKind()); 11400 } 11401 11402 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 11403 assert(UnOp->getOpcode() == UO_AddrOf && 11404 "Can only take the address of an overloaded function"); 11405 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 11406 if (Method->isStatic()) { 11407 // Do nothing: static member functions aren't any different 11408 // from non-member functions. 11409 } else { 11410 // Fix the sub expression, which really has to be an 11411 // UnresolvedLookupExpr holding an overloaded member function 11412 // or template. 11413 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 11414 Found, Fn); 11415 if (SubExpr == UnOp->getSubExpr()) 11416 return UnOp; 11417 11418 assert(isa<DeclRefExpr>(SubExpr) 11419 && "fixed to something other than a decl ref"); 11420 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 11421 && "fixed to a member ref with no nested name qualifier"); 11422 11423 // We have taken the address of a pointer to member 11424 // function. Perform the computation here so that we get the 11425 // appropriate pointer to member type. 11426 QualType ClassType 11427 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 11428 QualType MemPtrType 11429 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 11430 11431 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 11432 VK_RValue, OK_Ordinary, 11433 UnOp->getOperatorLoc()); 11434 } 11435 } 11436 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 11437 Found, Fn); 11438 if (SubExpr == UnOp->getSubExpr()) 11439 return UnOp; 11440 11441 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 11442 Context.getPointerType(SubExpr->getType()), 11443 VK_RValue, OK_Ordinary, 11444 UnOp->getOperatorLoc()); 11445 } 11446 11447 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 11448 // FIXME: avoid copy. 11449 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 11450 if (ULE->hasExplicitTemplateArgs()) { 11451 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 11452 TemplateArgs = &TemplateArgsBuffer; 11453 } 11454 11455 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 11456 ULE->getQualifierLoc(), 11457 ULE->getTemplateKeywordLoc(), 11458 Fn, 11459 /*enclosing*/ false, // FIXME? 11460 ULE->getNameLoc(), 11461 Fn->getType(), 11462 VK_LValue, 11463 Found.getDecl(), 11464 TemplateArgs); 11465 MarkDeclRefReferenced(DRE); 11466 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1); 11467 return DRE; 11468 } 11469 11470 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 11471 // FIXME: avoid copy. 11472 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 11473 if (MemExpr->hasExplicitTemplateArgs()) { 11474 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 11475 TemplateArgs = &TemplateArgsBuffer; 11476 } 11477 11478 Expr *Base; 11479 11480 // If we're filling in a static method where we used to have an 11481 // implicit member access, rewrite to a simple decl ref. 11482 if (MemExpr->isImplicitAccess()) { 11483 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 11484 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 11485 MemExpr->getQualifierLoc(), 11486 MemExpr->getTemplateKeywordLoc(), 11487 Fn, 11488 /*enclosing*/ false, 11489 MemExpr->getMemberLoc(), 11490 Fn->getType(), 11491 VK_LValue, 11492 Found.getDecl(), 11493 TemplateArgs); 11494 MarkDeclRefReferenced(DRE); 11495 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1); 11496 return DRE; 11497 } else { 11498 SourceLocation Loc = MemExpr->getMemberLoc(); 11499 if (MemExpr->getQualifier()) 11500 Loc = MemExpr->getQualifierLoc().getBeginLoc(); 11501 CheckCXXThisCapture(Loc); 11502 Base = new (Context) CXXThisExpr(Loc, 11503 MemExpr->getBaseType(), 11504 /*isImplicit=*/true); 11505 } 11506 } else 11507 Base = MemExpr->getBase(); 11508 11509 ExprValueKind valueKind; 11510 QualType type; 11511 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 11512 valueKind = VK_LValue; 11513 type = Fn->getType(); 11514 } else { 11515 valueKind = VK_RValue; 11516 type = Context.BoundMemberTy; 11517 } 11518 11519 MemberExpr *ME = MemberExpr::Create(Context, Base, 11520 MemExpr->isArrow(), 11521 MemExpr->getQualifierLoc(), 11522 MemExpr->getTemplateKeywordLoc(), 11523 Fn, 11524 Found, 11525 MemExpr->getMemberNameInfo(), 11526 TemplateArgs, 11527 type, valueKind, OK_Ordinary); 11528 ME->setHadMultipleCandidates(true); 11529 return ME; 11530 } 11531 11532 llvm_unreachable("Invalid reference to overloaded function"); 11533} 11534 11535ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 11536 DeclAccessPair Found, 11537 FunctionDecl *Fn) { 11538 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 11539} 11540 11541} // end namespace clang 11542