SemaOverload.cpp revision afc5b15022886c9e9e84d7aa0f2168b83e712310
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/STLExtras.h" 32#include <algorithm> 33 34namespace clang { 35using namespace sema; 36 37/// A convenience routine for creating a decayed reference to a 38/// function. 39static ExprResult 40CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, 41 SourceLocation Loc = SourceLocation(), 42 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){ 43 ExprResult E = S.Owned(new (S.Context) DeclRefExpr(Fn, Fn->getType(), 44 VK_LValue, Loc, LocInfo)); 45 E = S.DefaultFunctionArrayConversion(E.take()); 46 if (E.isInvalid()) 47 return ExprError(); 48 return move(E); 49} 50 51static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 52 bool InOverloadResolution, 53 StandardConversionSequence &SCS, 54 bool CStyle, 55 bool AllowObjCWritebackConversion); 56 57static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From, 58 QualType &ToType, 59 bool InOverloadResolution, 60 StandardConversionSequence &SCS, 61 bool CStyle); 62static OverloadingResult 63IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 64 UserDefinedConversionSequence& User, 65 OverloadCandidateSet& Conversions, 66 bool AllowExplicit); 67 68 69static ImplicitConversionSequence::CompareKind 70CompareStandardConversionSequences(Sema &S, 71 const StandardConversionSequence& SCS1, 72 const StandardConversionSequence& SCS2); 73 74static ImplicitConversionSequence::CompareKind 75CompareQualificationConversions(Sema &S, 76 const StandardConversionSequence& SCS1, 77 const StandardConversionSequence& SCS2); 78 79static ImplicitConversionSequence::CompareKind 80CompareDerivedToBaseConversions(Sema &S, 81 const StandardConversionSequence& SCS1, 82 const StandardConversionSequence& SCS2); 83 84 85 86/// GetConversionCategory - Retrieve the implicit conversion 87/// category corresponding to the given implicit conversion kind. 88ImplicitConversionCategory 89GetConversionCategory(ImplicitConversionKind Kind) { 90 static const ImplicitConversionCategory 91 Category[(int)ICK_Num_Conversion_Kinds] = { 92 ICC_Identity, 93 ICC_Lvalue_Transformation, 94 ICC_Lvalue_Transformation, 95 ICC_Lvalue_Transformation, 96 ICC_Identity, 97 ICC_Qualification_Adjustment, 98 ICC_Promotion, 99 ICC_Promotion, 100 ICC_Promotion, 101 ICC_Conversion, 102 ICC_Conversion, 103 ICC_Conversion, 104 ICC_Conversion, 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 }; 115 return Category[(int)Kind]; 116} 117 118/// GetConversionRank - Retrieve the implicit conversion rank 119/// corresponding to the given implicit conversion kind. 120ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 121 static const ImplicitConversionRank 122 Rank[(int)ICK_Num_Conversion_Kinds] = { 123 ICR_Exact_Match, 124 ICR_Exact_Match, 125 ICR_Exact_Match, 126 ICR_Exact_Match, 127 ICR_Exact_Match, 128 ICR_Exact_Match, 129 ICR_Promotion, 130 ICR_Promotion, 131 ICR_Promotion, 132 ICR_Conversion, 133 ICR_Conversion, 134 ICR_Conversion, 135 ICR_Conversion, 136 ICR_Conversion, 137 ICR_Conversion, 138 ICR_Conversion, 139 ICR_Conversion, 140 ICR_Conversion, 141 ICR_Conversion, 142 ICR_Conversion, 143 ICR_Complex_Real_Conversion, 144 ICR_Conversion, 145 ICR_Conversion, 146 ICR_Writeback_Conversion 147 }; 148 return Rank[(int)Kind]; 149} 150 151/// GetImplicitConversionName - Return the name of this kind of 152/// implicit conversion. 153const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 154 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 155 "No conversion", 156 "Lvalue-to-rvalue", 157 "Array-to-pointer", 158 "Function-to-pointer", 159 "Noreturn adjustment", 160 "Qualification", 161 "Integral promotion", 162 "Floating point promotion", 163 "Complex promotion", 164 "Integral conversion", 165 "Floating conversion", 166 "Complex conversion", 167 "Floating-integral conversion", 168 "Pointer conversion", 169 "Pointer-to-member conversion", 170 "Boolean conversion", 171 "Compatible-types conversion", 172 "Derived-to-base conversion", 173 "Vector conversion", 174 "Vector splat", 175 "Complex-real conversion", 176 "Block Pointer conversion", 177 "Transparent Union Conversion" 178 "Writeback conversion" 179 }; 180 return Name[Kind]; 181} 182 183/// StandardConversionSequence - Set the standard conversion 184/// sequence to the identity conversion. 185void StandardConversionSequence::setAsIdentityConversion() { 186 First = ICK_Identity; 187 Second = ICK_Identity; 188 Third = ICK_Identity; 189 DeprecatedStringLiteralToCharPtr = false; 190 QualificationIncludesObjCLifetime = false; 191 ReferenceBinding = false; 192 DirectBinding = false; 193 IsLvalueReference = true; 194 BindsToFunctionLvalue = false; 195 BindsToRvalue = false; 196 BindsImplicitObjectArgumentWithoutRefQualifier = false; 197 ObjCLifetimeConversionBinding = false; 198 CopyConstructor = 0; 199} 200 201/// getRank - Retrieve the rank of this standard conversion sequence 202/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 203/// implicit conversions. 204ImplicitConversionRank StandardConversionSequence::getRank() const { 205 ImplicitConversionRank Rank = ICR_Exact_Match; 206 if (GetConversionRank(First) > Rank) 207 Rank = GetConversionRank(First); 208 if (GetConversionRank(Second) > Rank) 209 Rank = GetConversionRank(Second); 210 if (GetConversionRank(Third) > Rank) 211 Rank = GetConversionRank(Third); 212 return Rank; 213} 214 215/// isPointerConversionToBool - Determines whether this conversion is 216/// a conversion of a pointer or pointer-to-member to bool. This is 217/// used as part of the ranking of standard conversion sequences 218/// (C++ 13.3.3.2p4). 219bool StandardConversionSequence::isPointerConversionToBool() const { 220 // Note that FromType has not necessarily been transformed by the 221 // array-to-pointer or function-to-pointer implicit conversions, so 222 // check for their presence as well as checking whether FromType is 223 // a pointer. 224 if (getToType(1)->isBooleanType() && 225 (getFromType()->isPointerType() || 226 getFromType()->isObjCObjectPointerType() || 227 getFromType()->isBlockPointerType() || 228 getFromType()->isNullPtrType() || 229 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 230 return true; 231 232 return false; 233} 234 235/// isPointerConversionToVoidPointer - Determines whether this 236/// conversion is a conversion of a pointer to a void pointer. This is 237/// used as part of the ranking of standard conversion sequences (C++ 238/// 13.3.3.2p4). 239bool 240StandardConversionSequence:: 241isPointerConversionToVoidPointer(ASTContext& Context) const { 242 QualType FromType = getFromType(); 243 QualType ToType = getToType(1); 244 245 // Note that FromType has not necessarily been transformed by the 246 // array-to-pointer implicit conversion, so check for its presence 247 // and redo the conversion to get a pointer. 248 if (First == ICK_Array_To_Pointer) 249 FromType = Context.getArrayDecayedType(FromType); 250 251 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType()) 252 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 253 return ToPtrType->getPointeeType()->isVoidType(); 254 255 return false; 256} 257 258/// DebugPrint - Print this standard conversion sequence to standard 259/// error. Useful for debugging overloading issues. 260void StandardConversionSequence::DebugPrint() const { 261 raw_ostream &OS = llvm::errs(); 262 bool PrintedSomething = false; 263 if (First != ICK_Identity) { 264 OS << GetImplicitConversionName(First); 265 PrintedSomething = true; 266 } 267 268 if (Second != ICK_Identity) { 269 if (PrintedSomething) { 270 OS << " -> "; 271 } 272 OS << GetImplicitConversionName(Second); 273 274 if (CopyConstructor) { 275 OS << " (by copy constructor)"; 276 } else if (DirectBinding) { 277 OS << " (direct reference binding)"; 278 } else if (ReferenceBinding) { 279 OS << " (reference binding)"; 280 } 281 PrintedSomething = true; 282 } 283 284 if (Third != ICK_Identity) { 285 if (PrintedSomething) { 286 OS << " -> "; 287 } 288 OS << GetImplicitConversionName(Third); 289 PrintedSomething = true; 290 } 291 292 if (!PrintedSomething) { 293 OS << "No conversions required"; 294 } 295} 296 297/// DebugPrint - Print this user-defined conversion sequence to standard 298/// error. Useful for debugging overloading issues. 299void UserDefinedConversionSequence::DebugPrint() const { 300 raw_ostream &OS = llvm::errs(); 301 if (Before.First || Before.Second || Before.Third) { 302 Before.DebugPrint(); 303 OS << " -> "; 304 } 305 OS << '\'' << ConversionFunction << '\''; 306 if (After.First || After.Second || After.Third) { 307 OS << " -> "; 308 After.DebugPrint(); 309 } 310} 311 312/// DebugPrint - Print this implicit conversion sequence to standard 313/// error. Useful for debugging overloading issues. 314void ImplicitConversionSequence::DebugPrint() const { 315 raw_ostream &OS = llvm::errs(); 316 switch (ConversionKind) { 317 case StandardConversion: 318 OS << "Standard conversion: "; 319 Standard.DebugPrint(); 320 break; 321 case UserDefinedConversion: 322 OS << "User-defined conversion: "; 323 UserDefined.DebugPrint(); 324 break; 325 case EllipsisConversion: 326 OS << "Ellipsis conversion"; 327 break; 328 case AmbiguousConversion: 329 OS << "Ambiguous conversion"; 330 break; 331 case BadConversion: 332 OS << "Bad conversion"; 333 break; 334 } 335 336 OS << "\n"; 337} 338 339void AmbiguousConversionSequence::construct() { 340 new (&conversions()) ConversionSet(); 341} 342 343void AmbiguousConversionSequence::destruct() { 344 conversions().~ConversionSet(); 345} 346 347void 348AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 349 FromTypePtr = O.FromTypePtr; 350 ToTypePtr = O.ToTypePtr; 351 new (&conversions()) ConversionSet(O.conversions()); 352} 353 354namespace { 355 // Structure used by OverloadCandidate::DeductionFailureInfo to store 356 // template parameter and template argument information. 357 struct DFIParamWithArguments { 358 TemplateParameter Param; 359 TemplateArgument FirstArg; 360 TemplateArgument SecondArg; 361 }; 362} 363 364/// \brief Convert from Sema's representation of template deduction information 365/// to the form used in overload-candidate information. 366OverloadCandidate::DeductionFailureInfo 367static MakeDeductionFailureInfo(ASTContext &Context, 368 Sema::TemplateDeductionResult TDK, 369 TemplateDeductionInfo &Info) { 370 OverloadCandidate::DeductionFailureInfo Result; 371 Result.Result = static_cast<unsigned>(TDK); 372 Result.Data = 0; 373 switch (TDK) { 374 case Sema::TDK_Success: 375 case Sema::TDK_InstantiationDepth: 376 case Sema::TDK_TooManyArguments: 377 case Sema::TDK_TooFewArguments: 378 break; 379 380 case Sema::TDK_Incomplete: 381 case Sema::TDK_InvalidExplicitArguments: 382 Result.Data = Info.Param.getOpaqueValue(); 383 break; 384 385 case Sema::TDK_Inconsistent: 386 case Sema::TDK_Underqualified: { 387 // FIXME: Should allocate from normal heap so that we can free this later. 388 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 389 Saved->Param = Info.Param; 390 Saved->FirstArg = Info.FirstArg; 391 Saved->SecondArg = Info.SecondArg; 392 Result.Data = Saved; 393 break; 394 } 395 396 case Sema::TDK_SubstitutionFailure: 397 Result.Data = Info.take(); 398 break; 399 400 case Sema::TDK_NonDeducedMismatch: 401 case Sema::TDK_FailedOverloadResolution: 402 break; 403 } 404 405 return Result; 406} 407 408void OverloadCandidate::DeductionFailureInfo::Destroy() { 409 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 410 case Sema::TDK_Success: 411 case Sema::TDK_InstantiationDepth: 412 case Sema::TDK_Incomplete: 413 case Sema::TDK_TooManyArguments: 414 case Sema::TDK_TooFewArguments: 415 case Sema::TDK_InvalidExplicitArguments: 416 break; 417 418 case Sema::TDK_Inconsistent: 419 case Sema::TDK_Underqualified: 420 // FIXME: Destroy the data? 421 Data = 0; 422 break; 423 424 case Sema::TDK_SubstitutionFailure: 425 // FIXME: Destroy the template arugment list? 426 Data = 0; 427 break; 428 429 // Unhandled 430 case Sema::TDK_NonDeducedMismatch: 431 case Sema::TDK_FailedOverloadResolution: 432 break; 433 } 434} 435 436TemplateParameter 437OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 438 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 439 case Sema::TDK_Success: 440 case Sema::TDK_InstantiationDepth: 441 case Sema::TDK_TooManyArguments: 442 case Sema::TDK_TooFewArguments: 443 case Sema::TDK_SubstitutionFailure: 444 return TemplateParameter(); 445 446 case Sema::TDK_Incomplete: 447 case Sema::TDK_InvalidExplicitArguments: 448 return TemplateParameter::getFromOpaqueValue(Data); 449 450 case Sema::TDK_Inconsistent: 451 case Sema::TDK_Underqualified: 452 return static_cast<DFIParamWithArguments*>(Data)->Param; 453 454 // Unhandled 455 case Sema::TDK_NonDeducedMismatch: 456 case Sema::TDK_FailedOverloadResolution: 457 break; 458 } 459 460 return TemplateParameter(); 461} 462 463TemplateArgumentList * 464OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 465 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 466 case Sema::TDK_Success: 467 case Sema::TDK_InstantiationDepth: 468 case Sema::TDK_TooManyArguments: 469 case Sema::TDK_TooFewArguments: 470 case Sema::TDK_Incomplete: 471 case Sema::TDK_InvalidExplicitArguments: 472 case Sema::TDK_Inconsistent: 473 case Sema::TDK_Underqualified: 474 return 0; 475 476 case Sema::TDK_SubstitutionFailure: 477 return static_cast<TemplateArgumentList*>(Data); 478 479 // Unhandled 480 case Sema::TDK_NonDeducedMismatch: 481 case Sema::TDK_FailedOverloadResolution: 482 break; 483 } 484 485 return 0; 486} 487 488const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 489 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 490 case Sema::TDK_Success: 491 case Sema::TDK_InstantiationDepth: 492 case Sema::TDK_Incomplete: 493 case Sema::TDK_TooManyArguments: 494 case Sema::TDK_TooFewArguments: 495 case Sema::TDK_InvalidExplicitArguments: 496 case Sema::TDK_SubstitutionFailure: 497 return 0; 498 499 case Sema::TDK_Inconsistent: 500 case Sema::TDK_Underqualified: 501 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 502 503 // Unhandled 504 case Sema::TDK_NonDeducedMismatch: 505 case Sema::TDK_FailedOverloadResolution: 506 break; 507 } 508 509 return 0; 510} 511 512const TemplateArgument * 513OverloadCandidate::DeductionFailureInfo::getSecondArg() { 514 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 515 case Sema::TDK_Success: 516 case Sema::TDK_InstantiationDepth: 517 case Sema::TDK_Incomplete: 518 case Sema::TDK_TooManyArguments: 519 case Sema::TDK_TooFewArguments: 520 case Sema::TDK_InvalidExplicitArguments: 521 case Sema::TDK_SubstitutionFailure: 522 return 0; 523 524 case Sema::TDK_Inconsistent: 525 case Sema::TDK_Underqualified: 526 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 527 528 // Unhandled 529 case Sema::TDK_NonDeducedMismatch: 530 case Sema::TDK_FailedOverloadResolution: 531 break; 532 } 533 534 return 0; 535} 536 537void OverloadCandidateSet::clear() { 538 inherited::clear(); 539 Functions.clear(); 540} 541 542// IsOverload - Determine whether the given New declaration is an 543// overload of the declarations in Old. This routine returns false if 544// New and Old cannot be overloaded, e.g., if New has the same 545// signature as some function in Old (C++ 1.3.10) or if the Old 546// declarations aren't functions (or function templates) at all. When 547// it does return false, MatchedDecl will point to the decl that New 548// cannot be overloaded with. This decl may be a UsingShadowDecl on 549// top of the underlying declaration. 550// 551// Example: Given the following input: 552// 553// void f(int, float); // #1 554// void f(int, int); // #2 555// int f(int, int); // #3 556// 557// When we process #1, there is no previous declaration of "f", 558// so IsOverload will not be used. 559// 560// When we process #2, Old contains only the FunctionDecl for #1. By 561// comparing the parameter types, we see that #1 and #2 are overloaded 562// (since they have different signatures), so this routine returns 563// false; MatchedDecl is unchanged. 564// 565// When we process #3, Old is an overload set containing #1 and #2. We 566// compare the signatures of #3 to #1 (they're overloaded, so we do 567// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 568// identical (return types of functions are not part of the 569// signature), IsOverload returns false and MatchedDecl will be set to 570// point to the FunctionDecl for #2. 571// 572// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 573// into a class by a using declaration. The rules for whether to hide 574// shadow declarations ignore some properties which otherwise figure 575// into a function template's signature. 576Sema::OverloadKind 577Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 578 NamedDecl *&Match, bool NewIsUsingDecl) { 579 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 580 I != E; ++I) { 581 NamedDecl *OldD = *I; 582 583 bool OldIsUsingDecl = false; 584 if (isa<UsingShadowDecl>(OldD)) { 585 OldIsUsingDecl = true; 586 587 // We can always introduce two using declarations into the same 588 // context, even if they have identical signatures. 589 if (NewIsUsingDecl) continue; 590 591 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 592 } 593 594 // If either declaration was introduced by a using declaration, 595 // we'll need to use slightly different rules for matching. 596 // Essentially, these rules are the normal rules, except that 597 // function templates hide function templates with different 598 // return types or template parameter lists. 599 bool UseMemberUsingDeclRules = 600 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 601 602 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 603 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 604 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 605 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 606 continue; 607 } 608 609 Match = *I; 610 return Ovl_Match; 611 } 612 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 613 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 614 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 615 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 616 continue; 617 } 618 619 Match = *I; 620 return Ovl_Match; 621 } 622 } else if (isa<UsingDecl>(OldD)) { 623 // We can overload with these, which can show up when doing 624 // redeclaration checks for UsingDecls. 625 assert(Old.getLookupKind() == LookupUsingDeclName); 626 } else if (isa<TagDecl>(OldD)) { 627 // We can always overload with tags by hiding them. 628 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 629 // Optimistically assume that an unresolved using decl will 630 // overload; if it doesn't, we'll have to diagnose during 631 // template instantiation. 632 } else { 633 // (C++ 13p1): 634 // Only function declarations can be overloaded; object and type 635 // declarations cannot be overloaded. 636 Match = *I; 637 return Ovl_NonFunction; 638 } 639 } 640 641 return Ovl_Overload; 642} 643 644bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 645 bool UseUsingDeclRules) { 646 // If both of the functions are extern "C", then they are not 647 // overloads. 648 if (Old->isExternC() && New->isExternC()) 649 return false; 650 651 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 652 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 653 654 // C++ [temp.fct]p2: 655 // A function template can be overloaded with other function templates 656 // and with normal (non-template) functions. 657 if ((OldTemplate == 0) != (NewTemplate == 0)) 658 return true; 659 660 // Is the function New an overload of the function Old? 661 QualType OldQType = Context.getCanonicalType(Old->getType()); 662 QualType NewQType = Context.getCanonicalType(New->getType()); 663 664 // Compare the signatures (C++ 1.3.10) of the two functions to 665 // determine whether they are overloads. If we find any mismatch 666 // in the signature, they are overloads. 667 668 // If either of these functions is a K&R-style function (no 669 // prototype), then we consider them to have matching signatures. 670 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 671 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 672 return false; 673 674 const FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 675 const FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 676 677 // The signature of a function includes the types of its 678 // parameters (C++ 1.3.10), which includes the presence or absence 679 // of the ellipsis; see C++ DR 357). 680 if (OldQType != NewQType && 681 (OldType->getNumArgs() != NewType->getNumArgs() || 682 OldType->isVariadic() != NewType->isVariadic() || 683 !FunctionArgTypesAreEqual(OldType, NewType))) 684 return true; 685 686 // C++ [temp.over.link]p4: 687 // The signature of a function template consists of its function 688 // signature, its return type and its template parameter list. The names 689 // of the template parameters are significant only for establishing the 690 // relationship between the template parameters and the rest of the 691 // signature. 692 // 693 // We check the return type and template parameter lists for function 694 // templates first; the remaining checks follow. 695 // 696 // However, we don't consider either of these when deciding whether 697 // a member introduced by a shadow declaration is hidden. 698 if (!UseUsingDeclRules && NewTemplate && 699 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 700 OldTemplate->getTemplateParameters(), 701 false, TPL_TemplateMatch) || 702 OldType->getResultType() != NewType->getResultType())) 703 return true; 704 705 // If the function is a class member, its signature includes the 706 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. 707 // 708 // As part of this, also check whether one of the member functions 709 // is static, in which case they are not overloads (C++ 710 // 13.1p2). While not part of the definition of the signature, 711 // this check is important to determine whether these functions 712 // can be overloaded. 713 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 714 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 715 if (OldMethod && NewMethod && 716 !OldMethod->isStatic() && !NewMethod->isStatic() && 717 (OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers() || 718 OldMethod->getRefQualifier() != NewMethod->getRefQualifier())) { 719 if (!UseUsingDeclRules && 720 OldMethod->getRefQualifier() != NewMethod->getRefQualifier() && 721 (OldMethod->getRefQualifier() == RQ_None || 722 NewMethod->getRefQualifier() == RQ_None)) { 723 // C++0x [over.load]p2: 724 // - Member function declarations with the same name and the same 725 // parameter-type-list as well as member function template 726 // declarations with the same name, the same parameter-type-list, and 727 // the same template parameter lists cannot be overloaded if any of 728 // them, but not all, have a ref-qualifier (8.3.5). 729 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) 730 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); 731 Diag(OldMethod->getLocation(), diag::note_previous_declaration); 732 } 733 734 return true; 735 } 736 737 // The signatures match; this is not an overload. 738 return false; 739} 740 741/// \brief Checks availability of the function depending on the current 742/// function context. Inside an unavailable function, unavailability is ignored. 743/// 744/// \returns true if \arg FD is unavailable and current context is inside 745/// an available function, false otherwise. 746bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) { 747 return FD->isUnavailable() && !cast<Decl>(CurContext)->isUnavailable(); 748} 749 750/// TryImplicitConversion - Attempt to perform an implicit conversion 751/// from the given expression (Expr) to the given type (ToType). This 752/// function returns an implicit conversion sequence that can be used 753/// to perform the initialization. Given 754/// 755/// void f(float f); 756/// void g(int i) { f(i); } 757/// 758/// this routine would produce an implicit conversion sequence to 759/// describe the initialization of f from i, which will be a standard 760/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 761/// 4.1) followed by a floating-integral conversion (C++ 4.9). 762// 763/// Note that this routine only determines how the conversion can be 764/// performed; it does not actually perform the conversion. As such, 765/// it will not produce any diagnostics if no conversion is available, 766/// but will instead return an implicit conversion sequence of kind 767/// "BadConversion". 768/// 769/// If @p SuppressUserConversions, then user-defined conversions are 770/// not permitted. 771/// If @p AllowExplicit, then explicit user-defined conversions are 772/// permitted. 773/// 774/// \param AllowObjCWritebackConversion Whether we allow the Objective-C 775/// writeback conversion, which allows __autoreleasing id* parameters to 776/// be initialized with __strong id* or __weak id* arguments. 777static ImplicitConversionSequence 778TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 779 bool SuppressUserConversions, 780 bool AllowExplicit, 781 bool InOverloadResolution, 782 bool CStyle, 783 bool AllowObjCWritebackConversion) { 784 ImplicitConversionSequence ICS; 785 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 786 ICS.Standard, CStyle, AllowObjCWritebackConversion)){ 787 ICS.setStandard(); 788 return ICS; 789 } 790 791 if (!S.getLangOptions().CPlusPlus) { 792 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 793 return ICS; 794 } 795 796 // C++ [over.ics.user]p4: 797 // A conversion of an expression of class type to the same class 798 // type is given Exact Match rank, and a conversion of an 799 // expression of class type to a base class of that type is 800 // given Conversion rank, in spite of the fact that a copy/move 801 // constructor (i.e., a user-defined conversion function) is 802 // called for those cases. 803 QualType FromType = From->getType(); 804 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 805 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 806 S.IsDerivedFrom(FromType, ToType))) { 807 ICS.setStandard(); 808 ICS.Standard.setAsIdentityConversion(); 809 ICS.Standard.setFromType(FromType); 810 ICS.Standard.setAllToTypes(ToType); 811 812 // We don't actually check at this point whether there is a valid 813 // copy/move constructor, since overloading just assumes that it 814 // exists. When we actually perform initialization, we'll find the 815 // appropriate constructor to copy the returned object, if needed. 816 ICS.Standard.CopyConstructor = 0; 817 818 // Determine whether this is considered a derived-to-base conversion. 819 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 820 ICS.Standard.Second = ICK_Derived_To_Base; 821 822 return ICS; 823 } 824 825 if (SuppressUserConversions) { 826 // We're not in the case above, so there is no conversion that 827 // we can perform. 828 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 829 return ICS; 830 } 831 832 // Attempt user-defined conversion. 833 OverloadCandidateSet Conversions(From->getExprLoc()); 834 OverloadingResult UserDefResult 835 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 836 AllowExplicit); 837 838 if (UserDefResult == OR_Success) { 839 ICS.setUserDefined(); 840 // C++ [over.ics.user]p4: 841 // A conversion of an expression of class type to the same class 842 // type is given Exact Match rank, and a conversion of an 843 // expression of class type to a base class of that type is 844 // given Conversion rank, in spite of the fact that a copy 845 // constructor (i.e., a user-defined conversion function) is 846 // called for those cases. 847 if (CXXConstructorDecl *Constructor 848 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 849 QualType FromCanon 850 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 851 QualType ToCanon 852 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 853 if (Constructor->isCopyConstructor() && 854 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 855 // Turn this into a "standard" conversion sequence, so that it 856 // gets ranked with standard conversion sequences. 857 ICS.setStandard(); 858 ICS.Standard.setAsIdentityConversion(); 859 ICS.Standard.setFromType(From->getType()); 860 ICS.Standard.setAllToTypes(ToType); 861 ICS.Standard.CopyConstructor = Constructor; 862 if (ToCanon != FromCanon) 863 ICS.Standard.Second = ICK_Derived_To_Base; 864 } 865 } 866 867 // C++ [over.best.ics]p4: 868 // However, when considering the argument of a user-defined 869 // conversion function that is a candidate by 13.3.1.3 when 870 // invoked for the copying of the temporary in the second step 871 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 872 // 13.3.1.6 in all cases, only standard conversion sequences and 873 // ellipsis conversion sequences are allowed. 874 if (SuppressUserConversions && ICS.isUserDefined()) { 875 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 876 } 877 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 878 ICS.setAmbiguous(); 879 ICS.Ambiguous.setFromType(From->getType()); 880 ICS.Ambiguous.setToType(ToType); 881 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 882 Cand != Conversions.end(); ++Cand) 883 if (Cand->Viable) 884 ICS.Ambiguous.addConversion(Cand->Function); 885 } else { 886 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 887 } 888 889 return ICS; 890} 891 892ImplicitConversionSequence 893Sema::TryImplicitConversion(Expr *From, QualType ToType, 894 bool SuppressUserConversions, 895 bool AllowExplicit, 896 bool InOverloadResolution, 897 bool CStyle, 898 bool AllowObjCWritebackConversion) { 899 return clang::TryImplicitConversion(*this, From, ToType, 900 SuppressUserConversions, AllowExplicit, 901 InOverloadResolution, CStyle, 902 AllowObjCWritebackConversion); 903} 904 905/// PerformImplicitConversion - Perform an implicit conversion of the 906/// expression From to the type ToType. Returns the 907/// converted expression. Flavor is the kind of conversion we're 908/// performing, used in the error message. If @p AllowExplicit, 909/// explicit user-defined conversions are permitted. 910ExprResult 911Sema::PerformImplicitConversion(Expr *From, QualType ToType, 912 AssignmentAction Action, bool AllowExplicit) { 913 ImplicitConversionSequence ICS; 914 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 915} 916 917ExprResult 918Sema::PerformImplicitConversion(Expr *From, QualType ToType, 919 AssignmentAction Action, bool AllowExplicit, 920 ImplicitConversionSequence& ICS) { 921 // Objective-C ARC: Determine whether we will allow the writeback conversion. 922 bool AllowObjCWritebackConversion 923 = getLangOptions().ObjCAutoRefCount && 924 (Action == AA_Passing || Action == AA_Sending); 925 926 927 ICS = clang::TryImplicitConversion(*this, From, ToType, 928 /*SuppressUserConversions=*/false, 929 AllowExplicit, 930 /*InOverloadResolution=*/false, 931 /*CStyle=*/false, 932 AllowObjCWritebackConversion); 933 return PerformImplicitConversion(From, ToType, ICS, Action); 934} 935 936/// \brief Determine whether the conversion from FromType to ToType is a valid 937/// conversion that strips "noreturn" off the nested function type. 938bool Sema::IsNoReturnConversion(QualType FromType, QualType ToType, 939 QualType &ResultTy) { 940 if (Context.hasSameUnqualifiedType(FromType, ToType)) 941 return false; 942 943 // Permit the conversion F(t __attribute__((noreturn))) -> F(t) 944 // where F adds one of the following at most once: 945 // - a pointer 946 // - a member pointer 947 // - a block pointer 948 CanQualType CanTo = Context.getCanonicalType(ToType); 949 CanQualType CanFrom = Context.getCanonicalType(FromType); 950 Type::TypeClass TyClass = CanTo->getTypeClass(); 951 if (TyClass != CanFrom->getTypeClass()) return false; 952 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { 953 if (TyClass == Type::Pointer) { 954 CanTo = CanTo.getAs<PointerType>()->getPointeeType(); 955 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType(); 956 } else if (TyClass == Type::BlockPointer) { 957 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType(); 958 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType(); 959 } else if (TyClass == Type::MemberPointer) { 960 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType(); 961 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType(); 962 } else { 963 return false; 964 } 965 966 TyClass = CanTo->getTypeClass(); 967 if (TyClass != CanFrom->getTypeClass()) return false; 968 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) 969 return false; 970 } 971 972 const FunctionType *FromFn = cast<FunctionType>(CanFrom); 973 FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); 974 if (!EInfo.getNoReturn()) return false; 975 976 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); 977 assert(QualType(FromFn, 0).isCanonical()); 978 if (QualType(FromFn, 0) != CanTo) return false; 979 980 ResultTy = ToType; 981 return true; 982} 983 984/// \brief Determine whether the conversion from FromType to ToType is a valid 985/// vector conversion. 986/// 987/// \param ICK Will be set to the vector conversion kind, if this is a vector 988/// conversion. 989static bool IsVectorConversion(ASTContext &Context, QualType FromType, 990 QualType ToType, ImplicitConversionKind &ICK) { 991 // We need at least one of these types to be a vector type to have a vector 992 // conversion. 993 if (!ToType->isVectorType() && !FromType->isVectorType()) 994 return false; 995 996 // Identical types require no conversions. 997 if (Context.hasSameUnqualifiedType(FromType, ToType)) 998 return false; 999 1000 // There are no conversions between extended vector types, only identity. 1001 if (ToType->isExtVectorType()) { 1002 // There are no conversions between extended vector types other than the 1003 // identity conversion. 1004 if (FromType->isExtVectorType()) 1005 return false; 1006 1007 // Vector splat from any arithmetic type to a vector. 1008 if (FromType->isArithmeticType()) { 1009 ICK = ICK_Vector_Splat; 1010 return true; 1011 } 1012 } 1013 1014 // We can perform the conversion between vector types in the following cases: 1015 // 1)vector types are equivalent AltiVec and GCC vector types 1016 // 2)lax vector conversions are permitted and the vector types are of the 1017 // same size 1018 if (ToType->isVectorType() && FromType->isVectorType()) { 1019 if (Context.areCompatibleVectorTypes(FromType, ToType) || 1020 (Context.getLangOptions().LaxVectorConversions && 1021 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 1022 ICK = ICK_Vector_Conversion; 1023 return true; 1024 } 1025 } 1026 1027 return false; 1028} 1029 1030/// IsStandardConversion - Determines whether there is a standard 1031/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 1032/// expression From to the type ToType. Standard conversion sequences 1033/// only consider non-class types; for conversions that involve class 1034/// types, use TryImplicitConversion. If a conversion exists, SCS will 1035/// contain the standard conversion sequence required to perform this 1036/// conversion and this routine will return true. Otherwise, this 1037/// routine will return false and the value of SCS is unspecified. 1038static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 1039 bool InOverloadResolution, 1040 StandardConversionSequence &SCS, 1041 bool CStyle, 1042 bool AllowObjCWritebackConversion) { 1043 QualType FromType = From->getType(); 1044 1045 // Standard conversions (C++ [conv]) 1046 SCS.setAsIdentityConversion(); 1047 SCS.DeprecatedStringLiteralToCharPtr = false; 1048 SCS.IncompatibleObjC = false; 1049 SCS.setFromType(FromType); 1050 SCS.CopyConstructor = 0; 1051 1052 // There are no standard conversions for class types in C++, so 1053 // abort early. When overloading in C, however, we do permit 1054 if (FromType->isRecordType() || ToType->isRecordType()) { 1055 if (S.getLangOptions().CPlusPlus) 1056 return false; 1057 1058 // When we're overloading in C, we allow, as standard conversions, 1059 } 1060 1061 // The first conversion can be an lvalue-to-rvalue conversion, 1062 // array-to-pointer conversion, or function-to-pointer conversion 1063 // (C++ 4p1). 1064 1065 if (FromType == S.Context.OverloadTy) { 1066 DeclAccessPair AccessPair; 1067 if (FunctionDecl *Fn 1068 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 1069 AccessPair)) { 1070 // We were able to resolve the address of the overloaded function, 1071 // so we can convert to the type of that function. 1072 FromType = Fn->getType(); 1073 1074 // we can sometimes resolve &foo<int> regardless of ToType, so check 1075 // if the type matches (identity) or we are converting to bool 1076 if (!S.Context.hasSameUnqualifiedType( 1077 S.ExtractUnqualifiedFunctionType(ToType), FromType)) { 1078 QualType resultTy; 1079 // if the function type matches except for [[noreturn]], it's ok 1080 if (!S.IsNoReturnConversion(FromType, 1081 S.ExtractUnqualifiedFunctionType(ToType), resultTy)) 1082 // otherwise, only a boolean conversion is standard 1083 if (!ToType->isBooleanType()) 1084 return false; 1085 } 1086 1087 // Check if the "from" expression is taking the address of an overloaded 1088 // function and recompute the FromType accordingly. Take advantage of the 1089 // fact that non-static member functions *must* have such an address-of 1090 // expression. 1091 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn); 1092 if (Method && !Method->isStatic()) { 1093 assert(isa<UnaryOperator>(From->IgnoreParens()) && 1094 "Non-unary operator on non-static member address"); 1095 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() 1096 == UO_AddrOf && 1097 "Non-address-of operator on non-static member address"); 1098 const Type *ClassType 1099 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1100 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1101 } else if (isa<UnaryOperator>(From->IgnoreParens())) { 1102 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == 1103 UO_AddrOf && 1104 "Non-address-of operator for overloaded function expression"); 1105 FromType = S.Context.getPointerType(FromType); 1106 } 1107 1108 // Check that we've computed the proper type after overload resolution. 1109 assert(S.Context.hasSameType( 1110 FromType, 1111 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1112 } else { 1113 return false; 1114 } 1115 } 1116 // Lvalue-to-rvalue conversion (C++11 4.1): 1117 // A glvalue (3.10) of a non-function, non-array type T can 1118 // be converted to a prvalue. 1119 bool argIsLValue = From->isGLValue(); 1120 if (argIsLValue && 1121 !FromType->isFunctionType() && !FromType->isArrayType() && 1122 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1123 SCS.First = ICK_Lvalue_To_Rvalue; 1124 1125 // If T is a non-class type, the type of the rvalue is the 1126 // cv-unqualified version of T. Otherwise, the type of the rvalue 1127 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1128 // just strip the qualifiers because they don't matter. 1129 FromType = FromType.getUnqualifiedType(); 1130 } else if (FromType->isArrayType()) { 1131 // Array-to-pointer conversion (C++ 4.2) 1132 SCS.First = ICK_Array_To_Pointer; 1133 1134 // An lvalue or rvalue of type "array of N T" or "array of unknown 1135 // bound of T" can be converted to an rvalue of type "pointer to 1136 // T" (C++ 4.2p1). 1137 FromType = S.Context.getArrayDecayedType(FromType); 1138 1139 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1140 // This conversion is deprecated. (C++ D.4). 1141 SCS.DeprecatedStringLiteralToCharPtr = true; 1142 1143 // For the purpose of ranking in overload resolution 1144 // (13.3.3.1.1), this conversion is considered an 1145 // array-to-pointer conversion followed by a qualification 1146 // conversion (4.4). (C++ 4.2p2) 1147 SCS.Second = ICK_Identity; 1148 SCS.Third = ICK_Qualification; 1149 SCS.QualificationIncludesObjCLifetime = false; 1150 SCS.setAllToTypes(FromType); 1151 return true; 1152 } 1153 } else if (FromType->isFunctionType() && argIsLValue) { 1154 // Function-to-pointer conversion (C++ 4.3). 1155 SCS.First = ICK_Function_To_Pointer; 1156 1157 // An lvalue of function type T can be converted to an rvalue of 1158 // type "pointer to T." The result is a pointer to the 1159 // function. (C++ 4.3p1). 1160 FromType = S.Context.getPointerType(FromType); 1161 } else { 1162 // We don't require any conversions for the first step. 1163 SCS.First = ICK_Identity; 1164 } 1165 SCS.setToType(0, FromType); 1166 1167 // The second conversion can be an integral promotion, floating 1168 // point promotion, integral conversion, floating point conversion, 1169 // floating-integral conversion, pointer conversion, 1170 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1171 // For overloading in C, this can also be a "compatible-type" 1172 // conversion. 1173 bool IncompatibleObjC = false; 1174 ImplicitConversionKind SecondICK = ICK_Identity; 1175 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1176 // The unqualified versions of the types are the same: there's no 1177 // conversion to do. 1178 SCS.Second = ICK_Identity; 1179 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1180 // Integral promotion (C++ 4.5). 1181 SCS.Second = ICK_Integral_Promotion; 1182 FromType = ToType.getUnqualifiedType(); 1183 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1184 // Floating point promotion (C++ 4.6). 1185 SCS.Second = ICK_Floating_Promotion; 1186 FromType = ToType.getUnqualifiedType(); 1187 } else if (S.IsComplexPromotion(FromType, ToType)) { 1188 // Complex promotion (Clang extension) 1189 SCS.Second = ICK_Complex_Promotion; 1190 FromType = ToType.getUnqualifiedType(); 1191 } else if (ToType->isBooleanType() && 1192 (FromType->isArithmeticType() || 1193 FromType->isAnyPointerType() || 1194 FromType->isBlockPointerType() || 1195 FromType->isMemberPointerType() || 1196 FromType->isNullPtrType())) { 1197 // Boolean conversions (C++ 4.12). 1198 SCS.Second = ICK_Boolean_Conversion; 1199 FromType = S.Context.BoolTy; 1200 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1201 ToType->isIntegralType(S.Context)) { 1202 // Integral conversions (C++ 4.7). 1203 SCS.Second = ICK_Integral_Conversion; 1204 FromType = ToType.getUnqualifiedType(); 1205 } else if (FromType->isAnyComplexType() && ToType->isComplexType()) { 1206 // Complex conversions (C99 6.3.1.6) 1207 SCS.Second = ICK_Complex_Conversion; 1208 FromType = ToType.getUnqualifiedType(); 1209 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1210 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1211 // Complex-real conversions (C99 6.3.1.7) 1212 SCS.Second = ICK_Complex_Real; 1213 FromType = ToType.getUnqualifiedType(); 1214 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1215 // Floating point conversions (C++ 4.8). 1216 SCS.Second = ICK_Floating_Conversion; 1217 FromType = ToType.getUnqualifiedType(); 1218 } else if ((FromType->isRealFloatingType() && 1219 ToType->isIntegralType(S.Context)) || 1220 (FromType->isIntegralOrUnscopedEnumerationType() && 1221 ToType->isRealFloatingType())) { 1222 // Floating-integral conversions (C++ 4.9). 1223 SCS.Second = ICK_Floating_Integral; 1224 FromType = ToType.getUnqualifiedType(); 1225 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { 1226 SCS.Second = ICK_Block_Pointer_Conversion; 1227 } else if (AllowObjCWritebackConversion && 1228 S.isObjCWritebackConversion(FromType, ToType, FromType)) { 1229 SCS.Second = ICK_Writeback_Conversion; 1230 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1231 FromType, IncompatibleObjC)) { 1232 // Pointer conversions (C++ 4.10). 1233 SCS.Second = ICK_Pointer_Conversion; 1234 SCS.IncompatibleObjC = IncompatibleObjC; 1235 FromType = FromType.getUnqualifiedType(); 1236 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1237 InOverloadResolution, FromType)) { 1238 // Pointer to member conversions (4.11). 1239 SCS.Second = ICK_Pointer_Member; 1240 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1241 SCS.Second = SecondICK; 1242 FromType = ToType.getUnqualifiedType(); 1243 } else if (!S.getLangOptions().CPlusPlus && 1244 S.Context.typesAreCompatible(ToType, FromType)) { 1245 // Compatible conversions (Clang extension for C function overloading) 1246 SCS.Second = ICK_Compatible_Conversion; 1247 FromType = ToType.getUnqualifiedType(); 1248 } else if (S.IsNoReturnConversion(FromType, ToType, FromType)) { 1249 // Treat a conversion that strips "noreturn" as an identity conversion. 1250 SCS.Second = ICK_NoReturn_Adjustment; 1251 } else if (IsTransparentUnionStandardConversion(S, From, ToType, 1252 InOverloadResolution, 1253 SCS, CStyle)) { 1254 SCS.Second = ICK_TransparentUnionConversion; 1255 FromType = ToType; 1256 } else { 1257 // No second conversion required. 1258 SCS.Second = ICK_Identity; 1259 } 1260 SCS.setToType(1, FromType); 1261 1262 QualType CanonFrom; 1263 QualType CanonTo; 1264 // The third conversion can be a qualification conversion (C++ 4p1). 1265 bool ObjCLifetimeConversion; 1266 if (S.IsQualificationConversion(FromType, ToType, CStyle, 1267 ObjCLifetimeConversion)) { 1268 SCS.Third = ICK_Qualification; 1269 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion; 1270 FromType = ToType; 1271 CanonFrom = S.Context.getCanonicalType(FromType); 1272 CanonTo = S.Context.getCanonicalType(ToType); 1273 } else { 1274 // No conversion required 1275 SCS.Third = ICK_Identity; 1276 1277 // C++ [over.best.ics]p6: 1278 // [...] Any difference in top-level cv-qualification is 1279 // subsumed by the initialization itself and does not constitute 1280 // a conversion. [...] 1281 CanonFrom = S.Context.getCanonicalType(FromType); 1282 CanonTo = S.Context.getCanonicalType(ToType); 1283 if (CanonFrom.getLocalUnqualifiedType() 1284 == CanonTo.getLocalUnqualifiedType() && 1285 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1286 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr() 1287 || CanonFrom.getObjCLifetime() != CanonTo.getObjCLifetime())) { 1288 FromType = ToType; 1289 CanonFrom = CanonTo; 1290 } 1291 } 1292 SCS.setToType(2, FromType); 1293 1294 // If we have not converted the argument type to the parameter type, 1295 // this is a bad conversion sequence. 1296 if (CanonFrom != CanonTo) 1297 return false; 1298 1299 return true; 1300} 1301 1302static bool 1303IsTransparentUnionStandardConversion(Sema &S, Expr* From, 1304 QualType &ToType, 1305 bool InOverloadResolution, 1306 StandardConversionSequence &SCS, 1307 bool CStyle) { 1308 1309 const RecordType *UT = ToType->getAsUnionType(); 1310 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 1311 return false; 1312 // The field to initialize within the transparent union. 1313 RecordDecl *UD = UT->getDecl(); 1314 // It's compatible if the expression matches any of the fields. 1315 for (RecordDecl::field_iterator it = UD->field_begin(), 1316 itend = UD->field_end(); 1317 it != itend; ++it) { 1318 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, 1319 CStyle, /*ObjCWritebackConversion=*/false)) { 1320 ToType = it->getType(); 1321 return true; 1322 } 1323 } 1324 return false; 1325} 1326 1327/// IsIntegralPromotion - Determines whether the conversion from the 1328/// expression From (whose potentially-adjusted type is FromType) to 1329/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1330/// sets PromotedType to the promoted type. 1331bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1332 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1333 // All integers are built-in. 1334 if (!To) { 1335 return false; 1336 } 1337 1338 // An rvalue of type char, signed char, unsigned char, short int, or 1339 // unsigned short int can be converted to an rvalue of type int if 1340 // int can represent all the values of the source type; otherwise, 1341 // the source rvalue can be converted to an rvalue of type unsigned 1342 // int (C++ 4.5p1). 1343 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1344 !FromType->isEnumeralType()) { 1345 if (// We can promote any signed, promotable integer type to an int 1346 (FromType->isSignedIntegerType() || 1347 // We can promote any unsigned integer type whose size is 1348 // less than int to an int. 1349 (!FromType->isSignedIntegerType() && 1350 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1351 return To->getKind() == BuiltinType::Int; 1352 } 1353 1354 return To->getKind() == BuiltinType::UInt; 1355 } 1356 1357 // C++0x [conv.prom]p3: 1358 // A prvalue of an unscoped enumeration type whose underlying type is not 1359 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1360 // following types that can represent all the values of the enumeration 1361 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1362 // unsigned int, long int, unsigned long int, long long int, or unsigned 1363 // long long int. If none of the types in that list can represent all the 1364 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1365 // type can be converted to an rvalue a prvalue of the extended integer type 1366 // with lowest integer conversion rank (4.13) greater than the rank of long 1367 // long in which all the values of the enumeration can be represented. If 1368 // there are two such extended types, the signed one is chosen. 1369 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1370 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1371 // provided for a scoped enumeration. 1372 if (FromEnumType->getDecl()->isScoped()) 1373 return false; 1374 1375 // We have already pre-calculated the promotion type, so this is trivial. 1376 if (ToType->isIntegerType() && 1377 !RequireCompleteType(From->getLocStart(), FromType, PDiag())) 1378 return Context.hasSameUnqualifiedType(ToType, 1379 FromEnumType->getDecl()->getPromotionType()); 1380 } 1381 1382 // C++0x [conv.prom]p2: 1383 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1384 // to an rvalue a prvalue of the first of the following types that can 1385 // represent all the values of its underlying type: int, unsigned int, 1386 // long int, unsigned long int, long long int, or unsigned long long int. 1387 // If none of the types in that list can represent all the values of its 1388 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1389 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1390 // type. 1391 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1392 ToType->isIntegerType()) { 1393 // Determine whether the type we're converting from is signed or 1394 // unsigned. 1395 bool FromIsSigned = FromType->isSignedIntegerType(); 1396 uint64_t FromSize = Context.getTypeSize(FromType); 1397 1398 // The types we'll try to promote to, in the appropriate 1399 // order. Try each of these types. 1400 QualType PromoteTypes[6] = { 1401 Context.IntTy, Context.UnsignedIntTy, 1402 Context.LongTy, Context.UnsignedLongTy , 1403 Context.LongLongTy, Context.UnsignedLongLongTy 1404 }; 1405 for (int Idx = 0; Idx < 6; ++Idx) { 1406 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1407 if (FromSize < ToSize || 1408 (FromSize == ToSize && 1409 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1410 // We found the type that we can promote to. If this is the 1411 // type we wanted, we have a promotion. Otherwise, no 1412 // promotion. 1413 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1414 } 1415 } 1416 } 1417 1418 // An rvalue for an integral bit-field (9.6) can be converted to an 1419 // rvalue of type int if int can represent all the values of the 1420 // bit-field; otherwise, it can be converted to unsigned int if 1421 // unsigned int can represent all the values of the bit-field. If 1422 // the bit-field is larger yet, no integral promotion applies to 1423 // it. If the bit-field has an enumerated type, it is treated as any 1424 // other value of that type for promotion purposes (C++ 4.5p3). 1425 // FIXME: We should delay checking of bit-fields until we actually perform the 1426 // conversion. 1427 using llvm::APSInt; 1428 if (From) 1429 if (FieldDecl *MemberDecl = From->getBitField()) { 1430 APSInt BitWidth; 1431 if (FromType->isIntegralType(Context) && 1432 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1433 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1434 ToSize = Context.getTypeSize(ToType); 1435 1436 // Are we promoting to an int from a bitfield that fits in an int? 1437 if (BitWidth < ToSize || 1438 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1439 return To->getKind() == BuiltinType::Int; 1440 } 1441 1442 // Are we promoting to an unsigned int from an unsigned bitfield 1443 // that fits into an unsigned int? 1444 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1445 return To->getKind() == BuiltinType::UInt; 1446 } 1447 1448 return false; 1449 } 1450 } 1451 1452 // An rvalue of type bool can be converted to an rvalue of type int, 1453 // with false becoming zero and true becoming one (C++ 4.5p4). 1454 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1455 return true; 1456 } 1457 1458 return false; 1459} 1460 1461/// IsFloatingPointPromotion - Determines whether the conversion from 1462/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1463/// returns true and sets PromotedType to the promoted type. 1464bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1465 /// An rvalue of type float can be converted to an rvalue of type 1466 /// double. (C++ 4.6p1). 1467 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1468 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1469 if (FromBuiltin->getKind() == BuiltinType::Float && 1470 ToBuiltin->getKind() == BuiltinType::Double) 1471 return true; 1472 1473 // C99 6.3.1.5p1: 1474 // When a float is promoted to double or long double, or a 1475 // double is promoted to long double [...]. 1476 if (!getLangOptions().CPlusPlus && 1477 (FromBuiltin->getKind() == BuiltinType::Float || 1478 FromBuiltin->getKind() == BuiltinType::Double) && 1479 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1480 return true; 1481 } 1482 1483 return false; 1484} 1485 1486/// \brief Determine if a conversion is a complex promotion. 1487/// 1488/// A complex promotion is defined as a complex -> complex conversion 1489/// where the conversion between the underlying real types is a 1490/// floating-point or integral promotion. 1491bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1492 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1493 if (!FromComplex) 1494 return false; 1495 1496 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1497 if (!ToComplex) 1498 return false; 1499 1500 return IsFloatingPointPromotion(FromComplex->getElementType(), 1501 ToComplex->getElementType()) || 1502 IsIntegralPromotion(0, FromComplex->getElementType(), 1503 ToComplex->getElementType()); 1504} 1505 1506/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1507/// the pointer type FromPtr to a pointer to type ToPointee, with the 1508/// same type qualifiers as FromPtr has on its pointee type. ToType, 1509/// if non-empty, will be a pointer to ToType that may or may not have 1510/// the right set of qualifiers on its pointee. 1511/// 1512static QualType 1513BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1514 QualType ToPointee, QualType ToType, 1515 ASTContext &Context, 1516 bool StripObjCLifetime = false) { 1517 assert((FromPtr->getTypeClass() == Type::Pointer || 1518 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1519 "Invalid similarly-qualified pointer type"); 1520 1521 /// Conversions to 'id' subsume cv-qualifier conversions. 1522 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1523 return ToType.getUnqualifiedType(); 1524 1525 QualType CanonFromPointee 1526 = Context.getCanonicalType(FromPtr->getPointeeType()); 1527 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1528 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1529 1530 if (StripObjCLifetime) 1531 Quals.removeObjCLifetime(); 1532 1533 // Exact qualifier match -> return the pointer type we're converting to. 1534 if (CanonToPointee.getLocalQualifiers() == Quals) { 1535 // ToType is exactly what we need. Return it. 1536 if (!ToType.isNull()) 1537 return ToType.getUnqualifiedType(); 1538 1539 // Build a pointer to ToPointee. It has the right qualifiers 1540 // already. 1541 if (isa<ObjCObjectPointerType>(ToType)) 1542 return Context.getObjCObjectPointerType(ToPointee); 1543 return Context.getPointerType(ToPointee); 1544 } 1545 1546 // Just build a canonical type that has the right qualifiers. 1547 QualType QualifiedCanonToPointee 1548 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1549 1550 if (isa<ObjCObjectPointerType>(ToType)) 1551 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1552 return Context.getPointerType(QualifiedCanonToPointee); 1553} 1554 1555static bool isNullPointerConstantForConversion(Expr *Expr, 1556 bool InOverloadResolution, 1557 ASTContext &Context) { 1558 // Handle value-dependent integral null pointer constants correctly. 1559 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1560 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1561 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1562 return !InOverloadResolution; 1563 1564 return Expr->isNullPointerConstant(Context, 1565 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1566 : Expr::NPC_ValueDependentIsNull); 1567} 1568 1569/// IsPointerConversion - Determines whether the conversion of the 1570/// expression From, which has the (possibly adjusted) type FromType, 1571/// can be converted to the type ToType via a pointer conversion (C++ 1572/// 4.10). If so, returns true and places the converted type (that 1573/// might differ from ToType in its cv-qualifiers at some level) into 1574/// ConvertedType. 1575/// 1576/// This routine also supports conversions to and from block pointers 1577/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1578/// pointers to interfaces. FIXME: Once we've determined the 1579/// appropriate overloading rules for Objective-C, we may want to 1580/// split the Objective-C checks into a different routine; however, 1581/// GCC seems to consider all of these conversions to be pointer 1582/// conversions, so for now they live here. IncompatibleObjC will be 1583/// set if the conversion is an allowed Objective-C conversion that 1584/// should result in a warning. 1585bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1586 bool InOverloadResolution, 1587 QualType& ConvertedType, 1588 bool &IncompatibleObjC) { 1589 IncompatibleObjC = false; 1590 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 1591 IncompatibleObjC)) 1592 return true; 1593 1594 // Conversion from a null pointer constant to any Objective-C pointer type. 1595 if (ToType->isObjCObjectPointerType() && 1596 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1597 ConvertedType = ToType; 1598 return true; 1599 } 1600 1601 // Blocks: Block pointers can be converted to void*. 1602 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1603 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1604 ConvertedType = ToType; 1605 return true; 1606 } 1607 // Blocks: A null pointer constant can be converted to a block 1608 // pointer type. 1609 if (ToType->isBlockPointerType() && 1610 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1611 ConvertedType = ToType; 1612 return true; 1613 } 1614 1615 // If the left-hand-side is nullptr_t, the right side can be a null 1616 // pointer constant. 1617 if (ToType->isNullPtrType() && 1618 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1619 ConvertedType = ToType; 1620 return true; 1621 } 1622 1623 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1624 if (!ToTypePtr) 1625 return false; 1626 1627 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1628 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1629 ConvertedType = ToType; 1630 return true; 1631 } 1632 1633 // Beyond this point, both types need to be pointers 1634 // , including objective-c pointers. 1635 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1636 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() && 1637 !getLangOptions().ObjCAutoRefCount) { 1638 ConvertedType = BuildSimilarlyQualifiedPointerType( 1639 FromType->getAs<ObjCObjectPointerType>(), 1640 ToPointeeType, 1641 ToType, Context); 1642 return true; 1643 } 1644 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1645 if (!FromTypePtr) 1646 return false; 1647 1648 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1649 1650 // If the unqualified pointee types are the same, this can't be a 1651 // pointer conversion, so don't do all of the work below. 1652 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1653 return false; 1654 1655 // An rvalue of type "pointer to cv T," where T is an object type, 1656 // can be converted to an rvalue of type "pointer to cv void" (C++ 1657 // 4.10p2). 1658 if (FromPointeeType->isIncompleteOrObjectType() && 1659 ToPointeeType->isVoidType()) { 1660 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1661 ToPointeeType, 1662 ToType, Context, 1663 /*StripObjCLifetime=*/true); 1664 return true; 1665 } 1666 1667 // MSVC allows implicit function to void* type conversion. 1668 if (getLangOptions().Microsoft && FromPointeeType->isFunctionType() && 1669 ToPointeeType->isVoidType()) { 1670 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1671 ToPointeeType, 1672 ToType, Context); 1673 return true; 1674 } 1675 1676 // When we're overloading in C, we allow a special kind of pointer 1677 // conversion for compatible-but-not-identical pointee types. 1678 if (!getLangOptions().CPlusPlus && 1679 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1680 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1681 ToPointeeType, 1682 ToType, Context); 1683 return true; 1684 } 1685 1686 // C++ [conv.ptr]p3: 1687 // 1688 // An rvalue of type "pointer to cv D," where D is a class type, 1689 // can be converted to an rvalue of type "pointer to cv B," where 1690 // B is a base class (clause 10) of D. If B is an inaccessible 1691 // (clause 11) or ambiguous (10.2) base class of D, a program that 1692 // necessitates this conversion is ill-formed. The result of the 1693 // conversion is a pointer to the base class sub-object of the 1694 // derived class object. The null pointer value is converted to 1695 // the null pointer value of the destination type. 1696 // 1697 // Note that we do not check for ambiguity or inaccessibility 1698 // here. That is handled by CheckPointerConversion. 1699 if (getLangOptions().CPlusPlus && 1700 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1701 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1702 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1703 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1704 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1705 ToPointeeType, 1706 ToType, Context); 1707 return true; 1708 } 1709 1710 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() && 1711 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) { 1712 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1713 ToPointeeType, 1714 ToType, Context); 1715 return true; 1716 } 1717 1718 return false; 1719} 1720 1721/// \brief Adopt the given qualifiers for the given type. 1722static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){ 1723 Qualifiers TQs = T.getQualifiers(); 1724 1725 // Check whether qualifiers already match. 1726 if (TQs == Qs) 1727 return T; 1728 1729 if (Qs.compatiblyIncludes(TQs)) 1730 return Context.getQualifiedType(T, Qs); 1731 1732 return Context.getQualifiedType(T.getUnqualifiedType(), Qs); 1733} 1734 1735/// isObjCPointerConversion - Determines whether this is an 1736/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1737/// with the same arguments and return values. 1738bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1739 QualType& ConvertedType, 1740 bool &IncompatibleObjC) { 1741 if (!getLangOptions().ObjC1) 1742 return false; 1743 1744 // The set of qualifiers on the type we're converting from. 1745 Qualifiers FromQualifiers = FromType.getQualifiers(); 1746 1747 // First, we handle all conversions on ObjC object pointer types. 1748 const ObjCObjectPointerType* ToObjCPtr = 1749 ToType->getAs<ObjCObjectPointerType>(); 1750 const ObjCObjectPointerType *FromObjCPtr = 1751 FromType->getAs<ObjCObjectPointerType>(); 1752 1753 if (ToObjCPtr && FromObjCPtr) { 1754 // If the pointee types are the same (ignoring qualifications), 1755 // then this is not a pointer conversion. 1756 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 1757 FromObjCPtr->getPointeeType())) 1758 return false; 1759 1760 // Check for compatible 1761 // Objective C++: We're able to convert between "id" or "Class" and a 1762 // pointer to any interface (in both directions). 1763 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1764 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1765 return true; 1766 } 1767 // Conversions with Objective-C's id<...>. 1768 if ((FromObjCPtr->isObjCQualifiedIdType() || 1769 ToObjCPtr->isObjCQualifiedIdType()) && 1770 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1771 /*compare=*/false)) { 1772 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1773 return true; 1774 } 1775 // Objective C++: We're able to convert from a pointer to an 1776 // interface to a pointer to a different interface. 1777 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1778 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1779 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1780 if (getLangOptions().CPlusPlus && LHS && RHS && 1781 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1782 FromObjCPtr->getPointeeType())) 1783 return false; 1784 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1785 ToObjCPtr->getPointeeType(), 1786 ToType, Context); 1787 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 1788 return true; 1789 } 1790 1791 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1792 // Okay: this is some kind of implicit downcast of Objective-C 1793 // interfaces, which is permitted. However, we're going to 1794 // complain about it. 1795 IncompatibleObjC = true; 1796 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1797 ToObjCPtr->getPointeeType(), 1798 ToType, Context); 1799 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 1800 return true; 1801 } 1802 } 1803 // Beyond this point, both types need to be C pointers or block pointers. 1804 QualType ToPointeeType; 1805 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1806 ToPointeeType = ToCPtr->getPointeeType(); 1807 else if (const BlockPointerType *ToBlockPtr = 1808 ToType->getAs<BlockPointerType>()) { 1809 // Objective C++: We're able to convert from a pointer to any object 1810 // to a block pointer type. 1811 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1812 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1813 return true; 1814 } 1815 ToPointeeType = ToBlockPtr->getPointeeType(); 1816 } 1817 else if (FromType->getAs<BlockPointerType>() && 1818 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1819 // Objective C++: We're able to convert from a block pointer type to a 1820 // pointer to any object. 1821 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1822 return true; 1823 } 1824 else 1825 return false; 1826 1827 QualType FromPointeeType; 1828 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1829 FromPointeeType = FromCPtr->getPointeeType(); 1830 else if (const BlockPointerType *FromBlockPtr = 1831 FromType->getAs<BlockPointerType>()) 1832 FromPointeeType = FromBlockPtr->getPointeeType(); 1833 else 1834 return false; 1835 1836 // If we have pointers to pointers, recursively check whether this 1837 // is an Objective-C conversion. 1838 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1839 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1840 IncompatibleObjC)) { 1841 // We always complain about this conversion. 1842 IncompatibleObjC = true; 1843 ConvertedType = Context.getPointerType(ConvertedType); 1844 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 1845 return true; 1846 } 1847 // Allow conversion of pointee being objective-c pointer to another one; 1848 // as in I* to id. 1849 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1850 ToPointeeType->getAs<ObjCObjectPointerType>() && 1851 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1852 IncompatibleObjC)) { 1853 1854 ConvertedType = Context.getPointerType(ConvertedType); 1855 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 1856 return true; 1857 } 1858 1859 // If we have pointers to functions or blocks, check whether the only 1860 // differences in the argument and result types are in Objective-C 1861 // pointer conversions. If so, we permit the conversion (but 1862 // complain about it). 1863 const FunctionProtoType *FromFunctionType 1864 = FromPointeeType->getAs<FunctionProtoType>(); 1865 const FunctionProtoType *ToFunctionType 1866 = ToPointeeType->getAs<FunctionProtoType>(); 1867 if (FromFunctionType && ToFunctionType) { 1868 // If the function types are exactly the same, this isn't an 1869 // Objective-C pointer conversion. 1870 if (Context.getCanonicalType(FromPointeeType) 1871 == Context.getCanonicalType(ToPointeeType)) 1872 return false; 1873 1874 // Perform the quick checks that will tell us whether these 1875 // function types are obviously different. 1876 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1877 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1878 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1879 return false; 1880 1881 bool HasObjCConversion = false; 1882 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1883 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1884 // Okay, the types match exactly. Nothing to do. 1885 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1886 ToFunctionType->getResultType(), 1887 ConvertedType, IncompatibleObjC)) { 1888 // Okay, we have an Objective-C pointer conversion. 1889 HasObjCConversion = true; 1890 } else { 1891 // Function types are too different. Abort. 1892 return false; 1893 } 1894 1895 // Check argument types. 1896 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1897 ArgIdx != NumArgs; ++ArgIdx) { 1898 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1899 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1900 if (Context.getCanonicalType(FromArgType) 1901 == Context.getCanonicalType(ToArgType)) { 1902 // Okay, the types match exactly. Nothing to do. 1903 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1904 ConvertedType, IncompatibleObjC)) { 1905 // Okay, we have an Objective-C pointer conversion. 1906 HasObjCConversion = true; 1907 } else { 1908 // Argument types are too different. Abort. 1909 return false; 1910 } 1911 } 1912 1913 if (HasObjCConversion) { 1914 // We had an Objective-C conversion. Allow this pointer 1915 // conversion, but complain about it. 1916 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1917 IncompatibleObjC = true; 1918 return true; 1919 } 1920 } 1921 1922 return false; 1923} 1924 1925/// \brief Determine whether this is an Objective-C writeback conversion, 1926/// used for parameter passing when performing automatic reference counting. 1927/// 1928/// \param FromType The type we're converting form. 1929/// 1930/// \param ToType The type we're converting to. 1931/// 1932/// \param ConvertedType The type that will be produced after applying 1933/// this conversion. 1934bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType, 1935 QualType &ConvertedType) { 1936 if (!getLangOptions().ObjCAutoRefCount || 1937 Context.hasSameUnqualifiedType(FromType, ToType)) 1938 return false; 1939 1940 // Parameter must be a pointer to __autoreleasing (with no other qualifiers). 1941 QualType ToPointee; 1942 if (const PointerType *ToPointer = ToType->getAs<PointerType>()) 1943 ToPointee = ToPointer->getPointeeType(); 1944 else 1945 return false; 1946 1947 Qualifiers ToQuals = ToPointee.getQualifiers(); 1948 if (!ToPointee->isObjCLifetimeType() || 1949 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing || 1950 !ToQuals.withoutObjCGLifetime().empty()) 1951 return false; 1952 1953 // Argument must be a pointer to __strong to __weak. 1954 QualType FromPointee; 1955 if (const PointerType *FromPointer = FromType->getAs<PointerType>()) 1956 FromPointee = FromPointer->getPointeeType(); 1957 else 1958 return false; 1959 1960 Qualifiers FromQuals = FromPointee.getQualifiers(); 1961 if (!FromPointee->isObjCLifetimeType() || 1962 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong && 1963 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak)) 1964 return false; 1965 1966 // Make sure that we have compatible qualifiers. 1967 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing); 1968 if (!ToQuals.compatiblyIncludes(FromQuals)) 1969 return false; 1970 1971 // Remove qualifiers from the pointee type we're converting from; they 1972 // aren't used in the compatibility check belong, and we'll be adding back 1973 // qualifiers (with __autoreleasing) if the compatibility check succeeds. 1974 FromPointee = FromPointee.getUnqualifiedType(); 1975 1976 // The unqualified form of the pointee types must be compatible. 1977 ToPointee = ToPointee.getUnqualifiedType(); 1978 bool IncompatibleObjC; 1979 if (Context.typesAreCompatible(FromPointee, ToPointee)) 1980 FromPointee = ToPointee; 1981 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee, 1982 IncompatibleObjC)) 1983 return false; 1984 1985 /// \brief Construct the type we're converting to, which is a pointer to 1986 /// __autoreleasing pointee. 1987 FromPointee = Context.getQualifiedType(FromPointee, FromQuals); 1988 ConvertedType = Context.getPointerType(FromPointee); 1989 return true; 1990} 1991 1992bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, 1993 QualType& ConvertedType) { 1994 QualType ToPointeeType; 1995 if (const BlockPointerType *ToBlockPtr = 1996 ToType->getAs<BlockPointerType>()) 1997 ToPointeeType = ToBlockPtr->getPointeeType(); 1998 else 1999 return false; 2000 2001 QualType FromPointeeType; 2002 if (const BlockPointerType *FromBlockPtr = 2003 FromType->getAs<BlockPointerType>()) 2004 FromPointeeType = FromBlockPtr->getPointeeType(); 2005 else 2006 return false; 2007 // We have pointer to blocks, check whether the only 2008 // differences in the argument and result types are in Objective-C 2009 // pointer conversions. If so, we permit the conversion. 2010 2011 const FunctionProtoType *FromFunctionType 2012 = FromPointeeType->getAs<FunctionProtoType>(); 2013 const FunctionProtoType *ToFunctionType 2014 = ToPointeeType->getAs<FunctionProtoType>(); 2015 2016 if (!FromFunctionType || !ToFunctionType) 2017 return false; 2018 2019 if (Context.hasSameType(FromPointeeType, ToPointeeType)) 2020 return true; 2021 2022 // Perform the quick checks that will tell us whether these 2023 // function types are obviously different. 2024 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 2025 FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) 2026 return false; 2027 2028 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); 2029 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); 2030 if (FromEInfo != ToEInfo) 2031 return false; 2032 2033 bool IncompatibleObjC = false; 2034 if (Context.hasSameType(FromFunctionType->getResultType(), 2035 ToFunctionType->getResultType())) { 2036 // Okay, the types match exactly. Nothing to do. 2037 } else { 2038 QualType RHS = FromFunctionType->getResultType(); 2039 QualType LHS = ToFunctionType->getResultType(); 2040 if ((!getLangOptions().CPlusPlus || !RHS->isRecordType()) && 2041 !RHS.hasQualifiers() && LHS.hasQualifiers()) 2042 LHS = LHS.getUnqualifiedType(); 2043 2044 if (Context.hasSameType(RHS,LHS)) { 2045 // OK exact match. 2046 } else if (isObjCPointerConversion(RHS, LHS, 2047 ConvertedType, IncompatibleObjC)) { 2048 if (IncompatibleObjC) 2049 return false; 2050 // Okay, we have an Objective-C pointer conversion. 2051 } 2052 else 2053 return false; 2054 } 2055 2056 // Check argument types. 2057 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 2058 ArgIdx != NumArgs; ++ArgIdx) { 2059 IncompatibleObjC = false; 2060 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 2061 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 2062 if (Context.hasSameType(FromArgType, ToArgType)) { 2063 // Okay, the types match exactly. Nothing to do. 2064 } else if (isObjCPointerConversion(ToArgType, FromArgType, 2065 ConvertedType, IncompatibleObjC)) { 2066 if (IncompatibleObjC) 2067 return false; 2068 // Okay, we have an Objective-C pointer conversion. 2069 } else 2070 // Argument types are too different. Abort. 2071 return false; 2072 } 2073 ConvertedType = ToType; 2074 return true; 2075} 2076 2077/// FunctionArgTypesAreEqual - This routine checks two function proto types 2078/// for equlity of their argument types. Caller has already checked that 2079/// they have same number of arguments. This routine assumes that Objective-C 2080/// pointer types which only differ in their protocol qualifiers are equal. 2081bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, 2082 const FunctionProtoType *NewType) { 2083 if (!getLangOptions().ObjC1) 2084 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 2085 NewType->arg_type_begin()); 2086 2087 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 2088 N = NewType->arg_type_begin(), 2089 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 2090 QualType ToType = (*O); 2091 QualType FromType = (*N); 2092 if (ToType != FromType) { 2093 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 2094 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 2095 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 2096 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 2097 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 2098 PTFr->getPointeeType()->isObjCQualifiedClassType())) 2099 continue; 2100 } 2101 else if (const ObjCObjectPointerType *PTTo = 2102 ToType->getAs<ObjCObjectPointerType>()) { 2103 if (const ObjCObjectPointerType *PTFr = 2104 FromType->getAs<ObjCObjectPointerType>()) 2105 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 2106 continue; 2107 } 2108 return false; 2109 } 2110 } 2111 return true; 2112} 2113 2114/// CheckPointerConversion - Check the pointer conversion from the 2115/// expression From to the type ToType. This routine checks for 2116/// ambiguous or inaccessible derived-to-base pointer 2117/// conversions for which IsPointerConversion has already returned 2118/// true. It returns true and produces a diagnostic if there was an 2119/// error, or returns false otherwise. 2120bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 2121 CastKind &Kind, 2122 CXXCastPath& BasePath, 2123 bool IgnoreBaseAccess) { 2124 QualType FromType = From->getType(); 2125 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 2126 2127 Kind = CK_BitCast; 2128 2129 if (!IsCStyleOrFunctionalCast && 2130 Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy) && 2131 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 2132 DiagRuntimeBehavior(From->getExprLoc(), From, 2133 PDiag(diag::warn_impcast_bool_to_null_pointer) 2134 << ToType << From->getSourceRange()); 2135 2136 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 2137 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) { 2138 QualType FromPointeeType = FromPtrType->getPointeeType(), 2139 ToPointeeType = ToPtrType->getPointeeType(); 2140 2141 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 2142 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 2143 // We must have a derived-to-base conversion. Check an 2144 // ambiguous or inaccessible conversion. 2145 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 2146 From->getExprLoc(), 2147 From->getSourceRange(), &BasePath, 2148 IgnoreBaseAccess)) 2149 return true; 2150 2151 // The conversion was successful. 2152 Kind = CK_DerivedToBase; 2153 } 2154 } 2155 } else if (const ObjCObjectPointerType *ToPtrType = 2156 ToType->getAs<ObjCObjectPointerType>()) { 2157 if (const ObjCObjectPointerType *FromPtrType = 2158 FromType->getAs<ObjCObjectPointerType>()) { 2159 // Objective-C++ conversions are always okay. 2160 // FIXME: We should have a different class of conversions for the 2161 // Objective-C++ implicit conversions. 2162 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 2163 return false; 2164 } else if (FromType->isBlockPointerType()) { 2165 Kind = CK_BlockPointerToObjCPointerCast; 2166 } else { 2167 Kind = CK_CPointerToObjCPointerCast; 2168 } 2169 } else if (ToType->isBlockPointerType()) { 2170 if (!FromType->isBlockPointerType()) 2171 Kind = CK_AnyPointerToBlockPointerCast; 2172 } 2173 2174 // We shouldn't fall into this case unless it's valid for other 2175 // reasons. 2176 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 2177 Kind = CK_NullToPointer; 2178 2179 return false; 2180} 2181 2182/// IsMemberPointerConversion - Determines whether the conversion of the 2183/// expression From, which has the (possibly adjusted) type FromType, can be 2184/// converted to the type ToType via a member pointer conversion (C++ 4.11). 2185/// If so, returns true and places the converted type (that might differ from 2186/// ToType in its cv-qualifiers at some level) into ConvertedType. 2187bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 2188 QualType ToType, 2189 bool InOverloadResolution, 2190 QualType &ConvertedType) { 2191 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 2192 if (!ToTypePtr) 2193 return false; 2194 2195 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 2196 if (From->isNullPointerConstant(Context, 2197 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 2198 : Expr::NPC_ValueDependentIsNull)) { 2199 ConvertedType = ToType; 2200 return true; 2201 } 2202 2203 // Otherwise, both types have to be member pointers. 2204 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 2205 if (!FromTypePtr) 2206 return false; 2207 2208 // A pointer to member of B can be converted to a pointer to member of D, 2209 // where D is derived from B (C++ 4.11p2). 2210 QualType FromClass(FromTypePtr->getClass(), 0); 2211 QualType ToClass(ToTypePtr->getClass(), 0); 2212 2213 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && 2214 !RequireCompleteType(From->getLocStart(), ToClass, PDiag()) && 2215 IsDerivedFrom(ToClass, FromClass)) { 2216 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 2217 ToClass.getTypePtr()); 2218 return true; 2219 } 2220 2221 return false; 2222} 2223 2224/// CheckMemberPointerConversion - Check the member pointer conversion from the 2225/// expression From to the type ToType. This routine checks for ambiguous or 2226/// virtual or inaccessible base-to-derived member pointer conversions 2227/// for which IsMemberPointerConversion has already returned true. It returns 2228/// true and produces a diagnostic if there was an error, or returns false 2229/// otherwise. 2230bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 2231 CastKind &Kind, 2232 CXXCastPath &BasePath, 2233 bool IgnoreBaseAccess) { 2234 QualType FromType = From->getType(); 2235 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 2236 if (!FromPtrType) { 2237 // This must be a null pointer to member pointer conversion 2238 assert(From->isNullPointerConstant(Context, 2239 Expr::NPC_ValueDependentIsNull) && 2240 "Expr must be null pointer constant!"); 2241 Kind = CK_NullToMemberPointer; 2242 return false; 2243 } 2244 2245 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 2246 assert(ToPtrType && "No member pointer cast has a target type " 2247 "that is not a member pointer."); 2248 2249 QualType FromClass = QualType(FromPtrType->getClass(), 0); 2250 QualType ToClass = QualType(ToPtrType->getClass(), 0); 2251 2252 // FIXME: What about dependent types? 2253 assert(FromClass->isRecordType() && "Pointer into non-class."); 2254 assert(ToClass->isRecordType() && "Pointer into non-class."); 2255 2256 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 2257 /*DetectVirtual=*/true); 2258 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 2259 assert(DerivationOkay && 2260 "Should not have been called if derivation isn't OK."); 2261 (void)DerivationOkay; 2262 2263 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 2264 getUnqualifiedType())) { 2265 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 2266 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 2267 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 2268 return true; 2269 } 2270 2271 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 2272 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 2273 << FromClass << ToClass << QualType(VBase, 0) 2274 << From->getSourceRange(); 2275 return true; 2276 } 2277 2278 if (!IgnoreBaseAccess) 2279 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 2280 Paths.front(), 2281 diag::err_downcast_from_inaccessible_base); 2282 2283 // Must be a base to derived member conversion. 2284 BuildBasePathArray(Paths, BasePath); 2285 Kind = CK_BaseToDerivedMemberPointer; 2286 return false; 2287} 2288 2289/// IsQualificationConversion - Determines whether the conversion from 2290/// an rvalue of type FromType to ToType is a qualification conversion 2291/// (C++ 4.4). 2292/// 2293/// \param ObjCLifetimeConversion Output parameter that will be set to indicate 2294/// when the qualification conversion involves a change in the Objective-C 2295/// object lifetime. 2296bool 2297Sema::IsQualificationConversion(QualType FromType, QualType ToType, 2298 bool CStyle, bool &ObjCLifetimeConversion) { 2299 FromType = Context.getCanonicalType(FromType); 2300 ToType = Context.getCanonicalType(ToType); 2301 ObjCLifetimeConversion = false; 2302 2303 // If FromType and ToType are the same type, this is not a 2304 // qualification conversion. 2305 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 2306 return false; 2307 2308 // (C++ 4.4p4): 2309 // A conversion can add cv-qualifiers at levels other than the first 2310 // in multi-level pointers, subject to the following rules: [...] 2311 bool PreviousToQualsIncludeConst = true; 2312 bool UnwrappedAnyPointer = false; 2313 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 2314 // Within each iteration of the loop, we check the qualifiers to 2315 // determine if this still looks like a qualification 2316 // conversion. Then, if all is well, we unwrap one more level of 2317 // pointers or pointers-to-members and do it all again 2318 // until there are no more pointers or pointers-to-members left to 2319 // unwrap. 2320 UnwrappedAnyPointer = true; 2321 2322 Qualifiers FromQuals = FromType.getQualifiers(); 2323 Qualifiers ToQuals = ToType.getQualifiers(); 2324 2325 // Objective-C ARC: 2326 // Check Objective-C lifetime conversions. 2327 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() && 2328 UnwrappedAnyPointer) { 2329 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) { 2330 ObjCLifetimeConversion = true; 2331 FromQuals.removeObjCLifetime(); 2332 ToQuals.removeObjCLifetime(); 2333 } else { 2334 // Qualification conversions cannot cast between different 2335 // Objective-C lifetime qualifiers. 2336 return false; 2337 } 2338 } 2339 2340 // Allow addition/removal of GC attributes but not changing GC attributes. 2341 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() && 2342 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) { 2343 FromQuals.removeObjCGCAttr(); 2344 ToQuals.removeObjCGCAttr(); 2345 } 2346 2347 // -- for every j > 0, if const is in cv 1,j then const is in cv 2348 // 2,j, and similarly for volatile. 2349 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals)) 2350 return false; 2351 2352 // -- if the cv 1,j and cv 2,j are different, then const is in 2353 // every cv for 0 < k < j. 2354 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers() 2355 && !PreviousToQualsIncludeConst) 2356 return false; 2357 2358 // Keep track of whether all prior cv-qualifiers in the "to" type 2359 // include const. 2360 PreviousToQualsIncludeConst 2361 = PreviousToQualsIncludeConst && ToQuals.hasConst(); 2362 } 2363 2364 // We are left with FromType and ToType being the pointee types 2365 // after unwrapping the original FromType and ToType the same number 2366 // of types. If we unwrapped any pointers, and if FromType and 2367 // ToType have the same unqualified type (since we checked 2368 // qualifiers above), then this is a qualification conversion. 2369 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2370} 2371 2372/// Determines whether there is a user-defined conversion sequence 2373/// (C++ [over.ics.user]) that converts expression From to the type 2374/// ToType. If such a conversion exists, User will contain the 2375/// user-defined conversion sequence that performs such a conversion 2376/// and this routine will return true. Otherwise, this routine returns 2377/// false and User is unspecified. 2378/// 2379/// \param AllowExplicit true if the conversion should consider C++0x 2380/// "explicit" conversion functions as well as non-explicit conversion 2381/// functions (C++0x [class.conv.fct]p2). 2382static OverloadingResult 2383IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 2384 UserDefinedConversionSequence& User, 2385 OverloadCandidateSet& CandidateSet, 2386 bool AllowExplicit) { 2387 // Whether we will only visit constructors. 2388 bool ConstructorsOnly = false; 2389 2390 // If the type we are conversion to is a class type, enumerate its 2391 // constructors. 2392 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 2393 // C++ [over.match.ctor]p1: 2394 // When objects of class type are direct-initialized (8.5), or 2395 // copy-initialized from an expression of the same or a 2396 // derived class type (8.5), overload resolution selects the 2397 // constructor. [...] For copy-initialization, the candidate 2398 // functions are all the converting constructors (12.3.1) of 2399 // that class. The argument list is the expression-list within 2400 // the parentheses of the initializer. 2401 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 2402 (From->getType()->getAs<RecordType>() && 2403 S.IsDerivedFrom(From->getType(), ToType))) 2404 ConstructorsOnly = true; 2405 2406 S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag()); 2407 // RequireCompleteType may have returned true due to some invalid decl 2408 // during template instantiation, but ToType may be complete enough now 2409 // to try to recover. 2410 if (ToType->isIncompleteType()) { 2411 // We're not going to find any constructors. 2412 } else if (CXXRecordDecl *ToRecordDecl 2413 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 2414 DeclContext::lookup_iterator Con, ConEnd; 2415 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 2416 Con != ConEnd; ++Con) { 2417 NamedDecl *D = *Con; 2418 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2419 2420 // Find the constructor (which may be a template). 2421 CXXConstructorDecl *Constructor = 0; 2422 FunctionTemplateDecl *ConstructorTmpl 2423 = dyn_cast<FunctionTemplateDecl>(D); 2424 if (ConstructorTmpl) 2425 Constructor 2426 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2427 else 2428 Constructor = cast<CXXConstructorDecl>(D); 2429 2430 if (!Constructor->isInvalidDecl() && 2431 Constructor->isConvertingConstructor(AllowExplicit)) { 2432 if (ConstructorTmpl) 2433 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2434 /*ExplicitArgs*/ 0, 2435 &From, 1, CandidateSet, 2436 /*SuppressUserConversions=*/ 2437 !ConstructorsOnly); 2438 else 2439 // Allow one user-defined conversion when user specifies a 2440 // From->ToType conversion via an static cast (c-style, etc). 2441 S.AddOverloadCandidate(Constructor, FoundDecl, 2442 &From, 1, CandidateSet, 2443 /*SuppressUserConversions=*/ 2444 !ConstructorsOnly); 2445 } 2446 } 2447 } 2448 } 2449 2450 // Enumerate conversion functions, if we're allowed to. 2451 if (ConstructorsOnly) { 2452 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 2453 S.PDiag(0) << From->getSourceRange())) { 2454 // No conversion functions from incomplete types. 2455 } else if (const RecordType *FromRecordType 2456 = From->getType()->getAs<RecordType>()) { 2457 if (CXXRecordDecl *FromRecordDecl 2458 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 2459 // Add all of the conversion functions as candidates. 2460 const UnresolvedSetImpl *Conversions 2461 = FromRecordDecl->getVisibleConversionFunctions(); 2462 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2463 E = Conversions->end(); I != E; ++I) { 2464 DeclAccessPair FoundDecl = I.getPair(); 2465 NamedDecl *D = FoundDecl.getDecl(); 2466 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 2467 if (isa<UsingShadowDecl>(D)) 2468 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2469 2470 CXXConversionDecl *Conv; 2471 FunctionTemplateDecl *ConvTemplate; 2472 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 2473 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2474 else 2475 Conv = cast<CXXConversionDecl>(D); 2476 2477 if (AllowExplicit || !Conv->isExplicit()) { 2478 if (ConvTemplate) 2479 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 2480 ActingContext, From, ToType, 2481 CandidateSet); 2482 else 2483 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 2484 From, ToType, CandidateSet); 2485 } 2486 } 2487 } 2488 } 2489 2490 OverloadCandidateSet::iterator Best; 2491 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2492 case OR_Success: 2493 // Record the standard conversion we used and the conversion function. 2494 if (CXXConstructorDecl *Constructor 2495 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 2496 S.MarkDeclarationReferenced(From->getLocStart(), Constructor); 2497 2498 // C++ [over.ics.user]p1: 2499 // If the user-defined conversion is specified by a 2500 // constructor (12.3.1), the initial standard conversion 2501 // sequence converts the source type to the type required by 2502 // the argument of the constructor. 2503 // 2504 QualType ThisType = Constructor->getThisType(S.Context); 2505 if (Best->Conversions[0].isEllipsis()) 2506 User.EllipsisConversion = true; 2507 else { 2508 User.Before = Best->Conversions[0].Standard; 2509 User.EllipsisConversion = false; 2510 } 2511 User.ConversionFunction = Constructor; 2512 User.FoundConversionFunction = Best->FoundDecl.getDecl(); 2513 User.After.setAsIdentityConversion(); 2514 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2515 User.After.setAllToTypes(ToType); 2516 return OR_Success; 2517 } else if (CXXConversionDecl *Conversion 2518 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2519 S.MarkDeclarationReferenced(From->getLocStart(), Conversion); 2520 2521 // C++ [over.ics.user]p1: 2522 // 2523 // [...] If the user-defined conversion is specified by a 2524 // conversion function (12.3.2), the initial standard 2525 // conversion sequence converts the source type to the 2526 // implicit object parameter of the conversion function. 2527 User.Before = Best->Conversions[0].Standard; 2528 User.ConversionFunction = Conversion; 2529 User.FoundConversionFunction = Best->FoundDecl.getDecl(); 2530 User.EllipsisConversion = false; 2531 2532 // C++ [over.ics.user]p2: 2533 // The second standard conversion sequence converts the 2534 // result of the user-defined conversion to the target type 2535 // for the sequence. Since an implicit conversion sequence 2536 // is an initialization, the special rules for 2537 // initialization by user-defined conversion apply when 2538 // selecting the best user-defined conversion for a 2539 // user-defined conversion sequence (see 13.3.3 and 2540 // 13.3.3.1). 2541 User.After = Best->FinalConversion; 2542 return OR_Success; 2543 } else { 2544 llvm_unreachable("Not a constructor or conversion function?"); 2545 return OR_No_Viable_Function; 2546 } 2547 2548 case OR_No_Viable_Function: 2549 return OR_No_Viable_Function; 2550 case OR_Deleted: 2551 // No conversion here! We're done. 2552 return OR_Deleted; 2553 2554 case OR_Ambiguous: 2555 return OR_Ambiguous; 2556 } 2557 2558 return OR_No_Viable_Function; 2559} 2560 2561bool 2562Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2563 ImplicitConversionSequence ICS; 2564 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2565 OverloadingResult OvResult = 2566 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 2567 CandidateSet, false); 2568 if (OvResult == OR_Ambiguous) 2569 Diag(From->getSourceRange().getBegin(), 2570 diag::err_typecheck_ambiguous_condition) 2571 << From->getType() << ToType << From->getSourceRange(); 2572 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2573 Diag(From->getSourceRange().getBegin(), 2574 diag::err_typecheck_nonviable_condition) 2575 << From->getType() << ToType << From->getSourceRange(); 2576 else 2577 return false; 2578 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &From, 1); 2579 return true; 2580} 2581 2582/// CompareImplicitConversionSequences - Compare two implicit 2583/// conversion sequences to determine whether one is better than the 2584/// other or if they are indistinguishable (C++ 13.3.3.2). 2585static ImplicitConversionSequence::CompareKind 2586CompareImplicitConversionSequences(Sema &S, 2587 const ImplicitConversionSequence& ICS1, 2588 const ImplicitConversionSequence& ICS2) 2589{ 2590 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2591 // conversion sequences (as defined in 13.3.3.1) 2592 // -- a standard conversion sequence (13.3.3.1.1) is a better 2593 // conversion sequence than a user-defined conversion sequence or 2594 // an ellipsis conversion sequence, and 2595 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2596 // conversion sequence than an ellipsis conversion sequence 2597 // (13.3.3.1.3). 2598 // 2599 // C++0x [over.best.ics]p10: 2600 // For the purpose of ranking implicit conversion sequences as 2601 // described in 13.3.3.2, the ambiguous conversion sequence is 2602 // treated as a user-defined sequence that is indistinguishable 2603 // from any other user-defined conversion sequence. 2604 if (ICS1.getKindRank() < ICS2.getKindRank()) 2605 return ImplicitConversionSequence::Better; 2606 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2607 return ImplicitConversionSequence::Worse; 2608 2609 // The following checks require both conversion sequences to be of 2610 // the same kind. 2611 if (ICS1.getKind() != ICS2.getKind()) 2612 return ImplicitConversionSequence::Indistinguishable; 2613 2614 // Two implicit conversion sequences of the same form are 2615 // indistinguishable conversion sequences unless one of the 2616 // following rules apply: (C++ 13.3.3.2p3): 2617 if (ICS1.isStandard()) 2618 return CompareStandardConversionSequences(S, ICS1.Standard, ICS2.Standard); 2619 else if (ICS1.isUserDefined()) { 2620 // User-defined conversion sequence U1 is a better conversion 2621 // sequence than another user-defined conversion sequence U2 if 2622 // they contain the same user-defined conversion function or 2623 // constructor and if the second standard conversion sequence of 2624 // U1 is better than the second standard conversion sequence of 2625 // U2 (C++ 13.3.3.2p3). 2626 if (ICS1.UserDefined.ConversionFunction == 2627 ICS2.UserDefined.ConversionFunction) 2628 return CompareStandardConversionSequences(S, 2629 ICS1.UserDefined.After, 2630 ICS2.UserDefined.After); 2631 } 2632 2633 return ImplicitConversionSequence::Indistinguishable; 2634} 2635 2636static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2637 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2638 Qualifiers Quals; 2639 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2640 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2641 } 2642 2643 return Context.hasSameUnqualifiedType(T1, T2); 2644} 2645 2646// Per 13.3.3.2p3, compare the given standard conversion sequences to 2647// determine if one is a proper subset of the other. 2648static ImplicitConversionSequence::CompareKind 2649compareStandardConversionSubsets(ASTContext &Context, 2650 const StandardConversionSequence& SCS1, 2651 const StandardConversionSequence& SCS2) { 2652 ImplicitConversionSequence::CompareKind Result 2653 = ImplicitConversionSequence::Indistinguishable; 2654 2655 // the identity conversion sequence is considered to be a subsequence of 2656 // any non-identity conversion sequence 2657 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2658 return ImplicitConversionSequence::Better; 2659 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2660 return ImplicitConversionSequence::Worse; 2661 2662 if (SCS1.Second != SCS2.Second) { 2663 if (SCS1.Second == ICK_Identity) 2664 Result = ImplicitConversionSequence::Better; 2665 else if (SCS2.Second == ICK_Identity) 2666 Result = ImplicitConversionSequence::Worse; 2667 else 2668 return ImplicitConversionSequence::Indistinguishable; 2669 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2670 return ImplicitConversionSequence::Indistinguishable; 2671 2672 if (SCS1.Third == SCS2.Third) { 2673 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2674 : ImplicitConversionSequence::Indistinguishable; 2675 } 2676 2677 if (SCS1.Third == ICK_Identity) 2678 return Result == ImplicitConversionSequence::Worse 2679 ? ImplicitConversionSequence::Indistinguishable 2680 : ImplicitConversionSequence::Better; 2681 2682 if (SCS2.Third == ICK_Identity) 2683 return Result == ImplicitConversionSequence::Better 2684 ? ImplicitConversionSequence::Indistinguishable 2685 : ImplicitConversionSequence::Worse; 2686 2687 return ImplicitConversionSequence::Indistinguishable; 2688} 2689 2690/// \brief Determine whether one of the given reference bindings is better 2691/// than the other based on what kind of bindings they are. 2692static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 2693 const StandardConversionSequence &SCS2) { 2694 // C++0x [over.ics.rank]p3b4: 2695 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2696 // implicit object parameter of a non-static member function declared 2697 // without a ref-qualifier, and *either* S1 binds an rvalue reference 2698 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 2699 // lvalue reference to a function lvalue and S2 binds an rvalue 2700 // reference*. 2701 // 2702 // FIXME: Rvalue references. We're going rogue with the above edits, 2703 // because the semantics in the current C++0x working paper (N3225 at the 2704 // time of this writing) break the standard definition of std::forward 2705 // and std::reference_wrapper when dealing with references to functions. 2706 // Proposed wording changes submitted to CWG for consideration. 2707 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 2708 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 2709 return false; 2710 2711 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 2712 SCS2.IsLvalueReference) || 2713 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 2714 !SCS2.IsLvalueReference); 2715} 2716 2717/// CompareStandardConversionSequences - Compare two standard 2718/// conversion sequences to determine whether one is better than the 2719/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2720static ImplicitConversionSequence::CompareKind 2721CompareStandardConversionSequences(Sema &S, 2722 const StandardConversionSequence& SCS1, 2723 const StandardConversionSequence& SCS2) 2724{ 2725 // Standard conversion sequence S1 is a better conversion sequence 2726 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2727 2728 // -- S1 is a proper subsequence of S2 (comparing the conversion 2729 // sequences in the canonical form defined by 13.3.3.1.1, 2730 // excluding any Lvalue Transformation; the identity conversion 2731 // sequence is considered to be a subsequence of any 2732 // non-identity conversion sequence) or, if not that, 2733 if (ImplicitConversionSequence::CompareKind CK 2734 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 2735 return CK; 2736 2737 // -- the rank of S1 is better than the rank of S2 (by the rules 2738 // defined below), or, if not that, 2739 ImplicitConversionRank Rank1 = SCS1.getRank(); 2740 ImplicitConversionRank Rank2 = SCS2.getRank(); 2741 if (Rank1 < Rank2) 2742 return ImplicitConversionSequence::Better; 2743 else if (Rank2 < Rank1) 2744 return ImplicitConversionSequence::Worse; 2745 2746 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2747 // are indistinguishable unless one of the following rules 2748 // applies: 2749 2750 // A conversion that is not a conversion of a pointer, or 2751 // pointer to member, to bool is better than another conversion 2752 // that is such a conversion. 2753 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2754 return SCS2.isPointerConversionToBool() 2755 ? ImplicitConversionSequence::Better 2756 : ImplicitConversionSequence::Worse; 2757 2758 // C++ [over.ics.rank]p4b2: 2759 // 2760 // If class B is derived directly or indirectly from class A, 2761 // conversion of B* to A* is better than conversion of B* to 2762 // void*, and conversion of A* to void* is better than conversion 2763 // of B* to void*. 2764 bool SCS1ConvertsToVoid 2765 = SCS1.isPointerConversionToVoidPointer(S.Context); 2766 bool SCS2ConvertsToVoid 2767 = SCS2.isPointerConversionToVoidPointer(S.Context); 2768 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2769 // Exactly one of the conversion sequences is a conversion to 2770 // a void pointer; it's the worse conversion. 2771 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2772 : ImplicitConversionSequence::Worse; 2773 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2774 // Neither conversion sequence converts to a void pointer; compare 2775 // their derived-to-base conversions. 2776 if (ImplicitConversionSequence::CompareKind DerivedCK 2777 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 2778 return DerivedCK; 2779 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid && 2780 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) { 2781 // Both conversion sequences are conversions to void 2782 // pointers. Compare the source types to determine if there's an 2783 // inheritance relationship in their sources. 2784 QualType FromType1 = SCS1.getFromType(); 2785 QualType FromType2 = SCS2.getFromType(); 2786 2787 // Adjust the types we're converting from via the array-to-pointer 2788 // conversion, if we need to. 2789 if (SCS1.First == ICK_Array_To_Pointer) 2790 FromType1 = S.Context.getArrayDecayedType(FromType1); 2791 if (SCS2.First == ICK_Array_To_Pointer) 2792 FromType2 = S.Context.getArrayDecayedType(FromType2); 2793 2794 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType(); 2795 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType(); 2796 2797 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2798 return ImplicitConversionSequence::Better; 2799 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2800 return ImplicitConversionSequence::Worse; 2801 2802 // Objective-C++: If one interface is more specific than the 2803 // other, it is the better one. 2804 const ObjCObjectPointerType* FromObjCPtr1 2805 = FromType1->getAs<ObjCObjectPointerType>(); 2806 const ObjCObjectPointerType* FromObjCPtr2 2807 = FromType2->getAs<ObjCObjectPointerType>(); 2808 if (FromObjCPtr1 && FromObjCPtr2) { 2809 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1, 2810 FromObjCPtr2); 2811 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2, 2812 FromObjCPtr1); 2813 if (AssignLeft != AssignRight) { 2814 return AssignLeft? ImplicitConversionSequence::Better 2815 : ImplicitConversionSequence::Worse; 2816 } 2817 } 2818 } 2819 2820 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2821 // bullet 3). 2822 if (ImplicitConversionSequence::CompareKind QualCK 2823 = CompareQualificationConversions(S, SCS1, SCS2)) 2824 return QualCK; 2825 2826 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2827 // Check for a better reference binding based on the kind of bindings. 2828 if (isBetterReferenceBindingKind(SCS1, SCS2)) 2829 return ImplicitConversionSequence::Better; 2830 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 2831 return ImplicitConversionSequence::Worse; 2832 2833 // C++ [over.ics.rank]p3b4: 2834 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2835 // which the references refer are the same type except for 2836 // top-level cv-qualifiers, and the type to which the reference 2837 // initialized by S2 refers is more cv-qualified than the type 2838 // to which the reference initialized by S1 refers. 2839 QualType T1 = SCS1.getToType(2); 2840 QualType T2 = SCS2.getToType(2); 2841 T1 = S.Context.getCanonicalType(T1); 2842 T2 = S.Context.getCanonicalType(T2); 2843 Qualifiers T1Quals, T2Quals; 2844 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2845 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2846 if (UnqualT1 == UnqualT2) { 2847 // Objective-C++ ARC: If the references refer to objects with different 2848 // lifetimes, prefer bindings that don't change lifetime. 2849 if (SCS1.ObjCLifetimeConversionBinding != 2850 SCS2.ObjCLifetimeConversionBinding) { 2851 return SCS1.ObjCLifetimeConversionBinding 2852 ? ImplicitConversionSequence::Worse 2853 : ImplicitConversionSequence::Better; 2854 } 2855 2856 // If the type is an array type, promote the element qualifiers to the 2857 // type for comparison. 2858 if (isa<ArrayType>(T1) && T1Quals) 2859 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2860 if (isa<ArrayType>(T2) && T2Quals) 2861 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2862 if (T2.isMoreQualifiedThan(T1)) 2863 return ImplicitConversionSequence::Better; 2864 else if (T1.isMoreQualifiedThan(T2)) 2865 return ImplicitConversionSequence::Worse; 2866 } 2867 } 2868 2869 return ImplicitConversionSequence::Indistinguishable; 2870} 2871 2872/// CompareQualificationConversions - Compares two standard conversion 2873/// sequences to determine whether they can be ranked based on their 2874/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2875ImplicitConversionSequence::CompareKind 2876CompareQualificationConversions(Sema &S, 2877 const StandardConversionSequence& SCS1, 2878 const StandardConversionSequence& SCS2) { 2879 // C++ 13.3.3.2p3: 2880 // -- S1 and S2 differ only in their qualification conversion and 2881 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2882 // cv-qualification signature of type T1 is a proper subset of 2883 // the cv-qualification signature of type T2, and S1 is not the 2884 // deprecated string literal array-to-pointer conversion (4.2). 2885 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2886 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2887 return ImplicitConversionSequence::Indistinguishable; 2888 2889 // FIXME: the example in the standard doesn't use a qualification 2890 // conversion (!) 2891 QualType T1 = SCS1.getToType(2); 2892 QualType T2 = SCS2.getToType(2); 2893 T1 = S.Context.getCanonicalType(T1); 2894 T2 = S.Context.getCanonicalType(T2); 2895 Qualifiers T1Quals, T2Quals; 2896 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2897 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2898 2899 // If the types are the same, we won't learn anything by unwrapped 2900 // them. 2901 if (UnqualT1 == UnqualT2) 2902 return ImplicitConversionSequence::Indistinguishable; 2903 2904 // If the type is an array type, promote the element qualifiers to the type 2905 // for comparison. 2906 if (isa<ArrayType>(T1) && T1Quals) 2907 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2908 if (isa<ArrayType>(T2) && T2Quals) 2909 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2910 2911 ImplicitConversionSequence::CompareKind Result 2912 = ImplicitConversionSequence::Indistinguishable; 2913 2914 // Objective-C++ ARC: 2915 // Prefer qualification conversions not involving a change in lifetime 2916 // to qualification conversions that do not change lifetime. 2917 if (SCS1.QualificationIncludesObjCLifetime != 2918 SCS2.QualificationIncludesObjCLifetime) { 2919 Result = SCS1.QualificationIncludesObjCLifetime 2920 ? ImplicitConversionSequence::Worse 2921 : ImplicitConversionSequence::Better; 2922 } 2923 2924 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 2925 // Within each iteration of the loop, we check the qualifiers to 2926 // determine if this still looks like a qualification 2927 // conversion. Then, if all is well, we unwrap one more level of 2928 // pointers or pointers-to-members and do it all again 2929 // until there are no more pointers or pointers-to-members left 2930 // to unwrap. This essentially mimics what 2931 // IsQualificationConversion does, but here we're checking for a 2932 // strict subset of qualifiers. 2933 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2934 // The qualifiers are the same, so this doesn't tell us anything 2935 // about how the sequences rank. 2936 ; 2937 else if (T2.isMoreQualifiedThan(T1)) { 2938 // T1 has fewer qualifiers, so it could be the better sequence. 2939 if (Result == ImplicitConversionSequence::Worse) 2940 // Neither has qualifiers that are a subset of the other's 2941 // qualifiers. 2942 return ImplicitConversionSequence::Indistinguishable; 2943 2944 Result = ImplicitConversionSequence::Better; 2945 } else if (T1.isMoreQualifiedThan(T2)) { 2946 // T2 has fewer qualifiers, so it could be the better sequence. 2947 if (Result == ImplicitConversionSequence::Better) 2948 // Neither has qualifiers that are a subset of the other's 2949 // qualifiers. 2950 return ImplicitConversionSequence::Indistinguishable; 2951 2952 Result = ImplicitConversionSequence::Worse; 2953 } else { 2954 // Qualifiers are disjoint. 2955 return ImplicitConversionSequence::Indistinguishable; 2956 } 2957 2958 // If the types after this point are equivalent, we're done. 2959 if (S.Context.hasSameUnqualifiedType(T1, T2)) 2960 break; 2961 } 2962 2963 // Check that the winning standard conversion sequence isn't using 2964 // the deprecated string literal array to pointer conversion. 2965 switch (Result) { 2966 case ImplicitConversionSequence::Better: 2967 if (SCS1.DeprecatedStringLiteralToCharPtr) 2968 Result = ImplicitConversionSequence::Indistinguishable; 2969 break; 2970 2971 case ImplicitConversionSequence::Indistinguishable: 2972 break; 2973 2974 case ImplicitConversionSequence::Worse: 2975 if (SCS2.DeprecatedStringLiteralToCharPtr) 2976 Result = ImplicitConversionSequence::Indistinguishable; 2977 break; 2978 } 2979 2980 return Result; 2981} 2982 2983/// CompareDerivedToBaseConversions - Compares two standard conversion 2984/// sequences to determine whether they can be ranked based on their 2985/// various kinds of derived-to-base conversions (C++ 2986/// [over.ics.rank]p4b3). As part of these checks, we also look at 2987/// conversions between Objective-C interface types. 2988ImplicitConversionSequence::CompareKind 2989CompareDerivedToBaseConversions(Sema &S, 2990 const StandardConversionSequence& SCS1, 2991 const StandardConversionSequence& SCS2) { 2992 QualType FromType1 = SCS1.getFromType(); 2993 QualType ToType1 = SCS1.getToType(1); 2994 QualType FromType2 = SCS2.getFromType(); 2995 QualType ToType2 = SCS2.getToType(1); 2996 2997 // Adjust the types we're converting from via the array-to-pointer 2998 // conversion, if we need to. 2999 if (SCS1.First == ICK_Array_To_Pointer) 3000 FromType1 = S.Context.getArrayDecayedType(FromType1); 3001 if (SCS2.First == ICK_Array_To_Pointer) 3002 FromType2 = S.Context.getArrayDecayedType(FromType2); 3003 3004 // Canonicalize all of the types. 3005 FromType1 = S.Context.getCanonicalType(FromType1); 3006 ToType1 = S.Context.getCanonicalType(ToType1); 3007 FromType2 = S.Context.getCanonicalType(FromType2); 3008 ToType2 = S.Context.getCanonicalType(ToType2); 3009 3010 // C++ [over.ics.rank]p4b3: 3011 // 3012 // If class B is derived directly or indirectly from class A and 3013 // class C is derived directly or indirectly from B, 3014 // 3015 // Compare based on pointer conversions. 3016 if (SCS1.Second == ICK_Pointer_Conversion && 3017 SCS2.Second == ICK_Pointer_Conversion && 3018 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 3019 FromType1->isPointerType() && FromType2->isPointerType() && 3020 ToType1->isPointerType() && ToType2->isPointerType()) { 3021 QualType FromPointee1 3022 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3023 QualType ToPointee1 3024 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3025 QualType FromPointee2 3026 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3027 QualType ToPointee2 3028 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3029 3030 // -- conversion of C* to B* is better than conversion of C* to A*, 3031 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3032 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3033 return ImplicitConversionSequence::Better; 3034 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3035 return ImplicitConversionSequence::Worse; 3036 } 3037 3038 // -- conversion of B* to A* is better than conversion of C* to A*, 3039 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 3040 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3041 return ImplicitConversionSequence::Better; 3042 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3043 return ImplicitConversionSequence::Worse; 3044 } 3045 } else if (SCS1.Second == ICK_Pointer_Conversion && 3046 SCS2.Second == ICK_Pointer_Conversion) { 3047 const ObjCObjectPointerType *FromPtr1 3048 = FromType1->getAs<ObjCObjectPointerType>(); 3049 const ObjCObjectPointerType *FromPtr2 3050 = FromType2->getAs<ObjCObjectPointerType>(); 3051 const ObjCObjectPointerType *ToPtr1 3052 = ToType1->getAs<ObjCObjectPointerType>(); 3053 const ObjCObjectPointerType *ToPtr2 3054 = ToType2->getAs<ObjCObjectPointerType>(); 3055 3056 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 3057 // Apply the same conversion ranking rules for Objective-C pointer types 3058 // that we do for C++ pointers to class types. However, we employ the 3059 // Objective-C pseudo-subtyping relationship used for assignment of 3060 // Objective-C pointer types. 3061 bool FromAssignLeft 3062 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 3063 bool FromAssignRight 3064 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 3065 bool ToAssignLeft 3066 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 3067 bool ToAssignRight 3068 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 3069 3070 // A conversion to an a non-id object pointer type or qualified 'id' 3071 // type is better than a conversion to 'id'. 3072 if (ToPtr1->isObjCIdType() && 3073 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 3074 return ImplicitConversionSequence::Worse; 3075 if (ToPtr2->isObjCIdType() && 3076 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 3077 return ImplicitConversionSequence::Better; 3078 3079 // A conversion to a non-id object pointer type is better than a 3080 // conversion to a qualified 'id' type 3081 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 3082 return ImplicitConversionSequence::Worse; 3083 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 3084 return ImplicitConversionSequence::Better; 3085 3086 // A conversion to an a non-Class object pointer type or qualified 'Class' 3087 // type is better than a conversion to 'Class'. 3088 if (ToPtr1->isObjCClassType() && 3089 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 3090 return ImplicitConversionSequence::Worse; 3091 if (ToPtr2->isObjCClassType() && 3092 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 3093 return ImplicitConversionSequence::Better; 3094 3095 // A conversion to a non-Class object pointer type is better than a 3096 // conversion to a qualified 'Class' type. 3097 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 3098 return ImplicitConversionSequence::Worse; 3099 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 3100 return ImplicitConversionSequence::Better; 3101 3102 // -- "conversion of C* to B* is better than conversion of C* to A*," 3103 if (S.Context.hasSameType(FromType1, FromType2) && 3104 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 3105 (ToAssignLeft != ToAssignRight)) 3106 return ToAssignLeft? ImplicitConversionSequence::Worse 3107 : ImplicitConversionSequence::Better; 3108 3109 // -- "conversion of B* to A* is better than conversion of C* to A*," 3110 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 3111 (FromAssignLeft != FromAssignRight)) 3112 return FromAssignLeft? ImplicitConversionSequence::Better 3113 : ImplicitConversionSequence::Worse; 3114 } 3115 } 3116 3117 // Ranking of member-pointer types. 3118 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 3119 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 3120 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 3121 const MemberPointerType * FromMemPointer1 = 3122 FromType1->getAs<MemberPointerType>(); 3123 const MemberPointerType * ToMemPointer1 = 3124 ToType1->getAs<MemberPointerType>(); 3125 const MemberPointerType * FromMemPointer2 = 3126 FromType2->getAs<MemberPointerType>(); 3127 const MemberPointerType * ToMemPointer2 = 3128 ToType2->getAs<MemberPointerType>(); 3129 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 3130 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 3131 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 3132 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 3133 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 3134 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 3135 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 3136 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 3137 // conversion of A::* to B::* is better than conversion of A::* to C::*, 3138 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3139 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3140 return ImplicitConversionSequence::Worse; 3141 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3142 return ImplicitConversionSequence::Better; 3143 } 3144 // conversion of B::* to C::* is better than conversion of A::* to C::* 3145 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 3146 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3147 return ImplicitConversionSequence::Better; 3148 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3149 return ImplicitConversionSequence::Worse; 3150 } 3151 } 3152 3153 if (SCS1.Second == ICK_Derived_To_Base) { 3154 // -- conversion of C to B is better than conversion of C to A, 3155 // -- binding of an expression of type C to a reference of type 3156 // B& is better than binding an expression of type C to a 3157 // reference of type A&, 3158 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3159 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3160 if (S.IsDerivedFrom(ToType1, ToType2)) 3161 return ImplicitConversionSequence::Better; 3162 else if (S.IsDerivedFrom(ToType2, ToType1)) 3163 return ImplicitConversionSequence::Worse; 3164 } 3165 3166 // -- conversion of B to A is better than conversion of C to A. 3167 // -- binding of an expression of type B to a reference of type 3168 // A& is better than binding an expression of type C to a 3169 // reference of type A&, 3170 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3171 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3172 if (S.IsDerivedFrom(FromType2, FromType1)) 3173 return ImplicitConversionSequence::Better; 3174 else if (S.IsDerivedFrom(FromType1, FromType2)) 3175 return ImplicitConversionSequence::Worse; 3176 } 3177 } 3178 3179 return ImplicitConversionSequence::Indistinguishable; 3180} 3181 3182/// CompareReferenceRelationship - Compare the two types T1 and T2 to 3183/// determine whether they are reference-related, 3184/// reference-compatible, reference-compatible with added 3185/// qualification, or incompatible, for use in C++ initialization by 3186/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 3187/// type, and the first type (T1) is the pointee type of the reference 3188/// type being initialized. 3189Sema::ReferenceCompareResult 3190Sema::CompareReferenceRelationship(SourceLocation Loc, 3191 QualType OrigT1, QualType OrigT2, 3192 bool &DerivedToBase, 3193 bool &ObjCConversion, 3194 bool &ObjCLifetimeConversion) { 3195 assert(!OrigT1->isReferenceType() && 3196 "T1 must be the pointee type of the reference type"); 3197 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 3198 3199 QualType T1 = Context.getCanonicalType(OrigT1); 3200 QualType T2 = Context.getCanonicalType(OrigT2); 3201 Qualifiers T1Quals, T2Quals; 3202 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 3203 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 3204 3205 // C++ [dcl.init.ref]p4: 3206 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 3207 // reference-related to "cv2 T2" if T1 is the same type as T2, or 3208 // T1 is a base class of T2. 3209 DerivedToBase = false; 3210 ObjCConversion = false; 3211 ObjCLifetimeConversion = false; 3212 if (UnqualT1 == UnqualT2) { 3213 // Nothing to do. 3214 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 3215 IsDerivedFrom(UnqualT2, UnqualT1)) 3216 DerivedToBase = true; 3217 else if (UnqualT1->isObjCObjectOrInterfaceType() && 3218 UnqualT2->isObjCObjectOrInterfaceType() && 3219 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 3220 ObjCConversion = true; 3221 else 3222 return Ref_Incompatible; 3223 3224 // At this point, we know that T1 and T2 are reference-related (at 3225 // least). 3226 3227 // If the type is an array type, promote the element qualifiers to the type 3228 // for comparison. 3229 if (isa<ArrayType>(T1) && T1Quals) 3230 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 3231 if (isa<ArrayType>(T2) && T2Quals) 3232 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 3233 3234 // C++ [dcl.init.ref]p4: 3235 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 3236 // reference-related to T2 and cv1 is the same cv-qualification 3237 // as, or greater cv-qualification than, cv2. For purposes of 3238 // overload resolution, cases for which cv1 is greater 3239 // cv-qualification than cv2 are identified as 3240 // reference-compatible with added qualification (see 13.3.3.2). 3241 // 3242 // Note that we also require equivalence of Objective-C GC and address-space 3243 // qualifiers when performing these computations, so that e.g., an int in 3244 // address space 1 is not reference-compatible with an int in address 3245 // space 2. 3246 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() && 3247 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) { 3248 T1Quals.removeObjCLifetime(); 3249 T2Quals.removeObjCLifetime(); 3250 ObjCLifetimeConversion = true; 3251 } 3252 3253 if (T1Quals == T2Quals) 3254 return Ref_Compatible; 3255 else if (T1Quals.compatiblyIncludes(T2Quals)) 3256 return Ref_Compatible_With_Added_Qualification; 3257 else 3258 return Ref_Related; 3259} 3260 3261/// \brief Look for a user-defined conversion to an value reference-compatible 3262/// with DeclType. Return true if something definite is found. 3263static bool 3264FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 3265 QualType DeclType, SourceLocation DeclLoc, 3266 Expr *Init, QualType T2, bool AllowRvalues, 3267 bool AllowExplicit) { 3268 assert(T2->isRecordType() && "Can only find conversions of record types."); 3269 CXXRecordDecl *T2RecordDecl 3270 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 3271 3272 OverloadCandidateSet CandidateSet(DeclLoc); 3273 const UnresolvedSetImpl *Conversions 3274 = T2RecordDecl->getVisibleConversionFunctions(); 3275 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3276 E = Conversions->end(); I != E; ++I) { 3277 NamedDecl *D = *I; 3278 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3279 if (isa<UsingShadowDecl>(D)) 3280 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3281 3282 FunctionTemplateDecl *ConvTemplate 3283 = dyn_cast<FunctionTemplateDecl>(D); 3284 CXXConversionDecl *Conv; 3285 if (ConvTemplate) 3286 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3287 else 3288 Conv = cast<CXXConversionDecl>(D); 3289 3290 // If this is an explicit conversion, and we're not allowed to consider 3291 // explicit conversions, skip it. 3292 if (!AllowExplicit && Conv->isExplicit()) 3293 continue; 3294 3295 if (AllowRvalues) { 3296 bool DerivedToBase = false; 3297 bool ObjCConversion = false; 3298 bool ObjCLifetimeConversion = false; 3299 if (!ConvTemplate && 3300 S.CompareReferenceRelationship( 3301 DeclLoc, 3302 Conv->getConversionType().getNonReferenceType() 3303 .getUnqualifiedType(), 3304 DeclType.getNonReferenceType().getUnqualifiedType(), 3305 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) == 3306 Sema::Ref_Incompatible) 3307 continue; 3308 } else { 3309 // If the conversion function doesn't return a reference type, 3310 // it can't be considered for this conversion. An rvalue reference 3311 // is only acceptable if its referencee is a function type. 3312 3313 const ReferenceType *RefType = 3314 Conv->getConversionType()->getAs<ReferenceType>(); 3315 if (!RefType || 3316 (!RefType->isLValueReferenceType() && 3317 !RefType->getPointeeType()->isFunctionType())) 3318 continue; 3319 } 3320 3321 if (ConvTemplate) 3322 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 3323 Init, DeclType, CandidateSet); 3324 else 3325 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 3326 DeclType, CandidateSet); 3327 } 3328 3329 OverloadCandidateSet::iterator Best; 3330 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 3331 case OR_Success: 3332 // C++ [over.ics.ref]p1: 3333 // 3334 // [...] If the parameter binds directly to the result of 3335 // applying a conversion function to the argument 3336 // expression, the implicit conversion sequence is a 3337 // user-defined conversion sequence (13.3.3.1.2), with the 3338 // second standard conversion sequence either an identity 3339 // conversion or, if the conversion function returns an 3340 // entity of a type that is a derived class of the parameter 3341 // type, a derived-to-base Conversion. 3342 if (!Best->FinalConversion.DirectBinding) 3343 return false; 3344 3345 if (Best->Function) 3346 S.MarkDeclarationReferenced(DeclLoc, Best->Function); 3347 ICS.setUserDefined(); 3348 ICS.UserDefined.Before = Best->Conversions[0].Standard; 3349 ICS.UserDefined.After = Best->FinalConversion; 3350 ICS.UserDefined.ConversionFunction = Best->Function; 3351 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl.getDecl(); 3352 ICS.UserDefined.EllipsisConversion = false; 3353 assert(ICS.UserDefined.After.ReferenceBinding && 3354 ICS.UserDefined.After.DirectBinding && 3355 "Expected a direct reference binding!"); 3356 return true; 3357 3358 case OR_Ambiguous: 3359 ICS.setAmbiguous(); 3360 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3361 Cand != CandidateSet.end(); ++Cand) 3362 if (Cand->Viable) 3363 ICS.Ambiguous.addConversion(Cand->Function); 3364 return true; 3365 3366 case OR_No_Viable_Function: 3367 case OR_Deleted: 3368 // There was no suitable conversion, or we found a deleted 3369 // conversion; continue with other checks. 3370 return false; 3371 } 3372 3373 return false; 3374} 3375 3376/// \brief Compute an implicit conversion sequence for reference 3377/// initialization. 3378static ImplicitConversionSequence 3379TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 3380 SourceLocation DeclLoc, 3381 bool SuppressUserConversions, 3382 bool AllowExplicit) { 3383 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 3384 3385 // Most paths end in a failed conversion. 3386 ImplicitConversionSequence ICS; 3387 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3388 3389 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 3390 QualType T2 = Init->getType(); 3391 3392 // If the initializer is the address of an overloaded function, try 3393 // to resolve the overloaded function. If all goes well, T2 is the 3394 // type of the resulting function. 3395 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 3396 DeclAccessPair Found; 3397 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 3398 false, Found)) 3399 T2 = Fn->getType(); 3400 } 3401 3402 // Compute some basic properties of the types and the initializer. 3403 bool isRValRef = DeclType->isRValueReferenceType(); 3404 bool DerivedToBase = false; 3405 bool ObjCConversion = false; 3406 bool ObjCLifetimeConversion = false; 3407 Expr::Classification InitCategory = Init->Classify(S.Context); 3408 Sema::ReferenceCompareResult RefRelationship 3409 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 3410 ObjCConversion, ObjCLifetimeConversion); 3411 3412 3413 // C++0x [dcl.init.ref]p5: 3414 // A reference to type "cv1 T1" is initialized by an expression 3415 // of type "cv2 T2" as follows: 3416 3417 // -- If reference is an lvalue reference and the initializer expression 3418 if (!isRValRef) { 3419 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 3420 // reference-compatible with "cv2 T2," or 3421 // 3422 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 3423 if (InitCategory.isLValue() && 3424 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 3425 // C++ [over.ics.ref]p1: 3426 // When a parameter of reference type binds directly (8.5.3) 3427 // to an argument expression, the implicit conversion sequence 3428 // is the identity conversion, unless the argument expression 3429 // has a type that is a derived class of the parameter type, 3430 // in which case the implicit conversion sequence is a 3431 // derived-to-base Conversion (13.3.3.1). 3432 ICS.setStandard(); 3433 ICS.Standard.First = ICK_Identity; 3434 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3435 : ObjCConversion? ICK_Compatible_Conversion 3436 : ICK_Identity; 3437 ICS.Standard.Third = ICK_Identity; 3438 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3439 ICS.Standard.setToType(0, T2); 3440 ICS.Standard.setToType(1, T1); 3441 ICS.Standard.setToType(2, T1); 3442 ICS.Standard.ReferenceBinding = true; 3443 ICS.Standard.DirectBinding = true; 3444 ICS.Standard.IsLvalueReference = !isRValRef; 3445 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3446 ICS.Standard.BindsToRvalue = false; 3447 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3448 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 3449 ICS.Standard.CopyConstructor = 0; 3450 3451 // Nothing more to do: the inaccessibility/ambiguity check for 3452 // derived-to-base conversions is suppressed when we're 3453 // computing the implicit conversion sequence (C++ 3454 // [over.best.ics]p2). 3455 return ICS; 3456 } 3457 3458 // -- has a class type (i.e., T2 is a class type), where T1 is 3459 // not reference-related to T2, and can be implicitly 3460 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 3461 // is reference-compatible with "cv3 T3" 92) (this 3462 // conversion is selected by enumerating the applicable 3463 // conversion functions (13.3.1.6) and choosing the best 3464 // one through overload resolution (13.3)), 3465 if (!SuppressUserConversions && T2->isRecordType() && 3466 !S.RequireCompleteType(DeclLoc, T2, 0) && 3467 RefRelationship == Sema::Ref_Incompatible) { 3468 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3469 Init, T2, /*AllowRvalues=*/false, 3470 AllowExplicit)) 3471 return ICS; 3472 } 3473 } 3474 3475 // -- Otherwise, the reference shall be an lvalue reference to a 3476 // non-volatile const type (i.e., cv1 shall be const), or the reference 3477 // shall be an rvalue reference. 3478 // 3479 // We actually handle one oddity of C++ [over.ics.ref] at this 3480 // point, which is that, due to p2 (which short-circuits reference 3481 // binding by only attempting a simple conversion for non-direct 3482 // bindings) and p3's strange wording, we allow a const volatile 3483 // reference to bind to an rvalue. Hence the check for the presence 3484 // of "const" rather than checking for "const" being the only 3485 // qualifier. 3486 // This is also the point where rvalue references and lvalue inits no longer 3487 // go together. 3488 if (!isRValRef && !T1.isConstQualified()) 3489 return ICS; 3490 3491 // -- If the initializer expression 3492 // 3493 // -- is an xvalue, class prvalue, array prvalue or function 3494 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or 3495 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 3496 (InitCategory.isXValue() || 3497 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 3498 (InitCategory.isLValue() && T2->isFunctionType()))) { 3499 ICS.setStandard(); 3500 ICS.Standard.First = ICK_Identity; 3501 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3502 : ObjCConversion? ICK_Compatible_Conversion 3503 : ICK_Identity; 3504 ICS.Standard.Third = ICK_Identity; 3505 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3506 ICS.Standard.setToType(0, T2); 3507 ICS.Standard.setToType(1, T1); 3508 ICS.Standard.setToType(2, T1); 3509 ICS.Standard.ReferenceBinding = true; 3510 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 3511 // binding unless we're binding to a class prvalue. 3512 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 3513 // allow the use of rvalue references in C++98/03 for the benefit of 3514 // standard library implementors; therefore, we need the xvalue check here. 3515 ICS.Standard.DirectBinding = 3516 S.getLangOptions().CPlusPlus0x || 3517 (InitCategory.isPRValue() && !T2->isRecordType()); 3518 ICS.Standard.IsLvalueReference = !isRValRef; 3519 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3520 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 3521 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3522 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 3523 ICS.Standard.CopyConstructor = 0; 3524 return ICS; 3525 } 3526 3527 // -- has a class type (i.e., T2 is a class type), where T1 is not 3528 // reference-related to T2, and can be implicitly converted to 3529 // an xvalue, class prvalue, or function lvalue of type 3530 // "cv3 T3", where "cv1 T1" is reference-compatible with 3531 // "cv3 T3", 3532 // 3533 // then the reference is bound to the value of the initializer 3534 // expression in the first case and to the result of the conversion 3535 // in the second case (or, in either case, to an appropriate base 3536 // class subobject). 3537 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3538 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 3539 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3540 Init, T2, /*AllowRvalues=*/true, 3541 AllowExplicit)) { 3542 // In the second case, if the reference is an rvalue reference 3543 // and the second standard conversion sequence of the 3544 // user-defined conversion sequence includes an lvalue-to-rvalue 3545 // conversion, the program is ill-formed. 3546 if (ICS.isUserDefined() && isRValRef && 3547 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 3548 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3549 3550 return ICS; 3551 } 3552 3553 // -- Otherwise, a temporary of type "cv1 T1" is created and 3554 // initialized from the initializer expression using the 3555 // rules for a non-reference copy initialization (8.5). The 3556 // reference is then bound to the temporary. If T1 is 3557 // reference-related to T2, cv1 must be the same 3558 // cv-qualification as, or greater cv-qualification than, 3559 // cv2; otherwise, the program is ill-formed. 3560 if (RefRelationship == Sema::Ref_Related) { 3561 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 3562 // we would be reference-compatible or reference-compatible with 3563 // added qualification. But that wasn't the case, so the reference 3564 // initialization fails. 3565 // 3566 // Note that we only want to check address spaces and cvr-qualifiers here. 3567 // ObjC GC and lifetime qualifiers aren't important. 3568 Qualifiers T1Quals = T1.getQualifiers(); 3569 Qualifiers T2Quals = T2.getQualifiers(); 3570 T1Quals.removeObjCGCAttr(); 3571 T1Quals.removeObjCLifetime(); 3572 T2Quals.removeObjCGCAttr(); 3573 T2Quals.removeObjCLifetime(); 3574 if (!T1Quals.compatiblyIncludes(T2Quals)) 3575 return ICS; 3576 } 3577 3578 // If at least one of the types is a class type, the types are not 3579 // related, and we aren't allowed any user conversions, the 3580 // reference binding fails. This case is important for breaking 3581 // recursion, since TryImplicitConversion below will attempt to 3582 // create a temporary through the use of a copy constructor. 3583 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3584 (T1->isRecordType() || T2->isRecordType())) 3585 return ICS; 3586 3587 // If T1 is reference-related to T2 and the reference is an rvalue 3588 // reference, the initializer expression shall not be an lvalue. 3589 if (RefRelationship >= Sema::Ref_Related && 3590 isRValRef && Init->Classify(S.Context).isLValue()) 3591 return ICS; 3592 3593 // C++ [over.ics.ref]p2: 3594 // When a parameter of reference type is not bound directly to 3595 // an argument expression, the conversion sequence is the one 3596 // required to convert the argument expression to the 3597 // underlying type of the reference according to 3598 // 13.3.3.1. Conceptually, this conversion sequence corresponds 3599 // to copy-initializing a temporary of the underlying type with 3600 // the argument expression. Any difference in top-level 3601 // cv-qualification is subsumed by the initialization itself 3602 // and does not constitute a conversion. 3603 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 3604 /*AllowExplicit=*/false, 3605 /*InOverloadResolution=*/false, 3606 /*CStyle=*/false, 3607 /*AllowObjCWritebackConversion=*/false); 3608 3609 // Of course, that's still a reference binding. 3610 if (ICS.isStandard()) { 3611 ICS.Standard.ReferenceBinding = true; 3612 ICS.Standard.IsLvalueReference = !isRValRef; 3613 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3614 ICS.Standard.BindsToRvalue = true; 3615 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3616 ICS.Standard.ObjCLifetimeConversionBinding = false; 3617 } else if (ICS.isUserDefined()) { 3618 ICS.UserDefined.After.ReferenceBinding = true; 3619 ICS.UserDefined.After.IsLvalueReference = !isRValRef; 3620 ICS.UserDefined.After.BindsToFunctionLvalue = T2->isFunctionType(); 3621 ICS.UserDefined.After.BindsToRvalue = true; 3622 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3623 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false; 3624 } 3625 3626 return ICS; 3627} 3628 3629/// TryCopyInitialization - Try to copy-initialize a value of type 3630/// ToType from the expression From. Return the implicit conversion 3631/// sequence required to pass this argument, which may be a bad 3632/// conversion sequence (meaning that the argument cannot be passed to 3633/// a parameter of this type). If @p SuppressUserConversions, then we 3634/// do not permit any user-defined conversion sequences. 3635static ImplicitConversionSequence 3636TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 3637 bool SuppressUserConversions, 3638 bool InOverloadResolution, 3639 bool AllowObjCWritebackConversion) { 3640 if (ToType->isReferenceType()) 3641 return TryReferenceInit(S, From, ToType, 3642 /*FIXME:*/From->getLocStart(), 3643 SuppressUserConversions, 3644 /*AllowExplicit=*/false); 3645 3646 return TryImplicitConversion(S, From, ToType, 3647 SuppressUserConversions, 3648 /*AllowExplicit=*/false, 3649 InOverloadResolution, 3650 /*CStyle=*/false, 3651 AllowObjCWritebackConversion); 3652} 3653 3654static bool TryCopyInitialization(const CanQualType FromQTy, 3655 const CanQualType ToQTy, 3656 Sema &S, 3657 SourceLocation Loc, 3658 ExprValueKind FromVK) { 3659 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK); 3660 ImplicitConversionSequence ICS = 3661 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false); 3662 3663 return !ICS.isBad(); 3664} 3665 3666/// TryObjectArgumentInitialization - Try to initialize the object 3667/// parameter of the given member function (@c Method) from the 3668/// expression @p From. 3669static ImplicitConversionSequence 3670TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 3671 Expr::Classification FromClassification, 3672 CXXMethodDecl *Method, 3673 CXXRecordDecl *ActingContext) { 3674 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 3675 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 3676 // const volatile object. 3677 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 3678 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 3679 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 3680 3681 // Set up the conversion sequence as a "bad" conversion, to allow us 3682 // to exit early. 3683 ImplicitConversionSequence ICS; 3684 3685 // We need to have an object of class type. 3686 QualType FromType = OrigFromType; 3687 if (const PointerType *PT = FromType->getAs<PointerType>()) { 3688 FromType = PT->getPointeeType(); 3689 3690 // When we had a pointer, it's implicitly dereferenced, so we 3691 // better have an lvalue. 3692 assert(FromClassification.isLValue()); 3693 } 3694 3695 assert(FromType->isRecordType()); 3696 3697 // C++0x [over.match.funcs]p4: 3698 // For non-static member functions, the type of the implicit object 3699 // parameter is 3700 // 3701 // - "lvalue reference to cv X" for functions declared without a 3702 // ref-qualifier or with the & ref-qualifier 3703 // - "rvalue reference to cv X" for functions declared with the && 3704 // ref-qualifier 3705 // 3706 // where X is the class of which the function is a member and cv is the 3707 // cv-qualification on the member function declaration. 3708 // 3709 // However, when finding an implicit conversion sequence for the argument, we 3710 // are not allowed to create temporaries or perform user-defined conversions 3711 // (C++ [over.match.funcs]p5). We perform a simplified version of 3712 // reference binding here, that allows class rvalues to bind to 3713 // non-constant references. 3714 3715 // First check the qualifiers. 3716 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 3717 if (ImplicitParamType.getCVRQualifiers() 3718 != FromTypeCanon.getLocalCVRQualifiers() && 3719 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 3720 ICS.setBad(BadConversionSequence::bad_qualifiers, 3721 OrigFromType, ImplicitParamType); 3722 return ICS; 3723 } 3724 3725 // Check that we have either the same type or a derived type. It 3726 // affects the conversion rank. 3727 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 3728 ImplicitConversionKind SecondKind; 3729 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 3730 SecondKind = ICK_Identity; 3731 } else if (S.IsDerivedFrom(FromType, ClassType)) 3732 SecondKind = ICK_Derived_To_Base; 3733 else { 3734 ICS.setBad(BadConversionSequence::unrelated_class, 3735 FromType, ImplicitParamType); 3736 return ICS; 3737 } 3738 3739 // Check the ref-qualifier. 3740 switch (Method->getRefQualifier()) { 3741 case RQ_None: 3742 // Do nothing; we don't care about lvalueness or rvalueness. 3743 break; 3744 3745 case RQ_LValue: 3746 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 3747 // non-const lvalue reference cannot bind to an rvalue 3748 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 3749 ImplicitParamType); 3750 return ICS; 3751 } 3752 break; 3753 3754 case RQ_RValue: 3755 if (!FromClassification.isRValue()) { 3756 // rvalue reference cannot bind to an lvalue 3757 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 3758 ImplicitParamType); 3759 return ICS; 3760 } 3761 break; 3762 } 3763 3764 // Success. Mark this as a reference binding. 3765 ICS.setStandard(); 3766 ICS.Standard.setAsIdentityConversion(); 3767 ICS.Standard.Second = SecondKind; 3768 ICS.Standard.setFromType(FromType); 3769 ICS.Standard.setAllToTypes(ImplicitParamType); 3770 ICS.Standard.ReferenceBinding = true; 3771 ICS.Standard.DirectBinding = true; 3772 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 3773 ICS.Standard.BindsToFunctionLvalue = false; 3774 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 3775 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 3776 = (Method->getRefQualifier() == RQ_None); 3777 return ICS; 3778} 3779 3780/// PerformObjectArgumentInitialization - Perform initialization of 3781/// the implicit object parameter for the given Method with the given 3782/// expression. 3783ExprResult 3784Sema::PerformObjectArgumentInitialization(Expr *From, 3785 NestedNameSpecifier *Qualifier, 3786 NamedDecl *FoundDecl, 3787 CXXMethodDecl *Method) { 3788 QualType FromRecordType, DestType; 3789 QualType ImplicitParamRecordType = 3790 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3791 3792 Expr::Classification FromClassification; 3793 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3794 FromRecordType = PT->getPointeeType(); 3795 DestType = Method->getThisType(Context); 3796 FromClassification = Expr::Classification::makeSimpleLValue(); 3797 } else { 3798 FromRecordType = From->getType(); 3799 DestType = ImplicitParamRecordType; 3800 FromClassification = From->Classify(Context); 3801 } 3802 3803 // Note that we always use the true parent context when performing 3804 // the actual argument initialization. 3805 ImplicitConversionSequence ICS 3806 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 3807 Method, Method->getParent()); 3808 if (ICS.isBad()) { 3809 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 3810 Qualifiers FromQs = FromRecordType.getQualifiers(); 3811 Qualifiers ToQs = DestType.getQualifiers(); 3812 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 3813 if (CVR) { 3814 Diag(From->getSourceRange().getBegin(), 3815 diag::err_member_function_call_bad_cvr) 3816 << Method->getDeclName() << FromRecordType << (CVR - 1) 3817 << From->getSourceRange(); 3818 Diag(Method->getLocation(), diag::note_previous_decl) 3819 << Method->getDeclName(); 3820 return ExprError(); 3821 } 3822 } 3823 3824 return Diag(From->getSourceRange().getBegin(), 3825 diag::err_implicit_object_parameter_init) 3826 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3827 } 3828 3829 if (ICS.Standard.Second == ICK_Derived_To_Base) { 3830 ExprResult FromRes = 3831 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3832 if (FromRes.isInvalid()) 3833 return ExprError(); 3834 From = FromRes.take(); 3835 } 3836 3837 if (!Context.hasSameType(From->getType(), DestType)) 3838 From = ImpCastExprToType(From, DestType, CK_NoOp, 3839 From->getType()->isPointerType() ? VK_RValue : VK_LValue).take(); 3840 return Owned(From); 3841} 3842 3843/// TryContextuallyConvertToBool - Attempt to contextually convert the 3844/// expression From to bool (C++0x [conv]p3). 3845static ImplicitConversionSequence 3846TryContextuallyConvertToBool(Sema &S, Expr *From) { 3847 // FIXME: This is pretty broken. 3848 return TryImplicitConversion(S, From, S.Context.BoolTy, 3849 // FIXME: Are these flags correct? 3850 /*SuppressUserConversions=*/false, 3851 /*AllowExplicit=*/true, 3852 /*InOverloadResolution=*/false, 3853 /*CStyle=*/false, 3854 /*AllowObjCWritebackConversion=*/false); 3855} 3856 3857/// PerformContextuallyConvertToBool - Perform a contextual conversion 3858/// of the expression From to bool (C++0x [conv]p3). 3859ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) { 3860 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 3861 if (!ICS.isBad()) 3862 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3863 3864 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3865 return Diag(From->getSourceRange().getBegin(), 3866 diag::err_typecheck_bool_condition) 3867 << From->getType() << From->getSourceRange(); 3868 return ExprError(); 3869} 3870 3871/// dropPointerConversions - If the given standard conversion sequence 3872/// involves any pointer conversions, remove them. This may change 3873/// the result type of the conversion sequence. 3874static void dropPointerConversion(StandardConversionSequence &SCS) { 3875 if (SCS.Second == ICK_Pointer_Conversion) { 3876 SCS.Second = ICK_Identity; 3877 SCS.Third = ICK_Identity; 3878 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0]; 3879 } 3880} 3881 3882/// TryContextuallyConvertToObjCPointer - Attempt to contextually 3883/// convert the expression From to an Objective-C pointer type. 3884static ImplicitConversionSequence 3885TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) { 3886 // Do an implicit conversion to 'id'. 3887 QualType Ty = S.Context.getObjCIdType(); 3888 ImplicitConversionSequence ICS 3889 = TryImplicitConversion(S, From, Ty, 3890 // FIXME: Are these flags correct? 3891 /*SuppressUserConversions=*/false, 3892 /*AllowExplicit=*/true, 3893 /*InOverloadResolution=*/false, 3894 /*CStyle=*/false, 3895 /*AllowObjCWritebackConversion=*/false); 3896 3897 // Strip off any final conversions to 'id'. 3898 switch (ICS.getKind()) { 3899 case ImplicitConversionSequence::BadConversion: 3900 case ImplicitConversionSequence::AmbiguousConversion: 3901 case ImplicitConversionSequence::EllipsisConversion: 3902 break; 3903 3904 case ImplicitConversionSequence::UserDefinedConversion: 3905 dropPointerConversion(ICS.UserDefined.After); 3906 break; 3907 3908 case ImplicitConversionSequence::StandardConversion: 3909 dropPointerConversion(ICS.Standard); 3910 break; 3911 } 3912 3913 return ICS; 3914} 3915 3916/// PerformContextuallyConvertToObjCPointer - Perform a contextual 3917/// conversion of the expression From to an Objective-C pointer type. 3918ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) { 3919 QualType Ty = Context.getObjCIdType(); 3920 ImplicitConversionSequence ICS = 3921 TryContextuallyConvertToObjCPointer(*this, From); 3922 if (!ICS.isBad()) 3923 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3924 return ExprError(); 3925} 3926 3927/// \brief Attempt to convert the given expression to an integral or 3928/// enumeration type. 3929/// 3930/// This routine will attempt to convert an expression of class type to an 3931/// integral or enumeration type, if that class type only has a single 3932/// conversion to an integral or enumeration type. 3933/// 3934/// \param Loc The source location of the construct that requires the 3935/// conversion. 3936/// 3937/// \param FromE The expression we're converting from. 3938/// 3939/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3940/// have integral or enumeration type. 3941/// 3942/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3943/// incomplete class type. 3944/// 3945/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3946/// explicit conversion function (because no implicit conversion functions 3947/// were available). This is a recovery mode. 3948/// 3949/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3950/// showing which conversion was picked. 3951/// 3952/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3953/// conversion function that could convert to integral or enumeration type. 3954/// 3955/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3956/// usable conversion function. 3957/// 3958/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3959/// function, which may be an extension in this case. 3960/// 3961/// \returns The expression, converted to an integral or enumeration type if 3962/// successful. 3963ExprResult 3964Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 3965 const PartialDiagnostic &NotIntDiag, 3966 const PartialDiagnostic &IncompleteDiag, 3967 const PartialDiagnostic &ExplicitConvDiag, 3968 const PartialDiagnostic &ExplicitConvNote, 3969 const PartialDiagnostic &AmbigDiag, 3970 const PartialDiagnostic &AmbigNote, 3971 const PartialDiagnostic &ConvDiag) { 3972 // We can't perform any more checking for type-dependent expressions. 3973 if (From->isTypeDependent()) 3974 return Owned(From); 3975 3976 // If the expression already has integral or enumeration type, we're golden. 3977 QualType T = From->getType(); 3978 if (T->isIntegralOrEnumerationType()) 3979 return Owned(From); 3980 3981 // FIXME: Check for missing '()' if T is a function type? 3982 3983 // If we don't have a class type in C++, there's no way we can get an 3984 // expression of integral or enumeration type. 3985 const RecordType *RecordTy = T->getAs<RecordType>(); 3986 if (!RecordTy || !getLangOptions().CPlusPlus) { 3987 Diag(Loc, NotIntDiag) 3988 << T << From->getSourceRange(); 3989 return Owned(From); 3990 } 3991 3992 // We must have a complete class type. 3993 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3994 return Owned(From); 3995 3996 // Look for a conversion to an integral or enumeration type. 3997 UnresolvedSet<4> ViableConversions; 3998 UnresolvedSet<4> ExplicitConversions; 3999 const UnresolvedSetImpl *Conversions 4000 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 4001 4002 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4003 E = Conversions->end(); 4004 I != E; 4005 ++I) { 4006 if (CXXConversionDecl *Conversion 4007 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 4008 if (Conversion->getConversionType().getNonReferenceType() 4009 ->isIntegralOrEnumerationType()) { 4010 if (Conversion->isExplicit()) 4011 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 4012 else 4013 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 4014 } 4015 } 4016 4017 switch (ViableConversions.size()) { 4018 case 0: 4019 if (ExplicitConversions.size() == 1) { 4020 DeclAccessPair Found = ExplicitConversions[0]; 4021 CXXConversionDecl *Conversion 4022 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 4023 4024 // The user probably meant to invoke the given explicit 4025 // conversion; use it. 4026 QualType ConvTy 4027 = Conversion->getConversionType().getNonReferenceType(); 4028 std::string TypeStr; 4029 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 4030 4031 Diag(Loc, ExplicitConvDiag) 4032 << T << ConvTy 4033 << FixItHint::CreateInsertion(From->getLocStart(), 4034 "static_cast<" + TypeStr + ">(") 4035 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 4036 ")"); 4037 Diag(Conversion->getLocation(), ExplicitConvNote) 4038 << ConvTy->isEnumeralType() << ConvTy; 4039 4040 // If we aren't in a SFINAE context, build a call to the 4041 // explicit conversion function. 4042 if (isSFINAEContext()) 4043 return ExprError(); 4044 4045 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 4046 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion); 4047 if (Result.isInvalid()) 4048 return ExprError(); 4049 4050 From = Result.get(); 4051 } 4052 4053 // We'll complain below about a non-integral condition type. 4054 break; 4055 4056 case 1: { 4057 // Apply this conversion. 4058 DeclAccessPair Found = ViableConversions[0]; 4059 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 4060 4061 CXXConversionDecl *Conversion 4062 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 4063 QualType ConvTy 4064 = Conversion->getConversionType().getNonReferenceType(); 4065 if (ConvDiag.getDiagID()) { 4066 if (isSFINAEContext()) 4067 return ExprError(); 4068 4069 Diag(Loc, ConvDiag) 4070 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 4071 } 4072 4073 ExprResult Result = BuildCXXMemberCallExpr(From, Found, 4074 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 4075 if (Result.isInvalid()) 4076 return ExprError(); 4077 4078 From = Result.get(); 4079 break; 4080 } 4081 4082 default: 4083 Diag(Loc, AmbigDiag) 4084 << T << From->getSourceRange(); 4085 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 4086 CXXConversionDecl *Conv 4087 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 4088 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 4089 Diag(Conv->getLocation(), AmbigNote) 4090 << ConvTy->isEnumeralType() << ConvTy; 4091 } 4092 return Owned(From); 4093 } 4094 4095 if (!From->getType()->isIntegralOrEnumerationType()) 4096 Diag(Loc, NotIntDiag) 4097 << From->getType() << From->getSourceRange(); 4098 4099 return Owned(From); 4100} 4101 4102/// AddOverloadCandidate - Adds the given function to the set of 4103/// candidate functions, using the given function call arguments. If 4104/// @p SuppressUserConversions, then don't allow user-defined 4105/// conversions via constructors or conversion operators. 4106/// 4107/// \para PartialOverloading true if we are performing "partial" overloading 4108/// based on an incomplete set of function arguments. This feature is used by 4109/// code completion. 4110void 4111Sema::AddOverloadCandidate(FunctionDecl *Function, 4112 DeclAccessPair FoundDecl, 4113 Expr **Args, unsigned NumArgs, 4114 OverloadCandidateSet& CandidateSet, 4115 bool SuppressUserConversions, 4116 bool PartialOverloading) { 4117 const FunctionProtoType* Proto 4118 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 4119 assert(Proto && "Functions without a prototype cannot be overloaded"); 4120 assert(!Function->getDescribedFunctionTemplate() && 4121 "Use AddTemplateOverloadCandidate for function templates"); 4122 4123 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 4124 if (!isa<CXXConstructorDecl>(Method)) { 4125 // If we get here, it's because we're calling a member function 4126 // that is named without a member access expression (e.g., 4127 // "this->f") that was either written explicitly or created 4128 // implicitly. This can happen with a qualified call to a member 4129 // function, e.g., X::f(). We use an empty type for the implied 4130 // object argument (C++ [over.call.func]p3), and the acting context 4131 // is irrelevant. 4132 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 4133 QualType(), Expr::Classification::makeSimpleLValue(), 4134 Args, NumArgs, CandidateSet, 4135 SuppressUserConversions); 4136 return; 4137 } 4138 // We treat a constructor like a non-member function, since its object 4139 // argument doesn't participate in overload resolution. 4140 } 4141 4142 if (!CandidateSet.isNewCandidate(Function)) 4143 return; 4144 4145 // Overload resolution is always an unevaluated context. 4146 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4147 4148 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 4149 // C++ [class.copy]p3: 4150 // A member function template is never instantiated to perform the copy 4151 // of a class object to an object of its class type. 4152 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 4153 if (NumArgs == 1 && 4154 Constructor->isSpecializationCopyingObject() && 4155 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 4156 IsDerivedFrom(Args[0]->getType(), ClassType))) 4157 return; 4158 } 4159 4160 // Add this candidate 4161 CandidateSet.push_back(OverloadCandidate()); 4162 OverloadCandidate& Candidate = CandidateSet.back(); 4163 Candidate.FoundDecl = FoundDecl; 4164 Candidate.Function = Function; 4165 Candidate.Viable = true; 4166 Candidate.IsSurrogate = false; 4167 Candidate.IgnoreObjectArgument = false; 4168 Candidate.ExplicitCallArguments = NumArgs; 4169 4170 unsigned NumArgsInProto = Proto->getNumArgs(); 4171 4172 // (C++ 13.3.2p2): A candidate function having fewer than m 4173 // parameters is viable only if it has an ellipsis in its parameter 4174 // list (8.3.5). 4175 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 4176 !Proto->isVariadic()) { 4177 Candidate.Viable = false; 4178 Candidate.FailureKind = ovl_fail_too_many_arguments; 4179 return; 4180 } 4181 4182 // (C++ 13.3.2p2): A candidate function having more than m parameters 4183 // is viable only if the (m+1)st parameter has a default argument 4184 // (8.3.6). For the purposes of overload resolution, the 4185 // parameter list is truncated on the right, so that there are 4186 // exactly m parameters. 4187 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 4188 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 4189 // Not enough arguments. 4190 Candidate.Viable = false; 4191 Candidate.FailureKind = ovl_fail_too_few_arguments; 4192 return; 4193 } 4194 4195 // Determine the implicit conversion sequences for each of the 4196 // arguments. 4197 Candidate.Conversions.resize(NumArgs); 4198 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4199 if (ArgIdx < NumArgsInProto) { 4200 // (C++ 13.3.2p3): for F to be a viable function, there shall 4201 // exist for each argument an implicit conversion sequence 4202 // (13.3.3.1) that converts that argument to the corresponding 4203 // parameter of F. 4204 QualType ParamType = Proto->getArgType(ArgIdx); 4205 Candidate.Conversions[ArgIdx] 4206 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4207 SuppressUserConversions, 4208 /*InOverloadResolution=*/true, 4209 /*AllowObjCWritebackConversion=*/ 4210 getLangOptions().ObjCAutoRefCount); 4211 if (Candidate.Conversions[ArgIdx].isBad()) { 4212 Candidate.Viable = false; 4213 Candidate.FailureKind = ovl_fail_bad_conversion; 4214 break; 4215 } 4216 } else { 4217 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4218 // argument for which there is no corresponding parameter is 4219 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4220 Candidate.Conversions[ArgIdx].setEllipsis(); 4221 } 4222 } 4223} 4224 4225/// \brief Add all of the function declarations in the given function set to 4226/// the overload canddiate set. 4227void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 4228 Expr **Args, unsigned NumArgs, 4229 OverloadCandidateSet& CandidateSet, 4230 bool SuppressUserConversions) { 4231 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 4232 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 4233 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 4234 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 4235 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 4236 cast<CXXMethodDecl>(FD)->getParent(), 4237 Args[0]->getType(), Args[0]->Classify(Context), 4238 Args + 1, NumArgs - 1, 4239 CandidateSet, SuppressUserConversions); 4240 else 4241 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 4242 SuppressUserConversions); 4243 } else { 4244 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 4245 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 4246 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 4247 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 4248 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 4249 /*FIXME: explicit args */ 0, 4250 Args[0]->getType(), 4251 Args[0]->Classify(Context), 4252 Args + 1, NumArgs - 1, 4253 CandidateSet, 4254 SuppressUserConversions); 4255 else 4256 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 4257 /*FIXME: explicit args */ 0, 4258 Args, NumArgs, CandidateSet, 4259 SuppressUserConversions); 4260 } 4261 } 4262} 4263 4264/// AddMethodCandidate - Adds a named decl (which is some kind of 4265/// method) as a method candidate to the given overload set. 4266void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 4267 QualType ObjectType, 4268 Expr::Classification ObjectClassification, 4269 Expr **Args, unsigned NumArgs, 4270 OverloadCandidateSet& CandidateSet, 4271 bool SuppressUserConversions) { 4272 NamedDecl *Decl = FoundDecl.getDecl(); 4273 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 4274 4275 if (isa<UsingShadowDecl>(Decl)) 4276 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 4277 4278 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 4279 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 4280 "Expected a member function template"); 4281 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 4282 /*ExplicitArgs*/ 0, 4283 ObjectType, ObjectClassification, Args, NumArgs, 4284 CandidateSet, 4285 SuppressUserConversions); 4286 } else { 4287 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 4288 ObjectType, ObjectClassification, Args, NumArgs, 4289 CandidateSet, SuppressUserConversions); 4290 } 4291} 4292 4293/// AddMethodCandidate - Adds the given C++ member function to the set 4294/// of candidate functions, using the given function call arguments 4295/// and the object argument (@c Object). For example, in a call 4296/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 4297/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 4298/// allow user-defined conversions via constructors or conversion 4299/// operators. 4300void 4301Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 4302 CXXRecordDecl *ActingContext, QualType ObjectType, 4303 Expr::Classification ObjectClassification, 4304 Expr **Args, unsigned NumArgs, 4305 OverloadCandidateSet& CandidateSet, 4306 bool SuppressUserConversions) { 4307 const FunctionProtoType* Proto 4308 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 4309 assert(Proto && "Methods without a prototype cannot be overloaded"); 4310 assert(!isa<CXXConstructorDecl>(Method) && 4311 "Use AddOverloadCandidate for constructors"); 4312 4313 if (!CandidateSet.isNewCandidate(Method)) 4314 return; 4315 4316 // Overload resolution is always an unevaluated context. 4317 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4318 4319 // Add this candidate 4320 CandidateSet.push_back(OverloadCandidate()); 4321 OverloadCandidate& Candidate = CandidateSet.back(); 4322 Candidate.FoundDecl = FoundDecl; 4323 Candidate.Function = Method; 4324 Candidate.IsSurrogate = false; 4325 Candidate.IgnoreObjectArgument = false; 4326 Candidate.ExplicitCallArguments = NumArgs; 4327 4328 unsigned NumArgsInProto = Proto->getNumArgs(); 4329 4330 // (C++ 13.3.2p2): A candidate function having fewer than m 4331 // parameters is viable only if it has an ellipsis in its parameter 4332 // list (8.3.5). 4333 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4334 Candidate.Viable = false; 4335 Candidate.FailureKind = ovl_fail_too_many_arguments; 4336 return; 4337 } 4338 4339 // (C++ 13.3.2p2): A candidate function having more than m parameters 4340 // is viable only if the (m+1)st parameter has a default argument 4341 // (8.3.6). For the purposes of overload resolution, the 4342 // parameter list is truncated on the right, so that there are 4343 // exactly m parameters. 4344 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 4345 if (NumArgs < MinRequiredArgs) { 4346 // Not enough arguments. 4347 Candidate.Viable = false; 4348 Candidate.FailureKind = ovl_fail_too_few_arguments; 4349 return; 4350 } 4351 4352 Candidate.Viable = true; 4353 Candidate.Conversions.resize(NumArgs + 1); 4354 4355 if (Method->isStatic() || ObjectType.isNull()) 4356 // The implicit object argument is ignored. 4357 Candidate.IgnoreObjectArgument = true; 4358 else { 4359 // Determine the implicit conversion sequence for the object 4360 // parameter. 4361 Candidate.Conversions[0] 4362 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 4363 Method, ActingContext); 4364 if (Candidate.Conversions[0].isBad()) { 4365 Candidate.Viable = false; 4366 Candidate.FailureKind = ovl_fail_bad_conversion; 4367 return; 4368 } 4369 } 4370 4371 // Determine the implicit conversion sequences for each of the 4372 // arguments. 4373 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4374 if (ArgIdx < NumArgsInProto) { 4375 // (C++ 13.3.2p3): for F to be a viable function, there shall 4376 // exist for each argument an implicit conversion sequence 4377 // (13.3.3.1) that converts that argument to the corresponding 4378 // parameter of F. 4379 QualType ParamType = Proto->getArgType(ArgIdx); 4380 Candidate.Conversions[ArgIdx + 1] 4381 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4382 SuppressUserConversions, 4383 /*InOverloadResolution=*/true, 4384 /*AllowObjCWritebackConversion=*/ 4385 getLangOptions().ObjCAutoRefCount); 4386 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4387 Candidate.Viable = false; 4388 Candidate.FailureKind = ovl_fail_bad_conversion; 4389 break; 4390 } 4391 } else { 4392 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4393 // argument for which there is no corresponding parameter is 4394 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4395 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4396 } 4397 } 4398} 4399 4400/// \brief Add a C++ member function template as a candidate to the candidate 4401/// set, using template argument deduction to produce an appropriate member 4402/// function template specialization. 4403void 4404Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 4405 DeclAccessPair FoundDecl, 4406 CXXRecordDecl *ActingContext, 4407 TemplateArgumentListInfo *ExplicitTemplateArgs, 4408 QualType ObjectType, 4409 Expr::Classification ObjectClassification, 4410 Expr **Args, unsigned NumArgs, 4411 OverloadCandidateSet& CandidateSet, 4412 bool SuppressUserConversions) { 4413 if (!CandidateSet.isNewCandidate(MethodTmpl)) 4414 return; 4415 4416 // C++ [over.match.funcs]p7: 4417 // In each case where a candidate is a function template, candidate 4418 // function template specializations are generated using template argument 4419 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4420 // candidate functions in the usual way.113) A given name can refer to one 4421 // or more function templates and also to a set of overloaded non-template 4422 // functions. In such a case, the candidate functions generated from each 4423 // function template are combined with the set of non-template candidate 4424 // functions. 4425 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4426 FunctionDecl *Specialization = 0; 4427 if (TemplateDeductionResult Result 4428 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 4429 Args, NumArgs, Specialization, Info)) { 4430 CandidateSet.push_back(OverloadCandidate()); 4431 OverloadCandidate &Candidate = CandidateSet.back(); 4432 Candidate.FoundDecl = FoundDecl; 4433 Candidate.Function = MethodTmpl->getTemplatedDecl(); 4434 Candidate.Viable = false; 4435 Candidate.FailureKind = ovl_fail_bad_deduction; 4436 Candidate.IsSurrogate = false; 4437 Candidate.IgnoreObjectArgument = false; 4438 Candidate.ExplicitCallArguments = NumArgs; 4439 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4440 Info); 4441 return; 4442 } 4443 4444 // Add the function template specialization produced by template argument 4445 // deduction as a candidate. 4446 assert(Specialization && "Missing member function template specialization?"); 4447 assert(isa<CXXMethodDecl>(Specialization) && 4448 "Specialization is not a member function?"); 4449 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 4450 ActingContext, ObjectType, ObjectClassification, 4451 Args, NumArgs, CandidateSet, SuppressUserConversions); 4452} 4453 4454/// \brief Add a C++ function template specialization as a candidate 4455/// in the candidate set, using template argument deduction to produce 4456/// an appropriate function template specialization. 4457void 4458Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 4459 DeclAccessPair FoundDecl, 4460 TemplateArgumentListInfo *ExplicitTemplateArgs, 4461 Expr **Args, unsigned NumArgs, 4462 OverloadCandidateSet& CandidateSet, 4463 bool SuppressUserConversions) { 4464 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4465 return; 4466 4467 // C++ [over.match.funcs]p7: 4468 // In each case where a candidate is a function template, candidate 4469 // function template specializations are generated using template argument 4470 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4471 // candidate functions in the usual way.113) A given name can refer to one 4472 // or more function templates and also to a set of overloaded non-template 4473 // functions. In such a case, the candidate functions generated from each 4474 // function template are combined with the set of non-template candidate 4475 // functions. 4476 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4477 FunctionDecl *Specialization = 0; 4478 if (TemplateDeductionResult Result 4479 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 4480 Args, NumArgs, Specialization, Info)) { 4481 CandidateSet.push_back(OverloadCandidate()); 4482 OverloadCandidate &Candidate = CandidateSet.back(); 4483 Candidate.FoundDecl = FoundDecl; 4484 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4485 Candidate.Viable = false; 4486 Candidate.FailureKind = ovl_fail_bad_deduction; 4487 Candidate.IsSurrogate = false; 4488 Candidate.IgnoreObjectArgument = false; 4489 Candidate.ExplicitCallArguments = NumArgs; 4490 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4491 Info); 4492 return; 4493 } 4494 4495 // Add the function template specialization produced by template argument 4496 // deduction as a candidate. 4497 assert(Specialization && "Missing function template specialization?"); 4498 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 4499 SuppressUserConversions); 4500} 4501 4502/// AddConversionCandidate - Add a C++ conversion function as a 4503/// candidate in the candidate set (C++ [over.match.conv], 4504/// C++ [over.match.copy]). From is the expression we're converting from, 4505/// and ToType is the type that we're eventually trying to convert to 4506/// (which may or may not be the same type as the type that the 4507/// conversion function produces). 4508void 4509Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 4510 DeclAccessPair FoundDecl, 4511 CXXRecordDecl *ActingContext, 4512 Expr *From, QualType ToType, 4513 OverloadCandidateSet& CandidateSet) { 4514 assert(!Conversion->getDescribedFunctionTemplate() && 4515 "Conversion function templates use AddTemplateConversionCandidate"); 4516 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 4517 if (!CandidateSet.isNewCandidate(Conversion)) 4518 return; 4519 4520 // Overload resolution is always an unevaluated context. 4521 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4522 4523 // Add this candidate 4524 CandidateSet.push_back(OverloadCandidate()); 4525 OverloadCandidate& Candidate = CandidateSet.back(); 4526 Candidate.FoundDecl = FoundDecl; 4527 Candidate.Function = Conversion; 4528 Candidate.IsSurrogate = false; 4529 Candidate.IgnoreObjectArgument = false; 4530 Candidate.FinalConversion.setAsIdentityConversion(); 4531 Candidate.FinalConversion.setFromType(ConvType); 4532 Candidate.FinalConversion.setAllToTypes(ToType); 4533 Candidate.Viable = true; 4534 Candidate.Conversions.resize(1); 4535 Candidate.ExplicitCallArguments = 1; 4536 4537 // C++ [over.match.funcs]p4: 4538 // For conversion functions, the function is considered to be a member of 4539 // the class of the implicit implied object argument for the purpose of 4540 // defining the type of the implicit object parameter. 4541 // 4542 // Determine the implicit conversion sequence for the implicit 4543 // object parameter. 4544 QualType ImplicitParamType = From->getType(); 4545 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 4546 ImplicitParamType = FromPtrType->getPointeeType(); 4547 CXXRecordDecl *ConversionContext 4548 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 4549 4550 Candidate.Conversions[0] 4551 = TryObjectArgumentInitialization(*this, From->getType(), 4552 From->Classify(Context), 4553 Conversion, ConversionContext); 4554 4555 if (Candidate.Conversions[0].isBad()) { 4556 Candidate.Viable = false; 4557 Candidate.FailureKind = ovl_fail_bad_conversion; 4558 return; 4559 } 4560 4561 // We won't go through a user-define type conversion function to convert a 4562 // derived to base as such conversions are given Conversion Rank. They only 4563 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 4564 QualType FromCanon 4565 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 4566 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 4567 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 4568 Candidate.Viable = false; 4569 Candidate.FailureKind = ovl_fail_trivial_conversion; 4570 return; 4571 } 4572 4573 // To determine what the conversion from the result of calling the 4574 // conversion function to the type we're eventually trying to 4575 // convert to (ToType), we need to synthesize a call to the 4576 // conversion function and attempt copy initialization from it. This 4577 // makes sure that we get the right semantics with respect to 4578 // lvalues/rvalues and the type. Fortunately, we can allocate this 4579 // call on the stack and we don't need its arguments to be 4580 // well-formed. 4581 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 4582 VK_LValue, From->getLocStart()); 4583 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 4584 Context.getPointerType(Conversion->getType()), 4585 CK_FunctionToPointerDecay, 4586 &ConversionRef, VK_RValue); 4587 4588 QualType ConversionType = Conversion->getConversionType(); 4589 if (RequireCompleteType(From->getLocStart(), ConversionType, 0)) { 4590 Candidate.Viable = false; 4591 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4592 return; 4593 } 4594 4595 ExprValueKind VK = Expr::getValueKindForType(ConversionType); 4596 4597 // Note that it is safe to allocate CallExpr on the stack here because 4598 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 4599 // allocator). 4600 QualType CallResultType = ConversionType.getNonLValueExprType(Context); 4601 CallExpr Call(Context, &ConversionFn, 0, 0, CallResultType, VK, 4602 From->getLocStart()); 4603 ImplicitConversionSequence ICS = 4604 TryCopyInitialization(*this, &Call, ToType, 4605 /*SuppressUserConversions=*/true, 4606 /*InOverloadResolution=*/false, 4607 /*AllowObjCWritebackConversion=*/false); 4608 4609 switch (ICS.getKind()) { 4610 case ImplicitConversionSequence::StandardConversion: 4611 Candidate.FinalConversion = ICS.Standard; 4612 4613 // C++ [over.ics.user]p3: 4614 // If the user-defined conversion is specified by a specialization of a 4615 // conversion function template, the second standard conversion sequence 4616 // shall have exact match rank. 4617 if (Conversion->getPrimaryTemplate() && 4618 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 4619 Candidate.Viable = false; 4620 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 4621 } 4622 4623 // C++0x [dcl.init.ref]p5: 4624 // In the second case, if the reference is an rvalue reference and 4625 // the second standard conversion sequence of the user-defined 4626 // conversion sequence includes an lvalue-to-rvalue conversion, the 4627 // program is ill-formed. 4628 if (ToType->isRValueReferenceType() && 4629 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 4630 Candidate.Viable = false; 4631 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4632 } 4633 break; 4634 4635 case ImplicitConversionSequence::BadConversion: 4636 Candidate.Viable = false; 4637 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4638 break; 4639 4640 default: 4641 assert(false && 4642 "Can only end up with a standard conversion sequence or failure"); 4643 } 4644} 4645 4646/// \brief Adds a conversion function template specialization 4647/// candidate to the overload set, using template argument deduction 4648/// to deduce the template arguments of the conversion function 4649/// template from the type that we are converting to (C++ 4650/// [temp.deduct.conv]). 4651void 4652Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 4653 DeclAccessPair FoundDecl, 4654 CXXRecordDecl *ActingDC, 4655 Expr *From, QualType ToType, 4656 OverloadCandidateSet &CandidateSet) { 4657 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 4658 "Only conversion function templates permitted here"); 4659 4660 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4661 return; 4662 4663 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4664 CXXConversionDecl *Specialization = 0; 4665 if (TemplateDeductionResult Result 4666 = DeduceTemplateArguments(FunctionTemplate, ToType, 4667 Specialization, Info)) { 4668 CandidateSet.push_back(OverloadCandidate()); 4669 OverloadCandidate &Candidate = CandidateSet.back(); 4670 Candidate.FoundDecl = FoundDecl; 4671 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4672 Candidate.Viable = false; 4673 Candidate.FailureKind = ovl_fail_bad_deduction; 4674 Candidate.IsSurrogate = false; 4675 Candidate.IgnoreObjectArgument = false; 4676 Candidate.ExplicitCallArguments = 1; 4677 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4678 Info); 4679 return; 4680 } 4681 4682 // Add the conversion function template specialization produced by 4683 // template argument deduction as a candidate. 4684 assert(Specialization && "Missing function template specialization?"); 4685 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 4686 CandidateSet); 4687} 4688 4689/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 4690/// converts the given @c Object to a function pointer via the 4691/// conversion function @c Conversion, and then attempts to call it 4692/// with the given arguments (C++ [over.call.object]p2-4). Proto is 4693/// the type of function that we'll eventually be calling. 4694void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 4695 DeclAccessPair FoundDecl, 4696 CXXRecordDecl *ActingContext, 4697 const FunctionProtoType *Proto, 4698 Expr *Object, 4699 Expr **Args, unsigned NumArgs, 4700 OverloadCandidateSet& CandidateSet) { 4701 if (!CandidateSet.isNewCandidate(Conversion)) 4702 return; 4703 4704 // Overload resolution is always an unevaluated context. 4705 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4706 4707 CandidateSet.push_back(OverloadCandidate()); 4708 OverloadCandidate& Candidate = CandidateSet.back(); 4709 Candidate.FoundDecl = FoundDecl; 4710 Candidate.Function = 0; 4711 Candidate.Surrogate = Conversion; 4712 Candidate.Viable = true; 4713 Candidate.IsSurrogate = true; 4714 Candidate.IgnoreObjectArgument = false; 4715 Candidate.Conversions.resize(NumArgs + 1); 4716 Candidate.ExplicitCallArguments = NumArgs; 4717 4718 // Determine the implicit conversion sequence for the implicit 4719 // object parameter. 4720 ImplicitConversionSequence ObjectInit 4721 = TryObjectArgumentInitialization(*this, Object->getType(), 4722 Object->Classify(Context), 4723 Conversion, ActingContext); 4724 if (ObjectInit.isBad()) { 4725 Candidate.Viable = false; 4726 Candidate.FailureKind = ovl_fail_bad_conversion; 4727 Candidate.Conversions[0] = ObjectInit; 4728 return; 4729 } 4730 4731 // The first conversion is actually a user-defined conversion whose 4732 // first conversion is ObjectInit's standard conversion (which is 4733 // effectively a reference binding). Record it as such. 4734 Candidate.Conversions[0].setUserDefined(); 4735 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 4736 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 4737 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 4738 Candidate.Conversions[0].UserDefined.FoundConversionFunction 4739 = FoundDecl.getDecl(); 4740 Candidate.Conversions[0].UserDefined.After 4741 = Candidate.Conversions[0].UserDefined.Before; 4742 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 4743 4744 // Find the 4745 unsigned NumArgsInProto = Proto->getNumArgs(); 4746 4747 // (C++ 13.3.2p2): A candidate function having fewer than m 4748 // parameters is viable only if it has an ellipsis in its parameter 4749 // list (8.3.5). 4750 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4751 Candidate.Viable = false; 4752 Candidate.FailureKind = ovl_fail_too_many_arguments; 4753 return; 4754 } 4755 4756 // Function types don't have any default arguments, so just check if 4757 // we have enough arguments. 4758 if (NumArgs < NumArgsInProto) { 4759 // Not enough arguments. 4760 Candidate.Viable = false; 4761 Candidate.FailureKind = ovl_fail_too_few_arguments; 4762 return; 4763 } 4764 4765 // Determine the implicit conversion sequences for each of the 4766 // arguments. 4767 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4768 if (ArgIdx < NumArgsInProto) { 4769 // (C++ 13.3.2p3): for F to be a viable function, there shall 4770 // exist for each argument an implicit conversion sequence 4771 // (13.3.3.1) that converts that argument to the corresponding 4772 // parameter of F. 4773 QualType ParamType = Proto->getArgType(ArgIdx); 4774 Candidate.Conversions[ArgIdx + 1] 4775 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4776 /*SuppressUserConversions=*/false, 4777 /*InOverloadResolution=*/false, 4778 /*AllowObjCWritebackConversion=*/ 4779 getLangOptions().ObjCAutoRefCount); 4780 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4781 Candidate.Viable = false; 4782 Candidate.FailureKind = ovl_fail_bad_conversion; 4783 break; 4784 } 4785 } else { 4786 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4787 // argument for which there is no corresponding parameter is 4788 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4789 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4790 } 4791 } 4792} 4793 4794/// \brief Add overload candidates for overloaded operators that are 4795/// member functions. 4796/// 4797/// Add the overloaded operator candidates that are member functions 4798/// for the operator Op that was used in an operator expression such 4799/// as "x Op y". , Args/NumArgs provides the operator arguments, and 4800/// CandidateSet will store the added overload candidates. (C++ 4801/// [over.match.oper]). 4802void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 4803 SourceLocation OpLoc, 4804 Expr **Args, unsigned NumArgs, 4805 OverloadCandidateSet& CandidateSet, 4806 SourceRange OpRange) { 4807 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4808 4809 // C++ [over.match.oper]p3: 4810 // For a unary operator @ with an operand of a type whose 4811 // cv-unqualified version is T1, and for a binary operator @ with 4812 // a left operand of a type whose cv-unqualified version is T1 and 4813 // a right operand of a type whose cv-unqualified version is T2, 4814 // three sets of candidate functions, designated member 4815 // candidates, non-member candidates and built-in candidates, are 4816 // constructed as follows: 4817 QualType T1 = Args[0]->getType(); 4818 4819 // -- If T1 is a class type, the set of member candidates is the 4820 // result of the qualified lookup of T1::operator@ 4821 // (13.3.1.1.1); otherwise, the set of member candidates is 4822 // empty. 4823 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 4824 // Complete the type if it can be completed. Otherwise, we're done. 4825 if (RequireCompleteType(OpLoc, T1, PDiag())) 4826 return; 4827 4828 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 4829 LookupQualifiedName(Operators, T1Rec->getDecl()); 4830 Operators.suppressDiagnostics(); 4831 4832 for (LookupResult::iterator Oper = Operators.begin(), 4833 OperEnd = Operators.end(); 4834 Oper != OperEnd; 4835 ++Oper) 4836 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 4837 Args[0]->Classify(Context), Args + 1, NumArgs - 1, 4838 CandidateSet, 4839 /* SuppressUserConversions = */ false); 4840 } 4841} 4842 4843/// AddBuiltinCandidate - Add a candidate for a built-in 4844/// operator. ResultTy and ParamTys are the result and parameter types 4845/// of the built-in candidate, respectively. Args and NumArgs are the 4846/// arguments being passed to the candidate. IsAssignmentOperator 4847/// should be true when this built-in candidate is an assignment 4848/// operator. NumContextualBoolArguments is the number of arguments 4849/// (at the beginning of the argument list) that will be contextually 4850/// converted to bool. 4851void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 4852 Expr **Args, unsigned NumArgs, 4853 OverloadCandidateSet& CandidateSet, 4854 bool IsAssignmentOperator, 4855 unsigned NumContextualBoolArguments) { 4856 // Overload resolution is always an unevaluated context. 4857 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4858 4859 // Add this candidate 4860 CandidateSet.push_back(OverloadCandidate()); 4861 OverloadCandidate& Candidate = CandidateSet.back(); 4862 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 4863 Candidate.Function = 0; 4864 Candidate.IsSurrogate = false; 4865 Candidate.IgnoreObjectArgument = false; 4866 Candidate.BuiltinTypes.ResultTy = ResultTy; 4867 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4868 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 4869 4870 // Determine the implicit conversion sequences for each of the 4871 // arguments. 4872 Candidate.Viable = true; 4873 Candidate.Conversions.resize(NumArgs); 4874 Candidate.ExplicitCallArguments = NumArgs; 4875 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4876 // C++ [over.match.oper]p4: 4877 // For the built-in assignment operators, conversions of the 4878 // left operand are restricted as follows: 4879 // -- no temporaries are introduced to hold the left operand, and 4880 // -- no user-defined conversions are applied to the left 4881 // operand to achieve a type match with the left-most 4882 // parameter of a built-in candidate. 4883 // 4884 // We block these conversions by turning off user-defined 4885 // conversions, since that is the only way that initialization of 4886 // a reference to a non-class type can occur from something that 4887 // is not of the same type. 4888 if (ArgIdx < NumContextualBoolArguments) { 4889 assert(ParamTys[ArgIdx] == Context.BoolTy && 4890 "Contextual conversion to bool requires bool type"); 4891 Candidate.Conversions[ArgIdx] 4892 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 4893 } else { 4894 Candidate.Conversions[ArgIdx] 4895 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4896 ArgIdx == 0 && IsAssignmentOperator, 4897 /*InOverloadResolution=*/false, 4898 /*AllowObjCWritebackConversion=*/ 4899 getLangOptions().ObjCAutoRefCount); 4900 } 4901 if (Candidate.Conversions[ArgIdx].isBad()) { 4902 Candidate.Viable = false; 4903 Candidate.FailureKind = ovl_fail_bad_conversion; 4904 break; 4905 } 4906 } 4907} 4908 4909/// BuiltinCandidateTypeSet - A set of types that will be used for the 4910/// candidate operator functions for built-in operators (C++ 4911/// [over.built]). The types are separated into pointer types and 4912/// enumeration types. 4913class BuiltinCandidateTypeSet { 4914 /// TypeSet - A set of types. 4915 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4916 4917 /// PointerTypes - The set of pointer types that will be used in the 4918 /// built-in candidates. 4919 TypeSet PointerTypes; 4920 4921 /// MemberPointerTypes - The set of member pointer types that will be 4922 /// used in the built-in candidates. 4923 TypeSet MemberPointerTypes; 4924 4925 /// EnumerationTypes - The set of enumeration types that will be 4926 /// used in the built-in candidates. 4927 TypeSet EnumerationTypes; 4928 4929 /// \brief The set of vector types that will be used in the built-in 4930 /// candidates. 4931 TypeSet VectorTypes; 4932 4933 /// \brief A flag indicating non-record types are viable candidates 4934 bool HasNonRecordTypes; 4935 4936 /// \brief A flag indicating whether either arithmetic or enumeration types 4937 /// were present in the candidate set. 4938 bool HasArithmeticOrEnumeralTypes; 4939 4940 /// \brief A flag indicating whether the nullptr type was present in the 4941 /// candidate set. 4942 bool HasNullPtrType; 4943 4944 /// Sema - The semantic analysis instance where we are building the 4945 /// candidate type set. 4946 Sema &SemaRef; 4947 4948 /// Context - The AST context in which we will build the type sets. 4949 ASTContext &Context; 4950 4951 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4952 const Qualifiers &VisibleQuals); 4953 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4954 4955public: 4956 /// iterator - Iterates through the types that are part of the set. 4957 typedef TypeSet::iterator iterator; 4958 4959 BuiltinCandidateTypeSet(Sema &SemaRef) 4960 : HasNonRecordTypes(false), 4961 HasArithmeticOrEnumeralTypes(false), 4962 HasNullPtrType(false), 4963 SemaRef(SemaRef), 4964 Context(SemaRef.Context) { } 4965 4966 void AddTypesConvertedFrom(QualType Ty, 4967 SourceLocation Loc, 4968 bool AllowUserConversions, 4969 bool AllowExplicitConversions, 4970 const Qualifiers &VisibleTypeConversionsQuals); 4971 4972 /// pointer_begin - First pointer type found; 4973 iterator pointer_begin() { return PointerTypes.begin(); } 4974 4975 /// pointer_end - Past the last pointer type found; 4976 iterator pointer_end() { return PointerTypes.end(); } 4977 4978 /// member_pointer_begin - First member pointer type found; 4979 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4980 4981 /// member_pointer_end - Past the last member pointer type found; 4982 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4983 4984 /// enumeration_begin - First enumeration type found; 4985 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4986 4987 /// enumeration_end - Past the last enumeration type found; 4988 iterator enumeration_end() { return EnumerationTypes.end(); } 4989 4990 iterator vector_begin() { return VectorTypes.begin(); } 4991 iterator vector_end() { return VectorTypes.end(); } 4992 4993 bool hasNonRecordTypes() { return HasNonRecordTypes; } 4994 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 4995 bool hasNullPtrType() const { return HasNullPtrType; } 4996}; 4997 4998/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4999/// the set of pointer types along with any more-qualified variants of 5000/// that type. For example, if @p Ty is "int const *", this routine 5001/// will add "int const *", "int const volatile *", "int const 5002/// restrict *", and "int const volatile restrict *" to the set of 5003/// pointer types. Returns true if the add of @p Ty itself succeeded, 5004/// false otherwise. 5005/// 5006/// FIXME: what to do about extended qualifiers? 5007bool 5008BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 5009 const Qualifiers &VisibleQuals) { 5010 5011 // Insert this type. 5012 if (!PointerTypes.insert(Ty)) 5013 return false; 5014 5015 QualType PointeeTy; 5016 const PointerType *PointerTy = Ty->getAs<PointerType>(); 5017 bool buildObjCPtr = false; 5018 if (!PointerTy) { 5019 if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) { 5020 PointeeTy = PTy->getPointeeType(); 5021 buildObjCPtr = true; 5022 } 5023 else 5024 assert(false && "type was not a pointer type!"); 5025 } 5026 else 5027 PointeeTy = PointerTy->getPointeeType(); 5028 5029 // Don't add qualified variants of arrays. For one, they're not allowed 5030 // (the qualifier would sink to the element type), and for another, the 5031 // only overload situation where it matters is subscript or pointer +- int, 5032 // and those shouldn't have qualifier variants anyway. 5033 if (PointeeTy->isArrayType()) 5034 return true; 5035 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 5036 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 5037 BaseCVR = Array->getElementType().getCVRQualifiers(); 5038 bool hasVolatile = VisibleQuals.hasVolatile(); 5039 bool hasRestrict = VisibleQuals.hasRestrict(); 5040 5041 // Iterate through all strict supersets of BaseCVR. 5042 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 5043 if ((CVR | BaseCVR) != CVR) continue; 5044 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 5045 // in the types. 5046 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 5047 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 5048 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 5049 if (!buildObjCPtr) 5050 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 5051 else 5052 PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); 5053 } 5054 5055 return true; 5056} 5057 5058/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 5059/// to the set of pointer types along with any more-qualified variants of 5060/// that type. For example, if @p Ty is "int const *", this routine 5061/// will add "int const *", "int const volatile *", "int const 5062/// restrict *", and "int const volatile restrict *" to the set of 5063/// pointer types. Returns true if the add of @p Ty itself succeeded, 5064/// false otherwise. 5065/// 5066/// FIXME: what to do about extended qualifiers? 5067bool 5068BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 5069 QualType Ty) { 5070 // Insert this type. 5071 if (!MemberPointerTypes.insert(Ty)) 5072 return false; 5073 5074 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 5075 assert(PointerTy && "type was not a member pointer type!"); 5076 5077 QualType PointeeTy = PointerTy->getPointeeType(); 5078 // Don't add qualified variants of arrays. For one, they're not allowed 5079 // (the qualifier would sink to the element type), and for another, the 5080 // only overload situation where it matters is subscript or pointer +- int, 5081 // and those shouldn't have qualifier variants anyway. 5082 if (PointeeTy->isArrayType()) 5083 return true; 5084 const Type *ClassTy = PointerTy->getClass(); 5085 5086 // Iterate through all strict supersets of the pointee type's CVR 5087 // qualifiers. 5088 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 5089 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 5090 if ((CVR | BaseCVR) != CVR) continue; 5091 5092 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 5093 MemberPointerTypes.insert( 5094 Context.getMemberPointerType(QPointeeTy, ClassTy)); 5095 } 5096 5097 return true; 5098} 5099 5100/// AddTypesConvertedFrom - Add each of the types to which the type @p 5101/// Ty can be implicit converted to the given set of @p Types. We're 5102/// primarily interested in pointer types and enumeration types. We also 5103/// take member pointer types, for the conditional operator. 5104/// AllowUserConversions is true if we should look at the conversion 5105/// functions of a class type, and AllowExplicitConversions if we 5106/// should also include the explicit conversion functions of a class 5107/// type. 5108void 5109BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 5110 SourceLocation Loc, 5111 bool AllowUserConversions, 5112 bool AllowExplicitConversions, 5113 const Qualifiers &VisibleQuals) { 5114 // Only deal with canonical types. 5115 Ty = Context.getCanonicalType(Ty); 5116 5117 // Look through reference types; they aren't part of the type of an 5118 // expression for the purposes of conversions. 5119 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 5120 Ty = RefTy->getPointeeType(); 5121 5122 // If we're dealing with an array type, decay to the pointer. 5123 if (Ty->isArrayType()) 5124 Ty = SemaRef.Context.getArrayDecayedType(Ty); 5125 5126 // Otherwise, we don't care about qualifiers on the type. 5127 Ty = Ty.getLocalUnqualifiedType(); 5128 5129 // Flag if we ever add a non-record type. 5130 const RecordType *TyRec = Ty->getAs<RecordType>(); 5131 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 5132 5133 // Flag if we encounter an arithmetic type. 5134 HasArithmeticOrEnumeralTypes = 5135 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 5136 5137 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 5138 PointerTypes.insert(Ty); 5139 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 5140 // Insert our type, and its more-qualified variants, into the set 5141 // of types. 5142 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 5143 return; 5144 } else if (Ty->isMemberPointerType()) { 5145 // Member pointers are far easier, since the pointee can't be converted. 5146 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 5147 return; 5148 } else if (Ty->isEnumeralType()) { 5149 HasArithmeticOrEnumeralTypes = true; 5150 EnumerationTypes.insert(Ty); 5151 } else if (Ty->isVectorType()) { 5152 // We treat vector types as arithmetic types in many contexts as an 5153 // extension. 5154 HasArithmeticOrEnumeralTypes = true; 5155 VectorTypes.insert(Ty); 5156 } else if (Ty->isNullPtrType()) { 5157 HasNullPtrType = true; 5158 } else if (AllowUserConversions && TyRec) { 5159 // No conversion functions in incomplete types. 5160 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 5161 return; 5162 5163 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 5164 const UnresolvedSetImpl *Conversions 5165 = ClassDecl->getVisibleConversionFunctions(); 5166 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 5167 E = Conversions->end(); I != E; ++I) { 5168 NamedDecl *D = I.getDecl(); 5169 if (isa<UsingShadowDecl>(D)) 5170 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 5171 5172 // Skip conversion function templates; they don't tell us anything 5173 // about which builtin types we can convert to. 5174 if (isa<FunctionTemplateDecl>(D)) 5175 continue; 5176 5177 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 5178 if (AllowExplicitConversions || !Conv->isExplicit()) { 5179 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 5180 VisibleQuals); 5181 } 5182 } 5183 } 5184} 5185 5186/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 5187/// the volatile- and non-volatile-qualified assignment operators for the 5188/// given type to the candidate set. 5189static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 5190 QualType T, 5191 Expr **Args, 5192 unsigned NumArgs, 5193 OverloadCandidateSet &CandidateSet) { 5194 QualType ParamTypes[2]; 5195 5196 // T& operator=(T&, T) 5197 ParamTypes[0] = S.Context.getLValueReferenceType(T); 5198 ParamTypes[1] = T; 5199 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5200 /*IsAssignmentOperator=*/true); 5201 5202 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 5203 // volatile T& operator=(volatile T&, T) 5204 ParamTypes[0] 5205 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 5206 ParamTypes[1] = T; 5207 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5208 /*IsAssignmentOperator=*/true); 5209 } 5210} 5211 5212/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 5213/// if any, found in visible type conversion functions found in ArgExpr's type. 5214static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 5215 Qualifiers VRQuals; 5216 const RecordType *TyRec; 5217 if (const MemberPointerType *RHSMPType = 5218 ArgExpr->getType()->getAs<MemberPointerType>()) 5219 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 5220 else 5221 TyRec = ArgExpr->getType()->getAs<RecordType>(); 5222 if (!TyRec) { 5223 // Just to be safe, assume the worst case. 5224 VRQuals.addVolatile(); 5225 VRQuals.addRestrict(); 5226 return VRQuals; 5227 } 5228 5229 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 5230 if (!ClassDecl->hasDefinition()) 5231 return VRQuals; 5232 5233 const UnresolvedSetImpl *Conversions = 5234 ClassDecl->getVisibleConversionFunctions(); 5235 5236 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 5237 E = Conversions->end(); I != E; ++I) { 5238 NamedDecl *D = I.getDecl(); 5239 if (isa<UsingShadowDecl>(D)) 5240 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 5241 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 5242 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 5243 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 5244 CanTy = ResTypeRef->getPointeeType(); 5245 // Need to go down the pointer/mempointer chain and add qualifiers 5246 // as see them. 5247 bool done = false; 5248 while (!done) { 5249 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 5250 CanTy = ResTypePtr->getPointeeType(); 5251 else if (const MemberPointerType *ResTypeMPtr = 5252 CanTy->getAs<MemberPointerType>()) 5253 CanTy = ResTypeMPtr->getPointeeType(); 5254 else 5255 done = true; 5256 if (CanTy.isVolatileQualified()) 5257 VRQuals.addVolatile(); 5258 if (CanTy.isRestrictQualified()) 5259 VRQuals.addRestrict(); 5260 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 5261 return VRQuals; 5262 } 5263 } 5264 } 5265 return VRQuals; 5266} 5267 5268namespace { 5269 5270/// \brief Helper class to manage the addition of builtin operator overload 5271/// candidates. It provides shared state and utility methods used throughout 5272/// the process, as well as a helper method to add each group of builtin 5273/// operator overloads from the standard to a candidate set. 5274class BuiltinOperatorOverloadBuilder { 5275 // Common instance state available to all overload candidate addition methods. 5276 Sema &S; 5277 Expr **Args; 5278 unsigned NumArgs; 5279 Qualifiers VisibleTypeConversionsQuals; 5280 bool HasArithmeticOrEnumeralCandidateType; 5281 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 5282 OverloadCandidateSet &CandidateSet; 5283 5284 // Define some constants used to index and iterate over the arithemetic types 5285 // provided via the getArithmeticType() method below. 5286 // The "promoted arithmetic types" are the arithmetic 5287 // types are that preserved by promotion (C++ [over.built]p2). 5288 static const unsigned FirstIntegralType = 3; 5289 static const unsigned LastIntegralType = 18; 5290 static const unsigned FirstPromotedIntegralType = 3, 5291 LastPromotedIntegralType = 9; 5292 static const unsigned FirstPromotedArithmeticType = 0, 5293 LastPromotedArithmeticType = 9; 5294 static const unsigned NumArithmeticTypes = 18; 5295 5296 /// \brief Get the canonical type for a given arithmetic type index. 5297 CanQualType getArithmeticType(unsigned index) { 5298 assert(index < NumArithmeticTypes); 5299 static CanQualType ASTContext::* const 5300 ArithmeticTypes[NumArithmeticTypes] = { 5301 // Start of promoted types. 5302 &ASTContext::FloatTy, 5303 &ASTContext::DoubleTy, 5304 &ASTContext::LongDoubleTy, 5305 5306 // Start of integral types. 5307 &ASTContext::IntTy, 5308 &ASTContext::LongTy, 5309 &ASTContext::LongLongTy, 5310 &ASTContext::UnsignedIntTy, 5311 &ASTContext::UnsignedLongTy, 5312 &ASTContext::UnsignedLongLongTy, 5313 // End of promoted types. 5314 5315 &ASTContext::BoolTy, 5316 &ASTContext::CharTy, 5317 &ASTContext::WCharTy, 5318 &ASTContext::Char16Ty, 5319 &ASTContext::Char32Ty, 5320 &ASTContext::SignedCharTy, 5321 &ASTContext::ShortTy, 5322 &ASTContext::UnsignedCharTy, 5323 &ASTContext::UnsignedShortTy, 5324 // End of integral types. 5325 // FIXME: What about complex? 5326 }; 5327 return S.Context.*ArithmeticTypes[index]; 5328 } 5329 5330 /// \brief Gets the canonical type resulting from the usual arithemetic 5331 /// converions for the given arithmetic types. 5332 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 5333 // Accelerator table for performing the usual arithmetic conversions. 5334 // The rules are basically: 5335 // - if either is floating-point, use the wider floating-point 5336 // - if same signedness, use the higher rank 5337 // - if same size, use unsigned of the higher rank 5338 // - use the larger type 5339 // These rules, together with the axiom that higher ranks are 5340 // never smaller, are sufficient to precompute all of these results 5341 // *except* when dealing with signed types of higher rank. 5342 // (we could precompute SLL x UI for all known platforms, but it's 5343 // better not to make any assumptions). 5344 enum PromotedType { 5345 Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL, Dep=-1 5346 }; 5347 static PromotedType ConversionsTable[LastPromotedArithmeticType] 5348 [LastPromotedArithmeticType] = { 5349 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt }, 5350 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 5351 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 5352 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL }, 5353 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, Dep, UL, ULL }, 5354 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, Dep, Dep, ULL }, 5355 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, UI, UL, ULL }, 5356 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, UL, UL, ULL }, 5357 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, ULL, ULL, ULL }, 5358 }; 5359 5360 assert(L < LastPromotedArithmeticType); 5361 assert(R < LastPromotedArithmeticType); 5362 int Idx = ConversionsTable[L][R]; 5363 5364 // Fast path: the table gives us a concrete answer. 5365 if (Idx != Dep) return getArithmeticType(Idx); 5366 5367 // Slow path: we need to compare widths. 5368 // An invariant is that the signed type has higher rank. 5369 CanQualType LT = getArithmeticType(L), 5370 RT = getArithmeticType(R); 5371 unsigned LW = S.Context.getIntWidth(LT), 5372 RW = S.Context.getIntWidth(RT); 5373 5374 // If they're different widths, use the signed type. 5375 if (LW > RW) return LT; 5376 else if (LW < RW) return RT; 5377 5378 // Otherwise, use the unsigned type of the signed type's rank. 5379 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 5380 assert(L == SLL || R == SLL); 5381 return S.Context.UnsignedLongLongTy; 5382 } 5383 5384 /// \brief Helper method to factor out the common pattern of adding overloads 5385 /// for '++' and '--' builtin operators. 5386 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 5387 bool HasVolatile) { 5388 QualType ParamTypes[2] = { 5389 S.Context.getLValueReferenceType(CandidateTy), 5390 S.Context.IntTy 5391 }; 5392 5393 // Non-volatile version. 5394 if (NumArgs == 1) 5395 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5396 else 5397 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5398 5399 // Use a heuristic to reduce number of builtin candidates in the set: 5400 // add volatile version only if there are conversions to a volatile type. 5401 if (HasVolatile) { 5402 ParamTypes[0] = 5403 S.Context.getLValueReferenceType( 5404 S.Context.getVolatileType(CandidateTy)); 5405 if (NumArgs == 1) 5406 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5407 else 5408 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5409 } 5410 } 5411 5412public: 5413 BuiltinOperatorOverloadBuilder( 5414 Sema &S, Expr **Args, unsigned NumArgs, 5415 Qualifiers VisibleTypeConversionsQuals, 5416 bool HasArithmeticOrEnumeralCandidateType, 5417 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 5418 OverloadCandidateSet &CandidateSet) 5419 : S(S), Args(Args), NumArgs(NumArgs), 5420 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 5421 HasArithmeticOrEnumeralCandidateType( 5422 HasArithmeticOrEnumeralCandidateType), 5423 CandidateTypes(CandidateTypes), 5424 CandidateSet(CandidateSet) { 5425 // Validate some of our static helper constants in debug builds. 5426 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 5427 "Invalid first promoted integral type"); 5428 assert(getArithmeticType(LastPromotedIntegralType - 1) 5429 == S.Context.UnsignedLongLongTy && 5430 "Invalid last promoted integral type"); 5431 assert(getArithmeticType(FirstPromotedArithmeticType) 5432 == S.Context.FloatTy && 5433 "Invalid first promoted arithmetic type"); 5434 assert(getArithmeticType(LastPromotedArithmeticType - 1) 5435 == S.Context.UnsignedLongLongTy && 5436 "Invalid last promoted arithmetic type"); 5437 } 5438 5439 // C++ [over.built]p3: 5440 // 5441 // For every pair (T, VQ), where T is an arithmetic type, and VQ 5442 // is either volatile or empty, there exist candidate operator 5443 // functions of the form 5444 // 5445 // VQ T& operator++(VQ T&); 5446 // T operator++(VQ T&, int); 5447 // 5448 // C++ [over.built]p4: 5449 // 5450 // For every pair (T, VQ), where T is an arithmetic type other 5451 // than bool, and VQ is either volatile or empty, there exist 5452 // candidate operator functions of the form 5453 // 5454 // VQ T& operator--(VQ T&); 5455 // T operator--(VQ T&, int); 5456 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 5457 if (!HasArithmeticOrEnumeralCandidateType) 5458 return; 5459 5460 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 5461 Arith < NumArithmeticTypes; ++Arith) { 5462 addPlusPlusMinusMinusStyleOverloads( 5463 getArithmeticType(Arith), 5464 VisibleTypeConversionsQuals.hasVolatile()); 5465 } 5466 } 5467 5468 // C++ [over.built]p5: 5469 // 5470 // For every pair (T, VQ), where T is a cv-qualified or 5471 // cv-unqualified object type, and VQ is either volatile or 5472 // empty, there exist candidate operator functions of the form 5473 // 5474 // T*VQ& operator++(T*VQ&); 5475 // T*VQ& operator--(T*VQ&); 5476 // T* operator++(T*VQ&, int); 5477 // T* operator--(T*VQ&, int); 5478 void addPlusPlusMinusMinusPointerOverloads() { 5479 for (BuiltinCandidateTypeSet::iterator 5480 Ptr = CandidateTypes[0].pointer_begin(), 5481 PtrEnd = CandidateTypes[0].pointer_end(); 5482 Ptr != PtrEnd; ++Ptr) { 5483 // Skip pointer types that aren't pointers to object types. 5484 if (!(*Ptr)->getPointeeType()->isObjectType()) 5485 continue; 5486 5487 addPlusPlusMinusMinusStyleOverloads(*Ptr, 5488 (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5489 VisibleTypeConversionsQuals.hasVolatile())); 5490 } 5491 } 5492 5493 // C++ [over.built]p6: 5494 // For every cv-qualified or cv-unqualified object type T, there 5495 // exist candidate operator functions of the form 5496 // 5497 // T& operator*(T*); 5498 // 5499 // C++ [over.built]p7: 5500 // For every function type T that does not have cv-qualifiers or a 5501 // ref-qualifier, there exist candidate operator functions of the form 5502 // T& operator*(T*); 5503 void addUnaryStarPointerOverloads() { 5504 for (BuiltinCandidateTypeSet::iterator 5505 Ptr = CandidateTypes[0].pointer_begin(), 5506 PtrEnd = CandidateTypes[0].pointer_end(); 5507 Ptr != PtrEnd; ++Ptr) { 5508 QualType ParamTy = *Ptr; 5509 QualType PointeeTy = ParamTy->getPointeeType(); 5510 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 5511 continue; 5512 5513 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 5514 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 5515 continue; 5516 5517 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 5518 &ParamTy, Args, 1, CandidateSet); 5519 } 5520 } 5521 5522 // C++ [over.built]p9: 5523 // For every promoted arithmetic type T, there exist candidate 5524 // operator functions of the form 5525 // 5526 // T operator+(T); 5527 // T operator-(T); 5528 void addUnaryPlusOrMinusArithmeticOverloads() { 5529 if (!HasArithmeticOrEnumeralCandidateType) 5530 return; 5531 5532 for (unsigned Arith = FirstPromotedArithmeticType; 5533 Arith < LastPromotedArithmeticType; ++Arith) { 5534 QualType ArithTy = getArithmeticType(Arith); 5535 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 5536 } 5537 5538 // Extension: We also add these operators for vector types. 5539 for (BuiltinCandidateTypeSet::iterator 5540 Vec = CandidateTypes[0].vector_begin(), 5541 VecEnd = CandidateTypes[0].vector_end(); 5542 Vec != VecEnd; ++Vec) { 5543 QualType VecTy = *Vec; 5544 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5545 } 5546 } 5547 5548 // C++ [over.built]p8: 5549 // For every type T, there exist candidate operator functions of 5550 // the form 5551 // 5552 // T* operator+(T*); 5553 void addUnaryPlusPointerOverloads() { 5554 for (BuiltinCandidateTypeSet::iterator 5555 Ptr = CandidateTypes[0].pointer_begin(), 5556 PtrEnd = CandidateTypes[0].pointer_end(); 5557 Ptr != PtrEnd; ++Ptr) { 5558 QualType ParamTy = *Ptr; 5559 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 5560 } 5561 } 5562 5563 // C++ [over.built]p10: 5564 // For every promoted integral type T, there exist candidate 5565 // operator functions of the form 5566 // 5567 // T operator~(T); 5568 void addUnaryTildePromotedIntegralOverloads() { 5569 if (!HasArithmeticOrEnumeralCandidateType) 5570 return; 5571 5572 for (unsigned Int = FirstPromotedIntegralType; 5573 Int < LastPromotedIntegralType; ++Int) { 5574 QualType IntTy = getArithmeticType(Int); 5575 S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 5576 } 5577 5578 // Extension: We also add this operator for vector types. 5579 for (BuiltinCandidateTypeSet::iterator 5580 Vec = CandidateTypes[0].vector_begin(), 5581 VecEnd = CandidateTypes[0].vector_end(); 5582 Vec != VecEnd; ++Vec) { 5583 QualType VecTy = *Vec; 5584 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5585 } 5586 } 5587 5588 // C++ [over.match.oper]p16: 5589 // For every pointer to member type T, there exist candidate operator 5590 // functions of the form 5591 // 5592 // bool operator==(T,T); 5593 // bool operator!=(T,T); 5594 void addEqualEqualOrNotEqualMemberPointerOverloads() { 5595 /// Set of (canonical) types that we've already handled. 5596 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5597 5598 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5599 for (BuiltinCandidateTypeSet::iterator 5600 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5601 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5602 MemPtr != MemPtrEnd; 5603 ++MemPtr) { 5604 // Don't add the same builtin candidate twice. 5605 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5606 continue; 5607 5608 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5609 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5610 CandidateSet); 5611 } 5612 } 5613 } 5614 5615 // C++ [over.built]p15: 5616 // 5617 // For every T, where T is an enumeration type, a pointer type, or 5618 // std::nullptr_t, there exist candidate operator functions of the form 5619 // 5620 // bool operator<(T, T); 5621 // bool operator>(T, T); 5622 // bool operator<=(T, T); 5623 // bool operator>=(T, T); 5624 // bool operator==(T, T); 5625 // bool operator!=(T, T); 5626 void addRelationalPointerOrEnumeralOverloads() { 5627 // C++ [over.built]p1: 5628 // If there is a user-written candidate with the same name and parameter 5629 // types as a built-in candidate operator function, the built-in operator 5630 // function is hidden and is not included in the set of candidate 5631 // functions. 5632 // 5633 // The text is actually in a note, but if we don't implement it then we end 5634 // up with ambiguities when the user provides an overloaded operator for 5635 // an enumeration type. Note that only enumeration types have this problem, 5636 // so we track which enumeration types we've seen operators for. Also, the 5637 // only other overloaded operator with enumeration argumenst, operator=, 5638 // cannot be overloaded for enumeration types, so this is the only place 5639 // where we must suppress candidates like this. 5640 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 5641 UserDefinedBinaryOperators; 5642 5643 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5644 if (CandidateTypes[ArgIdx].enumeration_begin() != 5645 CandidateTypes[ArgIdx].enumeration_end()) { 5646 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 5647 CEnd = CandidateSet.end(); 5648 C != CEnd; ++C) { 5649 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 5650 continue; 5651 5652 QualType FirstParamType = 5653 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 5654 QualType SecondParamType = 5655 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 5656 5657 // Skip if either parameter isn't of enumeral type. 5658 if (!FirstParamType->isEnumeralType() || 5659 !SecondParamType->isEnumeralType()) 5660 continue; 5661 5662 // Add this operator to the set of known user-defined operators. 5663 UserDefinedBinaryOperators.insert( 5664 std::make_pair(S.Context.getCanonicalType(FirstParamType), 5665 S.Context.getCanonicalType(SecondParamType))); 5666 } 5667 } 5668 } 5669 5670 /// Set of (canonical) types that we've already handled. 5671 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5672 5673 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5674 for (BuiltinCandidateTypeSet::iterator 5675 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5676 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5677 Ptr != PtrEnd; ++Ptr) { 5678 // Don't add the same builtin candidate twice. 5679 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5680 continue; 5681 5682 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5683 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5684 CandidateSet); 5685 } 5686 for (BuiltinCandidateTypeSet::iterator 5687 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5688 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5689 Enum != EnumEnd; ++Enum) { 5690 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 5691 5692 // Don't add the same builtin candidate twice, or if a user defined 5693 // candidate exists. 5694 if (!AddedTypes.insert(CanonType) || 5695 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 5696 CanonType))) 5697 continue; 5698 5699 QualType ParamTypes[2] = { *Enum, *Enum }; 5700 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5701 CandidateSet); 5702 } 5703 5704 if (CandidateTypes[ArgIdx].hasNullPtrType()) { 5705 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy); 5706 if (AddedTypes.insert(NullPtrTy) && 5707 !UserDefinedBinaryOperators.count(std::make_pair(NullPtrTy, 5708 NullPtrTy))) { 5709 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy }; 5710 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5711 CandidateSet); 5712 } 5713 } 5714 } 5715 } 5716 5717 // C++ [over.built]p13: 5718 // 5719 // For every cv-qualified or cv-unqualified object type T 5720 // there exist candidate operator functions of the form 5721 // 5722 // T* operator+(T*, ptrdiff_t); 5723 // T& operator[](T*, ptrdiff_t); [BELOW] 5724 // T* operator-(T*, ptrdiff_t); 5725 // T* operator+(ptrdiff_t, T*); 5726 // T& operator[](ptrdiff_t, T*); [BELOW] 5727 // 5728 // C++ [over.built]p14: 5729 // 5730 // For every T, where T is a pointer to object type, there 5731 // exist candidate operator functions of the form 5732 // 5733 // ptrdiff_t operator-(T, T); 5734 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 5735 /// Set of (canonical) types that we've already handled. 5736 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5737 5738 for (int Arg = 0; Arg < 2; ++Arg) { 5739 QualType AsymetricParamTypes[2] = { 5740 S.Context.getPointerDiffType(), 5741 S.Context.getPointerDiffType(), 5742 }; 5743 for (BuiltinCandidateTypeSet::iterator 5744 Ptr = CandidateTypes[Arg].pointer_begin(), 5745 PtrEnd = CandidateTypes[Arg].pointer_end(); 5746 Ptr != PtrEnd; ++Ptr) { 5747 QualType PointeeTy = (*Ptr)->getPointeeType(); 5748 if (!PointeeTy->isObjectType()) 5749 continue; 5750 5751 AsymetricParamTypes[Arg] = *Ptr; 5752 if (Arg == 0 || Op == OO_Plus) { 5753 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 5754 // T* operator+(ptrdiff_t, T*); 5755 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, 5756 CandidateSet); 5757 } 5758 if (Op == OO_Minus) { 5759 // ptrdiff_t operator-(T, T); 5760 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5761 continue; 5762 5763 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5764 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 5765 Args, 2, CandidateSet); 5766 } 5767 } 5768 } 5769 } 5770 5771 // C++ [over.built]p12: 5772 // 5773 // For every pair of promoted arithmetic types L and R, there 5774 // exist candidate operator functions of the form 5775 // 5776 // LR operator*(L, R); 5777 // LR operator/(L, R); 5778 // LR operator+(L, R); 5779 // LR operator-(L, R); 5780 // bool operator<(L, R); 5781 // bool operator>(L, R); 5782 // bool operator<=(L, R); 5783 // bool operator>=(L, R); 5784 // bool operator==(L, R); 5785 // bool operator!=(L, R); 5786 // 5787 // where LR is the result of the usual arithmetic conversions 5788 // between types L and R. 5789 // 5790 // C++ [over.built]p24: 5791 // 5792 // For every pair of promoted arithmetic types L and R, there exist 5793 // candidate operator functions of the form 5794 // 5795 // LR operator?(bool, L, R); 5796 // 5797 // where LR is the result of the usual arithmetic conversions 5798 // between types L and R. 5799 // Our candidates ignore the first parameter. 5800 void addGenericBinaryArithmeticOverloads(bool isComparison) { 5801 if (!HasArithmeticOrEnumeralCandidateType) 5802 return; 5803 5804 for (unsigned Left = FirstPromotedArithmeticType; 5805 Left < LastPromotedArithmeticType; ++Left) { 5806 for (unsigned Right = FirstPromotedArithmeticType; 5807 Right < LastPromotedArithmeticType; ++Right) { 5808 QualType LandR[2] = { getArithmeticType(Left), 5809 getArithmeticType(Right) }; 5810 QualType Result = 5811 isComparison ? S.Context.BoolTy 5812 : getUsualArithmeticConversions(Left, Right); 5813 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5814 } 5815 } 5816 5817 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 5818 // conditional operator for vector types. 5819 for (BuiltinCandidateTypeSet::iterator 5820 Vec1 = CandidateTypes[0].vector_begin(), 5821 Vec1End = CandidateTypes[0].vector_end(); 5822 Vec1 != Vec1End; ++Vec1) { 5823 for (BuiltinCandidateTypeSet::iterator 5824 Vec2 = CandidateTypes[1].vector_begin(), 5825 Vec2End = CandidateTypes[1].vector_end(); 5826 Vec2 != Vec2End; ++Vec2) { 5827 QualType LandR[2] = { *Vec1, *Vec2 }; 5828 QualType Result = S.Context.BoolTy; 5829 if (!isComparison) { 5830 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 5831 Result = *Vec1; 5832 else 5833 Result = *Vec2; 5834 } 5835 5836 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5837 } 5838 } 5839 } 5840 5841 // C++ [over.built]p17: 5842 // 5843 // For every pair of promoted integral types L and R, there 5844 // exist candidate operator functions of the form 5845 // 5846 // LR operator%(L, R); 5847 // LR operator&(L, R); 5848 // LR operator^(L, R); 5849 // LR operator|(L, R); 5850 // L operator<<(L, R); 5851 // L operator>>(L, R); 5852 // 5853 // where LR is the result of the usual arithmetic conversions 5854 // between types L and R. 5855 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 5856 if (!HasArithmeticOrEnumeralCandidateType) 5857 return; 5858 5859 for (unsigned Left = FirstPromotedIntegralType; 5860 Left < LastPromotedIntegralType; ++Left) { 5861 for (unsigned Right = FirstPromotedIntegralType; 5862 Right < LastPromotedIntegralType; ++Right) { 5863 QualType LandR[2] = { getArithmeticType(Left), 5864 getArithmeticType(Right) }; 5865 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 5866 ? LandR[0] 5867 : getUsualArithmeticConversions(Left, Right); 5868 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5869 } 5870 } 5871 } 5872 5873 // C++ [over.built]p20: 5874 // 5875 // For every pair (T, VQ), where T is an enumeration or 5876 // pointer to member type and VQ is either volatile or 5877 // empty, there exist candidate operator functions of the form 5878 // 5879 // VQ T& operator=(VQ T&, T); 5880 void addAssignmentMemberPointerOrEnumeralOverloads() { 5881 /// Set of (canonical) types that we've already handled. 5882 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5883 5884 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5885 for (BuiltinCandidateTypeSet::iterator 5886 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5887 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5888 Enum != EnumEnd; ++Enum) { 5889 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5890 continue; 5891 5892 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, 5893 CandidateSet); 5894 } 5895 5896 for (BuiltinCandidateTypeSet::iterator 5897 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5898 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5899 MemPtr != MemPtrEnd; ++MemPtr) { 5900 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5901 continue; 5902 5903 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, 5904 CandidateSet); 5905 } 5906 } 5907 } 5908 5909 // C++ [over.built]p19: 5910 // 5911 // For every pair (T, VQ), where T is any type and VQ is either 5912 // volatile or empty, there exist candidate operator functions 5913 // of the form 5914 // 5915 // T*VQ& operator=(T*VQ&, T*); 5916 // 5917 // C++ [over.built]p21: 5918 // 5919 // For every pair (T, VQ), where T is a cv-qualified or 5920 // cv-unqualified object type and VQ is either volatile or 5921 // empty, there exist candidate operator functions of the form 5922 // 5923 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 5924 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 5925 void addAssignmentPointerOverloads(bool isEqualOp) { 5926 /// Set of (canonical) types that we've already handled. 5927 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5928 5929 for (BuiltinCandidateTypeSet::iterator 5930 Ptr = CandidateTypes[0].pointer_begin(), 5931 PtrEnd = CandidateTypes[0].pointer_end(); 5932 Ptr != PtrEnd; ++Ptr) { 5933 // If this is operator=, keep track of the builtin candidates we added. 5934 if (isEqualOp) 5935 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 5936 else if (!(*Ptr)->getPointeeType()->isObjectType()) 5937 continue; 5938 5939 // non-volatile version 5940 QualType ParamTypes[2] = { 5941 S.Context.getLValueReferenceType(*Ptr), 5942 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 5943 }; 5944 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5945 /*IsAssigmentOperator=*/ isEqualOp); 5946 5947 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5948 VisibleTypeConversionsQuals.hasVolatile()) { 5949 // volatile version 5950 ParamTypes[0] = 5951 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5952 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5953 /*IsAssigmentOperator=*/isEqualOp); 5954 } 5955 } 5956 5957 if (isEqualOp) { 5958 for (BuiltinCandidateTypeSet::iterator 5959 Ptr = CandidateTypes[1].pointer_begin(), 5960 PtrEnd = CandidateTypes[1].pointer_end(); 5961 Ptr != PtrEnd; ++Ptr) { 5962 // Make sure we don't add the same candidate twice. 5963 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5964 continue; 5965 5966 QualType ParamTypes[2] = { 5967 S.Context.getLValueReferenceType(*Ptr), 5968 *Ptr, 5969 }; 5970 5971 // non-volatile version 5972 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5973 /*IsAssigmentOperator=*/true); 5974 5975 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5976 VisibleTypeConversionsQuals.hasVolatile()) { 5977 // volatile version 5978 ParamTypes[0] = 5979 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5980 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5981 CandidateSet, /*IsAssigmentOperator=*/true); 5982 } 5983 } 5984 } 5985 } 5986 5987 // C++ [over.built]p18: 5988 // 5989 // For every triple (L, VQ, R), where L is an arithmetic type, 5990 // VQ is either volatile or empty, and R is a promoted 5991 // arithmetic type, there exist candidate operator functions of 5992 // the form 5993 // 5994 // VQ L& operator=(VQ L&, R); 5995 // VQ L& operator*=(VQ L&, R); 5996 // VQ L& operator/=(VQ L&, R); 5997 // VQ L& operator+=(VQ L&, R); 5998 // VQ L& operator-=(VQ L&, R); 5999 void addAssignmentArithmeticOverloads(bool isEqualOp) { 6000 if (!HasArithmeticOrEnumeralCandidateType) 6001 return; 6002 6003 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 6004 for (unsigned Right = FirstPromotedArithmeticType; 6005 Right < LastPromotedArithmeticType; ++Right) { 6006 QualType ParamTypes[2]; 6007 ParamTypes[1] = getArithmeticType(Right); 6008 6009 // Add this built-in operator as a candidate (VQ is empty). 6010 ParamTypes[0] = 6011 S.Context.getLValueReferenceType(getArithmeticType(Left)); 6012 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6013 /*IsAssigmentOperator=*/isEqualOp); 6014 6015 // Add this built-in operator as a candidate (VQ is 'volatile'). 6016 if (VisibleTypeConversionsQuals.hasVolatile()) { 6017 ParamTypes[0] = 6018 S.Context.getVolatileType(getArithmeticType(Left)); 6019 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 6020 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 6021 CandidateSet, 6022 /*IsAssigmentOperator=*/isEqualOp); 6023 } 6024 } 6025 } 6026 6027 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 6028 for (BuiltinCandidateTypeSet::iterator 6029 Vec1 = CandidateTypes[0].vector_begin(), 6030 Vec1End = CandidateTypes[0].vector_end(); 6031 Vec1 != Vec1End; ++Vec1) { 6032 for (BuiltinCandidateTypeSet::iterator 6033 Vec2 = CandidateTypes[1].vector_begin(), 6034 Vec2End = CandidateTypes[1].vector_end(); 6035 Vec2 != Vec2End; ++Vec2) { 6036 QualType ParamTypes[2]; 6037 ParamTypes[1] = *Vec2; 6038 // Add this built-in operator as a candidate (VQ is empty). 6039 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 6040 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6041 /*IsAssigmentOperator=*/isEqualOp); 6042 6043 // Add this built-in operator as a candidate (VQ is 'volatile'). 6044 if (VisibleTypeConversionsQuals.hasVolatile()) { 6045 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 6046 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 6047 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 6048 CandidateSet, 6049 /*IsAssigmentOperator=*/isEqualOp); 6050 } 6051 } 6052 } 6053 } 6054 6055 // C++ [over.built]p22: 6056 // 6057 // For every triple (L, VQ, R), where L is an integral type, VQ 6058 // is either volatile or empty, and R is a promoted integral 6059 // type, there exist candidate operator functions of the form 6060 // 6061 // VQ L& operator%=(VQ L&, R); 6062 // VQ L& operator<<=(VQ L&, R); 6063 // VQ L& operator>>=(VQ L&, R); 6064 // VQ L& operator&=(VQ L&, R); 6065 // VQ L& operator^=(VQ L&, R); 6066 // VQ L& operator|=(VQ L&, R); 6067 void addAssignmentIntegralOverloads() { 6068 if (!HasArithmeticOrEnumeralCandidateType) 6069 return; 6070 6071 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 6072 for (unsigned Right = FirstPromotedIntegralType; 6073 Right < LastPromotedIntegralType; ++Right) { 6074 QualType ParamTypes[2]; 6075 ParamTypes[1] = getArithmeticType(Right); 6076 6077 // Add this built-in operator as a candidate (VQ is empty). 6078 ParamTypes[0] = 6079 S.Context.getLValueReferenceType(getArithmeticType(Left)); 6080 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 6081 if (VisibleTypeConversionsQuals.hasVolatile()) { 6082 // Add this built-in operator as a candidate (VQ is 'volatile'). 6083 ParamTypes[0] = getArithmeticType(Left); 6084 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 6085 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 6086 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 6087 CandidateSet); 6088 } 6089 } 6090 } 6091 } 6092 6093 // C++ [over.operator]p23: 6094 // 6095 // There also exist candidate operator functions of the form 6096 // 6097 // bool operator!(bool); 6098 // bool operator&&(bool, bool); 6099 // bool operator||(bool, bool); 6100 void addExclaimOverload() { 6101 QualType ParamTy = S.Context.BoolTy; 6102 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 6103 /*IsAssignmentOperator=*/false, 6104 /*NumContextualBoolArguments=*/1); 6105 } 6106 void addAmpAmpOrPipePipeOverload() { 6107 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 6108 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 6109 /*IsAssignmentOperator=*/false, 6110 /*NumContextualBoolArguments=*/2); 6111 } 6112 6113 // C++ [over.built]p13: 6114 // 6115 // For every cv-qualified or cv-unqualified object type T there 6116 // exist candidate operator functions of the form 6117 // 6118 // T* operator+(T*, ptrdiff_t); [ABOVE] 6119 // T& operator[](T*, ptrdiff_t); 6120 // T* operator-(T*, ptrdiff_t); [ABOVE] 6121 // T* operator+(ptrdiff_t, T*); [ABOVE] 6122 // T& operator[](ptrdiff_t, T*); 6123 void addSubscriptOverloads() { 6124 for (BuiltinCandidateTypeSet::iterator 6125 Ptr = CandidateTypes[0].pointer_begin(), 6126 PtrEnd = CandidateTypes[0].pointer_end(); 6127 Ptr != PtrEnd; ++Ptr) { 6128 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 6129 QualType PointeeType = (*Ptr)->getPointeeType(); 6130 if (!PointeeType->isObjectType()) 6131 continue; 6132 6133 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 6134 6135 // T& operator[](T*, ptrdiff_t) 6136 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 6137 } 6138 6139 for (BuiltinCandidateTypeSet::iterator 6140 Ptr = CandidateTypes[1].pointer_begin(), 6141 PtrEnd = CandidateTypes[1].pointer_end(); 6142 Ptr != PtrEnd; ++Ptr) { 6143 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 6144 QualType PointeeType = (*Ptr)->getPointeeType(); 6145 if (!PointeeType->isObjectType()) 6146 continue; 6147 6148 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 6149 6150 // T& operator[](ptrdiff_t, T*) 6151 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 6152 } 6153 } 6154 6155 // C++ [over.built]p11: 6156 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 6157 // C1 is the same type as C2 or is a derived class of C2, T is an object 6158 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 6159 // there exist candidate operator functions of the form 6160 // 6161 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 6162 // 6163 // where CV12 is the union of CV1 and CV2. 6164 void addArrowStarOverloads() { 6165 for (BuiltinCandidateTypeSet::iterator 6166 Ptr = CandidateTypes[0].pointer_begin(), 6167 PtrEnd = CandidateTypes[0].pointer_end(); 6168 Ptr != PtrEnd; ++Ptr) { 6169 QualType C1Ty = (*Ptr); 6170 QualType C1; 6171 QualifierCollector Q1; 6172 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 6173 if (!isa<RecordType>(C1)) 6174 continue; 6175 // heuristic to reduce number of builtin candidates in the set. 6176 // Add volatile/restrict version only if there are conversions to a 6177 // volatile/restrict type. 6178 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 6179 continue; 6180 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 6181 continue; 6182 for (BuiltinCandidateTypeSet::iterator 6183 MemPtr = CandidateTypes[1].member_pointer_begin(), 6184 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 6185 MemPtr != MemPtrEnd; ++MemPtr) { 6186 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 6187 QualType C2 = QualType(mptr->getClass(), 0); 6188 C2 = C2.getUnqualifiedType(); 6189 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 6190 break; 6191 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 6192 // build CV12 T& 6193 QualType T = mptr->getPointeeType(); 6194 if (!VisibleTypeConversionsQuals.hasVolatile() && 6195 T.isVolatileQualified()) 6196 continue; 6197 if (!VisibleTypeConversionsQuals.hasRestrict() && 6198 T.isRestrictQualified()) 6199 continue; 6200 T = Q1.apply(S.Context, T); 6201 QualType ResultTy = S.Context.getLValueReferenceType(T); 6202 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 6203 } 6204 } 6205 } 6206 6207 // Note that we don't consider the first argument, since it has been 6208 // contextually converted to bool long ago. The candidates below are 6209 // therefore added as binary. 6210 // 6211 // C++ [over.built]p25: 6212 // For every type T, where T is a pointer, pointer-to-member, or scoped 6213 // enumeration type, there exist candidate operator functions of the form 6214 // 6215 // T operator?(bool, T, T); 6216 // 6217 void addConditionalOperatorOverloads() { 6218 /// Set of (canonical) types that we've already handled. 6219 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6220 6221 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 6222 for (BuiltinCandidateTypeSet::iterator 6223 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 6224 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 6225 Ptr != PtrEnd; ++Ptr) { 6226 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6227 continue; 6228 6229 QualType ParamTypes[2] = { *Ptr, *Ptr }; 6230 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 6231 } 6232 6233 for (BuiltinCandidateTypeSet::iterator 6234 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 6235 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 6236 MemPtr != MemPtrEnd; ++MemPtr) { 6237 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 6238 continue; 6239 6240 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 6241 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); 6242 } 6243 6244 if (S.getLangOptions().CPlusPlus0x) { 6245 for (BuiltinCandidateTypeSet::iterator 6246 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 6247 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 6248 Enum != EnumEnd; ++Enum) { 6249 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 6250 continue; 6251 6252 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 6253 continue; 6254 6255 QualType ParamTypes[2] = { *Enum, *Enum }; 6256 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); 6257 } 6258 } 6259 } 6260 } 6261}; 6262 6263} // end anonymous namespace 6264 6265/// AddBuiltinOperatorCandidates - Add the appropriate built-in 6266/// operator overloads to the candidate set (C++ [over.built]), based 6267/// on the operator @p Op and the arguments given. For example, if the 6268/// operator is a binary '+', this routine might add "int 6269/// operator+(int, int)" to cover integer addition. 6270void 6271Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 6272 SourceLocation OpLoc, 6273 Expr **Args, unsigned NumArgs, 6274 OverloadCandidateSet& CandidateSet) { 6275 // Find all of the types that the arguments can convert to, but only 6276 // if the operator we're looking at has built-in operator candidates 6277 // that make use of these types. Also record whether we encounter non-record 6278 // candidate types or either arithmetic or enumeral candidate types. 6279 Qualifiers VisibleTypeConversionsQuals; 6280 VisibleTypeConversionsQuals.addConst(); 6281 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6282 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 6283 6284 bool HasNonRecordCandidateType = false; 6285 bool HasArithmeticOrEnumeralCandidateType = false; 6286 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 6287 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6288 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 6289 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 6290 OpLoc, 6291 true, 6292 (Op == OO_Exclaim || 6293 Op == OO_AmpAmp || 6294 Op == OO_PipePipe), 6295 VisibleTypeConversionsQuals); 6296 HasNonRecordCandidateType = HasNonRecordCandidateType || 6297 CandidateTypes[ArgIdx].hasNonRecordTypes(); 6298 HasArithmeticOrEnumeralCandidateType = 6299 HasArithmeticOrEnumeralCandidateType || 6300 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 6301 } 6302 6303 // Exit early when no non-record types have been added to the candidate set 6304 // for any of the arguments to the operator. 6305 if (!HasNonRecordCandidateType) 6306 return; 6307 6308 // Setup an object to manage the common state for building overloads. 6309 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, 6310 VisibleTypeConversionsQuals, 6311 HasArithmeticOrEnumeralCandidateType, 6312 CandidateTypes, CandidateSet); 6313 6314 // Dispatch over the operation to add in only those overloads which apply. 6315 switch (Op) { 6316 case OO_None: 6317 case NUM_OVERLOADED_OPERATORS: 6318 assert(false && "Expected an overloaded operator"); 6319 break; 6320 6321 case OO_New: 6322 case OO_Delete: 6323 case OO_Array_New: 6324 case OO_Array_Delete: 6325 case OO_Call: 6326 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 6327 break; 6328 6329 case OO_Comma: 6330 case OO_Arrow: 6331 // C++ [over.match.oper]p3: 6332 // -- For the operator ',', the unary operator '&', or the 6333 // operator '->', the built-in candidates set is empty. 6334 break; 6335 6336 case OO_Plus: // '+' is either unary or binary 6337 if (NumArgs == 1) 6338 OpBuilder.addUnaryPlusPointerOverloads(); 6339 // Fall through. 6340 6341 case OO_Minus: // '-' is either unary or binary 6342 if (NumArgs == 1) { 6343 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 6344 } else { 6345 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 6346 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6347 } 6348 break; 6349 6350 case OO_Star: // '*' is either unary or binary 6351 if (NumArgs == 1) 6352 OpBuilder.addUnaryStarPointerOverloads(); 6353 else 6354 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6355 break; 6356 6357 case OO_Slash: 6358 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6359 break; 6360 6361 case OO_PlusPlus: 6362 case OO_MinusMinus: 6363 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 6364 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 6365 break; 6366 6367 case OO_EqualEqual: 6368 case OO_ExclaimEqual: 6369 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 6370 // Fall through. 6371 6372 case OO_Less: 6373 case OO_Greater: 6374 case OO_LessEqual: 6375 case OO_GreaterEqual: 6376 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 6377 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 6378 break; 6379 6380 case OO_Percent: 6381 case OO_Caret: 6382 case OO_Pipe: 6383 case OO_LessLess: 6384 case OO_GreaterGreater: 6385 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6386 break; 6387 6388 case OO_Amp: // '&' is either unary or binary 6389 if (NumArgs == 1) 6390 // C++ [over.match.oper]p3: 6391 // -- For the operator ',', the unary operator '&', or the 6392 // operator '->', the built-in candidates set is empty. 6393 break; 6394 6395 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6396 break; 6397 6398 case OO_Tilde: 6399 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 6400 break; 6401 6402 case OO_Equal: 6403 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 6404 // Fall through. 6405 6406 case OO_PlusEqual: 6407 case OO_MinusEqual: 6408 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 6409 // Fall through. 6410 6411 case OO_StarEqual: 6412 case OO_SlashEqual: 6413 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 6414 break; 6415 6416 case OO_PercentEqual: 6417 case OO_LessLessEqual: 6418 case OO_GreaterGreaterEqual: 6419 case OO_AmpEqual: 6420 case OO_CaretEqual: 6421 case OO_PipeEqual: 6422 OpBuilder.addAssignmentIntegralOverloads(); 6423 break; 6424 6425 case OO_Exclaim: 6426 OpBuilder.addExclaimOverload(); 6427 break; 6428 6429 case OO_AmpAmp: 6430 case OO_PipePipe: 6431 OpBuilder.addAmpAmpOrPipePipeOverload(); 6432 break; 6433 6434 case OO_Subscript: 6435 OpBuilder.addSubscriptOverloads(); 6436 break; 6437 6438 case OO_ArrowStar: 6439 OpBuilder.addArrowStarOverloads(); 6440 break; 6441 6442 case OO_Conditional: 6443 OpBuilder.addConditionalOperatorOverloads(); 6444 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6445 break; 6446 } 6447} 6448 6449/// \brief Add function candidates found via argument-dependent lookup 6450/// to the set of overloading candidates. 6451/// 6452/// This routine performs argument-dependent name lookup based on the 6453/// given function name (which may also be an operator name) and adds 6454/// all of the overload candidates found by ADL to the overload 6455/// candidate set (C++ [basic.lookup.argdep]). 6456void 6457Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 6458 bool Operator, 6459 Expr **Args, unsigned NumArgs, 6460 TemplateArgumentListInfo *ExplicitTemplateArgs, 6461 OverloadCandidateSet& CandidateSet, 6462 bool PartialOverloading, 6463 bool StdNamespaceIsAssociated) { 6464 ADLResult Fns; 6465 6466 // FIXME: This approach for uniquing ADL results (and removing 6467 // redundant candidates from the set) relies on pointer-equality, 6468 // which means we need to key off the canonical decl. However, 6469 // always going back to the canonical decl might not get us the 6470 // right set of default arguments. What default arguments are 6471 // we supposed to consider on ADL candidates, anyway? 6472 6473 // FIXME: Pass in the explicit template arguments? 6474 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns, 6475 StdNamespaceIsAssociated); 6476 6477 // Erase all of the candidates we already knew about. 6478 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 6479 CandEnd = CandidateSet.end(); 6480 Cand != CandEnd; ++Cand) 6481 if (Cand->Function) { 6482 Fns.erase(Cand->Function); 6483 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 6484 Fns.erase(FunTmpl); 6485 } 6486 6487 // For each of the ADL candidates we found, add it to the overload 6488 // set. 6489 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 6490 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 6491 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 6492 if (ExplicitTemplateArgs) 6493 continue; 6494 6495 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 6496 false, PartialOverloading); 6497 } else 6498 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 6499 FoundDecl, ExplicitTemplateArgs, 6500 Args, NumArgs, CandidateSet); 6501 } 6502} 6503 6504/// isBetterOverloadCandidate - Determines whether the first overload 6505/// candidate is a better candidate than the second (C++ 13.3.3p1). 6506bool 6507isBetterOverloadCandidate(Sema &S, 6508 const OverloadCandidate &Cand1, 6509 const OverloadCandidate &Cand2, 6510 SourceLocation Loc, 6511 bool UserDefinedConversion) { 6512 // Define viable functions to be better candidates than non-viable 6513 // functions. 6514 if (!Cand2.Viable) 6515 return Cand1.Viable; 6516 else if (!Cand1.Viable) 6517 return false; 6518 6519 // C++ [over.match.best]p1: 6520 // 6521 // -- if F is a static member function, ICS1(F) is defined such 6522 // that ICS1(F) is neither better nor worse than ICS1(G) for 6523 // any function G, and, symmetrically, ICS1(G) is neither 6524 // better nor worse than ICS1(F). 6525 unsigned StartArg = 0; 6526 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 6527 StartArg = 1; 6528 6529 // C++ [over.match.best]p1: 6530 // A viable function F1 is defined to be a better function than another 6531 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 6532 // conversion sequence than ICSi(F2), and then... 6533 unsigned NumArgs = Cand1.Conversions.size(); 6534 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 6535 bool HasBetterConversion = false; 6536 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 6537 switch (CompareImplicitConversionSequences(S, 6538 Cand1.Conversions[ArgIdx], 6539 Cand2.Conversions[ArgIdx])) { 6540 case ImplicitConversionSequence::Better: 6541 // Cand1 has a better conversion sequence. 6542 HasBetterConversion = true; 6543 break; 6544 6545 case ImplicitConversionSequence::Worse: 6546 // Cand1 can't be better than Cand2. 6547 return false; 6548 6549 case ImplicitConversionSequence::Indistinguishable: 6550 // Do nothing. 6551 break; 6552 } 6553 } 6554 6555 // -- for some argument j, ICSj(F1) is a better conversion sequence than 6556 // ICSj(F2), or, if not that, 6557 if (HasBetterConversion) 6558 return true; 6559 6560 // - F1 is a non-template function and F2 is a function template 6561 // specialization, or, if not that, 6562 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 6563 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 6564 return true; 6565 6566 // -- F1 and F2 are function template specializations, and the function 6567 // template for F1 is more specialized than the template for F2 6568 // according to the partial ordering rules described in 14.5.5.2, or, 6569 // if not that, 6570 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 6571 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 6572 if (FunctionTemplateDecl *BetterTemplate 6573 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 6574 Cand2.Function->getPrimaryTemplate(), 6575 Loc, 6576 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 6577 : TPOC_Call, 6578 Cand1.ExplicitCallArguments)) 6579 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 6580 } 6581 6582 // -- the context is an initialization by user-defined conversion 6583 // (see 8.5, 13.3.1.5) and the standard conversion sequence 6584 // from the return type of F1 to the destination type (i.e., 6585 // the type of the entity being initialized) is a better 6586 // conversion sequence than the standard conversion sequence 6587 // from the return type of F2 to the destination type. 6588 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 6589 isa<CXXConversionDecl>(Cand1.Function) && 6590 isa<CXXConversionDecl>(Cand2.Function)) { 6591 switch (CompareStandardConversionSequences(S, 6592 Cand1.FinalConversion, 6593 Cand2.FinalConversion)) { 6594 case ImplicitConversionSequence::Better: 6595 // Cand1 has a better conversion sequence. 6596 return true; 6597 6598 case ImplicitConversionSequence::Worse: 6599 // Cand1 can't be better than Cand2. 6600 return false; 6601 6602 case ImplicitConversionSequence::Indistinguishable: 6603 // Do nothing 6604 break; 6605 } 6606 } 6607 6608 return false; 6609} 6610 6611/// \brief Computes the best viable function (C++ 13.3.3) 6612/// within an overload candidate set. 6613/// 6614/// \param CandidateSet the set of candidate functions. 6615/// 6616/// \param Loc the location of the function name (or operator symbol) for 6617/// which overload resolution occurs. 6618/// 6619/// \param Best f overload resolution was successful or found a deleted 6620/// function, Best points to the candidate function found. 6621/// 6622/// \returns The result of overload resolution. 6623OverloadingResult 6624OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 6625 iterator &Best, 6626 bool UserDefinedConversion) { 6627 // Find the best viable function. 6628 Best = end(); 6629 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6630 if (Cand->Viable) 6631 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 6632 UserDefinedConversion)) 6633 Best = Cand; 6634 } 6635 6636 // If we didn't find any viable functions, abort. 6637 if (Best == end()) 6638 return OR_No_Viable_Function; 6639 6640 // Make sure that this function is better than every other viable 6641 // function. If not, we have an ambiguity. 6642 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6643 if (Cand->Viable && 6644 Cand != Best && 6645 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 6646 UserDefinedConversion)) { 6647 Best = end(); 6648 return OR_Ambiguous; 6649 } 6650 } 6651 6652 // Best is the best viable function. 6653 if (Best->Function && 6654 (Best->Function->isDeleted() || 6655 S.isFunctionConsideredUnavailable(Best->Function))) 6656 return OR_Deleted; 6657 6658 return OR_Success; 6659} 6660 6661namespace { 6662 6663enum OverloadCandidateKind { 6664 oc_function, 6665 oc_method, 6666 oc_constructor, 6667 oc_function_template, 6668 oc_method_template, 6669 oc_constructor_template, 6670 oc_implicit_default_constructor, 6671 oc_implicit_copy_constructor, 6672 oc_implicit_move_constructor, 6673 oc_implicit_copy_assignment, 6674 oc_implicit_move_assignment, 6675 oc_implicit_inherited_constructor 6676}; 6677 6678OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 6679 FunctionDecl *Fn, 6680 std::string &Description) { 6681 bool isTemplate = false; 6682 6683 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 6684 isTemplate = true; 6685 Description = S.getTemplateArgumentBindingsText( 6686 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 6687 } 6688 6689 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 6690 if (!Ctor->isImplicit()) 6691 return isTemplate ? oc_constructor_template : oc_constructor; 6692 6693 if (Ctor->getInheritedConstructor()) 6694 return oc_implicit_inherited_constructor; 6695 6696 if (Ctor->isDefaultConstructor()) 6697 return oc_implicit_default_constructor; 6698 6699 if (Ctor->isMoveConstructor()) 6700 return oc_implicit_move_constructor; 6701 6702 assert(Ctor->isCopyConstructor() && 6703 "unexpected sort of implicit constructor"); 6704 return oc_implicit_copy_constructor; 6705 } 6706 6707 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 6708 // This actually gets spelled 'candidate function' for now, but 6709 // it doesn't hurt to split it out. 6710 if (!Meth->isImplicit()) 6711 return isTemplate ? oc_method_template : oc_method; 6712 6713 if (Meth->isMoveAssignmentOperator()) 6714 return oc_implicit_move_assignment; 6715 6716 assert(Meth->isCopyAssignmentOperator() 6717 && "implicit method is not copy assignment operator?"); 6718 return oc_implicit_copy_assignment; 6719 } 6720 6721 return isTemplate ? oc_function_template : oc_function; 6722} 6723 6724void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { 6725 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 6726 if (!Ctor) return; 6727 6728 Ctor = Ctor->getInheritedConstructor(); 6729 if (!Ctor) return; 6730 6731 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 6732} 6733 6734} // end anonymous namespace 6735 6736// Notes the location of an overload candidate. 6737void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 6738 std::string FnDesc; 6739 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 6740 Diag(Fn->getLocation(), diag::note_ovl_candidate) 6741 << (unsigned) K << FnDesc; 6742 MaybeEmitInheritedConstructorNote(*this, Fn); 6743} 6744 6745//Notes the location of all overload candidates designated through 6746// OverloadedExpr 6747void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr) { 6748 assert(OverloadedExpr->getType() == Context.OverloadTy); 6749 6750 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); 6751 OverloadExpr *OvlExpr = Ovl.Expression; 6752 6753 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6754 IEnd = OvlExpr->decls_end(); 6755 I != IEnd; ++I) { 6756 if (FunctionTemplateDecl *FunTmpl = 6757 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) { 6758 NoteOverloadCandidate(FunTmpl->getTemplatedDecl()); 6759 } else if (FunctionDecl *Fun 6760 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) { 6761 NoteOverloadCandidate(Fun); 6762 } 6763 } 6764} 6765 6766/// Diagnoses an ambiguous conversion. The partial diagnostic is the 6767/// "lead" diagnostic; it will be given two arguments, the source and 6768/// target types of the conversion. 6769void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 6770 Sema &S, 6771 SourceLocation CaretLoc, 6772 const PartialDiagnostic &PDiag) const { 6773 S.Diag(CaretLoc, PDiag) 6774 << Ambiguous.getFromType() << Ambiguous.getToType(); 6775 for (AmbiguousConversionSequence::const_iterator 6776 I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 6777 S.NoteOverloadCandidate(*I); 6778 } 6779} 6780 6781namespace { 6782 6783void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 6784 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 6785 assert(Conv.isBad()); 6786 assert(Cand->Function && "for now, candidate must be a function"); 6787 FunctionDecl *Fn = Cand->Function; 6788 6789 // There's a conversion slot for the object argument if this is a 6790 // non-constructor method. Note that 'I' corresponds the 6791 // conversion-slot index. 6792 bool isObjectArgument = false; 6793 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 6794 if (I == 0) 6795 isObjectArgument = true; 6796 else 6797 I--; 6798 } 6799 6800 std::string FnDesc; 6801 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6802 6803 Expr *FromExpr = Conv.Bad.FromExpr; 6804 QualType FromTy = Conv.Bad.getFromType(); 6805 QualType ToTy = Conv.Bad.getToType(); 6806 6807 if (FromTy == S.Context.OverloadTy) { 6808 assert(FromExpr && "overload set argument came from implicit argument?"); 6809 Expr *E = FromExpr->IgnoreParens(); 6810 if (isa<UnaryOperator>(E)) 6811 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 6812 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 6813 6814 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 6815 << (unsigned) FnKind << FnDesc 6816 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6817 << ToTy << Name << I+1; 6818 MaybeEmitInheritedConstructorNote(S, Fn); 6819 return; 6820 } 6821 6822 // Do some hand-waving analysis to see if the non-viability is due 6823 // to a qualifier mismatch. 6824 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 6825 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 6826 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 6827 CToTy = RT->getPointeeType(); 6828 else { 6829 // TODO: detect and diagnose the full richness of const mismatches. 6830 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 6831 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 6832 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 6833 } 6834 6835 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 6836 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 6837 // It is dumb that we have to do this here. 6838 while (isa<ArrayType>(CFromTy)) 6839 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 6840 while (isa<ArrayType>(CToTy)) 6841 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 6842 6843 Qualifiers FromQs = CFromTy.getQualifiers(); 6844 Qualifiers ToQs = CToTy.getQualifiers(); 6845 6846 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 6847 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 6848 << (unsigned) FnKind << FnDesc 6849 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6850 << FromTy 6851 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 6852 << (unsigned) isObjectArgument << I+1; 6853 MaybeEmitInheritedConstructorNote(S, Fn); 6854 return; 6855 } 6856 6857 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 6858 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership) 6859 << (unsigned) FnKind << FnDesc 6860 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6861 << FromTy 6862 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime() 6863 << (unsigned) isObjectArgument << I+1; 6864 MaybeEmitInheritedConstructorNote(S, Fn); 6865 return; 6866 } 6867 6868 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) { 6869 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc) 6870 << (unsigned) FnKind << FnDesc 6871 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6872 << FromTy 6873 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr() 6874 << (unsigned) isObjectArgument << I+1; 6875 MaybeEmitInheritedConstructorNote(S, Fn); 6876 return; 6877 } 6878 6879 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 6880 assert(CVR && "unexpected qualifiers mismatch"); 6881 6882 if (isObjectArgument) { 6883 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 6884 << (unsigned) FnKind << FnDesc 6885 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6886 << FromTy << (CVR - 1); 6887 } else { 6888 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 6889 << (unsigned) FnKind << FnDesc 6890 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6891 << FromTy << (CVR - 1) << I+1; 6892 } 6893 MaybeEmitInheritedConstructorNote(S, Fn); 6894 return; 6895 } 6896 6897 // Diagnose references or pointers to incomplete types differently, 6898 // since it's far from impossible that the incompleteness triggered 6899 // the failure. 6900 QualType TempFromTy = FromTy.getNonReferenceType(); 6901 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 6902 TempFromTy = PTy->getPointeeType(); 6903 if (TempFromTy->isIncompleteType()) { 6904 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 6905 << (unsigned) FnKind << FnDesc 6906 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6907 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6908 MaybeEmitInheritedConstructorNote(S, Fn); 6909 return; 6910 } 6911 6912 // Diagnose base -> derived pointer conversions. 6913 unsigned BaseToDerivedConversion = 0; 6914 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 6915 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 6916 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6917 FromPtrTy->getPointeeType()) && 6918 !FromPtrTy->getPointeeType()->isIncompleteType() && 6919 !ToPtrTy->getPointeeType()->isIncompleteType() && 6920 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 6921 FromPtrTy->getPointeeType())) 6922 BaseToDerivedConversion = 1; 6923 } 6924 } else if (const ObjCObjectPointerType *FromPtrTy 6925 = FromTy->getAs<ObjCObjectPointerType>()) { 6926 if (const ObjCObjectPointerType *ToPtrTy 6927 = ToTy->getAs<ObjCObjectPointerType>()) 6928 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 6929 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 6930 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6931 FromPtrTy->getPointeeType()) && 6932 FromIface->isSuperClassOf(ToIface)) 6933 BaseToDerivedConversion = 2; 6934 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 6935 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 6936 !FromTy->isIncompleteType() && 6937 !ToRefTy->getPointeeType()->isIncompleteType() && 6938 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 6939 BaseToDerivedConversion = 3; 6940 } 6941 6942 if (BaseToDerivedConversion) { 6943 S.Diag(Fn->getLocation(), 6944 diag::note_ovl_candidate_bad_base_to_derived_conv) 6945 << (unsigned) FnKind << FnDesc 6946 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6947 << (BaseToDerivedConversion - 1) 6948 << FromTy << ToTy << I+1; 6949 MaybeEmitInheritedConstructorNote(S, Fn); 6950 return; 6951 } 6952 6953 if (isa<ObjCObjectPointerType>(CFromTy) && 6954 isa<PointerType>(CToTy)) { 6955 Qualifiers FromQs = CFromTy.getQualifiers(); 6956 Qualifiers ToQs = CToTy.getQualifiers(); 6957 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 6958 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv) 6959 << (unsigned) FnKind << FnDesc 6960 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6961 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6962 MaybeEmitInheritedConstructorNote(S, Fn); 6963 return; 6964 } 6965 } 6966 6967 // Emit the generic diagnostic and, optionally, add the hints to it. 6968 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv); 6969 FDiag << (unsigned) FnKind << FnDesc 6970 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6971 << FromTy << ToTy << (unsigned) isObjectArgument << I + 1 6972 << (unsigned) (Cand->Fix.Kind); 6973 6974 // If we can fix the conversion, suggest the FixIts. 6975 for (SmallVector<FixItHint, 1>::iterator 6976 HI = Cand->Fix.Hints.begin(), HE = Cand->Fix.Hints.end(); 6977 HI != HE; ++HI) 6978 FDiag << *HI; 6979 S.Diag(Fn->getLocation(), FDiag); 6980 6981 MaybeEmitInheritedConstructorNote(S, Fn); 6982} 6983 6984void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 6985 unsigned NumFormalArgs) { 6986 // TODO: treat calls to a missing default constructor as a special case 6987 6988 FunctionDecl *Fn = Cand->Function; 6989 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 6990 6991 unsigned MinParams = Fn->getMinRequiredArguments(); 6992 6993 // With invalid overloaded operators, it's possible that we think we 6994 // have an arity mismatch when it fact it looks like we have the 6995 // right number of arguments, because only overloaded operators have 6996 // the weird behavior of overloading member and non-member functions. 6997 // Just don't report anything. 6998 if (Fn->isInvalidDecl() && 6999 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName) 7000 return; 7001 7002 // at least / at most / exactly 7003 unsigned mode, modeCount; 7004 if (NumFormalArgs < MinParams) { 7005 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 7006 (Cand->FailureKind == ovl_fail_bad_deduction && 7007 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 7008 if (MinParams != FnTy->getNumArgs() || 7009 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 7010 mode = 0; // "at least" 7011 else 7012 mode = 2; // "exactly" 7013 modeCount = MinParams; 7014 } else { 7015 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 7016 (Cand->FailureKind == ovl_fail_bad_deduction && 7017 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 7018 if (MinParams != FnTy->getNumArgs()) 7019 mode = 1; // "at most" 7020 else 7021 mode = 2; // "exactly" 7022 modeCount = FnTy->getNumArgs(); 7023 } 7024 7025 std::string Description; 7026 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 7027 7028 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 7029 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 7030 << modeCount << NumFormalArgs; 7031 MaybeEmitInheritedConstructorNote(S, Fn); 7032} 7033 7034/// Diagnose a failed template-argument deduction. 7035void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 7036 Expr **Args, unsigned NumArgs) { 7037 FunctionDecl *Fn = Cand->Function; // pattern 7038 7039 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 7040 NamedDecl *ParamD; 7041 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 7042 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 7043 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 7044 switch (Cand->DeductionFailure.Result) { 7045 case Sema::TDK_Success: 7046 llvm_unreachable("TDK_success while diagnosing bad deduction"); 7047 7048 case Sema::TDK_Incomplete: { 7049 assert(ParamD && "no parameter found for incomplete deduction result"); 7050 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 7051 << ParamD->getDeclName(); 7052 MaybeEmitInheritedConstructorNote(S, Fn); 7053 return; 7054 } 7055 7056 case Sema::TDK_Underqualified: { 7057 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 7058 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 7059 7060 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 7061 7062 // Param will have been canonicalized, but it should just be a 7063 // qualified version of ParamD, so move the qualifiers to that. 7064 QualifierCollector Qs; 7065 Qs.strip(Param); 7066 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 7067 assert(S.Context.hasSameType(Param, NonCanonParam)); 7068 7069 // Arg has also been canonicalized, but there's nothing we can do 7070 // about that. It also doesn't matter as much, because it won't 7071 // have any template parameters in it (because deduction isn't 7072 // done on dependent types). 7073 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 7074 7075 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 7076 << ParamD->getDeclName() << Arg << NonCanonParam; 7077 MaybeEmitInheritedConstructorNote(S, Fn); 7078 return; 7079 } 7080 7081 case Sema::TDK_Inconsistent: { 7082 assert(ParamD && "no parameter found for inconsistent deduction result"); 7083 int which = 0; 7084 if (isa<TemplateTypeParmDecl>(ParamD)) 7085 which = 0; 7086 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 7087 which = 1; 7088 else { 7089 which = 2; 7090 } 7091 7092 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 7093 << which << ParamD->getDeclName() 7094 << *Cand->DeductionFailure.getFirstArg() 7095 << *Cand->DeductionFailure.getSecondArg(); 7096 MaybeEmitInheritedConstructorNote(S, Fn); 7097 return; 7098 } 7099 7100 case Sema::TDK_InvalidExplicitArguments: 7101 assert(ParamD && "no parameter found for invalid explicit arguments"); 7102 if (ParamD->getDeclName()) 7103 S.Diag(Fn->getLocation(), 7104 diag::note_ovl_candidate_explicit_arg_mismatch_named) 7105 << ParamD->getDeclName(); 7106 else { 7107 int index = 0; 7108 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 7109 index = TTP->getIndex(); 7110 else if (NonTypeTemplateParmDecl *NTTP 7111 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 7112 index = NTTP->getIndex(); 7113 else 7114 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 7115 S.Diag(Fn->getLocation(), 7116 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 7117 << (index + 1); 7118 } 7119 MaybeEmitInheritedConstructorNote(S, Fn); 7120 return; 7121 7122 case Sema::TDK_TooManyArguments: 7123 case Sema::TDK_TooFewArguments: 7124 DiagnoseArityMismatch(S, Cand, NumArgs); 7125 return; 7126 7127 case Sema::TDK_InstantiationDepth: 7128 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 7129 MaybeEmitInheritedConstructorNote(S, Fn); 7130 return; 7131 7132 case Sema::TDK_SubstitutionFailure: { 7133 std::string ArgString; 7134 if (TemplateArgumentList *Args 7135 = Cand->DeductionFailure.getTemplateArgumentList()) 7136 ArgString = S.getTemplateArgumentBindingsText( 7137 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 7138 *Args); 7139 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 7140 << ArgString; 7141 MaybeEmitInheritedConstructorNote(S, Fn); 7142 return; 7143 } 7144 7145 // TODO: diagnose these individually, then kill off 7146 // note_ovl_candidate_bad_deduction, which is uselessly vague. 7147 case Sema::TDK_NonDeducedMismatch: 7148 case Sema::TDK_FailedOverloadResolution: 7149 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 7150 MaybeEmitInheritedConstructorNote(S, Fn); 7151 return; 7152 } 7153} 7154 7155/// Generates a 'note' diagnostic for an overload candidate. We've 7156/// already generated a primary error at the call site. 7157/// 7158/// It really does need to be a single diagnostic with its caret 7159/// pointed at the candidate declaration. Yes, this creates some 7160/// major challenges of technical writing. Yes, this makes pointing 7161/// out problems with specific arguments quite awkward. It's still 7162/// better than generating twenty screens of text for every failed 7163/// overload. 7164/// 7165/// It would be great to be able to express per-candidate problems 7166/// more richly for those diagnostic clients that cared, but we'd 7167/// still have to be just as careful with the default diagnostics. 7168void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 7169 Expr **Args, unsigned NumArgs) { 7170 FunctionDecl *Fn = Cand->Function; 7171 7172 // Note deleted candidates, but only if they're viable. 7173 if (Cand->Viable && (Fn->isDeleted() || 7174 S.isFunctionConsideredUnavailable(Fn))) { 7175 std::string FnDesc; 7176 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 7177 7178 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 7179 << FnKind << FnDesc << Fn->isDeleted(); 7180 MaybeEmitInheritedConstructorNote(S, Fn); 7181 return; 7182 } 7183 7184 // We don't really have anything else to say about viable candidates. 7185 if (Cand->Viable) { 7186 S.NoteOverloadCandidate(Fn); 7187 return; 7188 } 7189 7190 switch (Cand->FailureKind) { 7191 case ovl_fail_too_many_arguments: 7192 case ovl_fail_too_few_arguments: 7193 return DiagnoseArityMismatch(S, Cand, NumArgs); 7194 7195 case ovl_fail_bad_deduction: 7196 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 7197 7198 case ovl_fail_trivial_conversion: 7199 case ovl_fail_bad_final_conversion: 7200 case ovl_fail_final_conversion_not_exact: 7201 return S.NoteOverloadCandidate(Fn); 7202 7203 case ovl_fail_bad_conversion: { 7204 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 7205 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 7206 if (Cand->Conversions[I].isBad()) 7207 return DiagnoseBadConversion(S, Cand, I); 7208 7209 // FIXME: this currently happens when we're called from SemaInit 7210 // when user-conversion overload fails. Figure out how to handle 7211 // those conditions and diagnose them well. 7212 return S.NoteOverloadCandidate(Fn); 7213 } 7214 } 7215} 7216 7217void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 7218 // Desugar the type of the surrogate down to a function type, 7219 // retaining as many typedefs as possible while still showing 7220 // the function type (and, therefore, its parameter types). 7221 QualType FnType = Cand->Surrogate->getConversionType(); 7222 bool isLValueReference = false; 7223 bool isRValueReference = false; 7224 bool isPointer = false; 7225 if (const LValueReferenceType *FnTypeRef = 7226 FnType->getAs<LValueReferenceType>()) { 7227 FnType = FnTypeRef->getPointeeType(); 7228 isLValueReference = true; 7229 } else if (const RValueReferenceType *FnTypeRef = 7230 FnType->getAs<RValueReferenceType>()) { 7231 FnType = FnTypeRef->getPointeeType(); 7232 isRValueReference = true; 7233 } 7234 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 7235 FnType = FnTypePtr->getPointeeType(); 7236 isPointer = true; 7237 } 7238 // Desugar down to a function type. 7239 FnType = QualType(FnType->getAs<FunctionType>(), 0); 7240 // Reconstruct the pointer/reference as appropriate. 7241 if (isPointer) FnType = S.Context.getPointerType(FnType); 7242 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 7243 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 7244 7245 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 7246 << FnType; 7247 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 7248} 7249 7250void NoteBuiltinOperatorCandidate(Sema &S, 7251 const char *Opc, 7252 SourceLocation OpLoc, 7253 OverloadCandidate *Cand) { 7254 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 7255 std::string TypeStr("operator"); 7256 TypeStr += Opc; 7257 TypeStr += "("; 7258 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 7259 if (Cand->Conversions.size() == 1) { 7260 TypeStr += ")"; 7261 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 7262 } else { 7263 TypeStr += ", "; 7264 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 7265 TypeStr += ")"; 7266 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 7267 } 7268} 7269 7270void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 7271 OverloadCandidate *Cand) { 7272 unsigned NoOperands = Cand->Conversions.size(); 7273 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 7274 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 7275 if (ICS.isBad()) break; // all meaningless after first invalid 7276 if (!ICS.isAmbiguous()) continue; 7277 7278 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 7279 S.PDiag(diag::note_ambiguous_type_conversion)); 7280 } 7281} 7282 7283SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 7284 if (Cand->Function) 7285 return Cand->Function->getLocation(); 7286 if (Cand->IsSurrogate) 7287 return Cand->Surrogate->getLocation(); 7288 return SourceLocation(); 7289} 7290 7291static unsigned 7292RankDeductionFailure(const OverloadCandidate::DeductionFailureInfo &DFI) { 7293 switch ((Sema::TemplateDeductionResult)DFI.Result) { 7294 case Sema::TDK_Success: 7295 assert(0 && "TDK_success while diagnosing bad deduction"); 7296 7297 case Sema::TDK_Incomplete: 7298 return 1; 7299 7300 case Sema::TDK_Underqualified: 7301 case Sema::TDK_Inconsistent: 7302 return 2; 7303 7304 case Sema::TDK_SubstitutionFailure: 7305 case Sema::TDK_NonDeducedMismatch: 7306 return 3; 7307 7308 case Sema::TDK_InstantiationDepth: 7309 case Sema::TDK_FailedOverloadResolution: 7310 return 4; 7311 7312 case Sema::TDK_InvalidExplicitArguments: 7313 return 5; 7314 7315 case Sema::TDK_TooManyArguments: 7316 case Sema::TDK_TooFewArguments: 7317 return 6; 7318 } 7319 llvm_unreachable("Unhandled deduction result"); 7320} 7321 7322struct CompareOverloadCandidatesForDisplay { 7323 Sema &S; 7324 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 7325 7326 bool operator()(const OverloadCandidate *L, 7327 const OverloadCandidate *R) { 7328 // Fast-path this check. 7329 if (L == R) return false; 7330 7331 // Order first by viability. 7332 if (L->Viable) { 7333 if (!R->Viable) return true; 7334 7335 // TODO: introduce a tri-valued comparison for overload 7336 // candidates. Would be more worthwhile if we had a sort 7337 // that could exploit it. 7338 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 7339 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 7340 } else if (R->Viable) 7341 return false; 7342 7343 assert(L->Viable == R->Viable); 7344 7345 // Criteria by which we can sort non-viable candidates: 7346 if (!L->Viable) { 7347 // 1. Arity mismatches come after other candidates. 7348 if (L->FailureKind == ovl_fail_too_many_arguments || 7349 L->FailureKind == ovl_fail_too_few_arguments) 7350 return false; 7351 if (R->FailureKind == ovl_fail_too_many_arguments || 7352 R->FailureKind == ovl_fail_too_few_arguments) 7353 return true; 7354 7355 // 2. Bad conversions come first and are ordered by the number 7356 // of bad conversions and quality of good conversions. 7357 if (L->FailureKind == ovl_fail_bad_conversion) { 7358 if (R->FailureKind != ovl_fail_bad_conversion) 7359 return true; 7360 7361 // The conversion that can be fixed with a smaller number of changes, 7362 // comes first. 7363 unsigned numLFixes = L->Fix.NumConversionsFixed; 7364 unsigned numRFixes = R->Fix.NumConversionsFixed; 7365 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes; 7366 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes; 7367 if (numLFixes != numRFixes) { 7368 if (numLFixes < numRFixes) 7369 return true; 7370 else 7371 return false; 7372 } 7373 7374 // If there's any ordering between the defined conversions... 7375 // FIXME: this might not be transitive. 7376 assert(L->Conversions.size() == R->Conversions.size()); 7377 7378 int leftBetter = 0; 7379 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 7380 for (unsigned E = L->Conversions.size(); I != E; ++I) { 7381 switch (CompareImplicitConversionSequences(S, 7382 L->Conversions[I], 7383 R->Conversions[I])) { 7384 case ImplicitConversionSequence::Better: 7385 leftBetter++; 7386 break; 7387 7388 case ImplicitConversionSequence::Worse: 7389 leftBetter--; 7390 break; 7391 7392 case ImplicitConversionSequence::Indistinguishable: 7393 break; 7394 } 7395 } 7396 if (leftBetter > 0) return true; 7397 if (leftBetter < 0) return false; 7398 7399 } else if (R->FailureKind == ovl_fail_bad_conversion) 7400 return false; 7401 7402 if (L->FailureKind == ovl_fail_bad_deduction) { 7403 if (R->FailureKind != ovl_fail_bad_deduction) 7404 return true; 7405 7406 if (L->DeductionFailure.Result != R->DeductionFailure.Result) 7407 return RankDeductionFailure(L->DeductionFailure) 7408 <= RankDeductionFailure(R->DeductionFailure); 7409 } 7410 7411 // TODO: others? 7412 } 7413 7414 // Sort everything else by location. 7415 SourceLocation LLoc = GetLocationForCandidate(L); 7416 SourceLocation RLoc = GetLocationForCandidate(R); 7417 7418 // Put candidates without locations (e.g. builtins) at the end. 7419 if (LLoc.isInvalid()) return false; 7420 if (RLoc.isInvalid()) return true; 7421 7422 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 7423 } 7424}; 7425 7426/// CompleteNonViableCandidate - Normally, overload resolution only 7427/// computes up to the first. Produces the FixIt set if possible. 7428void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 7429 Expr **Args, unsigned NumArgs) { 7430 assert(!Cand->Viable); 7431 7432 // Don't do anything on failures other than bad conversion. 7433 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 7434 7435 // We only want the FixIts if all the arguments can be corrected. 7436 bool Unfixable = false; 7437 // Use a implicit copy initialization to check conversion fixes. 7438 Cand->Fix.setConversionChecker(TryCopyInitialization); 7439 7440 // Skip forward to the first bad conversion. 7441 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 7442 unsigned ConvCount = Cand->Conversions.size(); 7443 while (true) { 7444 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 7445 ConvIdx++; 7446 if (Cand->Conversions[ConvIdx - 1].isBad()) { 7447 Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S); 7448 break; 7449 } 7450 } 7451 7452 if (ConvIdx == ConvCount) 7453 return; 7454 7455 assert(!Cand->Conversions[ConvIdx].isInitialized() && 7456 "remaining conversion is initialized?"); 7457 7458 // FIXME: this should probably be preserved from the overload 7459 // operation somehow. 7460 bool SuppressUserConversions = false; 7461 7462 const FunctionProtoType* Proto; 7463 unsigned ArgIdx = ConvIdx; 7464 7465 if (Cand->IsSurrogate) { 7466 QualType ConvType 7467 = Cand->Surrogate->getConversionType().getNonReferenceType(); 7468 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7469 ConvType = ConvPtrType->getPointeeType(); 7470 Proto = ConvType->getAs<FunctionProtoType>(); 7471 ArgIdx--; 7472 } else if (Cand->Function) { 7473 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 7474 if (isa<CXXMethodDecl>(Cand->Function) && 7475 !isa<CXXConstructorDecl>(Cand->Function)) 7476 ArgIdx--; 7477 } else { 7478 // Builtin binary operator with a bad first conversion. 7479 assert(ConvCount <= 3); 7480 for (; ConvIdx != ConvCount; ++ConvIdx) 7481 Cand->Conversions[ConvIdx] 7482 = TryCopyInitialization(S, Args[ConvIdx], 7483 Cand->BuiltinTypes.ParamTypes[ConvIdx], 7484 SuppressUserConversions, 7485 /*InOverloadResolution*/ true, 7486 /*AllowObjCWritebackConversion=*/ 7487 S.getLangOptions().ObjCAutoRefCount); 7488 return; 7489 } 7490 7491 // Fill in the rest of the conversions. 7492 unsigned NumArgsInProto = Proto->getNumArgs(); 7493 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 7494 if (ArgIdx < NumArgsInProto) { 7495 Cand->Conversions[ConvIdx] 7496 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 7497 SuppressUserConversions, 7498 /*InOverloadResolution=*/true, 7499 /*AllowObjCWritebackConversion=*/ 7500 S.getLangOptions().ObjCAutoRefCount); 7501 // Store the FixIt in the candidate if it exists. 7502 if (!Unfixable && Cand->Conversions[ConvIdx].isBad()) 7503 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S); 7504 } 7505 else 7506 Cand->Conversions[ConvIdx].setEllipsis(); 7507 } 7508} 7509 7510} // end anonymous namespace 7511 7512/// PrintOverloadCandidates - When overload resolution fails, prints 7513/// diagnostic messages containing the candidates in the candidate 7514/// set. 7515void OverloadCandidateSet::NoteCandidates(Sema &S, 7516 OverloadCandidateDisplayKind OCD, 7517 Expr **Args, unsigned NumArgs, 7518 const char *Opc, 7519 SourceLocation OpLoc) { 7520 // Sort the candidates by viability and position. Sorting directly would 7521 // be prohibitive, so we make a set of pointers and sort those. 7522 SmallVector<OverloadCandidate*, 32> Cands; 7523 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 7524 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 7525 if (Cand->Viable) 7526 Cands.push_back(Cand); 7527 else if (OCD == OCD_AllCandidates) { 7528 CompleteNonViableCandidate(S, Cand, Args, NumArgs); 7529 if (Cand->Function || Cand->IsSurrogate) 7530 Cands.push_back(Cand); 7531 // Otherwise, this a non-viable builtin candidate. We do not, in general, 7532 // want to list every possible builtin candidate. 7533 } 7534 } 7535 7536 std::sort(Cands.begin(), Cands.end(), 7537 CompareOverloadCandidatesForDisplay(S)); 7538 7539 bool ReportedAmbiguousConversions = false; 7540 7541 SmallVectorImpl<OverloadCandidate*>::iterator I, E; 7542 const Diagnostic::OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 7543 unsigned CandsShown = 0; 7544 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 7545 OverloadCandidate *Cand = *I; 7546 7547 // Set an arbitrary limit on the number of candidate functions we'll spam 7548 // the user with. FIXME: This limit should depend on details of the 7549 // candidate list. 7550 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 7551 break; 7552 } 7553 ++CandsShown; 7554 7555 if (Cand->Function) 7556 NoteFunctionCandidate(S, Cand, Args, NumArgs); 7557 else if (Cand->IsSurrogate) 7558 NoteSurrogateCandidate(S, Cand); 7559 else { 7560 assert(Cand->Viable && 7561 "Non-viable built-in candidates are not added to Cands."); 7562 // Generally we only see ambiguities including viable builtin 7563 // operators if overload resolution got screwed up by an 7564 // ambiguous user-defined conversion. 7565 // 7566 // FIXME: It's quite possible for different conversions to see 7567 // different ambiguities, though. 7568 if (!ReportedAmbiguousConversions) { 7569 NoteAmbiguousUserConversions(S, OpLoc, Cand); 7570 ReportedAmbiguousConversions = true; 7571 } 7572 7573 // If this is a viable builtin, print it. 7574 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 7575 } 7576 } 7577 7578 if (I != E) 7579 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 7580} 7581 7582// [PossiblyAFunctionType] --> [Return] 7583// NonFunctionType --> NonFunctionType 7584// R (A) --> R(A) 7585// R (*)(A) --> R (A) 7586// R (&)(A) --> R (A) 7587// R (S::*)(A) --> R (A) 7588QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { 7589 QualType Ret = PossiblyAFunctionType; 7590 if (const PointerType *ToTypePtr = 7591 PossiblyAFunctionType->getAs<PointerType>()) 7592 Ret = ToTypePtr->getPointeeType(); 7593 else if (const ReferenceType *ToTypeRef = 7594 PossiblyAFunctionType->getAs<ReferenceType>()) 7595 Ret = ToTypeRef->getPointeeType(); 7596 else if (const MemberPointerType *MemTypePtr = 7597 PossiblyAFunctionType->getAs<MemberPointerType>()) 7598 Ret = MemTypePtr->getPointeeType(); 7599 Ret = 7600 Context.getCanonicalType(Ret).getUnqualifiedType(); 7601 return Ret; 7602} 7603 7604// A helper class to help with address of function resolution 7605// - allows us to avoid passing around all those ugly parameters 7606class AddressOfFunctionResolver 7607{ 7608 Sema& S; 7609 Expr* SourceExpr; 7610 const QualType& TargetType; 7611 QualType TargetFunctionType; // Extracted function type from target type 7612 7613 bool Complain; 7614 //DeclAccessPair& ResultFunctionAccessPair; 7615 ASTContext& Context; 7616 7617 bool TargetTypeIsNonStaticMemberFunction; 7618 bool FoundNonTemplateFunction; 7619 7620 OverloadExpr::FindResult OvlExprInfo; 7621 OverloadExpr *OvlExpr; 7622 TemplateArgumentListInfo OvlExplicitTemplateArgs; 7623 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 7624 7625public: 7626 AddressOfFunctionResolver(Sema &S, Expr* SourceExpr, 7627 const QualType& TargetType, bool Complain) 7628 : S(S), SourceExpr(SourceExpr), TargetType(TargetType), 7629 Complain(Complain), Context(S.getASTContext()), 7630 TargetTypeIsNonStaticMemberFunction( 7631 !!TargetType->getAs<MemberPointerType>()), 7632 FoundNonTemplateFunction(false), 7633 OvlExprInfo(OverloadExpr::find(SourceExpr)), 7634 OvlExpr(OvlExprInfo.Expression) 7635 { 7636 ExtractUnqualifiedFunctionTypeFromTargetType(); 7637 7638 if (!TargetFunctionType->isFunctionType()) { 7639 if (OvlExpr->hasExplicitTemplateArgs()) { 7640 DeclAccessPair dap; 7641 if (FunctionDecl* Fn = S.ResolveSingleFunctionTemplateSpecialization( 7642 OvlExpr, false, &dap) ) { 7643 7644 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7645 if (!Method->isStatic()) { 7646 // If the target type is a non-function type and the function 7647 // found is a non-static member function, pretend as if that was 7648 // the target, it's the only possible type to end up with. 7649 TargetTypeIsNonStaticMemberFunction = true; 7650 7651 // And skip adding the function if its not in the proper form. 7652 // We'll diagnose this due to an empty set of functions. 7653 if (!OvlExprInfo.HasFormOfMemberPointer) 7654 return; 7655 } 7656 } 7657 7658 Matches.push_back(std::make_pair(dap,Fn)); 7659 } 7660 } 7661 return; 7662 } 7663 7664 if (OvlExpr->hasExplicitTemplateArgs()) 7665 OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); 7666 7667 if (FindAllFunctionsThatMatchTargetTypeExactly()) { 7668 // C++ [over.over]p4: 7669 // If more than one function is selected, [...] 7670 if (Matches.size() > 1) { 7671 if (FoundNonTemplateFunction) 7672 EliminateAllTemplateMatches(); 7673 else 7674 EliminateAllExceptMostSpecializedTemplate(); 7675 } 7676 } 7677 } 7678 7679private: 7680 bool isTargetTypeAFunction() const { 7681 return TargetFunctionType->isFunctionType(); 7682 } 7683 7684 // [ToType] [Return] 7685 7686 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false 7687 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false 7688 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true 7689 void inline ExtractUnqualifiedFunctionTypeFromTargetType() { 7690 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); 7691 } 7692 7693 // return true if any matching specializations were found 7694 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, 7695 const DeclAccessPair& CurAccessFunPair) { 7696 if (CXXMethodDecl *Method 7697 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 7698 // Skip non-static function templates when converting to pointer, and 7699 // static when converting to member pointer. 7700 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 7701 return false; 7702 } 7703 else if (TargetTypeIsNonStaticMemberFunction) 7704 return false; 7705 7706 // C++ [over.over]p2: 7707 // If the name is a function template, template argument deduction is 7708 // done (14.8.2.2), and if the argument deduction succeeds, the 7709 // resulting template argument list is used to generate a single 7710 // function template specialization, which is added to the set of 7711 // overloaded functions considered. 7712 FunctionDecl *Specialization = 0; 7713 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 7714 if (Sema::TemplateDeductionResult Result 7715 = S.DeduceTemplateArguments(FunctionTemplate, 7716 &OvlExplicitTemplateArgs, 7717 TargetFunctionType, Specialization, 7718 Info)) { 7719 // FIXME: make a note of the failed deduction for diagnostics. 7720 (void)Result; 7721 return false; 7722 } 7723 7724 // Template argument deduction ensures that we have an exact match. 7725 // This function template specicalization works. 7726 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 7727 assert(TargetFunctionType 7728 == Context.getCanonicalType(Specialization->getType())); 7729 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); 7730 return true; 7731 } 7732 7733 bool AddMatchingNonTemplateFunction(NamedDecl* Fn, 7734 const DeclAccessPair& CurAccessFunPair) { 7735 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7736 // Skip non-static functions when converting to pointer, and static 7737 // when converting to member pointer. 7738 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 7739 return false; 7740 } 7741 else if (TargetTypeIsNonStaticMemberFunction) 7742 return false; 7743 7744 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 7745 QualType ResultTy; 7746 if (Context.hasSameUnqualifiedType(TargetFunctionType, 7747 FunDecl->getType()) || 7748 S.IsNoReturnConversion(FunDecl->getType(), TargetFunctionType, 7749 ResultTy)) { 7750 Matches.push_back(std::make_pair(CurAccessFunPair, 7751 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 7752 FoundNonTemplateFunction = true; 7753 return true; 7754 } 7755 } 7756 7757 return false; 7758 } 7759 7760 bool FindAllFunctionsThatMatchTargetTypeExactly() { 7761 bool Ret = false; 7762 7763 // If the overload expression doesn't have the form of a pointer to 7764 // member, don't try to convert it to a pointer-to-member type. 7765 if (IsInvalidFormOfPointerToMemberFunction()) 7766 return false; 7767 7768 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7769 E = OvlExpr->decls_end(); 7770 I != E; ++I) { 7771 // Look through any using declarations to find the underlying function. 7772 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 7773 7774 // C++ [over.over]p3: 7775 // Non-member functions and static member functions match 7776 // targets of type "pointer-to-function" or "reference-to-function." 7777 // Nonstatic member functions match targets of 7778 // type "pointer-to-member-function." 7779 // Note that according to DR 247, the containing class does not matter. 7780 if (FunctionTemplateDecl *FunctionTemplate 7781 = dyn_cast<FunctionTemplateDecl>(Fn)) { 7782 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) 7783 Ret = true; 7784 } 7785 // If we have explicit template arguments supplied, skip non-templates. 7786 else if (!OvlExpr->hasExplicitTemplateArgs() && 7787 AddMatchingNonTemplateFunction(Fn, I.getPair())) 7788 Ret = true; 7789 } 7790 assert(Ret || Matches.empty()); 7791 return Ret; 7792 } 7793 7794 void EliminateAllExceptMostSpecializedTemplate() { 7795 // [...] and any given function template specialization F1 is 7796 // eliminated if the set contains a second function template 7797 // specialization whose function template is more specialized 7798 // than the function template of F1 according to the partial 7799 // ordering rules of 14.5.5.2. 7800 7801 // The algorithm specified above is quadratic. We instead use a 7802 // two-pass algorithm (similar to the one used to identify the 7803 // best viable function in an overload set) that identifies the 7804 // best function template (if it exists). 7805 7806 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 7807 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 7808 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 7809 7810 UnresolvedSetIterator Result = 7811 S.getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 7812 TPOC_Other, 0, SourceExpr->getLocStart(), 7813 S.PDiag(), 7814 S.PDiag(diag::err_addr_ovl_ambiguous) 7815 << Matches[0].second->getDeclName(), 7816 S.PDiag(diag::note_ovl_candidate) 7817 << (unsigned) oc_function_template, 7818 Complain); 7819 7820 if (Result != MatchesCopy.end()) { 7821 // Make it the first and only element 7822 Matches[0].first = Matches[Result - MatchesCopy.begin()].first; 7823 Matches[0].second = cast<FunctionDecl>(*Result); 7824 Matches.resize(1); 7825 } 7826 } 7827 7828 void EliminateAllTemplateMatches() { 7829 // [...] any function template specializations in the set are 7830 // eliminated if the set also contains a non-template function, [...] 7831 for (unsigned I = 0, N = Matches.size(); I != N; ) { 7832 if (Matches[I].second->getPrimaryTemplate() == 0) 7833 ++I; 7834 else { 7835 Matches[I] = Matches[--N]; 7836 Matches.set_size(N); 7837 } 7838 } 7839 } 7840 7841public: 7842 void ComplainNoMatchesFound() const { 7843 assert(Matches.empty()); 7844 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) 7845 << OvlExpr->getName() << TargetFunctionType 7846 << OvlExpr->getSourceRange(); 7847 S.NoteAllOverloadCandidates(OvlExpr); 7848 } 7849 7850 bool IsInvalidFormOfPointerToMemberFunction() const { 7851 return TargetTypeIsNonStaticMemberFunction && 7852 !OvlExprInfo.HasFormOfMemberPointer; 7853 } 7854 7855 void ComplainIsInvalidFormOfPointerToMemberFunction() const { 7856 // TODO: Should we condition this on whether any functions might 7857 // have matched, or is it more appropriate to do that in callers? 7858 // TODO: a fixit wouldn't hurt. 7859 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 7860 << TargetType << OvlExpr->getSourceRange(); 7861 } 7862 7863 void ComplainOfInvalidConversion() const { 7864 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 7865 << OvlExpr->getName() << TargetType; 7866 } 7867 7868 void ComplainMultipleMatchesFound() const { 7869 assert(Matches.size() > 1); 7870 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) 7871 << OvlExpr->getName() 7872 << OvlExpr->getSourceRange(); 7873 S.NoteAllOverloadCandidates(OvlExpr); 7874 } 7875 7876 int getNumMatches() const { return Matches.size(); } 7877 7878 FunctionDecl* getMatchingFunctionDecl() const { 7879 if (Matches.size() != 1) return 0; 7880 return Matches[0].second; 7881 } 7882 7883 const DeclAccessPair* getMatchingFunctionAccessPair() const { 7884 if (Matches.size() != 1) return 0; 7885 return &Matches[0].first; 7886 } 7887}; 7888 7889/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 7890/// an overloaded function (C++ [over.over]), where @p From is an 7891/// expression with overloaded function type and @p ToType is the type 7892/// we're trying to resolve to. For example: 7893/// 7894/// @code 7895/// int f(double); 7896/// int f(int); 7897/// 7898/// int (*pfd)(double) = f; // selects f(double) 7899/// @endcode 7900/// 7901/// This routine returns the resulting FunctionDecl if it could be 7902/// resolved, and NULL otherwise. When @p Complain is true, this 7903/// routine will emit diagnostics if there is an error. 7904FunctionDecl * 7905Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, QualType TargetType, 7906 bool Complain, 7907 DeclAccessPair &FoundResult) { 7908 7909 assert(AddressOfExpr->getType() == Context.OverloadTy); 7910 7911 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, Complain); 7912 int NumMatches = Resolver.getNumMatches(); 7913 FunctionDecl* Fn = 0; 7914 if ( NumMatches == 0 && Complain) { 7915 if (Resolver.IsInvalidFormOfPointerToMemberFunction()) 7916 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); 7917 else 7918 Resolver.ComplainNoMatchesFound(); 7919 } 7920 else if (NumMatches > 1 && Complain) 7921 Resolver.ComplainMultipleMatchesFound(); 7922 else if (NumMatches == 1) { 7923 Fn = Resolver.getMatchingFunctionDecl(); 7924 assert(Fn); 7925 FoundResult = *Resolver.getMatchingFunctionAccessPair(); 7926 MarkDeclarationReferenced(AddressOfExpr->getLocStart(), Fn); 7927 if (Complain) 7928 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); 7929 } 7930 7931 return Fn; 7932} 7933 7934/// \brief Given an expression that refers to an overloaded function, try to 7935/// resolve that overloaded function expression down to a single function. 7936/// 7937/// This routine can only resolve template-ids that refer to a single function 7938/// template, where that template-id refers to a single template whose template 7939/// arguments are either provided by the template-id or have defaults, 7940/// as described in C++0x [temp.arg.explicit]p3. 7941FunctionDecl * 7942Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl, 7943 bool Complain, 7944 DeclAccessPair *FoundResult) { 7945 // C++ [over.over]p1: 7946 // [...] [Note: any redundant set of parentheses surrounding the 7947 // overloaded function name is ignored (5.1). ] 7948 // C++ [over.over]p1: 7949 // [...] The overloaded function name can be preceded by the & 7950 // operator. 7951 7952 // If we didn't actually find any template-ids, we're done. 7953 if (!ovl->hasExplicitTemplateArgs()) 7954 return 0; 7955 7956 TemplateArgumentListInfo ExplicitTemplateArgs; 7957 ovl->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 7958 7959 // Look through all of the overloaded functions, searching for one 7960 // whose type matches exactly. 7961 FunctionDecl *Matched = 0; 7962 for (UnresolvedSetIterator I = ovl->decls_begin(), 7963 E = ovl->decls_end(); I != E; ++I) { 7964 // C++0x [temp.arg.explicit]p3: 7965 // [...] In contexts where deduction is done and fails, or in contexts 7966 // where deduction is not done, if a template argument list is 7967 // specified and it, along with any default template arguments, 7968 // identifies a single function template specialization, then the 7969 // template-id is an lvalue for the function template specialization. 7970 FunctionTemplateDecl *FunctionTemplate 7971 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 7972 7973 // C++ [over.over]p2: 7974 // If the name is a function template, template argument deduction is 7975 // done (14.8.2.2), and if the argument deduction succeeds, the 7976 // resulting template argument list is used to generate a single 7977 // function template specialization, which is added to the set of 7978 // overloaded functions considered. 7979 FunctionDecl *Specialization = 0; 7980 TemplateDeductionInfo Info(Context, ovl->getNameLoc()); 7981 if (TemplateDeductionResult Result 7982 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 7983 Specialization, Info)) { 7984 // FIXME: make a note of the failed deduction for diagnostics. 7985 (void)Result; 7986 continue; 7987 } 7988 7989 assert(Specialization && "no specialization and no error?"); 7990 7991 // Multiple matches; we can't resolve to a single declaration. 7992 if (Matched) { 7993 if (Complain) { 7994 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous) 7995 << ovl->getName(); 7996 NoteAllOverloadCandidates(ovl); 7997 } 7998 return 0; 7999 } 8000 8001 Matched = Specialization; 8002 if (FoundResult) *FoundResult = I.getPair(); 8003 } 8004 8005 return Matched; 8006} 8007 8008 8009 8010 8011// Resolve and fix an overloaded expression that 8012// can be resolved because it identifies a single function 8013// template specialization 8014// Last three arguments should only be supplied if Complain = true 8015ExprResult Sema::ResolveAndFixSingleFunctionTemplateSpecialization( 8016 Expr *SrcExpr, bool doFunctionPointerConverion, bool complain, 8017 const SourceRange& OpRangeForComplaining, 8018 QualType DestTypeForComplaining, 8019 unsigned DiagIDForComplaining) { 8020 assert(SrcExpr->getType() == Context.OverloadTy); 8021 8022 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr); 8023 8024 DeclAccessPair found; 8025 ExprResult SingleFunctionExpression; 8026 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization( 8027 ovl.Expression, /*complain*/ false, &found)) { 8028 if (DiagnoseUseOfDecl(fn, SrcExpr->getSourceRange().getBegin())) 8029 return ExprError(); 8030 8031 // It is only correct to resolve to an instance method if we're 8032 // resolving a form that's permitted to be a pointer to member. 8033 // Otherwise we'll end up making a bound member expression, which 8034 // is illegal in all the contexts we resolve like this. 8035 if (!ovl.HasFormOfMemberPointer && 8036 isa<CXXMethodDecl>(fn) && 8037 cast<CXXMethodDecl>(fn)->isInstance()) { 8038 if (complain) { 8039 Diag(ovl.Expression->getExprLoc(), 8040 diag::err_invalid_use_of_bound_member_func) 8041 << ovl.Expression->getSourceRange(); 8042 // TODO: I believe we only end up here if there's a mix of 8043 // static and non-static candidates (otherwise the expression 8044 // would have 'bound member' type, not 'overload' type). 8045 // Ideally we would note which candidate was chosen and why 8046 // the static candidates were rejected. 8047 } 8048 8049 return ExprError(); 8050 } 8051 8052 // Fix the expresion to refer to 'fn'. 8053 SingleFunctionExpression = 8054 Owned(FixOverloadedFunctionReference(SrcExpr, found, fn)); 8055 8056 // If desired, do function-to-pointer decay. 8057 if (doFunctionPointerConverion) 8058 SingleFunctionExpression = 8059 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.take()); 8060 } 8061 8062 if (!SingleFunctionExpression.isUsable()) { 8063 if (complain) { 8064 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) 8065 << ovl.Expression->getName() 8066 << DestTypeForComplaining 8067 << OpRangeForComplaining 8068 << ovl.Expression->getQualifierLoc().getSourceRange(); 8069 NoteAllOverloadCandidates(SrcExpr); 8070 } 8071 return ExprError(); 8072 } 8073 8074 return SingleFunctionExpression; 8075} 8076 8077/// \brief Add a single candidate to the overload set. 8078static void AddOverloadedCallCandidate(Sema &S, 8079 DeclAccessPair FoundDecl, 8080 TemplateArgumentListInfo *ExplicitTemplateArgs, 8081 Expr **Args, unsigned NumArgs, 8082 OverloadCandidateSet &CandidateSet, 8083 bool PartialOverloading, 8084 bool KnownValid) { 8085 NamedDecl *Callee = FoundDecl.getDecl(); 8086 if (isa<UsingShadowDecl>(Callee)) 8087 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 8088 8089 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 8090 if (ExplicitTemplateArgs) { 8091 assert(!KnownValid && "Explicit template arguments?"); 8092 return; 8093 } 8094 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 8095 false, PartialOverloading); 8096 return; 8097 } 8098 8099 if (FunctionTemplateDecl *FuncTemplate 8100 = dyn_cast<FunctionTemplateDecl>(Callee)) { 8101 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 8102 ExplicitTemplateArgs, 8103 Args, NumArgs, CandidateSet); 8104 return; 8105 } 8106 8107 assert(!KnownValid && "unhandled case in overloaded call candidate"); 8108} 8109 8110/// \brief Add the overload candidates named by callee and/or found by argument 8111/// dependent lookup to the given overload set. 8112void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 8113 Expr **Args, unsigned NumArgs, 8114 OverloadCandidateSet &CandidateSet, 8115 bool PartialOverloading) { 8116 8117#ifndef NDEBUG 8118 // Verify that ArgumentDependentLookup is consistent with the rules 8119 // in C++0x [basic.lookup.argdep]p3: 8120 // 8121 // Let X be the lookup set produced by unqualified lookup (3.4.1) 8122 // and let Y be the lookup set produced by argument dependent 8123 // lookup (defined as follows). If X contains 8124 // 8125 // -- a declaration of a class member, or 8126 // 8127 // -- a block-scope function declaration that is not a 8128 // using-declaration, or 8129 // 8130 // -- a declaration that is neither a function or a function 8131 // template 8132 // 8133 // then Y is empty. 8134 8135 if (ULE->requiresADL()) { 8136 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 8137 E = ULE->decls_end(); I != E; ++I) { 8138 assert(!(*I)->getDeclContext()->isRecord()); 8139 assert(isa<UsingShadowDecl>(*I) || 8140 !(*I)->getDeclContext()->isFunctionOrMethod()); 8141 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 8142 } 8143 } 8144#endif 8145 8146 // It would be nice to avoid this copy. 8147 TemplateArgumentListInfo TABuffer; 8148 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 8149 if (ULE->hasExplicitTemplateArgs()) { 8150 ULE->copyTemplateArgumentsInto(TABuffer); 8151 ExplicitTemplateArgs = &TABuffer; 8152 } 8153 8154 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 8155 E = ULE->decls_end(); I != E; ++I) 8156 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 8157 Args, NumArgs, CandidateSet, 8158 PartialOverloading, /*KnownValid*/ true); 8159 8160 if (ULE->requiresADL()) 8161 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 8162 Args, NumArgs, 8163 ExplicitTemplateArgs, 8164 CandidateSet, 8165 PartialOverloading, 8166 ULE->isStdAssociatedNamespace()); 8167} 8168 8169/// Attempt to recover from an ill-formed use of a non-dependent name in a 8170/// template, where the non-dependent name was declared after the template 8171/// was defined. This is common in code written for a compilers which do not 8172/// correctly implement two-stage name lookup. 8173/// 8174/// Returns true if a viable candidate was found and a diagnostic was issued. 8175static bool 8176DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc, 8177 const CXXScopeSpec &SS, LookupResult &R, 8178 TemplateArgumentListInfo *ExplicitTemplateArgs, 8179 Expr **Args, unsigned NumArgs) { 8180 if (SemaRef.ActiveTemplateInstantiations.empty() || !SS.isEmpty()) 8181 return false; 8182 8183 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) { 8184 SemaRef.LookupQualifiedName(R, DC); 8185 8186 if (!R.empty()) { 8187 R.suppressDiagnostics(); 8188 8189 if (isa<CXXRecordDecl>(DC)) { 8190 // Don't diagnose names we find in classes; we get much better 8191 // diagnostics for these from DiagnoseEmptyLookup. 8192 R.clear(); 8193 return false; 8194 } 8195 8196 OverloadCandidateSet Candidates(FnLoc); 8197 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 8198 AddOverloadedCallCandidate(SemaRef, I.getPair(), 8199 ExplicitTemplateArgs, Args, NumArgs, 8200 Candidates, false, /*KnownValid*/ false); 8201 8202 OverloadCandidateSet::iterator Best; 8203 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) { 8204 // No viable functions. Don't bother the user with notes for functions 8205 // which don't work and shouldn't be found anyway. 8206 R.clear(); 8207 return false; 8208 } 8209 8210 // Find the namespaces where ADL would have looked, and suggest 8211 // declaring the function there instead. 8212 Sema::AssociatedNamespaceSet AssociatedNamespaces; 8213 Sema::AssociatedClassSet AssociatedClasses; 8214 SemaRef.FindAssociatedClassesAndNamespaces(Args, NumArgs, 8215 AssociatedNamespaces, 8216 AssociatedClasses); 8217 // Never suggest declaring a function within namespace 'std'. 8218 Sema::AssociatedNamespaceSet SuggestedNamespaces; 8219 if (DeclContext *Std = SemaRef.getStdNamespace()) { 8220 for (Sema::AssociatedNamespaceSet::iterator 8221 it = AssociatedNamespaces.begin(), 8222 end = AssociatedNamespaces.end(); it != end; ++it) { 8223 if (!Std->Encloses(*it)) 8224 SuggestedNamespaces.insert(*it); 8225 } 8226 } else { 8227 // Lacking the 'std::' namespace, use all of the associated namespaces. 8228 SuggestedNamespaces = AssociatedNamespaces; 8229 } 8230 8231 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup) 8232 << R.getLookupName(); 8233 if (SuggestedNamespaces.empty()) { 8234 SemaRef.Diag(Best->Function->getLocation(), 8235 diag::note_not_found_by_two_phase_lookup) 8236 << R.getLookupName() << 0; 8237 } else if (SuggestedNamespaces.size() == 1) { 8238 SemaRef.Diag(Best->Function->getLocation(), 8239 diag::note_not_found_by_two_phase_lookup) 8240 << R.getLookupName() << 1 << *SuggestedNamespaces.begin(); 8241 } else { 8242 // FIXME: It would be useful to list the associated namespaces here, 8243 // but the diagnostics infrastructure doesn't provide a way to produce 8244 // a localized representation of a list of items. 8245 SemaRef.Diag(Best->Function->getLocation(), 8246 diag::note_not_found_by_two_phase_lookup) 8247 << R.getLookupName() << 2; 8248 } 8249 8250 // Try to recover by calling this function. 8251 return true; 8252 } 8253 8254 R.clear(); 8255 } 8256 8257 return false; 8258} 8259 8260/// Attempt to recover from ill-formed use of a non-dependent operator in a 8261/// template, where the non-dependent operator was declared after the template 8262/// was defined. 8263/// 8264/// Returns true if a viable candidate was found and a diagnostic was issued. 8265static bool 8266DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op, 8267 SourceLocation OpLoc, 8268 Expr **Args, unsigned NumArgs) { 8269 DeclarationName OpName = 8270 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op); 8271 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName); 8272 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R, 8273 /*ExplicitTemplateArgs=*/0, Args, NumArgs); 8274} 8275 8276/// Attempts to recover from a call where no functions were found. 8277/// 8278/// Returns true if new candidates were found. 8279static ExprResult 8280BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 8281 UnresolvedLookupExpr *ULE, 8282 SourceLocation LParenLoc, 8283 Expr **Args, unsigned NumArgs, 8284 SourceLocation RParenLoc, 8285 bool EmptyLookup) { 8286 8287 CXXScopeSpec SS; 8288 SS.Adopt(ULE->getQualifierLoc()); 8289 8290 TemplateArgumentListInfo TABuffer; 8291 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 8292 if (ULE->hasExplicitTemplateArgs()) { 8293 ULE->copyTemplateArgumentsInto(TABuffer); 8294 ExplicitTemplateArgs = &TABuffer; 8295 } 8296 8297 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 8298 Sema::LookupOrdinaryName); 8299 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R, 8300 ExplicitTemplateArgs, Args, NumArgs) && 8301 (!EmptyLookup || 8302 SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression, 8303 ExplicitTemplateArgs, Args, NumArgs))) 8304 return ExprError(); 8305 8306 assert(!R.empty() && "lookup results empty despite recovery"); 8307 8308 // Build an implicit member call if appropriate. Just drop the 8309 // casts and such from the call, we don't really care. 8310 ExprResult NewFn = ExprError(); 8311 if ((*R.begin())->isCXXClassMember()) 8312 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, 8313 ExplicitTemplateArgs); 8314 else if (ExplicitTemplateArgs) 8315 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 8316 else 8317 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 8318 8319 if (NewFn.isInvalid()) 8320 return ExprError(); 8321 8322 // This shouldn't cause an infinite loop because we're giving it 8323 // an expression with viable lookup results, which should never 8324 // end up here. 8325 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 8326 MultiExprArg(Args, NumArgs), RParenLoc); 8327} 8328 8329/// ResolveOverloadedCallFn - Given the call expression that calls Fn 8330/// (which eventually refers to the declaration Func) and the call 8331/// arguments Args/NumArgs, attempt to resolve the function call down 8332/// to a specific function. If overload resolution succeeds, returns 8333/// the function declaration produced by overload 8334/// resolution. Otherwise, emits diagnostics, deletes all of the 8335/// arguments and Fn, and returns NULL. 8336ExprResult 8337Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 8338 SourceLocation LParenLoc, 8339 Expr **Args, unsigned NumArgs, 8340 SourceLocation RParenLoc, 8341 Expr *ExecConfig) { 8342#ifndef NDEBUG 8343 if (ULE->requiresADL()) { 8344 // To do ADL, we must have found an unqualified name. 8345 assert(!ULE->getQualifier() && "qualified name with ADL"); 8346 8347 // We don't perform ADL for implicit declarations of builtins. 8348 // Verify that this was correctly set up. 8349 FunctionDecl *F; 8350 if (ULE->decls_begin() + 1 == ULE->decls_end() && 8351 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 8352 F->getBuiltinID() && F->isImplicit()) 8353 assert(0 && "performing ADL for builtin"); 8354 8355 // We don't perform ADL in C. 8356 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 8357 } else 8358 assert(!ULE->isStdAssociatedNamespace() && 8359 "std is associated namespace but not doing ADL"); 8360#endif 8361 8362 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 8363 8364 // Add the functions denoted by the callee to the set of candidate 8365 // functions, including those from argument-dependent lookup. 8366 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 8367 8368 // If we found nothing, try to recover. 8369 // BuildRecoveryCallExpr diagnoses the error itself, so we just bail 8370 // out if it fails. 8371 if (CandidateSet.empty()) { 8372 // In Microsoft mode, if we are inside a template class member function then 8373 // create a type dependent CallExpr. The goal is to postpone name lookup 8374 // to instantiation time to be able to search into type dependent base 8375 // classes. 8376 if (getLangOptions().Microsoft && CurContext->isDependentContext() && 8377 isa<CXXMethodDecl>(CurContext)) { 8378 CallExpr *CE = new (Context) CallExpr(Context, Fn, Args, NumArgs, 8379 Context.DependentTy, VK_RValue, 8380 RParenLoc); 8381 CE->setTypeDependent(true); 8382 return Owned(CE); 8383 } 8384 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 8385 RParenLoc, /*EmptyLookup=*/true); 8386 } 8387 8388 OverloadCandidateSet::iterator Best; 8389 switch (CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best)) { 8390 case OR_Success: { 8391 FunctionDecl *FDecl = Best->Function; 8392 MarkDeclarationReferenced(Fn->getExprLoc(), FDecl); 8393 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 8394 DiagnoseUseOfDecl(FDecl? FDecl : Best->FoundDecl.getDecl(), 8395 ULE->getNameLoc()); 8396 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 8397 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc, 8398 ExecConfig); 8399 } 8400 8401 case OR_No_Viable_Function: { 8402 // Try to recover by looking for viable functions which the user might 8403 // have meant to call. 8404 ExprResult Recovery = BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, 8405 Args, NumArgs, RParenLoc, 8406 /*EmptyLookup=*/false); 8407 if (!Recovery.isInvalid()) 8408 return Recovery; 8409 8410 Diag(Fn->getSourceRange().getBegin(), 8411 diag::err_ovl_no_viable_function_in_call) 8412 << ULE->getName() << Fn->getSourceRange(); 8413 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8414 break; 8415 } 8416 8417 case OR_Ambiguous: 8418 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 8419 << ULE->getName() << Fn->getSourceRange(); 8420 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 8421 break; 8422 8423 case OR_Deleted: 8424 { 8425 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 8426 << Best->Function->isDeleted() 8427 << ULE->getName() 8428 << getDeletedOrUnavailableSuffix(Best->Function) 8429 << Fn->getSourceRange(); 8430 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8431 } 8432 break; 8433 } 8434 8435 // Overload resolution failed. 8436 return ExprError(); 8437} 8438 8439static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 8440 return Functions.size() > 1 || 8441 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 8442} 8443 8444/// \brief Create a unary operation that may resolve to an overloaded 8445/// operator. 8446/// 8447/// \param OpLoc The location of the operator itself (e.g., '*'). 8448/// 8449/// \param OpcIn The UnaryOperator::Opcode that describes this 8450/// operator. 8451/// 8452/// \param Functions The set of non-member functions that will be 8453/// considered by overload resolution. The caller needs to build this 8454/// set based on the context using, e.g., 8455/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 8456/// set should not contain any member functions; those will be added 8457/// by CreateOverloadedUnaryOp(). 8458/// 8459/// \param input The input argument. 8460ExprResult 8461Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 8462 const UnresolvedSetImpl &Fns, 8463 Expr *Input) { 8464 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 8465 8466 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 8467 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 8468 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 8469 // TODO: provide better source location info. 8470 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 8471 8472 if (Input->getObjectKind() == OK_ObjCProperty) { 8473 ExprResult Result = ConvertPropertyForRValue(Input); 8474 if (Result.isInvalid()) 8475 return ExprError(); 8476 Input = Result.take(); 8477 } 8478 8479 Expr *Args[2] = { Input, 0 }; 8480 unsigned NumArgs = 1; 8481 8482 // For post-increment and post-decrement, add the implicit '0' as 8483 // the second argument, so that we know this is a post-increment or 8484 // post-decrement. 8485 if (Opc == UO_PostInc || Opc == UO_PostDec) { 8486 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 8487 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 8488 SourceLocation()); 8489 NumArgs = 2; 8490 } 8491 8492 if (Input->isTypeDependent()) { 8493 if (Fns.empty()) 8494 return Owned(new (Context) UnaryOperator(Input, 8495 Opc, 8496 Context.DependentTy, 8497 VK_RValue, OK_Ordinary, 8498 OpLoc)); 8499 8500 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8501 UnresolvedLookupExpr *Fn 8502 = UnresolvedLookupExpr::Create(Context, NamingClass, 8503 NestedNameSpecifierLoc(), OpNameInfo, 8504 /*ADL*/ true, IsOverloaded(Fns), 8505 Fns.begin(), Fns.end()); 8506 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 8507 &Args[0], NumArgs, 8508 Context.DependentTy, 8509 VK_RValue, 8510 OpLoc)); 8511 } 8512 8513 // Build an empty overload set. 8514 OverloadCandidateSet CandidateSet(OpLoc); 8515 8516 // Add the candidates from the given function set. 8517 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 8518 8519 // Add operator candidates that are member functions. 8520 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 8521 8522 // Add candidates from ADL. 8523 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 8524 Args, NumArgs, 8525 /*ExplicitTemplateArgs*/ 0, 8526 CandidateSet); 8527 8528 // Add builtin operator candidates. 8529 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 8530 8531 // Perform overload resolution. 8532 OverloadCandidateSet::iterator Best; 8533 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8534 case OR_Success: { 8535 // We found a built-in operator or an overloaded operator. 8536 FunctionDecl *FnDecl = Best->Function; 8537 8538 if (FnDecl) { 8539 // We matched an overloaded operator. Build a call to that 8540 // operator. 8541 8542 MarkDeclarationReferenced(OpLoc, FnDecl); 8543 8544 // Convert the arguments. 8545 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 8546 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 8547 8548 ExprResult InputRes = 8549 PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 8550 Best->FoundDecl, Method); 8551 if (InputRes.isInvalid()) 8552 return ExprError(); 8553 Input = InputRes.take(); 8554 } else { 8555 // Convert the arguments. 8556 ExprResult InputInit 8557 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8558 Context, 8559 FnDecl->getParamDecl(0)), 8560 SourceLocation(), 8561 Input); 8562 if (InputInit.isInvalid()) 8563 return ExprError(); 8564 Input = InputInit.take(); 8565 } 8566 8567 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 8568 8569 // Determine the result type. 8570 QualType ResultTy = FnDecl->getResultType(); 8571 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8572 ResultTy = ResultTy.getNonLValueExprType(Context); 8573 8574 // Build the actual expression node. 8575 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl); 8576 if (FnExpr.isInvalid()) 8577 return ExprError(); 8578 8579 Args[0] = Input; 8580 CallExpr *TheCall = 8581 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 8582 Args, NumArgs, ResultTy, VK, OpLoc); 8583 8584 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 8585 FnDecl)) 8586 return ExprError(); 8587 8588 return MaybeBindToTemporary(TheCall); 8589 } else { 8590 // We matched a built-in operator. Convert the arguments, then 8591 // break out so that we will build the appropriate built-in 8592 // operator node. 8593 ExprResult InputRes = 8594 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 8595 Best->Conversions[0], AA_Passing); 8596 if (InputRes.isInvalid()) 8597 return ExprError(); 8598 Input = InputRes.take(); 8599 break; 8600 } 8601 } 8602 8603 case OR_No_Viable_Function: 8604 // This is an erroneous use of an operator which can be overloaded by 8605 // a non-member function. Check for non-member operators which were 8606 // defined too late to be candidates. 8607 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args, NumArgs)) 8608 // FIXME: Recover by calling the found function. 8609 return ExprError(); 8610 8611 // No viable function; fall through to handling this as a 8612 // built-in operator, which will produce an error message for us. 8613 break; 8614 8615 case OR_Ambiguous: 8616 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 8617 << UnaryOperator::getOpcodeStr(Opc) 8618 << Input->getType() 8619 << Input->getSourceRange(); 8620 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs, 8621 UnaryOperator::getOpcodeStr(Opc), OpLoc); 8622 return ExprError(); 8623 8624 case OR_Deleted: 8625 Diag(OpLoc, diag::err_ovl_deleted_oper) 8626 << Best->Function->isDeleted() 8627 << UnaryOperator::getOpcodeStr(Opc) 8628 << getDeletedOrUnavailableSuffix(Best->Function) 8629 << Input->getSourceRange(); 8630 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs, 8631 UnaryOperator::getOpcodeStr(Opc), OpLoc); 8632 return ExprError(); 8633 } 8634 8635 // Either we found no viable overloaded operator or we matched a 8636 // built-in operator. In either case, fall through to trying to 8637 // build a built-in operation. 8638 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 8639} 8640 8641/// \brief Create a binary operation that may resolve to an overloaded 8642/// operator. 8643/// 8644/// \param OpLoc The location of the operator itself (e.g., '+'). 8645/// 8646/// \param OpcIn The BinaryOperator::Opcode that describes this 8647/// operator. 8648/// 8649/// \param Functions The set of non-member functions that will be 8650/// considered by overload resolution. The caller needs to build this 8651/// set based on the context using, e.g., 8652/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 8653/// set should not contain any member functions; those will be added 8654/// by CreateOverloadedBinOp(). 8655/// 8656/// \param LHS Left-hand argument. 8657/// \param RHS Right-hand argument. 8658ExprResult 8659Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 8660 unsigned OpcIn, 8661 const UnresolvedSetImpl &Fns, 8662 Expr *LHS, Expr *RHS) { 8663 Expr *Args[2] = { LHS, RHS }; 8664 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 8665 8666 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 8667 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 8668 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 8669 8670 // If either side is type-dependent, create an appropriate dependent 8671 // expression. 8672 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 8673 if (Fns.empty()) { 8674 // If there are no functions to store, just build a dependent 8675 // BinaryOperator or CompoundAssignment. 8676 if (Opc <= BO_Assign || Opc > BO_OrAssign) 8677 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 8678 Context.DependentTy, 8679 VK_RValue, OK_Ordinary, 8680 OpLoc)); 8681 8682 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 8683 Context.DependentTy, 8684 VK_LValue, 8685 OK_Ordinary, 8686 Context.DependentTy, 8687 Context.DependentTy, 8688 OpLoc)); 8689 } 8690 8691 // FIXME: save results of ADL from here? 8692 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8693 // TODO: provide better source location info in DNLoc component. 8694 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 8695 UnresolvedLookupExpr *Fn 8696 = UnresolvedLookupExpr::Create(Context, NamingClass, 8697 NestedNameSpecifierLoc(), OpNameInfo, 8698 /*ADL*/ true, IsOverloaded(Fns), 8699 Fns.begin(), Fns.end()); 8700 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 8701 Args, 2, 8702 Context.DependentTy, 8703 VK_RValue, 8704 OpLoc)); 8705 } 8706 8707 // Always do property rvalue conversions on the RHS. 8708 if (Args[1]->getObjectKind() == OK_ObjCProperty) { 8709 ExprResult Result = ConvertPropertyForRValue(Args[1]); 8710 if (Result.isInvalid()) 8711 return ExprError(); 8712 Args[1] = Result.take(); 8713 } 8714 8715 // The LHS is more complicated. 8716 if (Args[0]->getObjectKind() == OK_ObjCProperty) { 8717 8718 // There's a tension for assignment operators between primitive 8719 // property assignment and the overloaded operators. 8720 if (BinaryOperator::isAssignmentOp(Opc)) { 8721 const ObjCPropertyRefExpr *PRE = LHS->getObjCProperty(); 8722 8723 // Is the property "logically" settable? 8724 bool Settable = (PRE->isExplicitProperty() || 8725 PRE->getImplicitPropertySetter()); 8726 8727 // To avoid gratuitously inventing semantics, use the primitive 8728 // unless it isn't. Thoughts in case we ever really care: 8729 // - If the property isn't logically settable, we have to 8730 // load and hope. 8731 // - If the property is settable and this is simple assignment, 8732 // we really should use the primitive. 8733 // - If the property is settable, then we could try overloading 8734 // on a generic lvalue of the appropriate type; if it works 8735 // out to a builtin candidate, we would do that same operation 8736 // on the property, and otherwise just error. 8737 if (Settable) 8738 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8739 } 8740 8741 ExprResult Result = ConvertPropertyForRValue(Args[0]); 8742 if (Result.isInvalid()) 8743 return ExprError(); 8744 Args[0] = Result.take(); 8745 } 8746 8747 // If this is the assignment operator, we only perform overload resolution 8748 // if the left-hand side is a class or enumeration type. This is actually 8749 // a hack. The standard requires that we do overload resolution between the 8750 // various built-in candidates, but as DR507 points out, this can lead to 8751 // problems. So we do it this way, which pretty much follows what GCC does. 8752 // Note that we go the traditional code path for compound assignment forms. 8753 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 8754 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8755 8756 // If this is the .* operator, which is not overloadable, just 8757 // create a built-in binary operator. 8758 if (Opc == BO_PtrMemD) 8759 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8760 8761 // Build an empty overload set. 8762 OverloadCandidateSet CandidateSet(OpLoc); 8763 8764 // Add the candidates from the given function set. 8765 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 8766 8767 // Add operator candidates that are member functions. 8768 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 8769 8770 // Add candidates from ADL. 8771 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 8772 Args, 2, 8773 /*ExplicitTemplateArgs*/ 0, 8774 CandidateSet); 8775 8776 // Add builtin operator candidates. 8777 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 8778 8779 // Perform overload resolution. 8780 OverloadCandidateSet::iterator Best; 8781 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8782 case OR_Success: { 8783 // We found a built-in operator or an overloaded operator. 8784 FunctionDecl *FnDecl = Best->Function; 8785 8786 if (FnDecl) { 8787 // We matched an overloaded operator. Build a call to that 8788 // operator. 8789 8790 MarkDeclarationReferenced(OpLoc, FnDecl); 8791 8792 // Convert the arguments. 8793 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 8794 // Best->Access is only meaningful for class members. 8795 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 8796 8797 ExprResult Arg1 = 8798 PerformCopyInitialization( 8799 InitializedEntity::InitializeParameter(Context, 8800 FnDecl->getParamDecl(0)), 8801 SourceLocation(), Owned(Args[1])); 8802 if (Arg1.isInvalid()) 8803 return ExprError(); 8804 8805 ExprResult Arg0 = 8806 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 8807 Best->FoundDecl, Method); 8808 if (Arg0.isInvalid()) 8809 return ExprError(); 8810 Args[0] = Arg0.takeAs<Expr>(); 8811 Args[1] = RHS = Arg1.takeAs<Expr>(); 8812 } else { 8813 // Convert the arguments. 8814 ExprResult Arg0 = PerformCopyInitialization( 8815 InitializedEntity::InitializeParameter(Context, 8816 FnDecl->getParamDecl(0)), 8817 SourceLocation(), Owned(Args[0])); 8818 if (Arg0.isInvalid()) 8819 return ExprError(); 8820 8821 ExprResult Arg1 = 8822 PerformCopyInitialization( 8823 InitializedEntity::InitializeParameter(Context, 8824 FnDecl->getParamDecl(1)), 8825 SourceLocation(), Owned(Args[1])); 8826 if (Arg1.isInvalid()) 8827 return ExprError(); 8828 Args[0] = LHS = Arg0.takeAs<Expr>(); 8829 Args[1] = RHS = Arg1.takeAs<Expr>(); 8830 } 8831 8832 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 8833 8834 // Determine the result type. 8835 QualType ResultTy = FnDecl->getResultType(); 8836 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8837 ResultTy = ResultTy.getNonLValueExprType(Context); 8838 8839 // Build the actual expression node. 8840 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, OpLoc); 8841 if (FnExpr.isInvalid()) 8842 return ExprError(); 8843 8844 CXXOperatorCallExpr *TheCall = 8845 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 8846 Args, 2, ResultTy, VK, OpLoc); 8847 8848 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 8849 FnDecl)) 8850 return ExprError(); 8851 8852 return MaybeBindToTemporary(TheCall); 8853 } else { 8854 // We matched a built-in operator. Convert the arguments, then 8855 // break out so that we will build the appropriate built-in 8856 // operator node. 8857 ExprResult ArgsRes0 = 8858 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 8859 Best->Conversions[0], AA_Passing); 8860 if (ArgsRes0.isInvalid()) 8861 return ExprError(); 8862 Args[0] = ArgsRes0.take(); 8863 8864 ExprResult ArgsRes1 = 8865 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 8866 Best->Conversions[1], AA_Passing); 8867 if (ArgsRes1.isInvalid()) 8868 return ExprError(); 8869 Args[1] = ArgsRes1.take(); 8870 break; 8871 } 8872 } 8873 8874 case OR_No_Viable_Function: { 8875 // C++ [over.match.oper]p9: 8876 // If the operator is the operator , [...] and there are no 8877 // viable functions, then the operator is assumed to be the 8878 // built-in operator and interpreted according to clause 5. 8879 if (Opc == BO_Comma) 8880 break; 8881 8882 // For class as left operand for assignment or compound assigment 8883 // operator do not fall through to handling in built-in, but report that 8884 // no overloaded assignment operator found 8885 ExprResult Result = ExprError(); 8886 if (Args[0]->getType()->isRecordType() && 8887 Opc >= BO_Assign && Opc <= BO_OrAssign) { 8888 Diag(OpLoc, diag::err_ovl_no_viable_oper) 8889 << BinaryOperator::getOpcodeStr(Opc) 8890 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8891 } else { 8892 // This is an erroneous use of an operator which can be overloaded by 8893 // a non-member function. Check for non-member operators which were 8894 // defined too late to be candidates. 8895 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args, 2)) 8896 // FIXME: Recover by calling the found function. 8897 return ExprError(); 8898 8899 // No viable function; try to create a built-in operation, which will 8900 // produce an error. Then, show the non-viable candidates. 8901 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8902 } 8903 assert(Result.isInvalid() && 8904 "C++ binary operator overloading is missing candidates!"); 8905 if (Result.isInvalid()) 8906 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8907 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8908 return move(Result); 8909 } 8910 8911 case OR_Ambiguous: 8912 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 8913 << BinaryOperator::getOpcodeStr(Opc) 8914 << Args[0]->getType() << Args[1]->getType() 8915 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8916 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 8917 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8918 return ExprError(); 8919 8920 case OR_Deleted: 8921 Diag(OpLoc, diag::err_ovl_deleted_oper) 8922 << Best->Function->isDeleted() 8923 << BinaryOperator::getOpcodeStr(Opc) 8924 << getDeletedOrUnavailableSuffix(Best->Function) 8925 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8926 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8927 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8928 return ExprError(); 8929 } 8930 8931 // We matched a built-in operator; build it. 8932 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8933} 8934 8935ExprResult 8936Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 8937 SourceLocation RLoc, 8938 Expr *Base, Expr *Idx) { 8939 Expr *Args[2] = { Base, Idx }; 8940 DeclarationName OpName = 8941 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 8942 8943 // If either side is type-dependent, create an appropriate dependent 8944 // expression. 8945 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 8946 8947 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8948 // CHECKME: no 'operator' keyword? 8949 DeclarationNameInfo OpNameInfo(OpName, LLoc); 8950 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 8951 UnresolvedLookupExpr *Fn 8952 = UnresolvedLookupExpr::Create(Context, NamingClass, 8953 NestedNameSpecifierLoc(), OpNameInfo, 8954 /*ADL*/ true, /*Overloaded*/ false, 8955 UnresolvedSetIterator(), 8956 UnresolvedSetIterator()); 8957 // Can't add any actual overloads yet 8958 8959 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 8960 Args, 2, 8961 Context.DependentTy, 8962 VK_RValue, 8963 RLoc)); 8964 } 8965 8966 if (Args[0]->getObjectKind() == OK_ObjCProperty) { 8967 ExprResult Result = ConvertPropertyForRValue(Args[0]); 8968 if (Result.isInvalid()) 8969 return ExprError(); 8970 Args[0] = Result.take(); 8971 } 8972 if (Args[1]->getObjectKind() == OK_ObjCProperty) { 8973 ExprResult Result = ConvertPropertyForRValue(Args[1]); 8974 if (Result.isInvalid()) 8975 return ExprError(); 8976 Args[1] = Result.take(); 8977 } 8978 8979 // Build an empty overload set. 8980 OverloadCandidateSet CandidateSet(LLoc); 8981 8982 // Subscript can only be overloaded as a member function. 8983 8984 // Add operator candidates that are member functions. 8985 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 8986 8987 // Add builtin operator candidates. 8988 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 8989 8990 // Perform overload resolution. 8991 OverloadCandidateSet::iterator Best; 8992 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 8993 case OR_Success: { 8994 // We found a built-in operator or an overloaded operator. 8995 FunctionDecl *FnDecl = Best->Function; 8996 8997 if (FnDecl) { 8998 // We matched an overloaded operator. Build a call to that 8999 // operator. 9000 9001 MarkDeclarationReferenced(LLoc, FnDecl); 9002 9003 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 9004 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 9005 9006 // Convert the arguments. 9007 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 9008 ExprResult Arg0 = 9009 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 9010 Best->FoundDecl, Method); 9011 if (Arg0.isInvalid()) 9012 return ExprError(); 9013 Args[0] = Arg0.take(); 9014 9015 // Convert the arguments. 9016 ExprResult InputInit 9017 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 9018 Context, 9019 FnDecl->getParamDecl(0)), 9020 SourceLocation(), 9021 Owned(Args[1])); 9022 if (InputInit.isInvalid()) 9023 return ExprError(); 9024 9025 Args[1] = InputInit.takeAs<Expr>(); 9026 9027 // Determine the result type 9028 QualType ResultTy = FnDecl->getResultType(); 9029 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 9030 ResultTy = ResultTy.getNonLValueExprType(Context); 9031 9032 // Build the actual expression node. 9033 DeclarationNameLoc LocInfo; 9034 LocInfo.CXXOperatorName.BeginOpNameLoc = LLoc.getRawEncoding(); 9035 LocInfo.CXXOperatorName.EndOpNameLoc = RLoc.getRawEncoding(); 9036 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, LLoc, LocInfo); 9037 if (FnExpr.isInvalid()) 9038 return ExprError(); 9039 9040 CXXOperatorCallExpr *TheCall = 9041 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 9042 FnExpr.take(), Args, 2, 9043 ResultTy, VK, RLoc); 9044 9045 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 9046 FnDecl)) 9047 return ExprError(); 9048 9049 return MaybeBindToTemporary(TheCall); 9050 } else { 9051 // We matched a built-in operator. Convert the arguments, then 9052 // break out so that we will build the appropriate built-in 9053 // operator node. 9054 ExprResult ArgsRes0 = 9055 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 9056 Best->Conversions[0], AA_Passing); 9057 if (ArgsRes0.isInvalid()) 9058 return ExprError(); 9059 Args[0] = ArgsRes0.take(); 9060 9061 ExprResult ArgsRes1 = 9062 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 9063 Best->Conversions[1], AA_Passing); 9064 if (ArgsRes1.isInvalid()) 9065 return ExprError(); 9066 Args[1] = ArgsRes1.take(); 9067 9068 break; 9069 } 9070 } 9071 9072 case OR_No_Viable_Function: { 9073 if (CandidateSet.empty()) 9074 Diag(LLoc, diag::err_ovl_no_oper) 9075 << Args[0]->getType() << /*subscript*/ 0 9076 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9077 else 9078 Diag(LLoc, diag::err_ovl_no_viable_subscript) 9079 << Args[0]->getType() 9080 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9081 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 9082 "[]", LLoc); 9083 return ExprError(); 9084 } 9085 9086 case OR_Ambiguous: 9087 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 9088 << "[]" 9089 << Args[0]->getType() << Args[1]->getType() 9090 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9091 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 9092 "[]", LLoc); 9093 return ExprError(); 9094 9095 case OR_Deleted: 9096 Diag(LLoc, diag::err_ovl_deleted_oper) 9097 << Best->Function->isDeleted() << "[]" 9098 << getDeletedOrUnavailableSuffix(Best->Function) 9099 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9100 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 9101 "[]", LLoc); 9102 return ExprError(); 9103 } 9104 9105 // We matched a built-in operator; build it. 9106 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 9107} 9108 9109/// BuildCallToMemberFunction - Build a call to a member 9110/// function. MemExpr is the expression that refers to the member 9111/// function (and includes the object parameter), Args/NumArgs are the 9112/// arguments to the function call (not including the object 9113/// parameter). The caller needs to validate that the member 9114/// expression refers to a non-static member function or an overloaded 9115/// member function. 9116ExprResult 9117Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 9118 SourceLocation LParenLoc, Expr **Args, 9119 unsigned NumArgs, SourceLocation RParenLoc) { 9120 assert(MemExprE->getType() == Context.BoundMemberTy || 9121 MemExprE->getType() == Context.OverloadTy); 9122 9123 // Dig out the member expression. This holds both the object 9124 // argument and the member function we're referring to. 9125 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 9126 9127 // Determine whether this is a call to a pointer-to-member function. 9128 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) { 9129 assert(op->getType() == Context.BoundMemberTy); 9130 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI); 9131 9132 QualType fnType = 9133 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType(); 9134 9135 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>(); 9136 QualType resultType = proto->getCallResultType(Context); 9137 ExprValueKind valueKind = Expr::getValueKindForType(proto->getResultType()); 9138 9139 // Check that the object type isn't more qualified than the 9140 // member function we're calling. 9141 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals()); 9142 9143 QualType objectType = op->getLHS()->getType(); 9144 if (op->getOpcode() == BO_PtrMemI) 9145 objectType = objectType->castAs<PointerType>()->getPointeeType(); 9146 Qualifiers objectQuals = objectType.getQualifiers(); 9147 9148 Qualifiers difference = objectQuals - funcQuals; 9149 difference.removeObjCGCAttr(); 9150 difference.removeAddressSpace(); 9151 if (difference) { 9152 std::string qualsString = difference.getAsString(); 9153 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals) 9154 << fnType.getUnqualifiedType() 9155 << qualsString 9156 << (qualsString.find(' ') == std::string::npos ? 1 : 2); 9157 } 9158 9159 CXXMemberCallExpr *call 9160 = new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 9161 resultType, valueKind, RParenLoc); 9162 9163 if (CheckCallReturnType(proto->getResultType(), 9164 op->getRHS()->getSourceRange().getBegin(), 9165 call, 0)) 9166 return ExprError(); 9167 9168 if (ConvertArgumentsForCall(call, op, 0, proto, Args, NumArgs, RParenLoc)) 9169 return ExprError(); 9170 9171 return MaybeBindToTemporary(call); 9172 } 9173 9174 MemberExpr *MemExpr; 9175 CXXMethodDecl *Method = 0; 9176 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 9177 NestedNameSpecifier *Qualifier = 0; 9178 if (isa<MemberExpr>(NakedMemExpr)) { 9179 MemExpr = cast<MemberExpr>(NakedMemExpr); 9180 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 9181 FoundDecl = MemExpr->getFoundDecl(); 9182 Qualifier = MemExpr->getQualifier(); 9183 } else { 9184 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 9185 Qualifier = UnresExpr->getQualifier(); 9186 9187 QualType ObjectType = UnresExpr->getBaseType(); 9188 Expr::Classification ObjectClassification 9189 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 9190 : UnresExpr->getBase()->Classify(Context); 9191 9192 // Add overload candidates 9193 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 9194 9195 // FIXME: avoid copy. 9196 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 9197 if (UnresExpr->hasExplicitTemplateArgs()) { 9198 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 9199 TemplateArgs = &TemplateArgsBuffer; 9200 } 9201 9202 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 9203 E = UnresExpr->decls_end(); I != E; ++I) { 9204 9205 NamedDecl *Func = *I; 9206 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 9207 if (isa<UsingShadowDecl>(Func)) 9208 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 9209 9210 9211 // Microsoft supports direct constructor calls. 9212 if (getLangOptions().Microsoft && isa<CXXConstructorDecl>(Func)) { 9213 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), Args, NumArgs, 9214 CandidateSet); 9215 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 9216 // If explicit template arguments were provided, we can't call a 9217 // non-template member function. 9218 if (TemplateArgs) 9219 continue; 9220 9221 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 9222 ObjectClassification, 9223 Args, NumArgs, CandidateSet, 9224 /*SuppressUserConversions=*/false); 9225 } else { 9226 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 9227 I.getPair(), ActingDC, TemplateArgs, 9228 ObjectType, ObjectClassification, 9229 Args, NumArgs, CandidateSet, 9230 /*SuppressUsedConversions=*/false); 9231 } 9232 } 9233 9234 DeclarationName DeclName = UnresExpr->getMemberName(); 9235 9236 OverloadCandidateSet::iterator Best; 9237 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 9238 Best)) { 9239 case OR_Success: 9240 Method = cast<CXXMethodDecl>(Best->Function); 9241 MarkDeclarationReferenced(UnresExpr->getMemberLoc(), Method); 9242 FoundDecl = Best->FoundDecl; 9243 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 9244 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 9245 break; 9246 9247 case OR_No_Viable_Function: 9248 Diag(UnresExpr->getMemberLoc(), 9249 diag::err_ovl_no_viable_member_function_in_call) 9250 << DeclName << MemExprE->getSourceRange(); 9251 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9252 // FIXME: Leaking incoming expressions! 9253 return ExprError(); 9254 9255 case OR_Ambiguous: 9256 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 9257 << DeclName << MemExprE->getSourceRange(); 9258 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9259 // FIXME: Leaking incoming expressions! 9260 return ExprError(); 9261 9262 case OR_Deleted: 9263 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 9264 << Best->Function->isDeleted() 9265 << DeclName 9266 << getDeletedOrUnavailableSuffix(Best->Function) 9267 << MemExprE->getSourceRange(); 9268 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9269 // FIXME: Leaking incoming expressions! 9270 return ExprError(); 9271 } 9272 9273 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 9274 9275 // If overload resolution picked a static member, build a 9276 // non-member call based on that function. 9277 if (Method->isStatic()) { 9278 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 9279 Args, NumArgs, RParenLoc); 9280 } 9281 9282 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 9283 } 9284 9285 QualType ResultType = Method->getResultType(); 9286 ExprValueKind VK = Expr::getValueKindForType(ResultType); 9287 ResultType = ResultType.getNonLValueExprType(Context); 9288 9289 assert(Method && "Member call to something that isn't a method?"); 9290 CXXMemberCallExpr *TheCall = 9291 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 9292 ResultType, VK, RParenLoc); 9293 9294 // Check for a valid return type. 9295 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 9296 TheCall, Method)) 9297 return ExprError(); 9298 9299 // Convert the object argument (for a non-static member function call). 9300 // We only need to do this if there was actually an overload; otherwise 9301 // it was done at lookup. 9302 if (!Method->isStatic()) { 9303 ExprResult ObjectArg = 9304 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier, 9305 FoundDecl, Method); 9306 if (ObjectArg.isInvalid()) 9307 return ExprError(); 9308 MemExpr->setBase(ObjectArg.take()); 9309 } 9310 9311 // Convert the rest of the arguments 9312 const FunctionProtoType *Proto = 9313 Method->getType()->getAs<FunctionProtoType>(); 9314 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 9315 RParenLoc)) 9316 return ExprError(); 9317 9318 if (CheckFunctionCall(Method, TheCall)) 9319 return ExprError(); 9320 9321 if ((isa<CXXConstructorDecl>(CurContext) || 9322 isa<CXXDestructorDecl>(CurContext)) && 9323 TheCall->getMethodDecl()->isPure()) { 9324 const CXXMethodDecl *MD = TheCall->getMethodDecl(); 9325 9326 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts())) { 9327 Diag(MemExpr->getLocStart(), 9328 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor) 9329 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext) 9330 << MD->getParent()->getDeclName(); 9331 9332 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName(); 9333 } 9334 } 9335 return MaybeBindToTemporary(TheCall); 9336} 9337 9338/// BuildCallToObjectOfClassType - Build a call to an object of class 9339/// type (C++ [over.call.object]), which can end up invoking an 9340/// overloaded function call operator (@c operator()) or performing a 9341/// user-defined conversion on the object argument. 9342ExprResult 9343Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj, 9344 SourceLocation LParenLoc, 9345 Expr **Args, unsigned NumArgs, 9346 SourceLocation RParenLoc) { 9347 ExprResult Object = Owned(Obj); 9348 if (Object.get()->getObjectKind() == OK_ObjCProperty) { 9349 Object = ConvertPropertyForRValue(Object.take()); 9350 if (Object.isInvalid()) 9351 return ExprError(); 9352 } 9353 9354 assert(Object.get()->getType()->isRecordType() && "Requires object type argument"); 9355 const RecordType *Record = Object.get()->getType()->getAs<RecordType>(); 9356 9357 // C++ [over.call.object]p1: 9358 // If the primary-expression E in the function call syntax 9359 // evaluates to a class object of type "cv T", then the set of 9360 // candidate functions includes at least the function call 9361 // operators of T. The function call operators of T are obtained by 9362 // ordinary lookup of the name operator() in the context of 9363 // (E).operator(). 9364 OverloadCandidateSet CandidateSet(LParenLoc); 9365 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 9366 9367 if (RequireCompleteType(LParenLoc, Object.get()->getType(), 9368 PDiag(diag::err_incomplete_object_call) 9369 << Object.get()->getSourceRange())) 9370 return true; 9371 9372 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 9373 LookupQualifiedName(R, Record->getDecl()); 9374 R.suppressDiagnostics(); 9375 9376 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 9377 Oper != OperEnd; ++Oper) { 9378 AddMethodCandidate(Oper.getPair(), Object.get()->getType(), 9379 Object.get()->Classify(Context), Args, NumArgs, CandidateSet, 9380 /*SuppressUserConversions=*/ false); 9381 } 9382 9383 // C++ [over.call.object]p2: 9384 // In addition, for each (non-explicit in C++0x) conversion function 9385 // declared in T of the form 9386 // 9387 // operator conversion-type-id () cv-qualifier; 9388 // 9389 // where cv-qualifier is the same cv-qualification as, or a 9390 // greater cv-qualification than, cv, and where conversion-type-id 9391 // denotes the type "pointer to function of (P1,...,Pn) returning 9392 // R", or the type "reference to pointer to function of 9393 // (P1,...,Pn) returning R", or the type "reference to function 9394 // of (P1,...,Pn) returning R", a surrogate call function [...] 9395 // is also considered as a candidate function. Similarly, 9396 // surrogate call functions are added to the set of candidate 9397 // functions for each conversion function declared in an 9398 // accessible base class provided the function is not hidden 9399 // within T by another intervening declaration. 9400 const UnresolvedSetImpl *Conversions 9401 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 9402 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 9403 E = Conversions->end(); I != E; ++I) { 9404 NamedDecl *D = *I; 9405 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 9406 if (isa<UsingShadowDecl>(D)) 9407 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 9408 9409 // Skip over templated conversion functions; they aren't 9410 // surrogates. 9411 if (isa<FunctionTemplateDecl>(D)) 9412 continue; 9413 9414 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 9415 if (!Conv->isExplicit()) { 9416 // Strip the reference type (if any) and then the pointer type (if 9417 // any) to get down to what might be a function type. 9418 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 9419 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 9420 ConvType = ConvPtrType->getPointeeType(); 9421 9422 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 9423 { 9424 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 9425 Object.get(), Args, NumArgs, CandidateSet); 9426 } 9427 } 9428 } 9429 9430 // Perform overload resolution. 9431 OverloadCandidateSet::iterator Best; 9432 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(), 9433 Best)) { 9434 case OR_Success: 9435 // Overload resolution succeeded; we'll build the appropriate call 9436 // below. 9437 break; 9438 9439 case OR_No_Viable_Function: 9440 if (CandidateSet.empty()) 9441 Diag(Object.get()->getSourceRange().getBegin(), diag::err_ovl_no_oper) 9442 << Object.get()->getType() << /*call*/ 1 9443 << Object.get()->getSourceRange(); 9444 else 9445 Diag(Object.get()->getSourceRange().getBegin(), 9446 diag::err_ovl_no_viable_object_call) 9447 << Object.get()->getType() << Object.get()->getSourceRange(); 9448 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9449 break; 9450 9451 case OR_Ambiguous: 9452 Diag(Object.get()->getSourceRange().getBegin(), 9453 diag::err_ovl_ambiguous_object_call) 9454 << Object.get()->getType() << Object.get()->getSourceRange(); 9455 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 9456 break; 9457 9458 case OR_Deleted: 9459 Diag(Object.get()->getSourceRange().getBegin(), 9460 diag::err_ovl_deleted_object_call) 9461 << Best->Function->isDeleted() 9462 << Object.get()->getType() 9463 << getDeletedOrUnavailableSuffix(Best->Function) 9464 << Object.get()->getSourceRange(); 9465 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9466 break; 9467 } 9468 9469 if (Best == CandidateSet.end()) 9470 return true; 9471 9472 if (Best->Function == 0) { 9473 // Since there is no function declaration, this is one of the 9474 // surrogate candidates. Dig out the conversion function. 9475 CXXConversionDecl *Conv 9476 = cast<CXXConversionDecl>( 9477 Best->Conversions[0].UserDefined.ConversionFunction); 9478 9479 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 9480 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 9481 9482 // We selected one of the surrogate functions that converts the 9483 // object parameter to a function pointer. Perform the conversion 9484 // on the object argument, then let ActOnCallExpr finish the job. 9485 9486 // Create an implicit member expr to refer to the conversion operator. 9487 // and then call it. 9488 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl, Conv); 9489 if (Call.isInvalid()) 9490 return ExprError(); 9491 9492 return ActOnCallExpr(S, Call.get(), LParenLoc, MultiExprArg(Args, NumArgs), 9493 RParenLoc); 9494 } 9495 9496 MarkDeclarationReferenced(LParenLoc, Best->Function); 9497 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 9498 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 9499 9500 // We found an overloaded operator(). Build a CXXOperatorCallExpr 9501 // that calls this method, using Object for the implicit object 9502 // parameter and passing along the remaining arguments. 9503 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 9504 const FunctionProtoType *Proto = 9505 Method->getType()->getAs<FunctionProtoType>(); 9506 9507 unsigned NumArgsInProto = Proto->getNumArgs(); 9508 unsigned NumArgsToCheck = NumArgs; 9509 9510 // Build the full argument list for the method call (the 9511 // implicit object parameter is placed at the beginning of the 9512 // list). 9513 Expr **MethodArgs; 9514 if (NumArgs < NumArgsInProto) { 9515 NumArgsToCheck = NumArgsInProto; 9516 MethodArgs = new Expr*[NumArgsInProto + 1]; 9517 } else { 9518 MethodArgs = new Expr*[NumArgs + 1]; 9519 } 9520 MethodArgs[0] = Object.get(); 9521 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 9522 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 9523 9524 ExprResult NewFn = CreateFunctionRefExpr(*this, Method); 9525 if (NewFn.isInvalid()) 9526 return true; 9527 9528 // Once we've built TheCall, all of the expressions are properly 9529 // owned. 9530 QualType ResultTy = Method->getResultType(); 9531 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 9532 ResultTy = ResultTy.getNonLValueExprType(Context); 9533 9534 CXXOperatorCallExpr *TheCall = 9535 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn.take(), 9536 MethodArgs, NumArgs + 1, 9537 ResultTy, VK, RParenLoc); 9538 delete [] MethodArgs; 9539 9540 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 9541 Method)) 9542 return true; 9543 9544 // We may have default arguments. If so, we need to allocate more 9545 // slots in the call for them. 9546 if (NumArgs < NumArgsInProto) 9547 TheCall->setNumArgs(Context, NumArgsInProto + 1); 9548 else if (NumArgs > NumArgsInProto) 9549 NumArgsToCheck = NumArgsInProto; 9550 9551 bool IsError = false; 9552 9553 // Initialize the implicit object parameter. 9554 ExprResult ObjRes = 9555 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/0, 9556 Best->FoundDecl, Method); 9557 if (ObjRes.isInvalid()) 9558 IsError = true; 9559 else 9560 Object = move(ObjRes); 9561 TheCall->setArg(0, Object.take()); 9562 9563 // Check the argument types. 9564 for (unsigned i = 0; i != NumArgsToCheck; i++) { 9565 Expr *Arg; 9566 if (i < NumArgs) { 9567 Arg = Args[i]; 9568 9569 // Pass the argument. 9570 9571 ExprResult InputInit 9572 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 9573 Context, 9574 Method->getParamDecl(i)), 9575 SourceLocation(), Arg); 9576 9577 IsError |= InputInit.isInvalid(); 9578 Arg = InputInit.takeAs<Expr>(); 9579 } else { 9580 ExprResult DefArg 9581 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 9582 if (DefArg.isInvalid()) { 9583 IsError = true; 9584 break; 9585 } 9586 9587 Arg = DefArg.takeAs<Expr>(); 9588 } 9589 9590 TheCall->setArg(i + 1, Arg); 9591 } 9592 9593 // If this is a variadic call, handle args passed through "...". 9594 if (Proto->isVariadic()) { 9595 // Promote the arguments (C99 6.5.2.2p7). 9596 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 9597 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod, 0); 9598 IsError |= Arg.isInvalid(); 9599 TheCall->setArg(i + 1, Arg.take()); 9600 } 9601 } 9602 9603 if (IsError) return true; 9604 9605 if (CheckFunctionCall(Method, TheCall)) 9606 return true; 9607 9608 return MaybeBindToTemporary(TheCall); 9609} 9610 9611/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 9612/// (if one exists), where @c Base is an expression of class type and 9613/// @c Member is the name of the member we're trying to find. 9614ExprResult 9615Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 9616 assert(Base->getType()->isRecordType() && 9617 "left-hand side must have class type"); 9618 9619 if (Base->getObjectKind() == OK_ObjCProperty) { 9620 ExprResult Result = ConvertPropertyForRValue(Base); 9621 if (Result.isInvalid()) 9622 return ExprError(); 9623 Base = Result.take(); 9624 } 9625 9626 SourceLocation Loc = Base->getExprLoc(); 9627 9628 // C++ [over.ref]p1: 9629 // 9630 // [...] An expression x->m is interpreted as (x.operator->())->m 9631 // for a class object x of type T if T::operator->() exists and if 9632 // the operator is selected as the best match function by the 9633 // overload resolution mechanism (13.3). 9634 DeclarationName OpName = 9635 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 9636 OverloadCandidateSet CandidateSet(Loc); 9637 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 9638 9639 if (RequireCompleteType(Loc, Base->getType(), 9640 PDiag(diag::err_typecheck_incomplete_tag) 9641 << Base->getSourceRange())) 9642 return ExprError(); 9643 9644 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 9645 LookupQualifiedName(R, BaseRecord->getDecl()); 9646 R.suppressDiagnostics(); 9647 9648 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 9649 Oper != OperEnd; ++Oper) { 9650 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 9651 0, 0, CandidateSet, /*SuppressUserConversions=*/false); 9652 } 9653 9654 // Perform overload resolution. 9655 OverloadCandidateSet::iterator Best; 9656 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 9657 case OR_Success: 9658 // Overload resolution succeeded; we'll build the call below. 9659 break; 9660 9661 case OR_No_Viable_Function: 9662 if (CandidateSet.empty()) 9663 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 9664 << Base->getType() << Base->getSourceRange(); 9665 else 9666 Diag(OpLoc, diag::err_ovl_no_viable_oper) 9667 << "operator->" << Base->getSourceRange(); 9668 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 9669 return ExprError(); 9670 9671 case OR_Ambiguous: 9672 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 9673 << "->" << Base->getType() << Base->getSourceRange(); 9674 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, &Base, 1); 9675 return ExprError(); 9676 9677 case OR_Deleted: 9678 Diag(OpLoc, diag::err_ovl_deleted_oper) 9679 << Best->Function->isDeleted() 9680 << "->" 9681 << getDeletedOrUnavailableSuffix(Best->Function) 9682 << Base->getSourceRange(); 9683 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 9684 return ExprError(); 9685 } 9686 9687 MarkDeclarationReferenced(OpLoc, Best->Function); 9688 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 9689 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 9690 9691 // Convert the object parameter. 9692 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 9693 ExprResult BaseResult = 9694 PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 9695 Best->FoundDecl, Method); 9696 if (BaseResult.isInvalid()) 9697 return ExprError(); 9698 Base = BaseResult.take(); 9699 9700 // Build the operator call. 9701 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method); 9702 if (FnExpr.isInvalid()) 9703 return ExprError(); 9704 9705 QualType ResultTy = Method->getResultType(); 9706 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 9707 ResultTy = ResultTy.getNonLValueExprType(Context); 9708 CXXOperatorCallExpr *TheCall = 9709 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.take(), 9710 &Base, 1, ResultTy, VK, OpLoc); 9711 9712 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 9713 Method)) 9714 return ExprError(); 9715 9716 return MaybeBindToTemporary(TheCall); 9717} 9718 9719/// FixOverloadedFunctionReference - E is an expression that refers to 9720/// a C++ overloaded function (possibly with some parentheses and 9721/// perhaps a '&' around it). We have resolved the overloaded function 9722/// to the function declaration Fn, so patch up the expression E to 9723/// refer (possibly indirectly) to Fn. Returns the new expr. 9724Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 9725 FunctionDecl *Fn) { 9726 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 9727 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 9728 Found, Fn); 9729 if (SubExpr == PE->getSubExpr()) 9730 return PE; 9731 9732 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 9733 } 9734 9735 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 9736 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 9737 Found, Fn); 9738 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 9739 SubExpr->getType()) && 9740 "Implicit cast type cannot be determined from overload"); 9741 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 9742 if (SubExpr == ICE->getSubExpr()) 9743 return ICE; 9744 9745 return ImplicitCastExpr::Create(Context, ICE->getType(), 9746 ICE->getCastKind(), 9747 SubExpr, 0, 9748 ICE->getValueKind()); 9749 } 9750 9751 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 9752 assert(UnOp->getOpcode() == UO_AddrOf && 9753 "Can only take the address of an overloaded function"); 9754 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 9755 if (Method->isStatic()) { 9756 // Do nothing: static member functions aren't any different 9757 // from non-member functions. 9758 } else { 9759 // Fix the sub expression, which really has to be an 9760 // UnresolvedLookupExpr holding an overloaded member function 9761 // or template. 9762 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 9763 Found, Fn); 9764 if (SubExpr == UnOp->getSubExpr()) 9765 return UnOp; 9766 9767 assert(isa<DeclRefExpr>(SubExpr) 9768 && "fixed to something other than a decl ref"); 9769 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 9770 && "fixed to a member ref with no nested name qualifier"); 9771 9772 // We have taken the address of a pointer to member 9773 // function. Perform the computation here so that we get the 9774 // appropriate pointer to member type. 9775 QualType ClassType 9776 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 9777 QualType MemPtrType 9778 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 9779 9780 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 9781 VK_RValue, OK_Ordinary, 9782 UnOp->getOperatorLoc()); 9783 } 9784 } 9785 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 9786 Found, Fn); 9787 if (SubExpr == UnOp->getSubExpr()) 9788 return UnOp; 9789 9790 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 9791 Context.getPointerType(SubExpr->getType()), 9792 VK_RValue, OK_Ordinary, 9793 UnOp->getOperatorLoc()); 9794 } 9795 9796 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 9797 // FIXME: avoid copy. 9798 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 9799 if (ULE->hasExplicitTemplateArgs()) { 9800 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 9801 TemplateArgs = &TemplateArgsBuffer; 9802 } 9803 9804 return DeclRefExpr::Create(Context, 9805 ULE->getQualifierLoc(), 9806 Fn, 9807 ULE->getNameLoc(), 9808 Fn->getType(), 9809 VK_LValue, 9810 Found.getDecl(), 9811 TemplateArgs); 9812 } 9813 9814 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 9815 // FIXME: avoid copy. 9816 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 9817 if (MemExpr->hasExplicitTemplateArgs()) { 9818 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 9819 TemplateArgs = &TemplateArgsBuffer; 9820 } 9821 9822 Expr *Base; 9823 9824 // If we're filling in a static method where we used to have an 9825 // implicit member access, rewrite to a simple decl ref. 9826 if (MemExpr->isImplicitAccess()) { 9827 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 9828 return DeclRefExpr::Create(Context, 9829 MemExpr->getQualifierLoc(), 9830 Fn, 9831 MemExpr->getMemberLoc(), 9832 Fn->getType(), 9833 VK_LValue, 9834 Found.getDecl(), 9835 TemplateArgs); 9836 } else { 9837 SourceLocation Loc = MemExpr->getMemberLoc(); 9838 if (MemExpr->getQualifier()) 9839 Loc = MemExpr->getQualifierLoc().getBeginLoc(); 9840 Base = new (Context) CXXThisExpr(Loc, 9841 MemExpr->getBaseType(), 9842 /*isImplicit=*/true); 9843 } 9844 } else 9845 Base = MemExpr->getBase(); 9846 9847 ExprValueKind valueKind; 9848 QualType type; 9849 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 9850 valueKind = VK_LValue; 9851 type = Fn->getType(); 9852 } else { 9853 valueKind = VK_RValue; 9854 type = Context.BoundMemberTy; 9855 } 9856 9857 return MemberExpr::Create(Context, Base, 9858 MemExpr->isArrow(), 9859 MemExpr->getQualifierLoc(), 9860 Fn, 9861 Found, 9862 MemExpr->getMemberNameInfo(), 9863 TemplateArgs, 9864 type, valueKind, OK_Ordinary); 9865 } 9866 9867 llvm_unreachable("Invalid reference to overloaded function"); 9868 return E; 9869} 9870 9871ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 9872 DeclAccessPair Found, 9873 FunctionDecl *Fn) { 9874 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 9875} 9876 9877} // end namespace clang 9878