SemaOverload.cpp revision d593190132244b0194d480ec3e55f94f369c8863
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 Expr * 40CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, 41 SourceLocation Loc = SourceLocation()) { 42 Expr *E = new (S.Context) DeclRefExpr(Fn, Fn->getType(), VK_LValue, Loc); 43 S.DefaultFunctionArrayConversion(E); 44 return E; 45} 46 47static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 48 bool InOverloadResolution, 49 StandardConversionSequence &SCS, 50 bool CStyle); 51 52static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From, 53 QualType &ToType, 54 bool InOverloadResolution, 55 StandardConversionSequence &SCS, 56 bool CStyle); 57static OverloadingResult 58IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 59 UserDefinedConversionSequence& User, 60 OverloadCandidateSet& Conversions, 61 bool AllowExplicit); 62 63 64static ImplicitConversionSequence::CompareKind 65CompareStandardConversionSequences(Sema &S, 66 const StandardConversionSequence& SCS1, 67 const StandardConversionSequence& SCS2); 68 69static ImplicitConversionSequence::CompareKind 70CompareQualificationConversions(Sema &S, 71 const StandardConversionSequence& SCS1, 72 const StandardConversionSequence& SCS2); 73 74static ImplicitConversionSequence::CompareKind 75CompareDerivedToBaseConversions(Sema &S, 76 const StandardConversionSequence& SCS1, 77 const StandardConversionSequence& SCS2); 78 79 80 81/// GetConversionCategory - Retrieve the implicit conversion 82/// category corresponding to the given implicit conversion kind. 83ImplicitConversionCategory 84GetConversionCategory(ImplicitConversionKind Kind) { 85 static const ImplicitConversionCategory 86 Category[(int)ICK_Num_Conversion_Kinds] = { 87 ICC_Identity, 88 ICC_Lvalue_Transformation, 89 ICC_Lvalue_Transformation, 90 ICC_Lvalue_Transformation, 91 ICC_Identity, 92 ICC_Qualification_Adjustment, 93 ICC_Promotion, 94 ICC_Promotion, 95 ICC_Promotion, 96 ICC_Conversion, 97 ICC_Conversion, 98 ICC_Conversion, 99 ICC_Conversion, 100 ICC_Conversion, 101 ICC_Conversion, 102 ICC_Conversion, 103 ICC_Conversion, 104 ICC_Conversion, 105 ICC_Conversion, 106 ICC_Conversion, 107 ICC_Conversion 108 }; 109 return Category[(int)Kind]; 110} 111 112/// GetConversionRank - Retrieve the implicit conversion rank 113/// corresponding to the given implicit conversion kind. 114ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 115 static const ImplicitConversionRank 116 Rank[(int)ICK_Num_Conversion_Kinds] = { 117 ICR_Exact_Match, 118 ICR_Exact_Match, 119 ICR_Exact_Match, 120 ICR_Exact_Match, 121 ICR_Exact_Match, 122 ICR_Exact_Match, 123 ICR_Promotion, 124 ICR_Promotion, 125 ICR_Promotion, 126 ICR_Conversion, 127 ICR_Conversion, 128 ICR_Conversion, 129 ICR_Conversion, 130 ICR_Conversion, 131 ICR_Conversion, 132 ICR_Conversion, 133 ICR_Conversion, 134 ICR_Conversion, 135 ICR_Conversion, 136 ICR_Conversion, 137 ICR_Complex_Real_Conversion, 138 ICR_Conversion, 139 ICR_Conversion 140 }; 141 return Rank[(int)Kind]; 142} 143 144/// GetImplicitConversionName - Return the name of this kind of 145/// implicit conversion. 146const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 147 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 148 "No conversion", 149 "Lvalue-to-rvalue", 150 "Array-to-pointer", 151 "Function-to-pointer", 152 "Noreturn adjustment", 153 "Qualification", 154 "Integral promotion", 155 "Floating point promotion", 156 "Complex promotion", 157 "Integral conversion", 158 "Floating conversion", 159 "Complex conversion", 160 "Floating-integral conversion", 161 "Pointer conversion", 162 "Pointer-to-member conversion", 163 "Boolean conversion", 164 "Compatible-types conversion", 165 "Derived-to-base conversion", 166 "Vector conversion", 167 "Vector splat", 168 "Complex-real conversion", 169 "Block Pointer conversion", 170 "Transparent Union Conversion" 171 }; 172 return Name[Kind]; 173} 174 175/// StandardConversionSequence - Set the standard conversion 176/// sequence to the identity conversion. 177void StandardConversionSequence::setAsIdentityConversion() { 178 First = ICK_Identity; 179 Second = ICK_Identity; 180 Third = ICK_Identity; 181 DeprecatedStringLiteralToCharPtr = false; 182 ReferenceBinding = false; 183 DirectBinding = false; 184 IsLvalueReference = true; 185 BindsToFunctionLvalue = false; 186 BindsToRvalue = false; 187 BindsImplicitObjectArgumentWithoutRefQualifier = false; 188 CopyConstructor = 0; 189} 190 191/// getRank - Retrieve the rank of this standard conversion sequence 192/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 193/// implicit conversions. 194ImplicitConversionRank StandardConversionSequence::getRank() const { 195 ImplicitConversionRank Rank = ICR_Exact_Match; 196 if (GetConversionRank(First) > Rank) 197 Rank = GetConversionRank(First); 198 if (GetConversionRank(Second) > Rank) 199 Rank = GetConversionRank(Second); 200 if (GetConversionRank(Third) > Rank) 201 Rank = GetConversionRank(Third); 202 return Rank; 203} 204 205/// isPointerConversionToBool - Determines whether this conversion is 206/// a conversion of a pointer or pointer-to-member to bool. This is 207/// used as part of the ranking of standard conversion sequences 208/// (C++ 13.3.3.2p4). 209bool StandardConversionSequence::isPointerConversionToBool() const { 210 // Note that FromType has not necessarily been transformed by the 211 // array-to-pointer or function-to-pointer implicit conversions, so 212 // check for their presence as well as checking whether FromType is 213 // a pointer. 214 if (getToType(1)->isBooleanType() && 215 (getFromType()->isPointerType() || 216 getFromType()->isObjCObjectPointerType() || 217 getFromType()->isBlockPointerType() || 218 getFromType()->isNullPtrType() || 219 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 220 return true; 221 222 return false; 223} 224 225/// isPointerConversionToVoidPointer - Determines whether this 226/// conversion is a conversion of a pointer to a void pointer. This is 227/// used as part of the ranking of standard conversion sequences (C++ 228/// 13.3.3.2p4). 229bool 230StandardConversionSequence:: 231isPointerConversionToVoidPointer(ASTContext& Context) const { 232 QualType FromType = getFromType(); 233 QualType ToType = getToType(1); 234 235 // Note that FromType has not necessarily been transformed by the 236 // array-to-pointer implicit conversion, so check for its presence 237 // and redo the conversion to get a pointer. 238 if (First == ICK_Array_To_Pointer) 239 FromType = Context.getArrayDecayedType(FromType); 240 241 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 242 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 243 return ToPtrType->getPointeeType()->isVoidType(); 244 245 return false; 246} 247 248/// DebugPrint - Print this standard conversion sequence to standard 249/// error. Useful for debugging overloading issues. 250void StandardConversionSequence::DebugPrint() const { 251 llvm::raw_ostream &OS = llvm::errs(); 252 bool PrintedSomething = false; 253 if (First != ICK_Identity) { 254 OS << GetImplicitConversionName(First); 255 PrintedSomething = true; 256 } 257 258 if (Second != ICK_Identity) { 259 if (PrintedSomething) { 260 OS << " -> "; 261 } 262 OS << GetImplicitConversionName(Second); 263 264 if (CopyConstructor) { 265 OS << " (by copy constructor)"; 266 } else if (DirectBinding) { 267 OS << " (direct reference binding)"; 268 } else if (ReferenceBinding) { 269 OS << " (reference binding)"; 270 } 271 PrintedSomething = true; 272 } 273 274 if (Third != ICK_Identity) { 275 if (PrintedSomething) { 276 OS << " -> "; 277 } 278 OS << GetImplicitConversionName(Third); 279 PrintedSomething = true; 280 } 281 282 if (!PrintedSomething) { 283 OS << "No conversions required"; 284 } 285} 286 287/// DebugPrint - Print this user-defined conversion sequence to standard 288/// error. Useful for debugging overloading issues. 289void UserDefinedConversionSequence::DebugPrint() const { 290 llvm::raw_ostream &OS = llvm::errs(); 291 if (Before.First || Before.Second || Before.Third) { 292 Before.DebugPrint(); 293 OS << " -> "; 294 } 295 OS << '\'' << ConversionFunction << '\''; 296 if (After.First || After.Second || After.Third) { 297 OS << " -> "; 298 After.DebugPrint(); 299 } 300} 301 302/// DebugPrint - Print this implicit conversion sequence to standard 303/// error. Useful for debugging overloading issues. 304void ImplicitConversionSequence::DebugPrint() const { 305 llvm::raw_ostream &OS = llvm::errs(); 306 switch (ConversionKind) { 307 case StandardConversion: 308 OS << "Standard conversion: "; 309 Standard.DebugPrint(); 310 break; 311 case UserDefinedConversion: 312 OS << "User-defined conversion: "; 313 UserDefined.DebugPrint(); 314 break; 315 case EllipsisConversion: 316 OS << "Ellipsis conversion"; 317 break; 318 case AmbiguousConversion: 319 OS << "Ambiguous conversion"; 320 break; 321 case BadConversion: 322 OS << "Bad conversion"; 323 break; 324 } 325 326 OS << "\n"; 327} 328 329void AmbiguousConversionSequence::construct() { 330 new (&conversions()) ConversionSet(); 331} 332 333void AmbiguousConversionSequence::destruct() { 334 conversions().~ConversionSet(); 335} 336 337void 338AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 339 FromTypePtr = O.FromTypePtr; 340 ToTypePtr = O.ToTypePtr; 341 new (&conversions()) ConversionSet(O.conversions()); 342} 343 344namespace { 345 // Structure used by OverloadCandidate::DeductionFailureInfo to store 346 // template parameter and template argument information. 347 struct DFIParamWithArguments { 348 TemplateParameter Param; 349 TemplateArgument FirstArg; 350 TemplateArgument SecondArg; 351 }; 352} 353 354/// \brief Convert from Sema's representation of template deduction information 355/// to the form used in overload-candidate information. 356OverloadCandidate::DeductionFailureInfo 357static MakeDeductionFailureInfo(ASTContext &Context, 358 Sema::TemplateDeductionResult TDK, 359 TemplateDeductionInfo &Info) { 360 OverloadCandidate::DeductionFailureInfo Result; 361 Result.Result = static_cast<unsigned>(TDK); 362 Result.Data = 0; 363 switch (TDK) { 364 case Sema::TDK_Success: 365 case Sema::TDK_InstantiationDepth: 366 case Sema::TDK_TooManyArguments: 367 case Sema::TDK_TooFewArguments: 368 break; 369 370 case Sema::TDK_Incomplete: 371 case Sema::TDK_InvalidExplicitArguments: 372 Result.Data = Info.Param.getOpaqueValue(); 373 break; 374 375 case Sema::TDK_Inconsistent: 376 case Sema::TDK_Underqualified: { 377 // FIXME: Should allocate from normal heap so that we can free this later. 378 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 379 Saved->Param = Info.Param; 380 Saved->FirstArg = Info.FirstArg; 381 Saved->SecondArg = Info.SecondArg; 382 Result.Data = Saved; 383 break; 384 } 385 386 case Sema::TDK_SubstitutionFailure: 387 Result.Data = Info.take(); 388 break; 389 390 case Sema::TDK_NonDeducedMismatch: 391 case Sema::TDK_FailedOverloadResolution: 392 break; 393 } 394 395 return Result; 396} 397 398void OverloadCandidate::DeductionFailureInfo::Destroy() { 399 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 400 case Sema::TDK_Success: 401 case Sema::TDK_InstantiationDepth: 402 case Sema::TDK_Incomplete: 403 case Sema::TDK_TooManyArguments: 404 case Sema::TDK_TooFewArguments: 405 case Sema::TDK_InvalidExplicitArguments: 406 break; 407 408 case Sema::TDK_Inconsistent: 409 case Sema::TDK_Underqualified: 410 // FIXME: Destroy the data? 411 Data = 0; 412 break; 413 414 case Sema::TDK_SubstitutionFailure: 415 // FIXME: Destroy the template arugment list? 416 Data = 0; 417 break; 418 419 // Unhandled 420 case Sema::TDK_NonDeducedMismatch: 421 case Sema::TDK_FailedOverloadResolution: 422 break; 423 } 424} 425 426TemplateParameter 427OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 428 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 429 case Sema::TDK_Success: 430 case Sema::TDK_InstantiationDepth: 431 case Sema::TDK_TooManyArguments: 432 case Sema::TDK_TooFewArguments: 433 case Sema::TDK_SubstitutionFailure: 434 return TemplateParameter(); 435 436 case Sema::TDK_Incomplete: 437 case Sema::TDK_InvalidExplicitArguments: 438 return TemplateParameter::getFromOpaqueValue(Data); 439 440 case Sema::TDK_Inconsistent: 441 case Sema::TDK_Underqualified: 442 return static_cast<DFIParamWithArguments*>(Data)->Param; 443 444 // Unhandled 445 case Sema::TDK_NonDeducedMismatch: 446 case Sema::TDK_FailedOverloadResolution: 447 break; 448 } 449 450 return TemplateParameter(); 451} 452 453TemplateArgumentList * 454OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 455 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 456 case Sema::TDK_Success: 457 case Sema::TDK_InstantiationDepth: 458 case Sema::TDK_TooManyArguments: 459 case Sema::TDK_TooFewArguments: 460 case Sema::TDK_Incomplete: 461 case Sema::TDK_InvalidExplicitArguments: 462 case Sema::TDK_Inconsistent: 463 case Sema::TDK_Underqualified: 464 return 0; 465 466 case Sema::TDK_SubstitutionFailure: 467 return static_cast<TemplateArgumentList*>(Data); 468 469 // Unhandled 470 case Sema::TDK_NonDeducedMismatch: 471 case Sema::TDK_FailedOverloadResolution: 472 break; 473 } 474 475 return 0; 476} 477 478const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 479 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 480 case Sema::TDK_Success: 481 case Sema::TDK_InstantiationDepth: 482 case Sema::TDK_Incomplete: 483 case Sema::TDK_TooManyArguments: 484 case Sema::TDK_TooFewArguments: 485 case Sema::TDK_InvalidExplicitArguments: 486 case Sema::TDK_SubstitutionFailure: 487 return 0; 488 489 case Sema::TDK_Inconsistent: 490 case Sema::TDK_Underqualified: 491 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 492 493 // Unhandled 494 case Sema::TDK_NonDeducedMismatch: 495 case Sema::TDK_FailedOverloadResolution: 496 break; 497 } 498 499 return 0; 500} 501 502const TemplateArgument * 503OverloadCandidate::DeductionFailureInfo::getSecondArg() { 504 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 505 case Sema::TDK_Success: 506 case Sema::TDK_InstantiationDepth: 507 case Sema::TDK_Incomplete: 508 case Sema::TDK_TooManyArguments: 509 case Sema::TDK_TooFewArguments: 510 case Sema::TDK_InvalidExplicitArguments: 511 case Sema::TDK_SubstitutionFailure: 512 return 0; 513 514 case Sema::TDK_Inconsistent: 515 case Sema::TDK_Underqualified: 516 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 517 518 // Unhandled 519 case Sema::TDK_NonDeducedMismatch: 520 case Sema::TDK_FailedOverloadResolution: 521 break; 522 } 523 524 return 0; 525} 526 527void OverloadCandidateSet::clear() { 528 inherited::clear(); 529 Functions.clear(); 530} 531 532// IsOverload - Determine whether the given New declaration is an 533// overload of the declarations in Old. This routine returns false if 534// New and Old cannot be overloaded, e.g., if New has the same 535// signature as some function in Old (C++ 1.3.10) or if the Old 536// declarations aren't functions (or function templates) at all. When 537// it does return false, MatchedDecl will point to the decl that New 538// cannot be overloaded with. This decl may be a UsingShadowDecl on 539// top of the underlying declaration. 540// 541// Example: Given the following input: 542// 543// void f(int, float); // #1 544// void f(int, int); // #2 545// int f(int, int); // #3 546// 547// When we process #1, there is no previous declaration of "f", 548// so IsOverload will not be used. 549// 550// When we process #2, Old contains only the FunctionDecl for #1. By 551// comparing the parameter types, we see that #1 and #2 are overloaded 552// (since they have different signatures), so this routine returns 553// false; MatchedDecl is unchanged. 554// 555// When we process #3, Old is an overload set containing #1 and #2. We 556// compare the signatures of #3 to #1 (they're overloaded, so we do 557// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 558// identical (return types of functions are not part of the 559// signature), IsOverload returns false and MatchedDecl will be set to 560// point to the FunctionDecl for #2. 561// 562// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 563// into a class by a using declaration. The rules for whether to hide 564// shadow declarations ignore some properties which otherwise figure 565// into a function template's signature. 566Sema::OverloadKind 567Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 568 NamedDecl *&Match, bool NewIsUsingDecl) { 569 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 570 I != E; ++I) { 571 NamedDecl *OldD = *I; 572 573 bool OldIsUsingDecl = false; 574 if (isa<UsingShadowDecl>(OldD)) { 575 OldIsUsingDecl = true; 576 577 // We can always introduce two using declarations into the same 578 // context, even if they have identical signatures. 579 if (NewIsUsingDecl) continue; 580 581 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 582 } 583 584 // If either declaration was introduced by a using declaration, 585 // we'll need to use slightly different rules for matching. 586 // Essentially, these rules are the normal rules, except that 587 // function templates hide function templates with different 588 // return types or template parameter lists. 589 bool UseMemberUsingDeclRules = 590 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 591 592 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 593 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 594 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 595 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 596 continue; 597 } 598 599 Match = *I; 600 return Ovl_Match; 601 } 602 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 603 if (!IsOverload(New, OldF, 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 (isa<UsingDecl>(OldD)) { 613 // We can overload with these, which can show up when doing 614 // redeclaration checks for UsingDecls. 615 assert(Old.getLookupKind() == LookupUsingDeclName); 616 } else if (isa<TagDecl>(OldD)) { 617 // We can always overload with tags by hiding them. 618 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 619 // Optimistically assume that an unresolved using decl will 620 // overload; if it doesn't, we'll have to diagnose during 621 // template instantiation. 622 } else { 623 // (C++ 13p1): 624 // Only function declarations can be overloaded; object and type 625 // declarations cannot be overloaded. 626 Match = *I; 627 return Ovl_NonFunction; 628 } 629 } 630 631 return Ovl_Overload; 632} 633 634bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 635 bool UseUsingDeclRules) { 636 // If both of the functions are extern "C", then they are not 637 // overloads. 638 if (Old->isExternC() && New->isExternC()) 639 return false; 640 641 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 642 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 643 644 // C++ [temp.fct]p2: 645 // A function template can be overloaded with other function templates 646 // and with normal (non-template) functions. 647 if ((OldTemplate == 0) != (NewTemplate == 0)) 648 return true; 649 650 // Is the function New an overload of the function Old? 651 QualType OldQType = Context.getCanonicalType(Old->getType()); 652 QualType NewQType = Context.getCanonicalType(New->getType()); 653 654 // Compare the signatures (C++ 1.3.10) of the two functions to 655 // determine whether they are overloads. If we find any mismatch 656 // in the signature, they are overloads. 657 658 // If either of these functions is a K&R-style function (no 659 // prototype), then we consider them to have matching signatures. 660 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 661 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 662 return false; 663 664 const FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 665 const FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 666 667 // The signature of a function includes the types of its 668 // parameters (C++ 1.3.10), which includes the presence or absence 669 // of the ellipsis; see C++ DR 357). 670 if (OldQType != NewQType && 671 (OldType->getNumArgs() != NewType->getNumArgs() || 672 OldType->isVariadic() != NewType->isVariadic() || 673 !FunctionArgTypesAreEqual(OldType, NewType))) 674 return true; 675 676 // C++ [temp.over.link]p4: 677 // The signature of a function template consists of its function 678 // signature, its return type and its template parameter list. The names 679 // of the template parameters are significant only for establishing the 680 // relationship between the template parameters and the rest of the 681 // signature. 682 // 683 // We check the return type and template parameter lists for function 684 // templates first; the remaining checks follow. 685 // 686 // However, we don't consider either of these when deciding whether 687 // a member introduced by a shadow declaration is hidden. 688 if (!UseUsingDeclRules && NewTemplate && 689 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 690 OldTemplate->getTemplateParameters(), 691 false, TPL_TemplateMatch) || 692 OldType->getResultType() != NewType->getResultType())) 693 return true; 694 695 // If the function is a class member, its signature includes the 696 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. 697 // 698 // As part of this, also check whether one of the member functions 699 // is static, in which case they are not overloads (C++ 700 // 13.1p2). While not part of the definition of the signature, 701 // this check is important to determine whether these functions 702 // can be overloaded. 703 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 704 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 705 if (OldMethod && NewMethod && 706 !OldMethod->isStatic() && !NewMethod->isStatic() && 707 (OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers() || 708 OldMethod->getRefQualifier() != NewMethod->getRefQualifier())) { 709 if (!UseUsingDeclRules && 710 OldMethod->getRefQualifier() != NewMethod->getRefQualifier() && 711 (OldMethod->getRefQualifier() == RQ_None || 712 NewMethod->getRefQualifier() == RQ_None)) { 713 // C++0x [over.load]p2: 714 // - Member function declarations with the same name and the same 715 // parameter-type-list as well as member function template 716 // declarations with the same name, the same parameter-type-list, and 717 // the same template parameter lists cannot be overloaded if any of 718 // them, but not all, have a ref-qualifier (8.3.5). 719 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) 720 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); 721 Diag(OldMethod->getLocation(), diag::note_previous_declaration); 722 } 723 724 return true; 725 } 726 727 // The signatures match; this is not an overload. 728 return false; 729} 730 731/// TryImplicitConversion - Attempt to perform an implicit conversion 732/// from the given expression (Expr) to the given type (ToType). This 733/// function returns an implicit conversion sequence that can be used 734/// to perform the initialization. Given 735/// 736/// void f(float f); 737/// void g(int i) { f(i); } 738/// 739/// this routine would produce an implicit conversion sequence to 740/// describe the initialization of f from i, which will be a standard 741/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 742/// 4.1) followed by a floating-integral conversion (C++ 4.9). 743// 744/// Note that this routine only determines how the conversion can be 745/// performed; it does not actually perform the conversion. As such, 746/// it will not produce any diagnostics if no conversion is available, 747/// but will instead return an implicit conversion sequence of kind 748/// "BadConversion". 749/// 750/// If @p SuppressUserConversions, then user-defined conversions are 751/// not permitted. 752/// If @p AllowExplicit, then explicit user-defined conversions are 753/// permitted. 754static ImplicitConversionSequence 755TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 756 bool SuppressUserConversions, 757 bool AllowExplicit, 758 bool InOverloadResolution, 759 bool CStyle) { 760 ImplicitConversionSequence ICS; 761 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 762 ICS.Standard, CStyle)) { 763 ICS.setStandard(); 764 return ICS; 765 } 766 767 if (!S.getLangOptions().CPlusPlus) { 768 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 769 return ICS; 770 } 771 772 // C++ [over.ics.user]p4: 773 // A conversion of an expression of class type to the same class 774 // type is given Exact Match rank, and a conversion of an 775 // expression of class type to a base class of that type is 776 // given Conversion rank, in spite of the fact that a copy/move 777 // constructor (i.e., a user-defined conversion function) is 778 // called for those cases. 779 QualType FromType = From->getType(); 780 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 781 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 782 S.IsDerivedFrom(FromType, ToType))) { 783 ICS.setStandard(); 784 ICS.Standard.setAsIdentityConversion(); 785 ICS.Standard.setFromType(FromType); 786 ICS.Standard.setAllToTypes(ToType); 787 788 // We don't actually check at this point whether there is a valid 789 // copy/move constructor, since overloading just assumes that it 790 // exists. When we actually perform initialization, we'll find the 791 // appropriate constructor to copy the returned object, if needed. 792 ICS.Standard.CopyConstructor = 0; 793 794 // Determine whether this is considered a derived-to-base conversion. 795 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 796 ICS.Standard.Second = ICK_Derived_To_Base; 797 798 return ICS; 799 } 800 801 if (SuppressUserConversions) { 802 // We're not in the case above, so there is no conversion that 803 // we can perform. 804 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 805 return ICS; 806 } 807 808 // Attempt user-defined conversion. 809 OverloadCandidateSet Conversions(From->getExprLoc()); 810 OverloadingResult UserDefResult 811 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 812 AllowExplicit); 813 814 if (UserDefResult == OR_Success) { 815 ICS.setUserDefined(); 816 // C++ [over.ics.user]p4: 817 // A conversion of an expression of class type to the same class 818 // type is given Exact Match rank, and a conversion of an 819 // expression of class type to a base class of that type is 820 // given Conversion rank, in spite of the fact that a copy 821 // constructor (i.e., a user-defined conversion function) is 822 // called for those cases. 823 if (CXXConstructorDecl *Constructor 824 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 825 QualType FromCanon 826 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 827 QualType ToCanon 828 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 829 if (Constructor->isCopyConstructor() && 830 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 831 // Turn this into a "standard" conversion sequence, so that it 832 // gets ranked with standard conversion sequences. 833 ICS.setStandard(); 834 ICS.Standard.setAsIdentityConversion(); 835 ICS.Standard.setFromType(From->getType()); 836 ICS.Standard.setAllToTypes(ToType); 837 ICS.Standard.CopyConstructor = Constructor; 838 if (ToCanon != FromCanon) 839 ICS.Standard.Second = ICK_Derived_To_Base; 840 } 841 } 842 843 // C++ [over.best.ics]p4: 844 // However, when considering the argument of a user-defined 845 // conversion function that is a candidate by 13.3.1.3 when 846 // invoked for the copying of the temporary in the second step 847 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 848 // 13.3.1.6 in all cases, only standard conversion sequences and 849 // ellipsis conversion sequences are allowed. 850 if (SuppressUserConversions && ICS.isUserDefined()) { 851 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 852 } 853 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 854 ICS.setAmbiguous(); 855 ICS.Ambiguous.setFromType(From->getType()); 856 ICS.Ambiguous.setToType(ToType); 857 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 858 Cand != Conversions.end(); ++Cand) 859 if (Cand->Viable) 860 ICS.Ambiguous.addConversion(Cand->Function); 861 } else { 862 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 863 } 864 865 return ICS; 866} 867 868bool Sema::TryImplicitConversion(InitializationSequence &Sequence, 869 const InitializedEntity &Entity, 870 Expr *Initializer, 871 bool SuppressUserConversions, 872 bool AllowExplicitConversions, 873 bool InOverloadResolution, 874 bool CStyle) { 875 ImplicitConversionSequence ICS 876 = clang::TryImplicitConversion(*this, Initializer, Entity.getType(), 877 SuppressUserConversions, 878 AllowExplicitConversions, 879 InOverloadResolution, 880 CStyle); 881 if (ICS.isBad()) return true; 882 883 // Perform the actual conversion. 884 Sequence.AddConversionSequenceStep(ICS, Entity.getType()); 885 return false; 886} 887 888/// PerformImplicitConversion - Perform an implicit conversion of the 889/// expression From to the type ToType. Returns true if there was an 890/// error, false otherwise. The expression From is replaced with the 891/// converted expression. Flavor is the kind of conversion we're 892/// performing, used in the error message. If @p AllowExplicit, 893/// explicit user-defined conversions are permitted. 894bool 895Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 896 AssignmentAction Action, bool AllowExplicit) { 897 ImplicitConversionSequence ICS; 898 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 899} 900 901bool 902Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 903 AssignmentAction Action, bool AllowExplicit, 904 ImplicitConversionSequence& ICS) { 905 ICS = clang::TryImplicitConversion(*this, From, ToType, 906 /*SuppressUserConversions=*/false, 907 AllowExplicit, 908 /*InOverloadResolution=*/false, 909 /*CStyle=*/false); 910 return PerformImplicitConversion(From, ToType, ICS, Action); 911} 912 913/// \brief Determine whether the conversion from FromType to ToType is a valid 914/// conversion that strips "noreturn" off the nested function type. 915static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 916 QualType ToType, QualType &ResultTy) { 917 if (Context.hasSameUnqualifiedType(FromType, ToType)) 918 return false; 919 920 // Permit the conversion F(t __attribute__((noreturn))) -> F(t) 921 // where F adds one of the following at most once: 922 // - a pointer 923 // - a member pointer 924 // - a block pointer 925 CanQualType CanTo = Context.getCanonicalType(ToType); 926 CanQualType CanFrom = Context.getCanonicalType(FromType); 927 Type::TypeClass TyClass = CanTo->getTypeClass(); 928 if (TyClass != CanFrom->getTypeClass()) return false; 929 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { 930 if (TyClass == Type::Pointer) { 931 CanTo = CanTo.getAs<PointerType>()->getPointeeType(); 932 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType(); 933 } else if (TyClass == Type::BlockPointer) { 934 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType(); 935 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType(); 936 } else if (TyClass == Type::MemberPointer) { 937 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType(); 938 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType(); 939 } else { 940 return false; 941 } 942 943 TyClass = CanTo->getTypeClass(); 944 if (TyClass != CanFrom->getTypeClass()) return false; 945 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) 946 return false; 947 } 948 949 const FunctionType *FromFn = cast<FunctionType>(CanFrom); 950 FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); 951 if (!EInfo.getNoReturn()) return false; 952 953 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); 954 assert(QualType(FromFn, 0).isCanonical()); 955 if (QualType(FromFn, 0) != CanTo) return false; 956 957 ResultTy = ToType; 958 return true; 959} 960 961/// \brief Determine whether the conversion from FromType to ToType is a valid 962/// vector conversion. 963/// 964/// \param ICK Will be set to the vector conversion kind, if this is a vector 965/// conversion. 966static bool IsVectorConversion(ASTContext &Context, QualType FromType, 967 QualType ToType, ImplicitConversionKind &ICK) { 968 // We need at least one of these types to be a vector type to have a vector 969 // conversion. 970 if (!ToType->isVectorType() && !FromType->isVectorType()) 971 return false; 972 973 // Identical types require no conversions. 974 if (Context.hasSameUnqualifiedType(FromType, ToType)) 975 return false; 976 977 // There are no conversions between extended vector types, only identity. 978 if (ToType->isExtVectorType()) { 979 // There are no conversions between extended vector types other than the 980 // identity conversion. 981 if (FromType->isExtVectorType()) 982 return false; 983 984 // Vector splat from any arithmetic type to a vector. 985 if (FromType->isArithmeticType()) { 986 ICK = ICK_Vector_Splat; 987 return true; 988 } 989 } 990 991 // We can perform the conversion between vector types in the following cases: 992 // 1)vector types are equivalent AltiVec and GCC vector types 993 // 2)lax vector conversions are permitted and the vector types are of the 994 // same size 995 if (ToType->isVectorType() && FromType->isVectorType()) { 996 if (Context.areCompatibleVectorTypes(FromType, ToType) || 997 (Context.getLangOptions().LaxVectorConversions && 998 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 999 ICK = ICK_Vector_Conversion; 1000 return true; 1001 } 1002 } 1003 1004 return false; 1005} 1006 1007/// IsStandardConversion - Determines whether there is a standard 1008/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 1009/// expression From to the type ToType. Standard conversion sequences 1010/// only consider non-class types; for conversions that involve class 1011/// types, use TryImplicitConversion. If a conversion exists, SCS will 1012/// contain the standard conversion sequence required to perform this 1013/// conversion and this routine will return true. Otherwise, this 1014/// routine will return false and the value of SCS is unspecified. 1015static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 1016 bool InOverloadResolution, 1017 StandardConversionSequence &SCS, 1018 bool CStyle) { 1019 QualType FromType = From->getType(); 1020 1021 // Standard conversions (C++ [conv]) 1022 SCS.setAsIdentityConversion(); 1023 SCS.DeprecatedStringLiteralToCharPtr = false; 1024 SCS.IncompatibleObjC = false; 1025 SCS.setFromType(FromType); 1026 SCS.CopyConstructor = 0; 1027 1028 // There are no standard conversions for class types in C++, so 1029 // abort early. When overloading in C, however, we do permit 1030 if (FromType->isRecordType() || ToType->isRecordType()) { 1031 if (S.getLangOptions().CPlusPlus) 1032 return false; 1033 1034 // When we're overloading in C, we allow, as standard conversions, 1035 } 1036 1037 // The first conversion can be an lvalue-to-rvalue conversion, 1038 // array-to-pointer conversion, or function-to-pointer conversion 1039 // (C++ 4p1). 1040 1041 if (FromType == S.Context.OverloadTy) { 1042 DeclAccessPair AccessPair; 1043 if (FunctionDecl *Fn 1044 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 1045 AccessPair)) { 1046 // We were able to resolve the address of the overloaded function, 1047 // so we can convert to the type of that function. 1048 FromType = Fn->getType(); 1049 1050 // we can sometimes resolve &foo<int> regardless of ToType, so check 1051 // if the type matches (identity) or we are converting to bool 1052 if (!S.Context.hasSameUnqualifiedType( 1053 S.ExtractUnqualifiedFunctionType(ToType), FromType)) { 1054 QualType resultTy; 1055 // if the function type matches except for [[noreturn]], it's ok 1056 if (!IsNoReturnConversion(S.Context, FromType, 1057 S.ExtractUnqualifiedFunctionType(ToType), resultTy)) 1058 // otherwise, only a boolean conversion is standard 1059 if (!ToType->isBooleanType()) 1060 return false; 1061 } 1062 1063 // Check if the "from" expression is taking the address of an overloaded 1064 // function and recompute the FromType accordingly. Take advantage of the 1065 // fact that non-static member functions *must* have such an address-of 1066 // expression. 1067 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn); 1068 if (Method && !Method->isStatic()) { 1069 assert(isa<UnaryOperator>(From->IgnoreParens()) && 1070 "Non-unary operator on non-static member address"); 1071 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() 1072 == UO_AddrOf && 1073 "Non-address-of operator on non-static member address"); 1074 const Type *ClassType 1075 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1076 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1077 } else if (isa<UnaryOperator>(From->IgnoreParens())) { 1078 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == 1079 UO_AddrOf && 1080 "Non-address-of operator for overloaded function expression"); 1081 FromType = S.Context.getPointerType(FromType); 1082 } 1083 1084 // Check that we've computed the proper type after overload resolution. 1085 assert(S.Context.hasSameType( 1086 FromType, 1087 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1088 } else { 1089 return false; 1090 } 1091 } 1092 // Lvalue-to-rvalue conversion (C++ 4.1): 1093 // An lvalue (3.10) of a non-function, non-array type T can be 1094 // converted to an rvalue. 1095 bool argIsLValue = From->isLValue(); 1096 if (argIsLValue && 1097 !FromType->isFunctionType() && !FromType->isArrayType() && 1098 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1099 SCS.First = ICK_Lvalue_To_Rvalue; 1100 1101 // If T is a non-class type, the type of the rvalue is the 1102 // cv-unqualified version of T. Otherwise, the type of the rvalue 1103 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1104 // just strip the qualifiers because they don't matter. 1105 FromType = FromType.getUnqualifiedType(); 1106 } else if (FromType->isArrayType()) { 1107 // Array-to-pointer conversion (C++ 4.2) 1108 SCS.First = ICK_Array_To_Pointer; 1109 1110 // An lvalue or rvalue of type "array of N T" or "array of unknown 1111 // bound of T" can be converted to an rvalue of type "pointer to 1112 // T" (C++ 4.2p1). 1113 FromType = S.Context.getArrayDecayedType(FromType); 1114 1115 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1116 // This conversion is deprecated. (C++ D.4). 1117 SCS.DeprecatedStringLiteralToCharPtr = true; 1118 1119 // For the purpose of ranking in overload resolution 1120 // (13.3.3.1.1), this conversion is considered an 1121 // array-to-pointer conversion followed by a qualification 1122 // conversion (4.4). (C++ 4.2p2) 1123 SCS.Second = ICK_Identity; 1124 SCS.Third = ICK_Qualification; 1125 SCS.setAllToTypes(FromType); 1126 return true; 1127 } 1128 } else if (FromType->isFunctionType() && argIsLValue) { 1129 // Function-to-pointer conversion (C++ 4.3). 1130 SCS.First = ICK_Function_To_Pointer; 1131 1132 // An lvalue of function type T can be converted to an rvalue of 1133 // type "pointer to T." The result is a pointer to the 1134 // function. (C++ 4.3p1). 1135 FromType = S.Context.getPointerType(FromType); 1136 } else { 1137 // We don't require any conversions for the first step. 1138 SCS.First = ICK_Identity; 1139 } 1140 SCS.setToType(0, FromType); 1141 1142 // The second conversion can be an integral promotion, floating 1143 // point promotion, integral conversion, floating point conversion, 1144 // floating-integral conversion, pointer conversion, 1145 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1146 // For overloading in C, this can also be a "compatible-type" 1147 // conversion. 1148 bool IncompatibleObjC = false; 1149 ImplicitConversionKind SecondICK = ICK_Identity; 1150 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1151 // The unqualified versions of the types are the same: there's no 1152 // conversion to do. 1153 SCS.Second = ICK_Identity; 1154 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1155 // Integral promotion (C++ 4.5). 1156 SCS.Second = ICK_Integral_Promotion; 1157 FromType = ToType.getUnqualifiedType(); 1158 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1159 // Floating point promotion (C++ 4.6). 1160 SCS.Second = ICK_Floating_Promotion; 1161 FromType = ToType.getUnqualifiedType(); 1162 } else if (S.IsComplexPromotion(FromType, ToType)) { 1163 // Complex promotion (Clang extension) 1164 SCS.Second = ICK_Complex_Promotion; 1165 FromType = ToType.getUnqualifiedType(); 1166 } else if (ToType->isBooleanType() && 1167 (FromType->isArithmeticType() || 1168 FromType->isAnyPointerType() || 1169 FromType->isBlockPointerType() || 1170 FromType->isMemberPointerType() || 1171 FromType->isNullPtrType())) { 1172 // Boolean conversions (C++ 4.12). 1173 SCS.Second = ICK_Boolean_Conversion; 1174 FromType = S.Context.BoolTy; 1175 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1176 ToType->isIntegralType(S.Context)) { 1177 // Integral conversions (C++ 4.7). 1178 SCS.Second = ICK_Integral_Conversion; 1179 FromType = ToType.getUnqualifiedType(); 1180 } else if (FromType->isAnyComplexType() && ToType->isComplexType()) { 1181 // Complex conversions (C99 6.3.1.6) 1182 SCS.Second = ICK_Complex_Conversion; 1183 FromType = ToType.getUnqualifiedType(); 1184 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1185 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1186 // Complex-real conversions (C99 6.3.1.7) 1187 SCS.Second = ICK_Complex_Real; 1188 FromType = ToType.getUnqualifiedType(); 1189 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1190 // Floating point conversions (C++ 4.8). 1191 SCS.Second = ICK_Floating_Conversion; 1192 FromType = ToType.getUnqualifiedType(); 1193 } else if ((FromType->isRealFloatingType() && 1194 ToType->isIntegralType(S.Context)) || 1195 (FromType->isIntegralOrUnscopedEnumerationType() && 1196 ToType->isRealFloatingType())) { 1197 // Floating-integral conversions (C++ 4.9). 1198 SCS.Second = ICK_Floating_Integral; 1199 FromType = ToType.getUnqualifiedType(); 1200 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { 1201 SCS.Second = ICK_Block_Pointer_Conversion; 1202 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1203 FromType, IncompatibleObjC)) { 1204 // Pointer conversions (C++ 4.10). 1205 SCS.Second = ICK_Pointer_Conversion; 1206 SCS.IncompatibleObjC = IncompatibleObjC; 1207 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1208 InOverloadResolution, FromType)) { 1209 // Pointer to member conversions (4.11). 1210 SCS.Second = ICK_Pointer_Member; 1211 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1212 SCS.Second = SecondICK; 1213 FromType = ToType.getUnqualifiedType(); 1214 } else if (!S.getLangOptions().CPlusPlus && 1215 S.Context.typesAreCompatible(ToType, FromType)) { 1216 // Compatible conversions (Clang extension for C function overloading) 1217 SCS.Second = ICK_Compatible_Conversion; 1218 FromType = ToType.getUnqualifiedType(); 1219 } else if (IsNoReturnConversion(S.Context, FromType, ToType, FromType)) { 1220 // Treat a conversion that strips "noreturn" as an identity conversion. 1221 SCS.Second = ICK_NoReturn_Adjustment; 1222 } else if (IsTransparentUnionStandardConversion(S, From, ToType, 1223 InOverloadResolution, 1224 SCS, CStyle)) { 1225 SCS.Second = ICK_TransparentUnionConversion; 1226 FromType = ToType; 1227 } else { 1228 // No second conversion required. 1229 SCS.Second = ICK_Identity; 1230 } 1231 SCS.setToType(1, FromType); 1232 1233 QualType CanonFrom; 1234 QualType CanonTo; 1235 // The third conversion can be a qualification conversion (C++ 4p1). 1236 if (S.IsQualificationConversion(FromType, ToType, CStyle)) { 1237 SCS.Third = ICK_Qualification; 1238 FromType = ToType; 1239 CanonFrom = S.Context.getCanonicalType(FromType); 1240 CanonTo = S.Context.getCanonicalType(ToType); 1241 } else { 1242 // No conversion required 1243 SCS.Third = ICK_Identity; 1244 1245 // C++ [over.best.ics]p6: 1246 // [...] Any difference in top-level cv-qualification is 1247 // subsumed by the initialization itself and does not constitute 1248 // a conversion. [...] 1249 CanonFrom = S.Context.getCanonicalType(FromType); 1250 CanonTo = S.Context.getCanonicalType(ToType); 1251 if (CanonFrom.getLocalUnqualifiedType() 1252 == CanonTo.getLocalUnqualifiedType() && 1253 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1254 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1255 FromType = ToType; 1256 CanonFrom = CanonTo; 1257 } 1258 } 1259 SCS.setToType(2, FromType); 1260 1261 // If we have not converted the argument type to the parameter type, 1262 // this is a bad conversion sequence. 1263 if (CanonFrom != CanonTo) 1264 return false; 1265 1266 return true; 1267} 1268 1269static bool 1270IsTransparentUnionStandardConversion(Sema &S, Expr* From, 1271 QualType &ToType, 1272 bool InOverloadResolution, 1273 StandardConversionSequence &SCS, 1274 bool CStyle) { 1275 1276 const RecordType *UT = ToType->getAsUnionType(); 1277 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 1278 return false; 1279 // The field to initialize within the transparent union. 1280 RecordDecl *UD = UT->getDecl(); 1281 // It's compatible if the expression matches any of the fields. 1282 for (RecordDecl::field_iterator it = UD->field_begin(), 1283 itend = UD->field_end(); 1284 it != itend; ++it) { 1285 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, CStyle)) { 1286 ToType = it->getType(); 1287 return true; 1288 } 1289 } 1290 return false; 1291} 1292 1293/// IsIntegralPromotion - Determines whether the conversion from the 1294/// expression From (whose potentially-adjusted type is FromType) to 1295/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1296/// sets PromotedType to the promoted type. 1297bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1298 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1299 // All integers are built-in. 1300 if (!To) { 1301 return false; 1302 } 1303 1304 // An rvalue of type char, signed char, unsigned char, short int, or 1305 // unsigned short int can be converted to an rvalue of type int if 1306 // int can represent all the values of the source type; otherwise, 1307 // the source rvalue can be converted to an rvalue of type unsigned 1308 // int (C++ 4.5p1). 1309 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1310 !FromType->isEnumeralType()) { 1311 if (// We can promote any signed, promotable integer type to an int 1312 (FromType->isSignedIntegerType() || 1313 // We can promote any unsigned integer type whose size is 1314 // less than int to an int. 1315 (!FromType->isSignedIntegerType() && 1316 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1317 return To->getKind() == BuiltinType::Int; 1318 } 1319 1320 return To->getKind() == BuiltinType::UInt; 1321 } 1322 1323 // C++0x [conv.prom]p3: 1324 // A prvalue of an unscoped enumeration type whose underlying type is not 1325 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1326 // following types that can represent all the values of the enumeration 1327 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1328 // unsigned int, long int, unsigned long int, long long int, or unsigned 1329 // long long int. If none of the types in that list can represent all the 1330 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1331 // type can be converted to an rvalue a prvalue of the extended integer type 1332 // with lowest integer conversion rank (4.13) greater than the rank of long 1333 // long in which all the values of the enumeration can be represented. If 1334 // there are two such extended types, the signed one is chosen. 1335 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1336 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1337 // provided for a scoped enumeration. 1338 if (FromEnumType->getDecl()->isScoped()) 1339 return false; 1340 1341 // We have already pre-calculated the promotion type, so this is trivial. 1342 if (ToType->isIntegerType() && 1343 !RequireCompleteType(From->getLocStart(), FromType, PDiag())) 1344 return Context.hasSameUnqualifiedType(ToType, 1345 FromEnumType->getDecl()->getPromotionType()); 1346 } 1347 1348 // C++0x [conv.prom]p2: 1349 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1350 // to an rvalue a prvalue of the first of the following types that can 1351 // represent all the values of its underlying type: int, unsigned int, 1352 // long int, unsigned long int, long long int, or unsigned long long int. 1353 // If none of the types in that list can represent all the values of its 1354 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1355 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1356 // type. 1357 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1358 ToType->isIntegerType()) { 1359 // Determine whether the type we're converting from is signed or 1360 // unsigned. 1361 bool FromIsSigned; 1362 uint64_t FromSize = Context.getTypeSize(FromType); 1363 1364 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1365 FromIsSigned = true; 1366 1367 // The types we'll try to promote to, in the appropriate 1368 // order. Try each of these types. 1369 QualType PromoteTypes[6] = { 1370 Context.IntTy, Context.UnsignedIntTy, 1371 Context.LongTy, Context.UnsignedLongTy , 1372 Context.LongLongTy, Context.UnsignedLongLongTy 1373 }; 1374 for (int Idx = 0; Idx < 6; ++Idx) { 1375 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1376 if (FromSize < ToSize || 1377 (FromSize == ToSize && 1378 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1379 // We found the type that we can promote to. If this is the 1380 // type we wanted, we have a promotion. Otherwise, no 1381 // promotion. 1382 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1383 } 1384 } 1385 } 1386 1387 // An rvalue for an integral bit-field (9.6) can be converted to an 1388 // rvalue of type int if int can represent all the values of the 1389 // bit-field; otherwise, it can be converted to unsigned int if 1390 // unsigned int can represent all the values of the bit-field. If 1391 // the bit-field is larger yet, no integral promotion applies to 1392 // it. If the bit-field has an enumerated type, it is treated as any 1393 // other value of that type for promotion purposes (C++ 4.5p3). 1394 // FIXME: We should delay checking of bit-fields until we actually perform the 1395 // conversion. 1396 using llvm::APSInt; 1397 if (From) 1398 if (FieldDecl *MemberDecl = From->getBitField()) { 1399 APSInt BitWidth; 1400 if (FromType->isIntegralType(Context) && 1401 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1402 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1403 ToSize = Context.getTypeSize(ToType); 1404 1405 // Are we promoting to an int from a bitfield that fits in an int? 1406 if (BitWidth < ToSize || 1407 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1408 return To->getKind() == BuiltinType::Int; 1409 } 1410 1411 // Are we promoting to an unsigned int from an unsigned bitfield 1412 // that fits into an unsigned int? 1413 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1414 return To->getKind() == BuiltinType::UInt; 1415 } 1416 1417 return false; 1418 } 1419 } 1420 1421 // An rvalue of type bool can be converted to an rvalue of type int, 1422 // with false becoming zero and true becoming one (C++ 4.5p4). 1423 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1424 return true; 1425 } 1426 1427 return false; 1428} 1429 1430/// IsFloatingPointPromotion - Determines whether the conversion from 1431/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1432/// returns true and sets PromotedType to the promoted type. 1433bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1434 /// An rvalue of type float can be converted to an rvalue of type 1435 /// double. (C++ 4.6p1). 1436 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1437 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1438 if (FromBuiltin->getKind() == BuiltinType::Float && 1439 ToBuiltin->getKind() == BuiltinType::Double) 1440 return true; 1441 1442 // C99 6.3.1.5p1: 1443 // When a float is promoted to double or long double, or a 1444 // double is promoted to long double [...]. 1445 if (!getLangOptions().CPlusPlus && 1446 (FromBuiltin->getKind() == BuiltinType::Float || 1447 FromBuiltin->getKind() == BuiltinType::Double) && 1448 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1449 return true; 1450 } 1451 1452 return false; 1453} 1454 1455/// \brief Determine if a conversion is a complex promotion. 1456/// 1457/// A complex promotion is defined as a complex -> complex conversion 1458/// where the conversion between the underlying real types is a 1459/// floating-point or integral promotion. 1460bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1461 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1462 if (!FromComplex) 1463 return false; 1464 1465 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1466 if (!ToComplex) 1467 return false; 1468 1469 return IsFloatingPointPromotion(FromComplex->getElementType(), 1470 ToComplex->getElementType()) || 1471 IsIntegralPromotion(0, FromComplex->getElementType(), 1472 ToComplex->getElementType()); 1473} 1474 1475/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1476/// the pointer type FromPtr to a pointer to type ToPointee, with the 1477/// same type qualifiers as FromPtr has on its pointee type. ToType, 1478/// if non-empty, will be a pointer to ToType that may or may not have 1479/// the right set of qualifiers on its pointee. 1480static QualType 1481BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1482 QualType ToPointee, QualType ToType, 1483 ASTContext &Context) { 1484 assert((FromPtr->getTypeClass() == Type::Pointer || 1485 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1486 "Invalid similarly-qualified pointer type"); 1487 1488 /// \brief Conversions to 'id' subsume cv-qualifier conversions. 1489 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1490 return ToType.getUnqualifiedType(); 1491 1492 QualType CanonFromPointee 1493 = Context.getCanonicalType(FromPtr->getPointeeType()); 1494 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1495 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1496 1497 // Exact qualifier match -> return the pointer type we're converting to. 1498 if (CanonToPointee.getLocalQualifiers() == Quals) { 1499 // ToType is exactly what we need. Return it. 1500 if (!ToType.isNull()) 1501 return ToType.getUnqualifiedType(); 1502 1503 // Build a pointer to ToPointee. It has the right qualifiers 1504 // already. 1505 if (isa<ObjCObjectPointerType>(ToType)) 1506 return Context.getObjCObjectPointerType(ToPointee); 1507 return Context.getPointerType(ToPointee); 1508 } 1509 1510 // Just build a canonical type that has the right qualifiers. 1511 QualType QualifiedCanonToPointee 1512 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1513 1514 if (isa<ObjCObjectPointerType>(ToType)) 1515 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1516 return Context.getPointerType(QualifiedCanonToPointee); 1517} 1518 1519static bool isNullPointerConstantForConversion(Expr *Expr, 1520 bool InOverloadResolution, 1521 ASTContext &Context) { 1522 // Handle value-dependent integral null pointer constants correctly. 1523 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1524 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1525 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1526 return !InOverloadResolution; 1527 1528 return Expr->isNullPointerConstant(Context, 1529 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1530 : Expr::NPC_ValueDependentIsNull); 1531} 1532 1533/// IsPointerConversion - Determines whether the conversion of the 1534/// expression From, which has the (possibly adjusted) type FromType, 1535/// can be converted to the type ToType via a pointer conversion (C++ 1536/// 4.10). If so, returns true and places the converted type (that 1537/// might differ from ToType in its cv-qualifiers at some level) into 1538/// ConvertedType. 1539/// 1540/// This routine also supports conversions to and from block pointers 1541/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1542/// pointers to interfaces. FIXME: Once we've determined the 1543/// appropriate overloading rules for Objective-C, we may want to 1544/// split the Objective-C checks into a different routine; however, 1545/// GCC seems to consider all of these conversions to be pointer 1546/// conversions, so for now they live here. IncompatibleObjC will be 1547/// set if the conversion is an allowed Objective-C conversion that 1548/// should result in a warning. 1549bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1550 bool InOverloadResolution, 1551 QualType& ConvertedType, 1552 bool &IncompatibleObjC) { 1553 IncompatibleObjC = false; 1554 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 1555 IncompatibleObjC)) 1556 return true; 1557 1558 // Conversion from a null pointer constant to any Objective-C pointer type. 1559 if (ToType->isObjCObjectPointerType() && 1560 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1561 ConvertedType = ToType; 1562 return true; 1563 } 1564 1565 // Blocks: Block pointers can be converted to void*. 1566 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1567 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1568 ConvertedType = ToType; 1569 return true; 1570 } 1571 // Blocks: A null pointer constant can be converted to a block 1572 // pointer type. 1573 if (ToType->isBlockPointerType() && 1574 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1575 ConvertedType = ToType; 1576 return true; 1577 } 1578 1579 // If the left-hand-side is nullptr_t, the right side can be a null 1580 // pointer constant. 1581 if (ToType->isNullPtrType() && 1582 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1583 ConvertedType = ToType; 1584 return true; 1585 } 1586 1587 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1588 if (!ToTypePtr) 1589 return false; 1590 1591 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1592 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1593 ConvertedType = ToType; 1594 return true; 1595 } 1596 1597 // Beyond this point, both types need to be pointers 1598 // , including objective-c pointers. 1599 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1600 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1601 ConvertedType = BuildSimilarlyQualifiedPointerType( 1602 FromType->getAs<ObjCObjectPointerType>(), 1603 ToPointeeType, 1604 ToType, Context); 1605 return true; 1606 } 1607 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1608 if (!FromTypePtr) 1609 return false; 1610 1611 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1612 1613 // If the unqualified pointee types are the same, this can't be a 1614 // pointer conversion, so don't do all of the work below. 1615 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1616 return false; 1617 1618 // An rvalue of type "pointer to cv T," where T is an object type, 1619 // can be converted to an rvalue of type "pointer to cv void" (C++ 1620 // 4.10p2). 1621 if (FromPointeeType->isIncompleteOrObjectType() && 1622 ToPointeeType->isVoidType()) { 1623 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1624 ToPointeeType, 1625 ToType, Context); 1626 return true; 1627 } 1628 1629 // When we're overloading in C, we allow a special kind of pointer 1630 // conversion for compatible-but-not-identical pointee types. 1631 if (!getLangOptions().CPlusPlus && 1632 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1633 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1634 ToPointeeType, 1635 ToType, Context); 1636 return true; 1637 } 1638 1639 // C++ [conv.ptr]p3: 1640 // 1641 // An rvalue of type "pointer to cv D," where D is a class type, 1642 // can be converted to an rvalue of type "pointer to cv B," where 1643 // B is a base class (clause 10) of D. If B is an inaccessible 1644 // (clause 11) or ambiguous (10.2) base class of D, a program that 1645 // necessitates this conversion is ill-formed. The result of the 1646 // conversion is a pointer to the base class sub-object of the 1647 // derived class object. The null pointer value is converted to 1648 // the null pointer value of the destination type. 1649 // 1650 // Note that we do not check for ambiguity or inaccessibility 1651 // here. That is handled by CheckPointerConversion. 1652 if (getLangOptions().CPlusPlus && 1653 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1654 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1655 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1656 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1657 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1658 ToPointeeType, 1659 ToType, Context); 1660 return true; 1661 } 1662 1663 return false; 1664} 1665 1666/// isObjCPointerConversion - Determines whether this is an 1667/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1668/// with the same arguments and return values. 1669bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1670 QualType& ConvertedType, 1671 bool &IncompatibleObjC) { 1672 if (!getLangOptions().ObjC1) 1673 return false; 1674 1675 // First, we handle all conversions on ObjC object pointer types. 1676 const ObjCObjectPointerType* ToObjCPtr = 1677 ToType->getAs<ObjCObjectPointerType>(); 1678 const ObjCObjectPointerType *FromObjCPtr = 1679 FromType->getAs<ObjCObjectPointerType>(); 1680 1681 if (ToObjCPtr && FromObjCPtr) { 1682 // If the pointee types are the same (ignoring qualifications), 1683 // then this is not a pointer conversion. 1684 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 1685 FromObjCPtr->getPointeeType())) 1686 return false; 1687 1688 // Objective C++: We're able to convert between "id" or "Class" and a 1689 // pointer to any interface (in both directions). 1690 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1691 ConvertedType = ToType; 1692 return true; 1693 } 1694 // Conversions with Objective-C's id<...>. 1695 if ((FromObjCPtr->isObjCQualifiedIdType() || 1696 ToObjCPtr->isObjCQualifiedIdType()) && 1697 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1698 /*compare=*/false)) { 1699 ConvertedType = ToType; 1700 return true; 1701 } 1702 // Objective C++: We're able to convert from a pointer to an 1703 // interface to a pointer to a different interface. 1704 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1705 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1706 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1707 if (getLangOptions().CPlusPlus && LHS && RHS && 1708 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1709 FromObjCPtr->getPointeeType())) 1710 return false; 1711 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1712 ToObjCPtr->getPointeeType(), 1713 ToType, Context); 1714 return true; 1715 } 1716 1717 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1718 // Okay: this is some kind of implicit downcast of Objective-C 1719 // interfaces, which is permitted. However, we're going to 1720 // complain about it. 1721 IncompatibleObjC = true; 1722 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1723 ToObjCPtr->getPointeeType(), 1724 ToType, Context); 1725 return true; 1726 } 1727 } 1728 // Beyond this point, both types need to be C pointers or block pointers. 1729 QualType ToPointeeType; 1730 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1731 ToPointeeType = ToCPtr->getPointeeType(); 1732 else if (const BlockPointerType *ToBlockPtr = 1733 ToType->getAs<BlockPointerType>()) { 1734 // Objective C++: We're able to convert from a pointer to any object 1735 // to a block pointer type. 1736 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1737 ConvertedType = ToType; 1738 return true; 1739 } 1740 ToPointeeType = ToBlockPtr->getPointeeType(); 1741 } 1742 else if (FromType->getAs<BlockPointerType>() && 1743 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1744 // Objective C++: We're able to convert from a block pointer type to a 1745 // pointer to any object. 1746 ConvertedType = ToType; 1747 return true; 1748 } 1749 else 1750 return false; 1751 1752 QualType FromPointeeType; 1753 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1754 FromPointeeType = FromCPtr->getPointeeType(); 1755 else if (const BlockPointerType *FromBlockPtr = 1756 FromType->getAs<BlockPointerType>()) 1757 FromPointeeType = FromBlockPtr->getPointeeType(); 1758 else 1759 return false; 1760 1761 // If we have pointers to pointers, recursively check whether this 1762 // is an Objective-C conversion. 1763 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1764 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1765 IncompatibleObjC)) { 1766 // We always complain about this conversion. 1767 IncompatibleObjC = true; 1768 ConvertedType = Context.getPointerType(ConvertedType); 1769 return true; 1770 } 1771 // Allow conversion of pointee being objective-c pointer to another one; 1772 // as in I* to id. 1773 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1774 ToPointeeType->getAs<ObjCObjectPointerType>() && 1775 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1776 IncompatibleObjC)) { 1777 ConvertedType = Context.getPointerType(ConvertedType); 1778 return true; 1779 } 1780 1781 // If we have pointers to functions or blocks, check whether the only 1782 // differences in the argument and result types are in Objective-C 1783 // pointer conversions. If so, we permit the conversion (but 1784 // complain about it). 1785 const FunctionProtoType *FromFunctionType 1786 = FromPointeeType->getAs<FunctionProtoType>(); 1787 const FunctionProtoType *ToFunctionType 1788 = ToPointeeType->getAs<FunctionProtoType>(); 1789 if (FromFunctionType && ToFunctionType) { 1790 // If the function types are exactly the same, this isn't an 1791 // Objective-C pointer conversion. 1792 if (Context.getCanonicalType(FromPointeeType) 1793 == Context.getCanonicalType(ToPointeeType)) 1794 return false; 1795 1796 // Perform the quick checks that will tell us whether these 1797 // function types are obviously different. 1798 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1799 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1800 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1801 return false; 1802 1803 bool HasObjCConversion = false; 1804 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1805 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1806 // Okay, the types match exactly. Nothing to do. 1807 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1808 ToFunctionType->getResultType(), 1809 ConvertedType, IncompatibleObjC)) { 1810 // Okay, we have an Objective-C pointer conversion. 1811 HasObjCConversion = true; 1812 } else { 1813 // Function types are too different. Abort. 1814 return false; 1815 } 1816 1817 // Check argument types. 1818 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1819 ArgIdx != NumArgs; ++ArgIdx) { 1820 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1821 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1822 if (Context.getCanonicalType(FromArgType) 1823 == Context.getCanonicalType(ToArgType)) { 1824 // Okay, the types match exactly. Nothing to do. 1825 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1826 ConvertedType, IncompatibleObjC)) { 1827 // Okay, we have an Objective-C pointer conversion. 1828 HasObjCConversion = true; 1829 } else { 1830 // Argument types are too different. Abort. 1831 return false; 1832 } 1833 } 1834 1835 if (HasObjCConversion) { 1836 // We had an Objective-C conversion. Allow this pointer 1837 // conversion, but complain about it. 1838 ConvertedType = ToType; 1839 IncompatibleObjC = true; 1840 return true; 1841 } 1842 } 1843 1844 return false; 1845} 1846 1847bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, 1848 QualType& ConvertedType) { 1849 QualType ToPointeeType; 1850 if (const BlockPointerType *ToBlockPtr = 1851 ToType->getAs<BlockPointerType>()) 1852 ToPointeeType = ToBlockPtr->getPointeeType(); 1853 else 1854 return false; 1855 1856 QualType FromPointeeType; 1857 if (const BlockPointerType *FromBlockPtr = 1858 FromType->getAs<BlockPointerType>()) 1859 FromPointeeType = FromBlockPtr->getPointeeType(); 1860 else 1861 return false; 1862 // We have pointer to blocks, check whether the only 1863 // differences in the argument and result types are in Objective-C 1864 // pointer conversions. If so, we permit the conversion. 1865 1866 const FunctionProtoType *FromFunctionType 1867 = FromPointeeType->getAs<FunctionProtoType>(); 1868 const FunctionProtoType *ToFunctionType 1869 = ToPointeeType->getAs<FunctionProtoType>(); 1870 1871 if (!FromFunctionType || !ToFunctionType) 1872 return false; 1873 1874 if (Context.hasSameType(FromPointeeType, ToPointeeType)) 1875 return true; 1876 1877 // Perform the quick checks that will tell us whether these 1878 // function types are obviously different. 1879 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1880 FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) 1881 return false; 1882 1883 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); 1884 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); 1885 if (FromEInfo != ToEInfo) 1886 return false; 1887 1888 bool IncompatibleObjC = false; 1889 if (Context.hasSameType(FromFunctionType->getResultType(), 1890 ToFunctionType->getResultType())) { 1891 // Okay, the types match exactly. Nothing to do. 1892 } else { 1893 QualType RHS = FromFunctionType->getResultType(); 1894 QualType LHS = ToFunctionType->getResultType(); 1895 if ((!getLangOptions().CPlusPlus || !RHS->isRecordType()) && 1896 !RHS.hasQualifiers() && LHS.hasQualifiers()) 1897 LHS = LHS.getUnqualifiedType(); 1898 1899 if (Context.hasSameType(RHS,LHS)) { 1900 // OK exact match. 1901 } else if (isObjCPointerConversion(RHS, LHS, 1902 ConvertedType, IncompatibleObjC)) { 1903 if (IncompatibleObjC) 1904 return false; 1905 // Okay, we have an Objective-C pointer conversion. 1906 } 1907 else 1908 return false; 1909 } 1910 1911 // Check argument types. 1912 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1913 ArgIdx != NumArgs; ++ArgIdx) { 1914 IncompatibleObjC = false; 1915 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1916 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1917 if (Context.hasSameType(FromArgType, ToArgType)) { 1918 // Okay, the types match exactly. Nothing to do. 1919 } else if (isObjCPointerConversion(ToArgType, FromArgType, 1920 ConvertedType, IncompatibleObjC)) { 1921 if (IncompatibleObjC) 1922 return false; 1923 // Okay, we have an Objective-C pointer conversion. 1924 } else 1925 // Argument types are too different. Abort. 1926 return false; 1927 } 1928 ConvertedType = ToType; 1929 return true; 1930} 1931 1932/// FunctionArgTypesAreEqual - This routine checks two function proto types 1933/// for equlity of their argument types. Caller has already checked that 1934/// they have same number of arguments. This routine assumes that Objective-C 1935/// pointer types which only differ in their protocol qualifiers are equal. 1936bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, 1937 const FunctionProtoType *NewType) { 1938 if (!getLangOptions().ObjC1) 1939 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1940 NewType->arg_type_begin()); 1941 1942 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1943 N = NewType->arg_type_begin(), 1944 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1945 QualType ToType = (*O); 1946 QualType FromType = (*N); 1947 if (ToType != FromType) { 1948 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1949 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1950 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1951 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1952 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1953 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1954 continue; 1955 } 1956 else if (const ObjCObjectPointerType *PTTo = 1957 ToType->getAs<ObjCObjectPointerType>()) { 1958 if (const ObjCObjectPointerType *PTFr = 1959 FromType->getAs<ObjCObjectPointerType>()) 1960 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1961 continue; 1962 } 1963 return false; 1964 } 1965 } 1966 return true; 1967} 1968 1969/// CheckPointerConversion - Check the pointer conversion from the 1970/// expression From to the type ToType. This routine checks for 1971/// ambiguous or inaccessible derived-to-base pointer 1972/// conversions for which IsPointerConversion has already returned 1973/// true. It returns true and produces a diagnostic if there was an 1974/// error, or returns false otherwise. 1975bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1976 CastKind &Kind, 1977 CXXCastPath& BasePath, 1978 bool IgnoreBaseAccess) { 1979 QualType FromType = From->getType(); 1980 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 1981 1982 Kind = CK_BitCast; 1983 1984 if (CXXBoolLiteralExpr* LitBool 1985 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1986 if (!IsCStyleOrFunctionalCast && LitBool->getValue() == false) 1987 DiagRuntimeBehavior(LitBool->getExprLoc(), From, 1988 PDiag(diag::warn_init_pointer_from_false) << ToType); 1989 1990 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1991 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1992 QualType FromPointeeType = FromPtrType->getPointeeType(), 1993 ToPointeeType = ToPtrType->getPointeeType(); 1994 1995 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1996 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1997 // We must have a derived-to-base conversion. Check an 1998 // ambiguous or inaccessible conversion. 1999 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 2000 From->getExprLoc(), 2001 From->getSourceRange(), &BasePath, 2002 IgnoreBaseAccess)) 2003 return true; 2004 2005 // The conversion was successful. 2006 Kind = CK_DerivedToBase; 2007 } 2008 } 2009 if (const ObjCObjectPointerType *FromPtrType = 2010 FromType->getAs<ObjCObjectPointerType>()) { 2011 if (const ObjCObjectPointerType *ToPtrType = 2012 ToType->getAs<ObjCObjectPointerType>()) { 2013 // Objective-C++ conversions are always okay. 2014 // FIXME: We should have a different class of conversions for the 2015 // Objective-C++ implicit conversions. 2016 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 2017 return false; 2018 } 2019 } 2020 2021 // We shouldn't fall into this case unless it's valid for other 2022 // reasons. 2023 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 2024 Kind = CK_NullToPointer; 2025 2026 return false; 2027} 2028 2029/// IsMemberPointerConversion - Determines whether the conversion of the 2030/// expression From, which has the (possibly adjusted) type FromType, can be 2031/// converted to the type ToType via a member pointer conversion (C++ 4.11). 2032/// If so, returns true and places the converted type (that might differ from 2033/// ToType in its cv-qualifiers at some level) into ConvertedType. 2034bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 2035 QualType ToType, 2036 bool InOverloadResolution, 2037 QualType &ConvertedType) { 2038 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 2039 if (!ToTypePtr) 2040 return false; 2041 2042 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 2043 if (From->isNullPointerConstant(Context, 2044 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 2045 : Expr::NPC_ValueDependentIsNull)) { 2046 ConvertedType = ToType; 2047 return true; 2048 } 2049 2050 // Otherwise, both types have to be member pointers. 2051 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 2052 if (!FromTypePtr) 2053 return false; 2054 2055 // A pointer to member of B can be converted to a pointer to member of D, 2056 // where D is derived from B (C++ 4.11p2). 2057 QualType FromClass(FromTypePtr->getClass(), 0); 2058 QualType ToClass(ToTypePtr->getClass(), 0); 2059 2060 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && 2061 !RequireCompleteType(From->getLocStart(), ToClass, PDiag()) && 2062 IsDerivedFrom(ToClass, FromClass)) { 2063 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 2064 ToClass.getTypePtr()); 2065 return true; 2066 } 2067 2068 return false; 2069} 2070 2071/// CheckMemberPointerConversion - Check the member pointer conversion from the 2072/// expression From to the type ToType. This routine checks for ambiguous or 2073/// virtual or inaccessible base-to-derived member pointer conversions 2074/// for which IsMemberPointerConversion has already returned true. It returns 2075/// true and produces a diagnostic if there was an error, or returns false 2076/// otherwise. 2077bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 2078 CastKind &Kind, 2079 CXXCastPath &BasePath, 2080 bool IgnoreBaseAccess) { 2081 QualType FromType = From->getType(); 2082 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 2083 if (!FromPtrType) { 2084 // This must be a null pointer to member pointer conversion 2085 assert(From->isNullPointerConstant(Context, 2086 Expr::NPC_ValueDependentIsNull) && 2087 "Expr must be null pointer constant!"); 2088 Kind = CK_NullToMemberPointer; 2089 return false; 2090 } 2091 2092 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 2093 assert(ToPtrType && "No member pointer cast has a target type " 2094 "that is not a member pointer."); 2095 2096 QualType FromClass = QualType(FromPtrType->getClass(), 0); 2097 QualType ToClass = QualType(ToPtrType->getClass(), 0); 2098 2099 // FIXME: What about dependent types? 2100 assert(FromClass->isRecordType() && "Pointer into non-class."); 2101 assert(ToClass->isRecordType() && "Pointer into non-class."); 2102 2103 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 2104 /*DetectVirtual=*/true); 2105 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 2106 assert(DerivationOkay && 2107 "Should not have been called if derivation isn't OK."); 2108 (void)DerivationOkay; 2109 2110 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 2111 getUnqualifiedType())) { 2112 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 2113 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 2114 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 2115 return true; 2116 } 2117 2118 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 2119 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 2120 << FromClass << ToClass << QualType(VBase, 0) 2121 << From->getSourceRange(); 2122 return true; 2123 } 2124 2125 if (!IgnoreBaseAccess) 2126 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 2127 Paths.front(), 2128 diag::err_downcast_from_inaccessible_base); 2129 2130 // Must be a base to derived member conversion. 2131 BuildBasePathArray(Paths, BasePath); 2132 Kind = CK_BaseToDerivedMemberPointer; 2133 return false; 2134} 2135 2136/// IsQualificationConversion - Determines whether the conversion from 2137/// an rvalue of type FromType to ToType is a qualification conversion 2138/// (C++ 4.4). 2139bool 2140Sema::IsQualificationConversion(QualType FromType, QualType ToType, 2141 bool CStyle) { 2142 FromType = Context.getCanonicalType(FromType); 2143 ToType = Context.getCanonicalType(ToType); 2144 2145 // If FromType and ToType are the same type, this is not a 2146 // qualification conversion. 2147 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 2148 return false; 2149 2150 // (C++ 4.4p4): 2151 // A conversion can add cv-qualifiers at levels other than the first 2152 // in multi-level pointers, subject to the following rules: [...] 2153 bool PreviousToQualsIncludeConst = true; 2154 bool UnwrappedAnyPointer = false; 2155 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 2156 // Within each iteration of the loop, we check the qualifiers to 2157 // determine if this still looks like a qualification 2158 // conversion. Then, if all is well, we unwrap one more level of 2159 // pointers or pointers-to-members and do it all again 2160 // until there are no more pointers or pointers-to-members left to 2161 // unwrap. 2162 UnwrappedAnyPointer = true; 2163 2164 // -- for every j > 0, if const is in cv 1,j then const is in cv 2165 // 2,j, and similarly for volatile. 2166 if (!CStyle && !ToType.isAtLeastAsQualifiedAs(FromType)) 2167 return false; 2168 2169 // -- if the cv 1,j and cv 2,j are different, then const is in 2170 // every cv for 0 < k < j. 2171 if (!CStyle && FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 2172 && !PreviousToQualsIncludeConst) 2173 return false; 2174 2175 // Keep track of whether all prior cv-qualifiers in the "to" type 2176 // include const. 2177 PreviousToQualsIncludeConst 2178 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 2179 } 2180 2181 // We are left with FromType and ToType being the pointee types 2182 // after unwrapping the original FromType and ToType the same number 2183 // of types. If we unwrapped any pointers, and if FromType and 2184 // ToType have the same unqualified type (since we checked 2185 // qualifiers above), then this is a qualification conversion. 2186 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2187} 2188 2189/// Determines whether there is a user-defined conversion sequence 2190/// (C++ [over.ics.user]) that converts expression From to the type 2191/// ToType. If such a conversion exists, User will contain the 2192/// user-defined conversion sequence that performs such a conversion 2193/// and this routine will return true. Otherwise, this routine returns 2194/// false and User is unspecified. 2195/// 2196/// \param AllowExplicit true if the conversion should consider C++0x 2197/// "explicit" conversion functions as well as non-explicit conversion 2198/// functions (C++0x [class.conv.fct]p2). 2199static OverloadingResult 2200IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 2201 UserDefinedConversionSequence& User, 2202 OverloadCandidateSet& CandidateSet, 2203 bool AllowExplicit) { 2204 // Whether we will only visit constructors. 2205 bool ConstructorsOnly = false; 2206 2207 // If the type we are conversion to is a class type, enumerate its 2208 // constructors. 2209 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 2210 // C++ [over.match.ctor]p1: 2211 // When objects of class type are direct-initialized (8.5), or 2212 // copy-initialized from an expression of the same or a 2213 // derived class type (8.5), overload resolution selects the 2214 // constructor. [...] For copy-initialization, the candidate 2215 // functions are all the converting constructors (12.3.1) of 2216 // that class. The argument list is the expression-list within 2217 // the parentheses of the initializer. 2218 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 2219 (From->getType()->getAs<RecordType>() && 2220 S.IsDerivedFrom(From->getType(), ToType))) 2221 ConstructorsOnly = true; 2222 2223 if (S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag())) { 2224 // We're not going to find any constructors. 2225 } else if (CXXRecordDecl *ToRecordDecl 2226 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 2227 DeclContext::lookup_iterator Con, ConEnd; 2228 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 2229 Con != ConEnd; ++Con) { 2230 NamedDecl *D = *Con; 2231 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2232 2233 // Find the constructor (which may be a template). 2234 CXXConstructorDecl *Constructor = 0; 2235 FunctionTemplateDecl *ConstructorTmpl 2236 = dyn_cast<FunctionTemplateDecl>(D); 2237 if (ConstructorTmpl) 2238 Constructor 2239 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2240 else 2241 Constructor = cast<CXXConstructorDecl>(D); 2242 2243 if (!Constructor->isInvalidDecl() && 2244 Constructor->isConvertingConstructor(AllowExplicit)) { 2245 if (ConstructorTmpl) 2246 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2247 /*ExplicitArgs*/ 0, 2248 &From, 1, CandidateSet, 2249 /*SuppressUserConversions=*/ 2250 !ConstructorsOnly); 2251 else 2252 // Allow one user-defined conversion when user specifies a 2253 // From->ToType conversion via an static cast (c-style, etc). 2254 S.AddOverloadCandidate(Constructor, FoundDecl, 2255 &From, 1, CandidateSet, 2256 /*SuppressUserConversions=*/ 2257 !ConstructorsOnly); 2258 } 2259 } 2260 } 2261 } 2262 2263 // Enumerate conversion functions, if we're allowed to. 2264 if (ConstructorsOnly) { 2265 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 2266 S.PDiag(0) << From->getSourceRange())) { 2267 // No conversion functions from incomplete types. 2268 } else if (const RecordType *FromRecordType 2269 = From->getType()->getAs<RecordType>()) { 2270 if (CXXRecordDecl *FromRecordDecl 2271 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 2272 // Add all of the conversion functions as candidates. 2273 const UnresolvedSetImpl *Conversions 2274 = FromRecordDecl->getVisibleConversionFunctions(); 2275 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2276 E = Conversions->end(); I != E; ++I) { 2277 DeclAccessPair FoundDecl = I.getPair(); 2278 NamedDecl *D = FoundDecl.getDecl(); 2279 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 2280 if (isa<UsingShadowDecl>(D)) 2281 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2282 2283 CXXConversionDecl *Conv; 2284 FunctionTemplateDecl *ConvTemplate; 2285 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 2286 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2287 else 2288 Conv = cast<CXXConversionDecl>(D); 2289 2290 if (AllowExplicit || !Conv->isExplicit()) { 2291 if (ConvTemplate) 2292 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 2293 ActingContext, From, ToType, 2294 CandidateSet); 2295 else 2296 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 2297 From, ToType, CandidateSet); 2298 } 2299 } 2300 } 2301 } 2302 2303 OverloadCandidateSet::iterator Best; 2304 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2305 case OR_Success: 2306 // Record the standard conversion we used and the conversion function. 2307 if (CXXConstructorDecl *Constructor 2308 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 2309 S.MarkDeclarationReferenced(From->getLocStart(), Constructor); 2310 2311 // C++ [over.ics.user]p1: 2312 // If the user-defined conversion is specified by a 2313 // constructor (12.3.1), the initial standard conversion 2314 // sequence converts the source type to the type required by 2315 // the argument of the constructor. 2316 // 2317 QualType ThisType = Constructor->getThisType(S.Context); 2318 if (Best->Conversions[0].isEllipsis()) 2319 User.EllipsisConversion = true; 2320 else { 2321 User.Before = Best->Conversions[0].Standard; 2322 User.EllipsisConversion = false; 2323 } 2324 User.ConversionFunction = Constructor; 2325 User.FoundConversionFunction = Best->FoundDecl.getDecl(); 2326 User.After.setAsIdentityConversion(); 2327 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2328 User.After.setAllToTypes(ToType); 2329 return OR_Success; 2330 } else if (CXXConversionDecl *Conversion 2331 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2332 S.MarkDeclarationReferenced(From->getLocStart(), Conversion); 2333 2334 // C++ [over.ics.user]p1: 2335 // 2336 // [...] If the user-defined conversion is specified by a 2337 // conversion function (12.3.2), the initial standard 2338 // conversion sequence converts the source type to the 2339 // implicit object parameter of the conversion function. 2340 User.Before = Best->Conversions[0].Standard; 2341 User.ConversionFunction = Conversion; 2342 User.FoundConversionFunction = Best->FoundDecl.getDecl(); 2343 User.EllipsisConversion = false; 2344 2345 // C++ [over.ics.user]p2: 2346 // The second standard conversion sequence converts the 2347 // result of the user-defined conversion to the target type 2348 // for the sequence. Since an implicit conversion sequence 2349 // is an initialization, the special rules for 2350 // initialization by user-defined conversion apply when 2351 // selecting the best user-defined conversion for a 2352 // user-defined conversion sequence (see 13.3.3 and 2353 // 13.3.3.1). 2354 User.After = Best->FinalConversion; 2355 return OR_Success; 2356 } else { 2357 llvm_unreachable("Not a constructor or conversion function?"); 2358 return OR_No_Viable_Function; 2359 } 2360 2361 case OR_No_Viable_Function: 2362 return OR_No_Viable_Function; 2363 case OR_Deleted: 2364 // No conversion here! We're done. 2365 return OR_Deleted; 2366 2367 case OR_Ambiguous: 2368 return OR_Ambiguous; 2369 } 2370 2371 return OR_No_Viable_Function; 2372} 2373 2374bool 2375Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2376 ImplicitConversionSequence ICS; 2377 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2378 OverloadingResult OvResult = 2379 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 2380 CandidateSet, false); 2381 if (OvResult == OR_Ambiguous) 2382 Diag(From->getSourceRange().getBegin(), 2383 diag::err_typecheck_ambiguous_condition) 2384 << From->getType() << ToType << From->getSourceRange(); 2385 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2386 Diag(From->getSourceRange().getBegin(), 2387 diag::err_typecheck_nonviable_condition) 2388 << From->getType() << ToType << From->getSourceRange(); 2389 else 2390 return false; 2391 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &From, 1); 2392 return true; 2393} 2394 2395/// CompareImplicitConversionSequences - Compare two implicit 2396/// conversion sequences to determine whether one is better than the 2397/// other or if they are indistinguishable (C++ 13.3.3.2). 2398static ImplicitConversionSequence::CompareKind 2399CompareImplicitConversionSequences(Sema &S, 2400 const ImplicitConversionSequence& ICS1, 2401 const ImplicitConversionSequence& ICS2) 2402{ 2403 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2404 // conversion sequences (as defined in 13.3.3.1) 2405 // -- a standard conversion sequence (13.3.3.1.1) is a better 2406 // conversion sequence than a user-defined conversion sequence or 2407 // an ellipsis conversion sequence, and 2408 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2409 // conversion sequence than an ellipsis conversion sequence 2410 // (13.3.3.1.3). 2411 // 2412 // C++0x [over.best.ics]p10: 2413 // For the purpose of ranking implicit conversion sequences as 2414 // described in 13.3.3.2, the ambiguous conversion sequence is 2415 // treated as a user-defined sequence that is indistinguishable 2416 // from any other user-defined conversion sequence. 2417 if (ICS1.getKindRank() < ICS2.getKindRank()) 2418 return ImplicitConversionSequence::Better; 2419 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2420 return ImplicitConversionSequence::Worse; 2421 2422 // The following checks require both conversion sequences to be of 2423 // the same kind. 2424 if (ICS1.getKind() != ICS2.getKind()) 2425 return ImplicitConversionSequence::Indistinguishable; 2426 2427 // Two implicit conversion sequences of the same form are 2428 // indistinguishable conversion sequences unless one of the 2429 // following rules apply: (C++ 13.3.3.2p3): 2430 if (ICS1.isStandard()) 2431 return CompareStandardConversionSequences(S, ICS1.Standard, ICS2.Standard); 2432 else if (ICS1.isUserDefined()) { 2433 // User-defined conversion sequence U1 is a better conversion 2434 // sequence than another user-defined conversion sequence U2 if 2435 // they contain the same user-defined conversion function or 2436 // constructor and if the second standard conversion sequence of 2437 // U1 is better than the second standard conversion sequence of 2438 // U2 (C++ 13.3.3.2p3). 2439 if (ICS1.UserDefined.ConversionFunction == 2440 ICS2.UserDefined.ConversionFunction) 2441 return CompareStandardConversionSequences(S, 2442 ICS1.UserDefined.After, 2443 ICS2.UserDefined.After); 2444 } 2445 2446 return ImplicitConversionSequence::Indistinguishable; 2447} 2448 2449static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2450 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2451 Qualifiers Quals; 2452 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2453 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2454 } 2455 2456 return Context.hasSameUnqualifiedType(T1, T2); 2457} 2458 2459// Per 13.3.3.2p3, compare the given standard conversion sequences to 2460// determine if one is a proper subset of the other. 2461static ImplicitConversionSequence::CompareKind 2462compareStandardConversionSubsets(ASTContext &Context, 2463 const StandardConversionSequence& SCS1, 2464 const StandardConversionSequence& SCS2) { 2465 ImplicitConversionSequence::CompareKind Result 2466 = ImplicitConversionSequence::Indistinguishable; 2467 2468 // the identity conversion sequence is considered to be a subsequence of 2469 // any non-identity conversion sequence 2470 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2471 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2472 return ImplicitConversionSequence::Better; 2473 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2474 return ImplicitConversionSequence::Worse; 2475 } 2476 2477 if (SCS1.Second != SCS2.Second) { 2478 if (SCS1.Second == ICK_Identity) 2479 Result = ImplicitConversionSequence::Better; 2480 else if (SCS2.Second == ICK_Identity) 2481 Result = ImplicitConversionSequence::Worse; 2482 else 2483 return ImplicitConversionSequence::Indistinguishable; 2484 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2485 return ImplicitConversionSequence::Indistinguishable; 2486 2487 if (SCS1.Third == SCS2.Third) { 2488 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2489 : ImplicitConversionSequence::Indistinguishable; 2490 } 2491 2492 if (SCS1.Third == ICK_Identity) 2493 return Result == ImplicitConversionSequence::Worse 2494 ? ImplicitConversionSequence::Indistinguishable 2495 : ImplicitConversionSequence::Better; 2496 2497 if (SCS2.Third == ICK_Identity) 2498 return Result == ImplicitConversionSequence::Better 2499 ? ImplicitConversionSequence::Indistinguishable 2500 : ImplicitConversionSequence::Worse; 2501 2502 return ImplicitConversionSequence::Indistinguishable; 2503} 2504 2505/// \brief Determine whether one of the given reference bindings is better 2506/// than the other based on what kind of bindings they are. 2507static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 2508 const StandardConversionSequence &SCS2) { 2509 // C++0x [over.ics.rank]p3b4: 2510 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2511 // implicit object parameter of a non-static member function declared 2512 // without a ref-qualifier, and *either* S1 binds an rvalue reference 2513 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 2514 // lvalue reference to a function lvalue and S2 binds an rvalue 2515 // reference*. 2516 // 2517 // FIXME: Rvalue references. We're going rogue with the above edits, 2518 // because the semantics in the current C++0x working paper (N3225 at the 2519 // time of this writing) break the standard definition of std::forward 2520 // and std::reference_wrapper when dealing with references to functions. 2521 // Proposed wording changes submitted to CWG for consideration. 2522 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 2523 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 2524 return false; 2525 2526 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 2527 SCS2.IsLvalueReference) || 2528 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 2529 !SCS2.IsLvalueReference); 2530} 2531 2532/// CompareStandardConversionSequences - Compare two standard 2533/// conversion sequences to determine whether one is better than the 2534/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2535static ImplicitConversionSequence::CompareKind 2536CompareStandardConversionSequences(Sema &S, 2537 const StandardConversionSequence& SCS1, 2538 const StandardConversionSequence& SCS2) 2539{ 2540 // Standard conversion sequence S1 is a better conversion sequence 2541 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2542 2543 // -- S1 is a proper subsequence of S2 (comparing the conversion 2544 // sequences in the canonical form defined by 13.3.3.1.1, 2545 // excluding any Lvalue Transformation; the identity conversion 2546 // sequence is considered to be a subsequence of any 2547 // non-identity conversion sequence) or, if not that, 2548 if (ImplicitConversionSequence::CompareKind CK 2549 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 2550 return CK; 2551 2552 // -- the rank of S1 is better than the rank of S2 (by the rules 2553 // defined below), or, if not that, 2554 ImplicitConversionRank Rank1 = SCS1.getRank(); 2555 ImplicitConversionRank Rank2 = SCS2.getRank(); 2556 if (Rank1 < Rank2) 2557 return ImplicitConversionSequence::Better; 2558 else if (Rank2 < Rank1) 2559 return ImplicitConversionSequence::Worse; 2560 2561 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2562 // are indistinguishable unless one of the following rules 2563 // applies: 2564 2565 // A conversion that is not a conversion of a pointer, or 2566 // pointer to member, to bool is better than another conversion 2567 // that is such a conversion. 2568 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2569 return SCS2.isPointerConversionToBool() 2570 ? ImplicitConversionSequence::Better 2571 : ImplicitConversionSequence::Worse; 2572 2573 // C++ [over.ics.rank]p4b2: 2574 // 2575 // If class B is derived directly or indirectly from class A, 2576 // conversion of B* to A* is better than conversion of B* to 2577 // void*, and conversion of A* to void* is better than conversion 2578 // of B* to void*. 2579 bool SCS1ConvertsToVoid 2580 = SCS1.isPointerConversionToVoidPointer(S.Context); 2581 bool SCS2ConvertsToVoid 2582 = SCS2.isPointerConversionToVoidPointer(S.Context); 2583 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2584 // Exactly one of the conversion sequences is a conversion to 2585 // a void pointer; it's the worse conversion. 2586 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2587 : ImplicitConversionSequence::Worse; 2588 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2589 // Neither conversion sequence converts to a void pointer; compare 2590 // their derived-to-base conversions. 2591 if (ImplicitConversionSequence::CompareKind DerivedCK 2592 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 2593 return DerivedCK; 2594 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2595 // Both conversion sequences are conversions to void 2596 // pointers. Compare the source types to determine if there's an 2597 // inheritance relationship in their sources. 2598 QualType FromType1 = SCS1.getFromType(); 2599 QualType FromType2 = SCS2.getFromType(); 2600 2601 // Adjust the types we're converting from via the array-to-pointer 2602 // conversion, if we need to. 2603 if (SCS1.First == ICK_Array_To_Pointer) 2604 FromType1 = S.Context.getArrayDecayedType(FromType1); 2605 if (SCS2.First == ICK_Array_To_Pointer) 2606 FromType2 = S.Context.getArrayDecayedType(FromType2); 2607 2608 QualType FromPointee1 2609 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2610 QualType FromPointee2 2611 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2612 2613 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2614 return ImplicitConversionSequence::Better; 2615 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2616 return ImplicitConversionSequence::Worse; 2617 2618 // Objective-C++: If one interface is more specific than the 2619 // other, it is the better one. 2620 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2621 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2622 if (FromIface1 && FromIface1) { 2623 if (S.Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2624 return ImplicitConversionSequence::Better; 2625 else if (S.Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2626 return ImplicitConversionSequence::Worse; 2627 } 2628 } 2629 2630 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2631 // bullet 3). 2632 if (ImplicitConversionSequence::CompareKind QualCK 2633 = CompareQualificationConversions(S, SCS1, SCS2)) 2634 return QualCK; 2635 2636 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2637 // Check for a better reference binding based on the kind of bindings. 2638 if (isBetterReferenceBindingKind(SCS1, SCS2)) 2639 return ImplicitConversionSequence::Better; 2640 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 2641 return ImplicitConversionSequence::Worse; 2642 2643 // C++ [over.ics.rank]p3b4: 2644 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2645 // which the references refer are the same type except for 2646 // top-level cv-qualifiers, and the type to which the reference 2647 // initialized by S2 refers is more cv-qualified than the type 2648 // to which the reference initialized by S1 refers. 2649 QualType T1 = SCS1.getToType(2); 2650 QualType T2 = SCS2.getToType(2); 2651 T1 = S.Context.getCanonicalType(T1); 2652 T2 = S.Context.getCanonicalType(T2); 2653 Qualifiers T1Quals, T2Quals; 2654 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2655 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2656 if (UnqualT1 == UnqualT2) { 2657 // If the type is an array type, promote the element qualifiers to the 2658 // type for comparison. 2659 if (isa<ArrayType>(T1) && T1Quals) 2660 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2661 if (isa<ArrayType>(T2) && T2Quals) 2662 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2663 if (T2.isMoreQualifiedThan(T1)) 2664 return ImplicitConversionSequence::Better; 2665 else if (T1.isMoreQualifiedThan(T2)) 2666 return ImplicitConversionSequence::Worse; 2667 } 2668 } 2669 2670 return ImplicitConversionSequence::Indistinguishable; 2671} 2672 2673/// CompareQualificationConversions - Compares two standard conversion 2674/// sequences to determine whether they can be ranked based on their 2675/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2676ImplicitConversionSequence::CompareKind 2677CompareQualificationConversions(Sema &S, 2678 const StandardConversionSequence& SCS1, 2679 const StandardConversionSequence& SCS2) { 2680 // C++ 13.3.3.2p3: 2681 // -- S1 and S2 differ only in their qualification conversion and 2682 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2683 // cv-qualification signature of type T1 is a proper subset of 2684 // the cv-qualification signature of type T2, and S1 is not the 2685 // deprecated string literal array-to-pointer conversion (4.2). 2686 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2687 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2688 return ImplicitConversionSequence::Indistinguishable; 2689 2690 // FIXME: the example in the standard doesn't use a qualification 2691 // conversion (!) 2692 QualType T1 = SCS1.getToType(2); 2693 QualType T2 = SCS2.getToType(2); 2694 T1 = S.Context.getCanonicalType(T1); 2695 T2 = S.Context.getCanonicalType(T2); 2696 Qualifiers T1Quals, T2Quals; 2697 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2698 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2699 2700 // If the types are the same, we won't learn anything by unwrapped 2701 // them. 2702 if (UnqualT1 == UnqualT2) 2703 return ImplicitConversionSequence::Indistinguishable; 2704 2705 // If the type is an array type, promote the element qualifiers to the type 2706 // for comparison. 2707 if (isa<ArrayType>(T1) && T1Quals) 2708 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2709 if (isa<ArrayType>(T2) && T2Quals) 2710 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2711 2712 ImplicitConversionSequence::CompareKind Result 2713 = ImplicitConversionSequence::Indistinguishable; 2714 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 2715 // Within each iteration of the loop, we check the qualifiers to 2716 // determine if this still looks like a qualification 2717 // conversion. Then, if all is well, we unwrap one more level of 2718 // pointers or pointers-to-members and do it all again 2719 // until there are no more pointers or pointers-to-members left 2720 // to unwrap. This essentially mimics what 2721 // IsQualificationConversion does, but here we're checking for a 2722 // strict subset of qualifiers. 2723 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2724 // The qualifiers are the same, so this doesn't tell us anything 2725 // about how the sequences rank. 2726 ; 2727 else if (T2.isMoreQualifiedThan(T1)) { 2728 // T1 has fewer qualifiers, so it could be the better sequence. 2729 if (Result == ImplicitConversionSequence::Worse) 2730 // Neither has qualifiers that are a subset of the other's 2731 // qualifiers. 2732 return ImplicitConversionSequence::Indistinguishable; 2733 2734 Result = ImplicitConversionSequence::Better; 2735 } else if (T1.isMoreQualifiedThan(T2)) { 2736 // T2 has fewer qualifiers, so it could be the better sequence. 2737 if (Result == ImplicitConversionSequence::Better) 2738 // Neither has qualifiers that are a subset of the other's 2739 // qualifiers. 2740 return ImplicitConversionSequence::Indistinguishable; 2741 2742 Result = ImplicitConversionSequence::Worse; 2743 } else { 2744 // Qualifiers are disjoint. 2745 return ImplicitConversionSequence::Indistinguishable; 2746 } 2747 2748 // If the types after this point are equivalent, we're done. 2749 if (S.Context.hasSameUnqualifiedType(T1, T2)) 2750 break; 2751 } 2752 2753 // Check that the winning standard conversion sequence isn't using 2754 // the deprecated string literal array to pointer conversion. 2755 switch (Result) { 2756 case ImplicitConversionSequence::Better: 2757 if (SCS1.DeprecatedStringLiteralToCharPtr) 2758 Result = ImplicitConversionSequence::Indistinguishable; 2759 break; 2760 2761 case ImplicitConversionSequence::Indistinguishable: 2762 break; 2763 2764 case ImplicitConversionSequence::Worse: 2765 if (SCS2.DeprecatedStringLiteralToCharPtr) 2766 Result = ImplicitConversionSequence::Indistinguishable; 2767 break; 2768 } 2769 2770 return Result; 2771} 2772 2773/// CompareDerivedToBaseConversions - Compares two standard conversion 2774/// sequences to determine whether they can be ranked based on their 2775/// various kinds of derived-to-base conversions (C++ 2776/// [over.ics.rank]p4b3). As part of these checks, we also look at 2777/// conversions between Objective-C interface types. 2778ImplicitConversionSequence::CompareKind 2779CompareDerivedToBaseConversions(Sema &S, 2780 const StandardConversionSequence& SCS1, 2781 const StandardConversionSequence& SCS2) { 2782 QualType FromType1 = SCS1.getFromType(); 2783 QualType ToType1 = SCS1.getToType(1); 2784 QualType FromType2 = SCS2.getFromType(); 2785 QualType ToType2 = SCS2.getToType(1); 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 // Canonicalize all of the types. 2795 FromType1 = S.Context.getCanonicalType(FromType1); 2796 ToType1 = S.Context.getCanonicalType(ToType1); 2797 FromType2 = S.Context.getCanonicalType(FromType2); 2798 ToType2 = S.Context.getCanonicalType(ToType2); 2799 2800 // C++ [over.ics.rank]p4b3: 2801 // 2802 // If class B is derived directly or indirectly from class A and 2803 // class C is derived directly or indirectly from B, 2804 // 2805 // Compare based on pointer conversions. 2806 if (SCS1.Second == ICK_Pointer_Conversion && 2807 SCS2.Second == ICK_Pointer_Conversion && 2808 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2809 FromType1->isPointerType() && FromType2->isPointerType() && 2810 ToType1->isPointerType() && ToType2->isPointerType()) { 2811 QualType FromPointee1 2812 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2813 QualType ToPointee1 2814 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2815 QualType FromPointee2 2816 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2817 QualType ToPointee2 2818 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2819 2820 // -- conversion of C* to B* is better than conversion of C* to A*, 2821 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2822 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2823 return ImplicitConversionSequence::Better; 2824 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2825 return ImplicitConversionSequence::Worse; 2826 } 2827 2828 // -- conversion of B* to A* is better than conversion of C* to A*, 2829 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2830 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2831 return ImplicitConversionSequence::Better; 2832 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2833 return ImplicitConversionSequence::Worse; 2834 } 2835 } else if (SCS1.Second == ICK_Pointer_Conversion && 2836 SCS2.Second == ICK_Pointer_Conversion) { 2837 const ObjCObjectPointerType *FromPtr1 2838 = FromType1->getAs<ObjCObjectPointerType>(); 2839 const ObjCObjectPointerType *FromPtr2 2840 = FromType2->getAs<ObjCObjectPointerType>(); 2841 const ObjCObjectPointerType *ToPtr1 2842 = ToType1->getAs<ObjCObjectPointerType>(); 2843 const ObjCObjectPointerType *ToPtr2 2844 = ToType2->getAs<ObjCObjectPointerType>(); 2845 2846 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 2847 // Apply the same conversion ranking rules for Objective-C pointer types 2848 // that we do for C++ pointers to class types. However, we employ the 2849 // Objective-C pseudo-subtyping relationship used for assignment of 2850 // Objective-C pointer types. 2851 bool FromAssignLeft 2852 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 2853 bool FromAssignRight 2854 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 2855 bool ToAssignLeft 2856 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 2857 bool ToAssignRight 2858 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 2859 2860 // A conversion to an a non-id object pointer type or qualified 'id' 2861 // type is better than a conversion to 'id'. 2862 if (ToPtr1->isObjCIdType() && 2863 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 2864 return ImplicitConversionSequence::Worse; 2865 if (ToPtr2->isObjCIdType() && 2866 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 2867 return ImplicitConversionSequence::Better; 2868 2869 // A conversion to a non-id object pointer type is better than a 2870 // conversion to a qualified 'id' type 2871 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 2872 return ImplicitConversionSequence::Worse; 2873 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 2874 return ImplicitConversionSequence::Better; 2875 2876 // A conversion to an a non-Class object pointer type or qualified 'Class' 2877 // type is better than a conversion to 'Class'. 2878 if (ToPtr1->isObjCClassType() && 2879 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 2880 return ImplicitConversionSequence::Worse; 2881 if (ToPtr2->isObjCClassType() && 2882 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 2883 return ImplicitConversionSequence::Better; 2884 2885 // A conversion to a non-Class object pointer type is better than a 2886 // conversion to a qualified 'Class' type. 2887 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 2888 return ImplicitConversionSequence::Worse; 2889 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 2890 return ImplicitConversionSequence::Better; 2891 2892 // -- "conversion of C* to B* is better than conversion of C* to A*," 2893 if (S.Context.hasSameType(FromType1, FromType2) && 2894 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 2895 (ToAssignLeft != ToAssignRight)) 2896 return ToAssignLeft? ImplicitConversionSequence::Worse 2897 : ImplicitConversionSequence::Better; 2898 2899 // -- "conversion of B* to A* is better than conversion of C* to A*," 2900 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 2901 (FromAssignLeft != FromAssignRight)) 2902 return FromAssignLeft? ImplicitConversionSequence::Better 2903 : ImplicitConversionSequence::Worse; 2904 } 2905 } 2906 2907 // Ranking of member-pointer types. 2908 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2909 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2910 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2911 const MemberPointerType * FromMemPointer1 = 2912 FromType1->getAs<MemberPointerType>(); 2913 const MemberPointerType * ToMemPointer1 = 2914 ToType1->getAs<MemberPointerType>(); 2915 const MemberPointerType * FromMemPointer2 = 2916 FromType2->getAs<MemberPointerType>(); 2917 const MemberPointerType * ToMemPointer2 = 2918 ToType2->getAs<MemberPointerType>(); 2919 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2920 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2921 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2922 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2923 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2924 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2925 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2926 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2927 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2928 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2929 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2930 return ImplicitConversionSequence::Worse; 2931 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2932 return ImplicitConversionSequence::Better; 2933 } 2934 // conversion of B::* to C::* is better than conversion of A::* to C::* 2935 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2936 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2937 return ImplicitConversionSequence::Better; 2938 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2939 return ImplicitConversionSequence::Worse; 2940 } 2941 } 2942 2943 if (SCS1.Second == ICK_Derived_To_Base) { 2944 // -- conversion of C to B is better than conversion of C to A, 2945 // -- binding of an expression of type C to a reference of type 2946 // B& is better than binding an expression of type C to a 2947 // reference of type A&, 2948 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2949 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2950 if (S.IsDerivedFrom(ToType1, ToType2)) 2951 return ImplicitConversionSequence::Better; 2952 else if (S.IsDerivedFrom(ToType2, ToType1)) 2953 return ImplicitConversionSequence::Worse; 2954 } 2955 2956 // -- conversion of B to A is better than conversion of C to A. 2957 // -- binding of an expression of type B to a reference of type 2958 // A& is better than binding an expression of type C to a 2959 // reference of type A&, 2960 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2961 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2962 if (S.IsDerivedFrom(FromType2, FromType1)) 2963 return ImplicitConversionSequence::Better; 2964 else if (S.IsDerivedFrom(FromType1, FromType2)) 2965 return ImplicitConversionSequence::Worse; 2966 } 2967 } 2968 2969 return ImplicitConversionSequence::Indistinguishable; 2970} 2971 2972/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2973/// determine whether they are reference-related, 2974/// reference-compatible, reference-compatible with added 2975/// qualification, or incompatible, for use in C++ initialization by 2976/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2977/// type, and the first type (T1) is the pointee type of the reference 2978/// type being initialized. 2979Sema::ReferenceCompareResult 2980Sema::CompareReferenceRelationship(SourceLocation Loc, 2981 QualType OrigT1, QualType OrigT2, 2982 bool &DerivedToBase, 2983 bool &ObjCConversion) { 2984 assert(!OrigT1->isReferenceType() && 2985 "T1 must be the pointee type of the reference type"); 2986 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2987 2988 QualType T1 = Context.getCanonicalType(OrigT1); 2989 QualType T2 = Context.getCanonicalType(OrigT2); 2990 Qualifiers T1Quals, T2Quals; 2991 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2992 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2993 2994 // C++ [dcl.init.ref]p4: 2995 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2996 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2997 // T1 is a base class of T2. 2998 DerivedToBase = false; 2999 ObjCConversion = false; 3000 if (UnqualT1 == UnqualT2) { 3001 // Nothing to do. 3002 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 3003 IsDerivedFrom(UnqualT2, UnqualT1)) 3004 DerivedToBase = true; 3005 else if (UnqualT1->isObjCObjectOrInterfaceType() && 3006 UnqualT2->isObjCObjectOrInterfaceType() && 3007 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 3008 ObjCConversion = true; 3009 else 3010 return Ref_Incompatible; 3011 3012 // At this point, we know that T1 and T2 are reference-related (at 3013 // least). 3014 3015 // If the type is an array type, promote the element qualifiers to the type 3016 // for comparison. 3017 if (isa<ArrayType>(T1) && T1Quals) 3018 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 3019 if (isa<ArrayType>(T2) && T2Quals) 3020 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 3021 3022 // C++ [dcl.init.ref]p4: 3023 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 3024 // reference-related to T2 and cv1 is the same cv-qualification 3025 // as, or greater cv-qualification than, cv2. For purposes of 3026 // overload resolution, cases for which cv1 is greater 3027 // cv-qualification than cv2 are identified as 3028 // reference-compatible with added qualification (see 13.3.3.2). 3029 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 3030 return Ref_Compatible; 3031 else if (T1.isMoreQualifiedThan(T2)) 3032 return Ref_Compatible_With_Added_Qualification; 3033 else 3034 return Ref_Related; 3035} 3036 3037/// \brief Look for a user-defined conversion to an value reference-compatible 3038/// with DeclType. Return true if something definite is found. 3039static bool 3040FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 3041 QualType DeclType, SourceLocation DeclLoc, 3042 Expr *Init, QualType T2, bool AllowRvalues, 3043 bool AllowExplicit) { 3044 assert(T2->isRecordType() && "Can only find conversions of record types."); 3045 CXXRecordDecl *T2RecordDecl 3046 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 3047 3048 OverloadCandidateSet CandidateSet(DeclLoc); 3049 const UnresolvedSetImpl *Conversions 3050 = T2RecordDecl->getVisibleConversionFunctions(); 3051 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3052 E = Conversions->end(); I != E; ++I) { 3053 NamedDecl *D = *I; 3054 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3055 if (isa<UsingShadowDecl>(D)) 3056 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3057 3058 FunctionTemplateDecl *ConvTemplate 3059 = dyn_cast<FunctionTemplateDecl>(D); 3060 CXXConversionDecl *Conv; 3061 if (ConvTemplate) 3062 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3063 else 3064 Conv = cast<CXXConversionDecl>(D); 3065 3066 // If this is an explicit conversion, and we're not allowed to consider 3067 // explicit conversions, skip it. 3068 if (!AllowExplicit && Conv->isExplicit()) 3069 continue; 3070 3071 if (AllowRvalues) { 3072 bool DerivedToBase = false; 3073 bool ObjCConversion = false; 3074 if (!ConvTemplate && 3075 S.CompareReferenceRelationship( 3076 DeclLoc, 3077 Conv->getConversionType().getNonReferenceType() 3078 .getUnqualifiedType(), 3079 DeclType.getNonReferenceType().getUnqualifiedType(), 3080 DerivedToBase, ObjCConversion) == 3081 Sema::Ref_Incompatible) 3082 continue; 3083 } else { 3084 // If the conversion function doesn't return a reference type, 3085 // it can't be considered for this conversion. An rvalue reference 3086 // is only acceptable if its referencee is a function type. 3087 3088 const ReferenceType *RefType = 3089 Conv->getConversionType()->getAs<ReferenceType>(); 3090 if (!RefType || 3091 (!RefType->isLValueReferenceType() && 3092 !RefType->getPointeeType()->isFunctionType())) 3093 continue; 3094 } 3095 3096 if (ConvTemplate) 3097 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 3098 Init, DeclType, CandidateSet); 3099 else 3100 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 3101 DeclType, CandidateSet); 3102 } 3103 3104 OverloadCandidateSet::iterator Best; 3105 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 3106 case OR_Success: 3107 // C++ [over.ics.ref]p1: 3108 // 3109 // [...] If the parameter binds directly to the result of 3110 // applying a conversion function to the argument 3111 // expression, the implicit conversion sequence is a 3112 // user-defined conversion sequence (13.3.3.1.2), with the 3113 // second standard conversion sequence either an identity 3114 // conversion or, if the conversion function returns an 3115 // entity of a type that is a derived class of the parameter 3116 // type, a derived-to-base Conversion. 3117 if (!Best->FinalConversion.DirectBinding) 3118 return false; 3119 3120 if (Best->Function) 3121 S.MarkDeclarationReferenced(DeclLoc, Best->Function); 3122 ICS.setUserDefined(); 3123 ICS.UserDefined.Before = Best->Conversions[0].Standard; 3124 ICS.UserDefined.After = Best->FinalConversion; 3125 ICS.UserDefined.ConversionFunction = Best->Function; 3126 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl.getDecl(); 3127 ICS.UserDefined.EllipsisConversion = false; 3128 assert(ICS.UserDefined.After.ReferenceBinding && 3129 ICS.UserDefined.After.DirectBinding && 3130 "Expected a direct reference binding!"); 3131 return true; 3132 3133 case OR_Ambiguous: 3134 ICS.setAmbiguous(); 3135 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3136 Cand != CandidateSet.end(); ++Cand) 3137 if (Cand->Viable) 3138 ICS.Ambiguous.addConversion(Cand->Function); 3139 return true; 3140 3141 case OR_No_Viable_Function: 3142 case OR_Deleted: 3143 // There was no suitable conversion, or we found a deleted 3144 // conversion; continue with other checks. 3145 return false; 3146 } 3147 3148 return false; 3149} 3150 3151/// \brief Compute an implicit conversion sequence for reference 3152/// initialization. 3153static ImplicitConversionSequence 3154TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 3155 SourceLocation DeclLoc, 3156 bool SuppressUserConversions, 3157 bool AllowExplicit) { 3158 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 3159 3160 // Most paths end in a failed conversion. 3161 ImplicitConversionSequence ICS; 3162 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3163 3164 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 3165 QualType T2 = Init->getType(); 3166 3167 // If the initializer is the address of an overloaded function, try 3168 // to resolve the overloaded function. If all goes well, T2 is the 3169 // type of the resulting function. 3170 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 3171 DeclAccessPair Found; 3172 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 3173 false, Found)) 3174 T2 = Fn->getType(); 3175 } 3176 3177 // Compute some basic properties of the types and the initializer. 3178 bool isRValRef = DeclType->isRValueReferenceType(); 3179 bool DerivedToBase = false; 3180 bool ObjCConversion = false; 3181 Expr::Classification InitCategory = Init->Classify(S.Context); 3182 Sema::ReferenceCompareResult RefRelationship 3183 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 3184 ObjCConversion); 3185 3186 3187 // C++0x [dcl.init.ref]p5: 3188 // A reference to type "cv1 T1" is initialized by an expression 3189 // of type "cv2 T2" as follows: 3190 3191 // -- If reference is an lvalue reference and the initializer expression 3192 if (!isRValRef) { 3193 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 3194 // reference-compatible with "cv2 T2," or 3195 // 3196 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 3197 if (InitCategory.isLValue() && 3198 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 3199 // C++ [over.ics.ref]p1: 3200 // When a parameter of reference type binds directly (8.5.3) 3201 // to an argument expression, the implicit conversion sequence 3202 // is the identity conversion, unless the argument expression 3203 // has a type that is a derived class of the parameter type, 3204 // in which case the implicit conversion sequence is a 3205 // derived-to-base Conversion (13.3.3.1). 3206 ICS.setStandard(); 3207 ICS.Standard.First = ICK_Identity; 3208 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3209 : ObjCConversion? ICK_Compatible_Conversion 3210 : ICK_Identity; 3211 ICS.Standard.Third = ICK_Identity; 3212 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3213 ICS.Standard.setToType(0, T2); 3214 ICS.Standard.setToType(1, T1); 3215 ICS.Standard.setToType(2, T1); 3216 ICS.Standard.ReferenceBinding = true; 3217 ICS.Standard.DirectBinding = true; 3218 ICS.Standard.IsLvalueReference = !isRValRef; 3219 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3220 ICS.Standard.BindsToRvalue = false; 3221 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3222 ICS.Standard.CopyConstructor = 0; 3223 3224 // Nothing more to do: the inaccessibility/ambiguity check for 3225 // derived-to-base conversions is suppressed when we're 3226 // computing the implicit conversion sequence (C++ 3227 // [over.best.ics]p2). 3228 return ICS; 3229 } 3230 3231 // -- has a class type (i.e., T2 is a class type), where T1 is 3232 // not reference-related to T2, and can be implicitly 3233 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 3234 // is reference-compatible with "cv3 T3" 92) (this 3235 // conversion is selected by enumerating the applicable 3236 // conversion functions (13.3.1.6) and choosing the best 3237 // one through overload resolution (13.3)), 3238 if (!SuppressUserConversions && T2->isRecordType() && 3239 !S.RequireCompleteType(DeclLoc, T2, 0) && 3240 RefRelationship == Sema::Ref_Incompatible) { 3241 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3242 Init, T2, /*AllowRvalues=*/false, 3243 AllowExplicit)) 3244 return ICS; 3245 } 3246 } 3247 3248 // -- Otherwise, the reference shall be an lvalue reference to a 3249 // non-volatile const type (i.e., cv1 shall be const), or the reference 3250 // shall be an rvalue reference. 3251 // 3252 // We actually handle one oddity of C++ [over.ics.ref] at this 3253 // point, which is that, due to p2 (which short-circuits reference 3254 // binding by only attempting a simple conversion for non-direct 3255 // bindings) and p3's strange wording, we allow a const volatile 3256 // reference to bind to an rvalue. Hence the check for the presence 3257 // of "const" rather than checking for "const" being the only 3258 // qualifier. 3259 // This is also the point where rvalue references and lvalue inits no longer 3260 // go together. 3261 if (!isRValRef && !T1.isConstQualified()) 3262 return ICS; 3263 3264 // -- If the initializer expression 3265 // 3266 // -- is an xvalue, class prvalue, array prvalue or function 3267 // lvalue and "cv1T1" is reference-compatible with "cv2 T2", or 3268 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 3269 (InitCategory.isXValue() || 3270 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 3271 (InitCategory.isLValue() && T2->isFunctionType()))) { 3272 ICS.setStandard(); 3273 ICS.Standard.First = ICK_Identity; 3274 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3275 : ObjCConversion? ICK_Compatible_Conversion 3276 : ICK_Identity; 3277 ICS.Standard.Third = ICK_Identity; 3278 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3279 ICS.Standard.setToType(0, T2); 3280 ICS.Standard.setToType(1, T1); 3281 ICS.Standard.setToType(2, T1); 3282 ICS.Standard.ReferenceBinding = true; 3283 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 3284 // binding unless we're binding to a class prvalue. 3285 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 3286 // allow the use of rvalue references in C++98/03 for the benefit of 3287 // standard library implementors; therefore, we need the xvalue check here. 3288 ICS.Standard.DirectBinding = 3289 S.getLangOptions().CPlusPlus0x || 3290 (InitCategory.isPRValue() && !T2->isRecordType()); 3291 ICS.Standard.IsLvalueReference = !isRValRef; 3292 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3293 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 3294 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3295 ICS.Standard.CopyConstructor = 0; 3296 return ICS; 3297 } 3298 3299 // -- has a class type (i.e., T2 is a class type), where T1 is not 3300 // reference-related to T2, and can be implicitly converted to 3301 // an xvalue, class prvalue, or function lvalue of type 3302 // "cv3 T3", where "cv1 T1" is reference-compatible with 3303 // "cv3 T3", 3304 // 3305 // then the reference is bound to the value of the initializer 3306 // expression in the first case and to the result of the conversion 3307 // in the second case (or, in either case, to an appropriate base 3308 // class subobject). 3309 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3310 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 3311 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3312 Init, T2, /*AllowRvalues=*/true, 3313 AllowExplicit)) { 3314 // In the second case, if the reference is an rvalue reference 3315 // and the second standard conversion sequence of the 3316 // user-defined conversion sequence includes an lvalue-to-rvalue 3317 // conversion, the program is ill-formed. 3318 if (ICS.isUserDefined() && isRValRef && 3319 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 3320 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3321 3322 return ICS; 3323 } 3324 3325 // -- Otherwise, a temporary of type "cv1 T1" is created and 3326 // initialized from the initializer expression using the 3327 // rules for a non-reference copy initialization (8.5). The 3328 // reference is then bound to the temporary. If T1 is 3329 // reference-related to T2, cv1 must be the same 3330 // cv-qualification as, or greater cv-qualification than, 3331 // cv2; otherwise, the program is ill-formed. 3332 if (RefRelationship == Sema::Ref_Related) { 3333 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 3334 // we would be reference-compatible or reference-compatible with 3335 // added qualification. But that wasn't the case, so the reference 3336 // initialization fails. 3337 return ICS; 3338 } 3339 3340 // If at least one of the types is a class type, the types are not 3341 // related, and we aren't allowed any user conversions, the 3342 // reference binding fails. This case is important for breaking 3343 // recursion, since TryImplicitConversion below will attempt to 3344 // create a temporary through the use of a copy constructor. 3345 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3346 (T1->isRecordType() || T2->isRecordType())) 3347 return ICS; 3348 3349 // If T1 is reference-related to T2 and the reference is an rvalue 3350 // reference, the initializer expression shall not be an lvalue. 3351 if (RefRelationship >= Sema::Ref_Related && 3352 isRValRef && Init->Classify(S.Context).isLValue()) 3353 return ICS; 3354 3355 // C++ [over.ics.ref]p2: 3356 // When a parameter of reference type is not bound directly to 3357 // an argument expression, the conversion sequence is the one 3358 // required to convert the argument expression to the 3359 // underlying type of the reference according to 3360 // 13.3.3.1. Conceptually, this conversion sequence corresponds 3361 // to copy-initializing a temporary of the underlying type with 3362 // the argument expression. Any difference in top-level 3363 // cv-qualification is subsumed by the initialization itself 3364 // and does not constitute a conversion. 3365 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 3366 /*AllowExplicit=*/false, 3367 /*InOverloadResolution=*/false, 3368 /*CStyle=*/false); 3369 3370 // Of course, that's still a reference binding. 3371 if (ICS.isStandard()) { 3372 ICS.Standard.ReferenceBinding = true; 3373 ICS.Standard.IsLvalueReference = !isRValRef; 3374 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3375 ICS.Standard.BindsToRvalue = true; 3376 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3377 } else if (ICS.isUserDefined()) { 3378 ICS.UserDefined.After.ReferenceBinding = true; 3379 ICS.Standard.IsLvalueReference = !isRValRef; 3380 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3381 ICS.Standard.BindsToRvalue = true; 3382 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3383 } 3384 3385 return ICS; 3386} 3387 3388/// TryCopyInitialization - Try to copy-initialize a value of type 3389/// ToType from the expression From. Return the implicit conversion 3390/// sequence required to pass this argument, which may be a bad 3391/// conversion sequence (meaning that the argument cannot be passed to 3392/// a parameter of this type). If @p SuppressUserConversions, then we 3393/// do not permit any user-defined conversion sequences. 3394static ImplicitConversionSequence 3395TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 3396 bool SuppressUserConversions, 3397 bool InOverloadResolution) { 3398 if (ToType->isReferenceType()) 3399 return TryReferenceInit(S, From, ToType, 3400 /*FIXME:*/From->getLocStart(), 3401 SuppressUserConversions, 3402 /*AllowExplicit=*/false); 3403 3404 return TryImplicitConversion(S, From, ToType, 3405 SuppressUserConversions, 3406 /*AllowExplicit=*/false, 3407 InOverloadResolution, 3408 /*CStyle=*/false); 3409} 3410 3411/// TryObjectArgumentInitialization - Try to initialize the object 3412/// parameter of the given member function (@c Method) from the 3413/// expression @p From. 3414static ImplicitConversionSequence 3415TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 3416 Expr::Classification FromClassification, 3417 CXXMethodDecl *Method, 3418 CXXRecordDecl *ActingContext) { 3419 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 3420 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 3421 // const volatile object. 3422 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 3423 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 3424 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 3425 3426 // Set up the conversion sequence as a "bad" conversion, to allow us 3427 // to exit early. 3428 ImplicitConversionSequence ICS; 3429 3430 // We need to have an object of class type. 3431 QualType FromType = OrigFromType; 3432 if (const PointerType *PT = FromType->getAs<PointerType>()) { 3433 FromType = PT->getPointeeType(); 3434 3435 // When we had a pointer, it's implicitly dereferenced, so we 3436 // better have an lvalue. 3437 assert(FromClassification.isLValue()); 3438 } 3439 3440 assert(FromType->isRecordType()); 3441 3442 // C++0x [over.match.funcs]p4: 3443 // For non-static member functions, the type of the implicit object 3444 // parameter is 3445 // 3446 // - "lvalue reference to cv X" for functions declared without a 3447 // ref-qualifier or with the & ref-qualifier 3448 // - "rvalue reference to cv X" for functions declared with the && 3449 // ref-qualifier 3450 // 3451 // where X is the class of which the function is a member and cv is the 3452 // cv-qualification on the member function declaration. 3453 // 3454 // However, when finding an implicit conversion sequence for the argument, we 3455 // are not allowed to create temporaries or perform user-defined conversions 3456 // (C++ [over.match.funcs]p5). We perform a simplified version of 3457 // reference binding here, that allows class rvalues to bind to 3458 // non-constant references. 3459 3460 // First check the qualifiers. 3461 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 3462 if (ImplicitParamType.getCVRQualifiers() 3463 != FromTypeCanon.getLocalCVRQualifiers() && 3464 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 3465 ICS.setBad(BadConversionSequence::bad_qualifiers, 3466 OrigFromType, ImplicitParamType); 3467 return ICS; 3468 } 3469 3470 // Check that we have either the same type or a derived type. It 3471 // affects the conversion rank. 3472 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 3473 ImplicitConversionKind SecondKind; 3474 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 3475 SecondKind = ICK_Identity; 3476 } else if (S.IsDerivedFrom(FromType, ClassType)) 3477 SecondKind = ICK_Derived_To_Base; 3478 else { 3479 ICS.setBad(BadConversionSequence::unrelated_class, 3480 FromType, ImplicitParamType); 3481 return ICS; 3482 } 3483 3484 // Check the ref-qualifier. 3485 switch (Method->getRefQualifier()) { 3486 case RQ_None: 3487 // Do nothing; we don't care about lvalueness or rvalueness. 3488 break; 3489 3490 case RQ_LValue: 3491 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 3492 // non-const lvalue reference cannot bind to an rvalue 3493 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 3494 ImplicitParamType); 3495 return ICS; 3496 } 3497 break; 3498 3499 case RQ_RValue: 3500 if (!FromClassification.isRValue()) { 3501 // rvalue reference cannot bind to an lvalue 3502 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 3503 ImplicitParamType); 3504 return ICS; 3505 } 3506 break; 3507 } 3508 3509 // Success. Mark this as a reference binding. 3510 ICS.setStandard(); 3511 ICS.Standard.setAsIdentityConversion(); 3512 ICS.Standard.Second = SecondKind; 3513 ICS.Standard.setFromType(FromType); 3514 ICS.Standard.setAllToTypes(ImplicitParamType); 3515 ICS.Standard.ReferenceBinding = true; 3516 ICS.Standard.DirectBinding = true; 3517 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 3518 ICS.Standard.BindsToFunctionLvalue = false; 3519 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 3520 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 3521 = (Method->getRefQualifier() == RQ_None); 3522 return ICS; 3523} 3524 3525/// PerformObjectArgumentInitialization - Perform initialization of 3526/// the implicit object parameter for the given Method with the given 3527/// expression. 3528bool 3529Sema::PerformObjectArgumentInitialization(Expr *&From, 3530 NestedNameSpecifier *Qualifier, 3531 NamedDecl *FoundDecl, 3532 CXXMethodDecl *Method) { 3533 QualType FromRecordType, DestType; 3534 QualType ImplicitParamRecordType = 3535 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3536 3537 Expr::Classification FromClassification; 3538 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3539 FromRecordType = PT->getPointeeType(); 3540 DestType = Method->getThisType(Context); 3541 FromClassification = Expr::Classification::makeSimpleLValue(); 3542 } else { 3543 FromRecordType = From->getType(); 3544 DestType = ImplicitParamRecordType; 3545 FromClassification = From->Classify(Context); 3546 } 3547 3548 // Note that we always use the true parent context when performing 3549 // the actual argument initialization. 3550 ImplicitConversionSequence ICS 3551 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 3552 Method, Method->getParent()); 3553 if (ICS.isBad()) { 3554 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 3555 Qualifiers FromQs = FromRecordType.getQualifiers(); 3556 Qualifiers ToQs = DestType.getQualifiers(); 3557 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 3558 if (CVR) { 3559 Diag(From->getSourceRange().getBegin(), 3560 diag::err_member_function_call_bad_cvr) 3561 << Method->getDeclName() << FromRecordType << (CVR - 1) 3562 << From->getSourceRange(); 3563 Diag(Method->getLocation(), diag::note_previous_decl) 3564 << Method->getDeclName(); 3565 return true; 3566 } 3567 } 3568 3569 return Diag(From->getSourceRange().getBegin(), 3570 diag::err_implicit_object_parameter_init) 3571 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3572 } 3573 3574 if (ICS.Standard.Second == ICK_Derived_To_Base) 3575 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3576 3577 if (!Context.hasSameType(From->getType(), DestType)) 3578 ImpCastExprToType(From, DestType, CK_NoOp, 3579 From->getType()->isPointerType() ? VK_RValue : VK_LValue); 3580 return false; 3581} 3582 3583/// TryContextuallyConvertToBool - Attempt to contextually convert the 3584/// expression From to bool (C++0x [conv]p3). 3585static ImplicitConversionSequence 3586TryContextuallyConvertToBool(Sema &S, Expr *From) { 3587 // FIXME: This is pretty broken. 3588 return TryImplicitConversion(S, From, S.Context.BoolTy, 3589 // FIXME: Are these flags correct? 3590 /*SuppressUserConversions=*/false, 3591 /*AllowExplicit=*/true, 3592 /*InOverloadResolution=*/false, 3593 /*CStyle=*/false); 3594} 3595 3596/// PerformContextuallyConvertToBool - Perform a contextual conversion 3597/// of the expression From to bool (C++0x [conv]p3). 3598bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3599 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 3600 if (!ICS.isBad()) 3601 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3602 3603 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3604 return Diag(From->getSourceRange().getBegin(), 3605 diag::err_typecheck_bool_condition) 3606 << From->getType() << From->getSourceRange(); 3607 return true; 3608} 3609 3610/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3611/// expression From to 'id'. 3612static ImplicitConversionSequence 3613TryContextuallyConvertToObjCId(Sema &S, Expr *From) { 3614 QualType Ty = S.Context.getObjCIdType(); 3615 return TryImplicitConversion(S, From, Ty, 3616 // FIXME: Are these flags correct? 3617 /*SuppressUserConversions=*/false, 3618 /*AllowExplicit=*/true, 3619 /*InOverloadResolution=*/false, 3620 /*CStyle=*/false); 3621} 3622 3623/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3624/// of the expression From to 'id'. 3625bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3626 QualType Ty = Context.getObjCIdType(); 3627 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(*this, From); 3628 if (!ICS.isBad()) 3629 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3630 return true; 3631} 3632 3633/// \brief Attempt to convert the given expression to an integral or 3634/// enumeration type. 3635/// 3636/// This routine will attempt to convert an expression of class type to an 3637/// integral or enumeration type, if that class type only has a single 3638/// conversion to an integral or enumeration type. 3639/// 3640/// \param Loc The source location of the construct that requires the 3641/// conversion. 3642/// 3643/// \param FromE The expression we're converting from. 3644/// 3645/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3646/// have integral or enumeration type. 3647/// 3648/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3649/// incomplete class type. 3650/// 3651/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3652/// explicit conversion function (because no implicit conversion functions 3653/// were available). This is a recovery mode. 3654/// 3655/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3656/// showing which conversion was picked. 3657/// 3658/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3659/// conversion function that could convert to integral or enumeration type. 3660/// 3661/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3662/// usable conversion function. 3663/// 3664/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3665/// function, which may be an extension in this case. 3666/// 3667/// \returns The expression, converted to an integral or enumeration type if 3668/// successful. 3669ExprResult 3670Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 3671 const PartialDiagnostic &NotIntDiag, 3672 const PartialDiagnostic &IncompleteDiag, 3673 const PartialDiagnostic &ExplicitConvDiag, 3674 const PartialDiagnostic &ExplicitConvNote, 3675 const PartialDiagnostic &AmbigDiag, 3676 const PartialDiagnostic &AmbigNote, 3677 const PartialDiagnostic &ConvDiag) { 3678 // We can't perform any more checking for type-dependent expressions. 3679 if (From->isTypeDependent()) 3680 return Owned(From); 3681 3682 // If the expression already has integral or enumeration type, we're golden. 3683 QualType T = From->getType(); 3684 if (T->isIntegralOrEnumerationType()) 3685 return Owned(From); 3686 3687 // FIXME: Check for missing '()' if T is a function type? 3688 3689 // If we don't have a class type in C++, there's no way we can get an 3690 // expression of integral or enumeration type. 3691 const RecordType *RecordTy = T->getAs<RecordType>(); 3692 if (!RecordTy || !getLangOptions().CPlusPlus) { 3693 Diag(Loc, NotIntDiag) 3694 << T << From->getSourceRange(); 3695 return Owned(From); 3696 } 3697 3698 // We must have a complete class type. 3699 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3700 return Owned(From); 3701 3702 // Look for a conversion to an integral or enumeration type. 3703 UnresolvedSet<4> ViableConversions; 3704 UnresolvedSet<4> ExplicitConversions; 3705 const UnresolvedSetImpl *Conversions 3706 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3707 3708 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3709 E = Conversions->end(); 3710 I != E; 3711 ++I) { 3712 if (CXXConversionDecl *Conversion 3713 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3714 if (Conversion->getConversionType().getNonReferenceType() 3715 ->isIntegralOrEnumerationType()) { 3716 if (Conversion->isExplicit()) 3717 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3718 else 3719 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3720 } 3721 } 3722 3723 switch (ViableConversions.size()) { 3724 case 0: 3725 if (ExplicitConversions.size() == 1) { 3726 DeclAccessPair Found = ExplicitConversions[0]; 3727 CXXConversionDecl *Conversion 3728 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3729 3730 // The user probably meant to invoke the given explicit 3731 // conversion; use it. 3732 QualType ConvTy 3733 = Conversion->getConversionType().getNonReferenceType(); 3734 std::string TypeStr; 3735 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3736 3737 Diag(Loc, ExplicitConvDiag) 3738 << T << ConvTy 3739 << FixItHint::CreateInsertion(From->getLocStart(), 3740 "static_cast<" + TypeStr + ">(") 3741 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3742 ")"); 3743 Diag(Conversion->getLocation(), ExplicitConvNote) 3744 << ConvTy->isEnumeralType() << ConvTy; 3745 3746 // If we aren't in a SFINAE context, build a call to the 3747 // explicit conversion function. 3748 if (isSFINAEContext()) 3749 return ExprError(); 3750 3751 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3752 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion); 3753 if (Result.isInvalid()) 3754 return ExprError(); 3755 3756 From = Result.get(); 3757 } 3758 3759 // We'll complain below about a non-integral condition type. 3760 break; 3761 3762 case 1: { 3763 // Apply this conversion. 3764 DeclAccessPair Found = ViableConversions[0]; 3765 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3766 3767 CXXConversionDecl *Conversion 3768 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3769 QualType ConvTy 3770 = Conversion->getConversionType().getNonReferenceType(); 3771 if (ConvDiag.getDiagID()) { 3772 if (isSFINAEContext()) 3773 return ExprError(); 3774 3775 Diag(Loc, ConvDiag) 3776 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 3777 } 3778 3779 ExprResult Result = BuildCXXMemberCallExpr(From, Found, 3780 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3781 if (Result.isInvalid()) 3782 return ExprError(); 3783 3784 From = Result.get(); 3785 break; 3786 } 3787 3788 default: 3789 Diag(Loc, AmbigDiag) 3790 << T << From->getSourceRange(); 3791 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3792 CXXConversionDecl *Conv 3793 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3794 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3795 Diag(Conv->getLocation(), AmbigNote) 3796 << ConvTy->isEnumeralType() << ConvTy; 3797 } 3798 return Owned(From); 3799 } 3800 3801 if (!From->getType()->isIntegralOrEnumerationType()) 3802 Diag(Loc, NotIntDiag) 3803 << From->getType() << From->getSourceRange(); 3804 3805 return Owned(From); 3806} 3807 3808/// AddOverloadCandidate - Adds the given function to the set of 3809/// candidate functions, using the given function call arguments. If 3810/// @p SuppressUserConversions, then don't allow user-defined 3811/// conversions via constructors or conversion operators. 3812/// 3813/// \para PartialOverloading true if we are performing "partial" overloading 3814/// based on an incomplete set of function arguments. This feature is used by 3815/// code completion. 3816void 3817Sema::AddOverloadCandidate(FunctionDecl *Function, 3818 DeclAccessPair FoundDecl, 3819 Expr **Args, unsigned NumArgs, 3820 OverloadCandidateSet& CandidateSet, 3821 bool SuppressUserConversions, 3822 bool PartialOverloading) { 3823 const FunctionProtoType* Proto 3824 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3825 assert(Proto && "Functions without a prototype cannot be overloaded"); 3826 assert(!Function->getDescribedFunctionTemplate() && 3827 "Use AddTemplateOverloadCandidate for function templates"); 3828 3829 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3830 if (!isa<CXXConstructorDecl>(Method)) { 3831 // If we get here, it's because we're calling a member function 3832 // that is named without a member access expression (e.g., 3833 // "this->f") that was either written explicitly or created 3834 // implicitly. This can happen with a qualified call to a member 3835 // function, e.g., X::f(). We use an empty type for the implied 3836 // object argument (C++ [over.call.func]p3), and the acting context 3837 // is irrelevant. 3838 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3839 QualType(), Expr::Classification::makeSimpleLValue(), 3840 Args, NumArgs, CandidateSet, 3841 SuppressUserConversions); 3842 return; 3843 } 3844 // We treat a constructor like a non-member function, since its object 3845 // argument doesn't participate in overload resolution. 3846 } 3847 3848 if (!CandidateSet.isNewCandidate(Function)) 3849 return; 3850 3851 // Overload resolution is always an unevaluated context. 3852 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 3853 3854 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3855 // C++ [class.copy]p3: 3856 // A member function template is never instantiated to perform the copy 3857 // of a class object to an object of its class type. 3858 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3859 if (NumArgs == 1 && 3860 Constructor->isSpecializationCopyingObject() && 3861 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3862 IsDerivedFrom(Args[0]->getType(), ClassType))) 3863 return; 3864 } 3865 3866 // Add this candidate 3867 CandidateSet.push_back(OverloadCandidate()); 3868 OverloadCandidate& Candidate = CandidateSet.back(); 3869 Candidate.FoundDecl = FoundDecl; 3870 Candidate.Function = Function; 3871 Candidate.Viable = true; 3872 Candidate.IsSurrogate = false; 3873 Candidate.IgnoreObjectArgument = false; 3874 Candidate.ExplicitCallArguments = NumArgs; 3875 3876 unsigned NumArgsInProto = Proto->getNumArgs(); 3877 3878 // (C++ 13.3.2p2): A candidate function having fewer than m 3879 // parameters is viable only if it has an ellipsis in its parameter 3880 // list (8.3.5). 3881 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3882 !Proto->isVariadic()) { 3883 Candidate.Viable = false; 3884 Candidate.FailureKind = ovl_fail_too_many_arguments; 3885 return; 3886 } 3887 3888 // (C++ 13.3.2p2): A candidate function having more than m parameters 3889 // is viable only if the (m+1)st parameter has a default argument 3890 // (8.3.6). For the purposes of overload resolution, the 3891 // parameter list is truncated on the right, so that there are 3892 // exactly m parameters. 3893 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3894 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3895 // Not enough arguments. 3896 Candidate.Viable = false; 3897 Candidate.FailureKind = ovl_fail_too_few_arguments; 3898 return; 3899 } 3900 3901 // Determine the implicit conversion sequences for each of the 3902 // arguments. 3903 Candidate.Conversions.resize(NumArgs); 3904 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3905 if (ArgIdx < NumArgsInProto) { 3906 // (C++ 13.3.2p3): for F to be a viable function, there shall 3907 // exist for each argument an implicit conversion sequence 3908 // (13.3.3.1) that converts that argument to the corresponding 3909 // parameter of F. 3910 QualType ParamType = Proto->getArgType(ArgIdx); 3911 Candidate.Conversions[ArgIdx] 3912 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3913 SuppressUserConversions, 3914 /*InOverloadResolution=*/true); 3915 if (Candidate.Conversions[ArgIdx].isBad()) { 3916 Candidate.Viable = false; 3917 Candidate.FailureKind = ovl_fail_bad_conversion; 3918 break; 3919 } 3920 } else { 3921 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3922 // argument for which there is no corresponding parameter is 3923 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3924 Candidate.Conversions[ArgIdx].setEllipsis(); 3925 } 3926 } 3927} 3928 3929/// \brief Add all of the function declarations in the given function set to 3930/// the overload canddiate set. 3931void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3932 Expr **Args, unsigned NumArgs, 3933 OverloadCandidateSet& CandidateSet, 3934 bool SuppressUserConversions) { 3935 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3936 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3937 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3938 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3939 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3940 cast<CXXMethodDecl>(FD)->getParent(), 3941 Args[0]->getType(), Args[0]->Classify(Context), 3942 Args + 1, NumArgs - 1, 3943 CandidateSet, SuppressUserConversions); 3944 else 3945 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3946 SuppressUserConversions); 3947 } else { 3948 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3949 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3950 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3951 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3952 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3953 /*FIXME: explicit args */ 0, 3954 Args[0]->getType(), 3955 Args[0]->Classify(Context), 3956 Args + 1, NumArgs - 1, 3957 CandidateSet, 3958 SuppressUserConversions); 3959 else 3960 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3961 /*FIXME: explicit args */ 0, 3962 Args, NumArgs, CandidateSet, 3963 SuppressUserConversions); 3964 } 3965 } 3966} 3967 3968/// AddMethodCandidate - Adds a named decl (which is some kind of 3969/// method) as a method candidate to the given overload set. 3970void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3971 QualType ObjectType, 3972 Expr::Classification ObjectClassification, 3973 Expr **Args, unsigned NumArgs, 3974 OverloadCandidateSet& CandidateSet, 3975 bool SuppressUserConversions) { 3976 NamedDecl *Decl = FoundDecl.getDecl(); 3977 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3978 3979 if (isa<UsingShadowDecl>(Decl)) 3980 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3981 3982 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3983 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3984 "Expected a member function template"); 3985 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3986 /*ExplicitArgs*/ 0, 3987 ObjectType, ObjectClassification, Args, NumArgs, 3988 CandidateSet, 3989 SuppressUserConversions); 3990 } else { 3991 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3992 ObjectType, ObjectClassification, Args, NumArgs, 3993 CandidateSet, SuppressUserConversions); 3994 } 3995} 3996 3997/// AddMethodCandidate - Adds the given C++ member function to the set 3998/// of candidate functions, using the given function call arguments 3999/// and the object argument (@c Object). For example, in a call 4000/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 4001/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 4002/// allow user-defined conversions via constructors or conversion 4003/// operators. 4004void 4005Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 4006 CXXRecordDecl *ActingContext, QualType ObjectType, 4007 Expr::Classification ObjectClassification, 4008 Expr **Args, unsigned NumArgs, 4009 OverloadCandidateSet& CandidateSet, 4010 bool SuppressUserConversions) { 4011 const FunctionProtoType* Proto 4012 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 4013 assert(Proto && "Methods without a prototype cannot be overloaded"); 4014 assert(!isa<CXXConstructorDecl>(Method) && 4015 "Use AddOverloadCandidate for constructors"); 4016 4017 if (!CandidateSet.isNewCandidate(Method)) 4018 return; 4019 4020 // Overload resolution is always an unevaluated context. 4021 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4022 4023 // Add this candidate 4024 CandidateSet.push_back(OverloadCandidate()); 4025 OverloadCandidate& Candidate = CandidateSet.back(); 4026 Candidate.FoundDecl = FoundDecl; 4027 Candidate.Function = Method; 4028 Candidate.IsSurrogate = false; 4029 Candidate.IgnoreObjectArgument = false; 4030 Candidate.ExplicitCallArguments = NumArgs; 4031 4032 unsigned NumArgsInProto = Proto->getNumArgs(); 4033 4034 // (C++ 13.3.2p2): A candidate function having fewer than m 4035 // parameters is viable only if it has an ellipsis in its parameter 4036 // list (8.3.5). 4037 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4038 Candidate.Viable = false; 4039 Candidate.FailureKind = ovl_fail_too_many_arguments; 4040 return; 4041 } 4042 4043 // (C++ 13.3.2p2): A candidate function having more than m parameters 4044 // is viable only if the (m+1)st parameter has a default argument 4045 // (8.3.6). For the purposes of overload resolution, the 4046 // parameter list is truncated on the right, so that there are 4047 // exactly m parameters. 4048 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 4049 if (NumArgs < MinRequiredArgs) { 4050 // Not enough arguments. 4051 Candidate.Viable = false; 4052 Candidate.FailureKind = ovl_fail_too_few_arguments; 4053 return; 4054 } 4055 4056 Candidate.Viable = true; 4057 Candidate.Conversions.resize(NumArgs + 1); 4058 4059 if (Method->isStatic() || ObjectType.isNull()) 4060 // The implicit object argument is ignored. 4061 Candidate.IgnoreObjectArgument = true; 4062 else { 4063 // Determine the implicit conversion sequence for the object 4064 // parameter. 4065 Candidate.Conversions[0] 4066 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 4067 Method, ActingContext); 4068 if (Candidate.Conversions[0].isBad()) { 4069 Candidate.Viable = false; 4070 Candidate.FailureKind = ovl_fail_bad_conversion; 4071 return; 4072 } 4073 } 4074 4075 // Determine the implicit conversion sequences for each of the 4076 // arguments. 4077 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4078 if (ArgIdx < NumArgsInProto) { 4079 // (C++ 13.3.2p3): for F to be a viable function, there shall 4080 // exist for each argument an implicit conversion sequence 4081 // (13.3.3.1) that converts that argument to the corresponding 4082 // parameter of F. 4083 QualType ParamType = Proto->getArgType(ArgIdx); 4084 Candidate.Conversions[ArgIdx + 1] 4085 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4086 SuppressUserConversions, 4087 /*InOverloadResolution=*/true); 4088 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4089 Candidate.Viable = false; 4090 Candidate.FailureKind = ovl_fail_bad_conversion; 4091 break; 4092 } 4093 } else { 4094 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4095 // argument for which there is no corresponding parameter is 4096 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4097 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4098 } 4099 } 4100} 4101 4102/// \brief Add a C++ member function template as a candidate to the candidate 4103/// set, using template argument deduction to produce an appropriate member 4104/// function template specialization. 4105void 4106Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 4107 DeclAccessPair FoundDecl, 4108 CXXRecordDecl *ActingContext, 4109 TemplateArgumentListInfo *ExplicitTemplateArgs, 4110 QualType ObjectType, 4111 Expr::Classification ObjectClassification, 4112 Expr **Args, unsigned NumArgs, 4113 OverloadCandidateSet& CandidateSet, 4114 bool SuppressUserConversions) { 4115 if (!CandidateSet.isNewCandidate(MethodTmpl)) 4116 return; 4117 4118 // C++ [over.match.funcs]p7: 4119 // In each case where a candidate is a function template, candidate 4120 // function template specializations are generated using template argument 4121 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4122 // candidate functions in the usual way.113) A given name can refer to one 4123 // or more function templates and also to a set of overloaded non-template 4124 // functions. In such a case, the candidate functions generated from each 4125 // function template are combined with the set of non-template candidate 4126 // functions. 4127 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4128 FunctionDecl *Specialization = 0; 4129 if (TemplateDeductionResult Result 4130 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 4131 Args, NumArgs, Specialization, Info)) { 4132 CandidateSet.push_back(OverloadCandidate()); 4133 OverloadCandidate &Candidate = CandidateSet.back(); 4134 Candidate.FoundDecl = FoundDecl; 4135 Candidate.Function = MethodTmpl->getTemplatedDecl(); 4136 Candidate.Viable = false; 4137 Candidate.FailureKind = ovl_fail_bad_deduction; 4138 Candidate.IsSurrogate = false; 4139 Candidate.IgnoreObjectArgument = false; 4140 Candidate.ExplicitCallArguments = NumArgs; 4141 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4142 Info); 4143 return; 4144 } 4145 4146 // Add the function template specialization produced by template argument 4147 // deduction as a candidate. 4148 assert(Specialization && "Missing member function template specialization?"); 4149 assert(isa<CXXMethodDecl>(Specialization) && 4150 "Specialization is not a member function?"); 4151 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 4152 ActingContext, ObjectType, ObjectClassification, 4153 Args, NumArgs, CandidateSet, SuppressUserConversions); 4154} 4155 4156/// \brief Add a C++ function template specialization as a candidate 4157/// in the candidate set, using template argument deduction to produce 4158/// an appropriate function template specialization. 4159void 4160Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 4161 DeclAccessPair FoundDecl, 4162 TemplateArgumentListInfo *ExplicitTemplateArgs, 4163 Expr **Args, unsigned NumArgs, 4164 OverloadCandidateSet& CandidateSet, 4165 bool SuppressUserConversions) { 4166 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4167 return; 4168 4169 // C++ [over.match.funcs]p7: 4170 // In each case where a candidate is a function template, candidate 4171 // function template specializations are generated using template argument 4172 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4173 // candidate functions in the usual way.113) A given name can refer to one 4174 // or more function templates and also to a set of overloaded non-template 4175 // functions. In such a case, the candidate functions generated from each 4176 // function template are combined with the set of non-template candidate 4177 // functions. 4178 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4179 FunctionDecl *Specialization = 0; 4180 if (TemplateDeductionResult Result 4181 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 4182 Args, NumArgs, Specialization, Info)) { 4183 CandidateSet.push_back(OverloadCandidate()); 4184 OverloadCandidate &Candidate = CandidateSet.back(); 4185 Candidate.FoundDecl = FoundDecl; 4186 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4187 Candidate.Viable = false; 4188 Candidate.FailureKind = ovl_fail_bad_deduction; 4189 Candidate.IsSurrogate = false; 4190 Candidate.IgnoreObjectArgument = false; 4191 Candidate.ExplicitCallArguments = NumArgs; 4192 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4193 Info); 4194 return; 4195 } 4196 4197 // Add the function template specialization produced by template argument 4198 // deduction as a candidate. 4199 assert(Specialization && "Missing function template specialization?"); 4200 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 4201 SuppressUserConversions); 4202} 4203 4204/// AddConversionCandidate - Add a C++ conversion function as a 4205/// candidate in the candidate set (C++ [over.match.conv], 4206/// C++ [over.match.copy]). From is the expression we're converting from, 4207/// and ToType is the type that we're eventually trying to convert to 4208/// (which may or may not be the same type as the type that the 4209/// conversion function produces). 4210void 4211Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 4212 DeclAccessPair FoundDecl, 4213 CXXRecordDecl *ActingContext, 4214 Expr *From, QualType ToType, 4215 OverloadCandidateSet& CandidateSet) { 4216 assert(!Conversion->getDescribedFunctionTemplate() && 4217 "Conversion function templates use AddTemplateConversionCandidate"); 4218 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 4219 if (!CandidateSet.isNewCandidate(Conversion)) 4220 return; 4221 4222 // Overload resolution is always an unevaluated context. 4223 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4224 4225 // Add this candidate 4226 CandidateSet.push_back(OverloadCandidate()); 4227 OverloadCandidate& Candidate = CandidateSet.back(); 4228 Candidate.FoundDecl = FoundDecl; 4229 Candidate.Function = Conversion; 4230 Candidate.IsSurrogate = false; 4231 Candidate.IgnoreObjectArgument = false; 4232 Candidate.FinalConversion.setAsIdentityConversion(); 4233 Candidate.FinalConversion.setFromType(ConvType); 4234 Candidate.FinalConversion.setAllToTypes(ToType); 4235 Candidate.Viable = true; 4236 Candidate.Conversions.resize(1); 4237 Candidate.ExplicitCallArguments = 1; 4238 4239 // C++ [over.match.funcs]p4: 4240 // For conversion functions, the function is considered to be a member of 4241 // the class of the implicit implied object argument for the purpose of 4242 // defining the type of the implicit object parameter. 4243 // 4244 // Determine the implicit conversion sequence for the implicit 4245 // object parameter. 4246 QualType ImplicitParamType = From->getType(); 4247 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 4248 ImplicitParamType = FromPtrType->getPointeeType(); 4249 CXXRecordDecl *ConversionContext 4250 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 4251 4252 Candidate.Conversions[0] 4253 = TryObjectArgumentInitialization(*this, From->getType(), 4254 From->Classify(Context), 4255 Conversion, ConversionContext); 4256 4257 if (Candidate.Conversions[0].isBad()) { 4258 Candidate.Viable = false; 4259 Candidate.FailureKind = ovl_fail_bad_conversion; 4260 return; 4261 } 4262 4263 // We won't go through a user-define type conversion function to convert a 4264 // derived to base as such conversions are given Conversion Rank. They only 4265 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 4266 QualType FromCanon 4267 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 4268 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 4269 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 4270 Candidate.Viable = false; 4271 Candidate.FailureKind = ovl_fail_trivial_conversion; 4272 return; 4273 } 4274 4275 // To determine what the conversion from the result of calling the 4276 // conversion function to the type we're eventually trying to 4277 // convert to (ToType), we need to synthesize a call to the 4278 // conversion function and attempt copy initialization from it. This 4279 // makes sure that we get the right semantics with respect to 4280 // lvalues/rvalues and the type. Fortunately, we can allocate this 4281 // call on the stack and we don't need its arguments to be 4282 // well-formed. 4283 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 4284 VK_LValue, From->getLocStart()); 4285 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 4286 Context.getPointerType(Conversion->getType()), 4287 CK_FunctionToPointerDecay, 4288 &ConversionRef, VK_RValue); 4289 4290 QualType CallResultType 4291 = Conversion->getConversionType().getNonLValueExprType(Context); 4292 if (RequireCompleteType(From->getLocStart(), CallResultType, 0)) { 4293 Candidate.Viable = false; 4294 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4295 return; 4296 } 4297 4298 ExprValueKind VK = Expr::getValueKindForType(Conversion->getConversionType()); 4299 4300 // Note that it is safe to allocate CallExpr on the stack here because 4301 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 4302 // allocator). 4303 CallExpr Call(Context, &ConversionFn, 0, 0, CallResultType, VK, 4304 From->getLocStart()); 4305 ImplicitConversionSequence ICS = 4306 TryCopyInitialization(*this, &Call, ToType, 4307 /*SuppressUserConversions=*/true, 4308 /*InOverloadResolution=*/false); 4309 4310 switch (ICS.getKind()) { 4311 case ImplicitConversionSequence::StandardConversion: 4312 Candidate.FinalConversion = ICS.Standard; 4313 4314 // C++ [over.ics.user]p3: 4315 // If the user-defined conversion is specified by a specialization of a 4316 // conversion function template, the second standard conversion sequence 4317 // shall have exact match rank. 4318 if (Conversion->getPrimaryTemplate() && 4319 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 4320 Candidate.Viable = false; 4321 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 4322 } 4323 4324 // C++0x [dcl.init.ref]p5: 4325 // In the second case, if the reference is an rvalue reference and 4326 // the second standard conversion sequence of the user-defined 4327 // conversion sequence includes an lvalue-to-rvalue conversion, the 4328 // program is ill-formed. 4329 if (ToType->isRValueReferenceType() && 4330 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 4331 Candidate.Viable = false; 4332 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4333 } 4334 break; 4335 4336 case ImplicitConversionSequence::BadConversion: 4337 Candidate.Viable = false; 4338 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4339 break; 4340 4341 default: 4342 assert(false && 4343 "Can only end up with a standard conversion sequence or failure"); 4344 } 4345} 4346 4347/// \brief Adds a conversion function template specialization 4348/// candidate to the overload set, using template argument deduction 4349/// to deduce the template arguments of the conversion function 4350/// template from the type that we are converting to (C++ 4351/// [temp.deduct.conv]). 4352void 4353Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 4354 DeclAccessPair FoundDecl, 4355 CXXRecordDecl *ActingDC, 4356 Expr *From, QualType ToType, 4357 OverloadCandidateSet &CandidateSet) { 4358 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 4359 "Only conversion function templates permitted here"); 4360 4361 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4362 return; 4363 4364 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4365 CXXConversionDecl *Specialization = 0; 4366 if (TemplateDeductionResult Result 4367 = DeduceTemplateArguments(FunctionTemplate, ToType, 4368 Specialization, Info)) { 4369 CandidateSet.push_back(OverloadCandidate()); 4370 OverloadCandidate &Candidate = CandidateSet.back(); 4371 Candidate.FoundDecl = FoundDecl; 4372 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4373 Candidate.Viable = false; 4374 Candidate.FailureKind = ovl_fail_bad_deduction; 4375 Candidate.IsSurrogate = false; 4376 Candidate.IgnoreObjectArgument = false; 4377 Candidate.ExplicitCallArguments = 1; 4378 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4379 Info); 4380 return; 4381 } 4382 4383 // Add the conversion function template specialization produced by 4384 // template argument deduction as a candidate. 4385 assert(Specialization && "Missing function template specialization?"); 4386 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 4387 CandidateSet); 4388} 4389 4390/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 4391/// converts the given @c Object to a function pointer via the 4392/// conversion function @c Conversion, and then attempts to call it 4393/// with the given arguments (C++ [over.call.object]p2-4). Proto is 4394/// the type of function that we'll eventually be calling. 4395void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 4396 DeclAccessPair FoundDecl, 4397 CXXRecordDecl *ActingContext, 4398 const FunctionProtoType *Proto, 4399 Expr *Object, 4400 Expr **Args, unsigned NumArgs, 4401 OverloadCandidateSet& CandidateSet) { 4402 if (!CandidateSet.isNewCandidate(Conversion)) 4403 return; 4404 4405 // Overload resolution is always an unevaluated context. 4406 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4407 4408 CandidateSet.push_back(OverloadCandidate()); 4409 OverloadCandidate& Candidate = CandidateSet.back(); 4410 Candidate.FoundDecl = FoundDecl; 4411 Candidate.Function = 0; 4412 Candidate.Surrogate = Conversion; 4413 Candidate.Viable = true; 4414 Candidate.IsSurrogate = true; 4415 Candidate.IgnoreObjectArgument = false; 4416 Candidate.Conversions.resize(NumArgs + 1); 4417 Candidate.ExplicitCallArguments = NumArgs; 4418 4419 // Determine the implicit conversion sequence for the implicit 4420 // object parameter. 4421 ImplicitConversionSequence ObjectInit 4422 = TryObjectArgumentInitialization(*this, Object->getType(), 4423 Object->Classify(Context), 4424 Conversion, ActingContext); 4425 if (ObjectInit.isBad()) { 4426 Candidate.Viable = false; 4427 Candidate.FailureKind = ovl_fail_bad_conversion; 4428 Candidate.Conversions[0] = ObjectInit; 4429 return; 4430 } 4431 4432 // The first conversion is actually a user-defined conversion whose 4433 // first conversion is ObjectInit's standard conversion (which is 4434 // effectively a reference binding). Record it as such. 4435 Candidate.Conversions[0].setUserDefined(); 4436 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 4437 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 4438 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 4439 Candidate.Conversions[0].UserDefined.FoundConversionFunction 4440 = FoundDecl.getDecl(); 4441 Candidate.Conversions[0].UserDefined.After 4442 = Candidate.Conversions[0].UserDefined.Before; 4443 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 4444 4445 // Find the 4446 unsigned NumArgsInProto = Proto->getNumArgs(); 4447 4448 // (C++ 13.3.2p2): A candidate function having fewer than m 4449 // parameters is viable only if it has an ellipsis in its parameter 4450 // list (8.3.5). 4451 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4452 Candidate.Viable = false; 4453 Candidate.FailureKind = ovl_fail_too_many_arguments; 4454 return; 4455 } 4456 4457 // Function types don't have any default arguments, so just check if 4458 // we have enough arguments. 4459 if (NumArgs < NumArgsInProto) { 4460 // Not enough arguments. 4461 Candidate.Viable = false; 4462 Candidate.FailureKind = ovl_fail_too_few_arguments; 4463 return; 4464 } 4465 4466 // Determine the implicit conversion sequences for each of the 4467 // arguments. 4468 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4469 if (ArgIdx < NumArgsInProto) { 4470 // (C++ 13.3.2p3): for F to be a viable function, there shall 4471 // exist for each argument an implicit conversion sequence 4472 // (13.3.3.1) that converts that argument to the corresponding 4473 // parameter of F. 4474 QualType ParamType = Proto->getArgType(ArgIdx); 4475 Candidate.Conversions[ArgIdx + 1] 4476 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4477 /*SuppressUserConversions=*/false, 4478 /*InOverloadResolution=*/false); 4479 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4480 Candidate.Viable = false; 4481 Candidate.FailureKind = ovl_fail_bad_conversion; 4482 break; 4483 } 4484 } else { 4485 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4486 // argument for which there is no corresponding parameter is 4487 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4488 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4489 } 4490 } 4491} 4492 4493/// \brief Add overload candidates for overloaded operators that are 4494/// member functions. 4495/// 4496/// Add the overloaded operator candidates that are member functions 4497/// for the operator Op that was used in an operator expression such 4498/// as "x Op y". , Args/NumArgs provides the operator arguments, and 4499/// CandidateSet will store the added overload candidates. (C++ 4500/// [over.match.oper]). 4501void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 4502 SourceLocation OpLoc, 4503 Expr **Args, unsigned NumArgs, 4504 OverloadCandidateSet& CandidateSet, 4505 SourceRange OpRange) { 4506 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4507 4508 // C++ [over.match.oper]p3: 4509 // For a unary operator @ with an operand of a type whose 4510 // cv-unqualified version is T1, and for a binary operator @ with 4511 // a left operand of a type whose cv-unqualified version is T1 and 4512 // a right operand of a type whose cv-unqualified version is T2, 4513 // three sets of candidate functions, designated member 4514 // candidates, non-member candidates and built-in candidates, are 4515 // constructed as follows: 4516 QualType T1 = Args[0]->getType(); 4517 4518 // -- If T1 is a class type, the set of member candidates is the 4519 // result of the qualified lookup of T1::operator@ 4520 // (13.3.1.1.1); otherwise, the set of member candidates is 4521 // empty. 4522 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 4523 // Complete the type if it can be completed. Otherwise, we're done. 4524 if (RequireCompleteType(OpLoc, T1, PDiag())) 4525 return; 4526 4527 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 4528 LookupQualifiedName(Operators, T1Rec->getDecl()); 4529 Operators.suppressDiagnostics(); 4530 4531 for (LookupResult::iterator Oper = Operators.begin(), 4532 OperEnd = Operators.end(); 4533 Oper != OperEnd; 4534 ++Oper) 4535 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 4536 Args[0]->Classify(Context), Args + 1, NumArgs - 1, 4537 CandidateSet, 4538 /* SuppressUserConversions = */ false); 4539 } 4540} 4541 4542/// AddBuiltinCandidate - Add a candidate for a built-in 4543/// operator. ResultTy and ParamTys are the result and parameter types 4544/// of the built-in candidate, respectively. Args and NumArgs are the 4545/// arguments being passed to the candidate. IsAssignmentOperator 4546/// should be true when this built-in candidate is an assignment 4547/// operator. NumContextualBoolArguments is the number of arguments 4548/// (at the beginning of the argument list) that will be contextually 4549/// converted to bool. 4550void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 4551 Expr **Args, unsigned NumArgs, 4552 OverloadCandidateSet& CandidateSet, 4553 bool IsAssignmentOperator, 4554 unsigned NumContextualBoolArguments) { 4555 // Overload resolution is always an unevaluated context. 4556 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4557 4558 // Add this candidate 4559 CandidateSet.push_back(OverloadCandidate()); 4560 OverloadCandidate& Candidate = CandidateSet.back(); 4561 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 4562 Candidate.Function = 0; 4563 Candidate.IsSurrogate = false; 4564 Candidate.IgnoreObjectArgument = false; 4565 Candidate.BuiltinTypes.ResultTy = ResultTy; 4566 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4567 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 4568 4569 // Determine the implicit conversion sequences for each of the 4570 // arguments. 4571 Candidate.Viable = true; 4572 Candidate.Conversions.resize(NumArgs); 4573 Candidate.ExplicitCallArguments = NumArgs; 4574 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4575 // C++ [over.match.oper]p4: 4576 // For the built-in assignment operators, conversions of the 4577 // left operand are restricted as follows: 4578 // -- no temporaries are introduced to hold the left operand, and 4579 // -- no user-defined conversions are applied to the left 4580 // operand to achieve a type match with the left-most 4581 // parameter of a built-in candidate. 4582 // 4583 // We block these conversions by turning off user-defined 4584 // conversions, since that is the only way that initialization of 4585 // a reference to a non-class type can occur from something that 4586 // is not of the same type. 4587 if (ArgIdx < NumContextualBoolArguments) { 4588 assert(ParamTys[ArgIdx] == Context.BoolTy && 4589 "Contextual conversion to bool requires bool type"); 4590 Candidate.Conversions[ArgIdx] 4591 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 4592 } else { 4593 Candidate.Conversions[ArgIdx] 4594 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4595 ArgIdx == 0 && IsAssignmentOperator, 4596 /*InOverloadResolution=*/false); 4597 } 4598 if (Candidate.Conversions[ArgIdx].isBad()) { 4599 Candidate.Viable = false; 4600 Candidate.FailureKind = ovl_fail_bad_conversion; 4601 break; 4602 } 4603 } 4604} 4605 4606/// BuiltinCandidateTypeSet - A set of types that will be used for the 4607/// candidate operator functions for built-in operators (C++ 4608/// [over.built]). The types are separated into pointer types and 4609/// enumeration types. 4610class BuiltinCandidateTypeSet { 4611 /// TypeSet - A set of types. 4612 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4613 4614 /// PointerTypes - The set of pointer types that will be used in the 4615 /// built-in candidates. 4616 TypeSet PointerTypes; 4617 4618 /// MemberPointerTypes - The set of member pointer types that will be 4619 /// used in the built-in candidates. 4620 TypeSet MemberPointerTypes; 4621 4622 /// EnumerationTypes - The set of enumeration types that will be 4623 /// used in the built-in candidates. 4624 TypeSet EnumerationTypes; 4625 4626 /// \brief The set of vector types that will be used in the built-in 4627 /// candidates. 4628 TypeSet VectorTypes; 4629 4630 /// \brief A flag indicating non-record types are viable candidates 4631 bool HasNonRecordTypes; 4632 4633 /// \brief A flag indicating whether either arithmetic or enumeration types 4634 /// were present in the candidate set. 4635 bool HasArithmeticOrEnumeralTypes; 4636 4637 /// Sema - The semantic analysis instance where we are building the 4638 /// candidate type set. 4639 Sema &SemaRef; 4640 4641 /// Context - The AST context in which we will build the type sets. 4642 ASTContext &Context; 4643 4644 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4645 const Qualifiers &VisibleQuals); 4646 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4647 4648public: 4649 /// iterator - Iterates through the types that are part of the set. 4650 typedef TypeSet::iterator iterator; 4651 4652 BuiltinCandidateTypeSet(Sema &SemaRef) 4653 : HasNonRecordTypes(false), 4654 HasArithmeticOrEnumeralTypes(false), 4655 SemaRef(SemaRef), 4656 Context(SemaRef.Context) { } 4657 4658 void AddTypesConvertedFrom(QualType Ty, 4659 SourceLocation Loc, 4660 bool AllowUserConversions, 4661 bool AllowExplicitConversions, 4662 const Qualifiers &VisibleTypeConversionsQuals); 4663 4664 /// pointer_begin - First pointer type found; 4665 iterator pointer_begin() { return PointerTypes.begin(); } 4666 4667 /// pointer_end - Past the last pointer type found; 4668 iterator pointer_end() { return PointerTypes.end(); } 4669 4670 /// member_pointer_begin - First member pointer type found; 4671 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4672 4673 /// member_pointer_end - Past the last member pointer type found; 4674 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4675 4676 /// enumeration_begin - First enumeration type found; 4677 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4678 4679 /// enumeration_end - Past the last enumeration type found; 4680 iterator enumeration_end() { return EnumerationTypes.end(); } 4681 4682 iterator vector_begin() { return VectorTypes.begin(); } 4683 iterator vector_end() { return VectorTypes.end(); } 4684 4685 bool hasNonRecordTypes() { return HasNonRecordTypes; } 4686 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 4687}; 4688 4689/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4690/// the set of pointer types along with any more-qualified variants of 4691/// that type. For example, if @p Ty is "int const *", this routine 4692/// will add "int const *", "int const volatile *", "int const 4693/// restrict *", and "int const volatile restrict *" to the set of 4694/// pointer types. Returns true if the add of @p Ty itself succeeded, 4695/// false otherwise. 4696/// 4697/// FIXME: what to do about extended qualifiers? 4698bool 4699BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4700 const Qualifiers &VisibleQuals) { 4701 4702 // Insert this type. 4703 if (!PointerTypes.insert(Ty)) 4704 return false; 4705 4706 QualType PointeeTy; 4707 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4708 bool buildObjCPtr = false; 4709 if (!PointerTy) { 4710 if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) { 4711 PointeeTy = PTy->getPointeeType(); 4712 buildObjCPtr = true; 4713 } 4714 else 4715 assert(false && "type was not a pointer type!"); 4716 } 4717 else 4718 PointeeTy = PointerTy->getPointeeType(); 4719 4720 // Don't add qualified variants of arrays. For one, they're not allowed 4721 // (the qualifier would sink to the element type), and for another, the 4722 // only overload situation where it matters is subscript or pointer +- int, 4723 // and those shouldn't have qualifier variants anyway. 4724 if (PointeeTy->isArrayType()) 4725 return true; 4726 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4727 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4728 BaseCVR = Array->getElementType().getCVRQualifiers(); 4729 bool hasVolatile = VisibleQuals.hasVolatile(); 4730 bool hasRestrict = VisibleQuals.hasRestrict(); 4731 4732 // Iterate through all strict supersets of BaseCVR. 4733 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4734 if ((CVR | BaseCVR) != CVR) continue; 4735 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4736 // in the types. 4737 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4738 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4739 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4740 if (!buildObjCPtr) 4741 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4742 else 4743 PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); 4744 } 4745 4746 return true; 4747} 4748 4749/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4750/// to the set of pointer types along with any more-qualified variants of 4751/// that type. For example, if @p Ty is "int const *", this routine 4752/// will add "int const *", "int const volatile *", "int const 4753/// restrict *", and "int const volatile restrict *" to the set of 4754/// pointer types. Returns true if the add of @p Ty itself succeeded, 4755/// false otherwise. 4756/// 4757/// FIXME: what to do about extended qualifiers? 4758bool 4759BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4760 QualType Ty) { 4761 // Insert this type. 4762 if (!MemberPointerTypes.insert(Ty)) 4763 return false; 4764 4765 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4766 assert(PointerTy && "type was not a member pointer type!"); 4767 4768 QualType PointeeTy = PointerTy->getPointeeType(); 4769 // Don't add qualified variants of arrays. For one, they're not allowed 4770 // (the qualifier would sink to the element type), and for another, the 4771 // only overload situation where it matters is subscript or pointer +- int, 4772 // and those shouldn't have qualifier variants anyway. 4773 if (PointeeTy->isArrayType()) 4774 return true; 4775 const Type *ClassTy = PointerTy->getClass(); 4776 4777 // Iterate through all strict supersets of the pointee type's CVR 4778 // qualifiers. 4779 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4780 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4781 if ((CVR | BaseCVR) != CVR) continue; 4782 4783 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4784 MemberPointerTypes.insert( 4785 Context.getMemberPointerType(QPointeeTy, ClassTy)); 4786 } 4787 4788 return true; 4789} 4790 4791/// AddTypesConvertedFrom - Add each of the types to which the type @p 4792/// Ty can be implicit converted to the given set of @p Types. We're 4793/// primarily interested in pointer types and enumeration types. We also 4794/// take member pointer types, for the conditional operator. 4795/// AllowUserConversions is true if we should look at the conversion 4796/// functions of a class type, and AllowExplicitConversions if we 4797/// should also include the explicit conversion functions of a class 4798/// type. 4799void 4800BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4801 SourceLocation Loc, 4802 bool AllowUserConversions, 4803 bool AllowExplicitConversions, 4804 const Qualifiers &VisibleQuals) { 4805 // Only deal with canonical types. 4806 Ty = Context.getCanonicalType(Ty); 4807 4808 // Look through reference types; they aren't part of the type of an 4809 // expression for the purposes of conversions. 4810 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4811 Ty = RefTy->getPointeeType(); 4812 4813 // If we're dealing with an array type, decay to the pointer. 4814 if (Ty->isArrayType()) 4815 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4816 4817 // Otherwise, we don't care about qualifiers on the type. 4818 Ty = Ty.getLocalUnqualifiedType(); 4819 4820 // Flag if we ever add a non-record type. 4821 const RecordType *TyRec = Ty->getAs<RecordType>(); 4822 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 4823 4824 // Flag if we encounter an arithmetic type. 4825 HasArithmeticOrEnumeralTypes = 4826 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 4827 4828 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 4829 PointerTypes.insert(Ty); 4830 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 4831 // Insert our type, and its more-qualified variants, into the set 4832 // of types. 4833 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4834 return; 4835 } else if (Ty->isMemberPointerType()) { 4836 // Member pointers are far easier, since the pointee can't be converted. 4837 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4838 return; 4839 } else if (Ty->isEnumeralType()) { 4840 HasArithmeticOrEnumeralTypes = true; 4841 EnumerationTypes.insert(Ty); 4842 } else if (Ty->isVectorType()) { 4843 // We treat vector types as arithmetic types in many contexts as an 4844 // extension. 4845 HasArithmeticOrEnumeralTypes = true; 4846 VectorTypes.insert(Ty); 4847 } else if (AllowUserConversions && TyRec) { 4848 // No conversion functions in incomplete types. 4849 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 4850 return; 4851 4852 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4853 const UnresolvedSetImpl *Conversions 4854 = ClassDecl->getVisibleConversionFunctions(); 4855 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4856 E = Conversions->end(); I != E; ++I) { 4857 NamedDecl *D = I.getDecl(); 4858 if (isa<UsingShadowDecl>(D)) 4859 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4860 4861 // Skip conversion function templates; they don't tell us anything 4862 // about which builtin types we can convert to. 4863 if (isa<FunctionTemplateDecl>(D)) 4864 continue; 4865 4866 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4867 if (AllowExplicitConversions || !Conv->isExplicit()) { 4868 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4869 VisibleQuals); 4870 } 4871 } 4872 } 4873} 4874 4875/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4876/// the volatile- and non-volatile-qualified assignment operators for the 4877/// given type to the candidate set. 4878static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4879 QualType T, 4880 Expr **Args, 4881 unsigned NumArgs, 4882 OverloadCandidateSet &CandidateSet) { 4883 QualType ParamTypes[2]; 4884 4885 // T& operator=(T&, T) 4886 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4887 ParamTypes[1] = T; 4888 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4889 /*IsAssignmentOperator=*/true); 4890 4891 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4892 // volatile T& operator=(volatile T&, T) 4893 ParamTypes[0] 4894 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4895 ParamTypes[1] = T; 4896 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4897 /*IsAssignmentOperator=*/true); 4898 } 4899} 4900 4901/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4902/// if any, found in visible type conversion functions found in ArgExpr's type. 4903static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4904 Qualifiers VRQuals; 4905 const RecordType *TyRec; 4906 if (const MemberPointerType *RHSMPType = 4907 ArgExpr->getType()->getAs<MemberPointerType>()) 4908 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4909 else 4910 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4911 if (!TyRec) { 4912 // Just to be safe, assume the worst case. 4913 VRQuals.addVolatile(); 4914 VRQuals.addRestrict(); 4915 return VRQuals; 4916 } 4917 4918 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4919 if (!ClassDecl->hasDefinition()) 4920 return VRQuals; 4921 4922 const UnresolvedSetImpl *Conversions = 4923 ClassDecl->getVisibleConversionFunctions(); 4924 4925 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4926 E = Conversions->end(); I != E; ++I) { 4927 NamedDecl *D = I.getDecl(); 4928 if (isa<UsingShadowDecl>(D)) 4929 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4930 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4931 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4932 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4933 CanTy = ResTypeRef->getPointeeType(); 4934 // Need to go down the pointer/mempointer chain and add qualifiers 4935 // as see them. 4936 bool done = false; 4937 while (!done) { 4938 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4939 CanTy = ResTypePtr->getPointeeType(); 4940 else if (const MemberPointerType *ResTypeMPtr = 4941 CanTy->getAs<MemberPointerType>()) 4942 CanTy = ResTypeMPtr->getPointeeType(); 4943 else 4944 done = true; 4945 if (CanTy.isVolatileQualified()) 4946 VRQuals.addVolatile(); 4947 if (CanTy.isRestrictQualified()) 4948 VRQuals.addRestrict(); 4949 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4950 return VRQuals; 4951 } 4952 } 4953 } 4954 return VRQuals; 4955} 4956 4957namespace { 4958 4959/// \brief Helper class to manage the addition of builtin operator overload 4960/// candidates. It provides shared state and utility methods used throughout 4961/// the process, as well as a helper method to add each group of builtin 4962/// operator overloads from the standard to a candidate set. 4963class BuiltinOperatorOverloadBuilder { 4964 // Common instance state available to all overload candidate addition methods. 4965 Sema &S; 4966 Expr **Args; 4967 unsigned NumArgs; 4968 Qualifiers VisibleTypeConversionsQuals; 4969 bool HasArithmeticOrEnumeralCandidateType; 4970 llvm::SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 4971 OverloadCandidateSet &CandidateSet; 4972 4973 // Define some constants used to index and iterate over the arithemetic types 4974 // provided via the getArithmeticType() method below. 4975 // The "promoted arithmetic types" are the arithmetic 4976 // types are that preserved by promotion (C++ [over.built]p2). 4977 static const unsigned FirstIntegralType = 3; 4978 static const unsigned LastIntegralType = 18; 4979 static const unsigned FirstPromotedIntegralType = 3, 4980 LastPromotedIntegralType = 9; 4981 static const unsigned FirstPromotedArithmeticType = 0, 4982 LastPromotedArithmeticType = 9; 4983 static const unsigned NumArithmeticTypes = 18; 4984 4985 /// \brief Get the canonical type for a given arithmetic type index. 4986 CanQualType getArithmeticType(unsigned index) { 4987 assert(index < NumArithmeticTypes); 4988 static CanQualType ASTContext::* const 4989 ArithmeticTypes[NumArithmeticTypes] = { 4990 // Start of promoted types. 4991 &ASTContext::FloatTy, 4992 &ASTContext::DoubleTy, 4993 &ASTContext::LongDoubleTy, 4994 4995 // Start of integral types. 4996 &ASTContext::IntTy, 4997 &ASTContext::LongTy, 4998 &ASTContext::LongLongTy, 4999 &ASTContext::UnsignedIntTy, 5000 &ASTContext::UnsignedLongTy, 5001 &ASTContext::UnsignedLongLongTy, 5002 // End of promoted types. 5003 5004 &ASTContext::BoolTy, 5005 &ASTContext::CharTy, 5006 &ASTContext::WCharTy, 5007 &ASTContext::Char16Ty, 5008 &ASTContext::Char32Ty, 5009 &ASTContext::SignedCharTy, 5010 &ASTContext::ShortTy, 5011 &ASTContext::UnsignedCharTy, 5012 &ASTContext::UnsignedShortTy, 5013 // End of integral types. 5014 // FIXME: What about complex? 5015 }; 5016 return S.Context.*ArithmeticTypes[index]; 5017 } 5018 5019 /// \brief Gets the canonical type resulting from the usual arithemetic 5020 /// converions for the given arithmetic types. 5021 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 5022 // Accelerator table for performing the usual arithmetic conversions. 5023 // The rules are basically: 5024 // - if either is floating-point, use the wider floating-point 5025 // - if same signedness, use the higher rank 5026 // - if same size, use unsigned of the higher rank 5027 // - use the larger type 5028 // These rules, together with the axiom that higher ranks are 5029 // never smaller, are sufficient to precompute all of these results 5030 // *except* when dealing with signed types of higher rank. 5031 // (we could precompute SLL x UI for all known platforms, but it's 5032 // better not to make any assumptions). 5033 enum PromotedType { 5034 Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL, Dep=-1 5035 }; 5036 static PromotedType ConversionsTable[LastPromotedArithmeticType] 5037 [LastPromotedArithmeticType] = { 5038 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt }, 5039 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 5040 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 5041 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL }, 5042 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, Dep, UL, ULL }, 5043 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, Dep, Dep, ULL }, 5044 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, UI, UL, ULL }, 5045 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, UL, UL, ULL }, 5046 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, ULL, ULL, ULL }, 5047 }; 5048 5049 assert(L < LastPromotedArithmeticType); 5050 assert(R < LastPromotedArithmeticType); 5051 int Idx = ConversionsTable[L][R]; 5052 5053 // Fast path: the table gives us a concrete answer. 5054 if (Idx != Dep) return getArithmeticType(Idx); 5055 5056 // Slow path: we need to compare widths. 5057 // An invariant is that the signed type has higher rank. 5058 CanQualType LT = getArithmeticType(L), 5059 RT = getArithmeticType(R); 5060 unsigned LW = S.Context.getIntWidth(LT), 5061 RW = S.Context.getIntWidth(RT); 5062 5063 // If they're different widths, use the signed type. 5064 if (LW > RW) return LT; 5065 else if (LW < RW) return RT; 5066 5067 // Otherwise, use the unsigned type of the signed type's rank. 5068 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 5069 assert(L == SLL || R == SLL); 5070 return S.Context.UnsignedLongLongTy; 5071 } 5072 5073 /// \brief Helper method to factor out the common pattern of adding overloads 5074 /// for '++' and '--' builtin operators. 5075 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 5076 bool HasVolatile) { 5077 QualType ParamTypes[2] = { 5078 S.Context.getLValueReferenceType(CandidateTy), 5079 S.Context.IntTy 5080 }; 5081 5082 // Non-volatile version. 5083 if (NumArgs == 1) 5084 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5085 else 5086 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5087 5088 // Use a heuristic to reduce number of builtin candidates in the set: 5089 // add volatile version only if there are conversions to a volatile type. 5090 if (HasVolatile) { 5091 ParamTypes[0] = 5092 S.Context.getLValueReferenceType( 5093 S.Context.getVolatileType(CandidateTy)); 5094 if (NumArgs == 1) 5095 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5096 else 5097 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5098 } 5099 } 5100 5101public: 5102 BuiltinOperatorOverloadBuilder( 5103 Sema &S, Expr **Args, unsigned NumArgs, 5104 Qualifiers VisibleTypeConversionsQuals, 5105 bool HasArithmeticOrEnumeralCandidateType, 5106 llvm::SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 5107 OverloadCandidateSet &CandidateSet) 5108 : S(S), Args(Args), NumArgs(NumArgs), 5109 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 5110 HasArithmeticOrEnumeralCandidateType( 5111 HasArithmeticOrEnumeralCandidateType), 5112 CandidateTypes(CandidateTypes), 5113 CandidateSet(CandidateSet) { 5114 // Validate some of our static helper constants in debug builds. 5115 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 5116 "Invalid first promoted integral type"); 5117 assert(getArithmeticType(LastPromotedIntegralType - 1) 5118 == S.Context.UnsignedLongLongTy && 5119 "Invalid last promoted integral type"); 5120 assert(getArithmeticType(FirstPromotedArithmeticType) 5121 == S.Context.FloatTy && 5122 "Invalid first promoted arithmetic type"); 5123 assert(getArithmeticType(LastPromotedArithmeticType - 1) 5124 == S.Context.UnsignedLongLongTy && 5125 "Invalid last promoted arithmetic type"); 5126 } 5127 5128 // C++ [over.built]p3: 5129 // 5130 // For every pair (T, VQ), where T is an arithmetic type, and VQ 5131 // is either volatile or empty, there exist candidate operator 5132 // functions of the form 5133 // 5134 // VQ T& operator++(VQ T&); 5135 // T operator++(VQ T&, int); 5136 // 5137 // C++ [over.built]p4: 5138 // 5139 // For every pair (T, VQ), where T is an arithmetic type other 5140 // than bool, and VQ is either volatile or empty, there exist 5141 // candidate operator functions of the form 5142 // 5143 // VQ T& operator--(VQ T&); 5144 // T operator--(VQ T&, int); 5145 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 5146 if (!HasArithmeticOrEnumeralCandidateType) 5147 return; 5148 5149 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 5150 Arith < NumArithmeticTypes; ++Arith) { 5151 addPlusPlusMinusMinusStyleOverloads( 5152 getArithmeticType(Arith), 5153 VisibleTypeConversionsQuals.hasVolatile()); 5154 } 5155 } 5156 5157 // C++ [over.built]p5: 5158 // 5159 // For every pair (T, VQ), where T is a cv-qualified or 5160 // cv-unqualified object type, and VQ is either volatile or 5161 // empty, there exist candidate operator functions of the form 5162 // 5163 // T*VQ& operator++(T*VQ&); 5164 // T*VQ& operator--(T*VQ&); 5165 // T* operator++(T*VQ&, int); 5166 // T* operator--(T*VQ&, int); 5167 void addPlusPlusMinusMinusPointerOverloads() { 5168 for (BuiltinCandidateTypeSet::iterator 5169 Ptr = CandidateTypes[0].pointer_begin(), 5170 PtrEnd = CandidateTypes[0].pointer_end(); 5171 Ptr != PtrEnd; ++Ptr) { 5172 // Skip pointer types that aren't pointers to object types. 5173 if (!(*Ptr)->getPointeeType()->isObjectType()) 5174 continue; 5175 5176 addPlusPlusMinusMinusStyleOverloads(*Ptr, 5177 (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5178 VisibleTypeConversionsQuals.hasVolatile())); 5179 } 5180 } 5181 5182 // C++ [over.built]p6: 5183 // For every cv-qualified or cv-unqualified object type T, there 5184 // exist candidate operator functions of the form 5185 // 5186 // T& operator*(T*); 5187 // 5188 // C++ [over.built]p7: 5189 // For every function type T that does not have cv-qualifiers or a 5190 // ref-qualifier, there exist candidate operator functions of the form 5191 // T& operator*(T*); 5192 void addUnaryStarPointerOverloads() { 5193 for (BuiltinCandidateTypeSet::iterator 5194 Ptr = CandidateTypes[0].pointer_begin(), 5195 PtrEnd = CandidateTypes[0].pointer_end(); 5196 Ptr != PtrEnd; ++Ptr) { 5197 QualType ParamTy = *Ptr; 5198 QualType PointeeTy = ParamTy->getPointeeType(); 5199 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 5200 continue; 5201 5202 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 5203 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 5204 continue; 5205 5206 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 5207 &ParamTy, Args, 1, CandidateSet); 5208 } 5209 } 5210 5211 // C++ [over.built]p9: 5212 // For every promoted arithmetic type T, there exist candidate 5213 // operator functions of the form 5214 // 5215 // T operator+(T); 5216 // T operator-(T); 5217 void addUnaryPlusOrMinusArithmeticOverloads() { 5218 if (!HasArithmeticOrEnumeralCandidateType) 5219 return; 5220 5221 for (unsigned Arith = FirstPromotedArithmeticType; 5222 Arith < LastPromotedArithmeticType; ++Arith) { 5223 QualType ArithTy = getArithmeticType(Arith); 5224 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 5225 } 5226 5227 // Extension: We also add these operators for vector types. 5228 for (BuiltinCandidateTypeSet::iterator 5229 Vec = CandidateTypes[0].vector_begin(), 5230 VecEnd = CandidateTypes[0].vector_end(); 5231 Vec != VecEnd; ++Vec) { 5232 QualType VecTy = *Vec; 5233 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5234 } 5235 } 5236 5237 // C++ [over.built]p8: 5238 // For every type T, there exist candidate operator functions of 5239 // the form 5240 // 5241 // T* operator+(T*); 5242 void addUnaryPlusPointerOverloads() { 5243 for (BuiltinCandidateTypeSet::iterator 5244 Ptr = CandidateTypes[0].pointer_begin(), 5245 PtrEnd = CandidateTypes[0].pointer_end(); 5246 Ptr != PtrEnd; ++Ptr) { 5247 QualType ParamTy = *Ptr; 5248 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 5249 } 5250 } 5251 5252 // C++ [over.built]p10: 5253 // For every promoted integral type T, there exist candidate 5254 // operator functions of the form 5255 // 5256 // T operator~(T); 5257 void addUnaryTildePromotedIntegralOverloads() { 5258 if (!HasArithmeticOrEnumeralCandidateType) 5259 return; 5260 5261 for (unsigned Int = FirstPromotedIntegralType; 5262 Int < LastPromotedIntegralType; ++Int) { 5263 QualType IntTy = getArithmeticType(Int); 5264 S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 5265 } 5266 5267 // Extension: We also add this operator for vector types. 5268 for (BuiltinCandidateTypeSet::iterator 5269 Vec = CandidateTypes[0].vector_begin(), 5270 VecEnd = CandidateTypes[0].vector_end(); 5271 Vec != VecEnd; ++Vec) { 5272 QualType VecTy = *Vec; 5273 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5274 } 5275 } 5276 5277 // C++ [over.match.oper]p16: 5278 // For every pointer to member type T, there exist candidate operator 5279 // functions of the form 5280 // 5281 // bool operator==(T,T); 5282 // bool operator!=(T,T); 5283 void addEqualEqualOrNotEqualMemberPointerOverloads() { 5284 /// Set of (canonical) types that we've already handled. 5285 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5286 5287 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5288 for (BuiltinCandidateTypeSet::iterator 5289 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5290 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5291 MemPtr != MemPtrEnd; 5292 ++MemPtr) { 5293 // Don't add the same builtin candidate twice. 5294 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5295 continue; 5296 5297 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5298 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5299 CandidateSet); 5300 } 5301 } 5302 } 5303 5304 // C++ [over.built]p15: 5305 // 5306 // For every pointer or enumeration type T, there exist 5307 // candidate operator functions of the form 5308 // 5309 // bool operator<(T, T); 5310 // bool operator>(T, T); 5311 // bool operator<=(T, T); 5312 // bool operator>=(T, T); 5313 // bool operator==(T, T); 5314 // bool operator!=(T, T); 5315 void addRelationalPointerOrEnumeralOverloads() { 5316 // C++ [over.built]p1: 5317 // If there is a user-written candidate with the same name and parameter 5318 // types as a built-in candidate operator function, the built-in operator 5319 // function is hidden and is not included in the set of candidate 5320 // functions. 5321 // 5322 // The text is actually in a note, but if we don't implement it then we end 5323 // up with ambiguities when the user provides an overloaded operator for 5324 // an enumeration type. Note that only enumeration types have this problem, 5325 // so we track which enumeration types we've seen operators for. Also, the 5326 // only other overloaded operator with enumeration argumenst, operator=, 5327 // cannot be overloaded for enumeration types, so this is the only place 5328 // where we must suppress candidates like this. 5329 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 5330 UserDefinedBinaryOperators; 5331 5332 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5333 if (CandidateTypes[ArgIdx].enumeration_begin() != 5334 CandidateTypes[ArgIdx].enumeration_end()) { 5335 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 5336 CEnd = CandidateSet.end(); 5337 C != CEnd; ++C) { 5338 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 5339 continue; 5340 5341 QualType FirstParamType = 5342 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 5343 QualType SecondParamType = 5344 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 5345 5346 // Skip if either parameter isn't of enumeral type. 5347 if (!FirstParamType->isEnumeralType() || 5348 !SecondParamType->isEnumeralType()) 5349 continue; 5350 5351 // Add this operator to the set of known user-defined operators. 5352 UserDefinedBinaryOperators.insert( 5353 std::make_pair(S.Context.getCanonicalType(FirstParamType), 5354 S.Context.getCanonicalType(SecondParamType))); 5355 } 5356 } 5357 } 5358 5359 /// Set of (canonical) types that we've already handled. 5360 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5361 5362 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5363 for (BuiltinCandidateTypeSet::iterator 5364 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5365 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5366 Ptr != PtrEnd; ++Ptr) { 5367 // Don't add the same builtin candidate twice. 5368 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5369 continue; 5370 5371 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5372 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5373 CandidateSet); 5374 } 5375 for (BuiltinCandidateTypeSet::iterator 5376 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5377 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5378 Enum != EnumEnd; ++Enum) { 5379 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 5380 5381 // Don't add the same builtin candidate twice, or if a user defined 5382 // candidate exists. 5383 if (!AddedTypes.insert(CanonType) || 5384 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 5385 CanonType))) 5386 continue; 5387 5388 QualType ParamTypes[2] = { *Enum, *Enum }; 5389 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5390 CandidateSet); 5391 } 5392 } 5393 } 5394 5395 // C++ [over.built]p13: 5396 // 5397 // For every cv-qualified or cv-unqualified object type T 5398 // there exist candidate operator functions of the form 5399 // 5400 // T* operator+(T*, ptrdiff_t); 5401 // T& operator[](T*, ptrdiff_t); [BELOW] 5402 // T* operator-(T*, ptrdiff_t); 5403 // T* operator+(ptrdiff_t, T*); 5404 // T& operator[](ptrdiff_t, T*); [BELOW] 5405 // 5406 // C++ [over.built]p14: 5407 // 5408 // For every T, where T is a pointer to object type, there 5409 // exist candidate operator functions of the form 5410 // 5411 // ptrdiff_t operator-(T, T); 5412 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 5413 /// Set of (canonical) types that we've already handled. 5414 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5415 5416 for (int Arg = 0; Arg < 2; ++Arg) { 5417 QualType AsymetricParamTypes[2] = { 5418 S.Context.getPointerDiffType(), 5419 S.Context.getPointerDiffType(), 5420 }; 5421 for (BuiltinCandidateTypeSet::iterator 5422 Ptr = CandidateTypes[Arg].pointer_begin(), 5423 PtrEnd = CandidateTypes[Arg].pointer_end(); 5424 Ptr != PtrEnd; ++Ptr) { 5425 QualType PointeeTy = (*Ptr)->getPointeeType(); 5426 if (!PointeeTy->isObjectType()) 5427 continue; 5428 5429 AsymetricParamTypes[Arg] = *Ptr; 5430 if (Arg == 0 || Op == OO_Plus) { 5431 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 5432 // T* operator+(ptrdiff_t, T*); 5433 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, 5434 CandidateSet); 5435 } 5436 if (Op == OO_Minus) { 5437 // ptrdiff_t operator-(T, T); 5438 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5439 continue; 5440 5441 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5442 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 5443 Args, 2, CandidateSet); 5444 } 5445 } 5446 } 5447 } 5448 5449 // C++ [over.built]p12: 5450 // 5451 // For every pair of promoted arithmetic types L and R, there 5452 // exist candidate operator functions of the form 5453 // 5454 // LR operator*(L, R); 5455 // LR operator/(L, R); 5456 // LR operator+(L, R); 5457 // LR operator-(L, R); 5458 // bool operator<(L, R); 5459 // bool operator>(L, R); 5460 // bool operator<=(L, R); 5461 // bool operator>=(L, R); 5462 // bool operator==(L, R); 5463 // bool operator!=(L, R); 5464 // 5465 // where LR is the result of the usual arithmetic conversions 5466 // between types L and R. 5467 // 5468 // C++ [over.built]p24: 5469 // 5470 // For every pair of promoted arithmetic types L and R, there exist 5471 // candidate operator functions of the form 5472 // 5473 // LR operator?(bool, L, R); 5474 // 5475 // where LR is the result of the usual arithmetic conversions 5476 // between types L and R. 5477 // Our candidates ignore the first parameter. 5478 void addGenericBinaryArithmeticOverloads(bool isComparison) { 5479 if (!HasArithmeticOrEnumeralCandidateType) 5480 return; 5481 5482 for (unsigned Left = FirstPromotedArithmeticType; 5483 Left < LastPromotedArithmeticType; ++Left) { 5484 for (unsigned Right = FirstPromotedArithmeticType; 5485 Right < LastPromotedArithmeticType; ++Right) { 5486 QualType LandR[2] = { getArithmeticType(Left), 5487 getArithmeticType(Right) }; 5488 QualType Result = 5489 isComparison ? S.Context.BoolTy 5490 : getUsualArithmeticConversions(Left, Right); 5491 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5492 } 5493 } 5494 5495 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 5496 // conditional operator for vector types. 5497 for (BuiltinCandidateTypeSet::iterator 5498 Vec1 = CandidateTypes[0].vector_begin(), 5499 Vec1End = CandidateTypes[0].vector_end(); 5500 Vec1 != Vec1End; ++Vec1) { 5501 for (BuiltinCandidateTypeSet::iterator 5502 Vec2 = CandidateTypes[1].vector_begin(), 5503 Vec2End = CandidateTypes[1].vector_end(); 5504 Vec2 != Vec2End; ++Vec2) { 5505 QualType LandR[2] = { *Vec1, *Vec2 }; 5506 QualType Result = S.Context.BoolTy; 5507 if (!isComparison) { 5508 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 5509 Result = *Vec1; 5510 else 5511 Result = *Vec2; 5512 } 5513 5514 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5515 } 5516 } 5517 } 5518 5519 // C++ [over.built]p17: 5520 // 5521 // For every pair of promoted integral types L and R, there 5522 // exist candidate operator functions of the form 5523 // 5524 // LR operator%(L, R); 5525 // LR operator&(L, R); 5526 // LR operator^(L, R); 5527 // LR operator|(L, R); 5528 // L operator<<(L, R); 5529 // L operator>>(L, R); 5530 // 5531 // where LR is the result of the usual arithmetic conversions 5532 // between types L and R. 5533 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 5534 if (!HasArithmeticOrEnumeralCandidateType) 5535 return; 5536 5537 for (unsigned Left = FirstPromotedIntegralType; 5538 Left < LastPromotedIntegralType; ++Left) { 5539 for (unsigned Right = FirstPromotedIntegralType; 5540 Right < LastPromotedIntegralType; ++Right) { 5541 QualType LandR[2] = { getArithmeticType(Left), 5542 getArithmeticType(Right) }; 5543 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 5544 ? LandR[0] 5545 : getUsualArithmeticConversions(Left, Right); 5546 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5547 } 5548 } 5549 } 5550 5551 // C++ [over.built]p20: 5552 // 5553 // For every pair (T, VQ), where T is an enumeration or 5554 // pointer to member type and VQ is either volatile or 5555 // empty, there exist candidate operator functions of the form 5556 // 5557 // VQ T& operator=(VQ T&, T); 5558 void addAssignmentMemberPointerOrEnumeralOverloads() { 5559 /// Set of (canonical) types that we've already handled. 5560 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5561 5562 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5563 for (BuiltinCandidateTypeSet::iterator 5564 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5565 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5566 Enum != EnumEnd; ++Enum) { 5567 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5568 continue; 5569 5570 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, 5571 CandidateSet); 5572 } 5573 5574 for (BuiltinCandidateTypeSet::iterator 5575 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5576 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5577 MemPtr != MemPtrEnd; ++MemPtr) { 5578 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5579 continue; 5580 5581 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, 5582 CandidateSet); 5583 } 5584 } 5585 } 5586 5587 // C++ [over.built]p19: 5588 // 5589 // For every pair (T, VQ), where T is any type and VQ is either 5590 // volatile or empty, there exist candidate operator functions 5591 // of the form 5592 // 5593 // T*VQ& operator=(T*VQ&, T*); 5594 // 5595 // C++ [over.built]p21: 5596 // 5597 // For every pair (T, VQ), where T is a cv-qualified or 5598 // cv-unqualified object type and VQ is either volatile or 5599 // empty, there exist candidate operator functions of the form 5600 // 5601 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 5602 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 5603 void addAssignmentPointerOverloads(bool isEqualOp) { 5604 /// Set of (canonical) types that we've already handled. 5605 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5606 5607 for (BuiltinCandidateTypeSet::iterator 5608 Ptr = CandidateTypes[0].pointer_begin(), 5609 PtrEnd = CandidateTypes[0].pointer_end(); 5610 Ptr != PtrEnd; ++Ptr) { 5611 // If this is operator=, keep track of the builtin candidates we added. 5612 if (isEqualOp) 5613 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 5614 else if (!(*Ptr)->getPointeeType()->isObjectType()) 5615 continue; 5616 5617 // non-volatile version 5618 QualType ParamTypes[2] = { 5619 S.Context.getLValueReferenceType(*Ptr), 5620 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 5621 }; 5622 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5623 /*IsAssigmentOperator=*/ isEqualOp); 5624 5625 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5626 VisibleTypeConversionsQuals.hasVolatile()) { 5627 // volatile version 5628 ParamTypes[0] = 5629 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5630 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5631 /*IsAssigmentOperator=*/isEqualOp); 5632 } 5633 } 5634 5635 if (isEqualOp) { 5636 for (BuiltinCandidateTypeSet::iterator 5637 Ptr = CandidateTypes[1].pointer_begin(), 5638 PtrEnd = CandidateTypes[1].pointer_end(); 5639 Ptr != PtrEnd; ++Ptr) { 5640 // Make sure we don't add the same candidate twice. 5641 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5642 continue; 5643 5644 QualType ParamTypes[2] = { 5645 S.Context.getLValueReferenceType(*Ptr), 5646 *Ptr, 5647 }; 5648 5649 // non-volatile version 5650 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5651 /*IsAssigmentOperator=*/true); 5652 5653 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5654 VisibleTypeConversionsQuals.hasVolatile()) { 5655 // volatile version 5656 ParamTypes[0] = 5657 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5658 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5659 CandidateSet, /*IsAssigmentOperator=*/true); 5660 } 5661 } 5662 } 5663 } 5664 5665 // C++ [over.built]p18: 5666 // 5667 // For every triple (L, VQ, R), where L is an arithmetic type, 5668 // VQ is either volatile or empty, and R is a promoted 5669 // arithmetic type, there exist candidate operator functions of 5670 // the form 5671 // 5672 // VQ L& operator=(VQ L&, R); 5673 // VQ L& operator*=(VQ L&, R); 5674 // VQ L& operator/=(VQ L&, R); 5675 // VQ L& operator+=(VQ L&, R); 5676 // VQ L& operator-=(VQ L&, R); 5677 void addAssignmentArithmeticOverloads(bool isEqualOp) { 5678 if (!HasArithmeticOrEnumeralCandidateType) 5679 return; 5680 5681 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 5682 for (unsigned Right = FirstPromotedArithmeticType; 5683 Right < LastPromotedArithmeticType; ++Right) { 5684 QualType ParamTypes[2]; 5685 ParamTypes[1] = getArithmeticType(Right); 5686 5687 // Add this built-in operator as a candidate (VQ is empty). 5688 ParamTypes[0] = 5689 S.Context.getLValueReferenceType(getArithmeticType(Left)); 5690 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5691 /*IsAssigmentOperator=*/isEqualOp); 5692 5693 // Add this built-in operator as a candidate (VQ is 'volatile'). 5694 if (VisibleTypeConversionsQuals.hasVolatile()) { 5695 ParamTypes[0] = 5696 S.Context.getVolatileType(getArithmeticType(Left)); 5697 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5698 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5699 CandidateSet, 5700 /*IsAssigmentOperator=*/isEqualOp); 5701 } 5702 } 5703 } 5704 5705 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 5706 for (BuiltinCandidateTypeSet::iterator 5707 Vec1 = CandidateTypes[0].vector_begin(), 5708 Vec1End = CandidateTypes[0].vector_end(); 5709 Vec1 != Vec1End; ++Vec1) { 5710 for (BuiltinCandidateTypeSet::iterator 5711 Vec2 = CandidateTypes[1].vector_begin(), 5712 Vec2End = CandidateTypes[1].vector_end(); 5713 Vec2 != Vec2End; ++Vec2) { 5714 QualType ParamTypes[2]; 5715 ParamTypes[1] = *Vec2; 5716 // Add this built-in operator as a candidate (VQ is empty). 5717 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 5718 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5719 /*IsAssigmentOperator=*/isEqualOp); 5720 5721 // Add this built-in operator as a candidate (VQ is 'volatile'). 5722 if (VisibleTypeConversionsQuals.hasVolatile()) { 5723 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 5724 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5725 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5726 CandidateSet, 5727 /*IsAssigmentOperator=*/isEqualOp); 5728 } 5729 } 5730 } 5731 } 5732 5733 // C++ [over.built]p22: 5734 // 5735 // For every triple (L, VQ, R), where L is an integral type, VQ 5736 // is either volatile or empty, and R is a promoted integral 5737 // type, there exist candidate operator functions of the form 5738 // 5739 // VQ L& operator%=(VQ L&, R); 5740 // VQ L& operator<<=(VQ L&, R); 5741 // VQ L& operator>>=(VQ L&, R); 5742 // VQ L& operator&=(VQ L&, R); 5743 // VQ L& operator^=(VQ L&, R); 5744 // VQ L& operator|=(VQ L&, R); 5745 void addAssignmentIntegralOverloads() { 5746 if (!HasArithmeticOrEnumeralCandidateType) 5747 return; 5748 5749 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 5750 for (unsigned Right = FirstPromotedIntegralType; 5751 Right < LastPromotedIntegralType; ++Right) { 5752 QualType ParamTypes[2]; 5753 ParamTypes[1] = getArithmeticType(Right); 5754 5755 // Add this built-in operator as a candidate (VQ is empty). 5756 ParamTypes[0] = 5757 S.Context.getLValueReferenceType(getArithmeticType(Left)); 5758 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5759 if (VisibleTypeConversionsQuals.hasVolatile()) { 5760 // Add this built-in operator as a candidate (VQ is 'volatile'). 5761 ParamTypes[0] = getArithmeticType(Left); 5762 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 5763 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5764 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5765 CandidateSet); 5766 } 5767 } 5768 } 5769 } 5770 5771 // C++ [over.operator]p23: 5772 // 5773 // There also exist candidate operator functions of the form 5774 // 5775 // bool operator!(bool); 5776 // bool operator&&(bool, bool); 5777 // bool operator||(bool, bool); 5778 void addExclaimOverload() { 5779 QualType ParamTy = S.Context.BoolTy; 5780 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 5781 /*IsAssignmentOperator=*/false, 5782 /*NumContextualBoolArguments=*/1); 5783 } 5784 void addAmpAmpOrPipePipeOverload() { 5785 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 5786 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 5787 /*IsAssignmentOperator=*/false, 5788 /*NumContextualBoolArguments=*/2); 5789 } 5790 5791 // C++ [over.built]p13: 5792 // 5793 // For every cv-qualified or cv-unqualified object type T there 5794 // exist candidate operator functions of the form 5795 // 5796 // T* operator+(T*, ptrdiff_t); [ABOVE] 5797 // T& operator[](T*, ptrdiff_t); 5798 // T* operator-(T*, ptrdiff_t); [ABOVE] 5799 // T* operator+(ptrdiff_t, T*); [ABOVE] 5800 // T& operator[](ptrdiff_t, T*); 5801 void addSubscriptOverloads() { 5802 for (BuiltinCandidateTypeSet::iterator 5803 Ptr = CandidateTypes[0].pointer_begin(), 5804 PtrEnd = CandidateTypes[0].pointer_end(); 5805 Ptr != PtrEnd; ++Ptr) { 5806 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 5807 QualType PointeeType = (*Ptr)->getPointeeType(); 5808 if (!PointeeType->isObjectType()) 5809 continue; 5810 5811 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 5812 5813 // T& operator[](T*, ptrdiff_t) 5814 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5815 } 5816 5817 for (BuiltinCandidateTypeSet::iterator 5818 Ptr = CandidateTypes[1].pointer_begin(), 5819 PtrEnd = CandidateTypes[1].pointer_end(); 5820 Ptr != PtrEnd; ++Ptr) { 5821 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 5822 QualType PointeeType = (*Ptr)->getPointeeType(); 5823 if (!PointeeType->isObjectType()) 5824 continue; 5825 5826 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 5827 5828 // T& operator[](ptrdiff_t, T*) 5829 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5830 } 5831 } 5832 5833 // C++ [over.built]p11: 5834 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 5835 // C1 is the same type as C2 or is a derived class of C2, T is an object 5836 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 5837 // there exist candidate operator functions of the form 5838 // 5839 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 5840 // 5841 // where CV12 is the union of CV1 and CV2. 5842 void addArrowStarOverloads() { 5843 for (BuiltinCandidateTypeSet::iterator 5844 Ptr = CandidateTypes[0].pointer_begin(), 5845 PtrEnd = CandidateTypes[0].pointer_end(); 5846 Ptr != PtrEnd; ++Ptr) { 5847 QualType C1Ty = (*Ptr); 5848 QualType C1; 5849 QualifierCollector Q1; 5850 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 5851 if (!isa<RecordType>(C1)) 5852 continue; 5853 // heuristic to reduce number of builtin candidates in the set. 5854 // Add volatile/restrict version only if there are conversions to a 5855 // volatile/restrict type. 5856 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 5857 continue; 5858 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 5859 continue; 5860 for (BuiltinCandidateTypeSet::iterator 5861 MemPtr = CandidateTypes[1].member_pointer_begin(), 5862 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 5863 MemPtr != MemPtrEnd; ++MemPtr) { 5864 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 5865 QualType C2 = QualType(mptr->getClass(), 0); 5866 C2 = C2.getUnqualifiedType(); 5867 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 5868 break; 5869 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 5870 // build CV12 T& 5871 QualType T = mptr->getPointeeType(); 5872 if (!VisibleTypeConversionsQuals.hasVolatile() && 5873 T.isVolatileQualified()) 5874 continue; 5875 if (!VisibleTypeConversionsQuals.hasRestrict() && 5876 T.isRestrictQualified()) 5877 continue; 5878 T = Q1.apply(S.Context, T); 5879 QualType ResultTy = S.Context.getLValueReferenceType(T); 5880 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5881 } 5882 } 5883 } 5884 5885 // Note that we don't consider the first argument, since it has been 5886 // contextually converted to bool long ago. The candidates below are 5887 // therefore added as binary. 5888 // 5889 // C++ [over.built]p25: 5890 // For every type T, where T is a pointer, pointer-to-member, or scoped 5891 // enumeration type, there exist candidate operator functions of the form 5892 // 5893 // T operator?(bool, T, T); 5894 // 5895 void addConditionalOperatorOverloads() { 5896 /// Set of (canonical) types that we've already handled. 5897 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5898 5899 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5900 for (BuiltinCandidateTypeSet::iterator 5901 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5902 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5903 Ptr != PtrEnd; ++Ptr) { 5904 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5905 continue; 5906 5907 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5908 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5909 } 5910 5911 for (BuiltinCandidateTypeSet::iterator 5912 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5913 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5914 MemPtr != MemPtrEnd; ++MemPtr) { 5915 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5916 continue; 5917 5918 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5919 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); 5920 } 5921 5922 if (S.getLangOptions().CPlusPlus0x) { 5923 for (BuiltinCandidateTypeSet::iterator 5924 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5925 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5926 Enum != EnumEnd; ++Enum) { 5927 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 5928 continue; 5929 5930 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5931 continue; 5932 5933 QualType ParamTypes[2] = { *Enum, *Enum }; 5934 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); 5935 } 5936 } 5937 } 5938 } 5939}; 5940 5941} // end anonymous namespace 5942 5943/// AddBuiltinOperatorCandidates - Add the appropriate built-in 5944/// operator overloads to the candidate set (C++ [over.built]), based 5945/// on the operator @p Op and the arguments given. For example, if the 5946/// operator is a binary '+', this routine might add "int 5947/// operator+(int, int)" to cover integer addition. 5948void 5949Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 5950 SourceLocation OpLoc, 5951 Expr **Args, unsigned NumArgs, 5952 OverloadCandidateSet& CandidateSet) { 5953 // Find all of the types that the arguments can convert to, but only 5954 // if the operator we're looking at has built-in operator candidates 5955 // that make use of these types. Also record whether we encounter non-record 5956 // candidate types or either arithmetic or enumeral candidate types. 5957 Qualifiers VisibleTypeConversionsQuals; 5958 VisibleTypeConversionsQuals.addConst(); 5959 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5960 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 5961 5962 bool HasNonRecordCandidateType = false; 5963 bool HasArithmeticOrEnumeralCandidateType = false; 5964 llvm::SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 5965 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5966 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 5967 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 5968 OpLoc, 5969 true, 5970 (Op == OO_Exclaim || 5971 Op == OO_AmpAmp || 5972 Op == OO_PipePipe), 5973 VisibleTypeConversionsQuals); 5974 HasNonRecordCandidateType = HasNonRecordCandidateType || 5975 CandidateTypes[ArgIdx].hasNonRecordTypes(); 5976 HasArithmeticOrEnumeralCandidateType = 5977 HasArithmeticOrEnumeralCandidateType || 5978 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 5979 } 5980 5981 // Exit early when no non-record types have been added to the candidate set 5982 // for any of the arguments to the operator. 5983 if (!HasNonRecordCandidateType) 5984 return; 5985 5986 // Setup an object to manage the common state for building overloads. 5987 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, 5988 VisibleTypeConversionsQuals, 5989 HasArithmeticOrEnumeralCandidateType, 5990 CandidateTypes, CandidateSet); 5991 5992 // Dispatch over the operation to add in only those overloads which apply. 5993 switch (Op) { 5994 case OO_None: 5995 case NUM_OVERLOADED_OPERATORS: 5996 assert(false && "Expected an overloaded operator"); 5997 break; 5998 5999 case OO_New: 6000 case OO_Delete: 6001 case OO_Array_New: 6002 case OO_Array_Delete: 6003 case OO_Call: 6004 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 6005 break; 6006 6007 case OO_Comma: 6008 case OO_Arrow: 6009 // C++ [over.match.oper]p3: 6010 // -- For the operator ',', the unary operator '&', or the 6011 // operator '->', the built-in candidates set is empty. 6012 break; 6013 6014 case OO_Plus: // '+' is either unary or binary 6015 if (NumArgs == 1) 6016 OpBuilder.addUnaryPlusPointerOverloads(); 6017 // Fall through. 6018 6019 case OO_Minus: // '-' is either unary or binary 6020 if (NumArgs == 1) { 6021 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 6022 } else { 6023 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 6024 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6025 } 6026 break; 6027 6028 case OO_Star: // '*' is either unary or binary 6029 if (NumArgs == 1) 6030 OpBuilder.addUnaryStarPointerOverloads(); 6031 else 6032 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6033 break; 6034 6035 case OO_Slash: 6036 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6037 break; 6038 6039 case OO_PlusPlus: 6040 case OO_MinusMinus: 6041 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 6042 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 6043 break; 6044 6045 case OO_EqualEqual: 6046 case OO_ExclaimEqual: 6047 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 6048 // Fall through. 6049 6050 case OO_Less: 6051 case OO_Greater: 6052 case OO_LessEqual: 6053 case OO_GreaterEqual: 6054 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 6055 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 6056 break; 6057 6058 case OO_Percent: 6059 case OO_Caret: 6060 case OO_Pipe: 6061 case OO_LessLess: 6062 case OO_GreaterGreater: 6063 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6064 break; 6065 6066 case OO_Amp: // '&' is either unary or binary 6067 if (NumArgs == 1) 6068 // C++ [over.match.oper]p3: 6069 // -- For the operator ',', the unary operator '&', or the 6070 // operator '->', the built-in candidates set is empty. 6071 break; 6072 6073 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6074 break; 6075 6076 case OO_Tilde: 6077 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 6078 break; 6079 6080 case OO_Equal: 6081 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 6082 // Fall through. 6083 6084 case OO_PlusEqual: 6085 case OO_MinusEqual: 6086 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 6087 // Fall through. 6088 6089 case OO_StarEqual: 6090 case OO_SlashEqual: 6091 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 6092 break; 6093 6094 case OO_PercentEqual: 6095 case OO_LessLessEqual: 6096 case OO_GreaterGreaterEqual: 6097 case OO_AmpEqual: 6098 case OO_CaretEqual: 6099 case OO_PipeEqual: 6100 OpBuilder.addAssignmentIntegralOverloads(); 6101 break; 6102 6103 case OO_Exclaim: 6104 OpBuilder.addExclaimOverload(); 6105 break; 6106 6107 case OO_AmpAmp: 6108 case OO_PipePipe: 6109 OpBuilder.addAmpAmpOrPipePipeOverload(); 6110 break; 6111 6112 case OO_Subscript: 6113 OpBuilder.addSubscriptOverloads(); 6114 break; 6115 6116 case OO_ArrowStar: 6117 OpBuilder.addArrowStarOverloads(); 6118 break; 6119 6120 case OO_Conditional: 6121 OpBuilder.addConditionalOperatorOverloads(); 6122 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6123 break; 6124 } 6125} 6126 6127/// \brief Add function candidates found via argument-dependent lookup 6128/// to the set of overloading candidates. 6129/// 6130/// This routine performs argument-dependent name lookup based on the 6131/// given function name (which may also be an operator name) and adds 6132/// all of the overload candidates found by ADL to the overload 6133/// candidate set (C++ [basic.lookup.argdep]). 6134void 6135Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 6136 bool Operator, 6137 Expr **Args, unsigned NumArgs, 6138 TemplateArgumentListInfo *ExplicitTemplateArgs, 6139 OverloadCandidateSet& CandidateSet, 6140 bool PartialOverloading) { 6141 ADLResult Fns; 6142 6143 // FIXME: This approach for uniquing ADL results (and removing 6144 // redundant candidates from the set) relies on pointer-equality, 6145 // which means we need to key off the canonical decl. However, 6146 // always going back to the canonical decl might not get us the 6147 // right set of default arguments. What default arguments are 6148 // we supposed to consider on ADL candidates, anyway? 6149 6150 // FIXME: Pass in the explicit template arguments? 6151 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 6152 6153 // Erase all of the candidates we already knew about. 6154 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 6155 CandEnd = CandidateSet.end(); 6156 Cand != CandEnd; ++Cand) 6157 if (Cand->Function) { 6158 Fns.erase(Cand->Function); 6159 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 6160 Fns.erase(FunTmpl); 6161 } 6162 6163 // For each of the ADL candidates we found, add it to the overload 6164 // set. 6165 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 6166 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 6167 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 6168 if (ExplicitTemplateArgs) 6169 continue; 6170 6171 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 6172 false, PartialOverloading); 6173 } else 6174 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 6175 FoundDecl, ExplicitTemplateArgs, 6176 Args, NumArgs, CandidateSet); 6177 } 6178} 6179 6180/// isBetterOverloadCandidate - Determines whether the first overload 6181/// candidate is a better candidate than the second (C++ 13.3.3p1). 6182bool 6183isBetterOverloadCandidate(Sema &S, 6184 const OverloadCandidate &Cand1, 6185 const OverloadCandidate &Cand2, 6186 SourceLocation Loc, 6187 bool UserDefinedConversion) { 6188 // Define viable functions to be better candidates than non-viable 6189 // functions. 6190 if (!Cand2.Viable) 6191 return Cand1.Viable; 6192 else if (!Cand1.Viable) 6193 return false; 6194 6195 // C++ [over.match.best]p1: 6196 // 6197 // -- if F is a static member function, ICS1(F) is defined such 6198 // that ICS1(F) is neither better nor worse than ICS1(G) for 6199 // any function G, and, symmetrically, ICS1(G) is neither 6200 // better nor worse than ICS1(F). 6201 unsigned StartArg = 0; 6202 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 6203 StartArg = 1; 6204 6205 // C++ [over.match.best]p1: 6206 // A viable function F1 is defined to be a better function than another 6207 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 6208 // conversion sequence than ICSi(F2), and then... 6209 unsigned NumArgs = Cand1.Conversions.size(); 6210 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 6211 bool HasBetterConversion = false; 6212 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 6213 switch (CompareImplicitConversionSequences(S, 6214 Cand1.Conversions[ArgIdx], 6215 Cand2.Conversions[ArgIdx])) { 6216 case ImplicitConversionSequence::Better: 6217 // Cand1 has a better conversion sequence. 6218 HasBetterConversion = true; 6219 break; 6220 6221 case ImplicitConversionSequence::Worse: 6222 // Cand1 can't be better than Cand2. 6223 return false; 6224 6225 case ImplicitConversionSequence::Indistinguishable: 6226 // Do nothing. 6227 break; 6228 } 6229 } 6230 6231 // -- for some argument j, ICSj(F1) is a better conversion sequence than 6232 // ICSj(F2), or, if not that, 6233 if (HasBetterConversion) 6234 return true; 6235 6236 // - F1 is a non-template function and F2 is a function template 6237 // specialization, or, if not that, 6238 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 6239 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 6240 return true; 6241 6242 // -- F1 and F2 are function template specializations, and the function 6243 // template for F1 is more specialized than the template for F2 6244 // according to the partial ordering rules described in 14.5.5.2, or, 6245 // if not that, 6246 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 6247 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 6248 if (FunctionTemplateDecl *BetterTemplate 6249 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 6250 Cand2.Function->getPrimaryTemplate(), 6251 Loc, 6252 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 6253 : TPOC_Call, 6254 Cand1.ExplicitCallArguments)) 6255 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 6256 } 6257 6258 // -- the context is an initialization by user-defined conversion 6259 // (see 8.5, 13.3.1.5) and the standard conversion sequence 6260 // from the return type of F1 to the destination type (i.e., 6261 // the type of the entity being initialized) is a better 6262 // conversion sequence than the standard conversion sequence 6263 // from the return type of F2 to the destination type. 6264 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 6265 isa<CXXConversionDecl>(Cand1.Function) && 6266 isa<CXXConversionDecl>(Cand2.Function)) { 6267 switch (CompareStandardConversionSequences(S, 6268 Cand1.FinalConversion, 6269 Cand2.FinalConversion)) { 6270 case ImplicitConversionSequence::Better: 6271 // Cand1 has a better conversion sequence. 6272 return true; 6273 6274 case ImplicitConversionSequence::Worse: 6275 // Cand1 can't be better than Cand2. 6276 return false; 6277 6278 case ImplicitConversionSequence::Indistinguishable: 6279 // Do nothing 6280 break; 6281 } 6282 } 6283 6284 return false; 6285} 6286 6287/// \brief Computes the best viable function (C++ 13.3.3) 6288/// within an overload candidate set. 6289/// 6290/// \param CandidateSet the set of candidate functions. 6291/// 6292/// \param Loc the location of the function name (or operator symbol) for 6293/// which overload resolution occurs. 6294/// 6295/// \param Best f overload resolution was successful or found a deleted 6296/// function, Best points to the candidate function found. 6297/// 6298/// \returns The result of overload resolution. 6299OverloadingResult 6300OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 6301 iterator &Best, 6302 bool UserDefinedConversion) { 6303 // Find the best viable function. 6304 Best = end(); 6305 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6306 if (Cand->Viable) 6307 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 6308 UserDefinedConversion)) 6309 Best = Cand; 6310 } 6311 6312 // If we didn't find any viable functions, abort. 6313 if (Best == end()) 6314 return OR_No_Viable_Function; 6315 6316 // Make sure that this function is better than every other viable 6317 // function. If not, we have an ambiguity. 6318 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6319 if (Cand->Viable && 6320 Cand != Best && 6321 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 6322 UserDefinedConversion)) { 6323 Best = end(); 6324 return OR_Ambiguous; 6325 } 6326 } 6327 6328 // Best is the best viable function. 6329 if (Best->Function && 6330 (Best->Function->isDeleted() || Best->Function->isUnavailable())) 6331 return OR_Deleted; 6332 6333 return OR_Success; 6334} 6335 6336namespace { 6337 6338enum OverloadCandidateKind { 6339 oc_function, 6340 oc_method, 6341 oc_constructor, 6342 oc_function_template, 6343 oc_method_template, 6344 oc_constructor_template, 6345 oc_implicit_default_constructor, 6346 oc_implicit_copy_constructor, 6347 oc_implicit_copy_assignment, 6348 oc_implicit_inherited_constructor 6349}; 6350 6351OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 6352 FunctionDecl *Fn, 6353 std::string &Description) { 6354 bool isTemplate = false; 6355 6356 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 6357 isTemplate = true; 6358 Description = S.getTemplateArgumentBindingsText( 6359 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 6360 } 6361 6362 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 6363 if (!Ctor->isImplicit()) 6364 return isTemplate ? oc_constructor_template : oc_constructor; 6365 6366 if (Ctor->getInheritedConstructor()) 6367 return oc_implicit_inherited_constructor; 6368 6369 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 6370 : oc_implicit_default_constructor; 6371 } 6372 6373 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 6374 // This actually gets spelled 'candidate function' for now, but 6375 // it doesn't hurt to split it out. 6376 if (!Meth->isImplicit()) 6377 return isTemplate ? oc_method_template : oc_method; 6378 6379 assert(Meth->isCopyAssignmentOperator() 6380 && "implicit method is not copy assignment operator?"); 6381 return oc_implicit_copy_assignment; 6382 } 6383 6384 return isTemplate ? oc_function_template : oc_function; 6385} 6386 6387void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { 6388 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 6389 if (!Ctor) return; 6390 6391 Ctor = Ctor->getInheritedConstructor(); 6392 if (!Ctor) return; 6393 6394 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 6395} 6396 6397} // end anonymous namespace 6398 6399// Notes the location of an overload candidate. 6400void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 6401 std::string FnDesc; 6402 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 6403 Diag(Fn->getLocation(), diag::note_ovl_candidate) 6404 << (unsigned) K << FnDesc; 6405 MaybeEmitInheritedConstructorNote(*this, Fn); 6406} 6407 6408//Notes the location of all overload candidates designated through 6409// OverloadedExpr 6410void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr) { 6411 assert(OverloadedExpr->getType() == Context.OverloadTy); 6412 6413 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); 6414 OverloadExpr *OvlExpr = Ovl.Expression; 6415 6416 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6417 IEnd = OvlExpr->decls_end(); 6418 I != IEnd; ++I) { 6419 if (FunctionTemplateDecl *FunTmpl = 6420 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) { 6421 NoteOverloadCandidate(FunTmpl->getTemplatedDecl()); 6422 } else if (FunctionDecl *Fun 6423 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) { 6424 NoteOverloadCandidate(Fun); 6425 } 6426 } 6427} 6428 6429/// Diagnoses an ambiguous conversion. The partial diagnostic is the 6430/// "lead" diagnostic; it will be given two arguments, the source and 6431/// target types of the conversion. 6432void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 6433 Sema &S, 6434 SourceLocation CaretLoc, 6435 const PartialDiagnostic &PDiag) const { 6436 S.Diag(CaretLoc, PDiag) 6437 << Ambiguous.getFromType() << Ambiguous.getToType(); 6438 for (AmbiguousConversionSequence::const_iterator 6439 I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 6440 S.NoteOverloadCandidate(*I); 6441 } 6442} 6443 6444namespace { 6445 6446void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 6447 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 6448 assert(Conv.isBad()); 6449 assert(Cand->Function && "for now, candidate must be a function"); 6450 FunctionDecl *Fn = Cand->Function; 6451 6452 // There's a conversion slot for the object argument if this is a 6453 // non-constructor method. Note that 'I' corresponds the 6454 // conversion-slot index. 6455 bool isObjectArgument = false; 6456 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 6457 if (I == 0) 6458 isObjectArgument = true; 6459 else 6460 I--; 6461 } 6462 6463 std::string FnDesc; 6464 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6465 6466 Expr *FromExpr = Conv.Bad.FromExpr; 6467 QualType FromTy = Conv.Bad.getFromType(); 6468 QualType ToTy = Conv.Bad.getToType(); 6469 6470 if (FromTy == S.Context.OverloadTy) { 6471 assert(FromExpr && "overload set argument came from implicit argument?"); 6472 Expr *E = FromExpr->IgnoreParens(); 6473 if (isa<UnaryOperator>(E)) 6474 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 6475 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 6476 6477 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 6478 << (unsigned) FnKind << FnDesc 6479 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6480 << ToTy << Name << I+1; 6481 MaybeEmitInheritedConstructorNote(S, Fn); 6482 return; 6483 } 6484 6485 // Do some hand-waving analysis to see if the non-viability is due 6486 // to a qualifier mismatch. 6487 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 6488 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 6489 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 6490 CToTy = RT->getPointeeType(); 6491 else { 6492 // TODO: detect and diagnose the full richness of const mismatches. 6493 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 6494 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 6495 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 6496 } 6497 6498 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 6499 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 6500 // It is dumb that we have to do this here. 6501 while (isa<ArrayType>(CFromTy)) 6502 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 6503 while (isa<ArrayType>(CToTy)) 6504 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 6505 6506 Qualifiers FromQs = CFromTy.getQualifiers(); 6507 Qualifiers ToQs = CToTy.getQualifiers(); 6508 6509 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 6510 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 6511 << (unsigned) FnKind << FnDesc 6512 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6513 << FromTy 6514 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 6515 << (unsigned) isObjectArgument << I+1; 6516 MaybeEmitInheritedConstructorNote(S, Fn); 6517 return; 6518 } 6519 6520 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 6521 assert(CVR && "unexpected qualifiers mismatch"); 6522 6523 if (isObjectArgument) { 6524 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 6525 << (unsigned) FnKind << FnDesc 6526 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6527 << FromTy << (CVR - 1); 6528 } else { 6529 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 6530 << (unsigned) FnKind << FnDesc 6531 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6532 << FromTy << (CVR - 1) << I+1; 6533 } 6534 MaybeEmitInheritedConstructorNote(S, Fn); 6535 return; 6536 } 6537 6538 // Diagnose references or pointers to incomplete types differently, 6539 // since it's far from impossible that the incompleteness triggered 6540 // the failure. 6541 QualType TempFromTy = FromTy.getNonReferenceType(); 6542 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 6543 TempFromTy = PTy->getPointeeType(); 6544 if (TempFromTy->isIncompleteType()) { 6545 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 6546 << (unsigned) FnKind << FnDesc 6547 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6548 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6549 MaybeEmitInheritedConstructorNote(S, Fn); 6550 return; 6551 } 6552 6553 // Diagnose base -> derived pointer conversions. 6554 unsigned BaseToDerivedConversion = 0; 6555 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 6556 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 6557 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6558 FromPtrTy->getPointeeType()) && 6559 !FromPtrTy->getPointeeType()->isIncompleteType() && 6560 !ToPtrTy->getPointeeType()->isIncompleteType() && 6561 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 6562 FromPtrTy->getPointeeType())) 6563 BaseToDerivedConversion = 1; 6564 } 6565 } else if (const ObjCObjectPointerType *FromPtrTy 6566 = FromTy->getAs<ObjCObjectPointerType>()) { 6567 if (const ObjCObjectPointerType *ToPtrTy 6568 = ToTy->getAs<ObjCObjectPointerType>()) 6569 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 6570 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 6571 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6572 FromPtrTy->getPointeeType()) && 6573 FromIface->isSuperClassOf(ToIface)) 6574 BaseToDerivedConversion = 2; 6575 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 6576 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 6577 !FromTy->isIncompleteType() && 6578 !ToRefTy->getPointeeType()->isIncompleteType() && 6579 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 6580 BaseToDerivedConversion = 3; 6581 } 6582 6583 if (BaseToDerivedConversion) { 6584 S.Diag(Fn->getLocation(), 6585 diag::note_ovl_candidate_bad_base_to_derived_conv) 6586 << (unsigned) FnKind << FnDesc 6587 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6588 << (BaseToDerivedConversion - 1) 6589 << FromTy << ToTy << I+1; 6590 MaybeEmitInheritedConstructorNote(S, Fn); 6591 return; 6592 } 6593 6594 // TODO: specialize more based on the kind of mismatch 6595 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 6596 << (unsigned) FnKind << FnDesc 6597 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6598 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6599 MaybeEmitInheritedConstructorNote(S, Fn); 6600} 6601 6602void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 6603 unsigned NumFormalArgs) { 6604 // TODO: treat calls to a missing default constructor as a special case 6605 6606 FunctionDecl *Fn = Cand->Function; 6607 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 6608 6609 unsigned MinParams = Fn->getMinRequiredArguments(); 6610 6611 // at least / at most / exactly 6612 unsigned mode, modeCount; 6613 if (NumFormalArgs < MinParams) { 6614 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 6615 (Cand->FailureKind == ovl_fail_bad_deduction && 6616 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 6617 if (MinParams != FnTy->getNumArgs() || 6618 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 6619 mode = 0; // "at least" 6620 else 6621 mode = 2; // "exactly" 6622 modeCount = MinParams; 6623 } else { 6624 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 6625 (Cand->FailureKind == ovl_fail_bad_deduction && 6626 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 6627 if (MinParams != FnTy->getNumArgs()) 6628 mode = 1; // "at most" 6629 else 6630 mode = 2; // "exactly" 6631 modeCount = FnTy->getNumArgs(); 6632 } 6633 6634 std::string Description; 6635 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 6636 6637 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 6638 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 6639 << modeCount << NumFormalArgs; 6640 MaybeEmitInheritedConstructorNote(S, Fn); 6641} 6642 6643/// Diagnose a failed template-argument deduction. 6644void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 6645 Expr **Args, unsigned NumArgs) { 6646 FunctionDecl *Fn = Cand->Function; // pattern 6647 6648 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 6649 NamedDecl *ParamD; 6650 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 6651 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 6652 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 6653 switch (Cand->DeductionFailure.Result) { 6654 case Sema::TDK_Success: 6655 llvm_unreachable("TDK_success while diagnosing bad deduction"); 6656 6657 case Sema::TDK_Incomplete: { 6658 assert(ParamD && "no parameter found for incomplete deduction result"); 6659 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 6660 << ParamD->getDeclName(); 6661 MaybeEmitInheritedConstructorNote(S, Fn); 6662 return; 6663 } 6664 6665 case Sema::TDK_Underqualified: { 6666 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 6667 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 6668 6669 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 6670 6671 // Param will have been canonicalized, but it should just be a 6672 // qualified version of ParamD, so move the qualifiers to that. 6673 QualifierCollector Qs; 6674 Qs.strip(Param); 6675 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 6676 assert(S.Context.hasSameType(Param, NonCanonParam)); 6677 6678 // Arg has also been canonicalized, but there's nothing we can do 6679 // about that. It also doesn't matter as much, because it won't 6680 // have any template parameters in it (because deduction isn't 6681 // done on dependent types). 6682 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 6683 6684 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 6685 << ParamD->getDeclName() << Arg << NonCanonParam; 6686 MaybeEmitInheritedConstructorNote(S, Fn); 6687 return; 6688 } 6689 6690 case Sema::TDK_Inconsistent: { 6691 assert(ParamD && "no parameter found for inconsistent deduction result"); 6692 int which = 0; 6693 if (isa<TemplateTypeParmDecl>(ParamD)) 6694 which = 0; 6695 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 6696 which = 1; 6697 else { 6698 which = 2; 6699 } 6700 6701 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 6702 << which << ParamD->getDeclName() 6703 << *Cand->DeductionFailure.getFirstArg() 6704 << *Cand->DeductionFailure.getSecondArg(); 6705 MaybeEmitInheritedConstructorNote(S, Fn); 6706 return; 6707 } 6708 6709 case Sema::TDK_InvalidExplicitArguments: 6710 assert(ParamD && "no parameter found for invalid explicit arguments"); 6711 if (ParamD->getDeclName()) 6712 S.Diag(Fn->getLocation(), 6713 diag::note_ovl_candidate_explicit_arg_mismatch_named) 6714 << ParamD->getDeclName(); 6715 else { 6716 int index = 0; 6717 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 6718 index = TTP->getIndex(); 6719 else if (NonTypeTemplateParmDecl *NTTP 6720 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 6721 index = NTTP->getIndex(); 6722 else 6723 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 6724 S.Diag(Fn->getLocation(), 6725 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 6726 << (index + 1); 6727 } 6728 MaybeEmitInheritedConstructorNote(S, Fn); 6729 return; 6730 6731 case Sema::TDK_TooManyArguments: 6732 case Sema::TDK_TooFewArguments: 6733 DiagnoseArityMismatch(S, Cand, NumArgs); 6734 return; 6735 6736 case Sema::TDK_InstantiationDepth: 6737 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 6738 MaybeEmitInheritedConstructorNote(S, Fn); 6739 return; 6740 6741 case Sema::TDK_SubstitutionFailure: { 6742 std::string ArgString; 6743 if (TemplateArgumentList *Args 6744 = Cand->DeductionFailure.getTemplateArgumentList()) 6745 ArgString = S.getTemplateArgumentBindingsText( 6746 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 6747 *Args); 6748 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 6749 << ArgString; 6750 MaybeEmitInheritedConstructorNote(S, Fn); 6751 return; 6752 } 6753 6754 // TODO: diagnose these individually, then kill off 6755 // note_ovl_candidate_bad_deduction, which is uselessly vague. 6756 case Sema::TDK_NonDeducedMismatch: 6757 case Sema::TDK_FailedOverloadResolution: 6758 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 6759 MaybeEmitInheritedConstructorNote(S, Fn); 6760 return; 6761 } 6762} 6763 6764/// Generates a 'note' diagnostic for an overload candidate. We've 6765/// already generated a primary error at the call site. 6766/// 6767/// It really does need to be a single diagnostic with its caret 6768/// pointed at the candidate declaration. Yes, this creates some 6769/// major challenges of technical writing. Yes, this makes pointing 6770/// out problems with specific arguments quite awkward. It's still 6771/// better than generating twenty screens of text for every failed 6772/// overload. 6773/// 6774/// It would be great to be able to express per-candidate problems 6775/// more richly for those diagnostic clients that cared, but we'd 6776/// still have to be just as careful with the default diagnostics. 6777void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 6778 Expr **Args, unsigned NumArgs) { 6779 FunctionDecl *Fn = Cand->Function; 6780 6781 // Note deleted candidates, but only if they're viable. 6782 if (Cand->Viable && (Fn->isDeleted() || Fn->isUnavailable())) { 6783 std::string FnDesc; 6784 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6785 6786 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 6787 << FnKind << FnDesc << Fn->isDeleted(); 6788 MaybeEmitInheritedConstructorNote(S, Fn); 6789 return; 6790 } 6791 6792 // We don't really have anything else to say about viable candidates. 6793 if (Cand->Viable) { 6794 S.NoteOverloadCandidate(Fn); 6795 return; 6796 } 6797 6798 switch (Cand->FailureKind) { 6799 case ovl_fail_too_many_arguments: 6800 case ovl_fail_too_few_arguments: 6801 return DiagnoseArityMismatch(S, Cand, NumArgs); 6802 6803 case ovl_fail_bad_deduction: 6804 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 6805 6806 case ovl_fail_trivial_conversion: 6807 case ovl_fail_bad_final_conversion: 6808 case ovl_fail_final_conversion_not_exact: 6809 return S.NoteOverloadCandidate(Fn); 6810 6811 case ovl_fail_bad_conversion: { 6812 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 6813 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 6814 if (Cand->Conversions[I].isBad()) 6815 return DiagnoseBadConversion(S, Cand, I); 6816 6817 // FIXME: this currently happens when we're called from SemaInit 6818 // when user-conversion overload fails. Figure out how to handle 6819 // those conditions and diagnose them well. 6820 return S.NoteOverloadCandidate(Fn); 6821 } 6822 } 6823} 6824 6825void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 6826 // Desugar the type of the surrogate down to a function type, 6827 // retaining as many typedefs as possible while still showing 6828 // the function type (and, therefore, its parameter types). 6829 QualType FnType = Cand->Surrogate->getConversionType(); 6830 bool isLValueReference = false; 6831 bool isRValueReference = false; 6832 bool isPointer = false; 6833 if (const LValueReferenceType *FnTypeRef = 6834 FnType->getAs<LValueReferenceType>()) { 6835 FnType = FnTypeRef->getPointeeType(); 6836 isLValueReference = true; 6837 } else if (const RValueReferenceType *FnTypeRef = 6838 FnType->getAs<RValueReferenceType>()) { 6839 FnType = FnTypeRef->getPointeeType(); 6840 isRValueReference = true; 6841 } 6842 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 6843 FnType = FnTypePtr->getPointeeType(); 6844 isPointer = true; 6845 } 6846 // Desugar down to a function type. 6847 FnType = QualType(FnType->getAs<FunctionType>(), 0); 6848 // Reconstruct the pointer/reference as appropriate. 6849 if (isPointer) FnType = S.Context.getPointerType(FnType); 6850 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 6851 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 6852 6853 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 6854 << FnType; 6855 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 6856} 6857 6858void NoteBuiltinOperatorCandidate(Sema &S, 6859 const char *Opc, 6860 SourceLocation OpLoc, 6861 OverloadCandidate *Cand) { 6862 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 6863 std::string TypeStr("operator"); 6864 TypeStr += Opc; 6865 TypeStr += "("; 6866 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 6867 if (Cand->Conversions.size() == 1) { 6868 TypeStr += ")"; 6869 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 6870 } else { 6871 TypeStr += ", "; 6872 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 6873 TypeStr += ")"; 6874 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 6875 } 6876} 6877 6878void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 6879 OverloadCandidate *Cand) { 6880 unsigned NoOperands = Cand->Conversions.size(); 6881 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 6882 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 6883 if (ICS.isBad()) break; // all meaningless after first invalid 6884 if (!ICS.isAmbiguous()) continue; 6885 6886 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 6887 S.PDiag(diag::note_ambiguous_type_conversion)); 6888 } 6889} 6890 6891SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 6892 if (Cand->Function) 6893 return Cand->Function->getLocation(); 6894 if (Cand->IsSurrogate) 6895 return Cand->Surrogate->getLocation(); 6896 return SourceLocation(); 6897} 6898 6899struct CompareOverloadCandidatesForDisplay { 6900 Sema &S; 6901 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 6902 6903 bool operator()(const OverloadCandidate *L, 6904 const OverloadCandidate *R) { 6905 // Fast-path this check. 6906 if (L == R) return false; 6907 6908 // Order first by viability. 6909 if (L->Viable) { 6910 if (!R->Viable) return true; 6911 6912 // TODO: introduce a tri-valued comparison for overload 6913 // candidates. Would be more worthwhile if we had a sort 6914 // that could exploit it. 6915 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 6916 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 6917 } else if (R->Viable) 6918 return false; 6919 6920 assert(L->Viable == R->Viable); 6921 6922 // Criteria by which we can sort non-viable candidates: 6923 if (!L->Viable) { 6924 // 1. Arity mismatches come after other candidates. 6925 if (L->FailureKind == ovl_fail_too_many_arguments || 6926 L->FailureKind == ovl_fail_too_few_arguments) 6927 return false; 6928 if (R->FailureKind == ovl_fail_too_many_arguments || 6929 R->FailureKind == ovl_fail_too_few_arguments) 6930 return true; 6931 6932 // 2. Bad conversions come first and are ordered by the number 6933 // of bad conversions and quality of good conversions. 6934 if (L->FailureKind == ovl_fail_bad_conversion) { 6935 if (R->FailureKind != ovl_fail_bad_conversion) 6936 return true; 6937 6938 // If there's any ordering between the defined conversions... 6939 // FIXME: this might not be transitive. 6940 assert(L->Conversions.size() == R->Conversions.size()); 6941 6942 int leftBetter = 0; 6943 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 6944 for (unsigned E = L->Conversions.size(); I != E; ++I) { 6945 switch (CompareImplicitConversionSequences(S, 6946 L->Conversions[I], 6947 R->Conversions[I])) { 6948 case ImplicitConversionSequence::Better: 6949 leftBetter++; 6950 break; 6951 6952 case ImplicitConversionSequence::Worse: 6953 leftBetter--; 6954 break; 6955 6956 case ImplicitConversionSequence::Indistinguishable: 6957 break; 6958 } 6959 } 6960 if (leftBetter > 0) return true; 6961 if (leftBetter < 0) return false; 6962 6963 } else if (R->FailureKind == ovl_fail_bad_conversion) 6964 return false; 6965 6966 // TODO: others? 6967 } 6968 6969 // Sort everything else by location. 6970 SourceLocation LLoc = GetLocationForCandidate(L); 6971 SourceLocation RLoc = GetLocationForCandidate(R); 6972 6973 // Put candidates without locations (e.g. builtins) at the end. 6974 if (LLoc.isInvalid()) return false; 6975 if (RLoc.isInvalid()) return true; 6976 6977 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 6978 } 6979}; 6980 6981/// CompleteNonViableCandidate - Normally, overload resolution only 6982/// computes up to the first 6983void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 6984 Expr **Args, unsigned NumArgs) { 6985 assert(!Cand->Viable); 6986 6987 // Don't do anything on failures other than bad conversion. 6988 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 6989 6990 // Skip forward to the first bad conversion. 6991 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 6992 unsigned ConvCount = Cand->Conversions.size(); 6993 while (true) { 6994 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 6995 ConvIdx++; 6996 if (Cand->Conversions[ConvIdx - 1].isBad()) 6997 break; 6998 } 6999 7000 if (ConvIdx == ConvCount) 7001 return; 7002 7003 assert(!Cand->Conversions[ConvIdx].isInitialized() && 7004 "remaining conversion is initialized?"); 7005 7006 // FIXME: this should probably be preserved from the overload 7007 // operation somehow. 7008 bool SuppressUserConversions = false; 7009 7010 const FunctionProtoType* Proto; 7011 unsigned ArgIdx = ConvIdx; 7012 7013 if (Cand->IsSurrogate) { 7014 QualType ConvType 7015 = Cand->Surrogate->getConversionType().getNonReferenceType(); 7016 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7017 ConvType = ConvPtrType->getPointeeType(); 7018 Proto = ConvType->getAs<FunctionProtoType>(); 7019 ArgIdx--; 7020 } else if (Cand->Function) { 7021 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 7022 if (isa<CXXMethodDecl>(Cand->Function) && 7023 !isa<CXXConstructorDecl>(Cand->Function)) 7024 ArgIdx--; 7025 } else { 7026 // Builtin binary operator with a bad first conversion. 7027 assert(ConvCount <= 3); 7028 for (; ConvIdx != ConvCount; ++ConvIdx) 7029 Cand->Conversions[ConvIdx] 7030 = TryCopyInitialization(S, Args[ConvIdx], 7031 Cand->BuiltinTypes.ParamTypes[ConvIdx], 7032 SuppressUserConversions, 7033 /*InOverloadResolution*/ true); 7034 return; 7035 } 7036 7037 // Fill in the rest of the conversions. 7038 unsigned NumArgsInProto = Proto->getNumArgs(); 7039 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 7040 if (ArgIdx < NumArgsInProto) 7041 Cand->Conversions[ConvIdx] 7042 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 7043 SuppressUserConversions, 7044 /*InOverloadResolution=*/true); 7045 else 7046 Cand->Conversions[ConvIdx].setEllipsis(); 7047 } 7048} 7049 7050} // end anonymous namespace 7051 7052/// PrintOverloadCandidates - When overload resolution fails, prints 7053/// diagnostic messages containing the candidates in the candidate 7054/// set. 7055void OverloadCandidateSet::NoteCandidates(Sema &S, 7056 OverloadCandidateDisplayKind OCD, 7057 Expr **Args, unsigned NumArgs, 7058 const char *Opc, 7059 SourceLocation OpLoc) { 7060 // Sort the candidates by viability and position. Sorting directly would 7061 // be prohibitive, so we make a set of pointers and sort those. 7062 llvm::SmallVector<OverloadCandidate*, 32> Cands; 7063 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 7064 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 7065 if (Cand->Viable) 7066 Cands.push_back(Cand); 7067 else if (OCD == OCD_AllCandidates) { 7068 CompleteNonViableCandidate(S, Cand, Args, NumArgs); 7069 if (Cand->Function || Cand->IsSurrogate) 7070 Cands.push_back(Cand); 7071 // Otherwise, this a non-viable builtin candidate. We do not, in general, 7072 // want to list every possible builtin candidate. 7073 } 7074 } 7075 7076 std::sort(Cands.begin(), Cands.end(), 7077 CompareOverloadCandidatesForDisplay(S)); 7078 7079 bool ReportedAmbiguousConversions = false; 7080 7081 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 7082 const Diagnostic::OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 7083 unsigned CandsShown = 0; 7084 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 7085 OverloadCandidate *Cand = *I; 7086 7087 // Set an arbitrary limit on the number of candidate functions we'll spam 7088 // the user with. FIXME: This limit should depend on details of the 7089 // candidate list. 7090 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 7091 break; 7092 } 7093 ++CandsShown; 7094 7095 if (Cand->Function) 7096 NoteFunctionCandidate(S, Cand, Args, NumArgs); 7097 else if (Cand->IsSurrogate) 7098 NoteSurrogateCandidate(S, Cand); 7099 else { 7100 assert(Cand->Viable && 7101 "Non-viable built-in candidates are not added to Cands."); 7102 // Generally we only see ambiguities including viable builtin 7103 // operators if overload resolution got screwed up by an 7104 // ambiguous user-defined conversion. 7105 // 7106 // FIXME: It's quite possible for different conversions to see 7107 // different ambiguities, though. 7108 if (!ReportedAmbiguousConversions) { 7109 NoteAmbiguousUserConversions(S, OpLoc, Cand); 7110 ReportedAmbiguousConversions = true; 7111 } 7112 7113 // If this is a viable builtin, print it. 7114 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 7115 } 7116 } 7117 7118 if (I != E) 7119 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 7120} 7121 7122// [PossiblyAFunctionType] --> [Return] 7123// NonFunctionType --> NonFunctionType 7124// R (A) --> R(A) 7125// R (*)(A) --> R (A) 7126// R (&)(A) --> R (A) 7127// R (S::*)(A) --> R (A) 7128QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { 7129 QualType Ret = PossiblyAFunctionType; 7130 if (const PointerType *ToTypePtr = 7131 PossiblyAFunctionType->getAs<PointerType>()) 7132 Ret = ToTypePtr->getPointeeType(); 7133 else if (const ReferenceType *ToTypeRef = 7134 PossiblyAFunctionType->getAs<ReferenceType>()) 7135 Ret = ToTypeRef->getPointeeType(); 7136 else if (const MemberPointerType *MemTypePtr = 7137 PossiblyAFunctionType->getAs<MemberPointerType>()) 7138 Ret = MemTypePtr->getPointeeType(); 7139 Ret = 7140 Context.getCanonicalType(Ret).getUnqualifiedType(); 7141 return Ret; 7142} 7143 7144// A helper class to help with address of function resolution 7145// - allows us to avoid passing around all those ugly parameters 7146class AddressOfFunctionResolver 7147{ 7148 Sema& S; 7149 Expr* SourceExpr; 7150 const QualType& TargetType; 7151 QualType TargetFunctionType; // Extracted function type from target type 7152 7153 bool Complain; 7154 //DeclAccessPair& ResultFunctionAccessPair; 7155 ASTContext& Context; 7156 7157 bool TargetTypeIsNonStaticMemberFunction; 7158 bool FoundNonTemplateFunction; 7159 7160 OverloadExpr::FindResult OvlExprInfo; 7161 OverloadExpr *OvlExpr; 7162 TemplateArgumentListInfo OvlExplicitTemplateArgs; 7163 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 7164 7165public: 7166 AddressOfFunctionResolver(Sema &S, Expr* SourceExpr, 7167 const QualType& TargetType, bool Complain) 7168 : S(S), SourceExpr(SourceExpr), TargetType(TargetType), 7169 Complain(Complain), Context(S.getASTContext()), 7170 TargetTypeIsNonStaticMemberFunction( 7171 !!TargetType->getAs<MemberPointerType>()), 7172 FoundNonTemplateFunction(false), 7173 OvlExprInfo(OverloadExpr::find(SourceExpr)), 7174 OvlExpr(OvlExprInfo.Expression) 7175 { 7176 ExtractUnqualifiedFunctionTypeFromTargetType(); 7177 7178 if (!TargetFunctionType->isFunctionType()) { 7179 if (OvlExpr->hasExplicitTemplateArgs()) { 7180 DeclAccessPair dap; 7181 if( FunctionDecl* Fn = S.ResolveSingleFunctionTemplateSpecialization( 7182 OvlExpr, false, &dap) ) { 7183 7184 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7185 if (!Method->isStatic()) { 7186 // If the target type is a non-function type and the function 7187 // found is a non-static member function, pretend as if that was 7188 // the target, it's the only possible type to end up with. 7189 TargetTypeIsNonStaticMemberFunction = true; 7190 7191 // And skip adding the function if its not in the proper form. 7192 // We'll diagnose this due to an empty set of functions. 7193 if (!OvlExprInfo.HasFormOfMemberPointer) 7194 return; 7195 } 7196 } 7197 7198 Matches.push_back(std::make_pair(dap,Fn)); 7199 } 7200 } 7201 return; 7202 } 7203 7204 if (OvlExpr->hasExplicitTemplateArgs()) 7205 OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); 7206 7207 if (FindAllFunctionsThatMatchTargetTypeExactly()) { 7208 // C++ [over.over]p4: 7209 // If more than one function is selected, [...] 7210 if (Matches.size() > 1) { 7211 if (FoundNonTemplateFunction) 7212 EliminateAllTemplateMatches(); 7213 else 7214 EliminateAllExceptMostSpecializedTemplate(); 7215 } 7216 } 7217 } 7218 7219private: 7220 bool isTargetTypeAFunction() const { 7221 return TargetFunctionType->isFunctionType(); 7222 } 7223 7224 // [ToType] [Return] 7225 7226 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false 7227 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false 7228 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true 7229 void inline ExtractUnqualifiedFunctionTypeFromTargetType() { 7230 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); 7231 } 7232 7233 // return true if any matching specializations were found 7234 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, 7235 const DeclAccessPair& CurAccessFunPair) { 7236 if (CXXMethodDecl *Method 7237 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 7238 // Skip non-static function templates when converting to pointer, and 7239 // static when converting to member pointer. 7240 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 7241 return false; 7242 } 7243 else if (TargetTypeIsNonStaticMemberFunction) 7244 return false; 7245 7246 // C++ [over.over]p2: 7247 // If the name is a function template, template argument deduction is 7248 // done (14.8.2.2), and if the argument deduction succeeds, the 7249 // resulting template argument list is used to generate a single 7250 // function template specialization, which is added to the set of 7251 // overloaded functions considered. 7252 FunctionDecl *Specialization = 0; 7253 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 7254 if (Sema::TemplateDeductionResult Result 7255 = S.DeduceTemplateArguments(FunctionTemplate, 7256 &OvlExplicitTemplateArgs, 7257 TargetFunctionType, Specialization, 7258 Info)) { 7259 // FIXME: make a note of the failed deduction for diagnostics. 7260 (void)Result; 7261 return false; 7262 } 7263 7264 // Template argument deduction ensures that we have an exact match. 7265 // This function template specicalization works. 7266 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 7267 assert(TargetFunctionType 7268 == Context.getCanonicalType(Specialization->getType())); 7269 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); 7270 return true; 7271 } 7272 7273 bool AddMatchingNonTemplateFunction(NamedDecl* Fn, 7274 const DeclAccessPair& CurAccessFunPair) { 7275 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7276 // Skip non-static functions when converting to pointer, and static 7277 // when converting to member pointer. 7278 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 7279 return false; 7280 } 7281 else if (TargetTypeIsNonStaticMemberFunction) 7282 return false; 7283 7284 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 7285 QualType ResultTy; 7286 if (Context.hasSameUnqualifiedType(TargetFunctionType, 7287 FunDecl->getType()) || 7288 IsNoReturnConversion(Context, FunDecl->getType(), TargetFunctionType, 7289 ResultTy)) { 7290 Matches.push_back(std::make_pair(CurAccessFunPair, 7291 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 7292 FoundNonTemplateFunction = true; 7293 return true; 7294 } 7295 } 7296 7297 return false; 7298 } 7299 7300 bool FindAllFunctionsThatMatchTargetTypeExactly() { 7301 bool Ret = false; 7302 7303 // If the overload expression doesn't have the form of a pointer to 7304 // member, don't try to convert it to a pointer-to-member type. 7305 if (IsInvalidFormOfPointerToMemberFunction()) 7306 return false; 7307 7308 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7309 E = OvlExpr->decls_end(); 7310 I != E; ++I) { 7311 // Look through any using declarations to find the underlying function. 7312 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 7313 7314 // C++ [over.over]p3: 7315 // Non-member functions and static member functions match 7316 // targets of type "pointer-to-function" or "reference-to-function." 7317 // Nonstatic member functions match targets of 7318 // type "pointer-to-member-function." 7319 // Note that according to DR 247, the containing class does not matter. 7320 if (FunctionTemplateDecl *FunctionTemplate 7321 = dyn_cast<FunctionTemplateDecl>(Fn)) { 7322 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) 7323 Ret = true; 7324 } 7325 // If we have explicit template arguments supplied, skip non-templates. 7326 else if (!OvlExpr->hasExplicitTemplateArgs() && 7327 AddMatchingNonTemplateFunction(Fn, I.getPair())) 7328 Ret = true; 7329 } 7330 assert(Ret || Matches.empty()); 7331 return Ret; 7332 } 7333 7334 void EliminateAllExceptMostSpecializedTemplate() { 7335 // [...] and any given function template specialization F1 is 7336 // eliminated if the set contains a second function template 7337 // specialization whose function template is more specialized 7338 // than the function template of F1 according to the partial 7339 // ordering rules of 14.5.5.2. 7340 7341 // The algorithm specified above is quadratic. We instead use a 7342 // two-pass algorithm (similar to the one used to identify the 7343 // best viable function in an overload set) that identifies the 7344 // best function template (if it exists). 7345 7346 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 7347 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 7348 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 7349 7350 UnresolvedSetIterator Result = 7351 S.getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 7352 TPOC_Other, 0, SourceExpr->getLocStart(), 7353 S.PDiag(), 7354 S.PDiag(diag::err_addr_ovl_ambiguous) 7355 << Matches[0].second->getDeclName(), 7356 S.PDiag(diag::note_ovl_candidate) 7357 << (unsigned) oc_function_template, 7358 Complain); 7359 7360 if (Result != MatchesCopy.end()) { 7361 // Make it the first and only element 7362 Matches[0].first = Matches[Result - MatchesCopy.begin()].first; 7363 Matches[0].second = cast<FunctionDecl>(*Result); 7364 Matches.resize(1); 7365 } 7366 } 7367 7368 void EliminateAllTemplateMatches() { 7369 // [...] any function template specializations in the set are 7370 // eliminated if the set also contains a non-template function, [...] 7371 for (unsigned I = 0, N = Matches.size(); I != N; ) { 7372 if (Matches[I].second->getPrimaryTemplate() == 0) 7373 ++I; 7374 else { 7375 Matches[I] = Matches[--N]; 7376 Matches.set_size(N); 7377 } 7378 } 7379 } 7380 7381public: 7382 void ComplainNoMatchesFound() const { 7383 assert(Matches.empty()); 7384 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) 7385 << OvlExpr->getName() << TargetFunctionType 7386 << OvlExpr->getSourceRange(); 7387 S.NoteAllOverloadCandidates(OvlExpr); 7388 } 7389 7390 bool IsInvalidFormOfPointerToMemberFunction() const { 7391 return TargetTypeIsNonStaticMemberFunction && 7392 !OvlExprInfo.HasFormOfMemberPointer; 7393 } 7394 7395 void ComplainIsInvalidFormOfPointerToMemberFunction() const { 7396 // TODO: Should we condition this on whether any functions might 7397 // have matched, or is it more appropriate to do that in callers? 7398 // TODO: a fixit wouldn't hurt. 7399 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 7400 << TargetType << OvlExpr->getSourceRange(); 7401 } 7402 7403 void ComplainOfInvalidConversion() const { 7404 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 7405 << OvlExpr->getName() << TargetType; 7406 } 7407 7408 void ComplainMultipleMatchesFound() const { 7409 assert(Matches.size() > 1); 7410 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) 7411 << OvlExpr->getName() 7412 << OvlExpr->getSourceRange(); 7413 S.NoteAllOverloadCandidates(OvlExpr); 7414 } 7415 7416 int getNumMatches() const { return Matches.size(); } 7417 7418 FunctionDecl* getMatchingFunctionDecl() const { 7419 if (Matches.size() != 1) return 0; 7420 return Matches[0].second; 7421 } 7422 7423 const DeclAccessPair* getMatchingFunctionAccessPair() const { 7424 if (Matches.size() != 1) return 0; 7425 return &Matches[0].first; 7426 } 7427}; 7428 7429/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 7430/// an overloaded function (C++ [over.over]), where @p From is an 7431/// expression with overloaded function type and @p ToType is the type 7432/// we're trying to resolve to. For example: 7433/// 7434/// @code 7435/// int f(double); 7436/// int f(int); 7437/// 7438/// int (*pfd)(double) = f; // selects f(double) 7439/// @endcode 7440/// 7441/// This routine returns the resulting FunctionDecl if it could be 7442/// resolved, and NULL otherwise. When @p Complain is true, this 7443/// routine will emit diagnostics if there is an error. 7444FunctionDecl * 7445Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, QualType TargetType, 7446 bool Complain, 7447 DeclAccessPair &FoundResult) { 7448 7449 assert(AddressOfExpr->getType() == Context.OverloadTy); 7450 7451 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, Complain); 7452 int NumMatches = Resolver.getNumMatches(); 7453 FunctionDecl* Fn = 0; 7454 if ( NumMatches == 0 && Complain) { 7455 if (Resolver.IsInvalidFormOfPointerToMemberFunction()) 7456 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); 7457 else 7458 Resolver.ComplainNoMatchesFound(); 7459 } 7460 else if (NumMatches > 1 && Complain) 7461 Resolver.ComplainMultipleMatchesFound(); 7462 else if (NumMatches == 1) { 7463 Fn = Resolver.getMatchingFunctionDecl(); 7464 assert(Fn); 7465 FoundResult = *Resolver.getMatchingFunctionAccessPair(); 7466 MarkDeclarationReferenced(AddressOfExpr->getLocStart(), Fn); 7467 if (Complain) 7468 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); 7469 } 7470 7471 return Fn; 7472} 7473 7474/// \brief Given an expression that refers to an overloaded function, try to 7475/// resolve that overloaded function expression down to a single function. 7476/// 7477/// This routine can only resolve template-ids that refer to a single function 7478/// template, where that template-id refers to a single template whose template 7479/// arguments are either provided by the template-id or have defaults, 7480/// as described in C++0x [temp.arg.explicit]p3. 7481FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From, 7482 bool Complain, 7483 DeclAccessPair* FoundResult) { 7484 // C++ [over.over]p1: 7485 // [...] [Note: any redundant set of parentheses surrounding the 7486 // overloaded function name is ignored (5.1). ] 7487 // C++ [over.over]p1: 7488 // [...] The overloaded function name can be preceded by the & 7489 // operator. 7490 if (From->getType() != Context.OverloadTy) 7491 return 0; 7492 7493 OverloadExpr *OvlExpr = OverloadExpr::find(From).Expression; 7494 7495 // If we didn't actually find any template-ids, we're done. 7496 if (!OvlExpr->hasExplicitTemplateArgs()) 7497 return 0; 7498 7499 TemplateArgumentListInfo ExplicitTemplateArgs; 7500 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 7501 7502 // Look through all of the overloaded functions, searching for one 7503 // whose type matches exactly. 7504 FunctionDecl *Matched = 0; 7505 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7506 E = OvlExpr->decls_end(); I != E; ++I) { 7507 // C++0x [temp.arg.explicit]p3: 7508 // [...] In contexts where deduction is done and fails, or in contexts 7509 // where deduction is not done, if a template argument list is 7510 // specified and it, along with any default template arguments, 7511 // identifies a single function template specialization, then the 7512 // template-id is an lvalue for the function template specialization. 7513 FunctionTemplateDecl *FunctionTemplate 7514 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 7515 7516 // C++ [over.over]p2: 7517 // If the name is a function template, template argument deduction is 7518 // done (14.8.2.2), and if the argument deduction succeeds, the 7519 // resulting template argument list is used to generate a single 7520 // function template specialization, which is added to the set of 7521 // overloaded functions considered. 7522 FunctionDecl *Specialization = 0; 7523 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 7524 if (TemplateDeductionResult Result 7525 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 7526 Specialization, Info)) { 7527 // FIXME: make a note of the failed deduction for diagnostics. 7528 (void)Result; 7529 continue; 7530 } 7531 7532 // Multiple matches; we can't resolve to a single declaration. 7533 if (Matched) { 7534 if (FoundResult) 7535 *FoundResult = DeclAccessPair(); 7536 7537 if (Complain) { 7538 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 7539 << OvlExpr->getName(); 7540 NoteAllOverloadCandidates(OvlExpr); 7541 } 7542 return 0; 7543 } 7544 7545 if ((Matched = Specialization) && FoundResult) 7546 *FoundResult = I.getPair(); 7547 } 7548 7549 return Matched; 7550} 7551 7552 7553 7554 7555// Resolve and fix an overloaded expression that 7556// can be resolved because it identifies a single function 7557// template specialization 7558// Last three arguments should only be supplied if Complain = true 7559ExprResult Sema::ResolveAndFixSingleFunctionTemplateSpecialization( 7560 Expr *SrcExpr, bool DoFunctionPointerConverion, bool Complain, 7561 const SourceRange& OpRangeForComplaining, 7562 QualType DestTypeForComplaining, 7563 unsigned DiagIDForComplaining ) { 7564 7565 assert(SrcExpr->getType() == Context.OverloadTy); 7566 7567 DeclAccessPair Found; 7568 Expr* SingleFunctionExpression = 0; 7569 if (FunctionDecl* Fn = ResolveSingleFunctionTemplateSpecialization( 7570 SrcExpr, false, // false -> Complain 7571 &Found)) { 7572 if (!DiagnoseUseOfDecl(Fn, SrcExpr->getSourceRange().getBegin())) { 7573 // mark the expression as resolved to Fn 7574 SingleFunctionExpression = FixOverloadedFunctionReference(SrcExpr, 7575 Found, Fn); 7576 if (DoFunctionPointerConverion) 7577 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression); 7578 } 7579 } 7580 if (!SingleFunctionExpression) { 7581 if (Complain) { 7582 OverloadExpr* oe = OverloadExpr::find(SrcExpr).Expression; 7583 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) 7584 << oe->getName() << DestTypeForComplaining << OpRangeForComplaining 7585 << oe->getQualifierLoc().getSourceRange(); 7586 NoteAllOverloadCandidates(SrcExpr); 7587 } 7588 return ExprError(); 7589 } 7590 7591 return SingleFunctionExpression; 7592} 7593 7594/// \brief Add a single candidate to the overload set. 7595static void AddOverloadedCallCandidate(Sema &S, 7596 DeclAccessPair FoundDecl, 7597 TemplateArgumentListInfo *ExplicitTemplateArgs, 7598 Expr **Args, unsigned NumArgs, 7599 OverloadCandidateSet &CandidateSet, 7600 bool PartialOverloading) { 7601 NamedDecl *Callee = FoundDecl.getDecl(); 7602 if (isa<UsingShadowDecl>(Callee)) 7603 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 7604 7605 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 7606 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 7607 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 7608 false, PartialOverloading); 7609 return; 7610 } 7611 7612 if (FunctionTemplateDecl *FuncTemplate 7613 = dyn_cast<FunctionTemplateDecl>(Callee)) { 7614 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 7615 ExplicitTemplateArgs, 7616 Args, NumArgs, CandidateSet); 7617 return; 7618 } 7619 7620 assert(false && "unhandled case in overloaded call candidate"); 7621 7622 // do nothing? 7623} 7624 7625/// \brief Add the overload candidates named by callee and/or found by argument 7626/// dependent lookup to the given overload set. 7627void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 7628 Expr **Args, unsigned NumArgs, 7629 OverloadCandidateSet &CandidateSet, 7630 bool PartialOverloading) { 7631 7632#ifndef NDEBUG 7633 // Verify that ArgumentDependentLookup is consistent with the rules 7634 // in C++0x [basic.lookup.argdep]p3: 7635 // 7636 // Let X be the lookup set produced by unqualified lookup (3.4.1) 7637 // and let Y be the lookup set produced by argument dependent 7638 // lookup (defined as follows). If X contains 7639 // 7640 // -- a declaration of a class member, or 7641 // 7642 // -- a block-scope function declaration that is not a 7643 // using-declaration, or 7644 // 7645 // -- a declaration that is neither a function or a function 7646 // template 7647 // 7648 // then Y is empty. 7649 7650 if (ULE->requiresADL()) { 7651 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 7652 E = ULE->decls_end(); I != E; ++I) { 7653 assert(!(*I)->getDeclContext()->isRecord()); 7654 assert(isa<UsingShadowDecl>(*I) || 7655 !(*I)->getDeclContext()->isFunctionOrMethod()); 7656 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 7657 } 7658 } 7659#endif 7660 7661 // It would be nice to avoid this copy. 7662 TemplateArgumentListInfo TABuffer; 7663 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 7664 if (ULE->hasExplicitTemplateArgs()) { 7665 ULE->copyTemplateArgumentsInto(TABuffer); 7666 ExplicitTemplateArgs = &TABuffer; 7667 } 7668 7669 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 7670 E = ULE->decls_end(); I != E; ++I) 7671 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 7672 Args, NumArgs, CandidateSet, 7673 PartialOverloading); 7674 7675 if (ULE->requiresADL()) 7676 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 7677 Args, NumArgs, 7678 ExplicitTemplateArgs, 7679 CandidateSet, 7680 PartialOverloading); 7681} 7682 7683/// Attempts to recover from a call where no functions were found. 7684/// 7685/// Returns true if new candidates were found. 7686static ExprResult 7687BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 7688 UnresolvedLookupExpr *ULE, 7689 SourceLocation LParenLoc, 7690 Expr **Args, unsigned NumArgs, 7691 SourceLocation RParenLoc) { 7692 7693 CXXScopeSpec SS; 7694 SS.Adopt(ULE->getQualifierLoc()); 7695 7696 TemplateArgumentListInfo TABuffer; 7697 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 7698 if (ULE->hasExplicitTemplateArgs()) { 7699 ULE->copyTemplateArgumentsInto(TABuffer); 7700 ExplicitTemplateArgs = &TABuffer; 7701 } 7702 7703 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 7704 Sema::LookupOrdinaryName); 7705 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 7706 return ExprError(); 7707 7708 assert(!R.empty() && "lookup results empty despite recovery"); 7709 7710 // Build an implicit member call if appropriate. Just drop the 7711 // casts and such from the call, we don't really care. 7712 ExprResult NewFn = ExprError(); 7713 if ((*R.begin())->isCXXClassMember()) 7714 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, 7715 ExplicitTemplateArgs); 7716 else if (ExplicitTemplateArgs) 7717 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 7718 else 7719 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 7720 7721 if (NewFn.isInvalid()) 7722 return ExprError(); 7723 7724 // This shouldn't cause an infinite loop because we're giving it 7725 // an expression with non-empty lookup results, which should never 7726 // end up here. 7727 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 7728 MultiExprArg(Args, NumArgs), RParenLoc); 7729} 7730 7731/// ResolveOverloadedCallFn - Given the call expression that calls Fn 7732/// (which eventually refers to the declaration Func) and the call 7733/// arguments Args/NumArgs, attempt to resolve the function call down 7734/// to a specific function. If overload resolution succeeds, returns 7735/// the function declaration produced by overload 7736/// resolution. Otherwise, emits diagnostics, deletes all of the 7737/// arguments and Fn, and returns NULL. 7738ExprResult 7739Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 7740 SourceLocation LParenLoc, 7741 Expr **Args, unsigned NumArgs, 7742 SourceLocation RParenLoc, 7743 Expr *ExecConfig) { 7744#ifndef NDEBUG 7745 if (ULE->requiresADL()) { 7746 // To do ADL, we must have found an unqualified name. 7747 assert(!ULE->getQualifier() && "qualified name with ADL"); 7748 7749 // We don't perform ADL for implicit declarations of builtins. 7750 // Verify that this was correctly set up. 7751 FunctionDecl *F; 7752 if (ULE->decls_begin() + 1 == ULE->decls_end() && 7753 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 7754 F->getBuiltinID() && F->isImplicit()) 7755 assert(0 && "performing ADL for builtin"); 7756 7757 // We don't perform ADL in C. 7758 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 7759 } 7760#endif 7761 7762 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 7763 7764 // Add the functions denoted by the callee to the set of candidate 7765 // functions, including those from argument-dependent lookup. 7766 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 7767 7768 // If we found nothing, try to recover. 7769 // AddRecoveryCallCandidates diagnoses the error itself, so we just 7770 // bailout out if it fails. 7771 if (CandidateSet.empty()) 7772 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 7773 RParenLoc); 7774 7775 OverloadCandidateSet::iterator Best; 7776 switch (CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best)) { 7777 case OR_Success: { 7778 FunctionDecl *FDecl = Best->Function; 7779 MarkDeclarationReferenced(Fn->getExprLoc(), FDecl); 7780 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 7781 DiagnoseUseOfDecl(FDecl? FDecl : Best->FoundDecl.getDecl(), 7782 ULE->getNameLoc()); 7783 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 7784 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc, 7785 ExecConfig); 7786 } 7787 7788 case OR_No_Viable_Function: 7789 Diag(Fn->getSourceRange().getBegin(), 7790 diag::err_ovl_no_viable_function_in_call) 7791 << ULE->getName() << Fn->getSourceRange(); 7792 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7793 break; 7794 7795 case OR_Ambiguous: 7796 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 7797 << ULE->getName() << Fn->getSourceRange(); 7798 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 7799 break; 7800 7801 case OR_Deleted: 7802 { 7803 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 7804 << Best->Function->isDeleted() 7805 << ULE->getName() 7806 << getDeletedOrUnavailableSuffix(Best->Function) 7807 << Fn->getSourceRange(); 7808 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7809 } 7810 break; 7811 } 7812 7813 // Overload resolution failed. 7814 return ExprError(); 7815} 7816 7817static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 7818 return Functions.size() > 1 || 7819 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 7820} 7821 7822/// \brief Create a unary operation that may resolve to an overloaded 7823/// operator. 7824/// 7825/// \param OpLoc The location of the operator itself (e.g., '*'). 7826/// 7827/// \param OpcIn The UnaryOperator::Opcode that describes this 7828/// operator. 7829/// 7830/// \param Functions The set of non-member functions that will be 7831/// considered by overload resolution. The caller needs to build this 7832/// set based on the context using, e.g., 7833/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 7834/// set should not contain any member functions; those will be added 7835/// by CreateOverloadedUnaryOp(). 7836/// 7837/// \param input The input argument. 7838ExprResult 7839Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 7840 const UnresolvedSetImpl &Fns, 7841 Expr *Input) { 7842 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 7843 7844 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 7845 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 7846 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 7847 // TODO: provide better source location info. 7848 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 7849 7850 if (Input->getObjectKind() == OK_ObjCProperty) 7851 ConvertPropertyForRValue(Input); 7852 7853 Expr *Args[2] = { Input, 0 }; 7854 unsigned NumArgs = 1; 7855 7856 // For post-increment and post-decrement, add the implicit '0' as 7857 // the second argument, so that we know this is a post-increment or 7858 // post-decrement. 7859 if (Opc == UO_PostInc || Opc == UO_PostDec) { 7860 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 7861 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 7862 SourceLocation()); 7863 NumArgs = 2; 7864 } 7865 7866 if (Input->isTypeDependent()) { 7867 if (Fns.empty()) 7868 return Owned(new (Context) UnaryOperator(Input, 7869 Opc, 7870 Context.DependentTy, 7871 VK_RValue, OK_Ordinary, 7872 OpLoc)); 7873 7874 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7875 UnresolvedLookupExpr *Fn 7876 = UnresolvedLookupExpr::Create(Context, NamingClass, 7877 NestedNameSpecifierLoc(), OpNameInfo, 7878 /*ADL*/ true, IsOverloaded(Fns), 7879 Fns.begin(), Fns.end()); 7880 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 7881 &Args[0], NumArgs, 7882 Context.DependentTy, 7883 VK_RValue, 7884 OpLoc)); 7885 } 7886 7887 // Build an empty overload set. 7888 OverloadCandidateSet CandidateSet(OpLoc); 7889 7890 // Add the candidates from the given function set. 7891 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 7892 7893 // Add operator candidates that are member functions. 7894 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 7895 7896 // Add candidates from ADL. 7897 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 7898 Args, NumArgs, 7899 /*ExplicitTemplateArgs*/ 0, 7900 CandidateSet); 7901 7902 // Add builtin operator candidates. 7903 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 7904 7905 // Perform overload resolution. 7906 OverloadCandidateSet::iterator Best; 7907 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 7908 case OR_Success: { 7909 // We found a built-in operator or an overloaded operator. 7910 FunctionDecl *FnDecl = Best->Function; 7911 7912 if (FnDecl) { 7913 // We matched an overloaded operator. Build a call to that 7914 // operator. 7915 7916 MarkDeclarationReferenced(OpLoc, FnDecl); 7917 7918 // Convert the arguments. 7919 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 7920 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 7921 7922 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 7923 Best->FoundDecl, Method)) 7924 return ExprError(); 7925 } else { 7926 // Convert the arguments. 7927 ExprResult InputInit 7928 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7929 Context, 7930 FnDecl->getParamDecl(0)), 7931 SourceLocation(), 7932 Input); 7933 if (InputInit.isInvalid()) 7934 return ExprError(); 7935 Input = InputInit.take(); 7936 } 7937 7938 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7939 7940 // Determine the result type. 7941 QualType ResultTy = FnDecl->getResultType(); 7942 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 7943 ResultTy = ResultTy.getNonLValueExprType(Context); 7944 7945 // Build the actual expression node. 7946 Expr *FnExpr = CreateFunctionRefExpr(*this, FnDecl); 7947 7948 Args[0] = Input; 7949 CallExpr *TheCall = 7950 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 7951 Args, NumArgs, ResultTy, VK, OpLoc); 7952 7953 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 7954 FnDecl)) 7955 return ExprError(); 7956 7957 return MaybeBindToTemporary(TheCall); 7958 } else { 7959 // We matched a built-in operator. Convert the arguments, then 7960 // break out so that we will build the appropriate built-in 7961 // operator node. 7962 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 7963 Best->Conversions[0], AA_Passing)) 7964 return ExprError(); 7965 7966 break; 7967 } 7968 } 7969 7970 case OR_No_Viable_Function: 7971 // No viable function; fall through to handling this as a 7972 // built-in operator, which will produce an error message for us. 7973 break; 7974 7975 case OR_Ambiguous: 7976 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 7977 << UnaryOperator::getOpcodeStr(Opc) 7978 << Input->getType() 7979 << Input->getSourceRange(); 7980 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 7981 Args, NumArgs, 7982 UnaryOperator::getOpcodeStr(Opc), OpLoc); 7983 return ExprError(); 7984 7985 case OR_Deleted: 7986 Diag(OpLoc, diag::err_ovl_deleted_oper) 7987 << Best->Function->isDeleted() 7988 << UnaryOperator::getOpcodeStr(Opc) 7989 << getDeletedOrUnavailableSuffix(Best->Function) 7990 << Input->getSourceRange(); 7991 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7992 return ExprError(); 7993 } 7994 7995 // Either we found no viable overloaded operator or we matched a 7996 // built-in operator. In either case, fall through to trying to 7997 // build a built-in operation. 7998 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 7999} 8000 8001/// \brief Create a binary operation that may resolve to an overloaded 8002/// operator. 8003/// 8004/// \param OpLoc The location of the operator itself (e.g., '+'). 8005/// 8006/// \param OpcIn The BinaryOperator::Opcode that describes this 8007/// operator. 8008/// 8009/// \param Functions The set of non-member functions that will be 8010/// considered by overload resolution. The caller needs to build this 8011/// set based on the context using, e.g., 8012/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 8013/// set should not contain any member functions; those will be added 8014/// by CreateOverloadedBinOp(). 8015/// 8016/// \param LHS Left-hand argument. 8017/// \param RHS Right-hand argument. 8018ExprResult 8019Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 8020 unsigned OpcIn, 8021 const UnresolvedSetImpl &Fns, 8022 Expr *LHS, Expr *RHS) { 8023 Expr *Args[2] = { LHS, RHS }; 8024 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 8025 8026 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 8027 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 8028 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 8029 8030 // If either side is type-dependent, create an appropriate dependent 8031 // expression. 8032 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 8033 if (Fns.empty()) { 8034 // If there are no functions to store, just build a dependent 8035 // BinaryOperator or CompoundAssignment. 8036 if (Opc <= BO_Assign || Opc > BO_OrAssign) 8037 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 8038 Context.DependentTy, 8039 VK_RValue, OK_Ordinary, 8040 OpLoc)); 8041 8042 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 8043 Context.DependentTy, 8044 VK_LValue, 8045 OK_Ordinary, 8046 Context.DependentTy, 8047 Context.DependentTy, 8048 OpLoc)); 8049 } 8050 8051 // FIXME: save results of ADL from here? 8052 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8053 // TODO: provide better source location info in DNLoc component. 8054 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 8055 UnresolvedLookupExpr *Fn 8056 = UnresolvedLookupExpr::Create(Context, NamingClass, 8057 NestedNameSpecifierLoc(), OpNameInfo, 8058 /*ADL*/ true, IsOverloaded(Fns), 8059 Fns.begin(), Fns.end()); 8060 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 8061 Args, 2, 8062 Context.DependentTy, 8063 VK_RValue, 8064 OpLoc)); 8065 } 8066 8067 // Always do property rvalue conversions on the RHS. 8068 if (Args[1]->getObjectKind() == OK_ObjCProperty) 8069 ConvertPropertyForRValue(Args[1]); 8070 8071 // The LHS is more complicated. 8072 if (Args[0]->getObjectKind() == OK_ObjCProperty) { 8073 8074 // There's a tension for assignment operators between primitive 8075 // property assignment and the overloaded operators. 8076 if (BinaryOperator::isAssignmentOp(Opc)) { 8077 const ObjCPropertyRefExpr *PRE = LHS->getObjCProperty(); 8078 8079 // Is the property "logically" settable? 8080 bool Settable = (PRE->isExplicitProperty() || 8081 PRE->getImplicitPropertySetter()); 8082 8083 // To avoid gratuitously inventing semantics, use the primitive 8084 // unless it isn't. Thoughts in case we ever really care: 8085 // - If the property isn't logically settable, we have to 8086 // load and hope. 8087 // - If the property is settable and this is simple assignment, 8088 // we really should use the primitive. 8089 // - If the property is settable, then we could try overloading 8090 // on a generic lvalue of the appropriate type; if it works 8091 // out to a builtin candidate, we would do that same operation 8092 // on the property, and otherwise just error. 8093 if (Settable) 8094 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8095 } 8096 8097 ConvertPropertyForRValue(Args[0]); 8098 } 8099 8100 // If this is the assignment operator, we only perform overload resolution 8101 // if the left-hand side is a class or enumeration type. This is actually 8102 // a hack. The standard requires that we do overload resolution between the 8103 // various built-in candidates, but as DR507 points out, this can lead to 8104 // problems. So we do it this way, which pretty much follows what GCC does. 8105 // Note that we go the traditional code path for compound assignment forms. 8106 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 8107 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8108 8109 // If this is the .* operator, which is not overloadable, just 8110 // create a built-in binary operator. 8111 if (Opc == BO_PtrMemD) 8112 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8113 8114 // Build an empty overload set. 8115 OverloadCandidateSet CandidateSet(OpLoc); 8116 8117 // Add the candidates from the given function set. 8118 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 8119 8120 // Add operator candidates that are member functions. 8121 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 8122 8123 // Add candidates from ADL. 8124 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 8125 Args, 2, 8126 /*ExplicitTemplateArgs*/ 0, 8127 CandidateSet); 8128 8129 // Add builtin operator candidates. 8130 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 8131 8132 // Perform overload resolution. 8133 OverloadCandidateSet::iterator Best; 8134 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8135 case OR_Success: { 8136 // We found a built-in operator or an overloaded operator. 8137 FunctionDecl *FnDecl = Best->Function; 8138 8139 if (FnDecl) { 8140 // We matched an overloaded operator. Build a call to that 8141 // operator. 8142 8143 MarkDeclarationReferenced(OpLoc, FnDecl); 8144 8145 // Convert the arguments. 8146 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 8147 // Best->Access is only meaningful for class members. 8148 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 8149 8150 ExprResult Arg1 = 8151 PerformCopyInitialization( 8152 InitializedEntity::InitializeParameter(Context, 8153 FnDecl->getParamDecl(0)), 8154 SourceLocation(), Owned(Args[1])); 8155 if (Arg1.isInvalid()) 8156 return ExprError(); 8157 8158 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 8159 Best->FoundDecl, Method)) 8160 return ExprError(); 8161 8162 Args[1] = RHS = Arg1.takeAs<Expr>(); 8163 } else { 8164 // Convert the arguments. 8165 ExprResult Arg0 = PerformCopyInitialization( 8166 InitializedEntity::InitializeParameter(Context, 8167 FnDecl->getParamDecl(0)), 8168 SourceLocation(), Owned(Args[0])); 8169 if (Arg0.isInvalid()) 8170 return ExprError(); 8171 8172 ExprResult Arg1 = 8173 PerformCopyInitialization( 8174 InitializedEntity::InitializeParameter(Context, 8175 FnDecl->getParamDecl(1)), 8176 SourceLocation(), Owned(Args[1])); 8177 if (Arg1.isInvalid()) 8178 return ExprError(); 8179 Args[0] = LHS = Arg0.takeAs<Expr>(); 8180 Args[1] = RHS = Arg1.takeAs<Expr>(); 8181 } 8182 8183 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 8184 8185 // Determine the result type. 8186 QualType ResultTy = FnDecl->getResultType(); 8187 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8188 ResultTy = ResultTy.getNonLValueExprType(Context); 8189 8190 // Build the actual expression node. 8191 Expr *FnExpr = CreateFunctionRefExpr(*this, FnDecl, OpLoc); 8192 8193 CXXOperatorCallExpr *TheCall = 8194 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 8195 Args, 2, ResultTy, VK, OpLoc); 8196 8197 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 8198 FnDecl)) 8199 return ExprError(); 8200 8201 return MaybeBindToTemporary(TheCall); 8202 } else { 8203 // We matched a built-in operator. Convert the arguments, then 8204 // break out so that we will build the appropriate built-in 8205 // operator node. 8206 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 8207 Best->Conversions[0], AA_Passing) || 8208 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 8209 Best->Conversions[1], AA_Passing)) 8210 return ExprError(); 8211 8212 break; 8213 } 8214 } 8215 8216 case OR_No_Viable_Function: { 8217 // C++ [over.match.oper]p9: 8218 // If the operator is the operator , [...] and there are no 8219 // viable functions, then the operator is assumed to be the 8220 // built-in operator and interpreted according to clause 5. 8221 if (Opc == BO_Comma) 8222 break; 8223 8224 // For class as left operand for assignment or compound assigment 8225 // operator do not fall through to handling in built-in, but report that 8226 // no overloaded assignment operator found 8227 ExprResult Result = ExprError(); 8228 if (Args[0]->getType()->isRecordType() && 8229 Opc >= BO_Assign && Opc <= BO_OrAssign) { 8230 Diag(OpLoc, diag::err_ovl_no_viable_oper) 8231 << BinaryOperator::getOpcodeStr(Opc) 8232 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8233 } else { 8234 // No viable function; try to create a built-in operation, which will 8235 // produce an error. Then, show the non-viable candidates. 8236 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8237 } 8238 assert(Result.isInvalid() && 8239 "C++ binary operator overloading is missing candidates!"); 8240 if (Result.isInvalid()) 8241 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8242 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8243 return move(Result); 8244 } 8245 8246 case OR_Ambiguous: 8247 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 8248 << BinaryOperator::getOpcodeStr(Opc) 8249 << Args[0]->getType() << Args[1]->getType() 8250 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8251 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 8252 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8253 return ExprError(); 8254 8255 case OR_Deleted: 8256 Diag(OpLoc, diag::err_ovl_deleted_oper) 8257 << Best->Function->isDeleted() 8258 << BinaryOperator::getOpcodeStr(Opc) 8259 << getDeletedOrUnavailableSuffix(Best->Function) 8260 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8261 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2); 8262 return ExprError(); 8263 } 8264 8265 // We matched a built-in operator; build it. 8266 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8267} 8268 8269ExprResult 8270Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 8271 SourceLocation RLoc, 8272 Expr *Base, Expr *Idx) { 8273 Expr *Args[2] = { Base, Idx }; 8274 DeclarationName OpName = 8275 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 8276 8277 // If either side is type-dependent, create an appropriate dependent 8278 // expression. 8279 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 8280 8281 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8282 // CHECKME: no 'operator' keyword? 8283 DeclarationNameInfo OpNameInfo(OpName, LLoc); 8284 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 8285 UnresolvedLookupExpr *Fn 8286 = UnresolvedLookupExpr::Create(Context, NamingClass, 8287 NestedNameSpecifierLoc(), OpNameInfo, 8288 /*ADL*/ true, /*Overloaded*/ false, 8289 UnresolvedSetIterator(), 8290 UnresolvedSetIterator()); 8291 // Can't add any actual overloads yet 8292 8293 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 8294 Args, 2, 8295 Context.DependentTy, 8296 VK_RValue, 8297 RLoc)); 8298 } 8299 8300 if (Args[0]->getObjectKind() == OK_ObjCProperty) 8301 ConvertPropertyForRValue(Args[0]); 8302 if (Args[1]->getObjectKind() == OK_ObjCProperty) 8303 ConvertPropertyForRValue(Args[1]); 8304 8305 // Build an empty overload set. 8306 OverloadCandidateSet CandidateSet(LLoc); 8307 8308 // Subscript can only be overloaded as a member function. 8309 8310 // Add operator candidates that are member functions. 8311 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 8312 8313 // Add builtin operator candidates. 8314 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 8315 8316 // Perform overload resolution. 8317 OverloadCandidateSet::iterator Best; 8318 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 8319 case OR_Success: { 8320 // We found a built-in operator or an overloaded operator. 8321 FunctionDecl *FnDecl = Best->Function; 8322 8323 if (FnDecl) { 8324 // We matched an overloaded operator. Build a call to that 8325 // operator. 8326 8327 MarkDeclarationReferenced(LLoc, FnDecl); 8328 8329 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 8330 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 8331 8332 // Convert the arguments. 8333 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 8334 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 8335 Best->FoundDecl, Method)) 8336 return ExprError(); 8337 8338 // Convert the arguments. 8339 ExprResult InputInit 8340 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8341 Context, 8342 FnDecl->getParamDecl(0)), 8343 SourceLocation(), 8344 Owned(Args[1])); 8345 if (InputInit.isInvalid()) 8346 return ExprError(); 8347 8348 Args[1] = InputInit.takeAs<Expr>(); 8349 8350 // Determine the result type 8351 QualType ResultTy = FnDecl->getResultType(); 8352 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8353 ResultTy = ResultTy.getNonLValueExprType(Context); 8354 8355 // Build the actual expression node. 8356 Expr *FnExpr = CreateFunctionRefExpr(*this, FnDecl, LLoc); 8357 8358 CXXOperatorCallExpr *TheCall = 8359 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 8360 FnExpr, Args, 2, 8361 ResultTy, VK, RLoc); 8362 8363 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 8364 FnDecl)) 8365 return ExprError(); 8366 8367 return MaybeBindToTemporary(TheCall); 8368 } else { 8369 // We matched a built-in operator. Convert the arguments, then 8370 // break out so that we will build the appropriate built-in 8371 // operator node. 8372 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 8373 Best->Conversions[0], AA_Passing) || 8374 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 8375 Best->Conversions[1], AA_Passing)) 8376 return ExprError(); 8377 8378 break; 8379 } 8380 } 8381 8382 case OR_No_Viable_Function: { 8383 if (CandidateSet.empty()) 8384 Diag(LLoc, diag::err_ovl_no_oper) 8385 << Args[0]->getType() << /*subscript*/ 0 8386 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8387 else 8388 Diag(LLoc, diag::err_ovl_no_viable_subscript) 8389 << Args[0]->getType() 8390 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8391 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8392 "[]", LLoc); 8393 return ExprError(); 8394 } 8395 8396 case OR_Ambiguous: 8397 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 8398 << "[]" 8399 << Args[0]->getType() << Args[1]->getType() 8400 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8401 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 8402 "[]", LLoc); 8403 return ExprError(); 8404 8405 case OR_Deleted: 8406 Diag(LLoc, diag::err_ovl_deleted_oper) 8407 << Best->Function->isDeleted() << "[]" 8408 << getDeletedOrUnavailableSuffix(Best->Function) 8409 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8410 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8411 "[]", LLoc); 8412 return ExprError(); 8413 } 8414 8415 // We matched a built-in operator; build it. 8416 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 8417} 8418 8419/// BuildCallToMemberFunction - Build a call to a member 8420/// function. MemExpr is the expression that refers to the member 8421/// function (and includes the object parameter), Args/NumArgs are the 8422/// arguments to the function call (not including the object 8423/// parameter). The caller needs to validate that the member 8424/// expression refers to a member function or an overloaded member 8425/// function. 8426ExprResult 8427Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 8428 SourceLocation LParenLoc, Expr **Args, 8429 unsigned NumArgs, SourceLocation RParenLoc) { 8430 // Dig out the member expression. This holds both the object 8431 // argument and the member function we're referring to. 8432 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 8433 8434 MemberExpr *MemExpr; 8435 CXXMethodDecl *Method = 0; 8436 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 8437 NestedNameSpecifier *Qualifier = 0; 8438 if (isa<MemberExpr>(NakedMemExpr)) { 8439 MemExpr = cast<MemberExpr>(NakedMemExpr); 8440 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 8441 FoundDecl = MemExpr->getFoundDecl(); 8442 Qualifier = MemExpr->getQualifier(); 8443 } else { 8444 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 8445 Qualifier = UnresExpr->getQualifier(); 8446 8447 QualType ObjectType = UnresExpr->getBaseType(); 8448 Expr::Classification ObjectClassification 8449 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 8450 : UnresExpr->getBase()->Classify(Context); 8451 8452 // Add overload candidates 8453 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 8454 8455 // FIXME: avoid copy. 8456 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 8457 if (UnresExpr->hasExplicitTemplateArgs()) { 8458 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 8459 TemplateArgs = &TemplateArgsBuffer; 8460 } 8461 8462 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 8463 E = UnresExpr->decls_end(); I != E; ++I) { 8464 8465 NamedDecl *Func = *I; 8466 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 8467 if (isa<UsingShadowDecl>(Func)) 8468 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 8469 8470 8471 // Microsoft supports direct constructor calls. 8472 if (getLangOptions().Microsoft && isa<CXXConstructorDecl>(Func)) { 8473 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), Args, NumArgs, 8474 CandidateSet); 8475 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 8476 // If explicit template arguments were provided, we can't call a 8477 // non-template member function. 8478 if (TemplateArgs) 8479 continue; 8480 8481 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 8482 ObjectClassification, 8483 Args, NumArgs, CandidateSet, 8484 /*SuppressUserConversions=*/false); 8485 } else { 8486 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 8487 I.getPair(), ActingDC, TemplateArgs, 8488 ObjectType, ObjectClassification, 8489 Args, NumArgs, CandidateSet, 8490 /*SuppressUsedConversions=*/false); 8491 } 8492 } 8493 8494 DeclarationName DeclName = UnresExpr->getMemberName(); 8495 8496 OverloadCandidateSet::iterator Best; 8497 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 8498 Best)) { 8499 case OR_Success: 8500 Method = cast<CXXMethodDecl>(Best->Function); 8501 MarkDeclarationReferenced(UnresExpr->getMemberLoc(), Method); 8502 FoundDecl = Best->FoundDecl; 8503 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 8504 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 8505 break; 8506 8507 case OR_No_Viable_Function: 8508 Diag(UnresExpr->getMemberLoc(), 8509 diag::err_ovl_no_viable_member_function_in_call) 8510 << DeclName << MemExprE->getSourceRange(); 8511 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8512 // FIXME: Leaking incoming expressions! 8513 return ExprError(); 8514 8515 case OR_Ambiguous: 8516 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 8517 << DeclName << MemExprE->getSourceRange(); 8518 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8519 // FIXME: Leaking incoming expressions! 8520 return ExprError(); 8521 8522 case OR_Deleted: 8523 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 8524 << Best->Function->isDeleted() 8525 << DeclName 8526 << getDeletedOrUnavailableSuffix(Best->Function) 8527 << MemExprE->getSourceRange(); 8528 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8529 // FIXME: Leaking incoming expressions! 8530 return ExprError(); 8531 } 8532 8533 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 8534 8535 // If overload resolution picked a static member, build a 8536 // non-member call based on that function. 8537 if (Method->isStatic()) { 8538 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 8539 Args, NumArgs, RParenLoc); 8540 } 8541 8542 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 8543 } 8544 8545 QualType ResultType = Method->getResultType(); 8546 ExprValueKind VK = Expr::getValueKindForType(ResultType); 8547 ResultType = ResultType.getNonLValueExprType(Context); 8548 8549 assert(Method && "Member call to something that isn't a method?"); 8550 CXXMemberCallExpr *TheCall = 8551 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 8552 ResultType, VK, RParenLoc); 8553 8554 // Check for a valid return type. 8555 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 8556 TheCall, Method)) 8557 return ExprError(); 8558 8559 // Convert the object argument (for a non-static member function call). 8560 // We only need to do this if there was actually an overload; otherwise 8561 // it was done at lookup. 8562 Expr *ObjectArg = MemExpr->getBase(); 8563 if (!Method->isStatic() && 8564 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 8565 FoundDecl, Method)) 8566 return ExprError(); 8567 MemExpr->setBase(ObjectArg); 8568 8569 // Convert the rest of the arguments 8570 const FunctionProtoType *Proto = 8571 Method->getType()->getAs<FunctionProtoType>(); 8572 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 8573 RParenLoc)) 8574 return ExprError(); 8575 8576 if (CheckFunctionCall(Method, TheCall)) 8577 return ExprError(); 8578 8579 return MaybeBindToTemporary(TheCall); 8580} 8581 8582/// BuildCallToObjectOfClassType - Build a call to an object of class 8583/// type (C++ [over.call.object]), which can end up invoking an 8584/// overloaded function call operator (@c operator()) or performing a 8585/// user-defined conversion on the object argument. 8586ExprResult 8587Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 8588 SourceLocation LParenLoc, 8589 Expr **Args, unsigned NumArgs, 8590 SourceLocation RParenLoc) { 8591 if (Object->getObjectKind() == OK_ObjCProperty) 8592 ConvertPropertyForRValue(Object); 8593 8594 assert(Object->getType()->isRecordType() && "Requires object type argument"); 8595 const RecordType *Record = Object->getType()->getAs<RecordType>(); 8596 8597 // C++ [over.call.object]p1: 8598 // If the primary-expression E in the function call syntax 8599 // evaluates to a class object of type "cv T", then the set of 8600 // candidate functions includes at least the function call 8601 // operators of T. The function call operators of T are obtained by 8602 // ordinary lookup of the name operator() in the context of 8603 // (E).operator(). 8604 OverloadCandidateSet CandidateSet(LParenLoc); 8605 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 8606 8607 if (RequireCompleteType(LParenLoc, Object->getType(), 8608 PDiag(diag::err_incomplete_object_call) 8609 << Object->getSourceRange())) 8610 return true; 8611 8612 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 8613 LookupQualifiedName(R, Record->getDecl()); 8614 R.suppressDiagnostics(); 8615 8616 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 8617 Oper != OperEnd; ++Oper) { 8618 AddMethodCandidate(Oper.getPair(), Object->getType(), 8619 Object->Classify(Context), Args, NumArgs, CandidateSet, 8620 /*SuppressUserConversions=*/ false); 8621 } 8622 8623 // C++ [over.call.object]p2: 8624 // In addition, for each conversion function declared in T of the 8625 // form 8626 // 8627 // operator conversion-type-id () cv-qualifier; 8628 // 8629 // where cv-qualifier is the same cv-qualification as, or a 8630 // greater cv-qualification than, cv, and where conversion-type-id 8631 // denotes the type "pointer to function of (P1,...,Pn) returning 8632 // R", or the type "reference to pointer to function of 8633 // (P1,...,Pn) returning R", or the type "reference to function 8634 // of (P1,...,Pn) returning R", a surrogate call function [...] 8635 // is also considered as a candidate function. Similarly, 8636 // surrogate call functions are added to the set of candidate 8637 // functions for each conversion function declared in an 8638 // accessible base class provided the function is not hidden 8639 // within T by another intervening declaration. 8640 const UnresolvedSetImpl *Conversions 8641 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 8642 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 8643 E = Conversions->end(); I != E; ++I) { 8644 NamedDecl *D = *I; 8645 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 8646 if (isa<UsingShadowDecl>(D)) 8647 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 8648 8649 // Skip over templated conversion functions; they aren't 8650 // surrogates. 8651 if (isa<FunctionTemplateDecl>(D)) 8652 continue; 8653 8654 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 8655 8656 // Strip the reference type (if any) and then the pointer type (if 8657 // any) to get down to what might be a function type. 8658 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 8659 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 8660 ConvType = ConvPtrType->getPointeeType(); 8661 8662 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 8663 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 8664 Object, Args, NumArgs, CandidateSet); 8665 } 8666 8667 // Perform overload resolution. 8668 OverloadCandidateSet::iterator Best; 8669 switch (CandidateSet.BestViableFunction(*this, Object->getLocStart(), 8670 Best)) { 8671 case OR_Success: 8672 // Overload resolution succeeded; we'll build the appropriate call 8673 // below. 8674 break; 8675 8676 case OR_No_Viable_Function: 8677 if (CandidateSet.empty()) 8678 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 8679 << Object->getType() << /*call*/ 1 8680 << Object->getSourceRange(); 8681 else 8682 Diag(Object->getSourceRange().getBegin(), 8683 diag::err_ovl_no_viable_object_call) 8684 << Object->getType() << Object->getSourceRange(); 8685 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8686 break; 8687 8688 case OR_Ambiguous: 8689 Diag(Object->getSourceRange().getBegin(), 8690 diag::err_ovl_ambiguous_object_call) 8691 << Object->getType() << Object->getSourceRange(); 8692 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 8693 break; 8694 8695 case OR_Deleted: 8696 Diag(Object->getSourceRange().getBegin(), 8697 diag::err_ovl_deleted_object_call) 8698 << Best->Function->isDeleted() 8699 << Object->getType() 8700 << getDeletedOrUnavailableSuffix(Best->Function) 8701 << Object->getSourceRange(); 8702 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8703 break; 8704 } 8705 8706 if (Best == CandidateSet.end()) 8707 return true; 8708 8709 if (Best->Function == 0) { 8710 // Since there is no function declaration, this is one of the 8711 // surrogate candidates. Dig out the conversion function. 8712 CXXConversionDecl *Conv 8713 = cast<CXXConversionDecl>( 8714 Best->Conversions[0].UserDefined.ConversionFunction); 8715 8716 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 8717 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 8718 8719 // We selected one of the surrogate functions that converts the 8720 // object parameter to a function pointer. Perform the conversion 8721 // on the object argument, then let ActOnCallExpr finish the job. 8722 8723 // Create an implicit member expr to refer to the conversion operator. 8724 // and then call it. 8725 ExprResult Call = BuildCXXMemberCallExpr(Object, Best->FoundDecl, Conv); 8726 if (Call.isInvalid()) 8727 return ExprError(); 8728 8729 return ActOnCallExpr(S, Call.get(), LParenLoc, MultiExprArg(Args, NumArgs), 8730 RParenLoc); 8731 } 8732 8733 MarkDeclarationReferenced(LParenLoc, Best->Function); 8734 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 8735 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 8736 8737 // We found an overloaded operator(). Build a CXXOperatorCallExpr 8738 // that calls this method, using Object for the implicit object 8739 // parameter and passing along the remaining arguments. 8740 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 8741 const FunctionProtoType *Proto = 8742 Method->getType()->getAs<FunctionProtoType>(); 8743 8744 unsigned NumArgsInProto = Proto->getNumArgs(); 8745 unsigned NumArgsToCheck = NumArgs; 8746 8747 // Build the full argument list for the method call (the 8748 // implicit object parameter is placed at the beginning of the 8749 // list). 8750 Expr **MethodArgs; 8751 if (NumArgs < NumArgsInProto) { 8752 NumArgsToCheck = NumArgsInProto; 8753 MethodArgs = new Expr*[NumArgsInProto + 1]; 8754 } else { 8755 MethodArgs = new Expr*[NumArgs + 1]; 8756 } 8757 MethodArgs[0] = Object; 8758 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 8759 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 8760 8761 Expr *NewFn = CreateFunctionRefExpr(*this, Method); 8762 8763 // Once we've built TheCall, all of the expressions are properly 8764 // owned. 8765 QualType ResultTy = Method->getResultType(); 8766 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8767 ResultTy = ResultTy.getNonLValueExprType(Context); 8768 8769 CXXOperatorCallExpr *TheCall = 8770 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 8771 MethodArgs, NumArgs + 1, 8772 ResultTy, VK, RParenLoc); 8773 delete [] MethodArgs; 8774 8775 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 8776 Method)) 8777 return true; 8778 8779 // We may have default arguments. If so, we need to allocate more 8780 // slots in the call for them. 8781 if (NumArgs < NumArgsInProto) 8782 TheCall->setNumArgs(Context, NumArgsInProto + 1); 8783 else if (NumArgs > NumArgsInProto) 8784 NumArgsToCheck = NumArgsInProto; 8785 8786 bool IsError = false; 8787 8788 // Initialize the implicit object parameter. 8789 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 8790 Best->FoundDecl, Method); 8791 TheCall->setArg(0, Object); 8792 8793 8794 // Check the argument types. 8795 for (unsigned i = 0; i != NumArgsToCheck; i++) { 8796 Expr *Arg; 8797 if (i < NumArgs) { 8798 Arg = Args[i]; 8799 8800 // Pass the argument. 8801 8802 ExprResult InputInit 8803 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8804 Context, 8805 Method->getParamDecl(i)), 8806 SourceLocation(), Arg); 8807 8808 IsError |= InputInit.isInvalid(); 8809 Arg = InputInit.takeAs<Expr>(); 8810 } else { 8811 ExprResult DefArg 8812 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 8813 if (DefArg.isInvalid()) { 8814 IsError = true; 8815 break; 8816 } 8817 8818 Arg = DefArg.takeAs<Expr>(); 8819 } 8820 8821 TheCall->setArg(i + 1, Arg); 8822 } 8823 8824 // If this is a variadic call, handle args passed through "...". 8825 if (Proto->isVariadic()) { 8826 // Promote the arguments (C99 6.5.2.2p7). 8827 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 8828 Expr *Arg = Args[i]; 8829 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 8830 TheCall->setArg(i + 1, Arg); 8831 } 8832 } 8833 8834 if (IsError) return true; 8835 8836 if (CheckFunctionCall(Method, TheCall)) 8837 return true; 8838 8839 return MaybeBindToTemporary(TheCall); 8840} 8841 8842/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 8843/// (if one exists), where @c Base is an expression of class type and 8844/// @c Member is the name of the member we're trying to find. 8845ExprResult 8846Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 8847 assert(Base->getType()->isRecordType() && 8848 "left-hand side must have class type"); 8849 8850 if (Base->getObjectKind() == OK_ObjCProperty) 8851 ConvertPropertyForRValue(Base); 8852 8853 SourceLocation Loc = Base->getExprLoc(); 8854 8855 // C++ [over.ref]p1: 8856 // 8857 // [...] An expression x->m is interpreted as (x.operator->())->m 8858 // for a class object x of type T if T::operator->() exists and if 8859 // the operator is selected as the best match function by the 8860 // overload resolution mechanism (13.3). 8861 DeclarationName OpName = 8862 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 8863 OverloadCandidateSet CandidateSet(Loc); 8864 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 8865 8866 if (RequireCompleteType(Loc, Base->getType(), 8867 PDiag(diag::err_typecheck_incomplete_tag) 8868 << Base->getSourceRange())) 8869 return ExprError(); 8870 8871 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 8872 LookupQualifiedName(R, BaseRecord->getDecl()); 8873 R.suppressDiagnostics(); 8874 8875 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 8876 Oper != OperEnd; ++Oper) { 8877 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 8878 0, 0, CandidateSet, /*SuppressUserConversions=*/false); 8879 } 8880 8881 // Perform overload resolution. 8882 OverloadCandidateSet::iterator Best; 8883 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8884 case OR_Success: 8885 // Overload resolution succeeded; we'll build the call below. 8886 break; 8887 8888 case OR_No_Viable_Function: 8889 if (CandidateSet.empty()) 8890 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 8891 << Base->getType() << Base->getSourceRange(); 8892 else 8893 Diag(OpLoc, diag::err_ovl_no_viable_oper) 8894 << "operator->" << Base->getSourceRange(); 8895 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 8896 return ExprError(); 8897 8898 case OR_Ambiguous: 8899 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 8900 << "->" << Base->getType() << Base->getSourceRange(); 8901 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, &Base, 1); 8902 return ExprError(); 8903 8904 case OR_Deleted: 8905 Diag(OpLoc, diag::err_ovl_deleted_oper) 8906 << Best->Function->isDeleted() 8907 << "->" 8908 << getDeletedOrUnavailableSuffix(Best->Function) 8909 << Base->getSourceRange(); 8910 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 8911 return ExprError(); 8912 } 8913 8914 MarkDeclarationReferenced(OpLoc, Best->Function); 8915 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 8916 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 8917 8918 // Convert the object parameter. 8919 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 8920 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 8921 Best->FoundDecl, Method)) 8922 return ExprError(); 8923 8924 // Build the operator call. 8925 Expr *FnExpr = CreateFunctionRefExpr(*this, Method); 8926 8927 QualType ResultTy = Method->getResultType(); 8928 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8929 ResultTy = ResultTy.getNonLValueExprType(Context); 8930 CXXOperatorCallExpr *TheCall = 8931 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 8932 &Base, 1, ResultTy, VK, OpLoc); 8933 8934 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 8935 Method)) 8936 return ExprError(); 8937 8938 return MaybeBindToTemporary(TheCall); 8939} 8940 8941/// FixOverloadedFunctionReference - E is an expression that refers to 8942/// a C++ overloaded function (possibly with some parentheses and 8943/// perhaps a '&' around it). We have resolved the overloaded function 8944/// to the function declaration Fn, so patch up the expression E to 8945/// refer (possibly indirectly) to Fn. Returns the new expr. 8946Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 8947 FunctionDecl *Fn) { 8948 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 8949 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 8950 Found, Fn); 8951 if (SubExpr == PE->getSubExpr()) 8952 return PE; 8953 8954 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 8955 } 8956 8957 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 8958 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 8959 Found, Fn); 8960 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 8961 SubExpr->getType()) && 8962 "Implicit cast type cannot be determined from overload"); 8963 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 8964 if (SubExpr == ICE->getSubExpr()) 8965 return ICE; 8966 8967 return ImplicitCastExpr::Create(Context, ICE->getType(), 8968 ICE->getCastKind(), 8969 SubExpr, 0, 8970 ICE->getValueKind()); 8971 } 8972 8973 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 8974 assert(UnOp->getOpcode() == UO_AddrOf && 8975 "Can only take the address of an overloaded function"); 8976 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 8977 if (Method->isStatic()) { 8978 // Do nothing: static member functions aren't any different 8979 // from non-member functions. 8980 } else { 8981 // Fix the sub expression, which really has to be an 8982 // UnresolvedLookupExpr holding an overloaded member function 8983 // or template. 8984 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 8985 Found, Fn); 8986 if (SubExpr == UnOp->getSubExpr()) 8987 return UnOp; 8988 8989 assert(isa<DeclRefExpr>(SubExpr) 8990 && "fixed to something other than a decl ref"); 8991 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 8992 && "fixed to a member ref with no nested name qualifier"); 8993 8994 // We have taken the address of a pointer to member 8995 // function. Perform the computation here so that we get the 8996 // appropriate pointer to member type. 8997 QualType ClassType 8998 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 8999 QualType MemPtrType 9000 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 9001 9002 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 9003 VK_RValue, OK_Ordinary, 9004 UnOp->getOperatorLoc()); 9005 } 9006 } 9007 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 9008 Found, Fn); 9009 if (SubExpr == UnOp->getSubExpr()) 9010 return UnOp; 9011 9012 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 9013 Context.getPointerType(SubExpr->getType()), 9014 VK_RValue, OK_Ordinary, 9015 UnOp->getOperatorLoc()); 9016 } 9017 9018 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 9019 // FIXME: avoid copy. 9020 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 9021 if (ULE->hasExplicitTemplateArgs()) { 9022 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 9023 TemplateArgs = &TemplateArgsBuffer; 9024 } 9025 9026 return DeclRefExpr::Create(Context, 9027 ULE->getQualifierLoc(), 9028 Fn, 9029 ULE->getNameLoc(), 9030 Fn->getType(), 9031 VK_LValue, 9032 TemplateArgs); 9033 } 9034 9035 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 9036 // FIXME: avoid copy. 9037 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 9038 if (MemExpr->hasExplicitTemplateArgs()) { 9039 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 9040 TemplateArgs = &TemplateArgsBuffer; 9041 } 9042 9043 Expr *Base; 9044 9045 // If we're filling in a static method where we used to have an 9046 // implicit member access, rewrite to a simple decl ref. 9047 if (MemExpr->isImplicitAccess()) { 9048 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 9049 return DeclRefExpr::Create(Context, 9050 MemExpr->getQualifierLoc(), 9051 Fn, 9052 MemExpr->getMemberLoc(), 9053 Fn->getType(), 9054 VK_LValue, 9055 TemplateArgs); 9056 } else { 9057 SourceLocation Loc = MemExpr->getMemberLoc(); 9058 if (MemExpr->getQualifier()) 9059 Loc = MemExpr->getQualifierLoc().getBeginLoc(); 9060 Base = new (Context) CXXThisExpr(Loc, 9061 MemExpr->getBaseType(), 9062 /*isImplicit=*/true); 9063 } 9064 } else 9065 Base = MemExpr->getBase(); 9066 9067 return MemberExpr::Create(Context, Base, 9068 MemExpr->isArrow(), 9069 MemExpr->getQualifierLoc(), 9070 Fn, 9071 Found, 9072 MemExpr->getMemberNameInfo(), 9073 TemplateArgs, 9074 Fn->getType(), 9075 cast<CXXMethodDecl>(Fn)->isStatic() 9076 ? VK_LValue : VK_RValue, 9077 OK_Ordinary); 9078 } 9079 9080 llvm_unreachable("Invalid reference to overloaded function"); 9081 return E; 9082} 9083 9084ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 9085 DeclAccessPair Found, 9086 FunctionDecl *Fn) { 9087 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 9088} 9089 9090} // end namespace clang 9091