SemaOverload.cpp revision d97f558f48865aa96e7bdf9c1c9315790c3d77c9
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 1064 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 1065 if (!Method->isStatic()) { 1066 const Type *ClassType 1067 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1068 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1069 } 1070 } 1071 1072 // If the "from" expression takes the address of the overloaded 1073 // function, update the type of the resulting expression accordingly. 1074 if (FromType->getAs<FunctionType>()) 1075 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens())) 1076 if (UnOp->getOpcode() == UO_AddrOf) 1077 FromType = S.Context.getPointerType(FromType); 1078 1079 // Check that we've computed the proper type after overload resolution. 1080 assert(S.Context.hasSameType(FromType, 1081 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1082 } else { 1083 return false; 1084 } 1085 } 1086 // Lvalue-to-rvalue conversion (C++ 4.1): 1087 // An lvalue (3.10) of a non-function, non-array type T can be 1088 // converted to an rvalue. 1089 bool argIsLValue = From->isLValue(); 1090 if (argIsLValue && 1091 !FromType->isFunctionType() && !FromType->isArrayType() && 1092 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1093 SCS.First = ICK_Lvalue_To_Rvalue; 1094 1095 // If T is a non-class type, the type of the rvalue is the 1096 // cv-unqualified version of T. Otherwise, the type of the rvalue 1097 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1098 // just strip the qualifiers because they don't matter. 1099 FromType = FromType.getUnqualifiedType(); 1100 } else if (FromType->isArrayType()) { 1101 // Array-to-pointer conversion (C++ 4.2) 1102 SCS.First = ICK_Array_To_Pointer; 1103 1104 // An lvalue or rvalue of type "array of N T" or "array of unknown 1105 // bound of T" can be converted to an rvalue of type "pointer to 1106 // T" (C++ 4.2p1). 1107 FromType = S.Context.getArrayDecayedType(FromType); 1108 1109 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1110 // This conversion is deprecated. (C++ D.4). 1111 SCS.DeprecatedStringLiteralToCharPtr = true; 1112 1113 // For the purpose of ranking in overload resolution 1114 // (13.3.3.1.1), this conversion is considered an 1115 // array-to-pointer conversion followed by a qualification 1116 // conversion (4.4). (C++ 4.2p2) 1117 SCS.Second = ICK_Identity; 1118 SCS.Third = ICK_Qualification; 1119 SCS.setAllToTypes(FromType); 1120 return true; 1121 } 1122 } else if (FromType->isFunctionType() && argIsLValue) { 1123 // Function-to-pointer conversion (C++ 4.3). 1124 SCS.First = ICK_Function_To_Pointer; 1125 1126 // An lvalue of function type T can be converted to an rvalue of 1127 // type "pointer to T." The result is a pointer to the 1128 // function. (C++ 4.3p1). 1129 FromType = S.Context.getPointerType(FromType); 1130 } else { 1131 // We don't require any conversions for the first step. 1132 SCS.First = ICK_Identity; 1133 } 1134 SCS.setToType(0, FromType); 1135 1136 // The second conversion can be an integral promotion, floating 1137 // point promotion, integral conversion, floating point conversion, 1138 // floating-integral conversion, pointer conversion, 1139 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1140 // For overloading in C, this can also be a "compatible-type" 1141 // conversion. 1142 bool IncompatibleObjC = false; 1143 ImplicitConversionKind SecondICK = ICK_Identity; 1144 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1145 // The unqualified versions of the types are the same: there's no 1146 // conversion to do. 1147 SCS.Second = ICK_Identity; 1148 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1149 // Integral promotion (C++ 4.5). 1150 SCS.Second = ICK_Integral_Promotion; 1151 FromType = ToType.getUnqualifiedType(); 1152 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1153 // Floating point promotion (C++ 4.6). 1154 SCS.Second = ICK_Floating_Promotion; 1155 FromType = ToType.getUnqualifiedType(); 1156 } else if (S.IsComplexPromotion(FromType, ToType)) { 1157 // Complex promotion (Clang extension) 1158 SCS.Second = ICK_Complex_Promotion; 1159 FromType = ToType.getUnqualifiedType(); 1160 } else if (ToType->isBooleanType() && 1161 (FromType->isArithmeticType() || 1162 FromType->isAnyPointerType() || 1163 FromType->isBlockPointerType() || 1164 FromType->isMemberPointerType() || 1165 FromType->isNullPtrType())) { 1166 // Boolean conversions (C++ 4.12). 1167 SCS.Second = ICK_Boolean_Conversion; 1168 FromType = S.Context.BoolTy; 1169 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1170 ToType->isIntegralType(S.Context)) { 1171 // Integral conversions (C++ 4.7). 1172 SCS.Second = ICK_Integral_Conversion; 1173 FromType = ToType.getUnqualifiedType(); 1174 } else if (FromType->isAnyComplexType() && ToType->isComplexType()) { 1175 // Complex conversions (C99 6.3.1.6) 1176 SCS.Second = ICK_Complex_Conversion; 1177 FromType = ToType.getUnqualifiedType(); 1178 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1179 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1180 // Complex-real conversions (C99 6.3.1.7) 1181 SCS.Second = ICK_Complex_Real; 1182 FromType = ToType.getUnqualifiedType(); 1183 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1184 // Floating point conversions (C++ 4.8). 1185 SCS.Second = ICK_Floating_Conversion; 1186 FromType = ToType.getUnqualifiedType(); 1187 } else if ((FromType->isRealFloatingType() && 1188 ToType->isIntegralType(S.Context)) || 1189 (FromType->isIntegralOrUnscopedEnumerationType() && 1190 ToType->isRealFloatingType())) { 1191 // Floating-integral conversions (C++ 4.9). 1192 SCS.Second = ICK_Floating_Integral; 1193 FromType = ToType.getUnqualifiedType(); 1194 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { 1195 SCS.Second = ICK_Block_Pointer_Conversion; 1196 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1197 FromType, IncompatibleObjC)) { 1198 // Pointer conversions (C++ 4.10). 1199 SCS.Second = ICK_Pointer_Conversion; 1200 SCS.IncompatibleObjC = IncompatibleObjC; 1201 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1202 InOverloadResolution, FromType)) { 1203 // Pointer to member conversions (4.11). 1204 SCS.Second = ICK_Pointer_Member; 1205 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1206 SCS.Second = SecondICK; 1207 FromType = ToType.getUnqualifiedType(); 1208 } else if (!S.getLangOptions().CPlusPlus && 1209 S.Context.typesAreCompatible(ToType, FromType)) { 1210 // Compatible conversions (Clang extension for C function overloading) 1211 SCS.Second = ICK_Compatible_Conversion; 1212 FromType = ToType.getUnqualifiedType(); 1213 } else if (IsNoReturnConversion(S.Context, FromType, ToType, FromType)) { 1214 // Treat a conversion that strips "noreturn" as an identity conversion. 1215 SCS.Second = ICK_NoReturn_Adjustment; 1216 } else if (IsTransparentUnionStandardConversion(S, From, ToType, 1217 InOverloadResolution, 1218 SCS, CStyle)) { 1219 SCS.Second = ICK_TransparentUnionConversion; 1220 FromType = ToType; 1221 } else { 1222 // No second conversion required. 1223 SCS.Second = ICK_Identity; 1224 } 1225 SCS.setToType(1, FromType); 1226 1227 QualType CanonFrom; 1228 QualType CanonTo; 1229 // The third conversion can be a qualification conversion (C++ 4p1). 1230 if (S.IsQualificationConversion(FromType, ToType, CStyle)) { 1231 SCS.Third = ICK_Qualification; 1232 FromType = ToType; 1233 CanonFrom = S.Context.getCanonicalType(FromType); 1234 CanonTo = S.Context.getCanonicalType(ToType); 1235 } else { 1236 // No conversion required 1237 SCS.Third = ICK_Identity; 1238 1239 // C++ [over.best.ics]p6: 1240 // [...] Any difference in top-level cv-qualification is 1241 // subsumed by the initialization itself and does not constitute 1242 // a conversion. [...] 1243 CanonFrom = S.Context.getCanonicalType(FromType); 1244 CanonTo = S.Context.getCanonicalType(ToType); 1245 if (CanonFrom.getLocalUnqualifiedType() 1246 == CanonTo.getLocalUnqualifiedType() && 1247 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1248 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1249 FromType = ToType; 1250 CanonFrom = CanonTo; 1251 } 1252 } 1253 SCS.setToType(2, FromType); 1254 1255 // If we have not converted the argument type to the parameter type, 1256 // this is a bad conversion sequence. 1257 if (CanonFrom != CanonTo) 1258 return false; 1259 1260 return true; 1261} 1262 1263static bool 1264IsTransparentUnionStandardConversion(Sema &S, Expr* From, 1265 QualType &ToType, 1266 bool InOverloadResolution, 1267 StandardConversionSequence &SCS, 1268 bool CStyle) { 1269 1270 const RecordType *UT = ToType->getAsUnionType(); 1271 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 1272 return false; 1273 // The field to initialize within the transparent union. 1274 RecordDecl *UD = UT->getDecl(); 1275 // It's compatible if the expression matches any of the fields. 1276 for (RecordDecl::field_iterator it = UD->field_begin(), 1277 itend = UD->field_end(); 1278 it != itend; ++it) { 1279 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, CStyle)) { 1280 ToType = it->getType(); 1281 return true; 1282 } 1283 } 1284 return false; 1285} 1286 1287/// IsIntegralPromotion - Determines whether the conversion from the 1288/// expression From (whose potentially-adjusted type is FromType) to 1289/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1290/// sets PromotedType to the promoted type. 1291bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1292 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1293 // All integers are built-in. 1294 if (!To) { 1295 return false; 1296 } 1297 1298 // An rvalue of type char, signed char, unsigned char, short int, or 1299 // unsigned short int can be converted to an rvalue of type int if 1300 // int can represent all the values of the source type; otherwise, 1301 // the source rvalue can be converted to an rvalue of type unsigned 1302 // int (C++ 4.5p1). 1303 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1304 !FromType->isEnumeralType()) { 1305 if (// We can promote any signed, promotable integer type to an int 1306 (FromType->isSignedIntegerType() || 1307 // We can promote any unsigned integer type whose size is 1308 // less than int to an int. 1309 (!FromType->isSignedIntegerType() && 1310 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1311 return To->getKind() == BuiltinType::Int; 1312 } 1313 1314 return To->getKind() == BuiltinType::UInt; 1315 } 1316 1317 // C++0x [conv.prom]p3: 1318 // A prvalue of an unscoped enumeration type whose underlying type is not 1319 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1320 // following types that can represent all the values of the enumeration 1321 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1322 // unsigned int, long int, unsigned long int, long long int, or unsigned 1323 // long long int. If none of the types in that list can represent all the 1324 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1325 // type can be converted to an rvalue a prvalue of the extended integer type 1326 // with lowest integer conversion rank (4.13) greater than the rank of long 1327 // long in which all the values of the enumeration can be represented. If 1328 // there are two such extended types, the signed one is chosen. 1329 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1330 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1331 // provided for a scoped enumeration. 1332 if (FromEnumType->getDecl()->isScoped()) 1333 return false; 1334 1335 // We have already pre-calculated the promotion type, so this is trivial. 1336 if (ToType->isIntegerType() && 1337 !RequireCompleteType(From->getLocStart(), FromType, PDiag())) 1338 return Context.hasSameUnqualifiedType(ToType, 1339 FromEnumType->getDecl()->getPromotionType()); 1340 } 1341 1342 // C++0x [conv.prom]p2: 1343 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1344 // to an rvalue a prvalue of the first of the following types that can 1345 // represent all the values of its underlying type: int, unsigned int, 1346 // long int, unsigned long int, long long int, or unsigned long long int. 1347 // If none of the types in that list can represent all the values of its 1348 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1349 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1350 // type. 1351 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1352 ToType->isIntegerType()) { 1353 // Determine whether the type we're converting from is signed or 1354 // unsigned. 1355 bool FromIsSigned; 1356 uint64_t FromSize = Context.getTypeSize(FromType); 1357 1358 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1359 FromIsSigned = true; 1360 1361 // The types we'll try to promote to, in the appropriate 1362 // order. Try each of these types. 1363 QualType PromoteTypes[6] = { 1364 Context.IntTy, Context.UnsignedIntTy, 1365 Context.LongTy, Context.UnsignedLongTy , 1366 Context.LongLongTy, Context.UnsignedLongLongTy 1367 }; 1368 for (int Idx = 0; Idx < 6; ++Idx) { 1369 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1370 if (FromSize < ToSize || 1371 (FromSize == ToSize && 1372 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1373 // We found the type that we can promote to. If this is the 1374 // type we wanted, we have a promotion. Otherwise, no 1375 // promotion. 1376 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1377 } 1378 } 1379 } 1380 1381 // An rvalue for an integral bit-field (9.6) can be converted to an 1382 // rvalue of type int if int can represent all the values of the 1383 // bit-field; otherwise, it can be converted to unsigned int if 1384 // unsigned int can represent all the values of the bit-field. If 1385 // the bit-field is larger yet, no integral promotion applies to 1386 // it. If the bit-field has an enumerated type, it is treated as any 1387 // other value of that type for promotion purposes (C++ 4.5p3). 1388 // FIXME: We should delay checking of bit-fields until we actually perform the 1389 // conversion. 1390 using llvm::APSInt; 1391 if (From) 1392 if (FieldDecl *MemberDecl = From->getBitField()) { 1393 APSInt BitWidth; 1394 if (FromType->isIntegralType(Context) && 1395 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1396 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1397 ToSize = Context.getTypeSize(ToType); 1398 1399 // Are we promoting to an int from a bitfield that fits in an int? 1400 if (BitWidth < ToSize || 1401 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1402 return To->getKind() == BuiltinType::Int; 1403 } 1404 1405 // Are we promoting to an unsigned int from an unsigned bitfield 1406 // that fits into an unsigned int? 1407 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1408 return To->getKind() == BuiltinType::UInt; 1409 } 1410 1411 return false; 1412 } 1413 } 1414 1415 // An rvalue of type bool can be converted to an rvalue of type int, 1416 // with false becoming zero and true becoming one (C++ 4.5p4). 1417 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1418 return true; 1419 } 1420 1421 return false; 1422} 1423 1424/// IsFloatingPointPromotion - Determines whether the conversion from 1425/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1426/// returns true and sets PromotedType to the promoted type. 1427bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1428 /// An rvalue of type float can be converted to an rvalue of type 1429 /// double. (C++ 4.6p1). 1430 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1431 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1432 if (FromBuiltin->getKind() == BuiltinType::Float && 1433 ToBuiltin->getKind() == BuiltinType::Double) 1434 return true; 1435 1436 // C99 6.3.1.5p1: 1437 // When a float is promoted to double or long double, or a 1438 // double is promoted to long double [...]. 1439 if (!getLangOptions().CPlusPlus && 1440 (FromBuiltin->getKind() == BuiltinType::Float || 1441 FromBuiltin->getKind() == BuiltinType::Double) && 1442 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1443 return true; 1444 } 1445 1446 return false; 1447} 1448 1449/// \brief Determine if a conversion is a complex promotion. 1450/// 1451/// A complex promotion is defined as a complex -> complex conversion 1452/// where the conversion between the underlying real types is a 1453/// floating-point or integral promotion. 1454bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1455 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1456 if (!FromComplex) 1457 return false; 1458 1459 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1460 if (!ToComplex) 1461 return false; 1462 1463 return IsFloatingPointPromotion(FromComplex->getElementType(), 1464 ToComplex->getElementType()) || 1465 IsIntegralPromotion(0, FromComplex->getElementType(), 1466 ToComplex->getElementType()); 1467} 1468 1469/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1470/// the pointer type FromPtr to a pointer to type ToPointee, with the 1471/// same type qualifiers as FromPtr has on its pointee type. ToType, 1472/// if non-empty, will be a pointer to ToType that may or may not have 1473/// the right set of qualifiers on its pointee. 1474static QualType 1475BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1476 QualType ToPointee, QualType ToType, 1477 ASTContext &Context) { 1478 assert((FromPtr->getTypeClass() == Type::Pointer || 1479 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1480 "Invalid similarly-qualified pointer type"); 1481 1482 /// \brief Conversions to 'id' subsume cv-qualifier conversions. 1483 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1484 return ToType.getUnqualifiedType(); 1485 1486 QualType CanonFromPointee 1487 = Context.getCanonicalType(FromPtr->getPointeeType()); 1488 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1489 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1490 1491 // Exact qualifier match -> return the pointer type we're converting to. 1492 if (CanonToPointee.getLocalQualifiers() == Quals) { 1493 // ToType is exactly what we need. Return it. 1494 if (!ToType.isNull()) 1495 return ToType.getUnqualifiedType(); 1496 1497 // Build a pointer to ToPointee. It has the right qualifiers 1498 // already. 1499 if (isa<ObjCObjectPointerType>(ToType)) 1500 return Context.getObjCObjectPointerType(ToPointee); 1501 return Context.getPointerType(ToPointee); 1502 } 1503 1504 // Just build a canonical type that has the right qualifiers. 1505 QualType QualifiedCanonToPointee 1506 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1507 1508 if (isa<ObjCObjectPointerType>(ToType)) 1509 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1510 return Context.getPointerType(QualifiedCanonToPointee); 1511} 1512 1513static bool isNullPointerConstantForConversion(Expr *Expr, 1514 bool InOverloadResolution, 1515 ASTContext &Context) { 1516 // Handle value-dependent integral null pointer constants correctly. 1517 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1518 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1519 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1520 return !InOverloadResolution; 1521 1522 return Expr->isNullPointerConstant(Context, 1523 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1524 : Expr::NPC_ValueDependentIsNull); 1525} 1526 1527/// IsPointerConversion - Determines whether the conversion of the 1528/// expression From, which has the (possibly adjusted) type FromType, 1529/// can be converted to the type ToType via a pointer conversion (C++ 1530/// 4.10). If so, returns true and places the converted type (that 1531/// might differ from ToType in its cv-qualifiers at some level) into 1532/// ConvertedType. 1533/// 1534/// This routine also supports conversions to and from block pointers 1535/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1536/// pointers to interfaces. FIXME: Once we've determined the 1537/// appropriate overloading rules for Objective-C, we may want to 1538/// split the Objective-C checks into a different routine; however, 1539/// GCC seems to consider all of these conversions to be pointer 1540/// conversions, so for now they live here. IncompatibleObjC will be 1541/// set if the conversion is an allowed Objective-C conversion that 1542/// should result in a warning. 1543bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1544 bool InOverloadResolution, 1545 QualType& ConvertedType, 1546 bool &IncompatibleObjC) { 1547 IncompatibleObjC = false; 1548 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 1549 IncompatibleObjC)) 1550 return true; 1551 1552 // Conversion from a null pointer constant to any Objective-C pointer type. 1553 if (ToType->isObjCObjectPointerType() && 1554 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1555 ConvertedType = ToType; 1556 return true; 1557 } 1558 1559 // Blocks: Block pointers can be converted to void*. 1560 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1561 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1562 ConvertedType = ToType; 1563 return true; 1564 } 1565 // Blocks: A null pointer constant can be converted to a block 1566 // pointer type. 1567 if (ToType->isBlockPointerType() && 1568 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1569 ConvertedType = ToType; 1570 return true; 1571 } 1572 1573 // If the left-hand-side is nullptr_t, the right side can be a null 1574 // pointer constant. 1575 if (ToType->isNullPtrType() && 1576 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1577 ConvertedType = ToType; 1578 return true; 1579 } 1580 1581 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1582 if (!ToTypePtr) 1583 return false; 1584 1585 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1586 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1587 ConvertedType = ToType; 1588 return true; 1589 } 1590 1591 // Beyond this point, both types need to be pointers 1592 // , including objective-c pointers. 1593 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1594 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1595 ConvertedType = BuildSimilarlyQualifiedPointerType( 1596 FromType->getAs<ObjCObjectPointerType>(), 1597 ToPointeeType, 1598 ToType, Context); 1599 return true; 1600 } 1601 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1602 if (!FromTypePtr) 1603 return false; 1604 1605 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1606 1607 // If the unqualified pointee types are the same, this can't be a 1608 // pointer conversion, so don't do all of the work below. 1609 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1610 return false; 1611 1612 // An rvalue of type "pointer to cv T," where T is an object type, 1613 // can be converted to an rvalue of type "pointer to cv void" (C++ 1614 // 4.10p2). 1615 if (FromPointeeType->isIncompleteOrObjectType() && 1616 ToPointeeType->isVoidType()) { 1617 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1618 ToPointeeType, 1619 ToType, Context); 1620 return true; 1621 } 1622 1623 // When we're overloading in C, we allow a special kind of pointer 1624 // conversion for compatible-but-not-identical pointee types. 1625 if (!getLangOptions().CPlusPlus && 1626 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1627 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1628 ToPointeeType, 1629 ToType, Context); 1630 return true; 1631 } 1632 1633 // C++ [conv.ptr]p3: 1634 // 1635 // An rvalue of type "pointer to cv D," where D is a class type, 1636 // can be converted to an rvalue of type "pointer to cv B," where 1637 // B is a base class (clause 10) of D. If B is an inaccessible 1638 // (clause 11) or ambiguous (10.2) base class of D, a program that 1639 // necessitates this conversion is ill-formed. The result of the 1640 // conversion is a pointer to the base class sub-object of the 1641 // derived class object. The null pointer value is converted to 1642 // the null pointer value of the destination type. 1643 // 1644 // Note that we do not check for ambiguity or inaccessibility 1645 // here. That is handled by CheckPointerConversion. 1646 if (getLangOptions().CPlusPlus && 1647 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1648 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1649 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1650 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1651 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1652 ToPointeeType, 1653 ToType, Context); 1654 return true; 1655 } 1656 1657 return false; 1658} 1659 1660/// isObjCPointerConversion - Determines whether this is an 1661/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1662/// with the same arguments and return values. 1663bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1664 QualType& ConvertedType, 1665 bool &IncompatibleObjC) { 1666 if (!getLangOptions().ObjC1) 1667 return false; 1668 1669 // First, we handle all conversions on ObjC object pointer types. 1670 const ObjCObjectPointerType* ToObjCPtr = 1671 ToType->getAs<ObjCObjectPointerType>(); 1672 const ObjCObjectPointerType *FromObjCPtr = 1673 FromType->getAs<ObjCObjectPointerType>(); 1674 1675 if (ToObjCPtr && FromObjCPtr) { 1676 // If the pointee types are the same (ignoring qualifications), 1677 // then this is not a pointer conversion. 1678 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 1679 FromObjCPtr->getPointeeType())) 1680 return false; 1681 1682 // Objective C++: We're able to convert between "id" or "Class" and a 1683 // pointer to any interface (in both directions). 1684 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1685 ConvertedType = ToType; 1686 return true; 1687 } 1688 // Conversions with Objective-C's id<...>. 1689 if ((FromObjCPtr->isObjCQualifiedIdType() || 1690 ToObjCPtr->isObjCQualifiedIdType()) && 1691 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1692 /*compare=*/false)) { 1693 ConvertedType = ToType; 1694 return true; 1695 } 1696 // Objective C++: We're able to convert from a pointer to an 1697 // interface to a pointer to a different interface. 1698 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1699 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1700 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1701 if (getLangOptions().CPlusPlus && LHS && RHS && 1702 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1703 FromObjCPtr->getPointeeType())) 1704 return false; 1705 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1706 ToObjCPtr->getPointeeType(), 1707 ToType, Context); 1708 return true; 1709 } 1710 1711 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1712 // Okay: this is some kind of implicit downcast of Objective-C 1713 // interfaces, which is permitted. However, we're going to 1714 // complain about it. 1715 IncompatibleObjC = true; 1716 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1717 ToObjCPtr->getPointeeType(), 1718 ToType, Context); 1719 return true; 1720 } 1721 } 1722 // Beyond this point, both types need to be C pointers or block pointers. 1723 QualType ToPointeeType; 1724 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1725 ToPointeeType = ToCPtr->getPointeeType(); 1726 else if (const BlockPointerType *ToBlockPtr = 1727 ToType->getAs<BlockPointerType>()) { 1728 // Objective C++: We're able to convert from a pointer to any object 1729 // to a block pointer type. 1730 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1731 ConvertedType = ToType; 1732 return true; 1733 } 1734 ToPointeeType = ToBlockPtr->getPointeeType(); 1735 } 1736 else if (FromType->getAs<BlockPointerType>() && 1737 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1738 // Objective C++: We're able to convert from a block pointer type to a 1739 // pointer to any object. 1740 ConvertedType = ToType; 1741 return true; 1742 } 1743 else 1744 return false; 1745 1746 QualType FromPointeeType; 1747 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1748 FromPointeeType = FromCPtr->getPointeeType(); 1749 else if (const BlockPointerType *FromBlockPtr = 1750 FromType->getAs<BlockPointerType>()) 1751 FromPointeeType = FromBlockPtr->getPointeeType(); 1752 else 1753 return false; 1754 1755 // If we have pointers to pointers, recursively check whether this 1756 // is an Objective-C conversion. 1757 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1758 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1759 IncompatibleObjC)) { 1760 // We always complain about this conversion. 1761 IncompatibleObjC = true; 1762 ConvertedType = Context.getPointerType(ConvertedType); 1763 return true; 1764 } 1765 // Allow conversion of pointee being objective-c pointer to another one; 1766 // as in I* to id. 1767 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1768 ToPointeeType->getAs<ObjCObjectPointerType>() && 1769 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1770 IncompatibleObjC)) { 1771 ConvertedType = Context.getPointerType(ConvertedType); 1772 return true; 1773 } 1774 1775 // If we have pointers to functions or blocks, check whether the only 1776 // differences in the argument and result types are in Objective-C 1777 // pointer conversions. If so, we permit the conversion (but 1778 // complain about it). 1779 const FunctionProtoType *FromFunctionType 1780 = FromPointeeType->getAs<FunctionProtoType>(); 1781 const FunctionProtoType *ToFunctionType 1782 = ToPointeeType->getAs<FunctionProtoType>(); 1783 if (FromFunctionType && ToFunctionType) { 1784 // If the function types are exactly the same, this isn't an 1785 // Objective-C pointer conversion. 1786 if (Context.getCanonicalType(FromPointeeType) 1787 == Context.getCanonicalType(ToPointeeType)) 1788 return false; 1789 1790 // Perform the quick checks that will tell us whether these 1791 // function types are obviously different. 1792 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1793 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1794 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1795 return false; 1796 1797 bool HasObjCConversion = false; 1798 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1799 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1800 // Okay, the types match exactly. Nothing to do. 1801 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1802 ToFunctionType->getResultType(), 1803 ConvertedType, IncompatibleObjC)) { 1804 // Okay, we have an Objective-C pointer conversion. 1805 HasObjCConversion = true; 1806 } else { 1807 // Function types are too different. Abort. 1808 return false; 1809 } 1810 1811 // Check argument types. 1812 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1813 ArgIdx != NumArgs; ++ArgIdx) { 1814 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1815 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1816 if (Context.getCanonicalType(FromArgType) 1817 == Context.getCanonicalType(ToArgType)) { 1818 // Okay, the types match exactly. Nothing to do. 1819 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1820 ConvertedType, IncompatibleObjC)) { 1821 // Okay, we have an Objective-C pointer conversion. 1822 HasObjCConversion = true; 1823 } else { 1824 // Argument types are too different. Abort. 1825 return false; 1826 } 1827 } 1828 1829 if (HasObjCConversion) { 1830 // We had an Objective-C conversion. Allow this pointer 1831 // conversion, but complain about it. 1832 ConvertedType = ToType; 1833 IncompatibleObjC = true; 1834 return true; 1835 } 1836 } 1837 1838 return false; 1839} 1840 1841bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, 1842 QualType& ConvertedType) { 1843 QualType ToPointeeType; 1844 if (const BlockPointerType *ToBlockPtr = 1845 ToType->getAs<BlockPointerType>()) 1846 ToPointeeType = ToBlockPtr->getPointeeType(); 1847 else 1848 return false; 1849 1850 QualType FromPointeeType; 1851 if (const BlockPointerType *FromBlockPtr = 1852 FromType->getAs<BlockPointerType>()) 1853 FromPointeeType = FromBlockPtr->getPointeeType(); 1854 else 1855 return false; 1856 // We have pointer to blocks, check whether the only 1857 // differences in the argument and result types are in Objective-C 1858 // pointer conversions. If so, we permit the conversion. 1859 1860 const FunctionProtoType *FromFunctionType 1861 = FromPointeeType->getAs<FunctionProtoType>(); 1862 const FunctionProtoType *ToFunctionType 1863 = ToPointeeType->getAs<FunctionProtoType>(); 1864 1865 if (!FromFunctionType || !ToFunctionType) 1866 return false; 1867 1868 if (Context.hasSameType(FromPointeeType, ToPointeeType)) 1869 return true; 1870 1871 // Perform the quick checks that will tell us whether these 1872 // function types are obviously different. 1873 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1874 FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) 1875 return false; 1876 1877 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); 1878 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); 1879 if (FromEInfo != ToEInfo) 1880 return false; 1881 1882 bool IncompatibleObjC = false; 1883 if (Context.hasSameType(FromFunctionType->getResultType(), 1884 ToFunctionType->getResultType())) { 1885 // Okay, the types match exactly. Nothing to do. 1886 } else { 1887 QualType RHS = FromFunctionType->getResultType(); 1888 QualType LHS = ToFunctionType->getResultType(); 1889 if ((!getLangOptions().CPlusPlus || !RHS->isRecordType()) && 1890 !RHS.hasQualifiers() && LHS.hasQualifiers()) 1891 LHS = LHS.getUnqualifiedType(); 1892 1893 if (Context.hasSameType(RHS,LHS)) { 1894 // OK exact match. 1895 } else if (isObjCPointerConversion(RHS, LHS, 1896 ConvertedType, IncompatibleObjC)) { 1897 if (IncompatibleObjC) 1898 return false; 1899 // Okay, we have an Objective-C pointer conversion. 1900 } 1901 else 1902 return false; 1903 } 1904 1905 // Check argument types. 1906 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1907 ArgIdx != NumArgs; ++ArgIdx) { 1908 IncompatibleObjC = false; 1909 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1910 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1911 if (Context.hasSameType(FromArgType, ToArgType)) { 1912 // Okay, the types match exactly. Nothing to do. 1913 } else if (isObjCPointerConversion(ToArgType, FromArgType, 1914 ConvertedType, IncompatibleObjC)) { 1915 if (IncompatibleObjC) 1916 return false; 1917 // Okay, we have an Objective-C pointer conversion. 1918 } else 1919 // Argument types are too different. Abort. 1920 return false; 1921 } 1922 ConvertedType = ToType; 1923 return true; 1924} 1925 1926/// FunctionArgTypesAreEqual - This routine checks two function proto types 1927/// for equlity of their argument types. Caller has already checked that 1928/// they have same number of arguments. This routine assumes that Objective-C 1929/// pointer types which only differ in their protocol qualifiers are equal. 1930bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, 1931 const FunctionProtoType *NewType) { 1932 if (!getLangOptions().ObjC1) 1933 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1934 NewType->arg_type_begin()); 1935 1936 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1937 N = NewType->arg_type_begin(), 1938 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1939 QualType ToType = (*O); 1940 QualType FromType = (*N); 1941 if (ToType != FromType) { 1942 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1943 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1944 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1945 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1946 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1947 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1948 continue; 1949 } 1950 else if (const ObjCObjectPointerType *PTTo = 1951 ToType->getAs<ObjCObjectPointerType>()) { 1952 if (const ObjCObjectPointerType *PTFr = 1953 FromType->getAs<ObjCObjectPointerType>()) 1954 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1955 continue; 1956 } 1957 return false; 1958 } 1959 } 1960 return true; 1961} 1962 1963/// CheckPointerConversion - Check the pointer conversion from the 1964/// expression From to the type ToType. This routine checks for 1965/// ambiguous or inaccessible derived-to-base pointer 1966/// conversions for which IsPointerConversion has already returned 1967/// true. It returns true and produces a diagnostic if there was an 1968/// error, or returns false otherwise. 1969bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1970 CastKind &Kind, 1971 CXXCastPath& BasePath, 1972 bool IgnoreBaseAccess) { 1973 QualType FromType = From->getType(); 1974 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 1975 1976 Kind = CK_BitCast; 1977 1978 if (CXXBoolLiteralExpr* LitBool 1979 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1980 if (!IsCStyleOrFunctionalCast && LitBool->getValue() == false) 1981 DiagRuntimeBehavior(LitBool->getExprLoc(), From, 1982 PDiag(diag::warn_init_pointer_from_false) << ToType); 1983 1984 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1985 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1986 QualType FromPointeeType = FromPtrType->getPointeeType(), 1987 ToPointeeType = ToPtrType->getPointeeType(); 1988 1989 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1990 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1991 // We must have a derived-to-base conversion. Check an 1992 // ambiguous or inaccessible conversion. 1993 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1994 From->getExprLoc(), 1995 From->getSourceRange(), &BasePath, 1996 IgnoreBaseAccess)) 1997 return true; 1998 1999 // The conversion was successful. 2000 Kind = CK_DerivedToBase; 2001 } 2002 } 2003 if (const ObjCObjectPointerType *FromPtrType = 2004 FromType->getAs<ObjCObjectPointerType>()) { 2005 if (const ObjCObjectPointerType *ToPtrType = 2006 ToType->getAs<ObjCObjectPointerType>()) { 2007 // Objective-C++ conversions are always okay. 2008 // FIXME: We should have a different class of conversions for the 2009 // Objective-C++ implicit conversions. 2010 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 2011 return false; 2012 } 2013 } 2014 2015 // We shouldn't fall into this case unless it's valid for other 2016 // reasons. 2017 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 2018 Kind = CK_NullToPointer; 2019 2020 return false; 2021} 2022 2023/// IsMemberPointerConversion - Determines whether the conversion of the 2024/// expression From, which has the (possibly adjusted) type FromType, can be 2025/// converted to the type ToType via a member pointer conversion (C++ 4.11). 2026/// If so, returns true and places the converted type (that might differ from 2027/// ToType in its cv-qualifiers at some level) into ConvertedType. 2028bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 2029 QualType ToType, 2030 bool InOverloadResolution, 2031 QualType &ConvertedType) { 2032 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 2033 if (!ToTypePtr) 2034 return false; 2035 2036 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 2037 if (From->isNullPointerConstant(Context, 2038 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 2039 : Expr::NPC_ValueDependentIsNull)) { 2040 ConvertedType = ToType; 2041 return true; 2042 } 2043 2044 // Otherwise, both types have to be member pointers. 2045 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 2046 if (!FromTypePtr) 2047 return false; 2048 2049 // A pointer to member of B can be converted to a pointer to member of D, 2050 // where D is derived from B (C++ 4.11p2). 2051 QualType FromClass(FromTypePtr->getClass(), 0); 2052 QualType ToClass(ToTypePtr->getClass(), 0); 2053 2054 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && 2055 !RequireCompleteType(From->getLocStart(), ToClass, PDiag()) && 2056 IsDerivedFrom(ToClass, FromClass)) { 2057 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 2058 ToClass.getTypePtr()); 2059 return true; 2060 } 2061 2062 return false; 2063} 2064 2065/// CheckMemberPointerConversion - Check the member pointer conversion from the 2066/// expression From to the type ToType. This routine checks for ambiguous or 2067/// virtual or inaccessible base-to-derived member pointer conversions 2068/// for which IsMemberPointerConversion has already returned true. It returns 2069/// true and produces a diagnostic if there was an error, or returns false 2070/// otherwise. 2071bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 2072 CastKind &Kind, 2073 CXXCastPath &BasePath, 2074 bool IgnoreBaseAccess) { 2075 QualType FromType = From->getType(); 2076 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 2077 if (!FromPtrType) { 2078 // This must be a null pointer to member pointer conversion 2079 assert(From->isNullPointerConstant(Context, 2080 Expr::NPC_ValueDependentIsNull) && 2081 "Expr must be null pointer constant!"); 2082 Kind = CK_NullToMemberPointer; 2083 return false; 2084 } 2085 2086 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 2087 assert(ToPtrType && "No member pointer cast has a target type " 2088 "that is not a member pointer."); 2089 2090 QualType FromClass = QualType(FromPtrType->getClass(), 0); 2091 QualType ToClass = QualType(ToPtrType->getClass(), 0); 2092 2093 // FIXME: What about dependent types? 2094 assert(FromClass->isRecordType() && "Pointer into non-class."); 2095 assert(ToClass->isRecordType() && "Pointer into non-class."); 2096 2097 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 2098 /*DetectVirtual=*/true); 2099 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 2100 assert(DerivationOkay && 2101 "Should not have been called if derivation isn't OK."); 2102 (void)DerivationOkay; 2103 2104 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 2105 getUnqualifiedType())) { 2106 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 2107 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 2108 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 2109 return true; 2110 } 2111 2112 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 2113 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 2114 << FromClass << ToClass << QualType(VBase, 0) 2115 << From->getSourceRange(); 2116 return true; 2117 } 2118 2119 if (!IgnoreBaseAccess) 2120 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 2121 Paths.front(), 2122 diag::err_downcast_from_inaccessible_base); 2123 2124 // Must be a base to derived member conversion. 2125 BuildBasePathArray(Paths, BasePath); 2126 Kind = CK_BaseToDerivedMemberPointer; 2127 return false; 2128} 2129 2130/// IsQualificationConversion - Determines whether the conversion from 2131/// an rvalue of type FromType to ToType is a qualification conversion 2132/// (C++ 4.4). 2133bool 2134Sema::IsQualificationConversion(QualType FromType, QualType ToType, 2135 bool CStyle) { 2136 FromType = Context.getCanonicalType(FromType); 2137 ToType = Context.getCanonicalType(ToType); 2138 2139 // If FromType and ToType are the same type, this is not a 2140 // qualification conversion. 2141 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 2142 return false; 2143 2144 // (C++ 4.4p4): 2145 // A conversion can add cv-qualifiers at levels other than the first 2146 // in multi-level pointers, subject to the following rules: [...] 2147 bool PreviousToQualsIncludeConst = true; 2148 bool UnwrappedAnyPointer = false; 2149 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 2150 // Within each iteration of the loop, we check the qualifiers to 2151 // determine if this still looks like a qualification 2152 // conversion. Then, if all is well, we unwrap one more level of 2153 // pointers or pointers-to-members and do it all again 2154 // until there are no more pointers or pointers-to-members left to 2155 // unwrap. 2156 UnwrappedAnyPointer = true; 2157 2158 // -- for every j > 0, if const is in cv 1,j then const is in cv 2159 // 2,j, and similarly for volatile. 2160 if (!CStyle && !ToType.isAtLeastAsQualifiedAs(FromType)) 2161 return false; 2162 2163 // -- if the cv 1,j and cv 2,j are different, then const is in 2164 // every cv for 0 < k < j. 2165 if (!CStyle && FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 2166 && !PreviousToQualsIncludeConst) 2167 return false; 2168 2169 // Keep track of whether all prior cv-qualifiers in the "to" type 2170 // include const. 2171 PreviousToQualsIncludeConst 2172 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 2173 } 2174 2175 // We are left with FromType and ToType being the pointee types 2176 // after unwrapping the original FromType and ToType the same number 2177 // of types. If we unwrapped any pointers, and if FromType and 2178 // ToType have the same unqualified type (since we checked 2179 // qualifiers above), then this is a qualification conversion. 2180 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2181} 2182 2183/// Determines whether there is a user-defined conversion sequence 2184/// (C++ [over.ics.user]) that converts expression From to the type 2185/// ToType. If such a conversion exists, User will contain the 2186/// user-defined conversion sequence that performs such a conversion 2187/// and this routine will return true. Otherwise, this routine returns 2188/// false and User is unspecified. 2189/// 2190/// \param AllowExplicit true if the conversion should consider C++0x 2191/// "explicit" conversion functions as well as non-explicit conversion 2192/// functions (C++0x [class.conv.fct]p2). 2193static OverloadingResult 2194IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 2195 UserDefinedConversionSequence& User, 2196 OverloadCandidateSet& CandidateSet, 2197 bool AllowExplicit) { 2198 // Whether we will only visit constructors. 2199 bool ConstructorsOnly = false; 2200 2201 // If the type we are conversion to is a class type, enumerate its 2202 // constructors. 2203 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 2204 // C++ [over.match.ctor]p1: 2205 // When objects of class type are direct-initialized (8.5), or 2206 // copy-initialized from an expression of the same or a 2207 // derived class type (8.5), overload resolution selects the 2208 // constructor. [...] For copy-initialization, the candidate 2209 // functions are all the converting constructors (12.3.1) of 2210 // that class. The argument list is the expression-list within 2211 // the parentheses of the initializer. 2212 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 2213 (From->getType()->getAs<RecordType>() && 2214 S.IsDerivedFrom(From->getType(), ToType))) 2215 ConstructorsOnly = true; 2216 2217 if (S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag())) { 2218 // We're not going to find any constructors. 2219 } else if (CXXRecordDecl *ToRecordDecl 2220 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 2221 DeclContext::lookup_iterator Con, ConEnd; 2222 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 2223 Con != ConEnd; ++Con) { 2224 NamedDecl *D = *Con; 2225 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2226 2227 // Find the constructor (which may be a template). 2228 CXXConstructorDecl *Constructor = 0; 2229 FunctionTemplateDecl *ConstructorTmpl 2230 = dyn_cast<FunctionTemplateDecl>(D); 2231 if (ConstructorTmpl) 2232 Constructor 2233 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2234 else 2235 Constructor = cast<CXXConstructorDecl>(D); 2236 2237 if (!Constructor->isInvalidDecl() && 2238 Constructor->isConvertingConstructor(AllowExplicit)) { 2239 if (ConstructorTmpl) 2240 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2241 /*ExplicitArgs*/ 0, 2242 &From, 1, CandidateSet, 2243 /*SuppressUserConversions=*/ 2244 !ConstructorsOnly); 2245 else 2246 // Allow one user-defined conversion when user specifies a 2247 // From->ToType conversion via an static cast (c-style, etc). 2248 S.AddOverloadCandidate(Constructor, FoundDecl, 2249 &From, 1, CandidateSet, 2250 /*SuppressUserConversions=*/ 2251 !ConstructorsOnly); 2252 } 2253 } 2254 } 2255 } 2256 2257 // Enumerate conversion functions, if we're allowed to. 2258 if (ConstructorsOnly) { 2259 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 2260 S.PDiag(0) << From->getSourceRange())) { 2261 // No conversion functions from incomplete types. 2262 } else if (const RecordType *FromRecordType 2263 = From->getType()->getAs<RecordType>()) { 2264 if (CXXRecordDecl *FromRecordDecl 2265 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 2266 // Add all of the conversion functions as candidates. 2267 const UnresolvedSetImpl *Conversions 2268 = FromRecordDecl->getVisibleConversionFunctions(); 2269 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2270 E = Conversions->end(); I != E; ++I) { 2271 DeclAccessPair FoundDecl = I.getPair(); 2272 NamedDecl *D = FoundDecl.getDecl(); 2273 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 2274 if (isa<UsingShadowDecl>(D)) 2275 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2276 2277 CXXConversionDecl *Conv; 2278 FunctionTemplateDecl *ConvTemplate; 2279 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 2280 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2281 else 2282 Conv = cast<CXXConversionDecl>(D); 2283 2284 if (AllowExplicit || !Conv->isExplicit()) { 2285 if (ConvTemplate) 2286 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 2287 ActingContext, From, ToType, 2288 CandidateSet); 2289 else 2290 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 2291 From, ToType, CandidateSet); 2292 } 2293 } 2294 } 2295 } 2296 2297 OverloadCandidateSet::iterator Best; 2298 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2299 case OR_Success: 2300 // Record the standard conversion we used and the conversion function. 2301 if (CXXConstructorDecl *Constructor 2302 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 2303 S.MarkDeclarationReferenced(From->getLocStart(), Constructor); 2304 2305 // C++ [over.ics.user]p1: 2306 // If the user-defined conversion is specified by a 2307 // constructor (12.3.1), the initial standard conversion 2308 // sequence converts the source type to the type required by 2309 // the argument of the constructor. 2310 // 2311 QualType ThisType = Constructor->getThisType(S.Context); 2312 if (Best->Conversions[0].isEllipsis()) 2313 User.EllipsisConversion = true; 2314 else { 2315 User.Before = Best->Conversions[0].Standard; 2316 User.EllipsisConversion = false; 2317 } 2318 User.ConversionFunction = Constructor; 2319 User.FoundConversionFunction = Best->FoundDecl.getDecl(); 2320 User.After.setAsIdentityConversion(); 2321 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2322 User.After.setAllToTypes(ToType); 2323 return OR_Success; 2324 } else if (CXXConversionDecl *Conversion 2325 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2326 S.MarkDeclarationReferenced(From->getLocStart(), Conversion); 2327 2328 // C++ [over.ics.user]p1: 2329 // 2330 // [...] If the user-defined conversion is specified by a 2331 // conversion function (12.3.2), the initial standard 2332 // conversion sequence converts the source type to the 2333 // implicit object parameter of the conversion function. 2334 User.Before = Best->Conversions[0].Standard; 2335 User.ConversionFunction = Conversion; 2336 User.FoundConversionFunction = Best->FoundDecl.getDecl(); 2337 User.EllipsisConversion = false; 2338 2339 // C++ [over.ics.user]p2: 2340 // The second standard conversion sequence converts the 2341 // result of the user-defined conversion to the target type 2342 // for the sequence. Since an implicit conversion sequence 2343 // is an initialization, the special rules for 2344 // initialization by user-defined conversion apply when 2345 // selecting the best user-defined conversion for a 2346 // user-defined conversion sequence (see 13.3.3 and 2347 // 13.3.3.1). 2348 User.After = Best->FinalConversion; 2349 return OR_Success; 2350 } else { 2351 llvm_unreachable("Not a constructor or conversion function?"); 2352 return OR_No_Viable_Function; 2353 } 2354 2355 case OR_No_Viable_Function: 2356 return OR_No_Viable_Function; 2357 case OR_Deleted: 2358 // No conversion here! We're done. 2359 return OR_Deleted; 2360 2361 case OR_Ambiguous: 2362 return OR_Ambiguous; 2363 } 2364 2365 return OR_No_Viable_Function; 2366} 2367 2368bool 2369Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2370 ImplicitConversionSequence ICS; 2371 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2372 OverloadingResult OvResult = 2373 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 2374 CandidateSet, false); 2375 if (OvResult == OR_Ambiguous) 2376 Diag(From->getSourceRange().getBegin(), 2377 diag::err_typecheck_ambiguous_condition) 2378 << From->getType() << ToType << From->getSourceRange(); 2379 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2380 Diag(From->getSourceRange().getBegin(), 2381 diag::err_typecheck_nonviable_condition) 2382 << From->getType() << ToType << From->getSourceRange(); 2383 else 2384 return false; 2385 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &From, 1); 2386 return true; 2387} 2388 2389/// CompareImplicitConversionSequences - Compare two implicit 2390/// conversion sequences to determine whether one is better than the 2391/// other or if they are indistinguishable (C++ 13.3.3.2). 2392static ImplicitConversionSequence::CompareKind 2393CompareImplicitConversionSequences(Sema &S, 2394 const ImplicitConversionSequence& ICS1, 2395 const ImplicitConversionSequence& ICS2) 2396{ 2397 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2398 // conversion sequences (as defined in 13.3.3.1) 2399 // -- a standard conversion sequence (13.3.3.1.1) is a better 2400 // conversion sequence than a user-defined conversion sequence or 2401 // an ellipsis conversion sequence, and 2402 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2403 // conversion sequence than an ellipsis conversion sequence 2404 // (13.3.3.1.3). 2405 // 2406 // C++0x [over.best.ics]p10: 2407 // For the purpose of ranking implicit conversion sequences as 2408 // described in 13.3.3.2, the ambiguous conversion sequence is 2409 // treated as a user-defined sequence that is indistinguishable 2410 // from any other user-defined conversion sequence. 2411 if (ICS1.getKindRank() < ICS2.getKindRank()) 2412 return ImplicitConversionSequence::Better; 2413 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2414 return ImplicitConversionSequence::Worse; 2415 2416 // The following checks require both conversion sequences to be of 2417 // the same kind. 2418 if (ICS1.getKind() != ICS2.getKind()) 2419 return ImplicitConversionSequence::Indistinguishable; 2420 2421 // Two implicit conversion sequences of the same form are 2422 // indistinguishable conversion sequences unless one of the 2423 // following rules apply: (C++ 13.3.3.2p3): 2424 if (ICS1.isStandard()) 2425 return CompareStandardConversionSequences(S, ICS1.Standard, ICS2.Standard); 2426 else if (ICS1.isUserDefined()) { 2427 // User-defined conversion sequence U1 is a better conversion 2428 // sequence than another user-defined conversion sequence U2 if 2429 // they contain the same user-defined conversion function or 2430 // constructor and if the second standard conversion sequence of 2431 // U1 is better than the second standard conversion sequence of 2432 // U2 (C++ 13.3.3.2p3). 2433 if (ICS1.UserDefined.ConversionFunction == 2434 ICS2.UserDefined.ConversionFunction) 2435 return CompareStandardConversionSequences(S, 2436 ICS1.UserDefined.After, 2437 ICS2.UserDefined.After); 2438 } 2439 2440 return ImplicitConversionSequence::Indistinguishable; 2441} 2442 2443static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2444 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2445 Qualifiers Quals; 2446 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2447 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2448 } 2449 2450 return Context.hasSameUnqualifiedType(T1, T2); 2451} 2452 2453// Per 13.3.3.2p3, compare the given standard conversion sequences to 2454// determine if one is a proper subset of the other. 2455static ImplicitConversionSequence::CompareKind 2456compareStandardConversionSubsets(ASTContext &Context, 2457 const StandardConversionSequence& SCS1, 2458 const StandardConversionSequence& SCS2) { 2459 ImplicitConversionSequence::CompareKind Result 2460 = ImplicitConversionSequence::Indistinguishable; 2461 2462 // the identity conversion sequence is considered to be a subsequence of 2463 // any non-identity conversion sequence 2464 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2465 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2466 return ImplicitConversionSequence::Better; 2467 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2468 return ImplicitConversionSequence::Worse; 2469 } 2470 2471 if (SCS1.Second != SCS2.Second) { 2472 if (SCS1.Second == ICK_Identity) 2473 Result = ImplicitConversionSequence::Better; 2474 else if (SCS2.Second == ICK_Identity) 2475 Result = ImplicitConversionSequence::Worse; 2476 else 2477 return ImplicitConversionSequence::Indistinguishable; 2478 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2479 return ImplicitConversionSequence::Indistinguishable; 2480 2481 if (SCS1.Third == SCS2.Third) { 2482 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2483 : ImplicitConversionSequence::Indistinguishable; 2484 } 2485 2486 if (SCS1.Third == ICK_Identity) 2487 return Result == ImplicitConversionSequence::Worse 2488 ? ImplicitConversionSequence::Indistinguishable 2489 : ImplicitConversionSequence::Better; 2490 2491 if (SCS2.Third == ICK_Identity) 2492 return Result == ImplicitConversionSequence::Better 2493 ? ImplicitConversionSequence::Indistinguishable 2494 : ImplicitConversionSequence::Worse; 2495 2496 return ImplicitConversionSequence::Indistinguishable; 2497} 2498 2499/// \brief Determine whether one of the given reference bindings is better 2500/// than the other based on what kind of bindings they are. 2501static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 2502 const StandardConversionSequence &SCS2) { 2503 // C++0x [over.ics.rank]p3b4: 2504 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2505 // implicit object parameter of a non-static member function declared 2506 // without a ref-qualifier, and *either* S1 binds an rvalue reference 2507 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 2508 // lvalue reference to a function lvalue and S2 binds an rvalue 2509 // reference*. 2510 // 2511 // FIXME: Rvalue references. We're going rogue with the above edits, 2512 // because the semantics in the current C++0x working paper (N3225 at the 2513 // time of this writing) break the standard definition of std::forward 2514 // and std::reference_wrapper when dealing with references to functions. 2515 // Proposed wording changes submitted to CWG for consideration. 2516 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 2517 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 2518 return false; 2519 2520 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 2521 SCS2.IsLvalueReference) || 2522 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 2523 !SCS2.IsLvalueReference); 2524} 2525 2526/// CompareStandardConversionSequences - Compare two standard 2527/// conversion sequences to determine whether one is better than the 2528/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2529static ImplicitConversionSequence::CompareKind 2530CompareStandardConversionSequences(Sema &S, 2531 const StandardConversionSequence& SCS1, 2532 const StandardConversionSequence& SCS2) 2533{ 2534 // Standard conversion sequence S1 is a better conversion sequence 2535 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2536 2537 // -- S1 is a proper subsequence of S2 (comparing the conversion 2538 // sequences in the canonical form defined by 13.3.3.1.1, 2539 // excluding any Lvalue Transformation; the identity conversion 2540 // sequence is considered to be a subsequence of any 2541 // non-identity conversion sequence) or, if not that, 2542 if (ImplicitConversionSequence::CompareKind CK 2543 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 2544 return CK; 2545 2546 // -- the rank of S1 is better than the rank of S2 (by the rules 2547 // defined below), or, if not that, 2548 ImplicitConversionRank Rank1 = SCS1.getRank(); 2549 ImplicitConversionRank Rank2 = SCS2.getRank(); 2550 if (Rank1 < Rank2) 2551 return ImplicitConversionSequence::Better; 2552 else if (Rank2 < Rank1) 2553 return ImplicitConversionSequence::Worse; 2554 2555 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2556 // are indistinguishable unless one of the following rules 2557 // applies: 2558 2559 // A conversion that is not a conversion of a pointer, or 2560 // pointer to member, to bool is better than another conversion 2561 // that is such a conversion. 2562 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2563 return SCS2.isPointerConversionToBool() 2564 ? ImplicitConversionSequence::Better 2565 : ImplicitConversionSequence::Worse; 2566 2567 // C++ [over.ics.rank]p4b2: 2568 // 2569 // If class B is derived directly or indirectly from class A, 2570 // conversion of B* to A* is better than conversion of B* to 2571 // void*, and conversion of A* to void* is better than conversion 2572 // of B* to void*. 2573 bool SCS1ConvertsToVoid 2574 = SCS1.isPointerConversionToVoidPointer(S.Context); 2575 bool SCS2ConvertsToVoid 2576 = SCS2.isPointerConversionToVoidPointer(S.Context); 2577 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2578 // Exactly one of the conversion sequences is a conversion to 2579 // a void pointer; it's the worse conversion. 2580 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2581 : ImplicitConversionSequence::Worse; 2582 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2583 // Neither conversion sequence converts to a void pointer; compare 2584 // their derived-to-base conversions. 2585 if (ImplicitConversionSequence::CompareKind DerivedCK 2586 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 2587 return DerivedCK; 2588 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2589 // Both conversion sequences are conversions to void 2590 // pointers. Compare the source types to determine if there's an 2591 // inheritance relationship in their sources. 2592 QualType FromType1 = SCS1.getFromType(); 2593 QualType FromType2 = SCS2.getFromType(); 2594 2595 // Adjust the types we're converting from via the array-to-pointer 2596 // conversion, if we need to. 2597 if (SCS1.First == ICK_Array_To_Pointer) 2598 FromType1 = S.Context.getArrayDecayedType(FromType1); 2599 if (SCS2.First == ICK_Array_To_Pointer) 2600 FromType2 = S.Context.getArrayDecayedType(FromType2); 2601 2602 QualType FromPointee1 2603 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2604 QualType FromPointee2 2605 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2606 2607 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2608 return ImplicitConversionSequence::Better; 2609 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2610 return ImplicitConversionSequence::Worse; 2611 2612 // Objective-C++: If one interface is more specific than the 2613 // other, it is the better one. 2614 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2615 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2616 if (FromIface1 && FromIface1) { 2617 if (S.Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2618 return ImplicitConversionSequence::Better; 2619 else if (S.Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2620 return ImplicitConversionSequence::Worse; 2621 } 2622 } 2623 2624 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2625 // bullet 3). 2626 if (ImplicitConversionSequence::CompareKind QualCK 2627 = CompareQualificationConversions(S, SCS1, SCS2)) 2628 return QualCK; 2629 2630 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2631 // Check for a better reference binding based on the kind of bindings. 2632 if (isBetterReferenceBindingKind(SCS1, SCS2)) 2633 return ImplicitConversionSequence::Better; 2634 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 2635 return ImplicitConversionSequence::Worse; 2636 2637 // C++ [over.ics.rank]p3b4: 2638 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2639 // which the references refer are the same type except for 2640 // top-level cv-qualifiers, and the type to which the reference 2641 // initialized by S2 refers is more cv-qualified than the type 2642 // to which the reference initialized by S1 refers. 2643 QualType T1 = SCS1.getToType(2); 2644 QualType T2 = SCS2.getToType(2); 2645 T1 = S.Context.getCanonicalType(T1); 2646 T2 = S.Context.getCanonicalType(T2); 2647 Qualifiers T1Quals, T2Quals; 2648 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2649 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2650 if (UnqualT1 == UnqualT2) { 2651 // If the type is an array type, promote the element qualifiers to the 2652 // type for comparison. 2653 if (isa<ArrayType>(T1) && T1Quals) 2654 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2655 if (isa<ArrayType>(T2) && T2Quals) 2656 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2657 if (T2.isMoreQualifiedThan(T1)) 2658 return ImplicitConversionSequence::Better; 2659 else if (T1.isMoreQualifiedThan(T2)) 2660 return ImplicitConversionSequence::Worse; 2661 } 2662 } 2663 2664 return ImplicitConversionSequence::Indistinguishable; 2665} 2666 2667/// CompareQualificationConversions - Compares two standard conversion 2668/// sequences to determine whether they can be ranked based on their 2669/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2670ImplicitConversionSequence::CompareKind 2671CompareQualificationConversions(Sema &S, 2672 const StandardConversionSequence& SCS1, 2673 const StandardConversionSequence& SCS2) { 2674 // C++ 13.3.3.2p3: 2675 // -- S1 and S2 differ only in their qualification conversion and 2676 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2677 // cv-qualification signature of type T1 is a proper subset of 2678 // the cv-qualification signature of type T2, and S1 is not the 2679 // deprecated string literal array-to-pointer conversion (4.2). 2680 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2681 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2682 return ImplicitConversionSequence::Indistinguishable; 2683 2684 // FIXME: the example in the standard doesn't use a qualification 2685 // conversion (!) 2686 QualType T1 = SCS1.getToType(2); 2687 QualType T2 = SCS2.getToType(2); 2688 T1 = S.Context.getCanonicalType(T1); 2689 T2 = S.Context.getCanonicalType(T2); 2690 Qualifiers T1Quals, T2Quals; 2691 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2692 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2693 2694 // If the types are the same, we won't learn anything by unwrapped 2695 // them. 2696 if (UnqualT1 == UnqualT2) 2697 return ImplicitConversionSequence::Indistinguishable; 2698 2699 // If the type is an array type, promote the element qualifiers to the type 2700 // for comparison. 2701 if (isa<ArrayType>(T1) && T1Quals) 2702 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2703 if (isa<ArrayType>(T2) && T2Quals) 2704 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2705 2706 ImplicitConversionSequence::CompareKind Result 2707 = ImplicitConversionSequence::Indistinguishable; 2708 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 2709 // Within each iteration of the loop, we check the qualifiers to 2710 // determine if this still looks like a qualification 2711 // conversion. Then, if all is well, we unwrap one more level of 2712 // pointers or pointers-to-members and do it all again 2713 // until there are no more pointers or pointers-to-members left 2714 // to unwrap. This essentially mimics what 2715 // IsQualificationConversion does, but here we're checking for a 2716 // strict subset of qualifiers. 2717 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2718 // The qualifiers are the same, so this doesn't tell us anything 2719 // about how the sequences rank. 2720 ; 2721 else if (T2.isMoreQualifiedThan(T1)) { 2722 // T1 has fewer qualifiers, so it could be the better sequence. 2723 if (Result == ImplicitConversionSequence::Worse) 2724 // Neither has qualifiers that are a subset of the other's 2725 // qualifiers. 2726 return ImplicitConversionSequence::Indistinguishable; 2727 2728 Result = ImplicitConversionSequence::Better; 2729 } else if (T1.isMoreQualifiedThan(T2)) { 2730 // T2 has fewer qualifiers, so it could be the better sequence. 2731 if (Result == ImplicitConversionSequence::Better) 2732 // Neither has qualifiers that are a subset of the other's 2733 // qualifiers. 2734 return ImplicitConversionSequence::Indistinguishable; 2735 2736 Result = ImplicitConversionSequence::Worse; 2737 } else { 2738 // Qualifiers are disjoint. 2739 return ImplicitConversionSequence::Indistinguishable; 2740 } 2741 2742 // If the types after this point are equivalent, we're done. 2743 if (S.Context.hasSameUnqualifiedType(T1, T2)) 2744 break; 2745 } 2746 2747 // Check that the winning standard conversion sequence isn't using 2748 // the deprecated string literal array to pointer conversion. 2749 switch (Result) { 2750 case ImplicitConversionSequence::Better: 2751 if (SCS1.DeprecatedStringLiteralToCharPtr) 2752 Result = ImplicitConversionSequence::Indistinguishable; 2753 break; 2754 2755 case ImplicitConversionSequence::Indistinguishable: 2756 break; 2757 2758 case ImplicitConversionSequence::Worse: 2759 if (SCS2.DeprecatedStringLiteralToCharPtr) 2760 Result = ImplicitConversionSequence::Indistinguishable; 2761 break; 2762 } 2763 2764 return Result; 2765} 2766 2767/// CompareDerivedToBaseConversions - Compares two standard conversion 2768/// sequences to determine whether they can be ranked based on their 2769/// various kinds of derived-to-base conversions (C++ 2770/// [over.ics.rank]p4b3). As part of these checks, we also look at 2771/// conversions between Objective-C interface types. 2772ImplicitConversionSequence::CompareKind 2773CompareDerivedToBaseConversions(Sema &S, 2774 const StandardConversionSequence& SCS1, 2775 const StandardConversionSequence& SCS2) { 2776 QualType FromType1 = SCS1.getFromType(); 2777 QualType ToType1 = SCS1.getToType(1); 2778 QualType FromType2 = SCS2.getFromType(); 2779 QualType ToType2 = SCS2.getToType(1); 2780 2781 // Adjust the types we're converting from via the array-to-pointer 2782 // conversion, if we need to. 2783 if (SCS1.First == ICK_Array_To_Pointer) 2784 FromType1 = S.Context.getArrayDecayedType(FromType1); 2785 if (SCS2.First == ICK_Array_To_Pointer) 2786 FromType2 = S.Context.getArrayDecayedType(FromType2); 2787 2788 // Canonicalize all of the types. 2789 FromType1 = S.Context.getCanonicalType(FromType1); 2790 ToType1 = S.Context.getCanonicalType(ToType1); 2791 FromType2 = S.Context.getCanonicalType(FromType2); 2792 ToType2 = S.Context.getCanonicalType(ToType2); 2793 2794 // C++ [over.ics.rank]p4b3: 2795 // 2796 // If class B is derived directly or indirectly from class A and 2797 // class C is derived directly or indirectly from B, 2798 // 2799 // Compare based on pointer conversions. 2800 if (SCS1.Second == ICK_Pointer_Conversion && 2801 SCS2.Second == ICK_Pointer_Conversion && 2802 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2803 FromType1->isPointerType() && FromType2->isPointerType() && 2804 ToType1->isPointerType() && ToType2->isPointerType()) { 2805 QualType FromPointee1 2806 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2807 QualType ToPointee1 2808 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2809 QualType FromPointee2 2810 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2811 QualType ToPointee2 2812 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2813 2814 // -- conversion of C* to B* is better than conversion of C* to A*, 2815 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2816 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2817 return ImplicitConversionSequence::Better; 2818 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2819 return ImplicitConversionSequence::Worse; 2820 } 2821 2822 // -- conversion of B* to A* is better than conversion of C* to A*, 2823 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2824 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2825 return ImplicitConversionSequence::Better; 2826 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2827 return ImplicitConversionSequence::Worse; 2828 } 2829 } else if (SCS1.Second == ICK_Pointer_Conversion && 2830 SCS2.Second == ICK_Pointer_Conversion) { 2831 const ObjCObjectPointerType *FromPtr1 2832 = FromType1->getAs<ObjCObjectPointerType>(); 2833 const ObjCObjectPointerType *FromPtr2 2834 = FromType2->getAs<ObjCObjectPointerType>(); 2835 const ObjCObjectPointerType *ToPtr1 2836 = ToType1->getAs<ObjCObjectPointerType>(); 2837 const ObjCObjectPointerType *ToPtr2 2838 = ToType2->getAs<ObjCObjectPointerType>(); 2839 2840 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 2841 // Apply the same conversion ranking rules for Objective-C pointer types 2842 // that we do for C++ pointers to class types. However, we employ the 2843 // Objective-C pseudo-subtyping relationship used for assignment of 2844 // Objective-C pointer types. 2845 bool FromAssignLeft 2846 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 2847 bool FromAssignRight 2848 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 2849 bool ToAssignLeft 2850 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 2851 bool ToAssignRight 2852 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 2853 2854 // A conversion to an a non-id object pointer type or qualified 'id' 2855 // type is better than a conversion to 'id'. 2856 if (ToPtr1->isObjCIdType() && 2857 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 2858 return ImplicitConversionSequence::Worse; 2859 if (ToPtr2->isObjCIdType() && 2860 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 2861 return ImplicitConversionSequence::Better; 2862 2863 // A conversion to a non-id object pointer type is better than a 2864 // conversion to a qualified 'id' type 2865 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 2866 return ImplicitConversionSequence::Worse; 2867 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 2868 return ImplicitConversionSequence::Better; 2869 2870 // A conversion to an a non-Class object pointer type or qualified 'Class' 2871 // type is better than a conversion to 'Class'. 2872 if (ToPtr1->isObjCClassType() && 2873 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 2874 return ImplicitConversionSequence::Worse; 2875 if (ToPtr2->isObjCClassType() && 2876 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 2877 return ImplicitConversionSequence::Better; 2878 2879 // A conversion to a non-Class object pointer type is better than a 2880 // conversion to a qualified 'Class' type. 2881 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 2882 return ImplicitConversionSequence::Worse; 2883 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 2884 return ImplicitConversionSequence::Better; 2885 2886 // -- "conversion of C* to B* is better than conversion of C* to A*," 2887 if (S.Context.hasSameType(FromType1, FromType2) && 2888 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 2889 (ToAssignLeft != ToAssignRight)) 2890 return ToAssignLeft? ImplicitConversionSequence::Worse 2891 : ImplicitConversionSequence::Better; 2892 2893 // -- "conversion of B* to A* is better than conversion of C* to A*," 2894 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 2895 (FromAssignLeft != FromAssignRight)) 2896 return FromAssignLeft? ImplicitConversionSequence::Better 2897 : ImplicitConversionSequence::Worse; 2898 } 2899 } 2900 2901 // Ranking of member-pointer types. 2902 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2903 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2904 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2905 const MemberPointerType * FromMemPointer1 = 2906 FromType1->getAs<MemberPointerType>(); 2907 const MemberPointerType * ToMemPointer1 = 2908 ToType1->getAs<MemberPointerType>(); 2909 const MemberPointerType * FromMemPointer2 = 2910 FromType2->getAs<MemberPointerType>(); 2911 const MemberPointerType * ToMemPointer2 = 2912 ToType2->getAs<MemberPointerType>(); 2913 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2914 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2915 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2916 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2917 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2918 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2919 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2920 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2921 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2922 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2923 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2924 return ImplicitConversionSequence::Worse; 2925 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2926 return ImplicitConversionSequence::Better; 2927 } 2928 // conversion of B::* to C::* is better than conversion of A::* to C::* 2929 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2930 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2931 return ImplicitConversionSequence::Better; 2932 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2933 return ImplicitConversionSequence::Worse; 2934 } 2935 } 2936 2937 if (SCS1.Second == ICK_Derived_To_Base) { 2938 // -- conversion of C to B is better than conversion of C to A, 2939 // -- binding of an expression of type C to a reference of type 2940 // B& is better than binding an expression of type C to a 2941 // reference of type A&, 2942 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2943 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2944 if (S.IsDerivedFrom(ToType1, ToType2)) 2945 return ImplicitConversionSequence::Better; 2946 else if (S.IsDerivedFrom(ToType2, ToType1)) 2947 return ImplicitConversionSequence::Worse; 2948 } 2949 2950 // -- conversion of B to A is better than conversion of C to A. 2951 // -- binding of an expression of type B to a reference of type 2952 // A& is better than binding an expression of type C to a 2953 // reference of type A&, 2954 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2955 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2956 if (S.IsDerivedFrom(FromType2, FromType1)) 2957 return ImplicitConversionSequence::Better; 2958 else if (S.IsDerivedFrom(FromType1, FromType2)) 2959 return ImplicitConversionSequence::Worse; 2960 } 2961 } 2962 2963 return ImplicitConversionSequence::Indistinguishable; 2964} 2965 2966/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2967/// determine whether they are reference-related, 2968/// reference-compatible, reference-compatible with added 2969/// qualification, or incompatible, for use in C++ initialization by 2970/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2971/// type, and the first type (T1) is the pointee type of the reference 2972/// type being initialized. 2973Sema::ReferenceCompareResult 2974Sema::CompareReferenceRelationship(SourceLocation Loc, 2975 QualType OrigT1, QualType OrigT2, 2976 bool &DerivedToBase, 2977 bool &ObjCConversion) { 2978 assert(!OrigT1->isReferenceType() && 2979 "T1 must be the pointee type of the reference type"); 2980 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2981 2982 QualType T1 = Context.getCanonicalType(OrigT1); 2983 QualType T2 = Context.getCanonicalType(OrigT2); 2984 Qualifiers T1Quals, T2Quals; 2985 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2986 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2987 2988 // C++ [dcl.init.ref]p4: 2989 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2990 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2991 // T1 is a base class of T2. 2992 DerivedToBase = false; 2993 ObjCConversion = false; 2994 if (UnqualT1 == UnqualT2) { 2995 // Nothing to do. 2996 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2997 IsDerivedFrom(UnqualT2, UnqualT1)) 2998 DerivedToBase = true; 2999 else if (UnqualT1->isObjCObjectOrInterfaceType() && 3000 UnqualT2->isObjCObjectOrInterfaceType() && 3001 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 3002 ObjCConversion = true; 3003 else 3004 return Ref_Incompatible; 3005 3006 // At this point, we know that T1 and T2 are reference-related (at 3007 // least). 3008 3009 // If the type is an array type, promote the element qualifiers to the type 3010 // for comparison. 3011 if (isa<ArrayType>(T1) && T1Quals) 3012 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 3013 if (isa<ArrayType>(T2) && T2Quals) 3014 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 3015 3016 // C++ [dcl.init.ref]p4: 3017 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 3018 // reference-related to T2 and cv1 is the same cv-qualification 3019 // as, or greater cv-qualification than, cv2. For purposes of 3020 // overload resolution, cases for which cv1 is greater 3021 // cv-qualification than cv2 are identified as 3022 // reference-compatible with added qualification (see 13.3.3.2). 3023 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 3024 return Ref_Compatible; 3025 else if (T1.isMoreQualifiedThan(T2)) 3026 return Ref_Compatible_With_Added_Qualification; 3027 else 3028 return Ref_Related; 3029} 3030 3031/// \brief Look for a user-defined conversion to an value reference-compatible 3032/// with DeclType. Return true if something definite is found. 3033static bool 3034FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 3035 QualType DeclType, SourceLocation DeclLoc, 3036 Expr *Init, QualType T2, bool AllowRvalues, 3037 bool AllowExplicit) { 3038 assert(T2->isRecordType() && "Can only find conversions of record types."); 3039 CXXRecordDecl *T2RecordDecl 3040 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 3041 3042 OverloadCandidateSet CandidateSet(DeclLoc); 3043 const UnresolvedSetImpl *Conversions 3044 = T2RecordDecl->getVisibleConversionFunctions(); 3045 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3046 E = Conversions->end(); I != E; ++I) { 3047 NamedDecl *D = *I; 3048 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3049 if (isa<UsingShadowDecl>(D)) 3050 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3051 3052 FunctionTemplateDecl *ConvTemplate 3053 = dyn_cast<FunctionTemplateDecl>(D); 3054 CXXConversionDecl *Conv; 3055 if (ConvTemplate) 3056 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3057 else 3058 Conv = cast<CXXConversionDecl>(D); 3059 3060 // If this is an explicit conversion, and we're not allowed to consider 3061 // explicit conversions, skip it. 3062 if (!AllowExplicit && Conv->isExplicit()) 3063 continue; 3064 3065 if (AllowRvalues) { 3066 bool DerivedToBase = false; 3067 bool ObjCConversion = false; 3068 if (!ConvTemplate && 3069 S.CompareReferenceRelationship( 3070 DeclLoc, 3071 Conv->getConversionType().getNonReferenceType() 3072 .getUnqualifiedType(), 3073 DeclType.getNonReferenceType().getUnqualifiedType(), 3074 DerivedToBase, ObjCConversion) == 3075 Sema::Ref_Incompatible) 3076 continue; 3077 } else { 3078 // If the conversion function doesn't return a reference type, 3079 // it can't be considered for this conversion. An rvalue reference 3080 // is only acceptable if its referencee is a function type. 3081 3082 const ReferenceType *RefType = 3083 Conv->getConversionType()->getAs<ReferenceType>(); 3084 if (!RefType || 3085 (!RefType->isLValueReferenceType() && 3086 !RefType->getPointeeType()->isFunctionType())) 3087 continue; 3088 } 3089 3090 if (ConvTemplate) 3091 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 3092 Init, DeclType, CandidateSet); 3093 else 3094 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 3095 DeclType, CandidateSet); 3096 } 3097 3098 OverloadCandidateSet::iterator Best; 3099 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 3100 case OR_Success: 3101 // C++ [over.ics.ref]p1: 3102 // 3103 // [...] If the parameter binds directly to the result of 3104 // applying a conversion function to the argument 3105 // expression, the implicit conversion sequence is a 3106 // user-defined conversion sequence (13.3.3.1.2), with the 3107 // second standard conversion sequence either an identity 3108 // conversion or, if the conversion function returns an 3109 // entity of a type that is a derived class of the parameter 3110 // type, a derived-to-base Conversion. 3111 if (!Best->FinalConversion.DirectBinding) 3112 return false; 3113 3114 if (Best->Function) 3115 S.MarkDeclarationReferenced(DeclLoc, Best->Function); 3116 ICS.setUserDefined(); 3117 ICS.UserDefined.Before = Best->Conversions[0].Standard; 3118 ICS.UserDefined.After = Best->FinalConversion; 3119 ICS.UserDefined.ConversionFunction = Best->Function; 3120 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl.getDecl(); 3121 ICS.UserDefined.EllipsisConversion = false; 3122 assert(ICS.UserDefined.After.ReferenceBinding && 3123 ICS.UserDefined.After.DirectBinding && 3124 "Expected a direct reference binding!"); 3125 return true; 3126 3127 case OR_Ambiguous: 3128 ICS.setAmbiguous(); 3129 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3130 Cand != CandidateSet.end(); ++Cand) 3131 if (Cand->Viable) 3132 ICS.Ambiguous.addConversion(Cand->Function); 3133 return true; 3134 3135 case OR_No_Viable_Function: 3136 case OR_Deleted: 3137 // There was no suitable conversion, or we found a deleted 3138 // conversion; continue with other checks. 3139 return false; 3140 } 3141 3142 return false; 3143} 3144 3145/// \brief Compute an implicit conversion sequence for reference 3146/// initialization. 3147static ImplicitConversionSequence 3148TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 3149 SourceLocation DeclLoc, 3150 bool SuppressUserConversions, 3151 bool AllowExplicit) { 3152 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 3153 3154 // Most paths end in a failed conversion. 3155 ImplicitConversionSequence ICS; 3156 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3157 3158 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 3159 QualType T2 = Init->getType(); 3160 3161 // If the initializer is the address of an overloaded function, try 3162 // to resolve the overloaded function. If all goes well, T2 is the 3163 // type of the resulting function. 3164 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 3165 DeclAccessPair Found; 3166 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 3167 false, Found)) 3168 T2 = Fn->getType(); 3169 } 3170 3171 // Compute some basic properties of the types and the initializer. 3172 bool isRValRef = DeclType->isRValueReferenceType(); 3173 bool DerivedToBase = false; 3174 bool ObjCConversion = false; 3175 Expr::Classification InitCategory = Init->Classify(S.Context); 3176 Sema::ReferenceCompareResult RefRelationship 3177 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 3178 ObjCConversion); 3179 3180 3181 // C++0x [dcl.init.ref]p5: 3182 // A reference to type "cv1 T1" is initialized by an expression 3183 // of type "cv2 T2" as follows: 3184 3185 // -- If reference is an lvalue reference and the initializer expression 3186 if (!isRValRef) { 3187 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 3188 // reference-compatible with "cv2 T2," or 3189 // 3190 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 3191 if (InitCategory.isLValue() && 3192 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 3193 // C++ [over.ics.ref]p1: 3194 // When a parameter of reference type binds directly (8.5.3) 3195 // to an argument expression, the implicit conversion sequence 3196 // is the identity conversion, unless the argument expression 3197 // has a type that is a derived class of the parameter type, 3198 // in which case the implicit conversion sequence is a 3199 // derived-to-base Conversion (13.3.3.1). 3200 ICS.setStandard(); 3201 ICS.Standard.First = ICK_Identity; 3202 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3203 : ObjCConversion? ICK_Compatible_Conversion 3204 : ICK_Identity; 3205 ICS.Standard.Third = ICK_Identity; 3206 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3207 ICS.Standard.setToType(0, T2); 3208 ICS.Standard.setToType(1, T1); 3209 ICS.Standard.setToType(2, T1); 3210 ICS.Standard.ReferenceBinding = true; 3211 ICS.Standard.DirectBinding = true; 3212 ICS.Standard.IsLvalueReference = !isRValRef; 3213 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3214 ICS.Standard.BindsToRvalue = false; 3215 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3216 ICS.Standard.CopyConstructor = 0; 3217 3218 // Nothing more to do: the inaccessibility/ambiguity check for 3219 // derived-to-base conversions is suppressed when we're 3220 // computing the implicit conversion sequence (C++ 3221 // [over.best.ics]p2). 3222 return ICS; 3223 } 3224 3225 // -- has a class type (i.e., T2 is a class type), where T1 is 3226 // not reference-related to T2, and can be implicitly 3227 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 3228 // is reference-compatible with "cv3 T3" 92) (this 3229 // conversion is selected by enumerating the applicable 3230 // conversion functions (13.3.1.6) and choosing the best 3231 // one through overload resolution (13.3)), 3232 if (!SuppressUserConversions && T2->isRecordType() && 3233 !S.RequireCompleteType(DeclLoc, T2, 0) && 3234 RefRelationship == Sema::Ref_Incompatible) { 3235 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3236 Init, T2, /*AllowRvalues=*/false, 3237 AllowExplicit)) 3238 return ICS; 3239 } 3240 } 3241 3242 // -- Otherwise, the reference shall be an lvalue reference to a 3243 // non-volatile const type (i.e., cv1 shall be const), or the reference 3244 // shall be an rvalue reference. 3245 // 3246 // We actually handle one oddity of C++ [over.ics.ref] at this 3247 // point, which is that, due to p2 (which short-circuits reference 3248 // binding by only attempting a simple conversion for non-direct 3249 // bindings) and p3's strange wording, we allow a const volatile 3250 // reference to bind to an rvalue. Hence the check for the presence 3251 // of "const" rather than checking for "const" being the only 3252 // qualifier. 3253 // This is also the point where rvalue references and lvalue inits no longer 3254 // go together. 3255 if (!isRValRef && !T1.isConstQualified()) 3256 return ICS; 3257 3258 // -- If the initializer expression 3259 // 3260 // -- is an xvalue, class prvalue, array prvalue or function 3261 // lvalue and "cv1T1" is reference-compatible with "cv2 T2", or 3262 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 3263 (InitCategory.isXValue() || 3264 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 3265 (InitCategory.isLValue() && T2->isFunctionType()))) { 3266 ICS.setStandard(); 3267 ICS.Standard.First = ICK_Identity; 3268 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3269 : ObjCConversion? ICK_Compatible_Conversion 3270 : ICK_Identity; 3271 ICS.Standard.Third = ICK_Identity; 3272 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3273 ICS.Standard.setToType(0, T2); 3274 ICS.Standard.setToType(1, T1); 3275 ICS.Standard.setToType(2, T1); 3276 ICS.Standard.ReferenceBinding = true; 3277 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 3278 // binding unless we're binding to a class prvalue. 3279 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 3280 // allow the use of rvalue references in C++98/03 for the benefit of 3281 // standard library implementors; therefore, we need the xvalue check here. 3282 ICS.Standard.DirectBinding = 3283 S.getLangOptions().CPlusPlus0x || 3284 (InitCategory.isPRValue() && !T2->isRecordType()); 3285 ICS.Standard.IsLvalueReference = !isRValRef; 3286 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3287 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 3288 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3289 ICS.Standard.CopyConstructor = 0; 3290 return ICS; 3291 } 3292 3293 // -- has a class type (i.e., T2 is a class type), where T1 is not 3294 // reference-related to T2, and can be implicitly converted to 3295 // an xvalue, class prvalue, or function lvalue of type 3296 // "cv3 T3", where "cv1 T1" is reference-compatible with 3297 // "cv3 T3", 3298 // 3299 // then the reference is bound to the value of the initializer 3300 // expression in the first case and to the result of the conversion 3301 // in the second case (or, in either case, to an appropriate base 3302 // class subobject). 3303 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3304 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 3305 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3306 Init, T2, /*AllowRvalues=*/true, 3307 AllowExplicit)) { 3308 // In the second case, if the reference is an rvalue reference 3309 // and the second standard conversion sequence of the 3310 // user-defined conversion sequence includes an lvalue-to-rvalue 3311 // conversion, the program is ill-formed. 3312 if (ICS.isUserDefined() && isRValRef && 3313 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 3314 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3315 3316 return ICS; 3317 } 3318 3319 // -- Otherwise, a temporary of type "cv1 T1" is created and 3320 // initialized from the initializer expression using the 3321 // rules for a non-reference copy initialization (8.5). The 3322 // reference is then bound to the temporary. If T1 is 3323 // reference-related to T2, cv1 must be the same 3324 // cv-qualification as, or greater cv-qualification than, 3325 // cv2; otherwise, the program is ill-formed. 3326 if (RefRelationship == Sema::Ref_Related) { 3327 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 3328 // we would be reference-compatible or reference-compatible with 3329 // added qualification. But that wasn't the case, so the reference 3330 // initialization fails. 3331 return ICS; 3332 } 3333 3334 // If at least one of the types is a class type, the types are not 3335 // related, and we aren't allowed any user conversions, the 3336 // reference binding fails. This case is important for breaking 3337 // recursion, since TryImplicitConversion below will attempt to 3338 // create a temporary through the use of a copy constructor. 3339 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3340 (T1->isRecordType() || T2->isRecordType())) 3341 return ICS; 3342 3343 // If T1 is reference-related to T2 and the reference is an rvalue 3344 // reference, the initializer expression shall not be an lvalue. 3345 if (RefRelationship >= Sema::Ref_Related && 3346 isRValRef && Init->Classify(S.Context).isLValue()) 3347 return ICS; 3348 3349 // C++ [over.ics.ref]p2: 3350 // When a parameter of reference type is not bound directly to 3351 // an argument expression, the conversion sequence is the one 3352 // required to convert the argument expression to the 3353 // underlying type of the reference according to 3354 // 13.3.3.1. Conceptually, this conversion sequence corresponds 3355 // to copy-initializing a temporary of the underlying type with 3356 // the argument expression. Any difference in top-level 3357 // cv-qualification is subsumed by the initialization itself 3358 // and does not constitute a conversion. 3359 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 3360 /*AllowExplicit=*/false, 3361 /*InOverloadResolution=*/false, 3362 /*CStyle=*/false); 3363 3364 // Of course, that's still a reference binding. 3365 if (ICS.isStandard()) { 3366 ICS.Standard.ReferenceBinding = true; 3367 ICS.Standard.IsLvalueReference = !isRValRef; 3368 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3369 ICS.Standard.BindsToRvalue = true; 3370 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3371 } else if (ICS.isUserDefined()) { 3372 ICS.UserDefined.After.ReferenceBinding = true; 3373 ICS.Standard.IsLvalueReference = !isRValRef; 3374 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3375 ICS.Standard.BindsToRvalue = true; 3376 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3377 } 3378 3379 return ICS; 3380} 3381 3382/// TryCopyInitialization - Try to copy-initialize a value of type 3383/// ToType from the expression From. Return the implicit conversion 3384/// sequence required to pass this argument, which may be a bad 3385/// conversion sequence (meaning that the argument cannot be passed to 3386/// a parameter of this type). If @p SuppressUserConversions, then we 3387/// do not permit any user-defined conversion sequences. 3388static ImplicitConversionSequence 3389TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 3390 bool SuppressUserConversions, 3391 bool InOverloadResolution) { 3392 if (ToType->isReferenceType()) 3393 return TryReferenceInit(S, From, ToType, 3394 /*FIXME:*/From->getLocStart(), 3395 SuppressUserConversions, 3396 /*AllowExplicit=*/false); 3397 3398 return TryImplicitConversion(S, From, ToType, 3399 SuppressUserConversions, 3400 /*AllowExplicit=*/false, 3401 InOverloadResolution, 3402 /*CStyle=*/false); 3403} 3404 3405/// TryObjectArgumentInitialization - Try to initialize the object 3406/// parameter of the given member function (@c Method) from the 3407/// expression @p From. 3408static ImplicitConversionSequence 3409TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 3410 Expr::Classification FromClassification, 3411 CXXMethodDecl *Method, 3412 CXXRecordDecl *ActingContext) { 3413 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 3414 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 3415 // const volatile object. 3416 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 3417 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 3418 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 3419 3420 // Set up the conversion sequence as a "bad" conversion, to allow us 3421 // to exit early. 3422 ImplicitConversionSequence ICS; 3423 3424 // We need to have an object of class type. 3425 QualType FromType = OrigFromType; 3426 if (const PointerType *PT = FromType->getAs<PointerType>()) { 3427 FromType = PT->getPointeeType(); 3428 3429 // When we had a pointer, it's implicitly dereferenced, so we 3430 // better have an lvalue. 3431 assert(FromClassification.isLValue()); 3432 } 3433 3434 assert(FromType->isRecordType()); 3435 3436 // C++0x [over.match.funcs]p4: 3437 // For non-static member functions, the type of the implicit object 3438 // parameter is 3439 // 3440 // - "lvalue reference to cv X" for functions declared without a 3441 // ref-qualifier or with the & ref-qualifier 3442 // - "rvalue reference to cv X" for functions declared with the && 3443 // ref-qualifier 3444 // 3445 // where X is the class of which the function is a member and cv is the 3446 // cv-qualification on the member function declaration. 3447 // 3448 // However, when finding an implicit conversion sequence for the argument, we 3449 // are not allowed to create temporaries or perform user-defined conversions 3450 // (C++ [over.match.funcs]p5). We perform a simplified version of 3451 // reference binding here, that allows class rvalues to bind to 3452 // non-constant references. 3453 3454 // First check the qualifiers. 3455 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 3456 if (ImplicitParamType.getCVRQualifiers() 3457 != FromTypeCanon.getLocalCVRQualifiers() && 3458 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 3459 ICS.setBad(BadConversionSequence::bad_qualifiers, 3460 OrigFromType, ImplicitParamType); 3461 return ICS; 3462 } 3463 3464 // Check that we have either the same type or a derived type. It 3465 // affects the conversion rank. 3466 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 3467 ImplicitConversionKind SecondKind; 3468 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 3469 SecondKind = ICK_Identity; 3470 } else if (S.IsDerivedFrom(FromType, ClassType)) 3471 SecondKind = ICK_Derived_To_Base; 3472 else { 3473 ICS.setBad(BadConversionSequence::unrelated_class, 3474 FromType, ImplicitParamType); 3475 return ICS; 3476 } 3477 3478 // Check the ref-qualifier. 3479 switch (Method->getRefQualifier()) { 3480 case RQ_None: 3481 // Do nothing; we don't care about lvalueness or rvalueness. 3482 break; 3483 3484 case RQ_LValue: 3485 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 3486 // non-const lvalue reference cannot bind to an rvalue 3487 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 3488 ImplicitParamType); 3489 return ICS; 3490 } 3491 break; 3492 3493 case RQ_RValue: 3494 if (!FromClassification.isRValue()) { 3495 // rvalue reference cannot bind to an lvalue 3496 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 3497 ImplicitParamType); 3498 return ICS; 3499 } 3500 break; 3501 } 3502 3503 // Success. Mark this as a reference binding. 3504 ICS.setStandard(); 3505 ICS.Standard.setAsIdentityConversion(); 3506 ICS.Standard.Second = SecondKind; 3507 ICS.Standard.setFromType(FromType); 3508 ICS.Standard.setAllToTypes(ImplicitParamType); 3509 ICS.Standard.ReferenceBinding = true; 3510 ICS.Standard.DirectBinding = true; 3511 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 3512 ICS.Standard.BindsToFunctionLvalue = false; 3513 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 3514 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 3515 = (Method->getRefQualifier() == RQ_None); 3516 return ICS; 3517} 3518 3519/// PerformObjectArgumentInitialization - Perform initialization of 3520/// the implicit object parameter for the given Method with the given 3521/// expression. 3522bool 3523Sema::PerformObjectArgumentInitialization(Expr *&From, 3524 NestedNameSpecifier *Qualifier, 3525 NamedDecl *FoundDecl, 3526 CXXMethodDecl *Method) { 3527 QualType FromRecordType, DestType; 3528 QualType ImplicitParamRecordType = 3529 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3530 3531 Expr::Classification FromClassification; 3532 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3533 FromRecordType = PT->getPointeeType(); 3534 DestType = Method->getThisType(Context); 3535 FromClassification = Expr::Classification::makeSimpleLValue(); 3536 } else { 3537 FromRecordType = From->getType(); 3538 DestType = ImplicitParamRecordType; 3539 FromClassification = From->Classify(Context); 3540 } 3541 3542 // Note that we always use the true parent context when performing 3543 // the actual argument initialization. 3544 ImplicitConversionSequence ICS 3545 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 3546 Method, Method->getParent()); 3547 if (ICS.isBad()) { 3548 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 3549 Qualifiers FromQs = FromRecordType.getQualifiers(); 3550 Qualifiers ToQs = DestType.getQualifiers(); 3551 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 3552 if (CVR) { 3553 Diag(From->getSourceRange().getBegin(), 3554 diag::err_member_function_call_bad_cvr) 3555 << Method->getDeclName() << FromRecordType << (CVR - 1) 3556 << From->getSourceRange(); 3557 Diag(Method->getLocation(), diag::note_previous_decl) 3558 << Method->getDeclName(); 3559 return true; 3560 } 3561 } 3562 3563 return Diag(From->getSourceRange().getBegin(), 3564 diag::err_implicit_object_parameter_init) 3565 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3566 } 3567 3568 if (ICS.Standard.Second == ICK_Derived_To_Base) 3569 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3570 3571 if (!Context.hasSameType(From->getType(), DestType)) 3572 ImpCastExprToType(From, DestType, CK_NoOp, 3573 From->getType()->isPointerType() ? VK_RValue : VK_LValue); 3574 return false; 3575} 3576 3577/// TryContextuallyConvertToBool - Attempt to contextually convert the 3578/// expression From to bool (C++0x [conv]p3). 3579static ImplicitConversionSequence 3580TryContextuallyConvertToBool(Sema &S, Expr *From) { 3581 // FIXME: This is pretty broken. 3582 return TryImplicitConversion(S, From, S.Context.BoolTy, 3583 // FIXME: Are these flags correct? 3584 /*SuppressUserConversions=*/false, 3585 /*AllowExplicit=*/true, 3586 /*InOverloadResolution=*/false, 3587 /*CStyle=*/false); 3588} 3589 3590/// PerformContextuallyConvertToBool - Perform a contextual conversion 3591/// of the expression From to bool (C++0x [conv]p3). 3592bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3593 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 3594 if (!ICS.isBad()) 3595 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3596 3597 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3598 return Diag(From->getSourceRange().getBegin(), 3599 diag::err_typecheck_bool_condition) 3600 << From->getType() << From->getSourceRange(); 3601 return true; 3602} 3603 3604/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3605/// expression From to 'id'. 3606static ImplicitConversionSequence 3607TryContextuallyConvertToObjCId(Sema &S, Expr *From) { 3608 QualType Ty = S.Context.getObjCIdType(); 3609 return TryImplicitConversion(S, From, Ty, 3610 // FIXME: Are these flags correct? 3611 /*SuppressUserConversions=*/false, 3612 /*AllowExplicit=*/true, 3613 /*InOverloadResolution=*/false, 3614 /*CStyle=*/false); 3615} 3616 3617/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3618/// of the expression From to 'id'. 3619bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3620 QualType Ty = Context.getObjCIdType(); 3621 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(*this, From); 3622 if (!ICS.isBad()) 3623 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3624 return true; 3625} 3626 3627/// \brief Attempt to convert the given expression to an integral or 3628/// enumeration type. 3629/// 3630/// This routine will attempt to convert an expression of class type to an 3631/// integral or enumeration type, if that class type only has a single 3632/// conversion to an integral or enumeration type. 3633/// 3634/// \param Loc The source location of the construct that requires the 3635/// conversion. 3636/// 3637/// \param FromE The expression we're converting from. 3638/// 3639/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3640/// have integral or enumeration type. 3641/// 3642/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3643/// incomplete class type. 3644/// 3645/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3646/// explicit conversion function (because no implicit conversion functions 3647/// were available). This is a recovery mode. 3648/// 3649/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3650/// showing which conversion was picked. 3651/// 3652/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3653/// conversion function that could convert to integral or enumeration type. 3654/// 3655/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3656/// usable conversion function. 3657/// 3658/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3659/// function, which may be an extension in this case. 3660/// 3661/// \returns The expression, converted to an integral or enumeration type if 3662/// successful. 3663ExprResult 3664Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 3665 const PartialDiagnostic &NotIntDiag, 3666 const PartialDiagnostic &IncompleteDiag, 3667 const PartialDiagnostic &ExplicitConvDiag, 3668 const PartialDiagnostic &ExplicitConvNote, 3669 const PartialDiagnostic &AmbigDiag, 3670 const PartialDiagnostic &AmbigNote, 3671 const PartialDiagnostic &ConvDiag) { 3672 // We can't perform any more checking for type-dependent expressions. 3673 if (From->isTypeDependent()) 3674 return Owned(From); 3675 3676 // If the expression already has integral or enumeration type, we're golden. 3677 QualType T = From->getType(); 3678 if (T->isIntegralOrEnumerationType()) 3679 return Owned(From); 3680 3681 // FIXME: Check for missing '()' if T is a function type? 3682 3683 // If we don't have a class type in C++, there's no way we can get an 3684 // expression of integral or enumeration type. 3685 const RecordType *RecordTy = T->getAs<RecordType>(); 3686 if (!RecordTy || !getLangOptions().CPlusPlus) { 3687 Diag(Loc, NotIntDiag) 3688 << T << From->getSourceRange(); 3689 return Owned(From); 3690 } 3691 3692 // We must have a complete class type. 3693 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3694 return Owned(From); 3695 3696 // Look for a conversion to an integral or enumeration type. 3697 UnresolvedSet<4> ViableConversions; 3698 UnresolvedSet<4> ExplicitConversions; 3699 const UnresolvedSetImpl *Conversions 3700 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3701 3702 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3703 E = Conversions->end(); 3704 I != E; 3705 ++I) { 3706 if (CXXConversionDecl *Conversion 3707 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3708 if (Conversion->getConversionType().getNonReferenceType() 3709 ->isIntegralOrEnumerationType()) { 3710 if (Conversion->isExplicit()) 3711 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3712 else 3713 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3714 } 3715 } 3716 3717 switch (ViableConversions.size()) { 3718 case 0: 3719 if (ExplicitConversions.size() == 1) { 3720 DeclAccessPair Found = ExplicitConversions[0]; 3721 CXXConversionDecl *Conversion 3722 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3723 3724 // The user probably meant to invoke the given explicit 3725 // conversion; use it. 3726 QualType ConvTy 3727 = Conversion->getConversionType().getNonReferenceType(); 3728 std::string TypeStr; 3729 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3730 3731 Diag(Loc, ExplicitConvDiag) 3732 << T << ConvTy 3733 << FixItHint::CreateInsertion(From->getLocStart(), 3734 "static_cast<" + TypeStr + ">(") 3735 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3736 ")"); 3737 Diag(Conversion->getLocation(), ExplicitConvNote) 3738 << ConvTy->isEnumeralType() << ConvTy; 3739 3740 // If we aren't in a SFINAE context, build a call to the 3741 // explicit conversion function. 3742 if (isSFINAEContext()) 3743 return ExprError(); 3744 3745 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3746 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion); 3747 if (Result.isInvalid()) 3748 return ExprError(); 3749 3750 From = Result.get(); 3751 } 3752 3753 // We'll complain below about a non-integral condition type. 3754 break; 3755 3756 case 1: { 3757 // Apply this conversion. 3758 DeclAccessPair Found = ViableConversions[0]; 3759 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3760 3761 CXXConversionDecl *Conversion 3762 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3763 QualType ConvTy 3764 = Conversion->getConversionType().getNonReferenceType(); 3765 if (ConvDiag.getDiagID()) { 3766 if (isSFINAEContext()) 3767 return ExprError(); 3768 3769 Diag(Loc, ConvDiag) 3770 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 3771 } 3772 3773 ExprResult Result = BuildCXXMemberCallExpr(From, Found, 3774 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3775 if (Result.isInvalid()) 3776 return ExprError(); 3777 3778 From = Result.get(); 3779 break; 3780 } 3781 3782 default: 3783 Diag(Loc, AmbigDiag) 3784 << T << From->getSourceRange(); 3785 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3786 CXXConversionDecl *Conv 3787 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3788 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3789 Diag(Conv->getLocation(), AmbigNote) 3790 << ConvTy->isEnumeralType() << ConvTy; 3791 } 3792 return Owned(From); 3793 } 3794 3795 if (!From->getType()->isIntegralOrEnumerationType()) 3796 Diag(Loc, NotIntDiag) 3797 << From->getType() << From->getSourceRange(); 3798 3799 return Owned(From); 3800} 3801 3802/// AddOverloadCandidate - Adds the given function to the set of 3803/// candidate functions, using the given function call arguments. If 3804/// @p SuppressUserConversions, then don't allow user-defined 3805/// conversions via constructors or conversion operators. 3806/// 3807/// \para PartialOverloading true if we are performing "partial" overloading 3808/// based on an incomplete set of function arguments. This feature is used by 3809/// code completion. 3810void 3811Sema::AddOverloadCandidate(FunctionDecl *Function, 3812 DeclAccessPair FoundDecl, 3813 Expr **Args, unsigned NumArgs, 3814 OverloadCandidateSet& CandidateSet, 3815 bool SuppressUserConversions, 3816 bool PartialOverloading) { 3817 const FunctionProtoType* Proto 3818 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3819 assert(Proto && "Functions without a prototype cannot be overloaded"); 3820 assert(!Function->getDescribedFunctionTemplate() && 3821 "Use AddTemplateOverloadCandidate for function templates"); 3822 3823 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3824 if (!isa<CXXConstructorDecl>(Method)) { 3825 // If we get here, it's because we're calling a member function 3826 // that is named without a member access expression (e.g., 3827 // "this->f") that was either written explicitly or created 3828 // implicitly. This can happen with a qualified call to a member 3829 // function, e.g., X::f(). We use an empty type for the implied 3830 // object argument (C++ [over.call.func]p3), and the acting context 3831 // is irrelevant. 3832 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3833 QualType(), Expr::Classification::makeSimpleLValue(), 3834 Args, NumArgs, CandidateSet, 3835 SuppressUserConversions); 3836 return; 3837 } 3838 // We treat a constructor like a non-member function, since its object 3839 // argument doesn't participate in overload resolution. 3840 } 3841 3842 if (!CandidateSet.isNewCandidate(Function)) 3843 return; 3844 3845 // Overload resolution is always an unevaluated context. 3846 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 3847 3848 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3849 // C++ [class.copy]p3: 3850 // A member function template is never instantiated to perform the copy 3851 // of a class object to an object of its class type. 3852 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3853 if (NumArgs == 1 && 3854 Constructor->isSpecializationCopyingObject() && 3855 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3856 IsDerivedFrom(Args[0]->getType(), ClassType))) 3857 return; 3858 } 3859 3860 // Add this candidate 3861 CandidateSet.push_back(OverloadCandidate()); 3862 OverloadCandidate& Candidate = CandidateSet.back(); 3863 Candidate.FoundDecl = FoundDecl; 3864 Candidate.Function = Function; 3865 Candidate.Viable = true; 3866 Candidate.IsSurrogate = false; 3867 Candidate.IgnoreObjectArgument = false; 3868 Candidate.ExplicitCallArguments = NumArgs; 3869 3870 unsigned NumArgsInProto = Proto->getNumArgs(); 3871 3872 // (C++ 13.3.2p2): A candidate function having fewer than m 3873 // parameters is viable only if it has an ellipsis in its parameter 3874 // list (8.3.5). 3875 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3876 !Proto->isVariadic()) { 3877 Candidate.Viable = false; 3878 Candidate.FailureKind = ovl_fail_too_many_arguments; 3879 return; 3880 } 3881 3882 // (C++ 13.3.2p2): A candidate function having more than m parameters 3883 // is viable only if the (m+1)st parameter has a default argument 3884 // (8.3.6). For the purposes of overload resolution, the 3885 // parameter list is truncated on the right, so that there are 3886 // exactly m parameters. 3887 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3888 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3889 // Not enough arguments. 3890 Candidate.Viable = false; 3891 Candidate.FailureKind = ovl_fail_too_few_arguments; 3892 return; 3893 } 3894 3895 // Determine the implicit conversion sequences for each of the 3896 // arguments. 3897 Candidate.Conversions.resize(NumArgs); 3898 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3899 if (ArgIdx < NumArgsInProto) { 3900 // (C++ 13.3.2p3): for F to be a viable function, there shall 3901 // exist for each argument an implicit conversion sequence 3902 // (13.3.3.1) that converts that argument to the corresponding 3903 // parameter of F. 3904 QualType ParamType = Proto->getArgType(ArgIdx); 3905 Candidate.Conversions[ArgIdx] 3906 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3907 SuppressUserConversions, 3908 /*InOverloadResolution=*/true); 3909 if (Candidate.Conversions[ArgIdx].isBad()) { 3910 Candidate.Viable = false; 3911 Candidate.FailureKind = ovl_fail_bad_conversion; 3912 break; 3913 } 3914 } else { 3915 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3916 // argument for which there is no corresponding parameter is 3917 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3918 Candidate.Conversions[ArgIdx].setEllipsis(); 3919 } 3920 } 3921} 3922 3923/// \brief Add all of the function declarations in the given function set to 3924/// the overload canddiate set. 3925void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3926 Expr **Args, unsigned NumArgs, 3927 OverloadCandidateSet& CandidateSet, 3928 bool SuppressUserConversions) { 3929 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3930 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3931 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3932 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3933 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3934 cast<CXXMethodDecl>(FD)->getParent(), 3935 Args[0]->getType(), Args[0]->Classify(Context), 3936 Args + 1, NumArgs - 1, 3937 CandidateSet, SuppressUserConversions); 3938 else 3939 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3940 SuppressUserConversions); 3941 } else { 3942 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3943 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3944 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3945 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3946 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3947 /*FIXME: explicit args */ 0, 3948 Args[0]->getType(), 3949 Args[0]->Classify(Context), 3950 Args + 1, NumArgs - 1, 3951 CandidateSet, 3952 SuppressUserConversions); 3953 else 3954 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3955 /*FIXME: explicit args */ 0, 3956 Args, NumArgs, CandidateSet, 3957 SuppressUserConversions); 3958 } 3959 } 3960} 3961 3962/// AddMethodCandidate - Adds a named decl (which is some kind of 3963/// method) as a method candidate to the given overload set. 3964void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3965 QualType ObjectType, 3966 Expr::Classification ObjectClassification, 3967 Expr **Args, unsigned NumArgs, 3968 OverloadCandidateSet& CandidateSet, 3969 bool SuppressUserConversions) { 3970 NamedDecl *Decl = FoundDecl.getDecl(); 3971 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3972 3973 if (isa<UsingShadowDecl>(Decl)) 3974 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3975 3976 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3977 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3978 "Expected a member function template"); 3979 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3980 /*ExplicitArgs*/ 0, 3981 ObjectType, ObjectClassification, Args, NumArgs, 3982 CandidateSet, 3983 SuppressUserConversions); 3984 } else { 3985 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3986 ObjectType, ObjectClassification, Args, NumArgs, 3987 CandidateSet, SuppressUserConversions); 3988 } 3989} 3990 3991/// AddMethodCandidate - Adds the given C++ member function to the set 3992/// of candidate functions, using the given function call arguments 3993/// and the object argument (@c Object). For example, in a call 3994/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3995/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3996/// allow user-defined conversions via constructors or conversion 3997/// operators. 3998void 3999Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 4000 CXXRecordDecl *ActingContext, QualType ObjectType, 4001 Expr::Classification ObjectClassification, 4002 Expr **Args, unsigned NumArgs, 4003 OverloadCandidateSet& CandidateSet, 4004 bool SuppressUserConversions) { 4005 const FunctionProtoType* Proto 4006 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 4007 assert(Proto && "Methods without a prototype cannot be overloaded"); 4008 assert(!isa<CXXConstructorDecl>(Method) && 4009 "Use AddOverloadCandidate for constructors"); 4010 4011 if (!CandidateSet.isNewCandidate(Method)) 4012 return; 4013 4014 // Overload resolution is always an unevaluated context. 4015 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4016 4017 // Add this candidate 4018 CandidateSet.push_back(OverloadCandidate()); 4019 OverloadCandidate& Candidate = CandidateSet.back(); 4020 Candidate.FoundDecl = FoundDecl; 4021 Candidate.Function = Method; 4022 Candidate.IsSurrogate = false; 4023 Candidate.IgnoreObjectArgument = false; 4024 Candidate.ExplicitCallArguments = NumArgs; 4025 4026 unsigned NumArgsInProto = Proto->getNumArgs(); 4027 4028 // (C++ 13.3.2p2): A candidate function having fewer than m 4029 // parameters is viable only if it has an ellipsis in its parameter 4030 // list (8.3.5). 4031 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4032 Candidate.Viable = false; 4033 Candidate.FailureKind = ovl_fail_too_many_arguments; 4034 return; 4035 } 4036 4037 // (C++ 13.3.2p2): A candidate function having more than m parameters 4038 // is viable only if the (m+1)st parameter has a default argument 4039 // (8.3.6). For the purposes of overload resolution, the 4040 // parameter list is truncated on the right, so that there are 4041 // exactly m parameters. 4042 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 4043 if (NumArgs < MinRequiredArgs) { 4044 // Not enough arguments. 4045 Candidate.Viable = false; 4046 Candidate.FailureKind = ovl_fail_too_few_arguments; 4047 return; 4048 } 4049 4050 Candidate.Viable = true; 4051 Candidate.Conversions.resize(NumArgs + 1); 4052 4053 if (Method->isStatic() || ObjectType.isNull()) 4054 // The implicit object argument is ignored. 4055 Candidate.IgnoreObjectArgument = true; 4056 else { 4057 // Determine the implicit conversion sequence for the object 4058 // parameter. 4059 Candidate.Conversions[0] 4060 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 4061 Method, ActingContext); 4062 if (Candidate.Conversions[0].isBad()) { 4063 Candidate.Viable = false; 4064 Candidate.FailureKind = ovl_fail_bad_conversion; 4065 return; 4066 } 4067 } 4068 4069 // Determine the implicit conversion sequences for each of the 4070 // arguments. 4071 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4072 if (ArgIdx < NumArgsInProto) { 4073 // (C++ 13.3.2p3): for F to be a viable function, there shall 4074 // exist for each argument an implicit conversion sequence 4075 // (13.3.3.1) that converts that argument to the corresponding 4076 // parameter of F. 4077 QualType ParamType = Proto->getArgType(ArgIdx); 4078 Candidate.Conversions[ArgIdx + 1] 4079 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4080 SuppressUserConversions, 4081 /*InOverloadResolution=*/true); 4082 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4083 Candidate.Viable = false; 4084 Candidate.FailureKind = ovl_fail_bad_conversion; 4085 break; 4086 } 4087 } else { 4088 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4089 // argument for which there is no corresponding parameter is 4090 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4091 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4092 } 4093 } 4094} 4095 4096/// \brief Add a C++ member function template as a candidate to the candidate 4097/// set, using template argument deduction to produce an appropriate member 4098/// function template specialization. 4099void 4100Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 4101 DeclAccessPair FoundDecl, 4102 CXXRecordDecl *ActingContext, 4103 TemplateArgumentListInfo *ExplicitTemplateArgs, 4104 QualType ObjectType, 4105 Expr::Classification ObjectClassification, 4106 Expr **Args, unsigned NumArgs, 4107 OverloadCandidateSet& CandidateSet, 4108 bool SuppressUserConversions) { 4109 if (!CandidateSet.isNewCandidate(MethodTmpl)) 4110 return; 4111 4112 // C++ [over.match.funcs]p7: 4113 // In each case where a candidate is a function template, candidate 4114 // function template specializations are generated using template argument 4115 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4116 // candidate functions in the usual way.113) A given name can refer to one 4117 // or more function templates and also to a set of overloaded non-template 4118 // functions. In such a case, the candidate functions generated from each 4119 // function template are combined with the set of non-template candidate 4120 // functions. 4121 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4122 FunctionDecl *Specialization = 0; 4123 if (TemplateDeductionResult Result 4124 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 4125 Args, NumArgs, Specialization, Info)) { 4126 CandidateSet.push_back(OverloadCandidate()); 4127 OverloadCandidate &Candidate = CandidateSet.back(); 4128 Candidate.FoundDecl = FoundDecl; 4129 Candidate.Function = MethodTmpl->getTemplatedDecl(); 4130 Candidate.Viable = false; 4131 Candidate.FailureKind = ovl_fail_bad_deduction; 4132 Candidate.IsSurrogate = false; 4133 Candidate.IgnoreObjectArgument = false; 4134 Candidate.ExplicitCallArguments = NumArgs; 4135 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4136 Info); 4137 return; 4138 } 4139 4140 // Add the function template specialization produced by template argument 4141 // deduction as a candidate. 4142 assert(Specialization && "Missing member function template specialization?"); 4143 assert(isa<CXXMethodDecl>(Specialization) && 4144 "Specialization is not a member function?"); 4145 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 4146 ActingContext, ObjectType, ObjectClassification, 4147 Args, NumArgs, CandidateSet, SuppressUserConversions); 4148} 4149 4150/// \brief Add a C++ function template specialization as a candidate 4151/// in the candidate set, using template argument deduction to produce 4152/// an appropriate function template specialization. 4153void 4154Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 4155 DeclAccessPair FoundDecl, 4156 TemplateArgumentListInfo *ExplicitTemplateArgs, 4157 Expr **Args, unsigned NumArgs, 4158 OverloadCandidateSet& CandidateSet, 4159 bool SuppressUserConversions) { 4160 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4161 return; 4162 4163 // C++ [over.match.funcs]p7: 4164 // In each case where a candidate is a function template, candidate 4165 // function template specializations are generated using template argument 4166 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4167 // candidate functions in the usual way.113) A given name can refer to one 4168 // or more function templates and also to a set of overloaded non-template 4169 // functions. In such a case, the candidate functions generated from each 4170 // function template are combined with the set of non-template candidate 4171 // functions. 4172 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4173 FunctionDecl *Specialization = 0; 4174 if (TemplateDeductionResult Result 4175 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 4176 Args, NumArgs, Specialization, Info)) { 4177 CandidateSet.push_back(OverloadCandidate()); 4178 OverloadCandidate &Candidate = CandidateSet.back(); 4179 Candidate.FoundDecl = FoundDecl; 4180 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4181 Candidate.Viable = false; 4182 Candidate.FailureKind = ovl_fail_bad_deduction; 4183 Candidate.IsSurrogate = false; 4184 Candidate.IgnoreObjectArgument = false; 4185 Candidate.ExplicitCallArguments = NumArgs; 4186 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4187 Info); 4188 return; 4189 } 4190 4191 // Add the function template specialization produced by template argument 4192 // deduction as a candidate. 4193 assert(Specialization && "Missing function template specialization?"); 4194 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 4195 SuppressUserConversions); 4196} 4197 4198/// AddConversionCandidate - Add a C++ conversion function as a 4199/// candidate in the candidate set (C++ [over.match.conv], 4200/// C++ [over.match.copy]). From is the expression we're converting from, 4201/// and ToType is the type that we're eventually trying to convert to 4202/// (which may or may not be the same type as the type that the 4203/// conversion function produces). 4204void 4205Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 4206 DeclAccessPair FoundDecl, 4207 CXXRecordDecl *ActingContext, 4208 Expr *From, QualType ToType, 4209 OverloadCandidateSet& CandidateSet) { 4210 assert(!Conversion->getDescribedFunctionTemplate() && 4211 "Conversion function templates use AddTemplateConversionCandidate"); 4212 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 4213 if (!CandidateSet.isNewCandidate(Conversion)) 4214 return; 4215 4216 // Overload resolution is always an unevaluated context. 4217 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4218 4219 // Add this candidate 4220 CandidateSet.push_back(OverloadCandidate()); 4221 OverloadCandidate& Candidate = CandidateSet.back(); 4222 Candidate.FoundDecl = FoundDecl; 4223 Candidate.Function = Conversion; 4224 Candidate.IsSurrogate = false; 4225 Candidate.IgnoreObjectArgument = false; 4226 Candidate.FinalConversion.setAsIdentityConversion(); 4227 Candidate.FinalConversion.setFromType(ConvType); 4228 Candidate.FinalConversion.setAllToTypes(ToType); 4229 Candidate.Viable = true; 4230 Candidate.Conversions.resize(1); 4231 Candidate.ExplicitCallArguments = 1; 4232 4233 // C++ [over.match.funcs]p4: 4234 // For conversion functions, the function is considered to be a member of 4235 // the class of the implicit implied object argument for the purpose of 4236 // defining the type of the implicit object parameter. 4237 // 4238 // Determine the implicit conversion sequence for the implicit 4239 // object parameter. 4240 QualType ImplicitParamType = From->getType(); 4241 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 4242 ImplicitParamType = FromPtrType->getPointeeType(); 4243 CXXRecordDecl *ConversionContext 4244 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 4245 4246 Candidate.Conversions[0] 4247 = TryObjectArgumentInitialization(*this, From->getType(), 4248 From->Classify(Context), 4249 Conversion, ConversionContext); 4250 4251 if (Candidate.Conversions[0].isBad()) { 4252 Candidate.Viable = false; 4253 Candidate.FailureKind = ovl_fail_bad_conversion; 4254 return; 4255 } 4256 4257 // We won't go through a user-define type conversion function to convert a 4258 // derived to base as such conversions are given Conversion Rank. They only 4259 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 4260 QualType FromCanon 4261 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 4262 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 4263 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 4264 Candidate.Viable = false; 4265 Candidate.FailureKind = ovl_fail_trivial_conversion; 4266 return; 4267 } 4268 4269 // To determine what the conversion from the result of calling the 4270 // conversion function to the type we're eventually trying to 4271 // convert to (ToType), we need to synthesize a call to the 4272 // conversion function and attempt copy initialization from it. This 4273 // makes sure that we get the right semantics with respect to 4274 // lvalues/rvalues and the type. Fortunately, we can allocate this 4275 // call on the stack and we don't need its arguments to be 4276 // well-formed. 4277 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 4278 VK_LValue, From->getLocStart()); 4279 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 4280 Context.getPointerType(Conversion->getType()), 4281 CK_FunctionToPointerDecay, 4282 &ConversionRef, VK_RValue); 4283 4284 QualType CallResultType 4285 = Conversion->getConversionType().getNonLValueExprType(Context); 4286 if (RequireCompleteType(From->getLocStart(), CallResultType, 0)) { 4287 Candidate.Viable = false; 4288 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4289 return; 4290 } 4291 4292 ExprValueKind VK = Expr::getValueKindForType(Conversion->getConversionType()); 4293 4294 // Note that it is safe to allocate CallExpr on the stack here because 4295 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 4296 // allocator). 4297 CallExpr Call(Context, &ConversionFn, 0, 0, CallResultType, VK, 4298 From->getLocStart()); 4299 ImplicitConversionSequence ICS = 4300 TryCopyInitialization(*this, &Call, ToType, 4301 /*SuppressUserConversions=*/true, 4302 /*InOverloadResolution=*/false); 4303 4304 switch (ICS.getKind()) { 4305 case ImplicitConversionSequence::StandardConversion: 4306 Candidate.FinalConversion = ICS.Standard; 4307 4308 // C++ [over.ics.user]p3: 4309 // If the user-defined conversion is specified by a specialization of a 4310 // conversion function template, the second standard conversion sequence 4311 // shall have exact match rank. 4312 if (Conversion->getPrimaryTemplate() && 4313 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 4314 Candidate.Viable = false; 4315 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 4316 } 4317 4318 // C++0x [dcl.init.ref]p5: 4319 // In the second case, if the reference is an rvalue reference and 4320 // the second standard conversion sequence of the user-defined 4321 // conversion sequence includes an lvalue-to-rvalue conversion, the 4322 // program is ill-formed. 4323 if (ToType->isRValueReferenceType() && 4324 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 4325 Candidate.Viable = false; 4326 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4327 } 4328 break; 4329 4330 case ImplicitConversionSequence::BadConversion: 4331 Candidate.Viable = false; 4332 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4333 break; 4334 4335 default: 4336 assert(false && 4337 "Can only end up with a standard conversion sequence or failure"); 4338 } 4339} 4340 4341/// \brief Adds a conversion function template specialization 4342/// candidate to the overload set, using template argument deduction 4343/// to deduce the template arguments of the conversion function 4344/// template from the type that we are converting to (C++ 4345/// [temp.deduct.conv]). 4346void 4347Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 4348 DeclAccessPair FoundDecl, 4349 CXXRecordDecl *ActingDC, 4350 Expr *From, QualType ToType, 4351 OverloadCandidateSet &CandidateSet) { 4352 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 4353 "Only conversion function templates permitted here"); 4354 4355 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4356 return; 4357 4358 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4359 CXXConversionDecl *Specialization = 0; 4360 if (TemplateDeductionResult Result 4361 = DeduceTemplateArguments(FunctionTemplate, ToType, 4362 Specialization, Info)) { 4363 CandidateSet.push_back(OverloadCandidate()); 4364 OverloadCandidate &Candidate = CandidateSet.back(); 4365 Candidate.FoundDecl = FoundDecl; 4366 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4367 Candidate.Viable = false; 4368 Candidate.FailureKind = ovl_fail_bad_deduction; 4369 Candidate.IsSurrogate = false; 4370 Candidate.IgnoreObjectArgument = false; 4371 Candidate.ExplicitCallArguments = 1; 4372 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4373 Info); 4374 return; 4375 } 4376 4377 // Add the conversion function template specialization produced by 4378 // template argument deduction as a candidate. 4379 assert(Specialization && "Missing function template specialization?"); 4380 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 4381 CandidateSet); 4382} 4383 4384/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 4385/// converts the given @c Object to a function pointer via the 4386/// conversion function @c Conversion, and then attempts to call it 4387/// with the given arguments (C++ [over.call.object]p2-4). Proto is 4388/// the type of function that we'll eventually be calling. 4389void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 4390 DeclAccessPair FoundDecl, 4391 CXXRecordDecl *ActingContext, 4392 const FunctionProtoType *Proto, 4393 Expr *Object, 4394 Expr **Args, unsigned NumArgs, 4395 OverloadCandidateSet& CandidateSet) { 4396 if (!CandidateSet.isNewCandidate(Conversion)) 4397 return; 4398 4399 // Overload resolution is always an unevaluated context. 4400 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4401 4402 CandidateSet.push_back(OverloadCandidate()); 4403 OverloadCandidate& Candidate = CandidateSet.back(); 4404 Candidate.FoundDecl = FoundDecl; 4405 Candidate.Function = 0; 4406 Candidate.Surrogate = Conversion; 4407 Candidate.Viable = true; 4408 Candidate.IsSurrogate = true; 4409 Candidate.IgnoreObjectArgument = false; 4410 Candidate.Conversions.resize(NumArgs + 1); 4411 Candidate.ExplicitCallArguments = NumArgs; 4412 4413 // Determine the implicit conversion sequence for the implicit 4414 // object parameter. 4415 ImplicitConversionSequence ObjectInit 4416 = TryObjectArgumentInitialization(*this, Object->getType(), 4417 Object->Classify(Context), 4418 Conversion, ActingContext); 4419 if (ObjectInit.isBad()) { 4420 Candidate.Viable = false; 4421 Candidate.FailureKind = ovl_fail_bad_conversion; 4422 Candidate.Conversions[0] = ObjectInit; 4423 return; 4424 } 4425 4426 // The first conversion is actually a user-defined conversion whose 4427 // first conversion is ObjectInit's standard conversion (which is 4428 // effectively a reference binding). Record it as such. 4429 Candidate.Conversions[0].setUserDefined(); 4430 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 4431 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 4432 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 4433 Candidate.Conversions[0].UserDefined.FoundConversionFunction 4434 = FoundDecl.getDecl(); 4435 Candidate.Conversions[0].UserDefined.After 4436 = Candidate.Conversions[0].UserDefined.Before; 4437 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 4438 4439 // Find the 4440 unsigned NumArgsInProto = Proto->getNumArgs(); 4441 4442 // (C++ 13.3.2p2): A candidate function having fewer than m 4443 // parameters is viable only if it has an ellipsis in its parameter 4444 // list (8.3.5). 4445 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4446 Candidate.Viable = false; 4447 Candidate.FailureKind = ovl_fail_too_many_arguments; 4448 return; 4449 } 4450 4451 // Function types don't have any default arguments, so just check if 4452 // we have enough arguments. 4453 if (NumArgs < NumArgsInProto) { 4454 // Not enough arguments. 4455 Candidate.Viable = false; 4456 Candidate.FailureKind = ovl_fail_too_few_arguments; 4457 return; 4458 } 4459 4460 // Determine the implicit conversion sequences for each of the 4461 // arguments. 4462 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4463 if (ArgIdx < NumArgsInProto) { 4464 // (C++ 13.3.2p3): for F to be a viable function, there shall 4465 // exist for each argument an implicit conversion sequence 4466 // (13.3.3.1) that converts that argument to the corresponding 4467 // parameter of F. 4468 QualType ParamType = Proto->getArgType(ArgIdx); 4469 Candidate.Conversions[ArgIdx + 1] 4470 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4471 /*SuppressUserConversions=*/false, 4472 /*InOverloadResolution=*/false); 4473 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4474 Candidate.Viable = false; 4475 Candidate.FailureKind = ovl_fail_bad_conversion; 4476 break; 4477 } 4478 } else { 4479 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4480 // argument for which there is no corresponding parameter is 4481 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4482 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4483 } 4484 } 4485} 4486 4487/// \brief Add overload candidates for overloaded operators that are 4488/// member functions. 4489/// 4490/// Add the overloaded operator candidates that are member functions 4491/// for the operator Op that was used in an operator expression such 4492/// as "x Op y". , Args/NumArgs provides the operator arguments, and 4493/// CandidateSet will store the added overload candidates. (C++ 4494/// [over.match.oper]). 4495void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 4496 SourceLocation OpLoc, 4497 Expr **Args, unsigned NumArgs, 4498 OverloadCandidateSet& CandidateSet, 4499 SourceRange OpRange) { 4500 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4501 4502 // C++ [over.match.oper]p3: 4503 // For a unary operator @ with an operand of a type whose 4504 // cv-unqualified version is T1, and for a binary operator @ with 4505 // a left operand of a type whose cv-unqualified version is T1 and 4506 // a right operand of a type whose cv-unqualified version is T2, 4507 // three sets of candidate functions, designated member 4508 // candidates, non-member candidates and built-in candidates, are 4509 // constructed as follows: 4510 QualType T1 = Args[0]->getType(); 4511 4512 // -- If T1 is a class type, the set of member candidates is the 4513 // result of the qualified lookup of T1::operator@ 4514 // (13.3.1.1.1); otherwise, the set of member candidates is 4515 // empty. 4516 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 4517 // Complete the type if it can be completed. Otherwise, we're done. 4518 if (RequireCompleteType(OpLoc, T1, PDiag())) 4519 return; 4520 4521 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 4522 LookupQualifiedName(Operators, T1Rec->getDecl()); 4523 Operators.suppressDiagnostics(); 4524 4525 for (LookupResult::iterator Oper = Operators.begin(), 4526 OperEnd = Operators.end(); 4527 Oper != OperEnd; 4528 ++Oper) 4529 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 4530 Args[0]->Classify(Context), Args + 1, NumArgs - 1, 4531 CandidateSet, 4532 /* SuppressUserConversions = */ false); 4533 } 4534} 4535 4536/// AddBuiltinCandidate - Add a candidate for a built-in 4537/// operator. ResultTy and ParamTys are the result and parameter types 4538/// of the built-in candidate, respectively. Args and NumArgs are the 4539/// arguments being passed to the candidate. IsAssignmentOperator 4540/// should be true when this built-in candidate is an assignment 4541/// operator. NumContextualBoolArguments is the number of arguments 4542/// (at the beginning of the argument list) that will be contextually 4543/// converted to bool. 4544void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 4545 Expr **Args, unsigned NumArgs, 4546 OverloadCandidateSet& CandidateSet, 4547 bool IsAssignmentOperator, 4548 unsigned NumContextualBoolArguments) { 4549 // Overload resolution is always an unevaluated context. 4550 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4551 4552 // Add this candidate 4553 CandidateSet.push_back(OverloadCandidate()); 4554 OverloadCandidate& Candidate = CandidateSet.back(); 4555 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 4556 Candidate.Function = 0; 4557 Candidate.IsSurrogate = false; 4558 Candidate.IgnoreObjectArgument = false; 4559 Candidate.BuiltinTypes.ResultTy = ResultTy; 4560 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4561 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 4562 4563 // Determine the implicit conversion sequences for each of the 4564 // arguments. 4565 Candidate.Viable = true; 4566 Candidate.Conversions.resize(NumArgs); 4567 Candidate.ExplicitCallArguments = NumArgs; 4568 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4569 // C++ [over.match.oper]p4: 4570 // For the built-in assignment operators, conversions of the 4571 // left operand are restricted as follows: 4572 // -- no temporaries are introduced to hold the left operand, and 4573 // -- no user-defined conversions are applied to the left 4574 // operand to achieve a type match with the left-most 4575 // parameter of a built-in candidate. 4576 // 4577 // We block these conversions by turning off user-defined 4578 // conversions, since that is the only way that initialization of 4579 // a reference to a non-class type can occur from something that 4580 // is not of the same type. 4581 if (ArgIdx < NumContextualBoolArguments) { 4582 assert(ParamTys[ArgIdx] == Context.BoolTy && 4583 "Contextual conversion to bool requires bool type"); 4584 Candidate.Conversions[ArgIdx] 4585 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 4586 } else { 4587 Candidate.Conversions[ArgIdx] 4588 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4589 ArgIdx == 0 && IsAssignmentOperator, 4590 /*InOverloadResolution=*/false); 4591 } 4592 if (Candidate.Conversions[ArgIdx].isBad()) { 4593 Candidate.Viable = false; 4594 Candidate.FailureKind = ovl_fail_bad_conversion; 4595 break; 4596 } 4597 } 4598} 4599 4600/// BuiltinCandidateTypeSet - A set of types that will be used for the 4601/// candidate operator functions for built-in operators (C++ 4602/// [over.built]). The types are separated into pointer types and 4603/// enumeration types. 4604class BuiltinCandidateTypeSet { 4605 /// TypeSet - A set of types. 4606 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4607 4608 /// PointerTypes - The set of pointer types that will be used in the 4609 /// built-in candidates. 4610 TypeSet PointerTypes; 4611 4612 /// MemberPointerTypes - The set of member pointer types that will be 4613 /// used in the built-in candidates. 4614 TypeSet MemberPointerTypes; 4615 4616 /// EnumerationTypes - The set of enumeration types that will be 4617 /// used in the built-in candidates. 4618 TypeSet EnumerationTypes; 4619 4620 /// \brief The set of vector types that will be used in the built-in 4621 /// candidates. 4622 TypeSet VectorTypes; 4623 4624 /// \brief A flag indicating non-record types are viable candidates 4625 bool HasNonRecordTypes; 4626 4627 /// \brief A flag indicating whether either arithmetic or enumeration types 4628 /// were present in the candidate set. 4629 bool HasArithmeticOrEnumeralTypes; 4630 4631 /// Sema - The semantic analysis instance where we are building the 4632 /// candidate type set. 4633 Sema &SemaRef; 4634 4635 /// Context - The AST context in which we will build the type sets. 4636 ASTContext &Context; 4637 4638 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4639 const Qualifiers &VisibleQuals); 4640 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4641 4642public: 4643 /// iterator - Iterates through the types that are part of the set. 4644 typedef TypeSet::iterator iterator; 4645 4646 BuiltinCandidateTypeSet(Sema &SemaRef) 4647 : HasNonRecordTypes(false), 4648 HasArithmeticOrEnumeralTypes(false), 4649 SemaRef(SemaRef), 4650 Context(SemaRef.Context) { } 4651 4652 void AddTypesConvertedFrom(QualType Ty, 4653 SourceLocation Loc, 4654 bool AllowUserConversions, 4655 bool AllowExplicitConversions, 4656 const Qualifiers &VisibleTypeConversionsQuals); 4657 4658 /// pointer_begin - First pointer type found; 4659 iterator pointer_begin() { return PointerTypes.begin(); } 4660 4661 /// pointer_end - Past the last pointer type found; 4662 iterator pointer_end() { return PointerTypes.end(); } 4663 4664 /// member_pointer_begin - First member pointer type found; 4665 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4666 4667 /// member_pointer_end - Past the last member pointer type found; 4668 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4669 4670 /// enumeration_begin - First enumeration type found; 4671 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4672 4673 /// enumeration_end - Past the last enumeration type found; 4674 iterator enumeration_end() { return EnumerationTypes.end(); } 4675 4676 iterator vector_begin() { return VectorTypes.begin(); } 4677 iterator vector_end() { return VectorTypes.end(); } 4678 4679 bool hasNonRecordTypes() { return HasNonRecordTypes; } 4680 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 4681}; 4682 4683/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4684/// the set of pointer types along with any more-qualified variants of 4685/// that type. For example, if @p Ty is "int const *", this routine 4686/// will add "int const *", "int const volatile *", "int const 4687/// restrict *", and "int const volatile restrict *" to the set of 4688/// pointer types. Returns true if the add of @p Ty itself succeeded, 4689/// false otherwise. 4690/// 4691/// FIXME: what to do about extended qualifiers? 4692bool 4693BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4694 const Qualifiers &VisibleQuals) { 4695 4696 // Insert this type. 4697 if (!PointerTypes.insert(Ty)) 4698 return false; 4699 4700 QualType PointeeTy; 4701 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4702 bool buildObjCPtr = false; 4703 if (!PointerTy) { 4704 if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) { 4705 PointeeTy = PTy->getPointeeType(); 4706 buildObjCPtr = true; 4707 } 4708 else 4709 assert(false && "type was not a pointer type!"); 4710 } 4711 else 4712 PointeeTy = PointerTy->getPointeeType(); 4713 4714 // Don't add qualified variants of arrays. For one, they're not allowed 4715 // (the qualifier would sink to the element type), and for another, the 4716 // only overload situation where it matters is subscript or pointer +- int, 4717 // and those shouldn't have qualifier variants anyway. 4718 if (PointeeTy->isArrayType()) 4719 return true; 4720 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4721 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4722 BaseCVR = Array->getElementType().getCVRQualifiers(); 4723 bool hasVolatile = VisibleQuals.hasVolatile(); 4724 bool hasRestrict = VisibleQuals.hasRestrict(); 4725 4726 // Iterate through all strict supersets of BaseCVR. 4727 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4728 if ((CVR | BaseCVR) != CVR) continue; 4729 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4730 // in the types. 4731 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4732 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4733 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4734 if (!buildObjCPtr) 4735 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4736 else 4737 PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); 4738 } 4739 4740 return true; 4741} 4742 4743/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4744/// to the set of pointer types along with any more-qualified variants of 4745/// that type. For example, if @p Ty is "int const *", this routine 4746/// will add "int const *", "int const volatile *", "int const 4747/// restrict *", and "int const volatile restrict *" to the set of 4748/// pointer types. Returns true if the add of @p Ty itself succeeded, 4749/// false otherwise. 4750/// 4751/// FIXME: what to do about extended qualifiers? 4752bool 4753BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4754 QualType Ty) { 4755 // Insert this type. 4756 if (!MemberPointerTypes.insert(Ty)) 4757 return false; 4758 4759 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4760 assert(PointerTy && "type was not a member pointer type!"); 4761 4762 QualType PointeeTy = PointerTy->getPointeeType(); 4763 // Don't add qualified variants of arrays. For one, they're not allowed 4764 // (the qualifier would sink to the element type), and for another, the 4765 // only overload situation where it matters is subscript or pointer +- int, 4766 // and those shouldn't have qualifier variants anyway. 4767 if (PointeeTy->isArrayType()) 4768 return true; 4769 const Type *ClassTy = PointerTy->getClass(); 4770 4771 // Iterate through all strict supersets of the pointee type's CVR 4772 // qualifiers. 4773 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4774 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4775 if ((CVR | BaseCVR) != CVR) continue; 4776 4777 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4778 MemberPointerTypes.insert( 4779 Context.getMemberPointerType(QPointeeTy, ClassTy)); 4780 } 4781 4782 return true; 4783} 4784 4785/// AddTypesConvertedFrom - Add each of the types to which the type @p 4786/// Ty can be implicit converted to the given set of @p Types. We're 4787/// primarily interested in pointer types and enumeration types. We also 4788/// take member pointer types, for the conditional operator. 4789/// AllowUserConversions is true if we should look at the conversion 4790/// functions of a class type, and AllowExplicitConversions if we 4791/// should also include the explicit conversion functions of a class 4792/// type. 4793void 4794BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4795 SourceLocation Loc, 4796 bool AllowUserConversions, 4797 bool AllowExplicitConversions, 4798 const Qualifiers &VisibleQuals) { 4799 // Only deal with canonical types. 4800 Ty = Context.getCanonicalType(Ty); 4801 4802 // Look through reference types; they aren't part of the type of an 4803 // expression for the purposes of conversions. 4804 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4805 Ty = RefTy->getPointeeType(); 4806 4807 // If we're dealing with an array type, decay to the pointer. 4808 if (Ty->isArrayType()) 4809 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4810 4811 // Otherwise, we don't care about qualifiers on the type. 4812 Ty = Ty.getLocalUnqualifiedType(); 4813 4814 // Flag if we ever add a non-record type. 4815 const RecordType *TyRec = Ty->getAs<RecordType>(); 4816 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 4817 4818 // Flag if we encounter an arithmetic type. 4819 HasArithmeticOrEnumeralTypes = 4820 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 4821 4822 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 4823 PointerTypes.insert(Ty); 4824 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 4825 // Insert our type, and its more-qualified variants, into the set 4826 // of types. 4827 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4828 return; 4829 } else if (Ty->isMemberPointerType()) { 4830 // Member pointers are far easier, since the pointee can't be converted. 4831 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4832 return; 4833 } else if (Ty->isEnumeralType()) { 4834 HasArithmeticOrEnumeralTypes = true; 4835 EnumerationTypes.insert(Ty); 4836 } else if (Ty->isVectorType()) { 4837 // We treat vector types as arithmetic types in many contexts as an 4838 // extension. 4839 HasArithmeticOrEnumeralTypes = true; 4840 VectorTypes.insert(Ty); 4841 } else if (AllowUserConversions && TyRec) { 4842 // No conversion functions in incomplete types. 4843 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 4844 return; 4845 4846 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4847 const UnresolvedSetImpl *Conversions 4848 = ClassDecl->getVisibleConversionFunctions(); 4849 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4850 E = Conversions->end(); I != E; ++I) { 4851 NamedDecl *D = I.getDecl(); 4852 if (isa<UsingShadowDecl>(D)) 4853 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4854 4855 // Skip conversion function templates; they don't tell us anything 4856 // about which builtin types we can convert to. 4857 if (isa<FunctionTemplateDecl>(D)) 4858 continue; 4859 4860 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4861 if (AllowExplicitConversions || !Conv->isExplicit()) { 4862 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4863 VisibleQuals); 4864 } 4865 } 4866 } 4867} 4868 4869/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4870/// the volatile- and non-volatile-qualified assignment operators for the 4871/// given type to the candidate set. 4872static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4873 QualType T, 4874 Expr **Args, 4875 unsigned NumArgs, 4876 OverloadCandidateSet &CandidateSet) { 4877 QualType ParamTypes[2]; 4878 4879 // T& operator=(T&, T) 4880 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4881 ParamTypes[1] = T; 4882 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4883 /*IsAssignmentOperator=*/true); 4884 4885 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4886 // volatile T& operator=(volatile T&, T) 4887 ParamTypes[0] 4888 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4889 ParamTypes[1] = T; 4890 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4891 /*IsAssignmentOperator=*/true); 4892 } 4893} 4894 4895/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4896/// if any, found in visible type conversion functions found in ArgExpr's type. 4897static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4898 Qualifiers VRQuals; 4899 const RecordType *TyRec; 4900 if (const MemberPointerType *RHSMPType = 4901 ArgExpr->getType()->getAs<MemberPointerType>()) 4902 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4903 else 4904 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4905 if (!TyRec) { 4906 // Just to be safe, assume the worst case. 4907 VRQuals.addVolatile(); 4908 VRQuals.addRestrict(); 4909 return VRQuals; 4910 } 4911 4912 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4913 if (!ClassDecl->hasDefinition()) 4914 return VRQuals; 4915 4916 const UnresolvedSetImpl *Conversions = 4917 ClassDecl->getVisibleConversionFunctions(); 4918 4919 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4920 E = Conversions->end(); I != E; ++I) { 4921 NamedDecl *D = I.getDecl(); 4922 if (isa<UsingShadowDecl>(D)) 4923 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4924 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4925 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4926 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4927 CanTy = ResTypeRef->getPointeeType(); 4928 // Need to go down the pointer/mempointer chain and add qualifiers 4929 // as see them. 4930 bool done = false; 4931 while (!done) { 4932 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4933 CanTy = ResTypePtr->getPointeeType(); 4934 else if (const MemberPointerType *ResTypeMPtr = 4935 CanTy->getAs<MemberPointerType>()) 4936 CanTy = ResTypeMPtr->getPointeeType(); 4937 else 4938 done = true; 4939 if (CanTy.isVolatileQualified()) 4940 VRQuals.addVolatile(); 4941 if (CanTy.isRestrictQualified()) 4942 VRQuals.addRestrict(); 4943 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4944 return VRQuals; 4945 } 4946 } 4947 } 4948 return VRQuals; 4949} 4950 4951namespace { 4952 4953/// \brief Helper class to manage the addition of builtin operator overload 4954/// candidates. It provides shared state and utility methods used throughout 4955/// the process, as well as a helper method to add each group of builtin 4956/// operator overloads from the standard to a candidate set. 4957class BuiltinOperatorOverloadBuilder { 4958 // Common instance state available to all overload candidate addition methods. 4959 Sema &S; 4960 Expr **Args; 4961 unsigned NumArgs; 4962 Qualifiers VisibleTypeConversionsQuals; 4963 bool HasArithmeticOrEnumeralCandidateType; 4964 llvm::SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 4965 OverloadCandidateSet &CandidateSet; 4966 4967 // Define some constants used to index and iterate over the arithemetic types 4968 // provided via the getArithmeticType() method below. 4969 // The "promoted arithmetic types" are the arithmetic 4970 // types are that preserved by promotion (C++ [over.built]p2). 4971 static const unsigned FirstIntegralType = 3; 4972 static const unsigned LastIntegralType = 18; 4973 static const unsigned FirstPromotedIntegralType = 3, 4974 LastPromotedIntegralType = 9; 4975 static const unsigned FirstPromotedArithmeticType = 0, 4976 LastPromotedArithmeticType = 9; 4977 static const unsigned NumArithmeticTypes = 18; 4978 4979 /// \brief Get the canonical type for a given arithmetic type index. 4980 CanQualType getArithmeticType(unsigned index) { 4981 assert(index < NumArithmeticTypes); 4982 static CanQualType ASTContext::* const 4983 ArithmeticTypes[NumArithmeticTypes] = { 4984 // Start of promoted types. 4985 &ASTContext::FloatTy, 4986 &ASTContext::DoubleTy, 4987 &ASTContext::LongDoubleTy, 4988 4989 // Start of integral types. 4990 &ASTContext::IntTy, 4991 &ASTContext::LongTy, 4992 &ASTContext::LongLongTy, 4993 &ASTContext::UnsignedIntTy, 4994 &ASTContext::UnsignedLongTy, 4995 &ASTContext::UnsignedLongLongTy, 4996 // End of promoted types. 4997 4998 &ASTContext::BoolTy, 4999 &ASTContext::CharTy, 5000 &ASTContext::WCharTy, 5001 &ASTContext::Char16Ty, 5002 &ASTContext::Char32Ty, 5003 &ASTContext::SignedCharTy, 5004 &ASTContext::ShortTy, 5005 &ASTContext::UnsignedCharTy, 5006 &ASTContext::UnsignedShortTy, 5007 // End of integral types. 5008 // FIXME: What about complex? 5009 }; 5010 return S.Context.*ArithmeticTypes[index]; 5011 } 5012 5013 /// \brief Gets the canonical type resulting from the usual arithemetic 5014 /// converions for the given arithmetic types. 5015 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 5016 // Accelerator table for performing the usual arithmetic conversions. 5017 // The rules are basically: 5018 // - if either is floating-point, use the wider floating-point 5019 // - if same signedness, use the higher rank 5020 // - if same size, use unsigned of the higher rank 5021 // - use the larger type 5022 // These rules, together with the axiom that higher ranks are 5023 // never smaller, are sufficient to precompute all of these results 5024 // *except* when dealing with signed types of higher rank. 5025 // (we could precompute SLL x UI for all known platforms, but it's 5026 // better not to make any assumptions). 5027 enum PromotedType { 5028 Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL, Dep=-1 5029 }; 5030 static PromotedType ConversionsTable[LastPromotedArithmeticType] 5031 [LastPromotedArithmeticType] = { 5032 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt }, 5033 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 5034 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 5035 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL }, 5036 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, Dep, UL, ULL }, 5037 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, Dep, Dep, ULL }, 5038 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, UI, UL, ULL }, 5039 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, UL, UL, ULL }, 5040 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, ULL, ULL, ULL }, 5041 }; 5042 5043 assert(L < LastPromotedArithmeticType); 5044 assert(R < LastPromotedArithmeticType); 5045 int Idx = ConversionsTable[L][R]; 5046 5047 // Fast path: the table gives us a concrete answer. 5048 if (Idx != Dep) return getArithmeticType(Idx); 5049 5050 // Slow path: we need to compare widths. 5051 // An invariant is that the signed type has higher rank. 5052 CanQualType LT = getArithmeticType(L), 5053 RT = getArithmeticType(R); 5054 unsigned LW = S.Context.getIntWidth(LT), 5055 RW = S.Context.getIntWidth(RT); 5056 5057 // If they're different widths, use the signed type. 5058 if (LW > RW) return LT; 5059 else if (LW < RW) return RT; 5060 5061 // Otherwise, use the unsigned type of the signed type's rank. 5062 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 5063 assert(L == SLL || R == SLL); 5064 return S.Context.UnsignedLongLongTy; 5065 } 5066 5067 /// \brief Helper method to factor out the common pattern of adding overloads 5068 /// for '++' and '--' builtin operators. 5069 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 5070 bool HasVolatile) { 5071 QualType ParamTypes[2] = { 5072 S.Context.getLValueReferenceType(CandidateTy), 5073 S.Context.IntTy 5074 }; 5075 5076 // Non-volatile version. 5077 if (NumArgs == 1) 5078 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5079 else 5080 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5081 5082 // Use a heuristic to reduce number of builtin candidates in the set: 5083 // add volatile version only if there are conversions to a volatile type. 5084 if (HasVolatile) { 5085 ParamTypes[0] = 5086 S.Context.getLValueReferenceType( 5087 S.Context.getVolatileType(CandidateTy)); 5088 if (NumArgs == 1) 5089 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5090 else 5091 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5092 } 5093 } 5094 5095public: 5096 BuiltinOperatorOverloadBuilder( 5097 Sema &S, Expr **Args, unsigned NumArgs, 5098 Qualifiers VisibleTypeConversionsQuals, 5099 bool HasArithmeticOrEnumeralCandidateType, 5100 llvm::SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 5101 OverloadCandidateSet &CandidateSet) 5102 : S(S), Args(Args), NumArgs(NumArgs), 5103 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 5104 HasArithmeticOrEnumeralCandidateType( 5105 HasArithmeticOrEnumeralCandidateType), 5106 CandidateTypes(CandidateTypes), 5107 CandidateSet(CandidateSet) { 5108 // Validate some of our static helper constants in debug builds. 5109 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 5110 "Invalid first promoted integral type"); 5111 assert(getArithmeticType(LastPromotedIntegralType - 1) 5112 == S.Context.UnsignedLongLongTy && 5113 "Invalid last promoted integral type"); 5114 assert(getArithmeticType(FirstPromotedArithmeticType) 5115 == S.Context.FloatTy && 5116 "Invalid first promoted arithmetic type"); 5117 assert(getArithmeticType(LastPromotedArithmeticType - 1) 5118 == S.Context.UnsignedLongLongTy && 5119 "Invalid last promoted arithmetic type"); 5120 } 5121 5122 // C++ [over.built]p3: 5123 // 5124 // For every pair (T, VQ), where T is an arithmetic type, and VQ 5125 // is either volatile or empty, there exist candidate operator 5126 // functions of the form 5127 // 5128 // VQ T& operator++(VQ T&); 5129 // T operator++(VQ T&, int); 5130 // 5131 // C++ [over.built]p4: 5132 // 5133 // For every pair (T, VQ), where T is an arithmetic type other 5134 // than bool, and VQ is either volatile or empty, there exist 5135 // candidate operator functions of the form 5136 // 5137 // VQ T& operator--(VQ T&); 5138 // T operator--(VQ T&, int); 5139 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 5140 if (!HasArithmeticOrEnumeralCandidateType) 5141 return; 5142 5143 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 5144 Arith < NumArithmeticTypes; ++Arith) { 5145 addPlusPlusMinusMinusStyleOverloads( 5146 getArithmeticType(Arith), 5147 VisibleTypeConversionsQuals.hasVolatile()); 5148 } 5149 } 5150 5151 // C++ [over.built]p5: 5152 // 5153 // For every pair (T, VQ), where T is a cv-qualified or 5154 // cv-unqualified object type, and VQ is either volatile or 5155 // empty, there exist candidate operator functions of the form 5156 // 5157 // T*VQ& operator++(T*VQ&); 5158 // T*VQ& operator--(T*VQ&); 5159 // T* operator++(T*VQ&, int); 5160 // T* operator--(T*VQ&, int); 5161 void addPlusPlusMinusMinusPointerOverloads() { 5162 for (BuiltinCandidateTypeSet::iterator 5163 Ptr = CandidateTypes[0].pointer_begin(), 5164 PtrEnd = CandidateTypes[0].pointer_end(); 5165 Ptr != PtrEnd; ++Ptr) { 5166 // Skip pointer types that aren't pointers to object types. 5167 if (!(*Ptr)->getPointeeType()->isObjectType()) 5168 continue; 5169 5170 addPlusPlusMinusMinusStyleOverloads(*Ptr, 5171 (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5172 VisibleTypeConversionsQuals.hasVolatile())); 5173 } 5174 } 5175 5176 // C++ [over.built]p6: 5177 // For every cv-qualified or cv-unqualified object type T, there 5178 // exist candidate operator functions of the form 5179 // 5180 // T& operator*(T*); 5181 // 5182 // C++ [over.built]p7: 5183 // For every function type T that does not have cv-qualifiers or a 5184 // ref-qualifier, there exist candidate operator functions of the form 5185 // T& operator*(T*); 5186 void addUnaryStarPointerOverloads() { 5187 for (BuiltinCandidateTypeSet::iterator 5188 Ptr = CandidateTypes[0].pointer_begin(), 5189 PtrEnd = CandidateTypes[0].pointer_end(); 5190 Ptr != PtrEnd; ++Ptr) { 5191 QualType ParamTy = *Ptr; 5192 QualType PointeeTy = ParamTy->getPointeeType(); 5193 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 5194 continue; 5195 5196 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 5197 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 5198 continue; 5199 5200 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 5201 &ParamTy, Args, 1, CandidateSet); 5202 } 5203 } 5204 5205 // C++ [over.built]p9: 5206 // For every promoted arithmetic type T, there exist candidate 5207 // operator functions of the form 5208 // 5209 // T operator+(T); 5210 // T operator-(T); 5211 void addUnaryPlusOrMinusArithmeticOverloads() { 5212 if (!HasArithmeticOrEnumeralCandidateType) 5213 return; 5214 5215 for (unsigned Arith = FirstPromotedArithmeticType; 5216 Arith < LastPromotedArithmeticType; ++Arith) { 5217 QualType ArithTy = getArithmeticType(Arith); 5218 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 5219 } 5220 5221 // Extension: We also add these operators for vector types. 5222 for (BuiltinCandidateTypeSet::iterator 5223 Vec = CandidateTypes[0].vector_begin(), 5224 VecEnd = CandidateTypes[0].vector_end(); 5225 Vec != VecEnd; ++Vec) { 5226 QualType VecTy = *Vec; 5227 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5228 } 5229 } 5230 5231 // C++ [over.built]p8: 5232 // For every type T, there exist candidate operator functions of 5233 // the form 5234 // 5235 // T* operator+(T*); 5236 void addUnaryPlusPointerOverloads() { 5237 for (BuiltinCandidateTypeSet::iterator 5238 Ptr = CandidateTypes[0].pointer_begin(), 5239 PtrEnd = CandidateTypes[0].pointer_end(); 5240 Ptr != PtrEnd; ++Ptr) { 5241 QualType ParamTy = *Ptr; 5242 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 5243 } 5244 } 5245 5246 // C++ [over.built]p10: 5247 // For every promoted integral type T, there exist candidate 5248 // operator functions of the form 5249 // 5250 // T operator~(T); 5251 void addUnaryTildePromotedIntegralOverloads() { 5252 if (!HasArithmeticOrEnumeralCandidateType) 5253 return; 5254 5255 for (unsigned Int = FirstPromotedIntegralType; 5256 Int < LastPromotedIntegralType; ++Int) { 5257 QualType IntTy = getArithmeticType(Int); 5258 S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 5259 } 5260 5261 // Extension: We also add this operator for vector types. 5262 for (BuiltinCandidateTypeSet::iterator 5263 Vec = CandidateTypes[0].vector_begin(), 5264 VecEnd = CandidateTypes[0].vector_end(); 5265 Vec != VecEnd; ++Vec) { 5266 QualType VecTy = *Vec; 5267 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5268 } 5269 } 5270 5271 // C++ [over.match.oper]p16: 5272 // For every pointer to member type T, there exist candidate operator 5273 // functions of the form 5274 // 5275 // bool operator==(T,T); 5276 // bool operator!=(T,T); 5277 void addEqualEqualOrNotEqualMemberPointerOverloads() { 5278 /// Set of (canonical) types that we've already handled. 5279 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5280 5281 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5282 for (BuiltinCandidateTypeSet::iterator 5283 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5284 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5285 MemPtr != MemPtrEnd; 5286 ++MemPtr) { 5287 // Don't add the same builtin candidate twice. 5288 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5289 continue; 5290 5291 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5292 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5293 CandidateSet); 5294 } 5295 } 5296 } 5297 5298 // C++ [over.built]p15: 5299 // 5300 // For every pointer or enumeration type T, there exist 5301 // candidate operator functions of the form 5302 // 5303 // bool operator<(T, T); 5304 // bool operator>(T, T); 5305 // bool operator<=(T, T); 5306 // bool operator>=(T, T); 5307 // bool operator==(T, T); 5308 // bool operator!=(T, T); 5309 void addRelationalPointerOrEnumeralOverloads() { 5310 // C++ [over.built]p1: 5311 // If there is a user-written candidate with the same name and parameter 5312 // types as a built-in candidate operator function, the built-in operator 5313 // function is hidden and is not included in the set of candidate 5314 // functions. 5315 // 5316 // The text is actually in a note, but if we don't implement it then we end 5317 // up with ambiguities when the user provides an overloaded operator for 5318 // an enumeration type. Note that only enumeration types have this problem, 5319 // so we track which enumeration types we've seen operators for. Also, the 5320 // only other overloaded operator with enumeration argumenst, operator=, 5321 // cannot be overloaded for enumeration types, so this is the only place 5322 // where we must suppress candidates like this. 5323 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 5324 UserDefinedBinaryOperators; 5325 5326 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5327 if (CandidateTypes[ArgIdx].enumeration_begin() != 5328 CandidateTypes[ArgIdx].enumeration_end()) { 5329 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 5330 CEnd = CandidateSet.end(); 5331 C != CEnd; ++C) { 5332 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 5333 continue; 5334 5335 QualType FirstParamType = 5336 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 5337 QualType SecondParamType = 5338 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 5339 5340 // Skip if either parameter isn't of enumeral type. 5341 if (!FirstParamType->isEnumeralType() || 5342 !SecondParamType->isEnumeralType()) 5343 continue; 5344 5345 // Add this operator to the set of known user-defined operators. 5346 UserDefinedBinaryOperators.insert( 5347 std::make_pair(S.Context.getCanonicalType(FirstParamType), 5348 S.Context.getCanonicalType(SecondParamType))); 5349 } 5350 } 5351 } 5352 5353 /// Set of (canonical) types that we've already handled. 5354 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5355 5356 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5357 for (BuiltinCandidateTypeSet::iterator 5358 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5359 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5360 Ptr != PtrEnd; ++Ptr) { 5361 // Don't add the same builtin candidate twice. 5362 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5363 continue; 5364 5365 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5366 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5367 CandidateSet); 5368 } 5369 for (BuiltinCandidateTypeSet::iterator 5370 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5371 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5372 Enum != EnumEnd; ++Enum) { 5373 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 5374 5375 // Don't add the same builtin candidate twice, or if a user defined 5376 // candidate exists. 5377 if (!AddedTypes.insert(CanonType) || 5378 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 5379 CanonType))) 5380 continue; 5381 5382 QualType ParamTypes[2] = { *Enum, *Enum }; 5383 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5384 CandidateSet); 5385 } 5386 } 5387 } 5388 5389 // C++ [over.built]p13: 5390 // 5391 // For every cv-qualified or cv-unqualified object type T 5392 // there exist candidate operator functions of the form 5393 // 5394 // T* operator+(T*, ptrdiff_t); 5395 // T& operator[](T*, ptrdiff_t); [BELOW] 5396 // T* operator-(T*, ptrdiff_t); 5397 // T* operator+(ptrdiff_t, T*); 5398 // T& operator[](ptrdiff_t, T*); [BELOW] 5399 // 5400 // C++ [over.built]p14: 5401 // 5402 // For every T, where T is a pointer to object type, there 5403 // exist candidate operator functions of the form 5404 // 5405 // ptrdiff_t operator-(T, T); 5406 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 5407 /// Set of (canonical) types that we've already handled. 5408 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5409 5410 for (int Arg = 0; Arg < 2; ++Arg) { 5411 QualType AsymetricParamTypes[2] = { 5412 S.Context.getPointerDiffType(), 5413 S.Context.getPointerDiffType(), 5414 }; 5415 for (BuiltinCandidateTypeSet::iterator 5416 Ptr = CandidateTypes[Arg].pointer_begin(), 5417 PtrEnd = CandidateTypes[Arg].pointer_end(); 5418 Ptr != PtrEnd; ++Ptr) { 5419 QualType PointeeTy = (*Ptr)->getPointeeType(); 5420 if (!PointeeTy->isObjectType()) 5421 continue; 5422 5423 AsymetricParamTypes[Arg] = *Ptr; 5424 if (Arg == 0 || Op == OO_Plus) { 5425 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 5426 // T* operator+(ptrdiff_t, T*); 5427 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, 5428 CandidateSet); 5429 } 5430 if (Op == OO_Minus) { 5431 // ptrdiff_t operator-(T, T); 5432 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5433 continue; 5434 5435 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5436 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 5437 Args, 2, CandidateSet); 5438 } 5439 } 5440 } 5441 } 5442 5443 // C++ [over.built]p12: 5444 // 5445 // For every pair of promoted arithmetic types L and R, there 5446 // exist candidate operator functions of the form 5447 // 5448 // LR operator*(L, R); 5449 // LR operator/(L, R); 5450 // LR operator+(L, R); 5451 // LR operator-(L, R); 5452 // bool operator<(L, R); 5453 // bool operator>(L, R); 5454 // bool operator<=(L, R); 5455 // bool operator>=(L, R); 5456 // bool operator==(L, R); 5457 // bool operator!=(L, R); 5458 // 5459 // where LR is the result of the usual arithmetic conversions 5460 // between types L and R. 5461 // 5462 // C++ [over.built]p24: 5463 // 5464 // For every pair of promoted arithmetic types L and R, there exist 5465 // candidate operator functions of the form 5466 // 5467 // LR operator?(bool, L, R); 5468 // 5469 // where LR is the result of the usual arithmetic conversions 5470 // between types L and R. 5471 // Our candidates ignore the first parameter. 5472 void addGenericBinaryArithmeticOverloads(bool isComparison) { 5473 if (!HasArithmeticOrEnumeralCandidateType) 5474 return; 5475 5476 for (unsigned Left = FirstPromotedArithmeticType; 5477 Left < LastPromotedArithmeticType; ++Left) { 5478 for (unsigned Right = FirstPromotedArithmeticType; 5479 Right < LastPromotedArithmeticType; ++Right) { 5480 QualType LandR[2] = { getArithmeticType(Left), 5481 getArithmeticType(Right) }; 5482 QualType Result = 5483 isComparison ? S.Context.BoolTy 5484 : getUsualArithmeticConversions(Left, Right); 5485 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5486 } 5487 } 5488 5489 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 5490 // conditional operator for vector types. 5491 for (BuiltinCandidateTypeSet::iterator 5492 Vec1 = CandidateTypes[0].vector_begin(), 5493 Vec1End = CandidateTypes[0].vector_end(); 5494 Vec1 != Vec1End; ++Vec1) { 5495 for (BuiltinCandidateTypeSet::iterator 5496 Vec2 = CandidateTypes[1].vector_begin(), 5497 Vec2End = CandidateTypes[1].vector_end(); 5498 Vec2 != Vec2End; ++Vec2) { 5499 QualType LandR[2] = { *Vec1, *Vec2 }; 5500 QualType Result = S.Context.BoolTy; 5501 if (!isComparison) { 5502 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 5503 Result = *Vec1; 5504 else 5505 Result = *Vec2; 5506 } 5507 5508 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5509 } 5510 } 5511 } 5512 5513 // C++ [over.built]p17: 5514 // 5515 // For every pair of promoted integral types L and R, there 5516 // exist candidate operator functions of the form 5517 // 5518 // LR operator%(L, R); 5519 // LR operator&(L, R); 5520 // LR operator^(L, R); 5521 // LR operator|(L, R); 5522 // L operator<<(L, R); 5523 // L operator>>(L, R); 5524 // 5525 // where LR is the result of the usual arithmetic conversions 5526 // between types L and R. 5527 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 5528 if (!HasArithmeticOrEnumeralCandidateType) 5529 return; 5530 5531 for (unsigned Left = FirstPromotedIntegralType; 5532 Left < LastPromotedIntegralType; ++Left) { 5533 for (unsigned Right = FirstPromotedIntegralType; 5534 Right < LastPromotedIntegralType; ++Right) { 5535 QualType LandR[2] = { getArithmeticType(Left), 5536 getArithmeticType(Right) }; 5537 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 5538 ? LandR[0] 5539 : getUsualArithmeticConversions(Left, Right); 5540 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5541 } 5542 } 5543 } 5544 5545 // C++ [over.built]p20: 5546 // 5547 // For every pair (T, VQ), where T is an enumeration or 5548 // pointer to member type and VQ is either volatile or 5549 // empty, there exist candidate operator functions of the form 5550 // 5551 // VQ T& operator=(VQ T&, T); 5552 void addAssignmentMemberPointerOrEnumeralOverloads() { 5553 /// Set of (canonical) types that we've already handled. 5554 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5555 5556 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5557 for (BuiltinCandidateTypeSet::iterator 5558 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5559 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5560 Enum != EnumEnd; ++Enum) { 5561 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5562 continue; 5563 5564 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, 5565 CandidateSet); 5566 } 5567 5568 for (BuiltinCandidateTypeSet::iterator 5569 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5570 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5571 MemPtr != MemPtrEnd; ++MemPtr) { 5572 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5573 continue; 5574 5575 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, 5576 CandidateSet); 5577 } 5578 } 5579 } 5580 5581 // C++ [over.built]p19: 5582 // 5583 // For every pair (T, VQ), where T is any type and VQ is either 5584 // volatile or empty, there exist candidate operator functions 5585 // of the form 5586 // 5587 // T*VQ& operator=(T*VQ&, T*); 5588 // 5589 // C++ [over.built]p21: 5590 // 5591 // For every pair (T, VQ), where T is a cv-qualified or 5592 // cv-unqualified object type and VQ is either volatile or 5593 // empty, there exist candidate operator functions of the form 5594 // 5595 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 5596 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 5597 void addAssignmentPointerOverloads(bool isEqualOp) { 5598 /// Set of (canonical) types that we've already handled. 5599 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5600 5601 for (BuiltinCandidateTypeSet::iterator 5602 Ptr = CandidateTypes[0].pointer_begin(), 5603 PtrEnd = CandidateTypes[0].pointer_end(); 5604 Ptr != PtrEnd; ++Ptr) { 5605 // If this is operator=, keep track of the builtin candidates we added. 5606 if (isEqualOp) 5607 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 5608 else if (!(*Ptr)->getPointeeType()->isObjectType()) 5609 continue; 5610 5611 // non-volatile version 5612 QualType ParamTypes[2] = { 5613 S.Context.getLValueReferenceType(*Ptr), 5614 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 5615 }; 5616 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5617 /*IsAssigmentOperator=*/ isEqualOp); 5618 5619 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5620 VisibleTypeConversionsQuals.hasVolatile()) { 5621 // volatile version 5622 ParamTypes[0] = 5623 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5624 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5625 /*IsAssigmentOperator=*/isEqualOp); 5626 } 5627 } 5628 5629 if (isEqualOp) { 5630 for (BuiltinCandidateTypeSet::iterator 5631 Ptr = CandidateTypes[1].pointer_begin(), 5632 PtrEnd = CandidateTypes[1].pointer_end(); 5633 Ptr != PtrEnd; ++Ptr) { 5634 // Make sure we don't add the same candidate twice. 5635 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5636 continue; 5637 5638 QualType ParamTypes[2] = { 5639 S.Context.getLValueReferenceType(*Ptr), 5640 *Ptr, 5641 }; 5642 5643 // non-volatile version 5644 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5645 /*IsAssigmentOperator=*/true); 5646 5647 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5648 VisibleTypeConversionsQuals.hasVolatile()) { 5649 // volatile version 5650 ParamTypes[0] = 5651 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5652 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5653 CandidateSet, /*IsAssigmentOperator=*/true); 5654 } 5655 } 5656 } 5657 } 5658 5659 // C++ [over.built]p18: 5660 // 5661 // For every triple (L, VQ, R), where L is an arithmetic type, 5662 // VQ is either volatile or empty, and R is a promoted 5663 // arithmetic type, there exist candidate operator functions of 5664 // the form 5665 // 5666 // VQ L& operator=(VQ L&, R); 5667 // VQ L& operator*=(VQ L&, R); 5668 // VQ L& operator/=(VQ L&, R); 5669 // VQ L& operator+=(VQ L&, R); 5670 // VQ L& operator-=(VQ L&, R); 5671 void addAssignmentArithmeticOverloads(bool isEqualOp) { 5672 if (!HasArithmeticOrEnumeralCandidateType) 5673 return; 5674 5675 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 5676 for (unsigned Right = FirstPromotedArithmeticType; 5677 Right < LastPromotedArithmeticType; ++Right) { 5678 QualType ParamTypes[2]; 5679 ParamTypes[1] = getArithmeticType(Right); 5680 5681 // Add this built-in operator as a candidate (VQ is empty). 5682 ParamTypes[0] = 5683 S.Context.getLValueReferenceType(getArithmeticType(Left)); 5684 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5685 /*IsAssigmentOperator=*/isEqualOp); 5686 5687 // Add this built-in operator as a candidate (VQ is 'volatile'). 5688 if (VisibleTypeConversionsQuals.hasVolatile()) { 5689 ParamTypes[0] = 5690 S.Context.getVolatileType(getArithmeticType(Left)); 5691 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5692 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5693 CandidateSet, 5694 /*IsAssigmentOperator=*/isEqualOp); 5695 } 5696 } 5697 } 5698 5699 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 5700 for (BuiltinCandidateTypeSet::iterator 5701 Vec1 = CandidateTypes[0].vector_begin(), 5702 Vec1End = CandidateTypes[0].vector_end(); 5703 Vec1 != Vec1End; ++Vec1) { 5704 for (BuiltinCandidateTypeSet::iterator 5705 Vec2 = CandidateTypes[1].vector_begin(), 5706 Vec2End = CandidateTypes[1].vector_end(); 5707 Vec2 != Vec2End; ++Vec2) { 5708 QualType ParamTypes[2]; 5709 ParamTypes[1] = *Vec2; 5710 // Add this built-in operator as a candidate (VQ is empty). 5711 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 5712 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5713 /*IsAssigmentOperator=*/isEqualOp); 5714 5715 // Add this built-in operator as a candidate (VQ is 'volatile'). 5716 if (VisibleTypeConversionsQuals.hasVolatile()) { 5717 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 5718 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5719 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5720 CandidateSet, 5721 /*IsAssigmentOperator=*/isEqualOp); 5722 } 5723 } 5724 } 5725 } 5726 5727 // C++ [over.built]p22: 5728 // 5729 // For every triple (L, VQ, R), where L is an integral type, VQ 5730 // is either volatile or empty, and R is a promoted integral 5731 // type, there exist candidate operator functions of the form 5732 // 5733 // VQ L& operator%=(VQ L&, R); 5734 // VQ L& operator<<=(VQ L&, R); 5735 // VQ L& operator>>=(VQ L&, R); 5736 // VQ L& operator&=(VQ L&, R); 5737 // VQ L& operator^=(VQ L&, R); 5738 // VQ L& operator|=(VQ L&, R); 5739 void addAssignmentIntegralOverloads() { 5740 if (!HasArithmeticOrEnumeralCandidateType) 5741 return; 5742 5743 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 5744 for (unsigned Right = FirstPromotedIntegralType; 5745 Right < LastPromotedIntegralType; ++Right) { 5746 QualType ParamTypes[2]; 5747 ParamTypes[1] = getArithmeticType(Right); 5748 5749 // Add this built-in operator as a candidate (VQ is empty). 5750 ParamTypes[0] = 5751 S.Context.getLValueReferenceType(getArithmeticType(Left)); 5752 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5753 if (VisibleTypeConversionsQuals.hasVolatile()) { 5754 // Add this built-in operator as a candidate (VQ is 'volatile'). 5755 ParamTypes[0] = getArithmeticType(Left); 5756 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 5757 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5758 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5759 CandidateSet); 5760 } 5761 } 5762 } 5763 } 5764 5765 // C++ [over.operator]p23: 5766 // 5767 // There also exist candidate operator functions of the form 5768 // 5769 // bool operator!(bool); 5770 // bool operator&&(bool, bool); 5771 // bool operator||(bool, bool); 5772 void addExclaimOverload() { 5773 QualType ParamTy = S.Context.BoolTy; 5774 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 5775 /*IsAssignmentOperator=*/false, 5776 /*NumContextualBoolArguments=*/1); 5777 } 5778 void addAmpAmpOrPipePipeOverload() { 5779 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 5780 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 5781 /*IsAssignmentOperator=*/false, 5782 /*NumContextualBoolArguments=*/2); 5783 } 5784 5785 // C++ [over.built]p13: 5786 // 5787 // For every cv-qualified or cv-unqualified object type T there 5788 // exist candidate operator functions of the form 5789 // 5790 // T* operator+(T*, ptrdiff_t); [ABOVE] 5791 // T& operator[](T*, ptrdiff_t); 5792 // T* operator-(T*, ptrdiff_t); [ABOVE] 5793 // T* operator+(ptrdiff_t, T*); [ABOVE] 5794 // T& operator[](ptrdiff_t, T*); 5795 void addSubscriptOverloads() { 5796 for (BuiltinCandidateTypeSet::iterator 5797 Ptr = CandidateTypes[0].pointer_begin(), 5798 PtrEnd = CandidateTypes[0].pointer_end(); 5799 Ptr != PtrEnd; ++Ptr) { 5800 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 5801 QualType PointeeType = (*Ptr)->getPointeeType(); 5802 if (!PointeeType->isObjectType()) 5803 continue; 5804 5805 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 5806 5807 // T& operator[](T*, ptrdiff_t) 5808 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5809 } 5810 5811 for (BuiltinCandidateTypeSet::iterator 5812 Ptr = CandidateTypes[1].pointer_begin(), 5813 PtrEnd = CandidateTypes[1].pointer_end(); 5814 Ptr != PtrEnd; ++Ptr) { 5815 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 5816 QualType PointeeType = (*Ptr)->getPointeeType(); 5817 if (!PointeeType->isObjectType()) 5818 continue; 5819 5820 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 5821 5822 // T& operator[](ptrdiff_t, T*) 5823 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5824 } 5825 } 5826 5827 // C++ [over.built]p11: 5828 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 5829 // C1 is the same type as C2 or is a derived class of C2, T is an object 5830 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 5831 // there exist candidate operator functions of the form 5832 // 5833 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 5834 // 5835 // where CV12 is the union of CV1 and CV2. 5836 void addArrowStarOverloads() { 5837 for (BuiltinCandidateTypeSet::iterator 5838 Ptr = CandidateTypes[0].pointer_begin(), 5839 PtrEnd = CandidateTypes[0].pointer_end(); 5840 Ptr != PtrEnd; ++Ptr) { 5841 QualType C1Ty = (*Ptr); 5842 QualType C1; 5843 QualifierCollector Q1; 5844 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 5845 if (!isa<RecordType>(C1)) 5846 continue; 5847 // heuristic to reduce number of builtin candidates in the set. 5848 // Add volatile/restrict version only if there are conversions to a 5849 // volatile/restrict type. 5850 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 5851 continue; 5852 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 5853 continue; 5854 for (BuiltinCandidateTypeSet::iterator 5855 MemPtr = CandidateTypes[1].member_pointer_begin(), 5856 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 5857 MemPtr != MemPtrEnd; ++MemPtr) { 5858 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 5859 QualType C2 = QualType(mptr->getClass(), 0); 5860 C2 = C2.getUnqualifiedType(); 5861 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 5862 break; 5863 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 5864 // build CV12 T& 5865 QualType T = mptr->getPointeeType(); 5866 if (!VisibleTypeConversionsQuals.hasVolatile() && 5867 T.isVolatileQualified()) 5868 continue; 5869 if (!VisibleTypeConversionsQuals.hasRestrict() && 5870 T.isRestrictQualified()) 5871 continue; 5872 T = Q1.apply(S.Context, T); 5873 QualType ResultTy = S.Context.getLValueReferenceType(T); 5874 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5875 } 5876 } 5877 } 5878 5879 // Note that we don't consider the first argument, since it has been 5880 // contextually converted to bool long ago. The candidates below are 5881 // therefore added as binary. 5882 // 5883 // C++ [over.built]p25: 5884 // For every type T, where T is a pointer, pointer-to-member, or scoped 5885 // enumeration type, there exist candidate operator functions of the form 5886 // 5887 // T operator?(bool, T, T); 5888 // 5889 void addConditionalOperatorOverloads() { 5890 /// Set of (canonical) types that we've already handled. 5891 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5892 5893 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5894 for (BuiltinCandidateTypeSet::iterator 5895 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5896 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5897 Ptr != PtrEnd; ++Ptr) { 5898 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5899 continue; 5900 5901 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5902 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5903 } 5904 5905 for (BuiltinCandidateTypeSet::iterator 5906 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5907 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5908 MemPtr != MemPtrEnd; ++MemPtr) { 5909 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5910 continue; 5911 5912 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5913 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); 5914 } 5915 5916 if (S.getLangOptions().CPlusPlus0x) { 5917 for (BuiltinCandidateTypeSet::iterator 5918 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5919 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5920 Enum != EnumEnd; ++Enum) { 5921 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 5922 continue; 5923 5924 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5925 continue; 5926 5927 QualType ParamTypes[2] = { *Enum, *Enum }; 5928 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); 5929 } 5930 } 5931 } 5932 } 5933}; 5934 5935} // end anonymous namespace 5936 5937/// AddBuiltinOperatorCandidates - Add the appropriate built-in 5938/// operator overloads to the candidate set (C++ [over.built]), based 5939/// on the operator @p Op and the arguments given. For example, if the 5940/// operator is a binary '+', this routine might add "int 5941/// operator+(int, int)" to cover integer addition. 5942void 5943Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 5944 SourceLocation OpLoc, 5945 Expr **Args, unsigned NumArgs, 5946 OverloadCandidateSet& CandidateSet) { 5947 // Find all of the types that the arguments can convert to, but only 5948 // if the operator we're looking at has built-in operator candidates 5949 // that make use of these types. Also record whether we encounter non-record 5950 // candidate types or either arithmetic or enumeral candidate types. 5951 Qualifiers VisibleTypeConversionsQuals; 5952 VisibleTypeConversionsQuals.addConst(); 5953 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5954 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 5955 5956 bool HasNonRecordCandidateType = false; 5957 bool HasArithmeticOrEnumeralCandidateType = false; 5958 llvm::SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 5959 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5960 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 5961 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 5962 OpLoc, 5963 true, 5964 (Op == OO_Exclaim || 5965 Op == OO_AmpAmp || 5966 Op == OO_PipePipe), 5967 VisibleTypeConversionsQuals); 5968 HasNonRecordCandidateType = HasNonRecordCandidateType || 5969 CandidateTypes[ArgIdx].hasNonRecordTypes(); 5970 HasArithmeticOrEnumeralCandidateType = 5971 HasArithmeticOrEnumeralCandidateType || 5972 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 5973 } 5974 5975 // Exit early when no non-record types have been added to the candidate set 5976 // for any of the arguments to the operator. 5977 if (!HasNonRecordCandidateType) 5978 return; 5979 5980 // Setup an object to manage the common state for building overloads. 5981 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, 5982 VisibleTypeConversionsQuals, 5983 HasArithmeticOrEnumeralCandidateType, 5984 CandidateTypes, CandidateSet); 5985 5986 // Dispatch over the operation to add in only those overloads which apply. 5987 switch (Op) { 5988 case OO_None: 5989 case NUM_OVERLOADED_OPERATORS: 5990 assert(false && "Expected an overloaded operator"); 5991 break; 5992 5993 case OO_New: 5994 case OO_Delete: 5995 case OO_Array_New: 5996 case OO_Array_Delete: 5997 case OO_Call: 5998 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 5999 break; 6000 6001 case OO_Comma: 6002 case OO_Arrow: 6003 // C++ [over.match.oper]p3: 6004 // -- For the operator ',', the unary operator '&', or the 6005 // operator '->', the built-in candidates set is empty. 6006 break; 6007 6008 case OO_Plus: // '+' is either unary or binary 6009 if (NumArgs == 1) 6010 OpBuilder.addUnaryPlusPointerOverloads(); 6011 // Fall through. 6012 6013 case OO_Minus: // '-' is either unary or binary 6014 if (NumArgs == 1) { 6015 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 6016 } else { 6017 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 6018 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6019 } 6020 break; 6021 6022 case OO_Star: // '*' is either unary or binary 6023 if (NumArgs == 1) 6024 OpBuilder.addUnaryStarPointerOverloads(); 6025 else 6026 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6027 break; 6028 6029 case OO_Slash: 6030 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6031 break; 6032 6033 case OO_PlusPlus: 6034 case OO_MinusMinus: 6035 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 6036 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 6037 break; 6038 6039 case OO_EqualEqual: 6040 case OO_ExclaimEqual: 6041 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 6042 // Fall through. 6043 6044 case OO_Less: 6045 case OO_Greater: 6046 case OO_LessEqual: 6047 case OO_GreaterEqual: 6048 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 6049 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 6050 break; 6051 6052 case OO_Percent: 6053 case OO_Caret: 6054 case OO_Pipe: 6055 case OO_LessLess: 6056 case OO_GreaterGreater: 6057 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6058 break; 6059 6060 case OO_Amp: // '&' is either unary or binary 6061 if (NumArgs == 1) 6062 // C++ [over.match.oper]p3: 6063 // -- For the operator ',', the unary operator '&', or the 6064 // operator '->', the built-in candidates set is empty. 6065 break; 6066 6067 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6068 break; 6069 6070 case OO_Tilde: 6071 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 6072 break; 6073 6074 case OO_Equal: 6075 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 6076 // Fall through. 6077 6078 case OO_PlusEqual: 6079 case OO_MinusEqual: 6080 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 6081 // Fall through. 6082 6083 case OO_StarEqual: 6084 case OO_SlashEqual: 6085 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 6086 break; 6087 6088 case OO_PercentEqual: 6089 case OO_LessLessEqual: 6090 case OO_GreaterGreaterEqual: 6091 case OO_AmpEqual: 6092 case OO_CaretEqual: 6093 case OO_PipeEqual: 6094 OpBuilder.addAssignmentIntegralOverloads(); 6095 break; 6096 6097 case OO_Exclaim: 6098 OpBuilder.addExclaimOverload(); 6099 break; 6100 6101 case OO_AmpAmp: 6102 case OO_PipePipe: 6103 OpBuilder.addAmpAmpOrPipePipeOverload(); 6104 break; 6105 6106 case OO_Subscript: 6107 OpBuilder.addSubscriptOverloads(); 6108 break; 6109 6110 case OO_ArrowStar: 6111 OpBuilder.addArrowStarOverloads(); 6112 break; 6113 6114 case OO_Conditional: 6115 OpBuilder.addConditionalOperatorOverloads(); 6116 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6117 break; 6118 } 6119} 6120 6121/// \brief Add function candidates found via argument-dependent lookup 6122/// to the set of overloading candidates. 6123/// 6124/// This routine performs argument-dependent name lookup based on the 6125/// given function name (which may also be an operator name) and adds 6126/// all of the overload candidates found by ADL to the overload 6127/// candidate set (C++ [basic.lookup.argdep]). 6128void 6129Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 6130 bool Operator, 6131 Expr **Args, unsigned NumArgs, 6132 TemplateArgumentListInfo *ExplicitTemplateArgs, 6133 OverloadCandidateSet& CandidateSet, 6134 bool PartialOverloading) { 6135 ADLResult Fns; 6136 6137 // FIXME: This approach for uniquing ADL results (and removing 6138 // redundant candidates from the set) relies on pointer-equality, 6139 // which means we need to key off the canonical decl. However, 6140 // always going back to the canonical decl might not get us the 6141 // right set of default arguments. What default arguments are 6142 // we supposed to consider on ADL candidates, anyway? 6143 6144 // FIXME: Pass in the explicit template arguments? 6145 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 6146 6147 // Erase all of the candidates we already knew about. 6148 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 6149 CandEnd = CandidateSet.end(); 6150 Cand != CandEnd; ++Cand) 6151 if (Cand->Function) { 6152 Fns.erase(Cand->Function); 6153 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 6154 Fns.erase(FunTmpl); 6155 } 6156 6157 // For each of the ADL candidates we found, add it to the overload 6158 // set. 6159 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 6160 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 6161 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 6162 if (ExplicitTemplateArgs) 6163 continue; 6164 6165 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 6166 false, PartialOverloading); 6167 } else 6168 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 6169 FoundDecl, ExplicitTemplateArgs, 6170 Args, NumArgs, CandidateSet); 6171 } 6172} 6173 6174/// isBetterOverloadCandidate - Determines whether the first overload 6175/// candidate is a better candidate than the second (C++ 13.3.3p1). 6176bool 6177isBetterOverloadCandidate(Sema &S, 6178 const OverloadCandidate &Cand1, 6179 const OverloadCandidate &Cand2, 6180 SourceLocation Loc, 6181 bool UserDefinedConversion) { 6182 // Define viable functions to be better candidates than non-viable 6183 // functions. 6184 if (!Cand2.Viable) 6185 return Cand1.Viable; 6186 else if (!Cand1.Viable) 6187 return false; 6188 6189 // C++ [over.match.best]p1: 6190 // 6191 // -- if F is a static member function, ICS1(F) is defined such 6192 // that ICS1(F) is neither better nor worse than ICS1(G) for 6193 // any function G, and, symmetrically, ICS1(G) is neither 6194 // better nor worse than ICS1(F). 6195 unsigned StartArg = 0; 6196 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 6197 StartArg = 1; 6198 6199 // C++ [over.match.best]p1: 6200 // A viable function F1 is defined to be a better function than another 6201 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 6202 // conversion sequence than ICSi(F2), and then... 6203 unsigned NumArgs = Cand1.Conversions.size(); 6204 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 6205 bool HasBetterConversion = false; 6206 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 6207 switch (CompareImplicitConversionSequences(S, 6208 Cand1.Conversions[ArgIdx], 6209 Cand2.Conversions[ArgIdx])) { 6210 case ImplicitConversionSequence::Better: 6211 // Cand1 has a better conversion sequence. 6212 HasBetterConversion = true; 6213 break; 6214 6215 case ImplicitConversionSequence::Worse: 6216 // Cand1 can't be better than Cand2. 6217 return false; 6218 6219 case ImplicitConversionSequence::Indistinguishable: 6220 // Do nothing. 6221 break; 6222 } 6223 } 6224 6225 // -- for some argument j, ICSj(F1) is a better conversion sequence than 6226 // ICSj(F2), or, if not that, 6227 if (HasBetterConversion) 6228 return true; 6229 6230 // - F1 is a non-template function and F2 is a function template 6231 // specialization, or, if not that, 6232 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 6233 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 6234 return true; 6235 6236 // -- F1 and F2 are function template specializations, and the function 6237 // template for F1 is more specialized than the template for F2 6238 // according to the partial ordering rules described in 14.5.5.2, or, 6239 // if not that, 6240 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 6241 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 6242 if (FunctionTemplateDecl *BetterTemplate 6243 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 6244 Cand2.Function->getPrimaryTemplate(), 6245 Loc, 6246 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 6247 : TPOC_Call, 6248 Cand1.ExplicitCallArguments)) 6249 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 6250 } 6251 6252 // -- the context is an initialization by user-defined conversion 6253 // (see 8.5, 13.3.1.5) and the standard conversion sequence 6254 // from the return type of F1 to the destination type (i.e., 6255 // the type of the entity being initialized) is a better 6256 // conversion sequence than the standard conversion sequence 6257 // from the return type of F2 to the destination type. 6258 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 6259 isa<CXXConversionDecl>(Cand1.Function) && 6260 isa<CXXConversionDecl>(Cand2.Function)) { 6261 switch (CompareStandardConversionSequences(S, 6262 Cand1.FinalConversion, 6263 Cand2.FinalConversion)) { 6264 case ImplicitConversionSequence::Better: 6265 // Cand1 has a better conversion sequence. 6266 return true; 6267 6268 case ImplicitConversionSequence::Worse: 6269 // Cand1 can't be better than Cand2. 6270 return false; 6271 6272 case ImplicitConversionSequence::Indistinguishable: 6273 // Do nothing 6274 break; 6275 } 6276 } 6277 6278 return false; 6279} 6280 6281/// \brief Computes the best viable function (C++ 13.3.3) 6282/// within an overload candidate set. 6283/// 6284/// \param CandidateSet the set of candidate functions. 6285/// 6286/// \param Loc the location of the function name (or operator symbol) for 6287/// which overload resolution occurs. 6288/// 6289/// \param Best f overload resolution was successful or found a deleted 6290/// function, Best points to the candidate function found. 6291/// 6292/// \returns The result of overload resolution. 6293OverloadingResult 6294OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 6295 iterator &Best, 6296 bool UserDefinedConversion) { 6297 // Find the best viable function. 6298 Best = end(); 6299 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6300 if (Cand->Viable) 6301 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 6302 UserDefinedConversion)) 6303 Best = Cand; 6304 } 6305 6306 // If we didn't find any viable functions, abort. 6307 if (Best == end()) 6308 return OR_No_Viable_Function; 6309 6310 // Make sure that this function is better than every other viable 6311 // function. If not, we have an ambiguity. 6312 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6313 if (Cand->Viable && 6314 Cand != Best && 6315 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 6316 UserDefinedConversion)) { 6317 Best = end(); 6318 return OR_Ambiguous; 6319 } 6320 } 6321 6322 // Best is the best viable function. 6323 if (Best->Function && 6324 (Best->Function->isDeleted() || Best->Function->isUnavailable())) 6325 return OR_Deleted; 6326 6327 return OR_Success; 6328} 6329 6330namespace { 6331 6332enum OverloadCandidateKind { 6333 oc_function, 6334 oc_method, 6335 oc_constructor, 6336 oc_function_template, 6337 oc_method_template, 6338 oc_constructor_template, 6339 oc_implicit_default_constructor, 6340 oc_implicit_copy_constructor, 6341 oc_implicit_copy_assignment, 6342 oc_implicit_inherited_constructor 6343}; 6344 6345OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 6346 FunctionDecl *Fn, 6347 std::string &Description) { 6348 bool isTemplate = false; 6349 6350 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 6351 isTemplate = true; 6352 Description = S.getTemplateArgumentBindingsText( 6353 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 6354 } 6355 6356 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 6357 if (!Ctor->isImplicit()) 6358 return isTemplate ? oc_constructor_template : oc_constructor; 6359 6360 if (Ctor->getInheritedConstructor()) 6361 return oc_implicit_inherited_constructor; 6362 6363 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 6364 : oc_implicit_default_constructor; 6365 } 6366 6367 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 6368 // This actually gets spelled 'candidate function' for now, but 6369 // it doesn't hurt to split it out. 6370 if (!Meth->isImplicit()) 6371 return isTemplate ? oc_method_template : oc_method; 6372 6373 assert(Meth->isCopyAssignmentOperator() 6374 && "implicit method is not copy assignment operator?"); 6375 return oc_implicit_copy_assignment; 6376 } 6377 6378 return isTemplate ? oc_function_template : oc_function; 6379} 6380 6381void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { 6382 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 6383 if (!Ctor) return; 6384 6385 Ctor = Ctor->getInheritedConstructor(); 6386 if (!Ctor) return; 6387 6388 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 6389} 6390 6391} // end anonymous namespace 6392 6393// Notes the location of an overload candidate. 6394void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 6395 std::string FnDesc; 6396 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 6397 Diag(Fn->getLocation(), diag::note_ovl_candidate) 6398 << (unsigned) K << FnDesc; 6399 MaybeEmitInheritedConstructorNote(*this, Fn); 6400} 6401 6402//Notes the location of all overload candidates designated through 6403// OverloadedExpr 6404void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr) { 6405 assert(OverloadedExpr->getType() == Context.OverloadTy); 6406 6407 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); 6408 OverloadExpr *OvlExpr = Ovl.Expression; 6409 6410 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6411 IEnd = OvlExpr->decls_end(); 6412 I != IEnd; ++I) { 6413 if (FunctionTemplateDecl *FunTmpl = 6414 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) { 6415 NoteOverloadCandidate(FunTmpl->getTemplatedDecl()); 6416 } else if (FunctionDecl *Fun 6417 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) { 6418 NoteOverloadCandidate(Fun); 6419 } 6420 } 6421} 6422 6423/// Diagnoses an ambiguous conversion. The partial diagnostic is the 6424/// "lead" diagnostic; it will be given two arguments, the source and 6425/// target types of the conversion. 6426void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 6427 Sema &S, 6428 SourceLocation CaretLoc, 6429 const PartialDiagnostic &PDiag) const { 6430 S.Diag(CaretLoc, PDiag) 6431 << Ambiguous.getFromType() << Ambiguous.getToType(); 6432 for (AmbiguousConversionSequence::const_iterator 6433 I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 6434 S.NoteOverloadCandidate(*I); 6435 } 6436} 6437 6438namespace { 6439 6440void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 6441 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 6442 assert(Conv.isBad()); 6443 assert(Cand->Function && "for now, candidate must be a function"); 6444 FunctionDecl *Fn = Cand->Function; 6445 6446 // There's a conversion slot for the object argument if this is a 6447 // non-constructor method. Note that 'I' corresponds the 6448 // conversion-slot index. 6449 bool isObjectArgument = false; 6450 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 6451 if (I == 0) 6452 isObjectArgument = true; 6453 else 6454 I--; 6455 } 6456 6457 std::string FnDesc; 6458 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6459 6460 Expr *FromExpr = Conv.Bad.FromExpr; 6461 QualType FromTy = Conv.Bad.getFromType(); 6462 QualType ToTy = Conv.Bad.getToType(); 6463 6464 if (FromTy == S.Context.OverloadTy) { 6465 assert(FromExpr && "overload set argument came from implicit argument?"); 6466 Expr *E = FromExpr->IgnoreParens(); 6467 if (isa<UnaryOperator>(E)) 6468 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 6469 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 6470 6471 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 6472 << (unsigned) FnKind << FnDesc 6473 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6474 << ToTy << Name << I+1; 6475 MaybeEmitInheritedConstructorNote(S, Fn); 6476 return; 6477 } 6478 6479 // Do some hand-waving analysis to see if the non-viability is due 6480 // to a qualifier mismatch. 6481 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 6482 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 6483 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 6484 CToTy = RT->getPointeeType(); 6485 else { 6486 // TODO: detect and diagnose the full richness of const mismatches. 6487 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 6488 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 6489 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 6490 } 6491 6492 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 6493 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 6494 // It is dumb that we have to do this here. 6495 while (isa<ArrayType>(CFromTy)) 6496 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 6497 while (isa<ArrayType>(CToTy)) 6498 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 6499 6500 Qualifiers FromQs = CFromTy.getQualifiers(); 6501 Qualifiers ToQs = CToTy.getQualifiers(); 6502 6503 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 6504 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 6505 << (unsigned) FnKind << FnDesc 6506 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6507 << FromTy 6508 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 6509 << (unsigned) isObjectArgument << I+1; 6510 MaybeEmitInheritedConstructorNote(S, Fn); 6511 return; 6512 } 6513 6514 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 6515 assert(CVR && "unexpected qualifiers mismatch"); 6516 6517 if (isObjectArgument) { 6518 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 6519 << (unsigned) FnKind << FnDesc 6520 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6521 << FromTy << (CVR - 1); 6522 } else { 6523 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 6524 << (unsigned) FnKind << FnDesc 6525 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6526 << FromTy << (CVR - 1) << I+1; 6527 } 6528 MaybeEmitInheritedConstructorNote(S, Fn); 6529 return; 6530 } 6531 6532 // Diagnose references or pointers to incomplete types differently, 6533 // since it's far from impossible that the incompleteness triggered 6534 // the failure. 6535 QualType TempFromTy = FromTy.getNonReferenceType(); 6536 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 6537 TempFromTy = PTy->getPointeeType(); 6538 if (TempFromTy->isIncompleteType()) { 6539 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 6540 << (unsigned) FnKind << FnDesc 6541 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6542 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6543 MaybeEmitInheritedConstructorNote(S, Fn); 6544 return; 6545 } 6546 6547 // Diagnose base -> derived pointer conversions. 6548 unsigned BaseToDerivedConversion = 0; 6549 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 6550 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 6551 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6552 FromPtrTy->getPointeeType()) && 6553 !FromPtrTy->getPointeeType()->isIncompleteType() && 6554 !ToPtrTy->getPointeeType()->isIncompleteType() && 6555 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 6556 FromPtrTy->getPointeeType())) 6557 BaseToDerivedConversion = 1; 6558 } 6559 } else if (const ObjCObjectPointerType *FromPtrTy 6560 = FromTy->getAs<ObjCObjectPointerType>()) { 6561 if (const ObjCObjectPointerType *ToPtrTy 6562 = ToTy->getAs<ObjCObjectPointerType>()) 6563 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 6564 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 6565 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6566 FromPtrTy->getPointeeType()) && 6567 FromIface->isSuperClassOf(ToIface)) 6568 BaseToDerivedConversion = 2; 6569 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 6570 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 6571 !FromTy->isIncompleteType() && 6572 !ToRefTy->getPointeeType()->isIncompleteType() && 6573 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 6574 BaseToDerivedConversion = 3; 6575 } 6576 6577 if (BaseToDerivedConversion) { 6578 S.Diag(Fn->getLocation(), 6579 diag::note_ovl_candidate_bad_base_to_derived_conv) 6580 << (unsigned) FnKind << FnDesc 6581 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6582 << (BaseToDerivedConversion - 1) 6583 << FromTy << ToTy << I+1; 6584 MaybeEmitInheritedConstructorNote(S, Fn); 6585 return; 6586 } 6587 6588 // TODO: specialize more based on the kind of mismatch 6589 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 6590 << (unsigned) FnKind << FnDesc 6591 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6592 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6593 MaybeEmitInheritedConstructorNote(S, Fn); 6594} 6595 6596void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 6597 unsigned NumFormalArgs) { 6598 // TODO: treat calls to a missing default constructor as a special case 6599 6600 FunctionDecl *Fn = Cand->Function; 6601 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 6602 6603 unsigned MinParams = Fn->getMinRequiredArguments(); 6604 6605 // at least / at most / exactly 6606 unsigned mode, modeCount; 6607 if (NumFormalArgs < MinParams) { 6608 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 6609 (Cand->FailureKind == ovl_fail_bad_deduction && 6610 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 6611 if (MinParams != FnTy->getNumArgs() || 6612 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 6613 mode = 0; // "at least" 6614 else 6615 mode = 2; // "exactly" 6616 modeCount = MinParams; 6617 } else { 6618 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 6619 (Cand->FailureKind == ovl_fail_bad_deduction && 6620 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 6621 if (MinParams != FnTy->getNumArgs()) 6622 mode = 1; // "at most" 6623 else 6624 mode = 2; // "exactly" 6625 modeCount = FnTy->getNumArgs(); 6626 } 6627 6628 std::string Description; 6629 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 6630 6631 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 6632 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 6633 << modeCount << NumFormalArgs; 6634 MaybeEmitInheritedConstructorNote(S, Fn); 6635} 6636 6637/// Diagnose a failed template-argument deduction. 6638void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 6639 Expr **Args, unsigned NumArgs) { 6640 FunctionDecl *Fn = Cand->Function; // pattern 6641 6642 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 6643 NamedDecl *ParamD; 6644 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 6645 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 6646 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 6647 switch (Cand->DeductionFailure.Result) { 6648 case Sema::TDK_Success: 6649 llvm_unreachable("TDK_success while diagnosing bad deduction"); 6650 6651 case Sema::TDK_Incomplete: { 6652 assert(ParamD && "no parameter found for incomplete deduction result"); 6653 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 6654 << ParamD->getDeclName(); 6655 MaybeEmitInheritedConstructorNote(S, Fn); 6656 return; 6657 } 6658 6659 case Sema::TDK_Underqualified: { 6660 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 6661 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 6662 6663 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 6664 6665 // Param will have been canonicalized, but it should just be a 6666 // qualified version of ParamD, so move the qualifiers to that. 6667 QualifierCollector Qs; 6668 Qs.strip(Param); 6669 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 6670 assert(S.Context.hasSameType(Param, NonCanonParam)); 6671 6672 // Arg has also been canonicalized, but there's nothing we can do 6673 // about that. It also doesn't matter as much, because it won't 6674 // have any template parameters in it (because deduction isn't 6675 // done on dependent types). 6676 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 6677 6678 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 6679 << ParamD->getDeclName() << Arg << NonCanonParam; 6680 MaybeEmitInheritedConstructorNote(S, Fn); 6681 return; 6682 } 6683 6684 case Sema::TDK_Inconsistent: { 6685 assert(ParamD && "no parameter found for inconsistent deduction result"); 6686 int which = 0; 6687 if (isa<TemplateTypeParmDecl>(ParamD)) 6688 which = 0; 6689 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 6690 which = 1; 6691 else { 6692 which = 2; 6693 } 6694 6695 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 6696 << which << ParamD->getDeclName() 6697 << *Cand->DeductionFailure.getFirstArg() 6698 << *Cand->DeductionFailure.getSecondArg(); 6699 MaybeEmitInheritedConstructorNote(S, Fn); 6700 return; 6701 } 6702 6703 case Sema::TDK_InvalidExplicitArguments: 6704 assert(ParamD && "no parameter found for invalid explicit arguments"); 6705 if (ParamD->getDeclName()) 6706 S.Diag(Fn->getLocation(), 6707 diag::note_ovl_candidate_explicit_arg_mismatch_named) 6708 << ParamD->getDeclName(); 6709 else { 6710 int index = 0; 6711 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 6712 index = TTP->getIndex(); 6713 else if (NonTypeTemplateParmDecl *NTTP 6714 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 6715 index = NTTP->getIndex(); 6716 else 6717 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 6718 S.Diag(Fn->getLocation(), 6719 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 6720 << (index + 1); 6721 } 6722 MaybeEmitInheritedConstructorNote(S, Fn); 6723 return; 6724 6725 case Sema::TDK_TooManyArguments: 6726 case Sema::TDK_TooFewArguments: 6727 DiagnoseArityMismatch(S, Cand, NumArgs); 6728 return; 6729 6730 case Sema::TDK_InstantiationDepth: 6731 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 6732 MaybeEmitInheritedConstructorNote(S, Fn); 6733 return; 6734 6735 case Sema::TDK_SubstitutionFailure: { 6736 std::string ArgString; 6737 if (TemplateArgumentList *Args 6738 = Cand->DeductionFailure.getTemplateArgumentList()) 6739 ArgString = S.getTemplateArgumentBindingsText( 6740 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 6741 *Args); 6742 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 6743 << ArgString; 6744 MaybeEmitInheritedConstructorNote(S, Fn); 6745 return; 6746 } 6747 6748 // TODO: diagnose these individually, then kill off 6749 // note_ovl_candidate_bad_deduction, which is uselessly vague. 6750 case Sema::TDK_NonDeducedMismatch: 6751 case Sema::TDK_FailedOverloadResolution: 6752 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 6753 MaybeEmitInheritedConstructorNote(S, Fn); 6754 return; 6755 } 6756} 6757 6758/// Generates a 'note' diagnostic for an overload candidate. We've 6759/// already generated a primary error at the call site. 6760/// 6761/// It really does need to be a single diagnostic with its caret 6762/// pointed at the candidate declaration. Yes, this creates some 6763/// major challenges of technical writing. Yes, this makes pointing 6764/// out problems with specific arguments quite awkward. It's still 6765/// better than generating twenty screens of text for every failed 6766/// overload. 6767/// 6768/// It would be great to be able to express per-candidate problems 6769/// more richly for those diagnostic clients that cared, but we'd 6770/// still have to be just as careful with the default diagnostics. 6771void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 6772 Expr **Args, unsigned NumArgs) { 6773 FunctionDecl *Fn = Cand->Function; 6774 6775 // Note deleted candidates, but only if they're viable. 6776 if (Cand->Viable && (Fn->isDeleted() || Fn->isUnavailable())) { 6777 std::string FnDesc; 6778 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6779 6780 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 6781 << FnKind << FnDesc << Fn->isDeleted(); 6782 MaybeEmitInheritedConstructorNote(S, Fn); 6783 return; 6784 } 6785 6786 // We don't really have anything else to say about viable candidates. 6787 if (Cand->Viable) { 6788 S.NoteOverloadCandidate(Fn); 6789 return; 6790 } 6791 6792 switch (Cand->FailureKind) { 6793 case ovl_fail_too_many_arguments: 6794 case ovl_fail_too_few_arguments: 6795 return DiagnoseArityMismatch(S, Cand, NumArgs); 6796 6797 case ovl_fail_bad_deduction: 6798 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 6799 6800 case ovl_fail_trivial_conversion: 6801 case ovl_fail_bad_final_conversion: 6802 case ovl_fail_final_conversion_not_exact: 6803 return S.NoteOverloadCandidate(Fn); 6804 6805 case ovl_fail_bad_conversion: { 6806 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 6807 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 6808 if (Cand->Conversions[I].isBad()) 6809 return DiagnoseBadConversion(S, Cand, I); 6810 6811 // FIXME: this currently happens when we're called from SemaInit 6812 // when user-conversion overload fails. Figure out how to handle 6813 // those conditions and diagnose them well. 6814 return S.NoteOverloadCandidate(Fn); 6815 } 6816 } 6817} 6818 6819void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 6820 // Desugar the type of the surrogate down to a function type, 6821 // retaining as many typedefs as possible while still showing 6822 // the function type (and, therefore, its parameter types). 6823 QualType FnType = Cand->Surrogate->getConversionType(); 6824 bool isLValueReference = false; 6825 bool isRValueReference = false; 6826 bool isPointer = false; 6827 if (const LValueReferenceType *FnTypeRef = 6828 FnType->getAs<LValueReferenceType>()) { 6829 FnType = FnTypeRef->getPointeeType(); 6830 isLValueReference = true; 6831 } else if (const RValueReferenceType *FnTypeRef = 6832 FnType->getAs<RValueReferenceType>()) { 6833 FnType = FnTypeRef->getPointeeType(); 6834 isRValueReference = true; 6835 } 6836 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 6837 FnType = FnTypePtr->getPointeeType(); 6838 isPointer = true; 6839 } 6840 // Desugar down to a function type. 6841 FnType = QualType(FnType->getAs<FunctionType>(), 0); 6842 // Reconstruct the pointer/reference as appropriate. 6843 if (isPointer) FnType = S.Context.getPointerType(FnType); 6844 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 6845 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 6846 6847 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 6848 << FnType; 6849 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 6850} 6851 6852void NoteBuiltinOperatorCandidate(Sema &S, 6853 const char *Opc, 6854 SourceLocation OpLoc, 6855 OverloadCandidate *Cand) { 6856 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 6857 std::string TypeStr("operator"); 6858 TypeStr += Opc; 6859 TypeStr += "("; 6860 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 6861 if (Cand->Conversions.size() == 1) { 6862 TypeStr += ")"; 6863 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 6864 } else { 6865 TypeStr += ", "; 6866 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 6867 TypeStr += ")"; 6868 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 6869 } 6870} 6871 6872void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 6873 OverloadCandidate *Cand) { 6874 unsigned NoOperands = Cand->Conversions.size(); 6875 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 6876 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 6877 if (ICS.isBad()) break; // all meaningless after first invalid 6878 if (!ICS.isAmbiguous()) continue; 6879 6880 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 6881 S.PDiag(diag::note_ambiguous_type_conversion)); 6882 } 6883} 6884 6885SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 6886 if (Cand->Function) 6887 return Cand->Function->getLocation(); 6888 if (Cand->IsSurrogate) 6889 return Cand->Surrogate->getLocation(); 6890 return SourceLocation(); 6891} 6892 6893struct CompareOverloadCandidatesForDisplay { 6894 Sema &S; 6895 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 6896 6897 bool operator()(const OverloadCandidate *L, 6898 const OverloadCandidate *R) { 6899 // Fast-path this check. 6900 if (L == R) return false; 6901 6902 // Order first by viability. 6903 if (L->Viable) { 6904 if (!R->Viable) return true; 6905 6906 // TODO: introduce a tri-valued comparison for overload 6907 // candidates. Would be more worthwhile if we had a sort 6908 // that could exploit it. 6909 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 6910 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 6911 } else if (R->Viable) 6912 return false; 6913 6914 assert(L->Viable == R->Viable); 6915 6916 // Criteria by which we can sort non-viable candidates: 6917 if (!L->Viable) { 6918 // 1. Arity mismatches come after other candidates. 6919 if (L->FailureKind == ovl_fail_too_many_arguments || 6920 L->FailureKind == ovl_fail_too_few_arguments) 6921 return false; 6922 if (R->FailureKind == ovl_fail_too_many_arguments || 6923 R->FailureKind == ovl_fail_too_few_arguments) 6924 return true; 6925 6926 // 2. Bad conversions come first and are ordered by the number 6927 // of bad conversions and quality of good conversions. 6928 if (L->FailureKind == ovl_fail_bad_conversion) { 6929 if (R->FailureKind != ovl_fail_bad_conversion) 6930 return true; 6931 6932 // If there's any ordering between the defined conversions... 6933 // FIXME: this might not be transitive. 6934 assert(L->Conversions.size() == R->Conversions.size()); 6935 6936 int leftBetter = 0; 6937 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 6938 for (unsigned E = L->Conversions.size(); I != E; ++I) { 6939 switch (CompareImplicitConversionSequences(S, 6940 L->Conversions[I], 6941 R->Conversions[I])) { 6942 case ImplicitConversionSequence::Better: 6943 leftBetter++; 6944 break; 6945 6946 case ImplicitConversionSequence::Worse: 6947 leftBetter--; 6948 break; 6949 6950 case ImplicitConversionSequence::Indistinguishable: 6951 break; 6952 } 6953 } 6954 if (leftBetter > 0) return true; 6955 if (leftBetter < 0) return false; 6956 6957 } else if (R->FailureKind == ovl_fail_bad_conversion) 6958 return false; 6959 6960 // TODO: others? 6961 } 6962 6963 // Sort everything else by location. 6964 SourceLocation LLoc = GetLocationForCandidate(L); 6965 SourceLocation RLoc = GetLocationForCandidate(R); 6966 6967 // Put candidates without locations (e.g. builtins) at the end. 6968 if (LLoc.isInvalid()) return false; 6969 if (RLoc.isInvalid()) return true; 6970 6971 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 6972 } 6973}; 6974 6975/// CompleteNonViableCandidate - Normally, overload resolution only 6976/// computes up to the first 6977void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 6978 Expr **Args, unsigned NumArgs) { 6979 assert(!Cand->Viable); 6980 6981 // Don't do anything on failures other than bad conversion. 6982 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 6983 6984 // Skip forward to the first bad conversion. 6985 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 6986 unsigned ConvCount = Cand->Conversions.size(); 6987 while (true) { 6988 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 6989 ConvIdx++; 6990 if (Cand->Conversions[ConvIdx - 1].isBad()) 6991 break; 6992 } 6993 6994 if (ConvIdx == ConvCount) 6995 return; 6996 6997 assert(!Cand->Conversions[ConvIdx].isInitialized() && 6998 "remaining conversion is initialized?"); 6999 7000 // FIXME: this should probably be preserved from the overload 7001 // operation somehow. 7002 bool SuppressUserConversions = false; 7003 7004 const FunctionProtoType* Proto; 7005 unsigned ArgIdx = ConvIdx; 7006 7007 if (Cand->IsSurrogate) { 7008 QualType ConvType 7009 = Cand->Surrogate->getConversionType().getNonReferenceType(); 7010 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7011 ConvType = ConvPtrType->getPointeeType(); 7012 Proto = ConvType->getAs<FunctionProtoType>(); 7013 ArgIdx--; 7014 } else if (Cand->Function) { 7015 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 7016 if (isa<CXXMethodDecl>(Cand->Function) && 7017 !isa<CXXConstructorDecl>(Cand->Function)) 7018 ArgIdx--; 7019 } else { 7020 // Builtin binary operator with a bad first conversion. 7021 assert(ConvCount <= 3); 7022 for (; ConvIdx != ConvCount; ++ConvIdx) 7023 Cand->Conversions[ConvIdx] 7024 = TryCopyInitialization(S, Args[ConvIdx], 7025 Cand->BuiltinTypes.ParamTypes[ConvIdx], 7026 SuppressUserConversions, 7027 /*InOverloadResolution*/ true); 7028 return; 7029 } 7030 7031 // Fill in the rest of the conversions. 7032 unsigned NumArgsInProto = Proto->getNumArgs(); 7033 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 7034 if (ArgIdx < NumArgsInProto) 7035 Cand->Conversions[ConvIdx] 7036 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 7037 SuppressUserConversions, 7038 /*InOverloadResolution=*/true); 7039 else 7040 Cand->Conversions[ConvIdx].setEllipsis(); 7041 } 7042} 7043 7044} // end anonymous namespace 7045 7046/// PrintOverloadCandidates - When overload resolution fails, prints 7047/// diagnostic messages containing the candidates in the candidate 7048/// set. 7049void OverloadCandidateSet::NoteCandidates(Sema &S, 7050 OverloadCandidateDisplayKind OCD, 7051 Expr **Args, unsigned NumArgs, 7052 const char *Opc, 7053 SourceLocation OpLoc) { 7054 // Sort the candidates by viability and position. Sorting directly would 7055 // be prohibitive, so we make a set of pointers and sort those. 7056 llvm::SmallVector<OverloadCandidate*, 32> Cands; 7057 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 7058 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 7059 if (Cand->Viable) 7060 Cands.push_back(Cand); 7061 else if (OCD == OCD_AllCandidates) { 7062 CompleteNonViableCandidate(S, Cand, Args, NumArgs); 7063 if (Cand->Function || Cand->IsSurrogate) 7064 Cands.push_back(Cand); 7065 // Otherwise, this a non-viable builtin candidate. We do not, in general, 7066 // want to list every possible builtin candidate. 7067 } 7068 } 7069 7070 std::sort(Cands.begin(), Cands.end(), 7071 CompareOverloadCandidatesForDisplay(S)); 7072 7073 bool ReportedAmbiguousConversions = false; 7074 7075 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 7076 const Diagnostic::OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 7077 unsigned CandsShown = 0; 7078 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 7079 OverloadCandidate *Cand = *I; 7080 7081 // Set an arbitrary limit on the number of candidate functions we'll spam 7082 // the user with. FIXME: This limit should depend on details of the 7083 // candidate list. 7084 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 7085 break; 7086 } 7087 ++CandsShown; 7088 7089 if (Cand->Function) 7090 NoteFunctionCandidate(S, Cand, Args, NumArgs); 7091 else if (Cand->IsSurrogate) 7092 NoteSurrogateCandidate(S, Cand); 7093 else { 7094 assert(Cand->Viable && 7095 "Non-viable built-in candidates are not added to Cands."); 7096 // Generally we only see ambiguities including viable builtin 7097 // operators if overload resolution got screwed up by an 7098 // ambiguous user-defined conversion. 7099 // 7100 // FIXME: It's quite possible for different conversions to see 7101 // different ambiguities, though. 7102 if (!ReportedAmbiguousConversions) { 7103 NoteAmbiguousUserConversions(S, OpLoc, Cand); 7104 ReportedAmbiguousConversions = true; 7105 } 7106 7107 // If this is a viable builtin, print it. 7108 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 7109 } 7110 } 7111 7112 if (I != E) 7113 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 7114} 7115 7116// [PossiblyAFunctionType] --> [Return] 7117// NonFunctionType --> NonFunctionType 7118// R (A) --> R(A) 7119// R (*)(A) --> R (A) 7120// R (&)(A) --> R (A) 7121// R (S::*)(A) --> R (A) 7122QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { 7123 QualType Ret = PossiblyAFunctionType; 7124 if (const PointerType *ToTypePtr = 7125 PossiblyAFunctionType->getAs<PointerType>()) 7126 Ret = ToTypePtr->getPointeeType(); 7127 else if (const ReferenceType *ToTypeRef = 7128 PossiblyAFunctionType->getAs<ReferenceType>()) 7129 Ret = ToTypeRef->getPointeeType(); 7130 else if (const MemberPointerType *MemTypePtr = 7131 PossiblyAFunctionType->getAs<MemberPointerType>()) 7132 Ret = MemTypePtr->getPointeeType(); 7133 Ret = 7134 Context.getCanonicalType(Ret).getUnqualifiedType(); 7135 return Ret; 7136} 7137 7138// A helper class to help with address of function resolution 7139// - allows us to avoid passing around all those ugly parameters 7140class AddressOfFunctionResolver 7141{ 7142 Sema& S; 7143 Expr* SourceExpr; 7144 const QualType& TargetType; 7145 QualType TargetFunctionType; // Extracted function type from target type 7146 7147 bool Complain; 7148 //DeclAccessPair& ResultFunctionAccessPair; 7149 ASTContext& Context; 7150 7151 bool TargetTypeIsNonStaticMemberFunction; 7152 bool FoundNonTemplateFunction; 7153 7154 OverloadExpr::FindResult OvlExprInfo; 7155 OverloadExpr *OvlExpr; 7156 TemplateArgumentListInfo OvlExplicitTemplateArgs; 7157 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 7158 7159public: 7160 AddressOfFunctionResolver(Sema &S, Expr* SourceExpr, 7161 const QualType& TargetType, bool Complain) 7162 : S(S), SourceExpr(SourceExpr), TargetType(TargetType), 7163 Complain(Complain), Context(S.getASTContext()), 7164 TargetTypeIsNonStaticMemberFunction( 7165 !!TargetType->getAs<MemberPointerType>()), 7166 FoundNonTemplateFunction(false), 7167 OvlExprInfo(OverloadExpr::find(SourceExpr)), 7168 OvlExpr(OvlExprInfo.Expression) 7169 { 7170 ExtractUnqualifiedFunctionTypeFromTargetType(); 7171 7172 if (!TargetFunctionType->isFunctionType()) { 7173 if (OvlExpr->hasExplicitTemplateArgs()) { 7174 DeclAccessPair dap; 7175 if( FunctionDecl* Fn = S.ResolveSingleFunctionTemplateSpecialization( 7176 OvlExpr, false, &dap) ) { 7177 Matches.push_back(std::make_pair(dap,Fn)); 7178 } 7179 } 7180 return; 7181 } 7182 7183 if (OvlExpr->hasExplicitTemplateArgs()) 7184 OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); 7185 7186 if (FindAllFunctionsThatMatchTargetTypeExactly()) { 7187 // C++ [over.over]p4: 7188 // If more than one function is selected, [...] 7189 if (Matches.size() > 1) { 7190 if (FoundNonTemplateFunction) 7191 EliminateAllTemplateMatches(); 7192 else 7193 EliminateAllExceptMostSpecializedTemplate(); 7194 } 7195 } 7196 } 7197 7198private: 7199 bool isTargetTypeAFunction() const { 7200 return TargetFunctionType->isFunctionType(); 7201 } 7202 7203 // [ToType] [Return] 7204 7205 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false 7206 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false 7207 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true 7208 void inline ExtractUnqualifiedFunctionTypeFromTargetType() { 7209 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); 7210 } 7211 7212 // return true if any matching specializations were found 7213 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, 7214 const DeclAccessPair& CurAccessFunPair) { 7215 if (CXXMethodDecl *Method 7216 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 7217 // Skip non-static function templates when converting to pointer, and 7218 // static when converting to member pointer. 7219 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 7220 return false; 7221 } 7222 else if (TargetTypeIsNonStaticMemberFunction) 7223 return false; 7224 7225 // C++ [over.over]p2: 7226 // If the name is a function template, template argument deduction is 7227 // done (14.8.2.2), and if the argument deduction succeeds, the 7228 // resulting template argument list is used to generate a single 7229 // function template specialization, which is added to the set of 7230 // overloaded functions considered. 7231 FunctionDecl *Specialization = 0; 7232 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 7233 if (Sema::TemplateDeductionResult Result 7234 = S.DeduceTemplateArguments(FunctionTemplate, 7235 &OvlExplicitTemplateArgs, 7236 TargetFunctionType, Specialization, 7237 Info)) { 7238 // FIXME: make a note of the failed deduction for diagnostics. 7239 (void)Result; 7240 return false; 7241 } 7242 7243 // Template argument deduction ensures that we have an exact match. 7244 // This function template specicalization works. 7245 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 7246 assert(TargetFunctionType 7247 == Context.getCanonicalType(Specialization->getType())); 7248 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); 7249 return true; 7250 } 7251 7252 bool AddMatchingNonTemplateFunction(NamedDecl* Fn, 7253 const DeclAccessPair& CurAccessFunPair) { 7254 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7255 // Skip non-static functions when converting to pointer, and static 7256 // when converting to member pointer. 7257 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 7258 return false; 7259 } 7260 else if (TargetTypeIsNonStaticMemberFunction) 7261 return false; 7262 7263 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 7264 QualType ResultTy; 7265 if (Context.hasSameUnqualifiedType(TargetFunctionType, 7266 FunDecl->getType()) || 7267 IsNoReturnConversion(Context, FunDecl->getType(), TargetFunctionType, 7268 ResultTy)) { 7269 Matches.push_back(std::make_pair(CurAccessFunPair, 7270 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 7271 FoundNonTemplateFunction = true; 7272 return true; 7273 } 7274 } 7275 7276 return false; 7277 } 7278 7279 bool FindAllFunctionsThatMatchTargetTypeExactly() { 7280 bool Ret = false; 7281 7282 // If the overload expression doesn't have the form of a pointer to 7283 // member, don't try to convert it to a pointer-to-member type. 7284 if (IsInvalidFormOfPointerToMemberFunction()) 7285 return false; 7286 7287 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7288 E = OvlExpr->decls_end(); 7289 I != E; ++I) { 7290 // Look through any using declarations to find the underlying function. 7291 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 7292 7293 // C++ [over.over]p3: 7294 // Non-member functions and static member functions match 7295 // targets of type "pointer-to-function" or "reference-to-function." 7296 // Nonstatic member functions match targets of 7297 // type "pointer-to-member-function." 7298 // Note that according to DR 247, the containing class does not matter. 7299 if (FunctionTemplateDecl *FunctionTemplate 7300 = dyn_cast<FunctionTemplateDecl>(Fn)) { 7301 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) 7302 Ret = true; 7303 } 7304 // If we have explicit template arguments supplied, skip non-templates. 7305 else if (!OvlExpr->hasExplicitTemplateArgs() && 7306 AddMatchingNonTemplateFunction(Fn, I.getPair())) 7307 Ret = true; 7308 } 7309 assert(Ret || Matches.empty()); 7310 return Ret; 7311 } 7312 7313 void EliminateAllExceptMostSpecializedTemplate() { 7314 // [...] and any given function template specialization F1 is 7315 // eliminated if the set contains a second function template 7316 // specialization whose function template is more specialized 7317 // than the function template of F1 according to the partial 7318 // ordering rules of 14.5.5.2. 7319 7320 // The algorithm specified above is quadratic. We instead use a 7321 // two-pass algorithm (similar to the one used to identify the 7322 // best viable function in an overload set) that identifies the 7323 // best function template (if it exists). 7324 7325 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 7326 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 7327 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 7328 7329 UnresolvedSetIterator Result = 7330 S.getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 7331 TPOC_Other, 0, SourceExpr->getLocStart(), 7332 S.PDiag(), 7333 S.PDiag(diag::err_addr_ovl_ambiguous) 7334 << Matches[0].second->getDeclName(), 7335 S.PDiag(diag::note_ovl_candidate) 7336 << (unsigned) oc_function_template, 7337 Complain); 7338 7339 if (Result != MatchesCopy.end()) { 7340 // Make it the first and only element 7341 Matches[0].first = Matches[Result - MatchesCopy.begin()].first; 7342 Matches[0].second = cast<FunctionDecl>(*Result); 7343 Matches.resize(1); 7344 } 7345 } 7346 7347 void EliminateAllTemplateMatches() { 7348 // [...] any function template specializations in the set are 7349 // eliminated if the set also contains a non-template function, [...] 7350 for (unsigned I = 0, N = Matches.size(); I != N; ) { 7351 if (Matches[I].second->getPrimaryTemplate() == 0) 7352 ++I; 7353 else { 7354 Matches[I] = Matches[--N]; 7355 Matches.set_size(N); 7356 } 7357 } 7358 } 7359 7360public: 7361 void ComplainNoMatchesFound() const { 7362 assert(Matches.empty()); 7363 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) 7364 << OvlExpr->getName() << TargetFunctionType 7365 << OvlExpr->getSourceRange(); 7366 S.NoteAllOverloadCandidates(OvlExpr); 7367 } 7368 7369 bool IsInvalidFormOfPointerToMemberFunction() const { 7370 return TargetTypeIsNonStaticMemberFunction && 7371 !OvlExprInfo.HasFormOfMemberPointer; 7372 } 7373 7374 void ComplainIsInvalidFormOfPointerToMemberFunction() const { 7375 // TODO: Should we condition this on whether any functions might 7376 // have matched, or is it more appropriate to do that in callers? 7377 // TODO: a fixit wouldn't hurt. 7378 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 7379 << TargetType << OvlExpr->getSourceRange(); 7380 } 7381 7382 void ComplainOfInvalidConversion() const { 7383 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 7384 << OvlExpr->getName() << TargetType; 7385 } 7386 7387 void ComplainMultipleMatchesFound() const { 7388 assert(Matches.size() > 1); 7389 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) 7390 << OvlExpr->getName() 7391 << OvlExpr->getSourceRange(); 7392 S.NoteAllOverloadCandidates(OvlExpr); 7393 } 7394 7395 int getNumMatches() const { return Matches.size(); } 7396 7397 FunctionDecl* getMatchingFunctionDecl() const { 7398 if (Matches.size() != 1) return 0; 7399 return Matches[0].second; 7400 } 7401 7402 const DeclAccessPair* getMatchingFunctionAccessPair() const { 7403 if (Matches.size() != 1) return 0; 7404 return &Matches[0].first; 7405 } 7406}; 7407 7408/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 7409/// an overloaded function (C++ [over.over]), where @p From is an 7410/// expression with overloaded function type and @p ToType is the type 7411/// we're trying to resolve to. For example: 7412/// 7413/// @code 7414/// int f(double); 7415/// int f(int); 7416/// 7417/// int (*pfd)(double) = f; // selects f(double) 7418/// @endcode 7419/// 7420/// This routine returns the resulting FunctionDecl if it could be 7421/// resolved, and NULL otherwise. When @p Complain is true, this 7422/// routine will emit diagnostics if there is an error. 7423FunctionDecl * 7424Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, QualType TargetType, 7425 bool Complain, 7426 DeclAccessPair &FoundResult) { 7427 7428 assert(AddressOfExpr->getType() == Context.OverloadTy); 7429 7430 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, Complain); 7431 int NumMatches = Resolver.getNumMatches(); 7432 FunctionDecl* Fn = 0; 7433 if ( NumMatches == 0 && Complain) { 7434 if (Resolver.IsInvalidFormOfPointerToMemberFunction()) 7435 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); 7436 else 7437 Resolver.ComplainNoMatchesFound(); 7438 } 7439 else if (NumMatches > 1 && Complain) 7440 Resolver.ComplainMultipleMatchesFound(); 7441 else if (NumMatches == 1) { 7442 Fn = Resolver.getMatchingFunctionDecl(); 7443 assert(Fn); 7444 FoundResult = *Resolver.getMatchingFunctionAccessPair(); 7445 MarkDeclarationReferenced(AddressOfExpr->getLocStart(), Fn); 7446 if (Complain) 7447 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); 7448 } 7449 7450 return Fn; 7451} 7452 7453/// \brief Given an expression that refers to an overloaded function, try to 7454/// resolve that overloaded function expression down to a single function. 7455/// 7456/// This routine can only resolve template-ids that refer to a single function 7457/// template, where that template-id refers to a single template whose template 7458/// arguments are either provided by the template-id or have defaults, 7459/// as described in C++0x [temp.arg.explicit]p3. 7460FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From, 7461 bool Complain, 7462 DeclAccessPair* FoundResult) { 7463 // C++ [over.over]p1: 7464 // [...] [Note: any redundant set of parentheses surrounding the 7465 // overloaded function name is ignored (5.1). ] 7466 // C++ [over.over]p1: 7467 // [...] The overloaded function name can be preceded by the & 7468 // operator. 7469 if (From->getType() != Context.OverloadTy) 7470 return 0; 7471 7472 OverloadExpr *OvlExpr = OverloadExpr::find(From).Expression; 7473 7474 // If we didn't actually find any template-ids, we're done. 7475 if (!OvlExpr->hasExplicitTemplateArgs()) 7476 return 0; 7477 7478 TemplateArgumentListInfo ExplicitTemplateArgs; 7479 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 7480 7481 // Look through all of the overloaded functions, searching for one 7482 // whose type matches exactly. 7483 FunctionDecl *Matched = 0; 7484 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7485 E = OvlExpr->decls_end(); I != E; ++I) { 7486 // C++0x [temp.arg.explicit]p3: 7487 // [...] In contexts where deduction is done and fails, or in contexts 7488 // where deduction is not done, if a template argument list is 7489 // specified and it, along with any default template arguments, 7490 // identifies a single function template specialization, then the 7491 // template-id is an lvalue for the function template specialization. 7492 FunctionTemplateDecl *FunctionTemplate 7493 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 7494 7495 // C++ [over.over]p2: 7496 // If the name is a function template, template argument deduction is 7497 // done (14.8.2.2), and if the argument deduction succeeds, the 7498 // resulting template argument list is used to generate a single 7499 // function template specialization, which is added to the set of 7500 // overloaded functions considered. 7501 FunctionDecl *Specialization = 0; 7502 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 7503 if (TemplateDeductionResult Result 7504 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 7505 Specialization, Info)) { 7506 // FIXME: make a note of the failed deduction for diagnostics. 7507 (void)Result; 7508 continue; 7509 } 7510 7511 // Multiple matches; we can't resolve to a single declaration. 7512 if (Matched) { 7513 if (FoundResult) 7514 *FoundResult = DeclAccessPair(); 7515 7516 if (Complain) { 7517 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 7518 << OvlExpr->getName(); 7519 NoteAllOverloadCandidates(OvlExpr); 7520 } 7521 return 0; 7522 } 7523 7524 if ((Matched = Specialization) && FoundResult) 7525 *FoundResult = I.getPair(); 7526 } 7527 7528 return Matched; 7529} 7530 7531 7532 7533 7534// Resolve and fix an overloaded expression that 7535// can be resolved because it identifies a single function 7536// template specialization 7537// Last three arguments should only be supplied if Complain = true 7538ExprResult Sema::ResolveAndFixSingleFunctionTemplateSpecialization( 7539 Expr *SrcExpr, bool DoFunctionPointerConverion, bool Complain, 7540 const SourceRange& OpRangeForComplaining, 7541 QualType DestTypeForComplaining, 7542 unsigned DiagIDForComplaining ) { 7543 7544 assert(SrcExpr->getType() == Context.OverloadTy); 7545 7546 DeclAccessPair Found; 7547 Expr* SingleFunctionExpression = 0; 7548 if (FunctionDecl* Fn = ResolveSingleFunctionTemplateSpecialization( 7549 SrcExpr, false, // false -> Complain 7550 &Found)) { 7551 if (!DiagnoseUseOfDecl(Fn, SrcExpr->getSourceRange().getBegin())) { 7552 // mark the expression as resolved to Fn 7553 SingleFunctionExpression = FixOverloadedFunctionReference(SrcExpr, 7554 Found, Fn); 7555 if (DoFunctionPointerConverion) 7556 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression); 7557 } 7558 } 7559 if (!SingleFunctionExpression) { 7560 if (Complain) { 7561 OverloadExpr* oe = OverloadExpr::find(SrcExpr).Expression; 7562 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) 7563 << oe->getName() << DestTypeForComplaining << OpRangeForComplaining 7564 << oe->getQualifierLoc().getSourceRange(); 7565 NoteAllOverloadCandidates(SrcExpr); 7566 } 7567 return ExprError(); 7568 } 7569 7570 return SingleFunctionExpression; 7571} 7572 7573/// \brief Add a single candidate to the overload set. 7574static void AddOverloadedCallCandidate(Sema &S, 7575 DeclAccessPair FoundDecl, 7576 TemplateArgumentListInfo *ExplicitTemplateArgs, 7577 Expr **Args, unsigned NumArgs, 7578 OverloadCandidateSet &CandidateSet, 7579 bool PartialOverloading) { 7580 NamedDecl *Callee = FoundDecl.getDecl(); 7581 if (isa<UsingShadowDecl>(Callee)) 7582 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 7583 7584 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 7585 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 7586 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 7587 false, PartialOverloading); 7588 return; 7589 } 7590 7591 if (FunctionTemplateDecl *FuncTemplate 7592 = dyn_cast<FunctionTemplateDecl>(Callee)) { 7593 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 7594 ExplicitTemplateArgs, 7595 Args, NumArgs, CandidateSet); 7596 return; 7597 } 7598 7599 assert(false && "unhandled case in overloaded call candidate"); 7600 7601 // do nothing? 7602} 7603 7604/// \brief Add the overload candidates named by callee and/or found by argument 7605/// dependent lookup to the given overload set. 7606void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 7607 Expr **Args, unsigned NumArgs, 7608 OverloadCandidateSet &CandidateSet, 7609 bool PartialOverloading) { 7610 7611#ifndef NDEBUG 7612 // Verify that ArgumentDependentLookup is consistent with the rules 7613 // in C++0x [basic.lookup.argdep]p3: 7614 // 7615 // Let X be the lookup set produced by unqualified lookup (3.4.1) 7616 // and let Y be the lookup set produced by argument dependent 7617 // lookup (defined as follows). If X contains 7618 // 7619 // -- a declaration of a class member, or 7620 // 7621 // -- a block-scope function declaration that is not a 7622 // using-declaration, or 7623 // 7624 // -- a declaration that is neither a function or a function 7625 // template 7626 // 7627 // then Y is empty. 7628 7629 if (ULE->requiresADL()) { 7630 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 7631 E = ULE->decls_end(); I != E; ++I) { 7632 assert(!(*I)->getDeclContext()->isRecord()); 7633 assert(isa<UsingShadowDecl>(*I) || 7634 !(*I)->getDeclContext()->isFunctionOrMethod()); 7635 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 7636 } 7637 } 7638#endif 7639 7640 // It would be nice to avoid this copy. 7641 TemplateArgumentListInfo TABuffer; 7642 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 7643 if (ULE->hasExplicitTemplateArgs()) { 7644 ULE->copyTemplateArgumentsInto(TABuffer); 7645 ExplicitTemplateArgs = &TABuffer; 7646 } 7647 7648 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 7649 E = ULE->decls_end(); I != E; ++I) 7650 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 7651 Args, NumArgs, CandidateSet, 7652 PartialOverloading); 7653 7654 if (ULE->requiresADL()) 7655 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 7656 Args, NumArgs, 7657 ExplicitTemplateArgs, 7658 CandidateSet, 7659 PartialOverloading); 7660} 7661 7662/// Attempts to recover from a call where no functions were found. 7663/// 7664/// Returns true if new candidates were found. 7665static ExprResult 7666BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 7667 UnresolvedLookupExpr *ULE, 7668 SourceLocation LParenLoc, 7669 Expr **Args, unsigned NumArgs, 7670 SourceLocation RParenLoc) { 7671 7672 CXXScopeSpec SS; 7673 SS.Adopt(ULE->getQualifierLoc()); 7674 7675 TemplateArgumentListInfo TABuffer; 7676 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 7677 if (ULE->hasExplicitTemplateArgs()) { 7678 ULE->copyTemplateArgumentsInto(TABuffer); 7679 ExplicitTemplateArgs = &TABuffer; 7680 } 7681 7682 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 7683 Sema::LookupOrdinaryName); 7684 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 7685 return ExprError(); 7686 7687 assert(!R.empty() && "lookup results empty despite recovery"); 7688 7689 // Build an implicit member call if appropriate. Just drop the 7690 // casts and such from the call, we don't really care. 7691 ExprResult NewFn = ExprError(); 7692 if ((*R.begin())->isCXXClassMember()) 7693 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, 7694 ExplicitTemplateArgs); 7695 else if (ExplicitTemplateArgs) 7696 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 7697 else 7698 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 7699 7700 if (NewFn.isInvalid()) 7701 return ExprError(); 7702 7703 // This shouldn't cause an infinite loop because we're giving it 7704 // an expression with non-empty lookup results, which should never 7705 // end up here. 7706 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 7707 MultiExprArg(Args, NumArgs), RParenLoc); 7708} 7709 7710/// ResolveOverloadedCallFn - Given the call expression that calls Fn 7711/// (which eventually refers to the declaration Func) and the call 7712/// arguments Args/NumArgs, attempt to resolve the function call down 7713/// to a specific function. If overload resolution succeeds, returns 7714/// the function declaration produced by overload 7715/// resolution. Otherwise, emits diagnostics, deletes all of the 7716/// arguments and Fn, and returns NULL. 7717ExprResult 7718Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 7719 SourceLocation LParenLoc, 7720 Expr **Args, unsigned NumArgs, 7721 SourceLocation RParenLoc, 7722 Expr *ExecConfig) { 7723#ifndef NDEBUG 7724 if (ULE->requiresADL()) { 7725 // To do ADL, we must have found an unqualified name. 7726 assert(!ULE->getQualifier() && "qualified name with ADL"); 7727 7728 // We don't perform ADL for implicit declarations of builtins. 7729 // Verify that this was correctly set up. 7730 FunctionDecl *F; 7731 if (ULE->decls_begin() + 1 == ULE->decls_end() && 7732 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 7733 F->getBuiltinID() && F->isImplicit()) 7734 assert(0 && "performing ADL for builtin"); 7735 7736 // We don't perform ADL in C. 7737 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 7738 } 7739#endif 7740 7741 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 7742 7743 // Add the functions denoted by the callee to the set of candidate 7744 // functions, including those from argument-dependent lookup. 7745 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 7746 7747 // If we found nothing, try to recover. 7748 // AddRecoveryCallCandidates diagnoses the error itself, so we just 7749 // bailout out if it fails. 7750 if (CandidateSet.empty()) 7751 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 7752 RParenLoc); 7753 7754 OverloadCandidateSet::iterator Best; 7755 switch (CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best)) { 7756 case OR_Success: { 7757 FunctionDecl *FDecl = Best->Function; 7758 MarkDeclarationReferenced(Fn->getExprLoc(), FDecl); 7759 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 7760 DiagnoseUseOfDecl(FDecl? FDecl : Best->FoundDecl.getDecl(), 7761 ULE->getNameLoc()); 7762 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 7763 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc, 7764 ExecConfig); 7765 } 7766 7767 case OR_No_Viable_Function: 7768 Diag(Fn->getSourceRange().getBegin(), 7769 diag::err_ovl_no_viable_function_in_call) 7770 << ULE->getName() << Fn->getSourceRange(); 7771 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7772 break; 7773 7774 case OR_Ambiguous: 7775 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 7776 << ULE->getName() << Fn->getSourceRange(); 7777 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 7778 break; 7779 7780 case OR_Deleted: 7781 { 7782 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 7783 << Best->Function->isDeleted() 7784 << ULE->getName() 7785 << getDeletedOrUnavailableSuffix(Best->Function) 7786 << Fn->getSourceRange(); 7787 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7788 } 7789 break; 7790 } 7791 7792 // Overload resolution failed. 7793 return ExprError(); 7794} 7795 7796static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 7797 return Functions.size() > 1 || 7798 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 7799} 7800 7801/// \brief Create a unary operation that may resolve to an overloaded 7802/// operator. 7803/// 7804/// \param OpLoc The location of the operator itself (e.g., '*'). 7805/// 7806/// \param OpcIn The UnaryOperator::Opcode that describes this 7807/// operator. 7808/// 7809/// \param Functions The set of non-member functions that will be 7810/// considered by overload resolution. The caller needs to build this 7811/// set based on the context using, e.g., 7812/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 7813/// set should not contain any member functions; those will be added 7814/// by CreateOverloadedUnaryOp(). 7815/// 7816/// \param input The input argument. 7817ExprResult 7818Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 7819 const UnresolvedSetImpl &Fns, 7820 Expr *Input) { 7821 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 7822 7823 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 7824 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 7825 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 7826 // TODO: provide better source location info. 7827 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 7828 7829 if (Input->getObjectKind() == OK_ObjCProperty) 7830 ConvertPropertyForRValue(Input); 7831 7832 Expr *Args[2] = { Input, 0 }; 7833 unsigned NumArgs = 1; 7834 7835 // For post-increment and post-decrement, add the implicit '0' as 7836 // the second argument, so that we know this is a post-increment or 7837 // post-decrement. 7838 if (Opc == UO_PostInc || Opc == UO_PostDec) { 7839 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 7840 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 7841 SourceLocation()); 7842 NumArgs = 2; 7843 } 7844 7845 if (Input->isTypeDependent()) { 7846 if (Fns.empty()) 7847 return Owned(new (Context) UnaryOperator(Input, 7848 Opc, 7849 Context.DependentTy, 7850 VK_RValue, OK_Ordinary, 7851 OpLoc)); 7852 7853 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7854 UnresolvedLookupExpr *Fn 7855 = UnresolvedLookupExpr::Create(Context, NamingClass, 7856 NestedNameSpecifierLoc(), OpNameInfo, 7857 /*ADL*/ true, IsOverloaded(Fns), 7858 Fns.begin(), Fns.end()); 7859 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 7860 &Args[0], NumArgs, 7861 Context.DependentTy, 7862 VK_RValue, 7863 OpLoc)); 7864 } 7865 7866 // Build an empty overload set. 7867 OverloadCandidateSet CandidateSet(OpLoc); 7868 7869 // Add the candidates from the given function set. 7870 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 7871 7872 // Add operator candidates that are member functions. 7873 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 7874 7875 // Add candidates from ADL. 7876 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 7877 Args, NumArgs, 7878 /*ExplicitTemplateArgs*/ 0, 7879 CandidateSet); 7880 7881 // Add builtin operator candidates. 7882 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 7883 7884 // Perform overload resolution. 7885 OverloadCandidateSet::iterator Best; 7886 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 7887 case OR_Success: { 7888 // We found a built-in operator or an overloaded operator. 7889 FunctionDecl *FnDecl = Best->Function; 7890 7891 if (FnDecl) { 7892 // We matched an overloaded operator. Build a call to that 7893 // operator. 7894 7895 MarkDeclarationReferenced(OpLoc, FnDecl); 7896 7897 // Convert the arguments. 7898 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 7899 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 7900 7901 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 7902 Best->FoundDecl, Method)) 7903 return ExprError(); 7904 } else { 7905 // Convert the arguments. 7906 ExprResult InputInit 7907 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7908 Context, 7909 FnDecl->getParamDecl(0)), 7910 SourceLocation(), 7911 Input); 7912 if (InputInit.isInvalid()) 7913 return ExprError(); 7914 Input = InputInit.take(); 7915 } 7916 7917 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7918 7919 // Determine the result type. 7920 QualType ResultTy = FnDecl->getResultType(); 7921 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 7922 ResultTy = ResultTy.getNonLValueExprType(Context); 7923 7924 // Build the actual expression node. 7925 Expr *FnExpr = CreateFunctionRefExpr(*this, FnDecl); 7926 7927 Args[0] = Input; 7928 CallExpr *TheCall = 7929 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 7930 Args, NumArgs, ResultTy, VK, OpLoc); 7931 7932 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 7933 FnDecl)) 7934 return ExprError(); 7935 7936 return MaybeBindToTemporary(TheCall); 7937 } else { 7938 // We matched a built-in operator. Convert the arguments, then 7939 // break out so that we will build the appropriate built-in 7940 // operator node. 7941 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 7942 Best->Conversions[0], AA_Passing)) 7943 return ExprError(); 7944 7945 break; 7946 } 7947 } 7948 7949 case OR_No_Viable_Function: 7950 // No viable function; fall through to handling this as a 7951 // built-in operator, which will produce an error message for us. 7952 break; 7953 7954 case OR_Ambiguous: 7955 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 7956 << UnaryOperator::getOpcodeStr(Opc) 7957 << Input->getType() 7958 << Input->getSourceRange(); 7959 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 7960 Args, NumArgs, 7961 UnaryOperator::getOpcodeStr(Opc), OpLoc); 7962 return ExprError(); 7963 7964 case OR_Deleted: 7965 Diag(OpLoc, diag::err_ovl_deleted_oper) 7966 << Best->Function->isDeleted() 7967 << UnaryOperator::getOpcodeStr(Opc) 7968 << getDeletedOrUnavailableSuffix(Best->Function) 7969 << Input->getSourceRange(); 7970 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7971 return ExprError(); 7972 } 7973 7974 // Either we found no viable overloaded operator or we matched a 7975 // built-in operator. In either case, fall through to trying to 7976 // build a built-in operation. 7977 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 7978} 7979 7980/// \brief Create a binary operation that may resolve to an overloaded 7981/// operator. 7982/// 7983/// \param OpLoc The location of the operator itself (e.g., '+'). 7984/// 7985/// \param OpcIn The BinaryOperator::Opcode that describes this 7986/// operator. 7987/// 7988/// \param Functions The set of non-member functions that will be 7989/// considered by overload resolution. The caller needs to build this 7990/// set based on the context using, e.g., 7991/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 7992/// set should not contain any member functions; those will be added 7993/// by CreateOverloadedBinOp(). 7994/// 7995/// \param LHS Left-hand argument. 7996/// \param RHS Right-hand argument. 7997ExprResult 7998Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 7999 unsigned OpcIn, 8000 const UnresolvedSetImpl &Fns, 8001 Expr *LHS, Expr *RHS) { 8002 Expr *Args[2] = { LHS, RHS }; 8003 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 8004 8005 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 8006 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 8007 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 8008 8009 // If either side is type-dependent, create an appropriate dependent 8010 // expression. 8011 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 8012 if (Fns.empty()) { 8013 // If there are no functions to store, just build a dependent 8014 // BinaryOperator or CompoundAssignment. 8015 if (Opc <= BO_Assign || Opc > BO_OrAssign) 8016 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 8017 Context.DependentTy, 8018 VK_RValue, OK_Ordinary, 8019 OpLoc)); 8020 8021 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 8022 Context.DependentTy, 8023 VK_LValue, 8024 OK_Ordinary, 8025 Context.DependentTy, 8026 Context.DependentTy, 8027 OpLoc)); 8028 } 8029 8030 // FIXME: save results of ADL from here? 8031 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8032 // TODO: provide better source location info in DNLoc component. 8033 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 8034 UnresolvedLookupExpr *Fn 8035 = UnresolvedLookupExpr::Create(Context, NamingClass, 8036 NestedNameSpecifierLoc(), OpNameInfo, 8037 /*ADL*/ true, IsOverloaded(Fns), 8038 Fns.begin(), Fns.end()); 8039 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 8040 Args, 2, 8041 Context.DependentTy, 8042 VK_RValue, 8043 OpLoc)); 8044 } 8045 8046 // Always do property rvalue conversions on the RHS. 8047 if (Args[1]->getObjectKind() == OK_ObjCProperty) 8048 ConvertPropertyForRValue(Args[1]); 8049 8050 // The LHS is more complicated. 8051 if (Args[0]->getObjectKind() == OK_ObjCProperty) { 8052 8053 // There's a tension for assignment operators between primitive 8054 // property assignment and the overloaded operators. 8055 if (BinaryOperator::isAssignmentOp(Opc)) { 8056 const ObjCPropertyRefExpr *PRE = LHS->getObjCProperty(); 8057 8058 // Is the property "logically" settable? 8059 bool Settable = (PRE->isExplicitProperty() || 8060 PRE->getImplicitPropertySetter()); 8061 8062 // To avoid gratuitously inventing semantics, use the primitive 8063 // unless it isn't. Thoughts in case we ever really care: 8064 // - If the property isn't logically settable, we have to 8065 // load and hope. 8066 // - If the property is settable and this is simple assignment, 8067 // we really should use the primitive. 8068 // - If the property is settable, then we could try overloading 8069 // on a generic lvalue of the appropriate type; if it works 8070 // out to a builtin candidate, we would do that same operation 8071 // on the property, and otherwise just error. 8072 if (Settable) 8073 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8074 } 8075 8076 ConvertPropertyForRValue(Args[0]); 8077 } 8078 8079 // If this is the assignment operator, we only perform overload resolution 8080 // if the left-hand side is a class or enumeration type. This is actually 8081 // a hack. The standard requires that we do overload resolution between the 8082 // various built-in candidates, but as DR507 points out, this can lead to 8083 // problems. So we do it this way, which pretty much follows what GCC does. 8084 // Note that we go the traditional code path for compound assignment forms. 8085 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 8086 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8087 8088 // If this is the .* operator, which is not overloadable, just 8089 // create a built-in binary operator. 8090 if (Opc == BO_PtrMemD) 8091 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8092 8093 // Build an empty overload set. 8094 OverloadCandidateSet CandidateSet(OpLoc); 8095 8096 // Add the candidates from the given function set. 8097 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 8098 8099 // Add operator candidates that are member functions. 8100 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 8101 8102 // Add candidates from ADL. 8103 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 8104 Args, 2, 8105 /*ExplicitTemplateArgs*/ 0, 8106 CandidateSet); 8107 8108 // Add builtin operator candidates. 8109 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 8110 8111 // Perform overload resolution. 8112 OverloadCandidateSet::iterator Best; 8113 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8114 case OR_Success: { 8115 // We found a built-in operator or an overloaded operator. 8116 FunctionDecl *FnDecl = Best->Function; 8117 8118 if (FnDecl) { 8119 // We matched an overloaded operator. Build a call to that 8120 // operator. 8121 8122 MarkDeclarationReferenced(OpLoc, FnDecl); 8123 8124 // Convert the arguments. 8125 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 8126 // Best->Access is only meaningful for class members. 8127 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 8128 8129 ExprResult Arg1 = 8130 PerformCopyInitialization( 8131 InitializedEntity::InitializeParameter(Context, 8132 FnDecl->getParamDecl(0)), 8133 SourceLocation(), Owned(Args[1])); 8134 if (Arg1.isInvalid()) 8135 return ExprError(); 8136 8137 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 8138 Best->FoundDecl, Method)) 8139 return ExprError(); 8140 8141 Args[1] = RHS = Arg1.takeAs<Expr>(); 8142 } else { 8143 // Convert the arguments. 8144 ExprResult Arg0 = PerformCopyInitialization( 8145 InitializedEntity::InitializeParameter(Context, 8146 FnDecl->getParamDecl(0)), 8147 SourceLocation(), Owned(Args[0])); 8148 if (Arg0.isInvalid()) 8149 return ExprError(); 8150 8151 ExprResult Arg1 = 8152 PerformCopyInitialization( 8153 InitializedEntity::InitializeParameter(Context, 8154 FnDecl->getParamDecl(1)), 8155 SourceLocation(), Owned(Args[1])); 8156 if (Arg1.isInvalid()) 8157 return ExprError(); 8158 Args[0] = LHS = Arg0.takeAs<Expr>(); 8159 Args[1] = RHS = Arg1.takeAs<Expr>(); 8160 } 8161 8162 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 8163 8164 // Determine the result type. 8165 QualType ResultTy = FnDecl->getResultType(); 8166 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8167 ResultTy = ResultTy.getNonLValueExprType(Context); 8168 8169 // Build the actual expression node. 8170 Expr *FnExpr = CreateFunctionRefExpr(*this, FnDecl, OpLoc); 8171 8172 CXXOperatorCallExpr *TheCall = 8173 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 8174 Args, 2, ResultTy, VK, OpLoc); 8175 8176 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 8177 FnDecl)) 8178 return ExprError(); 8179 8180 return MaybeBindToTemporary(TheCall); 8181 } else { 8182 // We matched a built-in operator. Convert the arguments, then 8183 // break out so that we will build the appropriate built-in 8184 // operator node. 8185 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 8186 Best->Conversions[0], AA_Passing) || 8187 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 8188 Best->Conversions[1], AA_Passing)) 8189 return ExprError(); 8190 8191 break; 8192 } 8193 } 8194 8195 case OR_No_Viable_Function: { 8196 // C++ [over.match.oper]p9: 8197 // If the operator is the operator , [...] and there are no 8198 // viable functions, then the operator is assumed to be the 8199 // built-in operator and interpreted according to clause 5. 8200 if (Opc == BO_Comma) 8201 break; 8202 8203 // For class as left operand for assignment or compound assigment 8204 // operator do not fall through to handling in built-in, but report that 8205 // no overloaded assignment operator found 8206 ExprResult Result = ExprError(); 8207 if (Args[0]->getType()->isRecordType() && 8208 Opc >= BO_Assign && Opc <= BO_OrAssign) { 8209 Diag(OpLoc, diag::err_ovl_no_viable_oper) 8210 << BinaryOperator::getOpcodeStr(Opc) 8211 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8212 } else { 8213 // No viable function; try to create a built-in operation, which will 8214 // produce an error. Then, show the non-viable candidates. 8215 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8216 } 8217 assert(Result.isInvalid() && 8218 "C++ binary operator overloading is missing candidates!"); 8219 if (Result.isInvalid()) 8220 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8221 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8222 return move(Result); 8223 } 8224 8225 case OR_Ambiguous: 8226 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 8227 << BinaryOperator::getOpcodeStr(Opc) 8228 << Args[0]->getType() << Args[1]->getType() 8229 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8230 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 8231 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8232 return ExprError(); 8233 8234 case OR_Deleted: 8235 Diag(OpLoc, diag::err_ovl_deleted_oper) 8236 << Best->Function->isDeleted() 8237 << BinaryOperator::getOpcodeStr(Opc) 8238 << getDeletedOrUnavailableSuffix(Best->Function) 8239 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8240 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2); 8241 return ExprError(); 8242 } 8243 8244 // We matched a built-in operator; build it. 8245 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8246} 8247 8248ExprResult 8249Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 8250 SourceLocation RLoc, 8251 Expr *Base, Expr *Idx) { 8252 Expr *Args[2] = { Base, Idx }; 8253 DeclarationName OpName = 8254 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 8255 8256 // If either side is type-dependent, create an appropriate dependent 8257 // expression. 8258 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 8259 8260 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8261 // CHECKME: no 'operator' keyword? 8262 DeclarationNameInfo OpNameInfo(OpName, LLoc); 8263 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 8264 UnresolvedLookupExpr *Fn 8265 = UnresolvedLookupExpr::Create(Context, NamingClass, 8266 NestedNameSpecifierLoc(), OpNameInfo, 8267 /*ADL*/ true, /*Overloaded*/ false, 8268 UnresolvedSetIterator(), 8269 UnresolvedSetIterator()); 8270 // Can't add any actual overloads yet 8271 8272 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 8273 Args, 2, 8274 Context.DependentTy, 8275 VK_RValue, 8276 RLoc)); 8277 } 8278 8279 if (Args[0]->getObjectKind() == OK_ObjCProperty) 8280 ConvertPropertyForRValue(Args[0]); 8281 if (Args[1]->getObjectKind() == OK_ObjCProperty) 8282 ConvertPropertyForRValue(Args[1]); 8283 8284 // Build an empty overload set. 8285 OverloadCandidateSet CandidateSet(LLoc); 8286 8287 // Subscript can only be overloaded as a member function. 8288 8289 // Add operator candidates that are member functions. 8290 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 8291 8292 // Add builtin operator candidates. 8293 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 8294 8295 // Perform overload resolution. 8296 OverloadCandidateSet::iterator Best; 8297 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 8298 case OR_Success: { 8299 // We found a built-in operator or an overloaded operator. 8300 FunctionDecl *FnDecl = Best->Function; 8301 8302 if (FnDecl) { 8303 // We matched an overloaded operator. Build a call to that 8304 // operator. 8305 8306 MarkDeclarationReferenced(LLoc, FnDecl); 8307 8308 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 8309 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 8310 8311 // Convert the arguments. 8312 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 8313 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 8314 Best->FoundDecl, Method)) 8315 return ExprError(); 8316 8317 // Convert the arguments. 8318 ExprResult InputInit 8319 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8320 Context, 8321 FnDecl->getParamDecl(0)), 8322 SourceLocation(), 8323 Owned(Args[1])); 8324 if (InputInit.isInvalid()) 8325 return ExprError(); 8326 8327 Args[1] = InputInit.takeAs<Expr>(); 8328 8329 // Determine the result type 8330 QualType ResultTy = FnDecl->getResultType(); 8331 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8332 ResultTy = ResultTy.getNonLValueExprType(Context); 8333 8334 // Build the actual expression node. 8335 Expr *FnExpr = CreateFunctionRefExpr(*this, FnDecl, LLoc); 8336 8337 CXXOperatorCallExpr *TheCall = 8338 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 8339 FnExpr, Args, 2, 8340 ResultTy, VK, RLoc); 8341 8342 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 8343 FnDecl)) 8344 return ExprError(); 8345 8346 return MaybeBindToTemporary(TheCall); 8347 } else { 8348 // We matched a built-in operator. Convert the arguments, then 8349 // break out so that we will build the appropriate built-in 8350 // operator node. 8351 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 8352 Best->Conversions[0], AA_Passing) || 8353 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 8354 Best->Conversions[1], AA_Passing)) 8355 return ExprError(); 8356 8357 break; 8358 } 8359 } 8360 8361 case OR_No_Viable_Function: { 8362 if (CandidateSet.empty()) 8363 Diag(LLoc, diag::err_ovl_no_oper) 8364 << Args[0]->getType() << /*subscript*/ 0 8365 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8366 else 8367 Diag(LLoc, diag::err_ovl_no_viable_subscript) 8368 << Args[0]->getType() 8369 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8370 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8371 "[]", LLoc); 8372 return ExprError(); 8373 } 8374 8375 case OR_Ambiguous: 8376 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 8377 << "[]" 8378 << Args[0]->getType() << Args[1]->getType() 8379 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8380 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 8381 "[]", LLoc); 8382 return ExprError(); 8383 8384 case OR_Deleted: 8385 Diag(LLoc, diag::err_ovl_deleted_oper) 8386 << Best->Function->isDeleted() << "[]" 8387 << getDeletedOrUnavailableSuffix(Best->Function) 8388 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8389 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8390 "[]", LLoc); 8391 return ExprError(); 8392 } 8393 8394 // We matched a built-in operator; build it. 8395 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 8396} 8397 8398/// BuildCallToMemberFunction - Build a call to a member 8399/// function. MemExpr is the expression that refers to the member 8400/// function (and includes the object parameter), Args/NumArgs are the 8401/// arguments to the function call (not including the object 8402/// parameter). The caller needs to validate that the member 8403/// expression refers to a member function or an overloaded member 8404/// function. 8405ExprResult 8406Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 8407 SourceLocation LParenLoc, Expr **Args, 8408 unsigned NumArgs, SourceLocation RParenLoc) { 8409 // Dig out the member expression. This holds both the object 8410 // argument and the member function we're referring to. 8411 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 8412 8413 MemberExpr *MemExpr; 8414 CXXMethodDecl *Method = 0; 8415 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 8416 NestedNameSpecifier *Qualifier = 0; 8417 if (isa<MemberExpr>(NakedMemExpr)) { 8418 MemExpr = cast<MemberExpr>(NakedMemExpr); 8419 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 8420 FoundDecl = MemExpr->getFoundDecl(); 8421 Qualifier = MemExpr->getQualifier(); 8422 } else { 8423 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 8424 Qualifier = UnresExpr->getQualifier(); 8425 8426 QualType ObjectType = UnresExpr->getBaseType(); 8427 Expr::Classification ObjectClassification 8428 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 8429 : UnresExpr->getBase()->Classify(Context); 8430 8431 // Add overload candidates 8432 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 8433 8434 // FIXME: avoid copy. 8435 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 8436 if (UnresExpr->hasExplicitTemplateArgs()) { 8437 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 8438 TemplateArgs = &TemplateArgsBuffer; 8439 } 8440 8441 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 8442 E = UnresExpr->decls_end(); I != E; ++I) { 8443 8444 NamedDecl *Func = *I; 8445 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 8446 if (isa<UsingShadowDecl>(Func)) 8447 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 8448 8449 8450 // Microsoft supports direct constructor calls. 8451 if (getLangOptions().Microsoft && isa<CXXConstructorDecl>(Func)) { 8452 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), Args, NumArgs, 8453 CandidateSet); 8454 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 8455 // If explicit template arguments were provided, we can't call a 8456 // non-template member function. 8457 if (TemplateArgs) 8458 continue; 8459 8460 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 8461 ObjectClassification, 8462 Args, NumArgs, CandidateSet, 8463 /*SuppressUserConversions=*/false); 8464 } else { 8465 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 8466 I.getPair(), ActingDC, TemplateArgs, 8467 ObjectType, ObjectClassification, 8468 Args, NumArgs, CandidateSet, 8469 /*SuppressUsedConversions=*/false); 8470 } 8471 } 8472 8473 DeclarationName DeclName = UnresExpr->getMemberName(); 8474 8475 OverloadCandidateSet::iterator Best; 8476 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 8477 Best)) { 8478 case OR_Success: 8479 Method = cast<CXXMethodDecl>(Best->Function); 8480 MarkDeclarationReferenced(UnresExpr->getMemberLoc(), Method); 8481 FoundDecl = Best->FoundDecl; 8482 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 8483 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 8484 break; 8485 8486 case OR_No_Viable_Function: 8487 Diag(UnresExpr->getMemberLoc(), 8488 diag::err_ovl_no_viable_member_function_in_call) 8489 << DeclName << MemExprE->getSourceRange(); 8490 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8491 // FIXME: Leaking incoming expressions! 8492 return ExprError(); 8493 8494 case OR_Ambiguous: 8495 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 8496 << DeclName << MemExprE->getSourceRange(); 8497 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8498 // FIXME: Leaking incoming expressions! 8499 return ExprError(); 8500 8501 case OR_Deleted: 8502 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 8503 << Best->Function->isDeleted() 8504 << DeclName 8505 << getDeletedOrUnavailableSuffix(Best->Function) 8506 << MemExprE->getSourceRange(); 8507 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8508 // FIXME: Leaking incoming expressions! 8509 return ExprError(); 8510 } 8511 8512 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 8513 8514 // If overload resolution picked a static member, build a 8515 // non-member call based on that function. 8516 if (Method->isStatic()) { 8517 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 8518 Args, NumArgs, RParenLoc); 8519 } 8520 8521 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 8522 } 8523 8524 QualType ResultType = Method->getResultType(); 8525 ExprValueKind VK = Expr::getValueKindForType(ResultType); 8526 ResultType = ResultType.getNonLValueExprType(Context); 8527 8528 assert(Method && "Member call to something that isn't a method?"); 8529 CXXMemberCallExpr *TheCall = 8530 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 8531 ResultType, VK, RParenLoc); 8532 8533 // Check for a valid return type. 8534 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 8535 TheCall, Method)) 8536 return ExprError(); 8537 8538 // Convert the object argument (for a non-static member function call). 8539 // We only need to do this if there was actually an overload; otherwise 8540 // it was done at lookup. 8541 Expr *ObjectArg = MemExpr->getBase(); 8542 if (!Method->isStatic() && 8543 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 8544 FoundDecl, Method)) 8545 return ExprError(); 8546 MemExpr->setBase(ObjectArg); 8547 8548 // Convert the rest of the arguments 8549 const FunctionProtoType *Proto = 8550 Method->getType()->getAs<FunctionProtoType>(); 8551 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 8552 RParenLoc)) 8553 return ExprError(); 8554 8555 if (CheckFunctionCall(Method, TheCall)) 8556 return ExprError(); 8557 8558 return MaybeBindToTemporary(TheCall); 8559} 8560 8561/// BuildCallToObjectOfClassType - Build a call to an object of class 8562/// type (C++ [over.call.object]), which can end up invoking an 8563/// overloaded function call operator (@c operator()) or performing a 8564/// user-defined conversion on the object argument. 8565ExprResult 8566Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 8567 SourceLocation LParenLoc, 8568 Expr **Args, unsigned NumArgs, 8569 SourceLocation RParenLoc) { 8570 if (Object->getObjectKind() == OK_ObjCProperty) 8571 ConvertPropertyForRValue(Object); 8572 8573 assert(Object->getType()->isRecordType() && "Requires object type argument"); 8574 const RecordType *Record = Object->getType()->getAs<RecordType>(); 8575 8576 // C++ [over.call.object]p1: 8577 // If the primary-expression E in the function call syntax 8578 // evaluates to a class object of type "cv T", then the set of 8579 // candidate functions includes at least the function call 8580 // operators of T. The function call operators of T are obtained by 8581 // ordinary lookup of the name operator() in the context of 8582 // (E).operator(). 8583 OverloadCandidateSet CandidateSet(LParenLoc); 8584 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 8585 8586 if (RequireCompleteType(LParenLoc, Object->getType(), 8587 PDiag(diag::err_incomplete_object_call) 8588 << Object->getSourceRange())) 8589 return true; 8590 8591 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 8592 LookupQualifiedName(R, Record->getDecl()); 8593 R.suppressDiagnostics(); 8594 8595 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 8596 Oper != OperEnd; ++Oper) { 8597 AddMethodCandidate(Oper.getPair(), Object->getType(), 8598 Object->Classify(Context), Args, NumArgs, CandidateSet, 8599 /*SuppressUserConversions=*/ false); 8600 } 8601 8602 // C++ [over.call.object]p2: 8603 // In addition, for each conversion function declared in T of the 8604 // form 8605 // 8606 // operator conversion-type-id () cv-qualifier; 8607 // 8608 // where cv-qualifier is the same cv-qualification as, or a 8609 // greater cv-qualification than, cv, and where conversion-type-id 8610 // denotes the type "pointer to function of (P1,...,Pn) returning 8611 // R", or the type "reference to pointer to function of 8612 // (P1,...,Pn) returning R", or the type "reference to function 8613 // of (P1,...,Pn) returning R", a surrogate call function [...] 8614 // is also considered as a candidate function. Similarly, 8615 // surrogate call functions are added to the set of candidate 8616 // functions for each conversion function declared in an 8617 // accessible base class provided the function is not hidden 8618 // within T by another intervening declaration. 8619 const UnresolvedSetImpl *Conversions 8620 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 8621 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 8622 E = Conversions->end(); I != E; ++I) { 8623 NamedDecl *D = *I; 8624 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 8625 if (isa<UsingShadowDecl>(D)) 8626 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 8627 8628 // Skip over templated conversion functions; they aren't 8629 // surrogates. 8630 if (isa<FunctionTemplateDecl>(D)) 8631 continue; 8632 8633 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 8634 8635 // Strip the reference type (if any) and then the pointer type (if 8636 // any) to get down to what might be a function type. 8637 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 8638 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 8639 ConvType = ConvPtrType->getPointeeType(); 8640 8641 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 8642 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 8643 Object, Args, NumArgs, CandidateSet); 8644 } 8645 8646 // Perform overload resolution. 8647 OverloadCandidateSet::iterator Best; 8648 switch (CandidateSet.BestViableFunction(*this, Object->getLocStart(), 8649 Best)) { 8650 case OR_Success: 8651 // Overload resolution succeeded; we'll build the appropriate call 8652 // below. 8653 break; 8654 8655 case OR_No_Viable_Function: 8656 if (CandidateSet.empty()) 8657 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 8658 << Object->getType() << /*call*/ 1 8659 << Object->getSourceRange(); 8660 else 8661 Diag(Object->getSourceRange().getBegin(), 8662 diag::err_ovl_no_viable_object_call) 8663 << Object->getType() << Object->getSourceRange(); 8664 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8665 break; 8666 8667 case OR_Ambiguous: 8668 Diag(Object->getSourceRange().getBegin(), 8669 diag::err_ovl_ambiguous_object_call) 8670 << Object->getType() << Object->getSourceRange(); 8671 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 8672 break; 8673 8674 case OR_Deleted: 8675 Diag(Object->getSourceRange().getBegin(), 8676 diag::err_ovl_deleted_object_call) 8677 << Best->Function->isDeleted() 8678 << Object->getType() 8679 << getDeletedOrUnavailableSuffix(Best->Function) 8680 << Object->getSourceRange(); 8681 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8682 break; 8683 } 8684 8685 if (Best == CandidateSet.end()) 8686 return true; 8687 8688 if (Best->Function == 0) { 8689 // Since there is no function declaration, this is one of the 8690 // surrogate candidates. Dig out the conversion function. 8691 CXXConversionDecl *Conv 8692 = cast<CXXConversionDecl>( 8693 Best->Conversions[0].UserDefined.ConversionFunction); 8694 8695 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 8696 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 8697 8698 // We selected one of the surrogate functions that converts the 8699 // object parameter to a function pointer. Perform the conversion 8700 // on the object argument, then let ActOnCallExpr finish the job. 8701 8702 // Create an implicit member expr to refer to the conversion operator. 8703 // and then call it. 8704 ExprResult Call = BuildCXXMemberCallExpr(Object, Best->FoundDecl, Conv); 8705 if (Call.isInvalid()) 8706 return ExprError(); 8707 8708 return ActOnCallExpr(S, Call.get(), LParenLoc, MultiExprArg(Args, NumArgs), 8709 RParenLoc); 8710 } 8711 8712 MarkDeclarationReferenced(LParenLoc, Best->Function); 8713 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 8714 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 8715 8716 // We found an overloaded operator(). Build a CXXOperatorCallExpr 8717 // that calls this method, using Object for the implicit object 8718 // parameter and passing along the remaining arguments. 8719 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 8720 const FunctionProtoType *Proto = 8721 Method->getType()->getAs<FunctionProtoType>(); 8722 8723 unsigned NumArgsInProto = Proto->getNumArgs(); 8724 unsigned NumArgsToCheck = NumArgs; 8725 8726 // Build the full argument list for the method call (the 8727 // implicit object parameter is placed at the beginning of the 8728 // list). 8729 Expr **MethodArgs; 8730 if (NumArgs < NumArgsInProto) { 8731 NumArgsToCheck = NumArgsInProto; 8732 MethodArgs = new Expr*[NumArgsInProto + 1]; 8733 } else { 8734 MethodArgs = new Expr*[NumArgs + 1]; 8735 } 8736 MethodArgs[0] = Object; 8737 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 8738 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 8739 8740 Expr *NewFn = CreateFunctionRefExpr(*this, Method); 8741 8742 // Once we've built TheCall, all of the expressions are properly 8743 // owned. 8744 QualType ResultTy = Method->getResultType(); 8745 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8746 ResultTy = ResultTy.getNonLValueExprType(Context); 8747 8748 CXXOperatorCallExpr *TheCall = 8749 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 8750 MethodArgs, NumArgs + 1, 8751 ResultTy, VK, RParenLoc); 8752 delete [] MethodArgs; 8753 8754 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 8755 Method)) 8756 return true; 8757 8758 // We may have default arguments. If so, we need to allocate more 8759 // slots in the call for them. 8760 if (NumArgs < NumArgsInProto) 8761 TheCall->setNumArgs(Context, NumArgsInProto + 1); 8762 else if (NumArgs > NumArgsInProto) 8763 NumArgsToCheck = NumArgsInProto; 8764 8765 bool IsError = false; 8766 8767 // Initialize the implicit object parameter. 8768 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 8769 Best->FoundDecl, Method); 8770 TheCall->setArg(0, Object); 8771 8772 8773 // Check the argument types. 8774 for (unsigned i = 0; i != NumArgsToCheck; i++) { 8775 Expr *Arg; 8776 if (i < NumArgs) { 8777 Arg = Args[i]; 8778 8779 // Pass the argument. 8780 8781 ExprResult InputInit 8782 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8783 Context, 8784 Method->getParamDecl(i)), 8785 SourceLocation(), Arg); 8786 8787 IsError |= InputInit.isInvalid(); 8788 Arg = InputInit.takeAs<Expr>(); 8789 } else { 8790 ExprResult DefArg 8791 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 8792 if (DefArg.isInvalid()) { 8793 IsError = true; 8794 break; 8795 } 8796 8797 Arg = DefArg.takeAs<Expr>(); 8798 } 8799 8800 TheCall->setArg(i + 1, Arg); 8801 } 8802 8803 // If this is a variadic call, handle args passed through "...". 8804 if (Proto->isVariadic()) { 8805 // Promote the arguments (C99 6.5.2.2p7). 8806 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 8807 Expr *Arg = Args[i]; 8808 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 8809 TheCall->setArg(i + 1, Arg); 8810 } 8811 } 8812 8813 if (IsError) return true; 8814 8815 if (CheckFunctionCall(Method, TheCall)) 8816 return true; 8817 8818 return MaybeBindToTemporary(TheCall); 8819} 8820 8821/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 8822/// (if one exists), where @c Base is an expression of class type and 8823/// @c Member is the name of the member we're trying to find. 8824ExprResult 8825Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 8826 assert(Base->getType()->isRecordType() && 8827 "left-hand side must have class type"); 8828 8829 if (Base->getObjectKind() == OK_ObjCProperty) 8830 ConvertPropertyForRValue(Base); 8831 8832 SourceLocation Loc = Base->getExprLoc(); 8833 8834 // C++ [over.ref]p1: 8835 // 8836 // [...] An expression x->m is interpreted as (x.operator->())->m 8837 // for a class object x of type T if T::operator->() exists and if 8838 // the operator is selected as the best match function by the 8839 // overload resolution mechanism (13.3). 8840 DeclarationName OpName = 8841 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 8842 OverloadCandidateSet CandidateSet(Loc); 8843 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 8844 8845 if (RequireCompleteType(Loc, Base->getType(), 8846 PDiag(diag::err_typecheck_incomplete_tag) 8847 << Base->getSourceRange())) 8848 return ExprError(); 8849 8850 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 8851 LookupQualifiedName(R, BaseRecord->getDecl()); 8852 R.suppressDiagnostics(); 8853 8854 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 8855 Oper != OperEnd; ++Oper) { 8856 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 8857 0, 0, CandidateSet, /*SuppressUserConversions=*/false); 8858 } 8859 8860 // Perform overload resolution. 8861 OverloadCandidateSet::iterator Best; 8862 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8863 case OR_Success: 8864 // Overload resolution succeeded; we'll build the call below. 8865 break; 8866 8867 case OR_No_Viable_Function: 8868 if (CandidateSet.empty()) 8869 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 8870 << Base->getType() << Base->getSourceRange(); 8871 else 8872 Diag(OpLoc, diag::err_ovl_no_viable_oper) 8873 << "operator->" << Base->getSourceRange(); 8874 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 8875 return ExprError(); 8876 8877 case OR_Ambiguous: 8878 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 8879 << "->" << Base->getType() << Base->getSourceRange(); 8880 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, &Base, 1); 8881 return ExprError(); 8882 8883 case OR_Deleted: 8884 Diag(OpLoc, diag::err_ovl_deleted_oper) 8885 << Best->Function->isDeleted() 8886 << "->" 8887 << getDeletedOrUnavailableSuffix(Best->Function) 8888 << Base->getSourceRange(); 8889 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 8890 return ExprError(); 8891 } 8892 8893 MarkDeclarationReferenced(OpLoc, Best->Function); 8894 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 8895 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 8896 8897 // Convert the object parameter. 8898 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 8899 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 8900 Best->FoundDecl, Method)) 8901 return ExprError(); 8902 8903 // Build the operator call. 8904 Expr *FnExpr = CreateFunctionRefExpr(*this, Method); 8905 8906 QualType ResultTy = Method->getResultType(); 8907 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8908 ResultTy = ResultTy.getNonLValueExprType(Context); 8909 CXXOperatorCallExpr *TheCall = 8910 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 8911 &Base, 1, ResultTy, VK, OpLoc); 8912 8913 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 8914 Method)) 8915 return ExprError(); 8916 return Owned(TheCall); 8917} 8918 8919/// FixOverloadedFunctionReference - E is an expression that refers to 8920/// a C++ overloaded function (possibly with some parentheses and 8921/// perhaps a '&' around it). We have resolved the overloaded function 8922/// to the function declaration Fn, so patch up the expression E to 8923/// refer (possibly indirectly) to Fn. Returns the new expr. 8924Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 8925 FunctionDecl *Fn) { 8926 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 8927 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 8928 Found, Fn); 8929 if (SubExpr == PE->getSubExpr()) 8930 return PE; 8931 8932 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 8933 } 8934 8935 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 8936 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 8937 Found, Fn); 8938 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 8939 SubExpr->getType()) && 8940 "Implicit cast type cannot be determined from overload"); 8941 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 8942 if (SubExpr == ICE->getSubExpr()) 8943 return ICE; 8944 8945 return ImplicitCastExpr::Create(Context, ICE->getType(), 8946 ICE->getCastKind(), 8947 SubExpr, 0, 8948 ICE->getValueKind()); 8949 } 8950 8951 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 8952 assert(UnOp->getOpcode() == UO_AddrOf && 8953 "Can only take the address of an overloaded function"); 8954 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 8955 if (Method->isStatic()) { 8956 // Do nothing: static member functions aren't any different 8957 // from non-member functions. 8958 } else { 8959 // Fix the sub expression, which really has to be an 8960 // UnresolvedLookupExpr holding an overloaded member function 8961 // or template. 8962 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 8963 Found, Fn); 8964 if (SubExpr == UnOp->getSubExpr()) 8965 return UnOp; 8966 8967 assert(isa<DeclRefExpr>(SubExpr) 8968 && "fixed to something other than a decl ref"); 8969 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 8970 && "fixed to a member ref with no nested name qualifier"); 8971 8972 // We have taken the address of a pointer to member 8973 // function. Perform the computation here so that we get the 8974 // appropriate pointer to member type. 8975 QualType ClassType 8976 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 8977 QualType MemPtrType 8978 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 8979 8980 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 8981 VK_RValue, OK_Ordinary, 8982 UnOp->getOperatorLoc()); 8983 } 8984 } 8985 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 8986 Found, Fn); 8987 if (SubExpr == UnOp->getSubExpr()) 8988 return UnOp; 8989 8990 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 8991 Context.getPointerType(SubExpr->getType()), 8992 VK_RValue, OK_Ordinary, 8993 UnOp->getOperatorLoc()); 8994 } 8995 8996 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 8997 // FIXME: avoid copy. 8998 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 8999 if (ULE->hasExplicitTemplateArgs()) { 9000 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 9001 TemplateArgs = &TemplateArgsBuffer; 9002 } 9003 9004 return DeclRefExpr::Create(Context, 9005 ULE->getQualifierLoc(), 9006 Fn, 9007 ULE->getNameLoc(), 9008 Fn->getType(), 9009 VK_LValue, 9010 TemplateArgs); 9011 } 9012 9013 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 9014 // FIXME: avoid copy. 9015 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 9016 if (MemExpr->hasExplicitTemplateArgs()) { 9017 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 9018 TemplateArgs = &TemplateArgsBuffer; 9019 } 9020 9021 Expr *Base; 9022 9023 // If we're filling in a static method where we used to have an 9024 // implicit member access, rewrite to a simple decl ref. 9025 if (MemExpr->isImplicitAccess()) { 9026 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 9027 return DeclRefExpr::Create(Context, 9028 MemExpr->getQualifierLoc(), 9029 Fn, 9030 MemExpr->getMemberLoc(), 9031 Fn->getType(), 9032 VK_LValue, 9033 TemplateArgs); 9034 } else { 9035 SourceLocation Loc = MemExpr->getMemberLoc(); 9036 if (MemExpr->getQualifier()) 9037 Loc = MemExpr->getQualifierLoc().getBeginLoc(); 9038 Base = new (Context) CXXThisExpr(Loc, 9039 MemExpr->getBaseType(), 9040 /*isImplicit=*/true); 9041 } 9042 } else 9043 Base = MemExpr->getBase(); 9044 9045 return MemberExpr::Create(Context, Base, 9046 MemExpr->isArrow(), 9047 MemExpr->getQualifierLoc(), 9048 Fn, 9049 Found, 9050 MemExpr->getMemberNameInfo(), 9051 TemplateArgs, 9052 Fn->getType(), 9053 cast<CXXMethodDecl>(Fn)->isStatic() 9054 ? VK_LValue : VK_RValue, 9055 OK_Ordinary); 9056 } 9057 9058 llvm_unreachable("Invalid reference to overloaded function"); 9059 return E; 9060} 9061 9062ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 9063 DeclAccessPair Found, 9064 FunctionDecl *Fn) { 9065 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 9066} 9067 9068} // end namespace clang 9069