SemaOverload.cpp revision 429bb276991ff2dbc7c5b438828b9b7737cb15eb
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Sema/SemaInternal.h" 15#include "clang/Sema/Lookup.h" 16#include "clang/Sema/Initialization.h" 17#include "clang/Sema/Template.h" 18#include "clang/Sema/TemplateDeduction.h" 19#include "clang/Basic/Diagnostic.h" 20#include "clang/Lex/Preprocessor.h" 21#include "clang/AST/ASTContext.h" 22#include "clang/AST/CXXInheritance.h" 23#include "clang/AST/DeclObjC.h" 24#include "clang/AST/Expr.h" 25#include "clang/AST/ExprCXX.h" 26#include "clang/AST/ExprObjC.h" 27#include "clang/AST/TypeOrdering.h" 28#include "clang/Basic/PartialDiagnostic.h" 29#include "llvm/ADT/DenseSet.h" 30#include "llvm/ADT/SmallPtrSet.h" 31#include "llvm/ADT/STLExtras.h" 32#include <algorithm> 33 34namespace clang { 35using namespace sema; 36 37/// A convenience routine for creating a decayed reference to a 38/// function. 39static ExprResult 40CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, 41 SourceLocation Loc = SourceLocation()) { 42 ExprResult E = S.Owned(new (S.Context) DeclRefExpr(Fn, Fn->getType(), VK_LValue, Loc)); 43 E = S.DefaultFunctionArrayConversion(E.take()); 44 if (E.isInvalid()) 45 return ExprError(); 46 return move(E); 47} 48 49static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 50 bool InOverloadResolution, 51 StandardConversionSequence &SCS, 52 bool CStyle); 53 54static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From, 55 QualType &ToType, 56 bool InOverloadResolution, 57 StandardConversionSequence &SCS, 58 bool CStyle); 59static OverloadingResult 60IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 61 UserDefinedConversionSequence& User, 62 OverloadCandidateSet& Conversions, 63 bool AllowExplicit); 64 65 66static ImplicitConversionSequence::CompareKind 67CompareStandardConversionSequences(Sema &S, 68 const StandardConversionSequence& SCS1, 69 const StandardConversionSequence& SCS2); 70 71static ImplicitConversionSequence::CompareKind 72CompareQualificationConversions(Sema &S, 73 const StandardConversionSequence& SCS1, 74 const StandardConversionSequence& SCS2); 75 76static ImplicitConversionSequence::CompareKind 77CompareDerivedToBaseConversions(Sema &S, 78 const StandardConversionSequence& SCS1, 79 const StandardConversionSequence& SCS2); 80 81 82 83/// GetConversionCategory - Retrieve the implicit conversion 84/// category corresponding to the given implicit conversion kind. 85ImplicitConversionCategory 86GetConversionCategory(ImplicitConversionKind Kind) { 87 static const ImplicitConversionCategory 88 Category[(int)ICK_Num_Conversion_Kinds] = { 89 ICC_Identity, 90 ICC_Lvalue_Transformation, 91 ICC_Lvalue_Transformation, 92 ICC_Lvalue_Transformation, 93 ICC_Identity, 94 ICC_Qualification_Adjustment, 95 ICC_Promotion, 96 ICC_Promotion, 97 ICC_Promotion, 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 ICC_Conversion, 109 ICC_Conversion 110 }; 111 return Category[(int)Kind]; 112} 113 114/// GetConversionRank - Retrieve the implicit conversion rank 115/// corresponding to the given implicit conversion kind. 116ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 117 static const ImplicitConversionRank 118 Rank[(int)ICK_Num_Conversion_Kinds] = { 119 ICR_Exact_Match, 120 ICR_Exact_Match, 121 ICR_Exact_Match, 122 ICR_Exact_Match, 123 ICR_Exact_Match, 124 ICR_Exact_Match, 125 ICR_Promotion, 126 ICR_Promotion, 127 ICR_Promotion, 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_Conversion, 138 ICR_Conversion, 139 ICR_Complex_Real_Conversion, 140 ICR_Conversion, 141 ICR_Conversion 142 }; 143 return Rank[(int)Kind]; 144} 145 146/// GetImplicitConversionName - Return the name of this kind of 147/// implicit conversion. 148const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 149 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 150 "No conversion", 151 "Lvalue-to-rvalue", 152 "Array-to-pointer", 153 "Function-to-pointer", 154 "Noreturn adjustment", 155 "Qualification", 156 "Integral promotion", 157 "Floating point promotion", 158 "Complex promotion", 159 "Integral conversion", 160 "Floating conversion", 161 "Complex conversion", 162 "Floating-integral conversion", 163 "Pointer conversion", 164 "Pointer-to-member conversion", 165 "Boolean conversion", 166 "Compatible-types conversion", 167 "Derived-to-base conversion", 168 "Vector conversion", 169 "Vector splat", 170 "Complex-real conversion", 171 "Block Pointer conversion", 172 "Transparent Union Conversion" 173 }; 174 return Name[Kind]; 175} 176 177/// StandardConversionSequence - Set the standard conversion 178/// sequence to the identity conversion. 179void StandardConversionSequence::setAsIdentityConversion() { 180 First = ICK_Identity; 181 Second = ICK_Identity; 182 Third = ICK_Identity; 183 DeprecatedStringLiteralToCharPtr = false; 184 ReferenceBinding = false; 185 DirectBinding = false; 186 IsLvalueReference = true; 187 BindsToFunctionLvalue = false; 188 BindsToRvalue = false; 189 BindsImplicitObjectArgumentWithoutRefQualifier = false; 190 CopyConstructor = 0; 191} 192 193/// getRank - Retrieve the rank of this standard conversion sequence 194/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 195/// implicit conversions. 196ImplicitConversionRank StandardConversionSequence::getRank() const { 197 ImplicitConversionRank Rank = ICR_Exact_Match; 198 if (GetConversionRank(First) > Rank) 199 Rank = GetConversionRank(First); 200 if (GetConversionRank(Second) > Rank) 201 Rank = GetConversionRank(Second); 202 if (GetConversionRank(Third) > Rank) 203 Rank = GetConversionRank(Third); 204 return Rank; 205} 206 207/// isPointerConversionToBool - Determines whether this conversion is 208/// a conversion of a pointer or pointer-to-member to bool. This is 209/// used as part of the ranking of standard conversion sequences 210/// (C++ 13.3.3.2p4). 211bool StandardConversionSequence::isPointerConversionToBool() const { 212 // Note that FromType has not necessarily been transformed by the 213 // array-to-pointer or function-to-pointer implicit conversions, so 214 // check for their presence as well as checking whether FromType is 215 // a pointer. 216 if (getToType(1)->isBooleanType() && 217 (getFromType()->isPointerType() || 218 getFromType()->isObjCObjectPointerType() || 219 getFromType()->isBlockPointerType() || 220 getFromType()->isNullPtrType() || 221 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 222 return true; 223 224 return false; 225} 226 227/// isPointerConversionToVoidPointer - Determines whether this 228/// conversion is a conversion of a pointer to a void pointer. This is 229/// used as part of the ranking of standard conversion sequences (C++ 230/// 13.3.3.2p4). 231bool 232StandardConversionSequence:: 233isPointerConversionToVoidPointer(ASTContext& Context) const { 234 QualType FromType = getFromType(); 235 QualType ToType = getToType(1); 236 237 // Note that FromType has not necessarily been transformed by the 238 // array-to-pointer implicit conversion, so check for its presence 239 // and redo the conversion to get a pointer. 240 if (First == ICK_Array_To_Pointer) 241 FromType = Context.getArrayDecayedType(FromType); 242 243 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 244 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 245 return ToPtrType->getPointeeType()->isVoidType(); 246 247 return false; 248} 249 250/// DebugPrint - Print this standard conversion sequence to standard 251/// error. Useful for debugging overloading issues. 252void StandardConversionSequence::DebugPrint() const { 253 llvm::raw_ostream &OS = llvm::errs(); 254 bool PrintedSomething = false; 255 if (First != ICK_Identity) { 256 OS << GetImplicitConversionName(First); 257 PrintedSomething = true; 258 } 259 260 if (Second != ICK_Identity) { 261 if (PrintedSomething) { 262 OS << " -> "; 263 } 264 OS << GetImplicitConversionName(Second); 265 266 if (CopyConstructor) { 267 OS << " (by copy constructor)"; 268 } else if (DirectBinding) { 269 OS << " (direct reference binding)"; 270 } else if (ReferenceBinding) { 271 OS << " (reference binding)"; 272 } 273 PrintedSomething = true; 274 } 275 276 if (Third != ICK_Identity) { 277 if (PrintedSomething) { 278 OS << " -> "; 279 } 280 OS << GetImplicitConversionName(Third); 281 PrintedSomething = true; 282 } 283 284 if (!PrintedSomething) { 285 OS << "No conversions required"; 286 } 287} 288 289/// DebugPrint - Print this user-defined conversion sequence to standard 290/// error. Useful for debugging overloading issues. 291void UserDefinedConversionSequence::DebugPrint() const { 292 llvm::raw_ostream &OS = llvm::errs(); 293 if (Before.First || Before.Second || Before.Third) { 294 Before.DebugPrint(); 295 OS << " -> "; 296 } 297 OS << '\'' << ConversionFunction << '\''; 298 if (After.First || After.Second || After.Third) { 299 OS << " -> "; 300 After.DebugPrint(); 301 } 302} 303 304/// DebugPrint - Print this implicit conversion sequence to standard 305/// error. Useful for debugging overloading issues. 306void ImplicitConversionSequence::DebugPrint() const { 307 llvm::raw_ostream &OS = llvm::errs(); 308 switch (ConversionKind) { 309 case StandardConversion: 310 OS << "Standard conversion: "; 311 Standard.DebugPrint(); 312 break; 313 case UserDefinedConversion: 314 OS << "User-defined conversion: "; 315 UserDefined.DebugPrint(); 316 break; 317 case EllipsisConversion: 318 OS << "Ellipsis conversion"; 319 break; 320 case AmbiguousConversion: 321 OS << "Ambiguous conversion"; 322 break; 323 case BadConversion: 324 OS << "Bad conversion"; 325 break; 326 } 327 328 OS << "\n"; 329} 330 331void AmbiguousConversionSequence::construct() { 332 new (&conversions()) ConversionSet(); 333} 334 335void AmbiguousConversionSequence::destruct() { 336 conversions().~ConversionSet(); 337} 338 339void 340AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 341 FromTypePtr = O.FromTypePtr; 342 ToTypePtr = O.ToTypePtr; 343 new (&conversions()) ConversionSet(O.conversions()); 344} 345 346namespace { 347 // Structure used by OverloadCandidate::DeductionFailureInfo to store 348 // template parameter and template argument information. 349 struct DFIParamWithArguments { 350 TemplateParameter Param; 351 TemplateArgument FirstArg; 352 TemplateArgument SecondArg; 353 }; 354} 355 356/// \brief Convert from Sema's representation of template deduction information 357/// to the form used in overload-candidate information. 358OverloadCandidate::DeductionFailureInfo 359static MakeDeductionFailureInfo(ASTContext &Context, 360 Sema::TemplateDeductionResult TDK, 361 TemplateDeductionInfo &Info) { 362 OverloadCandidate::DeductionFailureInfo Result; 363 Result.Result = static_cast<unsigned>(TDK); 364 Result.Data = 0; 365 switch (TDK) { 366 case Sema::TDK_Success: 367 case Sema::TDK_InstantiationDepth: 368 case Sema::TDK_TooManyArguments: 369 case Sema::TDK_TooFewArguments: 370 break; 371 372 case Sema::TDK_Incomplete: 373 case Sema::TDK_InvalidExplicitArguments: 374 Result.Data = Info.Param.getOpaqueValue(); 375 break; 376 377 case Sema::TDK_Inconsistent: 378 case Sema::TDK_Underqualified: { 379 // FIXME: Should allocate from normal heap so that we can free this later. 380 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 381 Saved->Param = Info.Param; 382 Saved->FirstArg = Info.FirstArg; 383 Saved->SecondArg = Info.SecondArg; 384 Result.Data = Saved; 385 break; 386 } 387 388 case Sema::TDK_SubstitutionFailure: 389 Result.Data = Info.take(); 390 break; 391 392 case Sema::TDK_NonDeducedMismatch: 393 case Sema::TDK_FailedOverloadResolution: 394 break; 395 } 396 397 return Result; 398} 399 400void OverloadCandidate::DeductionFailureInfo::Destroy() { 401 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 402 case Sema::TDK_Success: 403 case Sema::TDK_InstantiationDepth: 404 case Sema::TDK_Incomplete: 405 case Sema::TDK_TooManyArguments: 406 case Sema::TDK_TooFewArguments: 407 case Sema::TDK_InvalidExplicitArguments: 408 break; 409 410 case Sema::TDK_Inconsistent: 411 case Sema::TDK_Underqualified: 412 // FIXME: Destroy the data? 413 Data = 0; 414 break; 415 416 case Sema::TDK_SubstitutionFailure: 417 // FIXME: Destroy the template arugment list? 418 Data = 0; 419 break; 420 421 // Unhandled 422 case Sema::TDK_NonDeducedMismatch: 423 case Sema::TDK_FailedOverloadResolution: 424 break; 425 } 426} 427 428TemplateParameter 429OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 430 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 431 case Sema::TDK_Success: 432 case Sema::TDK_InstantiationDepth: 433 case Sema::TDK_TooManyArguments: 434 case Sema::TDK_TooFewArguments: 435 case Sema::TDK_SubstitutionFailure: 436 return TemplateParameter(); 437 438 case Sema::TDK_Incomplete: 439 case Sema::TDK_InvalidExplicitArguments: 440 return TemplateParameter::getFromOpaqueValue(Data); 441 442 case Sema::TDK_Inconsistent: 443 case Sema::TDK_Underqualified: 444 return static_cast<DFIParamWithArguments*>(Data)->Param; 445 446 // Unhandled 447 case Sema::TDK_NonDeducedMismatch: 448 case Sema::TDK_FailedOverloadResolution: 449 break; 450 } 451 452 return TemplateParameter(); 453} 454 455TemplateArgumentList * 456OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 457 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 458 case Sema::TDK_Success: 459 case Sema::TDK_InstantiationDepth: 460 case Sema::TDK_TooManyArguments: 461 case Sema::TDK_TooFewArguments: 462 case Sema::TDK_Incomplete: 463 case Sema::TDK_InvalidExplicitArguments: 464 case Sema::TDK_Inconsistent: 465 case Sema::TDK_Underqualified: 466 return 0; 467 468 case Sema::TDK_SubstitutionFailure: 469 return static_cast<TemplateArgumentList*>(Data); 470 471 // Unhandled 472 case Sema::TDK_NonDeducedMismatch: 473 case Sema::TDK_FailedOverloadResolution: 474 break; 475 } 476 477 return 0; 478} 479 480const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 481 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 482 case Sema::TDK_Success: 483 case Sema::TDK_InstantiationDepth: 484 case Sema::TDK_Incomplete: 485 case Sema::TDK_TooManyArguments: 486 case Sema::TDK_TooFewArguments: 487 case Sema::TDK_InvalidExplicitArguments: 488 case Sema::TDK_SubstitutionFailure: 489 return 0; 490 491 case Sema::TDK_Inconsistent: 492 case Sema::TDK_Underqualified: 493 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 494 495 // Unhandled 496 case Sema::TDK_NonDeducedMismatch: 497 case Sema::TDK_FailedOverloadResolution: 498 break; 499 } 500 501 return 0; 502} 503 504const TemplateArgument * 505OverloadCandidate::DeductionFailureInfo::getSecondArg() { 506 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 507 case Sema::TDK_Success: 508 case Sema::TDK_InstantiationDepth: 509 case Sema::TDK_Incomplete: 510 case Sema::TDK_TooManyArguments: 511 case Sema::TDK_TooFewArguments: 512 case Sema::TDK_InvalidExplicitArguments: 513 case Sema::TDK_SubstitutionFailure: 514 return 0; 515 516 case Sema::TDK_Inconsistent: 517 case Sema::TDK_Underqualified: 518 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 519 520 // Unhandled 521 case Sema::TDK_NonDeducedMismatch: 522 case Sema::TDK_FailedOverloadResolution: 523 break; 524 } 525 526 return 0; 527} 528 529void OverloadCandidateSet::clear() { 530 inherited::clear(); 531 Functions.clear(); 532} 533 534// IsOverload - Determine whether the given New declaration is an 535// overload of the declarations in Old. This routine returns false if 536// New and Old cannot be overloaded, e.g., if New has the same 537// signature as some function in Old (C++ 1.3.10) or if the Old 538// declarations aren't functions (or function templates) at all. When 539// it does return false, MatchedDecl will point to the decl that New 540// cannot be overloaded with. This decl may be a UsingShadowDecl on 541// top of the underlying declaration. 542// 543// Example: Given the following input: 544// 545// void f(int, float); // #1 546// void f(int, int); // #2 547// int f(int, int); // #3 548// 549// When we process #1, there is no previous declaration of "f", 550// so IsOverload will not be used. 551// 552// When we process #2, Old contains only the FunctionDecl for #1. By 553// comparing the parameter types, we see that #1 and #2 are overloaded 554// (since they have different signatures), so this routine returns 555// false; MatchedDecl is unchanged. 556// 557// When we process #3, Old is an overload set containing #1 and #2. We 558// compare the signatures of #3 to #1 (they're overloaded, so we do 559// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 560// identical (return types of functions are not part of the 561// signature), IsOverload returns false and MatchedDecl will be set to 562// point to the FunctionDecl for #2. 563// 564// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 565// into a class by a using declaration. The rules for whether to hide 566// shadow declarations ignore some properties which otherwise figure 567// into a function template's signature. 568Sema::OverloadKind 569Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 570 NamedDecl *&Match, bool NewIsUsingDecl) { 571 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 572 I != E; ++I) { 573 NamedDecl *OldD = *I; 574 575 bool OldIsUsingDecl = false; 576 if (isa<UsingShadowDecl>(OldD)) { 577 OldIsUsingDecl = true; 578 579 // We can always introduce two using declarations into the same 580 // context, even if they have identical signatures. 581 if (NewIsUsingDecl) continue; 582 583 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 584 } 585 586 // If either declaration was introduced by a using declaration, 587 // we'll need to use slightly different rules for matching. 588 // Essentially, these rules are the normal rules, except that 589 // function templates hide function templates with different 590 // return types or template parameter lists. 591 bool UseMemberUsingDeclRules = 592 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 593 594 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 595 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 596 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 597 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 598 continue; 599 } 600 601 Match = *I; 602 return Ovl_Match; 603 } 604 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 605 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 606 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 607 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 608 continue; 609 } 610 611 Match = *I; 612 return Ovl_Match; 613 } 614 } else if (isa<UsingDecl>(OldD)) { 615 // We can overload with these, which can show up when doing 616 // redeclaration checks for UsingDecls. 617 assert(Old.getLookupKind() == LookupUsingDeclName); 618 } else if (isa<TagDecl>(OldD)) { 619 // We can always overload with tags by hiding them. 620 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 621 // Optimistically assume that an unresolved using decl will 622 // overload; if it doesn't, we'll have to diagnose during 623 // template instantiation. 624 } else { 625 // (C++ 13p1): 626 // Only function declarations can be overloaded; object and type 627 // declarations cannot be overloaded. 628 Match = *I; 629 return Ovl_NonFunction; 630 } 631 } 632 633 return Ovl_Overload; 634} 635 636bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 637 bool UseUsingDeclRules) { 638 // If both of the functions are extern "C", then they are not 639 // overloads. 640 if (Old->isExternC() && New->isExternC()) 641 return false; 642 643 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 644 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 645 646 // C++ [temp.fct]p2: 647 // A function template can be overloaded with other function templates 648 // and with normal (non-template) functions. 649 if ((OldTemplate == 0) != (NewTemplate == 0)) 650 return true; 651 652 // Is the function New an overload of the function Old? 653 QualType OldQType = Context.getCanonicalType(Old->getType()); 654 QualType NewQType = Context.getCanonicalType(New->getType()); 655 656 // Compare the signatures (C++ 1.3.10) of the two functions to 657 // determine whether they are overloads. If we find any mismatch 658 // in the signature, they are overloads. 659 660 // If either of these functions is a K&R-style function (no 661 // prototype), then we consider them to have matching signatures. 662 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 663 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 664 return false; 665 666 const FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 667 const FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 668 669 // The signature of a function includes the types of its 670 // parameters (C++ 1.3.10), which includes the presence or absence 671 // of the ellipsis; see C++ DR 357). 672 if (OldQType != NewQType && 673 (OldType->getNumArgs() != NewType->getNumArgs() || 674 OldType->isVariadic() != NewType->isVariadic() || 675 !FunctionArgTypesAreEqual(OldType, NewType))) 676 return true; 677 678 // C++ [temp.over.link]p4: 679 // The signature of a function template consists of its function 680 // signature, its return type and its template parameter list. The names 681 // of the template parameters are significant only for establishing the 682 // relationship between the template parameters and the rest of the 683 // signature. 684 // 685 // We check the return type and template parameter lists for function 686 // templates first; the remaining checks follow. 687 // 688 // However, we don't consider either of these when deciding whether 689 // a member introduced by a shadow declaration is hidden. 690 if (!UseUsingDeclRules && NewTemplate && 691 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 692 OldTemplate->getTemplateParameters(), 693 false, TPL_TemplateMatch) || 694 OldType->getResultType() != NewType->getResultType())) 695 return true; 696 697 // If the function is a class member, its signature includes the 698 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. 699 // 700 // As part of this, also check whether one of the member functions 701 // is static, in which case they are not overloads (C++ 702 // 13.1p2). While not part of the definition of the signature, 703 // this check is important to determine whether these functions 704 // can be overloaded. 705 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 706 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 707 if (OldMethod && NewMethod && 708 !OldMethod->isStatic() && !NewMethod->isStatic() && 709 (OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers() || 710 OldMethod->getRefQualifier() != NewMethod->getRefQualifier())) { 711 if (!UseUsingDeclRules && 712 OldMethod->getRefQualifier() != NewMethod->getRefQualifier() && 713 (OldMethod->getRefQualifier() == RQ_None || 714 NewMethod->getRefQualifier() == RQ_None)) { 715 // C++0x [over.load]p2: 716 // - Member function declarations with the same name and the same 717 // parameter-type-list as well as member function template 718 // declarations with the same name, the same parameter-type-list, and 719 // the same template parameter lists cannot be overloaded if any of 720 // them, but not all, have a ref-qualifier (8.3.5). 721 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) 722 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); 723 Diag(OldMethod->getLocation(), diag::note_previous_declaration); 724 } 725 726 return true; 727 } 728 729 // The signatures match; this is not an overload. 730 return false; 731} 732 733/// TryImplicitConversion - Attempt to perform an implicit conversion 734/// from the given expression (Expr) to the given type (ToType). This 735/// function returns an implicit conversion sequence that can be used 736/// to perform the initialization. Given 737/// 738/// void f(float f); 739/// void g(int i) { f(i); } 740/// 741/// this routine would produce an implicit conversion sequence to 742/// describe the initialization of f from i, which will be a standard 743/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 744/// 4.1) followed by a floating-integral conversion (C++ 4.9). 745// 746/// Note that this routine only determines how the conversion can be 747/// performed; it does not actually perform the conversion. As such, 748/// it will not produce any diagnostics if no conversion is available, 749/// but will instead return an implicit conversion sequence of kind 750/// "BadConversion". 751/// 752/// If @p SuppressUserConversions, then user-defined conversions are 753/// not permitted. 754/// If @p AllowExplicit, then explicit user-defined conversions are 755/// permitted. 756static ImplicitConversionSequence 757TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 758 bool SuppressUserConversions, 759 bool AllowExplicit, 760 bool InOverloadResolution, 761 bool CStyle) { 762 ImplicitConversionSequence ICS; 763 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 764 ICS.Standard, CStyle)) { 765 ICS.setStandard(); 766 return ICS; 767 } 768 769 if (!S.getLangOptions().CPlusPlus) { 770 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 771 return ICS; 772 } 773 774 // C++ [over.ics.user]p4: 775 // A conversion of an expression of class type to the same class 776 // type is given Exact Match rank, and a conversion of an 777 // expression of class type to a base class of that type is 778 // given Conversion rank, in spite of the fact that a copy/move 779 // constructor (i.e., a user-defined conversion function) is 780 // called for those cases. 781 QualType FromType = From->getType(); 782 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 783 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 784 S.IsDerivedFrom(FromType, ToType))) { 785 ICS.setStandard(); 786 ICS.Standard.setAsIdentityConversion(); 787 ICS.Standard.setFromType(FromType); 788 ICS.Standard.setAllToTypes(ToType); 789 790 // We don't actually check at this point whether there is a valid 791 // copy/move constructor, since overloading just assumes that it 792 // exists. When we actually perform initialization, we'll find the 793 // appropriate constructor to copy the returned object, if needed. 794 ICS.Standard.CopyConstructor = 0; 795 796 // Determine whether this is considered a derived-to-base conversion. 797 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 798 ICS.Standard.Second = ICK_Derived_To_Base; 799 800 return ICS; 801 } 802 803 if (SuppressUserConversions) { 804 // We're not in the case above, so there is no conversion that 805 // we can perform. 806 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 807 return ICS; 808 } 809 810 // Attempt user-defined conversion. 811 OverloadCandidateSet Conversions(From->getExprLoc()); 812 OverloadingResult UserDefResult 813 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 814 AllowExplicit); 815 816 if (UserDefResult == OR_Success) { 817 ICS.setUserDefined(); 818 // C++ [over.ics.user]p4: 819 // A conversion of an expression of class type to the same class 820 // type is given Exact Match rank, and a conversion of an 821 // expression of class type to a base class of that type is 822 // given Conversion rank, in spite of the fact that a copy 823 // constructor (i.e., a user-defined conversion function) is 824 // called for those cases. 825 if (CXXConstructorDecl *Constructor 826 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 827 QualType FromCanon 828 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 829 QualType ToCanon 830 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 831 if (Constructor->isCopyConstructor() && 832 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 833 // Turn this into a "standard" conversion sequence, so that it 834 // gets ranked with standard conversion sequences. 835 ICS.setStandard(); 836 ICS.Standard.setAsIdentityConversion(); 837 ICS.Standard.setFromType(From->getType()); 838 ICS.Standard.setAllToTypes(ToType); 839 ICS.Standard.CopyConstructor = Constructor; 840 if (ToCanon != FromCanon) 841 ICS.Standard.Second = ICK_Derived_To_Base; 842 } 843 } 844 845 // C++ [over.best.ics]p4: 846 // However, when considering the argument of a user-defined 847 // conversion function that is a candidate by 13.3.1.3 when 848 // invoked for the copying of the temporary in the second step 849 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 850 // 13.3.1.6 in all cases, only standard conversion sequences and 851 // ellipsis conversion sequences are allowed. 852 if (SuppressUserConversions && ICS.isUserDefined()) { 853 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 854 } 855 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 856 ICS.setAmbiguous(); 857 ICS.Ambiguous.setFromType(From->getType()); 858 ICS.Ambiguous.setToType(ToType); 859 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 860 Cand != Conversions.end(); ++Cand) 861 if (Cand->Viable) 862 ICS.Ambiguous.addConversion(Cand->Function); 863 } else { 864 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 865 } 866 867 return ICS; 868} 869 870bool Sema::TryImplicitConversion(InitializationSequence &Sequence, 871 const InitializedEntity &Entity, 872 Expr *Initializer, 873 bool SuppressUserConversions, 874 bool AllowExplicitConversions, 875 bool InOverloadResolution, 876 bool CStyle) { 877 ImplicitConversionSequence ICS 878 = clang::TryImplicitConversion(*this, Initializer, Entity.getType(), 879 SuppressUserConversions, 880 AllowExplicitConversions, 881 InOverloadResolution, 882 CStyle); 883 if (ICS.isBad()) return true; 884 885 // Perform the actual conversion. 886 Sequence.AddConversionSequenceStep(ICS, Entity.getType()); 887 return false; 888} 889 890/// PerformImplicitConversion - Perform an implicit conversion of the 891/// expression From to the type ToType. Returns the 892/// converted expression. Flavor is the kind of conversion we're 893/// performing, used in the error message. If @p AllowExplicit, 894/// explicit user-defined conversions are permitted. 895ExprResult 896Sema::PerformImplicitConversion(Expr *From, QualType ToType, 897 AssignmentAction Action, bool AllowExplicit) { 898 ImplicitConversionSequence ICS; 899 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 900} 901 902ExprResult 903Sema::PerformImplicitConversion(Expr *From, QualType ToType, 904 AssignmentAction Action, bool AllowExplicit, 905 ImplicitConversionSequence& ICS) { 906 ICS = clang::TryImplicitConversion(*this, From, ToType, 907 /*SuppressUserConversions=*/false, 908 AllowExplicit, 909 /*InOverloadResolution=*/false, 910 /*CStyle=*/false); 911 return PerformImplicitConversion(From, ToType, ICS, Action); 912} 913 914/// \brief Determine whether the conversion from FromType to ToType is a valid 915/// conversion that strips "noreturn" off the nested function type. 916static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 917 QualType ToType, QualType &ResultTy) { 918 if (Context.hasSameUnqualifiedType(FromType, ToType)) 919 return false; 920 921 // Permit the conversion F(t __attribute__((noreturn))) -> F(t) 922 // where F adds one of the following at most once: 923 // - a pointer 924 // - a member pointer 925 // - a block pointer 926 CanQualType CanTo = Context.getCanonicalType(ToType); 927 CanQualType CanFrom = Context.getCanonicalType(FromType); 928 Type::TypeClass TyClass = CanTo->getTypeClass(); 929 if (TyClass != CanFrom->getTypeClass()) return false; 930 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { 931 if (TyClass == Type::Pointer) { 932 CanTo = CanTo.getAs<PointerType>()->getPointeeType(); 933 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType(); 934 } else if (TyClass == Type::BlockPointer) { 935 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType(); 936 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType(); 937 } else if (TyClass == Type::MemberPointer) { 938 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType(); 939 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType(); 940 } else { 941 return false; 942 } 943 944 TyClass = CanTo->getTypeClass(); 945 if (TyClass != CanFrom->getTypeClass()) return false; 946 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) 947 return false; 948 } 949 950 const FunctionType *FromFn = cast<FunctionType>(CanFrom); 951 FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); 952 if (!EInfo.getNoReturn()) return false; 953 954 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); 955 assert(QualType(FromFn, 0).isCanonical()); 956 if (QualType(FromFn, 0) != CanTo) return false; 957 958 ResultTy = ToType; 959 return true; 960} 961 962/// \brief Determine whether the conversion from FromType to ToType is a valid 963/// vector conversion. 964/// 965/// \param ICK Will be set to the vector conversion kind, if this is a vector 966/// conversion. 967static bool IsVectorConversion(ASTContext &Context, QualType FromType, 968 QualType ToType, ImplicitConversionKind &ICK) { 969 // We need at least one of these types to be a vector type to have a vector 970 // conversion. 971 if (!ToType->isVectorType() && !FromType->isVectorType()) 972 return false; 973 974 // Identical types require no conversions. 975 if (Context.hasSameUnqualifiedType(FromType, ToType)) 976 return false; 977 978 // There are no conversions between extended vector types, only identity. 979 if (ToType->isExtVectorType()) { 980 // There are no conversions between extended vector types other than the 981 // identity conversion. 982 if (FromType->isExtVectorType()) 983 return false; 984 985 // Vector splat from any arithmetic type to a vector. 986 if (FromType->isArithmeticType()) { 987 ICK = ICK_Vector_Splat; 988 return true; 989 } 990 } 991 992 // We can perform the conversion between vector types in the following cases: 993 // 1)vector types are equivalent AltiVec and GCC vector types 994 // 2)lax vector conversions are permitted and the vector types are of the 995 // same size 996 if (ToType->isVectorType() && FromType->isVectorType()) { 997 if (Context.areCompatibleVectorTypes(FromType, ToType) || 998 (Context.getLangOptions().LaxVectorConversions && 999 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 1000 ICK = ICK_Vector_Conversion; 1001 return true; 1002 } 1003 } 1004 1005 return false; 1006} 1007 1008/// IsStandardConversion - Determines whether there is a standard 1009/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 1010/// expression From to the type ToType. Standard conversion sequences 1011/// only consider non-class types; for conversions that involve class 1012/// types, use TryImplicitConversion. If a conversion exists, SCS will 1013/// contain the standard conversion sequence required to perform this 1014/// conversion and this routine will return true. Otherwise, this 1015/// routine will return false and the value of SCS is unspecified. 1016static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 1017 bool InOverloadResolution, 1018 StandardConversionSequence &SCS, 1019 bool CStyle) { 1020 QualType FromType = From->getType(); 1021 1022 // Standard conversions (C++ [conv]) 1023 SCS.setAsIdentityConversion(); 1024 SCS.DeprecatedStringLiteralToCharPtr = false; 1025 SCS.IncompatibleObjC = false; 1026 SCS.setFromType(FromType); 1027 SCS.CopyConstructor = 0; 1028 1029 // There are no standard conversions for class types in C++, so 1030 // abort early. When overloading in C, however, we do permit 1031 if (FromType->isRecordType() || ToType->isRecordType()) { 1032 if (S.getLangOptions().CPlusPlus) 1033 return false; 1034 1035 // When we're overloading in C, we allow, as standard conversions, 1036 } 1037 1038 // The first conversion can be an lvalue-to-rvalue conversion, 1039 // array-to-pointer conversion, or function-to-pointer conversion 1040 // (C++ 4p1). 1041 1042 if (FromType == S.Context.OverloadTy) { 1043 DeclAccessPair AccessPair; 1044 if (FunctionDecl *Fn 1045 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 1046 AccessPair)) { 1047 // We were able to resolve the address of the overloaded function, 1048 // so we can convert to the type of that function. 1049 FromType = Fn->getType(); 1050 1051 // we can sometimes resolve &foo<int> regardless of ToType, so check 1052 // if the type matches (identity) or we are converting to bool 1053 if (!S.Context.hasSameUnqualifiedType( 1054 S.ExtractUnqualifiedFunctionType(ToType), FromType)) { 1055 QualType resultTy; 1056 // if the function type matches except for [[noreturn]], it's ok 1057 if (!IsNoReturnConversion(S.Context, FromType, 1058 S.ExtractUnqualifiedFunctionType(ToType), resultTy)) 1059 // otherwise, only a boolean conversion is standard 1060 if (!ToType->isBooleanType()) 1061 return false; 1062 } 1063 1064 // Check if the "from" expression is taking the address of an overloaded 1065 // function and recompute the FromType accordingly. Take advantage of the 1066 // fact that non-static member functions *must* have such an address-of 1067 // expression. 1068 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn); 1069 if (Method && !Method->isStatic()) { 1070 assert(isa<UnaryOperator>(From->IgnoreParens()) && 1071 "Non-unary operator on non-static member address"); 1072 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() 1073 == UO_AddrOf && 1074 "Non-address-of operator on non-static member address"); 1075 const Type *ClassType 1076 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1077 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1078 } else if (isa<UnaryOperator>(From->IgnoreParens())) { 1079 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == 1080 UO_AddrOf && 1081 "Non-address-of operator for overloaded function expression"); 1082 FromType = S.Context.getPointerType(FromType); 1083 } 1084 1085 // Check that we've computed the proper type after overload resolution. 1086 assert(S.Context.hasSameType( 1087 FromType, 1088 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1089 } else { 1090 return false; 1091 } 1092 } 1093 // Lvalue-to-rvalue conversion (C++ 4.1): 1094 // An lvalue (3.10) of a non-function, non-array type T can be 1095 // converted to an rvalue. 1096 bool argIsLValue = From->isLValue(); 1097 if (argIsLValue && 1098 !FromType->isFunctionType() && !FromType->isArrayType() && 1099 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1100 SCS.First = ICK_Lvalue_To_Rvalue; 1101 1102 // If T is a non-class type, the type of the rvalue is the 1103 // cv-unqualified version of T. Otherwise, the type of the rvalue 1104 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1105 // just strip the qualifiers because they don't matter. 1106 FromType = FromType.getUnqualifiedType(); 1107 } else if (FromType->isArrayType()) { 1108 // Array-to-pointer conversion (C++ 4.2) 1109 SCS.First = ICK_Array_To_Pointer; 1110 1111 // An lvalue or rvalue of type "array of N T" or "array of unknown 1112 // bound of T" can be converted to an rvalue of type "pointer to 1113 // T" (C++ 4.2p1). 1114 FromType = S.Context.getArrayDecayedType(FromType); 1115 1116 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1117 // This conversion is deprecated. (C++ D.4). 1118 SCS.DeprecatedStringLiteralToCharPtr = true; 1119 1120 // For the purpose of ranking in overload resolution 1121 // (13.3.3.1.1), this conversion is considered an 1122 // array-to-pointer conversion followed by a qualification 1123 // conversion (4.4). (C++ 4.2p2) 1124 SCS.Second = ICK_Identity; 1125 SCS.Third = ICK_Qualification; 1126 SCS.setAllToTypes(FromType); 1127 return true; 1128 } 1129 } else if (FromType->isFunctionType() && argIsLValue) { 1130 // Function-to-pointer conversion (C++ 4.3). 1131 SCS.First = ICK_Function_To_Pointer; 1132 1133 // An lvalue of function type T can be converted to an rvalue of 1134 // type "pointer to T." The result is a pointer to the 1135 // function. (C++ 4.3p1). 1136 FromType = S.Context.getPointerType(FromType); 1137 } else { 1138 // We don't require any conversions for the first step. 1139 SCS.First = ICK_Identity; 1140 } 1141 SCS.setToType(0, FromType); 1142 1143 // The second conversion can be an integral promotion, floating 1144 // point promotion, integral conversion, floating point conversion, 1145 // floating-integral conversion, pointer conversion, 1146 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1147 // For overloading in C, this can also be a "compatible-type" 1148 // conversion. 1149 bool IncompatibleObjC = false; 1150 ImplicitConversionKind SecondICK = ICK_Identity; 1151 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1152 // The unqualified versions of the types are the same: there's no 1153 // conversion to do. 1154 SCS.Second = ICK_Identity; 1155 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1156 // Integral promotion (C++ 4.5). 1157 SCS.Second = ICK_Integral_Promotion; 1158 FromType = ToType.getUnqualifiedType(); 1159 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1160 // Floating point promotion (C++ 4.6). 1161 SCS.Second = ICK_Floating_Promotion; 1162 FromType = ToType.getUnqualifiedType(); 1163 } else if (S.IsComplexPromotion(FromType, ToType)) { 1164 // Complex promotion (Clang extension) 1165 SCS.Second = ICK_Complex_Promotion; 1166 FromType = ToType.getUnqualifiedType(); 1167 } else if (ToType->isBooleanType() && 1168 (FromType->isArithmeticType() || 1169 FromType->isAnyPointerType() || 1170 FromType->isBlockPointerType() || 1171 FromType->isMemberPointerType() || 1172 FromType->isNullPtrType())) { 1173 // Boolean conversions (C++ 4.12). 1174 SCS.Second = ICK_Boolean_Conversion; 1175 FromType = S.Context.BoolTy; 1176 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1177 ToType->isIntegralType(S.Context)) { 1178 // Integral conversions (C++ 4.7). 1179 SCS.Second = ICK_Integral_Conversion; 1180 FromType = ToType.getUnqualifiedType(); 1181 } else if (FromType->isAnyComplexType() && ToType->isComplexType()) { 1182 // Complex conversions (C99 6.3.1.6) 1183 SCS.Second = ICK_Complex_Conversion; 1184 FromType = ToType.getUnqualifiedType(); 1185 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1186 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1187 // Complex-real conversions (C99 6.3.1.7) 1188 SCS.Second = ICK_Complex_Real; 1189 FromType = ToType.getUnqualifiedType(); 1190 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1191 // Floating point conversions (C++ 4.8). 1192 SCS.Second = ICK_Floating_Conversion; 1193 FromType = ToType.getUnqualifiedType(); 1194 } else if ((FromType->isRealFloatingType() && 1195 ToType->isIntegralType(S.Context)) || 1196 (FromType->isIntegralOrUnscopedEnumerationType() && 1197 ToType->isRealFloatingType())) { 1198 // Floating-integral conversions (C++ 4.9). 1199 SCS.Second = ICK_Floating_Integral; 1200 FromType = ToType.getUnqualifiedType(); 1201 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { 1202 SCS.Second = ICK_Block_Pointer_Conversion; 1203 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1204 FromType, IncompatibleObjC)) { 1205 // Pointer conversions (C++ 4.10). 1206 SCS.Second = ICK_Pointer_Conversion; 1207 SCS.IncompatibleObjC = IncompatibleObjC; 1208 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1209 InOverloadResolution, FromType)) { 1210 // Pointer to member conversions (4.11). 1211 SCS.Second = ICK_Pointer_Member; 1212 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1213 SCS.Second = SecondICK; 1214 FromType = ToType.getUnqualifiedType(); 1215 } else if (!S.getLangOptions().CPlusPlus && 1216 S.Context.typesAreCompatible(ToType, FromType)) { 1217 // Compatible conversions (Clang extension for C function overloading) 1218 SCS.Second = ICK_Compatible_Conversion; 1219 FromType = ToType.getUnqualifiedType(); 1220 } else if (IsNoReturnConversion(S.Context, FromType, ToType, FromType)) { 1221 // Treat a conversion that strips "noreturn" as an identity conversion. 1222 SCS.Second = ICK_NoReturn_Adjustment; 1223 } else if (IsTransparentUnionStandardConversion(S, From, ToType, 1224 InOverloadResolution, 1225 SCS, CStyle)) { 1226 SCS.Second = ICK_TransparentUnionConversion; 1227 FromType = ToType; 1228 } else { 1229 // No second conversion required. 1230 SCS.Second = ICK_Identity; 1231 } 1232 SCS.setToType(1, FromType); 1233 1234 QualType CanonFrom; 1235 QualType CanonTo; 1236 // The third conversion can be a qualification conversion (C++ 4p1). 1237 if (S.IsQualificationConversion(FromType, ToType, CStyle)) { 1238 SCS.Third = ICK_Qualification; 1239 FromType = ToType; 1240 CanonFrom = S.Context.getCanonicalType(FromType); 1241 CanonTo = S.Context.getCanonicalType(ToType); 1242 } else { 1243 // No conversion required 1244 SCS.Third = ICK_Identity; 1245 1246 // C++ [over.best.ics]p6: 1247 // [...] Any difference in top-level cv-qualification is 1248 // subsumed by the initialization itself and does not constitute 1249 // a conversion. [...] 1250 CanonFrom = S.Context.getCanonicalType(FromType); 1251 CanonTo = S.Context.getCanonicalType(ToType); 1252 if (CanonFrom.getLocalUnqualifiedType() 1253 == CanonTo.getLocalUnqualifiedType() && 1254 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1255 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1256 FromType = ToType; 1257 CanonFrom = CanonTo; 1258 } 1259 } 1260 SCS.setToType(2, FromType); 1261 1262 // If we have not converted the argument type to the parameter type, 1263 // this is a bad conversion sequence. 1264 if (CanonFrom != CanonTo) 1265 return false; 1266 1267 return true; 1268} 1269 1270static bool 1271IsTransparentUnionStandardConversion(Sema &S, Expr* From, 1272 QualType &ToType, 1273 bool InOverloadResolution, 1274 StandardConversionSequence &SCS, 1275 bool CStyle) { 1276 1277 const RecordType *UT = ToType->getAsUnionType(); 1278 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 1279 return false; 1280 // The field to initialize within the transparent union. 1281 RecordDecl *UD = UT->getDecl(); 1282 // It's compatible if the expression matches any of the fields. 1283 for (RecordDecl::field_iterator it = UD->field_begin(), 1284 itend = UD->field_end(); 1285 it != itend; ++it) { 1286 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, CStyle)) { 1287 ToType = it->getType(); 1288 return true; 1289 } 1290 } 1291 return false; 1292} 1293 1294/// IsIntegralPromotion - Determines whether the conversion from the 1295/// expression From (whose potentially-adjusted type is FromType) to 1296/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1297/// sets PromotedType to the promoted type. 1298bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1299 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1300 // All integers are built-in. 1301 if (!To) { 1302 return false; 1303 } 1304 1305 // An rvalue of type char, signed char, unsigned char, short int, or 1306 // unsigned short int can be converted to an rvalue of type int if 1307 // int can represent all the values of the source type; otherwise, 1308 // the source rvalue can be converted to an rvalue of type unsigned 1309 // int (C++ 4.5p1). 1310 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1311 !FromType->isEnumeralType()) { 1312 if (// We can promote any signed, promotable integer type to an int 1313 (FromType->isSignedIntegerType() || 1314 // We can promote any unsigned integer type whose size is 1315 // less than int to an int. 1316 (!FromType->isSignedIntegerType() && 1317 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1318 return To->getKind() == BuiltinType::Int; 1319 } 1320 1321 return To->getKind() == BuiltinType::UInt; 1322 } 1323 1324 // C++0x [conv.prom]p3: 1325 // A prvalue of an unscoped enumeration type whose underlying type is not 1326 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1327 // following types that can represent all the values of the enumeration 1328 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1329 // unsigned int, long int, unsigned long int, long long int, or unsigned 1330 // long long int. If none of the types in that list can represent all the 1331 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1332 // type can be converted to an rvalue a prvalue of the extended integer type 1333 // with lowest integer conversion rank (4.13) greater than the rank of long 1334 // long in which all the values of the enumeration can be represented. If 1335 // there are two such extended types, the signed one is chosen. 1336 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1337 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1338 // provided for a scoped enumeration. 1339 if (FromEnumType->getDecl()->isScoped()) 1340 return false; 1341 1342 // We have already pre-calculated the promotion type, so this is trivial. 1343 if (ToType->isIntegerType() && 1344 !RequireCompleteType(From->getLocStart(), FromType, PDiag())) 1345 return Context.hasSameUnqualifiedType(ToType, 1346 FromEnumType->getDecl()->getPromotionType()); 1347 } 1348 1349 // C++0x [conv.prom]p2: 1350 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1351 // to an rvalue a prvalue of the first of the following types that can 1352 // represent all the values of its underlying type: int, unsigned int, 1353 // long int, unsigned long int, long long int, or unsigned long long int. 1354 // If none of the types in that list can represent all the values of its 1355 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1356 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1357 // type. 1358 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1359 ToType->isIntegerType()) { 1360 // Determine whether the type we're converting from is signed or 1361 // unsigned. 1362 bool FromIsSigned; 1363 uint64_t FromSize = Context.getTypeSize(FromType); 1364 1365 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1366 FromIsSigned = true; 1367 1368 // The types we'll try to promote to, in the appropriate 1369 // order. Try each of these types. 1370 QualType PromoteTypes[6] = { 1371 Context.IntTy, Context.UnsignedIntTy, 1372 Context.LongTy, Context.UnsignedLongTy , 1373 Context.LongLongTy, Context.UnsignedLongLongTy 1374 }; 1375 for (int Idx = 0; Idx < 6; ++Idx) { 1376 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1377 if (FromSize < ToSize || 1378 (FromSize == ToSize && 1379 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1380 // We found the type that we can promote to. If this is the 1381 // type we wanted, we have a promotion. Otherwise, no 1382 // promotion. 1383 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1384 } 1385 } 1386 } 1387 1388 // An rvalue for an integral bit-field (9.6) can be converted to an 1389 // rvalue of type int if int can represent all the values of the 1390 // bit-field; otherwise, it can be converted to unsigned int if 1391 // unsigned int can represent all the values of the bit-field. If 1392 // the bit-field is larger yet, no integral promotion applies to 1393 // it. If the bit-field has an enumerated type, it is treated as any 1394 // other value of that type for promotion purposes (C++ 4.5p3). 1395 // FIXME: We should delay checking of bit-fields until we actually perform the 1396 // conversion. 1397 using llvm::APSInt; 1398 if (From) 1399 if (FieldDecl *MemberDecl = From->getBitField()) { 1400 APSInt BitWidth; 1401 if (FromType->isIntegralType(Context) && 1402 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1403 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1404 ToSize = Context.getTypeSize(ToType); 1405 1406 // Are we promoting to an int from a bitfield that fits in an int? 1407 if (BitWidth < ToSize || 1408 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1409 return To->getKind() == BuiltinType::Int; 1410 } 1411 1412 // Are we promoting to an unsigned int from an unsigned bitfield 1413 // that fits into an unsigned int? 1414 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1415 return To->getKind() == BuiltinType::UInt; 1416 } 1417 1418 return false; 1419 } 1420 } 1421 1422 // An rvalue of type bool can be converted to an rvalue of type int, 1423 // with false becoming zero and true becoming one (C++ 4.5p4). 1424 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1425 return true; 1426 } 1427 1428 return false; 1429} 1430 1431/// IsFloatingPointPromotion - Determines whether the conversion from 1432/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1433/// returns true and sets PromotedType to the promoted type. 1434bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1435 /// An rvalue of type float can be converted to an rvalue of type 1436 /// double. (C++ 4.6p1). 1437 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1438 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1439 if (FromBuiltin->getKind() == BuiltinType::Float && 1440 ToBuiltin->getKind() == BuiltinType::Double) 1441 return true; 1442 1443 // C99 6.3.1.5p1: 1444 // When a float is promoted to double or long double, or a 1445 // double is promoted to long double [...]. 1446 if (!getLangOptions().CPlusPlus && 1447 (FromBuiltin->getKind() == BuiltinType::Float || 1448 FromBuiltin->getKind() == BuiltinType::Double) && 1449 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1450 return true; 1451 } 1452 1453 return false; 1454} 1455 1456/// \brief Determine if a conversion is a complex promotion. 1457/// 1458/// A complex promotion is defined as a complex -> complex conversion 1459/// where the conversion between the underlying real types is a 1460/// floating-point or integral promotion. 1461bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1462 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1463 if (!FromComplex) 1464 return false; 1465 1466 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1467 if (!ToComplex) 1468 return false; 1469 1470 return IsFloatingPointPromotion(FromComplex->getElementType(), 1471 ToComplex->getElementType()) || 1472 IsIntegralPromotion(0, FromComplex->getElementType(), 1473 ToComplex->getElementType()); 1474} 1475 1476/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1477/// the pointer type FromPtr to a pointer to type ToPointee, with the 1478/// same type qualifiers as FromPtr has on its pointee type. ToType, 1479/// if non-empty, will be a pointer to ToType that may or may not have 1480/// the right set of qualifiers on its pointee. 1481static QualType 1482BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1483 QualType ToPointee, QualType ToType, 1484 ASTContext &Context) { 1485 assert((FromPtr->getTypeClass() == Type::Pointer || 1486 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1487 "Invalid similarly-qualified pointer type"); 1488 1489 /// \brief Conversions to 'id' subsume cv-qualifier conversions. 1490 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1491 return ToType.getUnqualifiedType(); 1492 1493 QualType CanonFromPointee 1494 = Context.getCanonicalType(FromPtr->getPointeeType()); 1495 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1496 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1497 1498 // Exact qualifier match -> return the pointer type we're converting to. 1499 if (CanonToPointee.getLocalQualifiers() == Quals) { 1500 // ToType is exactly what we need. Return it. 1501 if (!ToType.isNull()) 1502 return ToType.getUnqualifiedType(); 1503 1504 // Build a pointer to ToPointee. It has the right qualifiers 1505 // already. 1506 if (isa<ObjCObjectPointerType>(ToType)) 1507 return Context.getObjCObjectPointerType(ToPointee); 1508 return Context.getPointerType(ToPointee); 1509 } 1510 1511 // Just build a canonical type that has the right qualifiers. 1512 QualType QualifiedCanonToPointee 1513 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1514 1515 if (isa<ObjCObjectPointerType>(ToType)) 1516 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1517 return Context.getPointerType(QualifiedCanonToPointee); 1518} 1519 1520static bool isNullPointerConstantForConversion(Expr *Expr, 1521 bool InOverloadResolution, 1522 ASTContext &Context) { 1523 // Handle value-dependent integral null pointer constants correctly. 1524 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1525 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1526 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1527 return !InOverloadResolution; 1528 1529 return Expr->isNullPointerConstant(Context, 1530 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1531 : Expr::NPC_ValueDependentIsNull); 1532} 1533 1534/// IsPointerConversion - Determines whether the conversion of the 1535/// expression From, which has the (possibly adjusted) type FromType, 1536/// can be converted to the type ToType via a pointer conversion (C++ 1537/// 4.10). If so, returns true and places the converted type (that 1538/// might differ from ToType in its cv-qualifiers at some level) into 1539/// ConvertedType. 1540/// 1541/// This routine also supports conversions to and from block pointers 1542/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1543/// pointers to interfaces. FIXME: Once we've determined the 1544/// appropriate overloading rules for Objective-C, we may want to 1545/// split the Objective-C checks into a different routine; however, 1546/// GCC seems to consider all of these conversions to be pointer 1547/// conversions, so for now they live here. IncompatibleObjC will be 1548/// set if the conversion is an allowed Objective-C conversion that 1549/// should result in a warning. 1550bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1551 bool InOverloadResolution, 1552 QualType& ConvertedType, 1553 bool &IncompatibleObjC) { 1554 IncompatibleObjC = false; 1555 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 1556 IncompatibleObjC)) 1557 return true; 1558 1559 // Conversion from a null pointer constant to any Objective-C pointer type. 1560 if (ToType->isObjCObjectPointerType() && 1561 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1562 ConvertedType = ToType; 1563 return true; 1564 } 1565 1566 // Blocks: Block pointers can be converted to void*. 1567 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1568 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1569 ConvertedType = ToType; 1570 return true; 1571 } 1572 // Blocks: A null pointer constant can be converted to a block 1573 // pointer type. 1574 if (ToType->isBlockPointerType() && 1575 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1576 ConvertedType = ToType; 1577 return true; 1578 } 1579 1580 // If the left-hand-side is nullptr_t, the right side can be a null 1581 // pointer constant. 1582 if (ToType->isNullPtrType() && 1583 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1584 ConvertedType = ToType; 1585 return true; 1586 } 1587 1588 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1589 if (!ToTypePtr) 1590 return false; 1591 1592 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1593 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1594 ConvertedType = ToType; 1595 return true; 1596 } 1597 1598 // Beyond this point, both types need to be pointers 1599 // , including objective-c pointers. 1600 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1601 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1602 ConvertedType = BuildSimilarlyQualifiedPointerType( 1603 FromType->getAs<ObjCObjectPointerType>(), 1604 ToPointeeType, 1605 ToType, Context); 1606 return true; 1607 } 1608 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1609 if (!FromTypePtr) 1610 return false; 1611 1612 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1613 1614 // If the unqualified pointee types are the same, this can't be a 1615 // pointer conversion, so don't do all of the work below. 1616 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1617 return false; 1618 1619 // An rvalue of type "pointer to cv T," where T is an object type, 1620 // can be converted to an rvalue of type "pointer to cv void" (C++ 1621 // 4.10p2). 1622 if (FromPointeeType->isIncompleteOrObjectType() && 1623 ToPointeeType->isVoidType()) { 1624 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1625 ToPointeeType, 1626 ToType, Context); 1627 return true; 1628 } 1629 1630 // When we're overloading in C, we allow a special kind of pointer 1631 // conversion for compatible-but-not-identical pointee types. 1632 if (!getLangOptions().CPlusPlus && 1633 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1634 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1635 ToPointeeType, 1636 ToType, Context); 1637 return true; 1638 } 1639 1640 // C++ [conv.ptr]p3: 1641 // 1642 // An rvalue of type "pointer to cv D," where D is a class type, 1643 // can be converted to an rvalue of type "pointer to cv B," where 1644 // B is a base class (clause 10) of D. If B is an inaccessible 1645 // (clause 11) or ambiguous (10.2) base class of D, a program that 1646 // necessitates this conversion is ill-formed. The result of the 1647 // conversion is a pointer to the base class sub-object of the 1648 // derived class object. The null pointer value is converted to 1649 // the null pointer value of the destination type. 1650 // 1651 // Note that we do not check for ambiguity or inaccessibility 1652 // here. That is handled by CheckPointerConversion. 1653 if (getLangOptions().CPlusPlus && 1654 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1655 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1656 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1657 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1658 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1659 ToPointeeType, 1660 ToType, Context); 1661 return true; 1662 } 1663 1664 return false; 1665} 1666 1667/// isObjCPointerConversion - Determines whether this is an 1668/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1669/// with the same arguments and return values. 1670bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1671 QualType& ConvertedType, 1672 bool &IncompatibleObjC) { 1673 if (!getLangOptions().ObjC1) 1674 return false; 1675 1676 // First, we handle all conversions on ObjC object pointer types. 1677 const ObjCObjectPointerType* ToObjCPtr = 1678 ToType->getAs<ObjCObjectPointerType>(); 1679 const ObjCObjectPointerType *FromObjCPtr = 1680 FromType->getAs<ObjCObjectPointerType>(); 1681 1682 if (ToObjCPtr && FromObjCPtr) { 1683 // If the pointee types are the same (ignoring qualifications), 1684 // then this is not a pointer conversion. 1685 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 1686 FromObjCPtr->getPointeeType())) 1687 return false; 1688 1689 // Objective C++: We're able to convert between "id" or "Class" and a 1690 // pointer to any interface (in both directions). 1691 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1692 ConvertedType = ToType; 1693 return true; 1694 } 1695 // Conversions with Objective-C's id<...>. 1696 if ((FromObjCPtr->isObjCQualifiedIdType() || 1697 ToObjCPtr->isObjCQualifiedIdType()) && 1698 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1699 /*compare=*/false)) { 1700 ConvertedType = ToType; 1701 return true; 1702 } 1703 // Objective C++: We're able to convert from a pointer to an 1704 // interface to a pointer to a different interface. 1705 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1706 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1707 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1708 if (getLangOptions().CPlusPlus && LHS && RHS && 1709 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1710 FromObjCPtr->getPointeeType())) 1711 return false; 1712 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1713 ToObjCPtr->getPointeeType(), 1714 ToType, Context); 1715 return true; 1716 } 1717 1718 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1719 // Okay: this is some kind of implicit downcast of Objective-C 1720 // interfaces, which is permitted. However, we're going to 1721 // complain about it. 1722 IncompatibleObjC = true; 1723 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1724 ToObjCPtr->getPointeeType(), 1725 ToType, Context); 1726 return true; 1727 } 1728 } 1729 // Beyond this point, both types need to be C pointers or block pointers. 1730 QualType ToPointeeType; 1731 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1732 ToPointeeType = ToCPtr->getPointeeType(); 1733 else if (const BlockPointerType *ToBlockPtr = 1734 ToType->getAs<BlockPointerType>()) { 1735 // Objective C++: We're able to convert from a pointer to any object 1736 // to a block pointer type. 1737 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1738 ConvertedType = ToType; 1739 return true; 1740 } 1741 ToPointeeType = ToBlockPtr->getPointeeType(); 1742 } 1743 else if (FromType->getAs<BlockPointerType>() && 1744 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1745 // Objective C++: We're able to convert from a block pointer type to a 1746 // pointer to any object. 1747 ConvertedType = ToType; 1748 return true; 1749 } 1750 else 1751 return false; 1752 1753 QualType FromPointeeType; 1754 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1755 FromPointeeType = FromCPtr->getPointeeType(); 1756 else if (const BlockPointerType *FromBlockPtr = 1757 FromType->getAs<BlockPointerType>()) 1758 FromPointeeType = FromBlockPtr->getPointeeType(); 1759 else 1760 return false; 1761 1762 // If we have pointers to pointers, recursively check whether this 1763 // is an Objective-C conversion. 1764 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1765 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1766 IncompatibleObjC)) { 1767 // We always complain about this conversion. 1768 IncompatibleObjC = true; 1769 ConvertedType = Context.getPointerType(ConvertedType); 1770 return true; 1771 } 1772 // Allow conversion of pointee being objective-c pointer to another one; 1773 // as in I* to id. 1774 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1775 ToPointeeType->getAs<ObjCObjectPointerType>() && 1776 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1777 IncompatibleObjC)) { 1778 ConvertedType = Context.getPointerType(ConvertedType); 1779 return true; 1780 } 1781 1782 // If we have pointers to functions or blocks, check whether the only 1783 // differences in the argument and result types are in Objective-C 1784 // pointer conversions. If so, we permit the conversion (but 1785 // complain about it). 1786 const FunctionProtoType *FromFunctionType 1787 = FromPointeeType->getAs<FunctionProtoType>(); 1788 const FunctionProtoType *ToFunctionType 1789 = ToPointeeType->getAs<FunctionProtoType>(); 1790 if (FromFunctionType && ToFunctionType) { 1791 // If the function types are exactly the same, this isn't an 1792 // Objective-C pointer conversion. 1793 if (Context.getCanonicalType(FromPointeeType) 1794 == Context.getCanonicalType(ToPointeeType)) 1795 return false; 1796 1797 // Perform the quick checks that will tell us whether these 1798 // function types are obviously different. 1799 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1800 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1801 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1802 return false; 1803 1804 bool HasObjCConversion = false; 1805 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1806 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1807 // Okay, the types match exactly. Nothing to do. 1808 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1809 ToFunctionType->getResultType(), 1810 ConvertedType, IncompatibleObjC)) { 1811 // Okay, we have an Objective-C pointer conversion. 1812 HasObjCConversion = true; 1813 } else { 1814 // Function types are too different. Abort. 1815 return false; 1816 } 1817 1818 // Check argument types. 1819 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1820 ArgIdx != NumArgs; ++ArgIdx) { 1821 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1822 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1823 if (Context.getCanonicalType(FromArgType) 1824 == Context.getCanonicalType(ToArgType)) { 1825 // Okay, the types match exactly. Nothing to do. 1826 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1827 ConvertedType, IncompatibleObjC)) { 1828 // Okay, we have an Objective-C pointer conversion. 1829 HasObjCConversion = true; 1830 } else { 1831 // Argument types are too different. Abort. 1832 return false; 1833 } 1834 } 1835 1836 if (HasObjCConversion) { 1837 // We had an Objective-C conversion. Allow this pointer 1838 // conversion, but complain about it. 1839 ConvertedType = ToType; 1840 IncompatibleObjC = true; 1841 return true; 1842 } 1843 } 1844 1845 return false; 1846} 1847 1848bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, 1849 QualType& ConvertedType) { 1850 QualType ToPointeeType; 1851 if (const BlockPointerType *ToBlockPtr = 1852 ToType->getAs<BlockPointerType>()) 1853 ToPointeeType = ToBlockPtr->getPointeeType(); 1854 else 1855 return false; 1856 1857 QualType FromPointeeType; 1858 if (const BlockPointerType *FromBlockPtr = 1859 FromType->getAs<BlockPointerType>()) 1860 FromPointeeType = FromBlockPtr->getPointeeType(); 1861 else 1862 return false; 1863 // We have pointer to blocks, check whether the only 1864 // differences in the argument and result types are in Objective-C 1865 // pointer conversions. If so, we permit the conversion. 1866 1867 const FunctionProtoType *FromFunctionType 1868 = FromPointeeType->getAs<FunctionProtoType>(); 1869 const FunctionProtoType *ToFunctionType 1870 = ToPointeeType->getAs<FunctionProtoType>(); 1871 1872 if (!FromFunctionType || !ToFunctionType) 1873 return false; 1874 1875 if (Context.hasSameType(FromPointeeType, ToPointeeType)) 1876 return true; 1877 1878 // Perform the quick checks that will tell us whether these 1879 // function types are obviously different. 1880 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1881 FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) 1882 return false; 1883 1884 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); 1885 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); 1886 if (FromEInfo != ToEInfo) 1887 return false; 1888 1889 bool IncompatibleObjC = false; 1890 if (Context.hasSameType(FromFunctionType->getResultType(), 1891 ToFunctionType->getResultType())) { 1892 // Okay, the types match exactly. Nothing to do. 1893 } else { 1894 QualType RHS = FromFunctionType->getResultType(); 1895 QualType LHS = ToFunctionType->getResultType(); 1896 if ((!getLangOptions().CPlusPlus || !RHS->isRecordType()) && 1897 !RHS.hasQualifiers() && LHS.hasQualifiers()) 1898 LHS = LHS.getUnqualifiedType(); 1899 1900 if (Context.hasSameType(RHS,LHS)) { 1901 // OK exact match. 1902 } else if (isObjCPointerConversion(RHS, LHS, 1903 ConvertedType, IncompatibleObjC)) { 1904 if (IncompatibleObjC) 1905 return false; 1906 // Okay, we have an Objective-C pointer conversion. 1907 } 1908 else 1909 return false; 1910 } 1911 1912 // Check argument types. 1913 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1914 ArgIdx != NumArgs; ++ArgIdx) { 1915 IncompatibleObjC = false; 1916 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1917 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1918 if (Context.hasSameType(FromArgType, ToArgType)) { 1919 // Okay, the types match exactly. Nothing to do. 1920 } else if (isObjCPointerConversion(ToArgType, FromArgType, 1921 ConvertedType, IncompatibleObjC)) { 1922 if (IncompatibleObjC) 1923 return false; 1924 // Okay, we have an Objective-C pointer conversion. 1925 } else 1926 // Argument types are too different. Abort. 1927 return false; 1928 } 1929 ConvertedType = ToType; 1930 return true; 1931} 1932 1933/// FunctionArgTypesAreEqual - This routine checks two function proto types 1934/// for equlity of their argument types. Caller has already checked that 1935/// they have same number of arguments. This routine assumes that Objective-C 1936/// pointer types which only differ in their protocol qualifiers are equal. 1937bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, 1938 const FunctionProtoType *NewType) { 1939 if (!getLangOptions().ObjC1) 1940 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1941 NewType->arg_type_begin()); 1942 1943 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1944 N = NewType->arg_type_begin(), 1945 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1946 QualType ToType = (*O); 1947 QualType FromType = (*N); 1948 if (ToType != FromType) { 1949 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1950 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1951 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1952 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1953 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1954 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1955 continue; 1956 } 1957 else if (const ObjCObjectPointerType *PTTo = 1958 ToType->getAs<ObjCObjectPointerType>()) { 1959 if (const ObjCObjectPointerType *PTFr = 1960 FromType->getAs<ObjCObjectPointerType>()) 1961 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1962 continue; 1963 } 1964 return false; 1965 } 1966 } 1967 return true; 1968} 1969 1970/// CheckPointerConversion - Check the pointer conversion from the 1971/// expression From to the type ToType. This routine checks for 1972/// ambiguous or inaccessible derived-to-base pointer 1973/// conversions for which IsPointerConversion has already returned 1974/// true. It returns true and produces a diagnostic if there was an 1975/// error, or returns false otherwise. 1976bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1977 CastKind &Kind, 1978 CXXCastPath& BasePath, 1979 bool IgnoreBaseAccess) { 1980 QualType FromType = From->getType(); 1981 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 1982 1983 Kind = CK_BitCast; 1984 1985 if (CXXBoolLiteralExpr* LitBool 1986 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1987 if (!IsCStyleOrFunctionalCast && LitBool->getValue() == false) 1988 DiagRuntimeBehavior(LitBool->getExprLoc(), From, 1989 PDiag(diag::warn_init_pointer_from_false) << ToType); 1990 1991 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1992 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1993 QualType FromPointeeType = FromPtrType->getPointeeType(), 1994 ToPointeeType = ToPtrType->getPointeeType(); 1995 1996 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1997 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1998 // We must have a derived-to-base conversion. Check an 1999 // ambiguous or inaccessible conversion. 2000 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 2001 From->getExprLoc(), 2002 From->getSourceRange(), &BasePath, 2003 IgnoreBaseAccess)) 2004 return true; 2005 2006 // The conversion was successful. 2007 Kind = CK_DerivedToBase; 2008 } 2009 } 2010 if (const ObjCObjectPointerType *FromPtrType = 2011 FromType->getAs<ObjCObjectPointerType>()) { 2012 if (const ObjCObjectPointerType *ToPtrType = 2013 ToType->getAs<ObjCObjectPointerType>()) { 2014 // Objective-C++ conversions are always okay. 2015 // FIXME: We should have a different class of conversions for the 2016 // Objective-C++ implicit conversions. 2017 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 2018 return false; 2019 } 2020 } 2021 2022 // We shouldn't fall into this case unless it's valid for other 2023 // reasons. 2024 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 2025 Kind = CK_NullToPointer; 2026 2027 return false; 2028} 2029 2030/// IsMemberPointerConversion - Determines whether the conversion of the 2031/// expression From, which has the (possibly adjusted) type FromType, can be 2032/// converted to the type ToType via a member pointer conversion (C++ 4.11). 2033/// If so, returns true and places the converted type (that might differ from 2034/// ToType in its cv-qualifiers at some level) into ConvertedType. 2035bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 2036 QualType ToType, 2037 bool InOverloadResolution, 2038 QualType &ConvertedType) { 2039 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 2040 if (!ToTypePtr) 2041 return false; 2042 2043 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 2044 if (From->isNullPointerConstant(Context, 2045 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 2046 : Expr::NPC_ValueDependentIsNull)) { 2047 ConvertedType = ToType; 2048 return true; 2049 } 2050 2051 // Otherwise, both types have to be member pointers. 2052 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 2053 if (!FromTypePtr) 2054 return false; 2055 2056 // A pointer to member of B can be converted to a pointer to member of D, 2057 // where D is derived from B (C++ 4.11p2). 2058 QualType FromClass(FromTypePtr->getClass(), 0); 2059 QualType ToClass(ToTypePtr->getClass(), 0); 2060 2061 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && 2062 !RequireCompleteType(From->getLocStart(), ToClass, PDiag()) && 2063 IsDerivedFrom(ToClass, FromClass)) { 2064 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 2065 ToClass.getTypePtr()); 2066 return true; 2067 } 2068 2069 return false; 2070} 2071 2072/// CheckMemberPointerConversion - Check the member pointer conversion from the 2073/// expression From to the type ToType. This routine checks for ambiguous or 2074/// virtual or inaccessible base-to-derived member pointer conversions 2075/// for which IsMemberPointerConversion has already returned true. It returns 2076/// true and produces a diagnostic if there was an error, or returns false 2077/// otherwise. 2078bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 2079 CastKind &Kind, 2080 CXXCastPath &BasePath, 2081 bool IgnoreBaseAccess) { 2082 QualType FromType = From->getType(); 2083 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 2084 if (!FromPtrType) { 2085 // This must be a null pointer to member pointer conversion 2086 assert(From->isNullPointerConstant(Context, 2087 Expr::NPC_ValueDependentIsNull) && 2088 "Expr must be null pointer constant!"); 2089 Kind = CK_NullToMemberPointer; 2090 return false; 2091 } 2092 2093 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 2094 assert(ToPtrType && "No member pointer cast has a target type " 2095 "that is not a member pointer."); 2096 2097 QualType FromClass = QualType(FromPtrType->getClass(), 0); 2098 QualType ToClass = QualType(ToPtrType->getClass(), 0); 2099 2100 // FIXME: What about dependent types? 2101 assert(FromClass->isRecordType() && "Pointer into non-class."); 2102 assert(ToClass->isRecordType() && "Pointer into non-class."); 2103 2104 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 2105 /*DetectVirtual=*/true); 2106 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 2107 assert(DerivationOkay && 2108 "Should not have been called if derivation isn't OK."); 2109 (void)DerivationOkay; 2110 2111 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 2112 getUnqualifiedType())) { 2113 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 2114 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 2115 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 2116 return true; 2117 } 2118 2119 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 2120 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 2121 << FromClass << ToClass << QualType(VBase, 0) 2122 << From->getSourceRange(); 2123 return true; 2124 } 2125 2126 if (!IgnoreBaseAccess) 2127 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 2128 Paths.front(), 2129 diag::err_downcast_from_inaccessible_base); 2130 2131 // Must be a base to derived member conversion. 2132 BuildBasePathArray(Paths, BasePath); 2133 Kind = CK_BaseToDerivedMemberPointer; 2134 return false; 2135} 2136 2137/// IsQualificationConversion - Determines whether the conversion from 2138/// an rvalue of type FromType to ToType is a qualification conversion 2139/// (C++ 4.4). 2140bool 2141Sema::IsQualificationConversion(QualType FromType, QualType ToType, 2142 bool CStyle) { 2143 FromType = Context.getCanonicalType(FromType); 2144 ToType = Context.getCanonicalType(ToType); 2145 2146 // If FromType and ToType are the same type, this is not a 2147 // qualification conversion. 2148 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 2149 return false; 2150 2151 // (C++ 4.4p4): 2152 // A conversion can add cv-qualifiers at levels other than the first 2153 // in multi-level pointers, subject to the following rules: [...] 2154 bool PreviousToQualsIncludeConst = true; 2155 bool UnwrappedAnyPointer = false; 2156 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 2157 // Within each iteration of the loop, we check the qualifiers to 2158 // determine if this still looks like a qualification 2159 // conversion. Then, if all is well, we unwrap one more level of 2160 // pointers or pointers-to-members and do it all again 2161 // until there are no more pointers or pointers-to-members left to 2162 // unwrap. 2163 UnwrappedAnyPointer = true; 2164 2165 // -- for every j > 0, if const is in cv 1,j then const is in cv 2166 // 2,j, and similarly for volatile. 2167 if (!CStyle && !ToType.isAtLeastAsQualifiedAs(FromType)) 2168 return false; 2169 2170 // -- if the cv 1,j and cv 2,j are different, then const is in 2171 // every cv for 0 < k < j. 2172 if (!CStyle && FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 2173 && !PreviousToQualsIncludeConst) 2174 return false; 2175 2176 // Keep track of whether all prior cv-qualifiers in the "to" type 2177 // include const. 2178 PreviousToQualsIncludeConst 2179 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 2180 } 2181 2182 // We are left with FromType and ToType being the pointee types 2183 // after unwrapping the original FromType and ToType the same number 2184 // of types. If we unwrapped any pointers, and if FromType and 2185 // ToType have the same unqualified type (since we checked 2186 // qualifiers above), then this is a qualification conversion. 2187 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2188} 2189 2190/// Determines whether there is a user-defined conversion sequence 2191/// (C++ [over.ics.user]) that converts expression From to the type 2192/// ToType. If such a conversion exists, User will contain the 2193/// user-defined conversion sequence that performs such a conversion 2194/// and this routine will return true. Otherwise, this routine returns 2195/// false and User is unspecified. 2196/// 2197/// \param AllowExplicit true if the conversion should consider C++0x 2198/// "explicit" conversion functions as well as non-explicit conversion 2199/// functions (C++0x [class.conv.fct]p2). 2200static OverloadingResult 2201IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 2202 UserDefinedConversionSequence& User, 2203 OverloadCandidateSet& CandidateSet, 2204 bool AllowExplicit) { 2205 // Whether we will only visit constructors. 2206 bool ConstructorsOnly = false; 2207 2208 // If the type we are conversion to is a class type, enumerate its 2209 // constructors. 2210 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 2211 // C++ [over.match.ctor]p1: 2212 // When objects of class type are direct-initialized (8.5), or 2213 // copy-initialized from an expression of the same or a 2214 // derived class type (8.5), overload resolution selects the 2215 // constructor. [...] For copy-initialization, the candidate 2216 // functions are all the converting constructors (12.3.1) of 2217 // that class. The argument list is the expression-list within 2218 // the parentheses of the initializer. 2219 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 2220 (From->getType()->getAs<RecordType>() && 2221 S.IsDerivedFrom(From->getType(), ToType))) 2222 ConstructorsOnly = true; 2223 2224 if (S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag())) { 2225 // We're not going to find any constructors. 2226 } else if (CXXRecordDecl *ToRecordDecl 2227 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 2228 DeclContext::lookup_iterator Con, ConEnd; 2229 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 2230 Con != ConEnd; ++Con) { 2231 NamedDecl *D = *Con; 2232 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2233 2234 // Find the constructor (which may be a template). 2235 CXXConstructorDecl *Constructor = 0; 2236 FunctionTemplateDecl *ConstructorTmpl 2237 = dyn_cast<FunctionTemplateDecl>(D); 2238 if (ConstructorTmpl) 2239 Constructor 2240 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2241 else 2242 Constructor = cast<CXXConstructorDecl>(D); 2243 2244 if (!Constructor->isInvalidDecl() && 2245 Constructor->isConvertingConstructor(AllowExplicit)) { 2246 if (ConstructorTmpl) 2247 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2248 /*ExplicitArgs*/ 0, 2249 &From, 1, CandidateSet, 2250 /*SuppressUserConversions=*/ 2251 !ConstructorsOnly); 2252 else 2253 // Allow one user-defined conversion when user specifies a 2254 // From->ToType conversion via an static cast (c-style, etc). 2255 S.AddOverloadCandidate(Constructor, FoundDecl, 2256 &From, 1, CandidateSet, 2257 /*SuppressUserConversions=*/ 2258 !ConstructorsOnly); 2259 } 2260 } 2261 } 2262 } 2263 2264 // Enumerate conversion functions, if we're allowed to. 2265 if (ConstructorsOnly) { 2266 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 2267 S.PDiag(0) << From->getSourceRange())) { 2268 // No conversion functions from incomplete types. 2269 } else if (const RecordType *FromRecordType 2270 = From->getType()->getAs<RecordType>()) { 2271 if (CXXRecordDecl *FromRecordDecl 2272 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 2273 // Add all of the conversion functions as candidates. 2274 const UnresolvedSetImpl *Conversions 2275 = FromRecordDecl->getVisibleConversionFunctions(); 2276 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2277 E = Conversions->end(); I != E; ++I) { 2278 DeclAccessPair FoundDecl = I.getPair(); 2279 NamedDecl *D = FoundDecl.getDecl(); 2280 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 2281 if (isa<UsingShadowDecl>(D)) 2282 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2283 2284 CXXConversionDecl *Conv; 2285 FunctionTemplateDecl *ConvTemplate; 2286 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 2287 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2288 else 2289 Conv = cast<CXXConversionDecl>(D); 2290 2291 if (AllowExplicit || !Conv->isExplicit()) { 2292 if (ConvTemplate) 2293 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 2294 ActingContext, From, ToType, 2295 CandidateSet); 2296 else 2297 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 2298 From, ToType, CandidateSet); 2299 } 2300 } 2301 } 2302 } 2303 2304 OverloadCandidateSet::iterator Best; 2305 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2306 case OR_Success: 2307 // Record the standard conversion we used and the conversion function. 2308 if (CXXConstructorDecl *Constructor 2309 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 2310 S.MarkDeclarationReferenced(From->getLocStart(), Constructor); 2311 2312 // C++ [over.ics.user]p1: 2313 // If the user-defined conversion is specified by a 2314 // constructor (12.3.1), the initial standard conversion 2315 // sequence converts the source type to the type required by 2316 // the argument of the constructor. 2317 // 2318 QualType ThisType = Constructor->getThisType(S.Context); 2319 if (Best->Conversions[0].isEllipsis()) 2320 User.EllipsisConversion = true; 2321 else { 2322 User.Before = Best->Conversions[0].Standard; 2323 User.EllipsisConversion = false; 2324 } 2325 User.ConversionFunction = Constructor; 2326 User.FoundConversionFunction = Best->FoundDecl.getDecl(); 2327 User.After.setAsIdentityConversion(); 2328 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2329 User.After.setAllToTypes(ToType); 2330 return OR_Success; 2331 } else if (CXXConversionDecl *Conversion 2332 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2333 S.MarkDeclarationReferenced(From->getLocStart(), Conversion); 2334 2335 // C++ [over.ics.user]p1: 2336 // 2337 // [...] If the user-defined conversion is specified by a 2338 // conversion function (12.3.2), the initial standard 2339 // conversion sequence converts the source type to the 2340 // implicit object parameter of the conversion function. 2341 User.Before = Best->Conversions[0].Standard; 2342 User.ConversionFunction = Conversion; 2343 User.FoundConversionFunction = Best->FoundDecl.getDecl(); 2344 User.EllipsisConversion = false; 2345 2346 // C++ [over.ics.user]p2: 2347 // The second standard conversion sequence converts the 2348 // result of the user-defined conversion to the target type 2349 // for the sequence. Since an implicit conversion sequence 2350 // is an initialization, the special rules for 2351 // initialization by user-defined conversion apply when 2352 // selecting the best user-defined conversion for a 2353 // user-defined conversion sequence (see 13.3.3 and 2354 // 13.3.3.1). 2355 User.After = Best->FinalConversion; 2356 return OR_Success; 2357 } else { 2358 llvm_unreachable("Not a constructor or conversion function?"); 2359 return OR_No_Viable_Function; 2360 } 2361 2362 case OR_No_Viable_Function: 2363 return OR_No_Viable_Function; 2364 case OR_Deleted: 2365 // No conversion here! We're done. 2366 return OR_Deleted; 2367 2368 case OR_Ambiguous: 2369 return OR_Ambiguous; 2370 } 2371 2372 return OR_No_Viable_Function; 2373} 2374 2375bool 2376Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2377 ImplicitConversionSequence ICS; 2378 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2379 OverloadingResult OvResult = 2380 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 2381 CandidateSet, false); 2382 if (OvResult == OR_Ambiguous) 2383 Diag(From->getSourceRange().getBegin(), 2384 diag::err_typecheck_ambiguous_condition) 2385 << From->getType() << ToType << From->getSourceRange(); 2386 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2387 Diag(From->getSourceRange().getBegin(), 2388 diag::err_typecheck_nonviable_condition) 2389 << From->getType() << ToType << From->getSourceRange(); 2390 else 2391 return false; 2392 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &From, 1); 2393 return true; 2394} 2395 2396/// CompareImplicitConversionSequences - Compare two implicit 2397/// conversion sequences to determine whether one is better than the 2398/// other or if they are indistinguishable (C++ 13.3.3.2). 2399static ImplicitConversionSequence::CompareKind 2400CompareImplicitConversionSequences(Sema &S, 2401 const ImplicitConversionSequence& ICS1, 2402 const ImplicitConversionSequence& ICS2) 2403{ 2404 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2405 // conversion sequences (as defined in 13.3.3.1) 2406 // -- a standard conversion sequence (13.3.3.1.1) is a better 2407 // conversion sequence than a user-defined conversion sequence or 2408 // an ellipsis conversion sequence, and 2409 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2410 // conversion sequence than an ellipsis conversion sequence 2411 // (13.3.3.1.3). 2412 // 2413 // C++0x [over.best.ics]p10: 2414 // For the purpose of ranking implicit conversion sequences as 2415 // described in 13.3.3.2, the ambiguous conversion sequence is 2416 // treated as a user-defined sequence that is indistinguishable 2417 // from any other user-defined conversion sequence. 2418 if (ICS1.getKindRank() < ICS2.getKindRank()) 2419 return ImplicitConversionSequence::Better; 2420 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2421 return ImplicitConversionSequence::Worse; 2422 2423 // The following checks require both conversion sequences to be of 2424 // the same kind. 2425 if (ICS1.getKind() != ICS2.getKind()) 2426 return ImplicitConversionSequence::Indistinguishable; 2427 2428 // Two implicit conversion sequences of the same form are 2429 // indistinguishable conversion sequences unless one of the 2430 // following rules apply: (C++ 13.3.3.2p3): 2431 if (ICS1.isStandard()) 2432 return CompareStandardConversionSequences(S, ICS1.Standard, ICS2.Standard); 2433 else if (ICS1.isUserDefined()) { 2434 // User-defined conversion sequence U1 is a better conversion 2435 // sequence than another user-defined conversion sequence U2 if 2436 // they contain the same user-defined conversion function or 2437 // constructor and if the second standard conversion sequence of 2438 // U1 is better than the second standard conversion sequence of 2439 // U2 (C++ 13.3.3.2p3). 2440 if (ICS1.UserDefined.ConversionFunction == 2441 ICS2.UserDefined.ConversionFunction) 2442 return CompareStandardConversionSequences(S, 2443 ICS1.UserDefined.After, 2444 ICS2.UserDefined.After); 2445 } 2446 2447 return ImplicitConversionSequence::Indistinguishable; 2448} 2449 2450static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2451 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2452 Qualifiers Quals; 2453 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2454 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2455 } 2456 2457 return Context.hasSameUnqualifiedType(T1, T2); 2458} 2459 2460// Per 13.3.3.2p3, compare the given standard conversion sequences to 2461// determine if one is a proper subset of the other. 2462static ImplicitConversionSequence::CompareKind 2463compareStandardConversionSubsets(ASTContext &Context, 2464 const StandardConversionSequence& SCS1, 2465 const StandardConversionSequence& SCS2) { 2466 ImplicitConversionSequence::CompareKind Result 2467 = ImplicitConversionSequence::Indistinguishable; 2468 2469 // the identity conversion sequence is considered to be a subsequence of 2470 // any non-identity conversion sequence 2471 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2472 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2473 return ImplicitConversionSequence::Better; 2474 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2475 return ImplicitConversionSequence::Worse; 2476 } 2477 2478 if (SCS1.Second != SCS2.Second) { 2479 if (SCS1.Second == ICK_Identity) 2480 Result = ImplicitConversionSequence::Better; 2481 else if (SCS2.Second == ICK_Identity) 2482 Result = ImplicitConversionSequence::Worse; 2483 else 2484 return ImplicitConversionSequence::Indistinguishable; 2485 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2486 return ImplicitConversionSequence::Indistinguishable; 2487 2488 if (SCS1.Third == SCS2.Third) { 2489 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2490 : ImplicitConversionSequence::Indistinguishable; 2491 } 2492 2493 if (SCS1.Third == ICK_Identity) 2494 return Result == ImplicitConversionSequence::Worse 2495 ? ImplicitConversionSequence::Indistinguishable 2496 : ImplicitConversionSequence::Better; 2497 2498 if (SCS2.Third == ICK_Identity) 2499 return Result == ImplicitConversionSequence::Better 2500 ? ImplicitConversionSequence::Indistinguishable 2501 : ImplicitConversionSequence::Worse; 2502 2503 return ImplicitConversionSequence::Indistinguishable; 2504} 2505 2506/// \brief Determine whether one of the given reference bindings is better 2507/// than the other based on what kind of bindings they are. 2508static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 2509 const StandardConversionSequence &SCS2) { 2510 // C++0x [over.ics.rank]p3b4: 2511 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2512 // implicit object parameter of a non-static member function declared 2513 // without a ref-qualifier, and *either* S1 binds an rvalue reference 2514 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 2515 // lvalue reference to a function lvalue and S2 binds an rvalue 2516 // reference*. 2517 // 2518 // FIXME: Rvalue references. We're going rogue with the above edits, 2519 // because the semantics in the current C++0x working paper (N3225 at the 2520 // time of this writing) break the standard definition of std::forward 2521 // and std::reference_wrapper when dealing with references to functions. 2522 // Proposed wording changes submitted to CWG for consideration. 2523 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 2524 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 2525 return false; 2526 2527 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 2528 SCS2.IsLvalueReference) || 2529 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 2530 !SCS2.IsLvalueReference); 2531} 2532 2533/// CompareStandardConversionSequences - Compare two standard 2534/// conversion sequences to determine whether one is better than the 2535/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2536static ImplicitConversionSequence::CompareKind 2537CompareStandardConversionSequences(Sema &S, 2538 const StandardConversionSequence& SCS1, 2539 const StandardConversionSequence& SCS2) 2540{ 2541 // Standard conversion sequence S1 is a better conversion sequence 2542 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2543 2544 // -- S1 is a proper subsequence of S2 (comparing the conversion 2545 // sequences in the canonical form defined by 13.3.3.1.1, 2546 // excluding any Lvalue Transformation; the identity conversion 2547 // sequence is considered to be a subsequence of any 2548 // non-identity conversion sequence) or, if not that, 2549 if (ImplicitConversionSequence::CompareKind CK 2550 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 2551 return CK; 2552 2553 // -- the rank of S1 is better than the rank of S2 (by the rules 2554 // defined below), or, if not that, 2555 ImplicitConversionRank Rank1 = SCS1.getRank(); 2556 ImplicitConversionRank Rank2 = SCS2.getRank(); 2557 if (Rank1 < Rank2) 2558 return ImplicitConversionSequence::Better; 2559 else if (Rank2 < Rank1) 2560 return ImplicitConversionSequence::Worse; 2561 2562 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2563 // are indistinguishable unless one of the following rules 2564 // applies: 2565 2566 // A conversion that is not a conversion of a pointer, or 2567 // pointer to member, to bool is better than another conversion 2568 // that is such a conversion. 2569 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2570 return SCS2.isPointerConversionToBool() 2571 ? ImplicitConversionSequence::Better 2572 : ImplicitConversionSequence::Worse; 2573 2574 // C++ [over.ics.rank]p4b2: 2575 // 2576 // If class B is derived directly or indirectly from class A, 2577 // conversion of B* to A* is better than conversion of B* to 2578 // void*, and conversion of A* to void* is better than conversion 2579 // of B* to void*. 2580 bool SCS1ConvertsToVoid 2581 = SCS1.isPointerConversionToVoidPointer(S.Context); 2582 bool SCS2ConvertsToVoid 2583 = SCS2.isPointerConversionToVoidPointer(S.Context); 2584 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2585 // Exactly one of the conversion sequences is a conversion to 2586 // a void pointer; it's the worse conversion. 2587 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2588 : ImplicitConversionSequence::Worse; 2589 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2590 // Neither conversion sequence converts to a void pointer; compare 2591 // their derived-to-base conversions. 2592 if (ImplicitConversionSequence::CompareKind DerivedCK 2593 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 2594 return DerivedCK; 2595 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2596 // Both conversion sequences are conversions to void 2597 // pointers. Compare the source types to determine if there's an 2598 // inheritance relationship in their sources. 2599 QualType FromType1 = SCS1.getFromType(); 2600 QualType FromType2 = SCS2.getFromType(); 2601 2602 // Adjust the types we're converting from via the array-to-pointer 2603 // conversion, if we need to. 2604 if (SCS1.First == ICK_Array_To_Pointer) 2605 FromType1 = S.Context.getArrayDecayedType(FromType1); 2606 if (SCS2.First == ICK_Array_To_Pointer) 2607 FromType2 = S.Context.getArrayDecayedType(FromType2); 2608 2609 QualType FromPointee1 2610 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2611 QualType FromPointee2 2612 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2613 2614 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2615 return ImplicitConversionSequence::Better; 2616 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2617 return ImplicitConversionSequence::Worse; 2618 2619 // Objective-C++: If one interface is more specific than the 2620 // other, it is the better one. 2621 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2622 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2623 if (FromIface1 && FromIface1) { 2624 if (S.Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2625 return ImplicitConversionSequence::Better; 2626 else if (S.Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2627 return ImplicitConversionSequence::Worse; 2628 } 2629 } 2630 2631 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2632 // bullet 3). 2633 if (ImplicitConversionSequence::CompareKind QualCK 2634 = CompareQualificationConversions(S, SCS1, SCS2)) 2635 return QualCK; 2636 2637 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2638 // Check for a better reference binding based on the kind of bindings. 2639 if (isBetterReferenceBindingKind(SCS1, SCS2)) 2640 return ImplicitConversionSequence::Better; 2641 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 2642 return ImplicitConversionSequence::Worse; 2643 2644 // C++ [over.ics.rank]p3b4: 2645 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2646 // which the references refer are the same type except for 2647 // top-level cv-qualifiers, and the type to which the reference 2648 // initialized by S2 refers is more cv-qualified than the type 2649 // to which the reference initialized by S1 refers. 2650 QualType T1 = SCS1.getToType(2); 2651 QualType T2 = SCS2.getToType(2); 2652 T1 = S.Context.getCanonicalType(T1); 2653 T2 = S.Context.getCanonicalType(T2); 2654 Qualifiers T1Quals, T2Quals; 2655 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2656 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2657 if (UnqualT1 == UnqualT2) { 2658 // If the type is an array type, promote the element qualifiers to the 2659 // type for comparison. 2660 if (isa<ArrayType>(T1) && T1Quals) 2661 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2662 if (isa<ArrayType>(T2) && T2Quals) 2663 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2664 if (T2.isMoreQualifiedThan(T1)) 2665 return ImplicitConversionSequence::Better; 2666 else if (T1.isMoreQualifiedThan(T2)) 2667 return ImplicitConversionSequence::Worse; 2668 } 2669 } 2670 2671 return ImplicitConversionSequence::Indistinguishable; 2672} 2673 2674/// CompareQualificationConversions - Compares two standard conversion 2675/// sequences to determine whether they can be ranked based on their 2676/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2677ImplicitConversionSequence::CompareKind 2678CompareQualificationConversions(Sema &S, 2679 const StandardConversionSequence& SCS1, 2680 const StandardConversionSequence& SCS2) { 2681 // C++ 13.3.3.2p3: 2682 // -- S1 and S2 differ only in their qualification conversion and 2683 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2684 // cv-qualification signature of type T1 is a proper subset of 2685 // the cv-qualification signature of type T2, and S1 is not the 2686 // deprecated string literal array-to-pointer conversion (4.2). 2687 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2688 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2689 return ImplicitConversionSequence::Indistinguishable; 2690 2691 // FIXME: the example in the standard doesn't use a qualification 2692 // conversion (!) 2693 QualType T1 = SCS1.getToType(2); 2694 QualType T2 = SCS2.getToType(2); 2695 T1 = S.Context.getCanonicalType(T1); 2696 T2 = S.Context.getCanonicalType(T2); 2697 Qualifiers T1Quals, T2Quals; 2698 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2699 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2700 2701 // If the types are the same, we won't learn anything by unwrapped 2702 // them. 2703 if (UnqualT1 == UnqualT2) 2704 return ImplicitConversionSequence::Indistinguishable; 2705 2706 // If the type is an array type, promote the element qualifiers to the type 2707 // for comparison. 2708 if (isa<ArrayType>(T1) && T1Quals) 2709 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2710 if (isa<ArrayType>(T2) && T2Quals) 2711 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2712 2713 ImplicitConversionSequence::CompareKind Result 2714 = ImplicitConversionSequence::Indistinguishable; 2715 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 2716 // Within each iteration of the loop, we check the qualifiers to 2717 // determine if this still looks like a qualification 2718 // conversion. Then, if all is well, we unwrap one more level of 2719 // pointers or pointers-to-members and do it all again 2720 // until there are no more pointers or pointers-to-members left 2721 // to unwrap. This essentially mimics what 2722 // IsQualificationConversion does, but here we're checking for a 2723 // strict subset of qualifiers. 2724 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2725 // The qualifiers are the same, so this doesn't tell us anything 2726 // about how the sequences rank. 2727 ; 2728 else if (T2.isMoreQualifiedThan(T1)) { 2729 // T1 has fewer qualifiers, so it could be the better sequence. 2730 if (Result == ImplicitConversionSequence::Worse) 2731 // Neither has qualifiers that are a subset of the other's 2732 // qualifiers. 2733 return ImplicitConversionSequence::Indistinguishable; 2734 2735 Result = ImplicitConversionSequence::Better; 2736 } else if (T1.isMoreQualifiedThan(T2)) { 2737 // T2 has fewer qualifiers, so it could be the better sequence. 2738 if (Result == ImplicitConversionSequence::Better) 2739 // Neither has qualifiers that are a subset of the other's 2740 // qualifiers. 2741 return ImplicitConversionSequence::Indistinguishable; 2742 2743 Result = ImplicitConversionSequence::Worse; 2744 } else { 2745 // Qualifiers are disjoint. 2746 return ImplicitConversionSequence::Indistinguishable; 2747 } 2748 2749 // If the types after this point are equivalent, we're done. 2750 if (S.Context.hasSameUnqualifiedType(T1, T2)) 2751 break; 2752 } 2753 2754 // Check that the winning standard conversion sequence isn't using 2755 // the deprecated string literal array to pointer conversion. 2756 switch (Result) { 2757 case ImplicitConversionSequence::Better: 2758 if (SCS1.DeprecatedStringLiteralToCharPtr) 2759 Result = ImplicitConversionSequence::Indistinguishable; 2760 break; 2761 2762 case ImplicitConversionSequence::Indistinguishable: 2763 break; 2764 2765 case ImplicitConversionSequence::Worse: 2766 if (SCS2.DeprecatedStringLiteralToCharPtr) 2767 Result = ImplicitConversionSequence::Indistinguishable; 2768 break; 2769 } 2770 2771 return Result; 2772} 2773 2774/// CompareDerivedToBaseConversions - Compares two standard conversion 2775/// sequences to determine whether they can be ranked based on their 2776/// various kinds of derived-to-base conversions (C++ 2777/// [over.ics.rank]p4b3). As part of these checks, we also look at 2778/// conversions between Objective-C interface types. 2779ImplicitConversionSequence::CompareKind 2780CompareDerivedToBaseConversions(Sema &S, 2781 const StandardConversionSequence& SCS1, 2782 const StandardConversionSequence& SCS2) { 2783 QualType FromType1 = SCS1.getFromType(); 2784 QualType ToType1 = SCS1.getToType(1); 2785 QualType FromType2 = SCS2.getFromType(); 2786 QualType ToType2 = SCS2.getToType(1); 2787 2788 // Adjust the types we're converting from via the array-to-pointer 2789 // conversion, if we need to. 2790 if (SCS1.First == ICK_Array_To_Pointer) 2791 FromType1 = S.Context.getArrayDecayedType(FromType1); 2792 if (SCS2.First == ICK_Array_To_Pointer) 2793 FromType2 = S.Context.getArrayDecayedType(FromType2); 2794 2795 // Canonicalize all of the types. 2796 FromType1 = S.Context.getCanonicalType(FromType1); 2797 ToType1 = S.Context.getCanonicalType(ToType1); 2798 FromType2 = S.Context.getCanonicalType(FromType2); 2799 ToType2 = S.Context.getCanonicalType(ToType2); 2800 2801 // C++ [over.ics.rank]p4b3: 2802 // 2803 // If class B is derived directly or indirectly from class A and 2804 // class C is derived directly or indirectly from B, 2805 // 2806 // Compare based on pointer conversions. 2807 if (SCS1.Second == ICK_Pointer_Conversion && 2808 SCS2.Second == ICK_Pointer_Conversion && 2809 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2810 FromType1->isPointerType() && FromType2->isPointerType() && 2811 ToType1->isPointerType() && ToType2->isPointerType()) { 2812 QualType FromPointee1 2813 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2814 QualType ToPointee1 2815 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2816 QualType FromPointee2 2817 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2818 QualType ToPointee2 2819 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2820 2821 // -- conversion of C* to B* is better than conversion of C* to A*, 2822 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2823 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2824 return ImplicitConversionSequence::Better; 2825 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2826 return ImplicitConversionSequence::Worse; 2827 } 2828 2829 // -- conversion of B* to A* is better than conversion of C* to A*, 2830 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2831 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2832 return ImplicitConversionSequence::Better; 2833 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2834 return ImplicitConversionSequence::Worse; 2835 } 2836 } else if (SCS1.Second == ICK_Pointer_Conversion && 2837 SCS2.Second == ICK_Pointer_Conversion) { 2838 const ObjCObjectPointerType *FromPtr1 2839 = FromType1->getAs<ObjCObjectPointerType>(); 2840 const ObjCObjectPointerType *FromPtr2 2841 = FromType2->getAs<ObjCObjectPointerType>(); 2842 const ObjCObjectPointerType *ToPtr1 2843 = ToType1->getAs<ObjCObjectPointerType>(); 2844 const ObjCObjectPointerType *ToPtr2 2845 = ToType2->getAs<ObjCObjectPointerType>(); 2846 2847 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 2848 // Apply the same conversion ranking rules for Objective-C pointer types 2849 // that we do for C++ pointers to class types. However, we employ the 2850 // Objective-C pseudo-subtyping relationship used for assignment of 2851 // Objective-C pointer types. 2852 bool FromAssignLeft 2853 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 2854 bool FromAssignRight 2855 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 2856 bool ToAssignLeft 2857 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 2858 bool ToAssignRight 2859 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 2860 2861 // A conversion to an a non-id object pointer type or qualified 'id' 2862 // type is better than a conversion to 'id'. 2863 if (ToPtr1->isObjCIdType() && 2864 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 2865 return ImplicitConversionSequence::Worse; 2866 if (ToPtr2->isObjCIdType() && 2867 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 2868 return ImplicitConversionSequence::Better; 2869 2870 // A conversion to a non-id object pointer type is better than a 2871 // conversion to a qualified 'id' type 2872 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 2873 return ImplicitConversionSequence::Worse; 2874 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 2875 return ImplicitConversionSequence::Better; 2876 2877 // A conversion to an a non-Class object pointer type or qualified 'Class' 2878 // type is better than a conversion to 'Class'. 2879 if (ToPtr1->isObjCClassType() && 2880 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 2881 return ImplicitConversionSequence::Worse; 2882 if (ToPtr2->isObjCClassType() && 2883 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 2884 return ImplicitConversionSequence::Better; 2885 2886 // A conversion to a non-Class object pointer type is better than a 2887 // conversion to a qualified 'Class' type. 2888 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 2889 return ImplicitConversionSequence::Worse; 2890 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 2891 return ImplicitConversionSequence::Better; 2892 2893 // -- "conversion of C* to B* is better than conversion of C* to A*," 2894 if (S.Context.hasSameType(FromType1, FromType2) && 2895 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 2896 (ToAssignLeft != ToAssignRight)) 2897 return ToAssignLeft? ImplicitConversionSequence::Worse 2898 : ImplicitConversionSequence::Better; 2899 2900 // -- "conversion of B* to A* is better than conversion of C* to A*," 2901 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 2902 (FromAssignLeft != FromAssignRight)) 2903 return FromAssignLeft? ImplicitConversionSequence::Better 2904 : ImplicitConversionSequence::Worse; 2905 } 2906 } 2907 2908 // Ranking of member-pointer types. 2909 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2910 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2911 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2912 const MemberPointerType * FromMemPointer1 = 2913 FromType1->getAs<MemberPointerType>(); 2914 const MemberPointerType * ToMemPointer1 = 2915 ToType1->getAs<MemberPointerType>(); 2916 const MemberPointerType * FromMemPointer2 = 2917 FromType2->getAs<MemberPointerType>(); 2918 const MemberPointerType * ToMemPointer2 = 2919 ToType2->getAs<MemberPointerType>(); 2920 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2921 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2922 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2923 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2924 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2925 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2926 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2927 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2928 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2929 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2930 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2931 return ImplicitConversionSequence::Worse; 2932 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2933 return ImplicitConversionSequence::Better; 2934 } 2935 // conversion of B::* to C::* is better than conversion of A::* to C::* 2936 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2937 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2938 return ImplicitConversionSequence::Better; 2939 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2940 return ImplicitConversionSequence::Worse; 2941 } 2942 } 2943 2944 if (SCS1.Second == ICK_Derived_To_Base) { 2945 // -- conversion of C to B is better than conversion of C to A, 2946 // -- binding of an expression of type C to a reference of type 2947 // B& is better than binding an expression of type C to a 2948 // reference of type A&, 2949 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2950 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2951 if (S.IsDerivedFrom(ToType1, ToType2)) 2952 return ImplicitConversionSequence::Better; 2953 else if (S.IsDerivedFrom(ToType2, ToType1)) 2954 return ImplicitConversionSequence::Worse; 2955 } 2956 2957 // -- conversion of B to A is better than conversion of C to A. 2958 // -- binding of an expression of type B to a reference of type 2959 // A& is better than binding an expression of type C to a 2960 // reference of type A&, 2961 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2962 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2963 if (S.IsDerivedFrom(FromType2, FromType1)) 2964 return ImplicitConversionSequence::Better; 2965 else if (S.IsDerivedFrom(FromType1, FromType2)) 2966 return ImplicitConversionSequence::Worse; 2967 } 2968 } 2969 2970 return ImplicitConversionSequence::Indistinguishable; 2971} 2972 2973/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2974/// determine whether they are reference-related, 2975/// reference-compatible, reference-compatible with added 2976/// qualification, or incompatible, for use in C++ initialization by 2977/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2978/// type, and the first type (T1) is the pointee type of the reference 2979/// type being initialized. 2980Sema::ReferenceCompareResult 2981Sema::CompareReferenceRelationship(SourceLocation Loc, 2982 QualType OrigT1, QualType OrigT2, 2983 bool &DerivedToBase, 2984 bool &ObjCConversion) { 2985 assert(!OrigT1->isReferenceType() && 2986 "T1 must be the pointee type of the reference type"); 2987 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2988 2989 QualType T1 = Context.getCanonicalType(OrigT1); 2990 QualType T2 = Context.getCanonicalType(OrigT2); 2991 Qualifiers T1Quals, T2Quals; 2992 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2993 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2994 2995 // C++ [dcl.init.ref]p4: 2996 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2997 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2998 // T1 is a base class of T2. 2999 DerivedToBase = false; 3000 ObjCConversion = false; 3001 if (UnqualT1 == UnqualT2) { 3002 // Nothing to do. 3003 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 3004 IsDerivedFrom(UnqualT2, UnqualT1)) 3005 DerivedToBase = true; 3006 else if (UnqualT1->isObjCObjectOrInterfaceType() && 3007 UnqualT2->isObjCObjectOrInterfaceType() && 3008 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 3009 ObjCConversion = true; 3010 else 3011 return Ref_Incompatible; 3012 3013 // At this point, we know that T1 and T2 are reference-related (at 3014 // least). 3015 3016 // If the type is an array type, promote the element qualifiers to the type 3017 // for comparison. 3018 if (isa<ArrayType>(T1) && T1Quals) 3019 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 3020 if (isa<ArrayType>(T2) && T2Quals) 3021 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 3022 3023 // C++ [dcl.init.ref]p4: 3024 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 3025 // reference-related to T2 and cv1 is the same cv-qualification 3026 // as, or greater cv-qualification than, cv2. For purposes of 3027 // overload resolution, cases for which cv1 is greater 3028 // cv-qualification than cv2 are identified as 3029 // reference-compatible with added qualification (see 13.3.3.2). 3030 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 3031 return Ref_Compatible; 3032 else if (T1.isMoreQualifiedThan(T2)) 3033 return Ref_Compatible_With_Added_Qualification; 3034 else 3035 return Ref_Related; 3036} 3037 3038/// \brief Look for a user-defined conversion to an value reference-compatible 3039/// with DeclType. Return true if something definite is found. 3040static bool 3041FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 3042 QualType DeclType, SourceLocation DeclLoc, 3043 Expr *Init, QualType T2, bool AllowRvalues, 3044 bool AllowExplicit) { 3045 assert(T2->isRecordType() && "Can only find conversions of record types."); 3046 CXXRecordDecl *T2RecordDecl 3047 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 3048 3049 OverloadCandidateSet CandidateSet(DeclLoc); 3050 const UnresolvedSetImpl *Conversions 3051 = T2RecordDecl->getVisibleConversionFunctions(); 3052 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3053 E = Conversions->end(); I != E; ++I) { 3054 NamedDecl *D = *I; 3055 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3056 if (isa<UsingShadowDecl>(D)) 3057 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3058 3059 FunctionTemplateDecl *ConvTemplate 3060 = dyn_cast<FunctionTemplateDecl>(D); 3061 CXXConversionDecl *Conv; 3062 if (ConvTemplate) 3063 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3064 else 3065 Conv = cast<CXXConversionDecl>(D); 3066 3067 // If this is an explicit conversion, and we're not allowed to consider 3068 // explicit conversions, skip it. 3069 if (!AllowExplicit && Conv->isExplicit()) 3070 continue; 3071 3072 if (AllowRvalues) { 3073 bool DerivedToBase = false; 3074 bool ObjCConversion = false; 3075 if (!ConvTemplate && 3076 S.CompareReferenceRelationship( 3077 DeclLoc, 3078 Conv->getConversionType().getNonReferenceType() 3079 .getUnqualifiedType(), 3080 DeclType.getNonReferenceType().getUnqualifiedType(), 3081 DerivedToBase, ObjCConversion) == 3082 Sema::Ref_Incompatible) 3083 continue; 3084 } else { 3085 // If the conversion function doesn't return a reference type, 3086 // it can't be considered for this conversion. An rvalue reference 3087 // is only acceptable if its referencee is a function type. 3088 3089 const ReferenceType *RefType = 3090 Conv->getConversionType()->getAs<ReferenceType>(); 3091 if (!RefType || 3092 (!RefType->isLValueReferenceType() && 3093 !RefType->getPointeeType()->isFunctionType())) 3094 continue; 3095 } 3096 3097 if (ConvTemplate) 3098 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 3099 Init, DeclType, CandidateSet); 3100 else 3101 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 3102 DeclType, CandidateSet); 3103 } 3104 3105 OverloadCandidateSet::iterator Best; 3106 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 3107 case OR_Success: 3108 // C++ [over.ics.ref]p1: 3109 // 3110 // [...] If the parameter binds directly to the result of 3111 // applying a conversion function to the argument 3112 // expression, the implicit conversion sequence is a 3113 // user-defined conversion sequence (13.3.3.1.2), with the 3114 // second standard conversion sequence either an identity 3115 // conversion or, if the conversion function returns an 3116 // entity of a type that is a derived class of the parameter 3117 // type, a derived-to-base Conversion. 3118 if (!Best->FinalConversion.DirectBinding) 3119 return false; 3120 3121 if (Best->Function) 3122 S.MarkDeclarationReferenced(DeclLoc, Best->Function); 3123 ICS.setUserDefined(); 3124 ICS.UserDefined.Before = Best->Conversions[0].Standard; 3125 ICS.UserDefined.After = Best->FinalConversion; 3126 ICS.UserDefined.ConversionFunction = Best->Function; 3127 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl.getDecl(); 3128 ICS.UserDefined.EllipsisConversion = false; 3129 assert(ICS.UserDefined.After.ReferenceBinding && 3130 ICS.UserDefined.After.DirectBinding && 3131 "Expected a direct reference binding!"); 3132 return true; 3133 3134 case OR_Ambiguous: 3135 ICS.setAmbiguous(); 3136 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3137 Cand != CandidateSet.end(); ++Cand) 3138 if (Cand->Viable) 3139 ICS.Ambiguous.addConversion(Cand->Function); 3140 return true; 3141 3142 case OR_No_Viable_Function: 3143 case OR_Deleted: 3144 // There was no suitable conversion, or we found a deleted 3145 // conversion; continue with other checks. 3146 return false; 3147 } 3148 3149 return false; 3150} 3151 3152/// \brief Compute an implicit conversion sequence for reference 3153/// initialization. 3154static ImplicitConversionSequence 3155TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 3156 SourceLocation DeclLoc, 3157 bool SuppressUserConversions, 3158 bool AllowExplicit) { 3159 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 3160 3161 // Most paths end in a failed conversion. 3162 ImplicitConversionSequence ICS; 3163 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3164 3165 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 3166 QualType T2 = Init->getType(); 3167 3168 // If the initializer is the address of an overloaded function, try 3169 // to resolve the overloaded function. If all goes well, T2 is the 3170 // type of the resulting function. 3171 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 3172 DeclAccessPair Found; 3173 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 3174 false, Found)) 3175 T2 = Fn->getType(); 3176 } 3177 3178 // Compute some basic properties of the types and the initializer. 3179 bool isRValRef = DeclType->isRValueReferenceType(); 3180 bool DerivedToBase = false; 3181 bool ObjCConversion = false; 3182 Expr::Classification InitCategory = Init->Classify(S.Context); 3183 Sema::ReferenceCompareResult RefRelationship 3184 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 3185 ObjCConversion); 3186 3187 3188 // C++0x [dcl.init.ref]p5: 3189 // A reference to type "cv1 T1" is initialized by an expression 3190 // of type "cv2 T2" as follows: 3191 3192 // -- If reference is an lvalue reference and the initializer expression 3193 if (!isRValRef) { 3194 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 3195 // reference-compatible with "cv2 T2," or 3196 // 3197 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 3198 if (InitCategory.isLValue() && 3199 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 3200 // C++ [over.ics.ref]p1: 3201 // When a parameter of reference type binds directly (8.5.3) 3202 // to an argument expression, the implicit conversion sequence 3203 // is the identity conversion, unless the argument expression 3204 // has a type that is a derived class of the parameter type, 3205 // in which case the implicit conversion sequence is a 3206 // derived-to-base Conversion (13.3.3.1). 3207 ICS.setStandard(); 3208 ICS.Standard.First = ICK_Identity; 3209 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3210 : ObjCConversion? ICK_Compatible_Conversion 3211 : ICK_Identity; 3212 ICS.Standard.Third = ICK_Identity; 3213 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3214 ICS.Standard.setToType(0, T2); 3215 ICS.Standard.setToType(1, T1); 3216 ICS.Standard.setToType(2, T1); 3217 ICS.Standard.ReferenceBinding = true; 3218 ICS.Standard.DirectBinding = true; 3219 ICS.Standard.IsLvalueReference = !isRValRef; 3220 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3221 ICS.Standard.BindsToRvalue = false; 3222 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3223 ICS.Standard.CopyConstructor = 0; 3224 3225 // Nothing more to do: the inaccessibility/ambiguity check for 3226 // derived-to-base conversions is suppressed when we're 3227 // computing the implicit conversion sequence (C++ 3228 // [over.best.ics]p2). 3229 return ICS; 3230 } 3231 3232 // -- has a class type (i.e., T2 is a class type), where T1 is 3233 // not reference-related to T2, and can be implicitly 3234 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 3235 // is reference-compatible with "cv3 T3" 92) (this 3236 // conversion is selected by enumerating the applicable 3237 // conversion functions (13.3.1.6) and choosing the best 3238 // one through overload resolution (13.3)), 3239 if (!SuppressUserConversions && T2->isRecordType() && 3240 !S.RequireCompleteType(DeclLoc, T2, 0) && 3241 RefRelationship == Sema::Ref_Incompatible) { 3242 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3243 Init, T2, /*AllowRvalues=*/false, 3244 AllowExplicit)) 3245 return ICS; 3246 } 3247 } 3248 3249 // -- Otherwise, the reference shall be an lvalue reference to a 3250 // non-volatile const type (i.e., cv1 shall be const), or the reference 3251 // shall be an rvalue reference. 3252 // 3253 // We actually handle one oddity of C++ [over.ics.ref] at this 3254 // point, which is that, due to p2 (which short-circuits reference 3255 // binding by only attempting a simple conversion for non-direct 3256 // bindings) and p3's strange wording, we allow a const volatile 3257 // reference to bind to an rvalue. Hence the check for the presence 3258 // of "const" rather than checking for "const" being the only 3259 // qualifier. 3260 // This is also the point where rvalue references and lvalue inits no longer 3261 // go together. 3262 if (!isRValRef && !T1.isConstQualified()) 3263 return ICS; 3264 3265 // -- If the initializer expression 3266 // 3267 // -- is an xvalue, class prvalue, array prvalue or function 3268 // lvalue and "cv1T1" is reference-compatible with "cv2 T2", or 3269 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 3270 (InitCategory.isXValue() || 3271 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 3272 (InitCategory.isLValue() && T2->isFunctionType()))) { 3273 ICS.setStandard(); 3274 ICS.Standard.First = ICK_Identity; 3275 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3276 : ObjCConversion? ICK_Compatible_Conversion 3277 : ICK_Identity; 3278 ICS.Standard.Third = ICK_Identity; 3279 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3280 ICS.Standard.setToType(0, T2); 3281 ICS.Standard.setToType(1, T1); 3282 ICS.Standard.setToType(2, T1); 3283 ICS.Standard.ReferenceBinding = true; 3284 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 3285 // binding unless we're binding to a class prvalue. 3286 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 3287 // allow the use of rvalue references in C++98/03 for the benefit of 3288 // standard library implementors; therefore, we need the xvalue check here. 3289 ICS.Standard.DirectBinding = 3290 S.getLangOptions().CPlusPlus0x || 3291 (InitCategory.isPRValue() && !T2->isRecordType()); 3292 ICS.Standard.IsLvalueReference = !isRValRef; 3293 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3294 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 3295 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3296 ICS.Standard.CopyConstructor = 0; 3297 return ICS; 3298 } 3299 3300 // -- has a class type (i.e., T2 is a class type), where T1 is not 3301 // reference-related to T2, and can be implicitly converted to 3302 // an xvalue, class prvalue, or function lvalue of type 3303 // "cv3 T3", where "cv1 T1" is reference-compatible with 3304 // "cv3 T3", 3305 // 3306 // then the reference is bound to the value of the initializer 3307 // expression in the first case and to the result of the conversion 3308 // in the second case (or, in either case, to an appropriate base 3309 // class subobject). 3310 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3311 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 3312 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3313 Init, T2, /*AllowRvalues=*/true, 3314 AllowExplicit)) { 3315 // In the second case, if the reference is an rvalue reference 3316 // and the second standard conversion sequence of the 3317 // user-defined conversion sequence includes an lvalue-to-rvalue 3318 // conversion, the program is ill-formed. 3319 if (ICS.isUserDefined() && isRValRef && 3320 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 3321 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3322 3323 return ICS; 3324 } 3325 3326 // -- Otherwise, a temporary of type "cv1 T1" is created and 3327 // initialized from the initializer expression using the 3328 // rules for a non-reference copy initialization (8.5). The 3329 // reference is then bound to the temporary. If T1 is 3330 // reference-related to T2, cv1 must be the same 3331 // cv-qualification as, or greater cv-qualification than, 3332 // cv2; otherwise, the program is ill-formed. 3333 if (RefRelationship == Sema::Ref_Related) { 3334 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 3335 // we would be reference-compatible or reference-compatible with 3336 // added qualification. But that wasn't the case, so the reference 3337 // initialization fails. 3338 return ICS; 3339 } 3340 3341 // If at least one of the types is a class type, the types are not 3342 // related, and we aren't allowed any user conversions, the 3343 // reference binding fails. This case is important for breaking 3344 // recursion, since TryImplicitConversion below will attempt to 3345 // create a temporary through the use of a copy constructor. 3346 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3347 (T1->isRecordType() || T2->isRecordType())) 3348 return ICS; 3349 3350 // If T1 is reference-related to T2 and the reference is an rvalue 3351 // reference, the initializer expression shall not be an lvalue. 3352 if (RefRelationship >= Sema::Ref_Related && 3353 isRValRef && Init->Classify(S.Context).isLValue()) 3354 return ICS; 3355 3356 // C++ [over.ics.ref]p2: 3357 // When a parameter of reference type is not bound directly to 3358 // an argument expression, the conversion sequence is the one 3359 // required to convert the argument expression to the 3360 // underlying type of the reference according to 3361 // 13.3.3.1. Conceptually, this conversion sequence corresponds 3362 // to copy-initializing a temporary of the underlying type with 3363 // the argument expression. Any difference in top-level 3364 // cv-qualification is subsumed by the initialization itself 3365 // and does not constitute a conversion. 3366 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 3367 /*AllowExplicit=*/false, 3368 /*InOverloadResolution=*/false, 3369 /*CStyle=*/false); 3370 3371 // Of course, that's still a reference binding. 3372 if (ICS.isStandard()) { 3373 ICS.Standard.ReferenceBinding = true; 3374 ICS.Standard.IsLvalueReference = !isRValRef; 3375 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3376 ICS.Standard.BindsToRvalue = true; 3377 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3378 } else if (ICS.isUserDefined()) { 3379 ICS.UserDefined.After.ReferenceBinding = true; 3380 ICS.Standard.IsLvalueReference = !isRValRef; 3381 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3382 ICS.Standard.BindsToRvalue = true; 3383 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3384 } 3385 3386 return ICS; 3387} 3388 3389/// TryCopyInitialization - Try to copy-initialize a value of type 3390/// ToType from the expression From. Return the implicit conversion 3391/// sequence required to pass this argument, which may be a bad 3392/// conversion sequence (meaning that the argument cannot be passed to 3393/// a parameter of this type). If @p SuppressUserConversions, then we 3394/// do not permit any user-defined conversion sequences. 3395static ImplicitConversionSequence 3396TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 3397 bool SuppressUserConversions, 3398 bool InOverloadResolution) { 3399 if (ToType->isReferenceType()) 3400 return TryReferenceInit(S, From, ToType, 3401 /*FIXME:*/From->getLocStart(), 3402 SuppressUserConversions, 3403 /*AllowExplicit=*/false); 3404 3405 return TryImplicitConversion(S, From, ToType, 3406 SuppressUserConversions, 3407 /*AllowExplicit=*/false, 3408 InOverloadResolution, 3409 /*CStyle=*/false); 3410} 3411 3412/// TryObjectArgumentInitialization - Try to initialize the object 3413/// parameter of the given member function (@c Method) from the 3414/// expression @p From. 3415static ImplicitConversionSequence 3416TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 3417 Expr::Classification FromClassification, 3418 CXXMethodDecl *Method, 3419 CXXRecordDecl *ActingContext) { 3420 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 3421 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 3422 // const volatile object. 3423 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 3424 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 3425 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 3426 3427 // Set up the conversion sequence as a "bad" conversion, to allow us 3428 // to exit early. 3429 ImplicitConversionSequence ICS; 3430 3431 // We need to have an object of class type. 3432 QualType FromType = OrigFromType; 3433 if (const PointerType *PT = FromType->getAs<PointerType>()) { 3434 FromType = PT->getPointeeType(); 3435 3436 // When we had a pointer, it's implicitly dereferenced, so we 3437 // better have an lvalue. 3438 assert(FromClassification.isLValue()); 3439 } 3440 3441 assert(FromType->isRecordType()); 3442 3443 // C++0x [over.match.funcs]p4: 3444 // For non-static member functions, the type of the implicit object 3445 // parameter is 3446 // 3447 // - "lvalue reference to cv X" for functions declared without a 3448 // ref-qualifier or with the & ref-qualifier 3449 // - "rvalue reference to cv X" for functions declared with the && 3450 // ref-qualifier 3451 // 3452 // where X is the class of which the function is a member and cv is the 3453 // cv-qualification on the member function declaration. 3454 // 3455 // However, when finding an implicit conversion sequence for the argument, we 3456 // are not allowed to create temporaries or perform user-defined conversions 3457 // (C++ [over.match.funcs]p5). We perform a simplified version of 3458 // reference binding here, that allows class rvalues to bind to 3459 // non-constant references. 3460 3461 // First check the qualifiers. 3462 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 3463 if (ImplicitParamType.getCVRQualifiers() 3464 != FromTypeCanon.getLocalCVRQualifiers() && 3465 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 3466 ICS.setBad(BadConversionSequence::bad_qualifiers, 3467 OrigFromType, ImplicitParamType); 3468 return ICS; 3469 } 3470 3471 // Check that we have either the same type or a derived type. It 3472 // affects the conversion rank. 3473 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 3474 ImplicitConversionKind SecondKind; 3475 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 3476 SecondKind = ICK_Identity; 3477 } else if (S.IsDerivedFrom(FromType, ClassType)) 3478 SecondKind = ICK_Derived_To_Base; 3479 else { 3480 ICS.setBad(BadConversionSequence::unrelated_class, 3481 FromType, ImplicitParamType); 3482 return ICS; 3483 } 3484 3485 // Check the ref-qualifier. 3486 switch (Method->getRefQualifier()) { 3487 case RQ_None: 3488 // Do nothing; we don't care about lvalueness or rvalueness. 3489 break; 3490 3491 case RQ_LValue: 3492 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 3493 // non-const lvalue reference cannot bind to an rvalue 3494 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 3495 ImplicitParamType); 3496 return ICS; 3497 } 3498 break; 3499 3500 case RQ_RValue: 3501 if (!FromClassification.isRValue()) { 3502 // rvalue reference cannot bind to an lvalue 3503 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 3504 ImplicitParamType); 3505 return ICS; 3506 } 3507 break; 3508 } 3509 3510 // Success. Mark this as a reference binding. 3511 ICS.setStandard(); 3512 ICS.Standard.setAsIdentityConversion(); 3513 ICS.Standard.Second = SecondKind; 3514 ICS.Standard.setFromType(FromType); 3515 ICS.Standard.setAllToTypes(ImplicitParamType); 3516 ICS.Standard.ReferenceBinding = true; 3517 ICS.Standard.DirectBinding = true; 3518 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 3519 ICS.Standard.BindsToFunctionLvalue = false; 3520 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 3521 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 3522 = (Method->getRefQualifier() == RQ_None); 3523 return ICS; 3524} 3525 3526/// PerformObjectArgumentInitialization - Perform initialization of 3527/// the implicit object parameter for the given Method with the given 3528/// expression. 3529ExprResult 3530Sema::PerformObjectArgumentInitialization(Expr *From, 3531 NestedNameSpecifier *Qualifier, 3532 NamedDecl *FoundDecl, 3533 CXXMethodDecl *Method) { 3534 QualType FromRecordType, DestType; 3535 QualType ImplicitParamRecordType = 3536 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3537 3538 Expr::Classification FromClassification; 3539 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3540 FromRecordType = PT->getPointeeType(); 3541 DestType = Method->getThisType(Context); 3542 FromClassification = Expr::Classification::makeSimpleLValue(); 3543 } else { 3544 FromRecordType = From->getType(); 3545 DestType = ImplicitParamRecordType; 3546 FromClassification = From->Classify(Context); 3547 } 3548 3549 // Note that we always use the true parent context when performing 3550 // the actual argument initialization. 3551 ImplicitConversionSequence ICS 3552 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 3553 Method, Method->getParent()); 3554 if (ICS.isBad()) { 3555 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 3556 Qualifiers FromQs = FromRecordType.getQualifiers(); 3557 Qualifiers ToQs = DestType.getQualifiers(); 3558 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 3559 if (CVR) { 3560 Diag(From->getSourceRange().getBegin(), 3561 diag::err_member_function_call_bad_cvr) 3562 << Method->getDeclName() << FromRecordType << (CVR - 1) 3563 << From->getSourceRange(); 3564 Diag(Method->getLocation(), diag::note_previous_decl) 3565 << Method->getDeclName(); 3566 return ExprError(); 3567 } 3568 } 3569 3570 return Diag(From->getSourceRange().getBegin(), 3571 diag::err_implicit_object_parameter_init) 3572 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3573 } 3574 3575 if (ICS.Standard.Second == ICK_Derived_To_Base) { 3576 ExprResult FromRes = 3577 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3578 if (FromRes.isInvalid()) 3579 return ExprError(); 3580 From = FromRes.take(); 3581 } 3582 3583 if (!Context.hasSameType(From->getType(), DestType)) 3584 From = ImpCastExprToType(From, DestType, CK_NoOp, 3585 From->getType()->isPointerType() ? VK_RValue : VK_LValue).take(); 3586 return Owned(From); 3587} 3588 3589/// TryContextuallyConvertToBool - Attempt to contextually convert the 3590/// expression From to bool (C++0x [conv]p3). 3591static ImplicitConversionSequence 3592TryContextuallyConvertToBool(Sema &S, Expr *From) { 3593 // FIXME: This is pretty broken. 3594 return TryImplicitConversion(S, From, S.Context.BoolTy, 3595 // FIXME: Are these flags correct? 3596 /*SuppressUserConversions=*/false, 3597 /*AllowExplicit=*/true, 3598 /*InOverloadResolution=*/false, 3599 /*CStyle=*/false); 3600} 3601 3602/// PerformContextuallyConvertToBool - Perform a contextual conversion 3603/// of the expression From to bool (C++0x [conv]p3). 3604ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) { 3605 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 3606 if (!ICS.isBad()) 3607 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3608 3609 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3610 return Diag(From->getSourceRange().getBegin(), 3611 diag::err_typecheck_bool_condition) 3612 << From->getType() << From->getSourceRange(); 3613 return ExprError(); 3614} 3615 3616/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3617/// expression From to 'id'. 3618static ImplicitConversionSequence 3619TryContextuallyConvertToObjCId(Sema &S, Expr *From) { 3620 QualType Ty = S.Context.getObjCIdType(); 3621 return TryImplicitConversion(S, From, Ty, 3622 // FIXME: Are these flags correct? 3623 /*SuppressUserConversions=*/false, 3624 /*AllowExplicit=*/true, 3625 /*InOverloadResolution=*/false, 3626 /*CStyle=*/false); 3627} 3628 3629/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3630/// of the expression From to 'id'. 3631ExprResult Sema::PerformContextuallyConvertToObjCId(Expr *From) { 3632 QualType Ty = Context.getObjCIdType(); 3633 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(*this, From); 3634 if (!ICS.isBad()) 3635 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3636 return ExprError(); 3637} 3638 3639/// \brief Attempt to convert the given expression to an integral or 3640/// enumeration type. 3641/// 3642/// This routine will attempt to convert an expression of class type to an 3643/// integral or enumeration type, if that class type only has a single 3644/// conversion to an integral or enumeration type. 3645/// 3646/// \param Loc The source location of the construct that requires the 3647/// conversion. 3648/// 3649/// \param FromE The expression we're converting from. 3650/// 3651/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3652/// have integral or enumeration type. 3653/// 3654/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3655/// incomplete class type. 3656/// 3657/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3658/// explicit conversion function (because no implicit conversion functions 3659/// were available). This is a recovery mode. 3660/// 3661/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3662/// showing which conversion was picked. 3663/// 3664/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3665/// conversion function that could convert to integral or enumeration type. 3666/// 3667/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3668/// usable conversion function. 3669/// 3670/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3671/// function, which may be an extension in this case. 3672/// 3673/// \returns The expression, converted to an integral or enumeration type if 3674/// successful. 3675ExprResult 3676Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 3677 const PartialDiagnostic &NotIntDiag, 3678 const PartialDiagnostic &IncompleteDiag, 3679 const PartialDiagnostic &ExplicitConvDiag, 3680 const PartialDiagnostic &ExplicitConvNote, 3681 const PartialDiagnostic &AmbigDiag, 3682 const PartialDiagnostic &AmbigNote, 3683 const PartialDiagnostic &ConvDiag) { 3684 // We can't perform any more checking for type-dependent expressions. 3685 if (From->isTypeDependent()) 3686 return Owned(From); 3687 3688 // If the expression already has integral or enumeration type, we're golden. 3689 QualType T = From->getType(); 3690 if (T->isIntegralOrEnumerationType()) 3691 return Owned(From); 3692 3693 // FIXME: Check for missing '()' if T is a function type? 3694 3695 // If we don't have a class type in C++, there's no way we can get an 3696 // expression of integral or enumeration type. 3697 const RecordType *RecordTy = T->getAs<RecordType>(); 3698 if (!RecordTy || !getLangOptions().CPlusPlus) { 3699 Diag(Loc, NotIntDiag) 3700 << T << From->getSourceRange(); 3701 return Owned(From); 3702 } 3703 3704 // We must have a complete class type. 3705 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3706 return Owned(From); 3707 3708 // Look for a conversion to an integral or enumeration type. 3709 UnresolvedSet<4> ViableConversions; 3710 UnresolvedSet<4> ExplicitConversions; 3711 const UnresolvedSetImpl *Conversions 3712 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3713 3714 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3715 E = Conversions->end(); 3716 I != E; 3717 ++I) { 3718 if (CXXConversionDecl *Conversion 3719 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3720 if (Conversion->getConversionType().getNonReferenceType() 3721 ->isIntegralOrEnumerationType()) { 3722 if (Conversion->isExplicit()) 3723 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3724 else 3725 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3726 } 3727 } 3728 3729 switch (ViableConversions.size()) { 3730 case 0: 3731 if (ExplicitConversions.size() == 1) { 3732 DeclAccessPair Found = ExplicitConversions[0]; 3733 CXXConversionDecl *Conversion 3734 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3735 3736 // The user probably meant to invoke the given explicit 3737 // conversion; use it. 3738 QualType ConvTy 3739 = Conversion->getConversionType().getNonReferenceType(); 3740 std::string TypeStr; 3741 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3742 3743 Diag(Loc, ExplicitConvDiag) 3744 << T << ConvTy 3745 << FixItHint::CreateInsertion(From->getLocStart(), 3746 "static_cast<" + TypeStr + ">(") 3747 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3748 ")"); 3749 Diag(Conversion->getLocation(), ExplicitConvNote) 3750 << ConvTy->isEnumeralType() << ConvTy; 3751 3752 // If we aren't in a SFINAE context, build a call to the 3753 // explicit conversion function. 3754 if (isSFINAEContext()) 3755 return ExprError(); 3756 3757 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3758 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion); 3759 if (Result.isInvalid()) 3760 return ExprError(); 3761 3762 From = Result.get(); 3763 } 3764 3765 // We'll complain below about a non-integral condition type. 3766 break; 3767 3768 case 1: { 3769 // Apply this conversion. 3770 DeclAccessPair Found = ViableConversions[0]; 3771 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3772 3773 CXXConversionDecl *Conversion 3774 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3775 QualType ConvTy 3776 = Conversion->getConversionType().getNonReferenceType(); 3777 if (ConvDiag.getDiagID()) { 3778 if (isSFINAEContext()) 3779 return ExprError(); 3780 3781 Diag(Loc, ConvDiag) 3782 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 3783 } 3784 3785 ExprResult Result = BuildCXXMemberCallExpr(From, Found, 3786 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3787 if (Result.isInvalid()) 3788 return ExprError(); 3789 3790 From = Result.get(); 3791 break; 3792 } 3793 3794 default: 3795 Diag(Loc, AmbigDiag) 3796 << T << From->getSourceRange(); 3797 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3798 CXXConversionDecl *Conv 3799 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3800 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3801 Diag(Conv->getLocation(), AmbigNote) 3802 << ConvTy->isEnumeralType() << ConvTy; 3803 } 3804 return Owned(From); 3805 } 3806 3807 if (!From->getType()->isIntegralOrEnumerationType()) 3808 Diag(Loc, NotIntDiag) 3809 << From->getType() << From->getSourceRange(); 3810 3811 return Owned(From); 3812} 3813 3814/// AddOverloadCandidate - Adds the given function to the set of 3815/// candidate functions, using the given function call arguments. If 3816/// @p SuppressUserConversions, then don't allow user-defined 3817/// conversions via constructors or conversion operators. 3818/// 3819/// \para PartialOverloading true if we are performing "partial" overloading 3820/// based on an incomplete set of function arguments. This feature is used by 3821/// code completion. 3822void 3823Sema::AddOverloadCandidate(FunctionDecl *Function, 3824 DeclAccessPair FoundDecl, 3825 Expr **Args, unsigned NumArgs, 3826 OverloadCandidateSet& CandidateSet, 3827 bool SuppressUserConversions, 3828 bool PartialOverloading) { 3829 const FunctionProtoType* Proto 3830 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3831 assert(Proto && "Functions without a prototype cannot be overloaded"); 3832 assert(!Function->getDescribedFunctionTemplate() && 3833 "Use AddTemplateOverloadCandidate for function templates"); 3834 3835 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3836 if (!isa<CXXConstructorDecl>(Method)) { 3837 // If we get here, it's because we're calling a member function 3838 // that is named without a member access expression (e.g., 3839 // "this->f") that was either written explicitly or created 3840 // implicitly. This can happen with a qualified call to a member 3841 // function, e.g., X::f(). We use an empty type for the implied 3842 // object argument (C++ [over.call.func]p3), and the acting context 3843 // is irrelevant. 3844 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3845 QualType(), Expr::Classification::makeSimpleLValue(), 3846 Args, NumArgs, CandidateSet, 3847 SuppressUserConversions); 3848 return; 3849 } 3850 // We treat a constructor like a non-member function, since its object 3851 // argument doesn't participate in overload resolution. 3852 } 3853 3854 if (!CandidateSet.isNewCandidate(Function)) 3855 return; 3856 3857 // Overload resolution is always an unevaluated context. 3858 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 3859 3860 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3861 // C++ [class.copy]p3: 3862 // A member function template is never instantiated to perform the copy 3863 // of a class object to an object of its class type. 3864 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3865 if (NumArgs == 1 && 3866 Constructor->isSpecializationCopyingObject() && 3867 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3868 IsDerivedFrom(Args[0]->getType(), ClassType))) 3869 return; 3870 } 3871 3872 // Add this candidate 3873 CandidateSet.push_back(OverloadCandidate()); 3874 OverloadCandidate& Candidate = CandidateSet.back(); 3875 Candidate.FoundDecl = FoundDecl; 3876 Candidate.Function = Function; 3877 Candidate.Viable = true; 3878 Candidate.IsSurrogate = false; 3879 Candidate.IgnoreObjectArgument = false; 3880 Candidate.ExplicitCallArguments = NumArgs; 3881 3882 unsigned NumArgsInProto = Proto->getNumArgs(); 3883 3884 // (C++ 13.3.2p2): A candidate function having fewer than m 3885 // parameters is viable only if it has an ellipsis in its parameter 3886 // list (8.3.5). 3887 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3888 !Proto->isVariadic()) { 3889 Candidate.Viable = false; 3890 Candidate.FailureKind = ovl_fail_too_many_arguments; 3891 return; 3892 } 3893 3894 // (C++ 13.3.2p2): A candidate function having more than m parameters 3895 // is viable only if the (m+1)st parameter has a default argument 3896 // (8.3.6). For the purposes of overload resolution, the 3897 // parameter list is truncated on the right, so that there are 3898 // exactly m parameters. 3899 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3900 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3901 // Not enough arguments. 3902 Candidate.Viable = false; 3903 Candidate.FailureKind = ovl_fail_too_few_arguments; 3904 return; 3905 } 3906 3907 // Determine the implicit conversion sequences for each of the 3908 // arguments. 3909 Candidate.Conversions.resize(NumArgs); 3910 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3911 if (ArgIdx < NumArgsInProto) { 3912 // (C++ 13.3.2p3): for F to be a viable function, there shall 3913 // exist for each argument an implicit conversion sequence 3914 // (13.3.3.1) that converts that argument to the corresponding 3915 // parameter of F. 3916 QualType ParamType = Proto->getArgType(ArgIdx); 3917 Candidate.Conversions[ArgIdx] 3918 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3919 SuppressUserConversions, 3920 /*InOverloadResolution=*/true); 3921 if (Candidate.Conversions[ArgIdx].isBad()) { 3922 Candidate.Viable = false; 3923 Candidate.FailureKind = ovl_fail_bad_conversion; 3924 break; 3925 } 3926 } else { 3927 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3928 // argument for which there is no corresponding parameter is 3929 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3930 Candidate.Conversions[ArgIdx].setEllipsis(); 3931 } 3932 } 3933} 3934 3935/// \brief Add all of the function declarations in the given function set to 3936/// the overload canddiate set. 3937void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3938 Expr **Args, unsigned NumArgs, 3939 OverloadCandidateSet& CandidateSet, 3940 bool SuppressUserConversions) { 3941 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3942 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3943 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3944 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3945 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3946 cast<CXXMethodDecl>(FD)->getParent(), 3947 Args[0]->getType(), Args[0]->Classify(Context), 3948 Args + 1, NumArgs - 1, 3949 CandidateSet, SuppressUserConversions); 3950 else 3951 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3952 SuppressUserConversions); 3953 } else { 3954 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3955 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3956 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3957 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3958 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3959 /*FIXME: explicit args */ 0, 3960 Args[0]->getType(), 3961 Args[0]->Classify(Context), 3962 Args + 1, NumArgs - 1, 3963 CandidateSet, 3964 SuppressUserConversions); 3965 else 3966 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3967 /*FIXME: explicit args */ 0, 3968 Args, NumArgs, CandidateSet, 3969 SuppressUserConversions); 3970 } 3971 } 3972} 3973 3974/// AddMethodCandidate - Adds a named decl (which is some kind of 3975/// method) as a method candidate to the given overload set. 3976void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3977 QualType ObjectType, 3978 Expr::Classification ObjectClassification, 3979 Expr **Args, unsigned NumArgs, 3980 OverloadCandidateSet& CandidateSet, 3981 bool SuppressUserConversions) { 3982 NamedDecl *Decl = FoundDecl.getDecl(); 3983 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3984 3985 if (isa<UsingShadowDecl>(Decl)) 3986 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3987 3988 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3989 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3990 "Expected a member function template"); 3991 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3992 /*ExplicitArgs*/ 0, 3993 ObjectType, ObjectClassification, Args, NumArgs, 3994 CandidateSet, 3995 SuppressUserConversions); 3996 } else { 3997 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3998 ObjectType, ObjectClassification, Args, NumArgs, 3999 CandidateSet, SuppressUserConversions); 4000 } 4001} 4002 4003/// AddMethodCandidate - Adds the given C++ member function to the set 4004/// of candidate functions, using the given function call arguments 4005/// and the object argument (@c Object). For example, in a call 4006/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 4007/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 4008/// allow user-defined conversions via constructors or conversion 4009/// operators. 4010void 4011Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 4012 CXXRecordDecl *ActingContext, QualType ObjectType, 4013 Expr::Classification ObjectClassification, 4014 Expr **Args, unsigned NumArgs, 4015 OverloadCandidateSet& CandidateSet, 4016 bool SuppressUserConversions) { 4017 const FunctionProtoType* Proto 4018 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 4019 assert(Proto && "Methods without a prototype cannot be overloaded"); 4020 assert(!isa<CXXConstructorDecl>(Method) && 4021 "Use AddOverloadCandidate for constructors"); 4022 4023 if (!CandidateSet.isNewCandidate(Method)) 4024 return; 4025 4026 // Overload resolution is always an unevaluated context. 4027 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4028 4029 // Add this candidate 4030 CandidateSet.push_back(OverloadCandidate()); 4031 OverloadCandidate& Candidate = CandidateSet.back(); 4032 Candidate.FoundDecl = FoundDecl; 4033 Candidate.Function = Method; 4034 Candidate.IsSurrogate = false; 4035 Candidate.IgnoreObjectArgument = false; 4036 Candidate.ExplicitCallArguments = NumArgs; 4037 4038 unsigned NumArgsInProto = Proto->getNumArgs(); 4039 4040 // (C++ 13.3.2p2): A candidate function having fewer than m 4041 // parameters is viable only if it has an ellipsis in its parameter 4042 // list (8.3.5). 4043 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4044 Candidate.Viable = false; 4045 Candidate.FailureKind = ovl_fail_too_many_arguments; 4046 return; 4047 } 4048 4049 // (C++ 13.3.2p2): A candidate function having more than m parameters 4050 // is viable only if the (m+1)st parameter has a default argument 4051 // (8.3.6). For the purposes of overload resolution, the 4052 // parameter list is truncated on the right, so that there are 4053 // exactly m parameters. 4054 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 4055 if (NumArgs < MinRequiredArgs) { 4056 // Not enough arguments. 4057 Candidate.Viable = false; 4058 Candidate.FailureKind = ovl_fail_too_few_arguments; 4059 return; 4060 } 4061 4062 Candidate.Viable = true; 4063 Candidate.Conversions.resize(NumArgs + 1); 4064 4065 if (Method->isStatic() || ObjectType.isNull()) 4066 // The implicit object argument is ignored. 4067 Candidate.IgnoreObjectArgument = true; 4068 else { 4069 // Determine the implicit conversion sequence for the object 4070 // parameter. 4071 Candidate.Conversions[0] 4072 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 4073 Method, ActingContext); 4074 if (Candidate.Conversions[0].isBad()) { 4075 Candidate.Viable = false; 4076 Candidate.FailureKind = ovl_fail_bad_conversion; 4077 return; 4078 } 4079 } 4080 4081 // Determine the implicit conversion sequences for each of the 4082 // arguments. 4083 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4084 if (ArgIdx < NumArgsInProto) { 4085 // (C++ 13.3.2p3): for F to be a viable function, there shall 4086 // exist for each argument an implicit conversion sequence 4087 // (13.3.3.1) that converts that argument to the corresponding 4088 // parameter of F. 4089 QualType ParamType = Proto->getArgType(ArgIdx); 4090 Candidate.Conversions[ArgIdx + 1] 4091 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4092 SuppressUserConversions, 4093 /*InOverloadResolution=*/true); 4094 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4095 Candidate.Viable = false; 4096 Candidate.FailureKind = ovl_fail_bad_conversion; 4097 break; 4098 } 4099 } else { 4100 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4101 // argument for which there is no corresponding parameter is 4102 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4103 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4104 } 4105 } 4106} 4107 4108/// \brief Add a C++ member function template as a candidate to the candidate 4109/// set, using template argument deduction to produce an appropriate member 4110/// function template specialization. 4111void 4112Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 4113 DeclAccessPair FoundDecl, 4114 CXXRecordDecl *ActingContext, 4115 TemplateArgumentListInfo *ExplicitTemplateArgs, 4116 QualType ObjectType, 4117 Expr::Classification ObjectClassification, 4118 Expr **Args, unsigned NumArgs, 4119 OverloadCandidateSet& CandidateSet, 4120 bool SuppressUserConversions) { 4121 if (!CandidateSet.isNewCandidate(MethodTmpl)) 4122 return; 4123 4124 // C++ [over.match.funcs]p7: 4125 // In each case where a candidate is a function template, candidate 4126 // function template specializations are generated using template argument 4127 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4128 // candidate functions in the usual way.113) A given name can refer to one 4129 // or more function templates and also to a set of overloaded non-template 4130 // functions. In such a case, the candidate functions generated from each 4131 // function template are combined with the set of non-template candidate 4132 // functions. 4133 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4134 FunctionDecl *Specialization = 0; 4135 if (TemplateDeductionResult Result 4136 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 4137 Args, NumArgs, Specialization, Info)) { 4138 CandidateSet.push_back(OverloadCandidate()); 4139 OverloadCandidate &Candidate = CandidateSet.back(); 4140 Candidate.FoundDecl = FoundDecl; 4141 Candidate.Function = MethodTmpl->getTemplatedDecl(); 4142 Candidate.Viable = false; 4143 Candidate.FailureKind = ovl_fail_bad_deduction; 4144 Candidate.IsSurrogate = false; 4145 Candidate.IgnoreObjectArgument = false; 4146 Candidate.ExplicitCallArguments = NumArgs; 4147 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4148 Info); 4149 return; 4150 } 4151 4152 // Add the function template specialization produced by template argument 4153 // deduction as a candidate. 4154 assert(Specialization && "Missing member function template specialization?"); 4155 assert(isa<CXXMethodDecl>(Specialization) && 4156 "Specialization is not a member function?"); 4157 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 4158 ActingContext, ObjectType, ObjectClassification, 4159 Args, NumArgs, CandidateSet, SuppressUserConversions); 4160} 4161 4162/// \brief Add a C++ function template specialization as a candidate 4163/// in the candidate set, using template argument deduction to produce 4164/// an appropriate function template specialization. 4165void 4166Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 4167 DeclAccessPair FoundDecl, 4168 TemplateArgumentListInfo *ExplicitTemplateArgs, 4169 Expr **Args, unsigned NumArgs, 4170 OverloadCandidateSet& CandidateSet, 4171 bool SuppressUserConversions) { 4172 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4173 return; 4174 4175 // C++ [over.match.funcs]p7: 4176 // In each case where a candidate is a function template, candidate 4177 // function template specializations are generated using template argument 4178 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4179 // candidate functions in the usual way.113) A given name can refer to one 4180 // or more function templates and also to a set of overloaded non-template 4181 // functions. In such a case, the candidate functions generated from each 4182 // function template are combined with the set of non-template candidate 4183 // functions. 4184 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4185 FunctionDecl *Specialization = 0; 4186 if (TemplateDeductionResult Result 4187 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 4188 Args, NumArgs, Specialization, Info)) { 4189 CandidateSet.push_back(OverloadCandidate()); 4190 OverloadCandidate &Candidate = CandidateSet.back(); 4191 Candidate.FoundDecl = FoundDecl; 4192 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4193 Candidate.Viable = false; 4194 Candidate.FailureKind = ovl_fail_bad_deduction; 4195 Candidate.IsSurrogate = false; 4196 Candidate.IgnoreObjectArgument = false; 4197 Candidate.ExplicitCallArguments = NumArgs; 4198 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4199 Info); 4200 return; 4201 } 4202 4203 // Add the function template specialization produced by template argument 4204 // deduction as a candidate. 4205 assert(Specialization && "Missing function template specialization?"); 4206 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 4207 SuppressUserConversions); 4208} 4209 4210/// AddConversionCandidate - Add a C++ conversion function as a 4211/// candidate in the candidate set (C++ [over.match.conv], 4212/// C++ [over.match.copy]). From is the expression we're converting from, 4213/// and ToType is the type that we're eventually trying to convert to 4214/// (which may or may not be the same type as the type that the 4215/// conversion function produces). 4216void 4217Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 4218 DeclAccessPair FoundDecl, 4219 CXXRecordDecl *ActingContext, 4220 Expr *From, QualType ToType, 4221 OverloadCandidateSet& CandidateSet) { 4222 assert(!Conversion->getDescribedFunctionTemplate() && 4223 "Conversion function templates use AddTemplateConversionCandidate"); 4224 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 4225 if (!CandidateSet.isNewCandidate(Conversion)) 4226 return; 4227 4228 // Overload resolution is always an unevaluated context. 4229 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4230 4231 // Add this candidate 4232 CandidateSet.push_back(OverloadCandidate()); 4233 OverloadCandidate& Candidate = CandidateSet.back(); 4234 Candidate.FoundDecl = FoundDecl; 4235 Candidate.Function = Conversion; 4236 Candidate.IsSurrogate = false; 4237 Candidate.IgnoreObjectArgument = false; 4238 Candidate.FinalConversion.setAsIdentityConversion(); 4239 Candidate.FinalConversion.setFromType(ConvType); 4240 Candidate.FinalConversion.setAllToTypes(ToType); 4241 Candidate.Viable = true; 4242 Candidate.Conversions.resize(1); 4243 Candidate.ExplicitCallArguments = 1; 4244 4245 // C++ [over.match.funcs]p4: 4246 // For conversion functions, the function is considered to be a member of 4247 // the class of the implicit implied object argument for the purpose of 4248 // defining the type of the implicit object parameter. 4249 // 4250 // Determine the implicit conversion sequence for the implicit 4251 // object parameter. 4252 QualType ImplicitParamType = From->getType(); 4253 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 4254 ImplicitParamType = FromPtrType->getPointeeType(); 4255 CXXRecordDecl *ConversionContext 4256 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 4257 4258 Candidate.Conversions[0] 4259 = TryObjectArgumentInitialization(*this, From->getType(), 4260 From->Classify(Context), 4261 Conversion, ConversionContext); 4262 4263 if (Candidate.Conversions[0].isBad()) { 4264 Candidate.Viable = false; 4265 Candidate.FailureKind = ovl_fail_bad_conversion; 4266 return; 4267 } 4268 4269 // We won't go through a user-define type conversion function to convert a 4270 // derived to base as such conversions are given Conversion Rank. They only 4271 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 4272 QualType FromCanon 4273 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 4274 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 4275 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 4276 Candidate.Viable = false; 4277 Candidate.FailureKind = ovl_fail_trivial_conversion; 4278 return; 4279 } 4280 4281 // To determine what the conversion from the result of calling the 4282 // conversion function to the type we're eventually trying to 4283 // convert to (ToType), we need to synthesize a call to the 4284 // conversion function and attempt copy initialization from it. This 4285 // makes sure that we get the right semantics with respect to 4286 // lvalues/rvalues and the type. Fortunately, we can allocate this 4287 // call on the stack and we don't need its arguments to be 4288 // well-formed. 4289 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 4290 VK_LValue, From->getLocStart()); 4291 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 4292 Context.getPointerType(Conversion->getType()), 4293 CK_FunctionToPointerDecay, 4294 &ConversionRef, VK_RValue); 4295 4296 QualType CallResultType 4297 = Conversion->getConversionType().getNonLValueExprType(Context); 4298 if (RequireCompleteType(From->getLocStart(), CallResultType, 0)) { 4299 Candidate.Viable = false; 4300 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4301 return; 4302 } 4303 4304 ExprValueKind VK = Expr::getValueKindForType(Conversion->getConversionType()); 4305 4306 // Note that it is safe to allocate CallExpr on the stack here because 4307 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 4308 // allocator). 4309 CallExpr Call(Context, &ConversionFn, 0, 0, CallResultType, VK, 4310 From->getLocStart()); 4311 ImplicitConversionSequence ICS = 4312 TryCopyInitialization(*this, &Call, ToType, 4313 /*SuppressUserConversions=*/true, 4314 /*InOverloadResolution=*/false); 4315 4316 switch (ICS.getKind()) { 4317 case ImplicitConversionSequence::StandardConversion: 4318 Candidate.FinalConversion = ICS.Standard; 4319 4320 // C++ [over.ics.user]p3: 4321 // If the user-defined conversion is specified by a specialization of a 4322 // conversion function template, the second standard conversion sequence 4323 // shall have exact match rank. 4324 if (Conversion->getPrimaryTemplate() && 4325 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 4326 Candidate.Viable = false; 4327 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 4328 } 4329 4330 // C++0x [dcl.init.ref]p5: 4331 // In the second case, if the reference is an rvalue reference and 4332 // the second standard conversion sequence of the user-defined 4333 // conversion sequence includes an lvalue-to-rvalue conversion, the 4334 // program is ill-formed. 4335 if (ToType->isRValueReferenceType() && 4336 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 4337 Candidate.Viable = false; 4338 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4339 } 4340 break; 4341 4342 case ImplicitConversionSequence::BadConversion: 4343 Candidate.Viable = false; 4344 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4345 break; 4346 4347 default: 4348 assert(false && 4349 "Can only end up with a standard conversion sequence or failure"); 4350 } 4351} 4352 4353/// \brief Adds a conversion function template specialization 4354/// candidate to the overload set, using template argument deduction 4355/// to deduce the template arguments of the conversion function 4356/// template from the type that we are converting to (C++ 4357/// [temp.deduct.conv]). 4358void 4359Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 4360 DeclAccessPair FoundDecl, 4361 CXXRecordDecl *ActingDC, 4362 Expr *From, QualType ToType, 4363 OverloadCandidateSet &CandidateSet) { 4364 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 4365 "Only conversion function templates permitted here"); 4366 4367 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4368 return; 4369 4370 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4371 CXXConversionDecl *Specialization = 0; 4372 if (TemplateDeductionResult Result 4373 = DeduceTemplateArguments(FunctionTemplate, ToType, 4374 Specialization, Info)) { 4375 CandidateSet.push_back(OverloadCandidate()); 4376 OverloadCandidate &Candidate = CandidateSet.back(); 4377 Candidate.FoundDecl = FoundDecl; 4378 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4379 Candidate.Viable = false; 4380 Candidate.FailureKind = ovl_fail_bad_deduction; 4381 Candidate.IsSurrogate = false; 4382 Candidate.IgnoreObjectArgument = false; 4383 Candidate.ExplicitCallArguments = 1; 4384 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4385 Info); 4386 return; 4387 } 4388 4389 // Add the conversion function template specialization produced by 4390 // template argument deduction as a candidate. 4391 assert(Specialization && "Missing function template specialization?"); 4392 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 4393 CandidateSet); 4394} 4395 4396/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 4397/// converts the given @c Object to a function pointer via the 4398/// conversion function @c Conversion, and then attempts to call it 4399/// with the given arguments (C++ [over.call.object]p2-4). Proto is 4400/// the type of function that we'll eventually be calling. 4401void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 4402 DeclAccessPair FoundDecl, 4403 CXXRecordDecl *ActingContext, 4404 const FunctionProtoType *Proto, 4405 Expr *Object, 4406 Expr **Args, unsigned NumArgs, 4407 OverloadCandidateSet& CandidateSet) { 4408 if (!CandidateSet.isNewCandidate(Conversion)) 4409 return; 4410 4411 // Overload resolution is always an unevaluated context. 4412 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4413 4414 CandidateSet.push_back(OverloadCandidate()); 4415 OverloadCandidate& Candidate = CandidateSet.back(); 4416 Candidate.FoundDecl = FoundDecl; 4417 Candidate.Function = 0; 4418 Candidate.Surrogate = Conversion; 4419 Candidate.Viable = true; 4420 Candidate.IsSurrogate = true; 4421 Candidate.IgnoreObjectArgument = false; 4422 Candidate.Conversions.resize(NumArgs + 1); 4423 Candidate.ExplicitCallArguments = NumArgs; 4424 4425 // Determine the implicit conversion sequence for the implicit 4426 // object parameter. 4427 ImplicitConversionSequence ObjectInit 4428 = TryObjectArgumentInitialization(*this, Object->getType(), 4429 Object->Classify(Context), 4430 Conversion, ActingContext); 4431 if (ObjectInit.isBad()) { 4432 Candidate.Viable = false; 4433 Candidate.FailureKind = ovl_fail_bad_conversion; 4434 Candidate.Conversions[0] = ObjectInit; 4435 return; 4436 } 4437 4438 // The first conversion is actually a user-defined conversion whose 4439 // first conversion is ObjectInit's standard conversion (which is 4440 // effectively a reference binding). Record it as such. 4441 Candidate.Conversions[0].setUserDefined(); 4442 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 4443 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 4444 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 4445 Candidate.Conversions[0].UserDefined.FoundConversionFunction 4446 = FoundDecl.getDecl(); 4447 Candidate.Conversions[0].UserDefined.After 4448 = Candidate.Conversions[0].UserDefined.Before; 4449 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 4450 4451 // Find the 4452 unsigned NumArgsInProto = Proto->getNumArgs(); 4453 4454 // (C++ 13.3.2p2): A candidate function having fewer than m 4455 // parameters is viable only if it has an ellipsis in its parameter 4456 // list (8.3.5). 4457 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4458 Candidate.Viable = false; 4459 Candidate.FailureKind = ovl_fail_too_many_arguments; 4460 return; 4461 } 4462 4463 // Function types don't have any default arguments, so just check if 4464 // we have enough arguments. 4465 if (NumArgs < NumArgsInProto) { 4466 // Not enough arguments. 4467 Candidate.Viable = false; 4468 Candidate.FailureKind = ovl_fail_too_few_arguments; 4469 return; 4470 } 4471 4472 // Determine the implicit conversion sequences for each of the 4473 // arguments. 4474 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4475 if (ArgIdx < NumArgsInProto) { 4476 // (C++ 13.3.2p3): for F to be a viable function, there shall 4477 // exist for each argument an implicit conversion sequence 4478 // (13.3.3.1) that converts that argument to the corresponding 4479 // parameter of F. 4480 QualType ParamType = Proto->getArgType(ArgIdx); 4481 Candidate.Conversions[ArgIdx + 1] 4482 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4483 /*SuppressUserConversions=*/false, 4484 /*InOverloadResolution=*/false); 4485 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4486 Candidate.Viable = false; 4487 Candidate.FailureKind = ovl_fail_bad_conversion; 4488 break; 4489 } 4490 } else { 4491 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4492 // argument for which there is no corresponding parameter is 4493 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4494 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4495 } 4496 } 4497} 4498 4499/// \brief Add overload candidates for overloaded operators that are 4500/// member functions. 4501/// 4502/// Add the overloaded operator candidates that are member functions 4503/// for the operator Op that was used in an operator expression such 4504/// as "x Op y". , Args/NumArgs provides the operator arguments, and 4505/// CandidateSet will store the added overload candidates. (C++ 4506/// [over.match.oper]). 4507void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 4508 SourceLocation OpLoc, 4509 Expr **Args, unsigned NumArgs, 4510 OverloadCandidateSet& CandidateSet, 4511 SourceRange OpRange) { 4512 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4513 4514 // C++ [over.match.oper]p3: 4515 // For a unary operator @ with an operand of a type whose 4516 // cv-unqualified version is T1, and for a binary operator @ with 4517 // a left operand of a type whose cv-unqualified version is T1 and 4518 // a right operand of a type whose cv-unqualified version is T2, 4519 // three sets of candidate functions, designated member 4520 // candidates, non-member candidates and built-in candidates, are 4521 // constructed as follows: 4522 QualType T1 = Args[0]->getType(); 4523 4524 // -- If T1 is a class type, the set of member candidates is the 4525 // result of the qualified lookup of T1::operator@ 4526 // (13.3.1.1.1); otherwise, the set of member candidates is 4527 // empty. 4528 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 4529 // Complete the type if it can be completed. Otherwise, we're done. 4530 if (RequireCompleteType(OpLoc, T1, PDiag())) 4531 return; 4532 4533 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 4534 LookupQualifiedName(Operators, T1Rec->getDecl()); 4535 Operators.suppressDiagnostics(); 4536 4537 for (LookupResult::iterator Oper = Operators.begin(), 4538 OperEnd = Operators.end(); 4539 Oper != OperEnd; 4540 ++Oper) 4541 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 4542 Args[0]->Classify(Context), Args + 1, NumArgs - 1, 4543 CandidateSet, 4544 /* SuppressUserConversions = */ false); 4545 } 4546} 4547 4548/// AddBuiltinCandidate - Add a candidate for a built-in 4549/// operator. ResultTy and ParamTys are the result and parameter types 4550/// of the built-in candidate, respectively. Args and NumArgs are the 4551/// arguments being passed to the candidate. IsAssignmentOperator 4552/// should be true when this built-in candidate is an assignment 4553/// operator. NumContextualBoolArguments is the number of arguments 4554/// (at the beginning of the argument list) that will be contextually 4555/// converted to bool. 4556void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 4557 Expr **Args, unsigned NumArgs, 4558 OverloadCandidateSet& CandidateSet, 4559 bool IsAssignmentOperator, 4560 unsigned NumContextualBoolArguments) { 4561 // Overload resolution is always an unevaluated context. 4562 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4563 4564 // Add this candidate 4565 CandidateSet.push_back(OverloadCandidate()); 4566 OverloadCandidate& Candidate = CandidateSet.back(); 4567 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 4568 Candidate.Function = 0; 4569 Candidate.IsSurrogate = false; 4570 Candidate.IgnoreObjectArgument = false; 4571 Candidate.BuiltinTypes.ResultTy = ResultTy; 4572 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4573 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 4574 4575 // Determine the implicit conversion sequences for each of the 4576 // arguments. 4577 Candidate.Viable = true; 4578 Candidate.Conversions.resize(NumArgs); 4579 Candidate.ExplicitCallArguments = NumArgs; 4580 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4581 // C++ [over.match.oper]p4: 4582 // For the built-in assignment operators, conversions of the 4583 // left operand are restricted as follows: 4584 // -- no temporaries are introduced to hold the left operand, and 4585 // -- no user-defined conversions are applied to the left 4586 // operand to achieve a type match with the left-most 4587 // parameter of a built-in candidate. 4588 // 4589 // We block these conversions by turning off user-defined 4590 // conversions, since that is the only way that initialization of 4591 // a reference to a non-class type can occur from something that 4592 // is not of the same type. 4593 if (ArgIdx < NumContextualBoolArguments) { 4594 assert(ParamTys[ArgIdx] == Context.BoolTy && 4595 "Contextual conversion to bool requires bool type"); 4596 Candidate.Conversions[ArgIdx] 4597 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 4598 } else { 4599 Candidate.Conversions[ArgIdx] 4600 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4601 ArgIdx == 0 && IsAssignmentOperator, 4602 /*InOverloadResolution=*/false); 4603 } 4604 if (Candidate.Conversions[ArgIdx].isBad()) { 4605 Candidate.Viable = false; 4606 Candidate.FailureKind = ovl_fail_bad_conversion; 4607 break; 4608 } 4609 } 4610} 4611 4612/// BuiltinCandidateTypeSet - A set of types that will be used for the 4613/// candidate operator functions for built-in operators (C++ 4614/// [over.built]). The types are separated into pointer types and 4615/// enumeration types. 4616class BuiltinCandidateTypeSet { 4617 /// TypeSet - A set of types. 4618 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4619 4620 /// PointerTypes - The set of pointer types that will be used in the 4621 /// built-in candidates. 4622 TypeSet PointerTypes; 4623 4624 /// MemberPointerTypes - The set of member pointer types that will be 4625 /// used in the built-in candidates. 4626 TypeSet MemberPointerTypes; 4627 4628 /// EnumerationTypes - The set of enumeration types that will be 4629 /// used in the built-in candidates. 4630 TypeSet EnumerationTypes; 4631 4632 /// \brief The set of vector types that will be used in the built-in 4633 /// candidates. 4634 TypeSet VectorTypes; 4635 4636 /// \brief A flag indicating non-record types are viable candidates 4637 bool HasNonRecordTypes; 4638 4639 /// \brief A flag indicating whether either arithmetic or enumeration types 4640 /// were present in the candidate set. 4641 bool HasArithmeticOrEnumeralTypes; 4642 4643 /// Sema - The semantic analysis instance where we are building the 4644 /// candidate type set. 4645 Sema &SemaRef; 4646 4647 /// Context - The AST context in which we will build the type sets. 4648 ASTContext &Context; 4649 4650 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4651 const Qualifiers &VisibleQuals); 4652 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4653 4654public: 4655 /// iterator - Iterates through the types that are part of the set. 4656 typedef TypeSet::iterator iterator; 4657 4658 BuiltinCandidateTypeSet(Sema &SemaRef) 4659 : HasNonRecordTypes(false), 4660 HasArithmeticOrEnumeralTypes(false), 4661 SemaRef(SemaRef), 4662 Context(SemaRef.Context) { } 4663 4664 void AddTypesConvertedFrom(QualType Ty, 4665 SourceLocation Loc, 4666 bool AllowUserConversions, 4667 bool AllowExplicitConversions, 4668 const Qualifiers &VisibleTypeConversionsQuals); 4669 4670 /// pointer_begin - First pointer type found; 4671 iterator pointer_begin() { return PointerTypes.begin(); } 4672 4673 /// pointer_end - Past the last pointer type found; 4674 iterator pointer_end() { return PointerTypes.end(); } 4675 4676 /// member_pointer_begin - First member pointer type found; 4677 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4678 4679 /// member_pointer_end - Past the last member pointer type found; 4680 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4681 4682 /// enumeration_begin - First enumeration type found; 4683 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4684 4685 /// enumeration_end - Past the last enumeration type found; 4686 iterator enumeration_end() { return EnumerationTypes.end(); } 4687 4688 iterator vector_begin() { return VectorTypes.begin(); } 4689 iterator vector_end() { return VectorTypes.end(); } 4690 4691 bool hasNonRecordTypes() { return HasNonRecordTypes; } 4692 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 4693}; 4694 4695/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4696/// the set of pointer types along with any more-qualified variants of 4697/// that type. For example, if @p Ty is "int const *", this routine 4698/// will add "int const *", "int const volatile *", "int const 4699/// restrict *", and "int const volatile restrict *" to the set of 4700/// pointer types. Returns true if the add of @p Ty itself succeeded, 4701/// false otherwise. 4702/// 4703/// FIXME: what to do about extended qualifiers? 4704bool 4705BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4706 const Qualifiers &VisibleQuals) { 4707 4708 // Insert this type. 4709 if (!PointerTypes.insert(Ty)) 4710 return false; 4711 4712 QualType PointeeTy; 4713 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4714 bool buildObjCPtr = false; 4715 if (!PointerTy) { 4716 if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) { 4717 PointeeTy = PTy->getPointeeType(); 4718 buildObjCPtr = true; 4719 } 4720 else 4721 assert(false && "type was not a pointer type!"); 4722 } 4723 else 4724 PointeeTy = PointerTy->getPointeeType(); 4725 4726 // Don't add qualified variants of arrays. For one, they're not allowed 4727 // (the qualifier would sink to the element type), and for another, the 4728 // only overload situation where it matters is subscript or pointer +- int, 4729 // and those shouldn't have qualifier variants anyway. 4730 if (PointeeTy->isArrayType()) 4731 return true; 4732 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4733 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4734 BaseCVR = Array->getElementType().getCVRQualifiers(); 4735 bool hasVolatile = VisibleQuals.hasVolatile(); 4736 bool hasRestrict = VisibleQuals.hasRestrict(); 4737 4738 // Iterate through all strict supersets of BaseCVR. 4739 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4740 if ((CVR | BaseCVR) != CVR) continue; 4741 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4742 // in the types. 4743 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4744 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4745 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4746 if (!buildObjCPtr) 4747 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4748 else 4749 PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); 4750 } 4751 4752 return true; 4753} 4754 4755/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4756/// to the set of pointer types along with any more-qualified variants of 4757/// that type. For example, if @p Ty is "int const *", this routine 4758/// will add "int const *", "int const volatile *", "int const 4759/// restrict *", and "int const volatile restrict *" to the set of 4760/// pointer types. Returns true if the add of @p Ty itself succeeded, 4761/// false otherwise. 4762/// 4763/// FIXME: what to do about extended qualifiers? 4764bool 4765BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4766 QualType Ty) { 4767 // Insert this type. 4768 if (!MemberPointerTypes.insert(Ty)) 4769 return false; 4770 4771 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4772 assert(PointerTy && "type was not a member pointer type!"); 4773 4774 QualType PointeeTy = PointerTy->getPointeeType(); 4775 // Don't add qualified variants of arrays. For one, they're not allowed 4776 // (the qualifier would sink to the element type), and for another, the 4777 // only overload situation where it matters is subscript or pointer +- int, 4778 // and those shouldn't have qualifier variants anyway. 4779 if (PointeeTy->isArrayType()) 4780 return true; 4781 const Type *ClassTy = PointerTy->getClass(); 4782 4783 // Iterate through all strict supersets of the pointee type's CVR 4784 // qualifiers. 4785 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4786 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4787 if ((CVR | BaseCVR) != CVR) continue; 4788 4789 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4790 MemberPointerTypes.insert( 4791 Context.getMemberPointerType(QPointeeTy, ClassTy)); 4792 } 4793 4794 return true; 4795} 4796 4797/// AddTypesConvertedFrom - Add each of the types to which the type @p 4798/// Ty can be implicit converted to the given set of @p Types. We're 4799/// primarily interested in pointer types and enumeration types. We also 4800/// take member pointer types, for the conditional operator. 4801/// AllowUserConversions is true if we should look at the conversion 4802/// functions of a class type, and AllowExplicitConversions if we 4803/// should also include the explicit conversion functions of a class 4804/// type. 4805void 4806BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4807 SourceLocation Loc, 4808 bool AllowUserConversions, 4809 bool AllowExplicitConversions, 4810 const Qualifiers &VisibleQuals) { 4811 // Only deal with canonical types. 4812 Ty = Context.getCanonicalType(Ty); 4813 4814 // Look through reference types; they aren't part of the type of an 4815 // expression for the purposes of conversions. 4816 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4817 Ty = RefTy->getPointeeType(); 4818 4819 // If we're dealing with an array type, decay to the pointer. 4820 if (Ty->isArrayType()) 4821 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4822 4823 // Otherwise, we don't care about qualifiers on the type. 4824 Ty = Ty.getLocalUnqualifiedType(); 4825 4826 // Flag if we ever add a non-record type. 4827 const RecordType *TyRec = Ty->getAs<RecordType>(); 4828 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 4829 4830 // Flag if we encounter an arithmetic type. 4831 HasArithmeticOrEnumeralTypes = 4832 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 4833 4834 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 4835 PointerTypes.insert(Ty); 4836 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 4837 // Insert our type, and its more-qualified variants, into the set 4838 // of types. 4839 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4840 return; 4841 } else if (Ty->isMemberPointerType()) { 4842 // Member pointers are far easier, since the pointee can't be converted. 4843 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4844 return; 4845 } else if (Ty->isEnumeralType()) { 4846 HasArithmeticOrEnumeralTypes = true; 4847 EnumerationTypes.insert(Ty); 4848 } else if (Ty->isVectorType()) { 4849 // We treat vector types as arithmetic types in many contexts as an 4850 // extension. 4851 HasArithmeticOrEnumeralTypes = true; 4852 VectorTypes.insert(Ty); 4853 } else if (AllowUserConversions && TyRec) { 4854 // No conversion functions in incomplete types. 4855 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 4856 return; 4857 4858 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4859 const UnresolvedSetImpl *Conversions 4860 = ClassDecl->getVisibleConversionFunctions(); 4861 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4862 E = Conversions->end(); I != E; ++I) { 4863 NamedDecl *D = I.getDecl(); 4864 if (isa<UsingShadowDecl>(D)) 4865 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4866 4867 // Skip conversion function templates; they don't tell us anything 4868 // about which builtin types we can convert to. 4869 if (isa<FunctionTemplateDecl>(D)) 4870 continue; 4871 4872 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4873 if (AllowExplicitConversions || !Conv->isExplicit()) { 4874 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4875 VisibleQuals); 4876 } 4877 } 4878 } 4879} 4880 4881/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4882/// the volatile- and non-volatile-qualified assignment operators for the 4883/// given type to the candidate set. 4884static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4885 QualType T, 4886 Expr **Args, 4887 unsigned NumArgs, 4888 OverloadCandidateSet &CandidateSet) { 4889 QualType ParamTypes[2]; 4890 4891 // T& operator=(T&, T) 4892 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4893 ParamTypes[1] = T; 4894 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4895 /*IsAssignmentOperator=*/true); 4896 4897 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4898 // volatile T& operator=(volatile T&, T) 4899 ParamTypes[0] 4900 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4901 ParamTypes[1] = T; 4902 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4903 /*IsAssignmentOperator=*/true); 4904 } 4905} 4906 4907/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4908/// if any, found in visible type conversion functions found in ArgExpr's type. 4909static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4910 Qualifiers VRQuals; 4911 const RecordType *TyRec; 4912 if (const MemberPointerType *RHSMPType = 4913 ArgExpr->getType()->getAs<MemberPointerType>()) 4914 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4915 else 4916 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4917 if (!TyRec) { 4918 // Just to be safe, assume the worst case. 4919 VRQuals.addVolatile(); 4920 VRQuals.addRestrict(); 4921 return VRQuals; 4922 } 4923 4924 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4925 if (!ClassDecl->hasDefinition()) 4926 return VRQuals; 4927 4928 const UnresolvedSetImpl *Conversions = 4929 ClassDecl->getVisibleConversionFunctions(); 4930 4931 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4932 E = Conversions->end(); I != E; ++I) { 4933 NamedDecl *D = I.getDecl(); 4934 if (isa<UsingShadowDecl>(D)) 4935 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4936 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4937 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4938 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4939 CanTy = ResTypeRef->getPointeeType(); 4940 // Need to go down the pointer/mempointer chain and add qualifiers 4941 // as see them. 4942 bool done = false; 4943 while (!done) { 4944 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4945 CanTy = ResTypePtr->getPointeeType(); 4946 else if (const MemberPointerType *ResTypeMPtr = 4947 CanTy->getAs<MemberPointerType>()) 4948 CanTy = ResTypeMPtr->getPointeeType(); 4949 else 4950 done = true; 4951 if (CanTy.isVolatileQualified()) 4952 VRQuals.addVolatile(); 4953 if (CanTy.isRestrictQualified()) 4954 VRQuals.addRestrict(); 4955 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4956 return VRQuals; 4957 } 4958 } 4959 } 4960 return VRQuals; 4961} 4962 4963namespace { 4964 4965/// \brief Helper class to manage the addition of builtin operator overload 4966/// candidates. It provides shared state and utility methods used throughout 4967/// the process, as well as a helper method to add each group of builtin 4968/// operator overloads from the standard to a candidate set. 4969class BuiltinOperatorOverloadBuilder { 4970 // Common instance state available to all overload candidate addition methods. 4971 Sema &S; 4972 Expr **Args; 4973 unsigned NumArgs; 4974 Qualifiers VisibleTypeConversionsQuals; 4975 bool HasArithmeticOrEnumeralCandidateType; 4976 llvm::SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 4977 OverloadCandidateSet &CandidateSet; 4978 4979 // Define some constants used to index and iterate over the arithemetic types 4980 // provided via the getArithmeticType() method below. 4981 // The "promoted arithmetic types" are the arithmetic 4982 // types are that preserved by promotion (C++ [over.built]p2). 4983 static const unsigned FirstIntegralType = 3; 4984 static const unsigned LastIntegralType = 18; 4985 static const unsigned FirstPromotedIntegralType = 3, 4986 LastPromotedIntegralType = 9; 4987 static const unsigned FirstPromotedArithmeticType = 0, 4988 LastPromotedArithmeticType = 9; 4989 static const unsigned NumArithmeticTypes = 18; 4990 4991 /// \brief Get the canonical type for a given arithmetic type index. 4992 CanQualType getArithmeticType(unsigned index) { 4993 assert(index < NumArithmeticTypes); 4994 static CanQualType ASTContext::* const 4995 ArithmeticTypes[NumArithmeticTypes] = { 4996 // Start of promoted types. 4997 &ASTContext::FloatTy, 4998 &ASTContext::DoubleTy, 4999 &ASTContext::LongDoubleTy, 5000 5001 // Start of integral types. 5002 &ASTContext::IntTy, 5003 &ASTContext::LongTy, 5004 &ASTContext::LongLongTy, 5005 &ASTContext::UnsignedIntTy, 5006 &ASTContext::UnsignedLongTy, 5007 &ASTContext::UnsignedLongLongTy, 5008 // End of promoted types. 5009 5010 &ASTContext::BoolTy, 5011 &ASTContext::CharTy, 5012 &ASTContext::WCharTy, 5013 &ASTContext::Char16Ty, 5014 &ASTContext::Char32Ty, 5015 &ASTContext::SignedCharTy, 5016 &ASTContext::ShortTy, 5017 &ASTContext::UnsignedCharTy, 5018 &ASTContext::UnsignedShortTy, 5019 // End of integral types. 5020 // FIXME: What about complex? 5021 }; 5022 return S.Context.*ArithmeticTypes[index]; 5023 } 5024 5025 /// \brief Gets the canonical type resulting from the usual arithemetic 5026 /// converions for the given arithmetic types. 5027 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 5028 // Accelerator table for performing the usual arithmetic conversions. 5029 // The rules are basically: 5030 // - if either is floating-point, use the wider floating-point 5031 // - if same signedness, use the higher rank 5032 // - if same size, use unsigned of the higher rank 5033 // - use the larger type 5034 // These rules, together with the axiom that higher ranks are 5035 // never smaller, are sufficient to precompute all of these results 5036 // *except* when dealing with signed types of higher rank. 5037 // (we could precompute SLL x UI for all known platforms, but it's 5038 // better not to make any assumptions). 5039 enum PromotedType { 5040 Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL, Dep=-1 5041 }; 5042 static PromotedType ConversionsTable[LastPromotedArithmeticType] 5043 [LastPromotedArithmeticType] = { 5044 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt }, 5045 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 5046 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 5047 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL }, 5048 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, Dep, UL, ULL }, 5049 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, Dep, Dep, ULL }, 5050 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, UI, UL, ULL }, 5051 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, UL, UL, ULL }, 5052 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, ULL, ULL, ULL }, 5053 }; 5054 5055 assert(L < LastPromotedArithmeticType); 5056 assert(R < LastPromotedArithmeticType); 5057 int Idx = ConversionsTable[L][R]; 5058 5059 // Fast path: the table gives us a concrete answer. 5060 if (Idx != Dep) return getArithmeticType(Idx); 5061 5062 // Slow path: we need to compare widths. 5063 // An invariant is that the signed type has higher rank. 5064 CanQualType LT = getArithmeticType(L), 5065 RT = getArithmeticType(R); 5066 unsigned LW = S.Context.getIntWidth(LT), 5067 RW = S.Context.getIntWidth(RT); 5068 5069 // If they're different widths, use the signed type. 5070 if (LW > RW) return LT; 5071 else if (LW < RW) return RT; 5072 5073 // Otherwise, use the unsigned type of the signed type's rank. 5074 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 5075 assert(L == SLL || R == SLL); 5076 return S.Context.UnsignedLongLongTy; 5077 } 5078 5079 /// \brief Helper method to factor out the common pattern of adding overloads 5080 /// for '++' and '--' builtin operators. 5081 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 5082 bool HasVolatile) { 5083 QualType ParamTypes[2] = { 5084 S.Context.getLValueReferenceType(CandidateTy), 5085 S.Context.IntTy 5086 }; 5087 5088 // Non-volatile version. 5089 if (NumArgs == 1) 5090 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5091 else 5092 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5093 5094 // Use a heuristic to reduce number of builtin candidates in the set: 5095 // add volatile version only if there are conversions to a volatile type. 5096 if (HasVolatile) { 5097 ParamTypes[0] = 5098 S.Context.getLValueReferenceType( 5099 S.Context.getVolatileType(CandidateTy)); 5100 if (NumArgs == 1) 5101 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5102 else 5103 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5104 } 5105 } 5106 5107public: 5108 BuiltinOperatorOverloadBuilder( 5109 Sema &S, Expr **Args, unsigned NumArgs, 5110 Qualifiers VisibleTypeConversionsQuals, 5111 bool HasArithmeticOrEnumeralCandidateType, 5112 llvm::SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 5113 OverloadCandidateSet &CandidateSet) 5114 : S(S), Args(Args), NumArgs(NumArgs), 5115 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 5116 HasArithmeticOrEnumeralCandidateType( 5117 HasArithmeticOrEnumeralCandidateType), 5118 CandidateTypes(CandidateTypes), 5119 CandidateSet(CandidateSet) { 5120 // Validate some of our static helper constants in debug builds. 5121 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 5122 "Invalid first promoted integral type"); 5123 assert(getArithmeticType(LastPromotedIntegralType - 1) 5124 == S.Context.UnsignedLongLongTy && 5125 "Invalid last promoted integral type"); 5126 assert(getArithmeticType(FirstPromotedArithmeticType) 5127 == S.Context.FloatTy && 5128 "Invalid first promoted arithmetic type"); 5129 assert(getArithmeticType(LastPromotedArithmeticType - 1) 5130 == S.Context.UnsignedLongLongTy && 5131 "Invalid last promoted arithmetic type"); 5132 } 5133 5134 // C++ [over.built]p3: 5135 // 5136 // For every pair (T, VQ), where T is an arithmetic type, and VQ 5137 // is either volatile or empty, there exist candidate operator 5138 // functions of the form 5139 // 5140 // VQ T& operator++(VQ T&); 5141 // T operator++(VQ T&, int); 5142 // 5143 // C++ [over.built]p4: 5144 // 5145 // For every pair (T, VQ), where T is an arithmetic type other 5146 // than bool, and VQ is either volatile or empty, there exist 5147 // candidate operator functions of the form 5148 // 5149 // VQ T& operator--(VQ T&); 5150 // T operator--(VQ T&, int); 5151 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 5152 if (!HasArithmeticOrEnumeralCandidateType) 5153 return; 5154 5155 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 5156 Arith < NumArithmeticTypes; ++Arith) { 5157 addPlusPlusMinusMinusStyleOverloads( 5158 getArithmeticType(Arith), 5159 VisibleTypeConversionsQuals.hasVolatile()); 5160 } 5161 } 5162 5163 // C++ [over.built]p5: 5164 // 5165 // For every pair (T, VQ), where T is a cv-qualified or 5166 // cv-unqualified object type, and VQ is either volatile or 5167 // empty, there exist candidate operator functions of the form 5168 // 5169 // T*VQ& operator++(T*VQ&); 5170 // T*VQ& operator--(T*VQ&); 5171 // T* operator++(T*VQ&, int); 5172 // T* operator--(T*VQ&, int); 5173 void addPlusPlusMinusMinusPointerOverloads() { 5174 for (BuiltinCandidateTypeSet::iterator 5175 Ptr = CandidateTypes[0].pointer_begin(), 5176 PtrEnd = CandidateTypes[0].pointer_end(); 5177 Ptr != PtrEnd; ++Ptr) { 5178 // Skip pointer types that aren't pointers to object types. 5179 if (!(*Ptr)->getPointeeType()->isObjectType()) 5180 continue; 5181 5182 addPlusPlusMinusMinusStyleOverloads(*Ptr, 5183 (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5184 VisibleTypeConversionsQuals.hasVolatile())); 5185 } 5186 } 5187 5188 // C++ [over.built]p6: 5189 // For every cv-qualified or cv-unqualified object type T, there 5190 // exist candidate operator functions of the form 5191 // 5192 // T& operator*(T*); 5193 // 5194 // C++ [over.built]p7: 5195 // For every function type T that does not have cv-qualifiers or a 5196 // ref-qualifier, there exist candidate operator functions of the form 5197 // T& operator*(T*); 5198 void addUnaryStarPointerOverloads() { 5199 for (BuiltinCandidateTypeSet::iterator 5200 Ptr = CandidateTypes[0].pointer_begin(), 5201 PtrEnd = CandidateTypes[0].pointer_end(); 5202 Ptr != PtrEnd; ++Ptr) { 5203 QualType ParamTy = *Ptr; 5204 QualType PointeeTy = ParamTy->getPointeeType(); 5205 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 5206 continue; 5207 5208 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 5209 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 5210 continue; 5211 5212 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 5213 &ParamTy, Args, 1, CandidateSet); 5214 } 5215 } 5216 5217 // C++ [over.built]p9: 5218 // For every promoted arithmetic type T, there exist candidate 5219 // operator functions of the form 5220 // 5221 // T operator+(T); 5222 // T operator-(T); 5223 void addUnaryPlusOrMinusArithmeticOverloads() { 5224 if (!HasArithmeticOrEnumeralCandidateType) 5225 return; 5226 5227 for (unsigned Arith = FirstPromotedArithmeticType; 5228 Arith < LastPromotedArithmeticType; ++Arith) { 5229 QualType ArithTy = getArithmeticType(Arith); 5230 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 5231 } 5232 5233 // Extension: We also add these operators for vector types. 5234 for (BuiltinCandidateTypeSet::iterator 5235 Vec = CandidateTypes[0].vector_begin(), 5236 VecEnd = CandidateTypes[0].vector_end(); 5237 Vec != VecEnd; ++Vec) { 5238 QualType VecTy = *Vec; 5239 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5240 } 5241 } 5242 5243 // C++ [over.built]p8: 5244 // For every type T, there exist candidate operator functions of 5245 // the form 5246 // 5247 // T* operator+(T*); 5248 void addUnaryPlusPointerOverloads() { 5249 for (BuiltinCandidateTypeSet::iterator 5250 Ptr = CandidateTypes[0].pointer_begin(), 5251 PtrEnd = CandidateTypes[0].pointer_end(); 5252 Ptr != PtrEnd; ++Ptr) { 5253 QualType ParamTy = *Ptr; 5254 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 5255 } 5256 } 5257 5258 // C++ [over.built]p10: 5259 // For every promoted integral type T, there exist candidate 5260 // operator functions of the form 5261 // 5262 // T operator~(T); 5263 void addUnaryTildePromotedIntegralOverloads() { 5264 if (!HasArithmeticOrEnumeralCandidateType) 5265 return; 5266 5267 for (unsigned Int = FirstPromotedIntegralType; 5268 Int < LastPromotedIntegralType; ++Int) { 5269 QualType IntTy = getArithmeticType(Int); 5270 S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 5271 } 5272 5273 // Extension: We also add this operator for vector types. 5274 for (BuiltinCandidateTypeSet::iterator 5275 Vec = CandidateTypes[0].vector_begin(), 5276 VecEnd = CandidateTypes[0].vector_end(); 5277 Vec != VecEnd; ++Vec) { 5278 QualType VecTy = *Vec; 5279 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5280 } 5281 } 5282 5283 // C++ [over.match.oper]p16: 5284 // For every pointer to member type T, there exist candidate operator 5285 // functions of the form 5286 // 5287 // bool operator==(T,T); 5288 // bool operator!=(T,T); 5289 void addEqualEqualOrNotEqualMemberPointerOverloads() { 5290 /// Set of (canonical) types that we've already handled. 5291 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5292 5293 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5294 for (BuiltinCandidateTypeSet::iterator 5295 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5296 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5297 MemPtr != MemPtrEnd; 5298 ++MemPtr) { 5299 // Don't add the same builtin candidate twice. 5300 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5301 continue; 5302 5303 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5304 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5305 CandidateSet); 5306 } 5307 } 5308 } 5309 5310 // C++ [over.built]p15: 5311 // 5312 // For every pointer or enumeration type T, there exist 5313 // candidate operator functions of the form 5314 // 5315 // bool operator<(T, T); 5316 // bool operator>(T, T); 5317 // bool operator<=(T, T); 5318 // bool operator>=(T, T); 5319 // bool operator==(T, T); 5320 // bool operator!=(T, T); 5321 void addRelationalPointerOrEnumeralOverloads() { 5322 // C++ [over.built]p1: 5323 // If there is a user-written candidate with the same name and parameter 5324 // types as a built-in candidate operator function, the built-in operator 5325 // function is hidden and is not included in the set of candidate 5326 // functions. 5327 // 5328 // The text is actually in a note, but if we don't implement it then we end 5329 // up with ambiguities when the user provides an overloaded operator for 5330 // an enumeration type. Note that only enumeration types have this problem, 5331 // so we track which enumeration types we've seen operators for. Also, the 5332 // only other overloaded operator with enumeration argumenst, operator=, 5333 // cannot be overloaded for enumeration types, so this is the only place 5334 // where we must suppress candidates like this. 5335 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 5336 UserDefinedBinaryOperators; 5337 5338 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5339 if (CandidateTypes[ArgIdx].enumeration_begin() != 5340 CandidateTypes[ArgIdx].enumeration_end()) { 5341 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 5342 CEnd = CandidateSet.end(); 5343 C != CEnd; ++C) { 5344 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 5345 continue; 5346 5347 QualType FirstParamType = 5348 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 5349 QualType SecondParamType = 5350 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 5351 5352 // Skip if either parameter isn't of enumeral type. 5353 if (!FirstParamType->isEnumeralType() || 5354 !SecondParamType->isEnumeralType()) 5355 continue; 5356 5357 // Add this operator to the set of known user-defined operators. 5358 UserDefinedBinaryOperators.insert( 5359 std::make_pair(S.Context.getCanonicalType(FirstParamType), 5360 S.Context.getCanonicalType(SecondParamType))); 5361 } 5362 } 5363 } 5364 5365 /// Set of (canonical) types that we've already handled. 5366 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5367 5368 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5369 for (BuiltinCandidateTypeSet::iterator 5370 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5371 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5372 Ptr != PtrEnd; ++Ptr) { 5373 // Don't add the same builtin candidate twice. 5374 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5375 continue; 5376 5377 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5378 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5379 CandidateSet); 5380 } 5381 for (BuiltinCandidateTypeSet::iterator 5382 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5383 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5384 Enum != EnumEnd; ++Enum) { 5385 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 5386 5387 // Don't add the same builtin candidate twice, or if a user defined 5388 // candidate exists. 5389 if (!AddedTypes.insert(CanonType) || 5390 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 5391 CanonType))) 5392 continue; 5393 5394 QualType ParamTypes[2] = { *Enum, *Enum }; 5395 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5396 CandidateSet); 5397 } 5398 } 5399 } 5400 5401 // C++ [over.built]p13: 5402 // 5403 // For every cv-qualified or cv-unqualified object type T 5404 // there exist candidate operator functions of the form 5405 // 5406 // T* operator+(T*, ptrdiff_t); 5407 // T& operator[](T*, ptrdiff_t); [BELOW] 5408 // T* operator-(T*, ptrdiff_t); 5409 // T* operator+(ptrdiff_t, T*); 5410 // T& operator[](ptrdiff_t, T*); [BELOW] 5411 // 5412 // C++ [over.built]p14: 5413 // 5414 // For every T, where T is a pointer to object type, there 5415 // exist candidate operator functions of the form 5416 // 5417 // ptrdiff_t operator-(T, T); 5418 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 5419 /// Set of (canonical) types that we've already handled. 5420 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5421 5422 for (int Arg = 0; Arg < 2; ++Arg) { 5423 QualType AsymetricParamTypes[2] = { 5424 S.Context.getPointerDiffType(), 5425 S.Context.getPointerDiffType(), 5426 }; 5427 for (BuiltinCandidateTypeSet::iterator 5428 Ptr = CandidateTypes[Arg].pointer_begin(), 5429 PtrEnd = CandidateTypes[Arg].pointer_end(); 5430 Ptr != PtrEnd; ++Ptr) { 5431 QualType PointeeTy = (*Ptr)->getPointeeType(); 5432 if (!PointeeTy->isObjectType()) 5433 continue; 5434 5435 AsymetricParamTypes[Arg] = *Ptr; 5436 if (Arg == 0 || Op == OO_Plus) { 5437 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 5438 // T* operator+(ptrdiff_t, T*); 5439 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, 5440 CandidateSet); 5441 } 5442 if (Op == OO_Minus) { 5443 // ptrdiff_t operator-(T, T); 5444 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5445 continue; 5446 5447 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5448 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 5449 Args, 2, CandidateSet); 5450 } 5451 } 5452 } 5453 } 5454 5455 // C++ [over.built]p12: 5456 // 5457 // For every pair of promoted arithmetic types L and R, there 5458 // exist candidate operator functions of the form 5459 // 5460 // LR operator*(L, R); 5461 // LR operator/(L, R); 5462 // LR operator+(L, R); 5463 // LR operator-(L, R); 5464 // bool operator<(L, R); 5465 // bool operator>(L, R); 5466 // bool operator<=(L, R); 5467 // bool operator>=(L, R); 5468 // bool operator==(L, R); 5469 // bool operator!=(L, R); 5470 // 5471 // where LR is the result of the usual arithmetic conversions 5472 // between types L and R. 5473 // 5474 // C++ [over.built]p24: 5475 // 5476 // For every pair of promoted arithmetic types L and R, there exist 5477 // candidate operator functions of the form 5478 // 5479 // LR operator?(bool, L, R); 5480 // 5481 // where LR is the result of the usual arithmetic conversions 5482 // between types L and R. 5483 // Our candidates ignore the first parameter. 5484 void addGenericBinaryArithmeticOverloads(bool isComparison) { 5485 if (!HasArithmeticOrEnumeralCandidateType) 5486 return; 5487 5488 for (unsigned Left = FirstPromotedArithmeticType; 5489 Left < LastPromotedArithmeticType; ++Left) { 5490 for (unsigned Right = FirstPromotedArithmeticType; 5491 Right < LastPromotedArithmeticType; ++Right) { 5492 QualType LandR[2] = { getArithmeticType(Left), 5493 getArithmeticType(Right) }; 5494 QualType Result = 5495 isComparison ? S.Context.BoolTy 5496 : getUsualArithmeticConversions(Left, Right); 5497 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5498 } 5499 } 5500 5501 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 5502 // conditional operator for vector types. 5503 for (BuiltinCandidateTypeSet::iterator 5504 Vec1 = CandidateTypes[0].vector_begin(), 5505 Vec1End = CandidateTypes[0].vector_end(); 5506 Vec1 != Vec1End; ++Vec1) { 5507 for (BuiltinCandidateTypeSet::iterator 5508 Vec2 = CandidateTypes[1].vector_begin(), 5509 Vec2End = CandidateTypes[1].vector_end(); 5510 Vec2 != Vec2End; ++Vec2) { 5511 QualType LandR[2] = { *Vec1, *Vec2 }; 5512 QualType Result = S.Context.BoolTy; 5513 if (!isComparison) { 5514 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 5515 Result = *Vec1; 5516 else 5517 Result = *Vec2; 5518 } 5519 5520 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5521 } 5522 } 5523 } 5524 5525 // C++ [over.built]p17: 5526 // 5527 // For every pair of promoted integral types L and R, there 5528 // exist candidate operator functions of the form 5529 // 5530 // LR operator%(L, R); 5531 // LR operator&(L, R); 5532 // LR operator^(L, R); 5533 // LR operator|(L, R); 5534 // L operator<<(L, R); 5535 // L operator>>(L, R); 5536 // 5537 // where LR is the result of the usual arithmetic conversions 5538 // between types L and R. 5539 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 5540 if (!HasArithmeticOrEnumeralCandidateType) 5541 return; 5542 5543 for (unsigned Left = FirstPromotedIntegralType; 5544 Left < LastPromotedIntegralType; ++Left) { 5545 for (unsigned Right = FirstPromotedIntegralType; 5546 Right < LastPromotedIntegralType; ++Right) { 5547 QualType LandR[2] = { getArithmeticType(Left), 5548 getArithmeticType(Right) }; 5549 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 5550 ? LandR[0] 5551 : getUsualArithmeticConversions(Left, Right); 5552 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5553 } 5554 } 5555 } 5556 5557 // C++ [over.built]p20: 5558 // 5559 // For every pair (T, VQ), where T is an enumeration or 5560 // pointer to member type and VQ is either volatile or 5561 // empty, there exist candidate operator functions of the form 5562 // 5563 // VQ T& operator=(VQ T&, T); 5564 void addAssignmentMemberPointerOrEnumeralOverloads() { 5565 /// Set of (canonical) types that we've already handled. 5566 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5567 5568 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5569 for (BuiltinCandidateTypeSet::iterator 5570 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5571 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5572 Enum != EnumEnd; ++Enum) { 5573 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5574 continue; 5575 5576 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, 5577 CandidateSet); 5578 } 5579 5580 for (BuiltinCandidateTypeSet::iterator 5581 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5582 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5583 MemPtr != MemPtrEnd; ++MemPtr) { 5584 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5585 continue; 5586 5587 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, 5588 CandidateSet); 5589 } 5590 } 5591 } 5592 5593 // C++ [over.built]p19: 5594 // 5595 // For every pair (T, VQ), where T is any type and VQ is either 5596 // volatile or empty, there exist candidate operator functions 5597 // of the form 5598 // 5599 // T*VQ& operator=(T*VQ&, T*); 5600 // 5601 // C++ [over.built]p21: 5602 // 5603 // For every pair (T, VQ), where T is a cv-qualified or 5604 // cv-unqualified object type and VQ is either volatile or 5605 // empty, there exist candidate operator functions of the form 5606 // 5607 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 5608 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 5609 void addAssignmentPointerOverloads(bool isEqualOp) { 5610 /// Set of (canonical) types that we've already handled. 5611 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5612 5613 for (BuiltinCandidateTypeSet::iterator 5614 Ptr = CandidateTypes[0].pointer_begin(), 5615 PtrEnd = CandidateTypes[0].pointer_end(); 5616 Ptr != PtrEnd; ++Ptr) { 5617 // If this is operator=, keep track of the builtin candidates we added. 5618 if (isEqualOp) 5619 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 5620 else if (!(*Ptr)->getPointeeType()->isObjectType()) 5621 continue; 5622 5623 // non-volatile version 5624 QualType ParamTypes[2] = { 5625 S.Context.getLValueReferenceType(*Ptr), 5626 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 5627 }; 5628 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5629 /*IsAssigmentOperator=*/ isEqualOp); 5630 5631 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5632 VisibleTypeConversionsQuals.hasVolatile()) { 5633 // volatile version 5634 ParamTypes[0] = 5635 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5636 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5637 /*IsAssigmentOperator=*/isEqualOp); 5638 } 5639 } 5640 5641 if (isEqualOp) { 5642 for (BuiltinCandidateTypeSet::iterator 5643 Ptr = CandidateTypes[1].pointer_begin(), 5644 PtrEnd = CandidateTypes[1].pointer_end(); 5645 Ptr != PtrEnd; ++Ptr) { 5646 // Make sure we don't add the same candidate twice. 5647 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5648 continue; 5649 5650 QualType ParamTypes[2] = { 5651 S.Context.getLValueReferenceType(*Ptr), 5652 *Ptr, 5653 }; 5654 5655 // non-volatile version 5656 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5657 /*IsAssigmentOperator=*/true); 5658 5659 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5660 VisibleTypeConversionsQuals.hasVolatile()) { 5661 // volatile version 5662 ParamTypes[0] = 5663 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5664 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5665 CandidateSet, /*IsAssigmentOperator=*/true); 5666 } 5667 } 5668 } 5669 } 5670 5671 // C++ [over.built]p18: 5672 // 5673 // For every triple (L, VQ, R), where L is an arithmetic type, 5674 // VQ is either volatile or empty, and R is a promoted 5675 // arithmetic type, there exist candidate operator functions of 5676 // the form 5677 // 5678 // VQ L& operator=(VQ L&, R); 5679 // VQ L& operator*=(VQ L&, R); 5680 // VQ L& operator/=(VQ L&, R); 5681 // VQ L& operator+=(VQ L&, R); 5682 // VQ L& operator-=(VQ L&, R); 5683 void addAssignmentArithmeticOverloads(bool isEqualOp) { 5684 if (!HasArithmeticOrEnumeralCandidateType) 5685 return; 5686 5687 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 5688 for (unsigned Right = FirstPromotedArithmeticType; 5689 Right < LastPromotedArithmeticType; ++Right) { 5690 QualType ParamTypes[2]; 5691 ParamTypes[1] = getArithmeticType(Right); 5692 5693 // Add this built-in operator as a candidate (VQ is empty). 5694 ParamTypes[0] = 5695 S.Context.getLValueReferenceType(getArithmeticType(Left)); 5696 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5697 /*IsAssigmentOperator=*/isEqualOp); 5698 5699 // Add this built-in operator as a candidate (VQ is 'volatile'). 5700 if (VisibleTypeConversionsQuals.hasVolatile()) { 5701 ParamTypes[0] = 5702 S.Context.getVolatileType(getArithmeticType(Left)); 5703 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5704 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5705 CandidateSet, 5706 /*IsAssigmentOperator=*/isEqualOp); 5707 } 5708 } 5709 } 5710 5711 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 5712 for (BuiltinCandidateTypeSet::iterator 5713 Vec1 = CandidateTypes[0].vector_begin(), 5714 Vec1End = CandidateTypes[0].vector_end(); 5715 Vec1 != Vec1End; ++Vec1) { 5716 for (BuiltinCandidateTypeSet::iterator 5717 Vec2 = CandidateTypes[1].vector_begin(), 5718 Vec2End = CandidateTypes[1].vector_end(); 5719 Vec2 != Vec2End; ++Vec2) { 5720 QualType ParamTypes[2]; 5721 ParamTypes[1] = *Vec2; 5722 // Add this built-in operator as a candidate (VQ is empty). 5723 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 5724 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5725 /*IsAssigmentOperator=*/isEqualOp); 5726 5727 // Add this built-in operator as a candidate (VQ is 'volatile'). 5728 if (VisibleTypeConversionsQuals.hasVolatile()) { 5729 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 5730 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5731 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5732 CandidateSet, 5733 /*IsAssigmentOperator=*/isEqualOp); 5734 } 5735 } 5736 } 5737 } 5738 5739 // C++ [over.built]p22: 5740 // 5741 // For every triple (L, VQ, R), where L is an integral type, VQ 5742 // is either volatile or empty, and R is a promoted integral 5743 // type, there exist candidate operator functions of the form 5744 // 5745 // VQ L& operator%=(VQ L&, R); 5746 // VQ L& operator<<=(VQ L&, R); 5747 // VQ L& operator>>=(VQ L&, R); 5748 // VQ L& operator&=(VQ L&, R); 5749 // VQ L& operator^=(VQ L&, R); 5750 // VQ L& operator|=(VQ L&, R); 5751 void addAssignmentIntegralOverloads() { 5752 if (!HasArithmeticOrEnumeralCandidateType) 5753 return; 5754 5755 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 5756 for (unsigned Right = FirstPromotedIntegralType; 5757 Right < LastPromotedIntegralType; ++Right) { 5758 QualType ParamTypes[2]; 5759 ParamTypes[1] = getArithmeticType(Right); 5760 5761 // Add this built-in operator as a candidate (VQ is empty). 5762 ParamTypes[0] = 5763 S.Context.getLValueReferenceType(getArithmeticType(Left)); 5764 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5765 if (VisibleTypeConversionsQuals.hasVolatile()) { 5766 // Add this built-in operator as a candidate (VQ is 'volatile'). 5767 ParamTypes[0] = getArithmeticType(Left); 5768 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 5769 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5770 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5771 CandidateSet); 5772 } 5773 } 5774 } 5775 } 5776 5777 // C++ [over.operator]p23: 5778 // 5779 // There also exist candidate operator functions of the form 5780 // 5781 // bool operator!(bool); 5782 // bool operator&&(bool, bool); 5783 // bool operator||(bool, bool); 5784 void addExclaimOverload() { 5785 QualType ParamTy = S.Context.BoolTy; 5786 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 5787 /*IsAssignmentOperator=*/false, 5788 /*NumContextualBoolArguments=*/1); 5789 } 5790 void addAmpAmpOrPipePipeOverload() { 5791 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 5792 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 5793 /*IsAssignmentOperator=*/false, 5794 /*NumContextualBoolArguments=*/2); 5795 } 5796 5797 // C++ [over.built]p13: 5798 // 5799 // For every cv-qualified or cv-unqualified object type T there 5800 // exist candidate operator functions of the form 5801 // 5802 // T* operator+(T*, ptrdiff_t); [ABOVE] 5803 // T& operator[](T*, ptrdiff_t); 5804 // T* operator-(T*, ptrdiff_t); [ABOVE] 5805 // T* operator+(ptrdiff_t, T*); [ABOVE] 5806 // T& operator[](ptrdiff_t, T*); 5807 void addSubscriptOverloads() { 5808 for (BuiltinCandidateTypeSet::iterator 5809 Ptr = CandidateTypes[0].pointer_begin(), 5810 PtrEnd = CandidateTypes[0].pointer_end(); 5811 Ptr != PtrEnd; ++Ptr) { 5812 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 5813 QualType PointeeType = (*Ptr)->getPointeeType(); 5814 if (!PointeeType->isObjectType()) 5815 continue; 5816 5817 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 5818 5819 // T& operator[](T*, ptrdiff_t) 5820 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5821 } 5822 5823 for (BuiltinCandidateTypeSet::iterator 5824 Ptr = CandidateTypes[1].pointer_begin(), 5825 PtrEnd = CandidateTypes[1].pointer_end(); 5826 Ptr != PtrEnd; ++Ptr) { 5827 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 5828 QualType PointeeType = (*Ptr)->getPointeeType(); 5829 if (!PointeeType->isObjectType()) 5830 continue; 5831 5832 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 5833 5834 // T& operator[](ptrdiff_t, T*) 5835 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5836 } 5837 } 5838 5839 // C++ [over.built]p11: 5840 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 5841 // C1 is the same type as C2 or is a derived class of C2, T is an object 5842 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 5843 // there exist candidate operator functions of the form 5844 // 5845 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 5846 // 5847 // where CV12 is the union of CV1 and CV2. 5848 void addArrowStarOverloads() { 5849 for (BuiltinCandidateTypeSet::iterator 5850 Ptr = CandidateTypes[0].pointer_begin(), 5851 PtrEnd = CandidateTypes[0].pointer_end(); 5852 Ptr != PtrEnd; ++Ptr) { 5853 QualType C1Ty = (*Ptr); 5854 QualType C1; 5855 QualifierCollector Q1; 5856 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 5857 if (!isa<RecordType>(C1)) 5858 continue; 5859 // heuristic to reduce number of builtin candidates in the set. 5860 // Add volatile/restrict version only if there are conversions to a 5861 // volatile/restrict type. 5862 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 5863 continue; 5864 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 5865 continue; 5866 for (BuiltinCandidateTypeSet::iterator 5867 MemPtr = CandidateTypes[1].member_pointer_begin(), 5868 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 5869 MemPtr != MemPtrEnd; ++MemPtr) { 5870 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 5871 QualType C2 = QualType(mptr->getClass(), 0); 5872 C2 = C2.getUnqualifiedType(); 5873 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 5874 break; 5875 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 5876 // build CV12 T& 5877 QualType T = mptr->getPointeeType(); 5878 if (!VisibleTypeConversionsQuals.hasVolatile() && 5879 T.isVolatileQualified()) 5880 continue; 5881 if (!VisibleTypeConversionsQuals.hasRestrict() && 5882 T.isRestrictQualified()) 5883 continue; 5884 T = Q1.apply(S.Context, T); 5885 QualType ResultTy = S.Context.getLValueReferenceType(T); 5886 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5887 } 5888 } 5889 } 5890 5891 // Note that we don't consider the first argument, since it has been 5892 // contextually converted to bool long ago. The candidates below are 5893 // therefore added as binary. 5894 // 5895 // C++ [over.built]p25: 5896 // For every type T, where T is a pointer, pointer-to-member, or scoped 5897 // enumeration type, there exist candidate operator functions of the form 5898 // 5899 // T operator?(bool, T, T); 5900 // 5901 void addConditionalOperatorOverloads() { 5902 /// Set of (canonical) types that we've already handled. 5903 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5904 5905 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5906 for (BuiltinCandidateTypeSet::iterator 5907 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5908 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5909 Ptr != PtrEnd; ++Ptr) { 5910 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5911 continue; 5912 5913 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5914 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5915 } 5916 5917 for (BuiltinCandidateTypeSet::iterator 5918 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5919 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5920 MemPtr != MemPtrEnd; ++MemPtr) { 5921 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5922 continue; 5923 5924 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5925 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); 5926 } 5927 5928 if (S.getLangOptions().CPlusPlus0x) { 5929 for (BuiltinCandidateTypeSet::iterator 5930 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5931 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5932 Enum != EnumEnd; ++Enum) { 5933 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 5934 continue; 5935 5936 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5937 continue; 5938 5939 QualType ParamTypes[2] = { *Enum, *Enum }; 5940 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); 5941 } 5942 } 5943 } 5944 } 5945}; 5946 5947} // end anonymous namespace 5948 5949/// AddBuiltinOperatorCandidates - Add the appropriate built-in 5950/// operator overloads to the candidate set (C++ [over.built]), based 5951/// on the operator @p Op and the arguments given. For example, if the 5952/// operator is a binary '+', this routine might add "int 5953/// operator+(int, int)" to cover integer addition. 5954void 5955Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 5956 SourceLocation OpLoc, 5957 Expr **Args, unsigned NumArgs, 5958 OverloadCandidateSet& CandidateSet) { 5959 // Find all of the types that the arguments can convert to, but only 5960 // if the operator we're looking at has built-in operator candidates 5961 // that make use of these types. Also record whether we encounter non-record 5962 // candidate types or either arithmetic or enumeral candidate types. 5963 Qualifiers VisibleTypeConversionsQuals; 5964 VisibleTypeConversionsQuals.addConst(); 5965 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5966 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 5967 5968 bool HasNonRecordCandidateType = false; 5969 bool HasArithmeticOrEnumeralCandidateType = false; 5970 llvm::SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 5971 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5972 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 5973 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 5974 OpLoc, 5975 true, 5976 (Op == OO_Exclaim || 5977 Op == OO_AmpAmp || 5978 Op == OO_PipePipe), 5979 VisibleTypeConversionsQuals); 5980 HasNonRecordCandidateType = HasNonRecordCandidateType || 5981 CandidateTypes[ArgIdx].hasNonRecordTypes(); 5982 HasArithmeticOrEnumeralCandidateType = 5983 HasArithmeticOrEnumeralCandidateType || 5984 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 5985 } 5986 5987 // Exit early when no non-record types have been added to the candidate set 5988 // for any of the arguments to the operator. 5989 if (!HasNonRecordCandidateType) 5990 return; 5991 5992 // Setup an object to manage the common state for building overloads. 5993 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, 5994 VisibleTypeConversionsQuals, 5995 HasArithmeticOrEnumeralCandidateType, 5996 CandidateTypes, CandidateSet); 5997 5998 // Dispatch over the operation to add in only those overloads which apply. 5999 switch (Op) { 6000 case OO_None: 6001 case NUM_OVERLOADED_OPERATORS: 6002 assert(false && "Expected an overloaded operator"); 6003 break; 6004 6005 case OO_New: 6006 case OO_Delete: 6007 case OO_Array_New: 6008 case OO_Array_Delete: 6009 case OO_Call: 6010 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 6011 break; 6012 6013 case OO_Comma: 6014 case OO_Arrow: 6015 // C++ [over.match.oper]p3: 6016 // -- For the operator ',', the unary operator '&', or the 6017 // operator '->', the built-in candidates set is empty. 6018 break; 6019 6020 case OO_Plus: // '+' is either unary or binary 6021 if (NumArgs == 1) 6022 OpBuilder.addUnaryPlusPointerOverloads(); 6023 // Fall through. 6024 6025 case OO_Minus: // '-' is either unary or binary 6026 if (NumArgs == 1) { 6027 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 6028 } else { 6029 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 6030 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6031 } 6032 break; 6033 6034 case OO_Star: // '*' is either unary or binary 6035 if (NumArgs == 1) 6036 OpBuilder.addUnaryStarPointerOverloads(); 6037 else 6038 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6039 break; 6040 6041 case OO_Slash: 6042 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6043 break; 6044 6045 case OO_PlusPlus: 6046 case OO_MinusMinus: 6047 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 6048 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 6049 break; 6050 6051 case OO_EqualEqual: 6052 case OO_ExclaimEqual: 6053 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 6054 // Fall through. 6055 6056 case OO_Less: 6057 case OO_Greater: 6058 case OO_LessEqual: 6059 case OO_GreaterEqual: 6060 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 6061 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 6062 break; 6063 6064 case OO_Percent: 6065 case OO_Caret: 6066 case OO_Pipe: 6067 case OO_LessLess: 6068 case OO_GreaterGreater: 6069 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6070 break; 6071 6072 case OO_Amp: // '&' is either unary or binary 6073 if (NumArgs == 1) 6074 // C++ [over.match.oper]p3: 6075 // -- For the operator ',', the unary operator '&', or the 6076 // operator '->', the built-in candidates set is empty. 6077 break; 6078 6079 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6080 break; 6081 6082 case OO_Tilde: 6083 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 6084 break; 6085 6086 case OO_Equal: 6087 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 6088 // Fall through. 6089 6090 case OO_PlusEqual: 6091 case OO_MinusEqual: 6092 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 6093 // Fall through. 6094 6095 case OO_StarEqual: 6096 case OO_SlashEqual: 6097 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 6098 break; 6099 6100 case OO_PercentEqual: 6101 case OO_LessLessEqual: 6102 case OO_GreaterGreaterEqual: 6103 case OO_AmpEqual: 6104 case OO_CaretEqual: 6105 case OO_PipeEqual: 6106 OpBuilder.addAssignmentIntegralOverloads(); 6107 break; 6108 6109 case OO_Exclaim: 6110 OpBuilder.addExclaimOverload(); 6111 break; 6112 6113 case OO_AmpAmp: 6114 case OO_PipePipe: 6115 OpBuilder.addAmpAmpOrPipePipeOverload(); 6116 break; 6117 6118 case OO_Subscript: 6119 OpBuilder.addSubscriptOverloads(); 6120 break; 6121 6122 case OO_ArrowStar: 6123 OpBuilder.addArrowStarOverloads(); 6124 break; 6125 6126 case OO_Conditional: 6127 OpBuilder.addConditionalOperatorOverloads(); 6128 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6129 break; 6130 } 6131} 6132 6133/// \brief Add function candidates found via argument-dependent lookup 6134/// to the set of overloading candidates. 6135/// 6136/// This routine performs argument-dependent name lookup based on the 6137/// given function name (which may also be an operator name) and adds 6138/// all of the overload candidates found by ADL to the overload 6139/// candidate set (C++ [basic.lookup.argdep]). 6140void 6141Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 6142 bool Operator, 6143 Expr **Args, unsigned NumArgs, 6144 TemplateArgumentListInfo *ExplicitTemplateArgs, 6145 OverloadCandidateSet& CandidateSet, 6146 bool PartialOverloading) { 6147 ADLResult Fns; 6148 6149 // FIXME: This approach for uniquing ADL results (and removing 6150 // redundant candidates from the set) relies on pointer-equality, 6151 // which means we need to key off the canonical decl. However, 6152 // always going back to the canonical decl might not get us the 6153 // right set of default arguments. What default arguments are 6154 // we supposed to consider on ADL candidates, anyway? 6155 6156 // FIXME: Pass in the explicit template arguments? 6157 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 6158 6159 // Erase all of the candidates we already knew about. 6160 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 6161 CandEnd = CandidateSet.end(); 6162 Cand != CandEnd; ++Cand) 6163 if (Cand->Function) { 6164 Fns.erase(Cand->Function); 6165 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 6166 Fns.erase(FunTmpl); 6167 } 6168 6169 // For each of the ADL candidates we found, add it to the overload 6170 // set. 6171 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 6172 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 6173 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 6174 if (ExplicitTemplateArgs) 6175 continue; 6176 6177 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 6178 false, PartialOverloading); 6179 } else 6180 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 6181 FoundDecl, ExplicitTemplateArgs, 6182 Args, NumArgs, CandidateSet); 6183 } 6184} 6185 6186/// isBetterOverloadCandidate - Determines whether the first overload 6187/// candidate is a better candidate than the second (C++ 13.3.3p1). 6188bool 6189isBetterOverloadCandidate(Sema &S, 6190 const OverloadCandidate &Cand1, 6191 const OverloadCandidate &Cand2, 6192 SourceLocation Loc, 6193 bool UserDefinedConversion) { 6194 // Define viable functions to be better candidates than non-viable 6195 // functions. 6196 if (!Cand2.Viable) 6197 return Cand1.Viable; 6198 else if (!Cand1.Viable) 6199 return false; 6200 6201 // C++ [over.match.best]p1: 6202 // 6203 // -- if F is a static member function, ICS1(F) is defined such 6204 // that ICS1(F) is neither better nor worse than ICS1(G) for 6205 // any function G, and, symmetrically, ICS1(G) is neither 6206 // better nor worse than ICS1(F). 6207 unsigned StartArg = 0; 6208 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 6209 StartArg = 1; 6210 6211 // C++ [over.match.best]p1: 6212 // A viable function F1 is defined to be a better function than another 6213 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 6214 // conversion sequence than ICSi(F2), and then... 6215 unsigned NumArgs = Cand1.Conversions.size(); 6216 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 6217 bool HasBetterConversion = false; 6218 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 6219 switch (CompareImplicitConversionSequences(S, 6220 Cand1.Conversions[ArgIdx], 6221 Cand2.Conversions[ArgIdx])) { 6222 case ImplicitConversionSequence::Better: 6223 // Cand1 has a better conversion sequence. 6224 HasBetterConversion = true; 6225 break; 6226 6227 case ImplicitConversionSequence::Worse: 6228 // Cand1 can't be better than Cand2. 6229 return false; 6230 6231 case ImplicitConversionSequence::Indistinguishable: 6232 // Do nothing. 6233 break; 6234 } 6235 } 6236 6237 // -- for some argument j, ICSj(F1) is a better conversion sequence than 6238 // ICSj(F2), or, if not that, 6239 if (HasBetterConversion) 6240 return true; 6241 6242 // - F1 is a non-template function and F2 is a function template 6243 // specialization, or, if not that, 6244 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 6245 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 6246 return true; 6247 6248 // -- F1 and F2 are function template specializations, and the function 6249 // template for F1 is more specialized than the template for F2 6250 // according to the partial ordering rules described in 14.5.5.2, or, 6251 // if not that, 6252 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 6253 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 6254 if (FunctionTemplateDecl *BetterTemplate 6255 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 6256 Cand2.Function->getPrimaryTemplate(), 6257 Loc, 6258 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 6259 : TPOC_Call, 6260 Cand1.ExplicitCallArguments)) 6261 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 6262 } 6263 6264 // -- the context is an initialization by user-defined conversion 6265 // (see 8.5, 13.3.1.5) and the standard conversion sequence 6266 // from the return type of F1 to the destination type (i.e., 6267 // the type of the entity being initialized) is a better 6268 // conversion sequence than the standard conversion sequence 6269 // from the return type of F2 to the destination type. 6270 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 6271 isa<CXXConversionDecl>(Cand1.Function) && 6272 isa<CXXConversionDecl>(Cand2.Function)) { 6273 switch (CompareStandardConversionSequences(S, 6274 Cand1.FinalConversion, 6275 Cand2.FinalConversion)) { 6276 case ImplicitConversionSequence::Better: 6277 // Cand1 has a better conversion sequence. 6278 return true; 6279 6280 case ImplicitConversionSequence::Worse: 6281 // Cand1 can't be better than Cand2. 6282 return false; 6283 6284 case ImplicitConversionSequence::Indistinguishable: 6285 // Do nothing 6286 break; 6287 } 6288 } 6289 6290 return false; 6291} 6292 6293/// \brief Computes the best viable function (C++ 13.3.3) 6294/// within an overload candidate set. 6295/// 6296/// \param CandidateSet the set of candidate functions. 6297/// 6298/// \param Loc the location of the function name (or operator symbol) for 6299/// which overload resolution occurs. 6300/// 6301/// \param Best f overload resolution was successful or found a deleted 6302/// function, Best points to the candidate function found. 6303/// 6304/// \returns The result of overload resolution. 6305OverloadingResult 6306OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 6307 iterator &Best, 6308 bool UserDefinedConversion) { 6309 // Find the best viable function. 6310 Best = end(); 6311 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6312 if (Cand->Viable) 6313 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 6314 UserDefinedConversion)) 6315 Best = Cand; 6316 } 6317 6318 // If we didn't find any viable functions, abort. 6319 if (Best == end()) 6320 return OR_No_Viable_Function; 6321 6322 // Make sure that this function is better than every other viable 6323 // function. If not, we have an ambiguity. 6324 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6325 if (Cand->Viable && 6326 Cand != Best && 6327 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 6328 UserDefinedConversion)) { 6329 Best = end(); 6330 return OR_Ambiguous; 6331 } 6332 } 6333 6334 // Best is the best viable function. 6335 if (Best->Function && 6336 (Best->Function->isDeleted() || Best->Function->isUnavailable())) 6337 return OR_Deleted; 6338 6339 return OR_Success; 6340} 6341 6342namespace { 6343 6344enum OverloadCandidateKind { 6345 oc_function, 6346 oc_method, 6347 oc_constructor, 6348 oc_function_template, 6349 oc_method_template, 6350 oc_constructor_template, 6351 oc_implicit_default_constructor, 6352 oc_implicit_copy_constructor, 6353 oc_implicit_copy_assignment, 6354 oc_implicit_inherited_constructor 6355}; 6356 6357OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 6358 FunctionDecl *Fn, 6359 std::string &Description) { 6360 bool isTemplate = false; 6361 6362 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 6363 isTemplate = true; 6364 Description = S.getTemplateArgumentBindingsText( 6365 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 6366 } 6367 6368 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 6369 if (!Ctor->isImplicit()) 6370 return isTemplate ? oc_constructor_template : oc_constructor; 6371 6372 if (Ctor->getInheritedConstructor()) 6373 return oc_implicit_inherited_constructor; 6374 6375 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 6376 : oc_implicit_default_constructor; 6377 } 6378 6379 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 6380 // This actually gets spelled 'candidate function' for now, but 6381 // it doesn't hurt to split it out. 6382 if (!Meth->isImplicit()) 6383 return isTemplate ? oc_method_template : oc_method; 6384 6385 assert(Meth->isCopyAssignmentOperator() 6386 && "implicit method is not copy assignment operator?"); 6387 return oc_implicit_copy_assignment; 6388 } 6389 6390 return isTemplate ? oc_function_template : oc_function; 6391} 6392 6393void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { 6394 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 6395 if (!Ctor) return; 6396 6397 Ctor = Ctor->getInheritedConstructor(); 6398 if (!Ctor) return; 6399 6400 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 6401} 6402 6403} // end anonymous namespace 6404 6405// Notes the location of an overload candidate. 6406void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 6407 std::string FnDesc; 6408 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 6409 Diag(Fn->getLocation(), diag::note_ovl_candidate) 6410 << (unsigned) K << FnDesc; 6411 MaybeEmitInheritedConstructorNote(*this, Fn); 6412} 6413 6414//Notes the location of all overload candidates designated through 6415// OverloadedExpr 6416void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr) { 6417 assert(OverloadedExpr->getType() == Context.OverloadTy); 6418 6419 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); 6420 OverloadExpr *OvlExpr = Ovl.Expression; 6421 6422 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6423 IEnd = OvlExpr->decls_end(); 6424 I != IEnd; ++I) { 6425 if (FunctionTemplateDecl *FunTmpl = 6426 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) { 6427 NoteOverloadCandidate(FunTmpl->getTemplatedDecl()); 6428 } else if (FunctionDecl *Fun 6429 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) { 6430 NoteOverloadCandidate(Fun); 6431 } 6432 } 6433} 6434 6435/// Diagnoses an ambiguous conversion. The partial diagnostic is the 6436/// "lead" diagnostic; it will be given two arguments, the source and 6437/// target types of the conversion. 6438void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 6439 Sema &S, 6440 SourceLocation CaretLoc, 6441 const PartialDiagnostic &PDiag) const { 6442 S.Diag(CaretLoc, PDiag) 6443 << Ambiguous.getFromType() << Ambiguous.getToType(); 6444 for (AmbiguousConversionSequence::const_iterator 6445 I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 6446 S.NoteOverloadCandidate(*I); 6447 } 6448} 6449 6450namespace { 6451 6452void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 6453 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 6454 assert(Conv.isBad()); 6455 assert(Cand->Function && "for now, candidate must be a function"); 6456 FunctionDecl *Fn = Cand->Function; 6457 6458 // There's a conversion slot for the object argument if this is a 6459 // non-constructor method. Note that 'I' corresponds the 6460 // conversion-slot index. 6461 bool isObjectArgument = false; 6462 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 6463 if (I == 0) 6464 isObjectArgument = true; 6465 else 6466 I--; 6467 } 6468 6469 std::string FnDesc; 6470 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6471 6472 Expr *FromExpr = Conv.Bad.FromExpr; 6473 QualType FromTy = Conv.Bad.getFromType(); 6474 QualType ToTy = Conv.Bad.getToType(); 6475 6476 if (FromTy == S.Context.OverloadTy) { 6477 assert(FromExpr && "overload set argument came from implicit argument?"); 6478 Expr *E = FromExpr->IgnoreParens(); 6479 if (isa<UnaryOperator>(E)) 6480 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 6481 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 6482 6483 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 6484 << (unsigned) FnKind << FnDesc 6485 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6486 << ToTy << Name << I+1; 6487 MaybeEmitInheritedConstructorNote(S, Fn); 6488 return; 6489 } 6490 6491 // Do some hand-waving analysis to see if the non-viability is due 6492 // to a qualifier mismatch. 6493 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 6494 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 6495 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 6496 CToTy = RT->getPointeeType(); 6497 else { 6498 // TODO: detect and diagnose the full richness of const mismatches. 6499 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 6500 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 6501 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 6502 } 6503 6504 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 6505 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 6506 // It is dumb that we have to do this here. 6507 while (isa<ArrayType>(CFromTy)) 6508 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 6509 while (isa<ArrayType>(CToTy)) 6510 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 6511 6512 Qualifiers FromQs = CFromTy.getQualifiers(); 6513 Qualifiers ToQs = CToTy.getQualifiers(); 6514 6515 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 6516 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 6517 << (unsigned) FnKind << FnDesc 6518 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6519 << FromTy 6520 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 6521 << (unsigned) isObjectArgument << I+1; 6522 MaybeEmitInheritedConstructorNote(S, Fn); 6523 return; 6524 } 6525 6526 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 6527 assert(CVR && "unexpected qualifiers mismatch"); 6528 6529 if (isObjectArgument) { 6530 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 6531 << (unsigned) FnKind << FnDesc 6532 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6533 << FromTy << (CVR - 1); 6534 } else { 6535 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 6536 << (unsigned) FnKind << FnDesc 6537 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6538 << FromTy << (CVR - 1) << I+1; 6539 } 6540 MaybeEmitInheritedConstructorNote(S, Fn); 6541 return; 6542 } 6543 6544 // Diagnose references or pointers to incomplete types differently, 6545 // since it's far from impossible that the incompleteness triggered 6546 // the failure. 6547 QualType TempFromTy = FromTy.getNonReferenceType(); 6548 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 6549 TempFromTy = PTy->getPointeeType(); 6550 if (TempFromTy->isIncompleteType()) { 6551 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 6552 << (unsigned) FnKind << FnDesc 6553 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6554 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6555 MaybeEmitInheritedConstructorNote(S, Fn); 6556 return; 6557 } 6558 6559 // Diagnose base -> derived pointer conversions. 6560 unsigned BaseToDerivedConversion = 0; 6561 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 6562 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 6563 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6564 FromPtrTy->getPointeeType()) && 6565 !FromPtrTy->getPointeeType()->isIncompleteType() && 6566 !ToPtrTy->getPointeeType()->isIncompleteType() && 6567 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 6568 FromPtrTy->getPointeeType())) 6569 BaseToDerivedConversion = 1; 6570 } 6571 } else if (const ObjCObjectPointerType *FromPtrTy 6572 = FromTy->getAs<ObjCObjectPointerType>()) { 6573 if (const ObjCObjectPointerType *ToPtrTy 6574 = ToTy->getAs<ObjCObjectPointerType>()) 6575 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 6576 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 6577 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6578 FromPtrTy->getPointeeType()) && 6579 FromIface->isSuperClassOf(ToIface)) 6580 BaseToDerivedConversion = 2; 6581 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 6582 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 6583 !FromTy->isIncompleteType() && 6584 !ToRefTy->getPointeeType()->isIncompleteType() && 6585 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 6586 BaseToDerivedConversion = 3; 6587 } 6588 6589 if (BaseToDerivedConversion) { 6590 S.Diag(Fn->getLocation(), 6591 diag::note_ovl_candidate_bad_base_to_derived_conv) 6592 << (unsigned) FnKind << FnDesc 6593 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6594 << (BaseToDerivedConversion - 1) 6595 << FromTy << ToTy << I+1; 6596 MaybeEmitInheritedConstructorNote(S, Fn); 6597 return; 6598 } 6599 6600 // TODO: specialize more based on the kind of mismatch 6601 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 6602 << (unsigned) FnKind << FnDesc 6603 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6604 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6605 MaybeEmitInheritedConstructorNote(S, Fn); 6606} 6607 6608void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 6609 unsigned NumFormalArgs) { 6610 // TODO: treat calls to a missing default constructor as a special case 6611 6612 FunctionDecl *Fn = Cand->Function; 6613 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 6614 6615 unsigned MinParams = Fn->getMinRequiredArguments(); 6616 6617 // at least / at most / exactly 6618 unsigned mode, modeCount; 6619 if (NumFormalArgs < MinParams) { 6620 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 6621 (Cand->FailureKind == ovl_fail_bad_deduction && 6622 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 6623 if (MinParams != FnTy->getNumArgs() || 6624 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 6625 mode = 0; // "at least" 6626 else 6627 mode = 2; // "exactly" 6628 modeCount = MinParams; 6629 } else { 6630 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 6631 (Cand->FailureKind == ovl_fail_bad_deduction && 6632 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 6633 if (MinParams != FnTy->getNumArgs()) 6634 mode = 1; // "at most" 6635 else 6636 mode = 2; // "exactly" 6637 modeCount = FnTy->getNumArgs(); 6638 } 6639 6640 std::string Description; 6641 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 6642 6643 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 6644 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 6645 << modeCount << NumFormalArgs; 6646 MaybeEmitInheritedConstructorNote(S, Fn); 6647} 6648 6649/// Diagnose a failed template-argument deduction. 6650void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 6651 Expr **Args, unsigned NumArgs) { 6652 FunctionDecl *Fn = Cand->Function; // pattern 6653 6654 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 6655 NamedDecl *ParamD; 6656 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 6657 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 6658 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 6659 switch (Cand->DeductionFailure.Result) { 6660 case Sema::TDK_Success: 6661 llvm_unreachable("TDK_success while diagnosing bad deduction"); 6662 6663 case Sema::TDK_Incomplete: { 6664 assert(ParamD && "no parameter found for incomplete deduction result"); 6665 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 6666 << ParamD->getDeclName(); 6667 MaybeEmitInheritedConstructorNote(S, Fn); 6668 return; 6669 } 6670 6671 case Sema::TDK_Underqualified: { 6672 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 6673 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 6674 6675 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 6676 6677 // Param will have been canonicalized, but it should just be a 6678 // qualified version of ParamD, so move the qualifiers to that. 6679 QualifierCollector Qs; 6680 Qs.strip(Param); 6681 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 6682 assert(S.Context.hasSameType(Param, NonCanonParam)); 6683 6684 // Arg has also been canonicalized, but there's nothing we can do 6685 // about that. It also doesn't matter as much, because it won't 6686 // have any template parameters in it (because deduction isn't 6687 // done on dependent types). 6688 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 6689 6690 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 6691 << ParamD->getDeclName() << Arg << NonCanonParam; 6692 MaybeEmitInheritedConstructorNote(S, Fn); 6693 return; 6694 } 6695 6696 case Sema::TDK_Inconsistent: { 6697 assert(ParamD && "no parameter found for inconsistent deduction result"); 6698 int which = 0; 6699 if (isa<TemplateTypeParmDecl>(ParamD)) 6700 which = 0; 6701 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 6702 which = 1; 6703 else { 6704 which = 2; 6705 } 6706 6707 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 6708 << which << ParamD->getDeclName() 6709 << *Cand->DeductionFailure.getFirstArg() 6710 << *Cand->DeductionFailure.getSecondArg(); 6711 MaybeEmitInheritedConstructorNote(S, Fn); 6712 return; 6713 } 6714 6715 case Sema::TDK_InvalidExplicitArguments: 6716 assert(ParamD && "no parameter found for invalid explicit arguments"); 6717 if (ParamD->getDeclName()) 6718 S.Diag(Fn->getLocation(), 6719 diag::note_ovl_candidate_explicit_arg_mismatch_named) 6720 << ParamD->getDeclName(); 6721 else { 6722 int index = 0; 6723 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 6724 index = TTP->getIndex(); 6725 else if (NonTypeTemplateParmDecl *NTTP 6726 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 6727 index = NTTP->getIndex(); 6728 else 6729 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 6730 S.Diag(Fn->getLocation(), 6731 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 6732 << (index + 1); 6733 } 6734 MaybeEmitInheritedConstructorNote(S, Fn); 6735 return; 6736 6737 case Sema::TDK_TooManyArguments: 6738 case Sema::TDK_TooFewArguments: 6739 DiagnoseArityMismatch(S, Cand, NumArgs); 6740 return; 6741 6742 case Sema::TDK_InstantiationDepth: 6743 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 6744 MaybeEmitInheritedConstructorNote(S, Fn); 6745 return; 6746 6747 case Sema::TDK_SubstitutionFailure: { 6748 std::string ArgString; 6749 if (TemplateArgumentList *Args 6750 = Cand->DeductionFailure.getTemplateArgumentList()) 6751 ArgString = S.getTemplateArgumentBindingsText( 6752 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 6753 *Args); 6754 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 6755 << ArgString; 6756 MaybeEmitInheritedConstructorNote(S, Fn); 6757 return; 6758 } 6759 6760 // TODO: diagnose these individually, then kill off 6761 // note_ovl_candidate_bad_deduction, which is uselessly vague. 6762 case Sema::TDK_NonDeducedMismatch: 6763 case Sema::TDK_FailedOverloadResolution: 6764 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 6765 MaybeEmitInheritedConstructorNote(S, Fn); 6766 return; 6767 } 6768} 6769 6770/// Generates a 'note' diagnostic for an overload candidate. We've 6771/// already generated a primary error at the call site. 6772/// 6773/// It really does need to be a single diagnostic with its caret 6774/// pointed at the candidate declaration. Yes, this creates some 6775/// major challenges of technical writing. Yes, this makes pointing 6776/// out problems with specific arguments quite awkward. It's still 6777/// better than generating twenty screens of text for every failed 6778/// overload. 6779/// 6780/// It would be great to be able to express per-candidate problems 6781/// more richly for those diagnostic clients that cared, but we'd 6782/// still have to be just as careful with the default diagnostics. 6783void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 6784 Expr **Args, unsigned NumArgs) { 6785 FunctionDecl *Fn = Cand->Function; 6786 6787 // Note deleted candidates, but only if they're viable. 6788 if (Cand->Viable && (Fn->isDeleted() || Fn->isUnavailable())) { 6789 std::string FnDesc; 6790 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6791 6792 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 6793 << FnKind << FnDesc << Fn->isDeleted(); 6794 MaybeEmitInheritedConstructorNote(S, Fn); 6795 return; 6796 } 6797 6798 // We don't really have anything else to say about viable candidates. 6799 if (Cand->Viable) { 6800 S.NoteOverloadCandidate(Fn); 6801 return; 6802 } 6803 6804 switch (Cand->FailureKind) { 6805 case ovl_fail_too_many_arguments: 6806 case ovl_fail_too_few_arguments: 6807 return DiagnoseArityMismatch(S, Cand, NumArgs); 6808 6809 case ovl_fail_bad_deduction: 6810 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 6811 6812 case ovl_fail_trivial_conversion: 6813 case ovl_fail_bad_final_conversion: 6814 case ovl_fail_final_conversion_not_exact: 6815 return S.NoteOverloadCandidate(Fn); 6816 6817 case ovl_fail_bad_conversion: { 6818 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 6819 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 6820 if (Cand->Conversions[I].isBad()) 6821 return DiagnoseBadConversion(S, Cand, I); 6822 6823 // FIXME: this currently happens when we're called from SemaInit 6824 // when user-conversion overload fails. Figure out how to handle 6825 // those conditions and diagnose them well. 6826 return S.NoteOverloadCandidate(Fn); 6827 } 6828 } 6829} 6830 6831void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 6832 // Desugar the type of the surrogate down to a function type, 6833 // retaining as many typedefs as possible while still showing 6834 // the function type (and, therefore, its parameter types). 6835 QualType FnType = Cand->Surrogate->getConversionType(); 6836 bool isLValueReference = false; 6837 bool isRValueReference = false; 6838 bool isPointer = false; 6839 if (const LValueReferenceType *FnTypeRef = 6840 FnType->getAs<LValueReferenceType>()) { 6841 FnType = FnTypeRef->getPointeeType(); 6842 isLValueReference = true; 6843 } else if (const RValueReferenceType *FnTypeRef = 6844 FnType->getAs<RValueReferenceType>()) { 6845 FnType = FnTypeRef->getPointeeType(); 6846 isRValueReference = true; 6847 } 6848 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 6849 FnType = FnTypePtr->getPointeeType(); 6850 isPointer = true; 6851 } 6852 // Desugar down to a function type. 6853 FnType = QualType(FnType->getAs<FunctionType>(), 0); 6854 // Reconstruct the pointer/reference as appropriate. 6855 if (isPointer) FnType = S.Context.getPointerType(FnType); 6856 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 6857 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 6858 6859 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 6860 << FnType; 6861 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 6862} 6863 6864void NoteBuiltinOperatorCandidate(Sema &S, 6865 const char *Opc, 6866 SourceLocation OpLoc, 6867 OverloadCandidate *Cand) { 6868 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 6869 std::string TypeStr("operator"); 6870 TypeStr += Opc; 6871 TypeStr += "("; 6872 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 6873 if (Cand->Conversions.size() == 1) { 6874 TypeStr += ")"; 6875 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 6876 } else { 6877 TypeStr += ", "; 6878 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 6879 TypeStr += ")"; 6880 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 6881 } 6882} 6883 6884void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 6885 OverloadCandidate *Cand) { 6886 unsigned NoOperands = Cand->Conversions.size(); 6887 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 6888 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 6889 if (ICS.isBad()) break; // all meaningless after first invalid 6890 if (!ICS.isAmbiguous()) continue; 6891 6892 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 6893 S.PDiag(diag::note_ambiguous_type_conversion)); 6894 } 6895} 6896 6897SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 6898 if (Cand->Function) 6899 return Cand->Function->getLocation(); 6900 if (Cand->IsSurrogate) 6901 return Cand->Surrogate->getLocation(); 6902 return SourceLocation(); 6903} 6904 6905struct CompareOverloadCandidatesForDisplay { 6906 Sema &S; 6907 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 6908 6909 bool operator()(const OverloadCandidate *L, 6910 const OverloadCandidate *R) { 6911 // Fast-path this check. 6912 if (L == R) return false; 6913 6914 // Order first by viability. 6915 if (L->Viable) { 6916 if (!R->Viable) return true; 6917 6918 // TODO: introduce a tri-valued comparison for overload 6919 // candidates. Would be more worthwhile if we had a sort 6920 // that could exploit it. 6921 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 6922 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 6923 } else if (R->Viable) 6924 return false; 6925 6926 assert(L->Viable == R->Viable); 6927 6928 // Criteria by which we can sort non-viable candidates: 6929 if (!L->Viable) { 6930 // 1. Arity mismatches come after other candidates. 6931 if (L->FailureKind == ovl_fail_too_many_arguments || 6932 L->FailureKind == ovl_fail_too_few_arguments) 6933 return false; 6934 if (R->FailureKind == ovl_fail_too_many_arguments || 6935 R->FailureKind == ovl_fail_too_few_arguments) 6936 return true; 6937 6938 // 2. Bad conversions come first and are ordered by the number 6939 // of bad conversions and quality of good conversions. 6940 if (L->FailureKind == ovl_fail_bad_conversion) { 6941 if (R->FailureKind != ovl_fail_bad_conversion) 6942 return true; 6943 6944 // If there's any ordering between the defined conversions... 6945 // FIXME: this might not be transitive. 6946 assert(L->Conversions.size() == R->Conversions.size()); 6947 6948 int leftBetter = 0; 6949 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 6950 for (unsigned E = L->Conversions.size(); I != E; ++I) { 6951 switch (CompareImplicitConversionSequences(S, 6952 L->Conversions[I], 6953 R->Conversions[I])) { 6954 case ImplicitConversionSequence::Better: 6955 leftBetter++; 6956 break; 6957 6958 case ImplicitConversionSequence::Worse: 6959 leftBetter--; 6960 break; 6961 6962 case ImplicitConversionSequence::Indistinguishable: 6963 break; 6964 } 6965 } 6966 if (leftBetter > 0) return true; 6967 if (leftBetter < 0) return false; 6968 6969 } else if (R->FailureKind == ovl_fail_bad_conversion) 6970 return false; 6971 6972 // TODO: others? 6973 } 6974 6975 // Sort everything else by location. 6976 SourceLocation LLoc = GetLocationForCandidate(L); 6977 SourceLocation RLoc = GetLocationForCandidate(R); 6978 6979 // Put candidates without locations (e.g. builtins) at the end. 6980 if (LLoc.isInvalid()) return false; 6981 if (RLoc.isInvalid()) return true; 6982 6983 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 6984 } 6985}; 6986 6987/// CompleteNonViableCandidate - Normally, overload resolution only 6988/// computes up to the first 6989void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 6990 Expr **Args, unsigned NumArgs) { 6991 assert(!Cand->Viable); 6992 6993 // Don't do anything on failures other than bad conversion. 6994 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 6995 6996 // Skip forward to the first bad conversion. 6997 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 6998 unsigned ConvCount = Cand->Conversions.size(); 6999 while (true) { 7000 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 7001 ConvIdx++; 7002 if (Cand->Conversions[ConvIdx - 1].isBad()) 7003 break; 7004 } 7005 7006 if (ConvIdx == ConvCount) 7007 return; 7008 7009 assert(!Cand->Conversions[ConvIdx].isInitialized() && 7010 "remaining conversion is initialized?"); 7011 7012 // FIXME: this should probably be preserved from the overload 7013 // operation somehow. 7014 bool SuppressUserConversions = false; 7015 7016 const FunctionProtoType* Proto; 7017 unsigned ArgIdx = ConvIdx; 7018 7019 if (Cand->IsSurrogate) { 7020 QualType ConvType 7021 = Cand->Surrogate->getConversionType().getNonReferenceType(); 7022 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7023 ConvType = ConvPtrType->getPointeeType(); 7024 Proto = ConvType->getAs<FunctionProtoType>(); 7025 ArgIdx--; 7026 } else if (Cand->Function) { 7027 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 7028 if (isa<CXXMethodDecl>(Cand->Function) && 7029 !isa<CXXConstructorDecl>(Cand->Function)) 7030 ArgIdx--; 7031 } else { 7032 // Builtin binary operator with a bad first conversion. 7033 assert(ConvCount <= 3); 7034 for (; ConvIdx != ConvCount; ++ConvIdx) 7035 Cand->Conversions[ConvIdx] 7036 = TryCopyInitialization(S, Args[ConvIdx], 7037 Cand->BuiltinTypes.ParamTypes[ConvIdx], 7038 SuppressUserConversions, 7039 /*InOverloadResolution*/ true); 7040 return; 7041 } 7042 7043 // Fill in the rest of the conversions. 7044 unsigned NumArgsInProto = Proto->getNumArgs(); 7045 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 7046 if (ArgIdx < NumArgsInProto) 7047 Cand->Conversions[ConvIdx] 7048 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 7049 SuppressUserConversions, 7050 /*InOverloadResolution=*/true); 7051 else 7052 Cand->Conversions[ConvIdx].setEllipsis(); 7053 } 7054} 7055 7056} // end anonymous namespace 7057 7058/// PrintOverloadCandidates - When overload resolution fails, prints 7059/// diagnostic messages containing the candidates in the candidate 7060/// set. 7061void OverloadCandidateSet::NoteCandidates(Sema &S, 7062 OverloadCandidateDisplayKind OCD, 7063 Expr **Args, unsigned NumArgs, 7064 const char *Opc, 7065 SourceLocation OpLoc) { 7066 // Sort the candidates by viability and position. Sorting directly would 7067 // be prohibitive, so we make a set of pointers and sort those. 7068 llvm::SmallVector<OverloadCandidate*, 32> Cands; 7069 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 7070 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 7071 if (Cand->Viable) 7072 Cands.push_back(Cand); 7073 else if (OCD == OCD_AllCandidates) { 7074 CompleteNonViableCandidate(S, Cand, Args, NumArgs); 7075 if (Cand->Function || Cand->IsSurrogate) 7076 Cands.push_back(Cand); 7077 // Otherwise, this a non-viable builtin candidate. We do not, in general, 7078 // want to list every possible builtin candidate. 7079 } 7080 } 7081 7082 std::sort(Cands.begin(), Cands.end(), 7083 CompareOverloadCandidatesForDisplay(S)); 7084 7085 bool ReportedAmbiguousConversions = false; 7086 7087 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 7088 const Diagnostic::OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 7089 unsigned CandsShown = 0; 7090 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 7091 OverloadCandidate *Cand = *I; 7092 7093 // Set an arbitrary limit on the number of candidate functions we'll spam 7094 // the user with. FIXME: This limit should depend on details of the 7095 // candidate list. 7096 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 7097 break; 7098 } 7099 ++CandsShown; 7100 7101 if (Cand->Function) 7102 NoteFunctionCandidate(S, Cand, Args, NumArgs); 7103 else if (Cand->IsSurrogate) 7104 NoteSurrogateCandidate(S, Cand); 7105 else { 7106 assert(Cand->Viable && 7107 "Non-viable built-in candidates are not added to Cands."); 7108 // Generally we only see ambiguities including viable builtin 7109 // operators if overload resolution got screwed up by an 7110 // ambiguous user-defined conversion. 7111 // 7112 // FIXME: It's quite possible for different conversions to see 7113 // different ambiguities, though. 7114 if (!ReportedAmbiguousConversions) { 7115 NoteAmbiguousUserConversions(S, OpLoc, Cand); 7116 ReportedAmbiguousConversions = true; 7117 } 7118 7119 // If this is a viable builtin, print it. 7120 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 7121 } 7122 } 7123 7124 if (I != E) 7125 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 7126} 7127 7128// [PossiblyAFunctionType] --> [Return] 7129// NonFunctionType --> NonFunctionType 7130// R (A) --> R(A) 7131// R (*)(A) --> R (A) 7132// R (&)(A) --> R (A) 7133// R (S::*)(A) --> R (A) 7134QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { 7135 QualType Ret = PossiblyAFunctionType; 7136 if (const PointerType *ToTypePtr = 7137 PossiblyAFunctionType->getAs<PointerType>()) 7138 Ret = ToTypePtr->getPointeeType(); 7139 else if (const ReferenceType *ToTypeRef = 7140 PossiblyAFunctionType->getAs<ReferenceType>()) 7141 Ret = ToTypeRef->getPointeeType(); 7142 else if (const MemberPointerType *MemTypePtr = 7143 PossiblyAFunctionType->getAs<MemberPointerType>()) 7144 Ret = MemTypePtr->getPointeeType(); 7145 Ret = 7146 Context.getCanonicalType(Ret).getUnqualifiedType(); 7147 return Ret; 7148} 7149 7150// A helper class to help with address of function resolution 7151// - allows us to avoid passing around all those ugly parameters 7152class AddressOfFunctionResolver 7153{ 7154 Sema& S; 7155 Expr* SourceExpr; 7156 const QualType& TargetType; 7157 QualType TargetFunctionType; // Extracted function type from target type 7158 7159 bool Complain; 7160 //DeclAccessPair& ResultFunctionAccessPair; 7161 ASTContext& Context; 7162 7163 bool TargetTypeIsNonStaticMemberFunction; 7164 bool FoundNonTemplateFunction; 7165 7166 OverloadExpr::FindResult OvlExprInfo; 7167 OverloadExpr *OvlExpr; 7168 TemplateArgumentListInfo OvlExplicitTemplateArgs; 7169 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 7170 7171public: 7172 AddressOfFunctionResolver(Sema &S, Expr* SourceExpr, 7173 const QualType& TargetType, bool Complain) 7174 : S(S), SourceExpr(SourceExpr), TargetType(TargetType), 7175 Complain(Complain), Context(S.getASTContext()), 7176 TargetTypeIsNonStaticMemberFunction( 7177 !!TargetType->getAs<MemberPointerType>()), 7178 FoundNonTemplateFunction(false), 7179 OvlExprInfo(OverloadExpr::find(SourceExpr)), 7180 OvlExpr(OvlExprInfo.Expression) 7181 { 7182 ExtractUnqualifiedFunctionTypeFromTargetType(); 7183 7184 if (!TargetFunctionType->isFunctionType()) { 7185 if (OvlExpr->hasExplicitTemplateArgs()) { 7186 DeclAccessPair dap; 7187 if( FunctionDecl* Fn = S.ResolveSingleFunctionTemplateSpecialization( 7188 OvlExpr, false, &dap) ) { 7189 7190 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7191 if (!Method->isStatic()) { 7192 // If the target type is a non-function type and the function 7193 // found is a non-static member function, pretend as if that was 7194 // the target, it's the only possible type to end up with. 7195 TargetTypeIsNonStaticMemberFunction = true; 7196 7197 // And skip adding the function if its not in the proper form. 7198 // We'll diagnose this due to an empty set of functions. 7199 if (!OvlExprInfo.HasFormOfMemberPointer) 7200 return; 7201 } 7202 } 7203 7204 Matches.push_back(std::make_pair(dap,Fn)); 7205 } 7206 } 7207 return; 7208 } 7209 7210 if (OvlExpr->hasExplicitTemplateArgs()) 7211 OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); 7212 7213 if (FindAllFunctionsThatMatchTargetTypeExactly()) { 7214 // C++ [over.over]p4: 7215 // If more than one function is selected, [...] 7216 if (Matches.size() > 1) { 7217 if (FoundNonTemplateFunction) 7218 EliminateAllTemplateMatches(); 7219 else 7220 EliminateAllExceptMostSpecializedTemplate(); 7221 } 7222 } 7223 } 7224 7225private: 7226 bool isTargetTypeAFunction() const { 7227 return TargetFunctionType->isFunctionType(); 7228 } 7229 7230 // [ToType] [Return] 7231 7232 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false 7233 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false 7234 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true 7235 void inline ExtractUnqualifiedFunctionTypeFromTargetType() { 7236 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); 7237 } 7238 7239 // return true if any matching specializations were found 7240 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, 7241 const DeclAccessPair& CurAccessFunPair) { 7242 if (CXXMethodDecl *Method 7243 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 7244 // Skip non-static function templates when converting to pointer, and 7245 // static when converting to member pointer. 7246 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 7247 return false; 7248 } 7249 else if (TargetTypeIsNonStaticMemberFunction) 7250 return false; 7251 7252 // C++ [over.over]p2: 7253 // If the name is a function template, template argument deduction is 7254 // done (14.8.2.2), and if the argument deduction succeeds, the 7255 // resulting template argument list is used to generate a single 7256 // function template specialization, which is added to the set of 7257 // overloaded functions considered. 7258 FunctionDecl *Specialization = 0; 7259 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 7260 if (Sema::TemplateDeductionResult Result 7261 = S.DeduceTemplateArguments(FunctionTemplate, 7262 &OvlExplicitTemplateArgs, 7263 TargetFunctionType, Specialization, 7264 Info)) { 7265 // FIXME: make a note of the failed deduction for diagnostics. 7266 (void)Result; 7267 return false; 7268 } 7269 7270 // Template argument deduction ensures that we have an exact match. 7271 // This function template specicalization works. 7272 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 7273 assert(TargetFunctionType 7274 == Context.getCanonicalType(Specialization->getType())); 7275 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); 7276 return true; 7277 } 7278 7279 bool AddMatchingNonTemplateFunction(NamedDecl* Fn, 7280 const DeclAccessPair& CurAccessFunPair) { 7281 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7282 // Skip non-static functions when converting to pointer, and static 7283 // when converting to member pointer. 7284 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 7285 return false; 7286 } 7287 else if (TargetTypeIsNonStaticMemberFunction) 7288 return false; 7289 7290 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 7291 QualType ResultTy; 7292 if (Context.hasSameUnqualifiedType(TargetFunctionType, 7293 FunDecl->getType()) || 7294 IsNoReturnConversion(Context, FunDecl->getType(), TargetFunctionType, 7295 ResultTy)) { 7296 Matches.push_back(std::make_pair(CurAccessFunPair, 7297 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 7298 FoundNonTemplateFunction = true; 7299 return true; 7300 } 7301 } 7302 7303 return false; 7304 } 7305 7306 bool FindAllFunctionsThatMatchTargetTypeExactly() { 7307 bool Ret = false; 7308 7309 // If the overload expression doesn't have the form of a pointer to 7310 // member, don't try to convert it to a pointer-to-member type. 7311 if (IsInvalidFormOfPointerToMemberFunction()) 7312 return false; 7313 7314 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7315 E = OvlExpr->decls_end(); 7316 I != E; ++I) { 7317 // Look through any using declarations to find the underlying function. 7318 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 7319 7320 // C++ [over.over]p3: 7321 // Non-member functions and static member functions match 7322 // targets of type "pointer-to-function" or "reference-to-function." 7323 // Nonstatic member functions match targets of 7324 // type "pointer-to-member-function." 7325 // Note that according to DR 247, the containing class does not matter. 7326 if (FunctionTemplateDecl *FunctionTemplate 7327 = dyn_cast<FunctionTemplateDecl>(Fn)) { 7328 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) 7329 Ret = true; 7330 } 7331 // If we have explicit template arguments supplied, skip non-templates. 7332 else if (!OvlExpr->hasExplicitTemplateArgs() && 7333 AddMatchingNonTemplateFunction(Fn, I.getPair())) 7334 Ret = true; 7335 } 7336 assert(Ret || Matches.empty()); 7337 return Ret; 7338 } 7339 7340 void EliminateAllExceptMostSpecializedTemplate() { 7341 // [...] and any given function template specialization F1 is 7342 // eliminated if the set contains a second function template 7343 // specialization whose function template is more specialized 7344 // than the function template of F1 according to the partial 7345 // ordering rules of 14.5.5.2. 7346 7347 // The algorithm specified above is quadratic. We instead use a 7348 // two-pass algorithm (similar to the one used to identify the 7349 // best viable function in an overload set) that identifies the 7350 // best function template (if it exists). 7351 7352 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 7353 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 7354 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 7355 7356 UnresolvedSetIterator Result = 7357 S.getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 7358 TPOC_Other, 0, SourceExpr->getLocStart(), 7359 S.PDiag(), 7360 S.PDiag(diag::err_addr_ovl_ambiguous) 7361 << Matches[0].second->getDeclName(), 7362 S.PDiag(diag::note_ovl_candidate) 7363 << (unsigned) oc_function_template, 7364 Complain); 7365 7366 if (Result != MatchesCopy.end()) { 7367 // Make it the first and only element 7368 Matches[0].first = Matches[Result - MatchesCopy.begin()].first; 7369 Matches[0].second = cast<FunctionDecl>(*Result); 7370 Matches.resize(1); 7371 } 7372 } 7373 7374 void EliminateAllTemplateMatches() { 7375 // [...] any function template specializations in the set are 7376 // eliminated if the set also contains a non-template function, [...] 7377 for (unsigned I = 0, N = Matches.size(); I != N; ) { 7378 if (Matches[I].second->getPrimaryTemplate() == 0) 7379 ++I; 7380 else { 7381 Matches[I] = Matches[--N]; 7382 Matches.set_size(N); 7383 } 7384 } 7385 } 7386 7387public: 7388 void ComplainNoMatchesFound() const { 7389 assert(Matches.empty()); 7390 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) 7391 << OvlExpr->getName() << TargetFunctionType 7392 << OvlExpr->getSourceRange(); 7393 S.NoteAllOverloadCandidates(OvlExpr); 7394 } 7395 7396 bool IsInvalidFormOfPointerToMemberFunction() const { 7397 return TargetTypeIsNonStaticMemberFunction && 7398 !OvlExprInfo.HasFormOfMemberPointer; 7399 } 7400 7401 void ComplainIsInvalidFormOfPointerToMemberFunction() const { 7402 // TODO: Should we condition this on whether any functions might 7403 // have matched, or is it more appropriate to do that in callers? 7404 // TODO: a fixit wouldn't hurt. 7405 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 7406 << TargetType << OvlExpr->getSourceRange(); 7407 } 7408 7409 void ComplainOfInvalidConversion() const { 7410 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 7411 << OvlExpr->getName() << TargetType; 7412 } 7413 7414 void ComplainMultipleMatchesFound() const { 7415 assert(Matches.size() > 1); 7416 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) 7417 << OvlExpr->getName() 7418 << OvlExpr->getSourceRange(); 7419 S.NoteAllOverloadCandidates(OvlExpr); 7420 } 7421 7422 int getNumMatches() const { return Matches.size(); } 7423 7424 FunctionDecl* getMatchingFunctionDecl() const { 7425 if (Matches.size() != 1) return 0; 7426 return Matches[0].second; 7427 } 7428 7429 const DeclAccessPair* getMatchingFunctionAccessPair() const { 7430 if (Matches.size() != 1) return 0; 7431 return &Matches[0].first; 7432 } 7433}; 7434 7435/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 7436/// an overloaded function (C++ [over.over]), where @p From is an 7437/// expression with overloaded function type and @p ToType is the type 7438/// we're trying to resolve to. For example: 7439/// 7440/// @code 7441/// int f(double); 7442/// int f(int); 7443/// 7444/// int (*pfd)(double) = f; // selects f(double) 7445/// @endcode 7446/// 7447/// This routine returns the resulting FunctionDecl if it could be 7448/// resolved, and NULL otherwise. When @p Complain is true, this 7449/// routine will emit diagnostics if there is an error. 7450FunctionDecl * 7451Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, QualType TargetType, 7452 bool Complain, 7453 DeclAccessPair &FoundResult) { 7454 7455 assert(AddressOfExpr->getType() == Context.OverloadTy); 7456 7457 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, Complain); 7458 int NumMatches = Resolver.getNumMatches(); 7459 FunctionDecl* Fn = 0; 7460 if ( NumMatches == 0 && Complain) { 7461 if (Resolver.IsInvalidFormOfPointerToMemberFunction()) 7462 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); 7463 else 7464 Resolver.ComplainNoMatchesFound(); 7465 } 7466 else if (NumMatches > 1 && Complain) 7467 Resolver.ComplainMultipleMatchesFound(); 7468 else if (NumMatches == 1) { 7469 Fn = Resolver.getMatchingFunctionDecl(); 7470 assert(Fn); 7471 FoundResult = *Resolver.getMatchingFunctionAccessPair(); 7472 MarkDeclarationReferenced(AddressOfExpr->getLocStart(), Fn); 7473 if (Complain) 7474 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); 7475 } 7476 7477 return Fn; 7478} 7479 7480/// \brief Given an expression that refers to an overloaded function, try to 7481/// resolve that overloaded function expression down to a single function. 7482/// 7483/// This routine can only resolve template-ids that refer to a single function 7484/// template, where that template-id refers to a single template whose template 7485/// arguments are either provided by the template-id or have defaults, 7486/// as described in C++0x [temp.arg.explicit]p3. 7487FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From, 7488 bool Complain, 7489 DeclAccessPair* FoundResult) { 7490 // C++ [over.over]p1: 7491 // [...] [Note: any redundant set of parentheses surrounding the 7492 // overloaded function name is ignored (5.1). ] 7493 // C++ [over.over]p1: 7494 // [...] The overloaded function name can be preceded by the & 7495 // operator. 7496 if (From->getType() != Context.OverloadTy) 7497 return 0; 7498 7499 OverloadExpr *OvlExpr = OverloadExpr::find(From).Expression; 7500 7501 // If we didn't actually find any template-ids, we're done. 7502 if (!OvlExpr->hasExplicitTemplateArgs()) 7503 return 0; 7504 7505 TemplateArgumentListInfo ExplicitTemplateArgs; 7506 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 7507 7508 // Look through all of the overloaded functions, searching for one 7509 // whose type matches exactly. 7510 FunctionDecl *Matched = 0; 7511 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7512 E = OvlExpr->decls_end(); I != E; ++I) { 7513 // C++0x [temp.arg.explicit]p3: 7514 // [...] In contexts where deduction is done and fails, or in contexts 7515 // where deduction is not done, if a template argument list is 7516 // specified and it, along with any default template arguments, 7517 // identifies a single function template specialization, then the 7518 // template-id is an lvalue for the function template specialization. 7519 FunctionTemplateDecl *FunctionTemplate 7520 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 7521 7522 // C++ [over.over]p2: 7523 // If the name is a function template, template argument deduction is 7524 // done (14.8.2.2), and if the argument deduction succeeds, the 7525 // resulting template argument list is used to generate a single 7526 // function template specialization, which is added to the set of 7527 // overloaded functions considered. 7528 FunctionDecl *Specialization = 0; 7529 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 7530 if (TemplateDeductionResult Result 7531 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 7532 Specialization, Info)) { 7533 // FIXME: make a note of the failed deduction for diagnostics. 7534 (void)Result; 7535 continue; 7536 } 7537 7538 // Multiple matches; we can't resolve to a single declaration. 7539 if (Matched) { 7540 if (FoundResult) 7541 *FoundResult = DeclAccessPair(); 7542 7543 if (Complain) { 7544 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 7545 << OvlExpr->getName(); 7546 NoteAllOverloadCandidates(OvlExpr); 7547 } 7548 return 0; 7549 } 7550 7551 if ((Matched = Specialization) && FoundResult) 7552 *FoundResult = I.getPair(); 7553 } 7554 7555 return Matched; 7556} 7557 7558 7559 7560 7561// Resolve and fix an overloaded expression that 7562// can be resolved because it identifies a single function 7563// template specialization 7564// Last three arguments should only be supplied if Complain = true 7565ExprResult Sema::ResolveAndFixSingleFunctionTemplateSpecialization( 7566 Expr *SrcExpr, bool DoFunctionPointerConverion, bool Complain, 7567 const SourceRange& OpRangeForComplaining, 7568 QualType DestTypeForComplaining, 7569 unsigned DiagIDForComplaining ) { 7570 7571 assert(SrcExpr->getType() == Context.OverloadTy); 7572 7573 DeclAccessPair Found; 7574 ExprResult SingleFunctionExpression; 7575 if (FunctionDecl* Fn = ResolveSingleFunctionTemplateSpecialization( 7576 SrcExpr, false, // false -> Complain 7577 &Found)) { 7578 if (!DiagnoseUseOfDecl(Fn, SrcExpr->getSourceRange().getBegin())) { 7579 // mark the expression as resolved to Fn 7580 SingleFunctionExpression = Owned(FixOverloadedFunctionReference(SrcExpr, 7581 Found, Fn)); 7582 if (DoFunctionPointerConverion) 7583 SingleFunctionExpression = 7584 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.take()); 7585 } 7586 } 7587 if (!SingleFunctionExpression.isUsable()) { 7588 if (Complain) { 7589 OverloadExpr* oe = OverloadExpr::find(SrcExpr).Expression; 7590 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) 7591 << oe->getName() << DestTypeForComplaining << OpRangeForComplaining 7592 << oe->getQualifierLoc().getSourceRange(); 7593 NoteAllOverloadCandidates(SrcExpr); 7594 } 7595 return ExprError(); 7596 } 7597 7598 return SingleFunctionExpression; 7599} 7600 7601/// \brief Add a single candidate to the overload set. 7602static void AddOverloadedCallCandidate(Sema &S, 7603 DeclAccessPair FoundDecl, 7604 TemplateArgumentListInfo *ExplicitTemplateArgs, 7605 Expr **Args, unsigned NumArgs, 7606 OverloadCandidateSet &CandidateSet, 7607 bool PartialOverloading) { 7608 NamedDecl *Callee = FoundDecl.getDecl(); 7609 if (isa<UsingShadowDecl>(Callee)) 7610 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 7611 7612 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 7613 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 7614 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 7615 false, PartialOverloading); 7616 return; 7617 } 7618 7619 if (FunctionTemplateDecl *FuncTemplate 7620 = dyn_cast<FunctionTemplateDecl>(Callee)) { 7621 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 7622 ExplicitTemplateArgs, 7623 Args, NumArgs, CandidateSet); 7624 return; 7625 } 7626 7627 assert(false && "unhandled case in overloaded call candidate"); 7628 7629 // do nothing? 7630} 7631 7632/// \brief Add the overload candidates named by callee and/or found by argument 7633/// dependent lookup to the given overload set. 7634void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 7635 Expr **Args, unsigned NumArgs, 7636 OverloadCandidateSet &CandidateSet, 7637 bool PartialOverloading) { 7638 7639#ifndef NDEBUG 7640 // Verify that ArgumentDependentLookup is consistent with the rules 7641 // in C++0x [basic.lookup.argdep]p3: 7642 // 7643 // Let X be the lookup set produced by unqualified lookup (3.4.1) 7644 // and let Y be the lookup set produced by argument dependent 7645 // lookup (defined as follows). If X contains 7646 // 7647 // -- a declaration of a class member, or 7648 // 7649 // -- a block-scope function declaration that is not a 7650 // using-declaration, or 7651 // 7652 // -- a declaration that is neither a function or a function 7653 // template 7654 // 7655 // then Y is empty. 7656 7657 if (ULE->requiresADL()) { 7658 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 7659 E = ULE->decls_end(); I != E; ++I) { 7660 assert(!(*I)->getDeclContext()->isRecord()); 7661 assert(isa<UsingShadowDecl>(*I) || 7662 !(*I)->getDeclContext()->isFunctionOrMethod()); 7663 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 7664 } 7665 } 7666#endif 7667 7668 // It would be nice to avoid this copy. 7669 TemplateArgumentListInfo TABuffer; 7670 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 7671 if (ULE->hasExplicitTemplateArgs()) { 7672 ULE->copyTemplateArgumentsInto(TABuffer); 7673 ExplicitTemplateArgs = &TABuffer; 7674 } 7675 7676 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 7677 E = ULE->decls_end(); I != E; ++I) 7678 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 7679 Args, NumArgs, CandidateSet, 7680 PartialOverloading); 7681 7682 if (ULE->requiresADL()) 7683 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 7684 Args, NumArgs, 7685 ExplicitTemplateArgs, 7686 CandidateSet, 7687 PartialOverloading); 7688} 7689 7690/// Attempts to recover from a call where no functions were found. 7691/// 7692/// Returns true if new candidates were found. 7693static ExprResult 7694BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 7695 UnresolvedLookupExpr *ULE, 7696 SourceLocation LParenLoc, 7697 Expr **Args, unsigned NumArgs, 7698 SourceLocation RParenLoc) { 7699 7700 CXXScopeSpec SS; 7701 SS.Adopt(ULE->getQualifierLoc()); 7702 7703 TemplateArgumentListInfo TABuffer; 7704 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 7705 if (ULE->hasExplicitTemplateArgs()) { 7706 ULE->copyTemplateArgumentsInto(TABuffer); 7707 ExplicitTemplateArgs = &TABuffer; 7708 } 7709 7710 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 7711 Sema::LookupOrdinaryName); 7712 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 7713 return ExprError(); 7714 7715 assert(!R.empty() && "lookup results empty despite recovery"); 7716 7717 // Build an implicit member call if appropriate. Just drop the 7718 // casts and such from the call, we don't really care. 7719 ExprResult NewFn = ExprError(); 7720 if ((*R.begin())->isCXXClassMember()) 7721 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, 7722 ExplicitTemplateArgs); 7723 else if (ExplicitTemplateArgs) 7724 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 7725 else 7726 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 7727 7728 if (NewFn.isInvalid()) 7729 return ExprError(); 7730 7731 // This shouldn't cause an infinite loop because we're giving it 7732 // an expression with non-empty lookup results, which should never 7733 // end up here. 7734 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 7735 MultiExprArg(Args, NumArgs), RParenLoc); 7736} 7737 7738/// ResolveOverloadedCallFn - Given the call expression that calls Fn 7739/// (which eventually refers to the declaration Func) and the call 7740/// arguments Args/NumArgs, attempt to resolve the function call down 7741/// to a specific function. If overload resolution succeeds, returns 7742/// the function declaration produced by overload 7743/// resolution. Otherwise, emits diagnostics, deletes all of the 7744/// arguments and Fn, and returns NULL. 7745ExprResult 7746Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 7747 SourceLocation LParenLoc, 7748 Expr **Args, unsigned NumArgs, 7749 SourceLocation RParenLoc, 7750 Expr *ExecConfig) { 7751#ifndef NDEBUG 7752 if (ULE->requiresADL()) { 7753 // To do ADL, we must have found an unqualified name. 7754 assert(!ULE->getQualifier() && "qualified name with ADL"); 7755 7756 // We don't perform ADL for implicit declarations of builtins. 7757 // Verify that this was correctly set up. 7758 FunctionDecl *F; 7759 if (ULE->decls_begin() + 1 == ULE->decls_end() && 7760 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 7761 F->getBuiltinID() && F->isImplicit()) 7762 assert(0 && "performing ADL for builtin"); 7763 7764 // We don't perform ADL in C. 7765 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 7766 } 7767#endif 7768 7769 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 7770 7771 // Add the functions denoted by the callee to the set of candidate 7772 // functions, including those from argument-dependent lookup. 7773 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 7774 7775 // If we found nothing, try to recover. 7776 // AddRecoveryCallCandidates diagnoses the error itself, so we just 7777 // bailout out if it fails. 7778 if (CandidateSet.empty()) 7779 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 7780 RParenLoc); 7781 7782 OverloadCandidateSet::iterator Best; 7783 switch (CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best)) { 7784 case OR_Success: { 7785 FunctionDecl *FDecl = Best->Function; 7786 MarkDeclarationReferenced(Fn->getExprLoc(), FDecl); 7787 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 7788 DiagnoseUseOfDecl(FDecl? FDecl : Best->FoundDecl.getDecl(), 7789 ULE->getNameLoc()); 7790 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 7791 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc, 7792 ExecConfig); 7793 } 7794 7795 case OR_No_Viable_Function: 7796 Diag(Fn->getSourceRange().getBegin(), 7797 diag::err_ovl_no_viable_function_in_call) 7798 << ULE->getName() << Fn->getSourceRange(); 7799 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7800 break; 7801 7802 case OR_Ambiguous: 7803 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 7804 << ULE->getName() << Fn->getSourceRange(); 7805 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 7806 break; 7807 7808 case OR_Deleted: 7809 { 7810 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 7811 << Best->Function->isDeleted() 7812 << ULE->getName() 7813 << getDeletedOrUnavailableSuffix(Best->Function) 7814 << Fn->getSourceRange(); 7815 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7816 } 7817 break; 7818 } 7819 7820 // Overload resolution failed. 7821 return ExprError(); 7822} 7823 7824static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 7825 return Functions.size() > 1 || 7826 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 7827} 7828 7829/// \brief Create a unary operation that may resolve to an overloaded 7830/// operator. 7831/// 7832/// \param OpLoc The location of the operator itself (e.g., '*'). 7833/// 7834/// \param OpcIn The UnaryOperator::Opcode that describes this 7835/// operator. 7836/// 7837/// \param Functions The set of non-member functions that will be 7838/// considered by overload resolution. The caller needs to build this 7839/// set based on the context using, e.g., 7840/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 7841/// set should not contain any member functions; those will be added 7842/// by CreateOverloadedUnaryOp(). 7843/// 7844/// \param input The input argument. 7845ExprResult 7846Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 7847 const UnresolvedSetImpl &Fns, 7848 Expr *Input) { 7849 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 7850 7851 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 7852 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 7853 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 7854 // TODO: provide better source location info. 7855 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 7856 7857 if (Input->getObjectKind() == OK_ObjCProperty) { 7858 ExprResult Result = ConvertPropertyForRValue(Input); 7859 if (Result.isInvalid()) 7860 return ExprError(); 7861 Input = Result.take(); 7862 } 7863 7864 Expr *Args[2] = { Input, 0 }; 7865 unsigned NumArgs = 1; 7866 7867 // For post-increment and post-decrement, add the implicit '0' as 7868 // the second argument, so that we know this is a post-increment or 7869 // post-decrement. 7870 if (Opc == UO_PostInc || Opc == UO_PostDec) { 7871 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 7872 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 7873 SourceLocation()); 7874 NumArgs = 2; 7875 } 7876 7877 if (Input->isTypeDependent()) { 7878 if (Fns.empty()) 7879 return Owned(new (Context) UnaryOperator(Input, 7880 Opc, 7881 Context.DependentTy, 7882 VK_RValue, OK_Ordinary, 7883 OpLoc)); 7884 7885 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7886 UnresolvedLookupExpr *Fn 7887 = UnresolvedLookupExpr::Create(Context, NamingClass, 7888 NestedNameSpecifierLoc(), OpNameInfo, 7889 /*ADL*/ true, IsOverloaded(Fns), 7890 Fns.begin(), Fns.end()); 7891 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 7892 &Args[0], NumArgs, 7893 Context.DependentTy, 7894 VK_RValue, 7895 OpLoc)); 7896 } 7897 7898 // Build an empty overload set. 7899 OverloadCandidateSet CandidateSet(OpLoc); 7900 7901 // Add the candidates from the given function set. 7902 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 7903 7904 // Add operator candidates that are member functions. 7905 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 7906 7907 // Add candidates from ADL. 7908 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 7909 Args, NumArgs, 7910 /*ExplicitTemplateArgs*/ 0, 7911 CandidateSet); 7912 7913 // Add builtin operator candidates. 7914 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 7915 7916 // Perform overload resolution. 7917 OverloadCandidateSet::iterator Best; 7918 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 7919 case OR_Success: { 7920 // We found a built-in operator or an overloaded operator. 7921 FunctionDecl *FnDecl = Best->Function; 7922 7923 if (FnDecl) { 7924 // We matched an overloaded operator. Build a call to that 7925 // operator. 7926 7927 MarkDeclarationReferenced(OpLoc, FnDecl); 7928 7929 // Convert the arguments. 7930 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 7931 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 7932 7933 ExprResult InputRes = 7934 PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 7935 Best->FoundDecl, Method); 7936 if (InputRes.isInvalid()) 7937 return ExprError(); 7938 Input = InputRes.take(); 7939 } else { 7940 // Convert the arguments. 7941 ExprResult InputInit 7942 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7943 Context, 7944 FnDecl->getParamDecl(0)), 7945 SourceLocation(), 7946 Input); 7947 if (InputInit.isInvalid()) 7948 return ExprError(); 7949 Input = InputInit.take(); 7950 } 7951 7952 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7953 7954 // Determine the result type. 7955 QualType ResultTy = FnDecl->getResultType(); 7956 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 7957 ResultTy = ResultTy.getNonLValueExprType(Context); 7958 7959 // Build the actual expression node. 7960 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl); 7961 if (FnExpr.isInvalid()) 7962 return ExprError(); 7963 7964 Args[0] = Input; 7965 CallExpr *TheCall = 7966 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 7967 Args, NumArgs, ResultTy, VK, OpLoc); 7968 7969 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 7970 FnDecl)) 7971 return ExprError(); 7972 7973 return MaybeBindToTemporary(TheCall); 7974 } else { 7975 // We matched a built-in operator. Convert the arguments, then 7976 // break out so that we will build the appropriate built-in 7977 // operator node. 7978 ExprResult InputRes = 7979 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 7980 Best->Conversions[0], AA_Passing); 7981 if (InputRes.isInvalid()) 7982 return ExprError(); 7983 Input = InputRes.take(); 7984 break; 7985 } 7986 } 7987 7988 case OR_No_Viable_Function: 7989 // No viable function; fall through to handling this as a 7990 // built-in operator, which will produce an error message for us. 7991 break; 7992 7993 case OR_Ambiguous: 7994 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 7995 << UnaryOperator::getOpcodeStr(Opc) 7996 << Input->getType() 7997 << Input->getSourceRange(); 7998 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 7999 Args, NumArgs, 8000 UnaryOperator::getOpcodeStr(Opc), OpLoc); 8001 return ExprError(); 8002 8003 case OR_Deleted: 8004 Diag(OpLoc, diag::err_ovl_deleted_oper) 8005 << Best->Function->isDeleted() 8006 << UnaryOperator::getOpcodeStr(Opc) 8007 << getDeletedOrUnavailableSuffix(Best->Function) 8008 << Input->getSourceRange(); 8009 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8010 return ExprError(); 8011 } 8012 8013 // Either we found no viable overloaded operator or we matched a 8014 // built-in operator. In either case, fall through to trying to 8015 // build a built-in operation. 8016 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 8017} 8018 8019/// \brief Create a binary operation that may resolve to an overloaded 8020/// operator. 8021/// 8022/// \param OpLoc The location of the operator itself (e.g., '+'). 8023/// 8024/// \param OpcIn The BinaryOperator::Opcode that describes this 8025/// operator. 8026/// 8027/// \param Functions The set of non-member functions that will be 8028/// considered by overload resolution. The caller needs to build this 8029/// set based on the context using, e.g., 8030/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 8031/// set should not contain any member functions; those will be added 8032/// by CreateOverloadedBinOp(). 8033/// 8034/// \param LHS Left-hand argument. 8035/// \param RHS Right-hand argument. 8036ExprResult 8037Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 8038 unsigned OpcIn, 8039 const UnresolvedSetImpl &Fns, 8040 Expr *LHS, Expr *RHS) { 8041 Expr *Args[2] = { LHS, RHS }; 8042 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 8043 8044 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 8045 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 8046 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 8047 8048 // If either side is type-dependent, create an appropriate dependent 8049 // expression. 8050 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 8051 if (Fns.empty()) { 8052 // If there are no functions to store, just build a dependent 8053 // BinaryOperator or CompoundAssignment. 8054 if (Opc <= BO_Assign || Opc > BO_OrAssign) 8055 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 8056 Context.DependentTy, 8057 VK_RValue, OK_Ordinary, 8058 OpLoc)); 8059 8060 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 8061 Context.DependentTy, 8062 VK_LValue, 8063 OK_Ordinary, 8064 Context.DependentTy, 8065 Context.DependentTy, 8066 OpLoc)); 8067 } 8068 8069 // FIXME: save results of ADL from here? 8070 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8071 // TODO: provide better source location info in DNLoc component. 8072 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 8073 UnresolvedLookupExpr *Fn 8074 = UnresolvedLookupExpr::Create(Context, NamingClass, 8075 NestedNameSpecifierLoc(), OpNameInfo, 8076 /*ADL*/ true, IsOverloaded(Fns), 8077 Fns.begin(), Fns.end()); 8078 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 8079 Args, 2, 8080 Context.DependentTy, 8081 VK_RValue, 8082 OpLoc)); 8083 } 8084 8085 // Always do property rvalue conversions on the RHS. 8086 if (Args[1]->getObjectKind() == OK_ObjCProperty) { 8087 ExprResult Result = ConvertPropertyForRValue(Args[1]); 8088 if (Result.isInvalid()) 8089 return ExprError(); 8090 Args[1] = Result.take(); 8091 } 8092 8093 // The LHS is more complicated. 8094 if (Args[0]->getObjectKind() == OK_ObjCProperty) { 8095 8096 // There's a tension for assignment operators between primitive 8097 // property assignment and the overloaded operators. 8098 if (BinaryOperator::isAssignmentOp(Opc)) { 8099 const ObjCPropertyRefExpr *PRE = LHS->getObjCProperty(); 8100 8101 // Is the property "logically" settable? 8102 bool Settable = (PRE->isExplicitProperty() || 8103 PRE->getImplicitPropertySetter()); 8104 8105 // To avoid gratuitously inventing semantics, use the primitive 8106 // unless it isn't. Thoughts in case we ever really care: 8107 // - If the property isn't logically settable, we have to 8108 // load and hope. 8109 // - If the property is settable and this is simple assignment, 8110 // we really should use the primitive. 8111 // - If the property is settable, then we could try overloading 8112 // on a generic lvalue of the appropriate type; if it works 8113 // out to a builtin candidate, we would do that same operation 8114 // on the property, and otherwise just error. 8115 if (Settable) 8116 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8117 } 8118 8119 ExprResult Result = ConvertPropertyForRValue(Args[0]); 8120 if (Result.isInvalid()) 8121 return ExprError(); 8122 Args[0] = Result.take(); 8123 } 8124 8125 // If this is the assignment operator, we only perform overload resolution 8126 // if the left-hand side is a class or enumeration type. This is actually 8127 // a hack. The standard requires that we do overload resolution between the 8128 // various built-in candidates, but as DR507 points out, this can lead to 8129 // problems. So we do it this way, which pretty much follows what GCC does. 8130 // Note that we go the traditional code path for compound assignment forms. 8131 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 8132 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8133 8134 // If this is the .* operator, which is not overloadable, just 8135 // create a built-in binary operator. 8136 if (Opc == BO_PtrMemD) 8137 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8138 8139 // Build an empty overload set. 8140 OverloadCandidateSet CandidateSet(OpLoc); 8141 8142 // Add the candidates from the given function set. 8143 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 8144 8145 // Add operator candidates that are member functions. 8146 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 8147 8148 // Add candidates from ADL. 8149 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 8150 Args, 2, 8151 /*ExplicitTemplateArgs*/ 0, 8152 CandidateSet); 8153 8154 // Add builtin operator candidates. 8155 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 8156 8157 // Perform overload resolution. 8158 OverloadCandidateSet::iterator Best; 8159 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8160 case OR_Success: { 8161 // We found a built-in operator or an overloaded operator. 8162 FunctionDecl *FnDecl = Best->Function; 8163 8164 if (FnDecl) { 8165 // We matched an overloaded operator. Build a call to that 8166 // operator. 8167 8168 MarkDeclarationReferenced(OpLoc, FnDecl); 8169 8170 // Convert the arguments. 8171 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 8172 // Best->Access is only meaningful for class members. 8173 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 8174 8175 ExprResult Arg1 = 8176 PerformCopyInitialization( 8177 InitializedEntity::InitializeParameter(Context, 8178 FnDecl->getParamDecl(0)), 8179 SourceLocation(), Owned(Args[1])); 8180 if (Arg1.isInvalid()) 8181 return ExprError(); 8182 8183 ExprResult Arg0 = 8184 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 8185 Best->FoundDecl, Method); 8186 if (Arg0.isInvalid()) 8187 return ExprError(); 8188 Args[0] = Arg0.takeAs<Expr>(); 8189 Args[1] = RHS = Arg1.takeAs<Expr>(); 8190 } else { 8191 // Convert the arguments. 8192 ExprResult Arg0 = PerformCopyInitialization( 8193 InitializedEntity::InitializeParameter(Context, 8194 FnDecl->getParamDecl(0)), 8195 SourceLocation(), Owned(Args[0])); 8196 if (Arg0.isInvalid()) 8197 return ExprError(); 8198 8199 ExprResult Arg1 = 8200 PerformCopyInitialization( 8201 InitializedEntity::InitializeParameter(Context, 8202 FnDecl->getParamDecl(1)), 8203 SourceLocation(), Owned(Args[1])); 8204 if (Arg1.isInvalid()) 8205 return ExprError(); 8206 Args[0] = LHS = Arg0.takeAs<Expr>(); 8207 Args[1] = RHS = Arg1.takeAs<Expr>(); 8208 } 8209 8210 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 8211 8212 // Determine the result type. 8213 QualType ResultTy = FnDecl->getResultType(); 8214 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8215 ResultTy = ResultTy.getNonLValueExprType(Context); 8216 8217 // Build the actual expression node. 8218 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, OpLoc); 8219 if (FnExpr.isInvalid()) 8220 return ExprError(); 8221 8222 CXXOperatorCallExpr *TheCall = 8223 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 8224 Args, 2, ResultTy, VK, OpLoc); 8225 8226 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 8227 FnDecl)) 8228 return ExprError(); 8229 8230 return MaybeBindToTemporary(TheCall); 8231 } else { 8232 // We matched a built-in operator. Convert the arguments, then 8233 // break out so that we will build the appropriate built-in 8234 // operator node. 8235 ExprResult ArgsRes0 = 8236 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 8237 Best->Conversions[0], AA_Passing); 8238 if (ArgsRes0.isInvalid()) 8239 return ExprError(); 8240 Args[0] = ArgsRes0.take(); 8241 8242 ExprResult ArgsRes1 = 8243 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 8244 Best->Conversions[1], AA_Passing); 8245 if (ArgsRes1.isInvalid()) 8246 return ExprError(); 8247 Args[1] = ArgsRes1.take(); 8248 break; 8249 } 8250 } 8251 8252 case OR_No_Viable_Function: { 8253 // C++ [over.match.oper]p9: 8254 // If the operator is the operator , [...] and there are no 8255 // viable functions, then the operator is assumed to be the 8256 // built-in operator and interpreted according to clause 5. 8257 if (Opc == BO_Comma) 8258 break; 8259 8260 // For class as left operand for assignment or compound assigment 8261 // operator do not fall through to handling in built-in, but report that 8262 // no overloaded assignment operator found 8263 ExprResult Result = ExprError(); 8264 if (Args[0]->getType()->isRecordType() && 8265 Opc >= BO_Assign && Opc <= BO_OrAssign) { 8266 Diag(OpLoc, diag::err_ovl_no_viable_oper) 8267 << BinaryOperator::getOpcodeStr(Opc) 8268 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8269 } else { 8270 // No viable function; try to create a built-in operation, which will 8271 // produce an error. Then, show the non-viable candidates. 8272 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8273 } 8274 assert(Result.isInvalid() && 8275 "C++ binary operator overloading is missing candidates!"); 8276 if (Result.isInvalid()) 8277 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8278 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8279 return move(Result); 8280 } 8281 8282 case OR_Ambiguous: 8283 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 8284 << BinaryOperator::getOpcodeStr(Opc) 8285 << Args[0]->getType() << Args[1]->getType() 8286 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8287 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 8288 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8289 return ExprError(); 8290 8291 case OR_Deleted: 8292 Diag(OpLoc, diag::err_ovl_deleted_oper) 8293 << Best->Function->isDeleted() 8294 << BinaryOperator::getOpcodeStr(Opc) 8295 << getDeletedOrUnavailableSuffix(Best->Function) 8296 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8297 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2); 8298 return ExprError(); 8299 } 8300 8301 // We matched a built-in operator; build it. 8302 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8303} 8304 8305ExprResult 8306Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 8307 SourceLocation RLoc, 8308 Expr *Base, Expr *Idx) { 8309 Expr *Args[2] = { Base, Idx }; 8310 DeclarationName OpName = 8311 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 8312 8313 // If either side is type-dependent, create an appropriate dependent 8314 // expression. 8315 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 8316 8317 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8318 // CHECKME: no 'operator' keyword? 8319 DeclarationNameInfo OpNameInfo(OpName, LLoc); 8320 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 8321 UnresolvedLookupExpr *Fn 8322 = UnresolvedLookupExpr::Create(Context, NamingClass, 8323 NestedNameSpecifierLoc(), OpNameInfo, 8324 /*ADL*/ true, /*Overloaded*/ false, 8325 UnresolvedSetIterator(), 8326 UnresolvedSetIterator()); 8327 // Can't add any actual overloads yet 8328 8329 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 8330 Args, 2, 8331 Context.DependentTy, 8332 VK_RValue, 8333 RLoc)); 8334 } 8335 8336 if (Args[0]->getObjectKind() == OK_ObjCProperty) { 8337 ExprResult Result = ConvertPropertyForRValue(Args[0]); 8338 if (Result.isInvalid()) 8339 return ExprError(); 8340 Args[0] = Result.take(); 8341 } 8342 if (Args[1]->getObjectKind() == OK_ObjCProperty) { 8343 ExprResult Result = ConvertPropertyForRValue(Args[1]); 8344 if (Result.isInvalid()) 8345 return ExprError(); 8346 Args[1] = Result.take(); 8347 } 8348 8349 // Build an empty overload set. 8350 OverloadCandidateSet CandidateSet(LLoc); 8351 8352 // Subscript can only be overloaded as a member function. 8353 8354 // Add operator candidates that are member functions. 8355 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 8356 8357 // Add builtin operator candidates. 8358 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 8359 8360 // Perform overload resolution. 8361 OverloadCandidateSet::iterator Best; 8362 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 8363 case OR_Success: { 8364 // We found a built-in operator or an overloaded operator. 8365 FunctionDecl *FnDecl = Best->Function; 8366 8367 if (FnDecl) { 8368 // We matched an overloaded operator. Build a call to that 8369 // operator. 8370 8371 MarkDeclarationReferenced(LLoc, FnDecl); 8372 8373 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 8374 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 8375 8376 // Convert the arguments. 8377 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 8378 ExprResult Arg0 = 8379 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 8380 Best->FoundDecl, Method); 8381 if (Arg0.isInvalid()) 8382 return ExprError(); 8383 Args[0] = Arg0.take(); 8384 8385 // Convert the arguments. 8386 ExprResult InputInit 8387 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8388 Context, 8389 FnDecl->getParamDecl(0)), 8390 SourceLocation(), 8391 Owned(Args[1])); 8392 if (InputInit.isInvalid()) 8393 return ExprError(); 8394 8395 Args[1] = InputInit.takeAs<Expr>(); 8396 8397 // Determine the result type 8398 QualType ResultTy = FnDecl->getResultType(); 8399 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8400 ResultTy = ResultTy.getNonLValueExprType(Context); 8401 8402 // Build the actual expression node. 8403 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, LLoc); 8404 if (FnExpr.isInvalid()) 8405 return ExprError(); 8406 8407 CXXOperatorCallExpr *TheCall = 8408 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 8409 FnExpr.take(), Args, 2, 8410 ResultTy, VK, RLoc); 8411 8412 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 8413 FnDecl)) 8414 return ExprError(); 8415 8416 return MaybeBindToTemporary(TheCall); 8417 } else { 8418 // We matched a built-in operator. Convert the arguments, then 8419 // break out so that we will build the appropriate built-in 8420 // operator node. 8421 ExprResult ArgsRes0 = 8422 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 8423 Best->Conversions[0], AA_Passing); 8424 if (ArgsRes0.isInvalid()) 8425 return ExprError(); 8426 Args[0] = ArgsRes0.take(); 8427 8428 ExprResult ArgsRes1 = 8429 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 8430 Best->Conversions[1], AA_Passing); 8431 if (ArgsRes1.isInvalid()) 8432 return ExprError(); 8433 Args[1] = ArgsRes1.take(); 8434 8435 break; 8436 } 8437 } 8438 8439 case OR_No_Viable_Function: { 8440 if (CandidateSet.empty()) 8441 Diag(LLoc, diag::err_ovl_no_oper) 8442 << Args[0]->getType() << /*subscript*/ 0 8443 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8444 else 8445 Diag(LLoc, diag::err_ovl_no_viable_subscript) 8446 << Args[0]->getType() 8447 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8448 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8449 "[]", LLoc); 8450 return ExprError(); 8451 } 8452 8453 case OR_Ambiguous: 8454 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 8455 << "[]" 8456 << Args[0]->getType() << Args[1]->getType() 8457 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8458 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 8459 "[]", LLoc); 8460 return ExprError(); 8461 8462 case OR_Deleted: 8463 Diag(LLoc, diag::err_ovl_deleted_oper) 8464 << Best->Function->isDeleted() << "[]" 8465 << getDeletedOrUnavailableSuffix(Best->Function) 8466 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8467 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8468 "[]", LLoc); 8469 return ExprError(); 8470 } 8471 8472 // We matched a built-in operator; build it. 8473 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 8474} 8475 8476/// BuildCallToMemberFunction - Build a call to a member 8477/// function. MemExpr is the expression that refers to the member 8478/// function (and includes the object parameter), Args/NumArgs are the 8479/// arguments to the function call (not including the object 8480/// parameter). The caller needs to validate that the member 8481/// expression refers to a member function or an overloaded member 8482/// function. 8483ExprResult 8484Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 8485 SourceLocation LParenLoc, Expr **Args, 8486 unsigned NumArgs, SourceLocation RParenLoc) { 8487 // Dig out the member expression. This holds both the object 8488 // argument and the member function we're referring to. 8489 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 8490 8491 MemberExpr *MemExpr; 8492 CXXMethodDecl *Method = 0; 8493 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 8494 NestedNameSpecifier *Qualifier = 0; 8495 if (isa<MemberExpr>(NakedMemExpr)) { 8496 MemExpr = cast<MemberExpr>(NakedMemExpr); 8497 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 8498 FoundDecl = MemExpr->getFoundDecl(); 8499 Qualifier = MemExpr->getQualifier(); 8500 } else { 8501 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 8502 Qualifier = UnresExpr->getQualifier(); 8503 8504 QualType ObjectType = UnresExpr->getBaseType(); 8505 Expr::Classification ObjectClassification 8506 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 8507 : UnresExpr->getBase()->Classify(Context); 8508 8509 // Add overload candidates 8510 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 8511 8512 // FIXME: avoid copy. 8513 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 8514 if (UnresExpr->hasExplicitTemplateArgs()) { 8515 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 8516 TemplateArgs = &TemplateArgsBuffer; 8517 } 8518 8519 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 8520 E = UnresExpr->decls_end(); I != E; ++I) { 8521 8522 NamedDecl *Func = *I; 8523 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 8524 if (isa<UsingShadowDecl>(Func)) 8525 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 8526 8527 8528 // Microsoft supports direct constructor calls. 8529 if (getLangOptions().Microsoft && isa<CXXConstructorDecl>(Func)) { 8530 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), Args, NumArgs, 8531 CandidateSet); 8532 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 8533 // If explicit template arguments were provided, we can't call a 8534 // non-template member function. 8535 if (TemplateArgs) 8536 continue; 8537 8538 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 8539 ObjectClassification, 8540 Args, NumArgs, CandidateSet, 8541 /*SuppressUserConversions=*/false); 8542 } else { 8543 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 8544 I.getPair(), ActingDC, TemplateArgs, 8545 ObjectType, ObjectClassification, 8546 Args, NumArgs, CandidateSet, 8547 /*SuppressUsedConversions=*/false); 8548 } 8549 } 8550 8551 DeclarationName DeclName = UnresExpr->getMemberName(); 8552 8553 OverloadCandidateSet::iterator Best; 8554 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 8555 Best)) { 8556 case OR_Success: 8557 Method = cast<CXXMethodDecl>(Best->Function); 8558 MarkDeclarationReferenced(UnresExpr->getMemberLoc(), Method); 8559 FoundDecl = Best->FoundDecl; 8560 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 8561 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 8562 break; 8563 8564 case OR_No_Viable_Function: 8565 Diag(UnresExpr->getMemberLoc(), 8566 diag::err_ovl_no_viable_member_function_in_call) 8567 << DeclName << MemExprE->getSourceRange(); 8568 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8569 // FIXME: Leaking incoming expressions! 8570 return ExprError(); 8571 8572 case OR_Ambiguous: 8573 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 8574 << DeclName << MemExprE->getSourceRange(); 8575 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8576 // FIXME: Leaking incoming expressions! 8577 return ExprError(); 8578 8579 case OR_Deleted: 8580 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 8581 << Best->Function->isDeleted() 8582 << DeclName 8583 << getDeletedOrUnavailableSuffix(Best->Function) 8584 << MemExprE->getSourceRange(); 8585 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8586 // FIXME: Leaking incoming expressions! 8587 return ExprError(); 8588 } 8589 8590 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 8591 8592 // If overload resolution picked a static member, build a 8593 // non-member call based on that function. 8594 if (Method->isStatic()) { 8595 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 8596 Args, NumArgs, RParenLoc); 8597 } 8598 8599 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 8600 } 8601 8602 QualType ResultType = Method->getResultType(); 8603 ExprValueKind VK = Expr::getValueKindForType(ResultType); 8604 ResultType = ResultType.getNonLValueExprType(Context); 8605 8606 assert(Method && "Member call to something that isn't a method?"); 8607 CXXMemberCallExpr *TheCall = 8608 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 8609 ResultType, VK, RParenLoc); 8610 8611 // Check for a valid return type. 8612 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 8613 TheCall, Method)) 8614 return ExprError(); 8615 8616 // Convert the object argument (for a non-static member function call). 8617 // We only need to do this if there was actually an overload; otherwise 8618 // it was done at lookup. 8619 if (!Method->isStatic()) { 8620 ExprResult ObjectArg = 8621 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier, 8622 FoundDecl, Method); 8623 if (ObjectArg.isInvalid()) 8624 return ExprError(); 8625 MemExpr->setBase(ObjectArg.take()); 8626 } 8627 8628 // Convert the rest of the arguments 8629 const FunctionProtoType *Proto = 8630 Method->getType()->getAs<FunctionProtoType>(); 8631 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 8632 RParenLoc)) 8633 return ExprError(); 8634 8635 if (CheckFunctionCall(Method, TheCall)) 8636 return ExprError(); 8637 8638 return MaybeBindToTemporary(TheCall); 8639} 8640 8641/// BuildCallToObjectOfClassType - Build a call to an object of class 8642/// type (C++ [over.call.object]), which can end up invoking an 8643/// overloaded function call operator (@c operator()) or performing a 8644/// user-defined conversion on the object argument. 8645ExprResult 8646Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj, 8647 SourceLocation LParenLoc, 8648 Expr **Args, unsigned NumArgs, 8649 SourceLocation RParenLoc) { 8650 ExprResult Object = Owned(Obj); 8651 if (Object.get()->getObjectKind() == OK_ObjCProperty) { 8652 Object = ConvertPropertyForRValue(Object.take()); 8653 if (Object.isInvalid()) 8654 return ExprError(); 8655 } 8656 8657 assert(Object.get()->getType()->isRecordType() && "Requires object type argument"); 8658 const RecordType *Record = Object.get()->getType()->getAs<RecordType>(); 8659 8660 // C++ [over.call.object]p1: 8661 // If the primary-expression E in the function call syntax 8662 // evaluates to a class object of type "cv T", then the set of 8663 // candidate functions includes at least the function call 8664 // operators of T. The function call operators of T are obtained by 8665 // ordinary lookup of the name operator() in the context of 8666 // (E).operator(). 8667 OverloadCandidateSet CandidateSet(LParenLoc); 8668 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 8669 8670 if (RequireCompleteType(LParenLoc, Object.get()->getType(), 8671 PDiag(diag::err_incomplete_object_call) 8672 << Object.get()->getSourceRange())) 8673 return true; 8674 8675 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 8676 LookupQualifiedName(R, Record->getDecl()); 8677 R.suppressDiagnostics(); 8678 8679 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 8680 Oper != OperEnd; ++Oper) { 8681 AddMethodCandidate(Oper.getPair(), Object.get()->getType(), 8682 Object.get()->Classify(Context), Args, NumArgs, CandidateSet, 8683 /*SuppressUserConversions=*/ false); 8684 } 8685 8686 // C++ [over.call.object]p2: 8687 // In addition, for each conversion function declared in T of the 8688 // form 8689 // 8690 // operator conversion-type-id () cv-qualifier; 8691 // 8692 // where cv-qualifier is the same cv-qualification as, or a 8693 // greater cv-qualification than, cv, and where conversion-type-id 8694 // denotes the type "pointer to function of (P1,...,Pn) returning 8695 // R", or the type "reference to pointer to function of 8696 // (P1,...,Pn) returning R", or the type "reference to function 8697 // of (P1,...,Pn) returning R", a surrogate call function [...] 8698 // is also considered as a candidate function. Similarly, 8699 // surrogate call functions are added to the set of candidate 8700 // functions for each conversion function declared in an 8701 // accessible base class provided the function is not hidden 8702 // within T by another intervening declaration. 8703 const UnresolvedSetImpl *Conversions 8704 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 8705 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 8706 E = Conversions->end(); I != E; ++I) { 8707 NamedDecl *D = *I; 8708 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 8709 if (isa<UsingShadowDecl>(D)) 8710 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 8711 8712 // Skip over templated conversion functions; they aren't 8713 // surrogates. 8714 if (isa<FunctionTemplateDecl>(D)) 8715 continue; 8716 8717 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 8718 8719 // Strip the reference type (if any) and then the pointer type (if 8720 // any) to get down to what might be a function type. 8721 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 8722 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 8723 ConvType = ConvPtrType->getPointeeType(); 8724 8725 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 8726 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 8727 Object.get(), Args, NumArgs, CandidateSet); 8728 } 8729 8730 // Perform overload resolution. 8731 OverloadCandidateSet::iterator Best; 8732 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(), 8733 Best)) { 8734 case OR_Success: 8735 // Overload resolution succeeded; we'll build the appropriate call 8736 // below. 8737 break; 8738 8739 case OR_No_Viable_Function: 8740 if (CandidateSet.empty()) 8741 Diag(Object.get()->getSourceRange().getBegin(), diag::err_ovl_no_oper) 8742 << Object.get()->getType() << /*call*/ 1 8743 << Object.get()->getSourceRange(); 8744 else 8745 Diag(Object.get()->getSourceRange().getBegin(), 8746 diag::err_ovl_no_viable_object_call) 8747 << Object.get()->getType() << Object.get()->getSourceRange(); 8748 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8749 break; 8750 8751 case OR_Ambiguous: 8752 Diag(Object.get()->getSourceRange().getBegin(), 8753 diag::err_ovl_ambiguous_object_call) 8754 << Object.get()->getType() << Object.get()->getSourceRange(); 8755 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 8756 break; 8757 8758 case OR_Deleted: 8759 Diag(Object.get()->getSourceRange().getBegin(), 8760 diag::err_ovl_deleted_object_call) 8761 << Best->Function->isDeleted() 8762 << Object.get()->getType() 8763 << getDeletedOrUnavailableSuffix(Best->Function) 8764 << Object.get()->getSourceRange(); 8765 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8766 break; 8767 } 8768 8769 if (Best == CandidateSet.end()) 8770 return true; 8771 8772 if (Best->Function == 0) { 8773 // Since there is no function declaration, this is one of the 8774 // surrogate candidates. Dig out the conversion function. 8775 CXXConversionDecl *Conv 8776 = cast<CXXConversionDecl>( 8777 Best->Conversions[0].UserDefined.ConversionFunction); 8778 8779 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 8780 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 8781 8782 // We selected one of the surrogate functions that converts the 8783 // object parameter to a function pointer. Perform the conversion 8784 // on the object argument, then let ActOnCallExpr finish the job. 8785 8786 // Create an implicit member expr to refer to the conversion operator. 8787 // and then call it. 8788 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl, Conv); 8789 if (Call.isInvalid()) 8790 return ExprError(); 8791 8792 return ActOnCallExpr(S, Call.get(), LParenLoc, MultiExprArg(Args, NumArgs), 8793 RParenLoc); 8794 } 8795 8796 MarkDeclarationReferenced(LParenLoc, Best->Function); 8797 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 8798 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 8799 8800 // We found an overloaded operator(). Build a CXXOperatorCallExpr 8801 // that calls this method, using Object for the implicit object 8802 // parameter and passing along the remaining arguments. 8803 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 8804 const FunctionProtoType *Proto = 8805 Method->getType()->getAs<FunctionProtoType>(); 8806 8807 unsigned NumArgsInProto = Proto->getNumArgs(); 8808 unsigned NumArgsToCheck = NumArgs; 8809 8810 // Build the full argument list for the method call (the 8811 // implicit object parameter is placed at the beginning of the 8812 // list). 8813 Expr **MethodArgs; 8814 if (NumArgs < NumArgsInProto) { 8815 NumArgsToCheck = NumArgsInProto; 8816 MethodArgs = new Expr*[NumArgsInProto + 1]; 8817 } else { 8818 MethodArgs = new Expr*[NumArgs + 1]; 8819 } 8820 MethodArgs[0] = Object.get(); 8821 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 8822 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 8823 8824 ExprResult NewFn = CreateFunctionRefExpr(*this, Method); 8825 if (NewFn.isInvalid()) 8826 return true; 8827 8828 // Once we've built TheCall, all of the expressions are properly 8829 // owned. 8830 QualType ResultTy = Method->getResultType(); 8831 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8832 ResultTy = ResultTy.getNonLValueExprType(Context); 8833 8834 CXXOperatorCallExpr *TheCall = 8835 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn.take(), 8836 MethodArgs, NumArgs + 1, 8837 ResultTy, VK, RParenLoc); 8838 delete [] MethodArgs; 8839 8840 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 8841 Method)) 8842 return true; 8843 8844 // We may have default arguments. If so, we need to allocate more 8845 // slots in the call for them. 8846 if (NumArgs < NumArgsInProto) 8847 TheCall->setNumArgs(Context, NumArgsInProto + 1); 8848 else if (NumArgs > NumArgsInProto) 8849 NumArgsToCheck = NumArgsInProto; 8850 8851 bool IsError = false; 8852 8853 // Initialize the implicit object parameter. 8854 ExprResult ObjRes = 8855 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/0, 8856 Best->FoundDecl, Method); 8857 if (ObjRes.isInvalid()) 8858 IsError = true; 8859 else 8860 Object = move(ObjRes); 8861 TheCall->setArg(0, Object.take()); 8862 8863 // Check the argument types. 8864 for (unsigned i = 0; i != NumArgsToCheck; i++) { 8865 Expr *Arg; 8866 if (i < NumArgs) { 8867 Arg = Args[i]; 8868 8869 // Pass the argument. 8870 8871 ExprResult InputInit 8872 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8873 Context, 8874 Method->getParamDecl(i)), 8875 SourceLocation(), Arg); 8876 8877 IsError |= InputInit.isInvalid(); 8878 Arg = InputInit.takeAs<Expr>(); 8879 } else { 8880 ExprResult DefArg 8881 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 8882 if (DefArg.isInvalid()) { 8883 IsError = true; 8884 break; 8885 } 8886 8887 Arg = DefArg.takeAs<Expr>(); 8888 } 8889 8890 TheCall->setArg(i + 1, Arg); 8891 } 8892 8893 // If this is a variadic call, handle args passed through "...". 8894 if (Proto->isVariadic()) { 8895 // Promote the arguments (C99 6.5.2.2p7). 8896 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 8897 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod, 0); 8898 IsError |= Arg.isInvalid(); 8899 TheCall->setArg(i + 1, Arg.take()); 8900 } 8901 } 8902 8903 if (IsError) return true; 8904 8905 if (CheckFunctionCall(Method, TheCall)) 8906 return true; 8907 8908 return MaybeBindToTemporary(TheCall); 8909} 8910 8911/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 8912/// (if one exists), where @c Base is an expression of class type and 8913/// @c Member is the name of the member we're trying to find. 8914ExprResult 8915Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 8916 assert(Base->getType()->isRecordType() && 8917 "left-hand side must have class type"); 8918 8919 if (Base->getObjectKind() == OK_ObjCProperty) { 8920 ExprResult Result = ConvertPropertyForRValue(Base); 8921 if (Result.isInvalid()) 8922 return ExprError(); 8923 Base = Result.take(); 8924 } 8925 8926 SourceLocation Loc = Base->getExprLoc(); 8927 8928 // C++ [over.ref]p1: 8929 // 8930 // [...] An expression x->m is interpreted as (x.operator->())->m 8931 // for a class object x of type T if T::operator->() exists and if 8932 // the operator is selected as the best match function by the 8933 // overload resolution mechanism (13.3). 8934 DeclarationName OpName = 8935 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 8936 OverloadCandidateSet CandidateSet(Loc); 8937 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 8938 8939 if (RequireCompleteType(Loc, Base->getType(), 8940 PDiag(diag::err_typecheck_incomplete_tag) 8941 << Base->getSourceRange())) 8942 return ExprError(); 8943 8944 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 8945 LookupQualifiedName(R, BaseRecord->getDecl()); 8946 R.suppressDiagnostics(); 8947 8948 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 8949 Oper != OperEnd; ++Oper) { 8950 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 8951 0, 0, CandidateSet, /*SuppressUserConversions=*/false); 8952 } 8953 8954 // Perform overload resolution. 8955 OverloadCandidateSet::iterator Best; 8956 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8957 case OR_Success: 8958 // Overload resolution succeeded; we'll build the call below. 8959 break; 8960 8961 case OR_No_Viable_Function: 8962 if (CandidateSet.empty()) 8963 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 8964 << Base->getType() << Base->getSourceRange(); 8965 else 8966 Diag(OpLoc, diag::err_ovl_no_viable_oper) 8967 << "operator->" << Base->getSourceRange(); 8968 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 8969 return ExprError(); 8970 8971 case OR_Ambiguous: 8972 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 8973 << "->" << Base->getType() << Base->getSourceRange(); 8974 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, &Base, 1); 8975 return ExprError(); 8976 8977 case OR_Deleted: 8978 Diag(OpLoc, diag::err_ovl_deleted_oper) 8979 << Best->Function->isDeleted() 8980 << "->" 8981 << getDeletedOrUnavailableSuffix(Best->Function) 8982 << Base->getSourceRange(); 8983 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 8984 return ExprError(); 8985 } 8986 8987 MarkDeclarationReferenced(OpLoc, Best->Function); 8988 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 8989 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 8990 8991 // Convert the object parameter. 8992 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 8993 ExprResult BaseResult = 8994 PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 8995 Best->FoundDecl, Method); 8996 if (BaseResult.isInvalid()) 8997 return ExprError(); 8998 Base = BaseResult.take(); 8999 9000 // Build the operator call. 9001 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method); 9002 if (FnExpr.isInvalid()) 9003 return ExprError(); 9004 9005 QualType ResultTy = Method->getResultType(); 9006 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 9007 ResultTy = ResultTy.getNonLValueExprType(Context); 9008 CXXOperatorCallExpr *TheCall = 9009 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.take(), 9010 &Base, 1, ResultTy, VK, OpLoc); 9011 9012 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 9013 Method)) 9014 return ExprError(); 9015 9016 return MaybeBindToTemporary(TheCall); 9017} 9018 9019/// FixOverloadedFunctionReference - E is an expression that refers to 9020/// a C++ overloaded function (possibly with some parentheses and 9021/// perhaps a '&' around it). We have resolved the overloaded function 9022/// to the function declaration Fn, so patch up the expression E to 9023/// refer (possibly indirectly) to Fn. Returns the new expr. 9024Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 9025 FunctionDecl *Fn) { 9026 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 9027 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 9028 Found, Fn); 9029 if (SubExpr == PE->getSubExpr()) 9030 return PE; 9031 9032 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 9033 } 9034 9035 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 9036 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 9037 Found, Fn); 9038 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 9039 SubExpr->getType()) && 9040 "Implicit cast type cannot be determined from overload"); 9041 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 9042 if (SubExpr == ICE->getSubExpr()) 9043 return ICE; 9044 9045 return ImplicitCastExpr::Create(Context, ICE->getType(), 9046 ICE->getCastKind(), 9047 SubExpr, 0, 9048 ICE->getValueKind()); 9049 } 9050 9051 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 9052 assert(UnOp->getOpcode() == UO_AddrOf && 9053 "Can only take the address of an overloaded function"); 9054 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 9055 if (Method->isStatic()) { 9056 // Do nothing: static member functions aren't any different 9057 // from non-member functions. 9058 } else { 9059 // Fix the sub expression, which really has to be an 9060 // UnresolvedLookupExpr holding an overloaded member function 9061 // or template. 9062 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 9063 Found, Fn); 9064 if (SubExpr == UnOp->getSubExpr()) 9065 return UnOp; 9066 9067 assert(isa<DeclRefExpr>(SubExpr) 9068 && "fixed to something other than a decl ref"); 9069 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 9070 && "fixed to a member ref with no nested name qualifier"); 9071 9072 // We have taken the address of a pointer to member 9073 // function. Perform the computation here so that we get the 9074 // appropriate pointer to member type. 9075 QualType ClassType 9076 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 9077 QualType MemPtrType 9078 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 9079 9080 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 9081 VK_RValue, OK_Ordinary, 9082 UnOp->getOperatorLoc()); 9083 } 9084 } 9085 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 9086 Found, Fn); 9087 if (SubExpr == UnOp->getSubExpr()) 9088 return UnOp; 9089 9090 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 9091 Context.getPointerType(SubExpr->getType()), 9092 VK_RValue, OK_Ordinary, 9093 UnOp->getOperatorLoc()); 9094 } 9095 9096 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 9097 // FIXME: avoid copy. 9098 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 9099 if (ULE->hasExplicitTemplateArgs()) { 9100 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 9101 TemplateArgs = &TemplateArgsBuffer; 9102 } 9103 9104 return DeclRefExpr::Create(Context, 9105 ULE->getQualifierLoc(), 9106 Fn, 9107 ULE->getNameLoc(), 9108 Fn->getType(), 9109 VK_LValue, 9110 TemplateArgs); 9111 } 9112 9113 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 9114 // FIXME: avoid copy. 9115 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 9116 if (MemExpr->hasExplicitTemplateArgs()) { 9117 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 9118 TemplateArgs = &TemplateArgsBuffer; 9119 } 9120 9121 Expr *Base; 9122 9123 // If we're filling in a static method where we used to have an 9124 // implicit member access, rewrite to a simple decl ref. 9125 if (MemExpr->isImplicitAccess()) { 9126 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 9127 return DeclRefExpr::Create(Context, 9128 MemExpr->getQualifierLoc(), 9129 Fn, 9130 MemExpr->getMemberLoc(), 9131 Fn->getType(), 9132 VK_LValue, 9133 TemplateArgs); 9134 } else { 9135 SourceLocation Loc = MemExpr->getMemberLoc(); 9136 if (MemExpr->getQualifier()) 9137 Loc = MemExpr->getQualifierLoc().getBeginLoc(); 9138 Base = new (Context) CXXThisExpr(Loc, 9139 MemExpr->getBaseType(), 9140 /*isImplicit=*/true); 9141 } 9142 } else 9143 Base = MemExpr->getBase(); 9144 9145 return MemberExpr::Create(Context, Base, 9146 MemExpr->isArrow(), 9147 MemExpr->getQualifierLoc(), 9148 Fn, 9149 Found, 9150 MemExpr->getMemberNameInfo(), 9151 TemplateArgs, 9152 Fn->getType(), 9153 cast<CXXMethodDecl>(Fn)->isStatic() 9154 ? VK_LValue : VK_RValue, 9155 OK_Ordinary); 9156 } 9157 9158 llvm_unreachable("Invalid reference to overloaded function"); 9159 return E; 9160} 9161 9162ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 9163 DeclAccessPair Found, 9164 FunctionDecl *Fn) { 9165 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 9166} 9167 9168} // end namespace clang 9169