SemaOverload.cpp revision 569bd8f4269df71b2176da940149aa5a959ae25d
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Sema/SemaInternal.h" 15#include "clang/Sema/Lookup.h" 16#include "clang/Sema/Initialization.h" 17#include "clang/Sema/Template.h" 18#include "clang/Sema/TemplateDeduction.h" 19#include "clang/Basic/Diagnostic.h" 20#include "clang/Lex/Preprocessor.h" 21#include "clang/AST/ASTContext.h" 22#include "clang/AST/CXXInheritance.h" 23#include "clang/AST/DeclObjC.h" 24#include "clang/AST/Expr.h" 25#include "clang/AST/ExprCXX.h" 26#include "clang/AST/ExprObjC.h" 27#include "clang/AST/TypeOrdering.h" 28#include "clang/Basic/PartialDiagnostic.h" 29#include "llvm/ADT/DenseSet.h" 30#include "llvm/ADT/SmallPtrSet.h" 31#include "llvm/ADT/STLExtras.h" 32#include <algorithm> 33 34namespace clang { 35using namespace sema; 36 37/// A convenience routine for creating a decayed reference to a 38/// function. 39static Expr * 40CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, 41 SourceLocation Loc = SourceLocation()) { 42 Expr *E = new (S.Context) DeclRefExpr(Fn, Fn->getType(), VK_LValue, Loc); 43 S.DefaultFunctionArrayConversion(E); 44 return E; 45} 46 47static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 48 bool InOverloadResolution, 49 StandardConversionSequence &SCS, 50 bool CStyle); 51static OverloadingResult 52IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 53 UserDefinedConversionSequence& User, 54 OverloadCandidateSet& Conversions, 55 bool AllowExplicit); 56 57 58static ImplicitConversionSequence::CompareKind 59CompareStandardConversionSequences(Sema &S, 60 const StandardConversionSequence& SCS1, 61 const StandardConversionSequence& SCS2); 62 63static ImplicitConversionSequence::CompareKind 64CompareQualificationConversions(Sema &S, 65 const StandardConversionSequence& SCS1, 66 const StandardConversionSequence& SCS2); 67 68static ImplicitConversionSequence::CompareKind 69CompareDerivedToBaseConversions(Sema &S, 70 const StandardConversionSequence& SCS1, 71 const StandardConversionSequence& SCS2); 72 73 74 75/// GetConversionCategory - Retrieve the implicit conversion 76/// category corresponding to the given implicit conversion kind. 77ImplicitConversionCategory 78GetConversionCategory(ImplicitConversionKind Kind) { 79 static const ImplicitConversionCategory 80 Category[(int)ICK_Num_Conversion_Kinds] = { 81 ICC_Identity, 82 ICC_Lvalue_Transformation, 83 ICC_Lvalue_Transformation, 84 ICC_Lvalue_Transformation, 85 ICC_Identity, 86 ICC_Qualification_Adjustment, 87 ICC_Promotion, 88 ICC_Promotion, 89 ICC_Promotion, 90 ICC_Conversion, 91 ICC_Conversion, 92 ICC_Conversion, 93 ICC_Conversion, 94 ICC_Conversion, 95 ICC_Conversion, 96 ICC_Conversion, 97 ICC_Conversion, 98 ICC_Conversion, 99 ICC_Conversion, 100 ICC_Conversion, 101 ICC_Conversion 102 }; 103 return Category[(int)Kind]; 104} 105 106/// GetConversionRank - Retrieve the implicit conversion rank 107/// corresponding to the given implicit conversion kind. 108ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 109 static const ImplicitConversionRank 110 Rank[(int)ICK_Num_Conversion_Kinds] = { 111 ICR_Exact_Match, 112 ICR_Exact_Match, 113 ICR_Exact_Match, 114 ICR_Exact_Match, 115 ICR_Exact_Match, 116 ICR_Exact_Match, 117 ICR_Promotion, 118 ICR_Promotion, 119 ICR_Promotion, 120 ICR_Conversion, 121 ICR_Conversion, 122 ICR_Conversion, 123 ICR_Conversion, 124 ICR_Conversion, 125 ICR_Conversion, 126 ICR_Conversion, 127 ICR_Conversion, 128 ICR_Conversion, 129 ICR_Conversion, 130 ICR_Conversion, 131 ICR_Complex_Real_Conversion 132 }; 133 return Rank[(int)Kind]; 134} 135 136/// GetImplicitConversionName - Return the name of this kind of 137/// implicit conversion. 138const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 139 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 140 "No conversion", 141 "Lvalue-to-rvalue", 142 "Array-to-pointer", 143 "Function-to-pointer", 144 "Noreturn adjustment", 145 "Qualification", 146 "Integral promotion", 147 "Floating point promotion", 148 "Complex promotion", 149 "Integral conversion", 150 "Floating conversion", 151 "Complex conversion", 152 "Floating-integral conversion", 153 "Pointer conversion", 154 "Pointer-to-member conversion", 155 "Boolean conversion", 156 "Compatible-types conversion", 157 "Derived-to-base conversion", 158 "Vector conversion", 159 "Vector splat", 160 "Complex-real conversion" 161 }; 162 return Name[Kind]; 163} 164 165/// StandardConversionSequence - Set the standard conversion 166/// sequence to the identity conversion. 167void StandardConversionSequence::setAsIdentityConversion() { 168 First = ICK_Identity; 169 Second = ICK_Identity; 170 Third = ICK_Identity; 171 DeprecatedStringLiteralToCharPtr = false; 172 ReferenceBinding = false; 173 DirectBinding = false; 174 IsLvalueReference = true; 175 BindsToFunctionLvalue = false; 176 BindsToRvalue = false; 177 BindsImplicitObjectArgumentWithoutRefQualifier = false; 178 CopyConstructor = 0; 179} 180 181/// getRank - Retrieve the rank of this standard conversion sequence 182/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 183/// implicit conversions. 184ImplicitConversionRank StandardConversionSequence::getRank() const { 185 ImplicitConversionRank Rank = ICR_Exact_Match; 186 if (GetConversionRank(First) > Rank) 187 Rank = GetConversionRank(First); 188 if (GetConversionRank(Second) > Rank) 189 Rank = GetConversionRank(Second); 190 if (GetConversionRank(Third) > Rank) 191 Rank = GetConversionRank(Third); 192 return Rank; 193} 194 195/// isPointerConversionToBool - Determines whether this conversion is 196/// a conversion of a pointer or pointer-to-member to bool. This is 197/// used as part of the ranking of standard conversion sequences 198/// (C++ 13.3.3.2p4). 199bool StandardConversionSequence::isPointerConversionToBool() const { 200 // Note that FromType has not necessarily been transformed by the 201 // array-to-pointer or function-to-pointer implicit conversions, so 202 // check for their presence as well as checking whether FromType is 203 // a pointer. 204 if (getToType(1)->isBooleanType() && 205 (getFromType()->isPointerType() || 206 getFromType()->isObjCObjectPointerType() || 207 getFromType()->isBlockPointerType() || 208 getFromType()->isNullPtrType() || 209 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 210 return true; 211 212 return false; 213} 214 215/// isPointerConversionToVoidPointer - Determines whether this 216/// conversion is a conversion of a pointer to a void pointer. This is 217/// used as part of the ranking of standard conversion sequences (C++ 218/// 13.3.3.2p4). 219bool 220StandardConversionSequence:: 221isPointerConversionToVoidPointer(ASTContext& Context) const { 222 QualType FromType = getFromType(); 223 QualType ToType = getToType(1); 224 225 // Note that FromType has not necessarily been transformed by the 226 // array-to-pointer implicit conversion, so check for its presence 227 // and redo the conversion to get a pointer. 228 if (First == ICK_Array_To_Pointer) 229 FromType = Context.getArrayDecayedType(FromType); 230 231 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 232 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 233 return ToPtrType->getPointeeType()->isVoidType(); 234 235 return false; 236} 237 238/// DebugPrint - Print this standard conversion sequence to standard 239/// error. Useful for debugging overloading issues. 240void StandardConversionSequence::DebugPrint() const { 241 llvm::raw_ostream &OS = llvm::errs(); 242 bool PrintedSomething = false; 243 if (First != ICK_Identity) { 244 OS << GetImplicitConversionName(First); 245 PrintedSomething = true; 246 } 247 248 if (Second != ICK_Identity) { 249 if (PrintedSomething) { 250 OS << " -> "; 251 } 252 OS << GetImplicitConversionName(Second); 253 254 if (CopyConstructor) { 255 OS << " (by copy constructor)"; 256 } else if (DirectBinding) { 257 OS << " (direct reference binding)"; 258 } else if (ReferenceBinding) { 259 OS << " (reference binding)"; 260 } 261 PrintedSomething = true; 262 } 263 264 if (Third != ICK_Identity) { 265 if (PrintedSomething) { 266 OS << " -> "; 267 } 268 OS << GetImplicitConversionName(Third); 269 PrintedSomething = true; 270 } 271 272 if (!PrintedSomething) { 273 OS << "No conversions required"; 274 } 275} 276 277/// DebugPrint - Print this user-defined conversion sequence to standard 278/// error. Useful for debugging overloading issues. 279void UserDefinedConversionSequence::DebugPrint() const { 280 llvm::raw_ostream &OS = llvm::errs(); 281 if (Before.First || Before.Second || Before.Third) { 282 Before.DebugPrint(); 283 OS << " -> "; 284 } 285 OS << '\'' << ConversionFunction << '\''; 286 if (After.First || After.Second || After.Third) { 287 OS << " -> "; 288 After.DebugPrint(); 289 } 290} 291 292/// DebugPrint - Print this implicit conversion sequence to standard 293/// error. Useful for debugging overloading issues. 294void ImplicitConversionSequence::DebugPrint() const { 295 llvm::raw_ostream &OS = llvm::errs(); 296 switch (ConversionKind) { 297 case StandardConversion: 298 OS << "Standard conversion: "; 299 Standard.DebugPrint(); 300 break; 301 case UserDefinedConversion: 302 OS << "User-defined conversion: "; 303 UserDefined.DebugPrint(); 304 break; 305 case EllipsisConversion: 306 OS << "Ellipsis conversion"; 307 break; 308 case AmbiguousConversion: 309 OS << "Ambiguous conversion"; 310 break; 311 case BadConversion: 312 OS << "Bad conversion"; 313 break; 314 } 315 316 OS << "\n"; 317} 318 319void AmbiguousConversionSequence::construct() { 320 new (&conversions()) ConversionSet(); 321} 322 323void AmbiguousConversionSequence::destruct() { 324 conversions().~ConversionSet(); 325} 326 327void 328AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 329 FromTypePtr = O.FromTypePtr; 330 ToTypePtr = O.ToTypePtr; 331 new (&conversions()) ConversionSet(O.conversions()); 332} 333 334namespace { 335 // Structure used by OverloadCandidate::DeductionFailureInfo to store 336 // template parameter and template argument information. 337 struct DFIParamWithArguments { 338 TemplateParameter Param; 339 TemplateArgument FirstArg; 340 TemplateArgument SecondArg; 341 }; 342} 343 344/// \brief Convert from Sema's representation of template deduction information 345/// to the form used in overload-candidate information. 346OverloadCandidate::DeductionFailureInfo 347static MakeDeductionFailureInfo(ASTContext &Context, 348 Sema::TemplateDeductionResult TDK, 349 TemplateDeductionInfo &Info) { 350 OverloadCandidate::DeductionFailureInfo Result; 351 Result.Result = static_cast<unsigned>(TDK); 352 Result.Data = 0; 353 switch (TDK) { 354 case Sema::TDK_Success: 355 case Sema::TDK_InstantiationDepth: 356 case Sema::TDK_TooManyArguments: 357 case Sema::TDK_TooFewArguments: 358 break; 359 360 case Sema::TDK_Incomplete: 361 case Sema::TDK_InvalidExplicitArguments: 362 Result.Data = Info.Param.getOpaqueValue(); 363 break; 364 365 case Sema::TDK_Inconsistent: 366 case Sema::TDK_Underqualified: { 367 // FIXME: Should allocate from normal heap so that we can free this later. 368 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 369 Saved->Param = Info.Param; 370 Saved->FirstArg = Info.FirstArg; 371 Saved->SecondArg = Info.SecondArg; 372 Result.Data = Saved; 373 break; 374 } 375 376 case Sema::TDK_SubstitutionFailure: 377 Result.Data = Info.take(); 378 break; 379 380 case Sema::TDK_NonDeducedMismatch: 381 case Sema::TDK_FailedOverloadResolution: 382 break; 383 } 384 385 return Result; 386} 387 388void OverloadCandidate::DeductionFailureInfo::Destroy() { 389 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 390 case Sema::TDK_Success: 391 case Sema::TDK_InstantiationDepth: 392 case Sema::TDK_Incomplete: 393 case Sema::TDK_TooManyArguments: 394 case Sema::TDK_TooFewArguments: 395 case Sema::TDK_InvalidExplicitArguments: 396 break; 397 398 case Sema::TDK_Inconsistent: 399 case Sema::TDK_Underqualified: 400 // FIXME: Destroy the data? 401 Data = 0; 402 break; 403 404 case Sema::TDK_SubstitutionFailure: 405 // FIXME: Destroy the template arugment list? 406 Data = 0; 407 break; 408 409 // Unhandled 410 case Sema::TDK_NonDeducedMismatch: 411 case Sema::TDK_FailedOverloadResolution: 412 break; 413 } 414} 415 416TemplateParameter 417OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 418 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 419 case Sema::TDK_Success: 420 case Sema::TDK_InstantiationDepth: 421 case Sema::TDK_TooManyArguments: 422 case Sema::TDK_TooFewArguments: 423 case Sema::TDK_SubstitutionFailure: 424 return TemplateParameter(); 425 426 case Sema::TDK_Incomplete: 427 case Sema::TDK_InvalidExplicitArguments: 428 return TemplateParameter::getFromOpaqueValue(Data); 429 430 case Sema::TDK_Inconsistent: 431 case Sema::TDK_Underqualified: 432 return static_cast<DFIParamWithArguments*>(Data)->Param; 433 434 // Unhandled 435 case Sema::TDK_NonDeducedMismatch: 436 case Sema::TDK_FailedOverloadResolution: 437 break; 438 } 439 440 return TemplateParameter(); 441} 442 443TemplateArgumentList * 444OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 445 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 446 case Sema::TDK_Success: 447 case Sema::TDK_InstantiationDepth: 448 case Sema::TDK_TooManyArguments: 449 case Sema::TDK_TooFewArguments: 450 case Sema::TDK_Incomplete: 451 case Sema::TDK_InvalidExplicitArguments: 452 case Sema::TDK_Inconsistent: 453 case Sema::TDK_Underqualified: 454 return 0; 455 456 case Sema::TDK_SubstitutionFailure: 457 return static_cast<TemplateArgumentList*>(Data); 458 459 // Unhandled 460 case Sema::TDK_NonDeducedMismatch: 461 case Sema::TDK_FailedOverloadResolution: 462 break; 463 } 464 465 return 0; 466} 467 468const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 469 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 470 case Sema::TDK_Success: 471 case Sema::TDK_InstantiationDepth: 472 case Sema::TDK_Incomplete: 473 case Sema::TDK_TooManyArguments: 474 case Sema::TDK_TooFewArguments: 475 case Sema::TDK_InvalidExplicitArguments: 476 case Sema::TDK_SubstitutionFailure: 477 return 0; 478 479 case Sema::TDK_Inconsistent: 480 case Sema::TDK_Underqualified: 481 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 482 483 // Unhandled 484 case Sema::TDK_NonDeducedMismatch: 485 case Sema::TDK_FailedOverloadResolution: 486 break; 487 } 488 489 return 0; 490} 491 492const TemplateArgument * 493OverloadCandidate::DeductionFailureInfo::getSecondArg() { 494 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 495 case Sema::TDK_Success: 496 case Sema::TDK_InstantiationDepth: 497 case Sema::TDK_Incomplete: 498 case Sema::TDK_TooManyArguments: 499 case Sema::TDK_TooFewArguments: 500 case Sema::TDK_InvalidExplicitArguments: 501 case Sema::TDK_SubstitutionFailure: 502 return 0; 503 504 case Sema::TDK_Inconsistent: 505 case Sema::TDK_Underqualified: 506 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 507 508 // Unhandled 509 case Sema::TDK_NonDeducedMismatch: 510 case Sema::TDK_FailedOverloadResolution: 511 break; 512 } 513 514 return 0; 515} 516 517void OverloadCandidateSet::clear() { 518 inherited::clear(); 519 Functions.clear(); 520} 521 522// IsOverload - Determine whether the given New declaration is an 523// overload of the declarations in Old. This routine returns false if 524// New and Old cannot be overloaded, e.g., if New has the same 525// signature as some function in Old (C++ 1.3.10) or if the Old 526// declarations aren't functions (or function templates) at all. When 527// it does return false, MatchedDecl will point to the decl that New 528// cannot be overloaded with. This decl may be a UsingShadowDecl on 529// top of the underlying declaration. 530// 531// Example: Given the following input: 532// 533// void f(int, float); // #1 534// void f(int, int); // #2 535// int f(int, int); // #3 536// 537// When we process #1, there is no previous declaration of "f", 538// so IsOverload will not be used. 539// 540// When we process #2, Old contains only the FunctionDecl for #1. By 541// comparing the parameter types, we see that #1 and #2 are overloaded 542// (since they have different signatures), so this routine returns 543// false; MatchedDecl is unchanged. 544// 545// When we process #3, Old is an overload set containing #1 and #2. We 546// compare the signatures of #3 to #1 (they're overloaded, so we do 547// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 548// identical (return types of functions are not part of the 549// signature), IsOverload returns false and MatchedDecl will be set to 550// point to the FunctionDecl for #2. 551// 552// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 553// into a class by a using declaration. The rules for whether to hide 554// shadow declarations ignore some properties which otherwise figure 555// into a function template's signature. 556Sema::OverloadKind 557Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 558 NamedDecl *&Match, bool NewIsUsingDecl) { 559 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 560 I != E; ++I) { 561 NamedDecl *OldD = *I; 562 563 bool OldIsUsingDecl = false; 564 if (isa<UsingShadowDecl>(OldD)) { 565 OldIsUsingDecl = true; 566 567 // We can always introduce two using declarations into the same 568 // context, even if they have identical signatures. 569 if (NewIsUsingDecl) continue; 570 571 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 572 } 573 574 // If either declaration was introduced by a using declaration, 575 // we'll need to use slightly different rules for matching. 576 // Essentially, these rules are the normal rules, except that 577 // function templates hide function templates with different 578 // return types or template parameter lists. 579 bool UseMemberUsingDeclRules = 580 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 581 582 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 583 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 584 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 585 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 586 continue; 587 } 588 589 Match = *I; 590 return Ovl_Match; 591 } 592 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 593 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 594 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 595 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 596 continue; 597 } 598 599 Match = *I; 600 return Ovl_Match; 601 } 602 } else if (isa<UsingDecl>(OldD)) { 603 // We can overload with these, which can show up when doing 604 // redeclaration checks for UsingDecls. 605 assert(Old.getLookupKind() == LookupUsingDeclName); 606 } else if (isa<TagDecl>(OldD)) { 607 // We can always overload with tags by hiding them. 608 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 609 // Optimistically assume that an unresolved using decl will 610 // overload; if it doesn't, we'll have to diagnose during 611 // template instantiation. 612 } else { 613 // (C++ 13p1): 614 // Only function declarations can be overloaded; object and type 615 // declarations cannot be overloaded. 616 Match = *I; 617 return Ovl_NonFunction; 618 } 619 } 620 621 return Ovl_Overload; 622} 623 624bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 625 bool UseUsingDeclRules) { 626 // If both of the functions are extern "C", then they are not 627 // overloads. 628 if (Old->isExternC() && New->isExternC()) 629 return false; 630 631 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 632 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 633 634 // C++ [temp.fct]p2: 635 // A function template can be overloaded with other function templates 636 // and with normal (non-template) functions. 637 if ((OldTemplate == 0) != (NewTemplate == 0)) 638 return true; 639 640 // Is the function New an overload of the function Old? 641 QualType OldQType = Context.getCanonicalType(Old->getType()); 642 QualType NewQType = Context.getCanonicalType(New->getType()); 643 644 // Compare the signatures (C++ 1.3.10) of the two functions to 645 // determine whether they are overloads. If we find any mismatch 646 // in the signature, they are overloads. 647 648 // If either of these functions is a K&R-style function (no 649 // prototype), then we consider them to have matching signatures. 650 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 651 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 652 return false; 653 654 const FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 655 const FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 656 657 // The signature of a function includes the types of its 658 // parameters (C++ 1.3.10), which includes the presence or absence 659 // of the ellipsis; see C++ DR 357). 660 if (OldQType != NewQType && 661 (OldType->getNumArgs() != NewType->getNumArgs() || 662 OldType->isVariadic() != NewType->isVariadic() || 663 !FunctionArgTypesAreEqual(OldType, NewType))) 664 return true; 665 666 // C++ [temp.over.link]p4: 667 // The signature of a function template consists of its function 668 // signature, its return type and its template parameter list. The names 669 // of the template parameters are significant only for establishing the 670 // relationship between the template parameters and the rest of the 671 // signature. 672 // 673 // We check the return type and template parameter lists for function 674 // templates first; the remaining checks follow. 675 // 676 // However, we don't consider either of these when deciding whether 677 // a member introduced by a shadow declaration is hidden. 678 if (!UseUsingDeclRules && NewTemplate && 679 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 680 OldTemplate->getTemplateParameters(), 681 false, TPL_TemplateMatch) || 682 OldType->getResultType() != NewType->getResultType())) 683 return true; 684 685 // If the function is a class member, its signature includes the 686 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. 687 // 688 // As part of this, also check whether one of the member functions 689 // is static, in which case they are not overloads (C++ 690 // 13.1p2). While not part of the definition of the signature, 691 // this check is important to determine whether these functions 692 // can be overloaded. 693 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 694 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 695 if (OldMethod && NewMethod && 696 !OldMethod->isStatic() && !NewMethod->isStatic() && 697 (OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers() || 698 OldMethod->getRefQualifier() != NewMethod->getRefQualifier())) { 699 if (!UseUsingDeclRules && 700 OldMethod->getRefQualifier() != NewMethod->getRefQualifier() && 701 (OldMethod->getRefQualifier() == RQ_None || 702 NewMethod->getRefQualifier() == RQ_None)) { 703 // C++0x [over.load]p2: 704 // - Member function declarations with the same name and the same 705 // parameter-type-list as well as member function template 706 // declarations with the same name, the same parameter-type-list, and 707 // the same template parameter lists cannot be overloaded if any of 708 // them, but not all, have a ref-qualifier (8.3.5). 709 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) 710 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); 711 Diag(OldMethod->getLocation(), diag::note_previous_declaration); 712 } 713 714 return true; 715 } 716 717 // The signatures match; this is not an overload. 718 return false; 719} 720 721/// TryImplicitConversion - Attempt to perform an implicit conversion 722/// from the given expression (Expr) to the given type (ToType). This 723/// function returns an implicit conversion sequence that can be used 724/// to perform the initialization. Given 725/// 726/// void f(float f); 727/// void g(int i) { f(i); } 728/// 729/// this routine would produce an implicit conversion sequence to 730/// describe the initialization of f from i, which will be a standard 731/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 732/// 4.1) followed by a floating-integral conversion (C++ 4.9). 733// 734/// Note that this routine only determines how the conversion can be 735/// performed; it does not actually perform the conversion. As such, 736/// it will not produce any diagnostics if no conversion is available, 737/// but will instead return an implicit conversion sequence of kind 738/// "BadConversion". 739/// 740/// If @p SuppressUserConversions, then user-defined conversions are 741/// not permitted. 742/// If @p AllowExplicit, then explicit user-defined conversions are 743/// permitted. 744static ImplicitConversionSequence 745TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 746 bool SuppressUserConversions, 747 bool AllowExplicit, 748 bool InOverloadResolution, 749 bool CStyle) { 750 ImplicitConversionSequence ICS; 751 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 752 ICS.Standard, CStyle)) { 753 ICS.setStandard(); 754 return ICS; 755 } 756 757 if (!S.getLangOptions().CPlusPlus) { 758 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 759 return ICS; 760 } 761 762 // C++ [over.ics.user]p4: 763 // A conversion of an expression of class type to the same class 764 // type is given Exact Match rank, and a conversion of an 765 // expression of class type to a base class of that type is 766 // given Conversion rank, in spite of the fact that a copy/move 767 // constructor (i.e., a user-defined conversion function) is 768 // called for those cases. 769 QualType FromType = From->getType(); 770 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 771 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 772 S.IsDerivedFrom(FromType, ToType))) { 773 ICS.setStandard(); 774 ICS.Standard.setAsIdentityConversion(); 775 ICS.Standard.setFromType(FromType); 776 ICS.Standard.setAllToTypes(ToType); 777 778 // We don't actually check at this point whether there is a valid 779 // copy/move constructor, since overloading just assumes that it 780 // exists. When we actually perform initialization, we'll find the 781 // appropriate constructor to copy the returned object, if needed. 782 ICS.Standard.CopyConstructor = 0; 783 784 // Determine whether this is considered a derived-to-base conversion. 785 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 786 ICS.Standard.Second = ICK_Derived_To_Base; 787 788 return ICS; 789 } 790 791 if (SuppressUserConversions) { 792 // We're not in the case above, so there is no conversion that 793 // we can perform. 794 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 795 return ICS; 796 } 797 798 // Attempt user-defined conversion. 799 OverloadCandidateSet Conversions(From->getExprLoc()); 800 OverloadingResult UserDefResult 801 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 802 AllowExplicit); 803 804 if (UserDefResult == OR_Success) { 805 ICS.setUserDefined(); 806 // C++ [over.ics.user]p4: 807 // A conversion of an expression of class type to the same class 808 // type is given Exact Match rank, and a conversion of an 809 // expression of class type to a base class of that type is 810 // given Conversion rank, in spite of the fact that a copy 811 // constructor (i.e., a user-defined conversion function) is 812 // called for those cases. 813 if (CXXConstructorDecl *Constructor 814 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 815 QualType FromCanon 816 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 817 QualType ToCanon 818 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 819 if (Constructor->isCopyConstructor() && 820 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 821 // Turn this into a "standard" conversion sequence, so that it 822 // gets ranked with standard conversion sequences. 823 ICS.setStandard(); 824 ICS.Standard.setAsIdentityConversion(); 825 ICS.Standard.setFromType(From->getType()); 826 ICS.Standard.setAllToTypes(ToType); 827 ICS.Standard.CopyConstructor = Constructor; 828 if (ToCanon != FromCanon) 829 ICS.Standard.Second = ICK_Derived_To_Base; 830 } 831 } 832 833 // C++ [over.best.ics]p4: 834 // However, when considering the argument of a user-defined 835 // conversion function that is a candidate by 13.3.1.3 when 836 // invoked for the copying of the temporary in the second step 837 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 838 // 13.3.1.6 in all cases, only standard conversion sequences and 839 // ellipsis conversion sequences are allowed. 840 if (SuppressUserConversions && ICS.isUserDefined()) { 841 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 842 } 843 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 844 ICS.setAmbiguous(); 845 ICS.Ambiguous.setFromType(From->getType()); 846 ICS.Ambiguous.setToType(ToType); 847 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 848 Cand != Conversions.end(); ++Cand) 849 if (Cand->Viable) 850 ICS.Ambiguous.addConversion(Cand->Function); 851 } else { 852 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 853 } 854 855 return ICS; 856} 857 858bool Sema::TryImplicitConversion(InitializationSequence &Sequence, 859 const InitializedEntity &Entity, 860 Expr *Initializer, 861 bool SuppressUserConversions, 862 bool AllowExplicitConversions, 863 bool InOverloadResolution, 864 bool CStyle) { 865 ImplicitConversionSequence ICS 866 = clang::TryImplicitConversion(*this, Initializer, Entity.getType(), 867 SuppressUserConversions, 868 AllowExplicitConversions, 869 InOverloadResolution, 870 CStyle); 871 if (ICS.isBad()) return true; 872 873 // Perform the actual conversion. 874 Sequence.AddConversionSequenceStep(ICS, Entity.getType()); 875 return false; 876} 877 878/// PerformImplicitConversion - Perform an implicit conversion of the 879/// expression From to the type ToType. Returns true if there was an 880/// error, false otherwise. The expression From is replaced with the 881/// converted expression. Flavor is the kind of conversion we're 882/// performing, used in the error message. If @p AllowExplicit, 883/// explicit user-defined conversions are permitted. 884bool 885Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 886 AssignmentAction Action, bool AllowExplicit) { 887 ImplicitConversionSequence ICS; 888 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 889} 890 891bool 892Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 893 AssignmentAction Action, bool AllowExplicit, 894 ImplicitConversionSequence& ICS) { 895 ICS = clang::TryImplicitConversion(*this, From, ToType, 896 /*SuppressUserConversions=*/false, 897 AllowExplicit, 898 /*InOverloadResolution=*/false, 899 /*CStyle=*/false); 900 return PerformImplicitConversion(From, ToType, ICS, Action); 901} 902 903/// \brief Determine whether the conversion from FromType to ToType is a valid 904/// conversion that strips "noreturn" off the nested function type. 905static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 906 QualType ToType, QualType &ResultTy) { 907 if (Context.hasSameUnqualifiedType(FromType, ToType)) 908 return false; 909 910 // Permit the conversion F(t __attribute__((noreturn))) -> F(t) 911 // where F adds one of the following at most once: 912 // - a pointer 913 // - a member pointer 914 // - a block pointer 915 CanQualType CanTo = Context.getCanonicalType(ToType); 916 CanQualType CanFrom = Context.getCanonicalType(FromType); 917 Type::TypeClass TyClass = CanTo->getTypeClass(); 918 if (TyClass != CanFrom->getTypeClass()) return false; 919 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { 920 if (TyClass == Type::Pointer) { 921 CanTo = CanTo.getAs<PointerType>()->getPointeeType(); 922 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType(); 923 } else if (TyClass == Type::BlockPointer) { 924 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType(); 925 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType(); 926 } else if (TyClass == Type::MemberPointer) { 927 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType(); 928 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType(); 929 } else { 930 return false; 931 } 932 933 TyClass = CanTo->getTypeClass(); 934 if (TyClass != CanFrom->getTypeClass()) return false; 935 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) 936 return false; 937 } 938 939 const FunctionType *FromFn = cast<FunctionType>(CanFrom); 940 FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); 941 if (!EInfo.getNoReturn()) return false; 942 943 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); 944 assert(QualType(FromFn, 0).isCanonical()); 945 if (QualType(FromFn, 0) != CanTo) return false; 946 947 ResultTy = ToType; 948 return true; 949} 950 951/// \brief Determine whether the conversion from FromType to ToType is a valid 952/// vector conversion. 953/// 954/// \param ICK Will be set to the vector conversion kind, if this is a vector 955/// conversion. 956static bool IsVectorConversion(ASTContext &Context, QualType FromType, 957 QualType ToType, ImplicitConversionKind &ICK) { 958 // We need at least one of these types to be a vector type to have a vector 959 // conversion. 960 if (!ToType->isVectorType() && !FromType->isVectorType()) 961 return false; 962 963 // Identical types require no conversions. 964 if (Context.hasSameUnqualifiedType(FromType, ToType)) 965 return false; 966 967 // There are no conversions between extended vector types, only identity. 968 if (ToType->isExtVectorType()) { 969 // There are no conversions between extended vector types other than the 970 // identity conversion. 971 if (FromType->isExtVectorType()) 972 return false; 973 974 // Vector splat from any arithmetic type to a vector. 975 if (FromType->isArithmeticType()) { 976 ICK = ICK_Vector_Splat; 977 return true; 978 } 979 } 980 981 // We can perform the conversion between vector types in the following cases: 982 // 1)vector types are equivalent AltiVec and GCC vector types 983 // 2)lax vector conversions are permitted and the vector types are of the 984 // same size 985 if (ToType->isVectorType() && FromType->isVectorType()) { 986 if (Context.areCompatibleVectorTypes(FromType, ToType) || 987 (Context.getLangOptions().LaxVectorConversions && 988 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 989 ICK = ICK_Vector_Conversion; 990 return true; 991 } 992 } 993 994 return false; 995} 996 997/// IsStandardConversion - Determines whether there is a standard 998/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 999/// expression From to the type ToType. Standard conversion sequences 1000/// only consider non-class types; for conversions that involve class 1001/// types, use TryImplicitConversion. If a conversion exists, SCS will 1002/// contain the standard conversion sequence required to perform this 1003/// conversion and this routine will return true. Otherwise, this 1004/// routine will return false and the value of SCS is unspecified. 1005static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 1006 bool InOverloadResolution, 1007 StandardConversionSequence &SCS, 1008 bool CStyle) { 1009 QualType FromType = From->getType(); 1010 1011 // Standard conversions (C++ [conv]) 1012 SCS.setAsIdentityConversion(); 1013 SCS.DeprecatedStringLiteralToCharPtr = false; 1014 SCS.IncompatibleObjC = false; 1015 SCS.setFromType(FromType); 1016 SCS.CopyConstructor = 0; 1017 1018 // There are no standard conversions for class types in C++, so 1019 // abort early. When overloading in C, however, we do permit 1020 if (FromType->isRecordType() || ToType->isRecordType()) { 1021 if (S.getLangOptions().CPlusPlus) 1022 return false; 1023 1024 // When we're overloading in C, we allow, as standard conversions, 1025 } 1026 1027 // The first conversion can be an lvalue-to-rvalue conversion, 1028 // array-to-pointer conversion, or function-to-pointer conversion 1029 // (C++ 4p1). 1030 1031 if (FromType == S.Context.OverloadTy) { 1032 DeclAccessPair AccessPair; 1033 if (FunctionDecl *Fn 1034 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 1035 AccessPair)) { 1036 // We were able to resolve the address of the overloaded function, 1037 // so we can convert to the type of that function. 1038 FromType = Fn->getType(); 1039 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 1040 if (!Method->isStatic()) { 1041 const Type *ClassType 1042 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1043 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1044 } 1045 } 1046 1047 // If the "from" expression takes the address of the overloaded 1048 // function, update the type of the resulting expression accordingly. 1049 if (FromType->getAs<FunctionType>()) 1050 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens())) 1051 if (UnOp->getOpcode() == UO_AddrOf) 1052 FromType = S.Context.getPointerType(FromType); 1053 1054 // Check that we've computed the proper type after overload resolution. 1055 assert(S.Context.hasSameType(FromType, 1056 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1057 } else { 1058 return false; 1059 } 1060 } 1061 // Lvalue-to-rvalue conversion (C++ 4.1): 1062 // An lvalue (3.10) of a non-function, non-array type T can be 1063 // converted to an rvalue. 1064 bool argIsLValue = From->isLValue(); 1065 if (argIsLValue && 1066 !FromType->isFunctionType() && !FromType->isArrayType() && 1067 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1068 SCS.First = ICK_Lvalue_To_Rvalue; 1069 1070 // If T is a non-class type, the type of the rvalue is the 1071 // cv-unqualified version of T. Otherwise, the type of the rvalue 1072 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1073 // just strip the qualifiers because they don't matter. 1074 FromType = FromType.getUnqualifiedType(); 1075 } else if (FromType->isArrayType()) { 1076 // Array-to-pointer conversion (C++ 4.2) 1077 SCS.First = ICK_Array_To_Pointer; 1078 1079 // An lvalue or rvalue of type "array of N T" or "array of unknown 1080 // bound of T" can be converted to an rvalue of type "pointer to 1081 // T" (C++ 4.2p1). 1082 FromType = S.Context.getArrayDecayedType(FromType); 1083 1084 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1085 // This conversion is deprecated. (C++ D.4). 1086 SCS.DeprecatedStringLiteralToCharPtr = true; 1087 1088 // For the purpose of ranking in overload resolution 1089 // (13.3.3.1.1), this conversion is considered an 1090 // array-to-pointer conversion followed by a qualification 1091 // conversion (4.4). (C++ 4.2p2) 1092 SCS.Second = ICK_Identity; 1093 SCS.Third = ICK_Qualification; 1094 SCS.setAllToTypes(FromType); 1095 return true; 1096 } 1097 } else if (FromType->isFunctionType() && argIsLValue) { 1098 // Function-to-pointer conversion (C++ 4.3). 1099 SCS.First = ICK_Function_To_Pointer; 1100 1101 // An lvalue of function type T can be converted to an rvalue of 1102 // type "pointer to T." The result is a pointer to the 1103 // function. (C++ 4.3p1). 1104 FromType = S.Context.getPointerType(FromType); 1105 } else { 1106 // We don't require any conversions for the first step. 1107 SCS.First = ICK_Identity; 1108 } 1109 SCS.setToType(0, FromType); 1110 1111 // The second conversion can be an integral promotion, floating 1112 // point promotion, integral conversion, floating point conversion, 1113 // floating-integral conversion, pointer conversion, 1114 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1115 // For overloading in C, this can also be a "compatible-type" 1116 // conversion. 1117 bool IncompatibleObjC = false; 1118 ImplicitConversionKind SecondICK = ICK_Identity; 1119 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1120 // The unqualified versions of the types are the same: there's no 1121 // conversion to do. 1122 SCS.Second = ICK_Identity; 1123 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1124 // Integral promotion (C++ 4.5). 1125 SCS.Second = ICK_Integral_Promotion; 1126 FromType = ToType.getUnqualifiedType(); 1127 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1128 // Floating point promotion (C++ 4.6). 1129 SCS.Second = ICK_Floating_Promotion; 1130 FromType = ToType.getUnqualifiedType(); 1131 } else if (S.IsComplexPromotion(FromType, ToType)) { 1132 // Complex promotion (Clang extension) 1133 SCS.Second = ICK_Complex_Promotion; 1134 FromType = ToType.getUnqualifiedType(); 1135 } else if (ToType->isBooleanType() && 1136 (FromType->isArithmeticType() || 1137 FromType->isAnyPointerType() || 1138 FromType->isBlockPointerType() || 1139 FromType->isMemberPointerType() || 1140 FromType->isNullPtrType())) { 1141 // Boolean conversions (C++ 4.12). 1142 SCS.Second = ICK_Boolean_Conversion; 1143 FromType = S.Context.BoolTy; 1144 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1145 ToType->isIntegralType(S.Context)) { 1146 // Integral conversions (C++ 4.7). 1147 SCS.Second = ICK_Integral_Conversion; 1148 FromType = ToType.getUnqualifiedType(); 1149 } else if (FromType->isAnyComplexType() && ToType->isComplexType()) { 1150 // Complex conversions (C99 6.3.1.6) 1151 SCS.Second = ICK_Complex_Conversion; 1152 FromType = ToType.getUnqualifiedType(); 1153 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1154 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1155 // Complex-real conversions (C99 6.3.1.7) 1156 SCS.Second = ICK_Complex_Real; 1157 FromType = ToType.getUnqualifiedType(); 1158 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1159 // Floating point conversions (C++ 4.8). 1160 SCS.Second = ICK_Floating_Conversion; 1161 FromType = ToType.getUnqualifiedType(); 1162 } else if ((FromType->isRealFloatingType() && 1163 ToType->isIntegralType(S.Context)) || 1164 (FromType->isIntegralOrUnscopedEnumerationType() && 1165 ToType->isRealFloatingType())) { 1166 // Floating-integral conversions (C++ 4.9). 1167 SCS.Second = ICK_Floating_Integral; 1168 FromType = ToType.getUnqualifiedType(); 1169 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { 1170 SCS.Second = ICK_Block_Pointer_Conversion; 1171 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1172 FromType, IncompatibleObjC)) { 1173 // Pointer conversions (C++ 4.10). 1174 SCS.Second = ICK_Pointer_Conversion; 1175 SCS.IncompatibleObjC = IncompatibleObjC; 1176 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1177 InOverloadResolution, FromType)) { 1178 // Pointer to member conversions (4.11). 1179 SCS.Second = ICK_Pointer_Member; 1180 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1181 SCS.Second = SecondICK; 1182 FromType = ToType.getUnqualifiedType(); 1183 } else if (!S.getLangOptions().CPlusPlus && 1184 S.Context.typesAreCompatible(ToType, FromType)) { 1185 // Compatible conversions (Clang extension for C function overloading) 1186 SCS.Second = ICK_Compatible_Conversion; 1187 FromType = ToType.getUnqualifiedType(); 1188 } else if (IsNoReturnConversion(S.Context, FromType, ToType, FromType)) { 1189 // Treat a conversion that strips "noreturn" as an identity conversion. 1190 SCS.Second = ICK_NoReturn_Adjustment; 1191 } else { 1192 // No second conversion required. 1193 SCS.Second = ICK_Identity; 1194 } 1195 SCS.setToType(1, FromType); 1196 1197 QualType CanonFrom; 1198 QualType CanonTo; 1199 // The third conversion can be a qualification conversion (C++ 4p1). 1200 if (S.IsQualificationConversion(FromType, ToType, CStyle)) { 1201 SCS.Third = ICK_Qualification; 1202 FromType = ToType; 1203 CanonFrom = S.Context.getCanonicalType(FromType); 1204 CanonTo = S.Context.getCanonicalType(ToType); 1205 } else { 1206 // No conversion required 1207 SCS.Third = ICK_Identity; 1208 1209 // C++ [over.best.ics]p6: 1210 // [...] Any difference in top-level cv-qualification is 1211 // subsumed by the initialization itself and does not constitute 1212 // a conversion. [...] 1213 CanonFrom = S.Context.getCanonicalType(FromType); 1214 CanonTo = S.Context.getCanonicalType(ToType); 1215 if (CanonFrom.getLocalUnqualifiedType() 1216 == CanonTo.getLocalUnqualifiedType() && 1217 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1218 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1219 FromType = ToType; 1220 CanonFrom = CanonTo; 1221 } 1222 } 1223 SCS.setToType(2, FromType); 1224 1225 // If we have not converted the argument type to the parameter type, 1226 // this is a bad conversion sequence. 1227 if (CanonFrom != CanonTo) 1228 return false; 1229 1230 return true; 1231} 1232 1233/// IsIntegralPromotion - Determines whether the conversion from the 1234/// expression From (whose potentially-adjusted type is FromType) to 1235/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1236/// sets PromotedType to the promoted type. 1237bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1238 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1239 // All integers are built-in. 1240 if (!To) { 1241 return false; 1242 } 1243 1244 // An rvalue of type char, signed char, unsigned char, short int, or 1245 // unsigned short int can be converted to an rvalue of type int if 1246 // int can represent all the values of the source type; otherwise, 1247 // the source rvalue can be converted to an rvalue of type unsigned 1248 // int (C++ 4.5p1). 1249 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1250 !FromType->isEnumeralType()) { 1251 if (// We can promote any signed, promotable integer type to an int 1252 (FromType->isSignedIntegerType() || 1253 // We can promote any unsigned integer type whose size is 1254 // less than int to an int. 1255 (!FromType->isSignedIntegerType() && 1256 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1257 return To->getKind() == BuiltinType::Int; 1258 } 1259 1260 return To->getKind() == BuiltinType::UInt; 1261 } 1262 1263 // C++0x [conv.prom]p3: 1264 // A prvalue of an unscoped enumeration type whose underlying type is not 1265 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1266 // following types that can represent all the values of the enumeration 1267 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1268 // unsigned int, long int, unsigned long int, long long int, or unsigned 1269 // long long int. If none of the types in that list can represent all the 1270 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1271 // type can be converted to an rvalue a prvalue of the extended integer type 1272 // with lowest integer conversion rank (4.13) greater than the rank of long 1273 // long in which all the values of the enumeration can be represented. If 1274 // there are two such extended types, the signed one is chosen. 1275 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1276 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1277 // provided for a scoped enumeration. 1278 if (FromEnumType->getDecl()->isScoped()) 1279 return false; 1280 1281 // We have already pre-calculated the promotion type, so this is trivial. 1282 if (ToType->isIntegerType() && 1283 !RequireCompleteType(From->getLocStart(), FromType, PDiag())) 1284 return Context.hasSameUnqualifiedType(ToType, 1285 FromEnumType->getDecl()->getPromotionType()); 1286 } 1287 1288 // C++0x [conv.prom]p2: 1289 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1290 // to an rvalue a prvalue of the first of the following types that can 1291 // represent all the values of its underlying type: int, unsigned int, 1292 // long int, unsigned long int, long long int, or unsigned long long int. 1293 // If none of the types in that list can represent all the values of its 1294 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1295 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1296 // type. 1297 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1298 ToType->isIntegerType()) { 1299 // Determine whether the type we're converting from is signed or 1300 // unsigned. 1301 bool FromIsSigned; 1302 uint64_t FromSize = Context.getTypeSize(FromType); 1303 1304 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1305 FromIsSigned = true; 1306 1307 // The types we'll try to promote to, in the appropriate 1308 // order. Try each of these types. 1309 QualType PromoteTypes[6] = { 1310 Context.IntTy, Context.UnsignedIntTy, 1311 Context.LongTy, Context.UnsignedLongTy , 1312 Context.LongLongTy, Context.UnsignedLongLongTy 1313 }; 1314 for (int Idx = 0; Idx < 6; ++Idx) { 1315 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1316 if (FromSize < ToSize || 1317 (FromSize == ToSize && 1318 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1319 // We found the type that we can promote to. If this is the 1320 // type we wanted, we have a promotion. Otherwise, no 1321 // promotion. 1322 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1323 } 1324 } 1325 } 1326 1327 // An rvalue for an integral bit-field (9.6) can be converted to an 1328 // rvalue of type int if int can represent all the values of the 1329 // bit-field; otherwise, it can be converted to unsigned int if 1330 // unsigned int can represent all the values of the bit-field. If 1331 // the bit-field is larger yet, no integral promotion applies to 1332 // it. If the bit-field has an enumerated type, it is treated as any 1333 // other value of that type for promotion purposes (C++ 4.5p3). 1334 // FIXME: We should delay checking of bit-fields until we actually perform the 1335 // conversion. 1336 using llvm::APSInt; 1337 if (From) 1338 if (FieldDecl *MemberDecl = From->getBitField()) { 1339 APSInt BitWidth; 1340 if (FromType->isIntegralType(Context) && 1341 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1342 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1343 ToSize = Context.getTypeSize(ToType); 1344 1345 // Are we promoting to an int from a bitfield that fits in an int? 1346 if (BitWidth < ToSize || 1347 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1348 return To->getKind() == BuiltinType::Int; 1349 } 1350 1351 // Are we promoting to an unsigned int from an unsigned bitfield 1352 // that fits into an unsigned int? 1353 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1354 return To->getKind() == BuiltinType::UInt; 1355 } 1356 1357 return false; 1358 } 1359 } 1360 1361 // An rvalue of type bool can be converted to an rvalue of type int, 1362 // with false becoming zero and true becoming one (C++ 4.5p4). 1363 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1364 return true; 1365 } 1366 1367 return false; 1368} 1369 1370/// IsFloatingPointPromotion - Determines whether the conversion from 1371/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1372/// returns true and sets PromotedType to the promoted type. 1373bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1374 /// An rvalue of type float can be converted to an rvalue of type 1375 /// double. (C++ 4.6p1). 1376 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1377 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1378 if (FromBuiltin->getKind() == BuiltinType::Float && 1379 ToBuiltin->getKind() == BuiltinType::Double) 1380 return true; 1381 1382 // C99 6.3.1.5p1: 1383 // When a float is promoted to double or long double, or a 1384 // double is promoted to long double [...]. 1385 if (!getLangOptions().CPlusPlus && 1386 (FromBuiltin->getKind() == BuiltinType::Float || 1387 FromBuiltin->getKind() == BuiltinType::Double) && 1388 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1389 return true; 1390 } 1391 1392 return false; 1393} 1394 1395/// \brief Determine if a conversion is a complex promotion. 1396/// 1397/// A complex promotion is defined as a complex -> complex conversion 1398/// where the conversion between the underlying real types is a 1399/// floating-point or integral promotion. 1400bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1401 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1402 if (!FromComplex) 1403 return false; 1404 1405 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1406 if (!ToComplex) 1407 return false; 1408 1409 return IsFloatingPointPromotion(FromComplex->getElementType(), 1410 ToComplex->getElementType()) || 1411 IsIntegralPromotion(0, FromComplex->getElementType(), 1412 ToComplex->getElementType()); 1413} 1414 1415/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1416/// the pointer type FromPtr to a pointer to type ToPointee, with the 1417/// same type qualifiers as FromPtr has on its pointee type. ToType, 1418/// if non-empty, will be a pointer to ToType that may or may not have 1419/// the right set of qualifiers on its pointee. 1420static QualType 1421BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1422 QualType ToPointee, QualType ToType, 1423 ASTContext &Context) { 1424 assert((FromPtr->getTypeClass() == Type::Pointer || 1425 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1426 "Invalid similarly-qualified pointer type"); 1427 1428 /// \brief Conversions to 'id' subsume cv-qualifier conversions. 1429 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1430 return ToType.getUnqualifiedType(); 1431 1432 QualType CanonFromPointee 1433 = Context.getCanonicalType(FromPtr->getPointeeType()); 1434 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1435 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1436 1437 // Exact qualifier match -> return the pointer type we're converting to. 1438 if (CanonToPointee.getLocalQualifiers() == Quals) { 1439 // ToType is exactly what we need. Return it. 1440 if (!ToType.isNull()) 1441 return ToType.getUnqualifiedType(); 1442 1443 // Build a pointer to ToPointee. It has the right qualifiers 1444 // already. 1445 if (isa<ObjCObjectPointerType>(ToType)) 1446 return Context.getObjCObjectPointerType(ToPointee); 1447 return Context.getPointerType(ToPointee); 1448 } 1449 1450 // Just build a canonical type that has the right qualifiers. 1451 QualType QualifiedCanonToPointee 1452 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1453 1454 if (isa<ObjCObjectPointerType>(ToType)) 1455 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1456 return Context.getPointerType(QualifiedCanonToPointee); 1457} 1458 1459static bool isNullPointerConstantForConversion(Expr *Expr, 1460 bool InOverloadResolution, 1461 ASTContext &Context) { 1462 // Handle value-dependent integral null pointer constants correctly. 1463 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1464 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1465 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1466 return !InOverloadResolution; 1467 1468 return Expr->isNullPointerConstant(Context, 1469 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1470 : Expr::NPC_ValueDependentIsNull); 1471} 1472 1473/// IsPointerConversion - Determines whether the conversion of the 1474/// expression From, which has the (possibly adjusted) type FromType, 1475/// can be converted to the type ToType via a pointer conversion (C++ 1476/// 4.10). If so, returns true and places the converted type (that 1477/// might differ from ToType in its cv-qualifiers at some level) into 1478/// ConvertedType. 1479/// 1480/// This routine also supports conversions to and from block pointers 1481/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1482/// pointers to interfaces. FIXME: Once we've determined the 1483/// appropriate overloading rules for Objective-C, we may want to 1484/// split the Objective-C checks into a different routine; however, 1485/// GCC seems to consider all of these conversions to be pointer 1486/// conversions, so for now they live here. IncompatibleObjC will be 1487/// set if the conversion is an allowed Objective-C conversion that 1488/// should result in a warning. 1489bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1490 bool InOverloadResolution, 1491 QualType& ConvertedType, 1492 bool &IncompatibleObjC) { 1493 IncompatibleObjC = false; 1494 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 1495 IncompatibleObjC)) 1496 return true; 1497 1498 // Conversion from a null pointer constant to any Objective-C pointer type. 1499 if (ToType->isObjCObjectPointerType() && 1500 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1501 ConvertedType = ToType; 1502 return true; 1503 } 1504 1505 // Blocks: Block pointers can be converted to void*. 1506 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1507 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1508 ConvertedType = ToType; 1509 return true; 1510 } 1511 // Blocks: A null pointer constant can be converted to a block 1512 // pointer type. 1513 if (ToType->isBlockPointerType() && 1514 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1515 ConvertedType = ToType; 1516 return true; 1517 } 1518 1519 // If the left-hand-side is nullptr_t, the right side can be a null 1520 // pointer constant. 1521 if (ToType->isNullPtrType() && 1522 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1523 ConvertedType = ToType; 1524 return true; 1525 } 1526 1527 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1528 if (!ToTypePtr) 1529 return false; 1530 1531 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1532 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1533 ConvertedType = ToType; 1534 return true; 1535 } 1536 1537 // Beyond this point, both types need to be pointers 1538 // , including objective-c pointers. 1539 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1540 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1541 ConvertedType = BuildSimilarlyQualifiedPointerType( 1542 FromType->getAs<ObjCObjectPointerType>(), 1543 ToPointeeType, 1544 ToType, Context); 1545 return true; 1546 } 1547 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1548 if (!FromTypePtr) 1549 return false; 1550 1551 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1552 1553 // If the unqualified pointee types are the same, this can't be a 1554 // pointer conversion, so don't do all of the work below. 1555 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1556 return false; 1557 1558 // An rvalue of type "pointer to cv T," where T is an object type, 1559 // can be converted to an rvalue of type "pointer to cv void" (C++ 1560 // 4.10p2). 1561 if (FromPointeeType->isIncompleteOrObjectType() && 1562 ToPointeeType->isVoidType()) { 1563 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1564 ToPointeeType, 1565 ToType, Context); 1566 return true; 1567 } 1568 1569 // When we're overloading in C, we allow a special kind of pointer 1570 // conversion for compatible-but-not-identical pointee types. 1571 if (!getLangOptions().CPlusPlus && 1572 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1573 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1574 ToPointeeType, 1575 ToType, Context); 1576 return true; 1577 } 1578 1579 // C++ [conv.ptr]p3: 1580 // 1581 // An rvalue of type "pointer to cv D," where D is a class type, 1582 // can be converted to an rvalue of type "pointer to cv B," where 1583 // B is a base class (clause 10) of D. If B is an inaccessible 1584 // (clause 11) or ambiguous (10.2) base class of D, a program that 1585 // necessitates this conversion is ill-formed. The result of the 1586 // conversion is a pointer to the base class sub-object of the 1587 // derived class object. The null pointer value is converted to 1588 // the null pointer value of the destination type. 1589 // 1590 // Note that we do not check for ambiguity or inaccessibility 1591 // here. That is handled by CheckPointerConversion. 1592 if (getLangOptions().CPlusPlus && 1593 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1594 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1595 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1596 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1597 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1598 ToPointeeType, 1599 ToType, Context); 1600 return true; 1601 } 1602 1603 return false; 1604} 1605 1606/// isObjCPointerConversion - Determines whether this is an 1607/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1608/// with the same arguments and return values. 1609bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1610 QualType& ConvertedType, 1611 bool &IncompatibleObjC) { 1612 if (!getLangOptions().ObjC1) 1613 return false; 1614 1615 // First, we handle all conversions on ObjC object pointer types. 1616 const ObjCObjectPointerType* ToObjCPtr = 1617 ToType->getAs<ObjCObjectPointerType>(); 1618 const ObjCObjectPointerType *FromObjCPtr = 1619 FromType->getAs<ObjCObjectPointerType>(); 1620 1621 if (ToObjCPtr && FromObjCPtr) { 1622 // If the pointee types are the same (ignoring qualifications), 1623 // then this is not a pointer conversion. 1624 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 1625 FromObjCPtr->getPointeeType())) 1626 return false; 1627 1628 // Objective C++: We're able to convert between "id" or "Class" and a 1629 // pointer to any interface (in both directions). 1630 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1631 ConvertedType = ToType; 1632 return true; 1633 } 1634 // Conversions with Objective-C's id<...>. 1635 if ((FromObjCPtr->isObjCQualifiedIdType() || 1636 ToObjCPtr->isObjCQualifiedIdType()) && 1637 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1638 /*compare=*/false)) { 1639 ConvertedType = ToType; 1640 return true; 1641 } 1642 // Objective C++: We're able to convert from a pointer to an 1643 // interface to a pointer to a different interface. 1644 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1645 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1646 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1647 if (getLangOptions().CPlusPlus && LHS && RHS && 1648 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1649 FromObjCPtr->getPointeeType())) 1650 return false; 1651 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1652 ToObjCPtr->getPointeeType(), 1653 ToType, Context); 1654 return true; 1655 } 1656 1657 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1658 // Okay: this is some kind of implicit downcast of Objective-C 1659 // interfaces, which is permitted. However, we're going to 1660 // complain about it. 1661 IncompatibleObjC = true; 1662 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1663 ToObjCPtr->getPointeeType(), 1664 ToType, Context); 1665 return true; 1666 } 1667 } 1668 // Beyond this point, both types need to be C pointers or block pointers. 1669 QualType ToPointeeType; 1670 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1671 ToPointeeType = ToCPtr->getPointeeType(); 1672 else if (const BlockPointerType *ToBlockPtr = 1673 ToType->getAs<BlockPointerType>()) { 1674 // Objective C++: We're able to convert from a pointer to any object 1675 // to a block pointer type. 1676 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1677 ConvertedType = ToType; 1678 return true; 1679 } 1680 ToPointeeType = ToBlockPtr->getPointeeType(); 1681 } 1682 else if (FromType->getAs<BlockPointerType>() && 1683 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1684 // Objective C++: We're able to convert from a block pointer type to a 1685 // pointer to any object. 1686 ConvertedType = ToType; 1687 return true; 1688 } 1689 else 1690 return false; 1691 1692 QualType FromPointeeType; 1693 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1694 FromPointeeType = FromCPtr->getPointeeType(); 1695 else if (const BlockPointerType *FromBlockPtr = 1696 FromType->getAs<BlockPointerType>()) 1697 FromPointeeType = FromBlockPtr->getPointeeType(); 1698 else 1699 return false; 1700 1701 // If we have pointers to pointers, recursively check whether this 1702 // is an Objective-C conversion. 1703 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1704 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1705 IncompatibleObjC)) { 1706 // We always complain about this conversion. 1707 IncompatibleObjC = true; 1708 ConvertedType = Context.getPointerType(ConvertedType); 1709 return true; 1710 } 1711 // Allow conversion of pointee being objective-c pointer to another one; 1712 // as in I* to id. 1713 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1714 ToPointeeType->getAs<ObjCObjectPointerType>() && 1715 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1716 IncompatibleObjC)) { 1717 ConvertedType = Context.getPointerType(ConvertedType); 1718 return true; 1719 } 1720 1721 // If we have pointers to functions or blocks, check whether the only 1722 // differences in the argument and result types are in Objective-C 1723 // pointer conversions. If so, we permit the conversion (but 1724 // complain about it). 1725 const FunctionProtoType *FromFunctionType 1726 = FromPointeeType->getAs<FunctionProtoType>(); 1727 const FunctionProtoType *ToFunctionType 1728 = ToPointeeType->getAs<FunctionProtoType>(); 1729 if (FromFunctionType && ToFunctionType) { 1730 // If the function types are exactly the same, this isn't an 1731 // Objective-C pointer conversion. 1732 if (Context.getCanonicalType(FromPointeeType) 1733 == Context.getCanonicalType(ToPointeeType)) 1734 return false; 1735 1736 // Perform the quick checks that will tell us whether these 1737 // function types are obviously different. 1738 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1739 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1740 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1741 return false; 1742 1743 bool HasObjCConversion = false; 1744 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1745 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1746 // Okay, the types match exactly. Nothing to do. 1747 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1748 ToFunctionType->getResultType(), 1749 ConvertedType, IncompatibleObjC)) { 1750 // Okay, we have an Objective-C pointer conversion. 1751 HasObjCConversion = true; 1752 } else { 1753 // Function types are too different. Abort. 1754 return false; 1755 } 1756 1757 // Check argument types. 1758 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1759 ArgIdx != NumArgs; ++ArgIdx) { 1760 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1761 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1762 if (Context.getCanonicalType(FromArgType) 1763 == Context.getCanonicalType(ToArgType)) { 1764 // Okay, the types match exactly. Nothing to do. 1765 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1766 ConvertedType, IncompatibleObjC)) { 1767 // Okay, we have an Objective-C pointer conversion. 1768 HasObjCConversion = true; 1769 } else { 1770 // Argument types are too different. Abort. 1771 return false; 1772 } 1773 } 1774 1775 if (HasObjCConversion) { 1776 // We had an Objective-C conversion. Allow this pointer 1777 // conversion, but complain about it. 1778 ConvertedType = ToType; 1779 IncompatibleObjC = true; 1780 return true; 1781 } 1782 } 1783 1784 return false; 1785} 1786 1787bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, 1788 QualType& ConvertedType) { 1789 QualType ToPointeeType; 1790 if (const BlockPointerType *ToBlockPtr = 1791 ToType->getAs<BlockPointerType>()) 1792 ToPointeeType = ToBlockPtr->getPointeeType(); 1793 else 1794 return false; 1795 1796 QualType FromPointeeType; 1797 if (const BlockPointerType *FromBlockPtr = 1798 FromType->getAs<BlockPointerType>()) 1799 FromPointeeType = FromBlockPtr->getPointeeType(); 1800 else 1801 return false; 1802 // We have pointer to blocks, check whether the only 1803 // differences in the argument and result types are in Objective-C 1804 // pointer conversions. If so, we permit the conversion. 1805 1806 const FunctionProtoType *FromFunctionType 1807 = FromPointeeType->getAs<FunctionProtoType>(); 1808 const FunctionProtoType *ToFunctionType 1809 = ToPointeeType->getAs<FunctionProtoType>(); 1810 1811 if (!FromFunctionType || !ToFunctionType) 1812 return false; 1813 1814 if (Context.hasSameType(FromPointeeType, ToPointeeType)) 1815 return true; 1816 1817 // Perform the quick checks that will tell us whether these 1818 // function types are obviously different. 1819 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1820 FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) 1821 return false; 1822 1823 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); 1824 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); 1825 if (FromEInfo != ToEInfo) 1826 return false; 1827 1828 bool IncompatibleObjC = false; 1829 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1830 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1831 // Okay, the types match exactly. Nothing to do. 1832 } else { 1833 QualType RHS = FromFunctionType->getResultType(); 1834 QualType LHS = ToFunctionType->getResultType(); 1835 if ((!getLangOptions().CPlusPlus || !RHS->isRecordType()) && 1836 !RHS.hasQualifiers() && LHS.hasQualifiers()) 1837 LHS = LHS.getUnqualifiedType(); 1838 1839 if (Context.hasSameType(RHS,LHS)) { 1840 // OK exact match. 1841 } else if (isObjCPointerConversion(RHS, LHS, 1842 ConvertedType, IncompatibleObjC)) { 1843 if (IncompatibleObjC) 1844 return false; 1845 // Okay, we have an Objective-C pointer conversion. 1846 } 1847 else 1848 return false; 1849 } 1850 1851 // Check argument types. 1852 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1853 ArgIdx != NumArgs; ++ArgIdx) { 1854 IncompatibleObjC = false; 1855 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1856 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1857 if (Context.hasSameType(FromArgType, ToArgType)) { 1858 // Okay, the types match exactly. Nothing to do. 1859 } else if (isObjCPointerConversion(ToArgType, FromArgType, 1860 ConvertedType, IncompatibleObjC)) { 1861 if (IncompatibleObjC) 1862 return false; 1863 // Okay, we have an Objective-C pointer conversion. 1864 } else 1865 // Argument types are too different. Abort. 1866 return false; 1867 } 1868 ConvertedType = ToType; 1869 return true; 1870} 1871 1872/// FunctionArgTypesAreEqual - This routine checks two function proto types 1873/// for equlity of their argument types. Caller has already checked that 1874/// they have same number of arguments. This routine assumes that Objective-C 1875/// pointer types which only differ in their protocol qualifiers are equal. 1876bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, 1877 const FunctionProtoType *NewType) { 1878 if (!getLangOptions().ObjC1) 1879 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1880 NewType->arg_type_begin()); 1881 1882 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1883 N = NewType->arg_type_begin(), 1884 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1885 QualType ToType = (*O); 1886 QualType FromType = (*N); 1887 if (ToType != FromType) { 1888 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1889 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1890 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1891 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1892 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1893 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1894 continue; 1895 } 1896 else if (const ObjCObjectPointerType *PTTo = 1897 ToType->getAs<ObjCObjectPointerType>()) { 1898 if (const ObjCObjectPointerType *PTFr = 1899 FromType->getAs<ObjCObjectPointerType>()) 1900 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1901 continue; 1902 } 1903 return false; 1904 } 1905 } 1906 return true; 1907} 1908 1909/// CheckPointerConversion - Check the pointer conversion from the 1910/// expression From to the type ToType. This routine checks for 1911/// ambiguous or inaccessible derived-to-base pointer 1912/// conversions for which IsPointerConversion has already returned 1913/// true. It returns true and produces a diagnostic if there was an 1914/// error, or returns false otherwise. 1915bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1916 CastKind &Kind, 1917 CXXCastPath& BasePath, 1918 bool IgnoreBaseAccess) { 1919 QualType FromType = From->getType(); 1920 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 1921 1922 Kind = CK_BitCast; 1923 1924 if (CXXBoolLiteralExpr* LitBool 1925 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1926 if (!IsCStyleOrFunctionalCast && LitBool->getValue() == false) 1927 Diag(LitBool->getExprLoc(), diag::warn_init_pointer_from_false) 1928 << ToType; 1929 1930 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1931 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1932 QualType FromPointeeType = FromPtrType->getPointeeType(), 1933 ToPointeeType = ToPtrType->getPointeeType(); 1934 1935 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1936 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1937 // We must have a derived-to-base conversion. Check an 1938 // ambiguous or inaccessible conversion. 1939 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1940 From->getExprLoc(), 1941 From->getSourceRange(), &BasePath, 1942 IgnoreBaseAccess)) 1943 return true; 1944 1945 // The conversion was successful. 1946 Kind = CK_DerivedToBase; 1947 } 1948 } 1949 if (const ObjCObjectPointerType *FromPtrType = 1950 FromType->getAs<ObjCObjectPointerType>()) { 1951 if (const ObjCObjectPointerType *ToPtrType = 1952 ToType->getAs<ObjCObjectPointerType>()) { 1953 // Objective-C++ conversions are always okay. 1954 // FIXME: We should have a different class of conversions for the 1955 // Objective-C++ implicit conversions. 1956 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1957 return false; 1958 } 1959 } 1960 1961 // We shouldn't fall into this case unless it's valid for other 1962 // reasons. 1963 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 1964 Kind = CK_NullToPointer; 1965 1966 return false; 1967} 1968 1969/// IsMemberPointerConversion - Determines whether the conversion of the 1970/// expression From, which has the (possibly adjusted) type FromType, can be 1971/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1972/// If so, returns true and places the converted type (that might differ from 1973/// ToType in its cv-qualifiers at some level) into ConvertedType. 1974bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1975 QualType ToType, 1976 bool InOverloadResolution, 1977 QualType &ConvertedType) { 1978 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1979 if (!ToTypePtr) 1980 return false; 1981 1982 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1983 if (From->isNullPointerConstant(Context, 1984 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1985 : Expr::NPC_ValueDependentIsNull)) { 1986 ConvertedType = ToType; 1987 return true; 1988 } 1989 1990 // Otherwise, both types have to be member pointers. 1991 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1992 if (!FromTypePtr) 1993 return false; 1994 1995 // A pointer to member of B can be converted to a pointer to member of D, 1996 // where D is derived from B (C++ 4.11p2). 1997 QualType FromClass(FromTypePtr->getClass(), 0); 1998 QualType ToClass(ToTypePtr->getClass(), 0); 1999 2000 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && 2001 !RequireCompleteType(From->getLocStart(), ToClass, PDiag()) && 2002 IsDerivedFrom(ToClass, FromClass)) { 2003 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 2004 ToClass.getTypePtr()); 2005 return true; 2006 } 2007 2008 return false; 2009} 2010 2011/// CheckMemberPointerConversion - Check the member pointer conversion from the 2012/// expression From to the type ToType. This routine checks for ambiguous or 2013/// virtual or inaccessible base-to-derived member pointer conversions 2014/// for which IsMemberPointerConversion has already returned true. It returns 2015/// true and produces a diagnostic if there was an error, or returns false 2016/// otherwise. 2017bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 2018 CastKind &Kind, 2019 CXXCastPath &BasePath, 2020 bool IgnoreBaseAccess) { 2021 QualType FromType = From->getType(); 2022 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 2023 if (!FromPtrType) { 2024 // This must be a null pointer to member pointer conversion 2025 assert(From->isNullPointerConstant(Context, 2026 Expr::NPC_ValueDependentIsNull) && 2027 "Expr must be null pointer constant!"); 2028 Kind = CK_NullToMemberPointer; 2029 return false; 2030 } 2031 2032 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 2033 assert(ToPtrType && "No member pointer cast has a target type " 2034 "that is not a member pointer."); 2035 2036 QualType FromClass = QualType(FromPtrType->getClass(), 0); 2037 QualType ToClass = QualType(ToPtrType->getClass(), 0); 2038 2039 // FIXME: What about dependent types? 2040 assert(FromClass->isRecordType() && "Pointer into non-class."); 2041 assert(ToClass->isRecordType() && "Pointer into non-class."); 2042 2043 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 2044 /*DetectVirtual=*/true); 2045 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 2046 assert(DerivationOkay && 2047 "Should not have been called if derivation isn't OK."); 2048 (void)DerivationOkay; 2049 2050 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 2051 getUnqualifiedType())) { 2052 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 2053 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 2054 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 2055 return true; 2056 } 2057 2058 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 2059 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 2060 << FromClass << ToClass << QualType(VBase, 0) 2061 << From->getSourceRange(); 2062 return true; 2063 } 2064 2065 if (!IgnoreBaseAccess) 2066 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 2067 Paths.front(), 2068 diag::err_downcast_from_inaccessible_base); 2069 2070 // Must be a base to derived member conversion. 2071 BuildBasePathArray(Paths, BasePath); 2072 Kind = CK_BaseToDerivedMemberPointer; 2073 return false; 2074} 2075 2076/// IsQualificationConversion - Determines whether the conversion from 2077/// an rvalue of type FromType to ToType is a qualification conversion 2078/// (C++ 4.4). 2079bool 2080Sema::IsQualificationConversion(QualType FromType, QualType ToType, 2081 bool CStyle) { 2082 FromType = Context.getCanonicalType(FromType); 2083 ToType = Context.getCanonicalType(ToType); 2084 2085 // If FromType and ToType are the same type, this is not a 2086 // qualification conversion. 2087 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 2088 return false; 2089 2090 // (C++ 4.4p4): 2091 // A conversion can add cv-qualifiers at levels other than the first 2092 // in multi-level pointers, subject to the following rules: [...] 2093 bool PreviousToQualsIncludeConst = true; 2094 bool UnwrappedAnyPointer = false; 2095 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 2096 // Within each iteration of the loop, we check the qualifiers to 2097 // determine if this still looks like a qualification 2098 // conversion. Then, if all is well, we unwrap one more level of 2099 // pointers or pointers-to-members and do it all again 2100 // until there are no more pointers or pointers-to-members left to 2101 // unwrap. 2102 UnwrappedAnyPointer = true; 2103 2104 // -- for every j > 0, if const is in cv 1,j then const is in cv 2105 // 2,j, and similarly for volatile. 2106 if (!CStyle && !ToType.isAtLeastAsQualifiedAs(FromType)) 2107 return false; 2108 2109 // -- if the cv 1,j and cv 2,j are different, then const is in 2110 // every cv for 0 < k < j. 2111 if (!CStyle && FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 2112 && !PreviousToQualsIncludeConst) 2113 return false; 2114 2115 // Keep track of whether all prior cv-qualifiers in the "to" type 2116 // include const. 2117 PreviousToQualsIncludeConst 2118 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 2119 } 2120 2121 // We are left with FromType and ToType being the pointee types 2122 // after unwrapping the original FromType and ToType the same number 2123 // of types. If we unwrapped any pointers, and if FromType and 2124 // ToType have the same unqualified type (since we checked 2125 // qualifiers above), then this is a qualification conversion. 2126 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2127} 2128 2129/// Determines whether there is a user-defined conversion sequence 2130/// (C++ [over.ics.user]) that converts expression From to the type 2131/// ToType. If such a conversion exists, User will contain the 2132/// user-defined conversion sequence that performs such a conversion 2133/// and this routine will return true. Otherwise, this routine returns 2134/// false and User is unspecified. 2135/// 2136/// \param AllowExplicit true if the conversion should consider C++0x 2137/// "explicit" conversion functions as well as non-explicit conversion 2138/// functions (C++0x [class.conv.fct]p2). 2139static OverloadingResult 2140IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 2141 UserDefinedConversionSequence& User, 2142 OverloadCandidateSet& CandidateSet, 2143 bool AllowExplicit) { 2144 // Whether we will only visit constructors. 2145 bool ConstructorsOnly = false; 2146 2147 // If the type we are conversion to is a class type, enumerate its 2148 // constructors. 2149 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 2150 // C++ [over.match.ctor]p1: 2151 // When objects of class type are direct-initialized (8.5), or 2152 // copy-initialized from an expression of the same or a 2153 // derived class type (8.5), overload resolution selects the 2154 // constructor. [...] For copy-initialization, the candidate 2155 // functions are all the converting constructors (12.3.1) of 2156 // that class. The argument list is the expression-list within 2157 // the parentheses of the initializer. 2158 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 2159 (From->getType()->getAs<RecordType>() && 2160 S.IsDerivedFrom(From->getType(), ToType))) 2161 ConstructorsOnly = true; 2162 2163 if (S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag())) { 2164 // We're not going to find any constructors. 2165 } else if (CXXRecordDecl *ToRecordDecl 2166 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 2167 DeclContext::lookup_iterator Con, ConEnd; 2168 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 2169 Con != ConEnd; ++Con) { 2170 NamedDecl *D = *Con; 2171 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2172 2173 // Find the constructor (which may be a template). 2174 CXXConstructorDecl *Constructor = 0; 2175 FunctionTemplateDecl *ConstructorTmpl 2176 = dyn_cast<FunctionTemplateDecl>(D); 2177 if (ConstructorTmpl) 2178 Constructor 2179 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2180 else 2181 Constructor = cast<CXXConstructorDecl>(D); 2182 2183 if (!Constructor->isInvalidDecl() && 2184 Constructor->isConvertingConstructor(AllowExplicit)) { 2185 if (ConstructorTmpl) 2186 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2187 /*ExplicitArgs*/ 0, 2188 &From, 1, CandidateSet, 2189 /*SuppressUserConversions=*/ 2190 !ConstructorsOnly); 2191 else 2192 // Allow one user-defined conversion when user specifies a 2193 // From->ToType conversion via an static cast (c-style, etc). 2194 S.AddOverloadCandidate(Constructor, FoundDecl, 2195 &From, 1, CandidateSet, 2196 /*SuppressUserConversions=*/ 2197 !ConstructorsOnly); 2198 } 2199 } 2200 } 2201 } 2202 2203 // Enumerate conversion functions, if we're allowed to. 2204 if (ConstructorsOnly) { 2205 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 2206 S.PDiag(0) << From->getSourceRange())) { 2207 // No conversion functions from incomplete types. 2208 } else if (const RecordType *FromRecordType 2209 = From->getType()->getAs<RecordType>()) { 2210 if (CXXRecordDecl *FromRecordDecl 2211 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 2212 // Add all of the conversion functions as candidates. 2213 const UnresolvedSetImpl *Conversions 2214 = FromRecordDecl->getVisibleConversionFunctions(); 2215 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2216 E = Conversions->end(); I != E; ++I) { 2217 DeclAccessPair FoundDecl = I.getPair(); 2218 NamedDecl *D = FoundDecl.getDecl(); 2219 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 2220 if (isa<UsingShadowDecl>(D)) 2221 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2222 2223 CXXConversionDecl *Conv; 2224 FunctionTemplateDecl *ConvTemplate; 2225 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 2226 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2227 else 2228 Conv = cast<CXXConversionDecl>(D); 2229 2230 if (AllowExplicit || !Conv->isExplicit()) { 2231 if (ConvTemplate) 2232 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 2233 ActingContext, From, ToType, 2234 CandidateSet); 2235 else 2236 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 2237 From, ToType, CandidateSet); 2238 } 2239 } 2240 } 2241 } 2242 2243 OverloadCandidateSet::iterator Best; 2244 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2245 case OR_Success: 2246 // Record the standard conversion we used and the conversion function. 2247 if (CXXConstructorDecl *Constructor 2248 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 2249 // C++ [over.ics.user]p1: 2250 // If the user-defined conversion is specified by a 2251 // constructor (12.3.1), the initial standard conversion 2252 // sequence converts the source type to the type required by 2253 // the argument of the constructor. 2254 // 2255 QualType ThisType = Constructor->getThisType(S.Context); 2256 if (Best->Conversions[0].isEllipsis()) 2257 User.EllipsisConversion = true; 2258 else { 2259 User.Before = Best->Conversions[0].Standard; 2260 User.EllipsisConversion = false; 2261 } 2262 User.ConversionFunction = Constructor; 2263 User.FoundConversionFunction = Best->FoundDecl.getDecl(); 2264 User.After.setAsIdentityConversion(); 2265 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2266 User.After.setAllToTypes(ToType); 2267 return OR_Success; 2268 } else if (CXXConversionDecl *Conversion 2269 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2270 // C++ [over.ics.user]p1: 2271 // 2272 // [...] If the user-defined conversion is specified by a 2273 // conversion function (12.3.2), the initial standard 2274 // conversion sequence converts the source type to the 2275 // implicit object parameter of the conversion function. 2276 User.Before = Best->Conversions[0].Standard; 2277 User.ConversionFunction = Conversion; 2278 User.FoundConversionFunction = Best->FoundDecl.getDecl(); 2279 User.EllipsisConversion = false; 2280 2281 // C++ [over.ics.user]p2: 2282 // The second standard conversion sequence converts the 2283 // result of the user-defined conversion to the target type 2284 // for the sequence. Since an implicit conversion sequence 2285 // is an initialization, the special rules for 2286 // initialization by user-defined conversion apply when 2287 // selecting the best user-defined conversion for a 2288 // user-defined conversion sequence (see 13.3.3 and 2289 // 13.3.3.1). 2290 User.After = Best->FinalConversion; 2291 return OR_Success; 2292 } else { 2293 llvm_unreachable("Not a constructor or conversion function?"); 2294 return OR_No_Viable_Function; 2295 } 2296 2297 case OR_No_Viable_Function: 2298 return OR_No_Viable_Function; 2299 case OR_Deleted: 2300 // No conversion here! We're done. 2301 return OR_Deleted; 2302 2303 case OR_Ambiguous: 2304 return OR_Ambiguous; 2305 } 2306 2307 return OR_No_Viable_Function; 2308} 2309 2310bool 2311Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2312 ImplicitConversionSequence ICS; 2313 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2314 OverloadingResult OvResult = 2315 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 2316 CandidateSet, false); 2317 if (OvResult == OR_Ambiguous) 2318 Diag(From->getSourceRange().getBegin(), 2319 diag::err_typecheck_ambiguous_condition) 2320 << From->getType() << ToType << From->getSourceRange(); 2321 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2322 Diag(From->getSourceRange().getBegin(), 2323 diag::err_typecheck_nonviable_condition) 2324 << From->getType() << ToType << From->getSourceRange(); 2325 else 2326 return false; 2327 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &From, 1); 2328 return true; 2329} 2330 2331/// CompareImplicitConversionSequences - Compare two implicit 2332/// conversion sequences to determine whether one is better than the 2333/// other or if they are indistinguishable (C++ 13.3.3.2). 2334static ImplicitConversionSequence::CompareKind 2335CompareImplicitConversionSequences(Sema &S, 2336 const ImplicitConversionSequence& ICS1, 2337 const ImplicitConversionSequence& ICS2) 2338{ 2339 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2340 // conversion sequences (as defined in 13.3.3.1) 2341 // -- a standard conversion sequence (13.3.3.1.1) is a better 2342 // conversion sequence than a user-defined conversion sequence or 2343 // an ellipsis conversion sequence, and 2344 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2345 // conversion sequence than an ellipsis conversion sequence 2346 // (13.3.3.1.3). 2347 // 2348 // C++0x [over.best.ics]p10: 2349 // For the purpose of ranking implicit conversion sequences as 2350 // described in 13.3.3.2, the ambiguous conversion sequence is 2351 // treated as a user-defined sequence that is indistinguishable 2352 // from any other user-defined conversion sequence. 2353 if (ICS1.getKindRank() < ICS2.getKindRank()) 2354 return ImplicitConversionSequence::Better; 2355 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2356 return ImplicitConversionSequence::Worse; 2357 2358 // The following checks require both conversion sequences to be of 2359 // the same kind. 2360 if (ICS1.getKind() != ICS2.getKind()) 2361 return ImplicitConversionSequence::Indistinguishable; 2362 2363 // Two implicit conversion sequences of the same form are 2364 // indistinguishable conversion sequences unless one of the 2365 // following rules apply: (C++ 13.3.3.2p3): 2366 if (ICS1.isStandard()) 2367 return CompareStandardConversionSequences(S, ICS1.Standard, ICS2.Standard); 2368 else if (ICS1.isUserDefined()) { 2369 // User-defined conversion sequence U1 is a better conversion 2370 // sequence than another user-defined conversion sequence U2 if 2371 // they contain the same user-defined conversion function or 2372 // constructor and if the second standard conversion sequence of 2373 // U1 is better than the second standard conversion sequence of 2374 // U2 (C++ 13.3.3.2p3). 2375 if (ICS1.UserDefined.ConversionFunction == 2376 ICS2.UserDefined.ConversionFunction) 2377 return CompareStandardConversionSequences(S, 2378 ICS1.UserDefined.After, 2379 ICS2.UserDefined.After); 2380 } 2381 2382 return ImplicitConversionSequence::Indistinguishable; 2383} 2384 2385static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2386 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2387 Qualifiers Quals; 2388 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2389 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2390 } 2391 2392 return Context.hasSameUnqualifiedType(T1, T2); 2393} 2394 2395// Per 13.3.3.2p3, compare the given standard conversion sequences to 2396// determine if one is a proper subset of the other. 2397static ImplicitConversionSequence::CompareKind 2398compareStandardConversionSubsets(ASTContext &Context, 2399 const StandardConversionSequence& SCS1, 2400 const StandardConversionSequence& SCS2) { 2401 ImplicitConversionSequence::CompareKind Result 2402 = ImplicitConversionSequence::Indistinguishable; 2403 2404 // the identity conversion sequence is considered to be a subsequence of 2405 // any non-identity conversion sequence 2406 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2407 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2408 return ImplicitConversionSequence::Better; 2409 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2410 return ImplicitConversionSequence::Worse; 2411 } 2412 2413 if (SCS1.Second != SCS2.Second) { 2414 if (SCS1.Second == ICK_Identity) 2415 Result = ImplicitConversionSequence::Better; 2416 else if (SCS2.Second == ICK_Identity) 2417 Result = ImplicitConversionSequence::Worse; 2418 else 2419 return ImplicitConversionSequence::Indistinguishable; 2420 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2421 return ImplicitConversionSequence::Indistinguishable; 2422 2423 if (SCS1.Third == SCS2.Third) { 2424 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2425 : ImplicitConversionSequence::Indistinguishable; 2426 } 2427 2428 if (SCS1.Third == ICK_Identity) 2429 return Result == ImplicitConversionSequence::Worse 2430 ? ImplicitConversionSequence::Indistinguishable 2431 : ImplicitConversionSequence::Better; 2432 2433 if (SCS2.Third == ICK_Identity) 2434 return Result == ImplicitConversionSequence::Better 2435 ? ImplicitConversionSequence::Indistinguishable 2436 : ImplicitConversionSequence::Worse; 2437 2438 return ImplicitConversionSequence::Indistinguishable; 2439} 2440 2441/// \brief Determine whether one of the given reference bindings is better 2442/// than the other based on what kind of bindings they are. 2443static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 2444 const StandardConversionSequence &SCS2) { 2445 // C++0x [over.ics.rank]p3b4: 2446 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2447 // implicit object parameter of a non-static member function declared 2448 // without a ref-qualifier, and *either* S1 binds an rvalue reference 2449 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 2450 // lvalue reference to a function lvalue and S2 binds an rvalue 2451 // reference*. 2452 // 2453 // FIXME: Rvalue references. We're going rogue with the above edits, 2454 // because the semantics in the current C++0x working paper (N3225 at the 2455 // time of this writing) break the standard definition of std::forward 2456 // and std::reference_wrapper when dealing with references to functions. 2457 // Proposed wording changes submitted to CWG for consideration. 2458 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 2459 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 2460 return false; 2461 2462 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 2463 SCS2.IsLvalueReference) || 2464 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 2465 !SCS2.IsLvalueReference); 2466} 2467 2468/// CompareStandardConversionSequences - Compare two standard 2469/// conversion sequences to determine whether one is better than the 2470/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2471static ImplicitConversionSequence::CompareKind 2472CompareStandardConversionSequences(Sema &S, 2473 const StandardConversionSequence& SCS1, 2474 const StandardConversionSequence& SCS2) 2475{ 2476 // Standard conversion sequence S1 is a better conversion sequence 2477 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2478 2479 // -- S1 is a proper subsequence of S2 (comparing the conversion 2480 // sequences in the canonical form defined by 13.3.3.1.1, 2481 // excluding any Lvalue Transformation; the identity conversion 2482 // sequence is considered to be a subsequence of any 2483 // non-identity conversion sequence) or, if not that, 2484 if (ImplicitConversionSequence::CompareKind CK 2485 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 2486 return CK; 2487 2488 // -- the rank of S1 is better than the rank of S2 (by the rules 2489 // defined below), or, if not that, 2490 ImplicitConversionRank Rank1 = SCS1.getRank(); 2491 ImplicitConversionRank Rank2 = SCS2.getRank(); 2492 if (Rank1 < Rank2) 2493 return ImplicitConversionSequence::Better; 2494 else if (Rank2 < Rank1) 2495 return ImplicitConversionSequence::Worse; 2496 2497 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2498 // are indistinguishable unless one of the following rules 2499 // applies: 2500 2501 // A conversion that is not a conversion of a pointer, or 2502 // pointer to member, to bool is better than another conversion 2503 // that is such a conversion. 2504 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2505 return SCS2.isPointerConversionToBool() 2506 ? ImplicitConversionSequence::Better 2507 : ImplicitConversionSequence::Worse; 2508 2509 // C++ [over.ics.rank]p4b2: 2510 // 2511 // If class B is derived directly or indirectly from class A, 2512 // conversion of B* to A* is better than conversion of B* to 2513 // void*, and conversion of A* to void* is better than conversion 2514 // of B* to void*. 2515 bool SCS1ConvertsToVoid 2516 = SCS1.isPointerConversionToVoidPointer(S.Context); 2517 bool SCS2ConvertsToVoid 2518 = SCS2.isPointerConversionToVoidPointer(S.Context); 2519 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2520 // Exactly one of the conversion sequences is a conversion to 2521 // a void pointer; it's the worse conversion. 2522 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2523 : ImplicitConversionSequence::Worse; 2524 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2525 // Neither conversion sequence converts to a void pointer; compare 2526 // their derived-to-base conversions. 2527 if (ImplicitConversionSequence::CompareKind DerivedCK 2528 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 2529 return DerivedCK; 2530 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2531 // Both conversion sequences are conversions to void 2532 // pointers. Compare the source types to determine if there's an 2533 // inheritance relationship in their sources. 2534 QualType FromType1 = SCS1.getFromType(); 2535 QualType FromType2 = SCS2.getFromType(); 2536 2537 // Adjust the types we're converting from via the array-to-pointer 2538 // conversion, if we need to. 2539 if (SCS1.First == ICK_Array_To_Pointer) 2540 FromType1 = S.Context.getArrayDecayedType(FromType1); 2541 if (SCS2.First == ICK_Array_To_Pointer) 2542 FromType2 = S.Context.getArrayDecayedType(FromType2); 2543 2544 QualType FromPointee1 2545 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2546 QualType FromPointee2 2547 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2548 2549 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2550 return ImplicitConversionSequence::Better; 2551 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2552 return ImplicitConversionSequence::Worse; 2553 2554 // Objective-C++: If one interface is more specific than the 2555 // other, it is the better one. 2556 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2557 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2558 if (FromIface1 && FromIface1) { 2559 if (S.Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2560 return ImplicitConversionSequence::Better; 2561 else if (S.Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2562 return ImplicitConversionSequence::Worse; 2563 } 2564 } 2565 2566 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2567 // bullet 3). 2568 if (ImplicitConversionSequence::CompareKind QualCK 2569 = CompareQualificationConversions(S, SCS1, SCS2)) 2570 return QualCK; 2571 2572 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2573 // Check for a better reference binding based on the kind of bindings. 2574 if (isBetterReferenceBindingKind(SCS1, SCS2)) 2575 return ImplicitConversionSequence::Better; 2576 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 2577 return ImplicitConversionSequence::Worse; 2578 2579 // C++ [over.ics.rank]p3b4: 2580 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2581 // which the references refer are the same type except for 2582 // top-level cv-qualifiers, and the type to which the reference 2583 // initialized by S2 refers is more cv-qualified than the type 2584 // to which the reference initialized by S1 refers. 2585 QualType T1 = SCS1.getToType(2); 2586 QualType T2 = SCS2.getToType(2); 2587 T1 = S.Context.getCanonicalType(T1); 2588 T2 = S.Context.getCanonicalType(T2); 2589 Qualifiers T1Quals, T2Quals; 2590 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2591 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2592 if (UnqualT1 == UnqualT2) { 2593 // If the type is an array type, promote the element qualifiers to the 2594 // type for comparison. 2595 if (isa<ArrayType>(T1) && T1Quals) 2596 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2597 if (isa<ArrayType>(T2) && T2Quals) 2598 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2599 if (T2.isMoreQualifiedThan(T1)) 2600 return ImplicitConversionSequence::Better; 2601 else if (T1.isMoreQualifiedThan(T2)) 2602 return ImplicitConversionSequence::Worse; 2603 } 2604 } 2605 2606 return ImplicitConversionSequence::Indistinguishable; 2607} 2608 2609/// CompareQualificationConversions - Compares two standard conversion 2610/// sequences to determine whether they can be ranked based on their 2611/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2612ImplicitConversionSequence::CompareKind 2613CompareQualificationConversions(Sema &S, 2614 const StandardConversionSequence& SCS1, 2615 const StandardConversionSequence& SCS2) { 2616 // C++ 13.3.3.2p3: 2617 // -- S1 and S2 differ only in their qualification conversion and 2618 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2619 // cv-qualification signature of type T1 is a proper subset of 2620 // the cv-qualification signature of type T2, and S1 is not the 2621 // deprecated string literal array-to-pointer conversion (4.2). 2622 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2623 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2624 return ImplicitConversionSequence::Indistinguishable; 2625 2626 // FIXME: the example in the standard doesn't use a qualification 2627 // conversion (!) 2628 QualType T1 = SCS1.getToType(2); 2629 QualType T2 = SCS2.getToType(2); 2630 T1 = S.Context.getCanonicalType(T1); 2631 T2 = S.Context.getCanonicalType(T2); 2632 Qualifiers T1Quals, T2Quals; 2633 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2634 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2635 2636 // If the types are the same, we won't learn anything by unwrapped 2637 // them. 2638 if (UnqualT1 == UnqualT2) 2639 return ImplicitConversionSequence::Indistinguishable; 2640 2641 // If the type is an array type, promote the element qualifiers to the type 2642 // for comparison. 2643 if (isa<ArrayType>(T1) && T1Quals) 2644 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2645 if (isa<ArrayType>(T2) && T2Quals) 2646 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2647 2648 ImplicitConversionSequence::CompareKind Result 2649 = ImplicitConversionSequence::Indistinguishable; 2650 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 2651 // Within each iteration of the loop, we check the qualifiers to 2652 // determine if this still looks like a qualification 2653 // conversion. Then, if all is well, we unwrap one more level of 2654 // pointers or pointers-to-members and do it all again 2655 // until there are no more pointers or pointers-to-members left 2656 // to unwrap. This essentially mimics what 2657 // IsQualificationConversion does, but here we're checking for a 2658 // strict subset of qualifiers. 2659 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2660 // The qualifiers are the same, so this doesn't tell us anything 2661 // about how the sequences rank. 2662 ; 2663 else if (T2.isMoreQualifiedThan(T1)) { 2664 // T1 has fewer qualifiers, so it could be the better sequence. 2665 if (Result == ImplicitConversionSequence::Worse) 2666 // Neither has qualifiers that are a subset of the other's 2667 // qualifiers. 2668 return ImplicitConversionSequence::Indistinguishable; 2669 2670 Result = ImplicitConversionSequence::Better; 2671 } else if (T1.isMoreQualifiedThan(T2)) { 2672 // T2 has fewer qualifiers, so it could be the better sequence. 2673 if (Result == ImplicitConversionSequence::Better) 2674 // Neither has qualifiers that are a subset of the other's 2675 // qualifiers. 2676 return ImplicitConversionSequence::Indistinguishable; 2677 2678 Result = ImplicitConversionSequence::Worse; 2679 } else { 2680 // Qualifiers are disjoint. 2681 return ImplicitConversionSequence::Indistinguishable; 2682 } 2683 2684 // If the types after this point are equivalent, we're done. 2685 if (S.Context.hasSameUnqualifiedType(T1, T2)) 2686 break; 2687 } 2688 2689 // Check that the winning standard conversion sequence isn't using 2690 // the deprecated string literal array to pointer conversion. 2691 switch (Result) { 2692 case ImplicitConversionSequence::Better: 2693 if (SCS1.DeprecatedStringLiteralToCharPtr) 2694 Result = ImplicitConversionSequence::Indistinguishable; 2695 break; 2696 2697 case ImplicitConversionSequence::Indistinguishable: 2698 break; 2699 2700 case ImplicitConversionSequence::Worse: 2701 if (SCS2.DeprecatedStringLiteralToCharPtr) 2702 Result = ImplicitConversionSequence::Indistinguishable; 2703 break; 2704 } 2705 2706 return Result; 2707} 2708 2709/// CompareDerivedToBaseConversions - Compares two standard conversion 2710/// sequences to determine whether they can be ranked based on their 2711/// various kinds of derived-to-base conversions (C++ 2712/// [over.ics.rank]p4b3). As part of these checks, we also look at 2713/// conversions between Objective-C interface types. 2714ImplicitConversionSequence::CompareKind 2715CompareDerivedToBaseConversions(Sema &S, 2716 const StandardConversionSequence& SCS1, 2717 const StandardConversionSequence& SCS2) { 2718 QualType FromType1 = SCS1.getFromType(); 2719 QualType ToType1 = SCS1.getToType(1); 2720 QualType FromType2 = SCS2.getFromType(); 2721 QualType ToType2 = SCS2.getToType(1); 2722 2723 // Adjust the types we're converting from via the array-to-pointer 2724 // conversion, if we need to. 2725 if (SCS1.First == ICK_Array_To_Pointer) 2726 FromType1 = S.Context.getArrayDecayedType(FromType1); 2727 if (SCS2.First == ICK_Array_To_Pointer) 2728 FromType2 = S.Context.getArrayDecayedType(FromType2); 2729 2730 // Canonicalize all of the types. 2731 FromType1 = S.Context.getCanonicalType(FromType1); 2732 ToType1 = S.Context.getCanonicalType(ToType1); 2733 FromType2 = S.Context.getCanonicalType(FromType2); 2734 ToType2 = S.Context.getCanonicalType(ToType2); 2735 2736 // C++ [over.ics.rank]p4b3: 2737 // 2738 // If class B is derived directly or indirectly from class A and 2739 // class C is derived directly or indirectly from B, 2740 // 2741 // Compare based on pointer conversions. 2742 if (SCS1.Second == ICK_Pointer_Conversion && 2743 SCS2.Second == ICK_Pointer_Conversion && 2744 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2745 FromType1->isPointerType() && FromType2->isPointerType() && 2746 ToType1->isPointerType() && ToType2->isPointerType()) { 2747 QualType FromPointee1 2748 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2749 QualType ToPointee1 2750 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2751 QualType FromPointee2 2752 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2753 QualType ToPointee2 2754 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2755 2756 // -- conversion of C* to B* is better than conversion of C* to A*, 2757 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2758 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2759 return ImplicitConversionSequence::Better; 2760 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2761 return ImplicitConversionSequence::Worse; 2762 } 2763 2764 // -- conversion of B* to A* is better than conversion of C* to A*, 2765 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2766 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2767 return ImplicitConversionSequence::Better; 2768 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2769 return ImplicitConversionSequence::Worse; 2770 } 2771 } else if (SCS1.Second == ICK_Pointer_Conversion && 2772 SCS2.Second == ICK_Pointer_Conversion) { 2773 const ObjCObjectPointerType *FromPtr1 2774 = FromType1->getAs<ObjCObjectPointerType>(); 2775 const ObjCObjectPointerType *FromPtr2 2776 = FromType2->getAs<ObjCObjectPointerType>(); 2777 const ObjCObjectPointerType *ToPtr1 2778 = ToType1->getAs<ObjCObjectPointerType>(); 2779 const ObjCObjectPointerType *ToPtr2 2780 = ToType2->getAs<ObjCObjectPointerType>(); 2781 2782 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 2783 // Apply the same conversion ranking rules for Objective-C pointer types 2784 // that we do for C++ pointers to class types. However, we employ the 2785 // Objective-C pseudo-subtyping relationship used for assignment of 2786 // Objective-C pointer types. 2787 bool FromAssignLeft 2788 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 2789 bool FromAssignRight 2790 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 2791 bool ToAssignLeft 2792 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 2793 bool ToAssignRight 2794 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 2795 2796 // A conversion to an a non-id object pointer type or qualified 'id' 2797 // type is better than a conversion to 'id'. 2798 if (ToPtr1->isObjCIdType() && 2799 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 2800 return ImplicitConversionSequence::Worse; 2801 if (ToPtr2->isObjCIdType() && 2802 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 2803 return ImplicitConversionSequence::Better; 2804 2805 // A conversion to a non-id object pointer type is better than a 2806 // conversion to a qualified 'id' type 2807 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 2808 return ImplicitConversionSequence::Worse; 2809 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 2810 return ImplicitConversionSequence::Better; 2811 2812 // A conversion to an a non-Class object pointer type or qualified 'Class' 2813 // type is better than a conversion to 'Class'. 2814 if (ToPtr1->isObjCClassType() && 2815 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 2816 return ImplicitConversionSequence::Worse; 2817 if (ToPtr2->isObjCClassType() && 2818 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 2819 return ImplicitConversionSequence::Better; 2820 2821 // A conversion to a non-Class object pointer type is better than a 2822 // conversion to a qualified 'Class' type. 2823 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 2824 return ImplicitConversionSequence::Worse; 2825 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 2826 return ImplicitConversionSequence::Better; 2827 2828 // -- "conversion of C* to B* is better than conversion of C* to A*," 2829 if (S.Context.hasSameType(FromType1, FromType2) && 2830 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 2831 (ToAssignLeft != ToAssignRight)) 2832 return ToAssignLeft? ImplicitConversionSequence::Worse 2833 : ImplicitConversionSequence::Better; 2834 2835 // -- "conversion of B* to A* is better than conversion of C* to A*," 2836 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 2837 (FromAssignLeft != FromAssignRight)) 2838 return FromAssignLeft? ImplicitConversionSequence::Better 2839 : ImplicitConversionSequence::Worse; 2840 } 2841 } 2842 2843 // Ranking of member-pointer types. 2844 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2845 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2846 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2847 const MemberPointerType * FromMemPointer1 = 2848 FromType1->getAs<MemberPointerType>(); 2849 const MemberPointerType * ToMemPointer1 = 2850 ToType1->getAs<MemberPointerType>(); 2851 const MemberPointerType * FromMemPointer2 = 2852 FromType2->getAs<MemberPointerType>(); 2853 const MemberPointerType * ToMemPointer2 = 2854 ToType2->getAs<MemberPointerType>(); 2855 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2856 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2857 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2858 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2859 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2860 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2861 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2862 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2863 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2864 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2865 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2866 return ImplicitConversionSequence::Worse; 2867 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2868 return ImplicitConversionSequence::Better; 2869 } 2870 // conversion of B::* to C::* is better than conversion of A::* to C::* 2871 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2872 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2873 return ImplicitConversionSequence::Better; 2874 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2875 return ImplicitConversionSequence::Worse; 2876 } 2877 } 2878 2879 if (SCS1.Second == ICK_Derived_To_Base) { 2880 // -- conversion of C to B is better than conversion of C to A, 2881 // -- binding of an expression of type C to a reference of type 2882 // B& is better than binding an expression of type C to a 2883 // reference of type A&, 2884 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2885 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2886 if (S.IsDerivedFrom(ToType1, ToType2)) 2887 return ImplicitConversionSequence::Better; 2888 else if (S.IsDerivedFrom(ToType2, ToType1)) 2889 return ImplicitConversionSequence::Worse; 2890 } 2891 2892 // -- conversion of B to A is better than conversion of C to A. 2893 // -- binding of an expression of type B to a reference of type 2894 // A& is better than binding an expression of type C to a 2895 // reference of type A&, 2896 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2897 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2898 if (S.IsDerivedFrom(FromType2, FromType1)) 2899 return ImplicitConversionSequence::Better; 2900 else if (S.IsDerivedFrom(FromType1, FromType2)) 2901 return ImplicitConversionSequence::Worse; 2902 } 2903 } 2904 2905 return ImplicitConversionSequence::Indistinguishable; 2906} 2907 2908/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2909/// determine whether they are reference-related, 2910/// reference-compatible, reference-compatible with added 2911/// qualification, or incompatible, for use in C++ initialization by 2912/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2913/// type, and the first type (T1) is the pointee type of the reference 2914/// type being initialized. 2915Sema::ReferenceCompareResult 2916Sema::CompareReferenceRelationship(SourceLocation Loc, 2917 QualType OrigT1, QualType OrigT2, 2918 bool &DerivedToBase, 2919 bool &ObjCConversion) { 2920 assert(!OrigT1->isReferenceType() && 2921 "T1 must be the pointee type of the reference type"); 2922 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2923 2924 QualType T1 = Context.getCanonicalType(OrigT1); 2925 QualType T2 = Context.getCanonicalType(OrigT2); 2926 Qualifiers T1Quals, T2Quals; 2927 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2928 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2929 2930 // C++ [dcl.init.ref]p4: 2931 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2932 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2933 // T1 is a base class of T2. 2934 DerivedToBase = false; 2935 ObjCConversion = false; 2936 if (UnqualT1 == UnqualT2) { 2937 // Nothing to do. 2938 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2939 IsDerivedFrom(UnqualT2, UnqualT1)) 2940 DerivedToBase = true; 2941 else if (UnqualT1->isObjCObjectOrInterfaceType() && 2942 UnqualT2->isObjCObjectOrInterfaceType() && 2943 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 2944 ObjCConversion = true; 2945 else 2946 return Ref_Incompatible; 2947 2948 // At this point, we know that T1 and T2 are reference-related (at 2949 // least). 2950 2951 // If the type is an array type, promote the element qualifiers to the type 2952 // for comparison. 2953 if (isa<ArrayType>(T1) && T1Quals) 2954 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2955 if (isa<ArrayType>(T2) && T2Quals) 2956 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2957 2958 // C++ [dcl.init.ref]p4: 2959 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2960 // reference-related to T2 and cv1 is the same cv-qualification 2961 // as, or greater cv-qualification than, cv2. For purposes of 2962 // overload resolution, cases for which cv1 is greater 2963 // cv-qualification than cv2 are identified as 2964 // reference-compatible with added qualification (see 13.3.3.2). 2965 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2966 return Ref_Compatible; 2967 else if (T1.isMoreQualifiedThan(T2)) 2968 return Ref_Compatible_With_Added_Qualification; 2969 else 2970 return Ref_Related; 2971} 2972 2973/// \brief Look for a user-defined conversion to an value reference-compatible 2974/// with DeclType. Return true if something definite is found. 2975static bool 2976FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 2977 QualType DeclType, SourceLocation DeclLoc, 2978 Expr *Init, QualType T2, bool AllowRvalues, 2979 bool AllowExplicit) { 2980 assert(T2->isRecordType() && "Can only find conversions of record types."); 2981 CXXRecordDecl *T2RecordDecl 2982 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2983 2984 OverloadCandidateSet CandidateSet(DeclLoc); 2985 const UnresolvedSetImpl *Conversions 2986 = T2RecordDecl->getVisibleConversionFunctions(); 2987 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2988 E = Conversions->end(); I != E; ++I) { 2989 NamedDecl *D = *I; 2990 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2991 if (isa<UsingShadowDecl>(D)) 2992 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2993 2994 FunctionTemplateDecl *ConvTemplate 2995 = dyn_cast<FunctionTemplateDecl>(D); 2996 CXXConversionDecl *Conv; 2997 if (ConvTemplate) 2998 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2999 else 3000 Conv = cast<CXXConversionDecl>(D); 3001 3002 // If this is an explicit conversion, and we're not allowed to consider 3003 // explicit conversions, skip it. 3004 if (!AllowExplicit && Conv->isExplicit()) 3005 continue; 3006 3007 if (AllowRvalues) { 3008 bool DerivedToBase = false; 3009 bool ObjCConversion = false; 3010 if (!ConvTemplate && 3011 S.CompareReferenceRelationship( 3012 DeclLoc, 3013 Conv->getConversionType().getNonReferenceType() 3014 .getUnqualifiedType(), 3015 DeclType.getNonReferenceType().getUnqualifiedType(), 3016 DerivedToBase, ObjCConversion) == 3017 Sema::Ref_Incompatible) 3018 continue; 3019 } else { 3020 // If the conversion function doesn't return a reference type, 3021 // it can't be considered for this conversion. An rvalue reference 3022 // is only acceptable if its referencee is a function type. 3023 3024 const ReferenceType *RefType = 3025 Conv->getConversionType()->getAs<ReferenceType>(); 3026 if (!RefType || 3027 (!RefType->isLValueReferenceType() && 3028 !RefType->getPointeeType()->isFunctionType())) 3029 continue; 3030 } 3031 3032 if (ConvTemplate) 3033 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 3034 Init, DeclType, CandidateSet); 3035 else 3036 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 3037 DeclType, CandidateSet); 3038 } 3039 3040 OverloadCandidateSet::iterator Best; 3041 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 3042 case OR_Success: 3043 // C++ [over.ics.ref]p1: 3044 // 3045 // [...] If the parameter binds directly to the result of 3046 // applying a conversion function to the argument 3047 // expression, the implicit conversion sequence is a 3048 // user-defined conversion sequence (13.3.3.1.2), with the 3049 // second standard conversion sequence either an identity 3050 // conversion or, if the conversion function returns an 3051 // entity of a type that is a derived class of the parameter 3052 // type, a derived-to-base Conversion. 3053 if (!Best->FinalConversion.DirectBinding) 3054 return false; 3055 3056 ICS.setUserDefined(); 3057 ICS.UserDefined.Before = Best->Conversions[0].Standard; 3058 ICS.UserDefined.After = Best->FinalConversion; 3059 ICS.UserDefined.ConversionFunction = Best->Function; 3060 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl.getDecl(); 3061 ICS.UserDefined.EllipsisConversion = false; 3062 assert(ICS.UserDefined.After.ReferenceBinding && 3063 ICS.UserDefined.After.DirectBinding && 3064 "Expected a direct reference binding!"); 3065 return true; 3066 3067 case OR_Ambiguous: 3068 ICS.setAmbiguous(); 3069 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3070 Cand != CandidateSet.end(); ++Cand) 3071 if (Cand->Viable) 3072 ICS.Ambiguous.addConversion(Cand->Function); 3073 return true; 3074 3075 case OR_No_Viable_Function: 3076 case OR_Deleted: 3077 // There was no suitable conversion, or we found a deleted 3078 // conversion; continue with other checks. 3079 return false; 3080 } 3081 3082 return false; 3083} 3084 3085/// \brief Compute an implicit conversion sequence for reference 3086/// initialization. 3087static ImplicitConversionSequence 3088TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 3089 SourceLocation DeclLoc, 3090 bool SuppressUserConversions, 3091 bool AllowExplicit) { 3092 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 3093 3094 // Most paths end in a failed conversion. 3095 ImplicitConversionSequence ICS; 3096 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3097 3098 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 3099 QualType T2 = Init->getType(); 3100 3101 // If the initializer is the address of an overloaded function, try 3102 // to resolve the overloaded function. If all goes well, T2 is the 3103 // type of the resulting function. 3104 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 3105 DeclAccessPair Found; 3106 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 3107 false, Found)) 3108 T2 = Fn->getType(); 3109 } 3110 3111 // Compute some basic properties of the types and the initializer. 3112 bool isRValRef = DeclType->isRValueReferenceType(); 3113 bool DerivedToBase = false; 3114 bool ObjCConversion = false; 3115 Expr::Classification InitCategory = Init->Classify(S.Context); 3116 Sema::ReferenceCompareResult RefRelationship 3117 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 3118 ObjCConversion); 3119 3120 3121 // C++0x [dcl.init.ref]p5: 3122 // A reference to type "cv1 T1" is initialized by an expression 3123 // of type "cv2 T2" as follows: 3124 3125 // -- If reference is an lvalue reference and the initializer expression 3126 if (!isRValRef) { 3127 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 3128 // reference-compatible with "cv2 T2," or 3129 // 3130 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 3131 if (InitCategory.isLValue() && 3132 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 3133 // C++ [over.ics.ref]p1: 3134 // When a parameter of reference type binds directly (8.5.3) 3135 // to an argument expression, the implicit conversion sequence 3136 // is the identity conversion, unless the argument expression 3137 // has a type that is a derived class of the parameter type, 3138 // in which case the implicit conversion sequence is a 3139 // derived-to-base Conversion (13.3.3.1). 3140 ICS.setStandard(); 3141 ICS.Standard.First = ICK_Identity; 3142 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3143 : ObjCConversion? ICK_Compatible_Conversion 3144 : ICK_Identity; 3145 ICS.Standard.Third = ICK_Identity; 3146 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3147 ICS.Standard.setToType(0, T2); 3148 ICS.Standard.setToType(1, T1); 3149 ICS.Standard.setToType(2, T1); 3150 ICS.Standard.ReferenceBinding = true; 3151 ICS.Standard.DirectBinding = true; 3152 ICS.Standard.IsLvalueReference = !isRValRef; 3153 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3154 ICS.Standard.BindsToRvalue = false; 3155 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3156 ICS.Standard.CopyConstructor = 0; 3157 3158 // Nothing more to do: the inaccessibility/ambiguity check for 3159 // derived-to-base conversions is suppressed when we're 3160 // computing the implicit conversion sequence (C++ 3161 // [over.best.ics]p2). 3162 return ICS; 3163 } 3164 3165 // -- has a class type (i.e., T2 is a class type), where T1 is 3166 // not reference-related to T2, and can be implicitly 3167 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 3168 // is reference-compatible with "cv3 T3" 92) (this 3169 // conversion is selected by enumerating the applicable 3170 // conversion functions (13.3.1.6) and choosing the best 3171 // one through overload resolution (13.3)), 3172 if (!SuppressUserConversions && T2->isRecordType() && 3173 !S.RequireCompleteType(DeclLoc, T2, 0) && 3174 RefRelationship == Sema::Ref_Incompatible) { 3175 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3176 Init, T2, /*AllowRvalues=*/false, 3177 AllowExplicit)) 3178 return ICS; 3179 } 3180 } 3181 3182 // -- Otherwise, the reference shall be an lvalue reference to a 3183 // non-volatile const type (i.e., cv1 shall be const), or the reference 3184 // shall be an rvalue reference. 3185 // 3186 // We actually handle one oddity of C++ [over.ics.ref] at this 3187 // point, which is that, due to p2 (which short-circuits reference 3188 // binding by only attempting a simple conversion for non-direct 3189 // bindings) and p3's strange wording, we allow a const volatile 3190 // reference to bind to an rvalue. Hence the check for the presence 3191 // of "const" rather than checking for "const" being the only 3192 // qualifier. 3193 // This is also the point where rvalue references and lvalue inits no longer 3194 // go together. 3195 if (!isRValRef && !T1.isConstQualified()) 3196 return ICS; 3197 3198 // -- If the initializer expression 3199 // 3200 // -- is an xvalue, class prvalue, array prvalue or function 3201 // lvalue and "cv1T1" is reference-compatible with "cv2 T2", or 3202 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 3203 (InitCategory.isXValue() || 3204 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 3205 (InitCategory.isLValue() && T2->isFunctionType()))) { 3206 ICS.setStandard(); 3207 ICS.Standard.First = ICK_Identity; 3208 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3209 : ObjCConversion? ICK_Compatible_Conversion 3210 : ICK_Identity; 3211 ICS.Standard.Third = ICK_Identity; 3212 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3213 ICS.Standard.setToType(0, T2); 3214 ICS.Standard.setToType(1, T1); 3215 ICS.Standard.setToType(2, T1); 3216 ICS.Standard.ReferenceBinding = true; 3217 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 3218 // binding unless we're binding to a class prvalue. 3219 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 3220 // allow the use of rvalue references in C++98/03 for the benefit of 3221 // standard library implementors; therefore, we need the xvalue check here. 3222 ICS.Standard.DirectBinding = 3223 S.getLangOptions().CPlusPlus0x || 3224 (InitCategory.isPRValue() && !T2->isRecordType()); 3225 ICS.Standard.IsLvalueReference = !isRValRef; 3226 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3227 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 3228 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3229 ICS.Standard.CopyConstructor = 0; 3230 return ICS; 3231 } 3232 3233 // -- has a class type (i.e., T2 is a class type), where T1 is not 3234 // reference-related to T2, and can be implicitly converted to 3235 // an xvalue, class prvalue, or function lvalue of type 3236 // "cv3 T3", where "cv1 T1" is reference-compatible with 3237 // "cv3 T3", 3238 // 3239 // then the reference is bound to the value of the initializer 3240 // expression in the first case and to the result of the conversion 3241 // in the second case (or, in either case, to an appropriate base 3242 // class subobject). 3243 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3244 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 3245 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3246 Init, T2, /*AllowRvalues=*/true, 3247 AllowExplicit)) { 3248 // In the second case, if the reference is an rvalue reference 3249 // and the second standard conversion sequence of the 3250 // user-defined conversion sequence includes an lvalue-to-rvalue 3251 // conversion, the program is ill-formed. 3252 if (ICS.isUserDefined() && isRValRef && 3253 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 3254 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3255 3256 return ICS; 3257 } 3258 3259 // -- Otherwise, a temporary of type "cv1 T1" is created and 3260 // initialized from the initializer expression using the 3261 // rules for a non-reference copy initialization (8.5). The 3262 // reference is then bound to the temporary. If T1 is 3263 // reference-related to T2, cv1 must be the same 3264 // cv-qualification as, or greater cv-qualification than, 3265 // cv2; otherwise, the program is ill-formed. 3266 if (RefRelationship == Sema::Ref_Related) { 3267 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 3268 // we would be reference-compatible or reference-compatible with 3269 // added qualification. But that wasn't the case, so the reference 3270 // initialization fails. 3271 return ICS; 3272 } 3273 3274 // If at least one of the types is a class type, the types are not 3275 // related, and we aren't allowed any user conversions, the 3276 // reference binding fails. This case is important for breaking 3277 // recursion, since TryImplicitConversion below will attempt to 3278 // create a temporary through the use of a copy constructor. 3279 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3280 (T1->isRecordType() || T2->isRecordType())) 3281 return ICS; 3282 3283 // If T1 is reference-related to T2 and the reference is an rvalue 3284 // reference, the initializer expression shall not be an lvalue. 3285 if (RefRelationship >= Sema::Ref_Related && 3286 isRValRef && Init->Classify(S.Context).isLValue()) 3287 return ICS; 3288 3289 // C++ [over.ics.ref]p2: 3290 // When a parameter of reference type is not bound directly to 3291 // an argument expression, the conversion sequence is the one 3292 // required to convert the argument expression to the 3293 // underlying type of the reference according to 3294 // 13.3.3.1. Conceptually, this conversion sequence corresponds 3295 // to copy-initializing a temporary of the underlying type with 3296 // the argument expression. Any difference in top-level 3297 // cv-qualification is subsumed by the initialization itself 3298 // and does not constitute a conversion. 3299 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 3300 /*AllowExplicit=*/false, 3301 /*InOverloadResolution=*/false, 3302 /*CStyle=*/false); 3303 3304 // Of course, that's still a reference binding. 3305 if (ICS.isStandard()) { 3306 ICS.Standard.ReferenceBinding = true; 3307 ICS.Standard.IsLvalueReference = !isRValRef; 3308 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3309 ICS.Standard.BindsToRvalue = true; 3310 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3311 } else if (ICS.isUserDefined()) { 3312 ICS.UserDefined.After.ReferenceBinding = true; 3313 ICS.Standard.IsLvalueReference = !isRValRef; 3314 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3315 ICS.Standard.BindsToRvalue = true; 3316 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3317 } 3318 3319 return ICS; 3320} 3321 3322/// TryCopyInitialization - Try to copy-initialize a value of type 3323/// ToType from the expression From. Return the implicit conversion 3324/// sequence required to pass this argument, which may be a bad 3325/// conversion sequence (meaning that the argument cannot be passed to 3326/// a parameter of this type). If @p SuppressUserConversions, then we 3327/// do not permit any user-defined conversion sequences. 3328static ImplicitConversionSequence 3329TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 3330 bool SuppressUserConversions, 3331 bool InOverloadResolution) { 3332 if (ToType->isReferenceType()) 3333 return TryReferenceInit(S, From, ToType, 3334 /*FIXME:*/From->getLocStart(), 3335 SuppressUserConversions, 3336 /*AllowExplicit=*/false); 3337 3338 return TryImplicitConversion(S, From, ToType, 3339 SuppressUserConversions, 3340 /*AllowExplicit=*/false, 3341 InOverloadResolution, 3342 /*CStyle=*/false); 3343} 3344 3345/// TryObjectArgumentInitialization - Try to initialize the object 3346/// parameter of the given member function (@c Method) from the 3347/// expression @p From. 3348static ImplicitConversionSequence 3349TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 3350 Expr::Classification FromClassification, 3351 CXXMethodDecl *Method, 3352 CXXRecordDecl *ActingContext) { 3353 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 3354 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 3355 // const volatile object. 3356 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 3357 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 3358 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 3359 3360 // Set up the conversion sequence as a "bad" conversion, to allow us 3361 // to exit early. 3362 ImplicitConversionSequence ICS; 3363 3364 // We need to have an object of class type. 3365 QualType FromType = OrigFromType; 3366 if (const PointerType *PT = FromType->getAs<PointerType>()) { 3367 FromType = PT->getPointeeType(); 3368 3369 // When we had a pointer, it's implicitly dereferenced, so we 3370 // better have an lvalue. 3371 assert(FromClassification.isLValue()); 3372 } 3373 3374 assert(FromType->isRecordType()); 3375 3376 // C++0x [over.match.funcs]p4: 3377 // For non-static member functions, the type of the implicit object 3378 // parameter is 3379 // 3380 // - "lvalue reference to cv X" for functions declared without a 3381 // ref-qualifier or with the & ref-qualifier 3382 // - "rvalue reference to cv X" for functions declared with the && 3383 // ref-qualifier 3384 // 3385 // where X is the class of which the function is a member and cv is the 3386 // cv-qualification on the member function declaration. 3387 // 3388 // However, when finding an implicit conversion sequence for the argument, we 3389 // are not allowed to create temporaries or perform user-defined conversions 3390 // (C++ [over.match.funcs]p5). We perform a simplified version of 3391 // reference binding here, that allows class rvalues to bind to 3392 // non-constant references. 3393 3394 // First check the qualifiers. 3395 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 3396 if (ImplicitParamType.getCVRQualifiers() 3397 != FromTypeCanon.getLocalCVRQualifiers() && 3398 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 3399 ICS.setBad(BadConversionSequence::bad_qualifiers, 3400 OrigFromType, ImplicitParamType); 3401 return ICS; 3402 } 3403 3404 // Check that we have either the same type or a derived type. It 3405 // affects the conversion rank. 3406 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 3407 ImplicitConversionKind SecondKind; 3408 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 3409 SecondKind = ICK_Identity; 3410 } else if (S.IsDerivedFrom(FromType, ClassType)) 3411 SecondKind = ICK_Derived_To_Base; 3412 else { 3413 ICS.setBad(BadConversionSequence::unrelated_class, 3414 FromType, ImplicitParamType); 3415 return ICS; 3416 } 3417 3418 // Check the ref-qualifier. 3419 switch (Method->getRefQualifier()) { 3420 case RQ_None: 3421 // Do nothing; we don't care about lvalueness or rvalueness. 3422 break; 3423 3424 case RQ_LValue: 3425 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 3426 // non-const lvalue reference cannot bind to an rvalue 3427 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 3428 ImplicitParamType); 3429 return ICS; 3430 } 3431 break; 3432 3433 case RQ_RValue: 3434 if (!FromClassification.isRValue()) { 3435 // rvalue reference cannot bind to an lvalue 3436 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 3437 ImplicitParamType); 3438 return ICS; 3439 } 3440 break; 3441 } 3442 3443 // Success. Mark this as a reference binding. 3444 ICS.setStandard(); 3445 ICS.Standard.setAsIdentityConversion(); 3446 ICS.Standard.Second = SecondKind; 3447 ICS.Standard.setFromType(FromType); 3448 ICS.Standard.setAllToTypes(ImplicitParamType); 3449 ICS.Standard.ReferenceBinding = true; 3450 ICS.Standard.DirectBinding = true; 3451 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 3452 ICS.Standard.BindsToFunctionLvalue = false; 3453 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 3454 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 3455 = (Method->getRefQualifier() == RQ_None); 3456 return ICS; 3457} 3458 3459/// PerformObjectArgumentInitialization - Perform initialization of 3460/// the implicit object parameter for the given Method with the given 3461/// expression. 3462bool 3463Sema::PerformObjectArgumentInitialization(Expr *&From, 3464 NestedNameSpecifier *Qualifier, 3465 NamedDecl *FoundDecl, 3466 CXXMethodDecl *Method) { 3467 QualType FromRecordType, DestType; 3468 QualType ImplicitParamRecordType = 3469 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3470 3471 Expr::Classification FromClassification; 3472 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3473 FromRecordType = PT->getPointeeType(); 3474 DestType = Method->getThisType(Context); 3475 FromClassification = Expr::Classification::makeSimpleLValue(); 3476 } else { 3477 FromRecordType = From->getType(); 3478 DestType = ImplicitParamRecordType; 3479 FromClassification = From->Classify(Context); 3480 } 3481 3482 // Note that we always use the true parent context when performing 3483 // the actual argument initialization. 3484 ImplicitConversionSequence ICS 3485 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 3486 Method, Method->getParent()); 3487 if (ICS.isBad()) { 3488 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 3489 Qualifiers FromQs = FromRecordType.getQualifiers(); 3490 Qualifiers ToQs = DestType.getQualifiers(); 3491 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 3492 if (CVR) { 3493 Diag(From->getSourceRange().getBegin(), 3494 diag::err_member_function_call_bad_cvr) 3495 << Method->getDeclName() << FromRecordType << (CVR - 1) 3496 << From->getSourceRange(); 3497 Diag(Method->getLocation(), diag::note_previous_decl) 3498 << Method->getDeclName(); 3499 return true; 3500 } 3501 } 3502 3503 return Diag(From->getSourceRange().getBegin(), 3504 diag::err_implicit_object_parameter_init) 3505 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3506 } 3507 3508 if (ICS.Standard.Second == ICK_Derived_To_Base) 3509 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3510 3511 if (!Context.hasSameType(From->getType(), DestType)) 3512 ImpCastExprToType(From, DestType, CK_NoOp, 3513 From->getType()->isPointerType() ? VK_RValue : VK_LValue); 3514 return false; 3515} 3516 3517/// TryContextuallyConvertToBool - Attempt to contextually convert the 3518/// expression From to bool (C++0x [conv]p3). 3519static ImplicitConversionSequence 3520TryContextuallyConvertToBool(Sema &S, Expr *From) { 3521 // FIXME: This is pretty broken. 3522 return TryImplicitConversion(S, From, S.Context.BoolTy, 3523 // FIXME: Are these flags correct? 3524 /*SuppressUserConversions=*/false, 3525 /*AllowExplicit=*/true, 3526 /*InOverloadResolution=*/false, 3527 /*CStyle=*/false); 3528} 3529 3530/// PerformContextuallyConvertToBool - Perform a contextual conversion 3531/// of the expression From to bool (C++0x [conv]p3). 3532bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3533 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 3534 if (!ICS.isBad()) 3535 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3536 3537 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3538 return Diag(From->getSourceRange().getBegin(), 3539 diag::err_typecheck_bool_condition) 3540 << From->getType() << From->getSourceRange(); 3541 return true; 3542} 3543 3544/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3545/// expression From to 'id'. 3546static ImplicitConversionSequence 3547TryContextuallyConvertToObjCId(Sema &S, Expr *From) { 3548 QualType Ty = S.Context.getObjCIdType(); 3549 return TryImplicitConversion(S, From, Ty, 3550 // FIXME: Are these flags correct? 3551 /*SuppressUserConversions=*/false, 3552 /*AllowExplicit=*/true, 3553 /*InOverloadResolution=*/false, 3554 /*CStyle=*/false); 3555} 3556 3557/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3558/// of the expression From to 'id'. 3559bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3560 QualType Ty = Context.getObjCIdType(); 3561 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(*this, From); 3562 if (!ICS.isBad()) 3563 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3564 return true; 3565} 3566 3567/// \brief Attempt to convert the given expression to an integral or 3568/// enumeration type. 3569/// 3570/// This routine will attempt to convert an expression of class type to an 3571/// integral or enumeration type, if that class type only has a single 3572/// conversion to an integral or enumeration type. 3573/// 3574/// \param Loc The source location of the construct that requires the 3575/// conversion. 3576/// 3577/// \param FromE The expression we're converting from. 3578/// 3579/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3580/// have integral or enumeration type. 3581/// 3582/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3583/// incomplete class type. 3584/// 3585/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3586/// explicit conversion function (because no implicit conversion functions 3587/// were available). This is a recovery mode. 3588/// 3589/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3590/// showing which conversion was picked. 3591/// 3592/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3593/// conversion function that could convert to integral or enumeration type. 3594/// 3595/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3596/// usable conversion function. 3597/// 3598/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3599/// function, which may be an extension in this case. 3600/// 3601/// \returns The expression, converted to an integral or enumeration type if 3602/// successful. 3603ExprResult 3604Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 3605 const PartialDiagnostic &NotIntDiag, 3606 const PartialDiagnostic &IncompleteDiag, 3607 const PartialDiagnostic &ExplicitConvDiag, 3608 const PartialDiagnostic &ExplicitConvNote, 3609 const PartialDiagnostic &AmbigDiag, 3610 const PartialDiagnostic &AmbigNote, 3611 const PartialDiagnostic &ConvDiag) { 3612 // We can't perform any more checking for type-dependent expressions. 3613 if (From->isTypeDependent()) 3614 return Owned(From); 3615 3616 // If the expression already has integral or enumeration type, we're golden. 3617 QualType T = From->getType(); 3618 if (T->isIntegralOrEnumerationType()) 3619 return Owned(From); 3620 3621 // FIXME: Check for missing '()' if T is a function type? 3622 3623 // If we don't have a class type in C++, there's no way we can get an 3624 // expression of integral or enumeration type. 3625 const RecordType *RecordTy = T->getAs<RecordType>(); 3626 if (!RecordTy || !getLangOptions().CPlusPlus) { 3627 Diag(Loc, NotIntDiag) 3628 << T << From->getSourceRange(); 3629 return Owned(From); 3630 } 3631 3632 // We must have a complete class type. 3633 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3634 return Owned(From); 3635 3636 // Look for a conversion to an integral or enumeration type. 3637 UnresolvedSet<4> ViableConversions; 3638 UnresolvedSet<4> ExplicitConversions; 3639 const UnresolvedSetImpl *Conversions 3640 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3641 3642 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3643 E = Conversions->end(); 3644 I != E; 3645 ++I) { 3646 if (CXXConversionDecl *Conversion 3647 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3648 if (Conversion->getConversionType().getNonReferenceType() 3649 ->isIntegralOrEnumerationType()) { 3650 if (Conversion->isExplicit()) 3651 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3652 else 3653 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3654 } 3655 } 3656 3657 switch (ViableConversions.size()) { 3658 case 0: 3659 if (ExplicitConversions.size() == 1) { 3660 DeclAccessPair Found = ExplicitConversions[0]; 3661 CXXConversionDecl *Conversion 3662 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3663 3664 // The user probably meant to invoke the given explicit 3665 // conversion; use it. 3666 QualType ConvTy 3667 = Conversion->getConversionType().getNonReferenceType(); 3668 std::string TypeStr; 3669 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3670 3671 Diag(Loc, ExplicitConvDiag) 3672 << T << ConvTy 3673 << FixItHint::CreateInsertion(From->getLocStart(), 3674 "static_cast<" + TypeStr + ">(") 3675 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3676 ")"); 3677 Diag(Conversion->getLocation(), ExplicitConvNote) 3678 << ConvTy->isEnumeralType() << ConvTy; 3679 3680 // If we aren't in a SFINAE context, build a call to the 3681 // explicit conversion function. 3682 if (isSFINAEContext()) 3683 return ExprError(); 3684 3685 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3686 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion); 3687 if (Result.isInvalid()) 3688 return ExprError(); 3689 3690 From = Result.get(); 3691 } 3692 3693 // We'll complain below about a non-integral condition type. 3694 break; 3695 3696 case 1: { 3697 // Apply this conversion. 3698 DeclAccessPair Found = ViableConversions[0]; 3699 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3700 3701 CXXConversionDecl *Conversion 3702 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3703 QualType ConvTy 3704 = Conversion->getConversionType().getNonReferenceType(); 3705 if (ConvDiag.getDiagID()) { 3706 if (isSFINAEContext()) 3707 return ExprError(); 3708 3709 Diag(Loc, ConvDiag) 3710 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 3711 } 3712 3713 ExprResult Result = BuildCXXMemberCallExpr(From, Found, 3714 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3715 if (Result.isInvalid()) 3716 return ExprError(); 3717 3718 From = Result.get(); 3719 break; 3720 } 3721 3722 default: 3723 Diag(Loc, AmbigDiag) 3724 << T << From->getSourceRange(); 3725 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3726 CXXConversionDecl *Conv 3727 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3728 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3729 Diag(Conv->getLocation(), AmbigNote) 3730 << ConvTy->isEnumeralType() << ConvTy; 3731 } 3732 return Owned(From); 3733 } 3734 3735 if (!From->getType()->isIntegralOrEnumerationType()) 3736 Diag(Loc, NotIntDiag) 3737 << From->getType() << From->getSourceRange(); 3738 3739 return Owned(From); 3740} 3741 3742/// AddOverloadCandidate - Adds the given function to the set of 3743/// candidate functions, using the given function call arguments. If 3744/// @p SuppressUserConversions, then don't allow user-defined 3745/// conversions via constructors or conversion operators. 3746/// 3747/// \para PartialOverloading true if we are performing "partial" overloading 3748/// based on an incomplete set of function arguments. This feature is used by 3749/// code completion. 3750void 3751Sema::AddOverloadCandidate(FunctionDecl *Function, 3752 DeclAccessPair FoundDecl, 3753 Expr **Args, unsigned NumArgs, 3754 OverloadCandidateSet& CandidateSet, 3755 bool SuppressUserConversions, 3756 bool PartialOverloading) { 3757 const FunctionProtoType* Proto 3758 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3759 assert(Proto && "Functions without a prototype cannot be overloaded"); 3760 assert(!Function->getDescribedFunctionTemplate() && 3761 "Use AddTemplateOverloadCandidate for function templates"); 3762 3763 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3764 if (!isa<CXXConstructorDecl>(Method)) { 3765 // If we get here, it's because we're calling a member function 3766 // that is named without a member access expression (e.g., 3767 // "this->f") that was either written explicitly or created 3768 // implicitly. This can happen with a qualified call to a member 3769 // function, e.g., X::f(). We use an empty type for the implied 3770 // object argument (C++ [over.call.func]p3), and the acting context 3771 // is irrelevant. 3772 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3773 QualType(), Expr::Classification::makeSimpleLValue(), 3774 Args, NumArgs, CandidateSet, 3775 SuppressUserConversions); 3776 return; 3777 } 3778 // We treat a constructor like a non-member function, since its object 3779 // argument doesn't participate in overload resolution. 3780 } 3781 3782 if (!CandidateSet.isNewCandidate(Function)) 3783 return; 3784 3785 // Overload resolution is always an unevaluated context. 3786 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 3787 3788 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3789 // C++ [class.copy]p3: 3790 // A member function template is never instantiated to perform the copy 3791 // of a class object to an object of its class type. 3792 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3793 if (NumArgs == 1 && 3794 Constructor->isSpecializationCopyingObject() && 3795 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3796 IsDerivedFrom(Args[0]->getType(), ClassType))) 3797 return; 3798 } 3799 3800 // Add this candidate 3801 CandidateSet.push_back(OverloadCandidate()); 3802 OverloadCandidate& Candidate = CandidateSet.back(); 3803 Candidate.FoundDecl = FoundDecl; 3804 Candidate.Function = Function; 3805 Candidate.Viable = true; 3806 Candidate.IsSurrogate = false; 3807 Candidate.IgnoreObjectArgument = false; 3808 Candidate.ExplicitCallArguments = NumArgs; 3809 3810 unsigned NumArgsInProto = Proto->getNumArgs(); 3811 3812 // (C++ 13.3.2p2): A candidate function having fewer than m 3813 // parameters is viable only if it has an ellipsis in its parameter 3814 // list (8.3.5). 3815 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3816 !Proto->isVariadic()) { 3817 Candidate.Viable = false; 3818 Candidate.FailureKind = ovl_fail_too_many_arguments; 3819 return; 3820 } 3821 3822 // (C++ 13.3.2p2): A candidate function having more than m parameters 3823 // is viable only if the (m+1)st parameter has a default argument 3824 // (8.3.6). For the purposes of overload resolution, the 3825 // parameter list is truncated on the right, so that there are 3826 // exactly m parameters. 3827 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3828 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3829 // Not enough arguments. 3830 Candidate.Viable = false; 3831 Candidate.FailureKind = ovl_fail_too_few_arguments; 3832 return; 3833 } 3834 3835 // Determine the implicit conversion sequences for each of the 3836 // arguments. 3837 Candidate.Conversions.resize(NumArgs); 3838 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3839 if (ArgIdx < NumArgsInProto) { 3840 // (C++ 13.3.2p3): for F to be a viable function, there shall 3841 // exist for each argument an implicit conversion sequence 3842 // (13.3.3.1) that converts that argument to the corresponding 3843 // parameter of F. 3844 QualType ParamType = Proto->getArgType(ArgIdx); 3845 Candidate.Conversions[ArgIdx] 3846 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3847 SuppressUserConversions, 3848 /*InOverloadResolution=*/true); 3849 if (Candidate.Conversions[ArgIdx].isBad()) { 3850 Candidate.Viable = false; 3851 Candidate.FailureKind = ovl_fail_bad_conversion; 3852 break; 3853 } 3854 } else { 3855 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3856 // argument for which there is no corresponding parameter is 3857 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3858 Candidate.Conversions[ArgIdx].setEllipsis(); 3859 } 3860 } 3861} 3862 3863/// \brief Add all of the function declarations in the given function set to 3864/// the overload canddiate set. 3865void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3866 Expr **Args, unsigned NumArgs, 3867 OverloadCandidateSet& CandidateSet, 3868 bool SuppressUserConversions) { 3869 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3870 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3871 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3872 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3873 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3874 cast<CXXMethodDecl>(FD)->getParent(), 3875 Args[0]->getType(), Args[0]->Classify(Context), 3876 Args + 1, NumArgs - 1, 3877 CandidateSet, SuppressUserConversions); 3878 else 3879 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3880 SuppressUserConversions); 3881 } else { 3882 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3883 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3884 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3885 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3886 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3887 /*FIXME: explicit args */ 0, 3888 Args[0]->getType(), 3889 Args[0]->Classify(Context), 3890 Args + 1, NumArgs - 1, 3891 CandidateSet, 3892 SuppressUserConversions); 3893 else 3894 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3895 /*FIXME: explicit args */ 0, 3896 Args, NumArgs, CandidateSet, 3897 SuppressUserConversions); 3898 } 3899 } 3900} 3901 3902/// AddMethodCandidate - Adds a named decl (which is some kind of 3903/// method) as a method candidate to the given overload set. 3904void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3905 QualType ObjectType, 3906 Expr::Classification ObjectClassification, 3907 Expr **Args, unsigned NumArgs, 3908 OverloadCandidateSet& CandidateSet, 3909 bool SuppressUserConversions) { 3910 NamedDecl *Decl = FoundDecl.getDecl(); 3911 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3912 3913 if (isa<UsingShadowDecl>(Decl)) 3914 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3915 3916 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3917 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3918 "Expected a member function template"); 3919 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3920 /*ExplicitArgs*/ 0, 3921 ObjectType, ObjectClassification, Args, NumArgs, 3922 CandidateSet, 3923 SuppressUserConversions); 3924 } else { 3925 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3926 ObjectType, ObjectClassification, Args, NumArgs, 3927 CandidateSet, SuppressUserConversions); 3928 } 3929} 3930 3931/// AddMethodCandidate - Adds the given C++ member function to the set 3932/// of candidate functions, using the given function call arguments 3933/// and the object argument (@c Object). For example, in a call 3934/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3935/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3936/// allow user-defined conversions via constructors or conversion 3937/// operators. 3938void 3939Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3940 CXXRecordDecl *ActingContext, QualType ObjectType, 3941 Expr::Classification ObjectClassification, 3942 Expr **Args, unsigned NumArgs, 3943 OverloadCandidateSet& CandidateSet, 3944 bool SuppressUserConversions) { 3945 const FunctionProtoType* Proto 3946 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3947 assert(Proto && "Methods without a prototype cannot be overloaded"); 3948 assert(!isa<CXXConstructorDecl>(Method) && 3949 "Use AddOverloadCandidate for constructors"); 3950 3951 if (!CandidateSet.isNewCandidate(Method)) 3952 return; 3953 3954 // Overload resolution is always an unevaluated context. 3955 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 3956 3957 // Add this candidate 3958 CandidateSet.push_back(OverloadCandidate()); 3959 OverloadCandidate& Candidate = CandidateSet.back(); 3960 Candidate.FoundDecl = FoundDecl; 3961 Candidate.Function = Method; 3962 Candidate.IsSurrogate = false; 3963 Candidate.IgnoreObjectArgument = false; 3964 Candidate.ExplicitCallArguments = NumArgs; 3965 3966 unsigned NumArgsInProto = Proto->getNumArgs(); 3967 3968 // (C++ 13.3.2p2): A candidate function having fewer than m 3969 // parameters is viable only if it has an ellipsis in its parameter 3970 // list (8.3.5). 3971 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3972 Candidate.Viable = false; 3973 Candidate.FailureKind = ovl_fail_too_many_arguments; 3974 return; 3975 } 3976 3977 // (C++ 13.3.2p2): A candidate function having more than m parameters 3978 // is viable only if the (m+1)st parameter has a default argument 3979 // (8.3.6). For the purposes of overload resolution, the 3980 // parameter list is truncated on the right, so that there are 3981 // exactly m parameters. 3982 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3983 if (NumArgs < MinRequiredArgs) { 3984 // Not enough arguments. 3985 Candidate.Viable = false; 3986 Candidate.FailureKind = ovl_fail_too_few_arguments; 3987 return; 3988 } 3989 3990 Candidate.Viable = true; 3991 Candidate.Conversions.resize(NumArgs + 1); 3992 3993 if (Method->isStatic() || ObjectType.isNull()) 3994 // The implicit object argument is ignored. 3995 Candidate.IgnoreObjectArgument = true; 3996 else { 3997 // Determine the implicit conversion sequence for the object 3998 // parameter. 3999 Candidate.Conversions[0] 4000 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 4001 Method, ActingContext); 4002 if (Candidate.Conversions[0].isBad()) { 4003 Candidate.Viable = false; 4004 Candidate.FailureKind = ovl_fail_bad_conversion; 4005 return; 4006 } 4007 } 4008 4009 // Determine the implicit conversion sequences for each of the 4010 // arguments. 4011 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4012 if (ArgIdx < NumArgsInProto) { 4013 // (C++ 13.3.2p3): for F to be a viable function, there shall 4014 // exist for each argument an implicit conversion sequence 4015 // (13.3.3.1) that converts that argument to the corresponding 4016 // parameter of F. 4017 QualType ParamType = Proto->getArgType(ArgIdx); 4018 Candidate.Conversions[ArgIdx + 1] 4019 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4020 SuppressUserConversions, 4021 /*InOverloadResolution=*/true); 4022 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4023 Candidate.Viable = false; 4024 Candidate.FailureKind = ovl_fail_bad_conversion; 4025 break; 4026 } 4027 } else { 4028 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4029 // argument for which there is no corresponding parameter is 4030 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4031 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4032 } 4033 } 4034} 4035 4036/// \brief Add a C++ member function template as a candidate to the candidate 4037/// set, using template argument deduction to produce an appropriate member 4038/// function template specialization. 4039void 4040Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 4041 DeclAccessPair FoundDecl, 4042 CXXRecordDecl *ActingContext, 4043 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4044 QualType ObjectType, 4045 Expr::Classification ObjectClassification, 4046 Expr **Args, unsigned NumArgs, 4047 OverloadCandidateSet& CandidateSet, 4048 bool SuppressUserConversions) { 4049 if (!CandidateSet.isNewCandidate(MethodTmpl)) 4050 return; 4051 4052 // C++ [over.match.funcs]p7: 4053 // In each case where a candidate is a function template, candidate 4054 // function template specializations are generated using template argument 4055 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4056 // candidate functions in the usual way.113) A given name can refer to one 4057 // or more function templates and also to a set of overloaded non-template 4058 // functions. In such a case, the candidate functions generated from each 4059 // function template are combined with the set of non-template candidate 4060 // functions. 4061 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4062 FunctionDecl *Specialization = 0; 4063 if (TemplateDeductionResult Result 4064 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 4065 Args, NumArgs, Specialization, Info)) { 4066 CandidateSet.push_back(OverloadCandidate()); 4067 OverloadCandidate &Candidate = CandidateSet.back(); 4068 Candidate.FoundDecl = FoundDecl; 4069 Candidate.Function = MethodTmpl->getTemplatedDecl(); 4070 Candidate.Viable = false; 4071 Candidate.FailureKind = ovl_fail_bad_deduction; 4072 Candidate.IsSurrogate = false; 4073 Candidate.IgnoreObjectArgument = false; 4074 Candidate.ExplicitCallArguments = NumArgs; 4075 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4076 Info); 4077 return; 4078 } 4079 4080 // Add the function template specialization produced by template argument 4081 // deduction as a candidate. 4082 assert(Specialization && "Missing member function template specialization?"); 4083 assert(isa<CXXMethodDecl>(Specialization) && 4084 "Specialization is not a member function?"); 4085 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 4086 ActingContext, ObjectType, ObjectClassification, 4087 Args, NumArgs, CandidateSet, SuppressUserConversions); 4088} 4089 4090/// \brief Add a C++ function template specialization as a candidate 4091/// in the candidate set, using template argument deduction to produce 4092/// an appropriate function template specialization. 4093void 4094Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 4095 DeclAccessPair FoundDecl, 4096 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4097 Expr **Args, unsigned NumArgs, 4098 OverloadCandidateSet& CandidateSet, 4099 bool SuppressUserConversions) { 4100 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4101 return; 4102 4103 // C++ [over.match.funcs]p7: 4104 // In each case where a candidate is a function template, candidate 4105 // function template specializations are generated using template argument 4106 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4107 // candidate functions in the usual way.113) A given name can refer to one 4108 // or more function templates and also to a set of overloaded non-template 4109 // functions. In such a case, the candidate functions generated from each 4110 // function template are combined with the set of non-template candidate 4111 // functions. 4112 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4113 FunctionDecl *Specialization = 0; 4114 if (TemplateDeductionResult Result 4115 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 4116 Args, NumArgs, Specialization, Info)) { 4117 CandidateSet.push_back(OverloadCandidate()); 4118 OverloadCandidate &Candidate = CandidateSet.back(); 4119 Candidate.FoundDecl = FoundDecl; 4120 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4121 Candidate.Viable = false; 4122 Candidate.FailureKind = ovl_fail_bad_deduction; 4123 Candidate.IsSurrogate = false; 4124 Candidate.IgnoreObjectArgument = false; 4125 Candidate.ExplicitCallArguments = NumArgs; 4126 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4127 Info); 4128 return; 4129 } 4130 4131 // Add the function template specialization produced by template argument 4132 // deduction as a candidate. 4133 assert(Specialization && "Missing function template specialization?"); 4134 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 4135 SuppressUserConversions); 4136} 4137 4138/// AddConversionCandidate - Add a C++ conversion function as a 4139/// candidate in the candidate set (C++ [over.match.conv], 4140/// C++ [over.match.copy]). From is the expression we're converting from, 4141/// and ToType is the type that we're eventually trying to convert to 4142/// (which may or may not be the same type as the type that the 4143/// conversion function produces). 4144void 4145Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 4146 DeclAccessPair FoundDecl, 4147 CXXRecordDecl *ActingContext, 4148 Expr *From, QualType ToType, 4149 OverloadCandidateSet& CandidateSet) { 4150 assert(!Conversion->getDescribedFunctionTemplate() && 4151 "Conversion function templates use AddTemplateConversionCandidate"); 4152 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 4153 if (!CandidateSet.isNewCandidate(Conversion)) 4154 return; 4155 4156 // Overload resolution is always an unevaluated context. 4157 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4158 4159 // Add this candidate 4160 CandidateSet.push_back(OverloadCandidate()); 4161 OverloadCandidate& Candidate = CandidateSet.back(); 4162 Candidate.FoundDecl = FoundDecl; 4163 Candidate.Function = Conversion; 4164 Candidate.IsSurrogate = false; 4165 Candidate.IgnoreObjectArgument = false; 4166 Candidate.FinalConversion.setAsIdentityConversion(); 4167 Candidate.FinalConversion.setFromType(ConvType); 4168 Candidate.FinalConversion.setAllToTypes(ToType); 4169 Candidate.Viable = true; 4170 Candidate.Conversions.resize(1); 4171 Candidate.ExplicitCallArguments = 1; 4172 4173 // C++ [over.match.funcs]p4: 4174 // For conversion functions, the function is considered to be a member of 4175 // the class of the implicit implied object argument for the purpose of 4176 // defining the type of the implicit object parameter. 4177 // 4178 // Determine the implicit conversion sequence for the implicit 4179 // object parameter. 4180 QualType ImplicitParamType = From->getType(); 4181 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 4182 ImplicitParamType = FromPtrType->getPointeeType(); 4183 CXXRecordDecl *ConversionContext 4184 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 4185 4186 Candidate.Conversions[0] 4187 = TryObjectArgumentInitialization(*this, From->getType(), 4188 From->Classify(Context), 4189 Conversion, ConversionContext); 4190 4191 if (Candidate.Conversions[0].isBad()) { 4192 Candidate.Viable = false; 4193 Candidate.FailureKind = ovl_fail_bad_conversion; 4194 return; 4195 } 4196 4197 // We won't go through a user-define type conversion function to convert a 4198 // derived to base as such conversions are given Conversion Rank. They only 4199 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 4200 QualType FromCanon 4201 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 4202 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 4203 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 4204 Candidate.Viable = false; 4205 Candidate.FailureKind = ovl_fail_trivial_conversion; 4206 return; 4207 } 4208 4209 // To determine what the conversion from the result of calling the 4210 // conversion function to the type we're eventually trying to 4211 // convert to (ToType), we need to synthesize a call to the 4212 // conversion function and attempt copy initialization from it. This 4213 // makes sure that we get the right semantics with respect to 4214 // lvalues/rvalues and the type. Fortunately, we can allocate this 4215 // call on the stack and we don't need its arguments to be 4216 // well-formed. 4217 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 4218 VK_LValue, From->getLocStart()); 4219 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 4220 Context.getPointerType(Conversion->getType()), 4221 CK_FunctionToPointerDecay, 4222 &ConversionRef, VK_RValue); 4223 4224 QualType CallResultType 4225 = Conversion->getConversionType().getNonLValueExprType(Context); 4226 if (RequireCompleteType(From->getLocStart(), CallResultType, 0)) { 4227 Candidate.Viable = false; 4228 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4229 return; 4230 } 4231 4232 ExprValueKind VK = Expr::getValueKindForType(Conversion->getConversionType()); 4233 4234 // Note that it is safe to allocate CallExpr on the stack here because 4235 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 4236 // allocator). 4237 CallExpr Call(Context, &ConversionFn, 0, 0, CallResultType, VK, 4238 From->getLocStart()); 4239 ImplicitConversionSequence ICS = 4240 TryCopyInitialization(*this, &Call, ToType, 4241 /*SuppressUserConversions=*/true, 4242 /*InOverloadResolution=*/false); 4243 4244 switch (ICS.getKind()) { 4245 case ImplicitConversionSequence::StandardConversion: 4246 Candidate.FinalConversion = ICS.Standard; 4247 4248 // C++ [over.ics.user]p3: 4249 // If the user-defined conversion is specified by a specialization of a 4250 // conversion function template, the second standard conversion sequence 4251 // shall have exact match rank. 4252 if (Conversion->getPrimaryTemplate() && 4253 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 4254 Candidate.Viable = false; 4255 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 4256 } 4257 4258 // C++0x [dcl.init.ref]p5: 4259 // In the second case, if the reference is an rvalue reference and 4260 // the second standard conversion sequence of the user-defined 4261 // conversion sequence includes an lvalue-to-rvalue conversion, the 4262 // program is ill-formed. 4263 if (ToType->isRValueReferenceType() && 4264 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 4265 Candidate.Viable = false; 4266 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4267 } 4268 break; 4269 4270 case ImplicitConversionSequence::BadConversion: 4271 Candidate.Viable = false; 4272 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4273 break; 4274 4275 default: 4276 assert(false && 4277 "Can only end up with a standard conversion sequence or failure"); 4278 } 4279} 4280 4281/// \brief Adds a conversion function template specialization 4282/// candidate to the overload set, using template argument deduction 4283/// to deduce the template arguments of the conversion function 4284/// template from the type that we are converting to (C++ 4285/// [temp.deduct.conv]). 4286void 4287Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 4288 DeclAccessPair FoundDecl, 4289 CXXRecordDecl *ActingDC, 4290 Expr *From, QualType ToType, 4291 OverloadCandidateSet &CandidateSet) { 4292 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 4293 "Only conversion function templates permitted here"); 4294 4295 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4296 return; 4297 4298 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4299 CXXConversionDecl *Specialization = 0; 4300 if (TemplateDeductionResult Result 4301 = DeduceTemplateArguments(FunctionTemplate, ToType, 4302 Specialization, Info)) { 4303 CandidateSet.push_back(OverloadCandidate()); 4304 OverloadCandidate &Candidate = CandidateSet.back(); 4305 Candidate.FoundDecl = FoundDecl; 4306 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4307 Candidate.Viable = false; 4308 Candidate.FailureKind = ovl_fail_bad_deduction; 4309 Candidate.IsSurrogate = false; 4310 Candidate.IgnoreObjectArgument = false; 4311 Candidate.ExplicitCallArguments = 1; 4312 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4313 Info); 4314 return; 4315 } 4316 4317 // Add the conversion function template specialization produced by 4318 // template argument deduction as a candidate. 4319 assert(Specialization && "Missing function template specialization?"); 4320 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 4321 CandidateSet); 4322} 4323 4324/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 4325/// converts the given @c Object to a function pointer via the 4326/// conversion function @c Conversion, and then attempts to call it 4327/// with the given arguments (C++ [over.call.object]p2-4). Proto is 4328/// the type of function that we'll eventually be calling. 4329void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 4330 DeclAccessPair FoundDecl, 4331 CXXRecordDecl *ActingContext, 4332 const FunctionProtoType *Proto, 4333 Expr *Object, 4334 Expr **Args, unsigned NumArgs, 4335 OverloadCandidateSet& CandidateSet) { 4336 if (!CandidateSet.isNewCandidate(Conversion)) 4337 return; 4338 4339 // Overload resolution is always an unevaluated context. 4340 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4341 4342 CandidateSet.push_back(OverloadCandidate()); 4343 OverloadCandidate& Candidate = CandidateSet.back(); 4344 Candidate.FoundDecl = FoundDecl; 4345 Candidate.Function = 0; 4346 Candidate.Surrogate = Conversion; 4347 Candidate.Viable = true; 4348 Candidate.IsSurrogate = true; 4349 Candidate.IgnoreObjectArgument = false; 4350 Candidate.Conversions.resize(NumArgs + 1); 4351 Candidate.ExplicitCallArguments = NumArgs; 4352 4353 // Determine the implicit conversion sequence for the implicit 4354 // object parameter. 4355 ImplicitConversionSequence ObjectInit 4356 = TryObjectArgumentInitialization(*this, Object->getType(), 4357 Object->Classify(Context), 4358 Conversion, ActingContext); 4359 if (ObjectInit.isBad()) { 4360 Candidate.Viable = false; 4361 Candidate.FailureKind = ovl_fail_bad_conversion; 4362 Candidate.Conversions[0] = ObjectInit; 4363 return; 4364 } 4365 4366 // The first conversion is actually a user-defined conversion whose 4367 // first conversion is ObjectInit's standard conversion (which is 4368 // effectively a reference binding). Record it as such. 4369 Candidate.Conversions[0].setUserDefined(); 4370 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 4371 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 4372 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 4373 Candidate.Conversions[0].UserDefined.FoundConversionFunction 4374 = FoundDecl.getDecl(); 4375 Candidate.Conversions[0].UserDefined.After 4376 = Candidate.Conversions[0].UserDefined.Before; 4377 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 4378 4379 // Find the 4380 unsigned NumArgsInProto = Proto->getNumArgs(); 4381 4382 // (C++ 13.3.2p2): A candidate function having fewer than m 4383 // parameters is viable only if it has an ellipsis in its parameter 4384 // list (8.3.5). 4385 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4386 Candidate.Viable = false; 4387 Candidate.FailureKind = ovl_fail_too_many_arguments; 4388 return; 4389 } 4390 4391 // Function types don't have any default arguments, so just check if 4392 // we have enough arguments. 4393 if (NumArgs < NumArgsInProto) { 4394 // Not enough arguments. 4395 Candidate.Viable = false; 4396 Candidate.FailureKind = ovl_fail_too_few_arguments; 4397 return; 4398 } 4399 4400 // Determine the implicit conversion sequences for each of the 4401 // arguments. 4402 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4403 if (ArgIdx < NumArgsInProto) { 4404 // (C++ 13.3.2p3): for F to be a viable function, there shall 4405 // exist for each argument an implicit conversion sequence 4406 // (13.3.3.1) that converts that argument to the corresponding 4407 // parameter of F. 4408 QualType ParamType = Proto->getArgType(ArgIdx); 4409 Candidate.Conversions[ArgIdx + 1] 4410 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4411 /*SuppressUserConversions=*/false, 4412 /*InOverloadResolution=*/false); 4413 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4414 Candidate.Viable = false; 4415 Candidate.FailureKind = ovl_fail_bad_conversion; 4416 break; 4417 } 4418 } else { 4419 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4420 // argument for which there is no corresponding parameter is 4421 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4422 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4423 } 4424 } 4425} 4426 4427/// \brief Add overload candidates for overloaded operators that are 4428/// member functions. 4429/// 4430/// Add the overloaded operator candidates that are member functions 4431/// for the operator Op that was used in an operator expression such 4432/// as "x Op y". , Args/NumArgs provides the operator arguments, and 4433/// CandidateSet will store the added overload candidates. (C++ 4434/// [over.match.oper]). 4435void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 4436 SourceLocation OpLoc, 4437 Expr **Args, unsigned NumArgs, 4438 OverloadCandidateSet& CandidateSet, 4439 SourceRange OpRange) { 4440 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4441 4442 // C++ [over.match.oper]p3: 4443 // For a unary operator @ with an operand of a type whose 4444 // cv-unqualified version is T1, and for a binary operator @ with 4445 // a left operand of a type whose cv-unqualified version is T1 and 4446 // a right operand of a type whose cv-unqualified version is T2, 4447 // three sets of candidate functions, designated member 4448 // candidates, non-member candidates and built-in candidates, are 4449 // constructed as follows: 4450 QualType T1 = Args[0]->getType(); 4451 4452 // -- If T1 is a class type, the set of member candidates is the 4453 // result of the qualified lookup of T1::operator@ 4454 // (13.3.1.1.1); otherwise, the set of member candidates is 4455 // empty. 4456 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 4457 // Complete the type if it can be completed. Otherwise, we're done. 4458 if (RequireCompleteType(OpLoc, T1, PDiag())) 4459 return; 4460 4461 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 4462 LookupQualifiedName(Operators, T1Rec->getDecl()); 4463 Operators.suppressDiagnostics(); 4464 4465 for (LookupResult::iterator Oper = Operators.begin(), 4466 OperEnd = Operators.end(); 4467 Oper != OperEnd; 4468 ++Oper) 4469 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 4470 Args[0]->Classify(Context), Args + 1, NumArgs - 1, 4471 CandidateSet, 4472 /* SuppressUserConversions = */ false); 4473 } 4474} 4475 4476/// AddBuiltinCandidate - Add a candidate for a built-in 4477/// operator. ResultTy and ParamTys are the result and parameter types 4478/// of the built-in candidate, respectively. Args and NumArgs are the 4479/// arguments being passed to the candidate. IsAssignmentOperator 4480/// should be true when this built-in candidate is an assignment 4481/// operator. NumContextualBoolArguments is the number of arguments 4482/// (at the beginning of the argument list) that will be contextually 4483/// converted to bool. 4484void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 4485 Expr **Args, unsigned NumArgs, 4486 OverloadCandidateSet& CandidateSet, 4487 bool IsAssignmentOperator, 4488 unsigned NumContextualBoolArguments) { 4489 // Overload resolution is always an unevaluated context. 4490 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4491 4492 // Add this candidate 4493 CandidateSet.push_back(OverloadCandidate()); 4494 OverloadCandidate& Candidate = CandidateSet.back(); 4495 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 4496 Candidate.Function = 0; 4497 Candidate.IsSurrogate = false; 4498 Candidate.IgnoreObjectArgument = false; 4499 Candidate.BuiltinTypes.ResultTy = ResultTy; 4500 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4501 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 4502 4503 // Determine the implicit conversion sequences for each of the 4504 // arguments. 4505 Candidate.Viable = true; 4506 Candidate.Conversions.resize(NumArgs); 4507 Candidate.ExplicitCallArguments = NumArgs; 4508 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4509 // C++ [over.match.oper]p4: 4510 // For the built-in assignment operators, conversions of the 4511 // left operand are restricted as follows: 4512 // -- no temporaries are introduced to hold the left operand, and 4513 // -- no user-defined conversions are applied to the left 4514 // operand to achieve a type match with the left-most 4515 // parameter of a built-in candidate. 4516 // 4517 // We block these conversions by turning off user-defined 4518 // conversions, since that is the only way that initialization of 4519 // a reference to a non-class type can occur from something that 4520 // is not of the same type. 4521 if (ArgIdx < NumContextualBoolArguments) { 4522 assert(ParamTys[ArgIdx] == Context.BoolTy && 4523 "Contextual conversion to bool requires bool type"); 4524 Candidate.Conversions[ArgIdx] 4525 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 4526 } else { 4527 Candidate.Conversions[ArgIdx] 4528 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4529 ArgIdx == 0 && IsAssignmentOperator, 4530 /*InOverloadResolution=*/false); 4531 } 4532 if (Candidate.Conversions[ArgIdx].isBad()) { 4533 Candidate.Viable = false; 4534 Candidate.FailureKind = ovl_fail_bad_conversion; 4535 break; 4536 } 4537 } 4538} 4539 4540/// BuiltinCandidateTypeSet - A set of types that will be used for the 4541/// candidate operator functions for built-in operators (C++ 4542/// [over.built]). The types are separated into pointer types and 4543/// enumeration types. 4544class BuiltinCandidateTypeSet { 4545 /// TypeSet - A set of types. 4546 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4547 4548 /// PointerTypes - The set of pointer types that will be used in the 4549 /// built-in candidates. 4550 TypeSet PointerTypes; 4551 4552 /// MemberPointerTypes - The set of member pointer types that will be 4553 /// used in the built-in candidates. 4554 TypeSet MemberPointerTypes; 4555 4556 /// EnumerationTypes - The set of enumeration types that will be 4557 /// used in the built-in candidates. 4558 TypeSet EnumerationTypes; 4559 4560 /// \brief The set of vector types that will be used in the built-in 4561 /// candidates. 4562 TypeSet VectorTypes; 4563 4564 /// \brief A flag indicating non-record types are viable candidates 4565 bool HasNonRecordTypes; 4566 4567 /// \brief A flag indicating whether either arithmetic or enumeration types 4568 /// were present in the candidate set. 4569 bool HasArithmeticOrEnumeralTypes; 4570 4571 /// Sema - The semantic analysis instance where we are building the 4572 /// candidate type set. 4573 Sema &SemaRef; 4574 4575 /// Context - The AST context in which we will build the type sets. 4576 ASTContext &Context; 4577 4578 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4579 const Qualifiers &VisibleQuals); 4580 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4581 4582public: 4583 /// iterator - Iterates through the types that are part of the set. 4584 typedef TypeSet::iterator iterator; 4585 4586 BuiltinCandidateTypeSet(Sema &SemaRef) 4587 : HasNonRecordTypes(false), 4588 HasArithmeticOrEnumeralTypes(false), 4589 SemaRef(SemaRef), 4590 Context(SemaRef.Context) { } 4591 4592 void AddTypesConvertedFrom(QualType Ty, 4593 SourceLocation Loc, 4594 bool AllowUserConversions, 4595 bool AllowExplicitConversions, 4596 const Qualifiers &VisibleTypeConversionsQuals); 4597 4598 /// pointer_begin - First pointer type found; 4599 iterator pointer_begin() { return PointerTypes.begin(); } 4600 4601 /// pointer_end - Past the last pointer type found; 4602 iterator pointer_end() { return PointerTypes.end(); } 4603 4604 /// member_pointer_begin - First member pointer type found; 4605 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4606 4607 /// member_pointer_end - Past the last member pointer type found; 4608 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4609 4610 /// enumeration_begin - First enumeration type found; 4611 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4612 4613 /// enumeration_end - Past the last enumeration type found; 4614 iterator enumeration_end() { return EnumerationTypes.end(); } 4615 4616 iterator vector_begin() { return VectorTypes.begin(); } 4617 iterator vector_end() { return VectorTypes.end(); } 4618 4619 bool hasNonRecordTypes() { return HasNonRecordTypes; } 4620 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 4621}; 4622 4623/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4624/// the set of pointer types along with any more-qualified variants of 4625/// that type. For example, if @p Ty is "int const *", this routine 4626/// will add "int const *", "int const volatile *", "int const 4627/// restrict *", and "int const volatile restrict *" to the set of 4628/// pointer types. Returns true if the add of @p Ty itself succeeded, 4629/// false otherwise. 4630/// 4631/// FIXME: what to do about extended qualifiers? 4632bool 4633BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4634 const Qualifiers &VisibleQuals) { 4635 4636 // Insert this type. 4637 if (!PointerTypes.insert(Ty)) 4638 return false; 4639 4640 QualType PointeeTy; 4641 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4642 bool buildObjCPtr = false; 4643 if (!PointerTy) { 4644 if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) { 4645 PointeeTy = PTy->getPointeeType(); 4646 buildObjCPtr = true; 4647 } 4648 else 4649 assert(false && "type was not a pointer type!"); 4650 } 4651 else 4652 PointeeTy = PointerTy->getPointeeType(); 4653 4654 // Don't add qualified variants of arrays. For one, they're not allowed 4655 // (the qualifier would sink to the element type), and for another, the 4656 // only overload situation where it matters is subscript or pointer +- int, 4657 // and those shouldn't have qualifier variants anyway. 4658 if (PointeeTy->isArrayType()) 4659 return true; 4660 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4661 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4662 BaseCVR = Array->getElementType().getCVRQualifiers(); 4663 bool hasVolatile = VisibleQuals.hasVolatile(); 4664 bool hasRestrict = VisibleQuals.hasRestrict(); 4665 4666 // Iterate through all strict supersets of BaseCVR. 4667 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4668 if ((CVR | BaseCVR) != CVR) continue; 4669 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4670 // in the types. 4671 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4672 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4673 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4674 if (!buildObjCPtr) 4675 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4676 else 4677 PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); 4678 } 4679 4680 return true; 4681} 4682 4683/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4684/// to the set of pointer types along with any more-qualified variants of 4685/// that type. For example, if @p Ty is "int const *", this routine 4686/// will add "int const *", "int const volatile *", "int const 4687/// restrict *", and "int const volatile restrict *" to the set of 4688/// pointer types. Returns true if the add of @p Ty itself succeeded, 4689/// false otherwise. 4690/// 4691/// FIXME: what to do about extended qualifiers? 4692bool 4693BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4694 QualType Ty) { 4695 // Insert this type. 4696 if (!MemberPointerTypes.insert(Ty)) 4697 return false; 4698 4699 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4700 assert(PointerTy && "type was not a member pointer type!"); 4701 4702 QualType PointeeTy = PointerTy->getPointeeType(); 4703 // Don't add qualified variants of arrays. For one, they're not allowed 4704 // (the qualifier would sink to the element type), and for another, the 4705 // only overload situation where it matters is subscript or pointer +- int, 4706 // and those shouldn't have qualifier variants anyway. 4707 if (PointeeTy->isArrayType()) 4708 return true; 4709 const Type *ClassTy = PointerTy->getClass(); 4710 4711 // Iterate through all strict supersets of the pointee type's CVR 4712 // qualifiers. 4713 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4714 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4715 if ((CVR | BaseCVR) != CVR) continue; 4716 4717 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4718 MemberPointerTypes.insert( 4719 Context.getMemberPointerType(QPointeeTy, ClassTy)); 4720 } 4721 4722 return true; 4723} 4724 4725/// AddTypesConvertedFrom - Add each of the types to which the type @p 4726/// Ty can be implicit converted to the given set of @p Types. We're 4727/// primarily interested in pointer types and enumeration types. We also 4728/// take member pointer types, for the conditional operator. 4729/// AllowUserConversions is true if we should look at the conversion 4730/// functions of a class type, and AllowExplicitConversions if we 4731/// should also include the explicit conversion functions of a class 4732/// type. 4733void 4734BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4735 SourceLocation Loc, 4736 bool AllowUserConversions, 4737 bool AllowExplicitConversions, 4738 const Qualifiers &VisibleQuals) { 4739 // Only deal with canonical types. 4740 Ty = Context.getCanonicalType(Ty); 4741 4742 // Look through reference types; they aren't part of the type of an 4743 // expression for the purposes of conversions. 4744 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4745 Ty = RefTy->getPointeeType(); 4746 4747 // If we're dealing with an array type, decay to the pointer. 4748 if (Ty->isArrayType()) 4749 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4750 4751 // Otherwise, we don't care about qualifiers on the type. 4752 Ty = Ty.getLocalUnqualifiedType(); 4753 4754 // Flag if we ever add a non-record type. 4755 const RecordType *TyRec = Ty->getAs<RecordType>(); 4756 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 4757 4758 // Flag if we encounter an arithmetic type. 4759 HasArithmeticOrEnumeralTypes = 4760 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 4761 4762 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 4763 PointerTypes.insert(Ty); 4764 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 4765 // Insert our type, and its more-qualified variants, into the set 4766 // of types. 4767 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4768 return; 4769 } else if (Ty->isMemberPointerType()) { 4770 // Member pointers are far easier, since the pointee can't be converted. 4771 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4772 return; 4773 } else if (Ty->isEnumeralType()) { 4774 HasArithmeticOrEnumeralTypes = true; 4775 EnumerationTypes.insert(Ty); 4776 } else if (Ty->isVectorType()) { 4777 // We treat vector types as arithmetic types in many contexts as an 4778 // extension. 4779 HasArithmeticOrEnumeralTypes = true; 4780 VectorTypes.insert(Ty); 4781 } else if (AllowUserConversions && TyRec) { 4782 // No conversion functions in incomplete types. 4783 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 4784 return; 4785 4786 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4787 const UnresolvedSetImpl *Conversions 4788 = ClassDecl->getVisibleConversionFunctions(); 4789 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4790 E = Conversions->end(); I != E; ++I) { 4791 NamedDecl *D = I.getDecl(); 4792 if (isa<UsingShadowDecl>(D)) 4793 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4794 4795 // Skip conversion function templates; they don't tell us anything 4796 // about which builtin types we can convert to. 4797 if (isa<FunctionTemplateDecl>(D)) 4798 continue; 4799 4800 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4801 if (AllowExplicitConversions || !Conv->isExplicit()) { 4802 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4803 VisibleQuals); 4804 } 4805 } 4806 } 4807} 4808 4809/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4810/// the volatile- and non-volatile-qualified assignment operators for the 4811/// given type to the candidate set. 4812static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4813 QualType T, 4814 Expr **Args, 4815 unsigned NumArgs, 4816 OverloadCandidateSet &CandidateSet) { 4817 QualType ParamTypes[2]; 4818 4819 // T& operator=(T&, T) 4820 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4821 ParamTypes[1] = T; 4822 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4823 /*IsAssignmentOperator=*/true); 4824 4825 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4826 // volatile T& operator=(volatile T&, T) 4827 ParamTypes[0] 4828 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4829 ParamTypes[1] = T; 4830 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4831 /*IsAssignmentOperator=*/true); 4832 } 4833} 4834 4835/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4836/// if any, found in visible type conversion functions found in ArgExpr's type. 4837static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4838 Qualifiers VRQuals; 4839 const RecordType *TyRec; 4840 if (const MemberPointerType *RHSMPType = 4841 ArgExpr->getType()->getAs<MemberPointerType>()) 4842 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4843 else 4844 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4845 if (!TyRec) { 4846 // Just to be safe, assume the worst case. 4847 VRQuals.addVolatile(); 4848 VRQuals.addRestrict(); 4849 return VRQuals; 4850 } 4851 4852 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4853 if (!ClassDecl->hasDefinition()) 4854 return VRQuals; 4855 4856 const UnresolvedSetImpl *Conversions = 4857 ClassDecl->getVisibleConversionFunctions(); 4858 4859 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4860 E = Conversions->end(); I != E; ++I) { 4861 NamedDecl *D = I.getDecl(); 4862 if (isa<UsingShadowDecl>(D)) 4863 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4864 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4865 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4866 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4867 CanTy = ResTypeRef->getPointeeType(); 4868 // Need to go down the pointer/mempointer chain and add qualifiers 4869 // as see them. 4870 bool done = false; 4871 while (!done) { 4872 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4873 CanTy = ResTypePtr->getPointeeType(); 4874 else if (const MemberPointerType *ResTypeMPtr = 4875 CanTy->getAs<MemberPointerType>()) 4876 CanTy = ResTypeMPtr->getPointeeType(); 4877 else 4878 done = true; 4879 if (CanTy.isVolatileQualified()) 4880 VRQuals.addVolatile(); 4881 if (CanTy.isRestrictQualified()) 4882 VRQuals.addRestrict(); 4883 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4884 return VRQuals; 4885 } 4886 } 4887 } 4888 return VRQuals; 4889} 4890 4891namespace { 4892 4893/// \brief Helper class to manage the addition of builtin operator overload 4894/// candidates. It provides shared state and utility methods used throughout 4895/// the process, as well as a helper method to add each group of builtin 4896/// operator overloads from the standard to a candidate set. 4897class BuiltinOperatorOverloadBuilder { 4898 // Common instance state available to all overload candidate addition methods. 4899 Sema &S; 4900 Expr **Args; 4901 unsigned NumArgs; 4902 Qualifiers VisibleTypeConversionsQuals; 4903 bool HasArithmeticOrEnumeralCandidateType; 4904 llvm::SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 4905 OverloadCandidateSet &CandidateSet; 4906 4907 // Define some constants used to index and iterate over the arithemetic types 4908 // provided via the getArithmeticType() method below. 4909 // The "promoted arithmetic types" are the arithmetic 4910 // types are that preserved by promotion (C++ [over.built]p2). 4911 static const unsigned FirstIntegralType = 3; 4912 static const unsigned LastIntegralType = 18; 4913 static const unsigned FirstPromotedIntegralType = 3, 4914 LastPromotedIntegralType = 9; 4915 static const unsigned FirstPromotedArithmeticType = 0, 4916 LastPromotedArithmeticType = 9; 4917 static const unsigned NumArithmeticTypes = 18; 4918 4919 /// \brief Get the canonical type for a given arithmetic type index. 4920 CanQualType getArithmeticType(unsigned index) { 4921 assert(index < NumArithmeticTypes); 4922 static CanQualType ASTContext::* const 4923 ArithmeticTypes[NumArithmeticTypes] = { 4924 // Start of promoted types. 4925 &ASTContext::FloatTy, 4926 &ASTContext::DoubleTy, 4927 &ASTContext::LongDoubleTy, 4928 4929 // Start of integral types. 4930 &ASTContext::IntTy, 4931 &ASTContext::LongTy, 4932 &ASTContext::LongLongTy, 4933 &ASTContext::UnsignedIntTy, 4934 &ASTContext::UnsignedLongTy, 4935 &ASTContext::UnsignedLongLongTy, 4936 // End of promoted types. 4937 4938 &ASTContext::BoolTy, 4939 &ASTContext::CharTy, 4940 &ASTContext::WCharTy, 4941 &ASTContext::Char16Ty, 4942 &ASTContext::Char32Ty, 4943 &ASTContext::SignedCharTy, 4944 &ASTContext::ShortTy, 4945 &ASTContext::UnsignedCharTy, 4946 &ASTContext::UnsignedShortTy, 4947 // End of integral types. 4948 // FIXME: What about complex? 4949 }; 4950 return S.Context.*ArithmeticTypes[index]; 4951 } 4952 4953 /// \brief Gets the canonical type resulting from the usual arithemetic 4954 /// converions for the given arithmetic types. 4955 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 4956 // Accelerator table for performing the usual arithmetic conversions. 4957 // The rules are basically: 4958 // - if either is floating-point, use the wider floating-point 4959 // - if same signedness, use the higher rank 4960 // - if same size, use unsigned of the higher rank 4961 // - use the larger type 4962 // These rules, together with the axiom that higher ranks are 4963 // never smaller, are sufficient to precompute all of these results 4964 // *except* when dealing with signed types of higher rank. 4965 // (we could precompute SLL x UI for all known platforms, but it's 4966 // better not to make any assumptions). 4967 enum PromotedType { 4968 Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL, Dep=-1 4969 }; 4970 static PromotedType ConversionsTable[LastPromotedArithmeticType] 4971 [LastPromotedArithmeticType] = { 4972 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt }, 4973 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 4974 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 4975 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL }, 4976 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, Dep, UL, ULL }, 4977 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, Dep, Dep, ULL }, 4978 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, UI, UL, ULL }, 4979 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, UL, UL, ULL }, 4980 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, ULL, ULL, ULL }, 4981 }; 4982 4983 assert(L < LastPromotedArithmeticType); 4984 assert(R < LastPromotedArithmeticType); 4985 int Idx = ConversionsTable[L][R]; 4986 4987 // Fast path: the table gives us a concrete answer. 4988 if (Idx != Dep) return getArithmeticType(Idx); 4989 4990 // Slow path: we need to compare widths. 4991 // An invariant is that the signed type has higher rank. 4992 CanQualType LT = getArithmeticType(L), 4993 RT = getArithmeticType(R); 4994 unsigned LW = S.Context.getIntWidth(LT), 4995 RW = S.Context.getIntWidth(RT); 4996 4997 // If they're different widths, use the signed type. 4998 if (LW > RW) return LT; 4999 else if (LW < RW) return RT; 5000 5001 // Otherwise, use the unsigned type of the signed type's rank. 5002 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 5003 assert(L == SLL || R == SLL); 5004 return S.Context.UnsignedLongLongTy; 5005 } 5006 5007 /// \brief Helper method to factor out the common pattern of adding overloads 5008 /// for '++' and '--' builtin operators. 5009 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 5010 bool HasVolatile) { 5011 QualType ParamTypes[2] = { 5012 S.Context.getLValueReferenceType(CandidateTy), 5013 S.Context.IntTy 5014 }; 5015 5016 // Non-volatile version. 5017 if (NumArgs == 1) 5018 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5019 else 5020 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5021 5022 // Use a heuristic to reduce number of builtin candidates in the set: 5023 // add volatile version only if there are conversions to a volatile type. 5024 if (HasVolatile) { 5025 ParamTypes[0] = 5026 S.Context.getLValueReferenceType( 5027 S.Context.getVolatileType(CandidateTy)); 5028 if (NumArgs == 1) 5029 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5030 else 5031 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5032 } 5033 } 5034 5035public: 5036 BuiltinOperatorOverloadBuilder( 5037 Sema &S, Expr **Args, unsigned NumArgs, 5038 Qualifiers VisibleTypeConversionsQuals, 5039 bool HasArithmeticOrEnumeralCandidateType, 5040 llvm::SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 5041 OverloadCandidateSet &CandidateSet) 5042 : S(S), Args(Args), NumArgs(NumArgs), 5043 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 5044 HasArithmeticOrEnumeralCandidateType( 5045 HasArithmeticOrEnumeralCandidateType), 5046 CandidateTypes(CandidateTypes), 5047 CandidateSet(CandidateSet) { 5048 // Validate some of our static helper constants in debug builds. 5049 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 5050 "Invalid first promoted integral type"); 5051 assert(getArithmeticType(LastPromotedIntegralType - 1) 5052 == S.Context.UnsignedLongLongTy && 5053 "Invalid last promoted integral type"); 5054 assert(getArithmeticType(FirstPromotedArithmeticType) 5055 == S.Context.FloatTy && 5056 "Invalid first promoted arithmetic type"); 5057 assert(getArithmeticType(LastPromotedArithmeticType - 1) 5058 == S.Context.UnsignedLongLongTy && 5059 "Invalid last promoted arithmetic type"); 5060 } 5061 5062 // C++ [over.built]p3: 5063 // 5064 // For every pair (T, VQ), where T is an arithmetic type, and VQ 5065 // is either volatile or empty, there exist candidate operator 5066 // functions of the form 5067 // 5068 // VQ T& operator++(VQ T&); 5069 // T operator++(VQ T&, int); 5070 // 5071 // C++ [over.built]p4: 5072 // 5073 // For every pair (T, VQ), where T is an arithmetic type other 5074 // than bool, and VQ is either volatile or empty, there exist 5075 // candidate operator functions of the form 5076 // 5077 // VQ T& operator--(VQ T&); 5078 // T operator--(VQ T&, int); 5079 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 5080 if (!HasArithmeticOrEnumeralCandidateType) 5081 return; 5082 5083 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 5084 Arith < NumArithmeticTypes; ++Arith) { 5085 addPlusPlusMinusMinusStyleOverloads( 5086 getArithmeticType(Arith), 5087 VisibleTypeConversionsQuals.hasVolatile()); 5088 } 5089 } 5090 5091 // C++ [over.built]p5: 5092 // 5093 // For every pair (T, VQ), where T is a cv-qualified or 5094 // cv-unqualified object type, and VQ is either volatile or 5095 // empty, there exist candidate operator functions of the form 5096 // 5097 // T*VQ& operator++(T*VQ&); 5098 // T*VQ& operator--(T*VQ&); 5099 // T* operator++(T*VQ&, int); 5100 // T* operator--(T*VQ&, int); 5101 void addPlusPlusMinusMinusPointerOverloads() { 5102 for (BuiltinCandidateTypeSet::iterator 5103 Ptr = CandidateTypes[0].pointer_begin(), 5104 PtrEnd = CandidateTypes[0].pointer_end(); 5105 Ptr != PtrEnd; ++Ptr) { 5106 // Skip pointer types that aren't pointers to object types. 5107 if (!(*Ptr)->getPointeeType()->isObjectType()) 5108 continue; 5109 5110 addPlusPlusMinusMinusStyleOverloads(*Ptr, 5111 (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5112 VisibleTypeConversionsQuals.hasVolatile())); 5113 } 5114 } 5115 5116 // C++ [over.built]p6: 5117 // For every cv-qualified or cv-unqualified object type T, there 5118 // exist candidate operator functions of the form 5119 // 5120 // T& operator*(T*); 5121 // 5122 // C++ [over.built]p7: 5123 // For every function type T that does not have cv-qualifiers or a 5124 // ref-qualifier, there exist candidate operator functions of the form 5125 // T& operator*(T*); 5126 void addUnaryStarPointerOverloads() { 5127 for (BuiltinCandidateTypeSet::iterator 5128 Ptr = CandidateTypes[0].pointer_begin(), 5129 PtrEnd = CandidateTypes[0].pointer_end(); 5130 Ptr != PtrEnd; ++Ptr) { 5131 QualType ParamTy = *Ptr; 5132 QualType PointeeTy = ParamTy->getPointeeType(); 5133 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 5134 continue; 5135 5136 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 5137 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 5138 continue; 5139 5140 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 5141 &ParamTy, Args, 1, CandidateSet); 5142 } 5143 } 5144 5145 // C++ [over.built]p9: 5146 // For every promoted arithmetic type T, there exist candidate 5147 // operator functions of the form 5148 // 5149 // T operator+(T); 5150 // T operator-(T); 5151 void addUnaryPlusOrMinusArithmeticOverloads() { 5152 if (!HasArithmeticOrEnumeralCandidateType) 5153 return; 5154 5155 for (unsigned Arith = FirstPromotedArithmeticType; 5156 Arith < LastPromotedArithmeticType; ++Arith) { 5157 QualType ArithTy = getArithmeticType(Arith); 5158 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 5159 } 5160 5161 // Extension: We also add these operators for vector types. 5162 for (BuiltinCandidateTypeSet::iterator 5163 Vec = CandidateTypes[0].vector_begin(), 5164 VecEnd = CandidateTypes[0].vector_end(); 5165 Vec != VecEnd; ++Vec) { 5166 QualType VecTy = *Vec; 5167 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5168 } 5169 } 5170 5171 // C++ [over.built]p8: 5172 // For every type T, there exist candidate operator functions of 5173 // the form 5174 // 5175 // T* operator+(T*); 5176 void addUnaryPlusPointerOverloads() { 5177 for (BuiltinCandidateTypeSet::iterator 5178 Ptr = CandidateTypes[0].pointer_begin(), 5179 PtrEnd = CandidateTypes[0].pointer_end(); 5180 Ptr != PtrEnd; ++Ptr) { 5181 QualType ParamTy = *Ptr; 5182 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 5183 } 5184 } 5185 5186 // C++ [over.built]p10: 5187 // For every promoted integral type T, there exist candidate 5188 // operator functions of the form 5189 // 5190 // T operator~(T); 5191 void addUnaryTildePromotedIntegralOverloads() { 5192 if (!HasArithmeticOrEnumeralCandidateType) 5193 return; 5194 5195 for (unsigned Int = FirstPromotedIntegralType; 5196 Int < LastPromotedIntegralType; ++Int) { 5197 QualType IntTy = getArithmeticType(Int); 5198 S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 5199 } 5200 5201 // Extension: We also add this operator for vector types. 5202 for (BuiltinCandidateTypeSet::iterator 5203 Vec = CandidateTypes[0].vector_begin(), 5204 VecEnd = CandidateTypes[0].vector_end(); 5205 Vec != VecEnd; ++Vec) { 5206 QualType VecTy = *Vec; 5207 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5208 } 5209 } 5210 5211 // C++ [over.match.oper]p16: 5212 // For every pointer to member type T, there exist candidate operator 5213 // functions of the form 5214 // 5215 // bool operator==(T,T); 5216 // bool operator!=(T,T); 5217 void addEqualEqualOrNotEqualMemberPointerOverloads() { 5218 /// Set of (canonical) types that we've already handled. 5219 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5220 5221 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5222 for (BuiltinCandidateTypeSet::iterator 5223 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5224 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5225 MemPtr != MemPtrEnd; 5226 ++MemPtr) { 5227 // Don't add the same builtin candidate twice. 5228 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5229 continue; 5230 5231 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5232 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5233 CandidateSet); 5234 } 5235 } 5236 } 5237 5238 // C++ [over.built]p15: 5239 // 5240 // For every pointer or enumeration type T, there exist 5241 // candidate operator functions of the form 5242 // 5243 // bool operator<(T, T); 5244 // bool operator>(T, T); 5245 // bool operator<=(T, T); 5246 // bool operator>=(T, T); 5247 // bool operator==(T, T); 5248 // bool operator!=(T, T); 5249 void addRelationalPointerOrEnumeralOverloads() { 5250 // C++ [over.built]p1: 5251 // If there is a user-written candidate with the same name and parameter 5252 // types as a built-in candidate operator function, the built-in operator 5253 // function is hidden and is not included in the set of candidate 5254 // functions. 5255 // 5256 // The text is actually in a note, but if we don't implement it then we end 5257 // up with ambiguities when the user provides an overloaded operator for 5258 // an enumeration type. Note that only enumeration types have this problem, 5259 // so we track which enumeration types we've seen operators for. Also, the 5260 // only other overloaded operator with enumeration argumenst, operator=, 5261 // cannot be overloaded for enumeration types, so this is the only place 5262 // where we must suppress candidates like this. 5263 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 5264 UserDefinedBinaryOperators; 5265 5266 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5267 if (CandidateTypes[ArgIdx].enumeration_begin() != 5268 CandidateTypes[ArgIdx].enumeration_end()) { 5269 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 5270 CEnd = CandidateSet.end(); 5271 C != CEnd; ++C) { 5272 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 5273 continue; 5274 5275 QualType FirstParamType = 5276 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 5277 QualType SecondParamType = 5278 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 5279 5280 // Skip if either parameter isn't of enumeral type. 5281 if (!FirstParamType->isEnumeralType() || 5282 !SecondParamType->isEnumeralType()) 5283 continue; 5284 5285 // Add this operator to the set of known user-defined operators. 5286 UserDefinedBinaryOperators.insert( 5287 std::make_pair(S.Context.getCanonicalType(FirstParamType), 5288 S.Context.getCanonicalType(SecondParamType))); 5289 } 5290 } 5291 } 5292 5293 /// Set of (canonical) types that we've already handled. 5294 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5295 5296 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5297 for (BuiltinCandidateTypeSet::iterator 5298 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5299 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5300 Ptr != PtrEnd; ++Ptr) { 5301 // Don't add the same builtin candidate twice. 5302 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5303 continue; 5304 5305 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5306 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5307 CandidateSet); 5308 } 5309 for (BuiltinCandidateTypeSet::iterator 5310 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5311 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5312 Enum != EnumEnd; ++Enum) { 5313 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 5314 5315 // Don't add the same builtin candidate twice, or if a user defined 5316 // candidate exists. 5317 if (!AddedTypes.insert(CanonType) || 5318 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 5319 CanonType))) 5320 continue; 5321 5322 QualType ParamTypes[2] = { *Enum, *Enum }; 5323 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5324 CandidateSet); 5325 } 5326 } 5327 } 5328 5329 // C++ [over.built]p13: 5330 // 5331 // For every cv-qualified or cv-unqualified object type T 5332 // there exist candidate operator functions of the form 5333 // 5334 // T* operator+(T*, ptrdiff_t); 5335 // T& operator[](T*, ptrdiff_t); [BELOW] 5336 // T* operator-(T*, ptrdiff_t); 5337 // T* operator+(ptrdiff_t, T*); 5338 // T& operator[](ptrdiff_t, T*); [BELOW] 5339 // 5340 // C++ [over.built]p14: 5341 // 5342 // For every T, where T is a pointer to object type, there 5343 // exist candidate operator functions of the form 5344 // 5345 // ptrdiff_t operator-(T, T); 5346 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 5347 /// Set of (canonical) types that we've already handled. 5348 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5349 5350 for (int Arg = 0; Arg < 2; ++Arg) { 5351 QualType AsymetricParamTypes[2] = { 5352 S.Context.getPointerDiffType(), 5353 S.Context.getPointerDiffType(), 5354 }; 5355 for (BuiltinCandidateTypeSet::iterator 5356 Ptr = CandidateTypes[Arg].pointer_begin(), 5357 PtrEnd = CandidateTypes[Arg].pointer_end(); 5358 Ptr != PtrEnd; ++Ptr) { 5359 QualType PointeeTy = (*Ptr)->getPointeeType(); 5360 if (!PointeeTy->isObjectType()) 5361 continue; 5362 5363 AsymetricParamTypes[Arg] = *Ptr; 5364 if (Arg == 0 || Op == OO_Plus) { 5365 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 5366 // T* operator+(ptrdiff_t, T*); 5367 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, 5368 CandidateSet); 5369 } 5370 if (Op == OO_Minus) { 5371 // ptrdiff_t operator-(T, T); 5372 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5373 continue; 5374 5375 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5376 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 5377 Args, 2, CandidateSet); 5378 } 5379 } 5380 } 5381 } 5382 5383 // C++ [over.built]p12: 5384 // 5385 // For every pair of promoted arithmetic types L and R, there 5386 // exist candidate operator functions of the form 5387 // 5388 // LR operator*(L, R); 5389 // LR operator/(L, R); 5390 // LR operator+(L, R); 5391 // LR operator-(L, R); 5392 // bool operator<(L, R); 5393 // bool operator>(L, R); 5394 // bool operator<=(L, R); 5395 // bool operator>=(L, R); 5396 // bool operator==(L, R); 5397 // bool operator!=(L, R); 5398 // 5399 // where LR is the result of the usual arithmetic conversions 5400 // between types L and R. 5401 // 5402 // C++ [over.built]p24: 5403 // 5404 // For every pair of promoted arithmetic types L and R, there exist 5405 // candidate operator functions of the form 5406 // 5407 // LR operator?(bool, L, R); 5408 // 5409 // where LR is the result of the usual arithmetic conversions 5410 // between types L and R. 5411 // Our candidates ignore the first parameter. 5412 void addGenericBinaryArithmeticOverloads(bool isComparison) { 5413 if (!HasArithmeticOrEnumeralCandidateType) 5414 return; 5415 5416 for (unsigned Left = FirstPromotedArithmeticType; 5417 Left < LastPromotedArithmeticType; ++Left) { 5418 for (unsigned Right = FirstPromotedArithmeticType; 5419 Right < LastPromotedArithmeticType; ++Right) { 5420 QualType LandR[2] = { getArithmeticType(Left), 5421 getArithmeticType(Right) }; 5422 QualType Result = 5423 isComparison ? S.Context.BoolTy 5424 : getUsualArithmeticConversions(Left, Right); 5425 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5426 } 5427 } 5428 5429 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 5430 // conditional operator for vector types. 5431 for (BuiltinCandidateTypeSet::iterator 5432 Vec1 = CandidateTypes[0].vector_begin(), 5433 Vec1End = CandidateTypes[0].vector_end(); 5434 Vec1 != Vec1End; ++Vec1) { 5435 for (BuiltinCandidateTypeSet::iterator 5436 Vec2 = CandidateTypes[1].vector_begin(), 5437 Vec2End = CandidateTypes[1].vector_end(); 5438 Vec2 != Vec2End; ++Vec2) { 5439 QualType LandR[2] = { *Vec1, *Vec2 }; 5440 QualType Result = S.Context.BoolTy; 5441 if (!isComparison) { 5442 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 5443 Result = *Vec1; 5444 else 5445 Result = *Vec2; 5446 } 5447 5448 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5449 } 5450 } 5451 } 5452 5453 // C++ [over.built]p17: 5454 // 5455 // For every pair of promoted integral types L and R, there 5456 // exist candidate operator functions of the form 5457 // 5458 // LR operator%(L, R); 5459 // LR operator&(L, R); 5460 // LR operator^(L, R); 5461 // LR operator|(L, R); 5462 // L operator<<(L, R); 5463 // L operator>>(L, R); 5464 // 5465 // where LR is the result of the usual arithmetic conversions 5466 // between types L and R. 5467 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 5468 if (!HasArithmeticOrEnumeralCandidateType) 5469 return; 5470 5471 for (unsigned Left = FirstPromotedIntegralType; 5472 Left < LastPromotedIntegralType; ++Left) { 5473 for (unsigned Right = FirstPromotedIntegralType; 5474 Right < LastPromotedIntegralType; ++Right) { 5475 QualType LandR[2] = { getArithmeticType(Left), 5476 getArithmeticType(Right) }; 5477 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 5478 ? LandR[0] 5479 : getUsualArithmeticConversions(Left, Right); 5480 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5481 } 5482 } 5483 } 5484 5485 // C++ [over.built]p20: 5486 // 5487 // For every pair (T, VQ), where T is an enumeration or 5488 // pointer to member type and VQ is either volatile or 5489 // empty, there exist candidate operator functions of the form 5490 // 5491 // VQ T& operator=(VQ T&, T); 5492 void addAssignmentMemberPointerOrEnumeralOverloads() { 5493 /// Set of (canonical) types that we've already handled. 5494 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5495 5496 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5497 for (BuiltinCandidateTypeSet::iterator 5498 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5499 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5500 Enum != EnumEnd; ++Enum) { 5501 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5502 continue; 5503 5504 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, 5505 CandidateSet); 5506 } 5507 5508 for (BuiltinCandidateTypeSet::iterator 5509 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5510 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5511 MemPtr != MemPtrEnd; ++MemPtr) { 5512 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5513 continue; 5514 5515 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, 5516 CandidateSet); 5517 } 5518 } 5519 } 5520 5521 // C++ [over.built]p19: 5522 // 5523 // For every pair (T, VQ), where T is any type and VQ is either 5524 // volatile or empty, there exist candidate operator functions 5525 // of the form 5526 // 5527 // T*VQ& operator=(T*VQ&, T*); 5528 // 5529 // C++ [over.built]p21: 5530 // 5531 // For every pair (T, VQ), where T is a cv-qualified or 5532 // cv-unqualified object type and VQ is either volatile or 5533 // empty, there exist candidate operator functions of the form 5534 // 5535 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 5536 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 5537 void addAssignmentPointerOverloads(bool isEqualOp) { 5538 /// Set of (canonical) types that we've already handled. 5539 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5540 5541 for (BuiltinCandidateTypeSet::iterator 5542 Ptr = CandidateTypes[0].pointer_begin(), 5543 PtrEnd = CandidateTypes[0].pointer_end(); 5544 Ptr != PtrEnd; ++Ptr) { 5545 // If this is operator=, keep track of the builtin candidates we added. 5546 if (isEqualOp) 5547 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 5548 else if (!(*Ptr)->getPointeeType()->isObjectType()) 5549 continue; 5550 5551 // non-volatile version 5552 QualType ParamTypes[2] = { 5553 S.Context.getLValueReferenceType(*Ptr), 5554 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 5555 }; 5556 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5557 /*IsAssigmentOperator=*/ isEqualOp); 5558 5559 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5560 VisibleTypeConversionsQuals.hasVolatile()) { 5561 // volatile version 5562 ParamTypes[0] = 5563 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5564 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5565 /*IsAssigmentOperator=*/isEqualOp); 5566 } 5567 } 5568 5569 if (isEqualOp) { 5570 for (BuiltinCandidateTypeSet::iterator 5571 Ptr = CandidateTypes[1].pointer_begin(), 5572 PtrEnd = CandidateTypes[1].pointer_end(); 5573 Ptr != PtrEnd; ++Ptr) { 5574 // Make sure we don't add the same candidate twice. 5575 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5576 continue; 5577 5578 QualType ParamTypes[2] = { 5579 S.Context.getLValueReferenceType(*Ptr), 5580 *Ptr, 5581 }; 5582 5583 // non-volatile version 5584 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5585 /*IsAssigmentOperator=*/true); 5586 5587 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5588 VisibleTypeConversionsQuals.hasVolatile()) { 5589 // volatile version 5590 ParamTypes[0] = 5591 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5592 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5593 CandidateSet, /*IsAssigmentOperator=*/true); 5594 } 5595 } 5596 } 5597 } 5598 5599 // C++ [over.built]p18: 5600 // 5601 // For every triple (L, VQ, R), where L is an arithmetic type, 5602 // VQ is either volatile or empty, and R is a promoted 5603 // arithmetic type, there exist candidate operator functions of 5604 // the form 5605 // 5606 // VQ L& operator=(VQ L&, R); 5607 // VQ L& operator*=(VQ L&, R); 5608 // VQ L& operator/=(VQ L&, R); 5609 // VQ L& operator+=(VQ L&, R); 5610 // VQ L& operator-=(VQ L&, R); 5611 void addAssignmentArithmeticOverloads(bool isEqualOp) { 5612 if (!HasArithmeticOrEnumeralCandidateType) 5613 return; 5614 5615 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 5616 for (unsigned Right = FirstPromotedArithmeticType; 5617 Right < LastPromotedArithmeticType; ++Right) { 5618 QualType ParamTypes[2]; 5619 ParamTypes[1] = getArithmeticType(Right); 5620 5621 // Add this built-in operator as a candidate (VQ is empty). 5622 ParamTypes[0] = 5623 S.Context.getLValueReferenceType(getArithmeticType(Left)); 5624 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5625 /*IsAssigmentOperator=*/isEqualOp); 5626 5627 // Add this built-in operator as a candidate (VQ is 'volatile'). 5628 if (VisibleTypeConversionsQuals.hasVolatile()) { 5629 ParamTypes[0] = 5630 S.Context.getVolatileType(getArithmeticType(Left)); 5631 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5632 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5633 CandidateSet, 5634 /*IsAssigmentOperator=*/isEqualOp); 5635 } 5636 } 5637 } 5638 5639 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 5640 for (BuiltinCandidateTypeSet::iterator 5641 Vec1 = CandidateTypes[0].vector_begin(), 5642 Vec1End = CandidateTypes[0].vector_end(); 5643 Vec1 != Vec1End; ++Vec1) { 5644 for (BuiltinCandidateTypeSet::iterator 5645 Vec2 = CandidateTypes[1].vector_begin(), 5646 Vec2End = CandidateTypes[1].vector_end(); 5647 Vec2 != Vec2End; ++Vec2) { 5648 QualType ParamTypes[2]; 5649 ParamTypes[1] = *Vec2; 5650 // Add this built-in operator as a candidate (VQ is empty). 5651 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 5652 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5653 /*IsAssigmentOperator=*/isEqualOp); 5654 5655 // Add this built-in operator as a candidate (VQ is 'volatile'). 5656 if (VisibleTypeConversionsQuals.hasVolatile()) { 5657 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 5658 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5659 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5660 CandidateSet, 5661 /*IsAssigmentOperator=*/isEqualOp); 5662 } 5663 } 5664 } 5665 } 5666 5667 // C++ [over.built]p22: 5668 // 5669 // For every triple (L, VQ, R), where L is an integral type, VQ 5670 // is either volatile or empty, and R is a promoted integral 5671 // type, there exist candidate operator functions of the form 5672 // 5673 // VQ L& operator%=(VQ L&, R); 5674 // VQ L& operator<<=(VQ L&, R); 5675 // VQ L& operator>>=(VQ L&, R); 5676 // VQ L& operator&=(VQ L&, R); 5677 // VQ L& operator^=(VQ L&, R); 5678 // VQ L& operator|=(VQ L&, R); 5679 void addAssignmentIntegralOverloads() { 5680 if (!HasArithmeticOrEnumeralCandidateType) 5681 return; 5682 5683 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 5684 for (unsigned Right = FirstPromotedIntegralType; 5685 Right < LastPromotedIntegralType; ++Right) { 5686 QualType ParamTypes[2]; 5687 ParamTypes[1] = getArithmeticType(Right); 5688 5689 // Add this built-in operator as a candidate (VQ is empty). 5690 ParamTypes[0] = 5691 S.Context.getLValueReferenceType(getArithmeticType(Left)); 5692 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5693 if (VisibleTypeConversionsQuals.hasVolatile()) { 5694 // Add this built-in operator as a candidate (VQ is 'volatile'). 5695 ParamTypes[0] = getArithmeticType(Left); 5696 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 5697 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5698 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5699 CandidateSet); 5700 } 5701 } 5702 } 5703 } 5704 5705 // C++ [over.operator]p23: 5706 // 5707 // There also exist candidate operator functions of the form 5708 // 5709 // bool operator!(bool); 5710 // bool operator&&(bool, bool); 5711 // bool operator||(bool, bool); 5712 void addExclaimOverload() { 5713 QualType ParamTy = S.Context.BoolTy; 5714 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 5715 /*IsAssignmentOperator=*/false, 5716 /*NumContextualBoolArguments=*/1); 5717 } 5718 void addAmpAmpOrPipePipeOverload() { 5719 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 5720 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 5721 /*IsAssignmentOperator=*/false, 5722 /*NumContextualBoolArguments=*/2); 5723 } 5724 5725 // C++ [over.built]p13: 5726 // 5727 // For every cv-qualified or cv-unqualified object type T there 5728 // exist candidate operator functions of the form 5729 // 5730 // T* operator+(T*, ptrdiff_t); [ABOVE] 5731 // T& operator[](T*, ptrdiff_t); 5732 // T* operator-(T*, ptrdiff_t); [ABOVE] 5733 // T* operator+(ptrdiff_t, T*); [ABOVE] 5734 // T& operator[](ptrdiff_t, T*); 5735 void addSubscriptOverloads() { 5736 for (BuiltinCandidateTypeSet::iterator 5737 Ptr = CandidateTypes[0].pointer_begin(), 5738 PtrEnd = CandidateTypes[0].pointer_end(); 5739 Ptr != PtrEnd; ++Ptr) { 5740 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 5741 QualType PointeeType = (*Ptr)->getPointeeType(); 5742 if (!PointeeType->isObjectType()) 5743 continue; 5744 5745 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 5746 5747 // T& operator[](T*, ptrdiff_t) 5748 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5749 } 5750 5751 for (BuiltinCandidateTypeSet::iterator 5752 Ptr = CandidateTypes[1].pointer_begin(), 5753 PtrEnd = CandidateTypes[1].pointer_end(); 5754 Ptr != PtrEnd; ++Ptr) { 5755 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 5756 QualType PointeeType = (*Ptr)->getPointeeType(); 5757 if (!PointeeType->isObjectType()) 5758 continue; 5759 5760 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 5761 5762 // T& operator[](ptrdiff_t, T*) 5763 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5764 } 5765 } 5766 5767 // C++ [over.built]p11: 5768 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 5769 // C1 is the same type as C2 or is a derived class of C2, T is an object 5770 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 5771 // there exist candidate operator functions of the form 5772 // 5773 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 5774 // 5775 // where CV12 is the union of CV1 and CV2. 5776 void addArrowStarOverloads() { 5777 for (BuiltinCandidateTypeSet::iterator 5778 Ptr = CandidateTypes[0].pointer_begin(), 5779 PtrEnd = CandidateTypes[0].pointer_end(); 5780 Ptr != PtrEnd; ++Ptr) { 5781 QualType C1Ty = (*Ptr); 5782 QualType C1; 5783 QualifierCollector Q1; 5784 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 5785 if (!isa<RecordType>(C1)) 5786 continue; 5787 // heuristic to reduce number of builtin candidates in the set. 5788 // Add volatile/restrict version only if there are conversions to a 5789 // volatile/restrict type. 5790 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 5791 continue; 5792 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 5793 continue; 5794 for (BuiltinCandidateTypeSet::iterator 5795 MemPtr = CandidateTypes[1].member_pointer_begin(), 5796 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 5797 MemPtr != MemPtrEnd; ++MemPtr) { 5798 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 5799 QualType C2 = QualType(mptr->getClass(), 0); 5800 C2 = C2.getUnqualifiedType(); 5801 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 5802 break; 5803 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 5804 // build CV12 T& 5805 QualType T = mptr->getPointeeType(); 5806 if (!VisibleTypeConversionsQuals.hasVolatile() && 5807 T.isVolatileQualified()) 5808 continue; 5809 if (!VisibleTypeConversionsQuals.hasRestrict() && 5810 T.isRestrictQualified()) 5811 continue; 5812 T = Q1.apply(S.Context, T); 5813 QualType ResultTy = S.Context.getLValueReferenceType(T); 5814 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5815 } 5816 } 5817 } 5818 5819 // Note that we don't consider the first argument, since it has been 5820 // contextually converted to bool long ago. The candidates below are 5821 // therefore added as binary. 5822 // 5823 // C++ [over.built]p25: 5824 // For every type T, where T is a pointer, pointer-to-member, or scoped 5825 // enumeration type, there exist candidate operator functions of the form 5826 // 5827 // T operator?(bool, T, T); 5828 // 5829 void addConditionalOperatorOverloads() { 5830 /// Set of (canonical) types that we've already handled. 5831 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5832 5833 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5834 for (BuiltinCandidateTypeSet::iterator 5835 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5836 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5837 Ptr != PtrEnd; ++Ptr) { 5838 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5839 continue; 5840 5841 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5842 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5843 } 5844 5845 for (BuiltinCandidateTypeSet::iterator 5846 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5847 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5848 MemPtr != MemPtrEnd; ++MemPtr) { 5849 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5850 continue; 5851 5852 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5853 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); 5854 } 5855 5856 if (S.getLangOptions().CPlusPlus0x) { 5857 for (BuiltinCandidateTypeSet::iterator 5858 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5859 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5860 Enum != EnumEnd; ++Enum) { 5861 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 5862 continue; 5863 5864 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5865 continue; 5866 5867 QualType ParamTypes[2] = { *Enum, *Enum }; 5868 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); 5869 } 5870 } 5871 } 5872 } 5873}; 5874 5875} // end anonymous namespace 5876 5877/// AddBuiltinOperatorCandidates - Add the appropriate built-in 5878/// operator overloads to the candidate set (C++ [over.built]), based 5879/// on the operator @p Op and the arguments given. For example, if the 5880/// operator is a binary '+', this routine might add "int 5881/// operator+(int, int)" to cover integer addition. 5882void 5883Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 5884 SourceLocation OpLoc, 5885 Expr **Args, unsigned NumArgs, 5886 OverloadCandidateSet& CandidateSet) { 5887 // Find all of the types that the arguments can convert to, but only 5888 // if the operator we're looking at has built-in operator candidates 5889 // that make use of these types. Also record whether we encounter non-record 5890 // candidate types or either arithmetic or enumeral candidate types. 5891 Qualifiers VisibleTypeConversionsQuals; 5892 VisibleTypeConversionsQuals.addConst(); 5893 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5894 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 5895 5896 bool HasNonRecordCandidateType = false; 5897 bool HasArithmeticOrEnumeralCandidateType = false; 5898 llvm::SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 5899 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5900 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 5901 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 5902 OpLoc, 5903 true, 5904 (Op == OO_Exclaim || 5905 Op == OO_AmpAmp || 5906 Op == OO_PipePipe), 5907 VisibleTypeConversionsQuals); 5908 HasNonRecordCandidateType = HasNonRecordCandidateType || 5909 CandidateTypes[ArgIdx].hasNonRecordTypes(); 5910 HasArithmeticOrEnumeralCandidateType = 5911 HasArithmeticOrEnumeralCandidateType || 5912 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 5913 } 5914 5915 // Exit early when no non-record types have been added to the candidate set 5916 // for any of the arguments to the operator. 5917 if (!HasNonRecordCandidateType) 5918 return; 5919 5920 // Setup an object to manage the common state for building overloads. 5921 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, 5922 VisibleTypeConversionsQuals, 5923 HasArithmeticOrEnumeralCandidateType, 5924 CandidateTypes, CandidateSet); 5925 5926 // Dispatch over the operation to add in only those overloads which apply. 5927 switch (Op) { 5928 case OO_None: 5929 case NUM_OVERLOADED_OPERATORS: 5930 assert(false && "Expected an overloaded operator"); 5931 break; 5932 5933 case OO_New: 5934 case OO_Delete: 5935 case OO_Array_New: 5936 case OO_Array_Delete: 5937 case OO_Call: 5938 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 5939 break; 5940 5941 case OO_Comma: 5942 case OO_Arrow: 5943 // C++ [over.match.oper]p3: 5944 // -- For the operator ',', the unary operator '&', or the 5945 // operator '->', the built-in candidates set is empty. 5946 break; 5947 5948 case OO_Plus: // '+' is either unary or binary 5949 if (NumArgs == 1) 5950 OpBuilder.addUnaryPlusPointerOverloads(); 5951 // Fall through. 5952 5953 case OO_Minus: // '-' is either unary or binary 5954 if (NumArgs == 1) { 5955 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 5956 } else { 5957 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 5958 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 5959 } 5960 break; 5961 5962 case OO_Star: // '*' is either unary or binary 5963 if (NumArgs == 1) 5964 OpBuilder.addUnaryStarPointerOverloads(); 5965 else 5966 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 5967 break; 5968 5969 case OO_Slash: 5970 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 5971 break; 5972 5973 case OO_PlusPlus: 5974 case OO_MinusMinus: 5975 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 5976 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 5977 break; 5978 5979 case OO_EqualEqual: 5980 case OO_ExclaimEqual: 5981 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 5982 // Fall through. 5983 5984 case OO_Less: 5985 case OO_Greater: 5986 case OO_LessEqual: 5987 case OO_GreaterEqual: 5988 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 5989 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 5990 break; 5991 5992 case OO_Percent: 5993 case OO_Caret: 5994 case OO_Pipe: 5995 case OO_LessLess: 5996 case OO_GreaterGreater: 5997 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 5998 break; 5999 6000 case OO_Amp: // '&' is either unary or binary 6001 if (NumArgs == 1) 6002 // C++ [over.match.oper]p3: 6003 // -- For the operator ',', the unary operator '&', or the 6004 // operator '->', the built-in candidates set is empty. 6005 break; 6006 6007 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6008 break; 6009 6010 case OO_Tilde: 6011 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 6012 break; 6013 6014 case OO_Equal: 6015 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 6016 // Fall through. 6017 6018 case OO_PlusEqual: 6019 case OO_MinusEqual: 6020 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 6021 // Fall through. 6022 6023 case OO_StarEqual: 6024 case OO_SlashEqual: 6025 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 6026 break; 6027 6028 case OO_PercentEqual: 6029 case OO_LessLessEqual: 6030 case OO_GreaterGreaterEqual: 6031 case OO_AmpEqual: 6032 case OO_CaretEqual: 6033 case OO_PipeEqual: 6034 OpBuilder.addAssignmentIntegralOverloads(); 6035 break; 6036 6037 case OO_Exclaim: 6038 OpBuilder.addExclaimOverload(); 6039 break; 6040 6041 case OO_AmpAmp: 6042 case OO_PipePipe: 6043 OpBuilder.addAmpAmpOrPipePipeOverload(); 6044 break; 6045 6046 case OO_Subscript: 6047 OpBuilder.addSubscriptOverloads(); 6048 break; 6049 6050 case OO_ArrowStar: 6051 OpBuilder.addArrowStarOverloads(); 6052 break; 6053 6054 case OO_Conditional: 6055 OpBuilder.addConditionalOperatorOverloads(); 6056 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6057 break; 6058 } 6059} 6060 6061/// \brief Add function candidates found via argument-dependent lookup 6062/// to the set of overloading candidates. 6063/// 6064/// This routine performs argument-dependent name lookup based on the 6065/// given function name (which may also be an operator name) and adds 6066/// all of the overload candidates found by ADL to the overload 6067/// candidate set (C++ [basic.lookup.argdep]). 6068void 6069Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 6070 bool Operator, 6071 Expr **Args, unsigned NumArgs, 6072 const TemplateArgumentListInfo *ExplicitTemplateArgs, 6073 OverloadCandidateSet& CandidateSet, 6074 bool PartialOverloading) { 6075 ADLResult Fns; 6076 6077 // FIXME: This approach for uniquing ADL results (and removing 6078 // redundant candidates from the set) relies on pointer-equality, 6079 // which means we need to key off the canonical decl. However, 6080 // always going back to the canonical decl might not get us the 6081 // right set of default arguments. What default arguments are 6082 // we supposed to consider on ADL candidates, anyway? 6083 6084 // FIXME: Pass in the explicit template arguments? 6085 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 6086 6087 // Erase all of the candidates we already knew about. 6088 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 6089 CandEnd = CandidateSet.end(); 6090 Cand != CandEnd; ++Cand) 6091 if (Cand->Function) { 6092 Fns.erase(Cand->Function); 6093 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 6094 Fns.erase(FunTmpl); 6095 } 6096 6097 // For each of the ADL candidates we found, add it to the overload 6098 // set. 6099 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 6100 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 6101 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 6102 if (ExplicitTemplateArgs) 6103 continue; 6104 6105 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 6106 false, PartialOverloading); 6107 } else 6108 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 6109 FoundDecl, ExplicitTemplateArgs, 6110 Args, NumArgs, CandidateSet); 6111 } 6112} 6113 6114/// isBetterOverloadCandidate - Determines whether the first overload 6115/// candidate is a better candidate than the second (C++ 13.3.3p1). 6116bool 6117isBetterOverloadCandidate(Sema &S, 6118 const OverloadCandidate &Cand1, 6119 const OverloadCandidate &Cand2, 6120 SourceLocation Loc, 6121 bool UserDefinedConversion) { 6122 // Define viable functions to be better candidates than non-viable 6123 // functions. 6124 if (!Cand2.Viable) 6125 return Cand1.Viable; 6126 else if (!Cand1.Viable) 6127 return false; 6128 6129 // C++ [over.match.best]p1: 6130 // 6131 // -- if F is a static member function, ICS1(F) is defined such 6132 // that ICS1(F) is neither better nor worse than ICS1(G) for 6133 // any function G, and, symmetrically, ICS1(G) is neither 6134 // better nor worse than ICS1(F). 6135 unsigned StartArg = 0; 6136 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 6137 StartArg = 1; 6138 6139 // C++ [over.match.best]p1: 6140 // A viable function F1 is defined to be a better function than another 6141 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 6142 // conversion sequence than ICSi(F2), and then... 6143 unsigned NumArgs = Cand1.Conversions.size(); 6144 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 6145 bool HasBetterConversion = false; 6146 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 6147 switch (CompareImplicitConversionSequences(S, 6148 Cand1.Conversions[ArgIdx], 6149 Cand2.Conversions[ArgIdx])) { 6150 case ImplicitConversionSequence::Better: 6151 // Cand1 has a better conversion sequence. 6152 HasBetterConversion = true; 6153 break; 6154 6155 case ImplicitConversionSequence::Worse: 6156 // Cand1 can't be better than Cand2. 6157 return false; 6158 6159 case ImplicitConversionSequence::Indistinguishable: 6160 // Do nothing. 6161 break; 6162 } 6163 } 6164 6165 // -- for some argument j, ICSj(F1) is a better conversion sequence than 6166 // ICSj(F2), or, if not that, 6167 if (HasBetterConversion) 6168 return true; 6169 6170 // - F1 is a non-template function and F2 is a function template 6171 // specialization, or, if not that, 6172 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 6173 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 6174 return true; 6175 6176 // -- F1 and F2 are function template specializations, and the function 6177 // template for F1 is more specialized than the template for F2 6178 // according to the partial ordering rules described in 14.5.5.2, or, 6179 // if not that, 6180 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 6181 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 6182 if (FunctionTemplateDecl *BetterTemplate 6183 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 6184 Cand2.Function->getPrimaryTemplate(), 6185 Loc, 6186 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 6187 : TPOC_Call, 6188 Cand1.ExplicitCallArguments)) 6189 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 6190 } 6191 6192 // -- the context is an initialization by user-defined conversion 6193 // (see 8.5, 13.3.1.5) and the standard conversion sequence 6194 // from the return type of F1 to the destination type (i.e., 6195 // the type of the entity being initialized) is a better 6196 // conversion sequence than the standard conversion sequence 6197 // from the return type of F2 to the destination type. 6198 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 6199 isa<CXXConversionDecl>(Cand1.Function) && 6200 isa<CXXConversionDecl>(Cand2.Function)) { 6201 switch (CompareStandardConversionSequences(S, 6202 Cand1.FinalConversion, 6203 Cand2.FinalConversion)) { 6204 case ImplicitConversionSequence::Better: 6205 // Cand1 has a better conversion sequence. 6206 return true; 6207 6208 case ImplicitConversionSequence::Worse: 6209 // Cand1 can't be better than Cand2. 6210 return false; 6211 6212 case ImplicitConversionSequence::Indistinguishable: 6213 // Do nothing 6214 break; 6215 } 6216 } 6217 6218 return false; 6219} 6220 6221/// \brief Computes the best viable function (C++ 13.3.3) 6222/// within an overload candidate set. 6223/// 6224/// \param CandidateSet the set of candidate functions. 6225/// 6226/// \param Loc the location of the function name (or operator symbol) for 6227/// which overload resolution occurs. 6228/// 6229/// \param Best f overload resolution was successful or found a deleted 6230/// function, Best points to the candidate function found. 6231/// 6232/// \returns The result of overload resolution. 6233OverloadingResult 6234OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 6235 iterator &Best, 6236 bool UserDefinedConversion) { 6237 // Find the best viable function. 6238 Best = end(); 6239 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6240 if (Cand->Viable) 6241 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 6242 UserDefinedConversion)) 6243 Best = Cand; 6244 } 6245 6246 // If we didn't find any viable functions, abort. 6247 if (Best == end()) 6248 return OR_No_Viable_Function; 6249 6250 // Make sure that this function is better than every other viable 6251 // function. If not, we have an ambiguity. 6252 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6253 if (Cand->Viable && 6254 Cand != Best && 6255 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 6256 UserDefinedConversion)) { 6257 Best = end(); 6258 return OR_Ambiguous; 6259 } 6260 } 6261 6262 // Best is the best viable function. 6263 if (Best->Function && 6264 (Best->Function->isDeleted() || 6265 Best->Function->getAttr<UnavailableAttr>())) 6266 return OR_Deleted; 6267 6268 // C++ [basic.def.odr]p2: 6269 // An overloaded function is used if it is selected by overload resolution 6270 // when referred to from a potentially-evaluated expression. [Note: this 6271 // covers calls to named functions (5.2.2), operator overloading 6272 // (clause 13), user-defined conversions (12.3.2), allocation function for 6273 // placement new (5.3.4), as well as non-default initialization (8.5). 6274 if (Best->Function) 6275 S.MarkDeclarationReferenced(Loc, Best->Function); 6276 6277 return OR_Success; 6278} 6279 6280namespace { 6281 6282enum OverloadCandidateKind { 6283 oc_function, 6284 oc_method, 6285 oc_constructor, 6286 oc_function_template, 6287 oc_method_template, 6288 oc_constructor_template, 6289 oc_implicit_default_constructor, 6290 oc_implicit_copy_constructor, 6291 oc_implicit_copy_assignment, 6292 oc_implicit_inherited_constructor 6293}; 6294 6295OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 6296 FunctionDecl *Fn, 6297 std::string &Description) { 6298 bool isTemplate = false; 6299 6300 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 6301 isTemplate = true; 6302 Description = S.getTemplateArgumentBindingsText( 6303 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 6304 } 6305 6306 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 6307 if (!Ctor->isImplicit()) 6308 return isTemplate ? oc_constructor_template : oc_constructor; 6309 6310 if (Ctor->getInheritedConstructor()) 6311 return oc_implicit_inherited_constructor; 6312 6313 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 6314 : oc_implicit_default_constructor; 6315 } 6316 6317 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 6318 // This actually gets spelled 'candidate function' for now, but 6319 // it doesn't hurt to split it out. 6320 if (!Meth->isImplicit()) 6321 return isTemplate ? oc_method_template : oc_method; 6322 6323 assert(Meth->isCopyAssignmentOperator() 6324 && "implicit method is not copy assignment operator?"); 6325 return oc_implicit_copy_assignment; 6326 } 6327 6328 return isTemplate ? oc_function_template : oc_function; 6329} 6330 6331void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { 6332 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 6333 if (!Ctor) return; 6334 6335 Ctor = Ctor->getInheritedConstructor(); 6336 if (!Ctor) return; 6337 6338 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 6339} 6340 6341} // end anonymous namespace 6342 6343// Notes the location of an overload candidate. 6344void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 6345 std::string FnDesc; 6346 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 6347 Diag(Fn->getLocation(), diag::note_ovl_candidate) 6348 << (unsigned) K << FnDesc; 6349 MaybeEmitInheritedConstructorNote(*this, Fn); 6350} 6351 6352/// Diagnoses an ambiguous conversion. The partial diagnostic is the 6353/// "lead" diagnostic; it will be given two arguments, the source and 6354/// target types of the conversion. 6355void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 6356 Sema &S, 6357 SourceLocation CaretLoc, 6358 const PartialDiagnostic &PDiag) const { 6359 S.Diag(CaretLoc, PDiag) 6360 << Ambiguous.getFromType() << Ambiguous.getToType(); 6361 for (AmbiguousConversionSequence::const_iterator 6362 I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 6363 S.NoteOverloadCandidate(*I); 6364 } 6365} 6366 6367namespace { 6368 6369void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 6370 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 6371 assert(Conv.isBad()); 6372 assert(Cand->Function && "for now, candidate must be a function"); 6373 FunctionDecl *Fn = Cand->Function; 6374 6375 // There's a conversion slot for the object argument if this is a 6376 // non-constructor method. Note that 'I' corresponds the 6377 // conversion-slot index. 6378 bool isObjectArgument = false; 6379 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 6380 if (I == 0) 6381 isObjectArgument = true; 6382 else 6383 I--; 6384 } 6385 6386 std::string FnDesc; 6387 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6388 6389 Expr *FromExpr = Conv.Bad.FromExpr; 6390 QualType FromTy = Conv.Bad.getFromType(); 6391 QualType ToTy = Conv.Bad.getToType(); 6392 6393 if (FromTy == S.Context.OverloadTy) { 6394 assert(FromExpr && "overload set argument came from implicit argument?"); 6395 Expr *E = FromExpr->IgnoreParens(); 6396 if (isa<UnaryOperator>(E)) 6397 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 6398 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 6399 6400 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 6401 << (unsigned) FnKind << FnDesc 6402 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6403 << ToTy << Name << I+1; 6404 MaybeEmitInheritedConstructorNote(S, Fn); 6405 return; 6406 } 6407 6408 // Do some hand-waving analysis to see if the non-viability is due 6409 // to a qualifier mismatch. 6410 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 6411 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 6412 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 6413 CToTy = RT->getPointeeType(); 6414 else { 6415 // TODO: detect and diagnose the full richness of const mismatches. 6416 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 6417 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 6418 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 6419 } 6420 6421 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 6422 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 6423 // It is dumb that we have to do this here. 6424 while (isa<ArrayType>(CFromTy)) 6425 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 6426 while (isa<ArrayType>(CToTy)) 6427 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 6428 6429 Qualifiers FromQs = CFromTy.getQualifiers(); 6430 Qualifiers ToQs = CToTy.getQualifiers(); 6431 6432 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 6433 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 6434 << (unsigned) FnKind << FnDesc 6435 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6436 << FromTy 6437 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 6438 << (unsigned) isObjectArgument << I+1; 6439 MaybeEmitInheritedConstructorNote(S, Fn); 6440 return; 6441 } 6442 6443 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 6444 assert(CVR && "unexpected qualifiers mismatch"); 6445 6446 if (isObjectArgument) { 6447 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 6448 << (unsigned) FnKind << FnDesc 6449 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6450 << FromTy << (CVR - 1); 6451 } else { 6452 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 6453 << (unsigned) FnKind << FnDesc 6454 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6455 << FromTy << (CVR - 1) << I+1; 6456 } 6457 MaybeEmitInheritedConstructorNote(S, Fn); 6458 return; 6459 } 6460 6461 // Diagnose references or pointers to incomplete types differently, 6462 // since it's far from impossible that the incompleteness triggered 6463 // the failure. 6464 QualType TempFromTy = FromTy.getNonReferenceType(); 6465 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 6466 TempFromTy = PTy->getPointeeType(); 6467 if (TempFromTy->isIncompleteType()) { 6468 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 6469 << (unsigned) FnKind << FnDesc 6470 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6471 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6472 MaybeEmitInheritedConstructorNote(S, Fn); 6473 return; 6474 } 6475 6476 // Diagnose base -> derived pointer conversions. 6477 unsigned BaseToDerivedConversion = 0; 6478 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 6479 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 6480 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6481 FromPtrTy->getPointeeType()) && 6482 !FromPtrTy->getPointeeType()->isIncompleteType() && 6483 !ToPtrTy->getPointeeType()->isIncompleteType() && 6484 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 6485 FromPtrTy->getPointeeType())) 6486 BaseToDerivedConversion = 1; 6487 } 6488 } else if (const ObjCObjectPointerType *FromPtrTy 6489 = FromTy->getAs<ObjCObjectPointerType>()) { 6490 if (const ObjCObjectPointerType *ToPtrTy 6491 = ToTy->getAs<ObjCObjectPointerType>()) 6492 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 6493 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 6494 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6495 FromPtrTy->getPointeeType()) && 6496 FromIface->isSuperClassOf(ToIface)) 6497 BaseToDerivedConversion = 2; 6498 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 6499 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 6500 !FromTy->isIncompleteType() && 6501 !ToRefTy->getPointeeType()->isIncompleteType() && 6502 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 6503 BaseToDerivedConversion = 3; 6504 } 6505 6506 if (BaseToDerivedConversion) { 6507 S.Diag(Fn->getLocation(), 6508 diag::note_ovl_candidate_bad_base_to_derived_conv) 6509 << (unsigned) FnKind << FnDesc 6510 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6511 << (BaseToDerivedConversion - 1) 6512 << FromTy << ToTy << I+1; 6513 MaybeEmitInheritedConstructorNote(S, Fn); 6514 return; 6515 } 6516 6517 // TODO: specialize more based on the kind of mismatch 6518 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 6519 << (unsigned) FnKind << FnDesc 6520 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6521 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6522 MaybeEmitInheritedConstructorNote(S, Fn); 6523} 6524 6525void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 6526 unsigned NumFormalArgs) { 6527 // TODO: treat calls to a missing default constructor as a special case 6528 6529 FunctionDecl *Fn = Cand->Function; 6530 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 6531 6532 unsigned MinParams = Fn->getMinRequiredArguments(); 6533 6534 // at least / at most / exactly 6535 unsigned mode, modeCount; 6536 if (NumFormalArgs < MinParams) { 6537 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 6538 (Cand->FailureKind == ovl_fail_bad_deduction && 6539 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 6540 if (MinParams != FnTy->getNumArgs() || 6541 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 6542 mode = 0; // "at least" 6543 else 6544 mode = 2; // "exactly" 6545 modeCount = MinParams; 6546 } else { 6547 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 6548 (Cand->FailureKind == ovl_fail_bad_deduction && 6549 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 6550 if (MinParams != FnTy->getNumArgs()) 6551 mode = 1; // "at most" 6552 else 6553 mode = 2; // "exactly" 6554 modeCount = FnTy->getNumArgs(); 6555 } 6556 6557 std::string Description; 6558 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 6559 6560 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 6561 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 6562 << modeCount << NumFormalArgs; 6563 MaybeEmitInheritedConstructorNote(S, Fn); 6564} 6565 6566/// Diagnose a failed template-argument deduction. 6567void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 6568 Expr **Args, unsigned NumArgs) { 6569 FunctionDecl *Fn = Cand->Function; // pattern 6570 6571 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 6572 NamedDecl *ParamD; 6573 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 6574 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 6575 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 6576 switch (Cand->DeductionFailure.Result) { 6577 case Sema::TDK_Success: 6578 llvm_unreachable("TDK_success while diagnosing bad deduction"); 6579 6580 case Sema::TDK_Incomplete: { 6581 assert(ParamD && "no parameter found for incomplete deduction result"); 6582 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 6583 << ParamD->getDeclName(); 6584 MaybeEmitInheritedConstructorNote(S, Fn); 6585 return; 6586 } 6587 6588 case Sema::TDK_Underqualified: { 6589 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 6590 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 6591 6592 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 6593 6594 // Param will have been canonicalized, but it should just be a 6595 // qualified version of ParamD, so move the qualifiers to that. 6596 QualifierCollector Qs; 6597 Qs.strip(Param); 6598 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 6599 assert(S.Context.hasSameType(Param, NonCanonParam)); 6600 6601 // Arg has also been canonicalized, but there's nothing we can do 6602 // about that. It also doesn't matter as much, because it won't 6603 // have any template parameters in it (because deduction isn't 6604 // done on dependent types). 6605 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 6606 6607 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 6608 << ParamD->getDeclName() << Arg << NonCanonParam; 6609 MaybeEmitInheritedConstructorNote(S, Fn); 6610 return; 6611 } 6612 6613 case Sema::TDK_Inconsistent: { 6614 assert(ParamD && "no parameter found for inconsistent deduction result"); 6615 int which = 0; 6616 if (isa<TemplateTypeParmDecl>(ParamD)) 6617 which = 0; 6618 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 6619 which = 1; 6620 else { 6621 which = 2; 6622 } 6623 6624 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 6625 << which << ParamD->getDeclName() 6626 << *Cand->DeductionFailure.getFirstArg() 6627 << *Cand->DeductionFailure.getSecondArg(); 6628 MaybeEmitInheritedConstructorNote(S, Fn); 6629 return; 6630 } 6631 6632 case Sema::TDK_InvalidExplicitArguments: 6633 assert(ParamD && "no parameter found for invalid explicit arguments"); 6634 if (ParamD->getDeclName()) 6635 S.Diag(Fn->getLocation(), 6636 diag::note_ovl_candidate_explicit_arg_mismatch_named) 6637 << ParamD->getDeclName(); 6638 else { 6639 int index = 0; 6640 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 6641 index = TTP->getIndex(); 6642 else if (NonTypeTemplateParmDecl *NTTP 6643 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 6644 index = NTTP->getIndex(); 6645 else 6646 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 6647 S.Diag(Fn->getLocation(), 6648 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 6649 << (index + 1); 6650 } 6651 MaybeEmitInheritedConstructorNote(S, Fn); 6652 return; 6653 6654 case Sema::TDK_TooManyArguments: 6655 case Sema::TDK_TooFewArguments: 6656 DiagnoseArityMismatch(S, Cand, NumArgs); 6657 return; 6658 6659 case Sema::TDK_InstantiationDepth: 6660 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 6661 MaybeEmitInheritedConstructorNote(S, Fn); 6662 return; 6663 6664 case Sema::TDK_SubstitutionFailure: { 6665 std::string ArgString; 6666 if (TemplateArgumentList *Args 6667 = Cand->DeductionFailure.getTemplateArgumentList()) 6668 ArgString = S.getTemplateArgumentBindingsText( 6669 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 6670 *Args); 6671 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 6672 << ArgString; 6673 MaybeEmitInheritedConstructorNote(S, Fn); 6674 return; 6675 } 6676 6677 // TODO: diagnose these individually, then kill off 6678 // note_ovl_candidate_bad_deduction, which is uselessly vague. 6679 case Sema::TDK_NonDeducedMismatch: 6680 case Sema::TDK_FailedOverloadResolution: 6681 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 6682 MaybeEmitInheritedConstructorNote(S, Fn); 6683 return; 6684 } 6685} 6686 6687/// Generates a 'note' diagnostic for an overload candidate. We've 6688/// already generated a primary error at the call site. 6689/// 6690/// It really does need to be a single diagnostic with its caret 6691/// pointed at the candidate declaration. Yes, this creates some 6692/// major challenges of technical writing. Yes, this makes pointing 6693/// out problems with specific arguments quite awkward. It's still 6694/// better than generating twenty screens of text for every failed 6695/// overload. 6696/// 6697/// It would be great to be able to express per-candidate problems 6698/// more richly for those diagnostic clients that cared, but we'd 6699/// still have to be just as careful with the default diagnostics. 6700void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 6701 Expr **Args, unsigned NumArgs) { 6702 FunctionDecl *Fn = Cand->Function; 6703 6704 // Note deleted candidates, but only if they're viable. 6705 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 6706 std::string FnDesc; 6707 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6708 6709 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 6710 << FnKind << FnDesc << Fn->isDeleted(); 6711 MaybeEmitInheritedConstructorNote(S, Fn); 6712 return; 6713 } 6714 6715 // We don't really have anything else to say about viable candidates. 6716 if (Cand->Viable) { 6717 S.NoteOverloadCandidate(Fn); 6718 return; 6719 } 6720 6721 switch (Cand->FailureKind) { 6722 case ovl_fail_too_many_arguments: 6723 case ovl_fail_too_few_arguments: 6724 return DiagnoseArityMismatch(S, Cand, NumArgs); 6725 6726 case ovl_fail_bad_deduction: 6727 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 6728 6729 case ovl_fail_trivial_conversion: 6730 case ovl_fail_bad_final_conversion: 6731 case ovl_fail_final_conversion_not_exact: 6732 return S.NoteOverloadCandidate(Fn); 6733 6734 case ovl_fail_bad_conversion: { 6735 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 6736 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 6737 if (Cand->Conversions[I].isBad()) 6738 return DiagnoseBadConversion(S, Cand, I); 6739 6740 // FIXME: this currently happens when we're called from SemaInit 6741 // when user-conversion overload fails. Figure out how to handle 6742 // those conditions and diagnose them well. 6743 return S.NoteOverloadCandidate(Fn); 6744 } 6745 } 6746} 6747 6748void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 6749 // Desugar the type of the surrogate down to a function type, 6750 // retaining as many typedefs as possible while still showing 6751 // the function type (and, therefore, its parameter types). 6752 QualType FnType = Cand->Surrogate->getConversionType(); 6753 bool isLValueReference = false; 6754 bool isRValueReference = false; 6755 bool isPointer = false; 6756 if (const LValueReferenceType *FnTypeRef = 6757 FnType->getAs<LValueReferenceType>()) { 6758 FnType = FnTypeRef->getPointeeType(); 6759 isLValueReference = true; 6760 } else if (const RValueReferenceType *FnTypeRef = 6761 FnType->getAs<RValueReferenceType>()) { 6762 FnType = FnTypeRef->getPointeeType(); 6763 isRValueReference = true; 6764 } 6765 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 6766 FnType = FnTypePtr->getPointeeType(); 6767 isPointer = true; 6768 } 6769 // Desugar down to a function type. 6770 FnType = QualType(FnType->getAs<FunctionType>(), 0); 6771 // Reconstruct the pointer/reference as appropriate. 6772 if (isPointer) FnType = S.Context.getPointerType(FnType); 6773 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 6774 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 6775 6776 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 6777 << FnType; 6778 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 6779} 6780 6781void NoteBuiltinOperatorCandidate(Sema &S, 6782 const char *Opc, 6783 SourceLocation OpLoc, 6784 OverloadCandidate *Cand) { 6785 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 6786 std::string TypeStr("operator"); 6787 TypeStr += Opc; 6788 TypeStr += "("; 6789 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 6790 if (Cand->Conversions.size() == 1) { 6791 TypeStr += ")"; 6792 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 6793 } else { 6794 TypeStr += ", "; 6795 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 6796 TypeStr += ")"; 6797 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 6798 } 6799} 6800 6801void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 6802 OverloadCandidate *Cand) { 6803 unsigned NoOperands = Cand->Conversions.size(); 6804 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 6805 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 6806 if (ICS.isBad()) break; // all meaningless after first invalid 6807 if (!ICS.isAmbiguous()) continue; 6808 6809 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 6810 S.PDiag(diag::note_ambiguous_type_conversion)); 6811 } 6812} 6813 6814SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 6815 if (Cand->Function) 6816 return Cand->Function->getLocation(); 6817 if (Cand->IsSurrogate) 6818 return Cand->Surrogate->getLocation(); 6819 return SourceLocation(); 6820} 6821 6822struct CompareOverloadCandidatesForDisplay { 6823 Sema &S; 6824 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 6825 6826 bool operator()(const OverloadCandidate *L, 6827 const OverloadCandidate *R) { 6828 // Fast-path this check. 6829 if (L == R) return false; 6830 6831 // Order first by viability. 6832 if (L->Viable) { 6833 if (!R->Viable) return true; 6834 6835 // TODO: introduce a tri-valued comparison for overload 6836 // candidates. Would be more worthwhile if we had a sort 6837 // that could exploit it. 6838 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 6839 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 6840 } else if (R->Viable) 6841 return false; 6842 6843 assert(L->Viable == R->Viable); 6844 6845 // Criteria by which we can sort non-viable candidates: 6846 if (!L->Viable) { 6847 // 1. Arity mismatches come after other candidates. 6848 if (L->FailureKind == ovl_fail_too_many_arguments || 6849 L->FailureKind == ovl_fail_too_few_arguments) 6850 return false; 6851 if (R->FailureKind == ovl_fail_too_many_arguments || 6852 R->FailureKind == ovl_fail_too_few_arguments) 6853 return true; 6854 6855 // 2. Bad conversions come first and are ordered by the number 6856 // of bad conversions and quality of good conversions. 6857 if (L->FailureKind == ovl_fail_bad_conversion) { 6858 if (R->FailureKind != ovl_fail_bad_conversion) 6859 return true; 6860 6861 // If there's any ordering between the defined conversions... 6862 // FIXME: this might not be transitive. 6863 assert(L->Conversions.size() == R->Conversions.size()); 6864 6865 int leftBetter = 0; 6866 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 6867 for (unsigned E = L->Conversions.size(); I != E; ++I) { 6868 switch (CompareImplicitConversionSequences(S, 6869 L->Conversions[I], 6870 R->Conversions[I])) { 6871 case ImplicitConversionSequence::Better: 6872 leftBetter++; 6873 break; 6874 6875 case ImplicitConversionSequence::Worse: 6876 leftBetter--; 6877 break; 6878 6879 case ImplicitConversionSequence::Indistinguishable: 6880 break; 6881 } 6882 } 6883 if (leftBetter > 0) return true; 6884 if (leftBetter < 0) return false; 6885 6886 } else if (R->FailureKind == ovl_fail_bad_conversion) 6887 return false; 6888 6889 // TODO: others? 6890 } 6891 6892 // Sort everything else by location. 6893 SourceLocation LLoc = GetLocationForCandidate(L); 6894 SourceLocation RLoc = GetLocationForCandidate(R); 6895 6896 // Put candidates without locations (e.g. builtins) at the end. 6897 if (LLoc.isInvalid()) return false; 6898 if (RLoc.isInvalid()) return true; 6899 6900 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 6901 } 6902}; 6903 6904/// CompleteNonViableCandidate - Normally, overload resolution only 6905/// computes up to the first 6906void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 6907 Expr **Args, unsigned NumArgs) { 6908 assert(!Cand->Viable); 6909 6910 // Don't do anything on failures other than bad conversion. 6911 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 6912 6913 // Skip forward to the first bad conversion. 6914 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 6915 unsigned ConvCount = Cand->Conversions.size(); 6916 while (true) { 6917 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 6918 ConvIdx++; 6919 if (Cand->Conversions[ConvIdx - 1].isBad()) 6920 break; 6921 } 6922 6923 if (ConvIdx == ConvCount) 6924 return; 6925 6926 assert(!Cand->Conversions[ConvIdx].isInitialized() && 6927 "remaining conversion is initialized?"); 6928 6929 // FIXME: this should probably be preserved from the overload 6930 // operation somehow. 6931 bool SuppressUserConversions = false; 6932 6933 const FunctionProtoType* Proto; 6934 unsigned ArgIdx = ConvIdx; 6935 6936 if (Cand->IsSurrogate) { 6937 QualType ConvType 6938 = Cand->Surrogate->getConversionType().getNonReferenceType(); 6939 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6940 ConvType = ConvPtrType->getPointeeType(); 6941 Proto = ConvType->getAs<FunctionProtoType>(); 6942 ArgIdx--; 6943 } else if (Cand->Function) { 6944 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 6945 if (isa<CXXMethodDecl>(Cand->Function) && 6946 !isa<CXXConstructorDecl>(Cand->Function)) 6947 ArgIdx--; 6948 } else { 6949 // Builtin binary operator with a bad first conversion. 6950 assert(ConvCount <= 3); 6951 for (; ConvIdx != ConvCount; ++ConvIdx) 6952 Cand->Conversions[ConvIdx] 6953 = TryCopyInitialization(S, Args[ConvIdx], 6954 Cand->BuiltinTypes.ParamTypes[ConvIdx], 6955 SuppressUserConversions, 6956 /*InOverloadResolution*/ true); 6957 return; 6958 } 6959 6960 // Fill in the rest of the conversions. 6961 unsigned NumArgsInProto = Proto->getNumArgs(); 6962 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 6963 if (ArgIdx < NumArgsInProto) 6964 Cand->Conversions[ConvIdx] 6965 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 6966 SuppressUserConversions, 6967 /*InOverloadResolution=*/true); 6968 else 6969 Cand->Conversions[ConvIdx].setEllipsis(); 6970 } 6971} 6972 6973} // end anonymous namespace 6974 6975/// PrintOverloadCandidates - When overload resolution fails, prints 6976/// diagnostic messages containing the candidates in the candidate 6977/// set. 6978void OverloadCandidateSet::NoteCandidates(Sema &S, 6979 OverloadCandidateDisplayKind OCD, 6980 Expr **Args, unsigned NumArgs, 6981 const char *Opc, 6982 SourceLocation OpLoc) { 6983 // Sort the candidates by viability and position. Sorting directly would 6984 // be prohibitive, so we make a set of pointers and sort those. 6985 llvm::SmallVector<OverloadCandidate*, 32> Cands; 6986 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 6987 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 6988 if (Cand->Viable) 6989 Cands.push_back(Cand); 6990 else if (OCD == OCD_AllCandidates) { 6991 CompleteNonViableCandidate(S, Cand, Args, NumArgs); 6992 if (Cand->Function || Cand->IsSurrogate) 6993 Cands.push_back(Cand); 6994 // Otherwise, this a non-viable builtin candidate. We do not, in general, 6995 // want to list every possible builtin candidate. 6996 } 6997 } 6998 6999 std::sort(Cands.begin(), Cands.end(), 7000 CompareOverloadCandidatesForDisplay(S)); 7001 7002 bool ReportedAmbiguousConversions = false; 7003 7004 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 7005 const Diagnostic::OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 7006 unsigned CandsShown = 0; 7007 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 7008 OverloadCandidate *Cand = *I; 7009 7010 // Set an arbitrary limit on the number of candidate functions we'll spam 7011 // the user with. FIXME: This limit should depend on details of the 7012 // candidate list. 7013 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 7014 break; 7015 } 7016 ++CandsShown; 7017 7018 if (Cand->Function) 7019 NoteFunctionCandidate(S, Cand, Args, NumArgs); 7020 else if (Cand->IsSurrogate) 7021 NoteSurrogateCandidate(S, Cand); 7022 else { 7023 assert(Cand->Viable && 7024 "Non-viable built-in candidates are not added to Cands."); 7025 // Generally we only see ambiguities including viable builtin 7026 // operators if overload resolution got screwed up by an 7027 // ambiguous user-defined conversion. 7028 // 7029 // FIXME: It's quite possible for different conversions to see 7030 // different ambiguities, though. 7031 if (!ReportedAmbiguousConversions) { 7032 NoteAmbiguousUserConversions(S, OpLoc, Cand); 7033 ReportedAmbiguousConversions = true; 7034 } 7035 7036 // If this is a viable builtin, print it. 7037 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 7038 } 7039 } 7040 7041 if (I != E) 7042 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 7043} 7044 7045static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 7046 if (isa<UnresolvedLookupExpr>(E)) 7047 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 7048 7049 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 7050} 7051 7052/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 7053/// an overloaded function (C++ [over.over]), where @p From is an 7054/// expression with overloaded function type and @p ToType is the type 7055/// we're trying to resolve to. For example: 7056/// 7057/// @code 7058/// int f(double); 7059/// int f(int); 7060/// 7061/// int (*pfd)(double) = f; // selects f(double) 7062/// @endcode 7063/// 7064/// This routine returns the resulting FunctionDecl if it could be 7065/// resolved, and NULL otherwise. When @p Complain is true, this 7066/// routine will emit diagnostics if there is an error. 7067FunctionDecl * 7068Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 7069 bool Complain, 7070 DeclAccessPair &FoundResult) { 7071 QualType FunctionType = ToType; 7072 bool IsMember = false; 7073 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 7074 FunctionType = ToTypePtr->getPointeeType(); 7075 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 7076 FunctionType = ToTypeRef->getPointeeType(); 7077 else if (const MemberPointerType *MemTypePtr = 7078 ToType->getAs<MemberPointerType>()) { 7079 FunctionType = MemTypePtr->getPointeeType(); 7080 IsMember = true; 7081 } 7082 7083 // C++ [over.over]p1: 7084 // [...] [Note: any redundant set of parentheses surrounding the 7085 // overloaded function name is ignored (5.1). ] 7086 // C++ [over.over]p1: 7087 // [...] The overloaded function name can be preceded by the & 7088 // operator. 7089 // However, remember whether the expression has member-pointer form: 7090 // C++ [expr.unary.op]p4: 7091 // A pointer to member is only formed when an explicit & is used 7092 // and its operand is a qualified-id not enclosed in 7093 // parentheses. 7094 OverloadExpr::FindResult Ovl = OverloadExpr::find(From); 7095 OverloadExpr *OvlExpr = Ovl.Expression; 7096 7097 // We expect a pointer or reference to function, or a function pointer. 7098 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 7099 if (!FunctionType->isFunctionType()) { 7100 if (Complain) 7101 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 7102 << OvlExpr->getName() << ToType; 7103 7104 return 0; 7105 } 7106 7107 // If the overload expression doesn't have the form of a pointer to 7108 // member, don't try to convert it to a pointer-to-member type. 7109 if (IsMember && !Ovl.HasFormOfMemberPointer) { 7110 if (!Complain) return 0; 7111 7112 // TODO: Should we condition this on whether any functions might 7113 // have matched, or is it more appropriate to do that in callers? 7114 // TODO: a fixit wouldn't hurt. 7115 Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 7116 << ToType << OvlExpr->getSourceRange(); 7117 return 0; 7118 } 7119 7120 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 7121 if (OvlExpr->hasExplicitTemplateArgs()) { 7122 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 7123 ExplicitTemplateArgs = &ETABuffer; 7124 } 7125 7126 assert(From->getType() == Context.OverloadTy); 7127 7128 // Look through all of the overloaded functions, searching for one 7129 // whose type matches exactly. 7130 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 7131 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 7132 7133 bool FoundNonTemplateFunction = false; 7134 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7135 E = OvlExpr->decls_end(); I != E; ++I) { 7136 // Look through any using declarations to find the underlying function. 7137 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 7138 7139 // C++ [over.over]p3: 7140 // Non-member functions and static member functions match 7141 // targets of type "pointer-to-function" or "reference-to-function." 7142 // Nonstatic member functions match targets of 7143 // type "pointer-to-member-function." 7144 // Note that according to DR 247, the containing class does not matter. 7145 7146 if (FunctionTemplateDecl *FunctionTemplate 7147 = dyn_cast<FunctionTemplateDecl>(Fn)) { 7148 if (CXXMethodDecl *Method 7149 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 7150 // Skip non-static function templates when converting to pointer, and 7151 // static when converting to member pointer. 7152 if (Method->isStatic() == IsMember) 7153 continue; 7154 } else if (IsMember) 7155 continue; 7156 7157 // C++ [over.over]p2: 7158 // If the name is a function template, template argument deduction is 7159 // done (14.8.2.2), and if the argument deduction succeeds, the 7160 // resulting template argument list is used to generate a single 7161 // function template specialization, which is added to the set of 7162 // overloaded functions considered. 7163 FunctionDecl *Specialization = 0; 7164 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 7165 if (TemplateDeductionResult Result 7166 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 7167 FunctionType, Specialization, Info)) { 7168 // FIXME: make a note of the failed deduction for diagnostics. 7169 (void)Result; 7170 } else { 7171 // Template argument deduction ensures that we have an exact match. 7172 // This function template specicalization works. 7173 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 7174 assert(FunctionType 7175 == Context.getCanonicalType(Specialization->getType())); 7176 Matches.push_back(std::make_pair(I.getPair(), Specialization)); 7177 } 7178 7179 continue; 7180 } 7181 7182 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7183 // Skip non-static functions when converting to pointer, and static 7184 // when converting to member pointer. 7185 if (Method->isStatic() == IsMember) 7186 continue; 7187 7188 // If we have explicit template arguments, skip non-templates. 7189 if (OvlExpr->hasExplicitTemplateArgs()) 7190 continue; 7191 } else if (IsMember) 7192 continue; 7193 7194 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 7195 QualType ResultTy; 7196 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 7197 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 7198 ResultTy)) { 7199 Matches.push_back(std::make_pair(I.getPair(), 7200 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 7201 FoundNonTemplateFunction = true; 7202 } 7203 } 7204 } 7205 7206 // If there were 0 or 1 matches, we're done. 7207 if (Matches.empty()) { 7208 if (Complain) { 7209 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 7210 << OvlExpr->getName() << FunctionType; 7211 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7212 E = OvlExpr->decls_end(); 7213 I != E; ++I) 7214 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 7215 NoteOverloadCandidate(F); 7216 } 7217 7218 return 0; 7219 } else if (Matches.size() == 1) { 7220 FunctionDecl *Result = Matches[0].second; 7221 FoundResult = Matches[0].first; 7222 MarkDeclarationReferenced(From->getLocStart(), Result); 7223 if (Complain) { 7224 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 7225 } 7226 return Result; 7227 } 7228 7229 // C++ [over.over]p4: 7230 // If more than one function is selected, [...] 7231 if (!FoundNonTemplateFunction) { 7232 // [...] and any given function template specialization F1 is 7233 // eliminated if the set contains a second function template 7234 // specialization whose function template is more specialized 7235 // than the function template of F1 according to the partial 7236 // ordering rules of 14.5.5.2. 7237 7238 // The algorithm specified above is quadratic. We instead use a 7239 // two-pass algorithm (similar to the one used to identify the 7240 // best viable function in an overload set) that identifies the 7241 // best function template (if it exists). 7242 7243 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 7244 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 7245 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 7246 7247 UnresolvedSetIterator Result = 7248 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 7249 TPOC_Other, 0, From->getLocStart(), 7250 PDiag(), 7251 PDiag(diag::err_addr_ovl_ambiguous) 7252 << Matches[0].second->getDeclName(), 7253 PDiag(diag::note_ovl_candidate) 7254 << (unsigned) oc_function_template); 7255 if (Result == MatchesCopy.end()) 7256 return 0; 7257 7258 MarkDeclarationReferenced(From->getLocStart(), *Result); 7259 FoundResult = Matches[Result - MatchesCopy.begin()].first; 7260 if (Complain) 7261 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 7262 return cast<FunctionDecl>(*Result); 7263 } 7264 7265 // [...] any function template specializations in the set are 7266 // eliminated if the set also contains a non-template function, [...] 7267 for (unsigned I = 0, N = Matches.size(); I != N; ) { 7268 if (Matches[I].second->getPrimaryTemplate() == 0) 7269 ++I; 7270 else { 7271 Matches[I] = Matches[--N]; 7272 Matches.set_size(N); 7273 } 7274 } 7275 7276 // [...] After such eliminations, if any, there shall remain exactly one 7277 // selected function. 7278 if (Matches.size() == 1) { 7279 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 7280 FoundResult = Matches[0].first; 7281 if (Complain) 7282 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 7283 return cast<FunctionDecl>(Matches[0].second); 7284 } 7285 7286 // FIXME: We should probably return the same thing that BestViableFunction 7287 // returns (even if we issue the diagnostics here). 7288 if (Complain) { 7289 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 7290 << Matches[0].second->getDeclName(); 7291 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 7292 NoteOverloadCandidate(Matches[I].second); 7293 } 7294 7295 return 0; 7296} 7297 7298/// \brief Given an expression that refers to an overloaded function, try to 7299/// resolve that overloaded function expression down to a single function. 7300/// 7301/// This routine can only resolve template-ids that refer to a single function 7302/// template, where that template-id refers to a single template whose template 7303/// arguments are either provided by the template-id or have defaults, 7304/// as described in C++0x [temp.arg.explicit]p3. 7305FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 7306 // C++ [over.over]p1: 7307 // [...] [Note: any redundant set of parentheses surrounding the 7308 // overloaded function name is ignored (5.1). ] 7309 // C++ [over.over]p1: 7310 // [...] The overloaded function name can be preceded by the & 7311 // operator. 7312 7313 if (From->getType() != Context.OverloadTy) 7314 return 0; 7315 7316 OverloadExpr *OvlExpr = OverloadExpr::find(From).Expression; 7317 7318 // If we didn't actually find any template-ids, we're done. 7319 if (!OvlExpr->hasExplicitTemplateArgs()) 7320 return 0; 7321 7322 TemplateArgumentListInfo ExplicitTemplateArgs; 7323 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 7324 7325 // Look through all of the overloaded functions, searching for one 7326 // whose type matches exactly. 7327 FunctionDecl *Matched = 0; 7328 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7329 E = OvlExpr->decls_end(); I != E; ++I) { 7330 // C++0x [temp.arg.explicit]p3: 7331 // [...] In contexts where deduction is done and fails, or in contexts 7332 // where deduction is not done, if a template argument list is 7333 // specified and it, along with any default template arguments, 7334 // identifies a single function template specialization, then the 7335 // template-id is an lvalue for the function template specialization. 7336 FunctionTemplateDecl *FunctionTemplate 7337 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 7338 7339 // C++ [over.over]p2: 7340 // If the name is a function template, template argument deduction is 7341 // done (14.8.2.2), and if the argument deduction succeeds, the 7342 // resulting template argument list is used to generate a single 7343 // function template specialization, which is added to the set of 7344 // overloaded functions considered. 7345 FunctionDecl *Specialization = 0; 7346 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 7347 if (TemplateDeductionResult Result 7348 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 7349 Specialization, Info)) { 7350 // FIXME: make a note of the failed deduction for diagnostics. 7351 (void)Result; 7352 continue; 7353 } 7354 7355 // Multiple matches; we can't resolve to a single declaration. 7356 if (Matched) 7357 return 0; 7358 7359 Matched = Specialization; 7360 } 7361 7362 return Matched; 7363} 7364 7365/// \brief Add a single candidate to the overload set. 7366static void AddOverloadedCallCandidate(Sema &S, 7367 DeclAccessPair FoundDecl, 7368 const TemplateArgumentListInfo *ExplicitTemplateArgs, 7369 Expr **Args, unsigned NumArgs, 7370 OverloadCandidateSet &CandidateSet, 7371 bool PartialOverloading) { 7372 NamedDecl *Callee = FoundDecl.getDecl(); 7373 if (isa<UsingShadowDecl>(Callee)) 7374 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 7375 7376 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 7377 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 7378 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 7379 false, PartialOverloading); 7380 return; 7381 } 7382 7383 if (FunctionTemplateDecl *FuncTemplate 7384 = dyn_cast<FunctionTemplateDecl>(Callee)) { 7385 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 7386 ExplicitTemplateArgs, 7387 Args, NumArgs, CandidateSet); 7388 return; 7389 } 7390 7391 assert(false && "unhandled case in overloaded call candidate"); 7392 7393 // do nothing? 7394} 7395 7396/// \brief Add the overload candidates named by callee and/or found by argument 7397/// dependent lookup to the given overload set. 7398void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 7399 Expr **Args, unsigned NumArgs, 7400 OverloadCandidateSet &CandidateSet, 7401 bool PartialOverloading) { 7402 7403#ifndef NDEBUG 7404 // Verify that ArgumentDependentLookup is consistent with the rules 7405 // in C++0x [basic.lookup.argdep]p3: 7406 // 7407 // Let X be the lookup set produced by unqualified lookup (3.4.1) 7408 // and let Y be the lookup set produced by argument dependent 7409 // lookup (defined as follows). If X contains 7410 // 7411 // -- a declaration of a class member, or 7412 // 7413 // -- a block-scope function declaration that is not a 7414 // using-declaration, or 7415 // 7416 // -- a declaration that is neither a function or a function 7417 // template 7418 // 7419 // then Y is empty. 7420 7421 if (ULE->requiresADL()) { 7422 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 7423 E = ULE->decls_end(); I != E; ++I) { 7424 assert(!(*I)->getDeclContext()->isRecord()); 7425 assert(isa<UsingShadowDecl>(*I) || 7426 !(*I)->getDeclContext()->isFunctionOrMethod()); 7427 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 7428 } 7429 } 7430#endif 7431 7432 // It would be nice to avoid this copy. 7433 TemplateArgumentListInfo TABuffer; 7434 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 7435 if (ULE->hasExplicitTemplateArgs()) { 7436 ULE->copyTemplateArgumentsInto(TABuffer); 7437 ExplicitTemplateArgs = &TABuffer; 7438 } 7439 7440 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 7441 E = ULE->decls_end(); I != E; ++I) 7442 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 7443 Args, NumArgs, CandidateSet, 7444 PartialOverloading); 7445 7446 if (ULE->requiresADL()) 7447 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 7448 Args, NumArgs, 7449 ExplicitTemplateArgs, 7450 CandidateSet, 7451 PartialOverloading); 7452} 7453 7454/// Attempts to recover from a call where no functions were found. 7455/// 7456/// Returns true if new candidates were found. 7457static ExprResult 7458BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 7459 UnresolvedLookupExpr *ULE, 7460 SourceLocation LParenLoc, 7461 Expr **Args, unsigned NumArgs, 7462 SourceLocation RParenLoc) { 7463 7464 CXXScopeSpec SS; 7465 if (ULE->getQualifier()) { 7466 SS.setScopeRep(ULE->getQualifier()); 7467 SS.setRange(ULE->getQualifierRange()); 7468 } 7469 7470 TemplateArgumentListInfo TABuffer; 7471 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 7472 if (ULE->hasExplicitTemplateArgs()) { 7473 ULE->copyTemplateArgumentsInto(TABuffer); 7474 ExplicitTemplateArgs = &TABuffer; 7475 } 7476 7477 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 7478 Sema::LookupOrdinaryName); 7479 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 7480 return ExprError(); 7481 7482 assert(!R.empty() && "lookup results empty despite recovery"); 7483 7484 // Build an implicit member call if appropriate. Just drop the 7485 // casts and such from the call, we don't really care. 7486 ExprResult NewFn = ExprError(); 7487 if ((*R.begin())->isCXXClassMember()) 7488 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, 7489 ExplicitTemplateArgs); 7490 else if (ExplicitTemplateArgs) 7491 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 7492 else 7493 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 7494 7495 if (NewFn.isInvalid()) 7496 return ExprError(); 7497 7498 // This shouldn't cause an infinite loop because we're giving it 7499 // an expression with non-empty lookup results, which should never 7500 // end up here. 7501 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 7502 MultiExprArg(Args, NumArgs), RParenLoc); 7503} 7504 7505/// ResolveOverloadedCallFn - Given the call expression that calls Fn 7506/// (which eventually refers to the declaration Func) and the call 7507/// arguments Args/NumArgs, attempt to resolve the function call down 7508/// to a specific function. If overload resolution succeeds, returns 7509/// the function declaration produced by overload 7510/// resolution. Otherwise, emits diagnostics, deletes all of the 7511/// arguments and Fn, and returns NULL. 7512ExprResult 7513Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 7514 SourceLocation LParenLoc, 7515 Expr **Args, unsigned NumArgs, 7516 SourceLocation RParenLoc, 7517 Expr *ExecConfig) { 7518#ifndef NDEBUG 7519 if (ULE->requiresADL()) { 7520 // To do ADL, we must have found an unqualified name. 7521 assert(!ULE->getQualifier() && "qualified name with ADL"); 7522 7523 // We don't perform ADL for implicit declarations of builtins. 7524 // Verify that this was correctly set up. 7525 FunctionDecl *F; 7526 if (ULE->decls_begin() + 1 == ULE->decls_end() && 7527 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 7528 F->getBuiltinID() && F->isImplicit()) 7529 assert(0 && "performing ADL for builtin"); 7530 7531 // We don't perform ADL in C. 7532 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 7533 } 7534#endif 7535 7536 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 7537 7538 // Add the functions denoted by the callee to the set of candidate 7539 // functions, including those from argument-dependent lookup. 7540 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 7541 7542 // If we found nothing, try to recover. 7543 // AddRecoveryCallCandidates diagnoses the error itself, so we just 7544 // bailout out if it fails. 7545 if (CandidateSet.empty()) 7546 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 7547 RParenLoc); 7548 7549 OverloadCandidateSet::iterator Best; 7550 switch (CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best)) { 7551 case OR_Success: { 7552 FunctionDecl *FDecl = Best->Function; 7553 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 7554 DiagnoseUseOfDecl(FDecl? FDecl : Best->FoundDecl.getDecl(), 7555 ULE->getNameLoc()); 7556 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 7557 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc, 7558 ExecConfig); 7559 } 7560 7561 case OR_No_Viable_Function: 7562 Diag(Fn->getSourceRange().getBegin(), 7563 diag::err_ovl_no_viable_function_in_call) 7564 << ULE->getName() << Fn->getSourceRange(); 7565 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7566 break; 7567 7568 case OR_Ambiguous: 7569 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 7570 << ULE->getName() << Fn->getSourceRange(); 7571 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 7572 break; 7573 7574 case OR_Deleted: 7575 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 7576 << Best->Function->isDeleted() 7577 << ULE->getName() 7578 << Fn->getSourceRange(); 7579 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7580 break; 7581 } 7582 7583 // Overload resolution failed. 7584 return ExprError(); 7585} 7586 7587static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 7588 return Functions.size() > 1 || 7589 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 7590} 7591 7592/// \brief Create a unary operation that may resolve to an overloaded 7593/// operator. 7594/// 7595/// \param OpLoc The location of the operator itself (e.g., '*'). 7596/// 7597/// \param OpcIn The UnaryOperator::Opcode that describes this 7598/// operator. 7599/// 7600/// \param Functions The set of non-member functions that will be 7601/// considered by overload resolution. The caller needs to build this 7602/// set based on the context using, e.g., 7603/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 7604/// set should not contain any member functions; those will be added 7605/// by CreateOverloadedUnaryOp(). 7606/// 7607/// \param input The input argument. 7608ExprResult 7609Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 7610 const UnresolvedSetImpl &Fns, 7611 Expr *Input) { 7612 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 7613 7614 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 7615 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 7616 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 7617 // TODO: provide better source location info. 7618 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 7619 7620 if (Input->getObjectKind() == OK_ObjCProperty) 7621 ConvertPropertyForRValue(Input); 7622 7623 Expr *Args[2] = { Input, 0 }; 7624 unsigned NumArgs = 1; 7625 7626 // For post-increment and post-decrement, add the implicit '0' as 7627 // the second argument, so that we know this is a post-increment or 7628 // post-decrement. 7629 if (Opc == UO_PostInc || Opc == UO_PostDec) { 7630 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 7631 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 7632 SourceLocation()); 7633 NumArgs = 2; 7634 } 7635 7636 if (Input->isTypeDependent()) { 7637 if (Fns.empty()) 7638 return Owned(new (Context) UnaryOperator(Input, 7639 Opc, 7640 Context.DependentTy, 7641 VK_RValue, OK_Ordinary, 7642 OpLoc)); 7643 7644 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7645 UnresolvedLookupExpr *Fn 7646 = UnresolvedLookupExpr::Create(Context, NamingClass, 7647 0, SourceRange(), OpNameInfo, 7648 /*ADL*/ true, IsOverloaded(Fns), 7649 Fns.begin(), Fns.end()); 7650 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 7651 &Args[0], NumArgs, 7652 Context.DependentTy, 7653 VK_RValue, 7654 OpLoc)); 7655 } 7656 7657 // Build an empty overload set. 7658 OverloadCandidateSet CandidateSet(OpLoc); 7659 7660 // Add the candidates from the given function set. 7661 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 7662 7663 // Add operator candidates that are member functions. 7664 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 7665 7666 // Add candidates from ADL. 7667 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 7668 Args, NumArgs, 7669 /*ExplicitTemplateArgs*/ 0, 7670 CandidateSet); 7671 7672 // Add builtin operator candidates. 7673 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 7674 7675 // Perform overload resolution. 7676 OverloadCandidateSet::iterator Best; 7677 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 7678 case OR_Success: { 7679 // We found a built-in operator or an overloaded operator. 7680 FunctionDecl *FnDecl = Best->Function; 7681 7682 if (FnDecl) { 7683 // We matched an overloaded operator. Build a call to that 7684 // operator. 7685 7686 // Convert the arguments. 7687 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 7688 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 7689 7690 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 7691 Best->FoundDecl, Method)) 7692 return ExprError(); 7693 } else { 7694 // Convert the arguments. 7695 ExprResult InputInit 7696 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7697 Context, 7698 FnDecl->getParamDecl(0)), 7699 SourceLocation(), 7700 Input); 7701 if (InputInit.isInvalid()) 7702 return ExprError(); 7703 Input = InputInit.take(); 7704 } 7705 7706 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7707 7708 // Determine the result type. 7709 QualType ResultTy = FnDecl->getResultType(); 7710 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 7711 ResultTy = ResultTy.getNonLValueExprType(Context); 7712 7713 // Build the actual expression node. 7714 Expr *FnExpr = CreateFunctionRefExpr(*this, FnDecl); 7715 7716 Args[0] = Input; 7717 CallExpr *TheCall = 7718 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 7719 Args, NumArgs, ResultTy, VK, OpLoc); 7720 7721 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 7722 FnDecl)) 7723 return ExprError(); 7724 7725 return MaybeBindToTemporary(TheCall); 7726 } else { 7727 // We matched a built-in operator. Convert the arguments, then 7728 // break out so that we will build the appropriate built-in 7729 // operator node. 7730 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 7731 Best->Conversions[0], AA_Passing)) 7732 return ExprError(); 7733 7734 break; 7735 } 7736 } 7737 7738 case OR_No_Viable_Function: 7739 // No viable function; fall through to handling this as a 7740 // built-in operator, which will produce an error message for us. 7741 break; 7742 7743 case OR_Ambiguous: 7744 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 7745 << UnaryOperator::getOpcodeStr(Opc) 7746 << Input->getType() 7747 << Input->getSourceRange(); 7748 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 7749 Args, NumArgs, 7750 UnaryOperator::getOpcodeStr(Opc), OpLoc); 7751 return ExprError(); 7752 7753 case OR_Deleted: 7754 Diag(OpLoc, diag::err_ovl_deleted_oper) 7755 << Best->Function->isDeleted() 7756 << UnaryOperator::getOpcodeStr(Opc) 7757 << Input->getSourceRange(); 7758 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7759 return ExprError(); 7760 } 7761 7762 // Either we found no viable overloaded operator or we matched a 7763 // built-in operator. In either case, fall through to trying to 7764 // build a built-in operation. 7765 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 7766} 7767 7768/// \brief Create a binary operation that may resolve to an overloaded 7769/// operator. 7770/// 7771/// \param OpLoc The location of the operator itself (e.g., '+'). 7772/// 7773/// \param OpcIn The BinaryOperator::Opcode that describes this 7774/// operator. 7775/// 7776/// \param Functions The set of non-member functions that will be 7777/// considered by overload resolution. The caller needs to build this 7778/// set based on the context using, e.g., 7779/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 7780/// set should not contain any member functions; those will be added 7781/// by CreateOverloadedBinOp(). 7782/// 7783/// \param LHS Left-hand argument. 7784/// \param RHS Right-hand argument. 7785ExprResult 7786Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 7787 unsigned OpcIn, 7788 const UnresolvedSetImpl &Fns, 7789 Expr *LHS, Expr *RHS) { 7790 Expr *Args[2] = { LHS, RHS }; 7791 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 7792 7793 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 7794 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 7795 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 7796 7797 // If either side is type-dependent, create an appropriate dependent 7798 // expression. 7799 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 7800 if (Fns.empty()) { 7801 // If there are no functions to store, just build a dependent 7802 // BinaryOperator or CompoundAssignment. 7803 if (Opc <= BO_Assign || Opc > BO_OrAssign) 7804 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 7805 Context.DependentTy, 7806 VK_RValue, OK_Ordinary, 7807 OpLoc)); 7808 7809 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 7810 Context.DependentTy, 7811 VK_LValue, 7812 OK_Ordinary, 7813 Context.DependentTy, 7814 Context.DependentTy, 7815 OpLoc)); 7816 } 7817 7818 // FIXME: save results of ADL from here? 7819 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7820 // TODO: provide better source location info in DNLoc component. 7821 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 7822 UnresolvedLookupExpr *Fn 7823 = UnresolvedLookupExpr::Create(Context, NamingClass, 0, SourceRange(), 7824 OpNameInfo, /*ADL*/ true, IsOverloaded(Fns), 7825 Fns.begin(), Fns.end()); 7826 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 7827 Args, 2, 7828 Context.DependentTy, 7829 VK_RValue, 7830 OpLoc)); 7831 } 7832 7833 // Always do property rvalue conversions on the RHS. 7834 if (Args[1]->getObjectKind() == OK_ObjCProperty) 7835 ConvertPropertyForRValue(Args[1]); 7836 7837 // The LHS is more complicated. 7838 if (Args[0]->getObjectKind() == OK_ObjCProperty) { 7839 7840 // There's a tension for assignment operators between primitive 7841 // property assignment and the overloaded operators. 7842 if (BinaryOperator::isAssignmentOp(Opc)) { 7843 const ObjCPropertyRefExpr *PRE = LHS->getObjCProperty(); 7844 7845 // Is the property "logically" settable? 7846 bool Settable = (PRE->isExplicitProperty() || 7847 PRE->getImplicitPropertySetter()); 7848 7849 // To avoid gratuitously inventing semantics, use the primitive 7850 // unless it isn't. Thoughts in case we ever really care: 7851 // - If the property isn't logically settable, we have to 7852 // load and hope. 7853 // - If the property is settable and this is simple assignment, 7854 // we really should use the primitive. 7855 // - If the property is settable, then we could try overloading 7856 // on a generic lvalue of the appropriate type; if it works 7857 // out to a builtin candidate, we would do that same operation 7858 // on the property, and otherwise just error. 7859 if (Settable) 7860 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7861 } 7862 7863 ConvertPropertyForRValue(Args[0]); 7864 } 7865 7866 // If this is the assignment operator, we only perform overload resolution 7867 // if the left-hand side is a class or enumeration type. This is actually 7868 // a hack. The standard requires that we do overload resolution between the 7869 // various built-in candidates, but as DR507 points out, this can lead to 7870 // problems. So we do it this way, which pretty much follows what GCC does. 7871 // Note that we go the traditional code path for compound assignment forms. 7872 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 7873 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7874 7875 // If this is the .* operator, which is not overloadable, just 7876 // create a built-in binary operator. 7877 if (Opc == BO_PtrMemD) 7878 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7879 7880 // Build an empty overload set. 7881 OverloadCandidateSet CandidateSet(OpLoc); 7882 7883 // Add the candidates from the given function set. 7884 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 7885 7886 // Add operator candidates that are member functions. 7887 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 7888 7889 // Add candidates from ADL. 7890 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 7891 Args, 2, 7892 /*ExplicitTemplateArgs*/ 0, 7893 CandidateSet); 7894 7895 // Add builtin operator candidates. 7896 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 7897 7898 // Perform overload resolution. 7899 OverloadCandidateSet::iterator Best; 7900 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 7901 case OR_Success: { 7902 // We found a built-in operator or an overloaded operator. 7903 FunctionDecl *FnDecl = Best->Function; 7904 7905 if (FnDecl) { 7906 // We matched an overloaded operator. Build a call to that 7907 // operator. 7908 7909 // Convert the arguments. 7910 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 7911 // Best->Access is only meaningful for class members. 7912 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 7913 7914 ExprResult Arg1 = 7915 PerformCopyInitialization( 7916 InitializedEntity::InitializeParameter(Context, 7917 FnDecl->getParamDecl(0)), 7918 SourceLocation(), Owned(Args[1])); 7919 if (Arg1.isInvalid()) 7920 return ExprError(); 7921 7922 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 7923 Best->FoundDecl, Method)) 7924 return ExprError(); 7925 7926 Args[1] = RHS = Arg1.takeAs<Expr>(); 7927 } else { 7928 // Convert the arguments. 7929 ExprResult Arg0 = PerformCopyInitialization( 7930 InitializedEntity::InitializeParameter(Context, 7931 FnDecl->getParamDecl(0)), 7932 SourceLocation(), Owned(Args[0])); 7933 if (Arg0.isInvalid()) 7934 return ExprError(); 7935 7936 ExprResult Arg1 = 7937 PerformCopyInitialization( 7938 InitializedEntity::InitializeParameter(Context, 7939 FnDecl->getParamDecl(1)), 7940 SourceLocation(), Owned(Args[1])); 7941 if (Arg1.isInvalid()) 7942 return ExprError(); 7943 Args[0] = LHS = Arg0.takeAs<Expr>(); 7944 Args[1] = RHS = Arg1.takeAs<Expr>(); 7945 } 7946 7947 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7948 7949 // Determine the result type. 7950 QualType ResultTy = FnDecl->getResultType(); 7951 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 7952 ResultTy = ResultTy.getNonLValueExprType(Context); 7953 7954 // Build the actual expression node. 7955 Expr *FnExpr = CreateFunctionRefExpr(*this, FnDecl, OpLoc); 7956 7957 CXXOperatorCallExpr *TheCall = 7958 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 7959 Args, 2, ResultTy, VK, OpLoc); 7960 7961 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 7962 FnDecl)) 7963 return ExprError(); 7964 7965 return MaybeBindToTemporary(TheCall); 7966 } else { 7967 // We matched a built-in operator. Convert the arguments, then 7968 // break out so that we will build the appropriate built-in 7969 // operator node. 7970 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 7971 Best->Conversions[0], AA_Passing) || 7972 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 7973 Best->Conversions[1], AA_Passing)) 7974 return ExprError(); 7975 7976 break; 7977 } 7978 } 7979 7980 case OR_No_Viable_Function: { 7981 // C++ [over.match.oper]p9: 7982 // If the operator is the operator , [...] and there are no 7983 // viable functions, then the operator is assumed to be the 7984 // built-in operator and interpreted according to clause 5. 7985 if (Opc == BO_Comma) 7986 break; 7987 7988 // For class as left operand for assignment or compound assigment 7989 // operator do not fall through to handling in built-in, but report that 7990 // no overloaded assignment operator found 7991 ExprResult Result = ExprError(); 7992 if (Args[0]->getType()->isRecordType() && 7993 Opc >= BO_Assign && Opc <= BO_OrAssign) { 7994 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7995 << BinaryOperator::getOpcodeStr(Opc) 7996 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7997 } else { 7998 // No viable function; try to create a built-in operation, which will 7999 // produce an error. Then, show the non-viable candidates. 8000 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8001 } 8002 assert(Result.isInvalid() && 8003 "C++ binary operator overloading is missing candidates!"); 8004 if (Result.isInvalid()) 8005 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8006 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8007 return move(Result); 8008 } 8009 8010 case OR_Ambiguous: 8011 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 8012 << BinaryOperator::getOpcodeStr(Opc) 8013 << Args[0]->getType() << Args[1]->getType() 8014 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8015 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 8016 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8017 return ExprError(); 8018 8019 case OR_Deleted: 8020 Diag(OpLoc, diag::err_ovl_deleted_oper) 8021 << Best->Function->isDeleted() 8022 << BinaryOperator::getOpcodeStr(Opc) 8023 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8024 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2); 8025 return ExprError(); 8026 } 8027 8028 // We matched a built-in operator; build it. 8029 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8030} 8031 8032ExprResult 8033Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 8034 SourceLocation RLoc, 8035 Expr *Base, Expr *Idx) { 8036 Expr *Args[2] = { Base, Idx }; 8037 DeclarationName OpName = 8038 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 8039 8040 // If either side is type-dependent, create an appropriate dependent 8041 // expression. 8042 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 8043 8044 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8045 // CHECKME: no 'operator' keyword? 8046 DeclarationNameInfo OpNameInfo(OpName, LLoc); 8047 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 8048 UnresolvedLookupExpr *Fn 8049 = UnresolvedLookupExpr::Create(Context, NamingClass, 8050 0, SourceRange(), OpNameInfo, 8051 /*ADL*/ true, /*Overloaded*/ false, 8052 UnresolvedSetIterator(), 8053 UnresolvedSetIterator()); 8054 // Can't add any actual overloads yet 8055 8056 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 8057 Args, 2, 8058 Context.DependentTy, 8059 VK_RValue, 8060 RLoc)); 8061 } 8062 8063 if (Args[0]->getObjectKind() == OK_ObjCProperty) 8064 ConvertPropertyForRValue(Args[0]); 8065 if (Args[1]->getObjectKind() == OK_ObjCProperty) 8066 ConvertPropertyForRValue(Args[1]); 8067 8068 // Build an empty overload set. 8069 OverloadCandidateSet CandidateSet(LLoc); 8070 8071 // Subscript can only be overloaded as a member function. 8072 8073 // Add operator candidates that are member functions. 8074 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 8075 8076 // Add builtin operator candidates. 8077 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 8078 8079 // Perform overload resolution. 8080 OverloadCandidateSet::iterator Best; 8081 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 8082 case OR_Success: { 8083 // We found a built-in operator or an overloaded operator. 8084 FunctionDecl *FnDecl = Best->Function; 8085 8086 if (FnDecl) { 8087 // We matched an overloaded operator. Build a call to that 8088 // operator. 8089 8090 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 8091 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 8092 8093 // Convert the arguments. 8094 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 8095 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 8096 Best->FoundDecl, Method)) 8097 return ExprError(); 8098 8099 // Convert the arguments. 8100 ExprResult InputInit 8101 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8102 Context, 8103 FnDecl->getParamDecl(0)), 8104 SourceLocation(), 8105 Owned(Args[1])); 8106 if (InputInit.isInvalid()) 8107 return ExprError(); 8108 8109 Args[1] = InputInit.takeAs<Expr>(); 8110 8111 // Determine the result type 8112 QualType ResultTy = FnDecl->getResultType(); 8113 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8114 ResultTy = ResultTy.getNonLValueExprType(Context); 8115 8116 // Build the actual expression node. 8117 Expr *FnExpr = CreateFunctionRefExpr(*this, FnDecl, LLoc); 8118 8119 CXXOperatorCallExpr *TheCall = 8120 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 8121 FnExpr, Args, 2, 8122 ResultTy, VK, RLoc); 8123 8124 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 8125 FnDecl)) 8126 return ExprError(); 8127 8128 return MaybeBindToTemporary(TheCall); 8129 } else { 8130 // We matched a built-in operator. Convert the arguments, then 8131 // break out so that we will build the appropriate built-in 8132 // operator node. 8133 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 8134 Best->Conversions[0], AA_Passing) || 8135 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 8136 Best->Conversions[1], AA_Passing)) 8137 return ExprError(); 8138 8139 break; 8140 } 8141 } 8142 8143 case OR_No_Viable_Function: { 8144 if (CandidateSet.empty()) 8145 Diag(LLoc, diag::err_ovl_no_oper) 8146 << Args[0]->getType() << /*subscript*/ 0 8147 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8148 else 8149 Diag(LLoc, diag::err_ovl_no_viable_subscript) 8150 << Args[0]->getType() 8151 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8152 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8153 "[]", LLoc); 8154 return ExprError(); 8155 } 8156 8157 case OR_Ambiguous: 8158 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 8159 << "[]" 8160 << Args[0]->getType() << Args[1]->getType() 8161 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8162 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 8163 "[]", LLoc); 8164 return ExprError(); 8165 8166 case OR_Deleted: 8167 Diag(LLoc, diag::err_ovl_deleted_oper) 8168 << Best->Function->isDeleted() << "[]" 8169 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8170 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8171 "[]", LLoc); 8172 return ExprError(); 8173 } 8174 8175 // We matched a built-in operator; build it. 8176 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 8177} 8178 8179/// BuildCallToMemberFunction - Build a call to a member 8180/// function. MemExpr is the expression that refers to the member 8181/// function (and includes the object parameter), Args/NumArgs are the 8182/// arguments to the function call (not including the object 8183/// parameter). The caller needs to validate that the member 8184/// expression refers to a member function or an overloaded member 8185/// function. 8186ExprResult 8187Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 8188 SourceLocation LParenLoc, Expr **Args, 8189 unsigned NumArgs, SourceLocation RParenLoc) { 8190 // Dig out the member expression. This holds both the object 8191 // argument and the member function we're referring to. 8192 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 8193 8194 MemberExpr *MemExpr; 8195 CXXMethodDecl *Method = 0; 8196 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 8197 NestedNameSpecifier *Qualifier = 0; 8198 if (isa<MemberExpr>(NakedMemExpr)) { 8199 MemExpr = cast<MemberExpr>(NakedMemExpr); 8200 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 8201 FoundDecl = MemExpr->getFoundDecl(); 8202 Qualifier = MemExpr->getQualifier(); 8203 } else { 8204 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 8205 Qualifier = UnresExpr->getQualifier(); 8206 8207 QualType ObjectType = UnresExpr->getBaseType(); 8208 Expr::Classification ObjectClassification 8209 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 8210 : UnresExpr->getBase()->Classify(Context); 8211 8212 // Add overload candidates 8213 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 8214 8215 // FIXME: avoid copy. 8216 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 8217 if (UnresExpr->hasExplicitTemplateArgs()) { 8218 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 8219 TemplateArgs = &TemplateArgsBuffer; 8220 } 8221 8222 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 8223 E = UnresExpr->decls_end(); I != E; ++I) { 8224 8225 NamedDecl *Func = *I; 8226 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 8227 if (isa<UsingShadowDecl>(Func)) 8228 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 8229 8230 8231 // Microsoft supports direct constructor calls. 8232 if (getLangOptions().Microsoft && isa<CXXConstructorDecl>(Func)) { 8233 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), Args, NumArgs, 8234 CandidateSet); 8235 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 8236 // If explicit template arguments were provided, we can't call a 8237 // non-template member function. 8238 if (TemplateArgs) 8239 continue; 8240 8241 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 8242 ObjectClassification, 8243 Args, NumArgs, CandidateSet, 8244 /*SuppressUserConversions=*/false); 8245 } else { 8246 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 8247 I.getPair(), ActingDC, TemplateArgs, 8248 ObjectType, ObjectClassification, 8249 Args, NumArgs, CandidateSet, 8250 /*SuppressUsedConversions=*/false); 8251 } 8252 } 8253 8254 DeclarationName DeclName = UnresExpr->getMemberName(); 8255 8256 OverloadCandidateSet::iterator Best; 8257 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 8258 Best)) { 8259 case OR_Success: 8260 Method = cast<CXXMethodDecl>(Best->Function); 8261 FoundDecl = Best->FoundDecl; 8262 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 8263 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 8264 break; 8265 8266 case OR_No_Viable_Function: 8267 Diag(UnresExpr->getMemberLoc(), 8268 diag::err_ovl_no_viable_member_function_in_call) 8269 << DeclName << MemExprE->getSourceRange(); 8270 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8271 // FIXME: Leaking incoming expressions! 8272 return ExprError(); 8273 8274 case OR_Ambiguous: 8275 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 8276 << DeclName << MemExprE->getSourceRange(); 8277 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8278 // FIXME: Leaking incoming expressions! 8279 return ExprError(); 8280 8281 case OR_Deleted: 8282 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 8283 << Best->Function->isDeleted() 8284 << DeclName << MemExprE->getSourceRange(); 8285 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8286 // FIXME: Leaking incoming expressions! 8287 return ExprError(); 8288 } 8289 8290 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 8291 8292 // If overload resolution picked a static member, build a 8293 // non-member call based on that function. 8294 if (Method->isStatic()) { 8295 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 8296 Args, NumArgs, RParenLoc); 8297 } 8298 8299 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 8300 } 8301 8302 QualType ResultType = Method->getResultType(); 8303 ExprValueKind VK = Expr::getValueKindForType(ResultType); 8304 ResultType = ResultType.getNonLValueExprType(Context); 8305 8306 assert(Method && "Member call to something that isn't a method?"); 8307 CXXMemberCallExpr *TheCall = 8308 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 8309 ResultType, VK, RParenLoc); 8310 8311 // Check for a valid return type. 8312 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 8313 TheCall, Method)) 8314 return ExprError(); 8315 8316 // Convert the object argument (for a non-static member function call). 8317 // We only need to do this if there was actually an overload; otherwise 8318 // it was done at lookup. 8319 Expr *ObjectArg = MemExpr->getBase(); 8320 if (!Method->isStatic() && 8321 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 8322 FoundDecl, Method)) 8323 return ExprError(); 8324 MemExpr->setBase(ObjectArg); 8325 8326 // Convert the rest of the arguments 8327 const FunctionProtoType *Proto = 8328 Method->getType()->getAs<FunctionProtoType>(); 8329 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 8330 RParenLoc)) 8331 return ExprError(); 8332 8333 if (CheckFunctionCall(Method, TheCall)) 8334 return ExprError(); 8335 8336 return MaybeBindToTemporary(TheCall); 8337} 8338 8339/// BuildCallToObjectOfClassType - Build a call to an object of class 8340/// type (C++ [over.call.object]), which can end up invoking an 8341/// overloaded function call operator (@c operator()) or performing a 8342/// user-defined conversion on the object argument. 8343ExprResult 8344Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 8345 SourceLocation LParenLoc, 8346 Expr **Args, unsigned NumArgs, 8347 SourceLocation RParenLoc) { 8348 if (Object->getObjectKind() == OK_ObjCProperty) 8349 ConvertPropertyForRValue(Object); 8350 8351 assert(Object->getType()->isRecordType() && "Requires object type argument"); 8352 const RecordType *Record = Object->getType()->getAs<RecordType>(); 8353 8354 // C++ [over.call.object]p1: 8355 // If the primary-expression E in the function call syntax 8356 // evaluates to a class object of type "cv T", then the set of 8357 // candidate functions includes at least the function call 8358 // operators of T. The function call operators of T are obtained by 8359 // ordinary lookup of the name operator() in the context of 8360 // (E).operator(). 8361 OverloadCandidateSet CandidateSet(LParenLoc); 8362 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 8363 8364 if (RequireCompleteType(LParenLoc, Object->getType(), 8365 PDiag(diag::err_incomplete_object_call) 8366 << Object->getSourceRange())) 8367 return true; 8368 8369 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 8370 LookupQualifiedName(R, Record->getDecl()); 8371 R.suppressDiagnostics(); 8372 8373 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 8374 Oper != OperEnd; ++Oper) { 8375 AddMethodCandidate(Oper.getPair(), Object->getType(), 8376 Object->Classify(Context), Args, NumArgs, CandidateSet, 8377 /*SuppressUserConversions=*/ false); 8378 } 8379 8380 // C++ [over.call.object]p2: 8381 // In addition, for each conversion function declared in T of the 8382 // form 8383 // 8384 // operator conversion-type-id () cv-qualifier; 8385 // 8386 // where cv-qualifier is the same cv-qualification as, or a 8387 // greater cv-qualification than, cv, and where conversion-type-id 8388 // denotes the type "pointer to function of (P1,...,Pn) returning 8389 // R", or the type "reference to pointer to function of 8390 // (P1,...,Pn) returning R", or the type "reference to function 8391 // of (P1,...,Pn) returning R", a surrogate call function [...] 8392 // is also considered as a candidate function. Similarly, 8393 // surrogate call functions are added to the set of candidate 8394 // functions for each conversion function declared in an 8395 // accessible base class provided the function is not hidden 8396 // within T by another intervening declaration. 8397 const UnresolvedSetImpl *Conversions 8398 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 8399 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 8400 E = Conversions->end(); I != E; ++I) { 8401 NamedDecl *D = *I; 8402 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 8403 if (isa<UsingShadowDecl>(D)) 8404 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 8405 8406 // Skip over templated conversion functions; they aren't 8407 // surrogates. 8408 if (isa<FunctionTemplateDecl>(D)) 8409 continue; 8410 8411 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 8412 8413 // Strip the reference type (if any) and then the pointer type (if 8414 // any) to get down to what might be a function type. 8415 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 8416 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 8417 ConvType = ConvPtrType->getPointeeType(); 8418 8419 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 8420 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 8421 Object, Args, NumArgs, CandidateSet); 8422 } 8423 8424 // Perform overload resolution. 8425 OverloadCandidateSet::iterator Best; 8426 switch (CandidateSet.BestViableFunction(*this, Object->getLocStart(), 8427 Best)) { 8428 case OR_Success: 8429 // Overload resolution succeeded; we'll build the appropriate call 8430 // below. 8431 break; 8432 8433 case OR_No_Viable_Function: 8434 if (CandidateSet.empty()) 8435 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 8436 << Object->getType() << /*call*/ 1 8437 << Object->getSourceRange(); 8438 else 8439 Diag(Object->getSourceRange().getBegin(), 8440 diag::err_ovl_no_viable_object_call) 8441 << Object->getType() << Object->getSourceRange(); 8442 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8443 break; 8444 8445 case OR_Ambiguous: 8446 Diag(Object->getSourceRange().getBegin(), 8447 diag::err_ovl_ambiguous_object_call) 8448 << Object->getType() << Object->getSourceRange(); 8449 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 8450 break; 8451 8452 case OR_Deleted: 8453 Diag(Object->getSourceRange().getBegin(), 8454 diag::err_ovl_deleted_object_call) 8455 << Best->Function->isDeleted() 8456 << Object->getType() << Object->getSourceRange(); 8457 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8458 break; 8459 } 8460 8461 if (Best == CandidateSet.end()) 8462 return true; 8463 8464 if (Best->Function == 0) { 8465 // Since there is no function declaration, this is one of the 8466 // surrogate candidates. Dig out the conversion function. 8467 CXXConversionDecl *Conv 8468 = cast<CXXConversionDecl>( 8469 Best->Conversions[0].UserDefined.ConversionFunction); 8470 8471 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 8472 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 8473 8474 // We selected one of the surrogate functions that converts the 8475 // object parameter to a function pointer. Perform the conversion 8476 // on the object argument, then let ActOnCallExpr finish the job. 8477 8478 // Create an implicit member expr to refer to the conversion operator. 8479 // and then call it. 8480 ExprResult Call = BuildCXXMemberCallExpr(Object, Best->FoundDecl, Conv); 8481 if (Call.isInvalid()) 8482 return ExprError(); 8483 8484 return ActOnCallExpr(S, Call.get(), LParenLoc, MultiExprArg(Args, NumArgs), 8485 RParenLoc); 8486 } 8487 8488 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 8489 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 8490 8491 // We found an overloaded operator(). Build a CXXOperatorCallExpr 8492 // that calls this method, using Object for the implicit object 8493 // parameter and passing along the remaining arguments. 8494 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 8495 const FunctionProtoType *Proto = 8496 Method->getType()->getAs<FunctionProtoType>(); 8497 8498 unsigned NumArgsInProto = Proto->getNumArgs(); 8499 unsigned NumArgsToCheck = NumArgs; 8500 8501 // Build the full argument list for the method call (the 8502 // implicit object parameter is placed at the beginning of the 8503 // list). 8504 Expr **MethodArgs; 8505 if (NumArgs < NumArgsInProto) { 8506 NumArgsToCheck = NumArgsInProto; 8507 MethodArgs = new Expr*[NumArgsInProto + 1]; 8508 } else { 8509 MethodArgs = new Expr*[NumArgs + 1]; 8510 } 8511 MethodArgs[0] = Object; 8512 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 8513 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 8514 8515 Expr *NewFn = CreateFunctionRefExpr(*this, Method); 8516 8517 // Once we've built TheCall, all of the expressions are properly 8518 // owned. 8519 QualType ResultTy = Method->getResultType(); 8520 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8521 ResultTy = ResultTy.getNonLValueExprType(Context); 8522 8523 CXXOperatorCallExpr *TheCall = 8524 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 8525 MethodArgs, NumArgs + 1, 8526 ResultTy, VK, RParenLoc); 8527 delete [] MethodArgs; 8528 8529 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 8530 Method)) 8531 return true; 8532 8533 // We may have default arguments. If so, we need to allocate more 8534 // slots in the call for them. 8535 if (NumArgs < NumArgsInProto) 8536 TheCall->setNumArgs(Context, NumArgsInProto + 1); 8537 else if (NumArgs > NumArgsInProto) 8538 NumArgsToCheck = NumArgsInProto; 8539 8540 bool IsError = false; 8541 8542 // Initialize the implicit object parameter. 8543 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 8544 Best->FoundDecl, Method); 8545 TheCall->setArg(0, Object); 8546 8547 8548 // Check the argument types. 8549 for (unsigned i = 0; i != NumArgsToCheck; i++) { 8550 Expr *Arg; 8551 if (i < NumArgs) { 8552 Arg = Args[i]; 8553 8554 // Pass the argument. 8555 8556 ExprResult InputInit 8557 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8558 Context, 8559 Method->getParamDecl(i)), 8560 SourceLocation(), Arg); 8561 8562 IsError |= InputInit.isInvalid(); 8563 Arg = InputInit.takeAs<Expr>(); 8564 } else { 8565 ExprResult DefArg 8566 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 8567 if (DefArg.isInvalid()) { 8568 IsError = true; 8569 break; 8570 } 8571 8572 Arg = DefArg.takeAs<Expr>(); 8573 } 8574 8575 TheCall->setArg(i + 1, Arg); 8576 } 8577 8578 // If this is a variadic call, handle args passed through "...". 8579 if (Proto->isVariadic()) { 8580 // Promote the arguments (C99 6.5.2.2p7). 8581 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 8582 Expr *Arg = Args[i]; 8583 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 8584 TheCall->setArg(i + 1, Arg); 8585 } 8586 } 8587 8588 if (IsError) return true; 8589 8590 if (CheckFunctionCall(Method, TheCall)) 8591 return true; 8592 8593 return MaybeBindToTemporary(TheCall); 8594} 8595 8596/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 8597/// (if one exists), where @c Base is an expression of class type and 8598/// @c Member is the name of the member we're trying to find. 8599ExprResult 8600Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 8601 assert(Base->getType()->isRecordType() && 8602 "left-hand side must have class type"); 8603 8604 if (Base->getObjectKind() == OK_ObjCProperty) 8605 ConvertPropertyForRValue(Base); 8606 8607 SourceLocation Loc = Base->getExprLoc(); 8608 8609 // C++ [over.ref]p1: 8610 // 8611 // [...] An expression x->m is interpreted as (x.operator->())->m 8612 // for a class object x of type T if T::operator->() exists and if 8613 // the operator is selected as the best match function by the 8614 // overload resolution mechanism (13.3). 8615 DeclarationName OpName = 8616 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 8617 OverloadCandidateSet CandidateSet(Loc); 8618 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 8619 8620 if (RequireCompleteType(Loc, Base->getType(), 8621 PDiag(diag::err_typecheck_incomplete_tag) 8622 << Base->getSourceRange())) 8623 return ExprError(); 8624 8625 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 8626 LookupQualifiedName(R, BaseRecord->getDecl()); 8627 R.suppressDiagnostics(); 8628 8629 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 8630 Oper != OperEnd; ++Oper) { 8631 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 8632 0, 0, CandidateSet, /*SuppressUserConversions=*/false); 8633 } 8634 8635 // Perform overload resolution. 8636 OverloadCandidateSet::iterator Best; 8637 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8638 case OR_Success: 8639 // Overload resolution succeeded; we'll build the call below. 8640 break; 8641 8642 case OR_No_Viable_Function: 8643 if (CandidateSet.empty()) 8644 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 8645 << Base->getType() << Base->getSourceRange(); 8646 else 8647 Diag(OpLoc, diag::err_ovl_no_viable_oper) 8648 << "operator->" << Base->getSourceRange(); 8649 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 8650 return ExprError(); 8651 8652 case OR_Ambiguous: 8653 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 8654 << "->" << Base->getType() << Base->getSourceRange(); 8655 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, &Base, 1); 8656 return ExprError(); 8657 8658 case OR_Deleted: 8659 Diag(OpLoc, diag::err_ovl_deleted_oper) 8660 << Best->Function->isDeleted() 8661 << "->" << Base->getSourceRange(); 8662 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 8663 return ExprError(); 8664 } 8665 8666 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 8667 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 8668 8669 // Convert the object parameter. 8670 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 8671 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 8672 Best->FoundDecl, Method)) 8673 return ExprError(); 8674 8675 // Build the operator call. 8676 Expr *FnExpr = CreateFunctionRefExpr(*this, Method); 8677 8678 QualType ResultTy = Method->getResultType(); 8679 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8680 ResultTy = ResultTy.getNonLValueExprType(Context); 8681 CXXOperatorCallExpr *TheCall = 8682 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 8683 &Base, 1, ResultTy, VK, OpLoc); 8684 8685 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 8686 Method)) 8687 return ExprError(); 8688 return Owned(TheCall); 8689} 8690 8691/// FixOverloadedFunctionReference - E is an expression that refers to 8692/// a C++ overloaded function (possibly with some parentheses and 8693/// perhaps a '&' around it). We have resolved the overloaded function 8694/// to the function declaration Fn, so patch up the expression E to 8695/// refer (possibly indirectly) to Fn. Returns the new expr. 8696Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 8697 FunctionDecl *Fn) { 8698 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 8699 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 8700 Found, Fn); 8701 if (SubExpr == PE->getSubExpr()) 8702 return PE; 8703 8704 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 8705 } 8706 8707 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 8708 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 8709 Found, Fn); 8710 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 8711 SubExpr->getType()) && 8712 "Implicit cast type cannot be determined from overload"); 8713 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 8714 if (SubExpr == ICE->getSubExpr()) 8715 return ICE; 8716 8717 return ImplicitCastExpr::Create(Context, ICE->getType(), 8718 ICE->getCastKind(), 8719 SubExpr, 0, 8720 ICE->getValueKind()); 8721 } 8722 8723 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 8724 assert(UnOp->getOpcode() == UO_AddrOf && 8725 "Can only take the address of an overloaded function"); 8726 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 8727 if (Method->isStatic()) { 8728 // Do nothing: static member functions aren't any different 8729 // from non-member functions. 8730 } else { 8731 // Fix the sub expression, which really has to be an 8732 // UnresolvedLookupExpr holding an overloaded member function 8733 // or template. 8734 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 8735 Found, Fn); 8736 if (SubExpr == UnOp->getSubExpr()) 8737 return UnOp; 8738 8739 assert(isa<DeclRefExpr>(SubExpr) 8740 && "fixed to something other than a decl ref"); 8741 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 8742 && "fixed to a member ref with no nested name qualifier"); 8743 8744 // We have taken the address of a pointer to member 8745 // function. Perform the computation here so that we get the 8746 // appropriate pointer to member type. 8747 QualType ClassType 8748 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 8749 QualType MemPtrType 8750 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 8751 8752 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 8753 VK_RValue, OK_Ordinary, 8754 UnOp->getOperatorLoc()); 8755 } 8756 } 8757 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 8758 Found, Fn); 8759 if (SubExpr == UnOp->getSubExpr()) 8760 return UnOp; 8761 8762 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 8763 Context.getPointerType(SubExpr->getType()), 8764 VK_RValue, OK_Ordinary, 8765 UnOp->getOperatorLoc()); 8766 } 8767 8768 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 8769 // FIXME: avoid copy. 8770 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 8771 if (ULE->hasExplicitTemplateArgs()) { 8772 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 8773 TemplateArgs = &TemplateArgsBuffer; 8774 } 8775 8776 return DeclRefExpr::Create(Context, 8777 ULE->getQualifier(), 8778 ULE->getQualifierRange(), 8779 Fn, 8780 ULE->getNameLoc(), 8781 Fn->getType(), 8782 VK_LValue, 8783 TemplateArgs); 8784 } 8785 8786 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 8787 // FIXME: avoid copy. 8788 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 8789 if (MemExpr->hasExplicitTemplateArgs()) { 8790 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 8791 TemplateArgs = &TemplateArgsBuffer; 8792 } 8793 8794 Expr *Base; 8795 8796 // If we're filling in a static method where we used to have an 8797 // implicit member access, rewrite to a simple decl ref. 8798 if (MemExpr->isImplicitAccess()) { 8799 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 8800 return DeclRefExpr::Create(Context, 8801 MemExpr->getQualifier(), 8802 MemExpr->getQualifierRange(), 8803 Fn, 8804 MemExpr->getMemberLoc(), 8805 Fn->getType(), 8806 VK_LValue, 8807 TemplateArgs); 8808 } else { 8809 SourceLocation Loc = MemExpr->getMemberLoc(); 8810 if (MemExpr->getQualifier()) 8811 Loc = MemExpr->getQualifierRange().getBegin(); 8812 Base = new (Context) CXXThisExpr(Loc, 8813 MemExpr->getBaseType(), 8814 /*isImplicit=*/true); 8815 } 8816 } else 8817 Base = MemExpr->getBase(); 8818 8819 return MemberExpr::Create(Context, Base, 8820 MemExpr->isArrow(), 8821 MemExpr->getQualifier(), 8822 MemExpr->getQualifierRange(), 8823 Fn, 8824 Found, 8825 MemExpr->getMemberNameInfo(), 8826 TemplateArgs, 8827 Fn->getType(), 8828 cast<CXXMethodDecl>(Fn)->isStatic() 8829 ? VK_LValue : VK_RValue, 8830 OK_Ordinary); 8831 } 8832 8833 llvm_unreachable("Invalid reference to overloaded function"); 8834 return E; 8835} 8836 8837ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 8838 DeclAccessPair Found, 8839 FunctionDecl *Fn) { 8840 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 8841} 8842 8843} // end namespace clang 8844