SemaOverload.cpp revision 00ccbefcffeb88ea3e2e6323e594fa968753ad14
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); 50static OverloadingResult 51IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 52 UserDefinedConversionSequence& User, 53 OverloadCandidateSet& Conversions, 54 bool AllowExplicit); 55 56 57static ImplicitConversionSequence::CompareKind 58CompareStandardConversionSequences(Sema &S, 59 const StandardConversionSequence& SCS1, 60 const StandardConversionSequence& SCS2); 61 62static ImplicitConversionSequence::CompareKind 63CompareQualificationConversions(Sema &S, 64 const StandardConversionSequence& SCS1, 65 const StandardConversionSequence& SCS2); 66 67static ImplicitConversionSequence::CompareKind 68CompareDerivedToBaseConversions(Sema &S, 69 const StandardConversionSequence& SCS1, 70 const StandardConversionSequence& SCS2); 71 72 73 74/// GetConversionCategory - Retrieve the implicit conversion 75/// category corresponding to the given implicit conversion kind. 76ImplicitConversionCategory 77GetConversionCategory(ImplicitConversionKind Kind) { 78 static const ImplicitConversionCategory 79 Category[(int)ICK_Num_Conversion_Kinds] = { 80 ICC_Identity, 81 ICC_Lvalue_Transformation, 82 ICC_Lvalue_Transformation, 83 ICC_Lvalue_Transformation, 84 ICC_Identity, 85 ICC_Qualification_Adjustment, 86 ICC_Promotion, 87 ICC_Promotion, 88 ICC_Promotion, 89 ICC_Conversion, 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 }; 102 return Category[(int)Kind]; 103} 104 105/// GetConversionRank - Retrieve the implicit conversion rank 106/// corresponding to the given implicit conversion kind. 107ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 108 static const ImplicitConversionRank 109 Rank[(int)ICK_Num_Conversion_Kinds] = { 110 ICR_Exact_Match, 111 ICR_Exact_Match, 112 ICR_Exact_Match, 113 ICR_Exact_Match, 114 ICR_Exact_Match, 115 ICR_Exact_Match, 116 ICR_Promotion, 117 ICR_Promotion, 118 ICR_Promotion, 119 ICR_Conversion, 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_Complex_Real_Conversion 131 }; 132 return Rank[(int)Kind]; 133} 134 135/// GetImplicitConversionName - Return the name of this kind of 136/// implicit conversion. 137const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 138 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 139 "No conversion", 140 "Lvalue-to-rvalue", 141 "Array-to-pointer", 142 "Function-to-pointer", 143 "Noreturn adjustment", 144 "Qualification", 145 "Integral promotion", 146 "Floating point promotion", 147 "Complex promotion", 148 "Integral conversion", 149 "Floating conversion", 150 "Complex conversion", 151 "Floating-integral conversion", 152 "Pointer conversion", 153 "Pointer-to-member conversion", 154 "Boolean conversion", 155 "Compatible-types conversion", 156 "Derived-to-base conversion", 157 "Vector conversion", 158 "Vector splat", 159 "Complex-real conversion" 160 }; 161 return Name[Kind]; 162} 163 164/// StandardConversionSequence - Set the standard conversion 165/// sequence to the identity conversion. 166void StandardConversionSequence::setAsIdentityConversion() { 167 First = ICK_Identity; 168 Second = ICK_Identity; 169 Third = ICK_Identity; 170 DeprecatedStringLiteralToCharPtr = false; 171 ReferenceBinding = false; 172 DirectBinding = false; 173 RRefBinding = false; 174 CopyConstructor = 0; 175} 176 177/// getRank - Retrieve the rank of this standard conversion sequence 178/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 179/// implicit conversions. 180ImplicitConversionRank StandardConversionSequence::getRank() const { 181 ImplicitConversionRank Rank = ICR_Exact_Match; 182 if (GetConversionRank(First) > Rank) 183 Rank = GetConversionRank(First); 184 if (GetConversionRank(Second) > Rank) 185 Rank = GetConversionRank(Second); 186 if (GetConversionRank(Third) > Rank) 187 Rank = GetConversionRank(Third); 188 return Rank; 189} 190 191/// isPointerConversionToBool - Determines whether this conversion is 192/// a conversion of a pointer or pointer-to-member to bool. This is 193/// used as part of the ranking of standard conversion sequences 194/// (C++ 13.3.3.2p4). 195bool StandardConversionSequence::isPointerConversionToBool() const { 196 // Note that FromType has not necessarily been transformed by the 197 // array-to-pointer or function-to-pointer implicit conversions, so 198 // check for their presence as well as checking whether FromType is 199 // a pointer. 200 if (getToType(1)->isBooleanType() && 201 (getFromType()->isPointerType() || 202 getFromType()->isObjCObjectPointerType() || 203 getFromType()->isBlockPointerType() || 204 getFromType()->isNullPtrType() || 205 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 206 return true; 207 208 return false; 209} 210 211/// isPointerConversionToVoidPointer - Determines whether this 212/// conversion is a conversion of a pointer to a void pointer. This is 213/// used as part of the ranking of standard conversion sequences (C++ 214/// 13.3.3.2p4). 215bool 216StandardConversionSequence:: 217isPointerConversionToVoidPointer(ASTContext& Context) const { 218 QualType FromType = getFromType(); 219 QualType ToType = getToType(1); 220 221 // Note that FromType has not necessarily been transformed by the 222 // array-to-pointer implicit conversion, so check for its presence 223 // and redo the conversion to get a pointer. 224 if (First == ICK_Array_To_Pointer) 225 FromType = Context.getArrayDecayedType(FromType); 226 227 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 228 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 229 return ToPtrType->getPointeeType()->isVoidType(); 230 231 return false; 232} 233 234/// DebugPrint - Print this standard conversion sequence to standard 235/// error. Useful for debugging overloading issues. 236void StandardConversionSequence::DebugPrint() const { 237 llvm::raw_ostream &OS = llvm::errs(); 238 bool PrintedSomething = false; 239 if (First != ICK_Identity) { 240 OS << GetImplicitConversionName(First); 241 PrintedSomething = true; 242 } 243 244 if (Second != ICK_Identity) { 245 if (PrintedSomething) { 246 OS << " -> "; 247 } 248 OS << GetImplicitConversionName(Second); 249 250 if (CopyConstructor) { 251 OS << " (by copy constructor)"; 252 } else if (DirectBinding) { 253 OS << " (direct reference binding)"; 254 } else if (ReferenceBinding) { 255 OS << " (reference binding)"; 256 } 257 PrintedSomething = true; 258 } 259 260 if (Third != ICK_Identity) { 261 if (PrintedSomething) { 262 OS << " -> "; 263 } 264 OS << GetImplicitConversionName(Third); 265 PrintedSomething = true; 266 } 267 268 if (!PrintedSomething) { 269 OS << "No conversions required"; 270 } 271} 272 273/// DebugPrint - Print this user-defined conversion sequence to standard 274/// error. Useful for debugging overloading issues. 275void UserDefinedConversionSequence::DebugPrint() const { 276 llvm::raw_ostream &OS = llvm::errs(); 277 if (Before.First || Before.Second || Before.Third) { 278 Before.DebugPrint(); 279 OS << " -> "; 280 } 281 OS << '\'' << ConversionFunction << '\''; 282 if (After.First || After.Second || After.Third) { 283 OS << " -> "; 284 After.DebugPrint(); 285 } 286} 287 288/// DebugPrint - Print this implicit conversion sequence to standard 289/// error. Useful for debugging overloading issues. 290void ImplicitConversionSequence::DebugPrint() const { 291 llvm::raw_ostream &OS = llvm::errs(); 292 switch (ConversionKind) { 293 case StandardConversion: 294 OS << "Standard conversion: "; 295 Standard.DebugPrint(); 296 break; 297 case UserDefinedConversion: 298 OS << "User-defined conversion: "; 299 UserDefined.DebugPrint(); 300 break; 301 case EllipsisConversion: 302 OS << "Ellipsis conversion"; 303 break; 304 case AmbiguousConversion: 305 OS << "Ambiguous conversion"; 306 break; 307 case BadConversion: 308 OS << "Bad conversion"; 309 break; 310 } 311 312 OS << "\n"; 313} 314 315void AmbiguousConversionSequence::construct() { 316 new (&conversions()) ConversionSet(); 317} 318 319void AmbiguousConversionSequence::destruct() { 320 conversions().~ConversionSet(); 321} 322 323void 324AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 325 FromTypePtr = O.FromTypePtr; 326 ToTypePtr = O.ToTypePtr; 327 new (&conversions()) ConversionSet(O.conversions()); 328} 329 330namespace { 331 // Structure used by OverloadCandidate::DeductionFailureInfo to store 332 // template parameter and template argument information. 333 struct DFIParamWithArguments { 334 TemplateParameter Param; 335 TemplateArgument FirstArg; 336 TemplateArgument SecondArg; 337 }; 338} 339 340/// \brief Convert from Sema's representation of template deduction information 341/// to the form used in overload-candidate information. 342OverloadCandidate::DeductionFailureInfo 343static MakeDeductionFailureInfo(ASTContext &Context, 344 Sema::TemplateDeductionResult TDK, 345 TemplateDeductionInfo &Info) { 346 OverloadCandidate::DeductionFailureInfo Result; 347 Result.Result = static_cast<unsigned>(TDK); 348 Result.Data = 0; 349 switch (TDK) { 350 case Sema::TDK_Success: 351 case Sema::TDK_InstantiationDepth: 352 case Sema::TDK_TooManyArguments: 353 case Sema::TDK_TooFewArguments: 354 break; 355 356 case Sema::TDK_Incomplete: 357 case Sema::TDK_InvalidExplicitArguments: 358 Result.Data = Info.Param.getOpaqueValue(); 359 break; 360 361 case Sema::TDK_Inconsistent: 362 case Sema::TDK_Underqualified: { 363 // FIXME: Should allocate from normal heap so that we can free this later. 364 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 365 Saved->Param = Info.Param; 366 Saved->FirstArg = Info.FirstArg; 367 Saved->SecondArg = Info.SecondArg; 368 Result.Data = Saved; 369 break; 370 } 371 372 case Sema::TDK_SubstitutionFailure: 373 Result.Data = Info.take(); 374 break; 375 376 case Sema::TDK_NonDeducedMismatch: 377 case Sema::TDK_FailedOverloadResolution: 378 break; 379 } 380 381 return Result; 382} 383 384void OverloadCandidate::DeductionFailureInfo::Destroy() { 385 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 386 case Sema::TDK_Success: 387 case Sema::TDK_InstantiationDepth: 388 case Sema::TDK_Incomplete: 389 case Sema::TDK_TooManyArguments: 390 case Sema::TDK_TooFewArguments: 391 case Sema::TDK_InvalidExplicitArguments: 392 break; 393 394 case Sema::TDK_Inconsistent: 395 case Sema::TDK_Underqualified: 396 // FIXME: Destroy the data? 397 Data = 0; 398 break; 399 400 case Sema::TDK_SubstitutionFailure: 401 // FIXME: Destroy the template arugment list? 402 Data = 0; 403 break; 404 405 // Unhandled 406 case Sema::TDK_NonDeducedMismatch: 407 case Sema::TDK_FailedOverloadResolution: 408 break; 409 } 410} 411 412TemplateParameter 413OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 414 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 415 case Sema::TDK_Success: 416 case Sema::TDK_InstantiationDepth: 417 case Sema::TDK_TooManyArguments: 418 case Sema::TDK_TooFewArguments: 419 case Sema::TDK_SubstitutionFailure: 420 return TemplateParameter(); 421 422 case Sema::TDK_Incomplete: 423 case Sema::TDK_InvalidExplicitArguments: 424 return TemplateParameter::getFromOpaqueValue(Data); 425 426 case Sema::TDK_Inconsistent: 427 case Sema::TDK_Underqualified: 428 return static_cast<DFIParamWithArguments*>(Data)->Param; 429 430 // Unhandled 431 case Sema::TDK_NonDeducedMismatch: 432 case Sema::TDK_FailedOverloadResolution: 433 break; 434 } 435 436 return TemplateParameter(); 437} 438 439TemplateArgumentList * 440OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 441 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 442 case Sema::TDK_Success: 443 case Sema::TDK_InstantiationDepth: 444 case Sema::TDK_TooManyArguments: 445 case Sema::TDK_TooFewArguments: 446 case Sema::TDK_Incomplete: 447 case Sema::TDK_InvalidExplicitArguments: 448 case Sema::TDK_Inconsistent: 449 case Sema::TDK_Underqualified: 450 return 0; 451 452 case Sema::TDK_SubstitutionFailure: 453 return static_cast<TemplateArgumentList*>(Data); 454 455 // Unhandled 456 case Sema::TDK_NonDeducedMismatch: 457 case Sema::TDK_FailedOverloadResolution: 458 break; 459 } 460 461 return 0; 462} 463 464const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 465 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 466 case Sema::TDK_Success: 467 case Sema::TDK_InstantiationDepth: 468 case Sema::TDK_Incomplete: 469 case Sema::TDK_TooManyArguments: 470 case Sema::TDK_TooFewArguments: 471 case Sema::TDK_InvalidExplicitArguments: 472 case Sema::TDK_SubstitutionFailure: 473 return 0; 474 475 case Sema::TDK_Inconsistent: 476 case Sema::TDK_Underqualified: 477 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 478 479 // Unhandled 480 case Sema::TDK_NonDeducedMismatch: 481 case Sema::TDK_FailedOverloadResolution: 482 break; 483 } 484 485 return 0; 486} 487 488const TemplateArgument * 489OverloadCandidate::DeductionFailureInfo::getSecondArg() { 490 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 491 case Sema::TDK_Success: 492 case Sema::TDK_InstantiationDepth: 493 case Sema::TDK_Incomplete: 494 case Sema::TDK_TooManyArguments: 495 case Sema::TDK_TooFewArguments: 496 case Sema::TDK_InvalidExplicitArguments: 497 case Sema::TDK_SubstitutionFailure: 498 return 0; 499 500 case Sema::TDK_Inconsistent: 501 case Sema::TDK_Underqualified: 502 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 503 504 // Unhandled 505 case Sema::TDK_NonDeducedMismatch: 506 case Sema::TDK_FailedOverloadResolution: 507 break; 508 } 509 510 return 0; 511} 512 513void OverloadCandidateSet::clear() { 514 inherited::clear(); 515 Functions.clear(); 516} 517 518// IsOverload - Determine whether the given New declaration is an 519// overload of the declarations in Old. This routine returns false if 520// New and Old cannot be overloaded, e.g., if New has the same 521// signature as some function in Old (C++ 1.3.10) or if the Old 522// declarations aren't functions (or function templates) at all. When 523// it does return false, MatchedDecl will point to the decl that New 524// cannot be overloaded with. This decl may be a UsingShadowDecl on 525// top of the underlying declaration. 526// 527// Example: Given the following input: 528// 529// void f(int, float); // #1 530// void f(int, int); // #2 531// int f(int, int); // #3 532// 533// When we process #1, there is no previous declaration of "f", 534// so IsOverload will not be used. 535// 536// When we process #2, Old contains only the FunctionDecl for #1. By 537// comparing the parameter types, we see that #1 and #2 are overloaded 538// (since they have different signatures), so this routine returns 539// false; MatchedDecl is unchanged. 540// 541// When we process #3, Old is an overload set containing #1 and #2. We 542// compare the signatures of #3 to #1 (they're overloaded, so we do 543// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 544// identical (return types of functions are not part of the 545// signature), IsOverload returns false and MatchedDecl will be set to 546// point to the FunctionDecl for #2. 547// 548// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 549// into a class by a using declaration. The rules for whether to hide 550// shadow declarations ignore some properties which otherwise figure 551// into a function template's signature. 552Sema::OverloadKind 553Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 554 NamedDecl *&Match, bool NewIsUsingDecl) { 555 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 556 I != E; ++I) { 557 NamedDecl *OldD = *I; 558 559 bool OldIsUsingDecl = false; 560 if (isa<UsingShadowDecl>(OldD)) { 561 OldIsUsingDecl = true; 562 563 // We can always introduce two using declarations into the same 564 // context, even if they have identical signatures. 565 if (NewIsUsingDecl) continue; 566 567 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 568 } 569 570 // If either declaration was introduced by a using declaration, 571 // we'll need to use slightly different rules for matching. 572 // Essentially, these rules are the normal rules, except that 573 // function templates hide function templates with different 574 // return types or template parameter lists. 575 bool UseMemberUsingDeclRules = 576 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 577 578 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 579 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 580 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 581 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 582 continue; 583 } 584 585 Match = *I; 586 return Ovl_Match; 587 } 588 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 589 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 590 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 591 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 592 continue; 593 } 594 595 Match = *I; 596 return Ovl_Match; 597 } 598 } else if (isa<UsingDecl>(OldD)) { 599 // We can overload with these, which can show up when doing 600 // redeclaration checks for UsingDecls. 601 assert(Old.getLookupKind() == LookupUsingDeclName); 602 } else if (isa<TagDecl>(OldD)) { 603 // We can always overload with tags by hiding them. 604 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 605 // Optimistically assume that an unresolved using decl will 606 // overload; if it doesn't, we'll have to diagnose during 607 // template instantiation. 608 } else { 609 // (C++ 13p1): 610 // Only function declarations can be overloaded; object and type 611 // declarations cannot be overloaded. 612 Match = *I; 613 return Ovl_NonFunction; 614 } 615 } 616 617 return Ovl_Overload; 618} 619 620bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 621 bool UseUsingDeclRules) { 622 // If both of the functions are extern "C", then they are not 623 // overloads. 624 if (Old->isExternC() && New->isExternC()) 625 return false; 626 627 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 628 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 629 630 // C++ [temp.fct]p2: 631 // A function template can be overloaded with other function templates 632 // and with normal (non-template) functions. 633 if ((OldTemplate == 0) != (NewTemplate == 0)) 634 return true; 635 636 // Is the function New an overload of the function Old? 637 QualType OldQType = Context.getCanonicalType(Old->getType()); 638 QualType NewQType = Context.getCanonicalType(New->getType()); 639 640 // Compare the signatures (C++ 1.3.10) of the two functions to 641 // determine whether they are overloads. If we find any mismatch 642 // in the signature, they are overloads. 643 644 // If either of these functions is a K&R-style function (no 645 // prototype), then we consider them to have matching signatures. 646 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 647 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 648 return false; 649 650 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 651 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 652 653 // The signature of a function includes the types of its 654 // parameters (C++ 1.3.10), which includes the presence or absence 655 // of the ellipsis; see C++ DR 357). 656 if (OldQType != NewQType && 657 (OldType->getNumArgs() != NewType->getNumArgs() || 658 OldType->isVariadic() != NewType->isVariadic() || 659 !FunctionArgTypesAreEqual(OldType, NewType))) 660 return true; 661 662 // C++ [temp.over.link]p4: 663 // The signature of a function template consists of its function 664 // signature, its return type and its template parameter list. The names 665 // of the template parameters are significant only for establishing the 666 // relationship between the template parameters and the rest of the 667 // signature. 668 // 669 // We check the return type and template parameter lists for function 670 // templates first; the remaining checks follow. 671 // 672 // However, we don't consider either of these when deciding whether 673 // a member introduced by a shadow declaration is hidden. 674 if (!UseUsingDeclRules && NewTemplate && 675 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 676 OldTemplate->getTemplateParameters(), 677 false, TPL_TemplateMatch) || 678 OldType->getResultType() != NewType->getResultType())) 679 return true; 680 681 // If the function is a class member, its signature includes the 682 // cv-qualifiers (if any) on the function itself. 683 // 684 // As part of this, also check whether one of the member functions 685 // is static, in which case they are not overloads (C++ 686 // 13.1p2). While not part of the definition of the signature, 687 // this check is important to determine whether these functions 688 // can be overloaded. 689 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 690 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 691 if (OldMethod && NewMethod && 692 !OldMethod->isStatic() && !NewMethod->isStatic() && 693 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 694 return true; 695 696 // The signatures match; this is not an overload. 697 return false; 698} 699 700/// TryImplicitConversion - Attempt to perform an implicit conversion 701/// from the given expression (Expr) to the given type (ToType). This 702/// function returns an implicit conversion sequence that can be used 703/// to perform the initialization. Given 704/// 705/// void f(float f); 706/// void g(int i) { f(i); } 707/// 708/// this routine would produce an implicit conversion sequence to 709/// describe the initialization of f from i, which will be a standard 710/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 711/// 4.1) followed by a floating-integral conversion (C++ 4.9). 712// 713/// Note that this routine only determines how the conversion can be 714/// performed; it does not actually perform the conversion. As such, 715/// it will not produce any diagnostics if no conversion is available, 716/// but will instead return an implicit conversion sequence of kind 717/// "BadConversion". 718/// 719/// If @p SuppressUserConversions, then user-defined conversions are 720/// not permitted. 721/// If @p AllowExplicit, then explicit user-defined conversions are 722/// permitted. 723static ImplicitConversionSequence 724TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 725 bool SuppressUserConversions, 726 bool AllowExplicit, 727 bool InOverloadResolution) { 728 ImplicitConversionSequence ICS; 729 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 730 ICS.Standard)) { 731 ICS.setStandard(); 732 return ICS; 733 } 734 735 if (!S.getLangOptions().CPlusPlus) { 736 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 737 return ICS; 738 } 739 740 // C++ [over.ics.user]p4: 741 // A conversion of an expression of class type to the same class 742 // type is given Exact Match rank, and a conversion of an 743 // expression of class type to a base class of that type is 744 // given Conversion rank, in spite of the fact that a copy/move 745 // constructor (i.e., a user-defined conversion function) is 746 // called for those cases. 747 QualType FromType = From->getType(); 748 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 749 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 750 S.IsDerivedFrom(FromType, ToType))) { 751 ICS.setStandard(); 752 ICS.Standard.setAsIdentityConversion(); 753 ICS.Standard.setFromType(FromType); 754 ICS.Standard.setAllToTypes(ToType); 755 756 // We don't actually check at this point whether there is a valid 757 // copy/move constructor, since overloading just assumes that it 758 // exists. When we actually perform initialization, we'll find the 759 // appropriate constructor to copy the returned object, if needed. 760 ICS.Standard.CopyConstructor = 0; 761 762 // Determine whether this is considered a derived-to-base conversion. 763 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 764 ICS.Standard.Second = ICK_Derived_To_Base; 765 766 return ICS; 767 } 768 769 if (SuppressUserConversions) { 770 // We're not in the case above, so there is no conversion that 771 // we can perform. 772 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 773 return ICS; 774 } 775 776 // Attempt user-defined conversion. 777 OverloadCandidateSet Conversions(From->getExprLoc()); 778 OverloadingResult UserDefResult 779 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 780 AllowExplicit); 781 782 if (UserDefResult == OR_Success) { 783 ICS.setUserDefined(); 784 // C++ [over.ics.user]p4: 785 // A conversion of an expression of class type to the same class 786 // type is given Exact Match rank, and a conversion of an 787 // expression of class type to a base class of that type is 788 // given Conversion rank, in spite of the fact that a copy 789 // constructor (i.e., a user-defined conversion function) is 790 // called for those cases. 791 if (CXXConstructorDecl *Constructor 792 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 793 QualType FromCanon 794 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 795 QualType ToCanon 796 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 797 if (Constructor->isCopyConstructor() && 798 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 799 // Turn this into a "standard" conversion sequence, so that it 800 // gets ranked with standard conversion sequences. 801 ICS.setStandard(); 802 ICS.Standard.setAsIdentityConversion(); 803 ICS.Standard.setFromType(From->getType()); 804 ICS.Standard.setAllToTypes(ToType); 805 ICS.Standard.CopyConstructor = Constructor; 806 if (ToCanon != FromCanon) 807 ICS.Standard.Second = ICK_Derived_To_Base; 808 } 809 } 810 811 // C++ [over.best.ics]p4: 812 // However, when considering the argument of a user-defined 813 // conversion function that is a candidate by 13.3.1.3 when 814 // invoked for the copying of the temporary in the second step 815 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 816 // 13.3.1.6 in all cases, only standard conversion sequences and 817 // ellipsis conversion sequences are allowed. 818 if (SuppressUserConversions && ICS.isUserDefined()) { 819 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 820 } 821 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 822 ICS.setAmbiguous(); 823 ICS.Ambiguous.setFromType(From->getType()); 824 ICS.Ambiguous.setToType(ToType); 825 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 826 Cand != Conversions.end(); ++Cand) 827 if (Cand->Viable) 828 ICS.Ambiguous.addConversion(Cand->Function); 829 } else { 830 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 831 } 832 833 return ICS; 834} 835 836bool Sema::TryImplicitConversion(InitializationSequence &Sequence, 837 const InitializedEntity &Entity, 838 Expr *Initializer, 839 bool SuppressUserConversions, 840 bool AllowExplicitConversions, 841 bool InOverloadResolution) { 842 ImplicitConversionSequence ICS 843 = clang::TryImplicitConversion(*this, Initializer, Entity.getType(), 844 SuppressUserConversions, 845 AllowExplicitConversions, 846 InOverloadResolution); 847 if (ICS.isBad()) return true; 848 849 // Perform the actual conversion. 850 Sequence.AddConversionSequenceStep(ICS, Entity.getType()); 851 return false; 852} 853 854/// PerformImplicitConversion - Perform an implicit conversion of the 855/// expression From to the type ToType. Returns true if there was an 856/// error, false otherwise. The expression From is replaced with the 857/// converted expression. Flavor is the kind of conversion we're 858/// performing, used in the error message. If @p AllowExplicit, 859/// explicit user-defined conversions are permitted. 860bool 861Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 862 AssignmentAction Action, bool AllowExplicit) { 863 ImplicitConversionSequence ICS; 864 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 865} 866 867bool 868Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 869 AssignmentAction Action, bool AllowExplicit, 870 ImplicitConversionSequence& ICS) { 871 ICS = clang::TryImplicitConversion(*this, From, ToType, 872 /*SuppressUserConversions=*/false, 873 AllowExplicit, 874 /*InOverloadResolution=*/false); 875 return PerformImplicitConversion(From, ToType, ICS, Action); 876} 877 878/// \brief Determine whether the conversion from FromType to ToType is a valid 879/// conversion that strips "noreturn" off the nested function type. 880static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 881 QualType ToType, QualType &ResultTy) { 882 if (Context.hasSameUnqualifiedType(FromType, ToType)) 883 return false; 884 885 // Permit the conversion F(t __attribute__((noreturn))) -> F(t) 886 // where F adds one of the following at most once: 887 // - a pointer 888 // - a member pointer 889 // - a block pointer 890 CanQualType CanTo = Context.getCanonicalType(ToType); 891 CanQualType CanFrom = Context.getCanonicalType(FromType); 892 Type::TypeClass TyClass = CanTo->getTypeClass(); 893 if (TyClass != CanFrom->getTypeClass()) return false; 894 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { 895 if (TyClass == Type::Pointer) { 896 CanTo = CanTo.getAs<PointerType>()->getPointeeType(); 897 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType(); 898 } else if (TyClass == Type::BlockPointer) { 899 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType(); 900 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType(); 901 } else if (TyClass == Type::MemberPointer) { 902 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType(); 903 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType(); 904 } else { 905 return false; 906 } 907 908 TyClass = CanTo->getTypeClass(); 909 if (TyClass != CanFrom->getTypeClass()) return false; 910 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) 911 return false; 912 } 913 914 const FunctionType *FromFn = cast<FunctionType>(CanFrom); 915 FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); 916 if (!EInfo.getNoReturn()) return false; 917 918 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); 919 assert(QualType(FromFn, 0).isCanonical()); 920 if (QualType(FromFn, 0) != CanTo) return false; 921 922 ResultTy = ToType; 923 return true; 924} 925 926/// \brief Determine whether the conversion from FromType to ToType is a valid 927/// vector conversion. 928/// 929/// \param ICK Will be set to the vector conversion kind, if this is a vector 930/// conversion. 931static bool IsVectorConversion(ASTContext &Context, QualType FromType, 932 QualType ToType, ImplicitConversionKind &ICK) { 933 // We need at least one of these types to be a vector type to have a vector 934 // conversion. 935 if (!ToType->isVectorType() && !FromType->isVectorType()) 936 return false; 937 938 // Identical types require no conversions. 939 if (Context.hasSameUnqualifiedType(FromType, ToType)) 940 return false; 941 942 // There are no conversions between extended vector types, only identity. 943 if (ToType->isExtVectorType()) { 944 // There are no conversions between extended vector types other than the 945 // identity conversion. 946 if (FromType->isExtVectorType()) 947 return false; 948 949 // Vector splat from any arithmetic type to a vector. 950 if (FromType->isArithmeticType()) { 951 ICK = ICK_Vector_Splat; 952 return true; 953 } 954 } 955 956 // We can perform the conversion between vector types in the following cases: 957 // 1)vector types are equivalent AltiVec and GCC vector types 958 // 2)lax vector conversions are permitted and the vector types are of the 959 // same size 960 if (ToType->isVectorType() && FromType->isVectorType()) { 961 if (Context.areCompatibleVectorTypes(FromType, ToType) || 962 (Context.getLangOptions().LaxVectorConversions && 963 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 964 ICK = ICK_Vector_Conversion; 965 return true; 966 } 967 } 968 969 return false; 970} 971 972/// IsStandardConversion - Determines whether there is a standard 973/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 974/// expression From to the type ToType. Standard conversion sequences 975/// only consider non-class types; for conversions that involve class 976/// types, use TryImplicitConversion. If a conversion exists, SCS will 977/// contain the standard conversion sequence required to perform this 978/// conversion and this routine will return true. Otherwise, this 979/// routine will return false and the value of SCS is unspecified. 980static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 981 bool InOverloadResolution, 982 StandardConversionSequence &SCS) { 983 QualType FromType = From->getType(); 984 985 // Standard conversions (C++ [conv]) 986 SCS.setAsIdentityConversion(); 987 SCS.DeprecatedStringLiteralToCharPtr = false; 988 SCS.IncompatibleObjC = false; 989 SCS.setFromType(FromType); 990 SCS.CopyConstructor = 0; 991 992 // There are no standard conversions for class types in C++, so 993 // abort early. When overloading in C, however, we do permit 994 if (FromType->isRecordType() || ToType->isRecordType()) { 995 if (S.getLangOptions().CPlusPlus) 996 return false; 997 998 // When we're overloading in C, we allow, as standard conversions, 999 } 1000 1001 // The first conversion can be an lvalue-to-rvalue conversion, 1002 // array-to-pointer conversion, or function-to-pointer conversion 1003 // (C++ 4p1). 1004 1005 if (FromType == S.Context.OverloadTy) { 1006 DeclAccessPair AccessPair; 1007 if (FunctionDecl *Fn 1008 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 1009 AccessPair)) { 1010 // We were able to resolve the address of the overloaded function, 1011 // so we can convert to the type of that function. 1012 FromType = Fn->getType(); 1013 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 1014 if (!Method->isStatic()) { 1015 Type *ClassType 1016 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1017 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1018 } 1019 } 1020 1021 // If the "from" expression takes the address of the overloaded 1022 // function, update the type of the resulting expression accordingly. 1023 if (FromType->getAs<FunctionType>()) 1024 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens())) 1025 if (UnOp->getOpcode() == UO_AddrOf) 1026 FromType = S.Context.getPointerType(FromType); 1027 1028 // Check that we've computed the proper type after overload resolution. 1029 assert(S.Context.hasSameType(FromType, 1030 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1031 } else { 1032 return false; 1033 } 1034 } 1035 // Lvalue-to-rvalue conversion (C++ 4.1): 1036 // An lvalue (3.10) of a non-function, non-array type T can be 1037 // converted to an rvalue. 1038 bool argIsLValue = From->isLValue(); 1039 if (argIsLValue && 1040 !FromType->isFunctionType() && !FromType->isArrayType() && 1041 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1042 SCS.First = ICK_Lvalue_To_Rvalue; 1043 1044 // If T is a non-class type, the type of the rvalue is the 1045 // cv-unqualified version of T. Otherwise, the type of the rvalue 1046 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1047 // just strip the qualifiers because they don't matter. 1048 FromType = FromType.getUnqualifiedType(); 1049 } else if (FromType->isArrayType()) { 1050 // Array-to-pointer conversion (C++ 4.2) 1051 SCS.First = ICK_Array_To_Pointer; 1052 1053 // An lvalue or rvalue of type "array of N T" or "array of unknown 1054 // bound of T" can be converted to an rvalue of type "pointer to 1055 // T" (C++ 4.2p1). 1056 FromType = S.Context.getArrayDecayedType(FromType); 1057 1058 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1059 // This conversion is deprecated. (C++ D.4). 1060 SCS.DeprecatedStringLiteralToCharPtr = true; 1061 1062 // For the purpose of ranking in overload resolution 1063 // (13.3.3.1.1), this conversion is considered an 1064 // array-to-pointer conversion followed by a qualification 1065 // conversion (4.4). (C++ 4.2p2) 1066 SCS.Second = ICK_Identity; 1067 SCS.Third = ICK_Qualification; 1068 SCS.setAllToTypes(FromType); 1069 return true; 1070 } 1071 } else if (FromType->isFunctionType() && argIsLValue) { 1072 // Function-to-pointer conversion (C++ 4.3). 1073 SCS.First = ICK_Function_To_Pointer; 1074 1075 // An lvalue of function type T can be converted to an rvalue of 1076 // type "pointer to T." The result is a pointer to the 1077 // function. (C++ 4.3p1). 1078 FromType = S.Context.getPointerType(FromType); 1079 } else { 1080 // We don't require any conversions for the first step. 1081 SCS.First = ICK_Identity; 1082 } 1083 SCS.setToType(0, FromType); 1084 1085 // The second conversion can be an integral promotion, floating 1086 // point promotion, integral conversion, floating point conversion, 1087 // floating-integral conversion, pointer conversion, 1088 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1089 // For overloading in C, this can also be a "compatible-type" 1090 // conversion. 1091 bool IncompatibleObjC = false; 1092 ImplicitConversionKind SecondICK = ICK_Identity; 1093 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1094 // The unqualified versions of the types are the same: there's no 1095 // conversion to do. 1096 SCS.Second = ICK_Identity; 1097 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1098 // Integral promotion (C++ 4.5). 1099 SCS.Second = ICK_Integral_Promotion; 1100 FromType = ToType.getUnqualifiedType(); 1101 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1102 // Floating point promotion (C++ 4.6). 1103 SCS.Second = ICK_Floating_Promotion; 1104 FromType = ToType.getUnqualifiedType(); 1105 } else if (S.IsComplexPromotion(FromType, ToType)) { 1106 // Complex promotion (Clang extension) 1107 SCS.Second = ICK_Complex_Promotion; 1108 FromType = ToType.getUnqualifiedType(); 1109 } else if (ToType->isBooleanType() && 1110 (FromType->isArithmeticType() || 1111 FromType->isAnyPointerType() || 1112 FromType->isBlockPointerType() || 1113 FromType->isMemberPointerType() || 1114 FromType->isNullPtrType())) { 1115 // Boolean conversions (C++ 4.12). 1116 SCS.Second = ICK_Boolean_Conversion; 1117 FromType = S.Context.BoolTy; 1118 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1119 ToType->isIntegralType(S.Context)) { 1120 // Integral conversions (C++ 4.7). 1121 SCS.Second = ICK_Integral_Conversion; 1122 FromType = ToType.getUnqualifiedType(); 1123 } else if (FromType->isAnyComplexType() && ToType->isComplexType()) { 1124 // Complex conversions (C99 6.3.1.6) 1125 SCS.Second = ICK_Complex_Conversion; 1126 FromType = ToType.getUnqualifiedType(); 1127 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1128 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1129 // Complex-real conversions (C99 6.3.1.7) 1130 SCS.Second = ICK_Complex_Real; 1131 FromType = ToType.getUnqualifiedType(); 1132 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1133 // Floating point conversions (C++ 4.8). 1134 SCS.Second = ICK_Floating_Conversion; 1135 FromType = ToType.getUnqualifiedType(); 1136 } else if ((FromType->isRealFloatingType() && 1137 ToType->isIntegralType(S.Context)) || 1138 (FromType->isIntegralOrUnscopedEnumerationType() && 1139 ToType->isRealFloatingType())) { 1140 // Floating-integral conversions (C++ 4.9). 1141 SCS.Second = ICK_Floating_Integral; 1142 FromType = ToType.getUnqualifiedType(); 1143 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1144 FromType, IncompatibleObjC)) { 1145 // Pointer conversions (C++ 4.10). 1146 SCS.Second = ICK_Pointer_Conversion; 1147 SCS.IncompatibleObjC = IncompatibleObjC; 1148 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1149 InOverloadResolution, FromType)) { 1150 // Pointer to member conversions (4.11). 1151 SCS.Second = ICK_Pointer_Member; 1152 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1153 SCS.Second = SecondICK; 1154 FromType = ToType.getUnqualifiedType(); 1155 } else if (!S.getLangOptions().CPlusPlus && 1156 S.Context.typesAreCompatible(ToType, FromType)) { 1157 // Compatible conversions (Clang extension for C function overloading) 1158 SCS.Second = ICK_Compatible_Conversion; 1159 FromType = ToType.getUnqualifiedType(); 1160 } else if (IsNoReturnConversion(S.Context, FromType, ToType, FromType)) { 1161 // Treat a conversion that strips "noreturn" as an identity conversion. 1162 SCS.Second = ICK_NoReturn_Adjustment; 1163 } else { 1164 // No second conversion required. 1165 SCS.Second = ICK_Identity; 1166 } 1167 SCS.setToType(1, FromType); 1168 1169 QualType CanonFrom; 1170 QualType CanonTo; 1171 // The third conversion can be a qualification conversion (C++ 4p1). 1172 if (S.IsQualificationConversion(FromType, ToType)) { 1173 SCS.Third = ICK_Qualification; 1174 FromType = ToType; 1175 CanonFrom = S.Context.getCanonicalType(FromType); 1176 CanonTo = S.Context.getCanonicalType(ToType); 1177 } else { 1178 // No conversion required 1179 SCS.Third = ICK_Identity; 1180 1181 // C++ [over.best.ics]p6: 1182 // [...] Any difference in top-level cv-qualification is 1183 // subsumed by the initialization itself and does not constitute 1184 // a conversion. [...] 1185 CanonFrom = S.Context.getCanonicalType(FromType); 1186 CanonTo = S.Context.getCanonicalType(ToType); 1187 if (CanonFrom.getLocalUnqualifiedType() 1188 == CanonTo.getLocalUnqualifiedType() && 1189 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1190 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1191 FromType = ToType; 1192 CanonFrom = CanonTo; 1193 } 1194 } 1195 SCS.setToType(2, FromType); 1196 1197 // If we have not converted the argument type to the parameter type, 1198 // this is a bad conversion sequence. 1199 if (CanonFrom != CanonTo) 1200 return false; 1201 1202 return true; 1203} 1204 1205/// IsIntegralPromotion - Determines whether the conversion from the 1206/// expression From (whose potentially-adjusted type is FromType) to 1207/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1208/// sets PromotedType to the promoted type. 1209bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1210 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1211 // All integers are built-in. 1212 if (!To) { 1213 return false; 1214 } 1215 1216 // An rvalue of type char, signed char, unsigned char, short int, or 1217 // unsigned short int can be converted to an rvalue of type int if 1218 // int can represent all the values of the source type; otherwise, 1219 // the source rvalue can be converted to an rvalue of type unsigned 1220 // int (C++ 4.5p1). 1221 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1222 !FromType->isEnumeralType()) { 1223 if (// We can promote any signed, promotable integer type to an int 1224 (FromType->isSignedIntegerType() || 1225 // We can promote any unsigned integer type whose size is 1226 // less than int to an int. 1227 (!FromType->isSignedIntegerType() && 1228 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1229 return To->getKind() == BuiltinType::Int; 1230 } 1231 1232 return To->getKind() == BuiltinType::UInt; 1233 } 1234 1235 // C++0x [conv.prom]p3: 1236 // A prvalue of an unscoped enumeration type whose underlying type is not 1237 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1238 // following types that can represent all the values of the enumeration 1239 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1240 // unsigned int, long int, unsigned long int, long long int, or unsigned 1241 // long long int. If none of the types in that list can represent all the 1242 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1243 // type can be converted to an rvalue a prvalue of the extended integer type 1244 // with lowest integer conversion rank (4.13) greater than the rank of long 1245 // long in which all the values of the enumeration can be represented. If 1246 // there are two such extended types, the signed one is chosen. 1247 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1248 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1249 // provided for a scoped enumeration. 1250 if (FromEnumType->getDecl()->isScoped()) 1251 return false; 1252 1253 // We have already pre-calculated the promotion type, so this is trivial. 1254 if (ToType->isIntegerType() && 1255 !RequireCompleteType(From->getLocStart(), FromType, PDiag())) 1256 return Context.hasSameUnqualifiedType(ToType, 1257 FromEnumType->getDecl()->getPromotionType()); 1258 } 1259 1260 // C++0x [conv.prom]p2: 1261 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1262 // to an rvalue a prvalue of the first of the following types that can 1263 // represent all the values of its underlying type: int, unsigned int, 1264 // long int, unsigned long int, long long int, or unsigned long long int. 1265 // If none of the types in that list can represent all the values of its 1266 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1267 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1268 // type. 1269 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1270 ToType->isIntegerType()) { 1271 // Determine whether the type we're converting from is signed or 1272 // unsigned. 1273 bool FromIsSigned; 1274 uint64_t FromSize = Context.getTypeSize(FromType); 1275 1276 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1277 FromIsSigned = true; 1278 1279 // The types we'll try to promote to, in the appropriate 1280 // order. Try each of these types. 1281 QualType PromoteTypes[6] = { 1282 Context.IntTy, Context.UnsignedIntTy, 1283 Context.LongTy, Context.UnsignedLongTy , 1284 Context.LongLongTy, Context.UnsignedLongLongTy 1285 }; 1286 for (int Idx = 0; Idx < 6; ++Idx) { 1287 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1288 if (FromSize < ToSize || 1289 (FromSize == ToSize && 1290 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1291 // We found the type that we can promote to. If this is the 1292 // type we wanted, we have a promotion. Otherwise, no 1293 // promotion. 1294 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1295 } 1296 } 1297 } 1298 1299 // An rvalue for an integral bit-field (9.6) can be converted to an 1300 // rvalue of type int if int can represent all the values of the 1301 // bit-field; otherwise, it can be converted to unsigned int if 1302 // unsigned int can represent all the values of the bit-field. If 1303 // the bit-field is larger yet, no integral promotion applies to 1304 // it. If the bit-field has an enumerated type, it is treated as any 1305 // other value of that type for promotion purposes (C++ 4.5p3). 1306 // FIXME: We should delay checking of bit-fields until we actually perform the 1307 // conversion. 1308 using llvm::APSInt; 1309 if (From) 1310 if (FieldDecl *MemberDecl = From->getBitField()) { 1311 APSInt BitWidth; 1312 if (FromType->isIntegralType(Context) && 1313 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1314 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1315 ToSize = Context.getTypeSize(ToType); 1316 1317 // Are we promoting to an int from a bitfield that fits in an int? 1318 if (BitWidth < ToSize || 1319 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1320 return To->getKind() == BuiltinType::Int; 1321 } 1322 1323 // Are we promoting to an unsigned int from an unsigned bitfield 1324 // that fits into an unsigned int? 1325 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1326 return To->getKind() == BuiltinType::UInt; 1327 } 1328 1329 return false; 1330 } 1331 } 1332 1333 // An rvalue of type bool can be converted to an rvalue of type int, 1334 // with false becoming zero and true becoming one (C++ 4.5p4). 1335 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1336 return true; 1337 } 1338 1339 return false; 1340} 1341 1342/// IsFloatingPointPromotion - Determines whether the conversion from 1343/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1344/// returns true and sets PromotedType to the promoted type. 1345bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1346 /// An rvalue of type float can be converted to an rvalue of type 1347 /// double. (C++ 4.6p1). 1348 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1349 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1350 if (FromBuiltin->getKind() == BuiltinType::Float && 1351 ToBuiltin->getKind() == BuiltinType::Double) 1352 return true; 1353 1354 // C99 6.3.1.5p1: 1355 // When a float is promoted to double or long double, or a 1356 // double is promoted to long double [...]. 1357 if (!getLangOptions().CPlusPlus && 1358 (FromBuiltin->getKind() == BuiltinType::Float || 1359 FromBuiltin->getKind() == BuiltinType::Double) && 1360 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1361 return true; 1362 } 1363 1364 return false; 1365} 1366 1367/// \brief Determine if a conversion is a complex promotion. 1368/// 1369/// A complex promotion is defined as a complex -> complex conversion 1370/// where the conversion between the underlying real types is a 1371/// floating-point or integral promotion. 1372bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1373 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1374 if (!FromComplex) 1375 return false; 1376 1377 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1378 if (!ToComplex) 1379 return false; 1380 1381 return IsFloatingPointPromotion(FromComplex->getElementType(), 1382 ToComplex->getElementType()) || 1383 IsIntegralPromotion(0, FromComplex->getElementType(), 1384 ToComplex->getElementType()); 1385} 1386 1387/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1388/// the pointer type FromPtr to a pointer to type ToPointee, with the 1389/// same type qualifiers as FromPtr has on its pointee type. ToType, 1390/// if non-empty, will be a pointer to ToType that may or may not have 1391/// the right set of qualifiers on its pointee. 1392static QualType 1393BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1394 QualType ToPointee, QualType ToType, 1395 ASTContext &Context) { 1396 assert((FromPtr->getTypeClass() == Type::Pointer || 1397 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1398 "Invalid similarly-qualified pointer type"); 1399 1400 /// \brief Conversions to 'id' subsume cv-qualifier conversions. 1401 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1402 return ToType.getUnqualifiedType(); 1403 1404 QualType CanonFromPointee 1405 = Context.getCanonicalType(FromPtr->getPointeeType()); 1406 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1407 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1408 1409 // Exact qualifier match -> return the pointer type we're converting to. 1410 if (CanonToPointee.getLocalQualifiers() == Quals) { 1411 // ToType is exactly what we need. Return it. 1412 if (!ToType.isNull()) 1413 return ToType.getUnqualifiedType(); 1414 1415 // Build a pointer to ToPointee. It has the right qualifiers 1416 // already. 1417 if (isa<ObjCObjectPointerType>(ToType)) 1418 return Context.getObjCObjectPointerType(ToPointee); 1419 return Context.getPointerType(ToPointee); 1420 } 1421 1422 // Just build a canonical type that has the right qualifiers. 1423 QualType QualifiedCanonToPointee 1424 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1425 1426 if (isa<ObjCObjectPointerType>(ToType)) 1427 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1428 return Context.getPointerType(QualifiedCanonToPointee); 1429} 1430 1431static bool isNullPointerConstantForConversion(Expr *Expr, 1432 bool InOverloadResolution, 1433 ASTContext &Context) { 1434 // Handle value-dependent integral null pointer constants correctly. 1435 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1436 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1437 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1438 return !InOverloadResolution; 1439 1440 return Expr->isNullPointerConstant(Context, 1441 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1442 : Expr::NPC_ValueDependentIsNull); 1443} 1444 1445/// IsPointerConversion - Determines whether the conversion of the 1446/// expression From, which has the (possibly adjusted) type FromType, 1447/// can be converted to the type ToType via a pointer conversion (C++ 1448/// 4.10). If so, returns true and places the converted type (that 1449/// might differ from ToType in its cv-qualifiers at some level) into 1450/// ConvertedType. 1451/// 1452/// This routine also supports conversions to and from block pointers 1453/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1454/// pointers to interfaces. FIXME: Once we've determined the 1455/// appropriate overloading rules for Objective-C, we may want to 1456/// split the Objective-C checks into a different routine; however, 1457/// GCC seems to consider all of these conversions to be pointer 1458/// conversions, so for now they live here. IncompatibleObjC will be 1459/// set if the conversion is an allowed Objective-C conversion that 1460/// should result in a warning. 1461bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1462 bool InOverloadResolution, 1463 QualType& ConvertedType, 1464 bool &IncompatibleObjC) { 1465 IncompatibleObjC = false; 1466 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 1467 IncompatibleObjC)) 1468 return true; 1469 1470 // Conversion from a null pointer constant to any Objective-C pointer type. 1471 if (ToType->isObjCObjectPointerType() && 1472 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1473 ConvertedType = ToType; 1474 return true; 1475 } 1476 1477 // Blocks: Block pointers can be converted to void*. 1478 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1479 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1480 ConvertedType = ToType; 1481 return true; 1482 } 1483 // Blocks: A null pointer constant can be converted to a block 1484 // pointer type. 1485 if (ToType->isBlockPointerType() && 1486 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1487 ConvertedType = ToType; 1488 return true; 1489 } 1490 1491 // If the left-hand-side is nullptr_t, the right side can be a null 1492 // pointer constant. 1493 if (ToType->isNullPtrType() && 1494 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1495 ConvertedType = ToType; 1496 return true; 1497 } 1498 1499 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1500 if (!ToTypePtr) 1501 return false; 1502 1503 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1504 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1505 ConvertedType = ToType; 1506 return true; 1507 } 1508 1509 // Beyond this point, both types need to be pointers 1510 // , including objective-c pointers. 1511 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1512 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1513 ConvertedType = BuildSimilarlyQualifiedPointerType( 1514 FromType->getAs<ObjCObjectPointerType>(), 1515 ToPointeeType, 1516 ToType, Context); 1517 return true; 1518 } 1519 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1520 if (!FromTypePtr) 1521 return false; 1522 1523 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1524 1525 // If the unqualified pointee types are the same, this can't be a 1526 // pointer conversion, so don't do all of the work below. 1527 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1528 return false; 1529 1530 // An rvalue of type "pointer to cv T," where T is an object type, 1531 // can be converted to an rvalue of type "pointer to cv void" (C++ 1532 // 4.10p2). 1533 if (FromPointeeType->isIncompleteOrObjectType() && 1534 ToPointeeType->isVoidType()) { 1535 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1536 ToPointeeType, 1537 ToType, Context); 1538 return true; 1539 } 1540 1541 // When we're overloading in C, we allow a special kind of pointer 1542 // conversion for compatible-but-not-identical pointee types. 1543 if (!getLangOptions().CPlusPlus && 1544 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1545 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1546 ToPointeeType, 1547 ToType, Context); 1548 return true; 1549 } 1550 1551 // C++ [conv.ptr]p3: 1552 // 1553 // An rvalue of type "pointer to cv D," where D is a class type, 1554 // can be converted to an rvalue of type "pointer to cv B," where 1555 // B is a base class (clause 10) of D. If B is an inaccessible 1556 // (clause 11) or ambiguous (10.2) base class of D, a program that 1557 // necessitates this conversion is ill-formed. The result of the 1558 // conversion is a pointer to the base class sub-object of the 1559 // derived class object. The null pointer value is converted to 1560 // the null pointer value of the destination type. 1561 // 1562 // Note that we do not check for ambiguity or inaccessibility 1563 // here. That is handled by CheckPointerConversion. 1564 if (getLangOptions().CPlusPlus && 1565 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1566 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1567 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1568 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1569 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1570 ToPointeeType, 1571 ToType, Context); 1572 return true; 1573 } 1574 1575 return false; 1576} 1577 1578/// isObjCPointerConversion - Determines whether this is an 1579/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1580/// with the same arguments and return values. 1581bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1582 QualType& ConvertedType, 1583 bool &IncompatibleObjC) { 1584 if (!getLangOptions().ObjC1) 1585 return false; 1586 1587 // First, we handle all conversions on ObjC object pointer types. 1588 const ObjCObjectPointerType* ToObjCPtr = 1589 ToType->getAs<ObjCObjectPointerType>(); 1590 const ObjCObjectPointerType *FromObjCPtr = 1591 FromType->getAs<ObjCObjectPointerType>(); 1592 1593 if (ToObjCPtr && FromObjCPtr) { 1594 // If the pointee types are the same (ignoring qualifications), 1595 // then this is not a pointer conversion. 1596 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 1597 FromObjCPtr->getPointeeType())) 1598 return false; 1599 1600 // Objective C++: We're able to convert between "id" or "Class" and a 1601 // pointer to any interface (in both directions). 1602 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1603 ConvertedType = ToType; 1604 return true; 1605 } 1606 // Conversions with Objective-C's id<...>. 1607 if ((FromObjCPtr->isObjCQualifiedIdType() || 1608 ToObjCPtr->isObjCQualifiedIdType()) && 1609 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1610 /*compare=*/false)) { 1611 ConvertedType = ToType; 1612 return true; 1613 } 1614 // Objective C++: We're able to convert from a pointer to an 1615 // interface to a pointer to a different interface. 1616 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1617 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1618 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1619 if (getLangOptions().CPlusPlus && LHS && RHS && 1620 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1621 FromObjCPtr->getPointeeType())) 1622 return false; 1623 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1624 ToObjCPtr->getPointeeType(), 1625 ToType, Context); 1626 return true; 1627 } 1628 1629 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1630 // Okay: this is some kind of implicit downcast of Objective-C 1631 // interfaces, which is permitted. However, we're going to 1632 // complain about it. 1633 IncompatibleObjC = true; 1634 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1635 ToObjCPtr->getPointeeType(), 1636 ToType, Context); 1637 return true; 1638 } 1639 } 1640 // Beyond this point, both types need to be C pointers or block pointers. 1641 QualType ToPointeeType; 1642 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1643 ToPointeeType = ToCPtr->getPointeeType(); 1644 else if (const BlockPointerType *ToBlockPtr = 1645 ToType->getAs<BlockPointerType>()) { 1646 // Objective C++: We're able to convert from a pointer to any object 1647 // to a block pointer type. 1648 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1649 ConvertedType = ToType; 1650 return true; 1651 } 1652 ToPointeeType = ToBlockPtr->getPointeeType(); 1653 } 1654 else if (FromType->getAs<BlockPointerType>() && 1655 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1656 // Objective C++: We're able to convert from a block pointer type to a 1657 // pointer to any object. 1658 ConvertedType = ToType; 1659 return true; 1660 } 1661 else 1662 return false; 1663 1664 QualType FromPointeeType; 1665 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1666 FromPointeeType = FromCPtr->getPointeeType(); 1667 else if (const BlockPointerType *FromBlockPtr = 1668 FromType->getAs<BlockPointerType>()) 1669 FromPointeeType = FromBlockPtr->getPointeeType(); 1670 else 1671 return false; 1672 1673 // If we have pointers to pointers, recursively check whether this 1674 // is an Objective-C conversion. 1675 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1676 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1677 IncompatibleObjC)) { 1678 // We always complain about this conversion. 1679 IncompatibleObjC = true; 1680 ConvertedType = Context.getPointerType(ConvertedType); 1681 return true; 1682 } 1683 // Allow conversion of pointee being objective-c pointer to another one; 1684 // as in I* to id. 1685 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1686 ToPointeeType->getAs<ObjCObjectPointerType>() && 1687 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1688 IncompatibleObjC)) { 1689 ConvertedType = Context.getPointerType(ConvertedType); 1690 return true; 1691 } 1692 1693 // If we have pointers to functions or blocks, check whether the only 1694 // differences in the argument and result types are in Objective-C 1695 // pointer conversions. If so, we permit the conversion (but 1696 // complain about it). 1697 const FunctionProtoType *FromFunctionType 1698 = FromPointeeType->getAs<FunctionProtoType>(); 1699 const FunctionProtoType *ToFunctionType 1700 = ToPointeeType->getAs<FunctionProtoType>(); 1701 if (FromFunctionType && ToFunctionType) { 1702 // If the function types are exactly the same, this isn't an 1703 // Objective-C pointer conversion. 1704 if (Context.getCanonicalType(FromPointeeType) 1705 == Context.getCanonicalType(ToPointeeType)) 1706 return false; 1707 1708 // Perform the quick checks that will tell us whether these 1709 // function types are obviously different. 1710 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1711 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1712 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1713 return false; 1714 1715 bool HasObjCConversion = false; 1716 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1717 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1718 // Okay, the types match exactly. Nothing to do. 1719 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1720 ToFunctionType->getResultType(), 1721 ConvertedType, IncompatibleObjC)) { 1722 // Okay, we have an Objective-C pointer conversion. 1723 HasObjCConversion = true; 1724 } else { 1725 // Function types are too different. Abort. 1726 return false; 1727 } 1728 1729 // Check argument types. 1730 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1731 ArgIdx != NumArgs; ++ArgIdx) { 1732 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1733 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1734 if (Context.getCanonicalType(FromArgType) 1735 == Context.getCanonicalType(ToArgType)) { 1736 // Okay, the types match exactly. Nothing to do. 1737 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1738 ConvertedType, IncompatibleObjC)) { 1739 // Okay, we have an Objective-C pointer conversion. 1740 HasObjCConversion = true; 1741 } else { 1742 // Argument types are too different. Abort. 1743 return false; 1744 } 1745 } 1746 1747 if (HasObjCConversion) { 1748 // We had an Objective-C conversion. Allow this pointer 1749 // conversion, but complain about it. 1750 ConvertedType = ToType; 1751 IncompatibleObjC = true; 1752 return true; 1753 } 1754 } 1755 1756 return false; 1757} 1758 1759/// FunctionArgTypesAreEqual - This routine checks two function proto types 1760/// for equlity of their argument types. Caller has already checked that 1761/// they have same number of arguments. This routine assumes that Objective-C 1762/// pointer types which only differ in their protocol qualifiers are equal. 1763bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, 1764 FunctionProtoType* NewType){ 1765 if (!getLangOptions().ObjC1) 1766 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1767 NewType->arg_type_begin()); 1768 1769 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1770 N = NewType->arg_type_begin(), 1771 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1772 QualType ToType = (*O); 1773 QualType FromType = (*N); 1774 if (ToType != FromType) { 1775 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1776 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1777 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1778 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1779 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1780 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1781 continue; 1782 } 1783 else if (const ObjCObjectPointerType *PTTo = 1784 ToType->getAs<ObjCObjectPointerType>()) { 1785 if (const ObjCObjectPointerType *PTFr = 1786 FromType->getAs<ObjCObjectPointerType>()) 1787 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1788 continue; 1789 } 1790 return false; 1791 } 1792 } 1793 return true; 1794} 1795 1796/// CheckPointerConversion - Check the pointer conversion from the 1797/// expression From to the type ToType. This routine checks for 1798/// ambiguous or inaccessible derived-to-base pointer 1799/// conversions for which IsPointerConversion has already returned 1800/// true. It returns true and produces a diagnostic if there was an 1801/// error, or returns false otherwise. 1802bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1803 CastKind &Kind, 1804 CXXCastPath& BasePath, 1805 bool IgnoreBaseAccess) { 1806 QualType FromType = From->getType(); 1807 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 1808 1809 Kind = CK_BitCast; 1810 1811 if (CXXBoolLiteralExpr* LitBool 1812 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1813 if (!IsCStyleOrFunctionalCast && LitBool->getValue() == false) 1814 Diag(LitBool->getExprLoc(), diag::warn_init_pointer_from_false) 1815 << ToType; 1816 1817 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1818 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1819 QualType FromPointeeType = FromPtrType->getPointeeType(), 1820 ToPointeeType = ToPtrType->getPointeeType(); 1821 1822 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1823 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1824 // We must have a derived-to-base conversion. Check an 1825 // ambiguous or inaccessible conversion. 1826 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1827 From->getExprLoc(), 1828 From->getSourceRange(), &BasePath, 1829 IgnoreBaseAccess)) 1830 return true; 1831 1832 // The conversion was successful. 1833 Kind = CK_DerivedToBase; 1834 } 1835 } 1836 if (const ObjCObjectPointerType *FromPtrType = 1837 FromType->getAs<ObjCObjectPointerType>()) { 1838 if (const ObjCObjectPointerType *ToPtrType = 1839 ToType->getAs<ObjCObjectPointerType>()) { 1840 // Objective-C++ conversions are always okay. 1841 // FIXME: We should have a different class of conversions for the 1842 // Objective-C++ implicit conversions. 1843 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1844 return false; 1845 } 1846 } 1847 1848 // We shouldn't fall into this case unless it's valid for other 1849 // reasons. 1850 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 1851 Kind = CK_NullToPointer; 1852 1853 return false; 1854} 1855 1856/// IsMemberPointerConversion - Determines whether the conversion of the 1857/// expression From, which has the (possibly adjusted) type FromType, can be 1858/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1859/// If so, returns true and places the converted type (that might differ from 1860/// ToType in its cv-qualifiers at some level) into ConvertedType. 1861bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1862 QualType ToType, 1863 bool InOverloadResolution, 1864 QualType &ConvertedType) { 1865 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1866 if (!ToTypePtr) 1867 return false; 1868 1869 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1870 if (From->isNullPointerConstant(Context, 1871 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1872 : Expr::NPC_ValueDependentIsNull)) { 1873 ConvertedType = ToType; 1874 return true; 1875 } 1876 1877 // Otherwise, both types have to be member pointers. 1878 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1879 if (!FromTypePtr) 1880 return false; 1881 1882 // A pointer to member of B can be converted to a pointer to member of D, 1883 // where D is derived from B (C++ 4.11p2). 1884 QualType FromClass(FromTypePtr->getClass(), 0); 1885 QualType ToClass(ToTypePtr->getClass(), 0); 1886 // FIXME: What happens when these are dependent? Is this function even called? 1887 1888 if (IsDerivedFrom(ToClass, FromClass)) { 1889 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1890 ToClass.getTypePtr()); 1891 return true; 1892 } 1893 1894 return false; 1895} 1896 1897/// CheckMemberPointerConversion - Check the member pointer conversion from the 1898/// expression From to the type ToType. This routine checks for ambiguous or 1899/// virtual or inaccessible base-to-derived member pointer conversions 1900/// for which IsMemberPointerConversion has already returned true. It returns 1901/// true and produces a diagnostic if there was an error, or returns false 1902/// otherwise. 1903bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1904 CastKind &Kind, 1905 CXXCastPath &BasePath, 1906 bool IgnoreBaseAccess) { 1907 QualType FromType = From->getType(); 1908 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1909 if (!FromPtrType) { 1910 // This must be a null pointer to member pointer conversion 1911 assert(From->isNullPointerConstant(Context, 1912 Expr::NPC_ValueDependentIsNull) && 1913 "Expr must be null pointer constant!"); 1914 Kind = CK_NullToMemberPointer; 1915 return false; 1916 } 1917 1918 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1919 assert(ToPtrType && "No member pointer cast has a target type " 1920 "that is not a member pointer."); 1921 1922 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1923 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1924 1925 // FIXME: What about dependent types? 1926 assert(FromClass->isRecordType() && "Pointer into non-class."); 1927 assert(ToClass->isRecordType() && "Pointer into non-class."); 1928 1929 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1930 /*DetectVirtual=*/true); 1931 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1932 assert(DerivationOkay && 1933 "Should not have been called if derivation isn't OK."); 1934 (void)DerivationOkay; 1935 1936 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1937 getUnqualifiedType())) { 1938 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1939 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1940 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1941 return true; 1942 } 1943 1944 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1945 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1946 << FromClass << ToClass << QualType(VBase, 0) 1947 << From->getSourceRange(); 1948 return true; 1949 } 1950 1951 if (!IgnoreBaseAccess) 1952 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1953 Paths.front(), 1954 diag::err_downcast_from_inaccessible_base); 1955 1956 // Must be a base to derived member conversion. 1957 BuildBasePathArray(Paths, BasePath); 1958 Kind = CK_BaseToDerivedMemberPointer; 1959 return false; 1960} 1961 1962/// IsQualificationConversion - Determines whether the conversion from 1963/// an rvalue of type FromType to ToType is a qualification conversion 1964/// (C++ 4.4). 1965bool 1966Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1967 FromType = Context.getCanonicalType(FromType); 1968 ToType = Context.getCanonicalType(ToType); 1969 1970 // If FromType and ToType are the same type, this is not a 1971 // qualification conversion. 1972 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1973 return false; 1974 1975 // (C++ 4.4p4): 1976 // A conversion can add cv-qualifiers at levels other than the first 1977 // in multi-level pointers, subject to the following rules: [...] 1978 bool PreviousToQualsIncludeConst = true; 1979 bool UnwrappedAnyPointer = false; 1980 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 1981 // Within each iteration of the loop, we check the qualifiers to 1982 // determine if this still looks like a qualification 1983 // conversion. Then, if all is well, we unwrap one more level of 1984 // pointers or pointers-to-members and do it all again 1985 // until there are no more pointers or pointers-to-members left to 1986 // unwrap. 1987 UnwrappedAnyPointer = true; 1988 1989 // -- for every j > 0, if const is in cv 1,j then const is in cv 1990 // 2,j, and similarly for volatile. 1991 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1992 return false; 1993 1994 // -- if the cv 1,j and cv 2,j are different, then const is in 1995 // every cv for 0 < k < j. 1996 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1997 && !PreviousToQualsIncludeConst) 1998 return false; 1999 2000 // Keep track of whether all prior cv-qualifiers in the "to" type 2001 // include const. 2002 PreviousToQualsIncludeConst 2003 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 2004 } 2005 2006 // We are left with FromType and ToType being the pointee types 2007 // after unwrapping the original FromType and ToType the same number 2008 // of types. If we unwrapped any pointers, and if FromType and 2009 // ToType have the same unqualified type (since we checked 2010 // qualifiers above), then this is a qualification conversion. 2011 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2012} 2013 2014/// Determines whether there is a user-defined conversion sequence 2015/// (C++ [over.ics.user]) that converts expression From to the type 2016/// ToType. If such a conversion exists, User will contain the 2017/// user-defined conversion sequence that performs such a conversion 2018/// and this routine will return true. Otherwise, this routine returns 2019/// false and User is unspecified. 2020/// 2021/// \param AllowExplicit true if the conversion should consider C++0x 2022/// "explicit" conversion functions as well as non-explicit conversion 2023/// functions (C++0x [class.conv.fct]p2). 2024static OverloadingResult 2025IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 2026 UserDefinedConversionSequence& User, 2027 OverloadCandidateSet& CandidateSet, 2028 bool AllowExplicit) { 2029 // Whether we will only visit constructors. 2030 bool ConstructorsOnly = false; 2031 2032 // If the type we are conversion to is a class type, enumerate its 2033 // constructors. 2034 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 2035 // C++ [over.match.ctor]p1: 2036 // When objects of class type are direct-initialized (8.5), or 2037 // copy-initialized from an expression of the same or a 2038 // derived class type (8.5), overload resolution selects the 2039 // constructor. [...] For copy-initialization, the candidate 2040 // functions are all the converting constructors (12.3.1) of 2041 // that class. The argument list is the expression-list within 2042 // the parentheses of the initializer. 2043 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 2044 (From->getType()->getAs<RecordType>() && 2045 S.IsDerivedFrom(From->getType(), ToType))) 2046 ConstructorsOnly = true; 2047 2048 if (S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag())) { 2049 // We're not going to find any constructors. 2050 } else if (CXXRecordDecl *ToRecordDecl 2051 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 2052 DeclContext::lookup_iterator Con, ConEnd; 2053 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 2054 Con != ConEnd; ++Con) { 2055 NamedDecl *D = *Con; 2056 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2057 2058 // Find the constructor (which may be a template). 2059 CXXConstructorDecl *Constructor = 0; 2060 FunctionTemplateDecl *ConstructorTmpl 2061 = dyn_cast<FunctionTemplateDecl>(D); 2062 if (ConstructorTmpl) 2063 Constructor 2064 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2065 else 2066 Constructor = cast<CXXConstructorDecl>(D); 2067 2068 if (!Constructor->isInvalidDecl() && 2069 Constructor->isConvertingConstructor(AllowExplicit)) { 2070 if (ConstructorTmpl) 2071 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2072 /*ExplicitArgs*/ 0, 2073 &From, 1, CandidateSet, 2074 /*SuppressUserConversions=*/ 2075 !ConstructorsOnly); 2076 else 2077 // Allow one user-defined conversion when user specifies a 2078 // From->ToType conversion via an static cast (c-style, etc). 2079 S.AddOverloadCandidate(Constructor, FoundDecl, 2080 &From, 1, CandidateSet, 2081 /*SuppressUserConversions=*/ 2082 !ConstructorsOnly); 2083 } 2084 } 2085 } 2086 } 2087 2088 // Enumerate conversion functions, if we're allowed to. 2089 if (ConstructorsOnly) { 2090 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 2091 S.PDiag(0) << From->getSourceRange())) { 2092 // No conversion functions from incomplete types. 2093 } else if (const RecordType *FromRecordType 2094 = From->getType()->getAs<RecordType>()) { 2095 if (CXXRecordDecl *FromRecordDecl 2096 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 2097 // Add all of the conversion functions as candidates. 2098 const UnresolvedSetImpl *Conversions 2099 = FromRecordDecl->getVisibleConversionFunctions(); 2100 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2101 E = Conversions->end(); I != E; ++I) { 2102 DeclAccessPair FoundDecl = I.getPair(); 2103 NamedDecl *D = FoundDecl.getDecl(); 2104 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 2105 if (isa<UsingShadowDecl>(D)) 2106 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2107 2108 CXXConversionDecl *Conv; 2109 FunctionTemplateDecl *ConvTemplate; 2110 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 2111 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2112 else 2113 Conv = cast<CXXConversionDecl>(D); 2114 2115 if (AllowExplicit || !Conv->isExplicit()) { 2116 if (ConvTemplate) 2117 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 2118 ActingContext, From, ToType, 2119 CandidateSet); 2120 else 2121 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 2122 From, ToType, CandidateSet); 2123 } 2124 } 2125 } 2126 } 2127 2128 OverloadCandidateSet::iterator Best; 2129 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2130 case OR_Success: 2131 // Record the standard conversion we used and the conversion function. 2132 if (CXXConstructorDecl *Constructor 2133 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 2134 // C++ [over.ics.user]p1: 2135 // If the user-defined conversion is specified by a 2136 // constructor (12.3.1), the initial standard conversion 2137 // sequence converts the source type to the type required by 2138 // the argument of the constructor. 2139 // 2140 QualType ThisType = Constructor->getThisType(S.Context); 2141 if (Best->Conversions[0].isEllipsis()) 2142 User.EllipsisConversion = true; 2143 else { 2144 User.Before = Best->Conversions[0].Standard; 2145 User.EllipsisConversion = false; 2146 } 2147 User.ConversionFunction = Constructor; 2148 User.After.setAsIdentityConversion(); 2149 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2150 User.After.setAllToTypes(ToType); 2151 return OR_Success; 2152 } else if (CXXConversionDecl *Conversion 2153 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2154 // C++ [over.ics.user]p1: 2155 // 2156 // [...] If the user-defined conversion is specified by a 2157 // conversion function (12.3.2), the initial standard 2158 // conversion sequence converts the source type to the 2159 // implicit object parameter of the conversion function. 2160 User.Before = Best->Conversions[0].Standard; 2161 User.ConversionFunction = Conversion; 2162 User.EllipsisConversion = false; 2163 2164 // C++ [over.ics.user]p2: 2165 // The second standard conversion sequence converts the 2166 // result of the user-defined conversion to the target type 2167 // for the sequence. Since an implicit conversion sequence 2168 // is an initialization, the special rules for 2169 // initialization by user-defined conversion apply when 2170 // selecting the best user-defined conversion for a 2171 // user-defined conversion sequence (see 13.3.3 and 2172 // 13.3.3.1). 2173 User.After = Best->FinalConversion; 2174 return OR_Success; 2175 } else { 2176 llvm_unreachable("Not a constructor or conversion function?"); 2177 return OR_No_Viable_Function; 2178 } 2179 2180 case OR_No_Viable_Function: 2181 return OR_No_Viable_Function; 2182 case OR_Deleted: 2183 // No conversion here! We're done. 2184 return OR_Deleted; 2185 2186 case OR_Ambiguous: 2187 return OR_Ambiguous; 2188 } 2189 2190 return OR_No_Viable_Function; 2191} 2192 2193bool 2194Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2195 ImplicitConversionSequence ICS; 2196 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2197 OverloadingResult OvResult = 2198 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 2199 CandidateSet, false); 2200 if (OvResult == OR_Ambiguous) 2201 Diag(From->getSourceRange().getBegin(), 2202 diag::err_typecheck_ambiguous_condition) 2203 << From->getType() << ToType << From->getSourceRange(); 2204 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2205 Diag(From->getSourceRange().getBegin(), 2206 diag::err_typecheck_nonviable_condition) 2207 << From->getType() << ToType << From->getSourceRange(); 2208 else 2209 return false; 2210 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &From, 1); 2211 return true; 2212} 2213 2214/// CompareImplicitConversionSequences - Compare two implicit 2215/// conversion sequences to determine whether one is better than the 2216/// other or if they are indistinguishable (C++ 13.3.3.2). 2217static ImplicitConversionSequence::CompareKind 2218CompareImplicitConversionSequences(Sema &S, 2219 const ImplicitConversionSequence& ICS1, 2220 const ImplicitConversionSequence& ICS2) 2221{ 2222 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2223 // conversion sequences (as defined in 13.3.3.1) 2224 // -- a standard conversion sequence (13.3.3.1.1) is a better 2225 // conversion sequence than a user-defined conversion sequence or 2226 // an ellipsis conversion sequence, and 2227 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2228 // conversion sequence than an ellipsis conversion sequence 2229 // (13.3.3.1.3). 2230 // 2231 // C++0x [over.best.ics]p10: 2232 // For the purpose of ranking implicit conversion sequences as 2233 // described in 13.3.3.2, the ambiguous conversion sequence is 2234 // treated as a user-defined sequence that is indistinguishable 2235 // from any other user-defined conversion sequence. 2236 if (ICS1.getKindRank() < ICS2.getKindRank()) 2237 return ImplicitConversionSequence::Better; 2238 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2239 return ImplicitConversionSequence::Worse; 2240 2241 // The following checks require both conversion sequences to be of 2242 // the same kind. 2243 if (ICS1.getKind() != ICS2.getKind()) 2244 return ImplicitConversionSequence::Indistinguishable; 2245 2246 // Two implicit conversion sequences of the same form are 2247 // indistinguishable conversion sequences unless one of the 2248 // following rules apply: (C++ 13.3.3.2p3): 2249 if (ICS1.isStandard()) 2250 return CompareStandardConversionSequences(S, ICS1.Standard, ICS2.Standard); 2251 else if (ICS1.isUserDefined()) { 2252 // User-defined conversion sequence U1 is a better conversion 2253 // sequence than another user-defined conversion sequence U2 if 2254 // they contain the same user-defined conversion function or 2255 // constructor and if the second standard conversion sequence of 2256 // U1 is better than the second standard conversion sequence of 2257 // U2 (C++ 13.3.3.2p3). 2258 if (ICS1.UserDefined.ConversionFunction == 2259 ICS2.UserDefined.ConversionFunction) 2260 return CompareStandardConversionSequences(S, 2261 ICS1.UserDefined.After, 2262 ICS2.UserDefined.After); 2263 } 2264 2265 return ImplicitConversionSequence::Indistinguishable; 2266} 2267 2268static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2269 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2270 Qualifiers Quals; 2271 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2272 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2273 } 2274 2275 return Context.hasSameUnqualifiedType(T1, T2); 2276} 2277 2278// Per 13.3.3.2p3, compare the given standard conversion sequences to 2279// determine if one is a proper subset of the other. 2280static ImplicitConversionSequence::CompareKind 2281compareStandardConversionSubsets(ASTContext &Context, 2282 const StandardConversionSequence& SCS1, 2283 const StandardConversionSequence& SCS2) { 2284 ImplicitConversionSequence::CompareKind Result 2285 = ImplicitConversionSequence::Indistinguishable; 2286 2287 // the identity conversion sequence is considered to be a subsequence of 2288 // any non-identity conversion sequence 2289 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2290 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2291 return ImplicitConversionSequence::Better; 2292 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2293 return ImplicitConversionSequence::Worse; 2294 } 2295 2296 if (SCS1.Second != SCS2.Second) { 2297 if (SCS1.Second == ICK_Identity) 2298 Result = ImplicitConversionSequence::Better; 2299 else if (SCS2.Second == ICK_Identity) 2300 Result = ImplicitConversionSequence::Worse; 2301 else 2302 return ImplicitConversionSequence::Indistinguishable; 2303 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2304 return ImplicitConversionSequence::Indistinguishable; 2305 2306 if (SCS1.Third == SCS2.Third) { 2307 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2308 : ImplicitConversionSequence::Indistinguishable; 2309 } 2310 2311 if (SCS1.Third == ICK_Identity) 2312 return Result == ImplicitConversionSequence::Worse 2313 ? ImplicitConversionSequence::Indistinguishable 2314 : ImplicitConversionSequence::Better; 2315 2316 if (SCS2.Third == ICK_Identity) 2317 return Result == ImplicitConversionSequence::Better 2318 ? ImplicitConversionSequence::Indistinguishable 2319 : ImplicitConversionSequence::Worse; 2320 2321 return ImplicitConversionSequence::Indistinguishable; 2322} 2323 2324/// CompareStandardConversionSequences - Compare two standard 2325/// conversion sequences to determine whether one is better than the 2326/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2327static ImplicitConversionSequence::CompareKind 2328CompareStandardConversionSequences(Sema &S, 2329 const StandardConversionSequence& SCS1, 2330 const StandardConversionSequence& SCS2) 2331{ 2332 // Standard conversion sequence S1 is a better conversion sequence 2333 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2334 2335 // -- S1 is a proper subsequence of S2 (comparing the conversion 2336 // sequences in the canonical form defined by 13.3.3.1.1, 2337 // excluding any Lvalue Transformation; the identity conversion 2338 // sequence is considered to be a subsequence of any 2339 // non-identity conversion sequence) or, if not that, 2340 if (ImplicitConversionSequence::CompareKind CK 2341 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 2342 return CK; 2343 2344 // -- the rank of S1 is better than the rank of S2 (by the rules 2345 // defined below), or, if not that, 2346 ImplicitConversionRank Rank1 = SCS1.getRank(); 2347 ImplicitConversionRank Rank2 = SCS2.getRank(); 2348 if (Rank1 < Rank2) 2349 return ImplicitConversionSequence::Better; 2350 else if (Rank2 < Rank1) 2351 return ImplicitConversionSequence::Worse; 2352 2353 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2354 // are indistinguishable unless one of the following rules 2355 // applies: 2356 2357 // A conversion that is not a conversion of a pointer, or 2358 // pointer to member, to bool is better than another conversion 2359 // that is such a conversion. 2360 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2361 return SCS2.isPointerConversionToBool() 2362 ? ImplicitConversionSequence::Better 2363 : ImplicitConversionSequence::Worse; 2364 2365 // C++ [over.ics.rank]p4b2: 2366 // 2367 // If class B is derived directly or indirectly from class A, 2368 // conversion of B* to A* is better than conversion of B* to 2369 // void*, and conversion of A* to void* is better than conversion 2370 // of B* to void*. 2371 bool SCS1ConvertsToVoid 2372 = SCS1.isPointerConversionToVoidPointer(S.Context); 2373 bool SCS2ConvertsToVoid 2374 = SCS2.isPointerConversionToVoidPointer(S.Context); 2375 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2376 // Exactly one of the conversion sequences is a conversion to 2377 // a void pointer; it's the worse conversion. 2378 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2379 : ImplicitConversionSequence::Worse; 2380 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2381 // Neither conversion sequence converts to a void pointer; compare 2382 // their derived-to-base conversions. 2383 if (ImplicitConversionSequence::CompareKind DerivedCK 2384 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 2385 return DerivedCK; 2386 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2387 // Both conversion sequences are conversions to void 2388 // pointers. Compare the source types to determine if there's an 2389 // inheritance relationship in their sources. 2390 QualType FromType1 = SCS1.getFromType(); 2391 QualType FromType2 = SCS2.getFromType(); 2392 2393 // Adjust the types we're converting from via the array-to-pointer 2394 // conversion, if we need to. 2395 if (SCS1.First == ICK_Array_To_Pointer) 2396 FromType1 = S.Context.getArrayDecayedType(FromType1); 2397 if (SCS2.First == ICK_Array_To_Pointer) 2398 FromType2 = S.Context.getArrayDecayedType(FromType2); 2399 2400 QualType FromPointee1 2401 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2402 QualType FromPointee2 2403 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2404 2405 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2406 return ImplicitConversionSequence::Better; 2407 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2408 return ImplicitConversionSequence::Worse; 2409 2410 // Objective-C++: If one interface is more specific than the 2411 // other, it is the better one. 2412 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2413 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2414 if (FromIface1 && FromIface1) { 2415 if (S.Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2416 return ImplicitConversionSequence::Better; 2417 else if (S.Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2418 return ImplicitConversionSequence::Worse; 2419 } 2420 } 2421 2422 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2423 // bullet 3). 2424 if (ImplicitConversionSequence::CompareKind QualCK 2425 = CompareQualificationConversions(S, SCS1, SCS2)) 2426 return QualCK; 2427 2428 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2429 // C++0x [over.ics.rank]p3b4: 2430 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2431 // implicit object parameter of a non-static member function declared 2432 // without a ref-qualifier, and S1 binds an rvalue reference to an 2433 // rvalue and S2 binds an lvalue reference. 2434 // FIXME: We don't know if we're dealing with the implicit object parameter, 2435 // or if the member function in this case has a ref qualifier. 2436 // (Of course, we don't have ref qualifiers yet.) 2437 if (SCS1.RRefBinding != SCS2.RRefBinding) 2438 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 2439 : ImplicitConversionSequence::Worse; 2440 2441 // C++ [over.ics.rank]p3b4: 2442 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2443 // which the references refer are the same type except for 2444 // top-level cv-qualifiers, and the type to which the reference 2445 // initialized by S2 refers is more cv-qualified than the type 2446 // to which the reference initialized by S1 refers. 2447 QualType T1 = SCS1.getToType(2); 2448 QualType T2 = SCS2.getToType(2); 2449 T1 = S.Context.getCanonicalType(T1); 2450 T2 = S.Context.getCanonicalType(T2); 2451 Qualifiers T1Quals, T2Quals; 2452 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2453 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2454 if (UnqualT1 == UnqualT2) { 2455 // If the type is an array type, promote the element qualifiers to the 2456 // type for comparison. 2457 if (isa<ArrayType>(T1) && T1Quals) 2458 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2459 if (isa<ArrayType>(T2) && T2Quals) 2460 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2461 if (T2.isMoreQualifiedThan(T1)) 2462 return ImplicitConversionSequence::Better; 2463 else if (T1.isMoreQualifiedThan(T2)) 2464 return ImplicitConversionSequence::Worse; 2465 } 2466 } 2467 2468 return ImplicitConversionSequence::Indistinguishable; 2469} 2470 2471/// CompareQualificationConversions - Compares two standard conversion 2472/// sequences to determine whether they can be ranked based on their 2473/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2474ImplicitConversionSequence::CompareKind 2475CompareQualificationConversions(Sema &S, 2476 const StandardConversionSequence& SCS1, 2477 const StandardConversionSequence& SCS2) { 2478 // C++ 13.3.3.2p3: 2479 // -- S1 and S2 differ only in their qualification conversion and 2480 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2481 // cv-qualification signature of type T1 is a proper subset of 2482 // the cv-qualification signature of type T2, and S1 is not the 2483 // deprecated string literal array-to-pointer conversion (4.2). 2484 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2485 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2486 return ImplicitConversionSequence::Indistinguishable; 2487 2488 // FIXME: the example in the standard doesn't use a qualification 2489 // conversion (!) 2490 QualType T1 = SCS1.getToType(2); 2491 QualType T2 = SCS2.getToType(2); 2492 T1 = S.Context.getCanonicalType(T1); 2493 T2 = S.Context.getCanonicalType(T2); 2494 Qualifiers T1Quals, T2Quals; 2495 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2496 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2497 2498 // If the types are the same, we won't learn anything by unwrapped 2499 // them. 2500 if (UnqualT1 == UnqualT2) 2501 return ImplicitConversionSequence::Indistinguishable; 2502 2503 // If the type is an array type, promote the element qualifiers to the type 2504 // for comparison. 2505 if (isa<ArrayType>(T1) && T1Quals) 2506 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2507 if (isa<ArrayType>(T2) && T2Quals) 2508 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2509 2510 ImplicitConversionSequence::CompareKind Result 2511 = ImplicitConversionSequence::Indistinguishable; 2512 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 2513 // Within each iteration of the loop, we check the qualifiers to 2514 // determine if this still looks like a qualification 2515 // conversion. Then, if all is well, we unwrap one more level of 2516 // pointers or pointers-to-members and do it all again 2517 // until there are no more pointers or pointers-to-members left 2518 // to unwrap. This essentially mimics what 2519 // IsQualificationConversion does, but here we're checking for a 2520 // strict subset of qualifiers. 2521 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2522 // The qualifiers are the same, so this doesn't tell us anything 2523 // about how the sequences rank. 2524 ; 2525 else if (T2.isMoreQualifiedThan(T1)) { 2526 // T1 has fewer qualifiers, so it could be the better sequence. 2527 if (Result == ImplicitConversionSequence::Worse) 2528 // Neither has qualifiers that are a subset of the other's 2529 // qualifiers. 2530 return ImplicitConversionSequence::Indistinguishable; 2531 2532 Result = ImplicitConversionSequence::Better; 2533 } else if (T1.isMoreQualifiedThan(T2)) { 2534 // T2 has fewer qualifiers, so it could be the better sequence. 2535 if (Result == ImplicitConversionSequence::Better) 2536 // Neither has qualifiers that are a subset of the other's 2537 // qualifiers. 2538 return ImplicitConversionSequence::Indistinguishable; 2539 2540 Result = ImplicitConversionSequence::Worse; 2541 } else { 2542 // Qualifiers are disjoint. 2543 return ImplicitConversionSequence::Indistinguishable; 2544 } 2545 2546 // If the types after this point are equivalent, we're done. 2547 if (S.Context.hasSameUnqualifiedType(T1, T2)) 2548 break; 2549 } 2550 2551 // Check that the winning standard conversion sequence isn't using 2552 // the deprecated string literal array to pointer conversion. 2553 switch (Result) { 2554 case ImplicitConversionSequence::Better: 2555 if (SCS1.DeprecatedStringLiteralToCharPtr) 2556 Result = ImplicitConversionSequence::Indistinguishable; 2557 break; 2558 2559 case ImplicitConversionSequence::Indistinguishable: 2560 break; 2561 2562 case ImplicitConversionSequence::Worse: 2563 if (SCS2.DeprecatedStringLiteralToCharPtr) 2564 Result = ImplicitConversionSequence::Indistinguishable; 2565 break; 2566 } 2567 2568 return Result; 2569} 2570 2571/// CompareDerivedToBaseConversions - Compares two standard conversion 2572/// sequences to determine whether they can be ranked based on their 2573/// various kinds of derived-to-base conversions (C++ 2574/// [over.ics.rank]p4b3). As part of these checks, we also look at 2575/// conversions between Objective-C interface types. 2576ImplicitConversionSequence::CompareKind 2577CompareDerivedToBaseConversions(Sema &S, 2578 const StandardConversionSequence& SCS1, 2579 const StandardConversionSequence& SCS2) { 2580 QualType FromType1 = SCS1.getFromType(); 2581 QualType ToType1 = SCS1.getToType(1); 2582 QualType FromType2 = SCS2.getFromType(); 2583 QualType ToType2 = SCS2.getToType(1); 2584 2585 // Adjust the types we're converting from via the array-to-pointer 2586 // conversion, if we need to. 2587 if (SCS1.First == ICK_Array_To_Pointer) 2588 FromType1 = S.Context.getArrayDecayedType(FromType1); 2589 if (SCS2.First == ICK_Array_To_Pointer) 2590 FromType2 = S.Context.getArrayDecayedType(FromType2); 2591 2592 // Canonicalize all of the types. 2593 FromType1 = S.Context.getCanonicalType(FromType1); 2594 ToType1 = S.Context.getCanonicalType(ToType1); 2595 FromType2 = S.Context.getCanonicalType(FromType2); 2596 ToType2 = S.Context.getCanonicalType(ToType2); 2597 2598 // C++ [over.ics.rank]p4b3: 2599 // 2600 // If class B is derived directly or indirectly from class A and 2601 // class C is derived directly or indirectly from B, 2602 // 2603 // For Objective-C, we let A, B, and C also be Objective-C 2604 // interfaces. 2605 2606 // Compare based on pointer conversions. 2607 if (SCS1.Second == ICK_Pointer_Conversion && 2608 SCS2.Second == ICK_Pointer_Conversion && 2609 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2610 FromType1->isPointerType() && FromType2->isPointerType() && 2611 ToType1->isPointerType() && ToType2->isPointerType()) { 2612 QualType FromPointee1 2613 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2614 QualType ToPointee1 2615 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2616 QualType FromPointee2 2617 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2618 QualType ToPointee2 2619 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2620 2621 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2622 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2623 const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>(); 2624 const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>(); 2625 2626 // -- conversion of C* to B* is better than conversion of C* to A*, 2627 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2628 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2629 return ImplicitConversionSequence::Better; 2630 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2631 return ImplicitConversionSequence::Worse; 2632 2633 if (ToIface1 && ToIface2) { 2634 if (S.Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2635 return ImplicitConversionSequence::Better; 2636 else if (S.Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2637 return ImplicitConversionSequence::Worse; 2638 } 2639 } 2640 2641 // -- conversion of B* to A* is better than conversion of C* to A*, 2642 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2643 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2644 return ImplicitConversionSequence::Better; 2645 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2646 return ImplicitConversionSequence::Worse; 2647 2648 if (FromIface1 && FromIface2) { 2649 if (S.Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2650 return ImplicitConversionSequence::Better; 2651 else if (S.Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2652 return ImplicitConversionSequence::Worse; 2653 } 2654 } 2655 } 2656 2657 // Ranking of member-pointer types. 2658 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2659 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2660 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2661 const MemberPointerType * FromMemPointer1 = 2662 FromType1->getAs<MemberPointerType>(); 2663 const MemberPointerType * ToMemPointer1 = 2664 ToType1->getAs<MemberPointerType>(); 2665 const MemberPointerType * FromMemPointer2 = 2666 FromType2->getAs<MemberPointerType>(); 2667 const MemberPointerType * ToMemPointer2 = 2668 ToType2->getAs<MemberPointerType>(); 2669 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2670 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2671 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2672 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2673 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2674 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2675 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2676 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2677 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2678 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2679 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2680 return ImplicitConversionSequence::Worse; 2681 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2682 return ImplicitConversionSequence::Better; 2683 } 2684 // conversion of B::* to C::* is better than conversion of A::* to C::* 2685 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2686 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2687 return ImplicitConversionSequence::Better; 2688 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2689 return ImplicitConversionSequence::Worse; 2690 } 2691 } 2692 2693 if (SCS1.Second == ICK_Derived_To_Base) { 2694 // -- conversion of C to B is better than conversion of C to A, 2695 // -- binding of an expression of type C to a reference of type 2696 // B& is better than binding an expression of type C to a 2697 // reference of type A&, 2698 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2699 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2700 if (S.IsDerivedFrom(ToType1, ToType2)) 2701 return ImplicitConversionSequence::Better; 2702 else if (S.IsDerivedFrom(ToType2, ToType1)) 2703 return ImplicitConversionSequence::Worse; 2704 } 2705 2706 // -- conversion of B to A is better than conversion of C to A. 2707 // -- binding of an expression of type B to a reference of type 2708 // A& is better than binding an expression of type C to a 2709 // reference of type A&, 2710 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2711 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2712 if (S.IsDerivedFrom(FromType2, FromType1)) 2713 return ImplicitConversionSequence::Better; 2714 else if (S.IsDerivedFrom(FromType1, FromType2)) 2715 return ImplicitConversionSequence::Worse; 2716 } 2717 } 2718 2719 return ImplicitConversionSequence::Indistinguishable; 2720} 2721 2722/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2723/// determine whether they are reference-related, 2724/// reference-compatible, reference-compatible with added 2725/// qualification, or incompatible, for use in C++ initialization by 2726/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2727/// type, and the first type (T1) is the pointee type of the reference 2728/// type being initialized. 2729Sema::ReferenceCompareResult 2730Sema::CompareReferenceRelationship(SourceLocation Loc, 2731 QualType OrigT1, QualType OrigT2, 2732 bool &DerivedToBase, 2733 bool &ObjCConversion) { 2734 assert(!OrigT1->isReferenceType() && 2735 "T1 must be the pointee type of the reference type"); 2736 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2737 2738 QualType T1 = Context.getCanonicalType(OrigT1); 2739 QualType T2 = Context.getCanonicalType(OrigT2); 2740 Qualifiers T1Quals, T2Quals; 2741 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2742 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2743 2744 // C++ [dcl.init.ref]p4: 2745 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2746 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2747 // T1 is a base class of T2. 2748 DerivedToBase = false; 2749 ObjCConversion = false; 2750 if (UnqualT1 == UnqualT2) { 2751 // Nothing to do. 2752 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2753 IsDerivedFrom(UnqualT2, UnqualT1)) 2754 DerivedToBase = true; 2755 else if (UnqualT1->isObjCObjectOrInterfaceType() && 2756 UnqualT2->isObjCObjectOrInterfaceType() && 2757 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 2758 ObjCConversion = true; 2759 else 2760 return Ref_Incompatible; 2761 2762 // At this point, we know that T1 and T2 are reference-related (at 2763 // least). 2764 2765 // If the type is an array type, promote the element qualifiers to the type 2766 // for comparison. 2767 if (isa<ArrayType>(T1) && T1Quals) 2768 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2769 if (isa<ArrayType>(T2) && T2Quals) 2770 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2771 2772 // C++ [dcl.init.ref]p4: 2773 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2774 // reference-related to T2 and cv1 is the same cv-qualification 2775 // as, or greater cv-qualification than, cv2. For purposes of 2776 // overload resolution, cases for which cv1 is greater 2777 // cv-qualification than cv2 are identified as 2778 // reference-compatible with added qualification (see 13.3.3.2). 2779 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2780 return Ref_Compatible; 2781 else if (T1.isMoreQualifiedThan(T2)) 2782 return Ref_Compatible_With_Added_Qualification; 2783 else 2784 return Ref_Related; 2785} 2786 2787/// \brief Look for a user-defined conversion to an value reference-compatible 2788/// with DeclType. Return true if something definite is found. 2789static bool 2790FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 2791 QualType DeclType, SourceLocation DeclLoc, 2792 Expr *Init, QualType T2, bool AllowRvalues, 2793 bool AllowExplicit) { 2794 assert(T2->isRecordType() && "Can only find conversions of record types."); 2795 CXXRecordDecl *T2RecordDecl 2796 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2797 2798 QualType ToType 2799 = AllowRvalues? DeclType->getAs<ReferenceType>()->getPointeeType() 2800 : DeclType; 2801 2802 OverloadCandidateSet CandidateSet(DeclLoc); 2803 const UnresolvedSetImpl *Conversions 2804 = T2RecordDecl->getVisibleConversionFunctions(); 2805 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2806 E = Conversions->end(); I != E; ++I) { 2807 NamedDecl *D = *I; 2808 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2809 if (isa<UsingShadowDecl>(D)) 2810 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2811 2812 FunctionTemplateDecl *ConvTemplate 2813 = dyn_cast<FunctionTemplateDecl>(D); 2814 CXXConversionDecl *Conv; 2815 if (ConvTemplate) 2816 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2817 else 2818 Conv = cast<CXXConversionDecl>(D); 2819 2820 // If this is an explicit conversion, and we're not allowed to consider 2821 // explicit conversions, skip it. 2822 if (!AllowExplicit && Conv->isExplicit()) 2823 continue; 2824 2825 if (AllowRvalues) { 2826 bool DerivedToBase = false; 2827 bool ObjCConversion = false; 2828 if (!ConvTemplate && 2829 S.CompareReferenceRelationship( 2830 DeclLoc, 2831 Conv->getConversionType().getNonReferenceType() 2832 .getUnqualifiedType(), 2833 DeclType.getNonReferenceType().getUnqualifiedType(), 2834 DerivedToBase, ObjCConversion) == 2835 Sema::Ref_Incompatible) 2836 continue; 2837 } else { 2838 // If the conversion function doesn't return a reference type, 2839 // it can't be considered for this conversion. An rvalue reference 2840 // is only acceptable if its referencee is a function type. 2841 2842 const ReferenceType *RefType = 2843 Conv->getConversionType()->getAs<ReferenceType>(); 2844 if (!RefType || 2845 (!RefType->isLValueReferenceType() && 2846 !RefType->getPointeeType()->isFunctionType())) 2847 continue; 2848 } 2849 2850 if (ConvTemplate) 2851 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2852 Init, ToType, CandidateSet); 2853 else 2854 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2855 ToType, CandidateSet); 2856 } 2857 2858 OverloadCandidateSet::iterator Best; 2859 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 2860 case OR_Success: 2861 // C++ [over.ics.ref]p1: 2862 // 2863 // [...] If the parameter binds directly to the result of 2864 // applying a conversion function to the argument 2865 // expression, the implicit conversion sequence is a 2866 // user-defined conversion sequence (13.3.3.1.2), with the 2867 // second standard conversion sequence either an identity 2868 // conversion or, if the conversion function returns an 2869 // entity of a type that is a derived class of the parameter 2870 // type, a derived-to-base Conversion. 2871 if (!Best->FinalConversion.DirectBinding) 2872 return false; 2873 2874 ICS.setUserDefined(); 2875 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2876 ICS.UserDefined.After = Best->FinalConversion; 2877 ICS.UserDefined.ConversionFunction = Best->Function; 2878 ICS.UserDefined.EllipsisConversion = false; 2879 assert(ICS.UserDefined.After.ReferenceBinding && 2880 ICS.UserDefined.After.DirectBinding && 2881 "Expected a direct reference binding!"); 2882 return true; 2883 2884 case OR_Ambiguous: 2885 ICS.setAmbiguous(); 2886 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2887 Cand != CandidateSet.end(); ++Cand) 2888 if (Cand->Viable) 2889 ICS.Ambiguous.addConversion(Cand->Function); 2890 return true; 2891 2892 case OR_No_Viable_Function: 2893 case OR_Deleted: 2894 // There was no suitable conversion, or we found a deleted 2895 // conversion; continue with other checks. 2896 return false; 2897 } 2898 2899 return false; 2900} 2901 2902/// \brief Compute an implicit conversion sequence for reference 2903/// initialization. 2904static ImplicitConversionSequence 2905TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2906 SourceLocation DeclLoc, 2907 bool SuppressUserConversions, 2908 bool AllowExplicit) { 2909 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2910 2911 // Most paths end in a failed conversion. 2912 ImplicitConversionSequence ICS; 2913 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2914 2915 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2916 QualType T2 = Init->getType(); 2917 2918 // If the initializer is the address of an overloaded function, try 2919 // to resolve the overloaded function. If all goes well, T2 is the 2920 // type of the resulting function. 2921 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2922 DeclAccessPair Found; 2923 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2924 false, Found)) 2925 T2 = Fn->getType(); 2926 } 2927 2928 // Compute some basic properties of the types and the initializer. 2929 bool isRValRef = DeclType->isRValueReferenceType(); 2930 bool DerivedToBase = false; 2931 bool ObjCConversion = false; 2932 Expr::Classification InitCategory = Init->Classify(S.Context); 2933 Sema::ReferenceCompareResult RefRelationship 2934 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 2935 ObjCConversion); 2936 2937 2938 // C++0x [dcl.init.ref]p5: 2939 // A reference to type "cv1 T1" is initialized by an expression 2940 // of type "cv2 T2" as follows: 2941 2942 // -- If reference is an lvalue reference and the initializer expression 2943 // The next bullet point (T1 is a function) is pretty much equivalent to this 2944 // one, so it's handled here. 2945 if (!isRValRef || T1->isFunctionType()) { 2946 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2947 // reference-compatible with "cv2 T2," or 2948 // 2949 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2950 if (InitCategory.isLValue() && 2951 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2952 // C++ [over.ics.ref]p1: 2953 // When a parameter of reference type binds directly (8.5.3) 2954 // to an argument expression, the implicit conversion sequence 2955 // is the identity conversion, unless the argument expression 2956 // has a type that is a derived class of the parameter type, 2957 // in which case the implicit conversion sequence is a 2958 // derived-to-base Conversion (13.3.3.1). 2959 ICS.setStandard(); 2960 ICS.Standard.First = ICK_Identity; 2961 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 2962 : ObjCConversion? ICK_Compatible_Conversion 2963 : ICK_Identity; 2964 ICS.Standard.Third = ICK_Identity; 2965 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2966 ICS.Standard.setToType(0, T2); 2967 ICS.Standard.setToType(1, T1); 2968 ICS.Standard.setToType(2, T1); 2969 ICS.Standard.ReferenceBinding = true; 2970 ICS.Standard.DirectBinding = true; 2971 ICS.Standard.RRefBinding = isRValRef; 2972 ICS.Standard.CopyConstructor = 0; 2973 2974 // Nothing more to do: the inaccessibility/ambiguity check for 2975 // derived-to-base conversions is suppressed when we're 2976 // computing the implicit conversion sequence (C++ 2977 // [over.best.ics]p2). 2978 return ICS; 2979 } 2980 2981 // -- has a class type (i.e., T2 is a class type), where T1 is 2982 // not reference-related to T2, and can be implicitly 2983 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2984 // is reference-compatible with "cv3 T3" 92) (this 2985 // conversion is selected by enumerating the applicable 2986 // conversion functions (13.3.1.6) and choosing the best 2987 // one through overload resolution (13.3)), 2988 if (!SuppressUserConversions && T2->isRecordType() && 2989 !S.RequireCompleteType(DeclLoc, T2, 0) && 2990 RefRelationship == Sema::Ref_Incompatible) { 2991 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 2992 Init, T2, /*AllowRvalues=*/false, 2993 AllowExplicit)) 2994 return ICS; 2995 } 2996 } 2997 2998 // -- Otherwise, the reference shall be an lvalue reference to a 2999 // non-volatile const type (i.e., cv1 shall be const), or the reference 3000 // shall be an rvalue reference and the initializer expression shall be 3001 // an rvalue or have a function type. 3002 // 3003 // We actually handle one oddity of C++ [over.ics.ref] at this 3004 // point, which is that, due to p2 (which short-circuits reference 3005 // binding by only attempting a simple conversion for non-direct 3006 // bindings) and p3's strange wording, we allow a const volatile 3007 // reference to bind to an rvalue. Hence the check for the presence 3008 // of "const" rather than checking for "const" being the only 3009 // qualifier. 3010 // This is also the point where rvalue references and lvalue inits no longer 3011 // go together. 3012 if ((!isRValRef && !T1.isConstQualified()) || 3013 (isRValRef && InitCategory.isLValue())) 3014 return ICS; 3015 3016 // -- If T1 is a function type, then 3017 // -- if T2 is the same type as T1, the reference is bound to the 3018 // initializer expression lvalue; 3019 // -- if T2 is a class type and the initializer expression can be 3020 // implicitly converted to an lvalue of type T1 [...], the 3021 // reference is bound to the function lvalue that is the result 3022 // of the conversion; 3023 // This is the same as for the lvalue case above, so it was handled there. 3024 // -- otherwise, the program is ill-formed. 3025 // This is the one difference to the lvalue case. 3026 if (T1->isFunctionType()) 3027 return ICS; 3028 3029 // -- Otherwise, if T2 is a class type and 3030 // -- the initializer expression is an rvalue and "cv1 T1" 3031 // is reference-compatible with "cv2 T2," or 3032 // 3033 // -- T1 is not reference-related to T2 and the initializer 3034 // expression can be implicitly converted to an rvalue 3035 // of type "cv3 T3" (this conversion is selected by 3036 // enumerating the applicable conversion functions 3037 // (13.3.1.6) and choosing the best one through overload 3038 // resolution (13.3)), 3039 // 3040 // then the reference is bound to the initializer 3041 // expression rvalue in the first case and to the object 3042 // that is the result of the conversion in the second case 3043 // (or, in either case, to the appropriate base class 3044 // subobject of the object). 3045 if (T2->isRecordType()) { 3046 // First case: "cv1 T1" is reference-compatible with "cv2 T2". This is a 3047 // direct binding in C++0x but not in C++03. 3048 if (InitCategory.isRValue() && 3049 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 3050 ICS.setStandard(); 3051 ICS.Standard.First = ICK_Identity; 3052 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3053 : ObjCConversion? ICK_Compatible_Conversion 3054 : ICK_Identity; 3055 ICS.Standard.Third = ICK_Identity; 3056 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3057 ICS.Standard.setToType(0, T2); 3058 ICS.Standard.setToType(1, T1); 3059 ICS.Standard.setToType(2, T1); 3060 ICS.Standard.ReferenceBinding = true; 3061 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 3062 ICS.Standard.RRefBinding = isRValRef; 3063 ICS.Standard.CopyConstructor = 0; 3064 return ICS; 3065 } 3066 3067 // Second case: not reference-related. 3068 if (RefRelationship == Sema::Ref_Incompatible && 3069 !S.RequireCompleteType(DeclLoc, T2, 0) && 3070 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3071 Init, T2, /*AllowRvalues=*/true, 3072 AllowExplicit)) 3073 return ICS; 3074 } 3075 3076 // -- Otherwise, a temporary of type "cv1 T1" is created and 3077 // initialized from the initializer expression using the 3078 // rules for a non-reference copy initialization (8.5). The 3079 // reference is then bound to the temporary. If T1 is 3080 // reference-related to T2, cv1 must be the same 3081 // cv-qualification as, or greater cv-qualification than, 3082 // cv2; otherwise, the program is ill-formed. 3083 if (RefRelationship == Sema::Ref_Related) { 3084 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 3085 // we would be reference-compatible or reference-compatible with 3086 // added qualification. But that wasn't the case, so the reference 3087 // initialization fails. 3088 return ICS; 3089 } 3090 3091 // If at least one of the types is a class type, the types are not 3092 // related, and we aren't allowed any user conversions, the 3093 // reference binding fails. This case is important for breaking 3094 // recursion, since TryImplicitConversion below will attempt to 3095 // create a temporary through the use of a copy constructor. 3096 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3097 (T1->isRecordType() || T2->isRecordType())) 3098 return ICS; 3099 3100 // C++ [over.ics.ref]p2: 3101 // When a parameter of reference type is not bound directly to 3102 // an argument expression, the conversion sequence is the one 3103 // required to convert the argument expression to the 3104 // underlying type of the reference according to 3105 // 13.3.3.1. Conceptually, this conversion sequence corresponds 3106 // to copy-initializing a temporary of the underlying type with 3107 // the argument expression. Any difference in top-level 3108 // cv-qualification is subsumed by the initialization itself 3109 // and does not constitute a conversion. 3110 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 3111 /*AllowExplicit=*/false, 3112 /*InOverloadResolution=*/false); 3113 3114 // Of course, that's still a reference binding. 3115 if (ICS.isStandard()) { 3116 ICS.Standard.ReferenceBinding = true; 3117 ICS.Standard.RRefBinding = isRValRef; 3118 } else if (ICS.isUserDefined()) { 3119 ICS.UserDefined.After.ReferenceBinding = true; 3120 ICS.UserDefined.After.RRefBinding = isRValRef; 3121 } 3122 return ICS; 3123} 3124 3125/// TryCopyInitialization - Try to copy-initialize a value of type 3126/// ToType from the expression From. Return the implicit conversion 3127/// sequence required to pass this argument, which may be a bad 3128/// conversion sequence (meaning that the argument cannot be passed to 3129/// a parameter of this type). If @p SuppressUserConversions, then we 3130/// do not permit any user-defined conversion sequences. 3131static ImplicitConversionSequence 3132TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 3133 bool SuppressUserConversions, 3134 bool InOverloadResolution) { 3135 if (ToType->isReferenceType()) 3136 return TryReferenceInit(S, From, ToType, 3137 /*FIXME:*/From->getLocStart(), 3138 SuppressUserConversions, 3139 /*AllowExplicit=*/false); 3140 3141 return TryImplicitConversion(S, From, ToType, 3142 SuppressUserConversions, 3143 /*AllowExplicit=*/false, 3144 InOverloadResolution); 3145} 3146 3147/// TryObjectArgumentInitialization - Try to initialize the object 3148/// parameter of the given member function (@c Method) from the 3149/// expression @p From. 3150static ImplicitConversionSequence 3151TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 3152 CXXMethodDecl *Method, 3153 CXXRecordDecl *ActingContext) { 3154 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 3155 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 3156 // const volatile object. 3157 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 3158 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 3159 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 3160 3161 // Set up the conversion sequence as a "bad" conversion, to allow us 3162 // to exit early. 3163 ImplicitConversionSequence ICS; 3164 3165 // We need to have an object of class type. 3166 QualType FromType = OrigFromType; 3167 if (const PointerType *PT = FromType->getAs<PointerType>()) 3168 FromType = PT->getPointeeType(); 3169 3170 assert(FromType->isRecordType()); 3171 3172 // The implicit object parameter is has the type "reference to cv X", 3173 // where X is the class of which the function is a member 3174 // (C++ [over.match.funcs]p4). However, when finding an implicit 3175 // conversion sequence for the argument, we are not allowed to 3176 // create temporaries or perform user-defined conversions 3177 // (C++ [over.match.funcs]p5). We perform a simplified version of 3178 // reference binding here, that allows class rvalues to bind to 3179 // non-constant references. 3180 3181 // First check the qualifiers. We don't care about lvalue-vs-rvalue 3182 // with the implicit object parameter (C++ [over.match.funcs]p5). 3183 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 3184 if (ImplicitParamType.getCVRQualifiers() 3185 != FromTypeCanon.getLocalCVRQualifiers() && 3186 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 3187 ICS.setBad(BadConversionSequence::bad_qualifiers, 3188 OrigFromType, ImplicitParamType); 3189 return ICS; 3190 } 3191 3192 // Check that we have either the same type or a derived type. It 3193 // affects the conversion rank. 3194 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 3195 ImplicitConversionKind SecondKind; 3196 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 3197 SecondKind = ICK_Identity; 3198 } else if (S.IsDerivedFrom(FromType, ClassType)) 3199 SecondKind = ICK_Derived_To_Base; 3200 else { 3201 ICS.setBad(BadConversionSequence::unrelated_class, 3202 FromType, ImplicitParamType); 3203 return ICS; 3204 } 3205 3206 // Success. Mark this as a reference binding. 3207 ICS.setStandard(); 3208 ICS.Standard.setAsIdentityConversion(); 3209 ICS.Standard.Second = SecondKind; 3210 ICS.Standard.setFromType(FromType); 3211 ICS.Standard.setAllToTypes(ImplicitParamType); 3212 ICS.Standard.ReferenceBinding = true; 3213 ICS.Standard.DirectBinding = true; 3214 ICS.Standard.RRefBinding = false; 3215 return ICS; 3216} 3217 3218/// PerformObjectArgumentInitialization - Perform initialization of 3219/// the implicit object parameter for the given Method with the given 3220/// expression. 3221bool 3222Sema::PerformObjectArgumentInitialization(Expr *&From, 3223 NestedNameSpecifier *Qualifier, 3224 NamedDecl *FoundDecl, 3225 CXXMethodDecl *Method) { 3226 QualType FromRecordType, DestType; 3227 QualType ImplicitParamRecordType = 3228 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3229 3230 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3231 FromRecordType = PT->getPointeeType(); 3232 DestType = Method->getThisType(Context); 3233 } else { 3234 FromRecordType = From->getType(); 3235 DestType = ImplicitParamRecordType; 3236 } 3237 3238 // Note that we always use the true parent context when performing 3239 // the actual argument initialization. 3240 ImplicitConversionSequence ICS 3241 = TryObjectArgumentInitialization(*this, From->getType(), Method, 3242 Method->getParent()); 3243 if (ICS.isBad()) { 3244 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 3245 Qualifiers FromQs = FromRecordType.getQualifiers(); 3246 Qualifiers ToQs = DestType.getQualifiers(); 3247 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 3248 if (CVR) { 3249 Diag(From->getSourceRange().getBegin(), 3250 diag::err_member_function_call_bad_cvr) 3251 << Method->getDeclName() << FromRecordType << (CVR - 1) 3252 << From->getSourceRange(); 3253 Diag(Method->getLocation(), diag::note_previous_decl) 3254 << Method->getDeclName(); 3255 return true; 3256 } 3257 } 3258 3259 return Diag(From->getSourceRange().getBegin(), 3260 diag::err_implicit_object_parameter_init) 3261 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3262 } 3263 3264 if (ICS.Standard.Second == ICK_Derived_To_Base) 3265 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3266 3267 if (!Context.hasSameType(From->getType(), DestType)) 3268 ImpCastExprToType(From, DestType, CK_NoOp, 3269 From->getType()->isPointerType() ? VK_RValue : VK_LValue); 3270 return false; 3271} 3272 3273/// TryContextuallyConvertToBool - Attempt to contextually convert the 3274/// expression From to bool (C++0x [conv]p3). 3275static ImplicitConversionSequence 3276TryContextuallyConvertToBool(Sema &S, Expr *From) { 3277 // FIXME: This is pretty broken. 3278 return TryImplicitConversion(S, From, S.Context.BoolTy, 3279 // FIXME: Are these flags correct? 3280 /*SuppressUserConversions=*/false, 3281 /*AllowExplicit=*/true, 3282 /*InOverloadResolution=*/false); 3283} 3284 3285/// PerformContextuallyConvertToBool - Perform a contextual conversion 3286/// of the expression From to bool (C++0x [conv]p3). 3287bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3288 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 3289 if (!ICS.isBad()) 3290 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3291 3292 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3293 return Diag(From->getSourceRange().getBegin(), 3294 diag::err_typecheck_bool_condition) 3295 << From->getType() << From->getSourceRange(); 3296 return true; 3297} 3298 3299/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3300/// expression From to 'id'. 3301static ImplicitConversionSequence 3302TryContextuallyConvertToObjCId(Sema &S, Expr *From) { 3303 QualType Ty = S.Context.getObjCIdType(); 3304 return TryImplicitConversion(S, From, Ty, 3305 // FIXME: Are these flags correct? 3306 /*SuppressUserConversions=*/false, 3307 /*AllowExplicit=*/true, 3308 /*InOverloadResolution=*/false); 3309} 3310 3311/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3312/// of the expression From to 'id'. 3313bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3314 QualType Ty = Context.getObjCIdType(); 3315 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(*this, From); 3316 if (!ICS.isBad()) 3317 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3318 return true; 3319} 3320 3321/// \brief Attempt to convert the given expression to an integral or 3322/// enumeration type. 3323/// 3324/// This routine will attempt to convert an expression of class type to an 3325/// integral or enumeration type, if that class type only has a single 3326/// conversion to an integral or enumeration type. 3327/// 3328/// \param Loc The source location of the construct that requires the 3329/// conversion. 3330/// 3331/// \param FromE The expression we're converting from. 3332/// 3333/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3334/// have integral or enumeration type. 3335/// 3336/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3337/// incomplete class type. 3338/// 3339/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3340/// explicit conversion function (because no implicit conversion functions 3341/// were available). This is a recovery mode. 3342/// 3343/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3344/// showing which conversion was picked. 3345/// 3346/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3347/// conversion function that could convert to integral or enumeration type. 3348/// 3349/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3350/// usable conversion function. 3351/// 3352/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3353/// function, which may be an extension in this case. 3354/// 3355/// \returns The expression, converted to an integral or enumeration type if 3356/// successful. 3357ExprResult 3358Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 3359 const PartialDiagnostic &NotIntDiag, 3360 const PartialDiagnostic &IncompleteDiag, 3361 const PartialDiagnostic &ExplicitConvDiag, 3362 const PartialDiagnostic &ExplicitConvNote, 3363 const PartialDiagnostic &AmbigDiag, 3364 const PartialDiagnostic &AmbigNote, 3365 const PartialDiagnostic &ConvDiag) { 3366 // We can't perform any more checking for type-dependent expressions. 3367 if (From->isTypeDependent()) 3368 return Owned(From); 3369 3370 // If the expression already has integral or enumeration type, we're golden. 3371 QualType T = From->getType(); 3372 if (T->isIntegralOrEnumerationType()) 3373 return Owned(From); 3374 3375 // FIXME: Check for missing '()' if T is a function type? 3376 3377 // If we don't have a class type in C++, there's no way we can get an 3378 // expression of integral or enumeration type. 3379 const RecordType *RecordTy = T->getAs<RecordType>(); 3380 if (!RecordTy || !getLangOptions().CPlusPlus) { 3381 Diag(Loc, NotIntDiag) 3382 << T << From->getSourceRange(); 3383 return Owned(From); 3384 } 3385 3386 // We must have a complete class type. 3387 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3388 return Owned(From); 3389 3390 // Look for a conversion to an integral or enumeration type. 3391 UnresolvedSet<4> ViableConversions; 3392 UnresolvedSet<4> ExplicitConversions; 3393 const UnresolvedSetImpl *Conversions 3394 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3395 3396 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3397 E = Conversions->end(); 3398 I != E; 3399 ++I) { 3400 if (CXXConversionDecl *Conversion 3401 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3402 if (Conversion->getConversionType().getNonReferenceType() 3403 ->isIntegralOrEnumerationType()) { 3404 if (Conversion->isExplicit()) 3405 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3406 else 3407 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3408 } 3409 } 3410 3411 switch (ViableConversions.size()) { 3412 case 0: 3413 if (ExplicitConversions.size() == 1) { 3414 DeclAccessPair Found = ExplicitConversions[0]; 3415 CXXConversionDecl *Conversion 3416 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3417 3418 // The user probably meant to invoke the given explicit 3419 // conversion; use it. 3420 QualType ConvTy 3421 = Conversion->getConversionType().getNonReferenceType(); 3422 std::string TypeStr; 3423 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3424 3425 Diag(Loc, ExplicitConvDiag) 3426 << T << ConvTy 3427 << FixItHint::CreateInsertion(From->getLocStart(), 3428 "static_cast<" + TypeStr + ">(") 3429 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3430 ")"); 3431 Diag(Conversion->getLocation(), ExplicitConvNote) 3432 << ConvTy->isEnumeralType() << ConvTy; 3433 3434 // If we aren't in a SFINAE context, build a call to the 3435 // explicit conversion function. 3436 if (isSFINAEContext()) 3437 return ExprError(); 3438 3439 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3440 From = BuildCXXMemberCallExpr(From, Found, Conversion); 3441 } 3442 3443 // We'll complain below about a non-integral condition type. 3444 break; 3445 3446 case 1: { 3447 // Apply this conversion. 3448 DeclAccessPair Found = ViableConversions[0]; 3449 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3450 3451 CXXConversionDecl *Conversion 3452 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3453 QualType ConvTy 3454 = Conversion->getConversionType().getNonReferenceType(); 3455 if (ConvDiag.getDiagID()) { 3456 if (isSFINAEContext()) 3457 return ExprError(); 3458 3459 Diag(Loc, ConvDiag) 3460 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 3461 } 3462 3463 From = BuildCXXMemberCallExpr(From, Found, 3464 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3465 break; 3466 } 3467 3468 default: 3469 Diag(Loc, AmbigDiag) 3470 << T << From->getSourceRange(); 3471 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3472 CXXConversionDecl *Conv 3473 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3474 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3475 Diag(Conv->getLocation(), AmbigNote) 3476 << ConvTy->isEnumeralType() << ConvTy; 3477 } 3478 return Owned(From); 3479 } 3480 3481 if (!From->getType()->isIntegralOrEnumerationType()) 3482 Diag(Loc, NotIntDiag) 3483 << From->getType() << From->getSourceRange(); 3484 3485 return Owned(From); 3486} 3487 3488/// AddOverloadCandidate - Adds the given function to the set of 3489/// candidate functions, using the given function call arguments. If 3490/// @p SuppressUserConversions, then don't allow user-defined 3491/// conversions via constructors or conversion operators. 3492/// 3493/// \para PartialOverloading true if we are performing "partial" overloading 3494/// based on an incomplete set of function arguments. This feature is used by 3495/// code completion. 3496void 3497Sema::AddOverloadCandidate(FunctionDecl *Function, 3498 DeclAccessPair FoundDecl, 3499 Expr **Args, unsigned NumArgs, 3500 OverloadCandidateSet& CandidateSet, 3501 bool SuppressUserConversions, 3502 bool PartialOverloading) { 3503 const FunctionProtoType* Proto 3504 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3505 assert(Proto && "Functions without a prototype cannot be overloaded"); 3506 assert(!Function->getDescribedFunctionTemplate() && 3507 "Use AddTemplateOverloadCandidate for function templates"); 3508 3509 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3510 if (!isa<CXXConstructorDecl>(Method)) { 3511 // If we get here, it's because we're calling a member function 3512 // that is named without a member access expression (e.g., 3513 // "this->f") that was either written explicitly or created 3514 // implicitly. This can happen with a qualified call to a member 3515 // function, e.g., X::f(). We use an empty type for the implied 3516 // object argument (C++ [over.call.func]p3), and the acting context 3517 // is irrelevant. 3518 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3519 QualType(), Args, NumArgs, CandidateSet, 3520 SuppressUserConversions); 3521 return; 3522 } 3523 // We treat a constructor like a non-member function, since its object 3524 // argument doesn't participate in overload resolution. 3525 } 3526 3527 if (!CandidateSet.isNewCandidate(Function)) 3528 return; 3529 3530 // Overload resolution is always an unevaluated context. 3531 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 3532 3533 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3534 // C++ [class.copy]p3: 3535 // A member function template is never instantiated to perform the copy 3536 // of a class object to an object of its class type. 3537 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3538 if (NumArgs == 1 && 3539 Constructor->isSpecializationCopyingObject() && 3540 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3541 IsDerivedFrom(Args[0]->getType(), ClassType))) 3542 return; 3543 } 3544 3545 // Add this candidate 3546 CandidateSet.push_back(OverloadCandidate()); 3547 OverloadCandidate& Candidate = CandidateSet.back(); 3548 Candidate.FoundDecl = FoundDecl; 3549 Candidate.Function = Function; 3550 Candidate.Viable = true; 3551 Candidate.IsSurrogate = false; 3552 Candidate.IgnoreObjectArgument = false; 3553 3554 unsigned NumArgsInProto = Proto->getNumArgs(); 3555 3556 // (C++ 13.3.2p2): A candidate function having fewer than m 3557 // parameters is viable only if it has an ellipsis in its parameter 3558 // list (8.3.5). 3559 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3560 !Proto->isVariadic()) { 3561 Candidate.Viable = false; 3562 Candidate.FailureKind = ovl_fail_too_many_arguments; 3563 return; 3564 } 3565 3566 // (C++ 13.3.2p2): A candidate function having more than m parameters 3567 // is viable only if the (m+1)st parameter has a default argument 3568 // (8.3.6). For the purposes of overload resolution, the 3569 // parameter list is truncated on the right, so that there are 3570 // exactly m parameters. 3571 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3572 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3573 // Not enough arguments. 3574 Candidate.Viable = false; 3575 Candidate.FailureKind = ovl_fail_too_few_arguments; 3576 return; 3577 } 3578 3579 // Determine the implicit conversion sequences for each of the 3580 // arguments. 3581 Candidate.Conversions.resize(NumArgs); 3582 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3583 if (ArgIdx < NumArgsInProto) { 3584 // (C++ 13.3.2p3): for F to be a viable function, there shall 3585 // exist for each argument an implicit conversion sequence 3586 // (13.3.3.1) that converts that argument to the corresponding 3587 // parameter of F. 3588 QualType ParamType = Proto->getArgType(ArgIdx); 3589 Candidate.Conversions[ArgIdx] 3590 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3591 SuppressUserConversions, 3592 /*InOverloadResolution=*/true); 3593 if (Candidate.Conversions[ArgIdx].isBad()) { 3594 Candidate.Viable = false; 3595 Candidate.FailureKind = ovl_fail_bad_conversion; 3596 break; 3597 } 3598 } else { 3599 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3600 // argument for which there is no corresponding parameter is 3601 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3602 Candidate.Conversions[ArgIdx].setEllipsis(); 3603 } 3604 } 3605} 3606 3607/// \brief Add all of the function declarations in the given function set to 3608/// the overload canddiate set. 3609void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3610 Expr **Args, unsigned NumArgs, 3611 OverloadCandidateSet& CandidateSet, 3612 bool SuppressUserConversions) { 3613 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3614 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3615 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3616 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3617 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3618 cast<CXXMethodDecl>(FD)->getParent(), 3619 Args[0]->getType(), Args + 1, NumArgs - 1, 3620 CandidateSet, SuppressUserConversions); 3621 else 3622 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3623 SuppressUserConversions); 3624 } else { 3625 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3626 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3627 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3628 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3629 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3630 /*FIXME: explicit args */ 0, 3631 Args[0]->getType(), Args + 1, NumArgs - 1, 3632 CandidateSet, 3633 SuppressUserConversions); 3634 else 3635 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3636 /*FIXME: explicit args */ 0, 3637 Args, NumArgs, CandidateSet, 3638 SuppressUserConversions); 3639 } 3640 } 3641} 3642 3643/// AddMethodCandidate - Adds a named decl (which is some kind of 3644/// method) as a method candidate to the given overload set. 3645void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3646 QualType ObjectType, 3647 Expr **Args, unsigned NumArgs, 3648 OverloadCandidateSet& CandidateSet, 3649 bool SuppressUserConversions) { 3650 NamedDecl *Decl = FoundDecl.getDecl(); 3651 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3652 3653 if (isa<UsingShadowDecl>(Decl)) 3654 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3655 3656 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3657 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3658 "Expected a member function template"); 3659 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3660 /*ExplicitArgs*/ 0, 3661 ObjectType, Args, NumArgs, 3662 CandidateSet, 3663 SuppressUserConversions); 3664 } else { 3665 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3666 ObjectType, Args, NumArgs, 3667 CandidateSet, SuppressUserConversions); 3668 } 3669} 3670 3671/// AddMethodCandidate - Adds the given C++ member function to the set 3672/// of candidate functions, using the given function call arguments 3673/// and the object argument (@c Object). For example, in a call 3674/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3675/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3676/// allow user-defined conversions via constructors or conversion 3677/// operators. 3678void 3679Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3680 CXXRecordDecl *ActingContext, QualType ObjectType, 3681 Expr **Args, unsigned NumArgs, 3682 OverloadCandidateSet& CandidateSet, 3683 bool SuppressUserConversions) { 3684 const FunctionProtoType* Proto 3685 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3686 assert(Proto && "Methods without a prototype cannot be overloaded"); 3687 assert(!isa<CXXConstructorDecl>(Method) && 3688 "Use AddOverloadCandidate for constructors"); 3689 3690 if (!CandidateSet.isNewCandidate(Method)) 3691 return; 3692 3693 // Overload resolution is always an unevaluated context. 3694 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 3695 3696 // Add this candidate 3697 CandidateSet.push_back(OverloadCandidate()); 3698 OverloadCandidate& Candidate = CandidateSet.back(); 3699 Candidate.FoundDecl = FoundDecl; 3700 Candidate.Function = Method; 3701 Candidate.IsSurrogate = false; 3702 Candidate.IgnoreObjectArgument = false; 3703 3704 unsigned NumArgsInProto = Proto->getNumArgs(); 3705 3706 // (C++ 13.3.2p2): A candidate function having fewer than m 3707 // parameters is viable only if it has an ellipsis in its parameter 3708 // list (8.3.5). 3709 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3710 Candidate.Viable = false; 3711 Candidate.FailureKind = ovl_fail_too_many_arguments; 3712 return; 3713 } 3714 3715 // (C++ 13.3.2p2): A candidate function having more than m parameters 3716 // is viable only if the (m+1)st parameter has a default argument 3717 // (8.3.6). For the purposes of overload resolution, the 3718 // parameter list is truncated on the right, so that there are 3719 // exactly m parameters. 3720 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3721 if (NumArgs < MinRequiredArgs) { 3722 // Not enough arguments. 3723 Candidate.Viable = false; 3724 Candidate.FailureKind = ovl_fail_too_few_arguments; 3725 return; 3726 } 3727 3728 Candidate.Viable = true; 3729 Candidate.Conversions.resize(NumArgs + 1); 3730 3731 if (Method->isStatic() || ObjectType.isNull()) 3732 // The implicit object argument is ignored. 3733 Candidate.IgnoreObjectArgument = true; 3734 else { 3735 // Determine the implicit conversion sequence for the object 3736 // parameter. 3737 Candidate.Conversions[0] 3738 = TryObjectArgumentInitialization(*this, ObjectType, Method, 3739 ActingContext); 3740 if (Candidate.Conversions[0].isBad()) { 3741 Candidate.Viable = false; 3742 Candidate.FailureKind = ovl_fail_bad_conversion; 3743 return; 3744 } 3745 } 3746 3747 // Determine the implicit conversion sequences for each of the 3748 // arguments. 3749 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3750 if (ArgIdx < NumArgsInProto) { 3751 // (C++ 13.3.2p3): for F to be a viable function, there shall 3752 // exist for each argument an implicit conversion sequence 3753 // (13.3.3.1) that converts that argument to the corresponding 3754 // parameter of F. 3755 QualType ParamType = Proto->getArgType(ArgIdx); 3756 Candidate.Conversions[ArgIdx + 1] 3757 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3758 SuppressUserConversions, 3759 /*InOverloadResolution=*/true); 3760 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3761 Candidate.Viable = false; 3762 Candidate.FailureKind = ovl_fail_bad_conversion; 3763 break; 3764 } 3765 } else { 3766 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3767 // argument for which there is no corresponding parameter is 3768 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3769 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3770 } 3771 } 3772} 3773 3774/// \brief Add a C++ member function template as a candidate to the candidate 3775/// set, using template argument deduction to produce an appropriate member 3776/// function template specialization. 3777void 3778Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3779 DeclAccessPair FoundDecl, 3780 CXXRecordDecl *ActingContext, 3781 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3782 QualType ObjectType, 3783 Expr **Args, unsigned NumArgs, 3784 OverloadCandidateSet& CandidateSet, 3785 bool SuppressUserConversions) { 3786 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3787 return; 3788 3789 // C++ [over.match.funcs]p7: 3790 // In each case where a candidate is a function template, candidate 3791 // function template specializations are generated using template argument 3792 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3793 // candidate functions in the usual way.113) A given name can refer to one 3794 // or more function templates and also to a set of overloaded non-template 3795 // functions. In such a case, the candidate functions generated from each 3796 // function template are combined with the set of non-template candidate 3797 // functions. 3798 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3799 FunctionDecl *Specialization = 0; 3800 if (TemplateDeductionResult Result 3801 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3802 Args, NumArgs, Specialization, Info)) { 3803 CandidateSet.push_back(OverloadCandidate()); 3804 OverloadCandidate &Candidate = CandidateSet.back(); 3805 Candidate.FoundDecl = FoundDecl; 3806 Candidate.Function = MethodTmpl->getTemplatedDecl(); 3807 Candidate.Viable = false; 3808 Candidate.FailureKind = ovl_fail_bad_deduction; 3809 Candidate.IsSurrogate = false; 3810 Candidate.IgnoreObjectArgument = false; 3811 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3812 Info); 3813 return; 3814 } 3815 3816 // Add the function template specialization produced by template argument 3817 // deduction as a candidate. 3818 assert(Specialization && "Missing member function template specialization?"); 3819 assert(isa<CXXMethodDecl>(Specialization) && 3820 "Specialization is not a member function?"); 3821 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3822 ActingContext, ObjectType, Args, NumArgs, 3823 CandidateSet, SuppressUserConversions); 3824} 3825 3826/// \brief Add a C++ function template specialization as a candidate 3827/// in the candidate set, using template argument deduction to produce 3828/// an appropriate function template specialization. 3829void 3830Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3831 DeclAccessPair FoundDecl, 3832 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3833 Expr **Args, unsigned NumArgs, 3834 OverloadCandidateSet& CandidateSet, 3835 bool SuppressUserConversions) { 3836 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3837 return; 3838 3839 // C++ [over.match.funcs]p7: 3840 // In each case where a candidate is a function template, candidate 3841 // function template specializations are generated using template argument 3842 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3843 // candidate functions in the usual way.113) A given name can refer to one 3844 // or more function templates and also to a set of overloaded non-template 3845 // functions. In such a case, the candidate functions generated from each 3846 // function template are combined with the set of non-template candidate 3847 // functions. 3848 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3849 FunctionDecl *Specialization = 0; 3850 if (TemplateDeductionResult Result 3851 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3852 Args, NumArgs, Specialization, Info)) { 3853 CandidateSet.push_back(OverloadCandidate()); 3854 OverloadCandidate &Candidate = CandidateSet.back(); 3855 Candidate.FoundDecl = FoundDecl; 3856 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3857 Candidate.Viable = false; 3858 Candidate.FailureKind = ovl_fail_bad_deduction; 3859 Candidate.IsSurrogate = false; 3860 Candidate.IgnoreObjectArgument = false; 3861 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3862 Info); 3863 return; 3864 } 3865 3866 // Add the function template specialization produced by template argument 3867 // deduction as a candidate. 3868 assert(Specialization && "Missing function template specialization?"); 3869 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3870 SuppressUserConversions); 3871} 3872 3873/// AddConversionCandidate - Add a C++ conversion function as a 3874/// candidate in the candidate set (C++ [over.match.conv], 3875/// C++ [over.match.copy]). From is the expression we're converting from, 3876/// and ToType is the type that we're eventually trying to convert to 3877/// (which may or may not be the same type as the type that the 3878/// conversion function produces). 3879void 3880Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3881 DeclAccessPair FoundDecl, 3882 CXXRecordDecl *ActingContext, 3883 Expr *From, QualType ToType, 3884 OverloadCandidateSet& CandidateSet) { 3885 assert(!Conversion->getDescribedFunctionTemplate() && 3886 "Conversion function templates use AddTemplateConversionCandidate"); 3887 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3888 if (!CandidateSet.isNewCandidate(Conversion)) 3889 return; 3890 3891 // Overload resolution is always an unevaluated context. 3892 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 3893 3894 // Add this candidate 3895 CandidateSet.push_back(OverloadCandidate()); 3896 OverloadCandidate& Candidate = CandidateSet.back(); 3897 Candidate.FoundDecl = FoundDecl; 3898 Candidate.Function = Conversion; 3899 Candidate.IsSurrogate = false; 3900 Candidate.IgnoreObjectArgument = false; 3901 Candidate.FinalConversion.setAsIdentityConversion(); 3902 Candidate.FinalConversion.setFromType(ConvType); 3903 Candidate.FinalConversion.setAllToTypes(ToType); 3904 Candidate.Viable = true; 3905 Candidate.Conversions.resize(1); 3906 3907 // C++ [over.match.funcs]p4: 3908 // For conversion functions, the function is considered to be a member of 3909 // the class of the implicit implied object argument for the purpose of 3910 // defining the type of the implicit object parameter. 3911 // 3912 // Determine the implicit conversion sequence for the implicit 3913 // object parameter. 3914 QualType ImplicitParamType = From->getType(); 3915 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 3916 ImplicitParamType = FromPtrType->getPointeeType(); 3917 CXXRecordDecl *ConversionContext 3918 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 3919 3920 Candidate.Conversions[0] 3921 = TryObjectArgumentInitialization(*this, From->getType(), Conversion, 3922 ConversionContext); 3923 3924 if (Candidate.Conversions[0].isBad()) { 3925 Candidate.Viable = false; 3926 Candidate.FailureKind = ovl_fail_bad_conversion; 3927 return; 3928 } 3929 3930 // We won't go through a user-define type conversion function to convert a 3931 // derived to base as such conversions are given Conversion Rank. They only 3932 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3933 QualType FromCanon 3934 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3935 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3936 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3937 Candidate.Viable = false; 3938 Candidate.FailureKind = ovl_fail_trivial_conversion; 3939 return; 3940 } 3941 3942 // To determine what the conversion from the result of calling the 3943 // conversion function to the type we're eventually trying to 3944 // convert to (ToType), we need to synthesize a call to the 3945 // conversion function and attempt copy initialization from it. This 3946 // makes sure that we get the right semantics with respect to 3947 // lvalues/rvalues and the type. Fortunately, we can allocate this 3948 // call on the stack and we don't need its arguments to be 3949 // well-formed. 3950 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3951 VK_LValue, From->getLocStart()); 3952 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 3953 Context.getPointerType(Conversion->getType()), 3954 CK_FunctionToPointerDecay, 3955 &ConversionRef, VK_RValue); 3956 3957 QualType CallResultType 3958 = Conversion->getConversionType().getNonLValueExprType(Context); 3959 if (RequireCompleteType(From->getLocStart(), CallResultType, 0)) { 3960 Candidate.Viable = false; 3961 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3962 return; 3963 } 3964 3965 ExprValueKind VK = Expr::getValueKindForType(Conversion->getConversionType()); 3966 3967 // Note that it is safe to allocate CallExpr on the stack here because 3968 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3969 // allocator). 3970 CallExpr Call(Context, &ConversionFn, 0, 0, CallResultType, VK, 3971 From->getLocStart()); 3972 ImplicitConversionSequence ICS = 3973 TryCopyInitialization(*this, &Call, ToType, 3974 /*SuppressUserConversions=*/true, 3975 /*InOverloadResolution=*/false); 3976 3977 switch (ICS.getKind()) { 3978 case ImplicitConversionSequence::StandardConversion: 3979 Candidate.FinalConversion = ICS.Standard; 3980 3981 // C++ [over.ics.user]p3: 3982 // If the user-defined conversion is specified by a specialization of a 3983 // conversion function template, the second standard conversion sequence 3984 // shall have exact match rank. 3985 if (Conversion->getPrimaryTemplate() && 3986 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3987 Candidate.Viable = false; 3988 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3989 } 3990 3991 break; 3992 3993 case ImplicitConversionSequence::BadConversion: 3994 Candidate.Viable = false; 3995 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3996 break; 3997 3998 default: 3999 assert(false && 4000 "Can only end up with a standard conversion sequence or failure"); 4001 } 4002} 4003 4004/// \brief Adds a conversion function template specialization 4005/// candidate to the overload set, using template argument deduction 4006/// to deduce the template arguments of the conversion function 4007/// template from the type that we are converting to (C++ 4008/// [temp.deduct.conv]). 4009void 4010Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 4011 DeclAccessPair FoundDecl, 4012 CXXRecordDecl *ActingDC, 4013 Expr *From, QualType ToType, 4014 OverloadCandidateSet &CandidateSet) { 4015 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 4016 "Only conversion function templates permitted here"); 4017 4018 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4019 return; 4020 4021 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4022 CXXConversionDecl *Specialization = 0; 4023 if (TemplateDeductionResult Result 4024 = DeduceTemplateArguments(FunctionTemplate, ToType, 4025 Specialization, Info)) { 4026 CandidateSet.push_back(OverloadCandidate()); 4027 OverloadCandidate &Candidate = CandidateSet.back(); 4028 Candidate.FoundDecl = FoundDecl; 4029 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4030 Candidate.Viable = false; 4031 Candidate.FailureKind = ovl_fail_bad_deduction; 4032 Candidate.IsSurrogate = false; 4033 Candidate.IgnoreObjectArgument = false; 4034 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4035 Info); 4036 return; 4037 } 4038 4039 // Add the conversion function template specialization produced by 4040 // template argument deduction as a candidate. 4041 assert(Specialization && "Missing function template specialization?"); 4042 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 4043 CandidateSet); 4044} 4045 4046/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 4047/// converts the given @c Object to a function pointer via the 4048/// conversion function @c Conversion, and then attempts to call it 4049/// with the given arguments (C++ [over.call.object]p2-4). Proto is 4050/// the type of function that we'll eventually be calling. 4051void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 4052 DeclAccessPair FoundDecl, 4053 CXXRecordDecl *ActingContext, 4054 const FunctionProtoType *Proto, 4055 QualType ObjectType, 4056 Expr **Args, unsigned NumArgs, 4057 OverloadCandidateSet& CandidateSet) { 4058 if (!CandidateSet.isNewCandidate(Conversion)) 4059 return; 4060 4061 // Overload resolution is always an unevaluated context. 4062 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4063 4064 CandidateSet.push_back(OverloadCandidate()); 4065 OverloadCandidate& Candidate = CandidateSet.back(); 4066 Candidate.FoundDecl = FoundDecl; 4067 Candidate.Function = 0; 4068 Candidate.Surrogate = Conversion; 4069 Candidate.Viable = true; 4070 Candidate.IsSurrogate = true; 4071 Candidate.IgnoreObjectArgument = false; 4072 Candidate.Conversions.resize(NumArgs + 1); 4073 4074 // Determine the implicit conversion sequence for the implicit 4075 // object parameter. 4076 ImplicitConversionSequence ObjectInit 4077 = TryObjectArgumentInitialization(*this, ObjectType, Conversion, 4078 ActingContext); 4079 if (ObjectInit.isBad()) { 4080 Candidate.Viable = false; 4081 Candidate.FailureKind = ovl_fail_bad_conversion; 4082 Candidate.Conversions[0] = ObjectInit; 4083 return; 4084 } 4085 4086 // The first conversion is actually a user-defined conversion whose 4087 // first conversion is ObjectInit's standard conversion (which is 4088 // effectively a reference binding). Record it as such. 4089 Candidate.Conversions[0].setUserDefined(); 4090 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 4091 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 4092 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 4093 Candidate.Conversions[0].UserDefined.After 4094 = Candidate.Conversions[0].UserDefined.Before; 4095 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 4096 4097 // Find the 4098 unsigned NumArgsInProto = Proto->getNumArgs(); 4099 4100 // (C++ 13.3.2p2): A candidate function having fewer than m 4101 // parameters is viable only if it has an ellipsis in its parameter 4102 // list (8.3.5). 4103 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4104 Candidate.Viable = false; 4105 Candidate.FailureKind = ovl_fail_too_many_arguments; 4106 return; 4107 } 4108 4109 // Function types don't have any default arguments, so just check if 4110 // we have enough arguments. 4111 if (NumArgs < NumArgsInProto) { 4112 // Not enough arguments. 4113 Candidate.Viable = false; 4114 Candidate.FailureKind = ovl_fail_too_few_arguments; 4115 return; 4116 } 4117 4118 // Determine the implicit conversion sequences for each of the 4119 // arguments. 4120 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4121 if (ArgIdx < NumArgsInProto) { 4122 // (C++ 13.3.2p3): for F to be a viable function, there shall 4123 // exist for each argument an implicit conversion sequence 4124 // (13.3.3.1) that converts that argument to the corresponding 4125 // parameter of F. 4126 QualType ParamType = Proto->getArgType(ArgIdx); 4127 Candidate.Conversions[ArgIdx + 1] 4128 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4129 /*SuppressUserConversions=*/false, 4130 /*InOverloadResolution=*/false); 4131 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4132 Candidate.Viable = false; 4133 Candidate.FailureKind = ovl_fail_bad_conversion; 4134 break; 4135 } 4136 } else { 4137 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4138 // argument for which there is no corresponding parameter is 4139 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4140 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4141 } 4142 } 4143} 4144 4145/// \brief Add overload candidates for overloaded operators that are 4146/// member functions. 4147/// 4148/// Add the overloaded operator candidates that are member functions 4149/// for the operator Op that was used in an operator expression such 4150/// as "x Op y". , Args/NumArgs provides the operator arguments, and 4151/// CandidateSet will store the added overload candidates. (C++ 4152/// [over.match.oper]). 4153void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 4154 SourceLocation OpLoc, 4155 Expr **Args, unsigned NumArgs, 4156 OverloadCandidateSet& CandidateSet, 4157 SourceRange OpRange) { 4158 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4159 4160 // C++ [over.match.oper]p3: 4161 // For a unary operator @ with an operand of a type whose 4162 // cv-unqualified version is T1, and for a binary operator @ with 4163 // a left operand of a type whose cv-unqualified version is T1 and 4164 // a right operand of a type whose cv-unqualified version is T2, 4165 // three sets of candidate functions, designated member 4166 // candidates, non-member candidates and built-in candidates, are 4167 // constructed as follows: 4168 QualType T1 = Args[0]->getType(); 4169 4170 // -- If T1 is a class type, the set of member candidates is the 4171 // result of the qualified lookup of T1::operator@ 4172 // (13.3.1.1.1); otherwise, the set of member candidates is 4173 // empty. 4174 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 4175 // Complete the type if it can be completed. Otherwise, we're done. 4176 if (RequireCompleteType(OpLoc, T1, PDiag())) 4177 return; 4178 4179 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 4180 LookupQualifiedName(Operators, T1Rec->getDecl()); 4181 Operators.suppressDiagnostics(); 4182 4183 for (LookupResult::iterator Oper = Operators.begin(), 4184 OperEnd = Operators.end(); 4185 Oper != OperEnd; 4186 ++Oper) 4187 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 4188 Args + 1, NumArgs - 1, CandidateSet, 4189 /* SuppressUserConversions = */ false); 4190 } 4191} 4192 4193/// AddBuiltinCandidate - Add a candidate for a built-in 4194/// operator. ResultTy and ParamTys are the result and parameter types 4195/// of the built-in candidate, respectively. Args and NumArgs are the 4196/// arguments being passed to the candidate. IsAssignmentOperator 4197/// should be true when this built-in candidate is an assignment 4198/// operator. NumContextualBoolArguments is the number of arguments 4199/// (at the beginning of the argument list) that will be contextually 4200/// converted to bool. 4201void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 4202 Expr **Args, unsigned NumArgs, 4203 OverloadCandidateSet& CandidateSet, 4204 bool IsAssignmentOperator, 4205 unsigned NumContextualBoolArguments) { 4206 // Overload resolution is always an unevaluated context. 4207 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4208 4209 // Add this candidate 4210 CandidateSet.push_back(OverloadCandidate()); 4211 OverloadCandidate& Candidate = CandidateSet.back(); 4212 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 4213 Candidate.Function = 0; 4214 Candidate.IsSurrogate = false; 4215 Candidate.IgnoreObjectArgument = false; 4216 Candidate.BuiltinTypes.ResultTy = ResultTy; 4217 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4218 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 4219 4220 // Determine the implicit conversion sequences for each of the 4221 // arguments. 4222 Candidate.Viable = true; 4223 Candidate.Conversions.resize(NumArgs); 4224 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4225 // C++ [over.match.oper]p4: 4226 // For the built-in assignment operators, conversions of the 4227 // left operand are restricted as follows: 4228 // -- no temporaries are introduced to hold the left operand, and 4229 // -- no user-defined conversions are applied to the left 4230 // operand to achieve a type match with the left-most 4231 // parameter of a built-in candidate. 4232 // 4233 // We block these conversions by turning off user-defined 4234 // conversions, since that is the only way that initialization of 4235 // a reference to a non-class type can occur from something that 4236 // is not of the same type. 4237 if (ArgIdx < NumContextualBoolArguments) { 4238 assert(ParamTys[ArgIdx] == Context.BoolTy && 4239 "Contextual conversion to bool requires bool type"); 4240 Candidate.Conversions[ArgIdx] 4241 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 4242 } else { 4243 Candidate.Conversions[ArgIdx] 4244 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4245 ArgIdx == 0 && IsAssignmentOperator, 4246 /*InOverloadResolution=*/false); 4247 } 4248 if (Candidate.Conversions[ArgIdx].isBad()) { 4249 Candidate.Viable = false; 4250 Candidate.FailureKind = ovl_fail_bad_conversion; 4251 break; 4252 } 4253 } 4254} 4255 4256/// BuiltinCandidateTypeSet - A set of types that will be used for the 4257/// candidate operator functions for built-in operators (C++ 4258/// [over.built]). The types are separated into pointer types and 4259/// enumeration types. 4260class BuiltinCandidateTypeSet { 4261 /// TypeSet - A set of types. 4262 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4263 4264 /// PointerTypes - The set of pointer types that will be used in the 4265 /// built-in candidates. 4266 TypeSet PointerTypes; 4267 4268 /// MemberPointerTypes - The set of member pointer types that will be 4269 /// used in the built-in candidates. 4270 TypeSet MemberPointerTypes; 4271 4272 /// EnumerationTypes - The set of enumeration types that will be 4273 /// used in the built-in candidates. 4274 TypeSet EnumerationTypes; 4275 4276 /// \brief The set of vector types that will be used in the built-in 4277 /// candidates. 4278 TypeSet VectorTypes; 4279 4280 /// \brief A flag indicating non-record types are viable candidates 4281 bool HasNonRecordTypes; 4282 4283 /// \brief A flag indicating whether either arithmetic or enumeration types 4284 /// were present in the candidate set. 4285 bool HasArithmeticOrEnumeralTypes; 4286 4287 /// Sema - The semantic analysis instance where we are building the 4288 /// candidate type set. 4289 Sema &SemaRef; 4290 4291 /// Context - The AST context in which we will build the type sets. 4292 ASTContext &Context; 4293 4294 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4295 const Qualifiers &VisibleQuals); 4296 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4297 4298public: 4299 /// iterator - Iterates through the types that are part of the set. 4300 typedef TypeSet::iterator iterator; 4301 4302 BuiltinCandidateTypeSet(Sema &SemaRef) 4303 : HasNonRecordTypes(false), 4304 HasArithmeticOrEnumeralTypes(false), 4305 SemaRef(SemaRef), 4306 Context(SemaRef.Context) { } 4307 4308 void AddTypesConvertedFrom(QualType Ty, 4309 SourceLocation Loc, 4310 bool AllowUserConversions, 4311 bool AllowExplicitConversions, 4312 const Qualifiers &VisibleTypeConversionsQuals); 4313 4314 /// pointer_begin - First pointer type found; 4315 iterator pointer_begin() { return PointerTypes.begin(); } 4316 4317 /// pointer_end - Past the last pointer type found; 4318 iterator pointer_end() { return PointerTypes.end(); } 4319 4320 /// member_pointer_begin - First member pointer type found; 4321 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4322 4323 /// member_pointer_end - Past the last member pointer type found; 4324 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4325 4326 /// enumeration_begin - First enumeration type found; 4327 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4328 4329 /// enumeration_end - Past the last enumeration type found; 4330 iterator enumeration_end() { return EnumerationTypes.end(); } 4331 4332 iterator vector_begin() { return VectorTypes.begin(); } 4333 iterator vector_end() { return VectorTypes.end(); } 4334 4335 bool hasNonRecordTypes() { return HasNonRecordTypes; } 4336 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 4337}; 4338 4339/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4340/// the set of pointer types along with any more-qualified variants of 4341/// that type. For example, if @p Ty is "int const *", this routine 4342/// will add "int const *", "int const volatile *", "int const 4343/// restrict *", and "int const volatile restrict *" to the set of 4344/// pointer types. Returns true if the add of @p Ty itself succeeded, 4345/// false otherwise. 4346/// 4347/// FIXME: what to do about extended qualifiers? 4348bool 4349BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4350 const Qualifiers &VisibleQuals) { 4351 4352 // Insert this type. 4353 if (!PointerTypes.insert(Ty)) 4354 return false; 4355 4356 QualType PointeeTy; 4357 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4358 bool buildObjCPtr = false; 4359 if (!PointerTy) { 4360 if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) { 4361 PointeeTy = PTy->getPointeeType(); 4362 buildObjCPtr = true; 4363 } 4364 else 4365 assert(false && "type was not a pointer type!"); 4366 } 4367 else 4368 PointeeTy = PointerTy->getPointeeType(); 4369 4370 // Don't add qualified variants of arrays. For one, they're not allowed 4371 // (the qualifier would sink to the element type), and for another, the 4372 // only overload situation where it matters is subscript or pointer +- int, 4373 // and those shouldn't have qualifier variants anyway. 4374 if (PointeeTy->isArrayType()) 4375 return true; 4376 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4377 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4378 BaseCVR = Array->getElementType().getCVRQualifiers(); 4379 bool hasVolatile = VisibleQuals.hasVolatile(); 4380 bool hasRestrict = VisibleQuals.hasRestrict(); 4381 4382 // Iterate through all strict supersets of BaseCVR. 4383 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4384 if ((CVR | BaseCVR) != CVR) continue; 4385 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4386 // in the types. 4387 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4388 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4389 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4390 if (!buildObjCPtr) 4391 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4392 else 4393 PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); 4394 } 4395 4396 return true; 4397} 4398 4399/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4400/// to the set of pointer types along with any more-qualified variants of 4401/// that type. For example, if @p Ty is "int const *", this routine 4402/// will add "int const *", "int const volatile *", "int const 4403/// restrict *", and "int const volatile restrict *" to the set of 4404/// pointer types. Returns true if the add of @p Ty itself succeeded, 4405/// false otherwise. 4406/// 4407/// FIXME: what to do about extended qualifiers? 4408bool 4409BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4410 QualType Ty) { 4411 // Insert this type. 4412 if (!MemberPointerTypes.insert(Ty)) 4413 return false; 4414 4415 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4416 assert(PointerTy && "type was not a member pointer type!"); 4417 4418 QualType PointeeTy = PointerTy->getPointeeType(); 4419 // Don't add qualified variants of arrays. For one, they're not allowed 4420 // (the qualifier would sink to the element type), and for another, the 4421 // only overload situation where it matters is subscript or pointer +- int, 4422 // and those shouldn't have qualifier variants anyway. 4423 if (PointeeTy->isArrayType()) 4424 return true; 4425 const Type *ClassTy = PointerTy->getClass(); 4426 4427 // Iterate through all strict supersets of the pointee type's CVR 4428 // qualifiers. 4429 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4430 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4431 if ((CVR | BaseCVR) != CVR) continue; 4432 4433 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4434 MemberPointerTypes.insert( 4435 Context.getMemberPointerType(QPointeeTy, ClassTy)); 4436 } 4437 4438 return true; 4439} 4440 4441/// AddTypesConvertedFrom - Add each of the types to which the type @p 4442/// Ty can be implicit converted to the given set of @p Types. We're 4443/// primarily interested in pointer types and enumeration types. We also 4444/// take member pointer types, for the conditional operator. 4445/// AllowUserConversions is true if we should look at the conversion 4446/// functions of a class type, and AllowExplicitConversions if we 4447/// should also include the explicit conversion functions of a class 4448/// type. 4449void 4450BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4451 SourceLocation Loc, 4452 bool AllowUserConversions, 4453 bool AllowExplicitConversions, 4454 const Qualifiers &VisibleQuals) { 4455 // Only deal with canonical types. 4456 Ty = Context.getCanonicalType(Ty); 4457 4458 // Look through reference types; they aren't part of the type of an 4459 // expression for the purposes of conversions. 4460 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4461 Ty = RefTy->getPointeeType(); 4462 4463 // We don't care about qualifiers on the type. 4464 Ty = Ty.getLocalUnqualifiedType(); 4465 4466 // Flag if we ever add a non-record type. 4467 const RecordType *TyRec = Ty->getAs<RecordType>(); 4468 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 4469 4470 // If we're dealing with an array type, decay to the pointer. 4471 if (Ty->isArrayType()) 4472 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4473 4474 // Flag if we encounter an arithmetic type. 4475 HasArithmeticOrEnumeralTypes = 4476 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 4477 4478 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 4479 PointerTypes.insert(Ty); 4480 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 4481 // Insert our type, and its more-qualified variants, into the set 4482 // of types. 4483 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4484 return; 4485 } else if (Ty->isMemberPointerType()) { 4486 // Member pointers are far easier, since the pointee can't be converted. 4487 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4488 return; 4489 } else if (Ty->isEnumeralType()) { 4490 HasArithmeticOrEnumeralTypes = true; 4491 EnumerationTypes.insert(Ty); 4492 } else if (Ty->isVectorType()) { 4493 // We treat vector types as arithmetic types in many contexts as an 4494 // extension. 4495 HasArithmeticOrEnumeralTypes = true; 4496 VectorTypes.insert(Ty); 4497 } else if (AllowUserConversions && TyRec) { 4498 // No conversion functions in incomplete types. 4499 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 4500 return; 4501 4502 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4503 const UnresolvedSetImpl *Conversions 4504 = ClassDecl->getVisibleConversionFunctions(); 4505 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4506 E = Conversions->end(); I != E; ++I) { 4507 NamedDecl *D = I.getDecl(); 4508 if (isa<UsingShadowDecl>(D)) 4509 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4510 4511 // Skip conversion function templates; they don't tell us anything 4512 // about which builtin types we can convert to. 4513 if (isa<FunctionTemplateDecl>(D)) 4514 continue; 4515 4516 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4517 if (AllowExplicitConversions || !Conv->isExplicit()) { 4518 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4519 VisibleQuals); 4520 } 4521 } 4522 } 4523} 4524 4525/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4526/// the volatile- and non-volatile-qualified assignment operators for the 4527/// given type to the candidate set. 4528static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4529 QualType T, 4530 Expr **Args, 4531 unsigned NumArgs, 4532 OverloadCandidateSet &CandidateSet) { 4533 QualType ParamTypes[2]; 4534 4535 // T& operator=(T&, T) 4536 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4537 ParamTypes[1] = T; 4538 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4539 /*IsAssignmentOperator=*/true); 4540 4541 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4542 // volatile T& operator=(volatile T&, T) 4543 ParamTypes[0] 4544 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4545 ParamTypes[1] = T; 4546 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4547 /*IsAssignmentOperator=*/true); 4548 } 4549} 4550 4551/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4552/// if any, found in visible type conversion functions found in ArgExpr's type. 4553static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4554 Qualifiers VRQuals; 4555 const RecordType *TyRec; 4556 if (const MemberPointerType *RHSMPType = 4557 ArgExpr->getType()->getAs<MemberPointerType>()) 4558 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4559 else 4560 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4561 if (!TyRec) { 4562 // Just to be safe, assume the worst case. 4563 VRQuals.addVolatile(); 4564 VRQuals.addRestrict(); 4565 return VRQuals; 4566 } 4567 4568 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4569 if (!ClassDecl->hasDefinition()) 4570 return VRQuals; 4571 4572 const UnresolvedSetImpl *Conversions = 4573 ClassDecl->getVisibleConversionFunctions(); 4574 4575 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4576 E = Conversions->end(); I != E; ++I) { 4577 NamedDecl *D = I.getDecl(); 4578 if (isa<UsingShadowDecl>(D)) 4579 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4580 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4581 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4582 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4583 CanTy = ResTypeRef->getPointeeType(); 4584 // Need to go down the pointer/mempointer chain and add qualifiers 4585 // as see them. 4586 bool done = false; 4587 while (!done) { 4588 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4589 CanTy = ResTypePtr->getPointeeType(); 4590 else if (const MemberPointerType *ResTypeMPtr = 4591 CanTy->getAs<MemberPointerType>()) 4592 CanTy = ResTypeMPtr->getPointeeType(); 4593 else 4594 done = true; 4595 if (CanTy.isVolatileQualified()) 4596 VRQuals.addVolatile(); 4597 if (CanTy.isRestrictQualified()) 4598 VRQuals.addRestrict(); 4599 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4600 return VRQuals; 4601 } 4602 } 4603 } 4604 return VRQuals; 4605} 4606 4607namespace { 4608 4609/// \brief Helper class to manage the addition of builtin operator overload 4610/// candidates. It provides shared state and utility methods used throughout 4611/// the process, as well as a helper method to add each group of builtin 4612/// operator overloads from the standard to a candidate set. 4613class BuiltinOperatorOverloadBuilder { 4614 // Common instance state available to all overload candidate addition methods. 4615 Sema &S; 4616 Expr **Args; 4617 unsigned NumArgs; 4618 Qualifiers VisibleTypeConversionsQuals; 4619 bool HasArithmeticOrEnumeralCandidateType; 4620 llvm::SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 4621 OverloadCandidateSet &CandidateSet; 4622 4623 // Define some constants used to index and iterate over the arithemetic types 4624 // provided via the getArithmeticType() method below. 4625 // The "promoted arithmetic types" are the arithmetic 4626 // types are that preserved by promotion (C++ [over.built]p2). 4627 static const unsigned FirstIntegralType = 3; 4628 static const unsigned LastIntegralType = 18; 4629 static const unsigned FirstPromotedIntegralType = 3, 4630 LastPromotedIntegralType = 9; 4631 static const unsigned FirstPromotedArithmeticType = 0, 4632 LastPromotedArithmeticType = 9; 4633 static const unsigned NumArithmeticTypes = 18; 4634 4635 /// \brief Get the canonical type for a given arithmetic type index. 4636 CanQualType getArithmeticType(unsigned index) { 4637 assert(index < NumArithmeticTypes); 4638 static CanQualType ASTContext::* const 4639 ArithmeticTypes[NumArithmeticTypes] = { 4640 // Start of promoted types. 4641 &ASTContext::FloatTy, 4642 &ASTContext::DoubleTy, 4643 &ASTContext::LongDoubleTy, 4644 4645 // Start of integral types. 4646 &ASTContext::IntTy, 4647 &ASTContext::LongTy, 4648 &ASTContext::LongLongTy, 4649 &ASTContext::UnsignedIntTy, 4650 &ASTContext::UnsignedLongTy, 4651 &ASTContext::UnsignedLongLongTy, 4652 // End of promoted types. 4653 4654 &ASTContext::BoolTy, 4655 &ASTContext::CharTy, 4656 &ASTContext::WCharTy, 4657 &ASTContext::Char16Ty, 4658 &ASTContext::Char32Ty, 4659 &ASTContext::SignedCharTy, 4660 &ASTContext::ShortTy, 4661 &ASTContext::UnsignedCharTy, 4662 &ASTContext::UnsignedShortTy, 4663 // End of integral types. 4664 // FIXME: What about complex? 4665 }; 4666 return S.Context.*ArithmeticTypes[index]; 4667 } 4668 4669 /// \brief Gets the canonical type resulting from the usual arithemetic 4670 /// converions for the given arithmetic types. 4671 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 4672 // Accelerator table for performing the usual arithmetic conversions. 4673 // The rules are basically: 4674 // - if either is floating-point, use the wider floating-point 4675 // - if same signedness, use the higher rank 4676 // - if same size, use unsigned of the higher rank 4677 // - use the larger type 4678 // These rules, together with the axiom that higher ranks are 4679 // never smaller, are sufficient to precompute all of these results 4680 // *except* when dealing with signed types of higher rank. 4681 // (we could precompute SLL x UI for all known platforms, but it's 4682 // better not to make any assumptions). 4683 enum PromotedType { 4684 Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL, Dep=-1 4685 }; 4686 static PromotedType ConversionsTable[LastPromotedArithmeticType] 4687 [LastPromotedArithmeticType] = { 4688 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt }, 4689 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 4690 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 4691 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL }, 4692 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, Dep, UL, ULL }, 4693 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, Dep, Dep, ULL }, 4694 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, UI, UL, ULL }, 4695 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, UL, UL, ULL }, 4696 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, ULL, ULL, ULL }, 4697 }; 4698 4699 assert(L < LastPromotedArithmeticType); 4700 assert(R < LastPromotedArithmeticType); 4701 int Idx = ConversionsTable[L][R]; 4702 4703 // Fast path: the table gives us a concrete answer. 4704 if (Idx != Dep) return getArithmeticType(Idx); 4705 4706 // Slow path: we need to compare widths. 4707 // An invariant is that the signed type has higher rank. 4708 CanQualType LT = getArithmeticType(L), 4709 RT = getArithmeticType(R); 4710 unsigned LW = S.Context.getIntWidth(LT), 4711 RW = S.Context.getIntWidth(RT); 4712 4713 // If they're different widths, use the signed type. 4714 if (LW > RW) return LT; 4715 else if (LW < RW) return RT; 4716 4717 // Otherwise, use the unsigned type of the signed type's rank. 4718 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 4719 assert(L == SLL || R == SLL); 4720 return S.Context.UnsignedLongLongTy; 4721 } 4722 4723 /// \brief Helper method to factor out the common pattern of adding overloads 4724 /// for '++' and '--' builtin operators. 4725 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 4726 bool HasVolatile) { 4727 QualType ParamTypes[2] = { 4728 S.Context.getLValueReferenceType(CandidateTy), 4729 S.Context.IntTy 4730 }; 4731 4732 // Non-volatile version. 4733 if (NumArgs == 1) 4734 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4735 else 4736 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 4737 4738 // Use a heuristic to reduce number of builtin candidates in the set: 4739 // add volatile version only if there are conversions to a volatile type. 4740 if (HasVolatile) { 4741 ParamTypes[0] = 4742 S.Context.getLValueReferenceType( 4743 S.Context.getVolatileType(CandidateTy)); 4744 if (NumArgs == 1) 4745 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4746 else 4747 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 4748 } 4749 } 4750 4751public: 4752 BuiltinOperatorOverloadBuilder( 4753 Sema &S, Expr **Args, unsigned NumArgs, 4754 Qualifiers VisibleTypeConversionsQuals, 4755 bool HasArithmeticOrEnumeralCandidateType, 4756 llvm::SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 4757 OverloadCandidateSet &CandidateSet) 4758 : S(S), Args(Args), NumArgs(NumArgs), 4759 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 4760 HasArithmeticOrEnumeralCandidateType( 4761 HasArithmeticOrEnumeralCandidateType), 4762 CandidateTypes(CandidateTypes), 4763 CandidateSet(CandidateSet) { 4764 // Validate some of our static helper constants in debug builds. 4765 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 4766 "Invalid first promoted integral type"); 4767 assert(getArithmeticType(LastPromotedIntegralType - 1) 4768 == S.Context.UnsignedLongLongTy && 4769 "Invalid last promoted integral type"); 4770 assert(getArithmeticType(FirstPromotedArithmeticType) 4771 == S.Context.FloatTy && 4772 "Invalid first promoted arithmetic type"); 4773 assert(getArithmeticType(LastPromotedArithmeticType - 1) 4774 == S.Context.UnsignedLongLongTy && 4775 "Invalid last promoted arithmetic type"); 4776 } 4777 4778 // C++ [over.built]p3: 4779 // 4780 // For every pair (T, VQ), where T is an arithmetic type, and VQ 4781 // is either volatile or empty, there exist candidate operator 4782 // functions of the form 4783 // 4784 // VQ T& operator++(VQ T&); 4785 // T operator++(VQ T&, int); 4786 // 4787 // C++ [over.built]p4: 4788 // 4789 // For every pair (T, VQ), where T is an arithmetic type other 4790 // than bool, and VQ is either volatile or empty, there exist 4791 // candidate operator functions of the form 4792 // 4793 // VQ T& operator--(VQ T&); 4794 // T operator--(VQ T&, int); 4795 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 4796 if (!HasArithmeticOrEnumeralCandidateType) 4797 return; 4798 4799 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 4800 Arith < NumArithmeticTypes; ++Arith) { 4801 addPlusPlusMinusMinusStyleOverloads( 4802 getArithmeticType(Arith), 4803 VisibleTypeConversionsQuals.hasVolatile()); 4804 } 4805 } 4806 4807 // C++ [over.built]p5: 4808 // 4809 // For every pair (T, VQ), where T is a cv-qualified or 4810 // cv-unqualified object type, and VQ is either volatile or 4811 // empty, there exist candidate operator functions of the form 4812 // 4813 // T*VQ& operator++(T*VQ&); 4814 // T*VQ& operator--(T*VQ&); 4815 // T* operator++(T*VQ&, int); 4816 // T* operator--(T*VQ&, int); 4817 void addPlusPlusMinusMinusPointerOverloads() { 4818 for (BuiltinCandidateTypeSet::iterator 4819 Ptr = CandidateTypes[0].pointer_begin(), 4820 PtrEnd = CandidateTypes[0].pointer_end(); 4821 Ptr != PtrEnd; ++Ptr) { 4822 // Skip pointer types that aren't pointers to object types. 4823 if (!(*Ptr)->getPointeeType()->isIncompleteOrObjectType()) 4824 continue; 4825 4826 addPlusPlusMinusMinusStyleOverloads(*Ptr, 4827 (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 4828 VisibleTypeConversionsQuals.hasVolatile())); 4829 } 4830 } 4831 4832 // C++ [over.built]p6: 4833 // For every cv-qualified or cv-unqualified object type T, there 4834 // exist candidate operator functions of the form 4835 // 4836 // T& operator*(T*); 4837 // 4838 // C++ [over.built]p7: 4839 // For every function type T, there exist candidate operator 4840 // functions of the form 4841 // T& operator*(T*); 4842 void addUnaryStarPointerOverloads() { 4843 for (BuiltinCandidateTypeSet::iterator 4844 Ptr = CandidateTypes[0].pointer_begin(), 4845 PtrEnd = CandidateTypes[0].pointer_end(); 4846 Ptr != PtrEnd; ++Ptr) { 4847 QualType ParamTy = *Ptr; 4848 QualType PointeeTy = ParamTy->getPointeeType(); 4849 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 4850 &ParamTy, Args, 1, CandidateSet); 4851 } 4852 } 4853 4854 // C++ [over.built]p9: 4855 // For every promoted arithmetic type T, there exist candidate 4856 // operator functions of the form 4857 // 4858 // T operator+(T); 4859 // T operator-(T); 4860 void addUnaryPlusOrMinusArithmeticOverloads() { 4861 if (!HasArithmeticOrEnumeralCandidateType) 4862 return; 4863 4864 for (unsigned Arith = FirstPromotedArithmeticType; 4865 Arith < LastPromotedArithmeticType; ++Arith) { 4866 QualType ArithTy = getArithmeticType(Arith); 4867 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4868 } 4869 4870 // Extension: We also add these operators for vector types. 4871 for (BuiltinCandidateTypeSet::iterator 4872 Vec = CandidateTypes[0].vector_begin(), 4873 VecEnd = CandidateTypes[0].vector_end(); 4874 Vec != VecEnd; ++Vec) { 4875 QualType VecTy = *Vec; 4876 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4877 } 4878 } 4879 4880 // C++ [over.built]p8: 4881 // For every type T, there exist candidate operator functions of 4882 // the form 4883 // 4884 // T* operator+(T*); 4885 void addUnaryPlusPointerOverloads() { 4886 for (BuiltinCandidateTypeSet::iterator 4887 Ptr = CandidateTypes[0].pointer_begin(), 4888 PtrEnd = CandidateTypes[0].pointer_end(); 4889 Ptr != PtrEnd; ++Ptr) { 4890 QualType ParamTy = *Ptr; 4891 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4892 } 4893 } 4894 4895 // C++ [over.built]p10: 4896 // For every promoted integral type T, there exist candidate 4897 // operator functions of the form 4898 // 4899 // T operator~(T); 4900 void addUnaryTildePromotedIntegralOverloads() { 4901 if (!HasArithmeticOrEnumeralCandidateType) 4902 return; 4903 4904 for (unsigned Int = FirstPromotedIntegralType; 4905 Int < LastPromotedIntegralType; ++Int) { 4906 QualType IntTy = getArithmeticType(Int); 4907 S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4908 } 4909 4910 // Extension: We also add this operator for vector types. 4911 for (BuiltinCandidateTypeSet::iterator 4912 Vec = CandidateTypes[0].vector_begin(), 4913 VecEnd = CandidateTypes[0].vector_end(); 4914 Vec != VecEnd; ++Vec) { 4915 QualType VecTy = *Vec; 4916 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4917 } 4918 } 4919 4920 // C++ [over.match.oper]p16: 4921 // For every pointer to member type T, there exist candidate operator 4922 // functions of the form 4923 // 4924 // bool operator==(T,T); 4925 // bool operator!=(T,T); 4926 void addEqualEqualOrNotEqualMemberPointerOverloads() { 4927 /// Set of (canonical) types that we've already handled. 4928 llvm::SmallPtrSet<QualType, 8> AddedTypes; 4929 4930 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4931 for (BuiltinCandidateTypeSet::iterator 4932 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 4933 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 4934 MemPtr != MemPtrEnd; 4935 ++MemPtr) { 4936 // Don't add the same builtin candidate twice. 4937 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 4938 continue; 4939 4940 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4941 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 4942 CandidateSet); 4943 } 4944 } 4945 } 4946 4947 // C++ [over.built]p15: 4948 // 4949 // For every pointer or enumeration type T, there exist 4950 // candidate operator functions of the form 4951 // 4952 // bool operator<(T, T); 4953 // bool operator>(T, T); 4954 // bool operator<=(T, T); 4955 // bool operator>=(T, T); 4956 // bool operator==(T, T); 4957 // bool operator!=(T, T); 4958 void addRelationalPointerOrEnumeralOverloads() { 4959 // C++ [over.built]p1: 4960 // If there is a user-written candidate with the same name and parameter 4961 // types as a built-in candidate operator function, the built-in operator 4962 // function is hidden and is not included in the set of candidate 4963 // functions. 4964 // 4965 // The text is actually in a note, but if we don't implement it then we end 4966 // up with ambiguities when the user provides an overloaded operator for 4967 // an enumeration type. Note that only enumeration types have this problem, 4968 // so we track which enumeration types we've seen operators for. Also, the 4969 // only other overloaded operator with enumeration argumenst, operator=, 4970 // cannot be overloaded for enumeration types, so this is the only place 4971 // where we must suppress candidates like this. 4972 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 4973 UserDefinedBinaryOperators; 4974 4975 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4976 if (CandidateTypes[ArgIdx].enumeration_begin() != 4977 CandidateTypes[ArgIdx].enumeration_end()) { 4978 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 4979 CEnd = CandidateSet.end(); 4980 C != CEnd; ++C) { 4981 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 4982 continue; 4983 4984 QualType FirstParamType = 4985 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 4986 QualType SecondParamType = 4987 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 4988 4989 // Skip if either parameter isn't of enumeral type. 4990 if (!FirstParamType->isEnumeralType() || 4991 !SecondParamType->isEnumeralType()) 4992 continue; 4993 4994 // Add this operator to the set of known user-defined operators. 4995 UserDefinedBinaryOperators.insert( 4996 std::make_pair(S.Context.getCanonicalType(FirstParamType), 4997 S.Context.getCanonicalType(SecondParamType))); 4998 } 4999 } 5000 } 5001 5002 /// Set of (canonical) types that we've already handled. 5003 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5004 5005 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5006 for (BuiltinCandidateTypeSet::iterator 5007 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5008 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5009 Ptr != PtrEnd; ++Ptr) { 5010 // Don't add the same builtin candidate twice. 5011 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5012 continue; 5013 5014 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5015 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5016 CandidateSet); 5017 } 5018 for (BuiltinCandidateTypeSet::iterator 5019 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5020 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5021 Enum != EnumEnd; ++Enum) { 5022 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 5023 5024 // Don't add the same builtin candidate twice, or if a user defined 5025 // candidate exists. 5026 if (!AddedTypes.insert(CanonType) || 5027 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 5028 CanonType))) 5029 continue; 5030 5031 QualType ParamTypes[2] = { *Enum, *Enum }; 5032 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5033 CandidateSet); 5034 } 5035 } 5036 } 5037 5038 // C++ [over.built]p13: 5039 // 5040 // For every cv-qualified or cv-unqualified object type T 5041 // there exist candidate operator functions of the form 5042 // 5043 // T* operator+(T*, ptrdiff_t); 5044 // T& operator[](T*, ptrdiff_t); [BELOW] 5045 // T* operator-(T*, ptrdiff_t); 5046 // T* operator+(ptrdiff_t, T*); 5047 // T& operator[](ptrdiff_t, T*); [BELOW] 5048 // 5049 // C++ [over.built]p14: 5050 // 5051 // For every T, where T is a pointer to object type, there 5052 // exist candidate operator functions of the form 5053 // 5054 // ptrdiff_t operator-(T, T); 5055 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 5056 /// Set of (canonical) types that we've already handled. 5057 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5058 5059 for (int Arg = 0; Arg < 2; ++Arg) { 5060 QualType AsymetricParamTypes[2] = { 5061 S.Context.getPointerDiffType(), 5062 S.Context.getPointerDiffType(), 5063 }; 5064 for (BuiltinCandidateTypeSet::iterator 5065 Ptr = CandidateTypes[Arg].pointer_begin(), 5066 PtrEnd = CandidateTypes[Arg].pointer_end(); 5067 Ptr != PtrEnd; ++Ptr) { 5068 AsymetricParamTypes[Arg] = *Ptr; 5069 if (Arg == 0 || Op == OO_Plus) { 5070 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 5071 // T* operator+(ptrdiff_t, T*); 5072 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, 5073 CandidateSet); 5074 } 5075 if (Op == OO_Minus) { 5076 // ptrdiff_t operator-(T, T); 5077 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5078 continue; 5079 5080 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5081 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 5082 Args, 2, CandidateSet); 5083 } 5084 } 5085 } 5086 } 5087 5088 // C++ [over.built]p12: 5089 // 5090 // For every pair of promoted arithmetic types L and R, there 5091 // exist candidate operator functions of the form 5092 // 5093 // LR operator*(L, R); 5094 // LR operator/(L, R); 5095 // LR operator+(L, R); 5096 // LR operator-(L, R); 5097 // bool operator<(L, R); 5098 // bool operator>(L, R); 5099 // bool operator<=(L, R); 5100 // bool operator>=(L, R); 5101 // bool operator==(L, R); 5102 // bool operator!=(L, R); 5103 // 5104 // where LR is the result of the usual arithmetic conversions 5105 // between types L and R. 5106 // 5107 // C++ [over.built]p24: 5108 // 5109 // For every pair of promoted arithmetic types L and R, there exist 5110 // candidate operator functions of the form 5111 // 5112 // LR operator?(bool, L, R); 5113 // 5114 // where LR is the result of the usual arithmetic conversions 5115 // between types L and R. 5116 // Our candidates ignore the first parameter. 5117 void addGenericBinaryArithmeticOverloads(bool isComparison) { 5118 if (!HasArithmeticOrEnumeralCandidateType) 5119 return; 5120 5121 for (unsigned Left = FirstPromotedArithmeticType; 5122 Left < LastPromotedArithmeticType; ++Left) { 5123 for (unsigned Right = FirstPromotedArithmeticType; 5124 Right < LastPromotedArithmeticType; ++Right) { 5125 QualType LandR[2] = { getArithmeticType(Left), 5126 getArithmeticType(Right) }; 5127 QualType Result = 5128 isComparison ? S.Context.BoolTy 5129 : getUsualArithmeticConversions(Left, Right); 5130 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5131 } 5132 } 5133 5134 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 5135 // conditional operator for vector types. 5136 for (BuiltinCandidateTypeSet::iterator 5137 Vec1 = CandidateTypes[0].vector_begin(), 5138 Vec1End = CandidateTypes[0].vector_end(); 5139 Vec1 != Vec1End; ++Vec1) { 5140 for (BuiltinCandidateTypeSet::iterator 5141 Vec2 = CandidateTypes[1].vector_begin(), 5142 Vec2End = CandidateTypes[1].vector_end(); 5143 Vec2 != Vec2End; ++Vec2) { 5144 QualType LandR[2] = { *Vec1, *Vec2 }; 5145 QualType Result = S.Context.BoolTy; 5146 if (!isComparison) { 5147 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 5148 Result = *Vec1; 5149 else 5150 Result = *Vec2; 5151 } 5152 5153 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5154 } 5155 } 5156 } 5157 5158 // C++ [over.built]p17: 5159 // 5160 // For every pair of promoted integral types L and R, there 5161 // exist candidate operator functions of the form 5162 // 5163 // LR operator%(L, R); 5164 // LR operator&(L, R); 5165 // LR operator^(L, R); 5166 // LR operator|(L, R); 5167 // L operator<<(L, R); 5168 // L operator>>(L, R); 5169 // 5170 // where LR is the result of the usual arithmetic conversions 5171 // between types L and R. 5172 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 5173 if (!HasArithmeticOrEnumeralCandidateType) 5174 return; 5175 5176 for (unsigned Left = FirstPromotedIntegralType; 5177 Left < LastPromotedIntegralType; ++Left) { 5178 for (unsigned Right = FirstPromotedIntegralType; 5179 Right < LastPromotedIntegralType; ++Right) { 5180 QualType LandR[2] = { getArithmeticType(Left), 5181 getArithmeticType(Right) }; 5182 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 5183 ? LandR[0] 5184 : getUsualArithmeticConversions(Left, Right); 5185 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5186 } 5187 } 5188 } 5189 5190 // C++ [over.built]p20: 5191 // 5192 // For every pair (T, VQ), where T is an enumeration or 5193 // pointer to member type and VQ is either volatile or 5194 // empty, there exist candidate operator functions of the form 5195 // 5196 // VQ T& operator=(VQ T&, T); 5197 void addAssignmentMemberPointerOrEnumeralOverloads() { 5198 /// Set of (canonical) types that we've already handled. 5199 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5200 5201 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5202 for (BuiltinCandidateTypeSet::iterator 5203 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5204 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5205 Enum != EnumEnd; ++Enum) { 5206 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5207 continue; 5208 5209 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, 5210 CandidateSet); 5211 } 5212 5213 for (BuiltinCandidateTypeSet::iterator 5214 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5215 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5216 MemPtr != MemPtrEnd; ++MemPtr) { 5217 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5218 continue; 5219 5220 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, 5221 CandidateSet); 5222 } 5223 } 5224 } 5225 5226 // C++ [over.built]p19: 5227 // 5228 // For every pair (T, VQ), where T is any type and VQ is either 5229 // volatile or empty, there exist candidate operator functions 5230 // of the form 5231 // 5232 // T*VQ& operator=(T*VQ&, T*); 5233 // 5234 // C++ [over.built]p21: 5235 // 5236 // For every pair (T, VQ), where T is a cv-qualified or 5237 // cv-unqualified object type and VQ is either volatile or 5238 // empty, there exist candidate operator functions of the form 5239 // 5240 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 5241 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 5242 void addAssignmentPointerOverloads(bool isEqualOp) { 5243 /// Set of (canonical) types that we've already handled. 5244 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5245 5246 for (BuiltinCandidateTypeSet::iterator 5247 Ptr = CandidateTypes[0].pointer_begin(), 5248 PtrEnd = CandidateTypes[0].pointer_end(); 5249 Ptr != PtrEnd; ++Ptr) { 5250 // If this is operator=, keep track of the builtin candidates we added. 5251 if (isEqualOp) 5252 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 5253 5254 // non-volatile version 5255 QualType ParamTypes[2] = { 5256 S.Context.getLValueReferenceType(*Ptr), 5257 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 5258 }; 5259 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5260 /*IsAssigmentOperator=*/ isEqualOp); 5261 5262 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5263 VisibleTypeConversionsQuals.hasVolatile()) { 5264 // volatile version 5265 ParamTypes[0] = 5266 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5267 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5268 /*IsAssigmentOperator=*/isEqualOp); 5269 } 5270 } 5271 5272 if (isEqualOp) { 5273 for (BuiltinCandidateTypeSet::iterator 5274 Ptr = CandidateTypes[1].pointer_begin(), 5275 PtrEnd = CandidateTypes[1].pointer_end(); 5276 Ptr != PtrEnd; ++Ptr) { 5277 // Make sure we don't add the same candidate twice. 5278 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5279 continue; 5280 5281 QualType ParamTypes[2] = { 5282 S.Context.getLValueReferenceType(*Ptr), 5283 *Ptr, 5284 }; 5285 5286 // non-volatile version 5287 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5288 /*IsAssigmentOperator=*/true); 5289 5290 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5291 VisibleTypeConversionsQuals.hasVolatile()) { 5292 // volatile version 5293 ParamTypes[0] = 5294 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5295 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5296 CandidateSet, /*IsAssigmentOperator=*/true); 5297 } 5298 } 5299 } 5300 } 5301 5302 // C++ [over.built]p18: 5303 // 5304 // For every triple (L, VQ, R), where L is an arithmetic type, 5305 // VQ is either volatile or empty, and R is a promoted 5306 // arithmetic type, there exist candidate operator functions of 5307 // the form 5308 // 5309 // VQ L& operator=(VQ L&, R); 5310 // VQ L& operator*=(VQ L&, R); 5311 // VQ L& operator/=(VQ L&, R); 5312 // VQ L& operator+=(VQ L&, R); 5313 // VQ L& operator-=(VQ L&, R); 5314 void addAssignmentArithmeticOverloads(bool isEqualOp) { 5315 if (!HasArithmeticOrEnumeralCandidateType) 5316 return; 5317 5318 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 5319 for (unsigned Right = FirstPromotedArithmeticType; 5320 Right < LastPromotedArithmeticType; ++Right) { 5321 QualType ParamTypes[2]; 5322 ParamTypes[1] = getArithmeticType(Right); 5323 5324 // Add this built-in operator as a candidate (VQ is empty). 5325 ParamTypes[0] = 5326 S.Context.getLValueReferenceType(getArithmeticType(Left)); 5327 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5328 /*IsAssigmentOperator=*/isEqualOp); 5329 5330 // Add this built-in operator as a candidate (VQ is 'volatile'). 5331 if (VisibleTypeConversionsQuals.hasVolatile()) { 5332 ParamTypes[0] = 5333 S.Context.getVolatileType(getArithmeticType(Left)); 5334 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5335 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5336 CandidateSet, 5337 /*IsAssigmentOperator=*/isEqualOp); 5338 } 5339 } 5340 } 5341 5342 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 5343 for (BuiltinCandidateTypeSet::iterator 5344 Vec1 = CandidateTypes[0].vector_begin(), 5345 Vec1End = CandidateTypes[0].vector_end(); 5346 Vec1 != Vec1End; ++Vec1) { 5347 for (BuiltinCandidateTypeSet::iterator 5348 Vec2 = CandidateTypes[1].vector_begin(), 5349 Vec2End = CandidateTypes[1].vector_end(); 5350 Vec2 != Vec2End; ++Vec2) { 5351 QualType ParamTypes[2]; 5352 ParamTypes[1] = *Vec2; 5353 // Add this built-in operator as a candidate (VQ is empty). 5354 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 5355 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5356 /*IsAssigmentOperator=*/isEqualOp); 5357 5358 // Add this built-in operator as a candidate (VQ is 'volatile'). 5359 if (VisibleTypeConversionsQuals.hasVolatile()) { 5360 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 5361 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5362 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5363 CandidateSet, 5364 /*IsAssigmentOperator=*/isEqualOp); 5365 } 5366 } 5367 } 5368 } 5369 5370 // C++ [over.built]p22: 5371 // 5372 // For every triple (L, VQ, R), where L is an integral type, VQ 5373 // is either volatile or empty, and R is a promoted integral 5374 // type, there exist candidate operator functions of the form 5375 // 5376 // VQ L& operator%=(VQ L&, R); 5377 // VQ L& operator<<=(VQ L&, R); 5378 // VQ L& operator>>=(VQ L&, R); 5379 // VQ L& operator&=(VQ L&, R); 5380 // VQ L& operator^=(VQ L&, R); 5381 // VQ L& operator|=(VQ L&, R); 5382 void addAssignmentIntegralOverloads() { 5383 if (!HasArithmeticOrEnumeralCandidateType) 5384 return; 5385 5386 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 5387 for (unsigned Right = FirstPromotedIntegralType; 5388 Right < LastPromotedIntegralType; ++Right) { 5389 QualType ParamTypes[2]; 5390 ParamTypes[1] = getArithmeticType(Right); 5391 5392 // Add this built-in operator as a candidate (VQ is empty). 5393 ParamTypes[0] = 5394 S.Context.getLValueReferenceType(getArithmeticType(Left)); 5395 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5396 if (VisibleTypeConversionsQuals.hasVolatile()) { 5397 // Add this built-in operator as a candidate (VQ is 'volatile'). 5398 ParamTypes[0] = getArithmeticType(Left); 5399 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 5400 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5401 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5402 CandidateSet); 5403 } 5404 } 5405 } 5406 } 5407 5408 // C++ [over.operator]p23: 5409 // 5410 // There also exist candidate operator functions of the form 5411 // 5412 // bool operator!(bool); 5413 // bool operator&&(bool, bool); 5414 // bool operator||(bool, bool); 5415 void addExclaimOverload() { 5416 QualType ParamTy = S.Context.BoolTy; 5417 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 5418 /*IsAssignmentOperator=*/false, 5419 /*NumContextualBoolArguments=*/1); 5420 } 5421 void addAmpAmpOrPipePipeOverload() { 5422 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 5423 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 5424 /*IsAssignmentOperator=*/false, 5425 /*NumContextualBoolArguments=*/2); 5426 } 5427 5428 // C++ [over.built]p13: 5429 // 5430 // For every cv-qualified or cv-unqualified object type T there 5431 // exist candidate operator functions of the form 5432 // 5433 // T* operator+(T*, ptrdiff_t); [ABOVE] 5434 // T& operator[](T*, ptrdiff_t); 5435 // T* operator-(T*, ptrdiff_t); [ABOVE] 5436 // T* operator+(ptrdiff_t, T*); [ABOVE] 5437 // T& operator[](ptrdiff_t, T*); 5438 void addSubscriptOverloads() { 5439 for (BuiltinCandidateTypeSet::iterator 5440 Ptr = CandidateTypes[0].pointer_begin(), 5441 PtrEnd = CandidateTypes[0].pointer_end(); 5442 Ptr != PtrEnd; ++Ptr) { 5443 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 5444 QualType PointeeType = (*Ptr)->getPointeeType(); 5445 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 5446 5447 // T& operator[](T*, ptrdiff_t) 5448 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5449 } 5450 5451 for (BuiltinCandidateTypeSet::iterator 5452 Ptr = CandidateTypes[1].pointer_begin(), 5453 PtrEnd = CandidateTypes[1].pointer_end(); 5454 Ptr != PtrEnd; ++Ptr) { 5455 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 5456 QualType PointeeType = (*Ptr)->getPointeeType(); 5457 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 5458 5459 // T& operator[](ptrdiff_t, T*) 5460 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5461 } 5462 } 5463 5464 // C++ [over.built]p11: 5465 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 5466 // C1 is the same type as C2 or is a derived class of C2, T is an object 5467 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 5468 // there exist candidate operator functions of the form 5469 // 5470 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 5471 // 5472 // where CV12 is the union of CV1 and CV2. 5473 void addArrowStarOverloads() { 5474 for (BuiltinCandidateTypeSet::iterator 5475 Ptr = CandidateTypes[0].pointer_begin(), 5476 PtrEnd = CandidateTypes[0].pointer_end(); 5477 Ptr != PtrEnd; ++Ptr) { 5478 QualType C1Ty = (*Ptr); 5479 QualType C1; 5480 QualifierCollector Q1; 5481 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 5482 if (!isa<RecordType>(C1)) 5483 continue; 5484 // heuristic to reduce number of builtin candidates in the set. 5485 // Add volatile/restrict version only if there are conversions to a 5486 // volatile/restrict type. 5487 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 5488 continue; 5489 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 5490 continue; 5491 for (BuiltinCandidateTypeSet::iterator 5492 MemPtr = CandidateTypes[1].member_pointer_begin(), 5493 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 5494 MemPtr != MemPtrEnd; ++MemPtr) { 5495 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 5496 QualType C2 = QualType(mptr->getClass(), 0); 5497 C2 = C2.getUnqualifiedType(); 5498 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 5499 break; 5500 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 5501 // build CV12 T& 5502 QualType T = mptr->getPointeeType(); 5503 if (!VisibleTypeConversionsQuals.hasVolatile() && 5504 T.isVolatileQualified()) 5505 continue; 5506 if (!VisibleTypeConversionsQuals.hasRestrict() && 5507 T.isRestrictQualified()) 5508 continue; 5509 T = Q1.apply(S.Context, T); 5510 QualType ResultTy = S.Context.getLValueReferenceType(T); 5511 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5512 } 5513 } 5514 } 5515 5516 // Note that we don't consider the first argument, since it has been 5517 // contextually converted to bool long ago. The candidates below are 5518 // therefore added as binary. 5519 // 5520 // C++ [over.built]p25: 5521 // For every type T, where T is a pointer, pointer-to-member, or scoped 5522 // enumeration type, there exist candidate operator functions of the form 5523 // 5524 // T operator?(bool, T, T); 5525 // 5526 void addConditionalOperatorOverloads() { 5527 /// Set of (canonical) types that we've already handled. 5528 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5529 5530 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5531 for (BuiltinCandidateTypeSet::iterator 5532 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5533 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5534 Ptr != PtrEnd; ++Ptr) { 5535 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5536 continue; 5537 5538 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5539 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5540 } 5541 5542 for (BuiltinCandidateTypeSet::iterator 5543 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5544 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5545 MemPtr != MemPtrEnd; ++MemPtr) { 5546 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5547 continue; 5548 5549 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5550 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); 5551 } 5552 5553 if (S.getLangOptions().CPlusPlus0x) { 5554 for (BuiltinCandidateTypeSet::iterator 5555 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5556 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5557 Enum != EnumEnd; ++Enum) { 5558 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 5559 continue; 5560 5561 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5562 continue; 5563 5564 QualType ParamTypes[2] = { *Enum, *Enum }; 5565 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); 5566 } 5567 } 5568 } 5569 } 5570}; 5571 5572} // end anonymous namespace 5573 5574/// AddBuiltinOperatorCandidates - Add the appropriate built-in 5575/// operator overloads to the candidate set (C++ [over.built]), based 5576/// on the operator @p Op and the arguments given. For example, if the 5577/// operator is a binary '+', this routine might add "int 5578/// operator+(int, int)" to cover integer addition. 5579void 5580Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 5581 SourceLocation OpLoc, 5582 Expr **Args, unsigned NumArgs, 5583 OverloadCandidateSet& CandidateSet) { 5584 // Find all of the types that the arguments can convert to, but only 5585 // if the operator we're looking at has built-in operator candidates 5586 // that make use of these types. Also record whether we encounter non-record 5587 // candidate types or either arithmetic or enumeral candidate types. 5588 Qualifiers VisibleTypeConversionsQuals; 5589 VisibleTypeConversionsQuals.addConst(); 5590 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5591 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 5592 5593 bool HasNonRecordCandidateType = false; 5594 bool HasArithmeticOrEnumeralCandidateType = false; 5595 llvm::SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 5596 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5597 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 5598 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 5599 OpLoc, 5600 true, 5601 (Op == OO_Exclaim || 5602 Op == OO_AmpAmp || 5603 Op == OO_PipePipe), 5604 VisibleTypeConversionsQuals); 5605 HasNonRecordCandidateType = HasNonRecordCandidateType || 5606 CandidateTypes[ArgIdx].hasNonRecordTypes(); 5607 HasArithmeticOrEnumeralCandidateType = 5608 HasArithmeticOrEnumeralCandidateType || 5609 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 5610 } 5611 5612 // Exit early when no non-record types have been added to the candidate set 5613 // for any of the arguments to the operator. 5614 if (!HasNonRecordCandidateType) 5615 return; 5616 5617 // Setup an object to manage the common state for building overloads. 5618 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, 5619 VisibleTypeConversionsQuals, 5620 HasArithmeticOrEnumeralCandidateType, 5621 CandidateTypes, CandidateSet); 5622 5623 // Dispatch over the operation to add in only those overloads which apply. 5624 switch (Op) { 5625 case OO_None: 5626 case NUM_OVERLOADED_OPERATORS: 5627 assert(false && "Expected an overloaded operator"); 5628 break; 5629 5630 case OO_New: 5631 case OO_Delete: 5632 case OO_Array_New: 5633 case OO_Array_Delete: 5634 case OO_Call: 5635 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 5636 break; 5637 5638 case OO_Comma: 5639 case OO_Arrow: 5640 // C++ [over.match.oper]p3: 5641 // -- For the operator ',', the unary operator '&', or the 5642 // operator '->', the built-in candidates set is empty. 5643 break; 5644 5645 case OO_Plus: // '+' is either unary or binary 5646 if (NumArgs == 1) 5647 OpBuilder.addUnaryPlusPointerOverloads(); 5648 // Fall through. 5649 5650 case OO_Minus: // '-' is either unary or binary 5651 if (NumArgs == 1) { 5652 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 5653 } else { 5654 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 5655 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 5656 } 5657 break; 5658 5659 case OO_Star: // '*' is either unary or binary 5660 if (NumArgs == 1) 5661 OpBuilder.addUnaryStarPointerOverloads(); 5662 else 5663 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 5664 break; 5665 5666 case OO_Slash: 5667 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 5668 break; 5669 5670 case OO_PlusPlus: 5671 case OO_MinusMinus: 5672 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 5673 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 5674 break; 5675 5676 case OO_EqualEqual: 5677 case OO_ExclaimEqual: 5678 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 5679 // Fall through. 5680 5681 case OO_Less: 5682 case OO_Greater: 5683 case OO_LessEqual: 5684 case OO_GreaterEqual: 5685 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 5686 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 5687 break; 5688 5689 case OO_Percent: 5690 case OO_Caret: 5691 case OO_Pipe: 5692 case OO_LessLess: 5693 case OO_GreaterGreater: 5694 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 5695 break; 5696 5697 case OO_Amp: // '&' is either unary or binary 5698 if (NumArgs == 1) 5699 // C++ [over.match.oper]p3: 5700 // -- For the operator ',', the unary operator '&', or the 5701 // operator '->', the built-in candidates set is empty. 5702 break; 5703 5704 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 5705 break; 5706 5707 case OO_Tilde: 5708 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 5709 break; 5710 5711 case OO_Equal: 5712 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 5713 // Fall through. 5714 5715 case OO_PlusEqual: 5716 case OO_MinusEqual: 5717 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 5718 // Fall through. 5719 5720 case OO_StarEqual: 5721 case OO_SlashEqual: 5722 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 5723 break; 5724 5725 case OO_PercentEqual: 5726 case OO_LessLessEqual: 5727 case OO_GreaterGreaterEqual: 5728 case OO_AmpEqual: 5729 case OO_CaretEqual: 5730 case OO_PipeEqual: 5731 OpBuilder.addAssignmentIntegralOverloads(); 5732 break; 5733 5734 case OO_Exclaim: 5735 OpBuilder.addExclaimOverload(); 5736 break; 5737 5738 case OO_AmpAmp: 5739 case OO_PipePipe: 5740 OpBuilder.addAmpAmpOrPipePipeOverload(); 5741 break; 5742 5743 case OO_Subscript: 5744 OpBuilder.addSubscriptOverloads(); 5745 break; 5746 5747 case OO_ArrowStar: 5748 OpBuilder.addArrowStarOverloads(); 5749 break; 5750 5751 case OO_Conditional: 5752 OpBuilder.addConditionalOperatorOverloads(); 5753 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 5754 break; 5755 } 5756} 5757 5758/// \brief Add function candidates found via argument-dependent lookup 5759/// to the set of overloading candidates. 5760/// 5761/// This routine performs argument-dependent name lookup based on the 5762/// given function name (which may also be an operator name) and adds 5763/// all of the overload candidates found by ADL to the overload 5764/// candidate set (C++ [basic.lookup.argdep]). 5765void 5766Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 5767 bool Operator, 5768 Expr **Args, unsigned NumArgs, 5769 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5770 OverloadCandidateSet& CandidateSet, 5771 bool PartialOverloading) { 5772 ADLResult Fns; 5773 5774 // FIXME: This approach for uniquing ADL results (and removing 5775 // redundant candidates from the set) relies on pointer-equality, 5776 // which means we need to key off the canonical decl. However, 5777 // always going back to the canonical decl might not get us the 5778 // right set of default arguments. What default arguments are 5779 // we supposed to consider on ADL candidates, anyway? 5780 5781 // FIXME: Pass in the explicit template arguments? 5782 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 5783 5784 // Erase all of the candidates we already knew about. 5785 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5786 CandEnd = CandidateSet.end(); 5787 Cand != CandEnd; ++Cand) 5788 if (Cand->Function) { 5789 Fns.erase(Cand->Function); 5790 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 5791 Fns.erase(FunTmpl); 5792 } 5793 5794 // For each of the ADL candidates we found, add it to the overload 5795 // set. 5796 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 5797 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 5798 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 5799 if (ExplicitTemplateArgs) 5800 continue; 5801 5802 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 5803 false, PartialOverloading); 5804 } else 5805 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 5806 FoundDecl, ExplicitTemplateArgs, 5807 Args, NumArgs, CandidateSet); 5808 } 5809} 5810 5811/// isBetterOverloadCandidate - Determines whether the first overload 5812/// candidate is a better candidate than the second (C++ 13.3.3p1). 5813bool 5814isBetterOverloadCandidate(Sema &S, 5815 const OverloadCandidate &Cand1, 5816 const OverloadCandidate &Cand2, 5817 SourceLocation Loc, 5818 bool UserDefinedConversion) { 5819 // Define viable functions to be better candidates than non-viable 5820 // functions. 5821 if (!Cand2.Viable) 5822 return Cand1.Viable; 5823 else if (!Cand1.Viable) 5824 return false; 5825 5826 // C++ [over.match.best]p1: 5827 // 5828 // -- if F is a static member function, ICS1(F) is defined such 5829 // that ICS1(F) is neither better nor worse than ICS1(G) for 5830 // any function G, and, symmetrically, ICS1(G) is neither 5831 // better nor worse than ICS1(F). 5832 unsigned StartArg = 0; 5833 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 5834 StartArg = 1; 5835 5836 // C++ [over.match.best]p1: 5837 // A viable function F1 is defined to be a better function than another 5838 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 5839 // conversion sequence than ICSi(F2), and then... 5840 unsigned NumArgs = Cand1.Conversions.size(); 5841 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 5842 bool HasBetterConversion = false; 5843 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 5844 switch (CompareImplicitConversionSequences(S, 5845 Cand1.Conversions[ArgIdx], 5846 Cand2.Conversions[ArgIdx])) { 5847 case ImplicitConversionSequence::Better: 5848 // Cand1 has a better conversion sequence. 5849 HasBetterConversion = true; 5850 break; 5851 5852 case ImplicitConversionSequence::Worse: 5853 // Cand1 can't be better than Cand2. 5854 return false; 5855 5856 case ImplicitConversionSequence::Indistinguishable: 5857 // Do nothing. 5858 break; 5859 } 5860 } 5861 5862 // -- for some argument j, ICSj(F1) is a better conversion sequence than 5863 // ICSj(F2), or, if not that, 5864 if (HasBetterConversion) 5865 return true; 5866 5867 // - F1 is a non-template function and F2 is a function template 5868 // specialization, or, if not that, 5869 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 5870 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5871 return true; 5872 5873 // -- F1 and F2 are function template specializations, and the function 5874 // template for F1 is more specialized than the template for F2 5875 // according to the partial ordering rules described in 14.5.5.2, or, 5876 // if not that, 5877 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 5878 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5879 if (FunctionTemplateDecl *BetterTemplate 5880 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 5881 Cand2.Function->getPrimaryTemplate(), 5882 Loc, 5883 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 5884 : TPOC_Call)) 5885 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 5886 5887 // -- the context is an initialization by user-defined conversion 5888 // (see 8.5, 13.3.1.5) and the standard conversion sequence 5889 // from the return type of F1 to the destination type (i.e., 5890 // the type of the entity being initialized) is a better 5891 // conversion sequence than the standard conversion sequence 5892 // from the return type of F2 to the destination type. 5893 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 5894 isa<CXXConversionDecl>(Cand1.Function) && 5895 isa<CXXConversionDecl>(Cand2.Function)) { 5896 switch (CompareStandardConversionSequences(S, 5897 Cand1.FinalConversion, 5898 Cand2.FinalConversion)) { 5899 case ImplicitConversionSequence::Better: 5900 // Cand1 has a better conversion sequence. 5901 return true; 5902 5903 case ImplicitConversionSequence::Worse: 5904 // Cand1 can't be better than Cand2. 5905 return false; 5906 5907 case ImplicitConversionSequence::Indistinguishable: 5908 // Do nothing 5909 break; 5910 } 5911 } 5912 5913 return false; 5914} 5915 5916/// \brief Computes the best viable function (C++ 13.3.3) 5917/// within an overload candidate set. 5918/// 5919/// \param CandidateSet the set of candidate functions. 5920/// 5921/// \param Loc the location of the function name (or operator symbol) for 5922/// which overload resolution occurs. 5923/// 5924/// \param Best f overload resolution was successful or found a deleted 5925/// function, Best points to the candidate function found. 5926/// 5927/// \returns The result of overload resolution. 5928OverloadingResult 5929OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 5930 iterator &Best, 5931 bool UserDefinedConversion) { 5932 // Find the best viable function. 5933 Best = end(); 5934 for (iterator Cand = begin(); Cand != end(); ++Cand) { 5935 if (Cand->Viable) 5936 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 5937 UserDefinedConversion)) 5938 Best = Cand; 5939 } 5940 5941 // If we didn't find any viable functions, abort. 5942 if (Best == end()) 5943 return OR_No_Viable_Function; 5944 5945 // Make sure that this function is better than every other viable 5946 // function. If not, we have an ambiguity. 5947 for (iterator Cand = begin(); Cand != end(); ++Cand) { 5948 if (Cand->Viable && 5949 Cand != Best && 5950 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 5951 UserDefinedConversion)) { 5952 Best = end(); 5953 return OR_Ambiguous; 5954 } 5955 } 5956 5957 // Best is the best viable function. 5958 if (Best->Function && 5959 (Best->Function->isDeleted() || 5960 Best->Function->getAttr<UnavailableAttr>())) 5961 return OR_Deleted; 5962 5963 // C++ [basic.def.odr]p2: 5964 // An overloaded function is used if it is selected by overload resolution 5965 // when referred to from a potentially-evaluated expression. [Note: this 5966 // covers calls to named functions (5.2.2), operator overloading 5967 // (clause 13), user-defined conversions (12.3.2), allocation function for 5968 // placement new (5.3.4), as well as non-default initialization (8.5). 5969 if (Best->Function) 5970 S.MarkDeclarationReferenced(Loc, Best->Function); 5971 5972 return OR_Success; 5973} 5974 5975namespace { 5976 5977enum OverloadCandidateKind { 5978 oc_function, 5979 oc_method, 5980 oc_constructor, 5981 oc_function_template, 5982 oc_method_template, 5983 oc_constructor_template, 5984 oc_implicit_default_constructor, 5985 oc_implicit_copy_constructor, 5986 oc_implicit_copy_assignment 5987}; 5988 5989OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 5990 FunctionDecl *Fn, 5991 std::string &Description) { 5992 bool isTemplate = false; 5993 5994 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 5995 isTemplate = true; 5996 Description = S.getTemplateArgumentBindingsText( 5997 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 5998 } 5999 6000 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 6001 if (!Ctor->isImplicit()) 6002 return isTemplate ? oc_constructor_template : oc_constructor; 6003 6004 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 6005 : oc_implicit_default_constructor; 6006 } 6007 6008 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 6009 // This actually gets spelled 'candidate function' for now, but 6010 // it doesn't hurt to split it out. 6011 if (!Meth->isImplicit()) 6012 return isTemplate ? oc_method_template : oc_method; 6013 6014 assert(Meth->isCopyAssignmentOperator() 6015 && "implicit method is not copy assignment operator?"); 6016 return oc_implicit_copy_assignment; 6017 } 6018 6019 return isTemplate ? oc_function_template : oc_function; 6020} 6021 6022} // end anonymous namespace 6023 6024// Notes the location of an overload candidate. 6025void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 6026 std::string FnDesc; 6027 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 6028 Diag(Fn->getLocation(), diag::note_ovl_candidate) 6029 << (unsigned) K << FnDesc; 6030} 6031 6032/// Diagnoses an ambiguous conversion. The partial diagnostic is the 6033/// "lead" diagnostic; it will be given two arguments, the source and 6034/// target types of the conversion. 6035void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 6036 Sema &S, 6037 SourceLocation CaretLoc, 6038 const PartialDiagnostic &PDiag) const { 6039 S.Diag(CaretLoc, PDiag) 6040 << Ambiguous.getFromType() << Ambiguous.getToType(); 6041 for (AmbiguousConversionSequence::const_iterator 6042 I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 6043 S.NoteOverloadCandidate(*I); 6044 } 6045} 6046 6047namespace { 6048 6049void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 6050 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 6051 assert(Conv.isBad()); 6052 assert(Cand->Function && "for now, candidate must be a function"); 6053 FunctionDecl *Fn = Cand->Function; 6054 6055 // There's a conversion slot for the object argument if this is a 6056 // non-constructor method. Note that 'I' corresponds the 6057 // conversion-slot index. 6058 bool isObjectArgument = false; 6059 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 6060 if (I == 0) 6061 isObjectArgument = true; 6062 else 6063 I--; 6064 } 6065 6066 std::string FnDesc; 6067 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6068 6069 Expr *FromExpr = Conv.Bad.FromExpr; 6070 QualType FromTy = Conv.Bad.getFromType(); 6071 QualType ToTy = Conv.Bad.getToType(); 6072 6073 if (FromTy == S.Context.OverloadTy) { 6074 assert(FromExpr && "overload set argument came from implicit argument?"); 6075 Expr *E = FromExpr->IgnoreParens(); 6076 if (isa<UnaryOperator>(E)) 6077 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 6078 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 6079 6080 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 6081 << (unsigned) FnKind << FnDesc 6082 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6083 << ToTy << Name << I+1; 6084 return; 6085 } 6086 6087 // Do some hand-waving analysis to see if the non-viability is due 6088 // to a qualifier mismatch. 6089 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 6090 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 6091 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 6092 CToTy = RT->getPointeeType(); 6093 else { 6094 // TODO: detect and diagnose the full richness of const mismatches. 6095 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 6096 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 6097 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 6098 } 6099 6100 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 6101 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 6102 // It is dumb that we have to do this here. 6103 while (isa<ArrayType>(CFromTy)) 6104 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 6105 while (isa<ArrayType>(CToTy)) 6106 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 6107 6108 Qualifiers FromQs = CFromTy.getQualifiers(); 6109 Qualifiers ToQs = CToTy.getQualifiers(); 6110 6111 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 6112 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 6113 << (unsigned) FnKind << FnDesc 6114 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6115 << FromTy 6116 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 6117 << (unsigned) isObjectArgument << I+1; 6118 return; 6119 } 6120 6121 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 6122 assert(CVR && "unexpected qualifiers mismatch"); 6123 6124 if (isObjectArgument) { 6125 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 6126 << (unsigned) FnKind << FnDesc 6127 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6128 << FromTy << (CVR - 1); 6129 } else { 6130 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 6131 << (unsigned) FnKind << FnDesc 6132 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6133 << FromTy << (CVR - 1) << I+1; 6134 } 6135 return; 6136 } 6137 6138 // Diagnose references or pointers to incomplete types differently, 6139 // since it's far from impossible that the incompleteness triggered 6140 // the failure. 6141 QualType TempFromTy = FromTy.getNonReferenceType(); 6142 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 6143 TempFromTy = PTy->getPointeeType(); 6144 if (TempFromTy->isIncompleteType()) { 6145 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 6146 << (unsigned) FnKind << FnDesc 6147 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6148 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6149 return; 6150 } 6151 6152 // Diagnose base -> derived pointer conversions. 6153 unsigned BaseToDerivedConversion = 0; 6154 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 6155 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 6156 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6157 FromPtrTy->getPointeeType()) && 6158 !FromPtrTy->getPointeeType()->isIncompleteType() && 6159 !ToPtrTy->getPointeeType()->isIncompleteType() && 6160 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 6161 FromPtrTy->getPointeeType())) 6162 BaseToDerivedConversion = 1; 6163 } 6164 } else if (const ObjCObjectPointerType *FromPtrTy 6165 = FromTy->getAs<ObjCObjectPointerType>()) { 6166 if (const ObjCObjectPointerType *ToPtrTy 6167 = ToTy->getAs<ObjCObjectPointerType>()) 6168 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 6169 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 6170 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6171 FromPtrTy->getPointeeType()) && 6172 FromIface->isSuperClassOf(ToIface)) 6173 BaseToDerivedConversion = 2; 6174 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 6175 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 6176 !FromTy->isIncompleteType() && 6177 !ToRefTy->getPointeeType()->isIncompleteType() && 6178 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 6179 BaseToDerivedConversion = 3; 6180 } 6181 6182 if (BaseToDerivedConversion) { 6183 S.Diag(Fn->getLocation(), 6184 diag::note_ovl_candidate_bad_base_to_derived_conv) 6185 << (unsigned) FnKind << FnDesc 6186 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6187 << (BaseToDerivedConversion - 1) 6188 << FromTy << ToTy << I+1; 6189 return; 6190 } 6191 6192 // TODO: specialize more based on the kind of mismatch 6193 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 6194 << (unsigned) FnKind << FnDesc 6195 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6196 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6197} 6198 6199void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 6200 unsigned NumFormalArgs) { 6201 // TODO: treat calls to a missing default constructor as a special case 6202 6203 FunctionDecl *Fn = Cand->Function; 6204 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 6205 6206 unsigned MinParams = Fn->getMinRequiredArguments(); 6207 6208 // at least / at most / exactly 6209 // FIXME: variadic templates "at most" should account for parameter packs 6210 unsigned mode, modeCount; 6211 if (NumFormalArgs < MinParams) { 6212 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 6213 (Cand->FailureKind == ovl_fail_bad_deduction && 6214 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 6215 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 6216 mode = 0; // "at least" 6217 else 6218 mode = 2; // "exactly" 6219 modeCount = MinParams; 6220 } else { 6221 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 6222 (Cand->FailureKind == ovl_fail_bad_deduction && 6223 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 6224 if (MinParams != FnTy->getNumArgs()) 6225 mode = 1; // "at most" 6226 else 6227 mode = 2; // "exactly" 6228 modeCount = FnTy->getNumArgs(); 6229 } 6230 6231 std::string Description; 6232 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 6233 6234 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 6235 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 6236 << modeCount << NumFormalArgs; 6237} 6238 6239/// Diagnose a failed template-argument deduction. 6240void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 6241 Expr **Args, unsigned NumArgs) { 6242 FunctionDecl *Fn = Cand->Function; // pattern 6243 6244 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 6245 NamedDecl *ParamD; 6246 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 6247 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 6248 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 6249 switch (Cand->DeductionFailure.Result) { 6250 case Sema::TDK_Success: 6251 llvm_unreachable("TDK_success while diagnosing bad deduction"); 6252 6253 case Sema::TDK_Incomplete: { 6254 assert(ParamD && "no parameter found for incomplete deduction result"); 6255 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 6256 << ParamD->getDeclName(); 6257 return; 6258 } 6259 6260 case Sema::TDK_Underqualified: { 6261 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 6262 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 6263 6264 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 6265 6266 // Param will have been canonicalized, but it should just be a 6267 // qualified version of ParamD, so move the qualifiers to that. 6268 QualifierCollector Qs; 6269 Qs.strip(Param); 6270 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 6271 assert(S.Context.hasSameType(Param, NonCanonParam)); 6272 6273 // Arg has also been canonicalized, but there's nothing we can do 6274 // about that. It also doesn't matter as much, because it won't 6275 // have any template parameters in it (because deduction isn't 6276 // done on dependent types). 6277 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 6278 6279 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 6280 << ParamD->getDeclName() << Arg << NonCanonParam; 6281 return; 6282 } 6283 6284 case Sema::TDK_Inconsistent: { 6285 assert(ParamD && "no parameter found for inconsistent deduction result"); 6286 int which = 0; 6287 if (isa<TemplateTypeParmDecl>(ParamD)) 6288 which = 0; 6289 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 6290 which = 1; 6291 else { 6292 which = 2; 6293 } 6294 6295 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 6296 << which << ParamD->getDeclName() 6297 << *Cand->DeductionFailure.getFirstArg() 6298 << *Cand->DeductionFailure.getSecondArg(); 6299 return; 6300 } 6301 6302 case Sema::TDK_InvalidExplicitArguments: 6303 assert(ParamD && "no parameter found for invalid explicit arguments"); 6304 if (ParamD->getDeclName()) 6305 S.Diag(Fn->getLocation(), 6306 diag::note_ovl_candidate_explicit_arg_mismatch_named) 6307 << ParamD->getDeclName(); 6308 else { 6309 int index = 0; 6310 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 6311 index = TTP->getIndex(); 6312 else if (NonTypeTemplateParmDecl *NTTP 6313 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 6314 index = NTTP->getIndex(); 6315 else 6316 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 6317 S.Diag(Fn->getLocation(), 6318 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 6319 << (index + 1); 6320 } 6321 return; 6322 6323 case Sema::TDK_TooManyArguments: 6324 case Sema::TDK_TooFewArguments: 6325 DiagnoseArityMismatch(S, Cand, NumArgs); 6326 return; 6327 6328 case Sema::TDK_InstantiationDepth: 6329 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 6330 return; 6331 6332 case Sema::TDK_SubstitutionFailure: { 6333 std::string ArgString; 6334 if (TemplateArgumentList *Args 6335 = Cand->DeductionFailure.getTemplateArgumentList()) 6336 ArgString = S.getTemplateArgumentBindingsText( 6337 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 6338 *Args); 6339 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 6340 << ArgString; 6341 return; 6342 } 6343 6344 // TODO: diagnose these individually, then kill off 6345 // note_ovl_candidate_bad_deduction, which is uselessly vague. 6346 case Sema::TDK_NonDeducedMismatch: 6347 case Sema::TDK_FailedOverloadResolution: 6348 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 6349 return; 6350 } 6351} 6352 6353/// Generates a 'note' diagnostic for an overload candidate. We've 6354/// already generated a primary error at the call site. 6355/// 6356/// It really does need to be a single diagnostic with its caret 6357/// pointed at the candidate declaration. Yes, this creates some 6358/// major challenges of technical writing. Yes, this makes pointing 6359/// out problems with specific arguments quite awkward. It's still 6360/// better than generating twenty screens of text for every failed 6361/// overload. 6362/// 6363/// It would be great to be able to express per-candidate problems 6364/// more richly for those diagnostic clients that cared, but we'd 6365/// still have to be just as careful with the default diagnostics. 6366void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 6367 Expr **Args, unsigned NumArgs) { 6368 FunctionDecl *Fn = Cand->Function; 6369 6370 // Note deleted candidates, but only if they're viable. 6371 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 6372 std::string FnDesc; 6373 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6374 6375 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 6376 << FnKind << FnDesc << Fn->isDeleted(); 6377 return; 6378 } 6379 6380 // We don't really have anything else to say about viable candidates. 6381 if (Cand->Viable) { 6382 S.NoteOverloadCandidate(Fn); 6383 return; 6384 } 6385 6386 switch (Cand->FailureKind) { 6387 case ovl_fail_too_many_arguments: 6388 case ovl_fail_too_few_arguments: 6389 return DiagnoseArityMismatch(S, Cand, NumArgs); 6390 6391 case ovl_fail_bad_deduction: 6392 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 6393 6394 case ovl_fail_trivial_conversion: 6395 case ovl_fail_bad_final_conversion: 6396 case ovl_fail_final_conversion_not_exact: 6397 return S.NoteOverloadCandidate(Fn); 6398 6399 case ovl_fail_bad_conversion: { 6400 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 6401 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 6402 if (Cand->Conversions[I].isBad()) 6403 return DiagnoseBadConversion(S, Cand, I); 6404 6405 // FIXME: this currently happens when we're called from SemaInit 6406 // when user-conversion overload fails. Figure out how to handle 6407 // those conditions and diagnose them well. 6408 return S.NoteOverloadCandidate(Fn); 6409 } 6410 } 6411} 6412 6413void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 6414 // Desugar the type of the surrogate down to a function type, 6415 // retaining as many typedefs as possible while still showing 6416 // the function type (and, therefore, its parameter types). 6417 QualType FnType = Cand->Surrogate->getConversionType(); 6418 bool isLValueReference = false; 6419 bool isRValueReference = false; 6420 bool isPointer = false; 6421 if (const LValueReferenceType *FnTypeRef = 6422 FnType->getAs<LValueReferenceType>()) { 6423 FnType = FnTypeRef->getPointeeType(); 6424 isLValueReference = true; 6425 } else if (const RValueReferenceType *FnTypeRef = 6426 FnType->getAs<RValueReferenceType>()) { 6427 FnType = FnTypeRef->getPointeeType(); 6428 isRValueReference = true; 6429 } 6430 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 6431 FnType = FnTypePtr->getPointeeType(); 6432 isPointer = true; 6433 } 6434 // Desugar down to a function type. 6435 FnType = QualType(FnType->getAs<FunctionType>(), 0); 6436 // Reconstruct the pointer/reference as appropriate. 6437 if (isPointer) FnType = S.Context.getPointerType(FnType); 6438 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 6439 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 6440 6441 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 6442 << FnType; 6443} 6444 6445void NoteBuiltinOperatorCandidate(Sema &S, 6446 const char *Opc, 6447 SourceLocation OpLoc, 6448 OverloadCandidate *Cand) { 6449 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 6450 std::string TypeStr("operator"); 6451 TypeStr += Opc; 6452 TypeStr += "("; 6453 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 6454 if (Cand->Conversions.size() == 1) { 6455 TypeStr += ")"; 6456 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 6457 } else { 6458 TypeStr += ", "; 6459 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 6460 TypeStr += ")"; 6461 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 6462 } 6463} 6464 6465void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 6466 OverloadCandidate *Cand) { 6467 unsigned NoOperands = Cand->Conversions.size(); 6468 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 6469 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 6470 if (ICS.isBad()) break; // all meaningless after first invalid 6471 if (!ICS.isAmbiguous()) continue; 6472 6473 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 6474 S.PDiag(diag::note_ambiguous_type_conversion)); 6475 } 6476} 6477 6478SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 6479 if (Cand->Function) 6480 return Cand->Function->getLocation(); 6481 if (Cand->IsSurrogate) 6482 return Cand->Surrogate->getLocation(); 6483 return SourceLocation(); 6484} 6485 6486struct CompareOverloadCandidatesForDisplay { 6487 Sema &S; 6488 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 6489 6490 bool operator()(const OverloadCandidate *L, 6491 const OverloadCandidate *R) { 6492 // Fast-path this check. 6493 if (L == R) return false; 6494 6495 // Order first by viability. 6496 if (L->Viable) { 6497 if (!R->Viable) return true; 6498 6499 // TODO: introduce a tri-valued comparison for overload 6500 // candidates. Would be more worthwhile if we had a sort 6501 // that could exploit it. 6502 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 6503 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 6504 } else if (R->Viable) 6505 return false; 6506 6507 assert(L->Viable == R->Viable); 6508 6509 // Criteria by which we can sort non-viable candidates: 6510 if (!L->Viable) { 6511 // 1. Arity mismatches come after other candidates. 6512 if (L->FailureKind == ovl_fail_too_many_arguments || 6513 L->FailureKind == ovl_fail_too_few_arguments) 6514 return false; 6515 if (R->FailureKind == ovl_fail_too_many_arguments || 6516 R->FailureKind == ovl_fail_too_few_arguments) 6517 return true; 6518 6519 // 2. Bad conversions come first and are ordered by the number 6520 // of bad conversions and quality of good conversions. 6521 if (L->FailureKind == ovl_fail_bad_conversion) { 6522 if (R->FailureKind != ovl_fail_bad_conversion) 6523 return true; 6524 6525 // If there's any ordering between the defined conversions... 6526 // FIXME: this might not be transitive. 6527 assert(L->Conversions.size() == R->Conversions.size()); 6528 6529 int leftBetter = 0; 6530 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 6531 for (unsigned E = L->Conversions.size(); I != E; ++I) { 6532 switch (CompareImplicitConversionSequences(S, 6533 L->Conversions[I], 6534 R->Conversions[I])) { 6535 case ImplicitConversionSequence::Better: 6536 leftBetter++; 6537 break; 6538 6539 case ImplicitConversionSequence::Worse: 6540 leftBetter--; 6541 break; 6542 6543 case ImplicitConversionSequence::Indistinguishable: 6544 break; 6545 } 6546 } 6547 if (leftBetter > 0) return true; 6548 if (leftBetter < 0) return false; 6549 6550 } else if (R->FailureKind == ovl_fail_bad_conversion) 6551 return false; 6552 6553 // TODO: others? 6554 } 6555 6556 // Sort everything else by location. 6557 SourceLocation LLoc = GetLocationForCandidate(L); 6558 SourceLocation RLoc = GetLocationForCandidate(R); 6559 6560 // Put candidates without locations (e.g. builtins) at the end. 6561 if (LLoc.isInvalid()) return false; 6562 if (RLoc.isInvalid()) return true; 6563 6564 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 6565 } 6566}; 6567 6568/// CompleteNonViableCandidate - Normally, overload resolution only 6569/// computes up to the first 6570void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 6571 Expr **Args, unsigned NumArgs) { 6572 assert(!Cand->Viable); 6573 6574 // Don't do anything on failures other than bad conversion. 6575 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 6576 6577 // Skip forward to the first bad conversion. 6578 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 6579 unsigned ConvCount = Cand->Conversions.size(); 6580 while (true) { 6581 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 6582 ConvIdx++; 6583 if (Cand->Conversions[ConvIdx - 1].isBad()) 6584 break; 6585 } 6586 6587 if (ConvIdx == ConvCount) 6588 return; 6589 6590 assert(!Cand->Conversions[ConvIdx].isInitialized() && 6591 "remaining conversion is initialized?"); 6592 6593 // FIXME: this should probably be preserved from the overload 6594 // operation somehow. 6595 bool SuppressUserConversions = false; 6596 6597 const FunctionProtoType* Proto; 6598 unsigned ArgIdx = ConvIdx; 6599 6600 if (Cand->IsSurrogate) { 6601 QualType ConvType 6602 = Cand->Surrogate->getConversionType().getNonReferenceType(); 6603 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6604 ConvType = ConvPtrType->getPointeeType(); 6605 Proto = ConvType->getAs<FunctionProtoType>(); 6606 ArgIdx--; 6607 } else if (Cand->Function) { 6608 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 6609 if (isa<CXXMethodDecl>(Cand->Function) && 6610 !isa<CXXConstructorDecl>(Cand->Function)) 6611 ArgIdx--; 6612 } else { 6613 // Builtin binary operator with a bad first conversion. 6614 assert(ConvCount <= 3); 6615 for (; ConvIdx != ConvCount; ++ConvIdx) 6616 Cand->Conversions[ConvIdx] 6617 = TryCopyInitialization(S, Args[ConvIdx], 6618 Cand->BuiltinTypes.ParamTypes[ConvIdx], 6619 SuppressUserConversions, 6620 /*InOverloadResolution*/ true); 6621 return; 6622 } 6623 6624 // Fill in the rest of the conversions. 6625 unsigned NumArgsInProto = Proto->getNumArgs(); 6626 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 6627 if (ArgIdx < NumArgsInProto) 6628 Cand->Conversions[ConvIdx] 6629 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 6630 SuppressUserConversions, 6631 /*InOverloadResolution=*/true); 6632 else 6633 Cand->Conversions[ConvIdx].setEllipsis(); 6634 } 6635} 6636 6637} // end anonymous namespace 6638 6639/// PrintOverloadCandidates - When overload resolution fails, prints 6640/// diagnostic messages containing the candidates in the candidate 6641/// set. 6642void OverloadCandidateSet::NoteCandidates(Sema &S, 6643 OverloadCandidateDisplayKind OCD, 6644 Expr **Args, unsigned NumArgs, 6645 const char *Opc, 6646 SourceLocation OpLoc) { 6647 // Sort the candidates by viability and position. Sorting directly would 6648 // be prohibitive, so we make a set of pointers and sort those. 6649 llvm::SmallVector<OverloadCandidate*, 32> Cands; 6650 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 6651 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 6652 if (Cand->Viable) 6653 Cands.push_back(Cand); 6654 else if (OCD == OCD_AllCandidates) { 6655 CompleteNonViableCandidate(S, Cand, Args, NumArgs); 6656 if (Cand->Function || Cand->IsSurrogate) 6657 Cands.push_back(Cand); 6658 // Otherwise, this a non-viable builtin candidate. We do not, in general, 6659 // want to list every possible builtin candidate. 6660 } 6661 } 6662 6663 std::sort(Cands.begin(), Cands.end(), 6664 CompareOverloadCandidatesForDisplay(S)); 6665 6666 bool ReportedAmbiguousConversions = false; 6667 6668 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 6669 const Diagnostic::OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 6670 unsigned CandsShown = 0; 6671 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 6672 OverloadCandidate *Cand = *I; 6673 6674 // Set an arbitrary limit on the number of candidate functions we'll spam 6675 // the user with. FIXME: This limit should depend on details of the 6676 // candidate list. 6677 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 6678 break; 6679 } 6680 ++CandsShown; 6681 6682 if (Cand->Function) 6683 NoteFunctionCandidate(S, Cand, Args, NumArgs); 6684 else if (Cand->IsSurrogate) 6685 NoteSurrogateCandidate(S, Cand); 6686 else { 6687 assert(Cand->Viable && 6688 "Non-viable built-in candidates are not added to Cands."); 6689 // Generally we only see ambiguities including viable builtin 6690 // operators if overload resolution got screwed up by an 6691 // ambiguous user-defined conversion. 6692 // 6693 // FIXME: It's quite possible for different conversions to see 6694 // different ambiguities, though. 6695 if (!ReportedAmbiguousConversions) { 6696 NoteAmbiguousUserConversions(S, OpLoc, Cand); 6697 ReportedAmbiguousConversions = true; 6698 } 6699 6700 // If this is a viable builtin, print it. 6701 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 6702 } 6703 } 6704 6705 if (I != E) 6706 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 6707} 6708 6709static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 6710 if (isa<UnresolvedLookupExpr>(E)) 6711 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 6712 6713 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 6714} 6715 6716/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 6717/// an overloaded function (C++ [over.over]), where @p From is an 6718/// expression with overloaded function type and @p ToType is the type 6719/// we're trying to resolve to. For example: 6720/// 6721/// @code 6722/// int f(double); 6723/// int f(int); 6724/// 6725/// int (*pfd)(double) = f; // selects f(double) 6726/// @endcode 6727/// 6728/// This routine returns the resulting FunctionDecl if it could be 6729/// resolved, and NULL otherwise. When @p Complain is true, this 6730/// routine will emit diagnostics if there is an error. 6731FunctionDecl * 6732Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 6733 bool Complain, 6734 DeclAccessPair &FoundResult) { 6735 QualType FunctionType = ToType; 6736 bool IsMember = false; 6737 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 6738 FunctionType = ToTypePtr->getPointeeType(); 6739 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 6740 FunctionType = ToTypeRef->getPointeeType(); 6741 else if (const MemberPointerType *MemTypePtr = 6742 ToType->getAs<MemberPointerType>()) { 6743 FunctionType = MemTypePtr->getPointeeType(); 6744 IsMember = true; 6745 } 6746 6747 // C++ [over.over]p1: 6748 // [...] [Note: any redundant set of parentheses surrounding the 6749 // overloaded function name is ignored (5.1). ] 6750 // C++ [over.over]p1: 6751 // [...] The overloaded function name can be preceded by the & 6752 // operator. 6753 // However, remember whether the expression has member-pointer form: 6754 // C++ [expr.unary.op]p4: 6755 // A pointer to member is only formed when an explicit & is used 6756 // and its operand is a qualified-id not enclosed in 6757 // parentheses. 6758 OverloadExpr::FindResult Ovl = OverloadExpr::find(From); 6759 OverloadExpr *OvlExpr = Ovl.Expression; 6760 6761 // We expect a pointer or reference to function, or a function pointer. 6762 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 6763 if (!FunctionType->isFunctionType()) { 6764 if (Complain) 6765 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 6766 << OvlExpr->getName() << ToType; 6767 6768 return 0; 6769 } 6770 6771 // If the overload expression doesn't have the form of a pointer to 6772 // member, don't try to convert it to a pointer-to-member type. 6773 if (IsMember && !Ovl.HasFormOfMemberPointer) { 6774 if (!Complain) return 0; 6775 6776 // TODO: Should we condition this on whether any functions might 6777 // have matched, or is it more appropriate to do that in callers? 6778 // TODO: a fixit wouldn't hurt. 6779 Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 6780 << ToType << OvlExpr->getSourceRange(); 6781 return 0; 6782 } 6783 6784 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 6785 if (OvlExpr->hasExplicitTemplateArgs()) { 6786 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 6787 ExplicitTemplateArgs = &ETABuffer; 6788 } 6789 6790 assert(From->getType() == Context.OverloadTy); 6791 6792 // Look through all of the overloaded functions, searching for one 6793 // whose type matches exactly. 6794 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 6795 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 6796 6797 bool FoundNonTemplateFunction = false; 6798 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6799 E = OvlExpr->decls_end(); I != E; ++I) { 6800 // Look through any using declarations to find the underlying function. 6801 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 6802 6803 // C++ [over.over]p3: 6804 // Non-member functions and static member functions match 6805 // targets of type "pointer-to-function" or "reference-to-function." 6806 // Nonstatic member functions match targets of 6807 // type "pointer-to-member-function." 6808 // Note that according to DR 247, the containing class does not matter. 6809 6810 if (FunctionTemplateDecl *FunctionTemplate 6811 = dyn_cast<FunctionTemplateDecl>(Fn)) { 6812 if (CXXMethodDecl *Method 6813 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 6814 // Skip non-static function templates when converting to pointer, and 6815 // static when converting to member pointer. 6816 if (Method->isStatic() == IsMember) 6817 continue; 6818 } else if (IsMember) 6819 continue; 6820 6821 // C++ [over.over]p2: 6822 // If the name is a function template, template argument deduction is 6823 // done (14.8.2.2), and if the argument deduction succeeds, the 6824 // resulting template argument list is used to generate a single 6825 // function template specialization, which is added to the set of 6826 // overloaded functions considered. 6827 FunctionDecl *Specialization = 0; 6828 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6829 if (TemplateDeductionResult Result 6830 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 6831 FunctionType, Specialization, Info)) { 6832 // FIXME: make a note of the failed deduction for diagnostics. 6833 (void)Result; 6834 } else { 6835 // Template argument deduction ensures that we have an exact match. 6836 // This function template specicalization works. 6837 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 6838 assert(FunctionType 6839 == Context.getCanonicalType(Specialization->getType())); 6840 Matches.push_back(std::make_pair(I.getPair(), Specialization)); 6841 } 6842 6843 continue; 6844 } 6845 6846 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6847 // Skip non-static functions when converting to pointer, and static 6848 // when converting to member pointer. 6849 if (Method->isStatic() == IsMember) 6850 continue; 6851 6852 // If we have explicit template arguments, skip non-templates. 6853 if (OvlExpr->hasExplicitTemplateArgs()) 6854 continue; 6855 } else if (IsMember) 6856 continue; 6857 6858 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 6859 QualType ResultTy; 6860 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 6861 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 6862 ResultTy)) { 6863 Matches.push_back(std::make_pair(I.getPair(), 6864 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 6865 FoundNonTemplateFunction = true; 6866 } 6867 } 6868 } 6869 6870 // If there were 0 or 1 matches, we're done. 6871 if (Matches.empty()) { 6872 if (Complain) { 6873 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 6874 << OvlExpr->getName() << FunctionType; 6875 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6876 E = OvlExpr->decls_end(); 6877 I != E; ++I) 6878 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 6879 NoteOverloadCandidate(F); 6880 } 6881 6882 return 0; 6883 } else if (Matches.size() == 1) { 6884 FunctionDecl *Result = Matches[0].second; 6885 FoundResult = Matches[0].first; 6886 MarkDeclarationReferenced(From->getLocStart(), Result); 6887 if (Complain) { 6888 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 6889 } 6890 return Result; 6891 } 6892 6893 // C++ [over.over]p4: 6894 // If more than one function is selected, [...] 6895 if (!FoundNonTemplateFunction) { 6896 // [...] and any given function template specialization F1 is 6897 // eliminated if the set contains a second function template 6898 // specialization whose function template is more specialized 6899 // than the function template of F1 according to the partial 6900 // ordering rules of 14.5.5.2. 6901 6902 // The algorithm specified above is quadratic. We instead use a 6903 // two-pass algorithm (similar to the one used to identify the 6904 // best viable function in an overload set) that identifies the 6905 // best function template (if it exists). 6906 6907 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 6908 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6909 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 6910 6911 UnresolvedSetIterator Result = 6912 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 6913 TPOC_Other, From->getLocStart(), 6914 PDiag(), 6915 PDiag(diag::err_addr_ovl_ambiguous) 6916 << Matches[0].second->getDeclName(), 6917 PDiag(diag::note_ovl_candidate) 6918 << (unsigned) oc_function_template); 6919 if (Result == MatchesCopy.end()) 6920 return 0; 6921 6922 MarkDeclarationReferenced(From->getLocStart(), *Result); 6923 FoundResult = Matches[Result - MatchesCopy.begin()].first; 6924 if (Complain) 6925 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 6926 return cast<FunctionDecl>(*Result); 6927 } 6928 6929 // [...] any function template specializations in the set are 6930 // eliminated if the set also contains a non-template function, [...] 6931 for (unsigned I = 0, N = Matches.size(); I != N; ) { 6932 if (Matches[I].second->getPrimaryTemplate() == 0) 6933 ++I; 6934 else { 6935 Matches[I] = Matches[--N]; 6936 Matches.set_size(N); 6937 } 6938 } 6939 6940 // [...] After such eliminations, if any, there shall remain exactly one 6941 // selected function. 6942 if (Matches.size() == 1) { 6943 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 6944 FoundResult = Matches[0].first; 6945 if (Complain) 6946 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 6947 return cast<FunctionDecl>(Matches[0].second); 6948 } 6949 6950 // FIXME: We should probably return the same thing that BestViableFunction 6951 // returns (even if we issue the diagnostics here). 6952 if (Complain) { 6953 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 6954 << Matches[0].second->getDeclName(); 6955 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6956 NoteOverloadCandidate(Matches[I].second); 6957 } 6958 6959 return 0; 6960} 6961 6962/// \brief Given an expression that refers to an overloaded function, try to 6963/// resolve that overloaded function expression down to a single function. 6964/// 6965/// This routine can only resolve template-ids that refer to a single function 6966/// template, where that template-id refers to a single template whose template 6967/// arguments are either provided by the template-id or have defaults, 6968/// as described in C++0x [temp.arg.explicit]p3. 6969FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 6970 // C++ [over.over]p1: 6971 // [...] [Note: any redundant set of parentheses surrounding the 6972 // overloaded function name is ignored (5.1). ] 6973 // C++ [over.over]p1: 6974 // [...] The overloaded function name can be preceded by the & 6975 // operator. 6976 6977 if (From->getType() != Context.OverloadTy) 6978 return 0; 6979 6980 OverloadExpr *OvlExpr = OverloadExpr::find(From).Expression; 6981 6982 // If we didn't actually find any template-ids, we're done. 6983 if (!OvlExpr->hasExplicitTemplateArgs()) 6984 return 0; 6985 6986 TemplateArgumentListInfo ExplicitTemplateArgs; 6987 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 6988 6989 // Look through all of the overloaded functions, searching for one 6990 // whose type matches exactly. 6991 FunctionDecl *Matched = 0; 6992 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6993 E = OvlExpr->decls_end(); I != E; ++I) { 6994 // C++0x [temp.arg.explicit]p3: 6995 // [...] In contexts where deduction is done and fails, or in contexts 6996 // where deduction is not done, if a template argument list is 6997 // specified and it, along with any default template arguments, 6998 // identifies a single function template specialization, then the 6999 // template-id is an lvalue for the function template specialization. 7000 FunctionTemplateDecl *FunctionTemplate 7001 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 7002 7003 // C++ [over.over]p2: 7004 // If the name is a function template, template argument deduction is 7005 // done (14.8.2.2), and if the argument deduction succeeds, the 7006 // resulting template argument list is used to generate a single 7007 // function template specialization, which is added to the set of 7008 // overloaded functions considered. 7009 FunctionDecl *Specialization = 0; 7010 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 7011 if (TemplateDeductionResult Result 7012 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 7013 Specialization, Info)) { 7014 // FIXME: make a note of the failed deduction for diagnostics. 7015 (void)Result; 7016 continue; 7017 } 7018 7019 // Multiple matches; we can't resolve to a single declaration. 7020 if (Matched) 7021 return 0; 7022 7023 Matched = Specialization; 7024 } 7025 7026 return Matched; 7027} 7028 7029/// \brief Add a single candidate to the overload set. 7030static void AddOverloadedCallCandidate(Sema &S, 7031 DeclAccessPair FoundDecl, 7032 const TemplateArgumentListInfo *ExplicitTemplateArgs, 7033 Expr **Args, unsigned NumArgs, 7034 OverloadCandidateSet &CandidateSet, 7035 bool PartialOverloading) { 7036 NamedDecl *Callee = FoundDecl.getDecl(); 7037 if (isa<UsingShadowDecl>(Callee)) 7038 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 7039 7040 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 7041 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 7042 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 7043 false, PartialOverloading); 7044 return; 7045 } 7046 7047 if (FunctionTemplateDecl *FuncTemplate 7048 = dyn_cast<FunctionTemplateDecl>(Callee)) { 7049 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 7050 ExplicitTemplateArgs, 7051 Args, NumArgs, CandidateSet); 7052 return; 7053 } 7054 7055 assert(false && "unhandled case in overloaded call candidate"); 7056 7057 // do nothing? 7058} 7059 7060/// \brief Add the overload candidates named by callee and/or found by argument 7061/// dependent lookup to the given overload set. 7062void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 7063 Expr **Args, unsigned NumArgs, 7064 OverloadCandidateSet &CandidateSet, 7065 bool PartialOverloading) { 7066 7067#ifndef NDEBUG 7068 // Verify that ArgumentDependentLookup is consistent with the rules 7069 // in C++0x [basic.lookup.argdep]p3: 7070 // 7071 // Let X be the lookup set produced by unqualified lookup (3.4.1) 7072 // and let Y be the lookup set produced by argument dependent 7073 // lookup (defined as follows). If X contains 7074 // 7075 // -- a declaration of a class member, or 7076 // 7077 // -- a block-scope function declaration that is not a 7078 // using-declaration, or 7079 // 7080 // -- a declaration that is neither a function or a function 7081 // template 7082 // 7083 // then Y is empty. 7084 7085 if (ULE->requiresADL()) { 7086 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 7087 E = ULE->decls_end(); I != E; ++I) { 7088 assert(!(*I)->getDeclContext()->isRecord()); 7089 assert(isa<UsingShadowDecl>(*I) || 7090 !(*I)->getDeclContext()->isFunctionOrMethod()); 7091 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 7092 } 7093 } 7094#endif 7095 7096 // It would be nice to avoid this copy. 7097 TemplateArgumentListInfo TABuffer; 7098 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 7099 if (ULE->hasExplicitTemplateArgs()) { 7100 ULE->copyTemplateArgumentsInto(TABuffer); 7101 ExplicitTemplateArgs = &TABuffer; 7102 } 7103 7104 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 7105 E = ULE->decls_end(); I != E; ++I) 7106 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 7107 Args, NumArgs, CandidateSet, 7108 PartialOverloading); 7109 7110 if (ULE->requiresADL()) 7111 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 7112 Args, NumArgs, 7113 ExplicitTemplateArgs, 7114 CandidateSet, 7115 PartialOverloading); 7116} 7117 7118/// Attempts to recover from a call where no functions were found. 7119/// 7120/// Returns true if new candidates were found. 7121static ExprResult 7122BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 7123 UnresolvedLookupExpr *ULE, 7124 SourceLocation LParenLoc, 7125 Expr **Args, unsigned NumArgs, 7126 SourceLocation RParenLoc) { 7127 7128 CXXScopeSpec SS; 7129 if (ULE->getQualifier()) { 7130 SS.setScopeRep(ULE->getQualifier()); 7131 SS.setRange(ULE->getQualifierRange()); 7132 } 7133 7134 TemplateArgumentListInfo TABuffer; 7135 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 7136 if (ULE->hasExplicitTemplateArgs()) { 7137 ULE->copyTemplateArgumentsInto(TABuffer); 7138 ExplicitTemplateArgs = &TABuffer; 7139 } 7140 7141 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 7142 Sema::LookupOrdinaryName); 7143 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 7144 return ExprError(); 7145 7146 assert(!R.empty() && "lookup results empty despite recovery"); 7147 7148 // Build an implicit member call if appropriate. Just drop the 7149 // casts and such from the call, we don't really care. 7150 ExprResult NewFn = ExprError(); 7151 if ((*R.begin())->isCXXClassMember()) 7152 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, 7153 ExplicitTemplateArgs); 7154 else if (ExplicitTemplateArgs) 7155 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 7156 else 7157 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 7158 7159 if (NewFn.isInvalid()) 7160 return ExprError(); 7161 7162 // This shouldn't cause an infinite loop because we're giving it 7163 // an expression with non-empty lookup results, which should never 7164 // end up here. 7165 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 7166 MultiExprArg(Args, NumArgs), RParenLoc); 7167} 7168 7169/// ResolveOverloadedCallFn - Given the call expression that calls Fn 7170/// (which eventually refers to the declaration Func) and the call 7171/// arguments Args/NumArgs, attempt to resolve the function call down 7172/// to a specific function. If overload resolution succeeds, returns 7173/// the function declaration produced by overload 7174/// resolution. Otherwise, emits diagnostics, deletes all of the 7175/// arguments and Fn, and returns NULL. 7176ExprResult 7177Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 7178 SourceLocation LParenLoc, 7179 Expr **Args, unsigned NumArgs, 7180 SourceLocation RParenLoc) { 7181#ifndef NDEBUG 7182 if (ULE->requiresADL()) { 7183 // To do ADL, we must have found an unqualified name. 7184 assert(!ULE->getQualifier() && "qualified name with ADL"); 7185 7186 // We don't perform ADL for implicit declarations of builtins. 7187 // Verify that this was correctly set up. 7188 FunctionDecl *F; 7189 if (ULE->decls_begin() + 1 == ULE->decls_end() && 7190 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 7191 F->getBuiltinID() && F->isImplicit()) 7192 assert(0 && "performing ADL for builtin"); 7193 7194 // We don't perform ADL in C. 7195 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 7196 } 7197#endif 7198 7199 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 7200 7201 // Add the functions denoted by the callee to the set of candidate 7202 // functions, including those from argument-dependent lookup. 7203 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 7204 7205 // If we found nothing, try to recover. 7206 // AddRecoveryCallCandidates diagnoses the error itself, so we just 7207 // bailout out if it fails. 7208 if (CandidateSet.empty()) 7209 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 7210 RParenLoc); 7211 7212 OverloadCandidateSet::iterator Best; 7213 switch (CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best)) { 7214 case OR_Success: { 7215 FunctionDecl *FDecl = Best->Function; 7216 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 7217 DiagnoseUseOfDecl(FDecl? FDecl : Best->FoundDecl.getDecl(), 7218 ULE->getNameLoc()); 7219 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 7220 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, 7221 RParenLoc); 7222 } 7223 7224 case OR_No_Viable_Function: 7225 Diag(Fn->getSourceRange().getBegin(), 7226 diag::err_ovl_no_viable_function_in_call) 7227 << ULE->getName() << Fn->getSourceRange(); 7228 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7229 break; 7230 7231 case OR_Ambiguous: 7232 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 7233 << ULE->getName() << Fn->getSourceRange(); 7234 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 7235 break; 7236 7237 case OR_Deleted: 7238 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 7239 << Best->Function->isDeleted() 7240 << ULE->getName() 7241 << Fn->getSourceRange(); 7242 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7243 break; 7244 } 7245 7246 // Overload resolution failed. 7247 return ExprError(); 7248} 7249 7250static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 7251 return Functions.size() > 1 || 7252 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 7253} 7254 7255/// \brief Create a unary operation that may resolve to an overloaded 7256/// operator. 7257/// 7258/// \param OpLoc The location of the operator itself (e.g., '*'). 7259/// 7260/// \param OpcIn The UnaryOperator::Opcode that describes this 7261/// operator. 7262/// 7263/// \param Functions The set of non-member functions that will be 7264/// considered by overload resolution. The caller needs to build this 7265/// set based on the context using, e.g., 7266/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 7267/// set should not contain any member functions; those will be added 7268/// by CreateOverloadedUnaryOp(). 7269/// 7270/// \param input The input argument. 7271ExprResult 7272Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 7273 const UnresolvedSetImpl &Fns, 7274 Expr *Input) { 7275 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 7276 7277 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 7278 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 7279 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 7280 // TODO: provide better source location info. 7281 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 7282 7283 if (Input->getObjectKind() == OK_ObjCProperty) 7284 ConvertPropertyForRValue(Input); 7285 7286 Expr *Args[2] = { Input, 0 }; 7287 unsigned NumArgs = 1; 7288 7289 // For post-increment and post-decrement, add the implicit '0' as 7290 // the second argument, so that we know this is a post-increment or 7291 // post-decrement. 7292 if (Opc == UO_PostInc || Opc == UO_PostDec) { 7293 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 7294 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 7295 SourceLocation()); 7296 NumArgs = 2; 7297 } 7298 7299 if (Input->isTypeDependent()) { 7300 if (Fns.empty()) 7301 return Owned(new (Context) UnaryOperator(Input, 7302 Opc, 7303 Context.DependentTy, 7304 VK_RValue, OK_Ordinary, 7305 OpLoc)); 7306 7307 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7308 UnresolvedLookupExpr *Fn 7309 = UnresolvedLookupExpr::Create(Context, NamingClass, 7310 0, SourceRange(), OpNameInfo, 7311 /*ADL*/ true, IsOverloaded(Fns), 7312 Fns.begin(), Fns.end()); 7313 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 7314 &Args[0], NumArgs, 7315 Context.DependentTy, 7316 VK_RValue, 7317 OpLoc)); 7318 } 7319 7320 // Build an empty overload set. 7321 OverloadCandidateSet CandidateSet(OpLoc); 7322 7323 // Add the candidates from the given function set. 7324 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 7325 7326 // Add operator candidates that are member functions. 7327 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 7328 7329 // Add candidates from ADL. 7330 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 7331 Args, NumArgs, 7332 /*ExplicitTemplateArgs*/ 0, 7333 CandidateSet); 7334 7335 // Add builtin operator candidates. 7336 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 7337 7338 // Perform overload resolution. 7339 OverloadCandidateSet::iterator Best; 7340 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 7341 case OR_Success: { 7342 // We found a built-in operator or an overloaded operator. 7343 FunctionDecl *FnDecl = Best->Function; 7344 7345 if (FnDecl) { 7346 // We matched an overloaded operator. Build a call to that 7347 // operator. 7348 7349 // Convert the arguments. 7350 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 7351 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 7352 7353 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 7354 Best->FoundDecl, Method)) 7355 return ExprError(); 7356 } else { 7357 // Convert the arguments. 7358 ExprResult InputInit 7359 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7360 Context, 7361 FnDecl->getParamDecl(0)), 7362 SourceLocation(), 7363 Input); 7364 if (InputInit.isInvalid()) 7365 return ExprError(); 7366 Input = InputInit.take(); 7367 } 7368 7369 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7370 7371 // Determine the result type. 7372 QualType ResultTy = FnDecl->getResultType(); 7373 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 7374 ResultTy = ResultTy.getNonLValueExprType(Context); 7375 7376 // Build the actual expression node. 7377 Expr *FnExpr = CreateFunctionRefExpr(*this, FnDecl); 7378 7379 Args[0] = Input; 7380 CallExpr *TheCall = 7381 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 7382 Args, NumArgs, ResultTy, VK, OpLoc); 7383 7384 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 7385 FnDecl)) 7386 return ExprError(); 7387 7388 return MaybeBindToTemporary(TheCall); 7389 } else { 7390 // We matched a built-in operator. Convert the arguments, then 7391 // break out so that we will build the appropriate built-in 7392 // operator node. 7393 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 7394 Best->Conversions[0], AA_Passing)) 7395 return ExprError(); 7396 7397 break; 7398 } 7399 } 7400 7401 case OR_No_Viable_Function: 7402 // No viable function; fall through to handling this as a 7403 // built-in operator, which will produce an error message for us. 7404 break; 7405 7406 case OR_Ambiguous: 7407 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 7408 << UnaryOperator::getOpcodeStr(Opc) 7409 << Input->getType() 7410 << Input->getSourceRange(); 7411 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 7412 Args, NumArgs, 7413 UnaryOperator::getOpcodeStr(Opc), OpLoc); 7414 return ExprError(); 7415 7416 case OR_Deleted: 7417 Diag(OpLoc, diag::err_ovl_deleted_oper) 7418 << Best->Function->isDeleted() 7419 << UnaryOperator::getOpcodeStr(Opc) 7420 << Input->getSourceRange(); 7421 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7422 return ExprError(); 7423 } 7424 7425 // Either we found no viable overloaded operator or we matched a 7426 // built-in operator. In either case, fall through to trying to 7427 // build a built-in operation. 7428 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 7429} 7430 7431/// \brief Create a binary operation that may resolve to an overloaded 7432/// operator. 7433/// 7434/// \param OpLoc The location of the operator itself (e.g., '+'). 7435/// 7436/// \param OpcIn The BinaryOperator::Opcode that describes this 7437/// operator. 7438/// 7439/// \param Functions The set of non-member functions that will be 7440/// considered by overload resolution. The caller needs to build this 7441/// set based on the context using, e.g., 7442/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 7443/// set should not contain any member functions; those will be added 7444/// by CreateOverloadedBinOp(). 7445/// 7446/// \param LHS Left-hand argument. 7447/// \param RHS Right-hand argument. 7448ExprResult 7449Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 7450 unsigned OpcIn, 7451 const UnresolvedSetImpl &Fns, 7452 Expr *LHS, Expr *RHS) { 7453 Expr *Args[2] = { LHS, RHS }; 7454 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 7455 7456 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 7457 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 7458 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 7459 7460 // If either side is type-dependent, create an appropriate dependent 7461 // expression. 7462 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 7463 if (Fns.empty()) { 7464 // If there are no functions to store, just build a dependent 7465 // BinaryOperator or CompoundAssignment. 7466 if (Opc <= BO_Assign || Opc > BO_OrAssign) 7467 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 7468 Context.DependentTy, 7469 VK_RValue, OK_Ordinary, 7470 OpLoc)); 7471 7472 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 7473 Context.DependentTy, 7474 VK_LValue, 7475 OK_Ordinary, 7476 Context.DependentTy, 7477 Context.DependentTy, 7478 OpLoc)); 7479 } 7480 7481 // FIXME: save results of ADL from here? 7482 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7483 // TODO: provide better source location info in DNLoc component. 7484 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 7485 UnresolvedLookupExpr *Fn 7486 = UnresolvedLookupExpr::Create(Context, NamingClass, 0, SourceRange(), 7487 OpNameInfo, /*ADL*/ true, IsOverloaded(Fns), 7488 Fns.begin(), Fns.end()); 7489 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 7490 Args, 2, 7491 Context.DependentTy, 7492 VK_RValue, 7493 OpLoc)); 7494 } 7495 7496 // Always do property rvalue conversions on the RHS. 7497 if (Args[1]->getObjectKind() == OK_ObjCProperty) 7498 ConvertPropertyForRValue(Args[1]); 7499 7500 // The LHS is more complicated. 7501 if (Args[0]->getObjectKind() == OK_ObjCProperty) { 7502 7503 // There's a tension for assignment operators between primitive 7504 // property assignment and the overloaded operators. 7505 if (BinaryOperator::isAssignmentOp(Opc)) { 7506 const ObjCPropertyRefExpr *PRE = LHS->getObjCProperty(); 7507 7508 // Is the property "logically" settable? 7509 bool Settable = (PRE->isExplicitProperty() || 7510 PRE->getImplicitPropertySetter()); 7511 7512 // To avoid gratuitously inventing semantics, use the primitive 7513 // unless it isn't. Thoughts in case we ever really care: 7514 // - If the property isn't logically settable, we have to 7515 // load and hope. 7516 // - If the property is settable and this is simple assignment, 7517 // we really should use the primitive. 7518 // - If the property is settable, then we could try overloading 7519 // on a generic lvalue of the appropriate type; if it works 7520 // out to a builtin candidate, we would do that same operation 7521 // on the property, and otherwise just error. 7522 if (Settable) 7523 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7524 } 7525 7526 ConvertPropertyForRValue(Args[0]); 7527 } 7528 7529 // If this is the assignment operator, we only perform overload resolution 7530 // if the left-hand side is a class or enumeration type. This is actually 7531 // a hack. The standard requires that we do overload resolution between the 7532 // various built-in candidates, but as DR507 points out, this can lead to 7533 // problems. So we do it this way, which pretty much follows what GCC does. 7534 // Note that we go the traditional code path for compound assignment forms. 7535 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 7536 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7537 7538 // If this is the .* operator, which is not overloadable, just 7539 // create a built-in binary operator. 7540 if (Opc == BO_PtrMemD) 7541 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7542 7543 // Build an empty overload set. 7544 OverloadCandidateSet CandidateSet(OpLoc); 7545 7546 // Add the candidates from the given function set. 7547 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 7548 7549 // Add operator candidates that are member functions. 7550 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 7551 7552 // Add candidates from ADL. 7553 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 7554 Args, 2, 7555 /*ExplicitTemplateArgs*/ 0, 7556 CandidateSet); 7557 7558 // Add builtin operator candidates. 7559 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 7560 7561 // Perform overload resolution. 7562 OverloadCandidateSet::iterator Best; 7563 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 7564 case OR_Success: { 7565 // We found a built-in operator or an overloaded operator. 7566 FunctionDecl *FnDecl = Best->Function; 7567 7568 if (FnDecl) { 7569 // We matched an overloaded operator. Build a call to that 7570 // operator. 7571 7572 // Convert the arguments. 7573 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 7574 // Best->Access is only meaningful for class members. 7575 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 7576 7577 ExprResult Arg1 = 7578 PerformCopyInitialization( 7579 InitializedEntity::InitializeParameter(Context, 7580 FnDecl->getParamDecl(0)), 7581 SourceLocation(), Owned(Args[1])); 7582 if (Arg1.isInvalid()) 7583 return ExprError(); 7584 7585 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 7586 Best->FoundDecl, Method)) 7587 return ExprError(); 7588 7589 Args[1] = RHS = Arg1.takeAs<Expr>(); 7590 } else { 7591 // Convert the arguments. 7592 ExprResult Arg0 = PerformCopyInitialization( 7593 InitializedEntity::InitializeParameter(Context, 7594 FnDecl->getParamDecl(0)), 7595 SourceLocation(), Owned(Args[0])); 7596 if (Arg0.isInvalid()) 7597 return ExprError(); 7598 7599 ExprResult Arg1 = 7600 PerformCopyInitialization( 7601 InitializedEntity::InitializeParameter(Context, 7602 FnDecl->getParamDecl(1)), 7603 SourceLocation(), Owned(Args[1])); 7604 if (Arg1.isInvalid()) 7605 return ExprError(); 7606 Args[0] = LHS = Arg0.takeAs<Expr>(); 7607 Args[1] = RHS = Arg1.takeAs<Expr>(); 7608 } 7609 7610 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7611 7612 // Determine the result type. 7613 QualType ResultTy = FnDecl->getResultType(); 7614 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 7615 ResultTy = ResultTy.getNonLValueExprType(Context); 7616 7617 // Build the actual expression node. 7618 Expr *FnExpr = CreateFunctionRefExpr(*this, FnDecl, OpLoc); 7619 7620 CXXOperatorCallExpr *TheCall = 7621 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 7622 Args, 2, ResultTy, VK, OpLoc); 7623 7624 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 7625 FnDecl)) 7626 return ExprError(); 7627 7628 return MaybeBindToTemporary(TheCall); 7629 } else { 7630 // We matched a built-in operator. Convert the arguments, then 7631 // break out so that we will build the appropriate built-in 7632 // operator node. 7633 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 7634 Best->Conversions[0], AA_Passing) || 7635 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 7636 Best->Conversions[1], AA_Passing)) 7637 return ExprError(); 7638 7639 break; 7640 } 7641 } 7642 7643 case OR_No_Viable_Function: { 7644 // C++ [over.match.oper]p9: 7645 // If the operator is the operator , [...] and there are no 7646 // viable functions, then the operator is assumed to be the 7647 // built-in operator and interpreted according to clause 5. 7648 if (Opc == BO_Comma) 7649 break; 7650 7651 // For class as left operand for assignment or compound assigment 7652 // operator do not fall through to handling in built-in, but report that 7653 // no overloaded assignment operator found 7654 ExprResult Result = ExprError(); 7655 if (Args[0]->getType()->isRecordType() && 7656 Opc >= BO_Assign && Opc <= BO_OrAssign) { 7657 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7658 << BinaryOperator::getOpcodeStr(Opc) 7659 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7660 } else { 7661 // No viable function; try to create a built-in operation, which will 7662 // produce an error. Then, show the non-viable candidates. 7663 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7664 } 7665 assert(Result.isInvalid() && 7666 "C++ binary operator overloading is missing candidates!"); 7667 if (Result.isInvalid()) 7668 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 7669 BinaryOperator::getOpcodeStr(Opc), OpLoc); 7670 return move(Result); 7671 } 7672 7673 case OR_Ambiguous: 7674 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 7675 << BinaryOperator::getOpcodeStr(Opc) 7676 << Args[0]->getType() << Args[1]->getType() 7677 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7678 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 7679 BinaryOperator::getOpcodeStr(Opc), OpLoc); 7680 return ExprError(); 7681 7682 case OR_Deleted: 7683 Diag(OpLoc, diag::err_ovl_deleted_oper) 7684 << Best->Function->isDeleted() 7685 << BinaryOperator::getOpcodeStr(Opc) 7686 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7687 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2); 7688 return ExprError(); 7689 } 7690 7691 // We matched a built-in operator; build it. 7692 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7693} 7694 7695ExprResult 7696Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 7697 SourceLocation RLoc, 7698 Expr *Base, Expr *Idx) { 7699 Expr *Args[2] = { Base, Idx }; 7700 DeclarationName OpName = 7701 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 7702 7703 // If either side is type-dependent, create an appropriate dependent 7704 // expression. 7705 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 7706 7707 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7708 // CHECKME: no 'operator' keyword? 7709 DeclarationNameInfo OpNameInfo(OpName, LLoc); 7710 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 7711 UnresolvedLookupExpr *Fn 7712 = UnresolvedLookupExpr::Create(Context, NamingClass, 7713 0, SourceRange(), OpNameInfo, 7714 /*ADL*/ true, /*Overloaded*/ false, 7715 UnresolvedSetIterator(), 7716 UnresolvedSetIterator()); 7717 // Can't add any actual overloads yet 7718 7719 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 7720 Args, 2, 7721 Context.DependentTy, 7722 VK_RValue, 7723 RLoc)); 7724 } 7725 7726 if (Args[0]->getObjectKind() == OK_ObjCProperty) 7727 ConvertPropertyForRValue(Args[0]); 7728 if (Args[1]->getObjectKind() == OK_ObjCProperty) 7729 ConvertPropertyForRValue(Args[1]); 7730 7731 // Build an empty overload set. 7732 OverloadCandidateSet CandidateSet(LLoc); 7733 7734 // Subscript can only be overloaded as a member function. 7735 7736 // Add operator candidates that are member functions. 7737 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 7738 7739 // Add builtin operator candidates. 7740 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 7741 7742 // Perform overload resolution. 7743 OverloadCandidateSet::iterator Best; 7744 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 7745 case OR_Success: { 7746 // We found a built-in operator or an overloaded operator. 7747 FunctionDecl *FnDecl = Best->Function; 7748 7749 if (FnDecl) { 7750 // We matched an overloaded operator. Build a call to that 7751 // operator. 7752 7753 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 7754 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 7755 7756 // Convert the arguments. 7757 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 7758 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 7759 Best->FoundDecl, Method)) 7760 return ExprError(); 7761 7762 // Convert the arguments. 7763 ExprResult InputInit 7764 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7765 Context, 7766 FnDecl->getParamDecl(0)), 7767 SourceLocation(), 7768 Owned(Args[1])); 7769 if (InputInit.isInvalid()) 7770 return ExprError(); 7771 7772 Args[1] = InputInit.takeAs<Expr>(); 7773 7774 // Determine the result type 7775 QualType ResultTy = FnDecl->getResultType(); 7776 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 7777 ResultTy = ResultTy.getNonLValueExprType(Context); 7778 7779 // Build the actual expression node. 7780 Expr *FnExpr = CreateFunctionRefExpr(*this, FnDecl, LLoc); 7781 7782 CXXOperatorCallExpr *TheCall = 7783 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 7784 FnExpr, Args, 2, 7785 ResultTy, VK, RLoc); 7786 7787 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 7788 FnDecl)) 7789 return ExprError(); 7790 7791 return MaybeBindToTemporary(TheCall); 7792 } else { 7793 // We matched a built-in operator. Convert the arguments, then 7794 // break out so that we will build the appropriate built-in 7795 // operator node. 7796 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 7797 Best->Conversions[0], AA_Passing) || 7798 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 7799 Best->Conversions[1], AA_Passing)) 7800 return ExprError(); 7801 7802 break; 7803 } 7804 } 7805 7806 case OR_No_Viable_Function: { 7807 if (CandidateSet.empty()) 7808 Diag(LLoc, diag::err_ovl_no_oper) 7809 << Args[0]->getType() << /*subscript*/ 0 7810 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7811 else 7812 Diag(LLoc, diag::err_ovl_no_viable_subscript) 7813 << Args[0]->getType() 7814 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7815 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 7816 "[]", LLoc); 7817 return ExprError(); 7818 } 7819 7820 case OR_Ambiguous: 7821 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 7822 << "[]" 7823 << Args[0]->getType() << Args[1]->getType() 7824 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7825 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 7826 "[]", LLoc); 7827 return ExprError(); 7828 7829 case OR_Deleted: 7830 Diag(LLoc, diag::err_ovl_deleted_oper) 7831 << Best->Function->isDeleted() << "[]" 7832 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7833 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 7834 "[]", LLoc); 7835 return ExprError(); 7836 } 7837 7838 // We matched a built-in operator; build it. 7839 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 7840} 7841 7842/// BuildCallToMemberFunction - Build a call to a member 7843/// function. MemExpr is the expression that refers to the member 7844/// function (and includes the object parameter), Args/NumArgs are the 7845/// arguments to the function call (not including the object 7846/// parameter). The caller needs to validate that the member 7847/// expression refers to a member function or an overloaded member 7848/// function. 7849ExprResult 7850Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 7851 SourceLocation LParenLoc, Expr **Args, 7852 unsigned NumArgs, SourceLocation RParenLoc) { 7853 // Dig out the member expression. This holds both the object 7854 // argument and the member function we're referring to. 7855 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 7856 7857 MemberExpr *MemExpr; 7858 CXXMethodDecl *Method = 0; 7859 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 7860 NestedNameSpecifier *Qualifier = 0; 7861 if (isa<MemberExpr>(NakedMemExpr)) { 7862 MemExpr = cast<MemberExpr>(NakedMemExpr); 7863 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 7864 FoundDecl = MemExpr->getFoundDecl(); 7865 Qualifier = MemExpr->getQualifier(); 7866 } else { 7867 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 7868 Qualifier = UnresExpr->getQualifier(); 7869 7870 QualType ObjectType = UnresExpr->getBaseType(); 7871 7872 // Add overload candidates 7873 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 7874 7875 // FIXME: avoid copy. 7876 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7877 if (UnresExpr->hasExplicitTemplateArgs()) { 7878 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7879 TemplateArgs = &TemplateArgsBuffer; 7880 } 7881 7882 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 7883 E = UnresExpr->decls_end(); I != E; ++I) { 7884 7885 NamedDecl *Func = *I; 7886 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 7887 if (isa<UsingShadowDecl>(Func)) 7888 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 7889 7890 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 7891 // If explicit template arguments were provided, we can't call a 7892 // non-template member function. 7893 if (TemplateArgs) 7894 continue; 7895 7896 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 7897 Args, NumArgs, 7898 CandidateSet, /*SuppressUserConversions=*/false); 7899 } else { 7900 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 7901 I.getPair(), ActingDC, TemplateArgs, 7902 ObjectType, Args, NumArgs, 7903 CandidateSet, 7904 /*SuppressUsedConversions=*/false); 7905 } 7906 } 7907 7908 DeclarationName DeclName = UnresExpr->getMemberName(); 7909 7910 OverloadCandidateSet::iterator Best; 7911 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 7912 Best)) { 7913 case OR_Success: 7914 Method = cast<CXXMethodDecl>(Best->Function); 7915 FoundDecl = Best->FoundDecl; 7916 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 7917 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 7918 break; 7919 7920 case OR_No_Viable_Function: 7921 Diag(UnresExpr->getMemberLoc(), 7922 diag::err_ovl_no_viable_member_function_in_call) 7923 << DeclName << MemExprE->getSourceRange(); 7924 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7925 // FIXME: Leaking incoming expressions! 7926 return ExprError(); 7927 7928 case OR_Ambiguous: 7929 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 7930 << DeclName << MemExprE->getSourceRange(); 7931 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7932 // FIXME: Leaking incoming expressions! 7933 return ExprError(); 7934 7935 case OR_Deleted: 7936 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 7937 << Best->Function->isDeleted() 7938 << DeclName << MemExprE->getSourceRange(); 7939 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7940 // FIXME: Leaking incoming expressions! 7941 return ExprError(); 7942 } 7943 7944 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 7945 7946 // If overload resolution picked a static member, build a 7947 // non-member call based on that function. 7948 if (Method->isStatic()) { 7949 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 7950 Args, NumArgs, RParenLoc); 7951 } 7952 7953 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 7954 } 7955 7956 QualType ResultType = Method->getResultType(); 7957 ExprValueKind VK = Expr::getValueKindForType(ResultType); 7958 ResultType = ResultType.getNonLValueExprType(Context); 7959 7960 assert(Method && "Member call to something that isn't a method?"); 7961 CXXMemberCallExpr *TheCall = 7962 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 7963 ResultType, VK, RParenLoc); 7964 7965 // Check for a valid return type. 7966 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 7967 TheCall, Method)) 7968 return ExprError(); 7969 7970 // Convert the object argument (for a non-static member function call). 7971 // We only need to do this if there was actually an overload; otherwise 7972 // it was done at lookup. 7973 Expr *ObjectArg = MemExpr->getBase(); 7974 if (!Method->isStatic() && 7975 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 7976 FoundDecl, Method)) 7977 return ExprError(); 7978 MemExpr->setBase(ObjectArg); 7979 7980 // Convert the rest of the arguments 7981 const FunctionProtoType *Proto = 7982 Method->getType()->getAs<FunctionProtoType>(); 7983 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 7984 RParenLoc)) 7985 return ExprError(); 7986 7987 if (CheckFunctionCall(Method, TheCall)) 7988 return ExprError(); 7989 7990 return MaybeBindToTemporary(TheCall); 7991} 7992 7993/// BuildCallToObjectOfClassType - Build a call to an object of class 7994/// type (C++ [over.call.object]), which can end up invoking an 7995/// overloaded function call operator (@c operator()) or performing a 7996/// user-defined conversion on the object argument. 7997ExprResult 7998Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 7999 SourceLocation LParenLoc, 8000 Expr **Args, unsigned NumArgs, 8001 SourceLocation RParenLoc) { 8002 if (Object->getObjectKind() == OK_ObjCProperty) 8003 ConvertPropertyForRValue(Object); 8004 8005 assert(Object->getType()->isRecordType() && "Requires object type argument"); 8006 const RecordType *Record = Object->getType()->getAs<RecordType>(); 8007 8008 // C++ [over.call.object]p1: 8009 // If the primary-expression E in the function call syntax 8010 // evaluates to a class object of type "cv T", then the set of 8011 // candidate functions includes at least the function call 8012 // operators of T. The function call operators of T are obtained by 8013 // ordinary lookup of the name operator() in the context of 8014 // (E).operator(). 8015 OverloadCandidateSet CandidateSet(LParenLoc); 8016 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 8017 8018 if (RequireCompleteType(LParenLoc, Object->getType(), 8019 PDiag(diag::err_incomplete_object_call) 8020 << Object->getSourceRange())) 8021 return true; 8022 8023 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 8024 LookupQualifiedName(R, Record->getDecl()); 8025 R.suppressDiagnostics(); 8026 8027 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 8028 Oper != OperEnd; ++Oper) { 8029 AddMethodCandidate(Oper.getPair(), Object->getType(), 8030 Args, NumArgs, CandidateSet, 8031 /*SuppressUserConversions=*/ false); 8032 } 8033 8034 // C++ [over.call.object]p2: 8035 // In addition, for each conversion function declared in T of the 8036 // form 8037 // 8038 // operator conversion-type-id () cv-qualifier; 8039 // 8040 // where cv-qualifier is the same cv-qualification as, or a 8041 // greater cv-qualification than, cv, and where conversion-type-id 8042 // denotes the type "pointer to function of (P1,...,Pn) returning 8043 // R", or the type "reference to pointer to function of 8044 // (P1,...,Pn) returning R", or the type "reference to function 8045 // of (P1,...,Pn) returning R", a surrogate call function [...] 8046 // is also considered as a candidate function. Similarly, 8047 // surrogate call functions are added to the set of candidate 8048 // functions for each conversion function declared in an 8049 // accessible base class provided the function is not hidden 8050 // within T by another intervening declaration. 8051 const UnresolvedSetImpl *Conversions 8052 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 8053 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 8054 E = Conversions->end(); I != E; ++I) { 8055 NamedDecl *D = *I; 8056 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 8057 if (isa<UsingShadowDecl>(D)) 8058 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 8059 8060 // Skip over templated conversion functions; they aren't 8061 // surrogates. 8062 if (isa<FunctionTemplateDecl>(D)) 8063 continue; 8064 8065 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 8066 8067 // Strip the reference type (if any) and then the pointer type (if 8068 // any) to get down to what might be a function type. 8069 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 8070 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 8071 ConvType = ConvPtrType->getPointeeType(); 8072 8073 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 8074 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 8075 Object->getType(), Args, NumArgs, 8076 CandidateSet); 8077 } 8078 8079 // Perform overload resolution. 8080 OverloadCandidateSet::iterator Best; 8081 switch (CandidateSet.BestViableFunction(*this, Object->getLocStart(), 8082 Best)) { 8083 case OR_Success: 8084 // Overload resolution succeeded; we'll build the appropriate call 8085 // below. 8086 break; 8087 8088 case OR_No_Viable_Function: 8089 if (CandidateSet.empty()) 8090 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 8091 << Object->getType() << /*call*/ 1 8092 << Object->getSourceRange(); 8093 else 8094 Diag(Object->getSourceRange().getBegin(), 8095 diag::err_ovl_no_viable_object_call) 8096 << Object->getType() << Object->getSourceRange(); 8097 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8098 break; 8099 8100 case OR_Ambiguous: 8101 Diag(Object->getSourceRange().getBegin(), 8102 diag::err_ovl_ambiguous_object_call) 8103 << Object->getType() << Object->getSourceRange(); 8104 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 8105 break; 8106 8107 case OR_Deleted: 8108 Diag(Object->getSourceRange().getBegin(), 8109 diag::err_ovl_deleted_object_call) 8110 << Best->Function->isDeleted() 8111 << Object->getType() << Object->getSourceRange(); 8112 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8113 break; 8114 } 8115 8116 if (Best == CandidateSet.end()) 8117 return true; 8118 8119 if (Best->Function == 0) { 8120 // Since there is no function declaration, this is one of the 8121 // surrogate candidates. Dig out the conversion function. 8122 CXXConversionDecl *Conv 8123 = cast<CXXConversionDecl>( 8124 Best->Conversions[0].UserDefined.ConversionFunction); 8125 8126 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 8127 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 8128 8129 // We selected one of the surrogate functions that converts the 8130 // object parameter to a function pointer. Perform the conversion 8131 // on the object argument, then let ActOnCallExpr finish the job. 8132 8133 // Create an implicit member expr to refer to the conversion operator. 8134 // and then call it. 8135 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 8136 Conv); 8137 8138 return ActOnCallExpr(S, CE, LParenLoc, MultiExprArg(Args, NumArgs), 8139 RParenLoc); 8140 } 8141 8142 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 8143 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 8144 8145 // We found an overloaded operator(). Build a CXXOperatorCallExpr 8146 // that calls this method, using Object for the implicit object 8147 // parameter and passing along the remaining arguments. 8148 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 8149 const FunctionProtoType *Proto = 8150 Method->getType()->getAs<FunctionProtoType>(); 8151 8152 unsigned NumArgsInProto = Proto->getNumArgs(); 8153 unsigned NumArgsToCheck = NumArgs; 8154 8155 // Build the full argument list for the method call (the 8156 // implicit object parameter is placed at the beginning of the 8157 // list). 8158 Expr **MethodArgs; 8159 if (NumArgs < NumArgsInProto) { 8160 NumArgsToCheck = NumArgsInProto; 8161 MethodArgs = new Expr*[NumArgsInProto + 1]; 8162 } else { 8163 MethodArgs = new Expr*[NumArgs + 1]; 8164 } 8165 MethodArgs[0] = Object; 8166 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 8167 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 8168 8169 Expr *NewFn = CreateFunctionRefExpr(*this, Method); 8170 8171 // Once we've built TheCall, all of the expressions are properly 8172 // owned. 8173 QualType ResultTy = Method->getResultType(); 8174 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8175 ResultTy = ResultTy.getNonLValueExprType(Context); 8176 8177 CXXOperatorCallExpr *TheCall = 8178 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 8179 MethodArgs, NumArgs + 1, 8180 ResultTy, VK, RParenLoc); 8181 delete [] MethodArgs; 8182 8183 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 8184 Method)) 8185 return true; 8186 8187 // We may have default arguments. If so, we need to allocate more 8188 // slots in the call for them. 8189 if (NumArgs < NumArgsInProto) 8190 TheCall->setNumArgs(Context, NumArgsInProto + 1); 8191 else if (NumArgs > NumArgsInProto) 8192 NumArgsToCheck = NumArgsInProto; 8193 8194 bool IsError = false; 8195 8196 // Initialize the implicit object parameter. 8197 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 8198 Best->FoundDecl, Method); 8199 TheCall->setArg(0, Object); 8200 8201 8202 // Check the argument types. 8203 for (unsigned i = 0; i != NumArgsToCheck; i++) { 8204 Expr *Arg; 8205 if (i < NumArgs) { 8206 Arg = Args[i]; 8207 8208 // Pass the argument. 8209 8210 ExprResult InputInit 8211 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8212 Context, 8213 Method->getParamDecl(i)), 8214 SourceLocation(), Arg); 8215 8216 IsError |= InputInit.isInvalid(); 8217 Arg = InputInit.takeAs<Expr>(); 8218 } else { 8219 ExprResult DefArg 8220 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 8221 if (DefArg.isInvalid()) { 8222 IsError = true; 8223 break; 8224 } 8225 8226 Arg = DefArg.takeAs<Expr>(); 8227 } 8228 8229 TheCall->setArg(i + 1, Arg); 8230 } 8231 8232 // If this is a variadic call, handle args passed through "...". 8233 if (Proto->isVariadic()) { 8234 // Promote the arguments (C99 6.5.2.2p7). 8235 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 8236 Expr *Arg = Args[i]; 8237 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 8238 TheCall->setArg(i + 1, Arg); 8239 } 8240 } 8241 8242 if (IsError) return true; 8243 8244 if (CheckFunctionCall(Method, TheCall)) 8245 return true; 8246 8247 return MaybeBindToTemporary(TheCall); 8248} 8249 8250/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 8251/// (if one exists), where @c Base is an expression of class type and 8252/// @c Member is the name of the member we're trying to find. 8253ExprResult 8254Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 8255 assert(Base->getType()->isRecordType() && 8256 "left-hand side must have class type"); 8257 8258 if (Base->getObjectKind() == OK_ObjCProperty) 8259 ConvertPropertyForRValue(Base); 8260 8261 SourceLocation Loc = Base->getExprLoc(); 8262 8263 // C++ [over.ref]p1: 8264 // 8265 // [...] An expression x->m is interpreted as (x.operator->())->m 8266 // for a class object x of type T if T::operator->() exists and if 8267 // the operator is selected as the best match function by the 8268 // overload resolution mechanism (13.3). 8269 DeclarationName OpName = 8270 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 8271 OverloadCandidateSet CandidateSet(Loc); 8272 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 8273 8274 if (RequireCompleteType(Loc, Base->getType(), 8275 PDiag(diag::err_typecheck_incomplete_tag) 8276 << Base->getSourceRange())) 8277 return ExprError(); 8278 8279 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 8280 LookupQualifiedName(R, BaseRecord->getDecl()); 8281 R.suppressDiagnostics(); 8282 8283 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 8284 Oper != OperEnd; ++Oper) { 8285 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 8286 /*SuppressUserConversions=*/false); 8287 } 8288 8289 // Perform overload resolution. 8290 OverloadCandidateSet::iterator Best; 8291 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8292 case OR_Success: 8293 // Overload resolution succeeded; we'll build the call below. 8294 break; 8295 8296 case OR_No_Viable_Function: 8297 if (CandidateSet.empty()) 8298 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 8299 << Base->getType() << Base->getSourceRange(); 8300 else 8301 Diag(OpLoc, diag::err_ovl_no_viable_oper) 8302 << "operator->" << Base->getSourceRange(); 8303 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 8304 return ExprError(); 8305 8306 case OR_Ambiguous: 8307 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 8308 << "->" << Base->getType() << Base->getSourceRange(); 8309 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, &Base, 1); 8310 return ExprError(); 8311 8312 case OR_Deleted: 8313 Diag(OpLoc, diag::err_ovl_deleted_oper) 8314 << Best->Function->isDeleted() 8315 << "->" << Base->getSourceRange(); 8316 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 8317 return ExprError(); 8318 } 8319 8320 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 8321 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 8322 8323 // Convert the object parameter. 8324 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 8325 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 8326 Best->FoundDecl, Method)) 8327 return ExprError(); 8328 8329 // Build the operator call. 8330 Expr *FnExpr = CreateFunctionRefExpr(*this, Method); 8331 8332 QualType ResultTy = Method->getResultType(); 8333 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8334 ResultTy = ResultTy.getNonLValueExprType(Context); 8335 CXXOperatorCallExpr *TheCall = 8336 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 8337 &Base, 1, ResultTy, VK, OpLoc); 8338 8339 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 8340 Method)) 8341 return ExprError(); 8342 return Owned(TheCall); 8343} 8344 8345/// FixOverloadedFunctionReference - E is an expression that refers to 8346/// a C++ overloaded function (possibly with some parentheses and 8347/// perhaps a '&' around it). We have resolved the overloaded function 8348/// to the function declaration Fn, so patch up the expression E to 8349/// refer (possibly indirectly) to Fn. Returns the new expr. 8350Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 8351 FunctionDecl *Fn) { 8352 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 8353 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 8354 Found, Fn); 8355 if (SubExpr == PE->getSubExpr()) 8356 return PE; 8357 8358 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 8359 } 8360 8361 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 8362 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 8363 Found, Fn); 8364 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 8365 SubExpr->getType()) && 8366 "Implicit cast type cannot be determined from overload"); 8367 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 8368 if (SubExpr == ICE->getSubExpr()) 8369 return ICE; 8370 8371 return ImplicitCastExpr::Create(Context, ICE->getType(), 8372 ICE->getCastKind(), 8373 SubExpr, 0, 8374 ICE->getValueKind()); 8375 } 8376 8377 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 8378 assert(UnOp->getOpcode() == UO_AddrOf && 8379 "Can only take the address of an overloaded function"); 8380 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 8381 if (Method->isStatic()) { 8382 // Do nothing: static member functions aren't any different 8383 // from non-member functions. 8384 } else { 8385 // Fix the sub expression, which really has to be an 8386 // UnresolvedLookupExpr holding an overloaded member function 8387 // or template. 8388 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 8389 Found, Fn); 8390 if (SubExpr == UnOp->getSubExpr()) 8391 return UnOp; 8392 8393 assert(isa<DeclRefExpr>(SubExpr) 8394 && "fixed to something other than a decl ref"); 8395 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 8396 && "fixed to a member ref with no nested name qualifier"); 8397 8398 // We have taken the address of a pointer to member 8399 // function. Perform the computation here so that we get the 8400 // appropriate pointer to member type. 8401 QualType ClassType 8402 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 8403 QualType MemPtrType 8404 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 8405 8406 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 8407 VK_RValue, OK_Ordinary, 8408 UnOp->getOperatorLoc()); 8409 } 8410 } 8411 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 8412 Found, Fn); 8413 if (SubExpr == UnOp->getSubExpr()) 8414 return UnOp; 8415 8416 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 8417 Context.getPointerType(SubExpr->getType()), 8418 VK_RValue, OK_Ordinary, 8419 UnOp->getOperatorLoc()); 8420 } 8421 8422 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 8423 // FIXME: avoid copy. 8424 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 8425 if (ULE->hasExplicitTemplateArgs()) { 8426 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 8427 TemplateArgs = &TemplateArgsBuffer; 8428 } 8429 8430 return DeclRefExpr::Create(Context, 8431 ULE->getQualifier(), 8432 ULE->getQualifierRange(), 8433 Fn, 8434 ULE->getNameLoc(), 8435 Fn->getType(), 8436 VK_LValue, 8437 TemplateArgs); 8438 } 8439 8440 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 8441 // FIXME: avoid copy. 8442 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 8443 if (MemExpr->hasExplicitTemplateArgs()) { 8444 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 8445 TemplateArgs = &TemplateArgsBuffer; 8446 } 8447 8448 Expr *Base; 8449 8450 // If we're filling in a static method where we used to have an 8451 // implicit member access, rewrite to a simple decl ref. 8452 if (MemExpr->isImplicitAccess()) { 8453 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 8454 return DeclRefExpr::Create(Context, 8455 MemExpr->getQualifier(), 8456 MemExpr->getQualifierRange(), 8457 Fn, 8458 MemExpr->getMemberLoc(), 8459 Fn->getType(), 8460 VK_LValue, 8461 TemplateArgs); 8462 } else { 8463 SourceLocation Loc = MemExpr->getMemberLoc(); 8464 if (MemExpr->getQualifier()) 8465 Loc = MemExpr->getQualifierRange().getBegin(); 8466 Base = new (Context) CXXThisExpr(Loc, 8467 MemExpr->getBaseType(), 8468 /*isImplicit=*/true); 8469 } 8470 } else 8471 Base = MemExpr->getBase(); 8472 8473 return MemberExpr::Create(Context, Base, 8474 MemExpr->isArrow(), 8475 MemExpr->getQualifier(), 8476 MemExpr->getQualifierRange(), 8477 Fn, 8478 Found, 8479 MemExpr->getMemberNameInfo(), 8480 TemplateArgs, 8481 Fn->getType(), 8482 cast<CXXMethodDecl>(Fn)->isStatic() 8483 ? VK_LValue : VK_RValue, 8484 OK_Ordinary); 8485 } 8486 8487 llvm_unreachable("Invalid reference to overloaded function"); 8488 return E; 8489} 8490 8491ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 8492 DeclAccessPair Found, 8493 FunctionDecl *Fn) { 8494 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 8495} 8496 8497} // end namespace clang 8498