SemaOverload.cpp revision 2d88708cbe4e4ec5e04e4acb6bd7f5be68557379
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/TypeOrdering.h" 27#include "clang/Basic/PartialDiagnostic.h" 28#include "llvm/ADT/SmallPtrSet.h" 29#include "llvm/ADT/STLExtras.h" 30#include <algorithm> 31 32namespace clang { 33using namespace sema; 34 35static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 36 bool InOverloadResolution, 37 StandardConversionSequence &SCS); 38static OverloadingResult 39IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 40 UserDefinedConversionSequence& User, 41 OverloadCandidateSet& Conversions, 42 bool AllowExplicit); 43 44 45static ImplicitConversionSequence::CompareKind 46CompareStandardConversionSequences(Sema &S, 47 const StandardConversionSequence& SCS1, 48 const StandardConversionSequence& SCS2); 49 50static ImplicitConversionSequence::CompareKind 51CompareQualificationConversions(Sema &S, 52 const StandardConversionSequence& SCS1, 53 const StandardConversionSequence& SCS2); 54 55static ImplicitConversionSequence::CompareKind 56CompareDerivedToBaseConversions(Sema &S, 57 const StandardConversionSequence& SCS1, 58 const StandardConversionSequence& SCS2); 59 60 61 62/// GetConversionCategory - Retrieve the implicit conversion 63/// category corresponding to the given implicit conversion kind. 64ImplicitConversionCategory 65GetConversionCategory(ImplicitConversionKind Kind) { 66 static const ImplicitConversionCategory 67 Category[(int)ICK_Num_Conversion_Kinds] = { 68 ICC_Identity, 69 ICC_Lvalue_Transformation, 70 ICC_Lvalue_Transformation, 71 ICC_Lvalue_Transformation, 72 ICC_Identity, 73 ICC_Qualification_Adjustment, 74 ICC_Promotion, 75 ICC_Promotion, 76 ICC_Promotion, 77 ICC_Conversion, 78 ICC_Conversion, 79 ICC_Conversion, 80 ICC_Conversion, 81 ICC_Conversion, 82 ICC_Conversion, 83 ICC_Conversion, 84 ICC_Conversion, 85 ICC_Conversion, 86 ICC_Conversion, 87 ICC_Conversion, 88 ICC_Conversion 89 }; 90 return Category[(int)Kind]; 91} 92 93/// GetConversionRank - Retrieve the implicit conversion rank 94/// corresponding to the given implicit conversion kind. 95ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 96 static const ImplicitConversionRank 97 Rank[(int)ICK_Num_Conversion_Kinds] = { 98 ICR_Exact_Match, 99 ICR_Exact_Match, 100 ICR_Exact_Match, 101 ICR_Exact_Match, 102 ICR_Exact_Match, 103 ICR_Exact_Match, 104 ICR_Promotion, 105 ICR_Promotion, 106 ICR_Promotion, 107 ICR_Conversion, 108 ICR_Conversion, 109 ICR_Conversion, 110 ICR_Conversion, 111 ICR_Conversion, 112 ICR_Conversion, 113 ICR_Conversion, 114 ICR_Conversion, 115 ICR_Conversion, 116 ICR_Conversion, 117 ICR_Conversion, 118 ICR_Complex_Real_Conversion 119 }; 120 return Rank[(int)Kind]; 121} 122 123/// GetImplicitConversionName - Return the name of this kind of 124/// implicit conversion. 125const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 126 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 127 "No conversion", 128 "Lvalue-to-rvalue", 129 "Array-to-pointer", 130 "Function-to-pointer", 131 "Noreturn adjustment", 132 "Qualification", 133 "Integral promotion", 134 "Floating point promotion", 135 "Complex promotion", 136 "Integral conversion", 137 "Floating conversion", 138 "Complex conversion", 139 "Floating-integral conversion", 140 "Pointer conversion", 141 "Pointer-to-member conversion", 142 "Boolean conversion", 143 "Compatible-types conversion", 144 "Derived-to-base conversion", 145 "Vector conversion", 146 "Vector splat", 147 "Complex-real conversion" 148 }; 149 return Name[Kind]; 150} 151 152/// StandardConversionSequence - Set the standard conversion 153/// sequence to the identity conversion. 154void StandardConversionSequence::setAsIdentityConversion() { 155 First = ICK_Identity; 156 Second = ICK_Identity; 157 Third = ICK_Identity; 158 DeprecatedStringLiteralToCharPtr = false; 159 ReferenceBinding = false; 160 DirectBinding = false; 161 RRefBinding = false; 162 CopyConstructor = 0; 163} 164 165/// getRank - Retrieve the rank of this standard conversion sequence 166/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 167/// implicit conversions. 168ImplicitConversionRank StandardConversionSequence::getRank() const { 169 ImplicitConversionRank Rank = ICR_Exact_Match; 170 if (GetConversionRank(First) > Rank) 171 Rank = GetConversionRank(First); 172 if (GetConversionRank(Second) > Rank) 173 Rank = GetConversionRank(Second); 174 if (GetConversionRank(Third) > Rank) 175 Rank = GetConversionRank(Third); 176 return Rank; 177} 178 179/// isPointerConversionToBool - Determines whether this conversion is 180/// a conversion of a pointer or pointer-to-member to bool. This is 181/// used as part of the ranking of standard conversion sequences 182/// (C++ 13.3.3.2p4). 183bool StandardConversionSequence::isPointerConversionToBool() const { 184 // Note that FromType has not necessarily been transformed by the 185 // array-to-pointer or function-to-pointer implicit conversions, so 186 // check for their presence as well as checking whether FromType is 187 // a pointer. 188 if (getToType(1)->isBooleanType() && 189 (getFromType()->isPointerType() || 190 getFromType()->isObjCObjectPointerType() || 191 getFromType()->isBlockPointerType() || 192 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 193 return true; 194 195 return false; 196} 197 198/// isPointerConversionToVoidPointer - Determines whether this 199/// conversion is a conversion of a pointer to a void pointer. This is 200/// used as part of the ranking of standard conversion sequences (C++ 201/// 13.3.3.2p4). 202bool 203StandardConversionSequence:: 204isPointerConversionToVoidPointer(ASTContext& Context) const { 205 QualType FromType = getFromType(); 206 QualType ToType = getToType(1); 207 208 // Note that FromType has not necessarily been transformed by the 209 // array-to-pointer implicit conversion, so check for its presence 210 // and redo the conversion to get a pointer. 211 if (First == ICK_Array_To_Pointer) 212 FromType = Context.getArrayDecayedType(FromType); 213 214 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 215 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 216 return ToPtrType->getPointeeType()->isVoidType(); 217 218 return false; 219} 220 221/// DebugPrint - Print this standard conversion sequence to standard 222/// error. Useful for debugging overloading issues. 223void StandardConversionSequence::DebugPrint() const { 224 llvm::raw_ostream &OS = llvm::errs(); 225 bool PrintedSomething = false; 226 if (First != ICK_Identity) { 227 OS << GetImplicitConversionName(First); 228 PrintedSomething = true; 229 } 230 231 if (Second != ICK_Identity) { 232 if (PrintedSomething) { 233 OS << " -> "; 234 } 235 OS << GetImplicitConversionName(Second); 236 237 if (CopyConstructor) { 238 OS << " (by copy constructor)"; 239 } else if (DirectBinding) { 240 OS << " (direct reference binding)"; 241 } else if (ReferenceBinding) { 242 OS << " (reference binding)"; 243 } 244 PrintedSomething = true; 245 } 246 247 if (Third != ICK_Identity) { 248 if (PrintedSomething) { 249 OS << " -> "; 250 } 251 OS << GetImplicitConversionName(Third); 252 PrintedSomething = true; 253 } 254 255 if (!PrintedSomething) { 256 OS << "No conversions required"; 257 } 258} 259 260/// DebugPrint - Print this user-defined conversion sequence to standard 261/// error. Useful for debugging overloading issues. 262void UserDefinedConversionSequence::DebugPrint() const { 263 llvm::raw_ostream &OS = llvm::errs(); 264 if (Before.First || Before.Second || Before.Third) { 265 Before.DebugPrint(); 266 OS << " -> "; 267 } 268 OS << '\'' << ConversionFunction << '\''; 269 if (After.First || After.Second || After.Third) { 270 OS << " -> "; 271 After.DebugPrint(); 272 } 273} 274 275/// DebugPrint - Print this implicit conversion sequence to standard 276/// error. Useful for debugging overloading issues. 277void ImplicitConversionSequence::DebugPrint() const { 278 llvm::raw_ostream &OS = llvm::errs(); 279 switch (ConversionKind) { 280 case StandardConversion: 281 OS << "Standard conversion: "; 282 Standard.DebugPrint(); 283 break; 284 case UserDefinedConversion: 285 OS << "User-defined conversion: "; 286 UserDefined.DebugPrint(); 287 break; 288 case EllipsisConversion: 289 OS << "Ellipsis conversion"; 290 break; 291 case AmbiguousConversion: 292 OS << "Ambiguous conversion"; 293 break; 294 case BadConversion: 295 OS << "Bad conversion"; 296 break; 297 } 298 299 OS << "\n"; 300} 301 302void AmbiguousConversionSequence::construct() { 303 new (&conversions()) ConversionSet(); 304} 305 306void AmbiguousConversionSequence::destruct() { 307 conversions().~ConversionSet(); 308} 309 310void 311AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 312 FromTypePtr = O.FromTypePtr; 313 ToTypePtr = O.ToTypePtr; 314 new (&conversions()) ConversionSet(O.conversions()); 315} 316 317namespace { 318 // Structure used by OverloadCandidate::DeductionFailureInfo to store 319 // template parameter and template argument information. 320 struct DFIParamWithArguments { 321 TemplateParameter Param; 322 TemplateArgument FirstArg; 323 TemplateArgument SecondArg; 324 }; 325} 326 327/// \brief Convert from Sema's representation of template deduction information 328/// to the form used in overload-candidate information. 329OverloadCandidate::DeductionFailureInfo 330static MakeDeductionFailureInfo(ASTContext &Context, 331 Sema::TemplateDeductionResult TDK, 332 TemplateDeductionInfo &Info) { 333 OverloadCandidate::DeductionFailureInfo Result; 334 Result.Result = static_cast<unsigned>(TDK); 335 Result.Data = 0; 336 switch (TDK) { 337 case Sema::TDK_Success: 338 case Sema::TDK_InstantiationDepth: 339 case Sema::TDK_TooManyArguments: 340 case Sema::TDK_TooFewArguments: 341 break; 342 343 case Sema::TDK_Incomplete: 344 case Sema::TDK_InvalidExplicitArguments: 345 Result.Data = Info.Param.getOpaqueValue(); 346 break; 347 348 case Sema::TDK_Inconsistent: 349 case Sema::TDK_Underqualified: { 350 // FIXME: Should allocate from normal heap so that we can free this later. 351 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 352 Saved->Param = Info.Param; 353 Saved->FirstArg = Info.FirstArg; 354 Saved->SecondArg = Info.SecondArg; 355 Result.Data = Saved; 356 break; 357 } 358 359 case Sema::TDK_SubstitutionFailure: 360 Result.Data = Info.take(); 361 break; 362 363 case Sema::TDK_NonDeducedMismatch: 364 case Sema::TDK_FailedOverloadResolution: 365 break; 366 } 367 368 return Result; 369} 370 371void OverloadCandidate::DeductionFailureInfo::Destroy() { 372 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 373 case Sema::TDK_Success: 374 case Sema::TDK_InstantiationDepth: 375 case Sema::TDK_Incomplete: 376 case Sema::TDK_TooManyArguments: 377 case Sema::TDK_TooFewArguments: 378 case Sema::TDK_InvalidExplicitArguments: 379 break; 380 381 case Sema::TDK_Inconsistent: 382 case Sema::TDK_Underqualified: 383 // FIXME: Destroy the data? 384 Data = 0; 385 break; 386 387 case Sema::TDK_SubstitutionFailure: 388 // FIXME: Destroy the template arugment list? 389 Data = 0; 390 break; 391 392 // Unhandled 393 case Sema::TDK_NonDeducedMismatch: 394 case Sema::TDK_FailedOverloadResolution: 395 break; 396 } 397} 398 399TemplateParameter 400OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 401 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 402 case Sema::TDK_Success: 403 case Sema::TDK_InstantiationDepth: 404 case Sema::TDK_TooManyArguments: 405 case Sema::TDK_TooFewArguments: 406 case Sema::TDK_SubstitutionFailure: 407 return TemplateParameter(); 408 409 case Sema::TDK_Incomplete: 410 case Sema::TDK_InvalidExplicitArguments: 411 return TemplateParameter::getFromOpaqueValue(Data); 412 413 case Sema::TDK_Inconsistent: 414 case Sema::TDK_Underqualified: 415 return static_cast<DFIParamWithArguments*>(Data)->Param; 416 417 // Unhandled 418 case Sema::TDK_NonDeducedMismatch: 419 case Sema::TDK_FailedOverloadResolution: 420 break; 421 } 422 423 return TemplateParameter(); 424} 425 426TemplateArgumentList * 427OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 428 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 429 case Sema::TDK_Success: 430 case Sema::TDK_InstantiationDepth: 431 case Sema::TDK_TooManyArguments: 432 case Sema::TDK_TooFewArguments: 433 case Sema::TDK_Incomplete: 434 case Sema::TDK_InvalidExplicitArguments: 435 case Sema::TDK_Inconsistent: 436 case Sema::TDK_Underqualified: 437 return 0; 438 439 case Sema::TDK_SubstitutionFailure: 440 return static_cast<TemplateArgumentList*>(Data); 441 442 // Unhandled 443 case Sema::TDK_NonDeducedMismatch: 444 case Sema::TDK_FailedOverloadResolution: 445 break; 446 } 447 448 return 0; 449} 450 451const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 452 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 453 case Sema::TDK_Success: 454 case Sema::TDK_InstantiationDepth: 455 case Sema::TDK_Incomplete: 456 case Sema::TDK_TooManyArguments: 457 case Sema::TDK_TooFewArguments: 458 case Sema::TDK_InvalidExplicitArguments: 459 case Sema::TDK_SubstitutionFailure: 460 return 0; 461 462 case Sema::TDK_Inconsistent: 463 case Sema::TDK_Underqualified: 464 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 465 466 // Unhandled 467 case Sema::TDK_NonDeducedMismatch: 468 case Sema::TDK_FailedOverloadResolution: 469 break; 470 } 471 472 return 0; 473} 474 475const TemplateArgument * 476OverloadCandidate::DeductionFailureInfo::getSecondArg() { 477 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 478 case Sema::TDK_Success: 479 case Sema::TDK_InstantiationDepth: 480 case Sema::TDK_Incomplete: 481 case Sema::TDK_TooManyArguments: 482 case Sema::TDK_TooFewArguments: 483 case Sema::TDK_InvalidExplicitArguments: 484 case Sema::TDK_SubstitutionFailure: 485 return 0; 486 487 case Sema::TDK_Inconsistent: 488 case Sema::TDK_Underqualified: 489 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 490 491 // Unhandled 492 case Sema::TDK_NonDeducedMismatch: 493 case Sema::TDK_FailedOverloadResolution: 494 break; 495 } 496 497 return 0; 498} 499 500void OverloadCandidateSet::clear() { 501 inherited::clear(); 502 Functions.clear(); 503} 504 505// IsOverload - Determine whether the given New declaration is an 506// overload of the declarations in Old. This routine returns false if 507// New and Old cannot be overloaded, e.g., if New has the same 508// signature as some function in Old (C++ 1.3.10) or if the Old 509// declarations aren't functions (or function templates) at all. When 510// it does return false, MatchedDecl will point to the decl that New 511// cannot be overloaded with. This decl may be a UsingShadowDecl on 512// top of the underlying declaration. 513// 514// Example: Given the following input: 515// 516// void f(int, float); // #1 517// void f(int, int); // #2 518// int f(int, int); // #3 519// 520// When we process #1, there is no previous declaration of "f", 521// so IsOverload will not be used. 522// 523// When we process #2, Old contains only the FunctionDecl for #1. By 524// comparing the parameter types, we see that #1 and #2 are overloaded 525// (since they have different signatures), so this routine returns 526// false; MatchedDecl is unchanged. 527// 528// When we process #3, Old is an overload set containing #1 and #2. We 529// compare the signatures of #3 to #1 (they're overloaded, so we do 530// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 531// identical (return types of functions are not part of the 532// signature), IsOverload returns false and MatchedDecl will be set to 533// point to the FunctionDecl for #2. 534// 535// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 536// into a class by a using declaration. The rules for whether to hide 537// shadow declarations ignore some properties which otherwise figure 538// into a function template's signature. 539Sema::OverloadKind 540Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 541 NamedDecl *&Match, bool NewIsUsingDecl) { 542 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 543 I != E; ++I) { 544 NamedDecl *OldD = *I; 545 546 bool OldIsUsingDecl = false; 547 if (isa<UsingShadowDecl>(OldD)) { 548 OldIsUsingDecl = true; 549 550 // We can always introduce two using declarations into the same 551 // context, even if they have identical signatures. 552 if (NewIsUsingDecl) continue; 553 554 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 555 } 556 557 // If either declaration was introduced by a using declaration, 558 // we'll need to use slightly different rules for matching. 559 // Essentially, these rules are the normal rules, except that 560 // function templates hide function templates with different 561 // return types or template parameter lists. 562 bool UseMemberUsingDeclRules = 563 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 564 565 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 566 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 567 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 568 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 569 continue; 570 } 571 572 Match = *I; 573 return Ovl_Match; 574 } 575 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 576 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 577 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 578 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 579 continue; 580 } 581 582 Match = *I; 583 return Ovl_Match; 584 } 585 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 586 // We can overload with these, which can show up when doing 587 // redeclaration checks for UsingDecls. 588 assert(Old.getLookupKind() == LookupUsingDeclName); 589 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 590 // Optimistically assume that an unresolved using decl will 591 // overload; if it doesn't, we'll have to diagnose during 592 // template instantiation. 593 } else { 594 // (C++ 13p1): 595 // Only function declarations can be overloaded; object and type 596 // declarations cannot be overloaded. 597 Match = *I; 598 return Ovl_NonFunction; 599 } 600 } 601 602 return Ovl_Overload; 603} 604 605bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 606 bool UseUsingDeclRules) { 607 // If both of the functions are extern "C", then they are not 608 // overloads. 609 if (Old->isExternC() && New->isExternC()) 610 return false; 611 612 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 613 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 614 615 // C++ [temp.fct]p2: 616 // A function template can be overloaded with other function templates 617 // and with normal (non-template) functions. 618 if ((OldTemplate == 0) != (NewTemplate == 0)) 619 return true; 620 621 // Is the function New an overload of the function Old? 622 QualType OldQType = Context.getCanonicalType(Old->getType()); 623 QualType NewQType = Context.getCanonicalType(New->getType()); 624 625 // Compare the signatures (C++ 1.3.10) of the two functions to 626 // determine whether they are overloads. If we find any mismatch 627 // in the signature, they are overloads. 628 629 // If either of these functions is a K&R-style function (no 630 // prototype), then we consider them to have matching signatures. 631 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 632 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 633 return false; 634 635 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 636 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 637 638 // The signature of a function includes the types of its 639 // parameters (C++ 1.3.10), which includes the presence or absence 640 // of the ellipsis; see C++ DR 357). 641 if (OldQType != NewQType && 642 (OldType->getNumArgs() != NewType->getNumArgs() || 643 OldType->isVariadic() != NewType->isVariadic() || 644 !FunctionArgTypesAreEqual(OldType, NewType))) 645 return true; 646 647 // C++ [temp.over.link]p4: 648 // The signature of a function template consists of its function 649 // signature, its return type and its template parameter list. The names 650 // of the template parameters are significant only for establishing the 651 // relationship between the template parameters and the rest of the 652 // signature. 653 // 654 // We check the return type and template parameter lists for function 655 // templates first; the remaining checks follow. 656 // 657 // However, we don't consider either of these when deciding whether 658 // a member introduced by a shadow declaration is hidden. 659 if (!UseUsingDeclRules && NewTemplate && 660 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 661 OldTemplate->getTemplateParameters(), 662 false, TPL_TemplateMatch) || 663 OldType->getResultType() != NewType->getResultType())) 664 return true; 665 666 // If the function is a class member, its signature includes the 667 // cv-qualifiers (if any) on the function itself. 668 // 669 // As part of this, also check whether one of the member functions 670 // is static, in which case they are not overloads (C++ 671 // 13.1p2). While not part of the definition of the signature, 672 // this check is important to determine whether these functions 673 // can be overloaded. 674 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 675 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 676 if (OldMethod && NewMethod && 677 !OldMethod->isStatic() && !NewMethod->isStatic() && 678 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 679 return true; 680 681 // The signatures match; this is not an overload. 682 return false; 683} 684 685/// TryImplicitConversion - Attempt to perform an implicit conversion 686/// from the given expression (Expr) to the given type (ToType). This 687/// function returns an implicit conversion sequence that can be used 688/// to perform the initialization. Given 689/// 690/// void f(float f); 691/// void g(int i) { f(i); } 692/// 693/// this routine would produce an implicit conversion sequence to 694/// describe the initialization of f from i, which will be a standard 695/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 696/// 4.1) followed by a floating-integral conversion (C++ 4.9). 697// 698/// Note that this routine only determines how the conversion can be 699/// performed; it does not actually perform the conversion. As such, 700/// it will not produce any diagnostics if no conversion is available, 701/// but will instead return an implicit conversion sequence of kind 702/// "BadConversion". 703/// 704/// If @p SuppressUserConversions, then user-defined conversions are 705/// not permitted. 706/// If @p AllowExplicit, then explicit user-defined conversions are 707/// permitted. 708static ImplicitConversionSequence 709TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 710 bool SuppressUserConversions, 711 bool AllowExplicit, 712 bool InOverloadResolution) { 713 ImplicitConversionSequence ICS; 714 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 715 ICS.Standard)) { 716 ICS.setStandard(); 717 return ICS; 718 } 719 720 if (!S.getLangOptions().CPlusPlus) { 721 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 722 return ICS; 723 } 724 725 // C++ [over.ics.user]p4: 726 // A conversion of an expression of class type to the same class 727 // type is given Exact Match rank, and a conversion of an 728 // expression of class type to a base class of that type is 729 // given Conversion rank, in spite of the fact that a copy/move 730 // constructor (i.e., a user-defined conversion function) is 731 // called for those cases. 732 QualType FromType = From->getType(); 733 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 734 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 735 S.IsDerivedFrom(FromType, ToType))) { 736 ICS.setStandard(); 737 ICS.Standard.setAsIdentityConversion(); 738 ICS.Standard.setFromType(FromType); 739 ICS.Standard.setAllToTypes(ToType); 740 741 // We don't actually check at this point whether there is a valid 742 // copy/move constructor, since overloading just assumes that it 743 // exists. When we actually perform initialization, we'll find the 744 // appropriate constructor to copy the returned object, if needed. 745 ICS.Standard.CopyConstructor = 0; 746 747 // Determine whether this is considered a derived-to-base conversion. 748 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 749 ICS.Standard.Second = ICK_Derived_To_Base; 750 751 return ICS; 752 } 753 754 if (SuppressUserConversions) { 755 // We're not in the case above, so there is no conversion that 756 // we can perform. 757 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 758 return ICS; 759 } 760 761 // Attempt user-defined conversion. 762 OverloadCandidateSet Conversions(From->getExprLoc()); 763 OverloadingResult UserDefResult 764 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 765 AllowExplicit); 766 767 if (UserDefResult == OR_Success) { 768 ICS.setUserDefined(); 769 // C++ [over.ics.user]p4: 770 // A conversion of an expression of class type to the same class 771 // type is given Exact Match rank, and a conversion of an 772 // expression of class type to a base class of that type is 773 // given Conversion rank, in spite of the fact that a copy 774 // constructor (i.e., a user-defined conversion function) is 775 // called for those cases. 776 if (CXXConstructorDecl *Constructor 777 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 778 QualType FromCanon 779 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 780 QualType ToCanon 781 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 782 if (Constructor->isCopyConstructor() && 783 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 784 // Turn this into a "standard" conversion sequence, so that it 785 // gets ranked with standard conversion sequences. 786 ICS.setStandard(); 787 ICS.Standard.setAsIdentityConversion(); 788 ICS.Standard.setFromType(From->getType()); 789 ICS.Standard.setAllToTypes(ToType); 790 ICS.Standard.CopyConstructor = Constructor; 791 if (ToCanon != FromCanon) 792 ICS.Standard.Second = ICK_Derived_To_Base; 793 } 794 } 795 796 // C++ [over.best.ics]p4: 797 // However, when considering the argument of a user-defined 798 // conversion function that is a candidate by 13.3.1.3 when 799 // invoked for the copying of the temporary in the second step 800 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 801 // 13.3.1.6 in all cases, only standard conversion sequences and 802 // ellipsis conversion sequences are allowed. 803 if (SuppressUserConversions && ICS.isUserDefined()) { 804 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 805 } 806 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 807 ICS.setAmbiguous(); 808 ICS.Ambiguous.setFromType(From->getType()); 809 ICS.Ambiguous.setToType(ToType); 810 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 811 Cand != Conversions.end(); ++Cand) 812 if (Cand->Viable) 813 ICS.Ambiguous.addConversion(Cand->Function); 814 } else { 815 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 816 } 817 818 return ICS; 819} 820 821bool Sema::TryImplicitConversion(InitializationSequence &Sequence, 822 const InitializedEntity &Entity, 823 Expr *Initializer, 824 bool SuppressUserConversions, 825 bool AllowExplicitConversions, 826 bool InOverloadResolution) { 827 ImplicitConversionSequence ICS 828 = clang::TryImplicitConversion(*this, Initializer, Entity.getType(), 829 SuppressUserConversions, 830 AllowExplicitConversions, 831 InOverloadResolution); 832 if (ICS.isBad()) return true; 833 834 // Perform the actual conversion. 835 Sequence.AddConversionSequenceStep(ICS, Entity.getType()); 836 return false; 837} 838 839/// PerformImplicitConversion - Perform an implicit conversion of the 840/// expression From to the type ToType. Returns true if there was an 841/// error, false otherwise. The expression From is replaced with the 842/// converted expression. Flavor is the kind of conversion we're 843/// performing, used in the error message. If @p AllowExplicit, 844/// explicit user-defined conversions are permitted. 845bool 846Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 847 AssignmentAction Action, bool AllowExplicit) { 848 ImplicitConversionSequence ICS; 849 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 850} 851 852bool 853Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 854 AssignmentAction Action, bool AllowExplicit, 855 ImplicitConversionSequence& ICS) { 856 ICS = clang::TryImplicitConversion(*this, From, ToType, 857 /*SuppressUserConversions=*/false, 858 AllowExplicit, 859 /*InOverloadResolution=*/false); 860 return PerformImplicitConversion(From, ToType, ICS, Action); 861} 862 863/// \brief Determine whether the conversion from FromType to ToType is a valid 864/// conversion that strips "noreturn" off the nested function type. 865static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 866 QualType ToType, QualType &ResultTy) { 867 if (Context.hasSameUnqualifiedType(FromType, ToType)) 868 return false; 869 870 // Strip the noreturn off the type we're converting from; noreturn can 871 // safely be removed. 872 FromType = Context.getNoReturnType(FromType, false); 873 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 874 return false; 875 876 ResultTy = FromType; 877 return true; 878} 879 880/// \brief Determine whether the conversion from FromType to ToType is a valid 881/// vector conversion. 882/// 883/// \param ICK Will be set to the vector conversion kind, if this is a vector 884/// conversion. 885static bool IsVectorConversion(ASTContext &Context, QualType FromType, 886 QualType ToType, ImplicitConversionKind &ICK) { 887 // We need at least one of these types to be a vector type to have a vector 888 // conversion. 889 if (!ToType->isVectorType() && !FromType->isVectorType()) 890 return false; 891 892 // Identical types require no conversions. 893 if (Context.hasSameUnqualifiedType(FromType, ToType)) 894 return false; 895 896 // There are no conversions between extended vector types, only identity. 897 if (ToType->isExtVectorType()) { 898 // There are no conversions between extended vector types other than the 899 // identity conversion. 900 if (FromType->isExtVectorType()) 901 return false; 902 903 // Vector splat from any arithmetic type to a vector. 904 if (FromType->isArithmeticType()) { 905 ICK = ICK_Vector_Splat; 906 return true; 907 } 908 } 909 910 // We can perform the conversion between vector types in the following cases: 911 // 1)vector types are equivalent AltiVec and GCC vector types 912 // 2)lax vector conversions are permitted and the vector types are of the 913 // same size 914 if (ToType->isVectorType() && FromType->isVectorType()) { 915 if (Context.areCompatibleVectorTypes(FromType, ToType) || 916 (Context.getLangOptions().LaxVectorConversions && 917 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 918 ICK = ICK_Vector_Conversion; 919 return true; 920 } 921 } 922 923 return false; 924} 925 926/// IsStandardConversion - Determines whether there is a standard 927/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 928/// expression From to the type ToType. Standard conversion sequences 929/// only consider non-class types; for conversions that involve class 930/// types, use TryImplicitConversion. If a conversion exists, SCS will 931/// contain the standard conversion sequence required to perform this 932/// conversion and this routine will return true. Otherwise, this 933/// routine will return false and the value of SCS is unspecified. 934static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 935 bool InOverloadResolution, 936 StandardConversionSequence &SCS) { 937 QualType FromType = From->getType(); 938 939 // Standard conversions (C++ [conv]) 940 SCS.setAsIdentityConversion(); 941 SCS.DeprecatedStringLiteralToCharPtr = false; 942 SCS.IncompatibleObjC = false; 943 SCS.setFromType(FromType); 944 SCS.CopyConstructor = 0; 945 946 // There are no standard conversions for class types in C++, so 947 // abort early. When overloading in C, however, we do permit 948 if (FromType->isRecordType() || ToType->isRecordType()) { 949 if (S.getLangOptions().CPlusPlus) 950 return false; 951 952 // When we're overloading in C, we allow, as standard conversions, 953 } 954 955 // The first conversion can be an lvalue-to-rvalue conversion, 956 // array-to-pointer conversion, or function-to-pointer conversion 957 // (C++ 4p1). 958 959 if (FromType == S.Context.OverloadTy) { 960 DeclAccessPair AccessPair; 961 if (FunctionDecl *Fn 962 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 963 AccessPair)) { 964 // We were able to resolve the address of the overloaded function, 965 // so we can convert to the type of that function. 966 FromType = Fn->getType(); 967 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 968 if (!Method->isStatic()) { 969 Type *ClassType 970 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 971 FromType = S.Context.getMemberPointerType(FromType, ClassType); 972 } 973 } 974 975 // If the "from" expression takes the address of the overloaded 976 // function, update the type of the resulting expression accordingly. 977 if (FromType->getAs<FunctionType>()) 978 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens())) 979 if (UnOp->getOpcode() == UO_AddrOf) 980 FromType = S.Context.getPointerType(FromType); 981 982 // Check that we've computed the proper type after overload resolution. 983 assert(S.Context.hasSameType(FromType, 984 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 985 } else { 986 return false; 987 } 988 } 989 // Lvalue-to-rvalue conversion (C++ 4.1): 990 // An lvalue (3.10) of a non-function, non-array type T can be 991 // converted to an rvalue. 992 Expr::isLvalueResult argIsLvalue = From->isLvalue(S.Context); 993 if (argIsLvalue == Expr::LV_Valid && 994 !FromType->isFunctionType() && !FromType->isArrayType() && 995 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 996 SCS.First = ICK_Lvalue_To_Rvalue; 997 998 // If T is a non-class type, the type of the rvalue is the 999 // cv-unqualified version of T. Otherwise, the type of the rvalue 1000 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1001 // just strip the qualifiers because they don't matter. 1002 FromType = FromType.getUnqualifiedType(); 1003 } else if (FromType->isArrayType()) { 1004 // Array-to-pointer conversion (C++ 4.2) 1005 SCS.First = ICK_Array_To_Pointer; 1006 1007 // An lvalue or rvalue of type "array of N T" or "array of unknown 1008 // bound of T" can be converted to an rvalue of type "pointer to 1009 // T" (C++ 4.2p1). 1010 FromType = S.Context.getArrayDecayedType(FromType); 1011 1012 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1013 // This conversion is deprecated. (C++ D.4). 1014 SCS.DeprecatedStringLiteralToCharPtr = true; 1015 1016 // For the purpose of ranking in overload resolution 1017 // (13.3.3.1.1), this conversion is considered an 1018 // array-to-pointer conversion followed by a qualification 1019 // conversion (4.4). (C++ 4.2p2) 1020 SCS.Second = ICK_Identity; 1021 SCS.Third = ICK_Qualification; 1022 SCS.setAllToTypes(FromType); 1023 return true; 1024 } 1025 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 1026 // Function-to-pointer conversion (C++ 4.3). 1027 SCS.First = ICK_Function_To_Pointer; 1028 1029 // An lvalue of function type T can be converted to an rvalue of 1030 // type "pointer to T." The result is a pointer to the 1031 // function. (C++ 4.3p1). 1032 FromType = S.Context.getPointerType(FromType); 1033 } else { 1034 // We don't require any conversions for the first step. 1035 SCS.First = ICK_Identity; 1036 } 1037 SCS.setToType(0, FromType); 1038 1039 // The second conversion can be an integral promotion, floating 1040 // point promotion, integral conversion, floating point conversion, 1041 // floating-integral conversion, pointer conversion, 1042 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1043 // For overloading in C, this can also be a "compatible-type" 1044 // conversion. 1045 bool IncompatibleObjC = false; 1046 ImplicitConversionKind SecondICK = ICK_Identity; 1047 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1048 // The unqualified versions of the types are the same: there's no 1049 // conversion to do. 1050 SCS.Second = ICK_Identity; 1051 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1052 // Integral promotion (C++ 4.5). 1053 SCS.Second = ICK_Integral_Promotion; 1054 FromType = ToType.getUnqualifiedType(); 1055 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1056 // Floating point promotion (C++ 4.6). 1057 SCS.Second = ICK_Floating_Promotion; 1058 FromType = ToType.getUnqualifiedType(); 1059 } else if (S.IsComplexPromotion(FromType, ToType)) { 1060 // Complex promotion (Clang extension) 1061 SCS.Second = ICK_Complex_Promotion; 1062 FromType = ToType.getUnqualifiedType(); 1063 } else if (FromType->isIntegralOrEnumerationType() && 1064 ToType->isIntegralType(S.Context)) { 1065 // Integral conversions (C++ 4.7). 1066 SCS.Second = ICK_Integral_Conversion; 1067 FromType = ToType.getUnqualifiedType(); 1068 } else if (FromType->isComplexType() && ToType->isComplexType()) { 1069 // Complex conversions (C99 6.3.1.6) 1070 SCS.Second = ICK_Complex_Conversion; 1071 FromType = ToType.getUnqualifiedType(); 1072 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 1073 (ToType->isComplexType() && FromType->isArithmeticType())) { 1074 // Complex-real conversions (C99 6.3.1.7) 1075 SCS.Second = ICK_Complex_Real; 1076 FromType = ToType.getUnqualifiedType(); 1077 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1078 // Floating point conversions (C++ 4.8). 1079 SCS.Second = ICK_Floating_Conversion; 1080 FromType = ToType.getUnqualifiedType(); 1081 } else if ((FromType->isRealFloatingType() && 1082 ToType->isIntegralType(S.Context) && !ToType->isBooleanType()) || 1083 (FromType->isIntegralOrEnumerationType() && 1084 ToType->isRealFloatingType())) { 1085 // Floating-integral conversions (C++ 4.9). 1086 SCS.Second = ICK_Floating_Integral; 1087 FromType = ToType.getUnqualifiedType(); 1088 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1089 FromType, IncompatibleObjC)) { 1090 // Pointer conversions (C++ 4.10). 1091 SCS.Second = ICK_Pointer_Conversion; 1092 SCS.IncompatibleObjC = IncompatibleObjC; 1093 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1094 InOverloadResolution, FromType)) { 1095 // Pointer to member conversions (4.11). 1096 SCS.Second = ICK_Pointer_Member; 1097 } else if (ToType->isBooleanType() && 1098 (FromType->isArithmeticType() || 1099 FromType->isEnumeralType() || 1100 FromType->isAnyPointerType() || 1101 FromType->isBlockPointerType() || 1102 FromType->isMemberPointerType() || 1103 FromType->isNullPtrType())) { 1104 // Boolean conversions (C++ 4.12). 1105 SCS.Second = ICK_Boolean_Conversion; 1106 FromType = S.Context.BoolTy; 1107 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1108 SCS.Second = SecondICK; 1109 FromType = ToType.getUnqualifiedType(); 1110 } else if (!S.getLangOptions().CPlusPlus && 1111 S.Context.typesAreCompatible(ToType, FromType)) { 1112 // Compatible conversions (Clang extension for C function overloading) 1113 SCS.Second = ICK_Compatible_Conversion; 1114 FromType = ToType.getUnqualifiedType(); 1115 } else if (IsNoReturnConversion(S.Context, FromType, ToType, FromType)) { 1116 // Treat a conversion that strips "noreturn" as an identity conversion. 1117 SCS.Second = ICK_NoReturn_Adjustment; 1118 } else { 1119 // No second conversion required. 1120 SCS.Second = ICK_Identity; 1121 } 1122 SCS.setToType(1, FromType); 1123 1124 QualType CanonFrom; 1125 QualType CanonTo; 1126 // The third conversion can be a qualification conversion (C++ 4p1). 1127 if (S.IsQualificationConversion(FromType, ToType)) { 1128 SCS.Third = ICK_Qualification; 1129 FromType = ToType; 1130 CanonFrom = S.Context.getCanonicalType(FromType); 1131 CanonTo = S.Context.getCanonicalType(ToType); 1132 } else { 1133 // No conversion required 1134 SCS.Third = ICK_Identity; 1135 1136 // C++ [over.best.ics]p6: 1137 // [...] Any difference in top-level cv-qualification is 1138 // subsumed by the initialization itself and does not constitute 1139 // a conversion. [...] 1140 CanonFrom = S.Context.getCanonicalType(FromType); 1141 CanonTo = S.Context.getCanonicalType(ToType); 1142 if (CanonFrom.getLocalUnqualifiedType() 1143 == CanonTo.getLocalUnqualifiedType() && 1144 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1145 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1146 FromType = ToType; 1147 CanonFrom = CanonTo; 1148 } 1149 } 1150 SCS.setToType(2, FromType); 1151 1152 // If we have not converted the argument type to the parameter type, 1153 // this is a bad conversion sequence. 1154 if (CanonFrom != CanonTo) 1155 return false; 1156 1157 return true; 1158} 1159 1160/// IsIntegralPromotion - Determines whether the conversion from the 1161/// expression From (whose potentially-adjusted type is FromType) to 1162/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1163/// sets PromotedType to the promoted type. 1164bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1165 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1166 // All integers are built-in. 1167 if (!To) { 1168 return false; 1169 } 1170 1171 // An rvalue of type char, signed char, unsigned char, short int, or 1172 // unsigned short int can be converted to an rvalue of type int if 1173 // int can represent all the values of the source type; otherwise, 1174 // the source rvalue can be converted to an rvalue of type unsigned 1175 // int (C++ 4.5p1). 1176 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1177 !FromType->isEnumeralType()) { 1178 if (// We can promote any signed, promotable integer type to an int 1179 (FromType->isSignedIntegerType() || 1180 // We can promote any unsigned integer type whose size is 1181 // less than int to an int. 1182 (!FromType->isSignedIntegerType() && 1183 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1184 return To->getKind() == BuiltinType::Int; 1185 } 1186 1187 return To->getKind() == BuiltinType::UInt; 1188 } 1189 1190 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 1191 // can be converted to an rvalue of the first of the following types 1192 // that can represent all the values of its underlying type: int, 1193 // unsigned int, long, or unsigned long (C++ 4.5p2). 1194 1195 // We pre-calculate the promotion type for enum types. 1196 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 1197 if (ToType->isIntegerType()) 1198 return Context.hasSameUnqualifiedType(ToType, 1199 FromEnumType->getDecl()->getPromotionType()); 1200 1201 if (FromType->isWideCharType() && ToType->isIntegerType()) { 1202 // Determine whether the type we're converting from is signed or 1203 // unsigned. 1204 bool FromIsSigned; 1205 uint64_t FromSize = Context.getTypeSize(FromType); 1206 1207 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1208 FromIsSigned = true; 1209 1210 // The types we'll try to promote to, in the appropriate 1211 // order. Try each of these types. 1212 QualType PromoteTypes[6] = { 1213 Context.IntTy, Context.UnsignedIntTy, 1214 Context.LongTy, Context.UnsignedLongTy , 1215 Context.LongLongTy, Context.UnsignedLongLongTy 1216 }; 1217 for (int Idx = 0; Idx < 6; ++Idx) { 1218 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1219 if (FromSize < ToSize || 1220 (FromSize == ToSize && 1221 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1222 // We found the type that we can promote to. If this is the 1223 // type we wanted, we have a promotion. Otherwise, no 1224 // promotion. 1225 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1226 } 1227 } 1228 } 1229 1230 // An rvalue for an integral bit-field (9.6) can be converted to an 1231 // rvalue of type int if int can represent all the values of the 1232 // bit-field; otherwise, it can be converted to unsigned int if 1233 // unsigned int can represent all the values of the bit-field. If 1234 // the bit-field is larger yet, no integral promotion applies to 1235 // it. If the bit-field has an enumerated type, it is treated as any 1236 // other value of that type for promotion purposes (C++ 4.5p3). 1237 // FIXME: We should delay checking of bit-fields until we actually perform the 1238 // conversion. 1239 using llvm::APSInt; 1240 if (From) 1241 if (FieldDecl *MemberDecl = From->getBitField()) { 1242 APSInt BitWidth; 1243 if (FromType->isIntegralType(Context) && 1244 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1245 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1246 ToSize = Context.getTypeSize(ToType); 1247 1248 // Are we promoting to an int from a bitfield that fits in an int? 1249 if (BitWidth < ToSize || 1250 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1251 return To->getKind() == BuiltinType::Int; 1252 } 1253 1254 // Are we promoting to an unsigned int from an unsigned bitfield 1255 // that fits into an unsigned int? 1256 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1257 return To->getKind() == BuiltinType::UInt; 1258 } 1259 1260 return false; 1261 } 1262 } 1263 1264 // An rvalue of type bool can be converted to an rvalue of type int, 1265 // with false becoming zero and true becoming one (C++ 4.5p4). 1266 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1267 return true; 1268 } 1269 1270 return false; 1271} 1272 1273/// IsFloatingPointPromotion - Determines whether the conversion from 1274/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1275/// returns true and sets PromotedType to the promoted type. 1276bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1277 /// An rvalue of type float can be converted to an rvalue of type 1278 /// double. (C++ 4.6p1). 1279 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1280 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1281 if (FromBuiltin->getKind() == BuiltinType::Float && 1282 ToBuiltin->getKind() == BuiltinType::Double) 1283 return true; 1284 1285 // C99 6.3.1.5p1: 1286 // When a float is promoted to double or long double, or a 1287 // double is promoted to long double [...]. 1288 if (!getLangOptions().CPlusPlus && 1289 (FromBuiltin->getKind() == BuiltinType::Float || 1290 FromBuiltin->getKind() == BuiltinType::Double) && 1291 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1292 return true; 1293 } 1294 1295 return false; 1296} 1297 1298/// \brief Determine if a conversion is a complex promotion. 1299/// 1300/// A complex promotion is defined as a complex -> complex conversion 1301/// where the conversion between the underlying real types is a 1302/// floating-point or integral promotion. 1303bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1304 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1305 if (!FromComplex) 1306 return false; 1307 1308 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1309 if (!ToComplex) 1310 return false; 1311 1312 return IsFloatingPointPromotion(FromComplex->getElementType(), 1313 ToComplex->getElementType()) || 1314 IsIntegralPromotion(0, FromComplex->getElementType(), 1315 ToComplex->getElementType()); 1316} 1317 1318/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1319/// the pointer type FromPtr to a pointer to type ToPointee, with the 1320/// same type qualifiers as FromPtr has on its pointee type. ToType, 1321/// if non-empty, will be a pointer to ToType that may or may not have 1322/// the right set of qualifiers on its pointee. 1323static QualType 1324BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 1325 QualType ToPointee, QualType ToType, 1326 ASTContext &Context) { 1327 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 1328 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1329 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1330 1331 // Exact qualifier match -> return the pointer type we're converting to. 1332 if (CanonToPointee.getLocalQualifiers() == Quals) { 1333 // ToType is exactly what we need. Return it. 1334 if (!ToType.isNull()) 1335 return ToType.getUnqualifiedType(); 1336 1337 // Build a pointer to ToPointee. It has the right qualifiers 1338 // already. 1339 return Context.getPointerType(ToPointee); 1340 } 1341 1342 // Just build a canonical type that has the right qualifiers. 1343 return Context.getPointerType( 1344 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 1345 Quals)); 1346} 1347 1348/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 1349/// the FromType, which is an objective-c pointer, to ToType, which may or may 1350/// not have the right set of qualifiers. 1351static QualType 1352BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 1353 QualType ToType, 1354 ASTContext &Context) { 1355 QualType CanonFromType = Context.getCanonicalType(FromType); 1356 QualType CanonToType = Context.getCanonicalType(ToType); 1357 Qualifiers Quals = CanonFromType.getQualifiers(); 1358 1359 // Exact qualifier match -> return the pointer type we're converting to. 1360 if (CanonToType.getLocalQualifiers() == Quals) 1361 return ToType; 1362 1363 // Just build a canonical type that has the right qualifiers. 1364 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 1365} 1366 1367static bool isNullPointerConstantForConversion(Expr *Expr, 1368 bool InOverloadResolution, 1369 ASTContext &Context) { 1370 // Handle value-dependent integral null pointer constants correctly. 1371 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1372 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1373 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1374 return !InOverloadResolution; 1375 1376 return Expr->isNullPointerConstant(Context, 1377 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1378 : Expr::NPC_ValueDependentIsNull); 1379} 1380 1381/// IsPointerConversion - Determines whether the conversion of the 1382/// expression From, which has the (possibly adjusted) type FromType, 1383/// can be converted to the type ToType via a pointer conversion (C++ 1384/// 4.10). If so, returns true and places the converted type (that 1385/// might differ from ToType in its cv-qualifiers at some level) into 1386/// ConvertedType. 1387/// 1388/// This routine also supports conversions to and from block pointers 1389/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1390/// pointers to interfaces. FIXME: Once we've determined the 1391/// appropriate overloading rules for Objective-C, we may want to 1392/// split the Objective-C checks into a different routine; however, 1393/// GCC seems to consider all of these conversions to be pointer 1394/// conversions, so for now they live here. IncompatibleObjC will be 1395/// set if the conversion is an allowed Objective-C conversion that 1396/// should result in a warning. 1397bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1398 bool InOverloadResolution, 1399 QualType& ConvertedType, 1400 bool &IncompatibleObjC) { 1401 IncompatibleObjC = false; 1402 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1403 return true; 1404 1405 // Conversion from a null pointer constant to any Objective-C pointer type. 1406 if (ToType->isObjCObjectPointerType() && 1407 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1408 ConvertedType = ToType; 1409 return true; 1410 } 1411 1412 // Blocks: Block pointers can be converted to void*. 1413 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1414 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1415 ConvertedType = ToType; 1416 return true; 1417 } 1418 // Blocks: A null pointer constant can be converted to a block 1419 // pointer type. 1420 if (ToType->isBlockPointerType() && 1421 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1422 ConvertedType = ToType; 1423 return true; 1424 } 1425 1426 // If the left-hand-side is nullptr_t, the right side can be a null 1427 // pointer constant. 1428 if (ToType->isNullPtrType() && 1429 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1430 ConvertedType = ToType; 1431 return true; 1432 } 1433 1434 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1435 if (!ToTypePtr) 1436 return false; 1437 1438 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1439 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1440 ConvertedType = ToType; 1441 return true; 1442 } 1443 1444 // Beyond this point, both types need to be pointers 1445 // , including objective-c pointers. 1446 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1447 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1448 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1449 ToType, Context); 1450 return true; 1451 1452 } 1453 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1454 if (!FromTypePtr) 1455 return false; 1456 1457 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1458 1459 // If the unqualified pointee types are the same, this can't be a 1460 // pointer conversion, so don't do all of the work below. 1461 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1462 return false; 1463 1464 // An rvalue of type "pointer to cv T," where T is an object type, 1465 // can be converted to an rvalue of type "pointer to cv void" (C++ 1466 // 4.10p2). 1467 if (FromPointeeType->isIncompleteOrObjectType() && 1468 ToPointeeType->isVoidType()) { 1469 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1470 ToPointeeType, 1471 ToType, Context); 1472 return true; 1473 } 1474 1475 // When we're overloading in C, we allow a special kind of pointer 1476 // conversion for compatible-but-not-identical pointee types. 1477 if (!getLangOptions().CPlusPlus && 1478 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1479 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1480 ToPointeeType, 1481 ToType, Context); 1482 return true; 1483 } 1484 1485 // C++ [conv.ptr]p3: 1486 // 1487 // An rvalue of type "pointer to cv D," where D is a class type, 1488 // can be converted to an rvalue of type "pointer to cv B," where 1489 // B is a base class (clause 10) of D. If B is an inaccessible 1490 // (clause 11) or ambiguous (10.2) base class of D, a program that 1491 // necessitates this conversion is ill-formed. The result of the 1492 // conversion is a pointer to the base class sub-object of the 1493 // derived class object. The null pointer value is converted to 1494 // the null pointer value of the destination type. 1495 // 1496 // Note that we do not check for ambiguity or inaccessibility 1497 // here. That is handled by CheckPointerConversion. 1498 if (getLangOptions().CPlusPlus && 1499 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1500 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1501 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1502 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1503 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1504 ToPointeeType, 1505 ToType, Context); 1506 return true; 1507 } 1508 1509 return false; 1510} 1511 1512/// isObjCPointerConversion - Determines whether this is an 1513/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1514/// with the same arguments and return values. 1515bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1516 QualType& ConvertedType, 1517 bool &IncompatibleObjC) { 1518 if (!getLangOptions().ObjC1) 1519 return false; 1520 1521 // First, we handle all conversions on ObjC object pointer types. 1522 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1523 const ObjCObjectPointerType *FromObjCPtr = 1524 FromType->getAs<ObjCObjectPointerType>(); 1525 1526 if (ToObjCPtr && FromObjCPtr) { 1527 // Objective C++: We're able to convert between "id" or "Class" and a 1528 // pointer to any interface (in both directions). 1529 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1530 ConvertedType = ToType; 1531 return true; 1532 } 1533 // Conversions with Objective-C's id<...>. 1534 if ((FromObjCPtr->isObjCQualifiedIdType() || 1535 ToObjCPtr->isObjCQualifiedIdType()) && 1536 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1537 /*compare=*/false)) { 1538 ConvertedType = ToType; 1539 return true; 1540 } 1541 // Objective C++: We're able to convert from a pointer to an 1542 // interface to a pointer to a different interface. 1543 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1544 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1545 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1546 if (getLangOptions().CPlusPlus && LHS && RHS && 1547 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1548 FromObjCPtr->getPointeeType())) 1549 return false; 1550 ConvertedType = ToType; 1551 return true; 1552 } 1553 1554 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1555 // Okay: this is some kind of implicit downcast of Objective-C 1556 // interfaces, which is permitted. However, we're going to 1557 // complain about it. 1558 IncompatibleObjC = true; 1559 ConvertedType = FromType; 1560 return true; 1561 } 1562 } 1563 // Beyond this point, both types need to be C pointers or block pointers. 1564 QualType ToPointeeType; 1565 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1566 ToPointeeType = ToCPtr->getPointeeType(); 1567 else if (const BlockPointerType *ToBlockPtr = 1568 ToType->getAs<BlockPointerType>()) { 1569 // Objective C++: We're able to convert from a pointer to any object 1570 // to a block pointer type. 1571 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1572 ConvertedType = ToType; 1573 return true; 1574 } 1575 ToPointeeType = ToBlockPtr->getPointeeType(); 1576 } 1577 else if (FromType->getAs<BlockPointerType>() && 1578 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1579 // Objective C++: We're able to convert from a block pointer type to a 1580 // pointer to any object. 1581 ConvertedType = ToType; 1582 return true; 1583 } 1584 else 1585 return false; 1586 1587 QualType FromPointeeType; 1588 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1589 FromPointeeType = FromCPtr->getPointeeType(); 1590 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1591 FromPointeeType = FromBlockPtr->getPointeeType(); 1592 else 1593 return false; 1594 1595 // If we have pointers to pointers, recursively check whether this 1596 // is an Objective-C conversion. 1597 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1598 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1599 IncompatibleObjC)) { 1600 // We always complain about this conversion. 1601 IncompatibleObjC = true; 1602 ConvertedType = ToType; 1603 return true; 1604 } 1605 // Allow conversion of pointee being objective-c pointer to another one; 1606 // as in I* to id. 1607 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1608 ToPointeeType->getAs<ObjCObjectPointerType>() && 1609 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1610 IncompatibleObjC)) { 1611 ConvertedType = ToType; 1612 return true; 1613 } 1614 1615 // If we have pointers to functions or blocks, check whether the only 1616 // differences in the argument and result types are in Objective-C 1617 // pointer conversions. If so, we permit the conversion (but 1618 // complain about it). 1619 const FunctionProtoType *FromFunctionType 1620 = FromPointeeType->getAs<FunctionProtoType>(); 1621 const FunctionProtoType *ToFunctionType 1622 = ToPointeeType->getAs<FunctionProtoType>(); 1623 if (FromFunctionType && ToFunctionType) { 1624 // If the function types are exactly the same, this isn't an 1625 // Objective-C pointer conversion. 1626 if (Context.getCanonicalType(FromPointeeType) 1627 == Context.getCanonicalType(ToPointeeType)) 1628 return false; 1629 1630 // Perform the quick checks that will tell us whether these 1631 // function types are obviously different. 1632 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1633 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1634 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1635 return false; 1636 1637 bool HasObjCConversion = false; 1638 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1639 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1640 // Okay, the types match exactly. Nothing to do. 1641 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1642 ToFunctionType->getResultType(), 1643 ConvertedType, IncompatibleObjC)) { 1644 // Okay, we have an Objective-C pointer conversion. 1645 HasObjCConversion = true; 1646 } else { 1647 // Function types are too different. Abort. 1648 return false; 1649 } 1650 1651 // Check argument types. 1652 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1653 ArgIdx != NumArgs; ++ArgIdx) { 1654 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1655 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1656 if (Context.getCanonicalType(FromArgType) 1657 == Context.getCanonicalType(ToArgType)) { 1658 // Okay, the types match exactly. Nothing to do. 1659 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1660 ConvertedType, IncompatibleObjC)) { 1661 // Okay, we have an Objective-C pointer conversion. 1662 HasObjCConversion = true; 1663 } else { 1664 // Argument types are too different. Abort. 1665 return false; 1666 } 1667 } 1668 1669 if (HasObjCConversion) { 1670 // We had an Objective-C conversion. Allow this pointer 1671 // conversion, but complain about it. 1672 ConvertedType = ToType; 1673 IncompatibleObjC = true; 1674 return true; 1675 } 1676 } 1677 1678 return false; 1679} 1680 1681/// FunctionArgTypesAreEqual - This routine checks two function proto types 1682/// for equlity of their argument types. Caller has already checked that 1683/// they have same number of arguments. This routine assumes that Objective-C 1684/// pointer types which only differ in their protocol qualifiers are equal. 1685bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, 1686 FunctionProtoType* NewType){ 1687 if (!getLangOptions().ObjC1) 1688 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1689 NewType->arg_type_begin()); 1690 1691 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1692 N = NewType->arg_type_begin(), 1693 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1694 QualType ToType = (*O); 1695 QualType FromType = (*N); 1696 if (ToType != FromType) { 1697 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1698 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1699 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1700 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1701 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1702 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1703 continue; 1704 } 1705 else if (const ObjCObjectPointerType *PTTo = 1706 ToType->getAs<ObjCObjectPointerType>()) { 1707 if (const ObjCObjectPointerType *PTFr = 1708 FromType->getAs<ObjCObjectPointerType>()) 1709 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1710 continue; 1711 } 1712 return false; 1713 } 1714 } 1715 return true; 1716} 1717 1718/// CheckPointerConversion - Check the pointer conversion from the 1719/// expression From to the type ToType. This routine checks for 1720/// ambiguous or inaccessible derived-to-base pointer 1721/// conversions for which IsPointerConversion has already returned 1722/// true. It returns true and produces a diagnostic if there was an 1723/// error, or returns false otherwise. 1724bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1725 CastKind &Kind, 1726 CXXCastPath& BasePath, 1727 bool IgnoreBaseAccess) { 1728 QualType FromType = From->getType(); 1729 1730 if (CXXBoolLiteralExpr* LitBool 1731 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1732 if (LitBool->getValue() == false) 1733 Diag(LitBool->getExprLoc(), diag::warn_init_pointer_from_false) 1734 << ToType; 1735 1736 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1737 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1738 QualType FromPointeeType = FromPtrType->getPointeeType(), 1739 ToPointeeType = ToPtrType->getPointeeType(); 1740 1741 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1742 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1743 // We must have a derived-to-base conversion. Check an 1744 // ambiguous or inaccessible conversion. 1745 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1746 From->getExprLoc(), 1747 From->getSourceRange(), &BasePath, 1748 IgnoreBaseAccess)) 1749 return true; 1750 1751 // The conversion was successful. 1752 Kind = CK_DerivedToBase; 1753 } 1754 } 1755 if (const ObjCObjectPointerType *FromPtrType = 1756 FromType->getAs<ObjCObjectPointerType>()) 1757 if (const ObjCObjectPointerType *ToPtrType = 1758 ToType->getAs<ObjCObjectPointerType>()) { 1759 // Objective-C++ conversions are always okay. 1760 // FIXME: We should have a different class of conversions for the 1761 // Objective-C++ implicit conversions. 1762 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1763 return false; 1764 1765 } 1766 return false; 1767} 1768 1769/// IsMemberPointerConversion - Determines whether the conversion of the 1770/// expression From, which has the (possibly adjusted) type FromType, can be 1771/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1772/// If so, returns true and places the converted type (that might differ from 1773/// ToType in its cv-qualifiers at some level) into ConvertedType. 1774bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1775 QualType ToType, 1776 bool InOverloadResolution, 1777 QualType &ConvertedType) { 1778 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1779 if (!ToTypePtr) 1780 return false; 1781 1782 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1783 if (From->isNullPointerConstant(Context, 1784 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1785 : Expr::NPC_ValueDependentIsNull)) { 1786 ConvertedType = ToType; 1787 return true; 1788 } 1789 1790 // Otherwise, both types have to be member pointers. 1791 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1792 if (!FromTypePtr) 1793 return false; 1794 1795 // A pointer to member of B can be converted to a pointer to member of D, 1796 // where D is derived from B (C++ 4.11p2). 1797 QualType FromClass(FromTypePtr->getClass(), 0); 1798 QualType ToClass(ToTypePtr->getClass(), 0); 1799 // FIXME: What happens when these are dependent? Is this function even called? 1800 1801 if (IsDerivedFrom(ToClass, FromClass)) { 1802 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1803 ToClass.getTypePtr()); 1804 return true; 1805 } 1806 1807 return false; 1808} 1809 1810/// CheckMemberPointerConversion - Check the member pointer conversion from the 1811/// expression From to the type ToType. This routine checks for ambiguous or 1812/// virtual or inaccessible base-to-derived member pointer conversions 1813/// for which IsMemberPointerConversion has already returned true. It returns 1814/// true and produces a diagnostic if there was an error, or returns false 1815/// otherwise. 1816bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1817 CastKind &Kind, 1818 CXXCastPath &BasePath, 1819 bool IgnoreBaseAccess) { 1820 QualType FromType = From->getType(); 1821 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1822 if (!FromPtrType) { 1823 // This must be a null pointer to member pointer conversion 1824 assert(From->isNullPointerConstant(Context, 1825 Expr::NPC_ValueDependentIsNull) && 1826 "Expr must be null pointer constant!"); 1827 Kind = CK_NullToMemberPointer; 1828 return false; 1829 } 1830 1831 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1832 assert(ToPtrType && "No member pointer cast has a target type " 1833 "that is not a member pointer."); 1834 1835 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1836 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1837 1838 // FIXME: What about dependent types? 1839 assert(FromClass->isRecordType() && "Pointer into non-class."); 1840 assert(ToClass->isRecordType() && "Pointer into non-class."); 1841 1842 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1843 /*DetectVirtual=*/true); 1844 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1845 assert(DerivationOkay && 1846 "Should not have been called if derivation isn't OK."); 1847 (void)DerivationOkay; 1848 1849 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1850 getUnqualifiedType())) { 1851 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1852 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1853 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1854 return true; 1855 } 1856 1857 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1858 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1859 << FromClass << ToClass << QualType(VBase, 0) 1860 << From->getSourceRange(); 1861 return true; 1862 } 1863 1864 if (!IgnoreBaseAccess) 1865 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1866 Paths.front(), 1867 diag::err_downcast_from_inaccessible_base); 1868 1869 // Must be a base to derived member conversion. 1870 BuildBasePathArray(Paths, BasePath); 1871 Kind = CK_BaseToDerivedMemberPointer; 1872 return false; 1873} 1874 1875/// IsQualificationConversion - Determines whether the conversion from 1876/// an rvalue of type FromType to ToType is a qualification conversion 1877/// (C++ 4.4). 1878bool 1879Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1880 FromType = Context.getCanonicalType(FromType); 1881 ToType = Context.getCanonicalType(ToType); 1882 1883 // If FromType and ToType are the same type, this is not a 1884 // qualification conversion. 1885 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1886 return false; 1887 1888 // (C++ 4.4p4): 1889 // A conversion can add cv-qualifiers at levels other than the first 1890 // in multi-level pointers, subject to the following rules: [...] 1891 bool PreviousToQualsIncludeConst = true; 1892 bool UnwrappedAnyPointer = false; 1893 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 1894 // Within each iteration of the loop, we check the qualifiers to 1895 // determine if this still looks like a qualification 1896 // conversion. Then, if all is well, we unwrap one more level of 1897 // pointers or pointers-to-members and do it all again 1898 // until there are no more pointers or pointers-to-members left to 1899 // unwrap. 1900 UnwrappedAnyPointer = true; 1901 1902 // -- for every j > 0, if const is in cv 1,j then const is in cv 1903 // 2,j, and similarly for volatile. 1904 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1905 return false; 1906 1907 // -- if the cv 1,j and cv 2,j are different, then const is in 1908 // every cv for 0 < k < j. 1909 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1910 && !PreviousToQualsIncludeConst) 1911 return false; 1912 1913 // Keep track of whether all prior cv-qualifiers in the "to" type 1914 // include const. 1915 PreviousToQualsIncludeConst 1916 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1917 } 1918 1919 // We are left with FromType and ToType being the pointee types 1920 // after unwrapping the original FromType and ToType the same number 1921 // of types. If we unwrapped any pointers, and if FromType and 1922 // ToType have the same unqualified type (since we checked 1923 // qualifiers above), then this is a qualification conversion. 1924 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1925} 1926 1927/// Determines whether there is a user-defined conversion sequence 1928/// (C++ [over.ics.user]) that converts expression From to the type 1929/// ToType. If such a conversion exists, User will contain the 1930/// user-defined conversion sequence that performs such a conversion 1931/// and this routine will return true. Otherwise, this routine returns 1932/// false and User is unspecified. 1933/// 1934/// \param AllowExplicit true if the conversion should consider C++0x 1935/// "explicit" conversion functions as well as non-explicit conversion 1936/// functions (C++0x [class.conv.fct]p2). 1937static OverloadingResult 1938IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 1939 UserDefinedConversionSequence& User, 1940 OverloadCandidateSet& CandidateSet, 1941 bool AllowExplicit) { 1942 // Whether we will only visit constructors. 1943 bool ConstructorsOnly = false; 1944 1945 // If the type we are conversion to is a class type, enumerate its 1946 // constructors. 1947 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1948 // C++ [over.match.ctor]p1: 1949 // When objects of class type are direct-initialized (8.5), or 1950 // copy-initialized from an expression of the same or a 1951 // derived class type (8.5), overload resolution selects the 1952 // constructor. [...] For copy-initialization, the candidate 1953 // functions are all the converting constructors (12.3.1) of 1954 // that class. The argument list is the expression-list within 1955 // the parentheses of the initializer. 1956 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 1957 (From->getType()->getAs<RecordType>() && 1958 S.IsDerivedFrom(From->getType(), ToType))) 1959 ConstructorsOnly = true; 1960 1961 if (S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag())) { 1962 // We're not going to find any constructors. 1963 } else if (CXXRecordDecl *ToRecordDecl 1964 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1965 DeclContext::lookup_iterator Con, ConEnd; 1966 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 1967 Con != ConEnd; ++Con) { 1968 NamedDecl *D = *Con; 1969 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1970 1971 // Find the constructor (which may be a template). 1972 CXXConstructorDecl *Constructor = 0; 1973 FunctionTemplateDecl *ConstructorTmpl 1974 = dyn_cast<FunctionTemplateDecl>(D); 1975 if (ConstructorTmpl) 1976 Constructor 1977 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1978 else 1979 Constructor = cast<CXXConstructorDecl>(D); 1980 1981 if (!Constructor->isInvalidDecl() && 1982 Constructor->isConvertingConstructor(AllowExplicit)) { 1983 if (ConstructorTmpl) 1984 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1985 /*ExplicitArgs*/ 0, 1986 &From, 1, CandidateSet, 1987 /*SuppressUserConversions=*/ 1988 !ConstructorsOnly); 1989 else 1990 // Allow one user-defined conversion when user specifies a 1991 // From->ToType conversion via an static cast (c-style, etc). 1992 S.AddOverloadCandidate(Constructor, FoundDecl, 1993 &From, 1, CandidateSet, 1994 /*SuppressUserConversions=*/ 1995 !ConstructorsOnly); 1996 } 1997 } 1998 } 1999 } 2000 2001 // Enumerate conversion functions, if we're allowed to. 2002 if (ConstructorsOnly) { 2003 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 2004 S.PDiag(0) << From->getSourceRange())) { 2005 // No conversion functions from incomplete types. 2006 } else if (const RecordType *FromRecordType 2007 = From->getType()->getAs<RecordType>()) { 2008 if (CXXRecordDecl *FromRecordDecl 2009 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 2010 // Add all of the conversion functions as candidates. 2011 const UnresolvedSetImpl *Conversions 2012 = FromRecordDecl->getVisibleConversionFunctions(); 2013 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2014 E = Conversions->end(); I != E; ++I) { 2015 DeclAccessPair FoundDecl = I.getPair(); 2016 NamedDecl *D = FoundDecl.getDecl(); 2017 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 2018 if (isa<UsingShadowDecl>(D)) 2019 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2020 2021 CXXConversionDecl *Conv; 2022 FunctionTemplateDecl *ConvTemplate; 2023 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 2024 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2025 else 2026 Conv = cast<CXXConversionDecl>(D); 2027 2028 if (AllowExplicit || !Conv->isExplicit()) { 2029 if (ConvTemplate) 2030 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 2031 ActingContext, From, ToType, 2032 CandidateSet); 2033 else 2034 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 2035 From, ToType, CandidateSet); 2036 } 2037 } 2038 } 2039 } 2040 2041 OverloadCandidateSet::iterator Best; 2042 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best)) { 2043 case OR_Success: 2044 // Record the standard conversion we used and the conversion function. 2045 if (CXXConstructorDecl *Constructor 2046 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 2047 // C++ [over.ics.user]p1: 2048 // If the user-defined conversion is specified by a 2049 // constructor (12.3.1), the initial standard conversion 2050 // sequence converts the source type to the type required by 2051 // the argument of the constructor. 2052 // 2053 QualType ThisType = Constructor->getThisType(S.Context); 2054 if (Best->Conversions[0].isEllipsis()) 2055 User.EllipsisConversion = true; 2056 else { 2057 User.Before = Best->Conversions[0].Standard; 2058 User.EllipsisConversion = false; 2059 } 2060 User.ConversionFunction = Constructor; 2061 User.After.setAsIdentityConversion(); 2062 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2063 User.After.setAllToTypes(ToType); 2064 return OR_Success; 2065 } else if (CXXConversionDecl *Conversion 2066 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2067 // C++ [over.ics.user]p1: 2068 // 2069 // [...] If the user-defined conversion is specified by a 2070 // conversion function (12.3.2), the initial standard 2071 // conversion sequence converts the source type to the 2072 // implicit object parameter of the conversion function. 2073 User.Before = Best->Conversions[0].Standard; 2074 User.ConversionFunction = Conversion; 2075 User.EllipsisConversion = false; 2076 2077 // C++ [over.ics.user]p2: 2078 // The second standard conversion sequence converts the 2079 // result of the user-defined conversion to the target type 2080 // for the sequence. Since an implicit conversion sequence 2081 // is an initialization, the special rules for 2082 // initialization by user-defined conversion apply when 2083 // selecting the best user-defined conversion for a 2084 // user-defined conversion sequence (see 13.3.3 and 2085 // 13.3.3.1). 2086 User.After = Best->FinalConversion; 2087 return OR_Success; 2088 } else { 2089 llvm_unreachable("Not a constructor or conversion function?"); 2090 return OR_No_Viable_Function; 2091 } 2092 2093 case OR_No_Viable_Function: 2094 return OR_No_Viable_Function; 2095 case OR_Deleted: 2096 // No conversion here! We're done. 2097 return OR_Deleted; 2098 2099 case OR_Ambiguous: 2100 return OR_Ambiguous; 2101 } 2102 2103 return OR_No_Viable_Function; 2104} 2105 2106bool 2107Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2108 ImplicitConversionSequence ICS; 2109 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2110 OverloadingResult OvResult = 2111 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 2112 CandidateSet, false); 2113 if (OvResult == OR_Ambiguous) 2114 Diag(From->getSourceRange().getBegin(), 2115 diag::err_typecheck_ambiguous_condition) 2116 << From->getType() << ToType << From->getSourceRange(); 2117 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2118 Diag(From->getSourceRange().getBegin(), 2119 diag::err_typecheck_nonviable_condition) 2120 << From->getType() << ToType << From->getSourceRange(); 2121 else 2122 return false; 2123 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &From, 1); 2124 return true; 2125} 2126 2127/// CompareImplicitConversionSequences - Compare two implicit 2128/// conversion sequences to determine whether one is better than the 2129/// other or if they are indistinguishable (C++ 13.3.3.2). 2130static ImplicitConversionSequence::CompareKind 2131CompareImplicitConversionSequences(Sema &S, 2132 const ImplicitConversionSequence& ICS1, 2133 const ImplicitConversionSequence& ICS2) 2134{ 2135 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2136 // conversion sequences (as defined in 13.3.3.1) 2137 // -- a standard conversion sequence (13.3.3.1.1) is a better 2138 // conversion sequence than a user-defined conversion sequence or 2139 // an ellipsis conversion sequence, and 2140 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2141 // conversion sequence than an ellipsis conversion sequence 2142 // (13.3.3.1.3). 2143 // 2144 // C++0x [over.best.ics]p10: 2145 // For the purpose of ranking implicit conversion sequences as 2146 // described in 13.3.3.2, the ambiguous conversion sequence is 2147 // treated as a user-defined sequence that is indistinguishable 2148 // from any other user-defined conversion sequence. 2149 if (ICS1.getKindRank() < ICS2.getKindRank()) 2150 return ImplicitConversionSequence::Better; 2151 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2152 return ImplicitConversionSequence::Worse; 2153 2154 // The following checks require both conversion sequences to be of 2155 // the same kind. 2156 if (ICS1.getKind() != ICS2.getKind()) 2157 return ImplicitConversionSequence::Indistinguishable; 2158 2159 // Two implicit conversion sequences of the same form are 2160 // indistinguishable conversion sequences unless one of the 2161 // following rules apply: (C++ 13.3.3.2p3): 2162 if (ICS1.isStandard()) 2163 return CompareStandardConversionSequences(S, ICS1.Standard, ICS2.Standard); 2164 else if (ICS1.isUserDefined()) { 2165 // User-defined conversion sequence U1 is a better conversion 2166 // sequence than another user-defined conversion sequence U2 if 2167 // they contain the same user-defined conversion function or 2168 // constructor and if the second standard conversion sequence of 2169 // U1 is better than the second standard conversion sequence of 2170 // U2 (C++ 13.3.3.2p3). 2171 if (ICS1.UserDefined.ConversionFunction == 2172 ICS2.UserDefined.ConversionFunction) 2173 return CompareStandardConversionSequences(S, 2174 ICS1.UserDefined.After, 2175 ICS2.UserDefined.After); 2176 } 2177 2178 return ImplicitConversionSequence::Indistinguishable; 2179} 2180 2181static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2182 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2183 Qualifiers Quals; 2184 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2185 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2186 } 2187 2188 return Context.hasSameUnqualifiedType(T1, T2); 2189} 2190 2191// Per 13.3.3.2p3, compare the given standard conversion sequences to 2192// determine if one is a proper subset of the other. 2193static ImplicitConversionSequence::CompareKind 2194compareStandardConversionSubsets(ASTContext &Context, 2195 const StandardConversionSequence& SCS1, 2196 const StandardConversionSequence& SCS2) { 2197 ImplicitConversionSequence::CompareKind Result 2198 = ImplicitConversionSequence::Indistinguishable; 2199 2200 // the identity conversion sequence is considered to be a subsequence of 2201 // any non-identity conversion sequence 2202 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2203 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2204 return ImplicitConversionSequence::Better; 2205 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2206 return ImplicitConversionSequence::Worse; 2207 } 2208 2209 if (SCS1.Second != SCS2.Second) { 2210 if (SCS1.Second == ICK_Identity) 2211 Result = ImplicitConversionSequence::Better; 2212 else if (SCS2.Second == ICK_Identity) 2213 Result = ImplicitConversionSequence::Worse; 2214 else 2215 return ImplicitConversionSequence::Indistinguishable; 2216 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2217 return ImplicitConversionSequence::Indistinguishable; 2218 2219 if (SCS1.Third == SCS2.Third) { 2220 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2221 : ImplicitConversionSequence::Indistinguishable; 2222 } 2223 2224 if (SCS1.Third == ICK_Identity) 2225 return Result == ImplicitConversionSequence::Worse 2226 ? ImplicitConversionSequence::Indistinguishable 2227 : ImplicitConversionSequence::Better; 2228 2229 if (SCS2.Third == ICK_Identity) 2230 return Result == ImplicitConversionSequence::Better 2231 ? ImplicitConversionSequence::Indistinguishable 2232 : ImplicitConversionSequence::Worse; 2233 2234 return ImplicitConversionSequence::Indistinguishable; 2235} 2236 2237/// CompareStandardConversionSequences - Compare two standard 2238/// conversion sequences to determine whether one is better than the 2239/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2240static ImplicitConversionSequence::CompareKind 2241CompareStandardConversionSequences(Sema &S, 2242 const StandardConversionSequence& SCS1, 2243 const StandardConversionSequence& SCS2) 2244{ 2245 // Standard conversion sequence S1 is a better conversion sequence 2246 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2247 2248 // -- S1 is a proper subsequence of S2 (comparing the conversion 2249 // sequences in the canonical form defined by 13.3.3.1.1, 2250 // excluding any Lvalue Transformation; the identity conversion 2251 // sequence is considered to be a subsequence of any 2252 // non-identity conversion sequence) or, if not that, 2253 if (ImplicitConversionSequence::CompareKind CK 2254 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 2255 return CK; 2256 2257 // -- the rank of S1 is better than the rank of S2 (by the rules 2258 // defined below), or, if not that, 2259 ImplicitConversionRank Rank1 = SCS1.getRank(); 2260 ImplicitConversionRank Rank2 = SCS2.getRank(); 2261 if (Rank1 < Rank2) 2262 return ImplicitConversionSequence::Better; 2263 else if (Rank2 < Rank1) 2264 return ImplicitConversionSequence::Worse; 2265 2266 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2267 // are indistinguishable unless one of the following rules 2268 // applies: 2269 2270 // A conversion that is not a conversion of a pointer, or 2271 // pointer to member, to bool is better than another conversion 2272 // that is such a conversion. 2273 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2274 return SCS2.isPointerConversionToBool() 2275 ? ImplicitConversionSequence::Better 2276 : ImplicitConversionSequence::Worse; 2277 2278 // C++ [over.ics.rank]p4b2: 2279 // 2280 // If class B is derived directly or indirectly from class A, 2281 // conversion of B* to A* is better than conversion of B* to 2282 // void*, and conversion of A* to void* is better than conversion 2283 // of B* to void*. 2284 bool SCS1ConvertsToVoid 2285 = SCS1.isPointerConversionToVoidPointer(S.Context); 2286 bool SCS2ConvertsToVoid 2287 = SCS2.isPointerConversionToVoidPointer(S.Context); 2288 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2289 // Exactly one of the conversion sequences is a conversion to 2290 // a void pointer; it's the worse conversion. 2291 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2292 : ImplicitConversionSequence::Worse; 2293 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2294 // Neither conversion sequence converts to a void pointer; compare 2295 // their derived-to-base conversions. 2296 if (ImplicitConversionSequence::CompareKind DerivedCK 2297 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 2298 return DerivedCK; 2299 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2300 // Both conversion sequences are conversions to void 2301 // pointers. Compare the source types to determine if there's an 2302 // inheritance relationship in their sources. 2303 QualType FromType1 = SCS1.getFromType(); 2304 QualType FromType2 = SCS2.getFromType(); 2305 2306 // Adjust the types we're converting from via the array-to-pointer 2307 // conversion, if we need to. 2308 if (SCS1.First == ICK_Array_To_Pointer) 2309 FromType1 = S.Context.getArrayDecayedType(FromType1); 2310 if (SCS2.First == ICK_Array_To_Pointer) 2311 FromType2 = S.Context.getArrayDecayedType(FromType2); 2312 2313 QualType FromPointee1 2314 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2315 QualType FromPointee2 2316 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2317 2318 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2319 return ImplicitConversionSequence::Better; 2320 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2321 return ImplicitConversionSequence::Worse; 2322 2323 // Objective-C++: If one interface is more specific than the 2324 // other, it is the better one. 2325 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2326 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2327 if (FromIface1 && FromIface1) { 2328 if (S.Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2329 return ImplicitConversionSequence::Better; 2330 else if (S.Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2331 return ImplicitConversionSequence::Worse; 2332 } 2333 } 2334 2335 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2336 // bullet 3). 2337 if (ImplicitConversionSequence::CompareKind QualCK 2338 = CompareQualificationConversions(S, SCS1, SCS2)) 2339 return QualCK; 2340 2341 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2342 // C++0x [over.ics.rank]p3b4: 2343 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2344 // implicit object parameter of a non-static member function declared 2345 // without a ref-qualifier, and S1 binds an rvalue reference to an 2346 // rvalue and S2 binds an lvalue reference. 2347 // FIXME: We don't know if we're dealing with the implicit object parameter, 2348 // or if the member function in this case has a ref qualifier. 2349 // (Of course, we don't have ref qualifiers yet.) 2350 if (SCS1.RRefBinding != SCS2.RRefBinding) 2351 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 2352 : ImplicitConversionSequence::Worse; 2353 2354 // C++ [over.ics.rank]p3b4: 2355 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2356 // which the references refer are the same type except for 2357 // top-level cv-qualifiers, and the type to which the reference 2358 // initialized by S2 refers is more cv-qualified than the type 2359 // to which the reference initialized by S1 refers. 2360 QualType T1 = SCS1.getToType(2); 2361 QualType T2 = SCS2.getToType(2); 2362 T1 = S.Context.getCanonicalType(T1); 2363 T2 = S.Context.getCanonicalType(T2); 2364 Qualifiers T1Quals, T2Quals; 2365 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2366 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2367 if (UnqualT1 == UnqualT2) { 2368 // If the type is an array type, promote the element qualifiers to the type 2369 // for comparison. 2370 if (isa<ArrayType>(T1) && T1Quals) 2371 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2372 if (isa<ArrayType>(T2) && T2Quals) 2373 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2374 if (T2.isMoreQualifiedThan(T1)) 2375 return ImplicitConversionSequence::Better; 2376 else if (T1.isMoreQualifiedThan(T2)) 2377 return ImplicitConversionSequence::Worse; 2378 } 2379 } 2380 2381 return ImplicitConversionSequence::Indistinguishable; 2382} 2383 2384/// CompareQualificationConversions - Compares two standard conversion 2385/// sequences to determine whether they can be ranked based on their 2386/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2387ImplicitConversionSequence::CompareKind 2388CompareQualificationConversions(Sema &S, 2389 const StandardConversionSequence& SCS1, 2390 const StandardConversionSequence& SCS2) { 2391 // C++ 13.3.3.2p3: 2392 // -- S1 and S2 differ only in their qualification conversion and 2393 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2394 // cv-qualification signature of type T1 is a proper subset of 2395 // the cv-qualification signature of type T2, and S1 is not the 2396 // deprecated string literal array-to-pointer conversion (4.2). 2397 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2398 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2399 return ImplicitConversionSequence::Indistinguishable; 2400 2401 // FIXME: the example in the standard doesn't use a qualification 2402 // conversion (!) 2403 QualType T1 = SCS1.getToType(2); 2404 QualType T2 = SCS2.getToType(2); 2405 T1 = S.Context.getCanonicalType(T1); 2406 T2 = S.Context.getCanonicalType(T2); 2407 Qualifiers T1Quals, T2Quals; 2408 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2409 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2410 2411 // If the types are the same, we won't learn anything by unwrapped 2412 // them. 2413 if (UnqualT1 == UnqualT2) 2414 return ImplicitConversionSequence::Indistinguishable; 2415 2416 // If the type is an array type, promote the element qualifiers to the type 2417 // for comparison. 2418 if (isa<ArrayType>(T1) && T1Quals) 2419 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2420 if (isa<ArrayType>(T2) && T2Quals) 2421 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2422 2423 ImplicitConversionSequence::CompareKind Result 2424 = ImplicitConversionSequence::Indistinguishable; 2425 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 2426 // Within each iteration of the loop, we check the qualifiers to 2427 // determine if this still looks like a qualification 2428 // conversion. Then, if all is well, we unwrap one more level of 2429 // pointers or pointers-to-members and do it all again 2430 // until there are no more pointers or pointers-to-members left 2431 // to unwrap. This essentially mimics what 2432 // IsQualificationConversion does, but here we're checking for a 2433 // strict subset of qualifiers. 2434 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2435 // The qualifiers are the same, so this doesn't tell us anything 2436 // about how the sequences rank. 2437 ; 2438 else if (T2.isMoreQualifiedThan(T1)) { 2439 // T1 has fewer qualifiers, so it could be the better sequence. 2440 if (Result == ImplicitConversionSequence::Worse) 2441 // Neither has qualifiers that are a subset of the other's 2442 // qualifiers. 2443 return ImplicitConversionSequence::Indistinguishable; 2444 2445 Result = ImplicitConversionSequence::Better; 2446 } else if (T1.isMoreQualifiedThan(T2)) { 2447 // T2 has fewer qualifiers, so it could be the better sequence. 2448 if (Result == ImplicitConversionSequence::Better) 2449 // Neither has qualifiers that are a subset of the other's 2450 // qualifiers. 2451 return ImplicitConversionSequence::Indistinguishable; 2452 2453 Result = ImplicitConversionSequence::Worse; 2454 } else { 2455 // Qualifiers are disjoint. 2456 return ImplicitConversionSequence::Indistinguishable; 2457 } 2458 2459 // If the types after this point are equivalent, we're done. 2460 if (S.Context.hasSameUnqualifiedType(T1, T2)) 2461 break; 2462 } 2463 2464 // Check that the winning standard conversion sequence isn't using 2465 // the deprecated string literal array to pointer conversion. 2466 switch (Result) { 2467 case ImplicitConversionSequence::Better: 2468 if (SCS1.DeprecatedStringLiteralToCharPtr) 2469 Result = ImplicitConversionSequence::Indistinguishable; 2470 break; 2471 2472 case ImplicitConversionSequence::Indistinguishable: 2473 break; 2474 2475 case ImplicitConversionSequence::Worse: 2476 if (SCS2.DeprecatedStringLiteralToCharPtr) 2477 Result = ImplicitConversionSequence::Indistinguishable; 2478 break; 2479 } 2480 2481 return Result; 2482} 2483 2484/// CompareDerivedToBaseConversions - Compares two standard conversion 2485/// sequences to determine whether they can be ranked based on their 2486/// various kinds of derived-to-base conversions (C++ 2487/// [over.ics.rank]p4b3). As part of these checks, we also look at 2488/// conversions between Objective-C interface types. 2489ImplicitConversionSequence::CompareKind 2490CompareDerivedToBaseConversions(Sema &S, 2491 const StandardConversionSequence& SCS1, 2492 const StandardConversionSequence& SCS2) { 2493 QualType FromType1 = SCS1.getFromType(); 2494 QualType ToType1 = SCS1.getToType(1); 2495 QualType FromType2 = SCS2.getFromType(); 2496 QualType ToType2 = SCS2.getToType(1); 2497 2498 // Adjust the types we're converting from via the array-to-pointer 2499 // conversion, if we need to. 2500 if (SCS1.First == ICK_Array_To_Pointer) 2501 FromType1 = S.Context.getArrayDecayedType(FromType1); 2502 if (SCS2.First == ICK_Array_To_Pointer) 2503 FromType2 = S.Context.getArrayDecayedType(FromType2); 2504 2505 // Canonicalize all of the types. 2506 FromType1 = S.Context.getCanonicalType(FromType1); 2507 ToType1 = S.Context.getCanonicalType(ToType1); 2508 FromType2 = S.Context.getCanonicalType(FromType2); 2509 ToType2 = S.Context.getCanonicalType(ToType2); 2510 2511 // C++ [over.ics.rank]p4b3: 2512 // 2513 // If class B is derived directly or indirectly from class A and 2514 // class C is derived directly or indirectly from B, 2515 // 2516 // For Objective-C, we let A, B, and C also be Objective-C 2517 // interfaces. 2518 2519 // Compare based on pointer conversions. 2520 if (SCS1.Second == ICK_Pointer_Conversion && 2521 SCS2.Second == ICK_Pointer_Conversion && 2522 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2523 FromType1->isPointerType() && FromType2->isPointerType() && 2524 ToType1->isPointerType() && ToType2->isPointerType()) { 2525 QualType FromPointee1 2526 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2527 QualType ToPointee1 2528 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2529 QualType FromPointee2 2530 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2531 QualType ToPointee2 2532 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2533 2534 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2535 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2536 const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>(); 2537 const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>(); 2538 2539 // -- conversion of C* to B* is better than conversion of C* to A*, 2540 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2541 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2542 return ImplicitConversionSequence::Better; 2543 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2544 return ImplicitConversionSequence::Worse; 2545 2546 if (ToIface1 && ToIface2) { 2547 if (S.Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2548 return ImplicitConversionSequence::Better; 2549 else if (S.Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2550 return ImplicitConversionSequence::Worse; 2551 } 2552 } 2553 2554 // -- conversion of B* to A* is better than conversion of C* to A*, 2555 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2556 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2557 return ImplicitConversionSequence::Better; 2558 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2559 return ImplicitConversionSequence::Worse; 2560 2561 if (FromIface1 && FromIface2) { 2562 if (S.Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2563 return ImplicitConversionSequence::Better; 2564 else if (S.Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2565 return ImplicitConversionSequence::Worse; 2566 } 2567 } 2568 } 2569 2570 // Ranking of member-pointer types. 2571 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2572 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2573 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2574 const MemberPointerType * FromMemPointer1 = 2575 FromType1->getAs<MemberPointerType>(); 2576 const MemberPointerType * ToMemPointer1 = 2577 ToType1->getAs<MemberPointerType>(); 2578 const MemberPointerType * FromMemPointer2 = 2579 FromType2->getAs<MemberPointerType>(); 2580 const MemberPointerType * ToMemPointer2 = 2581 ToType2->getAs<MemberPointerType>(); 2582 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2583 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2584 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2585 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2586 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2587 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2588 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2589 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2590 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2591 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2592 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2593 return ImplicitConversionSequence::Worse; 2594 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2595 return ImplicitConversionSequence::Better; 2596 } 2597 // conversion of B::* to C::* is better than conversion of A::* to C::* 2598 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2599 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2600 return ImplicitConversionSequence::Better; 2601 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2602 return ImplicitConversionSequence::Worse; 2603 } 2604 } 2605 2606 if (SCS1.Second == ICK_Derived_To_Base) { 2607 // -- conversion of C to B is better than conversion of C to A, 2608 // -- binding of an expression of type C to a reference of type 2609 // B& is better than binding an expression of type C to a 2610 // reference of type A&, 2611 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2612 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2613 if (S.IsDerivedFrom(ToType1, ToType2)) 2614 return ImplicitConversionSequence::Better; 2615 else if (S.IsDerivedFrom(ToType2, ToType1)) 2616 return ImplicitConversionSequence::Worse; 2617 } 2618 2619 // -- conversion of B to A is better than conversion of C to A. 2620 // -- binding of an expression of type B to a reference of type 2621 // A& is better than binding an expression of type C to a 2622 // reference of type A&, 2623 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2624 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2625 if (S.IsDerivedFrom(FromType2, FromType1)) 2626 return ImplicitConversionSequence::Better; 2627 else if (S.IsDerivedFrom(FromType1, FromType2)) 2628 return ImplicitConversionSequence::Worse; 2629 } 2630 } 2631 2632 return ImplicitConversionSequence::Indistinguishable; 2633} 2634 2635/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2636/// determine whether they are reference-related, 2637/// reference-compatible, reference-compatible with added 2638/// qualification, or incompatible, for use in C++ initialization by 2639/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2640/// type, and the first type (T1) is the pointee type of the reference 2641/// type being initialized. 2642Sema::ReferenceCompareResult 2643Sema::CompareReferenceRelationship(SourceLocation Loc, 2644 QualType OrigT1, QualType OrigT2, 2645 bool &DerivedToBase, 2646 bool &ObjCConversion) { 2647 assert(!OrigT1->isReferenceType() && 2648 "T1 must be the pointee type of the reference type"); 2649 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2650 2651 QualType T1 = Context.getCanonicalType(OrigT1); 2652 QualType T2 = Context.getCanonicalType(OrigT2); 2653 Qualifiers T1Quals, T2Quals; 2654 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2655 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2656 2657 // C++ [dcl.init.ref]p4: 2658 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2659 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2660 // T1 is a base class of T2. 2661 DerivedToBase = false; 2662 ObjCConversion = false; 2663 if (UnqualT1 == UnqualT2) { 2664 // Nothing to do. 2665 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2666 IsDerivedFrom(UnqualT2, UnqualT1)) 2667 DerivedToBase = true; 2668 else if (UnqualT1->isObjCObjectOrInterfaceType() && 2669 UnqualT2->isObjCObjectOrInterfaceType() && 2670 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 2671 ObjCConversion = true; 2672 else 2673 return Ref_Incompatible; 2674 2675 // At this point, we know that T1 and T2 are reference-related (at 2676 // least). 2677 2678 // If the type is an array type, promote the element qualifiers to the type 2679 // for comparison. 2680 if (isa<ArrayType>(T1) && T1Quals) 2681 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2682 if (isa<ArrayType>(T2) && T2Quals) 2683 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2684 2685 // C++ [dcl.init.ref]p4: 2686 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2687 // reference-related to T2 and cv1 is the same cv-qualification 2688 // as, or greater cv-qualification than, cv2. For purposes of 2689 // overload resolution, cases for which cv1 is greater 2690 // cv-qualification than cv2 are identified as 2691 // reference-compatible with added qualification (see 13.3.3.2). 2692 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2693 return Ref_Compatible; 2694 else if (T1.isMoreQualifiedThan(T2)) 2695 return Ref_Compatible_With_Added_Qualification; 2696 else 2697 return Ref_Related; 2698} 2699 2700/// \brief Look for a user-defined conversion to an value reference-compatible 2701/// with DeclType. Return true if something definite is found. 2702static bool 2703FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 2704 QualType DeclType, SourceLocation DeclLoc, 2705 Expr *Init, QualType T2, bool AllowRvalues, 2706 bool AllowExplicit) { 2707 assert(T2->isRecordType() && "Can only find conversions of record types."); 2708 CXXRecordDecl *T2RecordDecl 2709 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2710 2711 QualType ToType 2712 = AllowRvalues? DeclType->getAs<ReferenceType>()->getPointeeType() 2713 : DeclType; 2714 2715 OverloadCandidateSet CandidateSet(DeclLoc); 2716 const UnresolvedSetImpl *Conversions 2717 = T2RecordDecl->getVisibleConversionFunctions(); 2718 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2719 E = Conversions->end(); I != E; ++I) { 2720 NamedDecl *D = *I; 2721 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2722 if (isa<UsingShadowDecl>(D)) 2723 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2724 2725 FunctionTemplateDecl *ConvTemplate 2726 = dyn_cast<FunctionTemplateDecl>(D); 2727 CXXConversionDecl *Conv; 2728 if (ConvTemplate) 2729 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2730 else 2731 Conv = cast<CXXConversionDecl>(D); 2732 2733 // If this is an explicit conversion, and we're not allowed to consider 2734 // explicit conversions, skip it. 2735 if (!AllowExplicit && Conv->isExplicit()) 2736 continue; 2737 2738 if (AllowRvalues) { 2739 bool DerivedToBase = false; 2740 bool ObjCConversion = false; 2741 if (!ConvTemplate && 2742 S.CompareReferenceRelationship(DeclLoc, 2743 Conv->getConversionType().getNonReferenceType().getUnqualifiedType(), 2744 DeclType.getNonReferenceType().getUnqualifiedType(), 2745 DerivedToBase, ObjCConversion) 2746 == Sema::Ref_Incompatible) 2747 continue; 2748 } else { 2749 // If the conversion function doesn't return a reference type, 2750 // it can't be considered for this conversion. An rvalue reference 2751 // is only acceptable if its referencee is a function type. 2752 2753 const ReferenceType *RefType = 2754 Conv->getConversionType()->getAs<ReferenceType>(); 2755 if (!RefType || 2756 (!RefType->isLValueReferenceType() && 2757 !RefType->getPointeeType()->isFunctionType())) 2758 continue; 2759 } 2760 2761 if (ConvTemplate) 2762 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2763 Init, ToType, CandidateSet); 2764 else 2765 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2766 ToType, CandidateSet); 2767 } 2768 2769 OverloadCandidateSet::iterator Best; 2770 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best)) { 2771 case OR_Success: 2772 // C++ [over.ics.ref]p1: 2773 // 2774 // [...] If the parameter binds directly to the result of 2775 // applying a conversion function to the argument 2776 // expression, the implicit conversion sequence is a 2777 // user-defined conversion sequence (13.3.3.1.2), with the 2778 // second standard conversion sequence either an identity 2779 // conversion or, if the conversion function returns an 2780 // entity of a type that is a derived class of the parameter 2781 // type, a derived-to-base Conversion. 2782 if (!Best->FinalConversion.DirectBinding) 2783 return false; 2784 2785 ICS.setUserDefined(); 2786 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2787 ICS.UserDefined.After = Best->FinalConversion; 2788 ICS.UserDefined.ConversionFunction = Best->Function; 2789 ICS.UserDefined.EllipsisConversion = false; 2790 assert(ICS.UserDefined.After.ReferenceBinding && 2791 ICS.UserDefined.After.DirectBinding && 2792 "Expected a direct reference binding!"); 2793 return true; 2794 2795 case OR_Ambiguous: 2796 ICS.setAmbiguous(); 2797 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2798 Cand != CandidateSet.end(); ++Cand) 2799 if (Cand->Viable) 2800 ICS.Ambiguous.addConversion(Cand->Function); 2801 return true; 2802 2803 case OR_No_Viable_Function: 2804 case OR_Deleted: 2805 // There was no suitable conversion, or we found a deleted 2806 // conversion; continue with other checks. 2807 return false; 2808 } 2809 2810 return false; 2811} 2812 2813/// \brief Compute an implicit conversion sequence for reference 2814/// initialization. 2815static ImplicitConversionSequence 2816TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2817 SourceLocation DeclLoc, 2818 bool SuppressUserConversions, 2819 bool AllowExplicit) { 2820 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2821 2822 // Most paths end in a failed conversion. 2823 ImplicitConversionSequence ICS; 2824 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2825 2826 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2827 QualType T2 = Init->getType(); 2828 2829 // If the initializer is the address of an overloaded function, try 2830 // to resolve the overloaded function. If all goes well, T2 is the 2831 // type of the resulting function. 2832 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2833 DeclAccessPair Found; 2834 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2835 false, Found)) 2836 T2 = Fn->getType(); 2837 } 2838 2839 // Compute some basic properties of the types and the initializer. 2840 bool isRValRef = DeclType->isRValueReferenceType(); 2841 bool DerivedToBase = false; 2842 bool ObjCConversion = false; 2843 Expr::Classification InitCategory = Init->Classify(S.Context); 2844 Sema::ReferenceCompareResult RefRelationship 2845 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 2846 ObjCConversion); 2847 2848 2849 // C++0x [dcl.init.ref]p5: 2850 // A reference to type "cv1 T1" is initialized by an expression 2851 // of type "cv2 T2" as follows: 2852 2853 // -- If reference is an lvalue reference and the initializer expression 2854 // The next bullet point (T1 is a function) is pretty much equivalent to this 2855 // one, so it's handled here. 2856 if (!isRValRef || T1->isFunctionType()) { 2857 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2858 // reference-compatible with "cv2 T2," or 2859 // 2860 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2861 if (InitCategory.isLValue() && 2862 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2863 // C++ [over.ics.ref]p1: 2864 // When a parameter of reference type binds directly (8.5.3) 2865 // to an argument expression, the implicit conversion sequence 2866 // is the identity conversion, unless the argument expression 2867 // has a type that is a derived class of the parameter type, 2868 // in which case the implicit conversion sequence is a 2869 // derived-to-base Conversion (13.3.3.1). 2870 ICS.setStandard(); 2871 ICS.Standard.First = ICK_Identity; 2872 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 2873 : ObjCConversion? ICK_Compatible_Conversion 2874 : ICK_Identity; 2875 ICS.Standard.Third = ICK_Identity; 2876 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2877 ICS.Standard.setToType(0, T2); 2878 ICS.Standard.setToType(1, T1); 2879 ICS.Standard.setToType(2, T1); 2880 ICS.Standard.ReferenceBinding = true; 2881 ICS.Standard.DirectBinding = true; 2882 ICS.Standard.RRefBinding = isRValRef; 2883 ICS.Standard.CopyConstructor = 0; 2884 2885 // Nothing more to do: the inaccessibility/ambiguity check for 2886 // derived-to-base conversions is suppressed when we're 2887 // computing the implicit conversion sequence (C++ 2888 // [over.best.ics]p2). 2889 return ICS; 2890 } 2891 2892 // -- has a class type (i.e., T2 is a class type), where T1 is 2893 // not reference-related to T2, and can be implicitly 2894 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2895 // is reference-compatible with "cv3 T3" 92) (this 2896 // conversion is selected by enumerating the applicable 2897 // conversion functions (13.3.1.6) and choosing the best 2898 // one through overload resolution (13.3)), 2899 if (!SuppressUserConversions && T2->isRecordType() && 2900 !S.RequireCompleteType(DeclLoc, T2, 0) && 2901 RefRelationship == Sema::Ref_Incompatible) { 2902 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 2903 Init, T2, /*AllowRvalues=*/false, 2904 AllowExplicit)) 2905 return ICS; 2906 } 2907 } 2908 2909 // -- Otherwise, the reference shall be an lvalue reference to a 2910 // non-volatile const type (i.e., cv1 shall be const), or the reference 2911 // shall be an rvalue reference and the initializer expression shall be 2912 // an rvalue or have a function type. 2913 // 2914 // We actually handle one oddity of C++ [over.ics.ref] at this 2915 // point, which is that, due to p2 (which short-circuits reference 2916 // binding by only attempting a simple conversion for non-direct 2917 // bindings) and p3's strange wording, we allow a const volatile 2918 // reference to bind to an rvalue. Hence the check for the presence 2919 // of "const" rather than checking for "const" being the only 2920 // qualifier. 2921 // This is also the point where rvalue references and lvalue inits no longer 2922 // go together. 2923 if ((!isRValRef && !T1.isConstQualified()) || 2924 (isRValRef && InitCategory.isLValue())) 2925 return ICS; 2926 2927 // -- If T1 is a function type, then 2928 // -- if T2 is the same type as T1, the reference is bound to the 2929 // initializer expression lvalue; 2930 // -- if T2 is a class type and the initializer expression can be 2931 // implicitly converted to an lvalue of type T1 [...], the 2932 // reference is bound to the function lvalue that is the result 2933 // of the conversion; 2934 // This is the same as for the lvalue case above, so it was handled there. 2935 // -- otherwise, the program is ill-formed. 2936 // This is the one difference to the lvalue case. 2937 if (T1->isFunctionType()) 2938 return ICS; 2939 2940 // -- Otherwise, if T2 is a class type and 2941 // -- the initializer expression is an rvalue and "cv1 T1" 2942 // is reference-compatible with "cv2 T2," or 2943 // 2944 // -- T1 is not reference-related to T2 and the initializer 2945 // expression can be implicitly converted to an rvalue 2946 // of type "cv3 T3" (this conversion is selected by 2947 // enumerating the applicable conversion functions 2948 // (13.3.1.6) and choosing the best one through overload 2949 // resolution (13.3)), 2950 // 2951 // then the reference is bound to the initializer 2952 // expression rvalue in the first case and to the object 2953 // that is the result of the conversion in the second case 2954 // (or, in either case, to the appropriate base class 2955 // subobject of the object). 2956 if (T2->isRecordType()) { 2957 // First case: "cv1 T1" is reference-compatible with "cv2 T2". This is a 2958 // direct binding in C++0x but not in C++03. 2959 if (InitCategory.isRValue() && 2960 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2961 ICS.setStandard(); 2962 ICS.Standard.First = ICK_Identity; 2963 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 2964 : ObjCConversion? ICK_Compatible_Conversion 2965 : ICK_Identity; 2966 ICS.Standard.Third = ICK_Identity; 2967 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2968 ICS.Standard.setToType(0, T2); 2969 ICS.Standard.setToType(1, T1); 2970 ICS.Standard.setToType(2, T1); 2971 ICS.Standard.ReferenceBinding = true; 2972 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 2973 ICS.Standard.RRefBinding = isRValRef; 2974 ICS.Standard.CopyConstructor = 0; 2975 return ICS; 2976 } 2977 2978 // Second case: not reference-related. 2979 if (RefRelationship == Sema::Ref_Incompatible && 2980 !S.RequireCompleteType(DeclLoc, T2, 0) && 2981 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 2982 Init, T2, /*AllowRvalues=*/true, 2983 AllowExplicit)) 2984 return ICS; 2985 } 2986 2987 // -- Otherwise, a temporary of type "cv1 T1" is created and 2988 // initialized from the initializer expression using the 2989 // rules for a non-reference copy initialization (8.5). The 2990 // reference is then bound to the temporary. If T1 is 2991 // reference-related to T2, cv1 must be the same 2992 // cv-qualification as, or greater cv-qualification than, 2993 // cv2; otherwise, the program is ill-formed. 2994 if (RefRelationship == Sema::Ref_Related) { 2995 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2996 // we would be reference-compatible or reference-compatible with 2997 // added qualification. But that wasn't the case, so the reference 2998 // initialization fails. 2999 return ICS; 3000 } 3001 3002 // If at least one of the types is a class type, the types are not 3003 // related, and we aren't allowed any user conversions, the 3004 // reference binding fails. This case is important for breaking 3005 // recursion, since TryImplicitConversion below will attempt to 3006 // create a temporary through the use of a copy constructor. 3007 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3008 (T1->isRecordType() || T2->isRecordType())) 3009 return ICS; 3010 3011 // C++ [over.ics.ref]p2: 3012 // When a parameter of reference type is not bound directly to 3013 // an argument expression, the conversion sequence is the one 3014 // required to convert the argument expression to the 3015 // underlying type of the reference according to 3016 // 13.3.3.1. Conceptually, this conversion sequence corresponds 3017 // to copy-initializing a temporary of the underlying type with 3018 // the argument expression. Any difference in top-level 3019 // cv-qualification is subsumed by the initialization itself 3020 // and does not constitute a conversion. 3021 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 3022 /*AllowExplicit=*/false, 3023 /*InOverloadResolution=*/false); 3024 3025 // Of course, that's still a reference binding. 3026 if (ICS.isStandard()) { 3027 ICS.Standard.ReferenceBinding = true; 3028 ICS.Standard.RRefBinding = isRValRef; 3029 } else if (ICS.isUserDefined()) { 3030 ICS.UserDefined.After.ReferenceBinding = true; 3031 ICS.UserDefined.After.RRefBinding = isRValRef; 3032 } 3033 return ICS; 3034} 3035 3036/// TryCopyInitialization - Try to copy-initialize a value of type 3037/// ToType from the expression From. Return the implicit conversion 3038/// sequence required to pass this argument, which may be a bad 3039/// conversion sequence (meaning that the argument cannot be passed to 3040/// a parameter of this type). If @p SuppressUserConversions, then we 3041/// do not permit any user-defined conversion sequences. 3042static ImplicitConversionSequence 3043TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 3044 bool SuppressUserConversions, 3045 bool InOverloadResolution) { 3046 if (ToType->isReferenceType()) 3047 return TryReferenceInit(S, From, ToType, 3048 /*FIXME:*/From->getLocStart(), 3049 SuppressUserConversions, 3050 /*AllowExplicit=*/false); 3051 3052 return TryImplicitConversion(S, From, ToType, 3053 SuppressUserConversions, 3054 /*AllowExplicit=*/false, 3055 InOverloadResolution); 3056} 3057 3058/// TryObjectArgumentInitialization - Try to initialize the object 3059/// parameter of the given member function (@c Method) from the 3060/// expression @p From. 3061static ImplicitConversionSequence 3062TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 3063 CXXMethodDecl *Method, 3064 CXXRecordDecl *ActingContext) { 3065 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 3066 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 3067 // const volatile object. 3068 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 3069 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 3070 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 3071 3072 // Set up the conversion sequence as a "bad" conversion, to allow us 3073 // to exit early. 3074 ImplicitConversionSequence ICS; 3075 3076 // We need to have an object of class type. 3077 QualType FromType = OrigFromType; 3078 if (const PointerType *PT = FromType->getAs<PointerType>()) 3079 FromType = PT->getPointeeType(); 3080 3081 assert(FromType->isRecordType()); 3082 3083 // The implicit object parameter is has the type "reference to cv X", 3084 // where X is the class of which the function is a member 3085 // (C++ [over.match.funcs]p4). However, when finding an implicit 3086 // conversion sequence for the argument, we are not allowed to 3087 // create temporaries or perform user-defined conversions 3088 // (C++ [over.match.funcs]p5). We perform a simplified version of 3089 // reference binding here, that allows class rvalues to bind to 3090 // non-constant references. 3091 3092 // First check the qualifiers. We don't care about lvalue-vs-rvalue 3093 // with the implicit object parameter (C++ [over.match.funcs]p5). 3094 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 3095 if (ImplicitParamType.getCVRQualifiers() 3096 != FromTypeCanon.getLocalCVRQualifiers() && 3097 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 3098 ICS.setBad(BadConversionSequence::bad_qualifiers, 3099 OrigFromType, ImplicitParamType); 3100 return ICS; 3101 } 3102 3103 // Check that we have either the same type or a derived type. It 3104 // affects the conversion rank. 3105 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 3106 ImplicitConversionKind SecondKind; 3107 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 3108 SecondKind = ICK_Identity; 3109 } else if (S.IsDerivedFrom(FromType, ClassType)) 3110 SecondKind = ICK_Derived_To_Base; 3111 else { 3112 ICS.setBad(BadConversionSequence::unrelated_class, 3113 FromType, ImplicitParamType); 3114 return ICS; 3115 } 3116 3117 // Success. Mark this as a reference binding. 3118 ICS.setStandard(); 3119 ICS.Standard.setAsIdentityConversion(); 3120 ICS.Standard.Second = SecondKind; 3121 ICS.Standard.setFromType(FromType); 3122 ICS.Standard.setAllToTypes(ImplicitParamType); 3123 ICS.Standard.ReferenceBinding = true; 3124 ICS.Standard.DirectBinding = true; 3125 ICS.Standard.RRefBinding = false; 3126 return ICS; 3127} 3128 3129/// PerformObjectArgumentInitialization - Perform initialization of 3130/// the implicit object parameter for the given Method with the given 3131/// expression. 3132bool 3133Sema::PerformObjectArgumentInitialization(Expr *&From, 3134 NestedNameSpecifier *Qualifier, 3135 NamedDecl *FoundDecl, 3136 CXXMethodDecl *Method) { 3137 QualType FromRecordType, DestType; 3138 QualType ImplicitParamRecordType = 3139 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3140 3141 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3142 FromRecordType = PT->getPointeeType(); 3143 DestType = Method->getThisType(Context); 3144 } else { 3145 FromRecordType = From->getType(); 3146 DestType = ImplicitParamRecordType; 3147 } 3148 3149 // Note that we always use the true parent context when performing 3150 // the actual argument initialization. 3151 ImplicitConversionSequence ICS 3152 = TryObjectArgumentInitialization(*this, From->getType(), Method, 3153 Method->getParent()); 3154 if (ICS.isBad()) 3155 return Diag(From->getSourceRange().getBegin(), 3156 diag::err_implicit_object_parameter_init) 3157 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3158 3159 if (ICS.Standard.Second == ICK_Derived_To_Base) 3160 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3161 3162 if (!Context.hasSameType(From->getType(), DestType)) 3163 ImpCastExprToType(From, DestType, CK_NoOp, 3164 From->getType()->isPointerType() ? VK_RValue : VK_LValue); 3165 return false; 3166} 3167 3168/// TryContextuallyConvertToBool - Attempt to contextually convert the 3169/// expression From to bool (C++0x [conv]p3). 3170static ImplicitConversionSequence 3171TryContextuallyConvertToBool(Sema &S, Expr *From) { 3172 // FIXME: This is pretty broken. 3173 return TryImplicitConversion(S, From, S.Context.BoolTy, 3174 // FIXME: Are these flags correct? 3175 /*SuppressUserConversions=*/false, 3176 /*AllowExplicit=*/true, 3177 /*InOverloadResolution=*/false); 3178} 3179 3180/// PerformContextuallyConvertToBool - Perform a contextual conversion 3181/// of the expression From to bool (C++0x [conv]p3). 3182bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3183 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 3184 if (!ICS.isBad()) 3185 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3186 3187 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3188 return Diag(From->getSourceRange().getBegin(), 3189 diag::err_typecheck_bool_condition) 3190 << From->getType() << From->getSourceRange(); 3191 return true; 3192} 3193 3194/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3195/// expression From to 'id'. 3196static ImplicitConversionSequence 3197TryContextuallyConvertToObjCId(Sema &S, Expr *From) { 3198 QualType Ty = S.Context.getObjCIdType(); 3199 return TryImplicitConversion(S, From, Ty, 3200 // FIXME: Are these flags correct? 3201 /*SuppressUserConversions=*/false, 3202 /*AllowExplicit=*/true, 3203 /*InOverloadResolution=*/false); 3204} 3205 3206/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3207/// of the expression From to 'id'. 3208bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3209 QualType Ty = Context.getObjCIdType(); 3210 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(*this, From); 3211 if (!ICS.isBad()) 3212 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3213 return true; 3214} 3215 3216/// \brief Attempt to convert the given expression to an integral or 3217/// enumeration type. 3218/// 3219/// This routine will attempt to convert an expression of class type to an 3220/// integral or enumeration type, if that class type only has a single 3221/// conversion to an integral or enumeration type. 3222/// 3223/// \param Loc The source location of the construct that requires the 3224/// conversion. 3225/// 3226/// \param FromE The expression we're converting from. 3227/// 3228/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3229/// have integral or enumeration type. 3230/// 3231/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3232/// incomplete class type. 3233/// 3234/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3235/// explicit conversion function (because no implicit conversion functions 3236/// were available). This is a recovery mode. 3237/// 3238/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3239/// showing which conversion was picked. 3240/// 3241/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3242/// conversion function that could convert to integral or enumeration type. 3243/// 3244/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3245/// usable conversion function. 3246/// 3247/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3248/// function, which may be an extension in this case. 3249/// 3250/// \returns The expression, converted to an integral or enumeration type if 3251/// successful. 3252ExprResult 3253Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 3254 const PartialDiagnostic &NotIntDiag, 3255 const PartialDiagnostic &IncompleteDiag, 3256 const PartialDiagnostic &ExplicitConvDiag, 3257 const PartialDiagnostic &ExplicitConvNote, 3258 const PartialDiagnostic &AmbigDiag, 3259 const PartialDiagnostic &AmbigNote, 3260 const PartialDiagnostic &ConvDiag) { 3261 // We can't perform any more checking for type-dependent expressions. 3262 if (From->isTypeDependent()) 3263 return Owned(From); 3264 3265 // If the expression already has integral or enumeration type, we're golden. 3266 QualType T = From->getType(); 3267 if (T->isIntegralOrEnumerationType()) 3268 return Owned(From); 3269 3270 // FIXME: Check for missing '()' if T is a function type? 3271 3272 // If we don't have a class type in C++, there's no way we can get an 3273 // expression of integral or enumeration type. 3274 const RecordType *RecordTy = T->getAs<RecordType>(); 3275 if (!RecordTy || !getLangOptions().CPlusPlus) { 3276 Diag(Loc, NotIntDiag) 3277 << T << From->getSourceRange(); 3278 return Owned(From); 3279 } 3280 3281 // We must have a complete class type. 3282 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3283 return Owned(From); 3284 3285 // Look for a conversion to an integral or enumeration type. 3286 UnresolvedSet<4> ViableConversions; 3287 UnresolvedSet<4> ExplicitConversions; 3288 const UnresolvedSetImpl *Conversions 3289 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3290 3291 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3292 E = Conversions->end(); 3293 I != E; 3294 ++I) { 3295 if (CXXConversionDecl *Conversion 3296 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3297 if (Conversion->getConversionType().getNonReferenceType() 3298 ->isIntegralOrEnumerationType()) { 3299 if (Conversion->isExplicit()) 3300 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3301 else 3302 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3303 } 3304 } 3305 3306 switch (ViableConversions.size()) { 3307 case 0: 3308 if (ExplicitConversions.size() == 1) { 3309 DeclAccessPair Found = ExplicitConversions[0]; 3310 CXXConversionDecl *Conversion 3311 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3312 3313 // The user probably meant to invoke the given explicit 3314 // conversion; use it. 3315 QualType ConvTy 3316 = Conversion->getConversionType().getNonReferenceType(); 3317 std::string TypeStr; 3318 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3319 3320 Diag(Loc, ExplicitConvDiag) 3321 << T << ConvTy 3322 << FixItHint::CreateInsertion(From->getLocStart(), 3323 "static_cast<" + TypeStr + ">(") 3324 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3325 ")"); 3326 Diag(Conversion->getLocation(), ExplicitConvNote) 3327 << ConvTy->isEnumeralType() << ConvTy; 3328 3329 // If we aren't in a SFINAE context, build a call to the 3330 // explicit conversion function. 3331 if (isSFINAEContext()) 3332 return ExprError(); 3333 3334 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3335 From = BuildCXXMemberCallExpr(From, Found, Conversion); 3336 } 3337 3338 // We'll complain below about a non-integral condition type. 3339 break; 3340 3341 case 1: { 3342 // Apply this conversion. 3343 DeclAccessPair Found = ViableConversions[0]; 3344 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3345 3346 CXXConversionDecl *Conversion 3347 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3348 QualType ConvTy 3349 = Conversion->getConversionType().getNonReferenceType(); 3350 if (ConvDiag.getDiagID()) { 3351 if (isSFINAEContext()) 3352 return ExprError(); 3353 3354 Diag(Loc, ConvDiag) 3355 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 3356 } 3357 3358 From = BuildCXXMemberCallExpr(From, Found, 3359 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3360 break; 3361 } 3362 3363 default: 3364 Diag(Loc, AmbigDiag) 3365 << T << From->getSourceRange(); 3366 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3367 CXXConversionDecl *Conv 3368 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3369 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3370 Diag(Conv->getLocation(), AmbigNote) 3371 << ConvTy->isEnumeralType() << ConvTy; 3372 } 3373 return Owned(From); 3374 } 3375 3376 if (!From->getType()->isIntegralOrEnumerationType()) 3377 Diag(Loc, NotIntDiag) 3378 << From->getType() << From->getSourceRange(); 3379 3380 return Owned(From); 3381} 3382 3383/// AddOverloadCandidate - Adds the given function to the set of 3384/// candidate functions, using the given function call arguments. If 3385/// @p SuppressUserConversions, then don't allow user-defined 3386/// conversions via constructors or conversion operators. 3387/// 3388/// \para PartialOverloading true if we are performing "partial" overloading 3389/// based on an incomplete set of function arguments. This feature is used by 3390/// code completion. 3391void 3392Sema::AddOverloadCandidate(FunctionDecl *Function, 3393 DeclAccessPair FoundDecl, 3394 Expr **Args, unsigned NumArgs, 3395 OverloadCandidateSet& CandidateSet, 3396 bool SuppressUserConversions, 3397 bool PartialOverloading) { 3398 const FunctionProtoType* Proto 3399 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3400 assert(Proto && "Functions without a prototype cannot be overloaded"); 3401 assert(!Function->getDescribedFunctionTemplate() && 3402 "Use AddTemplateOverloadCandidate for function templates"); 3403 3404 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3405 if (!isa<CXXConstructorDecl>(Method)) { 3406 // If we get here, it's because we're calling a member function 3407 // that is named without a member access expression (e.g., 3408 // "this->f") that was either written explicitly or created 3409 // implicitly. This can happen with a qualified call to a member 3410 // function, e.g., X::f(). We use an empty type for the implied 3411 // object argument (C++ [over.call.func]p3), and the acting context 3412 // is irrelevant. 3413 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3414 QualType(), Args, NumArgs, CandidateSet, 3415 SuppressUserConversions); 3416 return; 3417 } 3418 // We treat a constructor like a non-member function, since its object 3419 // argument doesn't participate in overload resolution. 3420 } 3421 3422 if (!CandidateSet.isNewCandidate(Function)) 3423 return; 3424 3425 // Overload resolution is always an unevaluated context. 3426 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3427 3428 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3429 // C++ [class.copy]p3: 3430 // A member function template is never instantiated to perform the copy 3431 // of a class object to an object of its class type. 3432 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3433 if (NumArgs == 1 && 3434 Constructor->isCopyConstructorLikeSpecialization() && 3435 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3436 IsDerivedFrom(Args[0]->getType(), ClassType))) 3437 return; 3438 } 3439 3440 // Add this candidate 3441 CandidateSet.push_back(OverloadCandidate()); 3442 OverloadCandidate& Candidate = CandidateSet.back(); 3443 Candidate.FoundDecl = FoundDecl; 3444 Candidate.Function = Function; 3445 Candidate.Viable = true; 3446 Candidate.IsSurrogate = false; 3447 Candidate.IgnoreObjectArgument = false; 3448 3449 unsigned NumArgsInProto = Proto->getNumArgs(); 3450 3451 // (C++ 13.3.2p2): A candidate function having fewer than m 3452 // parameters is viable only if it has an ellipsis in its parameter 3453 // list (8.3.5). 3454 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3455 !Proto->isVariadic()) { 3456 Candidate.Viable = false; 3457 Candidate.FailureKind = ovl_fail_too_many_arguments; 3458 return; 3459 } 3460 3461 // (C++ 13.3.2p2): A candidate function having more than m parameters 3462 // is viable only if the (m+1)st parameter has a default argument 3463 // (8.3.6). For the purposes of overload resolution, the 3464 // parameter list is truncated on the right, so that there are 3465 // exactly m parameters. 3466 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3467 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3468 // Not enough arguments. 3469 Candidate.Viable = false; 3470 Candidate.FailureKind = ovl_fail_too_few_arguments; 3471 return; 3472 } 3473 3474 // Determine the implicit conversion sequences for each of the 3475 // arguments. 3476 Candidate.Conversions.resize(NumArgs); 3477 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3478 if (ArgIdx < NumArgsInProto) { 3479 // (C++ 13.3.2p3): for F to be a viable function, there shall 3480 // exist for each argument an implicit conversion sequence 3481 // (13.3.3.1) that converts that argument to the corresponding 3482 // parameter of F. 3483 QualType ParamType = Proto->getArgType(ArgIdx); 3484 Candidate.Conversions[ArgIdx] 3485 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3486 SuppressUserConversions, 3487 /*InOverloadResolution=*/true); 3488 if (Candidate.Conversions[ArgIdx].isBad()) { 3489 Candidate.Viable = false; 3490 Candidate.FailureKind = ovl_fail_bad_conversion; 3491 break; 3492 } 3493 } else { 3494 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3495 // argument for which there is no corresponding parameter is 3496 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3497 Candidate.Conversions[ArgIdx].setEllipsis(); 3498 } 3499 } 3500} 3501 3502/// \brief Add all of the function declarations in the given function set to 3503/// the overload canddiate set. 3504void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3505 Expr **Args, unsigned NumArgs, 3506 OverloadCandidateSet& CandidateSet, 3507 bool SuppressUserConversions) { 3508 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3509 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3510 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3511 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3512 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3513 cast<CXXMethodDecl>(FD)->getParent(), 3514 Args[0]->getType(), Args + 1, NumArgs - 1, 3515 CandidateSet, SuppressUserConversions); 3516 else 3517 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3518 SuppressUserConversions); 3519 } else { 3520 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3521 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3522 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3523 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3524 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3525 /*FIXME: explicit args */ 0, 3526 Args[0]->getType(), Args + 1, NumArgs - 1, 3527 CandidateSet, 3528 SuppressUserConversions); 3529 else 3530 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3531 /*FIXME: explicit args */ 0, 3532 Args, NumArgs, CandidateSet, 3533 SuppressUserConversions); 3534 } 3535 } 3536} 3537 3538/// AddMethodCandidate - Adds a named decl (which is some kind of 3539/// method) as a method candidate to the given overload set. 3540void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3541 QualType ObjectType, 3542 Expr **Args, unsigned NumArgs, 3543 OverloadCandidateSet& CandidateSet, 3544 bool SuppressUserConversions) { 3545 NamedDecl *Decl = FoundDecl.getDecl(); 3546 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3547 3548 if (isa<UsingShadowDecl>(Decl)) 3549 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3550 3551 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3552 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3553 "Expected a member function template"); 3554 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3555 /*ExplicitArgs*/ 0, 3556 ObjectType, Args, NumArgs, 3557 CandidateSet, 3558 SuppressUserConversions); 3559 } else { 3560 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3561 ObjectType, Args, NumArgs, 3562 CandidateSet, SuppressUserConversions); 3563 } 3564} 3565 3566/// AddMethodCandidate - Adds the given C++ member function to the set 3567/// of candidate functions, using the given function call arguments 3568/// and the object argument (@c Object). For example, in a call 3569/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3570/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3571/// allow user-defined conversions via constructors or conversion 3572/// operators. 3573void 3574Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3575 CXXRecordDecl *ActingContext, QualType ObjectType, 3576 Expr **Args, unsigned NumArgs, 3577 OverloadCandidateSet& CandidateSet, 3578 bool SuppressUserConversions) { 3579 const FunctionProtoType* Proto 3580 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3581 assert(Proto && "Methods without a prototype cannot be overloaded"); 3582 assert(!isa<CXXConstructorDecl>(Method) && 3583 "Use AddOverloadCandidate for constructors"); 3584 3585 if (!CandidateSet.isNewCandidate(Method)) 3586 return; 3587 3588 // Overload resolution is always an unevaluated context. 3589 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3590 3591 // Add this candidate 3592 CandidateSet.push_back(OverloadCandidate()); 3593 OverloadCandidate& Candidate = CandidateSet.back(); 3594 Candidate.FoundDecl = FoundDecl; 3595 Candidate.Function = Method; 3596 Candidate.IsSurrogate = false; 3597 Candidate.IgnoreObjectArgument = false; 3598 3599 unsigned NumArgsInProto = Proto->getNumArgs(); 3600 3601 // (C++ 13.3.2p2): A candidate function having fewer than m 3602 // parameters is viable only if it has an ellipsis in its parameter 3603 // list (8.3.5). 3604 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3605 Candidate.Viable = false; 3606 Candidate.FailureKind = ovl_fail_too_many_arguments; 3607 return; 3608 } 3609 3610 // (C++ 13.3.2p2): A candidate function having more than m parameters 3611 // is viable only if the (m+1)st parameter has a default argument 3612 // (8.3.6). For the purposes of overload resolution, the 3613 // parameter list is truncated on the right, so that there are 3614 // exactly m parameters. 3615 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3616 if (NumArgs < MinRequiredArgs) { 3617 // Not enough arguments. 3618 Candidate.Viable = false; 3619 Candidate.FailureKind = ovl_fail_too_few_arguments; 3620 return; 3621 } 3622 3623 Candidate.Viable = true; 3624 Candidate.Conversions.resize(NumArgs + 1); 3625 3626 if (Method->isStatic() || ObjectType.isNull()) 3627 // The implicit object argument is ignored. 3628 Candidate.IgnoreObjectArgument = true; 3629 else { 3630 // Determine the implicit conversion sequence for the object 3631 // parameter. 3632 Candidate.Conversions[0] 3633 = TryObjectArgumentInitialization(*this, ObjectType, Method, 3634 ActingContext); 3635 if (Candidate.Conversions[0].isBad()) { 3636 Candidate.Viable = false; 3637 Candidate.FailureKind = ovl_fail_bad_conversion; 3638 return; 3639 } 3640 } 3641 3642 // Determine the implicit conversion sequences for each of the 3643 // arguments. 3644 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3645 if (ArgIdx < NumArgsInProto) { 3646 // (C++ 13.3.2p3): for F to be a viable function, there shall 3647 // exist for each argument an implicit conversion sequence 3648 // (13.3.3.1) that converts that argument to the corresponding 3649 // parameter of F. 3650 QualType ParamType = Proto->getArgType(ArgIdx); 3651 Candidate.Conversions[ArgIdx + 1] 3652 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3653 SuppressUserConversions, 3654 /*InOverloadResolution=*/true); 3655 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3656 Candidate.Viable = false; 3657 Candidate.FailureKind = ovl_fail_bad_conversion; 3658 break; 3659 } 3660 } else { 3661 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3662 // argument for which there is no corresponding parameter is 3663 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3664 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3665 } 3666 } 3667} 3668 3669/// \brief Add a C++ member function template as a candidate to the candidate 3670/// set, using template argument deduction to produce an appropriate member 3671/// function template specialization. 3672void 3673Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3674 DeclAccessPair FoundDecl, 3675 CXXRecordDecl *ActingContext, 3676 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3677 QualType ObjectType, 3678 Expr **Args, unsigned NumArgs, 3679 OverloadCandidateSet& CandidateSet, 3680 bool SuppressUserConversions) { 3681 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3682 return; 3683 3684 // C++ [over.match.funcs]p7: 3685 // In each case where a candidate is a function template, candidate 3686 // function template specializations are generated using template argument 3687 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3688 // candidate functions in the usual way.113) A given name can refer to one 3689 // or more function templates and also to a set of overloaded non-template 3690 // functions. In such a case, the candidate functions generated from each 3691 // function template are combined with the set of non-template candidate 3692 // functions. 3693 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3694 FunctionDecl *Specialization = 0; 3695 if (TemplateDeductionResult Result 3696 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3697 Args, NumArgs, Specialization, Info)) { 3698 CandidateSet.push_back(OverloadCandidate()); 3699 OverloadCandidate &Candidate = CandidateSet.back(); 3700 Candidate.FoundDecl = FoundDecl; 3701 Candidate.Function = MethodTmpl->getTemplatedDecl(); 3702 Candidate.Viable = false; 3703 Candidate.FailureKind = ovl_fail_bad_deduction; 3704 Candidate.IsSurrogate = false; 3705 Candidate.IgnoreObjectArgument = false; 3706 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3707 Info); 3708 return; 3709 } 3710 3711 // Add the function template specialization produced by template argument 3712 // deduction as a candidate. 3713 assert(Specialization && "Missing member function template specialization?"); 3714 assert(isa<CXXMethodDecl>(Specialization) && 3715 "Specialization is not a member function?"); 3716 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3717 ActingContext, ObjectType, Args, NumArgs, 3718 CandidateSet, SuppressUserConversions); 3719} 3720 3721/// \brief Add a C++ function template specialization as a candidate 3722/// in the candidate set, using template argument deduction to produce 3723/// an appropriate function template specialization. 3724void 3725Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3726 DeclAccessPair FoundDecl, 3727 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3728 Expr **Args, unsigned NumArgs, 3729 OverloadCandidateSet& CandidateSet, 3730 bool SuppressUserConversions) { 3731 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3732 return; 3733 3734 // C++ [over.match.funcs]p7: 3735 // In each case where a candidate is a function template, candidate 3736 // function template specializations are generated using template argument 3737 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3738 // candidate functions in the usual way.113) A given name can refer to one 3739 // or more function templates and also to a set of overloaded non-template 3740 // functions. In such a case, the candidate functions generated from each 3741 // function template are combined with the set of non-template candidate 3742 // functions. 3743 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3744 FunctionDecl *Specialization = 0; 3745 if (TemplateDeductionResult Result 3746 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3747 Args, NumArgs, Specialization, Info)) { 3748 CandidateSet.push_back(OverloadCandidate()); 3749 OverloadCandidate &Candidate = CandidateSet.back(); 3750 Candidate.FoundDecl = FoundDecl; 3751 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3752 Candidate.Viable = false; 3753 Candidate.FailureKind = ovl_fail_bad_deduction; 3754 Candidate.IsSurrogate = false; 3755 Candidate.IgnoreObjectArgument = false; 3756 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3757 Info); 3758 return; 3759 } 3760 3761 // Add the function template specialization produced by template argument 3762 // deduction as a candidate. 3763 assert(Specialization && "Missing function template specialization?"); 3764 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3765 SuppressUserConversions); 3766} 3767 3768/// AddConversionCandidate - Add a C++ conversion function as a 3769/// candidate in the candidate set (C++ [over.match.conv], 3770/// C++ [over.match.copy]). From is the expression we're converting from, 3771/// and ToType is the type that we're eventually trying to convert to 3772/// (which may or may not be the same type as the type that the 3773/// conversion function produces). 3774void 3775Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3776 DeclAccessPair FoundDecl, 3777 CXXRecordDecl *ActingContext, 3778 Expr *From, QualType ToType, 3779 OverloadCandidateSet& CandidateSet) { 3780 assert(!Conversion->getDescribedFunctionTemplate() && 3781 "Conversion function templates use AddTemplateConversionCandidate"); 3782 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3783 if (!CandidateSet.isNewCandidate(Conversion)) 3784 return; 3785 3786 // Overload resolution is always an unevaluated context. 3787 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3788 3789 // Add this candidate 3790 CandidateSet.push_back(OverloadCandidate()); 3791 OverloadCandidate& Candidate = CandidateSet.back(); 3792 Candidate.FoundDecl = FoundDecl; 3793 Candidate.Function = Conversion; 3794 Candidate.IsSurrogate = false; 3795 Candidate.IgnoreObjectArgument = false; 3796 Candidate.FinalConversion.setAsIdentityConversion(); 3797 Candidate.FinalConversion.setFromType(ConvType); 3798 Candidate.FinalConversion.setAllToTypes(ToType); 3799 Candidate.Viable = true; 3800 Candidate.Conversions.resize(1); 3801 3802 // C++ [over.match.funcs]p4: 3803 // For conversion functions, the function is considered to be a member of 3804 // the class of the implicit implied object argument for the purpose of 3805 // defining the type of the implicit object parameter. 3806 // 3807 // Determine the implicit conversion sequence for the implicit 3808 // object parameter. 3809 QualType ImplicitParamType = From->getType(); 3810 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 3811 ImplicitParamType = FromPtrType->getPointeeType(); 3812 CXXRecordDecl *ConversionContext 3813 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 3814 3815 Candidate.Conversions[0] 3816 = TryObjectArgumentInitialization(*this, From->getType(), Conversion, 3817 ConversionContext); 3818 3819 if (Candidate.Conversions[0].isBad()) { 3820 Candidate.Viable = false; 3821 Candidate.FailureKind = ovl_fail_bad_conversion; 3822 return; 3823 } 3824 3825 // We won't go through a user-define type conversion function to convert a 3826 // derived to base as such conversions are given Conversion Rank. They only 3827 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3828 QualType FromCanon 3829 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3830 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3831 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3832 Candidate.Viable = false; 3833 Candidate.FailureKind = ovl_fail_trivial_conversion; 3834 return; 3835 } 3836 3837 // To determine what the conversion from the result of calling the 3838 // conversion function to the type we're eventually trying to 3839 // convert to (ToType), we need to synthesize a call to the 3840 // conversion function and attempt copy initialization from it. This 3841 // makes sure that we get the right semantics with respect to 3842 // lvalues/rvalues and the type. Fortunately, we can allocate this 3843 // call on the stack and we don't need its arguments to be 3844 // well-formed. 3845 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3846 From->getLocStart()); 3847 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 3848 Context.getPointerType(Conversion->getType()), 3849 CK_FunctionToPointerDecay, 3850 &ConversionRef, VK_RValue); 3851 3852 // Note that it is safe to allocate CallExpr on the stack here because 3853 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3854 // allocator). 3855 CallExpr Call(Context, &ConversionFn, 0, 0, 3856 Conversion->getConversionType().getNonLValueExprType(Context), 3857 From->getLocStart()); 3858 ImplicitConversionSequence ICS = 3859 TryCopyInitialization(*this, &Call, ToType, 3860 /*SuppressUserConversions=*/true, 3861 /*InOverloadResolution=*/false); 3862 3863 switch (ICS.getKind()) { 3864 case ImplicitConversionSequence::StandardConversion: 3865 Candidate.FinalConversion = ICS.Standard; 3866 3867 // C++ [over.ics.user]p3: 3868 // If the user-defined conversion is specified by a specialization of a 3869 // conversion function template, the second standard conversion sequence 3870 // shall have exact match rank. 3871 if (Conversion->getPrimaryTemplate() && 3872 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3873 Candidate.Viable = false; 3874 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3875 } 3876 3877 break; 3878 3879 case ImplicitConversionSequence::BadConversion: 3880 Candidate.Viable = false; 3881 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3882 break; 3883 3884 default: 3885 assert(false && 3886 "Can only end up with a standard conversion sequence or failure"); 3887 } 3888} 3889 3890/// \brief Adds a conversion function template specialization 3891/// candidate to the overload set, using template argument deduction 3892/// to deduce the template arguments of the conversion function 3893/// template from the type that we are converting to (C++ 3894/// [temp.deduct.conv]). 3895void 3896Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3897 DeclAccessPair FoundDecl, 3898 CXXRecordDecl *ActingDC, 3899 Expr *From, QualType ToType, 3900 OverloadCandidateSet &CandidateSet) { 3901 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3902 "Only conversion function templates permitted here"); 3903 3904 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3905 return; 3906 3907 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3908 CXXConversionDecl *Specialization = 0; 3909 if (TemplateDeductionResult Result 3910 = DeduceTemplateArguments(FunctionTemplate, ToType, 3911 Specialization, Info)) { 3912 CandidateSet.push_back(OverloadCandidate()); 3913 OverloadCandidate &Candidate = CandidateSet.back(); 3914 Candidate.FoundDecl = FoundDecl; 3915 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3916 Candidate.Viable = false; 3917 Candidate.FailureKind = ovl_fail_bad_deduction; 3918 Candidate.IsSurrogate = false; 3919 Candidate.IgnoreObjectArgument = false; 3920 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3921 Info); 3922 return; 3923 } 3924 3925 // Add the conversion function template specialization produced by 3926 // template argument deduction as a candidate. 3927 assert(Specialization && "Missing function template specialization?"); 3928 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3929 CandidateSet); 3930} 3931 3932/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3933/// converts the given @c Object to a function pointer via the 3934/// conversion function @c Conversion, and then attempts to call it 3935/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3936/// the type of function that we'll eventually be calling. 3937void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3938 DeclAccessPair FoundDecl, 3939 CXXRecordDecl *ActingContext, 3940 const FunctionProtoType *Proto, 3941 QualType ObjectType, 3942 Expr **Args, unsigned NumArgs, 3943 OverloadCandidateSet& CandidateSet) { 3944 if (!CandidateSet.isNewCandidate(Conversion)) 3945 return; 3946 3947 // Overload resolution is always an unevaluated context. 3948 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3949 3950 CandidateSet.push_back(OverloadCandidate()); 3951 OverloadCandidate& Candidate = CandidateSet.back(); 3952 Candidate.FoundDecl = FoundDecl; 3953 Candidate.Function = 0; 3954 Candidate.Surrogate = Conversion; 3955 Candidate.Viable = true; 3956 Candidate.IsSurrogate = true; 3957 Candidate.IgnoreObjectArgument = false; 3958 Candidate.Conversions.resize(NumArgs + 1); 3959 3960 // Determine the implicit conversion sequence for the implicit 3961 // object parameter. 3962 ImplicitConversionSequence ObjectInit 3963 = TryObjectArgumentInitialization(*this, ObjectType, Conversion, 3964 ActingContext); 3965 if (ObjectInit.isBad()) { 3966 Candidate.Viable = false; 3967 Candidate.FailureKind = ovl_fail_bad_conversion; 3968 Candidate.Conversions[0] = ObjectInit; 3969 return; 3970 } 3971 3972 // The first conversion is actually a user-defined conversion whose 3973 // first conversion is ObjectInit's standard conversion (which is 3974 // effectively a reference binding). Record it as such. 3975 Candidate.Conversions[0].setUserDefined(); 3976 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3977 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3978 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3979 Candidate.Conversions[0].UserDefined.After 3980 = Candidate.Conversions[0].UserDefined.Before; 3981 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3982 3983 // Find the 3984 unsigned NumArgsInProto = Proto->getNumArgs(); 3985 3986 // (C++ 13.3.2p2): A candidate function having fewer than m 3987 // parameters is viable only if it has an ellipsis in its parameter 3988 // list (8.3.5). 3989 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3990 Candidate.Viable = false; 3991 Candidate.FailureKind = ovl_fail_too_many_arguments; 3992 return; 3993 } 3994 3995 // Function types don't have any default arguments, so just check if 3996 // we have enough arguments. 3997 if (NumArgs < NumArgsInProto) { 3998 // Not enough arguments. 3999 Candidate.Viable = false; 4000 Candidate.FailureKind = ovl_fail_too_few_arguments; 4001 return; 4002 } 4003 4004 // Determine the implicit conversion sequences for each of the 4005 // arguments. 4006 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4007 if (ArgIdx < NumArgsInProto) { 4008 // (C++ 13.3.2p3): for F to be a viable function, there shall 4009 // exist for each argument an implicit conversion sequence 4010 // (13.3.3.1) that converts that argument to the corresponding 4011 // parameter of F. 4012 QualType ParamType = Proto->getArgType(ArgIdx); 4013 Candidate.Conversions[ArgIdx + 1] 4014 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4015 /*SuppressUserConversions=*/false, 4016 /*InOverloadResolution=*/false); 4017 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4018 Candidate.Viable = false; 4019 Candidate.FailureKind = ovl_fail_bad_conversion; 4020 break; 4021 } 4022 } else { 4023 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4024 // argument for which there is no corresponding parameter is 4025 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4026 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4027 } 4028 } 4029} 4030 4031/// \brief Add overload candidates for overloaded operators that are 4032/// member functions. 4033/// 4034/// Add the overloaded operator candidates that are member functions 4035/// for the operator Op that was used in an operator expression such 4036/// as "x Op y". , Args/NumArgs provides the operator arguments, and 4037/// CandidateSet will store the added overload candidates. (C++ 4038/// [over.match.oper]). 4039void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 4040 SourceLocation OpLoc, 4041 Expr **Args, unsigned NumArgs, 4042 OverloadCandidateSet& CandidateSet, 4043 SourceRange OpRange) { 4044 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4045 4046 // C++ [over.match.oper]p3: 4047 // For a unary operator @ with an operand of a type whose 4048 // cv-unqualified version is T1, and for a binary operator @ with 4049 // a left operand of a type whose cv-unqualified version is T1 and 4050 // a right operand of a type whose cv-unqualified version is T2, 4051 // three sets of candidate functions, designated member 4052 // candidates, non-member candidates and built-in candidates, are 4053 // constructed as follows: 4054 QualType T1 = Args[0]->getType(); 4055 4056 // -- If T1 is a class type, the set of member candidates is the 4057 // result of the qualified lookup of T1::operator@ 4058 // (13.3.1.1.1); otherwise, the set of member candidates is 4059 // empty. 4060 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 4061 // Complete the type if it can be completed. Otherwise, we're done. 4062 if (RequireCompleteType(OpLoc, T1, PDiag())) 4063 return; 4064 4065 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 4066 LookupQualifiedName(Operators, T1Rec->getDecl()); 4067 Operators.suppressDiagnostics(); 4068 4069 for (LookupResult::iterator Oper = Operators.begin(), 4070 OperEnd = Operators.end(); 4071 Oper != OperEnd; 4072 ++Oper) 4073 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 4074 Args + 1, NumArgs - 1, CandidateSet, 4075 /* SuppressUserConversions = */ false); 4076 } 4077} 4078 4079/// AddBuiltinCandidate - Add a candidate for a built-in 4080/// operator. ResultTy and ParamTys are the result and parameter types 4081/// of the built-in candidate, respectively. Args and NumArgs are the 4082/// arguments being passed to the candidate. IsAssignmentOperator 4083/// should be true when this built-in candidate is an assignment 4084/// operator. NumContextualBoolArguments is the number of arguments 4085/// (at the beginning of the argument list) that will be contextually 4086/// converted to bool. 4087void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 4088 Expr **Args, unsigned NumArgs, 4089 OverloadCandidateSet& CandidateSet, 4090 bool IsAssignmentOperator, 4091 unsigned NumContextualBoolArguments) { 4092 // Overload resolution is always an unevaluated context. 4093 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 4094 4095 // Add this candidate 4096 CandidateSet.push_back(OverloadCandidate()); 4097 OverloadCandidate& Candidate = CandidateSet.back(); 4098 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 4099 Candidate.Function = 0; 4100 Candidate.IsSurrogate = false; 4101 Candidate.IgnoreObjectArgument = false; 4102 Candidate.BuiltinTypes.ResultTy = ResultTy; 4103 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4104 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 4105 4106 // Determine the implicit conversion sequences for each of the 4107 // arguments. 4108 Candidate.Viable = true; 4109 Candidate.Conversions.resize(NumArgs); 4110 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4111 // C++ [over.match.oper]p4: 4112 // For the built-in assignment operators, conversions of the 4113 // left operand are restricted as follows: 4114 // -- no temporaries are introduced to hold the left operand, and 4115 // -- no user-defined conversions are applied to the left 4116 // operand to achieve a type match with the left-most 4117 // parameter of a built-in candidate. 4118 // 4119 // We block these conversions by turning off user-defined 4120 // conversions, since that is the only way that initialization of 4121 // a reference to a non-class type can occur from something that 4122 // is not of the same type. 4123 if (ArgIdx < NumContextualBoolArguments) { 4124 assert(ParamTys[ArgIdx] == Context.BoolTy && 4125 "Contextual conversion to bool requires bool type"); 4126 Candidate.Conversions[ArgIdx] 4127 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 4128 } else { 4129 Candidate.Conversions[ArgIdx] 4130 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4131 ArgIdx == 0 && IsAssignmentOperator, 4132 /*InOverloadResolution=*/false); 4133 } 4134 if (Candidate.Conversions[ArgIdx].isBad()) { 4135 Candidate.Viable = false; 4136 Candidate.FailureKind = ovl_fail_bad_conversion; 4137 break; 4138 } 4139 } 4140} 4141 4142/// BuiltinCandidateTypeSet - A set of types that will be used for the 4143/// candidate operator functions for built-in operators (C++ 4144/// [over.built]). The types are separated into pointer types and 4145/// enumeration types. 4146class BuiltinCandidateTypeSet { 4147 /// TypeSet - A set of types. 4148 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4149 4150 /// PointerTypes - The set of pointer types that will be used in the 4151 /// built-in candidates. 4152 TypeSet PointerTypes; 4153 4154 /// MemberPointerTypes - The set of member pointer types that will be 4155 /// used in the built-in candidates. 4156 TypeSet MemberPointerTypes; 4157 4158 /// EnumerationTypes - The set of enumeration types that will be 4159 /// used in the built-in candidates. 4160 TypeSet EnumerationTypes; 4161 4162 /// \brief The set of vector types that will be used in the built-in 4163 /// candidates. 4164 TypeSet VectorTypes; 4165 4166 /// Sema - The semantic analysis instance where we are building the 4167 /// candidate type set. 4168 Sema &SemaRef; 4169 4170 /// Context - The AST context in which we will build the type sets. 4171 ASTContext &Context; 4172 4173 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4174 const Qualifiers &VisibleQuals); 4175 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4176 4177public: 4178 /// iterator - Iterates through the types that are part of the set. 4179 typedef TypeSet::iterator iterator; 4180 4181 BuiltinCandidateTypeSet(Sema &SemaRef) 4182 : SemaRef(SemaRef), Context(SemaRef.Context) { } 4183 4184 void AddTypesConvertedFrom(QualType Ty, 4185 SourceLocation Loc, 4186 bool AllowUserConversions, 4187 bool AllowExplicitConversions, 4188 const Qualifiers &VisibleTypeConversionsQuals); 4189 4190 /// pointer_begin - First pointer type found; 4191 iterator pointer_begin() { return PointerTypes.begin(); } 4192 4193 /// pointer_end - Past the last pointer type found; 4194 iterator pointer_end() { return PointerTypes.end(); } 4195 4196 /// member_pointer_begin - First member pointer type found; 4197 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4198 4199 /// member_pointer_end - Past the last member pointer type found; 4200 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4201 4202 /// enumeration_begin - First enumeration type found; 4203 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4204 4205 /// enumeration_end - Past the last enumeration type found; 4206 iterator enumeration_end() { return EnumerationTypes.end(); } 4207 4208 iterator vector_begin() { return VectorTypes.begin(); } 4209 iterator vector_end() { return VectorTypes.end(); } 4210}; 4211 4212/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4213/// the set of pointer types along with any more-qualified variants of 4214/// that type. For example, if @p Ty is "int const *", this routine 4215/// will add "int const *", "int const volatile *", "int const 4216/// restrict *", and "int const volatile restrict *" to the set of 4217/// pointer types. Returns true if the add of @p Ty itself succeeded, 4218/// false otherwise. 4219/// 4220/// FIXME: what to do about extended qualifiers? 4221bool 4222BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4223 const Qualifiers &VisibleQuals) { 4224 4225 // Insert this type. 4226 if (!PointerTypes.insert(Ty)) 4227 return false; 4228 4229 QualType PointeeTy; 4230 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4231 bool buildObjCPtr = false; 4232 if (!PointerTy) { 4233 if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) { 4234 PointeeTy = PTy->getPointeeType(); 4235 buildObjCPtr = true; 4236 } 4237 else 4238 assert(false && "type was not a pointer type!"); 4239 } 4240 else 4241 PointeeTy = PointerTy->getPointeeType(); 4242 4243 // Don't add qualified variants of arrays. For one, they're not allowed 4244 // (the qualifier would sink to the element type), and for another, the 4245 // only overload situation where it matters is subscript or pointer +- int, 4246 // and those shouldn't have qualifier variants anyway. 4247 if (PointeeTy->isArrayType()) 4248 return true; 4249 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4250 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4251 BaseCVR = Array->getElementType().getCVRQualifiers(); 4252 bool hasVolatile = VisibleQuals.hasVolatile(); 4253 bool hasRestrict = VisibleQuals.hasRestrict(); 4254 4255 // Iterate through all strict supersets of BaseCVR. 4256 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4257 if ((CVR | BaseCVR) != CVR) continue; 4258 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4259 // in the types. 4260 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4261 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4262 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4263 if (!buildObjCPtr) 4264 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4265 else 4266 PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); 4267 } 4268 4269 return true; 4270} 4271 4272/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4273/// to the set of pointer types along with any more-qualified variants of 4274/// that type. For example, if @p Ty is "int const *", this routine 4275/// will add "int const *", "int const volatile *", "int const 4276/// restrict *", and "int const volatile restrict *" to the set of 4277/// pointer types. Returns true if the add of @p Ty itself succeeded, 4278/// false otherwise. 4279/// 4280/// FIXME: what to do about extended qualifiers? 4281bool 4282BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4283 QualType Ty) { 4284 // Insert this type. 4285 if (!MemberPointerTypes.insert(Ty)) 4286 return false; 4287 4288 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4289 assert(PointerTy && "type was not a member pointer type!"); 4290 4291 QualType PointeeTy = PointerTy->getPointeeType(); 4292 // Don't add qualified variants of arrays. For one, they're not allowed 4293 // (the qualifier would sink to the element type), and for another, the 4294 // only overload situation where it matters is subscript or pointer +- int, 4295 // and those shouldn't have qualifier variants anyway. 4296 if (PointeeTy->isArrayType()) 4297 return true; 4298 const Type *ClassTy = PointerTy->getClass(); 4299 4300 // Iterate through all strict supersets of the pointee type's CVR 4301 // qualifiers. 4302 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4303 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4304 if ((CVR | BaseCVR) != CVR) continue; 4305 4306 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4307 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 4308 } 4309 4310 return true; 4311} 4312 4313/// AddTypesConvertedFrom - Add each of the types to which the type @p 4314/// Ty can be implicit converted to the given set of @p Types. We're 4315/// primarily interested in pointer types and enumeration types. We also 4316/// take member pointer types, for the conditional operator. 4317/// AllowUserConversions is true if we should look at the conversion 4318/// functions of a class type, and AllowExplicitConversions if we 4319/// should also include the explicit conversion functions of a class 4320/// type. 4321void 4322BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4323 SourceLocation Loc, 4324 bool AllowUserConversions, 4325 bool AllowExplicitConversions, 4326 const Qualifiers &VisibleQuals) { 4327 // Only deal with canonical types. 4328 Ty = Context.getCanonicalType(Ty); 4329 4330 // Look through reference types; they aren't part of the type of an 4331 // expression for the purposes of conversions. 4332 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4333 Ty = RefTy->getPointeeType(); 4334 4335 // We don't care about qualifiers on the type. 4336 Ty = Ty.getLocalUnqualifiedType(); 4337 4338 // If we're dealing with an array type, decay to the pointer. 4339 if (Ty->isArrayType()) 4340 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4341 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 4342 PointerTypes.insert(Ty); 4343 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 4344 // Insert our type, and its more-qualified variants, into the set 4345 // of types. 4346 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4347 return; 4348 } else if (Ty->isMemberPointerType()) { 4349 // Member pointers are far easier, since the pointee can't be converted. 4350 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4351 return; 4352 } else if (Ty->isEnumeralType()) { 4353 EnumerationTypes.insert(Ty); 4354 } else if (Ty->isVectorType()) { 4355 VectorTypes.insert(Ty); 4356 } else if (AllowUserConversions) { 4357 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 4358 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 4359 // No conversion functions in incomplete types. 4360 return; 4361 } 4362 4363 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4364 const UnresolvedSetImpl *Conversions 4365 = ClassDecl->getVisibleConversionFunctions(); 4366 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4367 E = Conversions->end(); I != E; ++I) { 4368 NamedDecl *D = I.getDecl(); 4369 if (isa<UsingShadowDecl>(D)) 4370 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4371 4372 // Skip conversion function templates; they don't tell us anything 4373 // about which builtin types we can convert to. 4374 if (isa<FunctionTemplateDecl>(D)) 4375 continue; 4376 4377 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4378 if (AllowExplicitConversions || !Conv->isExplicit()) { 4379 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4380 VisibleQuals); 4381 } 4382 } 4383 } 4384 } 4385} 4386 4387/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4388/// the volatile- and non-volatile-qualified assignment operators for the 4389/// given type to the candidate set. 4390static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4391 QualType T, 4392 Expr **Args, 4393 unsigned NumArgs, 4394 OverloadCandidateSet &CandidateSet) { 4395 QualType ParamTypes[2]; 4396 4397 // T& operator=(T&, T) 4398 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4399 ParamTypes[1] = T; 4400 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4401 /*IsAssignmentOperator=*/true); 4402 4403 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4404 // volatile T& operator=(volatile T&, T) 4405 ParamTypes[0] 4406 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4407 ParamTypes[1] = T; 4408 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4409 /*IsAssignmentOperator=*/true); 4410 } 4411} 4412 4413/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4414/// if any, found in visible type conversion functions found in ArgExpr's type. 4415static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4416 Qualifiers VRQuals; 4417 const RecordType *TyRec; 4418 if (const MemberPointerType *RHSMPType = 4419 ArgExpr->getType()->getAs<MemberPointerType>()) 4420 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4421 else 4422 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4423 if (!TyRec) { 4424 // Just to be safe, assume the worst case. 4425 VRQuals.addVolatile(); 4426 VRQuals.addRestrict(); 4427 return VRQuals; 4428 } 4429 4430 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4431 if (!ClassDecl->hasDefinition()) 4432 return VRQuals; 4433 4434 const UnresolvedSetImpl *Conversions = 4435 ClassDecl->getVisibleConversionFunctions(); 4436 4437 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4438 E = Conversions->end(); I != E; ++I) { 4439 NamedDecl *D = I.getDecl(); 4440 if (isa<UsingShadowDecl>(D)) 4441 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4442 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4443 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4444 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4445 CanTy = ResTypeRef->getPointeeType(); 4446 // Need to go down the pointer/mempointer chain and add qualifiers 4447 // as see them. 4448 bool done = false; 4449 while (!done) { 4450 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4451 CanTy = ResTypePtr->getPointeeType(); 4452 else if (const MemberPointerType *ResTypeMPtr = 4453 CanTy->getAs<MemberPointerType>()) 4454 CanTy = ResTypeMPtr->getPointeeType(); 4455 else 4456 done = true; 4457 if (CanTy.isVolatileQualified()) 4458 VRQuals.addVolatile(); 4459 if (CanTy.isRestrictQualified()) 4460 VRQuals.addRestrict(); 4461 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4462 return VRQuals; 4463 } 4464 } 4465 } 4466 return VRQuals; 4467} 4468 4469/// AddBuiltinOperatorCandidates - Add the appropriate built-in 4470/// operator overloads to the candidate set (C++ [over.built]), based 4471/// on the operator @p Op and the arguments given. For example, if the 4472/// operator is a binary '+', this routine might add "int 4473/// operator+(int, int)" to cover integer addition. 4474void 4475Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 4476 SourceLocation OpLoc, 4477 Expr **Args, unsigned NumArgs, 4478 OverloadCandidateSet& CandidateSet) { 4479 // The set of "promoted arithmetic types", which are the arithmetic 4480 // types are that preserved by promotion (C++ [over.built]p2). Note 4481 // that the first few of these types are the promoted integral 4482 // types; these types need to be first. 4483 // FIXME: What about complex? 4484 const unsigned FirstIntegralType = 0; 4485 const unsigned LastIntegralType = 13; 4486 const unsigned FirstPromotedIntegralType = 7, 4487 LastPromotedIntegralType = 13; 4488 const unsigned FirstPromotedArithmeticType = 7, 4489 LastPromotedArithmeticType = 16; 4490 const unsigned NumArithmeticTypes = 16; 4491 QualType ArithmeticTypes[NumArithmeticTypes] = { 4492 Context.BoolTy, Context.CharTy, Context.WCharTy, 4493// FIXME: Context.Char16Ty, Context.Char32Ty, 4494 Context.SignedCharTy, Context.ShortTy, 4495 Context.UnsignedCharTy, Context.UnsignedShortTy, 4496 Context.IntTy, Context.LongTy, Context.LongLongTy, 4497 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 4498 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 4499 }; 4500 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 4501 "Invalid first promoted integral type"); 4502 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 4503 == Context.UnsignedLongLongTy && 4504 "Invalid last promoted integral type"); 4505 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 4506 "Invalid first promoted arithmetic type"); 4507 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 4508 == Context.LongDoubleTy && 4509 "Invalid last promoted arithmetic type"); 4510 4511 // Find all of the types that the arguments can convert to, but only 4512 // if the operator we're looking at has built-in operator candidates 4513 // that make use of these types. 4514 Qualifiers VisibleTypeConversionsQuals; 4515 VisibleTypeConversionsQuals.addConst(); 4516 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4517 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 4518 4519 BuiltinCandidateTypeSet CandidateTypes(*this); 4520 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4521 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 4522 OpLoc, 4523 true, 4524 (Op == OO_Exclaim || 4525 Op == OO_AmpAmp || 4526 Op == OO_PipePipe), 4527 VisibleTypeConversionsQuals); 4528 4529 bool isComparison = false; 4530 switch (Op) { 4531 case OO_None: 4532 case NUM_OVERLOADED_OPERATORS: 4533 assert(false && "Expected an overloaded operator"); 4534 break; 4535 4536 case OO_Star: // '*' is either unary or binary 4537 if (NumArgs == 1) 4538 goto UnaryStar; 4539 else 4540 goto BinaryStar; 4541 break; 4542 4543 case OO_Plus: // '+' is either unary or binary 4544 if (NumArgs == 1) 4545 goto UnaryPlus; 4546 else 4547 goto BinaryPlus; 4548 break; 4549 4550 case OO_Minus: // '-' is either unary or binary 4551 if (NumArgs == 1) 4552 goto UnaryMinus; 4553 else 4554 goto BinaryMinus; 4555 break; 4556 4557 case OO_Amp: // '&' is either unary or binary 4558 if (NumArgs == 1) 4559 goto UnaryAmp; 4560 else 4561 goto BinaryAmp; 4562 4563 case OO_PlusPlus: 4564 case OO_MinusMinus: 4565 // C++ [over.built]p3: 4566 // 4567 // For every pair (T, VQ), where T is an arithmetic type, and VQ 4568 // is either volatile or empty, there exist candidate operator 4569 // functions of the form 4570 // 4571 // VQ T& operator++(VQ T&); 4572 // T operator++(VQ T&, int); 4573 // 4574 // C++ [over.built]p4: 4575 // 4576 // For every pair (T, VQ), where T is an arithmetic type other 4577 // than bool, and VQ is either volatile or empty, there exist 4578 // candidate operator functions of the form 4579 // 4580 // VQ T& operator--(VQ T&); 4581 // T operator--(VQ T&, int); 4582 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 4583 Arith < NumArithmeticTypes; ++Arith) { 4584 QualType ArithTy = ArithmeticTypes[Arith]; 4585 QualType ParamTypes[2] 4586 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 4587 4588 // Non-volatile version. 4589 if (NumArgs == 1) 4590 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4591 else 4592 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4593 // heuristic to reduce number of builtin candidates in the set. 4594 // Add volatile version only if there are conversions to a volatile type. 4595 if (VisibleTypeConversionsQuals.hasVolatile()) { 4596 // Volatile version 4597 ParamTypes[0] 4598 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 4599 if (NumArgs == 1) 4600 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4601 else 4602 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4603 } 4604 } 4605 4606 // C++ [over.built]p5: 4607 // 4608 // For every pair (T, VQ), where T is a cv-qualified or 4609 // cv-unqualified object type, and VQ is either volatile or 4610 // empty, there exist candidate operator functions of the form 4611 // 4612 // T*VQ& operator++(T*VQ&); 4613 // T*VQ& operator--(T*VQ&); 4614 // T* operator++(T*VQ&, int); 4615 // T* operator--(T*VQ&, int); 4616 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4617 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4618 // Skip pointer types that aren't pointers to object types. 4619 if (!(*Ptr)->getPointeeType()->isIncompleteOrObjectType()) 4620 continue; 4621 4622 QualType ParamTypes[2] = { 4623 Context.getLValueReferenceType(*Ptr), Context.IntTy 4624 }; 4625 4626 // Without volatile 4627 if (NumArgs == 1) 4628 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4629 else 4630 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4631 4632 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4633 VisibleTypeConversionsQuals.hasVolatile()) { 4634 // With volatile 4635 ParamTypes[0] 4636 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4637 if (NumArgs == 1) 4638 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4639 else 4640 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4641 } 4642 } 4643 break; 4644 4645 UnaryStar: 4646 // C++ [over.built]p6: 4647 // For every cv-qualified or cv-unqualified object type T, there 4648 // exist candidate operator functions of the form 4649 // 4650 // T& operator*(T*); 4651 // 4652 // C++ [over.built]p7: 4653 // For every function type T, there exist candidate operator 4654 // functions of the form 4655 // T& operator*(T*); 4656 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4657 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4658 QualType ParamTy = *Ptr; 4659 QualType PointeeTy = ParamTy->getPointeeType(); 4660 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 4661 &ParamTy, Args, 1, CandidateSet); 4662 } 4663 break; 4664 4665 UnaryPlus: 4666 // C++ [over.built]p8: 4667 // For every type T, there exist candidate operator functions of 4668 // the form 4669 // 4670 // T* operator+(T*); 4671 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4672 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4673 QualType ParamTy = *Ptr; 4674 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4675 } 4676 4677 // Fall through 4678 4679 UnaryMinus: 4680 // C++ [over.built]p9: 4681 // For every promoted arithmetic type T, there exist candidate 4682 // operator functions of the form 4683 // 4684 // T operator+(T); 4685 // T operator-(T); 4686 for (unsigned Arith = FirstPromotedArithmeticType; 4687 Arith < LastPromotedArithmeticType; ++Arith) { 4688 QualType ArithTy = ArithmeticTypes[Arith]; 4689 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4690 } 4691 4692 // Extension: We also add these operators for vector types. 4693 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4694 VecEnd = CandidateTypes.vector_end(); 4695 Vec != VecEnd; ++Vec) { 4696 QualType VecTy = *Vec; 4697 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4698 } 4699 break; 4700 4701 case OO_Tilde: 4702 // C++ [over.built]p10: 4703 // For every promoted integral type T, there exist candidate 4704 // operator functions of the form 4705 // 4706 // T operator~(T); 4707 for (unsigned Int = FirstPromotedIntegralType; 4708 Int < LastPromotedIntegralType; ++Int) { 4709 QualType IntTy = ArithmeticTypes[Int]; 4710 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4711 } 4712 4713 // Extension: We also add this operator for vector types. 4714 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4715 VecEnd = CandidateTypes.vector_end(); 4716 Vec != VecEnd; ++Vec) { 4717 QualType VecTy = *Vec; 4718 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4719 } 4720 break; 4721 4722 case OO_New: 4723 case OO_Delete: 4724 case OO_Array_New: 4725 case OO_Array_Delete: 4726 case OO_Call: 4727 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 4728 break; 4729 4730 case OO_Comma: 4731 UnaryAmp: 4732 case OO_Arrow: 4733 // C++ [over.match.oper]p3: 4734 // -- For the operator ',', the unary operator '&', or the 4735 // operator '->', the built-in candidates set is empty. 4736 break; 4737 4738 case OO_EqualEqual: 4739 case OO_ExclaimEqual: 4740 // C++ [over.match.oper]p16: 4741 // For every pointer to member type T, there exist candidate operator 4742 // functions of the form 4743 // 4744 // bool operator==(T,T); 4745 // bool operator!=(T,T); 4746 for (BuiltinCandidateTypeSet::iterator 4747 MemPtr = CandidateTypes.member_pointer_begin(), 4748 MemPtrEnd = CandidateTypes.member_pointer_end(); 4749 MemPtr != MemPtrEnd; 4750 ++MemPtr) { 4751 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4752 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4753 } 4754 4755 // Fall through 4756 4757 case OO_Less: 4758 case OO_Greater: 4759 case OO_LessEqual: 4760 case OO_GreaterEqual: 4761 // C++ [over.built]p15: 4762 // 4763 // For every pointer or enumeration type T, there exist 4764 // candidate operator functions of the form 4765 // 4766 // bool operator<(T, T); 4767 // bool operator>(T, T); 4768 // bool operator<=(T, T); 4769 // bool operator>=(T, T); 4770 // bool operator==(T, T); 4771 // bool operator!=(T, T); 4772 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4773 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4774 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4775 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4776 } 4777 for (BuiltinCandidateTypeSet::iterator Enum 4778 = CandidateTypes.enumeration_begin(); 4779 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4780 QualType ParamTypes[2] = { *Enum, *Enum }; 4781 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4782 } 4783 4784 // Fall through. 4785 isComparison = true; 4786 4787 BinaryPlus: 4788 BinaryMinus: 4789 if (!isComparison) { 4790 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4791 4792 // C++ [over.built]p13: 4793 // 4794 // For every cv-qualified or cv-unqualified object type T 4795 // there exist candidate operator functions of the form 4796 // 4797 // T* operator+(T*, ptrdiff_t); 4798 // T& operator[](T*, ptrdiff_t); [BELOW] 4799 // T* operator-(T*, ptrdiff_t); 4800 // T* operator+(ptrdiff_t, T*); 4801 // T& operator[](ptrdiff_t, T*); [BELOW] 4802 // 4803 // C++ [over.built]p14: 4804 // 4805 // For every T, where T is a pointer to object type, there 4806 // exist candidate operator functions of the form 4807 // 4808 // ptrdiff_t operator-(T, T); 4809 for (BuiltinCandidateTypeSet::iterator Ptr 4810 = CandidateTypes.pointer_begin(); 4811 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4812 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4813 4814 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4815 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4816 4817 if (Op == OO_Plus) { 4818 // T* operator+(ptrdiff_t, T*); 4819 ParamTypes[0] = ParamTypes[1]; 4820 ParamTypes[1] = *Ptr; 4821 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4822 } else { 4823 // ptrdiff_t operator-(T, T); 4824 ParamTypes[1] = *Ptr; 4825 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4826 Args, 2, CandidateSet); 4827 } 4828 } 4829 } 4830 // Fall through 4831 4832 case OO_Slash: 4833 BinaryStar: 4834 Conditional: 4835 // C++ [over.built]p12: 4836 // 4837 // For every pair of promoted arithmetic types L and R, there 4838 // exist candidate operator functions of the form 4839 // 4840 // LR operator*(L, R); 4841 // LR operator/(L, R); 4842 // LR operator+(L, R); 4843 // LR operator-(L, R); 4844 // bool operator<(L, R); 4845 // bool operator>(L, R); 4846 // bool operator<=(L, R); 4847 // bool operator>=(L, R); 4848 // bool operator==(L, R); 4849 // bool operator!=(L, R); 4850 // 4851 // where LR is the result of the usual arithmetic conversions 4852 // between types L and R. 4853 // 4854 // C++ [over.built]p24: 4855 // 4856 // For every pair of promoted arithmetic types L and R, there exist 4857 // candidate operator functions of the form 4858 // 4859 // LR operator?(bool, L, R); 4860 // 4861 // where LR is the result of the usual arithmetic conversions 4862 // between types L and R. 4863 // Our candidates ignore the first parameter. 4864 for (unsigned Left = FirstPromotedArithmeticType; 4865 Left < LastPromotedArithmeticType; ++Left) { 4866 for (unsigned Right = FirstPromotedArithmeticType; 4867 Right < LastPromotedArithmeticType; ++Right) { 4868 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4869 QualType Result 4870 = isComparison 4871 ? Context.BoolTy 4872 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4873 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4874 } 4875 } 4876 4877 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 4878 // conditional operator for vector types. 4879 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4880 Vec1End = CandidateTypes.vector_end(); 4881 Vec1 != Vec1End; ++Vec1) 4882 for (BuiltinCandidateTypeSet::iterator 4883 Vec2 = CandidateTypes.vector_begin(), 4884 Vec2End = CandidateTypes.vector_end(); 4885 Vec2 != Vec2End; ++Vec2) { 4886 QualType LandR[2] = { *Vec1, *Vec2 }; 4887 QualType Result; 4888 if (isComparison) 4889 Result = Context.BoolTy; 4890 else { 4891 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 4892 Result = *Vec1; 4893 else 4894 Result = *Vec2; 4895 } 4896 4897 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4898 } 4899 4900 break; 4901 4902 case OO_Percent: 4903 BinaryAmp: 4904 case OO_Caret: 4905 case OO_Pipe: 4906 case OO_LessLess: 4907 case OO_GreaterGreater: 4908 // C++ [over.built]p17: 4909 // 4910 // For every pair of promoted integral types L and R, there 4911 // exist candidate operator functions of the form 4912 // 4913 // LR operator%(L, R); 4914 // LR operator&(L, R); 4915 // LR operator^(L, R); 4916 // LR operator|(L, R); 4917 // L operator<<(L, R); 4918 // L operator>>(L, R); 4919 // 4920 // where LR is the result of the usual arithmetic conversions 4921 // between types L and R. 4922 for (unsigned Left = FirstPromotedIntegralType; 4923 Left < LastPromotedIntegralType; ++Left) { 4924 for (unsigned Right = FirstPromotedIntegralType; 4925 Right < LastPromotedIntegralType; ++Right) { 4926 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4927 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4928 ? LandR[0] 4929 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4930 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4931 } 4932 } 4933 break; 4934 4935 case OO_Equal: 4936 // C++ [over.built]p20: 4937 // 4938 // For every pair (T, VQ), where T is an enumeration or 4939 // pointer to member type and VQ is either volatile or 4940 // empty, there exist candidate operator functions of the form 4941 // 4942 // VQ T& operator=(VQ T&, T); 4943 for (BuiltinCandidateTypeSet::iterator 4944 Enum = CandidateTypes.enumeration_begin(), 4945 EnumEnd = CandidateTypes.enumeration_end(); 4946 Enum != EnumEnd; ++Enum) 4947 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4948 CandidateSet); 4949 for (BuiltinCandidateTypeSet::iterator 4950 MemPtr = CandidateTypes.member_pointer_begin(), 4951 MemPtrEnd = CandidateTypes.member_pointer_end(); 4952 MemPtr != MemPtrEnd; ++MemPtr) 4953 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4954 CandidateSet); 4955 4956 // Fall through. 4957 4958 case OO_PlusEqual: 4959 case OO_MinusEqual: 4960 // C++ [over.built]p19: 4961 // 4962 // For every pair (T, VQ), where T is any type and VQ is either 4963 // volatile or empty, there exist candidate operator functions 4964 // of the form 4965 // 4966 // T*VQ& operator=(T*VQ&, T*); 4967 // 4968 // C++ [over.built]p21: 4969 // 4970 // For every pair (T, VQ), where T is a cv-qualified or 4971 // cv-unqualified object type and VQ is either volatile or 4972 // empty, there exist candidate operator functions of the form 4973 // 4974 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4975 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4976 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4977 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4978 QualType ParamTypes[2]; 4979 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4980 4981 // non-volatile version 4982 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4983 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4984 /*IsAssigmentOperator=*/Op == OO_Equal); 4985 4986 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4987 VisibleTypeConversionsQuals.hasVolatile()) { 4988 // volatile version 4989 ParamTypes[0] 4990 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4991 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4992 /*IsAssigmentOperator=*/Op == OO_Equal); 4993 } 4994 } 4995 // Fall through. 4996 4997 case OO_StarEqual: 4998 case OO_SlashEqual: 4999 // C++ [over.built]p18: 5000 // 5001 // For every triple (L, VQ, R), where L is an arithmetic type, 5002 // VQ is either volatile or empty, and R is a promoted 5003 // arithmetic type, there exist candidate operator functions of 5004 // the form 5005 // 5006 // VQ L& operator=(VQ L&, R); 5007 // VQ L& operator*=(VQ L&, R); 5008 // VQ L& operator/=(VQ L&, R); 5009 // VQ L& operator+=(VQ L&, R); 5010 // VQ L& operator-=(VQ L&, R); 5011 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 5012 for (unsigned Right = FirstPromotedArithmeticType; 5013 Right < LastPromotedArithmeticType; ++Right) { 5014 QualType ParamTypes[2]; 5015 ParamTypes[1] = ArithmeticTypes[Right]; 5016 5017 // Add this built-in operator as a candidate (VQ is empty). 5018 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 5019 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5020 /*IsAssigmentOperator=*/Op == OO_Equal); 5021 5022 // Add this built-in operator as a candidate (VQ is 'volatile'). 5023 if (VisibleTypeConversionsQuals.hasVolatile()) { 5024 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 5025 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 5026 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5027 /*IsAssigmentOperator=*/Op == OO_Equal); 5028 } 5029 } 5030 } 5031 5032 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 5033 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 5034 Vec1End = CandidateTypes.vector_end(); 5035 Vec1 != Vec1End; ++Vec1) 5036 for (BuiltinCandidateTypeSet::iterator 5037 Vec2 = CandidateTypes.vector_begin(), 5038 Vec2End = CandidateTypes.vector_end(); 5039 Vec2 != Vec2End; ++Vec2) { 5040 QualType ParamTypes[2]; 5041 ParamTypes[1] = *Vec2; 5042 // Add this built-in operator as a candidate (VQ is empty). 5043 ParamTypes[0] = Context.getLValueReferenceType(*Vec1); 5044 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5045 /*IsAssigmentOperator=*/Op == OO_Equal); 5046 5047 // Add this built-in operator as a candidate (VQ is 'volatile'). 5048 if (VisibleTypeConversionsQuals.hasVolatile()) { 5049 ParamTypes[0] = Context.getVolatileType(*Vec1); 5050 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 5051 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5052 /*IsAssigmentOperator=*/Op == OO_Equal); 5053 } 5054 } 5055 break; 5056 5057 case OO_PercentEqual: 5058 case OO_LessLessEqual: 5059 case OO_GreaterGreaterEqual: 5060 case OO_AmpEqual: 5061 case OO_CaretEqual: 5062 case OO_PipeEqual: 5063 // C++ [over.built]p22: 5064 // 5065 // For every triple (L, VQ, R), where L is an integral type, VQ 5066 // is either volatile or empty, and R is a promoted integral 5067 // type, there exist candidate operator functions of the form 5068 // 5069 // VQ L& operator%=(VQ L&, R); 5070 // VQ L& operator<<=(VQ L&, R); 5071 // VQ L& operator>>=(VQ L&, R); 5072 // VQ L& operator&=(VQ L&, R); 5073 // VQ L& operator^=(VQ L&, R); 5074 // VQ L& operator|=(VQ L&, R); 5075 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 5076 for (unsigned Right = FirstPromotedIntegralType; 5077 Right < LastPromotedIntegralType; ++Right) { 5078 QualType ParamTypes[2]; 5079 ParamTypes[1] = ArithmeticTypes[Right]; 5080 5081 // Add this built-in operator as a candidate (VQ is empty). 5082 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 5083 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5084 if (VisibleTypeConversionsQuals.hasVolatile()) { 5085 // Add this built-in operator as a candidate (VQ is 'volatile'). 5086 ParamTypes[0] = ArithmeticTypes[Left]; 5087 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 5088 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 5089 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5090 } 5091 } 5092 } 5093 break; 5094 5095 case OO_Exclaim: { 5096 // C++ [over.operator]p23: 5097 // 5098 // There also exist candidate operator functions of the form 5099 // 5100 // bool operator!(bool); 5101 // bool operator&&(bool, bool); [BELOW] 5102 // bool operator||(bool, bool); [BELOW] 5103 QualType ParamTy = Context.BoolTy; 5104 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 5105 /*IsAssignmentOperator=*/false, 5106 /*NumContextualBoolArguments=*/1); 5107 break; 5108 } 5109 5110 case OO_AmpAmp: 5111 case OO_PipePipe: { 5112 // C++ [over.operator]p23: 5113 // 5114 // There also exist candidate operator functions of the form 5115 // 5116 // bool operator!(bool); [ABOVE] 5117 // bool operator&&(bool, bool); 5118 // bool operator||(bool, bool); 5119 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 5120 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 5121 /*IsAssignmentOperator=*/false, 5122 /*NumContextualBoolArguments=*/2); 5123 break; 5124 } 5125 5126 case OO_Subscript: 5127 // C++ [over.built]p13: 5128 // 5129 // For every cv-qualified or cv-unqualified object type T there 5130 // exist candidate operator functions of the form 5131 // 5132 // T* operator+(T*, ptrdiff_t); [ABOVE] 5133 // T& operator[](T*, ptrdiff_t); 5134 // T* operator-(T*, ptrdiff_t); [ABOVE] 5135 // T* operator+(ptrdiff_t, T*); [ABOVE] 5136 // T& operator[](ptrdiff_t, T*); 5137 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 5138 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 5139 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 5140 QualType PointeeType = (*Ptr)->getPointeeType(); 5141 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 5142 5143 // T& operator[](T*, ptrdiff_t) 5144 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5145 5146 // T& operator[](ptrdiff_t, T*); 5147 ParamTypes[0] = ParamTypes[1]; 5148 ParamTypes[1] = *Ptr; 5149 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5150 } 5151 break; 5152 5153 case OO_ArrowStar: 5154 // C++ [over.built]p11: 5155 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 5156 // C1 is the same type as C2 or is a derived class of C2, T is an object 5157 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 5158 // there exist candidate operator functions of the form 5159 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 5160 // where CV12 is the union of CV1 and CV2. 5161 { 5162 for (BuiltinCandidateTypeSet::iterator Ptr = 5163 CandidateTypes.pointer_begin(); 5164 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 5165 QualType C1Ty = (*Ptr); 5166 QualType C1; 5167 QualifierCollector Q1; 5168 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 5169 if (!isa<RecordType>(C1)) 5170 continue; 5171 // heuristic to reduce number of builtin candidates in the set. 5172 // Add volatile/restrict version only if there are conversions to a 5173 // volatile/restrict type. 5174 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 5175 continue; 5176 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 5177 continue; 5178 for (BuiltinCandidateTypeSet::iterator 5179 MemPtr = CandidateTypes.member_pointer_begin(), 5180 MemPtrEnd = CandidateTypes.member_pointer_end(); 5181 MemPtr != MemPtrEnd; ++MemPtr) { 5182 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 5183 QualType C2 = QualType(mptr->getClass(), 0); 5184 C2 = C2.getUnqualifiedType(); 5185 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 5186 break; 5187 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 5188 // build CV12 T& 5189 QualType T = mptr->getPointeeType(); 5190 if (!VisibleTypeConversionsQuals.hasVolatile() && 5191 T.isVolatileQualified()) 5192 continue; 5193 if (!VisibleTypeConversionsQuals.hasRestrict() && 5194 T.isRestrictQualified()) 5195 continue; 5196 T = Q1.apply(T); 5197 QualType ResultTy = Context.getLValueReferenceType(T); 5198 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5199 } 5200 } 5201 } 5202 break; 5203 5204 case OO_Conditional: 5205 // Note that we don't consider the first argument, since it has been 5206 // contextually converted to bool long ago. The candidates below are 5207 // therefore added as binary. 5208 // 5209 // C++ [over.built]p24: 5210 // For every type T, where T is a pointer or pointer-to-member type, 5211 // there exist candidate operator functions of the form 5212 // 5213 // T operator?(bool, T, T); 5214 // 5215 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 5216 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 5217 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5218 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5219 } 5220 for (BuiltinCandidateTypeSet::iterator Ptr = 5221 CandidateTypes.member_pointer_begin(), 5222 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 5223 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5224 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5225 } 5226 goto Conditional; 5227 } 5228} 5229 5230/// \brief Add function candidates found via argument-dependent lookup 5231/// to the set of overloading candidates. 5232/// 5233/// This routine performs argument-dependent name lookup based on the 5234/// given function name (which may also be an operator name) and adds 5235/// all of the overload candidates found by ADL to the overload 5236/// candidate set (C++ [basic.lookup.argdep]). 5237void 5238Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 5239 bool Operator, 5240 Expr **Args, unsigned NumArgs, 5241 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5242 OverloadCandidateSet& CandidateSet, 5243 bool PartialOverloading) { 5244 ADLResult Fns; 5245 5246 // FIXME: This approach for uniquing ADL results (and removing 5247 // redundant candidates from the set) relies on pointer-equality, 5248 // which means we need to key off the canonical decl. However, 5249 // always going back to the canonical decl might not get us the 5250 // right set of default arguments. What default arguments are 5251 // we supposed to consider on ADL candidates, anyway? 5252 5253 // FIXME: Pass in the explicit template arguments? 5254 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 5255 5256 // Erase all of the candidates we already knew about. 5257 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5258 CandEnd = CandidateSet.end(); 5259 Cand != CandEnd; ++Cand) 5260 if (Cand->Function) { 5261 Fns.erase(Cand->Function); 5262 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 5263 Fns.erase(FunTmpl); 5264 } 5265 5266 // For each of the ADL candidates we found, add it to the overload 5267 // set. 5268 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 5269 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 5270 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 5271 if (ExplicitTemplateArgs) 5272 continue; 5273 5274 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 5275 false, PartialOverloading); 5276 } else 5277 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 5278 FoundDecl, ExplicitTemplateArgs, 5279 Args, NumArgs, CandidateSet); 5280 } 5281} 5282 5283/// isBetterOverloadCandidate - Determines whether the first overload 5284/// candidate is a better candidate than the second (C++ 13.3.3p1). 5285bool 5286isBetterOverloadCandidate(Sema &S, 5287 const OverloadCandidate& Cand1, 5288 const OverloadCandidate& Cand2, 5289 SourceLocation Loc) { 5290 // Define viable functions to be better candidates than non-viable 5291 // functions. 5292 if (!Cand2.Viable) 5293 return Cand1.Viable; 5294 else if (!Cand1.Viable) 5295 return false; 5296 5297 // C++ [over.match.best]p1: 5298 // 5299 // -- if F is a static member function, ICS1(F) is defined such 5300 // that ICS1(F) is neither better nor worse than ICS1(G) for 5301 // any function G, and, symmetrically, ICS1(G) is neither 5302 // better nor worse than ICS1(F). 5303 unsigned StartArg = 0; 5304 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 5305 StartArg = 1; 5306 5307 // C++ [over.match.best]p1: 5308 // A viable function F1 is defined to be a better function than another 5309 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 5310 // conversion sequence than ICSi(F2), and then... 5311 unsigned NumArgs = Cand1.Conversions.size(); 5312 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 5313 bool HasBetterConversion = false; 5314 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 5315 switch (CompareImplicitConversionSequences(S, 5316 Cand1.Conversions[ArgIdx], 5317 Cand2.Conversions[ArgIdx])) { 5318 case ImplicitConversionSequence::Better: 5319 // Cand1 has a better conversion sequence. 5320 HasBetterConversion = true; 5321 break; 5322 5323 case ImplicitConversionSequence::Worse: 5324 // Cand1 can't be better than Cand2. 5325 return false; 5326 5327 case ImplicitConversionSequence::Indistinguishable: 5328 // Do nothing. 5329 break; 5330 } 5331 } 5332 5333 // -- for some argument j, ICSj(F1) is a better conversion sequence than 5334 // ICSj(F2), or, if not that, 5335 if (HasBetterConversion) 5336 return true; 5337 5338 // - F1 is a non-template function and F2 is a function template 5339 // specialization, or, if not that, 5340 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 5341 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5342 return true; 5343 5344 // -- F1 and F2 are function template specializations, and the function 5345 // template for F1 is more specialized than the template for F2 5346 // according to the partial ordering rules described in 14.5.5.2, or, 5347 // if not that, 5348 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 5349 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5350 if (FunctionTemplateDecl *BetterTemplate 5351 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 5352 Cand2.Function->getPrimaryTemplate(), 5353 Loc, 5354 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 5355 : TPOC_Call)) 5356 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 5357 5358 // -- the context is an initialization by user-defined conversion 5359 // (see 8.5, 13.3.1.5) and the standard conversion sequence 5360 // from the return type of F1 to the destination type (i.e., 5361 // the type of the entity being initialized) is a better 5362 // conversion sequence than the standard conversion sequence 5363 // from the return type of F2 to the destination type. 5364 if (Cand1.Function && Cand2.Function && 5365 isa<CXXConversionDecl>(Cand1.Function) && 5366 isa<CXXConversionDecl>(Cand2.Function)) { 5367 switch (CompareStandardConversionSequences(S, 5368 Cand1.FinalConversion, 5369 Cand2.FinalConversion)) { 5370 case ImplicitConversionSequence::Better: 5371 // Cand1 has a better conversion sequence. 5372 return true; 5373 5374 case ImplicitConversionSequence::Worse: 5375 // Cand1 can't be better than Cand2. 5376 return false; 5377 5378 case ImplicitConversionSequence::Indistinguishable: 5379 // Do nothing 5380 break; 5381 } 5382 } 5383 5384 return false; 5385} 5386 5387/// \brief Computes the best viable function (C++ 13.3.3) 5388/// within an overload candidate set. 5389/// 5390/// \param CandidateSet the set of candidate functions. 5391/// 5392/// \param Loc the location of the function name (or operator symbol) for 5393/// which overload resolution occurs. 5394/// 5395/// \param Best f overload resolution was successful or found a deleted 5396/// function, Best points to the candidate function found. 5397/// 5398/// \returns The result of overload resolution. 5399OverloadingResult 5400OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 5401 iterator& Best) { 5402 // Find the best viable function. 5403 Best = end(); 5404 for (iterator Cand = begin(); Cand != end(); ++Cand) { 5405 if (Cand->Viable) 5406 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc)) 5407 Best = Cand; 5408 } 5409 5410 // If we didn't find any viable functions, abort. 5411 if (Best == end()) 5412 return OR_No_Viable_Function; 5413 5414 // Make sure that this function is better than every other viable 5415 // function. If not, we have an ambiguity. 5416 for (iterator Cand = begin(); Cand != end(); ++Cand) { 5417 if (Cand->Viable && 5418 Cand != Best && 5419 !isBetterOverloadCandidate(S, *Best, *Cand, Loc)) { 5420 Best = end(); 5421 return OR_Ambiguous; 5422 } 5423 } 5424 5425 // Best is the best viable function. 5426 if (Best->Function && 5427 (Best->Function->isDeleted() || 5428 Best->Function->getAttr<UnavailableAttr>())) 5429 return OR_Deleted; 5430 5431 // C++ [basic.def.odr]p2: 5432 // An overloaded function is used if it is selected by overload resolution 5433 // when referred to from a potentially-evaluated expression. [Note: this 5434 // covers calls to named functions (5.2.2), operator overloading 5435 // (clause 13), user-defined conversions (12.3.2), allocation function for 5436 // placement new (5.3.4), as well as non-default initialization (8.5). 5437 if (Best->Function) 5438 S.MarkDeclarationReferenced(Loc, Best->Function); 5439 return OR_Success; 5440} 5441 5442namespace { 5443 5444enum OverloadCandidateKind { 5445 oc_function, 5446 oc_method, 5447 oc_constructor, 5448 oc_function_template, 5449 oc_method_template, 5450 oc_constructor_template, 5451 oc_implicit_default_constructor, 5452 oc_implicit_copy_constructor, 5453 oc_implicit_copy_assignment 5454}; 5455 5456OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 5457 FunctionDecl *Fn, 5458 std::string &Description) { 5459 bool isTemplate = false; 5460 5461 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 5462 isTemplate = true; 5463 Description = S.getTemplateArgumentBindingsText( 5464 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 5465 } 5466 5467 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 5468 if (!Ctor->isImplicit()) 5469 return isTemplate ? oc_constructor_template : oc_constructor; 5470 5471 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 5472 : oc_implicit_default_constructor; 5473 } 5474 5475 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 5476 // This actually gets spelled 'candidate function' for now, but 5477 // it doesn't hurt to split it out. 5478 if (!Meth->isImplicit()) 5479 return isTemplate ? oc_method_template : oc_method; 5480 5481 assert(Meth->isCopyAssignment() 5482 && "implicit method is not copy assignment operator?"); 5483 return oc_implicit_copy_assignment; 5484 } 5485 5486 return isTemplate ? oc_function_template : oc_function; 5487} 5488 5489} // end anonymous namespace 5490 5491// Notes the location of an overload candidate. 5492void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 5493 std::string FnDesc; 5494 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 5495 Diag(Fn->getLocation(), diag::note_ovl_candidate) 5496 << (unsigned) K << FnDesc; 5497} 5498 5499/// Diagnoses an ambiguous conversion. The partial diagnostic is the 5500/// "lead" diagnostic; it will be given two arguments, the source and 5501/// target types of the conversion. 5502void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 5503 Sema &S, 5504 SourceLocation CaretLoc, 5505 const PartialDiagnostic &PDiag) const { 5506 S.Diag(CaretLoc, PDiag) 5507 << Ambiguous.getFromType() << Ambiguous.getToType(); 5508 for (AmbiguousConversionSequence::const_iterator 5509 I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 5510 S.NoteOverloadCandidate(*I); 5511 } 5512} 5513 5514namespace { 5515 5516void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 5517 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 5518 assert(Conv.isBad()); 5519 assert(Cand->Function && "for now, candidate must be a function"); 5520 FunctionDecl *Fn = Cand->Function; 5521 5522 // There's a conversion slot for the object argument if this is a 5523 // non-constructor method. Note that 'I' corresponds the 5524 // conversion-slot index. 5525 bool isObjectArgument = false; 5526 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 5527 if (I == 0) 5528 isObjectArgument = true; 5529 else 5530 I--; 5531 } 5532 5533 std::string FnDesc; 5534 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5535 5536 Expr *FromExpr = Conv.Bad.FromExpr; 5537 QualType FromTy = Conv.Bad.getFromType(); 5538 QualType ToTy = Conv.Bad.getToType(); 5539 5540 if (FromTy == S.Context.OverloadTy) { 5541 assert(FromExpr && "overload set argument came from implicit argument?"); 5542 Expr *E = FromExpr->IgnoreParens(); 5543 if (isa<UnaryOperator>(E)) 5544 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 5545 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 5546 5547 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 5548 << (unsigned) FnKind << FnDesc 5549 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5550 << ToTy << Name << I+1; 5551 return; 5552 } 5553 5554 // Do some hand-waving analysis to see if the non-viability is due 5555 // to a qualifier mismatch. 5556 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 5557 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 5558 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 5559 CToTy = RT->getPointeeType(); 5560 else { 5561 // TODO: detect and diagnose the full richness of const mismatches. 5562 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 5563 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 5564 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 5565 } 5566 5567 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 5568 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 5569 // It is dumb that we have to do this here. 5570 while (isa<ArrayType>(CFromTy)) 5571 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 5572 while (isa<ArrayType>(CToTy)) 5573 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 5574 5575 Qualifiers FromQs = CFromTy.getQualifiers(); 5576 Qualifiers ToQs = CToTy.getQualifiers(); 5577 5578 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 5579 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 5580 << (unsigned) FnKind << FnDesc 5581 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5582 << FromTy 5583 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 5584 << (unsigned) isObjectArgument << I+1; 5585 return; 5586 } 5587 5588 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 5589 assert(CVR && "unexpected qualifiers mismatch"); 5590 5591 if (isObjectArgument) { 5592 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 5593 << (unsigned) FnKind << FnDesc 5594 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5595 << FromTy << (CVR - 1); 5596 } else { 5597 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 5598 << (unsigned) FnKind << FnDesc 5599 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5600 << FromTy << (CVR - 1) << I+1; 5601 } 5602 return; 5603 } 5604 5605 // Diagnose references or pointers to incomplete types differently, 5606 // since it's far from impossible that the incompleteness triggered 5607 // the failure. 5608 QualType TempFromTy = FromTy.getNonReferenceType(); 5609 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 5610 TempFromTy = PTy->getPointeeType(); 5611 if (TempFromTy->isIncompleteType()) { 5612 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 5613 << (unsigned) FnKind << FnDesc 5614 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5615 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5616 return; 5617 } 5618 5619 // Diagnose base -> derived pointer conversions. 5620 unsigned BaseToDerivedConversion = 0; 5621 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 5622 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 5623 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 5624 FromPtrTy->getPointeeType()) && 5625 !FromPtrTy->getPointeeType()->isIncompleteType() && 5626 !ToPtrTy->getPointeeType()->isIncompleteType() && 5627 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 5628 FromPtrTy->getPointeeType())) 5629 BaseToDerivedConversion = 1; 5630 } 5631 } else if (const ObjCObjectPointerType *FromPtrTy 5632 = FromTy->getAs<ObjCObjectPointerType>()) { 5633 if (const ObjCObjectPointerType *ToPtrTy 5634 = ToTy->getAs<ObjCObjectPointerType>()) 5635 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 5636 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 5637 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 5638 FromPtrTy->getPointeeType()) && 5639 FromIface->isSuperClassOf(ToIface)) 5640 BaseToDerivedConversion = 2; 5641 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 5642 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 5643 !FromTy->isIncompleteType() && 5644 !ToRefTy->getPointeeType()->isIncompleteType() && 5645 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 5646 BaseToDerivedConversion = 3; 5647 } 5648 5649 if (BaseToDerivedConversion) { 5650 S.Diag(Fn->getLocation(), 5651 diag::note_ovl_candidate_bad_base_to_derived_conv) 5652 << (unsigned) FnKind << FnDesc 5653 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5654 << (BaseToDerivedConversion - 1) 5655 << FromTy << ToTy << I+1; 5656 return; 5657 } 5658 5659 // TODO: specialize more based on the kind of mismatch 5660 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 5661 << (unsigned) FnKind << FnDesc 5662 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5663 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5664} 5665 5666void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 5667 unsigned NumFormalArgs) { 5668 // TODO: treat calls to a missing default constructor as a special case 5669 5670 FunctionDecl *Fn = Cand->Function; 5671 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 5672 5673 unsigned MinParams = Fn->getMinRequiredArguments(); 5674 5675 // at least / at most / exactly 5676 // FIXME: variadic templates "at most" should account for parameter packs 5677 unsigned mode, modeCount; 5678 if (NumFormalArgs < MinParams) { 5679 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 5680 (Cand->FailureKind == ovl_fail_bad_deduction && 5681 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 5682 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 5683 mode = 0; // "at least" 5684 else 5685 mode = 2; // "exactly" 5686 modeCount = MinParams; 5687 } else { 5688 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 5689 (Cand->FailureKind == ovl_fail_bad_deduction && 5690 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 5691 if (MinParams != FnTy->getNumArgs()) 5692 mode = 1; // "at most" 5693 else 5694 mode = 2; // "exactly" 5695 modeCount = FnTy->getNumArgs(); 5696 } 5697 5698 std::string Description; 5699 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 5700 5701 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 5702 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 5703 << modeCount << NumFormalArgs; 5704} 5705 5706/// Diagnose a failed template-argument deduction. 5707void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 5708 Expr **Args, unsigned NumArgs) { 5709 FunctionDecl *Fn = Cand->Function; // pattern 5710 5711 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 5712 NamedDecl *ParamD; 5713 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 5714 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 5715 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 5716 switch (Cand->DeductionFailure.Result) { 5717 case Sema::TDK_Success: 5718 llvm_unreachable("TDK_success while diagnosing bad deduction"); 5719 5720 case Sema::TDK_Incomplete: { 5721 assert(ParamD && "no parameter found for incomplete deduction result"); 5722 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 5723 << ParamD->getDeclName(); 5724 return; 5725 } 5726 5727 case Sema::TDK_Underqualified: { 5728 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 5729 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 5730 5731 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 5732 5733 // Param will have been canonicalized, but it should just be a 5734 // qualified version of ParamD, so move the qualifiers to that. 5735 QualifierCollector Qs(S.Context); 5736 Qs.strip(Param); 5737 QualType NonCanonParam = Qs.apply(TParam->getTypeForDecl()); 5738 assert(S.Context.hasSameType(Param, NonCanonParam)); 5739 5740 // Arg has also been canonicalized, but there's nothing we can do 5741 // about that. It also doesn't matter as much, because it won't 5742 // have any template parameters in it (because deduction isn't 5743 // done on dependent types). 5744 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 5745 5746 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 5747 << ParamD->getDeclName() << Arg << NonCanonParam; 5748 return; 5749 } 5750 5751 case Sema::TDK_Inconsistent: { 5752 assert(ParamD && "no parameter found for inconsistent deduction result"); 5753 int which = 0; 5754 if (isa<TemplateTypeParmDecl>(ParamD)) 5755 which = 0; 5756 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 5757 which = 1; 5758 else { 5759 which = 2; 5760 } 5761 5762 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 5763 << which << ParamD->getDeclName() 5764 << *Cand->DeductionFailure.getFirstArg() 5765 << *Cand->DeductionFailure.getSecondArg(); 5766 return; 5767 } 5768 5769 case Sema::TDK_InvalidExplicitArguments: 5770 assert(ParamD && "no parameter found for invalid explicit arguments"); 5771 if (ParamD->getDeclName()) 5772 S.Diag(Fn->getLocation(), 5773 diag::note_ovl_candidate_explicit_arg_mismatch_named) 5774 << ParamD->getDeclName(); 5775 else { 5776 int index = 0; 5777 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 5778 index = TTP->getIndex(); 5779 else if (NonTypeTemplateParmDecl *NTTP 5780 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 5781 index = NTTP->getIndex(); 5782 else 5783 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 5784 S.Diag(Fn->getLocation(), 5785 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 5786 << (index + 1); 5787 } 5788 return; 5789 5790 case Sema::TDK_TooManyArguments: 5791 case Sema::TDK_TooFewArguments: 5792 DiagnoseArityMismatch(S, Cand, NumArgs); 5793 return; 5794 5795 case Sema::TDK_InstantiationDepth: 5796 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 5797 return; 5798 5799 case Sema::TDK_SubstitutionFailure: { 5800 std::string ArgString; 5801 if (TemplateArgumentList *Args 5802 = Cand->DeductionFailure.getTemplateArgumentList()) 5803 ArgString = S.getTemplateArgumentBindingsText( 5804 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 5805 *Args); 5806 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 5807 << ArgString; 5808 return; 5809 } 5810 5811 // TODO: diagnose these individually, then kill off 5812 // note_ovl_candidate_bad_deduction, which is uselessly vague. 5813 case Sema::TDK_NonDeducedMismatch: 5814 case Sema::TDK_FailedOverloadResolution: 5815 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 5816 return; 5817 } 5818} 5819 5820/// Generates a 'note' diagnostic for an overload candidate. We've 5821/// already generated a primary error at the call site. 5822/// 5823/// It really does need to be a single diagnostic with its caret 5824/// pointed at the candidate declaration. Yes, this creates some 5825/// major challenges of technical writing. Yes, this makes pointing 5826/// out problems with specific arguments quite awkward. It's still 5827/// better than generating twenty screens of text for every failed 5828/// overload. 5829/// 5830/// It would be great to be able to express per-candidate problems 5831/// more richly for those diagnostic clients that cared, but we'd 5832/// still have to be just as careful with the default diagnostics. 5833void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 5834 Expr **Args, unsigned NumArgs) { 5835 FunctionDecl *Fn = Cand->Function; 5836 5837 // Note deleted candidates, but only if they're viable. 5838 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 5839 std::string FnDesc; 5840 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5841 5842 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 5843 << FnKind << FnDesc << Fn->isDeleted(); 5844 return; 5845 } 5846 5847 // We don't really have anything else to say about viable candidates. 5848 if (Cand->Viable) { 5849 S.NoteOverloadCandidate(Fn); 5850 return; 5851 } 5852 5853 switch (Cand->FailureKind) { 5854 case ovl_fail_too_many_arguments: 5855 case ovl_fail_too_few_arguments: 5856 return DiagnoseArityMismatch(S, Cand, NumArgs); 5857 5858 case ovl_fail_bad_deduction: 5859 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 5860 5861 case ovl_fail_trivial_conversion: 5862 case ovl_fail_bad_final_conversion: 5863 case ovl_fail_final_conversion_not_exact: 5864 return S.NoteOverloadCandidate(Fn); 5865 5866 case ovl_fail_bad_conversion: { 5867 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 5868 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 5869 if (Cand->Conversions[I].isBad()) 5870 return DiagnoseBadConversion(S, Cand, I); 5871 5872 // FIXME: this currently happens when we're called from SemaInit 5873 // when user-conversion overload fails. Figure out how to handle 5874 // those conditions and diagnose them well. 5875 return S.NoteOverloadCandidate(Fn); 5876 } 5877 } 5878} 5879 5880void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 5881 // Desugar the type of the surrogate down to a function type, 5882 // retaining as many typedefs as possible while still showing 5883 // the function type (and, therefore, its parameter types). 5884 QualType FnType = Cand->Surrogate->getConversionType(); 5885 bool isLValueReference = false; 5886 bool isRValueReference = false; 5887 bool isPointer = false; 5888 if (const LValueReferenceType *FnTypeRef = 5889 FnType->getAs<LValueReferenceType>()) { 5890 FnType = FnTypeRef->getPointeeType(); 5891 isLValueReference = true; 5892 } else if (const RValueReferenceType *FnTypeRef = 5893 FnType->getAs<RValueReferenceType>()) { 5894 FnType = FnTypeRef->getPointeeType(); 5895 isRValueReference = true; 5896 } 5897 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 5898 FnType = FnTypePtr->getPointeeType(); 5899 isPointer = true; 5900 } 5901 // Desugar down to a function type. 5902 FnType = QualType(FnType->getAs<FunctionType>(), 0); 5903 // Reconstruct the pointer/reference as appropriate. 5904 if (isPointer) FnType = S.Context.getPointerType(FnType); 5905 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5906 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5907 5908 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5909 << FnType; 5910} 5911 5912void NoteBuiltinOperatorCandidate(Sema &S, 5913 const char *Opc, 5914 SourceLocation OpLoc, 5915 OverloadCandidate *Cand) { 5916 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5917 std::string TypeStr("operator"); 5918 TypeStr += Opc; 5919 TypeStr += "("; 5920 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5921 if (Cand->Conversions.size() == 1) { 5922 TypeStr += ")"; 5923 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5924 } else { 5925 TypeStr += ", "; 5926 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5927 TypeStr += ")"; 5928 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5929 } 5930} 5931 5932void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5933 OverloadCandidate *Cand) { 5934 unsigned NoOperands = Cand->Conversions.size(); 5935 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5936 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5937 if (ICS.isBad()) break; // all meaningless after first invalid 5938 if (!ICS.isAmbiguous()) continue; 5939 5940 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 5941 S.PDiag(diag::note_ambiguous_type_conversion)); 5942 } 5943} 5944 5945SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5946 if (Cand->Function) 5947 return Cand->Function->getLocation(); 5948 if (Cand->IsSurrogate) 5949 return Cand->Surrogate->getLocation(); 5950 return SourceLocation(); 5951} 5952 5953struct CompareOverloadCandidatesForDisplay { 5954 Sema &S; 5955 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5956 5957 bool operator()(const OverloadCandidate *L, 5958 const OverloadCandidate *R) { 5959 // Fast-path this check. 5960 if (L == R) return false; 5961 5962 // Order first by viability. 5963 if (L->Viable) { 5964 if (!R->Viable) return true; 5965 5966 // TODO: introduce a tri-valued comparison for overload 5967 // candidates. Would be more worthwhile if we had a sort 5968 // that could exploit it. 5969 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 5970 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 5971 } else if (R->Viable) 5972 return false; 5973 5974 assert(L->Viable == R->Viable); 5975 5976 // Criteria by which we can sort non-viable candidates: 5977 if (!L->Viable) { 5978 // 1. Arity mismatches come after other candidates. 5979 if (L->FailureKind == ovl_fail_too_many_arguments || 5980 L->FailureKind == ovl_fail_too_few_arguments) 5981 return false; 5982 if (R->FailureKind == ovl_fail_too_many_arguments || 5983 R->FailureKind == ovl_fail_too_few_arguments) 5984 return true; 5985 5986 // 2. Bad conversions come first and are ordered by the number 5987 // of bad conversions and quality of good conversions. 5988 if (L->FailureKind == ovl_fail_bad_conversion) { 5989 if (R->FailureKind != ovl_fail_bad_conversion) 5990 return true; 5991 5992 // If there's any ordering between the defined conversions... 5993 // FIXME: this might not be transitive. 5994 assert(L->Conversions.size() == R->Conversions.size()); 5995 5996 int leftBetter = 0; 5997 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5998 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5999 switch (CompareImplicitConversionSequences(S, 6000 L->Conversions[I], 6001 R->Conversions[I])) { 6002 case ImplicitConversionSequence::Better: 6003 leftBetter++; 6004 break; 6005 6006 case ImplicitConversionSequence::Worse: 6007 leftBetter--; 6008 break; 6009 6010 case ImplicitConversionSequence::Indistinguishable: 6011 break; 6012 } 6013 } 6014 if (leftBetter > 0) return true; 6015 if (leftBetter < 0) return false; 6016 6017 } else if (R->FailureKind == ovl_fail_bad_conversion) 6018 return false; 6019 6020 // TODO: others? 6021 } 6022 6023 // Sort everything else by location. 6024 SourceLocation LLoc = GetLocationForCandidate(L); 6025 SourceLocation RLoc = GetLocationForCandidate(R); 6026 6027 // Put candidates without locations (e.g. builtins) at the end. 6028 if (LLoc.isInvalid()) return false; 6029 if (RLoc.isInvalid()) return true; 6030 6031 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 6032 } 6033}; 6034 6035/// CompleteNonViableCandidate - Normally, overload resolution only 6036/// computes up to the first 6037void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 6038 Expr **Args, unsigned NumArgs) { 6039 assert(!Cand->Viable); 6040 6041 // Don't do anything on failures other than bad conversion. 6042 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 6043 6044 // Skip forward to the first bad conversion. 6045 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 6046 unsigned ConvCount = Cand->Conversions.size(); 6047 while (true) { 6048 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 6049 ConvIdx++; 6050 if (Cand->Conversions[ConvIdx - 1].isBad()) 6051 break; 6052 } 6053 6054 if (ConvIdx == ConvCount) 6055 return; 6056 6057 assert(!Cand->Conversions[ConvIdx].isInitialized() && 6058 "remaining conversion is initialized?"); 6059 6060 // FIXME: this should probably be preserved from the overload 6061 // operation somehow. 6062 bool SuppressUserConversions = false; 6063 6064 const FunctionProtoType* Proto; 6065 unsigned ArgIdx = ConvIdx; 6066 6067 if (Cand->IsSurrogate) { 6068 QualType ConvType 6069 = Cand->Surrogate->getConversionType().getNonReferenceType(); 6070 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6071 ConvType = ConvPtrType->getPointeeType(); 6072 Proto = ConvType->getAs<FunctionProtoType>(); 6073 ArgIdx--; 6074 } else if (Cand->Function) { 6075 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 6076 if (isa<CXXMethodDecl>(Cand->Function) && 6077 !isa<CXXConstructorDecl>(Cand->Function)) 6078 ArgIdx--; 6079 } else { 6080 // Builtin binary operator with a bad first conversion. 6081 assert(ConvCount <= 3); 6082 for (; ConvIdx != ConvCount; ++ConvIdx) 6083 Cand->Conversions[ConvIdx] 6084 = TryCopyInitialization(S, Args[ConvIdx], 6085 Cand->BuiltinTypes.ParamTypes[ConvIdx], 6086 SuppressUserConversions, 6087 /*InOverloadResolution*/ true); 6088 return; 6089 } 6090 6091 // Fill in the rest of the conversions. 6092 unsigned NumArgsInProto = Proto->getNumArgs(); 6093 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 6094 if (ArgIdx < NumArgsInProto) 6095 Cand->Conversions[ConvIdx] 6096 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 6097 SuppressUserConversions, 6098 /*InOverloadResolution=*/true); 6099 else 6100 Cand->Conversions[ConvIdx].setEllipsis(); 6101 } 6102} 6103 6104} // end anonymous namespace 6105 6106/// PrintOverloadCandidates - When overload resolution fails, prints 6107/// diagnostic messages containing the candidates in the candidate 6108/// set. 6109void OverloadCandidateSet::NoteCandidates(Sema &S, 6110 OverloadCandidateDisplayKind OCD, 6111 Expr **Args, unsigned NumArgs, 6112 const char *Opc, 6113 SourceLocation OpLoc) { 6114 // Sort the candidates by viability and position. Sorting directly would 6115 // be prohibitive, so we make a set of pointers and sort those. 6116 llvm::SmallVector<OverloadCandidate*, 32> Cands; 6117 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 6118 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 6119 if (Cand->Viable) 6120 Cands.push_back(Cand); 6121 else if (OCD == OCD_AllCandidates) { 6122 CompleteNonViableCandidate(S, Cand, Args, NumArgs); 6123 if (Cand->Function || Cand->IsSurrogate) 6124 Cands.push_back(Cand); 6125 // Otherwise, this a non-viable builtin candidate. We do not, in general, 6126 // want to list every possible builtin candidate. 6127 } 6128 } 6129 6130 std::sort(Cands.begin(), Cands.end(), 6131 CompareOverloadCandidatesForDisplay(S)); 6132 6133 bool ReportedAmbiguousConversions = false; 6134 6135 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 6136 const Diagnostic::OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 6137 unsigned CandsShown = 0; 6138 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 6139 OverloadCandidate *Cand = *I; 6140 6141 // Set an arbitrary limit on the number of candidate functions we'll spam 6142 // the user with. FIXME: This limit should depend on details of the 6143 // candidate list. 6144 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 6145 break; 6146 } 6147 ++CandsShown; 6148 6149 if (Cand->Function) 6150 NoteFunctionCandidate(S, Cand, Args, NumArgs); 6151 else if (Cand->IsSurrogate) 6152 NoteSurrogateCandidate(S, Cand); 6153 else { 6154 assert(Cand->Viable && 6155 "Non-viable built-in candidates are not added to Cands."); 6156 // Generally we only see ambiguities including viable builtin 6157 // operators if overload resolution got screwed up by an 6158 // ambiguous user-defined conversion. 6159 // 6160 // FIXME: It's quite possible for different conversions to see 6161 // different ambiguities, though. 6162 if (!ReportedAmbiguousConversions) { 6163 NoteAmbiguousUserConversions(S, OpLoc, Cand); 6164 ReportedAmbiguousConversions = true; 6165 } 6166 6167 // If this is a viable builtin, print it. 6168 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 6169 } 6170 } 6171 6172 if (I != E) 6173 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 6174} 6175 6176static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 6177 if (isa<UnresolvedLookupExpr>(E)) 6178 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 6179 6180 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 6181} 6182 6183/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 6184/// an overloaded function (C++ [over.over]), where @p From is an 6185/// expression with overloaded function type and @p ToType is the type 6186/// we're trying to resolve to. For example: 6187/// 6188/// @code 6189/// int f(double); 6190/// int f(int); 6191/// 6192/// int (*pfd)(double) = f; // selects f(double) 6193/// @endcode 6194/// 6195/// This routine returns the resulting FunctionDecl if it could be 6196/// resolved, and NULL otherwise. When @p Complain is true, this 6197/// routine will emit diagnostics if there is an error. 6198FunctionDecl * 6199Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 6200 bool Complain, 6201 DeclAccessPair &FoundResult) { 6202 QualType FunctionType = ToType; 6203 bool IsMember = false; 6204 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 6205 FunctionType = ToTypePtr->getPointeeType(); 6206 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 6207 FunctionType = ToTypeRef->getPointeeType(); 6208 else if (const MemberPointerType *MemTypePtr = 6209 ToType->getAs<MemberPointerType>()) { 6210 FunctionType = MemTypePtr->getPointeeType(); 6211 IsMember = true; 6212 } 6213 6214 // C++ [over.over]p1: 6215 // [...] [Note: any redundant set of parentheses surrounding the 6216 // overloaded function name is ignored (5.1). ] 6217 // C++ [over.over]p1: 6218 // [...] The overloaded function name can be preceded by the & 6219 // operator. 6220 // However, remember whether the expression has member-pointer form: 6221 // C++ [expr.unary.op]p4: 6222 // A pointer to member is only formed when an explicit & is used 6223 // and its operand is a qualified-id not enclosed in 6224 // parentheses. 6225 bool HasFormOfMemberPointer = false; 6226 OverloadExpr *OvlExpr; 6227 { 6228 Expr *Tmp = From->IgnoreParens(); 6229 if (isa<UnaryOperator>(Tmp)) { 6230 Tmp = cast<UnaryOperator>(Tmp)->getSubExpr(); 6231 OvlExpr = cast<OverloadExpr>(Tmp->IgnoreParens()); 6232 HasFormOfMemberPointer = (Tmp == OvlExpr && OvlExpr->getQualifier()); 6233 } else { 6234 OvlExpr = cast<OverloadExpr>(Tmp); 6235 } 6236 } 6237 6238 // We expect a pointer or reference to function, or a function pointer. 6239 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 6240 if (!FunctionType->isFunctionType()) { 6241 if (Complain) 6242 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 6243 << OvlExpr->getName() << ToType; 6244 6245 return 0; 6246 } 6247 6248 // If the overload expression doesn't have the form of a pointer to 6249 // member, don't try to convert it to a pointer-to-member type. 6250 if (IsMember && !HasFormOfMemberPointer) { 6251 if (!Complain) return 0; 6252 6253 // TODO: Should we condition this on whether any functions might 6254 // have matched, or is it more appropriate to do that in callers? 6255 // TODO: a fixit wouldn't hurt. 6256 Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 6257 << ToType << OvlExpr->getSourceRange(); 6258 return 0; 6259 } 6260 6261 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 6262 if (OvlExpr->hasExplicitTemplateArgs()) { 6263 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 6264 ExplicitTemplateArgs = &ETABuffer; 6265 } 6266 6267 assert(From->getType() == Context.OverloadTy); 6268 6269 // Look through all of the overloaded functions, searching for one 6270 // whose type matches exactly. 6271 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 6272 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 6273 6274 bool FoundNonTemplateFunction = false; 6275 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6276 E = OvlExpr->decls_end(); I != E; ++I) { 6277 // Look through any using declarations to find the underlying function. 6278 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 6279 6280 // C++ [over.over]p3: 6281 // Non-member functions and static member functions match 6282 // targets of type "pointer-to-function" or "reference-to-function." 6283 // Nonstatic member functions match targets of 6284 // type "pointer-to-member-function." 6285 // Note that according to DR 247, the containing class does not matter. 6286 6287 if (FunctionTemplateDecl *FunctionTemplate 6288 = dyn_cast<FunctionTemplateDecl>(Fn)) { 6289 if (CXXMethodDecl *Method 6290 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 6291 // Skip non-static function templates when converting to pointer, and 6292 // static when converting to member pointer. 6293 if (Method->isStatic() == IsMember) 6294 continue; 6295 } else if (IsMember) 6296 continue; 6297 6298 // C++ [over.over]p2: 6299 // If the name is a function template, template argument deduction is 6300 // done (14.8.2.2), and if the argument deduction succeeds, the 6301 // resulting template argument list is used to generate a single 6302 // function template specialization, which is added to the set of 6303 // overloaded functions considered. 6304 // FIXME: We don't really want to build the specialization here, do we? 6305 FunctionDecl *Specialization = 0; 6306 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6307 if (TemplateDeductionResult Result 6308 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 6309 FunctionType, Specialization, Info)) { 6310 // FIXME: make a note of the failed deduction for diagnostics. 6311 (void)Result; 6312 } else { 6313 // FIXME: If the match isn't exact, shouldn't we just drop this as 6314 // a candidate? Find a testcase before changing the code. 6315 assert(FunctionType 6316 == Context.getCanonicalType(Specialization->getType())); 6317 Matches.push_back(std::make_pair(I.getPair(), 6318 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 6319 } 6320 6321 continue; 6322 } 6323 6324 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6325 // Skip non-static functions when converting to pointer, and static 6326 // when converting to member pointer. 6327 if (Method->isStatic() == IsMember) 6328 continue; 6329 6330 // If we have explicit template arguments, skip non-templates. 6331 if (OvlExpr->hasExplicitTemplateArgs()) 6332 continue; 6333 } else if (IsMember) 6334 continue; 6335 6336 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 6337 QualType ResultTy; 6338 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 6339 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 6340 ResultTy)) { 6341 Matches.push_back(std::make_pair(I.getPair(), 6342 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 6343 FoundNonTemplateFunction = true; 6344 } 6345 } 6346 } 6347 6348 // If there were 0 or 1 matches, we're done. 6349 if (Matches.empty()) { 6350 if (Complain) { 6351 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 6352 << OvlExpr->getName() << FunctionType; 6353 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6354 E = OvlExpr->decls_end(); 6355 I != E; ++I) 6356 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 6357 NoteOverloadCandidate(F); 6358 } 6359 6360 return 0; 6361 } else if (Matches.size() == 1) { 6362 FunctionDecl *Result = Matches[0].second; 6363 FoundResult = Matches[0].first; 6364 MarkDeclarationReferenced(From->getLocStart(), Result); 6365 if (Complain) 6366 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 6367 return Result; 6368 } 6369 6370 // C++ [over.over]p4: 6371 // If more than one function is selected, [...] 6372 if (!FoundNonTemplateFunction) { 6373 // [...] and any given function template specialization F1 is 6374 // eliminated if the set contains a second function template 6375 // specialization whose function template is more specialized 6376 // than the function template of F1 according to the partial 6377 // ordering rules of 14.5.5.2. 6378 6379 // The algorithm specified above is quadratic. We instead use a 6380 // two-pass algorithm (similar to the one used to identify the 6381 // best viable function in an overload set) that identifies the 6382 // best function template (if it exists). 6383 6384 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 6385 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6386 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 6387 6388 UnresolvedSetIterator Result = 6389 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 6390 TPOC_Other, From->getLocStart(), 6391 PDiag(), 6392 PDiag(diag::err_addr_ovl_ambiguous) 6393 << Matches[0].second->getDeclName(), 6394 PDiag(diag::note_ovl_candidate) 6395 << (unsigned) oc_function_template); 6396 assert(Result != MatchesCopy.end() && "no most-specialized template"); 6397 MarkDeclarationReferenced(From->getLocStart(), *Result); 6398 FoundResult = Matches[Result - MatchesCopy.begin()].first; 6399 if (Complain) { 6400 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 6401 DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc()); 6402 } 6403 return cast<FunctionDecl>(*Result); 6404 } 6405 6406 // [...] any function template specializations in the set are 6407 // eliminated if the set also contains a non-template function, [...] 6408 for (unsigned I = 0, N = Matches.size(); I != N; ) { 6409 if (Matches[I].second->getPrimaryTemplate() == 0) 6410 ++I; 6411 else { 6412 Matches[I] = Matches[--N]; 6413 Matches.set_size(N); 6414 } 6415 } 6416 6417 // [...] After such eliminations, if any, there shall remain exactly one 6418 // selected function. 6419 if (Matches.size() == 1) { 6420 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 6421 FoundResult = Matches[0].first; 6422 if (Complain) { 6423 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 6424 DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc()); 6425 } 6426 return cast<FunctionDecl>(Matches[0].second); 6427 } 6428 6429 // FIXME: We should probably return the same thing that BestViableFunction 6430 // returns (even if we issue the diagnostics here). 6431 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 6432 << Matches[0].second->getDeclName(); 6433 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6434 NoteOverloadCandidate(Matches[I].second); 6435 return 0; 6436} 6437 6438/// \brief Given an expression that refers to an overloaded function, try to 6439/// resolve that overloaded function expression down to a single function. 6440/// 6441/// This routine can only resolve template-ids that refer to a single function 6442/// template, where that template-id refers to a single template whose template 6443/// arguments are either provided by the template-id or have defaults, 6444/// as described in C++0x [temp.arg.explicit]p3. 6445FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 6446 // C++ [over.over]p1: 6447 // [...] [Note: any redundant set of parentheses surrounding the 6448 // overloaded function name is ignored (5.1). ] 6449 // C++ [over.over]p1: 6450 // [...] The overloaded function name can be preceded by the & 6451 // operator. 6452 6453 if (From->getType() != Context.OverloadTy) 6454 return 0; 6455 6456 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6457 6458 // If we didn't actually find any template-ids, we're done. 6459 if (!OvlExpr->hasExplicitTemplateArgs()) 6460 return 0; 6461 6462 TemplateArgumentListInfo ExplicitTemplateArgs; 6463 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 6464 6465 // Look through all of the overloaded functions, searching for one 6466 // whose type matches exactly. 6467 FunctionDecl *Matched = 0; 6468 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6469 E = OvlExpr->decls_end(); I != E; ++I) { 6470 // C++0x [temp.arg.explicit]p3: 6471 // [...] In contexts where deduction is done and fails, or in contexts 6472 // where deduction is not done, if a template argument list is 6473 // specified and it, along with any default template arguments, 6474 // identifies a single function template specialization, then the 6475 // template-id is an lvalue for the function template specialization. 6476 FunctionTemplateDecl *FunctionTemplate 6477 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 6478 6479 // C++ [over.over]p2: 6480 // If the name is a function template, template argument deduction is 6481 // done (14.8.2.2), and if the argument deduction succeeds, the 6482 // resulting template argument list is used to generate a single 6483 // function template specialization, which is added to the set of 6484 // overloaded functions considered. 6485 FunctionDecl *Specialization = 0; 6486 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6487 if (TemplateDeductionResult Result 6488 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 6489 Specialization, Info)) { 6490 // FIXME: make a note of the failed deduction for diagnostics. 6491 (void)Result; 6492 continue; 6493 } 6494 6495 // Multiple matches; we can't resolve to a single declaration. 6496 if (Matched) 6497 return 0; 6498 6499 Matched = Specialization; 6500 } 6501 6502 return Matched; 6503} 6504 6505/// \brief Add a single candidate to the overload set. 6506static void AddOverloadedCallCandidate(Sema &S, 6507 DeclAccessPair FoundDecl, 6508 const TemplateArgumentListInfo *ExplicitTemplateArgs, 6509 Expr **Args, unsigned NumArgs, 6510 OverloadCandidateSet &CandidateSet, 6511 bool PartialOverloading) { 6512 NamedDecl *Callee = FoundDecl.getDecl(); 6513 if (isa<UsingShadowDecl>(Callee)) 6514 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 6515 6516 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 6517 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 6518 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 6519 false, PartialOverloading); 6520 return; 6521 } 6522 6523 if (FunctionTemplateDecl *FuncTemplate 6524 = dyn_cast<FunctionTemplateDecl>(Callee)) { 6525 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 6526 ExplicitTemplateArgs, 6527 Args, NumArgs, CandidateSet); 6528 return; 6529 } 6530 6531 assert(false && "unhandled case in overloaded call candidate"); 6532 6533 // do nothing? 6534} 6535 6536/// \brief Add the overload candidates named by callee and/or found by argument 6537/// dependent lookup to the given overload set. 6538void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 6539 Expr **Args, unsigned NumArgs, 6540 OverloadCandidateSet &CandidateSet, 6541 bool PartialOverloading) { 6542 6543#ifndef NDEBUG 6544 // Verify that ArgumentDependentLookup is consistent with the rules 6545 // in C++0x [basic.lookup.argdep]p3: 6546 // 6547 // Let X be the lookup set produced by unqualified lookup (3.4.1) 6548 // and let Y be the lookup set produced by argument dependent 6549 // lookup (defined as follows). If X contains 6550 // 6551 // -- a declaration of a class member, or 6552 // 6553 // -- a block-scope function declaration that is not a 6554 // using-declaration, or 6555 // 6556 // -- a declaration that is neither a function or a function 6557 // template 6558 // 6559 // then Y is empty. 6560 6561 if (ULE->requiresADL()) { 6562 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6563 E = ULE->decls_end(); I != E; ++I) { 6564 assert(!(*I)->getDeclContext()->isRecord()); 6565 assert(isa<UsingShadowDecl>(*I) || 6566 !(*I)->getDeclContext()->isFunctionOrMethod()); 6567 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 6568 } 6569 } 6570#endif 6571 6572 // It would be nice to avoid this copy. 6573 TemplateArgumentListInfo TABuffer; 6574 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6575 if (ULE->hasExplicitTemplateArgs()) { 6576 ULE->copyTemplateArgumentsInto(TABuffer); 6577 ExplicitTemplateArgs = &TABuffer; 6578 } 6579 6580 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6581 E = ULE->decls_end(); I != E; ++I) 6582 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 6583 Args, NumArgs, CandidateSet, 6584 PartialOverloading); 6585 6586 if (ULE->requiresADL()) 6587 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 6588 Args, NumArgs, 6589 ExplicitTemplateArgs, 6590 CandidateSet, 6591 PartialOverloading); 6592} 6593 6594/// Attempts to recover from a call where no functions were found. 6595/// 6596/// Returns true if new candidates were found. 6597static ExprResult 6598BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 6599 UnresolvedLookupExpr *ULE, 6600 SourceLocation LParenLoc, 6601 Expr **Args, unsigned NumArgs, 6602 SourceLocation *CommaLocs, 6603 SourceLocation RParenLoc) { 6604 6605 CXXScopeSpec SS; 6606 if (ULE->getQualifier()) { 6607 SS.setScopeRep(ULE->getQualifier()); 6608 SS.setRange(ULE->getQualifierRange()); 6609 } 6610 6611 TemplateArgumentListInfo TABuffer; 6612 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6613 if (ULE->hasExplicitTemplateArgs()) { 6614 ULE->copyTemplateArgumentsInto(TABuffer); 6615 ExplicitTemplateArgs = &TABuffer; 6616 } 6617 6618 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 6619 Sema::LookupOrdinaryName); 6620 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 6621 return SemaRef.ExprError(); 6622 6623 assert(!R.empty() && "lookup results empty despite recovery"); 6624 6625 // Build an implicit member call if appropriate. Just drop the 6626 // casts and such from the call, we don't really care. 6627 ExprResult NewFn = SemaRef.ExprError(); 6628 if ((*R.begin())->isCXXClassMember()) 6629 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 6630 else if (ExplicitTemplateArgs) 6631 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 6632 else 6633 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 6634 6635 if (NewFn.isInvalid()) 6636 return SemaRef.ExprError(); 6637 6638 // This shouldn't cause an infinite loop because we're giving it 6639 // an expression with non-empty lookup results, which should never 6640 // end up here. 6641 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 6642 Sema::MultiExprArg(SemaRef, Args, NumArgs), 6643 CommaLocs, RParenLoc); 6644} 6645 6646/// ResolveOverloadedCallFn - Given the call expression that calls Fn 6647/// (which eventually refers to the declaration Func) and the call 6648/// arguments Args/NumArgs, attempt to resolve the function call down 6649/// to a specific function. If overload resolution succeeds, returns 6650/// the function declaration produced by overload 6651/// resolution. Otherwise, emits diagnostics, deletes all of the 6652/// arguments and Fn, and returns NULL. 6653ExprResult 6654Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 6655 SourceLocation LParenLoc, 6656 Expr **Args, unsigned NumArgs, 6657 SourceLocation *CommaLocs, 6658 SourceLocation RParenLoc) { 6659#ifndef NDEBUG 6660 if (ULE->requiresADL()) { 6661 // To do ADL, we must have found an unqualified name. 6662 assert(!ULE->getQualifier() && "qualified name with ADL"); 6663 6664 // We don't perform ADL for implicit declarations of builtins. 6665 // Verify that this was correctly set up. 6666 FunctionDecl *F; 6667 if (ULE->decls_begin() + 1 == ULE->decls_end() && 6668 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 6669 F->getBuiltinID() && F->isImplicit()) 6670 assert(0 && "performing ADL for builtin"); 6671 6672 // We don't perform ADL in C. 6673 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 6674 } 6675#endif 6676 6677 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 6678 6679 // Add the functions denoted by the callee to the set of candidate 6680 // functions, including those from argument-dependent lookup. 6681 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 6682 6683 // If we found nothing, try to recover. 6684 // AddRecoveryCallCandidates diagnoses the error itself, so we just 6685 // bailout out if it fails. 6686 if (CandidateSet.empty()) 6687 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 6688 CommaLocs, RParenLoc); 6689 6690 OverloadCandidateSet::iterator Best; 6691 switch (CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best)) { 6692 case OR_Success: { 6693 FunctionDecl *FDecl = Best->Function; 6694 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 6695 DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc()); 6696 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 6697 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 6698 } 6699 6700 case OR_No_Viable_Function: 6701 Diag(Fn->getSourceRange().getBegin(), 6702 diag::err_ovl_no_viable_function_in_call) 6703 << ULE->getName() << Fn->getSourceRange(); 6704 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 6705 break; 6706 6707 case OR_Ambiguous: 6708 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 6709 << ULE->getName() << Fn->getSourceRange(); 6710 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 6711 break; 6712 6713 case OR_Deleted: 6714 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 6715 << Best->Function->isDeleted() 6716 << ULE->getName() 6717 << Fn->getSourceRange(); 6718 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 6719 break; 6720 } 6721 6722 // Overload resolution failed. 6723 return ExprError(); 6724} 6725 6726static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 6727 return Functions.size() > 1 || 6728 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 6729} 6730 6731/// \brief Create a unary operation that may resolve to an overloaded 6732/// operator. 6733/// 6734/// \param OpLoc The location of the operator itself (e.g., '*'). 6735/// 6736/// \param OpcIn The UnaryOperator::Opcode that describes this 6737/// operator. 6738/// 6739/// \param Functions The set of non-member functions that will be 6740/// considered by overload resolution. The caller needs to build this 6741/// set based on the context using, e.g., 6742/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6743/// set should not contain any member functions; those will be added 6744/// by CreateOverloadedUnaryOp(). 6745/// 6746/// \param input The input argument. 6747ExprResult 6748Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 6749 const UnresolvedSetImpl &Fns, 6750 Expr *Input) { 6751 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6752 6753 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 6754 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 6755 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6756 // TODO: provide better source location info. 6757 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 6758 6759 Expr *Args[2] = { Input, 0 }; 6760 unsigned NumArgs = 1; 6761 6762 // For post-increment and post-decrement, add the implicit '0' as 6763 // the second argument, so that we know this is a post-increment or 6764 // post-decrement. 6765 if (Opc == UO_PostInc || Opc == UO_PostDec) { 6766 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 6767 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 6768 SourceLocation()); 6769 NumArgs = 2; 6770 } 6771 6772 if (Input->isTypeDependent()) { 6773 if (Fns.empty()) 6774 return Owned(new (Context) UnaryOperator(Input, 6775 Opc, 6776 Context.DependentTy, 6777 OpLoc)); 6778 6779 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6780 UnresolvedLookupExpr *Fn 6781 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6782 0, SourceRange(), OpNameInfo, 6783 /*ADL*/ true, IsOverloaded(Fns), 6784 Fns.begin(), Fns.end()); 6785 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6786 &Args[0], NumArgs, 6787 Context.DependentTy, 6788 OpLoc)); 6789 } 6790 6791 // Build an empty overload set. 6792 OverloadCandidateSet CandidateSet(OpLoc); 6793 6794 // Add the candidates from the given function set. 6795 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 6796 6797 // Add operator candidates that are member functions. 6798 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6799 6800 // Add candidates from ADL. 6801 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6802 Args, NumArgs, 6803 /*ExplicitTemplateArgs*/ 0, 6804 CandidateSet); 6805 6806 // Add builtin operator candidates. 6807 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6808 6809 // Perform overload resolution. 6810 OverloadCandidateSet::iterator Best; 6811 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 6812 case OR_Success: { 6813 // We found a built-in operator or an overloaded operator. 6814 FunctionDecl *FnDecl = Best->Function; 6815 6816 if (FnDecl) { 6817 // We matched an overloaded operator. Build a call to that 6818 // operator. 6819 6820 // Convert the arguments. 6821 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6822 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 6823 6824 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 6825 Best->FoundDecl, Method)) 6826 return ExprError(); 6827 } else { 6828 // Convert the arguments. 6829 ExprResult InputInit 6830 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6831 FnDecl->getParamDecl(0)), 6832 SourceLocation(), 6833 Input); 6834 if (InputInit.isInvalid()) 6835 return ExprError(); 6836 Input = InputInit.take(); 6837 } 6838 6839 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6840 6841 // Determine the result type 6842 QualType ResultTy = FnDecl->getCallResultType(); 6843 6844 // Build the actual expression node. 6845 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6846 SourceLocation()); 6847 UsualUnaryConversions(FnExpr); 6848 6849 Args[0] = Input; 6850 CallExpr *TheCall = 6851 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6852 Args, NumArgs, ResultTy, OpLoc); 6853 6854 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 6855 FnDecl)) 6856 return ExprError(); 6857 6858 return MaybeBindToTemporary(TheCall); 6859 } else { 6860 // We matched a built-in operator. Convert the arguments, then 6861 // break out so that we will build the appropriate built-in 6862 // operator node. 6863 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 6864 Best->Conversions[0], AA_Passing)) 6865 return ExprError(); 6866 6867 break; 6868 } 6869 } 6870 6871 case OR_No_Viable_Function: 6872 // No viable function; fall through to handling this as a 6873 // built-in operator, which will produce an error message for us. 6874 break; 6875 6876 case OR_Ambiguous: 6877 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6878 << UnaryOperator::getOpcodeStr(Opc) 6879 << Input->getSourceRange(); 6880 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 6881 Args, NumArgs, 6882 UnaryOperator::getOpcodeStr(Opc), OpLoc); 6883 return ExprError(); 6884 6885 case OR_Deleted: 6886 Diag(OpLoc, diag::err_ovl_deleted_oper) 6887 << Best->Function->isDeleted() 6888 << UnaryOperator::getOpcodeStr(Opc) 6889 << Input->getSourceRange(); 6890 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 6891 return ExprError(); 6892 } 6893 6894 // Either we found no viable overloaded operator or we matched a 6895 // built-in operator. In either case, fall through to trying to 6896 // build a built-in operation. 6897 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 6898} 6899 6900/// \brief Create a binary operation that may resolve to an overloaded 6901/// operator. 6902/// 6903/// \param OpLoc The location of the operator itself (e.g., '+'). 6904/// 6905/// \param OpcIn The BinaryOperator::Opcode that describes this 6906/// operator. 6907/// 6908/// \param Functions The set of non-member functions that will be 6909/// considered by overload resolution. The caller needs to build this 6910/// set based on the context using, e.g., 6911/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6912/// set should not contain any member functions; those will be added 6913/// by CreateOverloadedBinOp(). 6914/// 6915/// \param LHS Left-hand argument. 6916/// \param RHS Right-hand argument. 6917ExprResult 6918Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 6919 unsigned OpcIn, 6920 const UnresolvedSetImpl &Fns, 6921 Expr *LHS, Expr *RHS) { 6922 Expr *Args[2] = { LHS, RHS }; 6923 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 6924 6925 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 6926 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 6927 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6928 6929 // If either side is type-dependent, create an appropriate dependent 6930 // expression. 6931 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6932 if (Fns.empty()) { 6933 // If there are no functions to store, just build a dependent 6934 // BinaryOperator or CompoundAssignment. 6935 if (Opc <= BO_Assign || Opc > BO_OrAssign) 6936 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 6937 Context.DependentTy, OpLoc)); 6938 6939 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 6940 Context.DependentTy, 6941 Context.DependentTy, 6942 Context.DependentTy, 6943 OpLoc)); 6944 } 6945 6946 // FIXME: save results of ADL from here? 6947 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6948 // TODO: provide better source location info in DNLoc component. 6949 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 6950 UnresolvedLookupExpr *Fn 6951 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6952 0, SourceRange(), OpNameInfo, 6953 /*ADL*/ true, IsOverloaded(Fns), 6954 Fns.begin(), Fns.end()); 6955 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6956 Args, 2, 6957 Context.DependentTy, 6958 OpLoc)); 6959 } 6960 6961 // If this is the .* operator, which is not overloadable, just 6962 // create a built-in binary operator. 6963 if (Opc == BO_PtrMemD) 6964 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6965 6966 // If this is the assignment operator, we only perform overload resolution 6967 // if the left-hand side is a class or enumeration type. This is actually 6968 // a hack. The standard requires that we do overload resolution between the 6969 // various built-in candidates, but as DR507 points out, this can lead to 6970 // problems. So we do it this way, which pretty much follows what GCC does. 6971 // Note that we go the traditional code path for compound assignment forms. 6972 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 6973 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6974 6975 // Build an empty overload set. 6976 OverloadCandidateSet CandidateSet(OpLoc); 6977 6978 // Add the candidates from the given function set. 6979 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6980 6981 // Add operator candidates that are member functions. 6982 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6983 6984 // Add candidates from ADL. 6985 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6986 Args, 2, 6987 /*ExplicitTemplateArgs*/ 0, 6988 CandidateSet); 6989 6990 // Add builtin operator candidates. 6991 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6992 6993 // Perform overload resolution. 6994 OverloadCandidateSet::iterator Best; 6995 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 6996 case OR_Success: { 6997 // We found a built-in operator or an overloaded operator. 6998 FunctionDecl *FnDecl = Best->Function; 6999 7000 if (FnDecl) { 7001 // We matched an overloaded operator. Build a call to that 7002 // operator. 7003 7004 // Convert the arguments. 7005 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 7006 // Best->Access is only meaningful for class members. 7007 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 7008 7009 ExprResult Arg1 7010 = PerformCopyInitialization( 7011 InitializedEntity::InitializeParameter( 7012 FnDecl->getParamDecl(0)), 7013 SourceLocation(), 7014 Owned(Args[1])); 7015 if (Arg1.isInvalid()) 7016 return ExprError(); 7017 7018 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 7019 Best->FoundDecl, Method)) 7020 return ExprError(); 7021 7022 Args[1] = RHS = Arg1.takeAs<Expr>(); 7023 } else { 7024 // Convert the arguments. 7025 ExprResult Arg0 7026 = PerformCopyInitialization( 7027 InitializedEntity::InitializeParameter( 7028 FnDecl->getParamDecl(0)), 7029 SourceLocation(), 7030 Owned(Args[0])); 7031 if (Arg0.isInvalid()) 7032 return ExprError(); 7033 7034 ExprResult Arg1 7035 = PerformCopyInitialization( 7036 InitializedEntity::InitializeParameter( 7037 FnDecl->getParamDecl(1)), 7038 SourceLocation(), 7039 Owned(Args[1])); 7040 if (Arg1.isInvalid()) 7041 return ExprError(); 7042 Args[0] = LHS = Arg0.takeAs<Expr>(); 7043 Args[1] = RHS = Arg1.takeAs<Expr>(); 7044 } 7045 7046 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7047 7048 // Determine the result type 7049 QualType ResultTy 7050 = FnDecl->getType()->getAs<FunctionType>() 7051 ->getCallResultType(Context); 7052 7053 // Build the actual expression node. 7054 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 7055 OpLoc); 7056 UsualUnaryConversions(FnExpr); 7057 7058 CXXOperatorCallExpr *TheCall = 7059 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 7060 Args, 2, ResultTy, OpLoc); 7061 7062 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 7063 FnDecl)) 7064 return ExprError(); 7065 7066 return MaybeBindToTemporary(TheCall); 7067 } else { 7068 // We matched a built-in operator. Convert the arguments, then 7069 // break out so that we will build the appropriate built-in 7070 // operator node. 7071 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 7072 Best->Conversions[0], AA_Passing) || 7073 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 7074 Best->Conversions[1], AA_Passing)) 7075 return ExprError(); 7076 7077 break; 7078 } 7079 } 7080 7081 case OR_No_Viable_Function: { 7082 // C++ [over.match.oper]p9: 7083 // If the operator is the operator , [...] and there are no 7084 // viable functions, then the operator is assumed to be the 7085 // built-in operator and interpreted according to clause 5. 7086 if (Opc == BO_Comma) 7087 break; 7088 7089 // For class as left operand for assignment or compound assigment operator 7090 // do not fall through to handling in built-in, but report that no overloaded 7091 // assignment operator found 7092 ExprResult Result = ExprError(); 7093 if (Args[0]->getType()->isRecordType() && 7094 Opc >= BO_Assign && Opc <= BO_OrAssign) { 7095 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7096 << BinaryOperator::getOpcodeStr(Opc) 7097 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7098 } else { 7099 // No viable function; try to create a built-in operation, which will 7100 // produce an error. Then, show the non-viable candidates. 7101 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7102 } 7103 assert(Result.isInvalid() && 7104 "C++ binary operator overloading is missing candidates!"); 7105 if (Result.isInvalid()) 7106 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 7107 BinaryOperator::getOpcodeStr(Opc), OpLoc); 7108 return move(Result); 7109 } 7110 7111 case OR_Ambiguous: 7112 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7113 << BinaryOperator::getOpcodeStr(Opc) 7114 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7115 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 7116 BinaryOperator::getOpcodeStr(Opc), OpLoc); 7117 return ExprError(); 7118 7119 case OR_Deleted: 7120 Diag(OpLoc, diag::err_ovl_deleted_oper) 7121 << Best->Function->isDeleted() 7122 << BinaryOperator::getOpcodeStr(Opc) 7123 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7124 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2); 7125 return ExprError(); 7126 } 7127 7128 // We matched a built-in operator; build it. 7129 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7130} 7131 7132ExprResult 7133Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 7134 SourceLocation RLoc, 7135 Expr *Base, Expr *Idx) { 7136 Expr *Args[2] = { Base, Idx }; 7137 DeclarationName OpName = 7138 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 7139 7140 // If either side is type-dependent, create an appropriate dependent 7141 // expression. 7142 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 7143 7144 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7145 // CHECKME: no 'operator' keyword? 7146 DeclarationNameInfo OpNameInfo(OpName, LLoc); 7147 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 7148 UnresolvedLookupExpr *Fn 7149 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 7150 0, SourceRange(), OpNameInfo, 7151 /*ADL*/ true, /*Overloaded*/ false, 7152 UnresolvedSetIterator(), 7153 UnresolvedSetIterator()); 7154 // Can't add any actual overloads yet 7155 7156 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 7157 Args, 2, 7158 Context.DependentTy, 7159 RLoc)); 7160 } 7161 7162 // Build an empty overload set. 7163 OverloadCandidateSet CandidateSet(LLoc); 7164 7165 // Subscript can only be overloaded as a member function. 7166 7167 // Add operator candidates that are member functions. 7168 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 7169 7170 // Add builtin operator candidates. 7171 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 7172 7173 // Perform overload resolution. 7174 OverloadCandidateSet::iterator Best; 7175 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 7176 case OR_Success: { 7177 // We found a built-in operator or an overloaded operator. 7178 FunctionDecl *FnDecl = Best->Function; 7179 7180 if (FnDecl) { 7181 // We matched an overloaded operator. Build a call to that 7182 // operator. 7183 7184 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 7185 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 7186 7187 // Convert the arguments. 7188 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 7189 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 7190 Best->FoundDecl, Method)) 7191 return ExprError(); 7192 7193 // Convert the arguments. 7194 ExprResult InputInit 7195 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7196 FnDecl->getParamDecl(0)), 7197 SourceLocation(), 7198 Owned(Args[1])); 7199 if (InputInit.isInvalid()) 7200 return ExprError(); 7201 7202 Args[1] = InputInit.takeAs<Expr>(); 7203 7204 // Determine the result type 7205 QualType ResultTy 7206 = FnDecl->getType()->getAs<FunctionType>() 7207 ->getCallResultType(Context); 7208 7209 // Build the actual expression node. 7210 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 7211 LLoc); 7212 UsualUnaryConversions(FnExpr); 7213 7214 CXXOperatorCallExpr *TheCall = 7215 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 7216 FnExpr, Args, 2, 7217 ResultTy, RLoc); 7218 7219 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 7220 FnDecl)) 7221 return ExprError(); 7222 7223 return MaybeBindToTemporary(TheCall); 7224 } else { 7225 // We matched a built-in operator. Convert the arguments, then 7226 // break out so that we will build the appropriate built-in 7227 // operator node. 7228 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 7229 Best->Conversions[0], AA_Passing) || 7230 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 7231 Best->Conversions[1], AA_Passing)) 7232 return ExprError(); 7233 7234 break; 7235 } 7236 } 7237 7238 case OR_No_Viable_Function: { 7239 if (CandidateSet.empty()) 7240 Diag(LLoc, diag::err_ovl_no_oper) 7241 << Args[0]->getType() << /*subscript*/ 0 7242 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7243 else 7244 Diag(LLoc, diag::err_ovl_no_viable_subscript) 7245 << Args[0]->getType() 7246 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7247 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 7248 "[]", LLoc); 7249 return ExprError(); 7250 } 7251 7252 case OR_Ambiguous: 7253 Diag(LLoc, diag::err_ovl_ambiguous_oper) 7254 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7255 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 7256 "[]", LLoc); 7257 return ExprError(); 7258 7259 case OR_Deleted: 7260 Diag(LLoc, diag::err_ovl_deleted_oper) 7261 << Best->Function->isDeleted() << "[]" 7262 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7263 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 7264 "[]", LLoc); 7265 return ExprError(); 7266 } 7267 7268 // We matched a built-in operator; build it. 7269 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 7270} 7271 7272/// BuildCallToMemberFunction - Build a call to a member 7273/// function. MemExpr is the expression that refers to the member 7274/// function (and includes the object parameter), Args/NumArgs are the 7275/// arguments to the function call (not including the object 7276/// parameter). The caller needs to validate that the member 7277/// expression refers to a member function or an overloaded member 7278/// function. 7279ExprResult 7280Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 7281 SourceLocation LParenLoc, Expr **Args, 7282 unsigned NumArgs, SourceLocation *CommaLocs, 7283 SourceLocation RParenLoc) { 7284 // Dig out the member expression. This holds both the object 7285 // argument and the member function we're referring to. 7286 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 7287 7288 MemberExpr *MemExpr; 7289 CXXMethodDecl *Method = 0; 7290 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 7291 NestedNameSpecifier *Qualifier = 0; 7292 if (isa<MemberExpr>(NakedMemExpr)) { 7293 MemExpr = cast<MemberExpr>(NakedMemExpr); 7294 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 7295 FoundDecl = MemExpr->getFoundDecl(); 7296 Qualifier = MemExpr->getQualifier(); 7297 } else { 7298 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 7299 Qualifier = UnresExpr->getQualifier(); 7300 7301 QualType ObjectType = UnresExpr->getBaseType(); 7302 7303 // Add overload candidates 7304 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 7305 7306 // FIXME: avoid copy. 7307 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7308 if (UnresExpr->hasExplicitTemplateArgs()) { 7309 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7310 TemplateArgs = &TemplateArgsBuffer; 7311 } 7312 7313 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 7314 E = UnresExpr->decls_end(); I != E; ++I) { 7315 7316 NamedDecl *Func = *I; 7317 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 7318 if (isa<UsingShadowDecl>(Func)) 7319 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 7320 7321 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 7322 // If explicit template arguments were provided, we can't call a 7323 // non-template member function. 7324 if (TemplateArgs) 7325 continue; 7326 7327 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 7328 Args, NumArgs, 7329 CandidateSet, /*SuppressUserConversions=*/false); 7330 } else { 7331 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 7332 I.getPair(), ActingDC, TemplateArgs, 7333 ObjectType, Args, NumArgs, 7334 CandidateSet, 7335 /*SuppressUsedConversions=*/false); 7336 } 7337 } 7338 7339 DeclarationName DeclName = UnresExpr->getMemberName(); 7340 7341 OverloadCandidateSet::iterator Best; 7342 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 7343 Best)) { 7344 case OR_Success: 7345 Method = cast<CXXMethodDecl>(Best->Function); 7346 FoundDecl = Best->FoundDecl; 7347 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 7348 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 7349 break; 7350 7351 case OR_No_Viable_Function: 7352 Diag(UnresExpr->getMemberLoc(), 7353 diag::err_ovl_no_viable_member_function_in_call) 7354 << DeclName << MemExprE->getSourceRange(); 7355 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7356 // FIXME: Leaking incoming expressions! 7357 return ExprError(); 7358 7359 case OR_Ambiguous: 7360 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 7361 << DeclName << MemExprE->getSourceRange(); 7362 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7363 // FIXME: Leaking incoming expressions! 7364 return ExprError(); 7365 7366 case OR_Deleted: 7367 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 7368 << Best->Function->isDeleted() 7369 << DeclName << MemExprE->getSourceRange(); 7370 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7371 // FIXME: Leaking incoming expressions! 7372 return ExprError(); 7373 } 7374 7375 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 7376 7377 // If overload resolution picked a static member, build a 7378 // non-member call based on that function. 7379 if (Method->isStatic()) { 7380 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 7381 Args, NumArgs, RParenLoc); 7382 } 7383 7384 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 7385 } 7386 7387 assert(Method && "Member call to something that isn't a method?"); 7388 CXXMemberCallExpr *TheCall = 7389 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 7390 Method->getCallResultType(), 7391 RParenLoc); 7392 7393 // Check for a valid return type. 7394 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 7395 TheCall, Method)) 7396 return ExprError(); 7397 7398 // Convert the object argument (for a non-static member function call). 7399 // We only need to do this if there was actually an overload; otherwise 7400 // it was done at lookup. 7401 Expr *ObjectArg = MemExpr->getBase(); 7402 if (!Method->isStatic() && 7403 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 7404 FoundDecl, Method)) 7405 return ExprError(); 7406 MemExpr->setBase(ObjectArg); 7407 7408 // Convert the rest of the arguments 7409 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7410 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 7411 RParenLoc)) 7412 return ExprError(); 7413 7414 if (CheckFunctionCall(Method, TheCall)) 7415 return ExprError(); 7416 7417 return MaybeBindToTemporary(TheCall); 7418} 7419 7420/// BuildCallToObjectOfClassType - Build a call to an object of class 7421/// type (C++ [over.call.object]), which can end up invoking an 7422/// overloaded function call operator (@c operator()) or performing a 7423/// user-defined conversion on the object argument. 7424Sema::ExprResult 7425Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 7426 SourceLocation LParenLoc, 7427 Expr **Args, unsigned NumArgs, 7428 SourceLocation *CommaLocs, 7429 SourceLocation RParenLoc) { 7430 assert(Object->getType()->isRecordType() && "Requires object type argument"); 7431 const RecordType *Record = Object->getType()->getAs<RecordType>(); 7432 7433 // C++ [over.call.object]p1: 7434 // If the primary-expression E in the function call syntax 7435 // evaluates to a class object of type "cv T", then the set of 7436 // candidate functions includes at least the function call 7437 // operators of T. The function call operators of T are obtained by 7438 // ordinary lookup of the name operator() in the context of 7439 // (E).operator(). 7440 OverloadCandidateSet CandidateSet(LParenLoc); 7441 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 7442 7443 if (RequireCompleteType(LParenLoc, Object->getType(), 7444 PDiag(diag::err_incomplete_object_call) 7445 << Object->getSourceRange())) 7446 return true; 7447 7448 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 7449 LookupQualifiedName(R, Record->getDecl()); 7450 R.suppressDiagnostics(); 7451 7452 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7453 Oper != OperEnd; ++Oper) { 7454 AddMethodCandidate(Oper.getPair(), Object->getType(), 7455 Args, NumArgs, CandidateSet, 7456 /*SuppressUserConversions=*/ false); 7457 } 7458 7459 // C++ [over.call.object]p2: 7460 // In addition, for each conversion function declared in T of the 7461 // form 7462 // 7463 // operator conversion-type-id () cv-qualifier; 7464 // 7465 // where cv-qualifier is the same cv-qualification as, or a 7466 // greater cv-qualification than, cv, and where conversion-type-id 7467 // denotes the type "pointer to function of (P1,...,Pn) returning 7468 // R", or the type "reference to pointer to function of 7469 // (P1,...,Pn) returning R", or the type "reference to function 7470 // of (P1,...,Pn) returning R", a surrogate call function [...] 7471 // is also considered as a candidate function. Similarly, 7472 // surrogate call functions are added to the set of candidate 7473 // functions for each conversion function declared in an 7474 // accessible base class provided the function is not hidden 7475 // within T by another intervening declaration. 7476 const UnresolvedSetImpl *Conversions 7477 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 7478 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 7479 E = Conversions->end(); I != E; ++I) { 7480 NamedDecl *D = *I; 7481 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 7482 if (isa<UsingShadowDecl>(D)) 7483 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 7484 7485 // Skip over templated conversion functions; they aren't 7486 // surrogates. 7487 if (isa<FunctionTemplateDecl>(D)) 7488 continue; 7489 7490 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 7491 7492 // Strip the reference type (if any) and then the pointer type (if 7493 // any) to get down to what might be a function type. 7494 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 7495 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7496 ConvType = ConvPtrType->getPointeeType(); 7497 7498 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 7499 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 7500 Object->getType(), Args, NumArgs, 7501 CandidateSet); 7502 } 7503 7504 // Perform overload resolution. 7505 OverloadCandidateSet::iterator Best; 7506 switch (CandidateSet.BestViableFunction(*this, Object->getLocStart(), 7507 Best)) { 7508 case OR_Success: 7509 // Overload resolution succeeded; we'll build the appropriate call 7510 // below. 7511 break; 7512 7513 case OR_No_Viable_Function: 7514 if (CandidateSet.empty()) 7515 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 7516 << Object->getType() << /*call*/ 1 7517 << Object->getSourceRange(); 7518 else 7519 Diag(Object->getSourceRange().getBegin(), 7520 diag::err_ovl_no_viable_object_call) 7521 << Object->getType() << Object->getSourceRange(); 7522 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7523 break; 7524 7525 case OR_Ambiguous: 7526 Diag(Object->getSourceRange().getBegin(), 7527 diag::err_ovl_ambiguous_object_call) 7528 << Object->getType() << Object->getSourceRange(); 7529 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 7530 break; 7531 7532 case OR_Deleted: 7533 Diag(Object->getSourceRange().getBegin(), 7534 diag::err_ovl_deleted_object_call) 7535 << Best->Function->isDeleted() 7536 << Object->getType() << Object->getSourceRange(); 7537 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7538 break; 7539 } 7540 7541 if (Best == CandidateSet.end()) 7542 return true; 7543 7544 if (Best->Function == 0) { 7545 // Since there is no function declaration, this is one of the 7546 // surrogate candidates. Dig out the conversion function. 7547 CXXConversionDecl *Conv 7548 = cast<CXXConversionDecl>( 7549 Best->Conversions[0].UserDefined.ConversionFunction); 7550 7551 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7552 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7553 7554 // We selected one of the surrogate functions that converts the 7555 // object parameter to a function pointer. Perform the conversion 7556 // on the object argument, then let ActOnCallExpr finish the job. 7557 7558 // Create an implicit member expr to refer to the conversion operator. 7559 // and then call it. 7560 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 7561 Conv); 7562 7563 return ActOnCallExpr(S, CE, LParenLoc, 7564 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 7565 CommaLocs, RParenLoc); 7566 } 7567 7568 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7569 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7570 7571 // We found an overloaded operator(). Build a CXXOperatorCallExpr 7572 // that calls this method, using Object for the implicit object 7573 // parameter and passing along the remaining arguments. 7574 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7575 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7576 7577 unsigned NumArgsInProto = Proto->getNumArgs(); 7578 unsigned NumArgsToCheck = NumArgs; 7579 7580 // Build the full argument list for the method call (the 7581 // implicit object parameter is placed at the beginning of the 7582 // list). 7583 Expr **MethodArgs; 7584 if (NumArgs < NumArgsInProto) { 7585 NumArgsToCheck = NumArgsInProto; 7586 MethodArgs = new Expr*[NumArgsInProto + 1]; 7587 } else { 7588 MethodArgs = new Expr*[NumArgs + 1]; 7589 } 7590 MethodArgs[0] = Object; 7591 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7592 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 7593 7594 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 7595 SourceLocation()); 7596 UsualUnaryConversions(NewFn); 7597 7598 // Once we've built TheCall, all of the expressions are properly 7599 // owned. 7600 QualType ResultTy = Method->getCallResultType(); 7601 CXXOperatorCallExpr *TheCall = 7602 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 7603 MethodArgs, NumArgs + 1, 7604 ResultTy, RParenLoc); 7605 delete [] MethodArgs; 7606 7607 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 7608 Method)) 7609 return true; 7610 7611 // We may have default arguments. If so, we need to allocate more 7612 // slots in the call for them. 7613 if (NumArgs < NumArgsInProto) 7614 TheCall->setNumArgs(Context, NumArgsInProto + 1); 7615 else if (NumArgs > NumArgsInProto) 7616 NumArgsToCheck = NumArgsInProto; 7617 7618 bool IsError = false; 7619 7620 // Initialize the implicit object parameter. 7621 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 7622 Best->FoundDecl, Method); 7623 TheCall->setArg(0, Object); 7624 7625 7626 // Check the argument types. 7627 for (unsigned i = 0; i != NumArgsToCheck; i++) { 7628 Expr *Arg; 7629 if (i < NumArgs) { 7630 Arg = Args[i]; 7631 7632 // Pass the argument. 7633 7634 ExprResult InputInit 7635 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7636 Method->getParamDecl(i)), 7637 SourceLocation(), Arg); 7638 7639 IsError |= InputInit.isInvalid(); 7640 Arg = InputInit.takeAs<Expr>(); 7641 } else { 7642 ExprResult DefArg 7643 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 7644 if (DefArg.isInvalid()) { 7645 IsError = true; 7646 break; 7647 } 7648 7649 Arg = DefArg.takeAs<Expr>(); 7650 } 7651 7652 TheCall->setArg(i + 1, Arg); 7653 } 7654 7655 // If this is a variadic call, handle args passed through "...". 7656 if (Proto->isVariadic()) { 7657 // Promote the arguments (C99 6.5.2.2p7). 7658 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 7659 Expr *Arg = Args[i]; 7660 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 7661 TheCall->setArg(i + 1, Arg); 7662 } 7663 } 7664 7665 if (IsError) return true; 7666 7667 if (CheckFunctionCall(Method, TheCall)) 7668 return true; 7669 7670 return MaybeBindToTemporary(TheCall); 7671} 7672 7673/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 7674/// (if one exists), where @c Base is an expression of class type and 7675/// @c Member is the name of the member we're trying to find. 7676ExprResult 7677Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 7678 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 7679 7680 SourceLocation Loc = Base->getExprLoc(); 7681 7682 // C++ [over.ref]p1: 7683 // 7684 // [...] An expression x->m is interpreted as (x.operator->())->m 7685 // for a class object x of type T if T::operator->() exists and if 7686 // the operator is selected as the best match function by the 7687 // overload resolution mechanism (13.3). 7688 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 7689 OverloadCandidateSet CandidateSet(Loc); 7690 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 7691 7692 if (RequireCompleteType(Loc, Base->getType(), 7693 PDiag(diag::err_typecheck_incomplete_tag) 7694 << Base->getSourceRange())) 7695 return ExprError(); 7696 7697 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 7698 LookupQualifiedName(R, BaseRecord->getDecl()); 7699 R.suppressDiagnostics(); 7700 7701 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7702 Oper != OperEnd; ++Oper) { 7703 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 7704 /*SuppressUserConversions=*/false); 7705 } 7706 7707 // Perform overload resolution. 7708 OverloadCandidateSet::iterator Best; 7709 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 7710 case OR_Success: 7711 // Overload resolution succeeded; we'll build the call below. 7712 break; 7713 7714 case OR_No_Viable_Function: 7715 if (CandidateSet.empty()) 7716 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 7717 << Base->getType() << Base->getSourceRange(); 7718 else 7719 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7720 << "operator->" << Base->getSourceRange(); 7721 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 7722 return ExprError(); 7723 7724 case OR_Ambiguous: 7725 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7726 << "->" << Base->getSourceRange(); 7727 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, &Base, 1); 7728 return ExprError(); 7729 7730 case OR_Deleted: 7731 Diag(OpLoc, diag::err_ovl_deleted_oper) 7732 << Best->Function->isDeleted() 7733 << "->" << Base->getSourceRange(); 7734 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 7735 return ExprError(); 7736 } 7737 7738 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 7739 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7740 7741 // Convert the object parameter. 7742 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7743 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 7744 Best->FoundDecl, Method)) 7745 return ExprError(); 7746 7747 // Build the operator call. 7748 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 7749 SourceLocation()); 7750 UsualUnaryConversions(FnExpr); 7751 7752 QualType ResultTy = Method->getCallResultType(); 7753 CXXOperatorCallExpr *TheCall = 7754 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 7755 &Base, 1, ResultTy, OpLoc); 7756 7757 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 7758 Method)) 7759 return ExprError(); 7760 return Owned(TheCall); 7761} 7762 7763/// FixOverloadedFunctionReference - E is an expression that refers to 7764/// a C++ overloaded function (possibly with some parentheses and 7765/// perhaps a '&' around it). We have resolved the overloaded function 7766/// to the function declaration Fn, so patch up the expression E to 7767/// refer (possibly indirectly) to Fn. Returns the new expr. 7768Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 7769 FunctionDecl *Fn) { 7770 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 7771 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 7772 Found, Fn); 7773 if (SubExpr == PE->getSubExpr()) 7774 return PE->Retain(); 7775 7776 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 7777 } 7778 7779 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 7780 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 7781 Found, Fn); 7782 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 7783 SubExpr->getType()) && 7784 "Implicit cast type cannot be determined from overload"); 7785 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 7786 if (SubExpr == ICE->getSubExpr()) 7787 return ICE->Retain(); 7788 7789 return ImplicitCastExpr::Create(Context, ICE->getType(), 7790 ICE->getCastKind(), 7791 SubExpr, 0, 7792 ICE->getValueKind()); 7793 } 7794 7795 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 7796 assert(UnOp->getOpcode() == UO_AddrOf && 7797 "Can only take the address of an overloaded function"); 7798 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7799 if (Method->isStatic()) { 7800 // Do nothing: static member functions aren't any different 7801 // from non-member functions. 7802 } else { 7803 // Fix the sub expression, which really has to be an 7804 // UnresolvedLookupExpr holding an overloaded member function 7805 // or template. 7806 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7807 Found, Fn); 7808 if (SubExpr == UnOp->getSubExpr()) 7809 return UnOp->Retain(); 7810 7811 assert(isa<DeclRefExpr>(SubExpr) 7812 && "fixed to something other than a decl ref"); 7813 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 7814 && "fixed to a member ref with no nested name qualifier"); 7815 7816 // We have taken the address of a pointer to member 7817 // function. Perform the computation here so that we get the 7818 // appropriate pointer to member type. 7819 QualType ClassType 7820 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 7821 QualType MemPtrType 7822 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 7823 7824 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 7825 MemPtrType, UnOp->getOperatorLoc()); 7826 } 7827 } 7828 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7829 Found, Fn); 7830 if (SubExpr == UnOp->getSubExpr()) 7831 return UnOp->Retain(); 7832 7833 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 7834 Context.getPointerType(SubExpr->getType()), 7835 UnOp->getOperatorLoc()); 7836 } 7837 7838 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 7839 // FIXME: avoid copy. 7840 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7841 if (ULE->hasExplicitTemplateArgs()) { 7842 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 7843 TemplateArgs = &TemplateArgsBuffer; 7844 } 7845 7846 return DeclRefExpr::Create(Context, 7847 ULE->getQualifier(), 7848 ULE->getQualifierRange(), 7849 Fn, 7850 ULE->getNameLoc(), 7851 Fn->getType(), 7852 TemplateArgs); 7853 } 7854 7855 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 7856 // FIXME: avoid copy. 7857 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7858 if (MemExpr->hasExplicitTemplateArgs()) { 7859 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7860 TemplateArgs = &TemplateArgsBuffer; 7861 } 7862 7863 Expr *Base; 7864 7865 // If we're filling in 7866 if (MemExpr->isImplicitAccess()) { 7867 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 7868 return DeclRefExpr::Create(Context, 7869 MemExpr->getQualifier(), 7870 MemExpr->getQualifierRange(), 7871 Fn, 7872 MemExpr->getMemberLoc(), 7873 Fn->getType(), 7874 TemplateArgs); 7875 } else { 7876 SourceLocation Loc = MemExpr->getMemberLoc(); 7877 if (MemExpr->getQualifier()) 7878 Loc = MemExpr->getQualifierRange().getBegin(); 7879 Base = new (Context) CXXThisExpr(Loc, 7880 MemExpr->getBaseType(), 7881 /*isImplicit=*/true); 7882 } 7883 } else 7884 Base = MemExpr->getBase()->Retain(); 7885 7886 return MemberExpr::Create(Context, Base, 7887 MemExpr->isArrow(), 7888 MemExpr->getQualifier(), 7889 MemExpr->getQualifierRange(), 7890 Fn, 7891 Found, 7892 MemExpr->getMemberNameInfo(), 7893 TemplateArgs, 7894 Fn->getType()); 7895 } 7896 7897 assert(false && "Invalid reference to overloaded function"); 7898 return E->Retain(); 7899} 7900 7901ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 7902 DeclAccessPair Found, 7903 FunctionDecl *Fn) { 7904 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 7905} 7906 7907} // end namespace clang 7908