SemaOverload.cpp revision ff416d486f6e34c46d299be8aa054cc1d501cd36
1//===--- SemaOverload.cpp - C++ Overloading ---------------------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file provides Sema routines for C++ overloading. 11// 12//===----------------------------------------------------------------------===// 13 14#include "clang/Sema/SemaInternal.h" 15#include "clang/Sema/Lookup.h" 16#include "clang/Sema/Initialization.h" 17#include "clang/Sema/Template.h" 18#include "clang/Sema/TemplateDeduction.h" 19#include "clang/Basic/Diagnostic.h" 20#include "clang/Lex/Preprocessor.h" 21#include "clang/AST/ASTContext.h" 22#include "clang/AST/CXXInheritance.h" 23#include "clang/AST/DeclObjC.h" 24#include "clang/AST/Expr.h" 25#include "clang/AST/ExprCXX.h" 26#include "clang/AST/ExprObjC.h" 27#include "clang/AST/TypeOrdering.h" 28#include "clang/Basic/PartialDiagnostic.h" 29#include "llvm/ADT/DenseSet.h" 30#include "llvm/ADT/SmallPtrSet.h" 31#include "llvm/ADT/STLExtras.h" 32#include <algorithm> 33 34namespace clang { 35using namespace sema; 36 37/// A convenience routine for creating a decayed reference to a 38/// function. 39static ExprResult 40CreateFunctionRefExpr(Sema &S, FunctionDecl *Fn, bool HadMultipleCandidates, 41 SourceLocation Loc = SourceLocation(), 42 const DeclarationNameLoc &LocInfo = DeclarationNameLoc()){ 43 DeclRefExpr *DRE = new (S.Context) DeclRefExpr(Fn, Fn->getType(), 44 VK_LValue, Loc, LocInfo); 45 if (HadMultipleCandidates) 46 DRE->setHadMultipleCandidates(true); 47 ExprResult E = S.Owned(DRE); 48 E = S.DefaultFunctionArrayConversion(E.take()); 49 if (E.isInvalid()) 50 return ExprError(); 51 return move(E); 52} 53 54static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 55 bool InOverloadResolution, 56 StandardConversionSequence &SCS, 57 bool CStyle, 58 bool AllowObjCWritebackConversion); 59 60static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From, 61 QualType &ToType, 62 bool InOverloadResolution, 63 StandardConversionSequence &SCS, 64 bool CStyle); 65static OverloadingResult 66IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 67 UserDefinedConversionSequence& User, 68 OverloadCandidateSet& Conversions, 69 bool AllowExplicit); 70 71 72static ImplicitConversionSequence::CompareKind 73CompareStandardConversionSequences(Sema &S, 74 const StandardConversionSequence& SCS1, 75 const StandardConversionSequence& SCS2); 76 77static ImplicitConversionSequence::CompareKind 78CompareQualificationConversions(Sema &S, 79 const StandardConversionSequence& SCS1, 80 const StandardConversionSequence& SCS2); 81 82static ImplicitConversionSequence::CompareKind 83CompareDerivedToBaseConversions(Sema &S, 84 const StandardConversionSequence& SCS1, 85 const StandardConversionSequence& SCS2); 86 87 88 89/// GetConversionCategory - Retrieve the implicit conversion 90/// category corresponding to the given implicit conversion kind. 91ImplicitConversionCategory 92GetConversionCategory(ImplicitConversionKind Kind) { 93 static const ImplicitConversionCategory 94 Category[(int)ICK_Num_Conversion_Kinds] = { 95 ICC_Identity, 96 ICC_Lvalue_Transformation, 97 ICC_Lvalue_Transformation, 98 ICC_Lvalue_Transformation, 99 ICC_Identity, 100 ICC_Qualification_Adjustment, 101 ICC_Promotion, 102 ICC_Promotion, 103 ICC_Promotion, 104 ICC_Conversion, 105 ICC_Conversion, 106 ICC_Conversion, 107 ICC_Conversion, 108 ICC_Conversion, 109 ICC_Conversion, 110 ICC_Conversion, 111 ICC_Conversion, 112 ICC_Conversion, 113 ICC_Conversion, 114 ICC_Conversion, 115 ICC_Conversion, 116 ICC_Conversion 117 }; 118 return Category[(int)Kind]; 119} 120 121/// GetConversionRank - Retrieve the implicit conversion rank 122/// corresponding to the given implicit conversion kind. 123ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 124 static const ImplicitConversionRank 125 Rank[(int)ICK_Num_Conversion_Kinds] = { 126 ICR_Exact_Match, 127 ICR_Exact_Match, 128 ICR_Exact_Match, 129 ICR_Exact_Match, 130 ICR_Exact_Match, 131 ICR_Exact_Match, 132 ICR_Promotion, 133 ICR_Promotion, 134 ICR_Promotion, 135 ICR_Conversion, 136 ICR_Conversion, 137 ICR_Conversion, 138 ICR_Conversion, 139 ICR_Conversion, 140 ICR_Conversion, 141 ICR_Conversion, 142 ICR_Conversion, 143 ICR_Conversion, 144 ICR_Conversion, 145 ICR_Conversion, 146 ICR_Complex_Real_Conversion, 147 ICR_Conversion, 148 ICR_Conversion, 149 ICR_Writeback_Conversion 150 }; 151 return Rank[(int)Kind]; 152} 153 154/// GetImplicitConversionName - Return the name of this kind of 155/// implicit conversion. 156const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 157 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 158 "No conversion", 159 "Lvalue-to-rvalue", 160 "Array-to-pointer", 161 "Function-to-pointer", 162 "Noreturn adjustment", 163 "Qualification", 164 "Integral promotion", 165 "Floating point promotion", 166 "Complex promotion", 167 "Integral conversion", 168 "Floating conversion", 169 "Complex conversion", 170 "Floating-integral conversion", 171 "Pointer conversion", 172 "Pointer-to-member conversion", 173 "Boolean conversion", 174 "Compatible-types conversion", 175 "Derived-to-base conversion", 176 "Vector conversion", 177 "Vector splat", 178 "Complex-real conversion", 179 "Block Pointer conversion", 180 "Transparent Union Conversion" 181 "Writeback conversion" 182 }; 183 return Name[Kind]; 184} 185 186/// StandardConversionSequence - Set the standard conversion 187/// sequence to the identity conversion. 188void StandardConversionSequence::setAsIdentityConversion() { 189 First = ICK_Identity; 190 Second = ICK_Identity; 191 Third = ICK_Identity; 192 DeprecatedStringLiteralToCharPtr = false; 193 QualificationIncludesObjCLifetime = false; 194 ReferenceBinding = false; 195 DirectBinding = false; 196 IsLvalueReference = true; 197 BindsToFunctionLvalue = false; 198 BindsToRvalue = false; 199 BindsImplicitObjectArgumentWithoutRefQualifier = false; 200 ObjCLifetimeConversionBinding = false; 201 CopyConstructor = 0; 202} 203 204/// getRank - Retrieve the rank of this standard conversion sequence 205/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 206/// implicit conversions. 207ImplicitConversionRank StandardConversionSequence::getRank() const { 208 ImplicitConversionRank Rank = ICR_Exact_Match; 209 if (GetConversionRank(First) > Rank) 210 Rank = GetConversionRank(First); 211 if (GetConversionRank(Second) > Rank) 212 Rank = GetConversionRank(Second); 213 if (GetConversionRank(Third) > Rank) 214 Rank = GetConversionRank(Third); 215 return Rank; 216} 217 218/// isPointerConversionToBool - Determines whether this conversion is 219/// a conversion of a pointer or pointer-to-member to bool. This is 220/// used as part of the ranking of standard conversion sequences 221/// (C++ 13.3.3.2p4). 222bool StandardConversionSequence::isPointerConversionToBool() const { 223 // Note that FromType has not necessarily been transformed by the 224 // array-to-pointer or function-to-pointer implicit conversions, so 225 // check for their presence as well as checking whether FromType is 226 // a pointer. 227 if (getToType(1)->isBooleanType() && 228 (getFromType()->isPointerType() || 229 getFromType()->isObjCObjectPointerType() || 230 getFromType()->isBlockPointerType() || 231 getFromType()->isNullPtrType() || 232 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 233 return true; 234 235 return false; 236} 237 238/// isPointerConversionToVoidPointer - Determines whether this 239/// conversion is a conversion of a pointer to a void pointer. This is 240/// used as part of the ranking of standard conversion sequences (C++ 241/// 13.3.3.2p4). 242bool 243StandardConversionSequence:: 244isPointerConversionToVoidPointer(ASTContext& Context) const { 245 QualType FromType = getFromType(); 246 QualType ToType = getToType(1); 247 248 // Note that FromType has not necessarily been transformed by the 249 // array-to-pointer implicit conversion, so check for its presence 250 // and redo the conversion to get a pointer. 251 if (First == ICK_Array_To_Pointer) 252 FromType = Context.getArrayDecayedType(FromType); 253 254 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType()) 255 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 256 return ToPtrType->getPointeeType()->isVoidType(); 257 258 return false; 259} 260 261/// DebugPrint - Print this standard conversion sequence to standard 262/// error. Useful for debugging overloading issues. 263void StandardConversionSequence::DebugPrint() const { 264 raw_ostream &OS = llvm::errs(); 265 bool PrintedSomething = false; 266 if (First != ICK_Identity) { 267 OS << GetImplicitConversionName(First); 268 PrintedSomething = true; 269 } 270 271 if (Second != ICK_Identity) { 272 if (PrintedSomething) { 273 OS << " -> "; 274 } 275 OS << GetImplicitConversionName(Second); 276 277 if (CopyConstructor) { 278 OS << " (by copy constructor)"; 279 } else if (DirectBinding) { 280 OS << " (direct reference binding)"; 281 } else if (ReferenceBinding) { 282 OS << " (reference binding)"; 283 } 284 PrintedSomething = true; 285 } 286 287 if (Third != ICK_Identity) { 288 if (PrintedSomething) { 289 OS << " -> "; 290 } 291 OS << GetImplicitConversionName(Third); 292 PrintedSomething = true; 293 } 294 295 if (!PrintedSomething) { 296 OS << "No conversions required"; 297 } 298} 299 300/// DebugPrint - Print this user-defined conversion sequence to standard 301/// error. Useful for debugging overloading issues. 302void UserDefinedConversionSequence::DebugPrint() const { 303 raw_ostream &OS = llvm::errs(); 304 if (Before.First || Before.Second || Before.Third) { 305 Before.DebugPrint(); 306 OS << " -> "; 307 } 308 if (ConversionFunction) 309 OS << '\'' << *ConversionFunction << '\''; 310 else 311 OS << "aggregate initialization"; 312 if (After.First || After.Second || After.Third) { 313 OS << " -> "; 314 After.DebugPrint(); 315 } 316} 317 318/// DebugPrint - Print this implicit conversion sequence to standard 319/// error. Useful for debugging overloading issues. 320void ImplicitConversionSequence::DebugPrint() const { 321 raw_ostream &OS = llvm::errs(); 322 switch (ConversionKind) { 323 case StandardConversion: 324 OS << "Standard conversion: "; 325 Standard.DebugPrint(); 326 break; 327 case UserDefinedConversion: 328 OS << "User-defined conversion: "; 329 UserDefined.DebugPrint(); 330 break; 331 case EllipsisConversion: 332 OS << "Ellipsis conversion"; 333 break; 334 case AmbiguousConversion: 335 OS << "Ambiguous conversion"; 336 break; 337 case BadConversion: 338 OS << "Bad conversion"; 339 break; 340 } 341 342 OS << "\n"; 343} 344 345void AmbiguousConversionSequence::construct() { 346 new (&conversions()) ConversionSet(); 347} 348 349void AmbiguousConversionSequence::destruct() { 350 conversions().~ConversionSet(); 351} 352 353void 354AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 355 FromTypePtr = O.FromTypePtr; 356 ToTypePtr = O.ToTypePtr; 357 new (&conversions()) ConversionSet(O.conversions()); 358} 359 360namespace { 361 // Structure used by OverloadCandidate::DeductionFailureInfo to store 362 // template parameter and template argument information. 363 struct DFIParamWithArguments { 364 TemplateParameter Param; 365 TemplateArgument FirstArg; 366 TemplateArgument SecondArg; 367 }; 368} 369 370/// \brief Convert from Sema's representation of template deduction information 371/// to the form used in overload-candidate information. 372OverloadCandidate::DeductionFailureInfo 373static MakeDeductionFailureInfo(ASTContext &Context, 374 Sema::TemplateDeductionResult TDK, 375 TemplateDeductionInfo &Info) { 376 OverloadCandidate::DeductionFailureInfo Result; 377 Result.Result = static_cast<unsigned>(TDK); 378 Result.Data = 0; 379 switch (TDK) { 380 case Sema::TDK_Success: 381 case Sema::TDK_InstantiationDepth: 382 case Sema::TDK_TooManyArguments: 383 case Sema::TDK_TooFewArguments: 384 break; 385 386 case Sema::TDK_Incomplete: 387 case Sema::TDK_InvalidExplicitArguments: 388 Result.Data = Info.Param.getOpaqueValue(); 389 break; 390 391 case Sema::TDK_Inconsistent: 392 case Sema::TDK_Underqualified: { 393 // FIXME: Should allocate from normal heap so that we can free this later. 394 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 395 Saved->Param = Info.Param; 396 Saved->FirstArg = Info.FirstArg; 397 Saved->SecondArg = Info.SecondArg; 398 Result.Data = Saved; 399 break; 400 } 401 402 case Sema::TDK_SubstitutionFailure: 403 Result.Data = Info.take(); 404 break; 405 406 case Sema::TDK_NonDeducedMismatch: 407 case Sema::TDK_FailedOverloadResolution: 408 break; 409 } 410 411 return Result; 412} 413 414void OverloadCandidate::DeductionFailureInfo::Destroy() { 415 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 416 case Sema::TDK_Success: 417 case Sema::TDK_InstantiationDepth: 418 case Sema::TDK_Incomplete: 419 case Sema::TDK_TooManyArguments: 420 case Sema::TDK_TooFewArguments: 421 case Sema::TDK_InvalidExplicitArguments: 422 break; 423 424 case Sema::TDK_Inconsistent: 425 case Sema::TDK_Underqualified: 426 // FIXME: Destroy the data? 427 Data = 0; 428 break; 429 430 case Sema::TDK_SubstitutionFailure: 431 // FIXME: Destroy the template arugment list? 432 Data = 0; 433 break; 434 435 // Unhandled 436 case Sema::TDK_NonDeducedMismatch: 437 case Sema::TDK_FailedOverloadResolution: 438 break; 439 } 440} 441 442TemplateParameter 443OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 444 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 445 case Sema::TDK_Success: 446 case Sema::TDK_InstantiationDepth: 447 case Sema::TDK_TooManyArguments: 448 case Sema::TDK_TooFewArguments: 449 case Sema::TDK_SubstitutionFailure: 450 return TemplateParameter(); 451 452 case Sema::TDK_Incomplete: 453 case Sema::TDK_InvalidExplicitArguments: 454 return TemplateParameter::getFromOpaqueValue(Data); 455 456 case Sema::TDK_Inconsistent: 457 case Sema::TDK_Underqualified: 458 return static_cast<DFIParamWithArguments*>(Data)->Param; 459 460 // Unhandled 461 case Sema::TDK_NonDeducedMismatch: 462 case Sema::TDK_FailedOverloadResolution: 463 break; 464 } 465 466 return TemplateParameter(); 467} 468 469TemplateArgumentList * 470OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 471 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 472 case Sema::TDK_Success: 473 case Sema::TDK_InstantiationDepth: 474 case Sema::TDK_TooManyArguments: 475 case Sema::TDK_TooFewArguments: 476 case Sema::TDK_Incomplete: 477 case Sema::TDK_InvalidExplicitArguments: 478 case Sema::TDK_Inconsistent: 479 case Sema::TDK_Underqualified: 480 return 0; 481 482 case Sema::TDK_SubstitutionFailure: 483 return static_cast<TemplateArgumentList*>(Data); 484 485 // Unhandled 486 case Sema::TDK_NonDeducedMismatch: 487 case Sema::TDK_FailedOverloadResolution: 488 break; 489 } 490 491 return 0; 492} 493 494const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 495 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 496 case Sema::TDK_Success: 497 case Sema::TDK_InstantiationDepth: 498 case Sema::TDK_Incomplete: 499 case Sema::TDK_TooManyArguments: 500 case Sema::TDK_TooFewArguments: 501 case Sema::TDK_InvalidExplicitArguments: 502 case Sema::TDK_SubstitutionFailure: 503 return 0; 504 505 case Sema::TDK_Inconsistent: 506 case Sema::TDK_Underqualified: 507 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 508 509 // Unhandled 510 case Sema::TDK_NonDeducedMismatch: 511 case Sema::TDK_FailedOverloadResolution: 512 break; 513 } 514 515 return 0; 516} 517 518const TemplateArgument * 519OverloadCandidate::DeductionFailureInfo::getSecondArg() { 520 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 521 case Sema::TDK_Success: 522 case Sema::TDK_InstantiationDepth: 523 case Sema::TDK_Incomplete: 524 case Sema::TDK_TooManyArguments: 525 case Sema::TDK_TooFewArguments: 526 case Sema::TDK_InvalidExplicitArguments: 527 case Sema::TDK_SubstitutionFailure: 528 return 0; 529 530 case Sema::TDK_Inconsistent: 531 case Sema::TDK_Underqualified: 532 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 533 534 // Unhandled 535 case Sema::TDK_NonDeducedMismatch: 536 case Sema::TDK_FailedOverloadResolution: 537 break; 538 } 539 540 return 0; 541} 542 543void OverloadCandidateSet::clear() { 544 inherited::clear(); 545 Functions.clear(); 546} 547 548namespace { 549 class UnbridgedCastsSet { 550 struct Entry { 551 Expr **Addr; 552 Expr *Saved; 553 }; 554 SmallVector<Entry, 2> Entries; 555 556 public: 557 void save(Sema &S, Expr *&E) { 558 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)); 559 Entry entry = { &E, E }; 560 Entries.push_back(entry); 561 E = S.stripARCUnbridgedCast(E); 562 } 563 564 void restore() { 565 for (SmallVectorImpl<Entry>::iterator 566 i = Entries.begin(), e = Entries.end(); i != e; ++i) 567 *i->Addr = i->Saved; 568 } 569 }; 570} 571 572/// checkPlaceholderForOverload - Do any interesting placeholder-like 573/// preprocessing on the given expression. 574/// 575/// \param unbridgedCasts a collection to which to add unbridged casts; 576/// without this, they will be immediately diagnosed as errors 577/// 578/// Return true on unrecoverable error. 579static bool checkPlaceholderForOverload(Sema &S, Expr *&E, 580 UnbridgedCastsSet *unbridgedCasts = 0) { 581 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) { 582 // We can't handle overloaded expressions here because overload 583 // resolution might reasonably tweak them. 584 if (placeholder->getKind() == BuiltinType::Overload) return false; 585 586 // If the context potentially accepts unbridged ARC casts, strip 587 // the unbridged cast and add it to the collection for later restoration. 588 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast && 589 unbridgedCasts) { 590 unbridgedCasts->save(S, E); 591 return false; 592 } 593 594 // Go ahead and check everything else. 595 ExprResult result = S.CheckPlaceholderExpr(E); 596 if (result.isInvalid()) 597 return true; 598 599 E = result.take(); 600 return false; 601 } 602 603 // Nothing to do. 604 return false; 605} 606 607/// checkArgPlaceholdersForOverload - Check a set of call operands for 608/// placeholders. 609static bool checkArgPlaceholdersForOverload(Sema &S, Expr **args, 610 unsigned numArgs, 611 UnbridgedCastsSet &unbridged) { 612 for (unsigned i = 0; i != numArgs; ++i) 613 if (checkPlaceholderForOverload(S, args[i], &unbridged)) 614 return true; 615 616 return false; 617} 618 619// IsOverload - Determine whether the given New declaration is an 620// overload of the declarations in Old. This routine returns false if 621// New and Old cannot be overloaded, e.g., if New has the same 622// signature as some function in Old (C++ 1.3.10) or if the Old 623// declarations aren't functions (or function templates) at all. When 624// it does return false, MatchedDecl will point to the decl that New 625// cannot be overloaded with. This decl may be a UsingShadowDecl on 626// top of the underlying declaration. 627// 628// Example: Given the following input: 629// 630// void f(int, float); // #1 631// void f(int, int); // #2 632// int f(int, int); // #3 633// 634// When we process #1, there is no previous declaration of "f", 635// so IsOverload will not be used. 636// 637// When we process #2, Old contains only the FunctionDecl for #1. By 638// comparing the parameter types, we see that #1 and #2 are overloaded 639// (since they have different signatures), so this routine returns 640// false; MatchedDecl is unchanged. 641// 642// When we process #3, Old is an overload set containing #1 and #2. We 643// compare the signatures of #3 to #1 (they're overloaded, so we do 644// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 645// identical (return types of functions are not part of the 646// signature), IsOverload returns false and MatchedDecl will be set to 647// point to the FunctionDecl for #2. 648// 649// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 650// into a class by a using declaration. The rules for whether to hide 651// shadow declarations ignore some properties which otherwise figure 652// into a function template's signature. 653Sema::OverloadKind 654Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 655 NamedDecl *&Match, bool NewIsUsingDecl) { 656 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 657 I != E; ++I) { 658 NamedDecl *OldD = *I; 659 660 bool OldIsUsingDecl = false; 661 if (isa<UsingShadowDecl>(OldD)) { 662 OldIsUsingDecl = true; 663 664 // We can always introduce two using declarations into the same 665 // context, even if they have identical signatures. 666 if (NewIsUsingDecl) continue; 667 668 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 669 } 670 671 // If either declaration was introduced by a using declaration, 672 // we'll need to use slightly different rules for matching. 673 // Essentially, these rules are the normal rules, except that 674 // function templates hide function templates with different 675 // return types or template parameter lists. 676 bool UseMemberUsingDeclRules = 677 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 678 679 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 680 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 681 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 682 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 683 continue; 684 } 685 686 Match = *I; 687 return Ovl_Match; 688 } 689 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 690 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 691 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 692 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 693 continue; 694 } 695 696 Match = *I; 697 return Ovl_Match; 698 } 699 } else if (isa<UsingDecl>(OldD)) { 700 // We can overload with these, which can show up when doing 701 // redeclaration checks for UsingDecls. 702 assert(Old.getLookupKind() == LookupUsingDeclName); 703 } else if (isa<TagDecl>(OldD)) { 704 // We can always overload with tags by hiding them. 705 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 706 // Optimistically assume that an unresolved using decl will 707 // overload; if it doesn't, we'll have to diagnose during 708 // template instantiation. 709 } else { 710 // (C++ 13p1): 711 // Only function declarations can be overloaded; object and type 712 // declarations cannot be overloaded. 713 Match = *I; 714 return Ovl_NonFunction; 715 } 716 } 717 718 return Ovl_Overload; 719} 720 721bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 722 bool UseUsingDeclRules) { 723 // If both of the functions are extern "C", then they are not 724 // overloads. 725 if (Old->isExternC() && New->isExternC()) 726 return false; 727 728 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 729 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 730 731 // C++ [temp.fct]p2: 732 // A function template can be overloaded with other function templates 733 // and with normal (non-template) functions. 734 if ((OldTemplate == 0) != (NewTemplate == 0)) 735 return true; 736 737 // Is the function New an overload of the function Old? 738 QualType OldQType = Context.getCanonicalType(Old->getType()); 739 QualType NewQType = Context.getCanonicalType(New->getType()); 740 741 // Compare the signatures (C++ 1.3.10) of the two functions to 742 // determine whether they are overloads. If we find any mismatch 743 // in the signature, they are overloads. 744 745 // If either of these functions is a K&R-style function (no 746 // prototype), then we consider them to have matching signatures. 747 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 748 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 749 return false; 750 751 const FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 752 const FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 753 754 // The signature of a function includes the types of its 755 // parameters (C++ 1.3.10), which includes the presence or absence 756 // of the ellipsis; see C++ DR 357). 757 if (OldQType != NewQType && 758 (OldType->getNumArgs() != NewType->getNumArgs() || 759 OldType->isVariadic() != NewType->isVariadic() || 760 !FunctionArgTypesAreEqual(OldType, NewType))) 761 return true; 762 763 // C++ [temp.over.link]p4: 764 // The signature of a function template consists of its function 765 // signature, its return type and its template parameter list. The names 766 // of the template parameters are significant only for establishing the 767 // relationship between the template parameters and the rest of the 768 // signature. 769 // 770 // We check the return type and template parameter lists for function 771 // templates first; the remaining checks follow. 772 // 773 // However, we don't consider either of these when deciding whether 774 // a member introduced by a shadow declaration is hidden. 775 if (!UseUsingDeclRules && NewTemplate && 776 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 777 OldTemplate->getTemplateParameters(), 778 false, TPL_TemplateMatch) || 779 OldType->getResultType() != NewType->getResultType())) 780 return true; 781 782 // If the function is a class member, its signature includes the 783 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. 784 // 785 // As part of this, also check whether one of the member functions 786 // is static, in which case they are not overloads (C++ 787 // 13.1p2). While not part of the definition of the signature, 788 // this check is important to determine whether these functions 789 // can be overloaded. 790 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 791 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 792 if (OldMethod && NewMethod && 793 !OldMethod->isStatic() && !NewMethod->isStatic() && 794 (OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers() || 795 OldMethod->getRefQualifier() != NewMethod->getRefQualifier())) { 796 if (!UseUsingDeclRules && 797 OldMethod->getRefQualifier() != NewMethod->getRefQualifier() && 798 (OldMethod->getRefQualifier() == RQ_None || 799 NewMethod->getRefQualifier() == RQ_None)) { 800 // C++0x [over.load]p2: 801 // - Member function declarations with the same name and the same 802 // parameter-type-list as well as member function template 803 // declarations with the same name, the same parameter-type-list, and 804 // the same template parameter lists cannot be overloaded if any of 805 // them, but not all, have a ref-qualifier (8.3.5). 806 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) 807 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); 808 Diag(OldMethod->getLocation(), diag::note_previous_declaration); 809 } 810 811 return true; 812 } 813 814 // The signatures match; this is not an overload. 815 return false; 816} 817 818/// \brief Checks availability of the function depending on the current 819/// function context. Inside an unavailable function, unavailability is ignored. 820/// 821/// \returns true if \arg FD is unavailable and current context is inside 822/// an available function, false otherwise. 823bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) { 824 return FD->isUnavailable() && !cast<Decl>(CurContext)->isUnavailable(); 825} 826 827/// TryImplicitConversion - Attempt to perform an implicit conversion 828/// from the given expression (Expr) to the given type (ToType). This 829/// function returns an implicit conversion sequence that can be used 830/// to perform the initialization. Given 831/// 832/// void f(float f); 833/// void g(int i) { f(i); } 834/// 835/// this routine would produce an implicit conversion sequence to 836/// describe the initialization of f from i, which will be a standard 837/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 838/// 4.1) followed by a floating-integral conversion (C++ 4.9). 839// 840/// Note that this routine only determines how the conversion can be 841/// performed; it does not actually perform the conversion. As such, 842/// it will not produce any diagnostics if no conversion is available, 843/// but will instead return an implicit conversion sequence of kind 844/// "BadConversion". 845/// 846/// If @p SuppressUserConversions, then user-defined conversions are 847/// not permitted. 848/// If @p AllowExplicit, then explicit user-defined conversions are 849/// permitted. 850/// 851/// \param AllowObjCWritebackConversion Whether we allow the Objective-C 852/// writeback conversion, which allows __autoreleasing id* parameters to 853/// be initialized with __strong id* or __weak id* arguments. 854static ImplicitConversionSequence 855TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 856 bool SuppressUserConversions, 857 bool AllowExplicit, 858 bool InOverloadResolution, 859 bool CStyle, 860 bool AllowObjCWritebackConversion) { 861 ImplicitConversionSequence ICS; 862 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 863 ICS.Standard, CStyle, AllowObjCWritebackConversion)){ 864 ICS.setStandard(); 865 return ICS; 866 } 867 868 if (!S.getLangOptions().CPlusPlus) { 869 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 870 return ICS; 871 } 872 873 // C++ [over.ics.user]p4: 874 // A conversion of an expression of class type to the same class 875 // type is given Exact Match rank, and a conversion of an 876 // expression of class type to a base class of that type is 877 // given Conversion rank, in spite of the fact that a copy/move 878 // constructor (i.e., a user-defined conversion function) is 879 // called for those cases. 880 QualType FromType = From->getType(); 881 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 882 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 883 S.IsDerivedFrom(FromType, ToType))) { 884 ICS.setStandard(); 885 ICS.Standard.setAsIdentityConversion(); 886 ICS.Standard.setFromType(FromType); 887 ICS.Standard.setAllToTypes(ToType); 888 889 // We don't actually check at this point whether there is a valid 890 // copy/move constructor, since overloading just assumes that it 891 // exists. When we actually perform initialization, we'll find the 892 // appropriate constructor to copy the returned object, if needed. 893 ICS.Standard.CopyConstructor = 0; 894 895 // Determine whether this is considered a derived-to-base conversion. 896 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 897 ICS.Standard.Second = ICK_Derived_To_Base; 898 899 return ICS; 900 } 901 902 if (SuppressUserConversions) { 903 // We're not in the case above, so there is no conversion that 904 // we can perform. 905 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 906 return ICS; 907 } 908 909 // Attempt user-defined conversion. 910 OverloadCandidateSet Conversions(From->getExprLoc()); 911 OverloadingResult UserDefResult 912 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 913 AllowExplicit); 914 915 if (UserDefResult == OR_Success) { 916 ICS.setUserDefined(); 917 // C++ [over.ics.user]p4: 918 // A conversion of an expression of class type to the same class 919 // type is given Exact Match rank, and a conversion of an 920 // expression of class type to a base class of that type is 921 // given Conversion rank, in spite of the fact that a copy 922 // constructor (i.e., a user-defined conversion function) is 923 // called for those cases. 924 if (CXXConstructorDecl *Constructor 925 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 926 QualType FromCanon 927 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 928 QualType ToCanon 929 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 930 if (Constructor->isCopyConstructor() && 931 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 932 // Turn this into a "standard" conversion sequence, so that it 933 // gets ranked with standard conversion sequences. 934 ICS.setStandard(); 935 ICS.Standard.setAsIdentityConversion(); 936 ICS.Standard.setFromType(From->getType()); 937 ICS.Standard.setAllToTypes(ToType); 938 ICS.Standard.CopyConstructor = Constructor; 939 if (ToCanon != FromCanon) 940 ICS.Standard.Second = ICK_Derived_To_Base; 941 } 942 } 943 944 // C++ [over.best.ics]p4: 945 // However, when considering the argument of a user-defined 946 // conversion function that is a candidate by 13.3.1.3 when 947 // invoked for the copying of the temporary in the second step 948 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 949 // 13.3.1.6 in all cases, only standard conversion sequences and 950 // ellipsis conversion sequences are allowed. 951 if (SuppressUserConversions && ICS.isUserDefined()) { 952 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 953 } 954 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 955 ICS.setAmbiguous(); 956 ICS.Ambiguous.setFromType(From->getType()); 957 ICS.Ambiguous.setToType(ToType); 958 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 959 Cand != Conversions.end(); ++Cand) 960 if (Cand->Viable) 961 ICS.Ambiguous.addConversion(Cand->Function); 962 } else { 963 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 964 } 965 966 return ICS; 967} 968 969ImplicitConversionSequence 970Sema::TryImplicitConversion(Expr *From, QualType ToType, 971 bool SuppressUserConversions, 972 bool AllowExplicit, 973 bool InOverloadResolution, 974 bool CStyle, 975 bool AllowObjCWritebackConversion) { 976 return clang::TryImplicitConversion(*this, From, ToType, 977 SuppressUserConversions, AllowExplicit, 978 InOverloadResolution, CStyle, 979 AllowObjCWritebackConversion); 980} 981 982/// PerformImplicitConversion - Perform an implicit conversion of the 983/// expression From to the type ToType. Returns the 984/// converted expression. Flavor is the kind of conversion we're 985/// performing, used in the error message. If @p AllowExplicit, 986/// explicit user-defined conversions are permitted. 987ExprResult 988Sema::PerformImplicitConversion(Expr *From, QualType ToType, 989 AssignmentAction Action, bool AllowExplicit) { 990 ImplicitConversionSequence ICS; 991 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 992} 993 994ExprResult 995Sema::PerformImplicitConversion(Expr *From, QualType ToType, 996 AssignmentAction Action, bool AllowExplicit, 997 ImplicitConversionSequence& ICS) { 998 if (checkPlaceholderForOverload(*this, From)) 999 return ExprError(); 1000 1001 // Objective-C ARC: Determine whether we will allow the writeback conversion. 1002 bool AllowObjCWritebackConversion 1003 = getLangOptions().ObjCAutoRefCount && 1004 (Action == AA_Passing || Action == AA_Sending); 1005 1006 ICS = clang::TryImplicitConversion(*this, From, ToType, 1007 /*SuppressUserConversions=*/false, 1008 AllowExplicit, 1009 /*InOverloadResolution=*/false, 1010 /*CStyle=*/false, 1011 AllowObjCWritebackConversion); 1012 return PerformImplicitConversion(From, ToType, ICS, Action); 1013} 1014 1015/// \brief Determine whether the conversion from FromType to ToType is a valid 1016/// conversion that strips "noreturn" off the nested function type. 1017bool Sema::IsNoReturnConversion(QualType FromType, QualType ToType, 1018 QualType &ResultTy) { 1019 if (Context.hasSameUnqualifiedType(FromType, ToType)) 1020 return false; 1021 1022 // Permit the conversion F(t __attribute__((noreturn))) -> F(t) 1023 // where F adds one of the following at most once: 1024 // - a pointer 1025 // - a member pointer 1026 // - a block pointer 1027 CanQualType CanTo = Context.getCanonicalType(ToType); 1028 CanQualType CanFrom = Context.getCanonicalType(FromType); 1029 Type::TypeClass TyClass = CanTo->getTypeClass(); 1030 if (TyClass != CanFrom->getTypeClass()) return false; 1031 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { 1032 if (TyClass == Type::Pointer) { 1033 CanTo = CanTo.getAs<PointerType>()->getPointeeType(); 1034 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType(); 1035 } else if (TyClass == Type::BlockPointer) { 1036 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType(); 1037 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType(); 1038 } else if (TyClass == Type::MemberPointer) { 1039 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType(); 1040 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType(); 1041 } else { 1042 return false; 1043 } 1044 1045 TyClass = CanTo->getTypeClass(); 1046 if (TyClass != CanFrom->getTypeClass()) return false; 1047 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) 1048 return false; 1049 } 1050 1051 const FunctionType *FromFn = cast<FunctionType>(CanFrom); 1052 FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); 1053 if (!EInfo.getNoReturn()) return false; 1054 1055 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); 1056 assert(QualType(FromFn, 0).isCanonical()); 1057 if (QualType(FromFn, 0) != CanTo) return false; 1058 1059 ResultTy = ToType; 1060 return true; 1061} 1062 1063/// \brief Determine whether the conversion from FromType to ToType is a valid 1064/// vector conversion. 1065/// 1066/// \param ICK Will be set to the vector conversion kind, if this is a vector 1067/// conversion. 1068static bool IsVectorConversion(ASTContext &Context, QualType FromType, 1069 QualType ToType, ImplicitConversionKind &ICK) { 1070 // We need at least one of these types to be a vector type to have a vector 1071 // conversion. 1072 if (!ToType->isVectorType() && !FromType->isVectorType()) 1073 return false; 1074 1075 // Identical types require no conversions. 1076 if (Context.hasSameUnqualifiedType(FromType, ToType)) 1077 return false; 1078 1079 // There are no conversions between extended vector types, only identity. 1080 if (ToType->isExtVectorType()) { 1081 // There are no conversions between extended vector types other than the 1082 // identity conversion. 1083 if (FromType->isExtVectorType()) 1084 return false; 1085 1086 // Vector splat from any arithmetic type to a vector. 1087 if (FromType->isArithmeticType()) { 1088 ICK = ICK_Vector_Splat; 1089 return true; 1090 } 1091 } 1092 1093 // We can perform the conversion between vector types in the following cases: 1094 // 1)vector types are equivalent AltiVec and GCC vector types 1095 // 2)lax vector conversions are permitted and the vector types are of the 1096 // same size 1097 if (ToType->isVectorType() && FromType->isVectorType()) { 1098 if (Context.areCompatibleVectorTypes(FromType, ToType) || 1099 (Context.getLangOptions().LaxVectorConversions && 1100 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 1101 ICK = ICK_Vector_Conversion; 1102 return true; 1103 } 1104 } 1105 1106 return false; 1107} 1108 1109/// IsStandardConversion - Determines whether there is a standard 1110/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 1111/// expression From to the type ToType. Standard conversion sequences 1112/// only consider non-class types; for conversions that involve class 1113/// types, use TryImplicitConversion. If a conversion exists, SCS will 1114/// contain the standard conversion sequence required to perform this 1115/// conversion and this routine will return true. Otherwise, this 1116/// routine will return false and the value of SCS is unspecified. 1117static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 1118 bool InOverloadResolution, 1119 StandardConversionSequence &SCS, 1120 bool CStyle, 1121 bool AllowObjCWritebackConversion) { 1122 QualType FromType = From->getType(); 1123 1124 // Standard conversions (C++ [conv]) 1125 SCS.setAsIdentityConversion(); 1126 SCS.DeprecatedStringLiteralToCharPtr = false; 1127 SCS.IncompatibleObjC = false; 1128 SCS.setFromType(FromType); 1129 SCS.CopyConstructor = 0; 1130 1131 // There are no standard conversions for class types in C++, so 1132 // abort early. When overloading in C, however, we do permit 1133 if (FromType->isRecordType() || ToType->isRecordType()) { 1134 if (S.getLangOptions().CPlusPlus) 1135 return false; 1136 1137 // When we're overloading in C, we allow, as standard conversions, 1138 } 1139 1140 // The first conversion can be an lvalue-to-rvalue conversion, 1141 // array-to-pointer conversion, or function-to-pointer conversion 1142 // (C++ 4p1). 1143 1144 if (FromType == S.Context.OverloadTy) { 1145 DeclAccessPair AccessPair; 1146 if (FunctionDecl *Fn 1147 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 1148 AccessPair)) { 1149 // We were able to resolve the address of the overloaded function, 1150 // so we can convert to the type of that function. 1151 FromType = Fn->getType(); 1152 1153 // we can sometimes resolve &foo<int> regardless of ToType, so check 1154 // if the type matches (identity) or we are converting to bool 1155 if (!S.Context.hasSameUnqualifiedType( 1156 S.ExtractUnqualifiedFunctionType(ToType), FromType)) { 1157 QualType resultTy; 1158 // if the function type matches except for [[noreturn]], it's ok 1159 if (!S.IsNoReturnConversion(FromType, 1160 S.ExtractUnqualifiedFunctionType(ToType), resultTy)) 1161 // otherwise, only a boolean conversion is standard 1162 if (!ToType->isBooleanType()) 1163 return false; 1164 } 1165 1166 // Check if the "from" expression is taking the address of an overloaded 1167 // function and recompute the FromType accordingly. Take advantage of the 1168 // fact that non-static member functions *must* have such an address-of 1169 // expression. 1170 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn); 1171 if (Method && !Method->isStatic()) { 1172 assert(isa<UnaryOperator>(From->IgnoreParens()) && 1173 "Non-unary operator on non-static member address"); 1174 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() 1175 == UO_AddrOf && 1176 "Non-address-of operator on non-static member address"); 1177 const Type *ClassType 1178 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1179 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1180 } else if (isa<UnaryOperator>(From->IgnoreParens())) { 1181 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == 1182 UO_AddrOf && 1183 "Non-address-of operator for overloaded function expression"); 1184 FromType = S.Context.getPointerType(FromType); 1185 } 1186 1187 // Check that we've computed the proper type after overload resolution. 1188 assert(S.Context.hasSameType( 1189 FromType, 1190 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1191 } else { 1192 return false; 1193 } 1194 } 1195 // Lvalue-to-rvalue conversion (C++11 4.1): 1196 // A glvalue (3.10) of a non-function, non-array type T can 1197 // be converted to a prvalue. 1198 bool argIsLValue = From->isGLValue(); 1199 if (argIsLValue && 1200 !FromType->isFunctionType() && !FromType->isArrayType() && 1201 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1202 SCS.First = ICK_Lvalue_To_Rvalue; 1203 1204 // If T is a non-class type, the type of the rvalue is the 1205 // cv-unqualified version of T. Otherwise, the type of the rvalue 1206 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1207 // just strip the qualifiers because they don't matter. 1208 FromType = FromType.getUnqualifiedType(); 1209 } else if (FromType->isArrayType()) { 1210 // Array-to-pointer conversion (C++ 4.2) 1211 SCS.First = ICK_Array_To_Pointer; 1212 1213 // An lvalue or rvalue of type "array of N T" or "array of unknown 1214 // bound of T" can be converted to an rvalue of type "pointer to 1215 // T" (C++ 4.2p1). 1216 FromType = S.Context.getArrayDecayedType(FromType); 1217 1218 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1219 // This conversion is deprecated. (C++ D.4). 1220 SCS.DeprecatedStringLiteralToCharPtr = true; 1221 1222 // For the purpose of ranking in overload resolution 1223 // (13.3.3.1.1), this conversion is considered an 1224 // array-to-pointer conversion followed by a qualification 1225 // conversion (4.4). (C++ 4.2p2) 1226 SCS.Second = ICK_Identity; 1227 SCS.Third = ICK_Qualification; 1228 SCS.QualificationIncludesObjCLifetime = false; 1229 SCS.setAllToTypes(FromType); 1230 return true; 1231 } 1232 } else if (FromType->isFunctionType() && argIsLValue) { 1233 // Function-to-pointer conversion (C++ 4.3). 1234 SCS.First = ICK_Function_To_Pointer; 1235 1236 // An lvalue of function type T can be converted to an rvalue of 1237 // type "pointer to T." The result is a pointer to the 1238 // function. (C++ 4.3p1). 1239 FromType = S.Context.getPointerType(FromType); 1240 } else { 1241 // We don't require any conversions for the first step. 1242 SCS.First = ICK_Identity; 1243 } 1244 SCS.setToType(0, FromType); 1245 1246 // The second conversion can be an integral promotion, floating 1247 // point promotion, integral conversion, floating point conversion, 1248 // floating-integral conversion, pointer conversion, 1249 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1250 // For overloading in C, this can also be a "compatible-type" 1251 // conversion. 1252 bool IncompatibleObjC = false; 1253 ImplicitConversionKind SecondICK = ICK_Identity; 1254 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1255 // The unqualified versions of the types are the same: there's no 1256 // conversion to do. 1257 SCS.Second = ICK_Identity; 1258 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1259 // Integral promotion (C++ 4.5). 1260 SCS.Second = ICK_Integral_Promotion; 1261 FromType = ToType.getUnqualifiedType(); 1262 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1263 // Floating point promotion (C++ 4.6). 1264 SCS.Second = ICK_Floating_Promotion; 1265 FromType = ToType.getUnqualifiedType(); 1266 } else if (S.IsComplexPromotion(FromType, ToType)) { 1267 // Complex promotion (Clang extension) 1268 SCS.Second = ICK_Complex_Promotion; 1269 FromType = ToType.getUnqualifiedType(); 1270 } else if (ToType->isBooleanType() && 1271 (FromType->isArithmeticType() || 1272 FromType->isAnyPointerType() || 1273 FromType->isBlockPointerType() || 1274 FromType->isMemberPointerType() || 1275 FromType->isNullPtrType())) { 1276 // Boolean conversions (C++ 4.12). 1277 SCS.Second = ICK_Boolean_Conversion; 1278 FromType = S.Context.BoolTy; 1279 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1280 ToType->isIntegralType(S.Context)) { 1281 // Integral conversions (C++ 4.7). 1282 SCS.Second = ICK_Integral_Conversion; 1283 FromType = ToType.getUnqualifiedType(); 1284 } else if (FromType->isAnyComplexType() && ToType->isComplexType()) { 1285 // Complex conversions (C99 6.3.1.6) 1286 SCS.Second = ICK_Complex_Conversion; 1287 FromType = ToType.getUnqualifiedType(); 1288 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1289 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1290 // Complex-real conversions (C99 6.3.1.7) 1291 SCS.Second = ICK_Complex_Real; 1292 FromType = ToType.getUnqualifiedType(); 1293 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1294 // Floating point conversions (C++ 4.8). 1295 SCS.Second = ICK_Floating_Conversion; 1296 FromType = ToType.getUnqualifiedType(); 1297 } else if ((FromType->isRealFloatingType() && 1298 ToType->isIntegralType(S.Context)) || 1299 (FromType->isIntegralOrUnscopedEnumerationType() && 1300 ToType->isRealFloatingType())) { 1301 // Floating-integral conversions (C++ 4.9). 1302 SCS.Second = ICK_Floating_Integral; 1303 FromType = ToType.getUnqualifiedType(); 1304 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { 1305 SCS.Second = ICK_Block_Pointer_Conversion; 1306 } else if (AllowObjCWritebackConversion && 1307 S.isObjCWritebackConversion(FromType, ToType, FromType)) { 1308 SCS.Second = ICK_Writeback_Conversion; 1309 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1310 FromType, IncompatibleObjC)) { 1311 // Pointer conversions (C++ 4.10). 1312 SCS.Second = ICK_Pointer_Conversion; 1313 SCS.IncompatibleObjC = IncompatibleObjC; 1314 FromType = FromType.getUnqualifiedType(); 1315 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1316 InOverloadResolution, FromType)) { 1317 // Pointer to member conversions (4.11). 1318 SCS.Second = ICK_Pointer_Member; 1319 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1320 SCS.Second = SecondICK; 1321 FromType = ToType.getUnqualifiedType(); 1322 } else if (!S.getLangOptions().CPlusPlus && 1323 S.Context.typesAreCompatible(ToType, FromType)) { 1324 // Compatible conversions (Clang extension for C function overloading) 1325 SCS.Second = ICK_Compatible_Conversion; 1326 FromType = ToType.getUnqualifiedType(); 1327 } else if (S.IsNoReturnConversion(FromType, ToType, FromType)) { 1328 // Treat a conversion that strips "noreturn" as an identity conversion. 1329 SCS.Second = ICK_NoReturn_Adjustment; 1330 } else if (IsTransparentUnionStandardConversion(S, From, ToType, 1331 InOverloadResolution, 1332 SCS, CStyle)) { 1333 SCS.Second = ICK_TransparentUnionConversion; 1334 FromType = ToType; 1335 } else { 1336 // No second conversion required. 1337 SCS.Second = ICK_Identity; 1338 } 1339 SCS.setToType(1, FromType); 1340 1341 QualType CanonFrom; 1342 QualType CanonTo; 1343 // The third conversion can be a qualification conversion (C++ 4p1). 1344 bool ObjCLifetimeConversion; 1345 if (S.IsQualificationConversion(FromType, ToType, CStyle, 1346 ObjCLifetimeConversion)) { 1347 SCS.Third = ICK_Qualification; 1348 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion; 1349 FromType = ToType; 1350 CanonFrom = S.Context.getCanonicalType(FromType); 1351 CanonTo = S.Context.getCanonicalType(ToType); 1352 } else { 1353 // No conversion required 1354 SCS.Third = ICK_Identity; 1355 1356 // C++ [over.best.ics]p6: 1357 // [...] Any difference in top-level cv-qualification is 1358 // subsumed by the initialization itself and does not constitute 1359 // a conversion. [...] 1360 CanonFrom = S.Context.getCanonicalType(FromType); 1361 CanonTo = S.Context.getCanonicalType(ToType); 1362 if (CanonFrom.getLocalUnqualifiedType() 1363 == CanonTo.getLocalUnqualifiedType() && 1364 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1365 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr() 1366 || CanonFrom.getObjCLifetime() != CanonTo.getObjCLifetime())) { 1367 FromType = ToType; 1368 CanonFrom = CanonTo; 1369 } 1370 } 1371 SCS.setToType(2, FromType); 1372 1373 // If we have not converted the argument type to the parameter type, 1374 // this is a bad conversion sequence. 1375 if (CanonFrom != CanonTo) 1376 return false; 1377 1378 return true; 1379} 1380 1381static bool 1382IsTransparentUnionStandardConversion(Sema &S, Expr* From, 1383 QualType &ToType, 1384 bool InOverloadResolution, 1385 StandardConversionSequence &SCS, 1386 bool CStyle) { 1387 1388 const RecordType *UT = ToType->getAsUnionType(); 1389 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 1390 return false; 1391 // The field to initialize within the transparent union. 1392 RecordDecl *UD = UT->getDecl(); 1393 // It's compatible if the expression matches any of the fields. 1394 for (RecordDecl::field_iterator it = UD->field_begin(), 1395 itend = UD->field_end(); 1396 it != itend; ++it) { 1397 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, 1398 CStyle, /*ObjCWritebackConversion=*/false)) { 1399 ToType = it->getType(); 1400 return true; 1401 } 1402 } 1403 return false; 1404} 1405 1406/// IsIntegralPromotion - Determines whether the conversion from the 1407/// expression From (whose potentially-adjusted type is FromType) to 1408/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1409/// sets PromotedType to the promoted type. 1410bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1411 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1412 // All integers are built-in. 1413 if (!To) { 1414 return false; 1415 } 1416 1417 // An rvalue of type char, signed char, unsigned char, short int, or 1418 // unsigned short int can be converted to an rvalue of type int if 1419 // int can represent all the values of the source type; otherwise, 1420 // the source rvalue can be converted to an rvalue of type unsigned 1421 // int (C++ 4.5p1). 1422 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1423 !FromType->isEnumeralType()) { 1424 if (// We can promote any signed, promotable integer type to an int 1425 (FromType->isSignedIntegerType() || 1426 // We can promote any unsigned integer type whose size is 1427 // less than int to an int. 1428 (!FromType->isSignedIntegerType() && 1429 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1430 return To->getKind() == BuiltinType::Int; 1431 } 1432 1433 return To->getKind() == BuiltinType::UInt; 1434 } 1435 1436 // C++0x [conv.prom]p3: 1437 // A prvalue of an unscoped enumeration type whose underlying type is not 1438 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1439 // following types that can represent all the values of the enumeration 1440 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1441 // unsigned int, long int, unsigned long int, long long int, or unsigned 1442 // long long int. If none of the types in that list can represent all the 1443 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1444 // type can be converted to an rvalue a prvalue of the extended integer type 1445 // with lowest integer conversion rank (4.13) greater than the rank of long 1446 // long in which all the values of the enumeration can be represented. If 1447 // there are two such extended types, the signed one is chosen. 1448 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1449 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1450 // provided for a scoped enumeration. 1451 if (FromEnumType->getDecl()->isScoped()) 1452 return false; 1453 1454 // We have already pre-calculated the promotion type, so this is trivial. 1455 if (ToType->isIntegerType() && 1456 !RequireCompleteType(From->getLocStart(), FromType, PDiag())) 1457 return Context.hasSameUnqualifiedType(ToType, 1458 FromEnumType->getDecl()->getPromotionType()); 1459 } 1460 1461 // C++0x [conv.prom]p2: 1462 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1463 // to an rvalue a prvalue of the first of the following types that can 1464 // represent all the values of its underlying type: int, unsigned int, 1465 // long int, unsigned long int, long long int, or unsigned long long int. 1466 // If none of the types in that list can represent all the values of its 1467 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1468 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1469 // type. 1470 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1471 ToType->isIntegerType()) { 1472 // Determine whether the type we're converting from is signed or 1473 // unsigned. 1474 bool FromIsSigned = FromType->isSignedIntegerType(); 1475 uint64_t FromSize = Context.getTypeSize(FromType); 1476 1477 // The types we'll try to promote to, in the appropriate 1478 // order. Try each of these types. 1479 QualType PromoteTypes[6] = { 1480 Context.IntTy, Context.UnsignedIntTy, 1481 Context.LongTy, Context.UnsignedLongTy , 1482 Context.LongLongTy, Context.UnsignedLongLongTy 1483 }; 1484 for (int Idx = 0; Idx < 6; ++Idx) { 1485 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1486 if (FromSize < ToSize || 1487 (FromSize == ToSize && 1488 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1489 // We found the type that we can promote to. If this is the 1490 // type we wanted, we have a promotion. Otherwise, no 1491 // promotion. 1492 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1493 } 1494 } 1495 } 1496 1497 // An rvalue for an integral bit-field (9.6) can be converted to an 1498 // rvalue of type int if int can represent all the values of the 1499 // bit-field; otherwise, it can be converted to unsigned int if 1500 // unsigned int can represent all the values of the bit-field. If 1501 // the bit-field is larger yet, no integral promotion applies to 1502 // it. If the bit-field has an enumerated type, it is treated as any 1503 // other value of that type for promotion purposes (C++ 4.5p3). 1504 // FIXME: We should delay checking of bit-fields until we actually perform the 1505 // conversion. 1506 using llvm::APSInt; 1507 if (From) 1508 if (FieldDecl *MemberDecl = From->getBitField()) { 1509 APSInt BitWidth; 1510 if (FromType->isIntegralType(Context) && 1511 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1512 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1513 ToSize = Context.getTypeSize(ToType); 1514 1515 // Are we promoting to an int from a bitfield that fits in an int? 1516 if (BitWidth < ToSize || 1517 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1518 return To->getKind() == BuiltinType::Int; 1519 } 1520 1521 // Are we promoting to an unsigned int from an unsigned bitfield 1522 // that fits into an unsigned int? 1523 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1524 return To->getKind() == BuiltinType::UInt; 1525 } 1526 1527 return false; 1528 } 1529 } 1530 1531 // An rvalue of type bool can be converted to an rvalue of type int, 1532 // with false becoming zero and true becoming one (C++ 4.5p4). 1533 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1534 return true; 1535 } 1536 1537 return false; 1538} 1539 1540/// IsFloatingPointPromotion - Determines whether the conversion from 1541/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1542/// returns true and sets PromotedType to the promoted type. 1543bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1544 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1545 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1546 /// An rvalue of type float can be converted to an rvalue of type 1547 /// double. (C++ 4.6p1). 1548 if (FromBuiltin->getKind() == BuiltinType::Float && 1549 ToBuiltin->getKind() == BuiltinType::Double) 1550 return true; 1551 1552 // C99 6.3.1.5p1: 1553 // When a float is promoted to double or long double, or a 1554 // double is promoted to long double [...]. 1555 if (!getLangOptions().CPlusPlus && 1556 (FromBuiltin->getKind() == BuiltinType::Float || 1557 FromBuiltin->getKind() == BuiltinType::Double) && 1558 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1559 return true; 1560 1561 // Half can be promoted to float. 1562 if (FromBuiltin->getKind() == BuiltinType::Half && 1563 ToBuiltin->getKind() == BuiltinType::Float) 1564 return true; 1565 } 1566 1567 return false; 1568} 1569 1570/// \brief Determine if a conversion is a complex promotion. 1571/// 1572/// A complex promotion is defined as a complex -> complex conversion 1573/// where the conversion between the underlying real types is a 1574/// floating-point or integral promotion. 1575bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1576 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1577 if (!FromComplex) 1578 return false; 1579 1580 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1581 if (!ToComplex) 1582 return false; 1583 1584 return IsFloatingPointPromotion(FromComplex->getElementType(), 1585 ToComplex->getElementType()) || 1586 IsIntegralPromotion(0, FromComplex->getElementType(), 1587 ToComplex->getElementType()); 1588} 1589 1590/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1591/// the pointer type FromPtr to a pointer to type ToPointee, with the 1592/// same type qualifiers as FromPtr has on its pointee type. ToType, 1593/// if non-empty, will be a pointer to ToType that may or may not have 1594/// the right set of qualifiers on its pointee. 1595/// 1596static QualType 1597BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1598 QualType ToPointee, QualType ToType, 1599 ASTContext &Context, 1600 bool StripObjCLifetime = false) { 1601 assert((FromPtr->getTypeClass() == Type::Pointer || 1602 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1603 "Invalid similarly-qualified pointer type"); 1604 1605 /// Conversions to 'id' subsume cv-qualifier conversions. 1606 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1607 return ToType.getUnqualifiedType(); 1608 1609 QualType CanonFromPointee 1610 = Context.getCanonicalType(FromPtr->getPointeeType()); 1611 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1612 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1613 1614 if (StripObjCLifetime) 1615 Quals.removeObjCLifetime(); 1616 1617 // Exact qualifier match -> return the pointer type we're converting to. 1618 if (CanonToPointee.getLocalQualifiers() == Quals) { 1619 // ToType is exactly what we need. Return it. 1620 if (!ToType.isNull()) 1621 return ToType.getUnqualifiedType(); 1622 1623 // Build a pointer to ToPointee. It has the right qualifiers 1624 // already. 1625 if (isa<ObjCObjectPointerType>(ToType)) 1626 return Context.getObjCObjectPointerType(ToPointee); 1627 return Context.getPointerType(ToPointee); 1628 } 1629 1630 // Just build a canonical type that has the right qualifiers. 1631 QualType QualifiedCanonToPointee 1632 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1633 1634 if (isa<ObjCObjectPointerType>(ToType)) 1635 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1636 return Context.getPointerType(QualifiedCanonToPointee); 1637} 1638 1639static bool isNullPointerConstantForConversion(Expr *Expr, 1640 bool InOverloadResolution, 1641 ASTContext &Context) { 1642 // Handle value-dependent integral null pointer constants correctly. 1643 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1644 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1645 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1646 return !InOverloadResolution; 1647 1648 return Expr->isNullPointerConstant(Context, 1649 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1650 : Expr::NPC_ValueDependentIsNull); 1651} 1652 1653/// IsPointerConversion - Determines whether the conversion of the 1654/// expression From, which has the (possibly adjusted) type FromType, 1655/// can be converted to the type ToType via a pointer conversion (C++ 1656/// 4.10). If so, returns true and places the converted type (that 1657/// might differ from ToType in its cv-qualifiers at some level) into 1658/// ConvertedType. 1659/// 1660/// This routine also supports conversions to and from block pointers 1661/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1662/// pointers to interfaces. FIXME: Once we've determined the 1663/// appropriate overloading rules for Objective-C, we may want to 1664/// split the Objective-C checks into a different routine; however, 1665/// GCC seems to consider all of these conversions to be pointer 1666/// conversions, so for now they live here. IncompatibleObjC will be 1667/// set if the conversion is an allowed Objective-C conversion that 1668/// should result in a warning. 1669bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1670 bool InOverloadResolution, 1671 QualType& ConvertedType, 1672 bool &IncompatibleObjC) { 1673 IncompatibleObjC = false; 1674 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 1675 IncompatibleObjC)) 1676 return true; 1677 1678 // Conversion from a null pointer constant to any Objective-C pointer type. 1679 if (ToType->isObjCObjectPointerType() && 1680 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1681 ConvertedType = ToType; 1682 return true; 1683 } 1684 1685 // Blocks: Block pointers can be converted to void*. 1686 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1687 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1688 ConvertedType = ToType; 1689 return true; 1690 } 1691 // Blocks: A null pointer constant can be converted to a block 1692 // pointer type. 1693 if (ToType->isBlockPointerType() && 1694 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1695 ConvertedType = ToType; 1696 return true; 1697 } 1698 1699 // If the left-hand-side is nullptr_t, the right side can be a null 1700 // pointer constant. 1701 if (ToType->isNullPtrType() && 1702 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1703 ConvertedType = ToType; 1704 return true; 1705 } 1706 1707 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1708 if (!ToTypePtr) 1709 return false; 1710 1711 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1712 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1713 ConvertedType = ToType; 1714 return true; 1715 } 1716 1717 // Beyond this point, both types need to be pointers 1718 // , including objective-c pointers. 1719 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1720 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() && 1721 !getLangOptions().ObjCAutoRefCount) { 1722 ConvertedType = BuildSimilarlyQualifiedPointerType( 1723 FromType->getAs<ObjCObjectPointerType>(), 1724 ToPointeeType, 1725 ToType, Context); 1726 return true; 1727 } 1728 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1729 if (!FromTypePtr) 1730 return false; 1731 1732 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1733 1734 // If the unqualified pointee types are the same, this can't be a 1735 // pointer conversion, so don't do all of the work below. 1736 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1737 return false; 1738 1739 // An rvalue of type "pointer to cv T," where T is an object type, 1740 // can be converted to an rvalue of type "pointer to cv void" (C++ 1741 // 4.10p2). 1742 if (FromPointeeType->isIncompleteOrObjectType() && 1743 ToPointeeType->isVoidType()) { 1744 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1745 ToPointeeType, 1746 ToType, Context, 1747 /*StripObjCLifetime=*/true); 1748 return true; 1749 } 1750 1751 // MSVC allows implicit function to void* type conversion. 1752 if (getLangOptions().MicrosoftExt && FromPointeeType->isFunctionType() && 1753 ToPointeeType->isVoidType()) { 1754 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1755 ToPointeeType, 1756 ToType, Context); 1757 return true; 1758 } 1759 1760 // When we're overloading in C, we allow a special kind of pointer 1761 // conversion for compatible-but-not-identical pointee types. 1762 if (!getLangOptions().CPlusPlus && 1763 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1764 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1765 ToPointeeType, 1766 ToType, Context); 1767 return true; 1768 } 1769 1770 // C++ [conv.ptr]p3: 1771 // 1772 // An rvalue of type "pointer to cv D," where D is a class type, 1773 // can be converted to an rvalue of type "pointer to cv B," where 1774 // B is a base class (clause 10) of D. If B is an inaccessible 1775 // (clause 11) or ambiguous (10.2) base class of D, a program that 1776 // necessitates this conversion is ill-formed. The result of the 1777 // conversion is a pointer to the base class sub-object of the 1778 // derived class object. The null pointer value is converted to 1779 // the null pointer value of the destination type. 1780 // 1781 // Note that we do not check for ambiguity or inaccessibility 1782 // here. That is handled by CheckPointerConversion. 1783 if (getLangOptions().CPlusPlus && 1784 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1785 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1786 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1787 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1788 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1789 ToPointeeType, 1790 ToType, Context); 1791 return true; 1792 } 1793 1794 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() && 1795 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) { 1796 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1797 ToPointeeType, 1798 ToType, Context); 1799 return true; 1800 } 1801 1802 return false; 1803} 1804 1805/// \brief Adopt the given qualifiers for the given type. 1806static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){ 1807 Qualifiers TQs = T.getQualifiers(); 1808 1809 // Check whether qualifiers already match. 1810 if (TQs == Qs) 1811 return T; 1812 1813 if (Qs.compatiblyIncludes(TQs)) 1814 return Context.getQualifiedType(T, Qs); 1815 1816 return Context.getQualifiedType(T.getUnqualifiedType(), Qs); 1817} 1818 1819/// isObjCPointerConversion - Determines whether this is an 1820/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1821/// with the same arguments and return values. 1822bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1823 QualType& ConvertedType, 1824 bool &IncompatibleObjC) { 1825 if (!getLangOptions().ObjC1) 1826 return false; 1827 1828 // The set of qualifiers on the type we're converting from. 1829 Qualifiers FromQualifiers = FromType.getQualifiers(); 1830 1831 // First, we handle all conversions on ObjC object pointer types. 1832 const ObjCObjectPointerType* ToObjCPtr = 1833 ToType->getAs<ObjCObjectPointerType>(); 1834 const ObjCObjectPointerType *FromObjCPtr = 1835 FromType->getAs<ObjCObjectPointerType>(); 1836 1837 if (ToObjCPtr && FromObjCPtr) { 1838 // If the pointee types are the same (ignoring qualifications), 1839 // then this is not a pointer conversion. 1840 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 1841 FromObjCPtr->getPointeeType())) 1842 return false; 1843 1844 // Check for compatible 1845 // Objective C++: We're able to convert between "id" or "Class" and a 1846 // pointer to any interface (in both directions). 1847 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1848 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1849 return true; 1850 } 1851 // Conversions with Objective-C's id<...>. 1852 if ((FromObjCPtr->isObjCQualifiedIdType() || 1853 ToObjCPtr->isObjCQualifiedIdType()) && 1854 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1855 /*compare=*/false)) { 1856 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1857 return true; 1858 } 1859 // Objective C++: We're able to convert from a pointer to an 1860 // interface to a pointer to a different interface. 1861 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1862 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1863 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1864 if (getLangOptions().CPlusPlus && LHS && RHS && 1865 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1866 FromObjCPtr->getPointeeType())) 1867 return false; 1868 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1869 ToObjCPtr->getPointeeType(), 1870 ToType, Context); 1871 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 1872 return true; 1873 } 1874 1875 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1876 // Okay: this is some kind of implicit downcast of Objective-C 1877 // interfaces, which is permitted. However, we're going to 1878 // complain about it. 1879 IncompatibleObjC = true; 1880 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1881 ToObjCPtr->getPointeeType(), 1882 ToType, Context); 1883 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 1884 return true; 1885 } 1886 } 1887 // Beyond this point, both types need to be C pointers or block pointers. 1888 QualType ToPointeeType; 1889 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1890 ToPointeeType = ToCPtr->getPointeeType(); 1891 else if (const BlockPointerType *ToBlockPtr = 1892 ToType->getAs<BlockPointerType>()) { 1893 // Objective C++: We're able to convert from a pointer to any object 1894 // to a block pointer type. 1895 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1896 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1897 return true; 1898 } 1899 ToPointeeType = ToBlockPtr->getPointeeType(); 1900 } 1901 else if (FromType->getAs<BlockPointerType>() && 1902 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1903 // Objective C++: We're able to convert from a block pointer type to a 1904 // pointer to any object. 1905 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1906 return true; 1907 } 1908 else 1909 return false; 1910 1911 QualType FromPointeeType; 1912 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1913 FromPointeeType = FromCPtr->getPointeeType(); 1914 else if (const BlockPointerType *FromBlockPtr = 1915 FromType->getAs<BlockPointerType>()) 1916 FromPointeeType = FromBlockPtr->getPointeeType(); 1917 else 1918 return false; 1919 1920 // If we have pointers to pointers, recursively check whether this 1921 // is an Objective-C conversion. 1922 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1923 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1924 IncompatibleObjC)) { 1925 // We always complain about this conversion. 1926 IncompatibleObjC = true; 1927 ConvertedType = Context.getPointerType(ConvertedType); 1928 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 1929 return true; 1930 } 1931 // Allow conversion of pointee being objective-c pointer to another one; 1932 // as in I* to id. 1933 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1934 ToPointeeType->getAs<ObjCObjectPointerType>() && 1935 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1936 IncompatibleObjC)) { 1937 1938 ConvertedType = Context.getPointerType(ConvertedType); 1939 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 1940 return true; 1941 } 1942 1943 // If we have pointers to functions or blocks, check whether the only 1944 // differences in the argument and result types are in Objective-C 1945 // pointer conversions. If so, we permit the conversion (but 1946 // complain about it). 1947 const FunctionProtoType *FromFunctionType 1948 = FromPointeeType->getAs<FunctionProtoType>(); 1949 const FunctionProtoType *ToFunctionType 1950 = ToPointeeType->getAs<FunctionProtoType>(); 1951 if (FromFunctionType && ToFunctionType) { 1952 // If the function types are exactly the same, this isn't an 1953 // Objective-C pointer conversion. 1954 if (Context.getCanonicalType(FromPointeeType) 1955 == Context.getCanonicalType(ToPointeeType)) 1956 return false; 1957 1958 // Perform the quick checks that will tell us whether these 1959 // function types are obviously different. 1960 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1961 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1962 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1963 return false; 1964 1965 bool HasObjCConversion = false; 1966 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1967 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1968 // Okay, the types match exactly. Nothing to do. 1969 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1970 ToFunctionType->getResultType(), 1971 ConvertedType, IncompatibleObjC)) { 1972 // Okay, we have an Objective-C pointer conversion. 1973 HasObjCConversion = true; 1974 } else { 1975 // Function types are too different. Abort. 1976 return false; 1977 } 1978 1979 // Check argument types. 1980 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1981 ArgIdx != NumArgs; ++ArgIdx) { 1982 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1983 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1984 if (Context.getCanonicalType(FromArgType) 1985 == Context.getCanonicalType(ToArgType)) { 1986 // Okay, the types match exactly. Nothing to do. 1987 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1988 ConvertedType, IncompatibleObjC)) { 1989 // Okay, we have an Objective-C pointer conversion. 1990 HasObjCConversion = true; 1991 } else { 1992 // Argument types are too different. Abort. 1993 return false; 1994 } 1995 } 1996 1997 if (HasObjCConversion) { 1998 // We had an Objective-C conversion. Allow this pointer 1999 // conversion, but complain about it. 2000 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2001 IncompatibleObjC = true; 2002 return true; 2003 } 2004 } 2005 2006 return false; 2007} 2008 2009/// \brief Determine whether this is an Objective-C writeback conversion, 2010/// used for parameter passing when performing automatic reference counting. 2011/// 2012/// \param FromType The type we're converting form. 2013/// 2014/// \param ToType The type we're converting to. 2015/// 2016/// \param ConvertedType The type that will be produced after applying 2017/// this conversion. 2018bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType, 2019 QualType &ConvertedType) { 2020 if (!getLangOptions().ObjCAutoRefCount || 2021 Context.hasSameUnqualifiedType(FromType, ToType)) 2022 return false; 2023 2024 // Parameter must be a pointer to __autoreleasing (with no other qualifiers). 2025 QualType ToPointee; 2026 if (const PointerType *ToPointer = ToType->getAs<PointerType>()) 2027 ToPointee = ToPointer->getPointeeType(); 2028 else 2029 return false; 2030 2031 Qualifiers ToQuals = ToPointee.getQualifiers(); 2032 if (!ToPointee->isObjCLifetimeType() || 2033 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing || 2034 !ToQuals.withoutObjCGLifetime().empty()) 2035 return false; 2036 2037 // Argument must be a pointer to __strong to __weak. 2038 QualType FromPointee; 2039 if (const PointerType *FromPointer = FromType->getAs<PointerType>()) 2040 FromPointee = FromPointer->getPointeeType(); 2041 else 2042 return false; 2043 2044 Qualifiers FromQuals = FromPointee.getQualifiers(); 2045 if (!FromPointee->isObjCLifetimeType() || 2046 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong && 2047 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak)) 2048 return false; 2049 2050 // Make sure that we have compatible qualifiers. 2051 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing); 2052 if (!ToQuals.compatiblyIncludes(FromQuals)) 2053 return false; 2054 2055 // Remove qualifiers from the pointee type we're converting from; they 2056 // aren't used in the compatibility check belong, and we'll be adding back 2057 // qualifiers (with __autoreleasing) if the compatibility check succeeds. 2058 FromPointee = FromPointee.getUnqualifiedType(); 2059 2060 // The unqualified form of the pointee types must be compatible. 2061 ToPointee = ToPointee.getUnqualifiedType(); 2062 bool IncompatibleObjC; 2063 if (Context.typesAreCompatible(FromPointee, ToPointee)) 2064 FromPointee = ToPointee; 2065 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee, 2066 IncompatibleObjC)) 2067 return false; 2068 2069 /// \brief Construct the type we're converting to, which is a pointer to 2070 /// __autoreleasing pointee. 2071 FromPointee = Context.getQualifiedType(FromPointee, FromQuals); 2072 ConvertedType = Context.getPointerType(FromPointee); 2073 return true; 2074} 2075 2076bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, 2077 QualType& ConvertedType) { 2078 QualType ToPointeeType; 2079 if (const BlockPointerType *ToBlockPtr = 2080 ToType->getAs<BlockPointerType>()) 2081 ToPointeeType = ToBlockPtr->getPointeeType(); 2082 else 2083 return false; 2084 2085 QualType FromPointeeType; 2086 if (const BlockPointerType *FromBlockPtr = 2087 FromType->getAs<BlockPointerType>()) 2088 FromPointeeType = FromBlockPtr->getPointeeType(); 2089 else 2090 return false; 2091 // We have pointer to blocks, check whether the only 2092 // differences in the argument and result types are in Objective-C 2093 // pointer conversions. If so, we permit the conversion. 2094 2095 const FunctionProtoType *FromFunctionType 2096 = FromPointeeType->getAs<FunctionProtoType>(); 2097 const FunctionProtoType *ToFunctionType 2098 = ToPointeeType->getAs<FunctionProtoType>(); 2099 2100 if (!FromFunctionType || !ToFunctionType) 2101 return false; 2102 2103 if (Context.hasSameType(FromPointeeType, ToPointeeType)) 2104 return true; 2105 2106 // Perform the quick checks that will tell us whether these 2107 // function types are obviously different. 2108 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 2109 FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) 2110 return false; 2111 2112 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); 2113 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); 2114 if (FromEInfo != ToEInfo) 2115 return false; 2116 2117 bool IncompatibleObjC = false; 2118 if (Context.hasSameType(FromFunctionType->getResultType(), 2119 ToFunctionType->getResultType())) { 2120 // Okay, the types match exactly. Nothing to do. 2121 } else { 2122 QualType RHS = FromFunctionType->getResultType(); 2123 QualType LHS = ToFunctionType->getResultType(); 2124 if ((!getLangOptions().CPlusPlus || !RHS->isRecordType()) && 2125 !RHS.hasQualifiers() && LHS.hasQualifiers()) 2126 LHS = LHS.getUnqualifiedType(); 2127 2128 if (Context.hasSameType(RHS,LHS)) { 2129 // OK exact match. 2130 } else if (isObjCPointerConversion(RHS, LHS, 2131 ConvertedType, IncompatibleObjC)) { 2132 if (IncompatibleObjC) 2133 return false; 2134 // Okay, we have an Objective-C pointer conversion. 2135 } 2136 else 2137 return false; 2138 } 2139 2140 // Check argument types. 2141 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 2142 ArgIdx != NumArgs; ++ArgIdx) { 2143 IncompatibleObjC = false; 2144 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 2145 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 2146 if (Context.hasSameType(FromArgType, ToArgType)) { 2147 // Okay, the types match exactly. Nothing to do. 2148 } else if (isObjCPointerConversion(ToArgType, FromArgType, 2149 ConvertedType, IncompatibleObjC)) { 2150 if (IncompatibleObjC) 2151 return false; 2152 // Okay, we have an Objective-C pointer conversion. 2153 } else 2154 // Argument types are too different. Abort. 2155 return false; 2156 } 2157 if (LangOpts.ObjCAutoRefCount && 2158 !Context.FunctionTypesMatchOnNSConsumedAttrs(FromFunctionType, 2159 ToFunctionType)) 2160 return false; 2161 2162 ConvertedType = ToType; 2163 return true; 2164} 2165 2166/// FunctionArgTypesAreEqual - This routine checks two function proto types 2167/// for equlity of their argument types. Caller has already checked that 2168/// they have same number of arguments. This routine assumes that Objective-C 2169/// pointer types which only differ in their protocol qualifiers are equal. 2170bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, 2171 const FunctionProtoType *NewType) { 2172 if (!getLangOptions().ObjC1) 2173 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 2174 NewType->arg_type_begin()); 2175 2176 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 2177 N = NewType->arg_type_begin(), 2178 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 2179 QualType ToType = (*O); 2180 QualType FromType = (*N); 2181 if (ToType != FromType) { 2182 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 2183 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 2184 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 2185 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 2186 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 2187 PTFr->getPointeeType()->isObjCQualifiedClassType())) 2188 continue; 2189 } 2190 else if (const ObjCObjectPointerType *PTTo = 2191 ToType->getAs<ObjCObjectPointerType>()) { 2192 if (const ObjCObjectPointerType *PTFr = 2193 FromType->getAs<ObjCObjectPointerType>()) 2194 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 2195 continue; 2196 } 2197 return false; 2198 } 2199 } 2200 return true; 2201} 2202 2203/// CheckPointerConversion - Check the pointer conversion from the 2204/// expression From to the type ToType. This routine checks for 2205/// ambiguous or inaccessible derived-to-base pointer 2206/// conversions for which IsPointerConversion has already returned 2207/// true. It returns true and produces a diagnostic if there was an 2208/// error, or returns false otherwise. 2209bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 2210 CastKind &Kind, 2211 CXXCastPath& BasePath, 2212 bool IgnoreBaseAccess) { 2213 QualType FromType = From->getType(); 2214 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 2215 2216 Kind = CK_BitCast; 2217 2218 if (!IsCStyleOrFunctionalCast && 2219 Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy) && 2220 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 2221 DiagRuntimeBehavior(From->getExprLoc(), From, 2222 PDiag(diag::warn_impcast_bool_to_null_pointer) 2223 << ToType << From->getSourceRange()); 2224 2225 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 2226 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) { 2227 QualType FromPointeeType = FromPtrType->getPointeeType(), 2228 ToPointeeType = ToPtrType->getPointeeType(); 2229 2230 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 2231 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 2232 // We must have a derived-to-base conversion. Check an 2233 // ambiguous or inaccessible conversion. 2234 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 2235 From->getExprLoc(), 2236 From->getSourceRange(), &BasePath, 2237 IgnoreBaseAccess)) 2238 return true; 2239 2240 // The conversion was successful. 2241 Kind = CK_DerivedToBase; 2242 } 2243 } 2244 } else if (const ObjCObjectPointerType *ToPtrType = 2245 ToType->getAs<ObjCObjectPointerType>()) { 2246 if (const ObjCObjectPointerType *FromPtrType = 2247 FromType->getAs<ObjCObjectPointerType>()) { 2248 // Objective-C++ conversions are always okay. 2249 // FIXME: We should have a different class of conversions for the 2250 // Objective-C++ implicit conversions. 2251 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 2252 return false; 2253 } else if (FromType->isBlockPointerType()) { 2254 Kind = CK_BlockPointerToObjCPointerCast; 2255 } else { 2256 Kind = CK_CPointerToObjCPointerCast; 2257 } 2258 } else if (ToType->isBlockPointerType()) { 2259 if (!FromType->isBlockPointerType()) 2260 Kind = CK_AnyPointerToBlockPointerCast; 2261 } 2262 2263 // We shouldn't fall into this case unless it's valid for other 2264 // reasons. 2265 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 2266 Kind = CK_NullToPointer; 2267 2268 return false; 2269} 2270 2271/// IsMemberPointerConversion - Determines whether the conversion of the 2272/// expression From, which has the (possibly adjusted) type FromType, can be 2273/// converted to the type ToType via a member pointer conversion (C++ 4.11). 2274/// If so, returns true and places the converted type (that might differ from 2275/// ToType in its cv-qualifiers at some level) into ConvertedType. 2276bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 2277 QualType ToType, 2278 bool InOverloadResolution, 2279 QualType &ConvertedType) { 2280 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 2281 if (!ToTypePtr) 2282 return false; 2283 2284 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 2285 if (From->isNullPointerConstant(Context, 2286 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 2287 : Expr::NPC_ValueDependentIsNull)) { 2288 ConvertedType = ToType; 2289 return true; 2290 } 2291 2292 // Otherwise, both types have to be member pointers. 2293 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 2294 if (!FromTypePtr) 2295 return false; 2296 2297 // A pointer to member of B can be converted to a pointer to member of D, 2298 // where D is derived from B (C++ 4.11p2). 2299 QualType FromClass(FromTypePtr->getClass(), 0); 2300 QualType ToClass(ToTypePtr->getClass(), 0); 2301 2302 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && 2303 !RequireCompleteType(From->getLocStart(), ToClass, PDiag()) && 2304 IsDerivedFrom(ToClass, FromClass)) { 2305 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 2306 ToClass.getTypePtr()); 2307 return true; 2308 } 2309 2310 return false; 2311} 2312 2313/// CheckMemberPointerConversion - Check the member pointer conversion from the 2314/// expression From to the type ToType. This routine checks for ambiguous or 2315/// virtual or inaccessible base-to-derived member pointer conversions 2316/// for which IsMemberPointerConversion has already returned true. It returns 2317/// true and produces a diagnostic if there was an error, or returns false 2318/// otherwise. 2319bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 2320 CastKind &Kind, 2321 CXXCastPath &BasePath, 2322 bool IgnoreBaseAccess) { 2323 QualType FromType = From->getType(); 2324 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 2325 if (!FromPtrType) { 2326 // This must be a null pointer to member pointer conversion 2327 assert(From->isNullPointerConstant(Context, 2328 Expr::NPC_ValueDependentIsNull) && 2329 "Expr must be null pointer constant!"); 2330 Kind = CK_NullToMemberPointer; 2331 return false; 2332 } 2333 2334 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 2335 assert(ToPtrType && "No member pointer cast has a target type " 2336 "that is not a member pointer."); 2337 2338 QualType FromClass = QualType(FromPtrType->getClass(), 0); 2339 QualType ToClass = QualType(ToPtrType->getClass(), 0); 2340 2341 // FIXME: What about dependent types? 2342 assert(FromClass->isRecordType() && "Pointer into non-class."); 2343 assert(ToClass->isRecordType() && "Pointer into non-class."); 2344 2345 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 2346 /*DetectVirtual=*/true); 2347 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 2348 assert(DerivationOkay && 2349 "Should not have been called if derivation isn't OK."); 2350 (void)DerivationOkay; 2351 2352 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 2353 getUnqualifiedType())) { 2354 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 2355 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 2356 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 2357 return true; 2358 } 2359 2360 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 2361 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 2362 << FromClass << ToClass << QualType(VBase, 0) 2363 << From->getSourceRange(); 2364 return true; 2365 } 2366 2367 if (!IgnoreBaseAccess) 2368 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 2369 Paths.front(), 2370 diag::err_downcast_from_inaccessible_base); 2371 2372 // Must be a base to derived member conversion. 2373 BuildBasePathArray(Paths, BasePath); 2374 Kind = CK_BaseToDerivedMemberPointer; 2375 return false; 2376} 2377 2378/// IsQualificationConversion - Determines whether the conversion from 2379/// an rvalue of type FromType to ToType is a qualification conversion 2380/// (C++ 4.4). 2381/// 2382/// \param ObjCLifetimeConversion Output parameter that will be set to indicate 2383/// when the qualification conversion involves a change in the Objective-C 2384/// object lifetime. 2385bool 2386Sema::IsQualificationConversion(QualType FromType, QualType ToType, 2387 bool CStyle, bool &ObjCLifetimeConversion) { 2388 FromType = Context.getCanonicalType(FromType); 2389 ToType = Context.getCanonicalType(ToType); 2390 ObjCLifetimeConversion = false; 2391 2392 // If FromType and ToType are the same type, this is not a 2393 // qualification conversion. 2394 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 2395 return false; 2396 2397 // (C++ 4.4p4): 2398 // A conversion can add cv-qualifiers at levels other than the first 2399 // in multi-level pointers, subject to the following rules: [...] 2400 bool PreviousToQualsIncludeConst = true; 2401 bool UnwrappedAnyPointer = false; 2402 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 2403 // Within each iteration of the loop, we check the qualifiers to 2404 // determine if this still looks like a qualification 2405 // conversion. Then, if all is well, we unwrap one more level of 2406 // pointers or pointers-to-members and do it all again 2407 // until there are no more pointers or pointers-to-members left to 2408 // unwrap. 2409 UnwrappedAnyPointer = true; 2410 2411 Qualifiers FromQuals = FromType.getQualifiers(); 2412 Qualifiers ToQuals = ToType.getQualifiers(); 2413 2414 // Objective-C ARC: 2415 // Check Objective-C lifetime conversions. 2416 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() && 2417 UnwrappedAnyPointer) { 2418 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) { 2419 ObjCLifetimeConversion = true; 2420 FromQuals.removeObjCLifetime(); 2421 ToQuals.removeObjCLifetime(); 2422 } else { 2423 // Qualification conversions cannot cast between different 2424 // Objective-C lifetime qualifiers. 2425 return false; 2426 } 2427 } 2428 2429 // Allow addition/removal of GC attributes but not changing GC attributes. 2430 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() && 2431 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) { 2432 FromQuals.removeObjCGCAttr(); 2433 ToQuals.removeObjCGCAttr(); 2434 } 2435 2436 // -- for every j > 0, if const is in cv 1,j then const is in cv 2437 // 2,j, and similarly for volatile. 2438 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals)) 2439 return false; 2440 2441 // -- if the cv 1,j and cv 2,j are different, then const is in 2442 // every cv for 0 < k < j. 2443 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers() 2444 && !PreviousToQualsIncludeConst) 2445 return false; 2446 2447 // Keep track of whether all prior cv-qualifiers in the "to" type 2448 // include const. 2449 PreviousToQualsIncludeConst 2450 = PreviousToQualsIncludeConst && ToQuals.hasConst(); 2451 } 2452 2453 // We are left with FromType and ToType being the pointee types 2454 // after unwrapping the original FromType and ToType the same number 2455 // of types. If we unwrapped any pointers, and if FromType and 2456 // ToType have the same unqualified type (since we checked 2457 // qualifiers above), then this is a qualification conversion. 2458 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2459} 2460 2461/// Determines whether there is a user-defined conversion sequence 2462/// (C++ [over.ics.user]) that converts expression From to the type 2463/// ToType. If such a conversion exists, User will contain the 2464/// user-defined conversion sequence that performs such a conversion 2465/// and this routine will return true. Otherwise, this routine returns 2466/// false and User is unspecified. 2467/// 2468/// \param AllowExplicit true if the conversion should consider C++0x 2469/// "explicit" conversion functions as well as non-explicit conversion 2470/// functions (C++0x [class.conv.fct]p2). 2471static OverloadingResult 2472IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 2473 UserDefinedConversionSequence& User, 2474 OverloadCandidateSet& CandidateSet, 2475 bool AllowExplicit) { 2476 // Whether we will only visit constructors. 2477 bool ConstructorsOnly = false; 2478 2479 // If the type we are conversion to is a class type, enumerate its 2480 // constructors. 2481 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 2482 // C++ [over.match.ctor]p1: 2483 // When objects of class type are direct-initialized (8.5), or 2484 // copy-initialized from an expression of the same or a 2485 // derived class type (8.5), overload resolution selects the 2486 // constructor. [...] For copy-initialization, the candidate 2487 // functions are all the converting constructors (12.3.1) of 2488 // that class. The argument list is the expression-list within 2489 // the parentheses of the initializer. 2490 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 2491 (From->getType()->getAs<RecordType>() && 2492 S.IsDerivedFrom(From->getType(), ToType))) 2493 ConstructorsOnly = true; 2494 2495 S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag()); 2496 // RequireCompleteType may have returned true due to some invalid decl 2497 // during template instantiation, but ToType may be complete enough now 2498 // to try to recover. 2499 if (ToType->isIncompleteType()) { 2500 // We're not going to find any constructors. 2501 } else if (CXXRecordDecl *ToRecordDecl 2502 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 2503 DeclContext::lookup_iterator Con, ConEnd; 2504 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 2505 Con != ConEnd; ++Con) { 2506 NamedDecl *D = *Con; 2507 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2508 2509 // Find the constructor (which may be a template). 2510 CXXConstructorDecl *Constructor = 0; 2511 FunctionTemplateDecl *ConstructorTmpl 2512 = dyn_cast<FunctionTemplateDecl>(D); 2513 if (ConstructorTmpl) 2514 Constructor 2515 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2516 else 2517 Constructor = cast<CXXConstructorDecl>(D); 2518 2519 if (!Constructor->isInvalidDecl() && 2520 Constructor->isConvertingConstructor(AllowExplicit)) { 2521 if (ConstructorTmpl) 2522 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2523 /*ExplicitArgs*/ 0, 2524 &From, 1, CandidateSet, 2525 /*SuppressUserConversions=*/ 2526 !ConstructorsOnly); 2527 else 2528 // Allow one user-defined conversion when user specifies a 2529 // From->ToType conversion via an static cast (c-style, etc). 2530 S.AddOverloadCandidate(Constructor, FoundDecl, 2531 &From, 1, CandidateSet, 2532 /*SuppressUserConversions=*/ 2533 !ConstructorsOnly); 2534 } 2535 } 2536 } 2537 } 2538 2539 // Enumerate conversion functions, if we're allowed to. 2540 if (ConstructorsOnly) { 2541 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 2542 S.PDiag(0) << From->getSourceRange())) { 2543 // No conversion functions from incomplete types. 2544 } else if (const RecordType *FromRecordType 2545 = From->getType()->getAs<RecordType>()) { 2546 if (CXXRecordDecl *FromRecordDecl 2547 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 2548 // Add all of the conversion functions as candidates. 2549 const UnresolvedSetImpl *Conversions 2550 = FromRecordDecl->getVisibleConversionFunctions(); 2551 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2552 E = Conversions->end(); I != E; ++I) { 2553 DeclAccessPair FoundDecl = I.getPair(); 2554 NamedDecl *D = FoundDecl.getDecl(); 2555 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 2556 if (isa<UsingShadowDecl>(D)) 2557 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2558 2559 CXXConversionDecl *Conv; 2560 FunctionTemplateDecl *ConvTemplate; 2561 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 2562 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2563 else 2564 Conv = cast<CXXConversionDecl>(D); 2565 2566 if (AllowExplicit || !Conv->isExplicit()) { 2567 if (ConvTemplate) 2568 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 2569 ActingContext, From, ToType, 2570 CandidateSet); 2571 else 2572 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 2573 From, ToType, CandidateSet); 2574 } 2575 } 2576 } 2577 } 2578 2579 bool HadMultipleCandidates = (CandidateSet.size() > 1); 2580 2581 OverloadCandidateSet::iterator Best; 2582 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2583 case OR_Success: 2584 // Record the standard conversion we used and the conversion function. 2585 if (CXXConstructorDecl *Constructor 2586 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 2587 S.MarkDeclarationReferenced(From->getLocStart(), Constructor); 2588 2589 // C++ [over.ics.user]p1: 2590 // If the user-defined conversion is specified by a 2591 // constructor (12.3.1), the initial standard conversion 2592 // sequence converts the source type to the type required by 2593 // the argument of the constructor. 2594 // 2595 QualType ThisType = Constructor->getThisType(S.Context); 2596 if (Best->Conversions[0].isEllipsis()) 2597 User.EllipsisConversion = true; 2598 else { 2599 User.Before = Best->Conversions[0].Standard; 2600 User.EllipsisConversion = false; 2601 } 2602 User.HadMultipleCandidates = HadMultipleCandidates; 2603 User.ConversionFunction = Constructor; 2604 User.FoundConversionFunction = Best->FoundDecl; 2605 User.After.setAsIdentityConversion(); 2606 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2607 User.After.setAllToTypes(ToType); 2608 return OR_Success; 2609 } else if (CXXConversionDecl *Conversion 2610 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2611 S.MarkDeclarationReferenced(From->getLocStart(), Conversion); 2612 2613 // C++ [over.ics.user]p1: 2614 // 2615 // [...] If the user-defined conversion is specified by a 2616 // conversion function (12.3.2), the initial standard 2617 // conversion sequence converts the source type to the 2618 // implicit object parameter of the conversion function. 2619 User.Before = Best->Conversions[0].Standard; 2620 User.HadMultipleCandidates = HadMultipleCandidates; 2621 User.ConversionFunction = Conversion; 2622 User.FoundConversionFunction = Best->FoundDecl; 2623 User.EllipsisConversion = false; 2624 2625 // C++ [over.ics.user]p2: 2626 // The second standard conversion sequence converts the 2627 // result of the user-defined conversion to the target type 2628 // for the sequence. Since an implicit conversion sequence 2629 // is an initialization, the special rules for 2630 // initialization by user-defined conversion apply when 2631 // selecting the best user-defined conversion for a 2632 // user-defined conversion sequence (see 13.3.3 and 2633 // 13.3.3.1). 2634 User.After = Best->FinalConversion; 2635 return OR_Success; 2636 } else { 2637 llvm_unreachable("Not a constructor or conversion function?"); 2638 return OR_No_Viable_Function; 2639 } 2640 2641 case OR_No_Viable_Function: 2642 return OR_No_Viable_Function; 2643 case OR_Deleted: 2644 // No conversion here! We're done. 2645 return OR_Deleted; 2646 2647 case OR_Ambiguous: 2648 return OR_Ambiguous; 2649 } 2650 2651 return OR_No_Viable_Function; 2652} 2653 2654bool 2655Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2656 ImplicitConversionSequence ICS; 2657 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2658 OverloadingResult OvResult = 2659 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 2660 CandidateSet, false); 2661 if (OvResult == OR_Ambiguous) 2662 Diag(From->getSourceRange().getBegin(), 2663 diag::err_typecheck_ambiguous_condition) 2664 << From->getType() << ToType << From->getSourceRange(); 2665 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2666 Diag(From->getSourceRange().getBegin(), 2667 diag::err_typecheck_nonviable_condition) 2668 << From->getType() << ToType << From->getSourceRange(); 2669 else 2670 return false; 2671 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &From, 1); 2672 return true; 2673} 2674 2675/// CompareImplicitConversionSequences - Compare two implicit 2676/// conversion sequences to determine whether one is better than the 2677/// other or if they are indistinguishable (C++ 13.3.3.2). 2678static ImplicitConversionSequence::CompareKind 2679CompareImplicitConversionSequences(Sema &S, 2680 const ImplicitConversionSequence& ICS1, 2681 const ImplicitConversionSequence& ICS2) 2682{ 2683 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2684 // conversion sequences (as defined in 13.3.3.1) 2685 // -- a standard conversion sequence (13.3.3.1.1) is a better 2686 // conversion sequence than a user-defined conversion sequence or 2687 // an ellipsis conversion sequence, and 2688 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2689 // conversion sequence than an ellipsis conversion sequence 2690 // (13.3.3.1.3). 2691 // 2692 // C++0x [over.best.ics]p10: 2693 // For the purpose of ranking implicit conversion sequences as 2694 // described in 13.3.3.2, the ambiguous conversion sequence is 2695 // treated as a user-defined sequence that is indistinguishable 2696 // from any other user-defined conversion sequence. 2697 if (ICS1.getKindRank() < ICS2.getKindRank()) 2698 return ImplicitConversionSequence::Better; 2699 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2700 return ImplicitConversionSequence::Worse; 2701 2702 // The following checks require both conversion sequences to be of 2703 // the same kind. 2704 if (ICS1.getKind() != ICS2.getKind()) 2705 return ImplicitConversionSequence::Indistinguishable; 2706 2707 ImplicitConversionSequence::CompareKind Result = 2708 ImplicitConversionSequence::Indistinguishable; 2709 2710 // Two implicit conversion sequences of the same form are 2711 // indistinguishable conversion sequences unless one of the 2712 // following rules apply: (C++ 13.3.3.2p3): 2713 if (ICS1.isStandard()) 2714 Result = CompareStandardConversionSequences(S, 2715 ICS1.Standard, ICS2.Standard); 2716 else if (ICS1.isUserDefined()) { 2717 // User-defined conversion sequence U1 is a better conversion 2718 // sequence than another user-defined conversion sequence U2 if 2719 // they contain the same user-defined conversion function or 2720 // constructor and if the second standard conversion sequence of 2721 // U1 is better than the second standard conversion sequence of 2722 // U2 (C++ 13.3.3.2p3). 2723 if (ICS1.UserDefined.ConversionFunction == 2724 ICS2.UserDefined.ConversionFunction) 2725 Result = CompareStandardConversionSequences(S, 2726 ICS1.UserDefined.After, 2727 ICS2.UserDefined.After); 2728 } 2729 2730 // List-initialization sequence L1 is a better conversion sequence than 2731 // list-initialization sequence L2 if L1 converts to std::initializer_list<X> 2732 // for some X and L2 does not. 2733 if (Result == ImplicitConversionSequence::Indistinguishable && 2734 ICS1.isListInitializationSequence() && 2735 ICS2.isListInitializationSequence()) { 2736 // FIXME: Find out if ICS1 converts to initializer_list and ICS2 doesn't. 2737 } 2738 2739 return Result; 2740} 2741 2742static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2743 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2744 Qualifiers Quals; 2745 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2746 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2747 } 2748 2749 return Context.hasSameUnqualifiedType(T1, T2); 2750} 2751 2752// Per 13.3.3.2p3, compare the given standard conversion sequences to 2753// determine if one is a proper subset of the other. 2754static ImplicitConversionSequence::CompareKind 2755compareStandardConversionSubsets(ASTContext &Context, 2756 const StandardConversionSequence& SCS1, 2757 const StandardConversionSequence& SCS2) { 2758 ImplicitConversionSequence::CompareKind Result 2759 = ImplicitConversionSequence::Indistinguishable; 2760 2761 // the identity conversion sequence is considered to be a subsequence of 2762 // any non-identity conversion sequence 2763 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2764 return ImplicitConversionSequence::Better; 2765 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2766 return ImplicitConversionSequence::Worse; 2767 2768 if (SCS1.Second != SCS2.Second) { 2769 if (SCS1.Second == ICK_Identity) 2770 Result = ImplicitConversionSequence::Better; 2771 else if (SCS2.Second == ICK_Identity) 2772 Result = ImplicitConversionSequence::Worse; 2773 else 2774 return ImplicitConversionSequence::Indistinguishable; 2775 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2776 return ImplicitConversionSequence::Indistinguishable; 2777 2778 if (SCS1.Third == SCS2.Third) { 2779 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2780 : ImplicitConversionSequence::Indistinguishable; 2781 } 2782 2783 if (SCS1.Third == ICK_Identity) 2784 return Result == ImplicitConversionSequence::Worse 2785 ? ImplicitConversionSequence::Indistinguishable 2786 : ImplicitConversionSequence::Better; 2787 2788 if (SCS2.Third == ICK_Identity) 2789 return Result == ImplicitConversionSequence::Better 2790 ? ImplicitConversionSequence::Indistinguishable 2791 : ImplicitConversionSequence::Worse; 2792 2793 return ImplicitConversionSequence::Indistinguishable; 2794} 2795 2796/// \brief Determine whether one of the given reference bindings is better 2797/// than the other based on what kind of bindings they are. 2798static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 2799 const StandardConversionSequence &SCS2) { 2800 // C++0x [over.ics.rank]p3b4: 2801 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2802 // implicit object parameter of a non-static member function declared 2803 // without a ref-qualifier, and *either* S1 binds an rvalue reference 2804 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 2805 // lvalue reference to a function lvalue and S2 binds an rvalue 2806 // reference*. 2807 // 2808 // FIXME: Rvalue references. We're going rogue with the above edits, 2809 // because the semantics in the current C++0x working paper (N3225 at the 2810 // time of this writing) break the standard definition of std::forward 2811 // and std::reference_wrapper when dealing with references to functions. 2812 // Proposed wording changes submitted to CWG for consideration. 2813 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 2814 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 2815 return false; 2816 2817 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 2818 SCS2.IsLvalueReference) || 2819 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 2820 !SCS2.IsLvalueReference); 2821} 2822 2823/// CompareStandardConversionSequences - Compare two standard 2824/// conversion sequences to determine whether one is better than the 2825/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2826static ImplicitConversionSequence::CompareKind 2827CompareStandardConversionSequences(Sema &S, 2828 const StandardConversionSequence& SCS1, 2829 const StandardConversionSequence& SCS2) 2830{ 2831 // Standard conversion sequence S1 is a better conversion sequence 2832 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2833 2834 // -- S1 is a proper subsequence of S2 (comparing the conversion 2835 // sequences in the canonical form defined by 13.3.3.1.1, 2836 // excluding any Lvalue Transformation; the identity conversion 2837 // sequence is considered to be a subsequence of any 2838 // non-identity conversion sequence) or, if not that, 2839 if (ImplicitConversionSequence::CompareKind CK 2840 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 2841 return CK; 2842 2843 // -- the rank of S1 is better than the rank of S2 (by the rules 2844 // defined below), or, if not that, 2845 ImplicitConversionRank Rank1 = SCS1.getRank(); 2846 ImplicitConversionRank Rank2 = SCS2.getRank(); 2847 if (Rank1 < Rank2) 2848 return ImplicitConversionSequence::Better; 2849 else if (Rank2 < Rank1) 2850 return ImplicitConversionSequence::Worse; 2851 2852 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2853 // are indistinguishable unless one of the following rules 2854 // applies: 2855 2856 // A conversion that is not a conversion of a pointer, or 2857 // pointer to member, to bool is better than another conversion 2858 // that is such a conversion. 2859 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2860 return SCS2.isPointerConversionToBool() 2861 ? ImplicitConversionSequence::Better 2862 : ImplicitConversionSequence::Worse; 2863 2864 // C++ [over.ics.rank]p4b2: 2865 // 2866 // If class B is derived directly or indirectly from class A, 2867 // conversion of B* to A* is better than conversion of B* to 2868 // void*, and conversion of A* to void* is better than conversion 2869 // of B* to void*. 2870 bool SCS1ConvertsToVoid 2871 = SCS1.isPointerConversionToVoidPointer(S.Context); 2872 bool SCS2ConvertsToVoid 2873 = SCS2.isPointerConversionToVoidPointer(S.Context); 2874 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2875 // Exactly one of the conversion sequences is a conversion to 2876 // a void pointer; it's the worse conversion. 2877 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2878 : ImplicitConversionSequence::Worse; 2879 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2880 // Neither conversion sequence converts to a void pointer; compare 2881 // their derived-to-base conversions. 2882 if (ImplicitConversionSequence::CompareKind DerivedCK 2883 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 2884 return DerivedCK; 2885 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid && 2886 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) { 2887 // Both conversion sequences are conversions to void 2888 // pointers. Compare the source types to determine if there's an 2889 // inheritance relationship in their sources. 2890 QualType FromType1 = SCS1.getFromType(); 2891 QualType FromType2 = SCS2.getFromType(); 2892 2893 // Adjust the types we're converting from via the array-to-pointer 2894 // conversion, if we need to. 2895 if (SCS1.First == ICK_Array_To_Pointer) 2896 FromType1 = S.Context.getArrayDecayedType(FromType1); 2897 if (SCS2.First == ICK_Array_To_Pointer) 2898 FromType2 = S.Context.getArrayDecayedType(FromType2); 2899 2900 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType(); 2901 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType(); 2902 2903 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2904 return ImplicitConversionSequence::Better; 2905 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2906 return ImplicitConversionSequence::Worse; 2907 2908 // Objective-C++: If one interface is more specific than the 2909 // other, it is the better one. 2910 const ObjCObjectPointerType* FromObjCPtr1 2911 = FromType1->getAs<ObjCObjectPointerType>(); 2912 const ObjCObjectPointerType* FromObjCPtr2 2913 = FromType2->getAs<ObjCObjectPointerType>(); 2914 if (FromObjCPtr1 && FromObjCPtr2) { 2915 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1, 2916 FromObjCPtr2); 2917 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2, 2918 FromObjCPtr1); 2919 if (AssignLeft != AssignRight) { 2920 return AssignLeft? ImplicitConversionSequence::Better 2921 : ImplicitConversionSequence::Worse; 2922 } 2923 } 2924 } 2925 2926 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2927 // bullet 3). 2928 if (ImplicitConversionSequence::CompareKind QualCK 2929 = CompareQualificationConversions(S, SCS1, SCS2)) 2930 return QualCK; 2931 2932 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2933 // Check for a better reference binding based on the kind of bindings. 2934 if (isBetterReferenceBindingKind(SCS1, SCS2)) 2935 return ImplicitConversionSequence::Better; 2936 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 2937 return ImplicitConversionSequence::Worse; 2938 2939 // C++ [over.ics.rank]p3b4: 2940 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2941 // which the references refer are the same type except for 2942 // top-level cv-qualifiers, and the type to which the reference 2943 // initialized by S2 refers is more cv-qualified than the type 2944 // to which the reference initialized by S1 refers. 2945 QualType T1 = SCS1.getToType(2); 2946 QualType T2 = SCS2.getToType(2); 2947 T1 = S.Context.getCanonicalType(T1); 2948 T2 = S.Context.getCanonicalType(T2); 2949 Qualifiers T1Quals, T2Quals; 2950 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2951 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2952 if (UnqualT1 == UnqualT2) { 2953 // Objective-C++ ARC: If the references refer to objects with different 2954 // lifetimes, prefer bindings that don't change lifetime. 2955 if (SCS1.ObjCLifetimeConversionBinding != 2956 SCS2.ObjCLifetimeConversionBinding) { 2957 return SCS1.ObjCLifetimeConversionBinding 2958 ? ImplicitConversionSequence::Worse 2959 : ImplicitConversionSequence::Better; 2960 } 2961 2962 // If the type is an array type, promote the element qualifiers to the 2963 // type for comparison. 2964 if (isa<ArrayType>(T1) && T1Quals) 2965 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2966 if (isa<ArrayType>(T2) && T2Quals) 2967 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2968 if (T2.isMoreQualifiedThan(T1)) 2969 return ImplicitConversionSequence::Better; 2970 else if (T1.isMoreQualifiedThan(T2)) 2971 return ImplicitConversionSequence::Worse; 2972 } 2973 } 2974 2975 // In Microsoft mode, prefer an integral conversion to a 2976 // floating-to-integral conversion if the integral conversion 2977 // is between types of the same size. 2978 // For example: 2979 // void f(float); 2980 // void f(int); 2981 // int main { 2982 // long a; 2983 // f(a); 2984 // } 2985 // Here, MSVC will call f(int) instead of generating a compile error 2986 // as clang will do in standard mode. 2987 if (S.getLangOptions().MicrosoftMode && 2988 SCS1.Second == ICK_Integral_Conversion && 2989 SCS2.Second == ICK_Floating_Integral && 2990 S.Context.getTypeSize(SCS1.getFromType()) == 2991 S.Context.getTypeSize(SCS1.getToType(2))) 2992 return ImplicitConversionSequence::Better; 2993 2994 return ImplicitConversionSequence::Indistinguishable; 2995} 2996 2997/// CompareQualificationConversions - Compares two standard conversion 2998/// sequences to determine whether they can be ranked based on their 2999/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 3000ImplicitConversionSequence::CompareKind 3001CompareQualificationConversions(Sema &S, 3002 const StandardConversionSequence& SCS1, 3003 const StandardConversionSequence& SCS2) { 3004 // C++ 13.3.3.2p3: 3005 // -- S1 and S2 differ only in their qualification conversion and 3006 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 3007 // cv-qualification signature of type T1 is a proper subset of 3008 // the cv-qualification signature of type T2, and S1 is not the 3009 // deprecated string literal array-to-pointer conversion (4.2). 3010 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 3011 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 3012 return ImplicitConversionSequence::Indistinguishable; 3013 3014 // FIXME: the example in the standard doesn't use a qualification 3015 // conversion (!) 3016 QualType T1 = SCS1.getToType(2); 3017 QualType T2 = SCS2.getToType(2); 3018 T1 = S.Context.getCanonicalType(T1); 3019 T2 = S.Context.getCanonicalType(T2); 3020 Qualifiers T1Quals, T2Quals; 3021 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3022 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3023 3024 // If the types are the same, we won't learn anything by unwrapped 3025 // them. 3026 if (UnqualT1 == UnqualT2) 3027 return ImplicitConversionSequence::Indistinguishable; 3028 3029 // If the type is an array type, promote the element qualifiers to the type 3030 // for comparison. 3031 if (isa<ArrayType>(T1) && T1Quals) 3032 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3033 if (isa<ArrayType>(T2) && T2Quals) 3034 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3035 3036 ImplicitConversionSequence::CompareKind Result 3037 = ImplicitConversionSequence::Indistinguishable; 3038 3039 // Objective-C++ ARC: 3040 // Prefer qualification conversions not involving a change in lifetime 3041 // to qualification conversions that do not change lifetime. 3042 if (SCS1.QualificationIncludesObjCLifetime != 3043 SCS2.QualificationIncludesObjCLifetime) { 3044 Result = SCS1.QualificationIncludesObjCLifetime 3045 ? ImplicitConversionSequence::Worse 3046 : ImplicitConversionSequence::Better; 3047 } 3048 3049 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 3050 // Within each iteration of the loop, we check the qualifiers to 3051 // determine if this still looks like a qualification 3052 // conversion. Then, if all is well, we unwrap one more level of 3053 // pointers or pointers-to-members and do it all again 3054 // until there are no more pointers or pointers-to-members left 3055 // to unwrap. This essentially mimics what 3056 // IsQualificationConversion does, but here we're checking for a 3057 // strict subset of qualifiers. 3058 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 3059 // The qualifiers are the same, so this doesn't tell us anything 3060 // about how the sequences rank. 3061 ; 3062 else if (T2.isMoreQualifiedThan(T1)) { 3063 // T1 has fewer qualifiers, so it could be the better sequence. 3064 if (Result == ImplicitConversionSequence::Worse) 3065 // Neither has qualifiers that are a subset of the other's 3066 // qualifiers. 3067 return ImplicitConversionSequence::Indistinguishable; 3068 3069 Result = ImplicitConversionSequence::Better; 3070 } else if (T1.isMoreQualifiedThan(T2)) { 3071 // T2 has fewer qualifiers, so it could be the better sequence. 3072 if (Result == ImplicitConversionSequence::Better) 3073 // Neither has qualifiers that are a subset of the other's 3074 // qualifiers. 3075 return ImplicitConversionSequence::Indistinguishable; 3076 3077 Result = ImplicitConversionSequence::Worse; 3078 } else { 3079 // Qualifiers are disjoint. 3080 return ImplicitConversionSequence::Indistinguishable; 3081 } 3082 3083 // If the types after this point are equivalent, we're done. 3084 if (S.Context.hasSameUnqualifiedType(T1, T2)) 3085 break; 3086 } 3087 3088 // Check that the winning standard conversion sequence isn't using 3089 // the deprecated string literal array to pointer conversion. 3090 switch (Result) { 3091 case ImplicitConversionSequence::Better: 3092 if (SCS1.DeprecatedStringLiteralToCharPtr) 3093 Result = ImplicitConversionSequence::Indistinguishable; 3094 break; 3095 3096 case ImplicitConversionSequence::Indistinguishable: 3097 break; 3098 3099 case ImplicitConversionSequence::Worse: 3100 if (SCS2.DeprecatedStringLiteralToCharPtr) 3101 Result = ImplicitConversionSequence::Indistinguishable; 3102 break; 3103 } 3104 3105 return Result; 3106} 3107 3108/// CompareDerivedToBaseConversions - Compares two standard conversion 3109/// sequences to determine whether they can be ranked based on their 3110/// various kinds of derived-to-base conversions (C++ 3111/// [over.ics.rank]p4b3). As part of these checks, we also look at 3112/// conversions between Objective-C interface types. 3113ImplicitConversionSequence::CompareKind 3114CompareDerivedToBaseConversions(Sema &S, 3115 const StandardConversionSequence& SCS1, 3116 const StandardConversionSequence& SCS2) { 3117 QualType FromType1 = SCS1.getFromType(); 3118 QualType ToType1 = SCS1.getToType(1); 3119 QualType FromType2 = SCS2.getFromType(); 3120 QualType ToType2 = SCS2.getToType(1); 3121 3122 // Adjust the types we're converting from via the array-to-pointer 3123 // conversion, if we need to. 3124 if (SCS1.First == ICK_Array_To_Pointer) 3125 FromType1 = S.Context.getArrayDecayedType(FromType1); 3126 if (SCS2.First == ICK_Array_To_Pointer) 3127 FromType2 = S.Context.getArrayDecayedType(FromType2); 3128 3129 // Canonicalize all of the types. 3130 FromType1 = S.Context.getCanonicalType(FromType1); 3131 ToType1 = S.Context.getCanonicalType(ToType1); 3132 FromType2 = S.Context.getCanonicalType(FromType2); 3133 ToType2 = S.Context.getCanonicalType(ToType2); 3134 3135 // C++ [over.ics.rank]p4b3: 3136 // 3137 // If class B is derived directly or indirectly from class A and 3138 // class C is derived directly or indirectly from B, 3139 // 3140 // Compare based on pointer conversions. 3141 if (SCS1.Second == ICK_Pointer_Conversion && 3142 SCS2.Second == ICK_Pointer_Conversion && 3143 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 3144 FromType1->isPointerType() && FromType2->isPointerType() && 3145 ToType1->isPointerType() && ToType2->isPointerType()) { 3146 QualType FromPointee1 3147 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3148 QualType ToPointee1 3149 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3150 QualType FromPointee2 3151 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3152 QualType ToPointee2 3153 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3154 3155 // -- conversion of C* to B* is better than conversion of C* to A*, 3156 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3157 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3158 return ImplicitConversionSequence::Better; 3159 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3160 return ImplicitConversionSequence::Worse; 3161 } 3162 3163 // -- conversion of B* to A* is better than conversion of C* to A*, 3164 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 3165 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3166 return ImplicitConversionSequence::Better; 3167 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3168 return ImplicitConversionSequence::Worse; 3169 } 3170 } else if (SCS1.Second == ICK_Pointer_Conversion && 3171 SCS2.Second == ICK_Pointer_Conversion) { 3172 const ObjCObjectPointerType *FromPtr1 3173 = FromType1->getAs<ObjCObjectPointerType>(); 3174 const ObjCObjectPointerType *FromPtr2 3175 = FromType2->getAs<ObjCObjectPointerType>(); 3176 const ObjCObjectPointerType *ToPtr1 3177 = ToType1->getAs<ObjCObjectPointerType>(); 3178 const ObjCObjectPointerType *ToPtr2 3179 = ToType2->getAs<ObjCObjectPointerType>(); 3180 3181 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 3182 // Apply the same conversion ranking rules for Objective-C pointer types 3183 // that we do for C++ pointers to class types. However, we employ the 3184 // Objective-C pseudo-subtyping relationship used for assignment of 3185 // Objective-C pointer types. 3186 bool FromAssignLeft 3187 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 3188 bool FromAssignRight 3189 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 3190 bool ToAssignLeft 3191 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 3192 bool ToAssignRight 3193 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 3194 3195 // A conversion to an a non-id object pointer type or qualified 'id' 3196 // type is better than a conversion to 'id'. 3197 if (ToPtr1->isObjCIdType() && 3198 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 3199 return ImplicitConversionSequence::Worse; 3200 if (ToPtr2->isObjCIdType() && 3201 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 3202 return ImplicitConversionSequence::Better; 3203 3204 // A conversion to a non-id object pointer type is better than a 3205 // conversion to a qualified 'id' type 3206 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 3207 return ImplicitConversionSequence::Worse; 3208 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 3209 return ImplicitConversionSequence::Better; 3210 3211 // A conversion to an a non-Class object pointer type or qualified 'Class' 3212 // type is better than a conversion to 'Class'. 3213 if (ToPtr1->isObjCClassType() && 3214 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 3215 return ImplicitConversionSequence::Worse; 3216 if (ToPtr2->isObjCClassType() && 3217 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 3218 return ImplicitConversionSequence::Better; 3219 3220 // A conversion to a non-Class object pointer type is better than a 3221 // conversion to a qualified 'Class' type. 3222 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 3223 return ImplicitConversionSequence::Worse; 3224 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 3225 return ImplicitConversionSequence::Better; 3226 3227 // -- "conversion of C* to B* is better than conversion of C* to A*," 3228 if (S.Context.hasSameType(FromType1, FromType2) && 3229 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 3230 (ToAssignLeft != ToAssignRight)) 3231 return ToAssignLeft? ImplicitConversionSequence::Worse 3232 : ImplicitConversionSequence::Better; 3233 3234 // -- "conversion of B* to A* is better than conversion of C* to A*," 3235 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 3236 (FromAssignLeft != FromAssignRight)) 3237 return FromAssignLeft? ImplicitConversionSequence::Better 3238 : ImplicitConversionSequence::Worse; 3239 } 3240 } 3241 3242 // Ranking of member-pointer types. 3243 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 3244 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 3245 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 3246 const MemberPointerType * FromMemPointer1 = 3247 FromType1->getAs<MemberPointerType>(); 3248 const MemberPointerType * ToMemPointer1 = 3249 ToType1->getAs<MemberPointerType>(); 3250 const MemberPointerType * FromMemPointer2 = 3251 FromType2->getAs<MemberPointerType>(); 3252 const MemberPointerType * ToMemPointer2 = 3253 ToType2->getAs<MemberPointerType>(); 3254 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 3255 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 3256 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 3257 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 3258 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 3259 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 3260 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 3261 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 3262 // conversion of A::* to B::* is better than conversion of A::* to C::*, 3263 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3264 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3265 return ImplicitConversionSequence::Worse; 3266 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3267 return ImplicitConversionSequence::Better; 3268 } 3269 // conversion of B::* to C::* is better than conversion of A::* to C::* 3270 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 3271 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3272 return ImplicitConversionSequence::Better; 3273 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3274 return ImplicitConversionSequence::Worse; 3275 } 3276 } 3277 3278 if (SCS1.Second == ICK_Derived_To_Base) { 3279 // -- conversion of C to B is better than conversion of C to A, 3280 // -- binding of an expression of type C to a reference of type 3281 // B& is better than binding an expression of type C to a 3282 // reference of type A&, 3283 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3284 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3285 if (S.IsDerivedFrom(ToType1, ToType2)) 3286 return ImplicitConversionSequence::Better; 3287 else if (S.IsDerivedFrom(ToType2, ToType1)) 3288 return ImplicitConversionSequence::Worse; 3289 } 3290 3291 // -- conversion of B to A is better than conversion of C to A. 3292 // -- binding of an expression of type B to a reference of type 3293 // A& is better than binding an expression of type C to a 3294 // reference of type A&, 3295 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3296 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3297 if (S.IsDerivedFrom(FromType2, FromType1)) 3298 return ImplicitConversionSequence::Better; 3299 else if (S.IsDerivedFrom(FromType1, FromType2)) 3300 return ImplicitConversionSequence::Worse; 3301 } 3302 } 3303 3304 return ImplicitConversionSequence::Indistinguishable; 3305} 3306 3307/// CompareReferenceRelationship - Compare the two types T1 and T2 to 3308/// determine whether they are reference-related, 3309/// reference-compatible, reference-compatible with added 3310/// qualification, or incompatible, for use in C++ initialization by 3311/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 3312/// type, and the first type (T1) is the pointee type of the reference 3313/// type being initialized. 3314Sema::ReferenceCompareResult 3315Sema::CompareReferenceRelationship(SourceLocation Loc, 3316 QualType OrigT1, QualType OrigT2, 3317 bool &DerivedToBase, 3318 bool &ObjCConversion, 3319 bool &ObjCLifetimeConversion) { 3320 assert(!OrigT1->isReferenceType() && 3321 "T1 must be the pointee type of the reference type"); 3322 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 3323 3324 QualType T1 = Context.getCanonicalType(OrigT1); 3325 QualType T2 = Context.getCanonicalType(OrigT2); 3326 Qualifiers T1Quals, T2Quals; 3327 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 3328 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 3329 3330 // C++ [dcl.init.ref]p4: 3331 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 3332 // reference-related to "cv2 T2" if T1 is the same type as T2, or 3333 // T1 is a base class of T2. 3334 DerivedToBase = false; 3335 ObjCConversion = false; 3336 ObjCLifetimeConversion = false; 3337 if (UnqualT1 == UnqualT2) { 3338 // Nothing to do. 3339 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 3340 IsDerivedFrom(UnqualT2, UnqualT1)) 3341 DerivedToBase = true; 3342 else if (UnqualT1->isObjCObjectOrInterfaceType() && 3343 UnqualT2->isObjCObjectOrInterfaceType() && 3344 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 3345 ObjCConversion = true; 3346 else 3347 return Ref_Incompatible; 3348 3349 // At this point, we know that T1 and T2 are reference-related (at 3350 // least). 3351 3352 // If the type is an array type, promote the element qualifiers to the type 3353 // for comparison. 3354 if (isa<ArrayType>(T1) && T1Quals) 3355 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 3356 if (isa<ArrayType>(T2) && T2Quals) 3357 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 3358 3359 // C++ [dcl.init.ref]p4: 3360 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 3361 // reference-related to T2 and cv1 is the same cv-qualification 3362 // as, or greater cv-qualification than, cv2. For purposes of 3363 // overload resolution, cases for which cv1 is greater 3364 // cv-qualification than cv2 are identified as 3365 // reference-compatible with added qualification (see 13.3.3.2). 3366 // 3367 // Note that we also require equivalence of Objective-C GC and address-space 3368 // qualifiers when performing these computations, so that e.g., an int in 3369 // address space 1 is not reference-compatible with an int in address 3370 // space 2. 3371 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() && 3372 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) { 3373 T1Quals.removeObjCLifetime(); 3374 T2Quals.removeObjCLifetime(); 3375 ObjCLifetimeConversion = true; 3376 } 3377 3378 if (T1Quals == T2Quals) 3379 return Ref_Compatible; 3380 else if (T1Quals.compatiblyIncludes(T2Quals)) 3381 return Ref_Compatible_With_Added_Qualification; 3382 else 3383 return Ref_Related; 3384} 3385 3386/// \brief Look for a user-defined conversion to an value reference-compatible 3387/// with DeclType. Return true if something definite is found. 3388static bool 3389FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 3390 QualType DeclType, SourceLocation DeclLoc, 3391 Expr *Init, QualType T2, bool AllowRvalues, 3392 bool AllowExplicit) { 3393 assert(T2->isRecordType() && "Can only find conversions of record types."); 3394 CXXRecordDecl *T2RecordDecl 3395 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 3396 3397 OverloadCandidateSet CandidateSet(DeclLoc); 3398 const UnresolvedSetImpl *Conversions 3399 = T2RecordDecl->getVisibleConversionFunctions(); 3400 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3401 E = Conversions->end(); I != E; ++I) { 3402 NamedDecl *D = *I; 3403 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3404 if (isa<UsingShadowDecl>(D)) 3405 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3406 3407 FunctionTemplateDecl *ConvTemplate 3408 = dyn_cast<FunctionTemplateDecl>(D); 3409 CXXConversionDecl *Conv; 3410 if (ConvTemplate) 3411 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3412 else 3413 Conv = cast<CXXConversionDecl>(D); 3414 3415 // If this is an explicit conversion, and we're not allowed to consider 3416 // explicit conversions, skip it. 3417 if (!AllowExplicit && Conv->isExplicit()) 3418 continue; 3419 3420 if (AllowRvalues) { 3421 bool DerivedToBase = false; 3422 bool ObjCConversion = false; 3423 bool ObjCLifetimeConversion = false; 3424 3425 // If we are initializing an rvalue reference, don't permit conversion 3426 // functions that return lvalues. 3427 if (!ConvTemplate && DeclType->isRValueReferenceType()) { 3428 const ReferenceType *RefType 3429 = Conv->getConversionType()->getAs<LValueReferenceType>(); 3430 if (RefType && !RefType->getPointeeType()->isFunctionType()) 3431 continue; 3432 } 3433 3434 if (!ConvTemplate && 3435 S.CompareReferenceRelationship( 3436 DeclLoc, 3437 Conv->getConversionType().getNonReferenceType() 3438 .getUnqualifiedType(), 3439 DeclType.getNonReferenceType().getUnqualifiedType(), 3440 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) == 3441 Sema::Ref_Incompatible) 3442 continue; 3443 } else { 3444 // If the conversion function doesn't return a reference type, 3445 // it can't be considered for this conversion. An rvalue reference 3446 // is only acceptable if its referencee is a function type. 3447 3448 const ReferenceType *RefType = 3449 Conv->getConversionType()->getAs<ReferenceType>(); 3450 if (!RefType || 3451 (!RefType->isLValueReferenceType() && 3452 !RefType->getPointeeType()->isFunctionType())) 3453 continue; 3454 } 3455 3456 if (ConvTemplate) 3457 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 3458 Init, DeclType, CandidateSet); 3459 else 3460 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 3461 DeclType, CandidateSet); 3462 } 3463 3464 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3465 3466 OverloadCandidateSet::iterator Best; 3467 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 3468 case OR_Success: 3469 // C++ [over.ics.ref]p1: 3470 // 3471 // [...] If the parameter binds directly to the result of 3472 // applying a conversion function to the argument 3473 // expression, the implicit conversion sequence is a 3474 // user-defined conversion sequence (13.3.3.1.2), with the 3475 // second standard conversion sequence either an identity 3476 // conversion or, if the conversion function returns an 3477 // entity of a type that is a derived class of the parameter 3478 // type, a derived-to-base Conversion. 3479 if (!Best->FinalConversion.DirectBinding) 3480 return false; 3481 3482 if (Best->Function) 3483 S.MarkDeclarationReferenced(DeclLoc, Best->Function); 3484 ICS.setUserDefined(); 3485 ICS.UserDefined.Before = Best->Conversions[0].Standard; 3486 ICS.UserDefined.After = Best->FinalConversion; 3487 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates; 3488 ICS.UserDefined.ConversionFunction = Best->Function; 3489 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl; 3490 ICS.UserDefined.EllipsisConversion = false; 3491 assert(ICS.UserDefined.After.ReferenceBinding && 3492 ICS.UserDefined.After.DirectBinding && 3493 "Expected a direct reference binding!"); 3494 return true; 3495 3496 case OR_Ambiguous: 3497 ICS.setAmbiguous(); 3498 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3499 Cand != CandidateSet.end(); ++Cand) 3500 if (Cand->Viable) 3501 ICS.Ambiguous.addConversion(Cand->Function); 3502 return true; 3503 3504 case OR_No_Viable_Function: 3505 case OR_Deleted: 3506 // There was no suitable conversion, or we found a deleted 3507 // conversion; continue with other checks. 3508 return false; 3509 } 3510 3511 return false; 3512} 3513 3514/// \brief Compute an implicit conversion sequence for reference 3515/// initialization. 3516static ImplicitConversionSequence 3517TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 3518 SourceLocation DeclLoc, 3519 bool SuppressUserConversions, 3520 bool AllowExplicit) { 3521 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 3522 3523 // Most paths end in a failed conversion. 3524 ImplicitConversionSequence ICS; 3525 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3526 3527 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 3528 QualType T2 = Init->getType(); 3529 3530 // If the initializer is the address of an overloaded function, try 3531 // to resolve the overloaded function. If all goes well, T2 is the 3532 // type of the resulting function. 3533 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 3534 DeclAccessPair Found; 3535 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 3536 false, Found)) 3537 T2 = Fn->getType(); 3538 } 3539 3540 // Compute some basic properties of the types and the initializer. 3541 bool isRValRef = DeclType->isRValueReferenceType(); 3542 bool DerivedToBase = false; 3543 bool ObjCConversion = false; 3544 bool ObjCLifetimeConversion = false; 3545 Expr::Classification InitCategory = Init->Classify(S.Context); 3546 Sema::ReferenceCompareResult RefRelationship 3547 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 3548 ObjCConversion, ObjCLifetimeConversion); 3549 3550 3551 // C++0x [dcl.init.ref]p5: 3552 // A reference to type "cv1 T1" is initialized by an expression 3553 // of type "cv2 T2" as follows: 3554 3555 // -- If reference is an lvalue reference and the initializer expression 3556 if (!isRValRef) { 3557 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 3558 // reference-compatible with "cv2 T2," or 3559 // 3560 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 3561 if (InitCategory.isLValue() && 3562 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 3563 // C++ [over.ics.ref]p1: 3564 // When a parameter of reference type binds directly (8.5.3) 3565 // to an argument expression, the implicit conversion sequence 3566 // is the identity conversion, unless the argument expression 3567 // has a type that is a derived class of the parameter type, 3568 // in which case the implicit conversion sequence is a 3569 // derived-to-base Conversion (13.3.3.1). 3570 ICS.setStandard(); 3571 ICS.Standard.First = ICK_Identity; 3572 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3573 : ObjCConversion? ICK_Compatible_Conversion 3574 : ICK_Identity; 3575 ICS.Standard.Third = ICK_Identity; 3576 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3577 ICS.Standard.setToType(0, T2); 3578 ICS.Standard.setToType(1, T1); 3579 ICS.Standard.setToType(2, T1); 3580 ICS.Standard.ReferenceBinding = true; 3581 ICS.Standard.DirectBinding = true; 3582 ICS.Standard.IsLvalueReference = !isRValRef; 3583 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3584 ICS.Standard.BindsToRvalue = false; 3585 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3586 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 3587 ICS.Standard.CopyConstructor = 0; 3588 3589 // Nothing more to do: the inaccessibility/ambiguity check for 3590 // derived-to-base conversions is suppressed when we're 3591 // computing the implicit conversion sequence (C++ 3592 // [over.best.ics]p2). 3593 return ICS; 3594 } 3595 3596 // -- has a class type (i.e., T2 is a class type), where T1 is 3597 // not reference-related to T2, and can be implicitly 3598 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 3599 // is reference-compatible with "cv3 T3" 92) (this 3600 // conversion is selected by enumerating the applicable 3601 // conversion functions (13.3.1.6) and choosing the best 3602 // one through overload resolution (13.3)), 3603 if (!SuppressUserConversions && T2->isRecordType() && 3604 !S.RequireCompleteType(DeclLoc, T2, 0) && 3605 RefRelationship == Sema::Ref_Incompatible) { 3606 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3607 Init, T2, /*AllowRvalues=*/false, 3608 AllowExplicit)) 3609 return ICS; 3610 } 3611 } 3612 3613 // -- Otherwise, the reference shall be an lvalue reference to a 3614 // non-volatile const type (i.e., cv1 shall be const), or the reference 3615 // shall be an rvalue reference. 3616 // 3617 // We actually handle one oddity of C++ [over.ics.ref] at this 3618 // point, which is that, due to p2 (which short-circuits reference 3619 // binding by only attempting a simple conversion for non-direct 3620 // bindings) and p3's strange wording, we allow a const volatile 3621 // reference to bind to an rvalue. Hence the check for the presence 3622 // of "const" rather than checking for "const" being the only 3623 // qualifier. 3624 // This is also the point where rvalue references and lvalue inits no longer 3625 // go together. 3626 if (!isRValRef && !T1.isConstQualified()) 3627 return ICS; 3628 3629 // -- If the initializer expression 3630 // 3631 // -- is an xvalue, class prvalue, array prvalue or function 3632 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or 3633 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 3634 (InitCategory.isXValue() || 3635 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 3636 (InitCategory.isLValue() && T2->isFunctionType()))) { 3637 ICS.setStandard(); 3638 ICS.Standard.First = ICK_Identity; 3639 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3640 : ObjCConversion? ICK_Compatible_Conversion 3641 : ICK_Identity; 3642 ICS.Standard.Third = ICK_Identity; 3643 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3644 ICS.Standard.setToType(0, T2); 3645 ICS.Standard.setToType(1, T1); 3646 ICS.Standard.setToType(2, T1); 3647 ICS.Standard.ReferenceBinding = true; 3648 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 3649 // binding unless we're binding to a class prvalue. 3650 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 3651 // allow the use of rvalue references in C++98/03 for the benefit of 3652 // standard library implementors; therefore, we need the xvalue check here. 3653 ICS.Standard.DirectBinding = 3654 S.getLangOptions().CPlusPlus0x || 3655 (InitCategory.isPRValue() && !T2->isRecordType()); 3656 ICS.Standard.IsLvalueReference = !isRValRef; 3657 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3658 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 3659 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3660 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 3661 ICS.Standard.CopyConstructor = 0; 3662 return ICS; 3663 } 3664 3665 // -- has a class type (i.e., T2 is a class type), where T1 is not 3666 // reference-related to T2, and can be implicitly converted to 3667 // an xvalue, class prvalue, or function lvalue of type 3668 // "cv3 T3", where "cv1 T1" is reference-compatible with 3669 // "cv3 T3", 3670 // 3671 // then the reference is bound to the value of the initializer 3672 // expression in the first case and to the result of the conversion 3673 // in the second case (or, in either case, to an appropriate base 3674 // class subobject). 3675 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3676 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 3677 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3678 Init, T2, /*AllowRvalues=*/true, 3679 AllowExplicit)) { 3680 // In the second case, if the reference is an rvalue reference 3681 // and the second standard conversion sequence of the 3682 // user-defined conversion sequence includes an lvalue-to-rvalue 3683 // conversion, the program is ill-formed. 3684 if (ICS.isUserDefined() && isRValRef && 3685 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 3686 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3687 3688 return ICS; 3689 } 3690 3691 // -- Otherwise, a temporary of type "cv1 T1" is created and 3692 // initialized from the initializer expression using the 3693 // rules for a non-reference copy initialization (8.5). The 3694 // reference is then bound to the temporary. If T1 is 3695 // reference-related to T2, cv1 must be the same 3696 // cv-qualification as, or greater cv-qualification than, 3697 // cv2; otherwise, the program is ill-formed. 3698 if (RefRelationship == Sema::Ref_Related) { 3699 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 3700 // we would be reference-compatible or reference-compatible with 3701 // added qualification. But that wasn't the case, so the reference 3702 // initialization fails. 3703 // 3704 // Note that we only want to check address spaces and cvr-qualifiers here. 3705 // ObjC GC and lifetime qualifiers aren't important. 3706 Qualifiers T1Quals = T1.getQualifiers(); 3707 Qualifiers T2Quals = T2.getQualifiers(); 3708 T1Quals.removeObjCGCAttr(); 3709 T1Quals.removeObjCLifetime(); 3710 T2Quals.removeObjCGCAttr(); 3711 T2Quals.removeObjCLifetime(); 3712 if (!T1Quals.compatiblyIncludes(T2Quals)) 3713 return ICS; 3714 } 3715 3716 // If at least one of the types is a class type, the types are not 3717 // related, and we aren't allowed any user conversions, the 3718 // reference binding fails. This case is important for breaking 3719 // recursion, since TryImplicitConversion below will attempt to 3720 // create a temporary through the use of a copy constructor. 3721 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3722 (T1->isRecordType() || T2->isRecordType())) 3723 return ICS; 3724 3725 // If T1 is reference-related to T2 and the reference is an rvalue 3726 // reference, the initializer expression shall not be an lvalue. 3727 if (RefRelationship >= Sema::Ref_Related && 3728 isRValRef && Init->Classify(S.Context).isLValue()) 3729 return ICS; 3730 3731 // C++ [over.ics.ref]p2: 3732 // When a parameter of reference type is not bound directly to 3733 // an argument expression, the conversion sequence is the one 3734 // required to convert the argument expression to the 3735 // underlying type of the reference according to 3736 // 13.3.3.1. Conceptually, this conversion sequence corresponds 3737 // to copy-initializing a temporary of the underlying type with 3738 // the argument expression. Any difference in top-level 3739 // cv-qualification is subsumed by the initialization itself 3740 // and does not constitute a conversion. 3741 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 3742 /*AllowExplicit=*/false, 3743 /*InOverloadResolution=*/false, 3744 /*CStyle=*/false, 3745 /*AllowObjCWritebackConversion=*/false); 3746 3747 // Of course, that's still a reference binding. 3748 if (ICS.isStandard()) { 3749 ICS.Standard.ReferenceBinding = true; 3750 ICS.Standard.IsLvalueReference = !isRValRef; 3751 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3752 ICS.Standard.BindsToRvalue = true; 3753 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3754 ICS.Standard.ObjCLifetimeConversionBinding = false; 3755 } else if (ICS.isUserDefined()) { 3756 // Don't allow rvalue references to bind to lvalues. 3757 if (DeclType->isRValueReferenceType()) { 3758 if (const ReferenceType *RefType 3759 = ICS.UserDefined.ConversionFunction->getResultType() 3760 ->getAs<LValueReferenceType>()) { 3761 if (!RefType->getPointeeType()->isFunctionType()) { 3762 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, 3763 DeclType); 3764 return ICS; 3765 } 3766 } 3767 } 3768 3769 ICS.UserDefined.After.ReferenceBinding = true; 3770 ICS.UserDefined.After.IsLvalueReference = !isRValRef; 3771 ICS.UserDefined.After.BindsToFunctionLvalue = T2->isFunctionType(); 3772 ICS.UserDefined.After.BindsToRvalue = true; 3773 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3774 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false; 3775 } 3776 3777 return ICS; 3778} 3779 3780static ImplicitConversionSequence 3781TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 3782 bool SuppressUserConversions, 3783 bool InOverloadResolution, 3784 bool AllowObjCWritebackConversion); 3785 3786/// TryListConversion - Try to copy-initialize a value of type ToType from the 3787/// initializer list From. 3788static ImplicitConversionSequence 3789TryListConversion(Sema &S, InitListExpr *From, QualType ToType, 3790 bool SuppressUserConversions, 3791 bool InOverloadResolution, 3792 bool AllowObjCWritebackConversion) { 3793 // C++11 [over.ics.list]p1: 3794 // When an argument is an initializer list, it is not an expression and 3795 // special rules apply for converting it to a parameter type. 3796 3797 ImplicitConversionSequence Result; 3798 Result.setBad(BadConversionSequence::no_conversion, From, ToType); 3799 Result.setListInitializationSequence(); 3800 3801 // C++11 [over.ics.list]p2: 3802 // If the parameter type is std::initializer_list<X> or "array of X" and 3803 // all the elements can be implicitly converted to X, the implicit 3804 // conversion sequence is the worst conversion necessary to convert an 3805 // element of the list to X. 3806 // FIXME: Recognize std::initializer_list. 3807 // FIXME: Arrays don't make sense until we can deal with references. 3808 if (ToType->isArrayType()) 3809 return Result; 3810 3811 // C++11 [over.ics.list]p3: 3812 // Otherwise, if the parameter is a non-aggregate class X and overload 3813 // resolution chooses a single best constructor [...] the implicit 3814 // conversion sequence is a user-defined conversion sequence. If multiple 3815 // constructors are viable but none is better than the others, the 3816 // implicit conversion sequence is a user-defined conversion sequence. 3817 // FIXME: Implement this. 3818 if (ToType->isRecordType() && !ToType->isAggregateType()) 3819 return Result; 3820 3821 // C++11 [over.ics.list]p4: 3822 // Otherwise, if the parameter has an aggregate type which can be 3823 // initialized from the initializer list [...] the implicit conversion 3824 // sequence is a user-defined conversion sequence. 3825 if (ToType->isAggregateType()) { 3826 // Type is an aggregate, argument is an init list. At this point it comes 3827 // down to checking whether the initialization works. 3828 // FIXME: Find out whether this parameter is consumed or not. 3829 InitializedEntity Entity = 3830 InitializedEntity::InitializeParameter(S.Context, ToType, 3831 /*Consumed=*/false); 3832 if (S.CanPerformCopyInitialization(Entity, S.Owned(From))) { 3833 Result.setUserDefined(); 3834 Result.UserDefined.Before.setAsIdentityConversion(); 3835 // Initializer lists don't have a type. 3836 Result.UserDefined.Before.setFromType(QualType()); 3837 Result.UserDefined.Before.setAllToTypes(QualType()); 3838 3839 Result.UserDefined.After.setAsIdentityConversion(); 3840 Result.UserDefined.After.setFromType(ToType); 3841 Result.UserDefined.After.setAllToTypes(ToType); 3842 } 3843 return Result; 3844 } 3845 3846 // C++11 [over.ics.list]p5: 3847 // Otherwise, if the parameter is a reference, see 13.3.3.1.4. 3848 // FIXME: Implement this. 3849 if (ToType->isReferenceType()) 3850 return Result; 3851 3852 // C++11 [over.ics.list]p6: 3853 // Otherwise, if the parameter type is not a class: 3854 if (!ToType->isRecordType()) { 3855 // - if the initializer list has one element, the implicit conversion 3856 // sequence is the one required to convert the element to the 3857 // parameter type. 3858 // FIXME: Catch narrowing here? 3859 unsigned NumInits = From->getNumInits(); 3860 if (NumInits == 1) 3861 Result = TryCopyInitialization(S, From->getInit(0), ToType, 3862 SuppressUserConversions, 3863 InOverloadResolution, 3864 AllowObjCWritebackConversion); 3865 // - if the initializer list has no elements, the implicit conversion 3866 // sequence is the identity conversion. 3867 else if (NumInits == 0) { 3868 Result.setStandard(); 3869 Result.Standard.setAsIdentityConversion(); 3870 } 3871 return Result; 3872 } 3873 3874 // C++11 [over.ics.list]p7: 3875 // In all cases other than those enumerated above, no conversion is possible 3876 return Result; 3877} 3878 3879/// TryCopyInitialization - Try to copy-initialize a value of type 3880/// ToType from the expression From. Return the implicit conversion 3881/// sequence required to pass this argument, which may be a bad 3882/// conversion sequence (meaning that the argument cannot be passed to 3883/// a parameter of this type). If @p SuppressUserConversions, then we 3884/// do not permit any user-defined conversion sequences. 3885static ImplicitConversionSequence 3886TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 3887 bool SuppressUserConversions, 3888 bool InOverloadResolution, 3889 bool AllowObjCWritebackConversion) { 3890 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From)) 3891 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions, 3892 InOverloadResolution,AllowObjCWritebackConversion); 3893 3894 if (ToType->isReferenceType()) 3895 return TryReferenceInit(S, From, ToType, 3896 /*FIXME:*/From->getLocStart(), 3897 SuppressUserConversions, 3898 /*AllowExplicit=*/false); 3899 3900 return TryImplicitConversion(S, From, ToType, 3901 SuppressUserConversions, 3902 /*AllowExplicit=*/false, 3903 InOverloadResolution, 3904 /*CStyle=*/false, 3905 AllowObjCWritebackConversion); 3906} 3907 3908static bool TryCopyInitialization(const CanQualType FromQTy, 3909 const CanQualType ToQTy, 3910 Sema &S, 3911 SourceLocation Loc, 3912 ExprValueKind FromVK) { 3913 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK); 3914 ImplicitConversionSequence ICS = 3915 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false); 3916 3917 return !ICS.isBad(); 3918} 3919 3920/// TryObjectArgumentInitialization - Try to initialize the object 3921/// parameter of the given member function (@c Method) from the 3922/// expression @p From. 3923static ImplicitConversionSequence 3924TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 3925 Expr::Classification FromClassification, 3926 CXXMethodDecl *Method, 3927 CXXRecordDecl *ActingContext) { 3928 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 3929 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 3930 // const volatile object. 3931 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 3932 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 3933 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 3934 3935 // Set up the conversion sequence as a "bad" conversion, to allow us 3936 // to exit early. 3937 ImplicitConversionSequence ICS; 3938 3939 // We need to have an object of class type. 3940 QualType FromType = OrigFromType; 3941 if (const PointerType *PT = FromType->getAs<PointerType>()) { 3942 FromType = PT->getPointeeType(); 3943 3944 // When we had a pointer, it's implicitly dereferenced, so we 3945 // better have an lvalue. 3946 assert(FromClassification.isLValue()); 3947 } 3948 3949 assert(FromType->isRecordType()); 3950 3951 // C++0x [over.match.funcs]p4: 3952 // For non-static member functions, the type of the implicit object 3953 // parameter is 3954 // 3955 // - "lvalue reference to cv X" for functions declared without a 3956 // ref-qualifier or with the & ref-qualifier 3957 // - "rvalue reference to cv X" for functions declared with the && 3958 // ref-qualifier 3959 // 3960 // where X is the class of which the function is a member and cv is the 3961 // cv-qualification on the member function declaration. 3962 // 3963 // However, when finding an implicit conversion sequence for the argument, we 3964 // are not allowed to create temporaries or perform user-defined conversions 3965 // (C++ [over.match.funcs]p5). We perform a simplified version of 3966 // reference binding here, that allows class rvalues to bind to 3967 // non-constant references. 3968 3969 // First check the qualifiers. 3970 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 3971 if (ImplicitParamType.getCVRQualifiers() 3972 != FromTypeCanon.getLocalCVRQualifiers() && 3973 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 3974 ICS.setBad(BadConversionSequence::bad_qualifiers, 3975 OrigFromType, ImplicitParamType); 3976 return ICS; 3977 } 3978 3979 // Check that we have either the same type or a derived type. It 3980 // affects the conversion rank. 3981 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 3982 ImplicitConversionKind SecondKind; 3983 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 3984 SecondKind = ICK_Identity; 3985 } else if (S.IsDerivedFrom(FromType, ClassType)) 3986 SecondKind = ICK_Derived_To_Base; 3987 else { 3988 ICS.setBad(BadConversionSequence::unrelated_class, 3989 FromType, ImplicitParamType); 3990 return ICS; 3991 } 3992 3993 // Check the ref-qualifier. 3994 switch (Method->getRefQualifier()) { 3995 case RQ_None: 3996 // Do nothing; we don't care about lvalueness or rvalueness. 3997 break; 3998 3999 case RQ_LValue: 4000 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 4001 // non-const lvalue reference cannot bind to an rvalue 4002 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 4003 ImplicitParamType); 4004 return ICS; 4005 } 4006 break; 4007 4008 case RQ_RValue: 4009 if (!FromClassification.isRValue()) { 4010 // rvalue reference cannot bind to an lvalue 4011 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 4012 ImplicitParamType); 4013 return ICS; 4014 } 4015 break; 4016 } 4017 4018 // Success. Mark this as a reference binding. 4019 ICS.setStandard(); 4020 ICS.Standard.setAsIdentityConversion(); 4021 ICS.Standard.Second = SecondKind; 4022 ICS.Standard.setFromType(FromType); 4023 ICS.Standard.setAllToTypes(ImplicitParamType); 4024 ICS.Standard.ReferenceBinding = true; 4025 ICS.Standard.DirectBinding = true; 4026 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 4027 ICS.Standard.BindsToFunctionLvalue = false; 4028 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 4029 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 4030 = (Method->getRefQualifier() == RQ_None); 4031 return ICS; 4032} 4033 4034/// PerformObjectArgumentInitialization - Perform initialization of 4035/// the implicit object parameter for the given Method with the given 4036/// expression. 4037ExprResult 4038Sema::PerformObjectArgumentInitialization(Expr *From, 4039 NestedNameSpecifier *Qualifier, 4040 NamedDecl *FoundDecl, 4041 CXXMethodDecl *Method) { 4042 QualType FromRecordType, DestType; 4043 QualType ImplicitParamRecordType = 4044 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 4045 4046 Expr::Classification FromClassification; 4047 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 4048 FromRecordType = PT->getPointeeType(); 4049 DestType = Method->getThisType(Context); 4050 FromClassification = Expr::Classification::makeSimpleLValue(); 4051 } else { 4052 FromRecordType = From->getType(); 4053 DestType = ImplicitParamRecordType; 4054 FromClassification = From->Classify(Context); 4055 } 4056 4057 // Note that we always use the true parent context when performing 4058 // the actual argument initialization. 4059 ImplicitConversionSequence ICS 4060 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 4061 Method, Method->getParent()); 4062 if (ICS.isBad()) { 4063 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 4064 Qualifiers FromQs = FromRecordType.getQualifiers(); 4065 Qualifiers ToQs = DestType.getQualifiers(); 4066 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4067 if (CVR) { 4068 Diag(From->getSourceRange().getBegin(), 4069 diag::err_member_function_call_bad_cvr) 4070 << Method->getDeclName() << FromRecordType << (CVR - 1) 4071 << From->getSourceRange(); 4072 Diag(Method->getLocation(), diag::note_previous_decl) 4073 << Method->getDeclName(); 4074 return ExprError(); 4075 } 4076 } 4077 4078 return Diag(From->getSourceRange().getBegin(), 4079 diag::err_implicit_object_parameter_init) 4080 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 4081 } 4082 4083 if (ICS.Standard.Second == ICK_Derived_To_Base) { 4084 ExprResult FromRes = 4085 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 4086 if (FromRes.isInvalid()) 4087 return ExprError(); 4088 From = FromRes.take(); 4089 } 4090 4091 if (!Context.hasSameType(From->getType(), DestType)) 4092 From = ImpCastExprToType(From, DestType, CK_NoOp, 4093 From->getValueKind()).take(); 4094 return Owned(From); 4095} 4096 4097/// TryContextuallyConvertToBool - Attempt to contextually convert the 4098/// expression From to bool (C++0x [conv]p3). 4099static ImplicitConversionSequence 4100TryContextuallyConvertToBool(Sema &S, Expr *From) { 4101 // FIXME: This is pretty broken. 4102 return TryImplicitConversion(S, From, S.Context.BoolTy, 4103 // FIXME: Are these flags correct? 4104 /*SuppressUserConversions=*/false, 4105 /*AllowExplicit=*/true, 4106 /*InOverloadResolution=*/false, 4107 /*CStyle=*/false, 4108 /*AllowObjCWritebackConversion=*/false); 4109} 4110 4111/// PerformContextuallyConvertToBool - Perform a contextual conversion 4112/// of the expression From to bool (C++0x [conv]p3). 4113ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) { 4114 if (checkPlaceholderForOverload(*this, From)) 4115 return ExprError(); 4116 4117 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 4118 if (!ICS.isBad()) 4119 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 4120 4121 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 4122 return Diag(From->getSourceRange().getBegin(), 4123 diag::err_typecheck_bool_condition) 4124 << From->getType() << From->getSourceRange(); 4125 return ExprError(); 4126} 4127 4128/// dropPointerConversions - If the given standard conversion sequence 4129/// involves any pointer conversions, remove them. This may change 4130/// the result type of the conversion sequence. 4131static void dropPointerConversion(StandardConversionSequence &SCS) { 4132 if (SCS.Second == ICK_Pointer_Conversion) { 4133 SCS.Second = ICK_Identity; 4134 SCS.Third = ICK_Identity; 4135 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0]; 4136 } 4137} 4138 4139/// TryContextuallyConvertToObjCPointer - Attempt to contextually 4140/// convert the expression From to an Objective-C pointer type. 4141static ImplicitConversionSequence 4142TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) { 4143 // Do an implicit conversion to 'id'. 4144 QualType Ty = S.Context.getObjCIdType(); 4145 ImplicitConversionSequence ICS 4146 = TryImplicitConversion(S, From, Ty, 4147 // FIXME: Are these flags correct? 4148 /*SuppressUserConversions=*/false, 4149 /*AllowExplicit=*/true, 4150 /*InOverloadResolution=*/false, 4151 /*CStyle=*/false, 4152 /*AllowObjCWritebackConversion=*/false); 4153 4154 // Strip off any final conversions to 'id'. 4155 switch (ICS.getKind()) { 4156 case ImplicitConversionSequence::BadConversion: 4157 case ImplicitConversionSequence::AmbiguousConversion: 4158 case ImplicitConversionSequence::EllipsisConversion: 4159 break; 4160 4161 case ImplicitConversionSequence::UserDefinedConversion: 4162 dropPointerConversion(ICS.UserDefined.After); 4163 break; 4164 4165 case ImplicitConversionSequence::StandardConversion: 4166 dropPointerConversion(ICS.Standard); 4167 break; 4168 } 4169 4170 return ICS; 4171} 4172 4173/// PerformContextuallyConvertToObjCPointer - Perform a contextual 4174/// conversion of the expression From to an Objective-C pointer type. 4175ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) { 4176 if (checkPlaceholderForOverload(*this, From)) 4177 return ExprError(); 4178 4179 QualType Ty = Context.getObjCIdType(); 4180 ImplicitConversionSequence ICS = 4181 TryContextuallyConvertToObjCPointer(*this, From); 4182 if (!ICS.isBad()) 4183 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 4184 return ExprError(); 4185} 4186 4187/// \brief Attempt to convert the given expression to an integral or 4188/// enumeration type. 4189/// 4190/// This routine will attempt to convert an expression of class type to an 4191/// integral or enumeration type, if that class type only has a single 4192/// conversion to an integral or enumeration type. 4193/// 4194/// \param Loc The source location of the construct that requires the 4195/// conversion. 4196/// 4197/// \param FromE The expression we're converting from. 4198/// 4199/// \param NotIntDiag The diagnostic to be emitted if the expression does not 4200/// have integral or enumeration type. 4201/// 4202/// \param IncompleteDiag The diagnostic to be emitted if the expression has 4203/// incomplete class type. 4204/// 4205/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 4206/// explicit conversion function (because no implicit conversion functions 4207/// were available). This is a recovery mode. 4208/// 4209/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 4210/// showing which conversion was picked. 4211/// 4212/// \param AmbigDiag The diagnostic to be emitted if there is more than one 4213/// conversion function that could convert to integral or enumeration type. 4214/// 4215/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 4216/// usable conversion function. 4217/// 4218/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 4219/// function, which may be an extension in this case. 4220/// 4221/// \returns The expression, converted to an integral or enumeration type if 4222/// successful. 4223ExprResult 4224Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 4225 const PartialDiagnostic &NotIntDiag, 4226 const PartialDiagnostic &IncompleteDiag, 4227 const PartialDiagnostic &ExplicitConvDiag, 4228 const PartialDiagnostic &ExplicitConvNote, 4229 const PartialDiagnostic &AmbigDiag, 4230 const PartialDiagnostic &AmbigNote, 4231 const PartialDiagnostic &ConvDiag) { 4232 // We can't perform any more checking for type-dependent expressions. 4233 if (From->isTypeDependent()) 4234 return Owned(From); 4235 4236 // If the expression already has integral or enumeration type, we're golden. 4237 QualType T = From->getType(); 4238 if (T->isIntegralOrEnumerationType()) 4239 return Owned(From); 4240 4241 // FIXME: Check for missing '()' if T is a function type? 4242 4243 // If we don't have a class type in C++, there's no way we can get an 4244 // expression of integral or enumeration type. 4245 const RecordType *RecordTy = T->getAs<RecordType>(); 4246 if (!RecordTy || !getLangOptions().CPlusPlus) { 4247 Diag(Loc, NotIntDiag) 4248 << T << From->getSourceRange(); 4249 return Owned(From); 4250 } 4251 4252 // We must have a complete class type. 4253 if (RequireCompleteType(Loc, T, IncompleteDiag)) 4254 return Owned(From); 4255 4256 // Look for a conversion to an integral or enumeration type. 4257 UnresolvedSet<4> ViableConversions; 4258 UnresolvedSet<4> ExplicitConversions; 4259 const UnresolvedSetImpl *Conversions 4260 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 4261 4262 bool HadMultipleCandidates = (Conversions->size() > 1); 4263 4264 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4265 E = Conversions->end(); 4266 I != E; 4267 ++I) { 4268 if (CXXConversionDecl *Conversion 4269 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 4270 if (Conversion->getConversionType().getNonReferenceType() 4271 ->isIntegralOrEnumerationType()) { 4272 if (Conversion->isExplicit()) 4273 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 4274 else 4275 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 4276 } 4277 } 4278 4279 switch (ViableConversions.size()) { 4280 case 0: 4281 if (ExplicitConversions.size() == 1) { 4282 DeclAccessPair Found = ExplicitConversions[0]; 4283 CXXConversionDecl *Conversion 4284 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 4285 4286 // The user probably meant to invoke the given explicit 4287 // conversion; use it. 4288 QualType ConvTy 4289 = Conversion->getConversionType().getNonReferenceType(); 4290 std::string TypeStr; 4291 ConvTy.getAsStringInternal(TypeStr, getPrintingPolicy()); 4292 4293 Diag(Loc, ExplicitConvDiag) 4294 << T << ConvTy 4295 << FixItHint::CreateInsertion(From->getLocStart(), 4296 "static_cast<" + TypeStr + ">(") 4297 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 4298 ")"); 4299 Diag(Conversion->getLocation(), ExplicitConvNote) 4300 << ConvTy->isEnumeralType() << ConvTy; 4301 4302 // If we aren't in a SFINAE context, build a call to the 4303 // explicit conversion function. 4304 if (isSFINAEContext()) 4305 return ExprError(); 4306 4307 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 4308 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion, 4309 HadMultipleCandidates); 4310 if (Result.isInvalid()) 4311 return ExprError(); 4312 4313 From = Result.get(); 4314 } 4315 4316 // We'll complain below about a non-integral condition type. 4317 break; 4318 4319 case 1: { 4320 // Apply this conversion. 4321 DeclAccessPair Found = ViableConversions[0]; 4322 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 4323 4324 CXXConversionDecl *Conversion 4325 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 4326 QualType ConvTy 4327 = Conversion->getConversionType().getNonReferenceType(); 4328 if (ConvDiag.getDiagID()) { 4329 if (isSFINAEContext()) 4330 return ExprError(); 4331 4332 Diag(Loc, ConvDiag) 4333 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 4334 } 4335 4336 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion, 4337 HadMultipleCandidates); 4338 if (Result.isInvalid()) 4339 return ExprError(); 4340 4341 From = Result.get(); 4342 break; 4343 } 4344 4345 default: 4346 Diag(Loc, AmbigDiag) 4347 << T << From->getSourceRange(); 4348 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 4349 CXXConversionDecl *Conv 4350 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 4351 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 4352 Diag(Conv->getLocation(), AmbigNote) 4353 << ConvTy->isEnumeralType() << ConvTy; 4354 } 4355 return Owned(From); 4356 } 4357 4358 if (!From->getType()->isIntegralOrEnumerationType()) 4359 Diag(Loc, NotIntDiag) 4360 << From->getType() << From->getSourceRange(); 4361 4362 return Owned(From); 4363} 4364 4365/// AddOverloadCandidate - Adds the given function to the set of 4366/// candidate functions, using the given function call arguments. If 4367/// @p SuppressUserConversions, then don't allow user-defined 4368/// conversions via constructors or conversion operators. 4369/// 4370/// \para PartialOverloading true if we are performing "partial" overloading 4371/// based on an incomplete set of function arguments. This feature is used by 4372/// code completion. 4373void 4374Sema::AddOverloadCandidate(FunctionDecl *Function, 4375 DeclAccessPair FoundDecl, 4376 Expr **Args, unsigned NumArgs, 4377 OverloadCandidateSet& CandidateSet, 4378 bool SuppressUserConversions, 4379 bool PartialOverloading) { 4380 const FunctionProtoType* Proto 4381 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 4382 assert(Proto && "Functions without a prototype cannot be overloaded"); 4383 assert(!Function->getDescribedFunctionTemplate() && 4384 "Use AddTemplateOverloadCandidate for function templates"); 4385 4386 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 4387 if (!isa<CXXConstructorDecl>(Method)) { 4388 // If we get here, it's because we're calling a member function 4389 // that is named without a member access expression (e.g., 4390 // "this->f") that was either written explicitly or created 4391 // implicitly. This can happen with a qualified call to a member 4392 // function, e.g., X::f(). We use an empty type for the implied 4393 // object argument (C++ [over.call.func]p3), and the acting context 4394 // is irrelevant. 4395 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 4396 QualType(), Expr::Classification::makeSimpleLValue(), 4397 Args, NumArgs, CandidateSet, 4398 SuppressUserConversions); 4399 return; 4400 } 4401 // We treat a constructor like a non-member function, since its object 4402 // argument doesn't participate in overload resolution. 4403 } 4404 4405 if (!CandidateSet.isNewCandidate(Function)) 4406 return; 4407 4408 // Overload resolution is always an unevaluated context. 4409 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4410 4411 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 4412 // C++ [class.copy]p3: 4413 // A member function template is never instantiated to perform the copy 4414 // of a class object to an object of its class type. 4415 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 4416 if (NumArgs == 1 && 4417 Constructor->isSpecializationCopyingObject() && 4418 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 4419 IsDerivedFrom(Args[0]->getType(), ClassType))) 4420 return; 4421 } 4422 4423 // Add this candidate 4424 CandidateSet.push_back(OverloadCandidate()); 4425 OverloadCandidate& Candidate = CandidateSet.back(); 4426 Candidate.FoundDecl = FoundDecl; 4427 Candidate.Function = Function; 4428 Candidate.Viable = true; 4429 Candidate.IsSurrogate = false; 4430 Candidate.IgnoreObjectArgument = false; 4431 Candidate.ExplicitCallArguments = NumArgs; 4432 4433 unsigned NumArgsInProto = Proto->getNumArgs(); 4434 4435 // (C++ 13.3.2p2): A candidate function having fewer than m 4436 // parameters is viable only if it has an ellipsis in its parameter 4437 // list (8.3.5). 4438 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 4439 !Proto->isVariadic()) { 4440 Candidate.Viable = false; 4441 Candidate.FailureKind = ovl_fail_too_many_arguments; 4442 return; 4443 } 4444 4445 // (C++ 13.3.2p2): A candidate function having more than m parameters 4446 // is viable only if the (m+1)st parameter has a default argument 4447 // (8.3.6). For the purposes of overload resolution, the 4448 // parameter list is truncated on the right, so that there are 4449 // exactly m parameters. 4450 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 4451 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 4452 // Not enough arguments. 4453 Candidate.Viable = false; 4454 Candidate.FailureKind = ovl_fail_too_few_arguments; 4455 return; 4456 } 4457 4458 // (CUDA B.1): Check for invalid calls between targets. 4459 if (getLangOptions().CUDA) 4460 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext)) 4461 if (CheckCUDATarget(Caller, Function)) { 4462 Candidate.Viable = false; 4463 Candidate.FailureKind = ovl_fail_bad_target; 4464 return; 4465 } 4466 4467 // Determine the implicit conversion sequences for each of the 4468 // arguments. 4469 Candidate.Conversions.resize(NumArgs); 4470 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4471 if (ArgIdx < NumArgsInProto) { 4472 // (C++ 13.3.2p3): for F to be a viable function, there shall 4473 // exist for each argument an implicit conversion sequence 4474 // (13.3.3.1) that converts that argument to the corresponding 4475 // parameter of F. 4476 QualType ParamType = Proto->getArgType(ArgIdx); 4477 Candidate.Conversions[ArgIdx] 4478 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4479 SuppressUserConversions, 4480 /*InOverloadResolution=*/true, 4481 /*AllowObjCWritebackConversion=*/ 4482 getLangOptions().ObjCAutoRefCount); 4483 if (Candidate.Conversions[ArgIdx].isBad()) { 4484 Candidate.Viable = false; 4485 Candidate.FailureKind = ovl_fail_bad_conversion; 4486 break; 4487 } 4488 } else { 4489 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4490 // argument for which there is no corresponding parameter is 4491 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4492 Candidate.Conversions[ArgIdx].setEllipsis(); 4493 } 4494 } 4495} 4496 4497/// \brief Add all of the function declarations in the given function set to 4498/// the overload canddiate set. 4499void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 4500 Expr **Args, unsigned NumArgs, 4501 OverloadCandidateSet& CandidateSet, 4502 bool SuppressUserConversions) { 4503 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 4504 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 4505 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 4506 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 4507 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 4508 cast<CXXMethodDecl>(FD)->getParent(), 4509 Args[0]->getType(), Args[0]->Classify(Context), 4510 Args + 1, NumArgs - 1, 4511 CandidateSet, SuppressUserConversions); 4512 else 4513 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 4514 SuppressUserConversions); 4515 } else { 4516 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 4517 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 4518 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 4519 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 4520 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 4521 /*FIXME: explicit args */ 0, 4522 Args[0]->getType(), 4523 Args[0]->Classify(Context), 4524 Args + 1, NumArgs - 1, 4525 CandidateSet, 4526 SuppressUserConversions); 4527 else 4528 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 4529 /*FIXME: explicit args */ 0, 4530 Args, NumArgs, CandidateSet, 4531 SuppressUserConversions); 4532 } 4533 } 4534} 4535 4536/// AddMethodCandidate - Adds a named decl (which is some kind of 4537/// method) as a method candidate to the given overload set. 4538void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 4539 QualType ObjectType, 4540 Expr::Classification ObjectClassification, 4541 Expr **Args, unsigned NumArgs, 4542 OverloadCandidateSet& CandidateSet, 4543 bool SuppressUserConversions) { 4544 NamedDecl *Decl = FoundDecl.getDecl(); 4545 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 4546 4547 if (isa<UsingShadowDecl>(Decl)) 4548 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 4549 4550 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 4551 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 4552 "Expected a member function template"); 4553 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 4554 /*ExplicitArgs*/ 0, 4555 ObjectType, ObjectClassification, Args, NumArgs, 4556 CandidateSet, 4557 SuppressUserConversions); 4558 } else { 4559 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 4560 ObjectType, ObjectClassification, Args, NumArgs, 4561 CandidateSet, SuppressUserConversions); 4562 } 4563} 4564 4565/// AddMethodCandidate - Adds the given C++ member function to the set 4566/// of candidate functions, using the given function call arguments 4567/// and the object argument (@c Object). For example, in a call 4568/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 4569/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 4570/// allow user-defined conversions via constructors or conversion 4571/// operators. 4572void 4573Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 4574 CXXRecordDecl *ActingContext, QualType ObjectType, 4575 Expr::Classification ObjectClassification, 4576 Expr **Args, unsigned NumArgs, 4577 OverloadCandidateSet& CandidateSet, 4578 bool SuppressUserConversions) { 4579 const FunctionProtoType* Proto 4580 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 4581 assert(Proto && "Methods without a prototype cannot be overloaded"); 4582 assert(!isa<CXXConstructorDecl>(Method) && 4583 "Use AddOverloadCandidate for constructors"); 4584 4585 if (!CandidateSet.isNewCandidate(Method)) 4586 return; 4587 4588 // Overload resolution is always an unevaluated context. 4589 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4590 4591 // Add this candidate 4592 CandidateSet.push_back(OverloadCandidate()); 4593 OverloadCandidate& Candidate = CandidateSet.back(); 4594 Candidate.FoundDecl = FoundDecl; 4595 Candidate.Function = Method; 4596 Candidate.IsSurrogate = false; 4597 Candidate.IgnoreObjectArgument = false; 4598 Candidate.ExplicitCallArguments = NumArgs; 4599 4600 unsigned NumArgsInProto = Proto->getNumArgs(); 4601 4602 // (C++ 13.3.2p2): A candidate function having fewer than m 4603 // parameters is viable only if it has an ellipsis in its parameter 4604 // list (8.3.5). 4605 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4606 Candidate.Viable = false; 4607 Candidate.FailureKind = ovl_fail_too_many_arguments; 4608 return; 4609 } 4610 4611 // (C++ 13.3.2p2): A candidate function having more than m parameters 4612 // is viable only if the (m+1)st parameter has a default argument 4613 // (8.3.6). For the purposes of overload resolution, the 4614 // parameter list is truncated on the right, so that there are 4615 // exactly m parameters. 4616 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 4617 if (NumArgs < MinRequiredArgs) { 4618 // Not enough arguments. 4619 Candidate.Viable = false; 4620 Candidate.FailureKind = ovl_fail_too_few_arguments; 4621 return; 4622 } 4623 4624 Candidate.Viable = true; 4625 Candidate.Conversions.resize(NumArgs + 1); 4626 4627 if (Method->isStatic() || ObjectType.isNull()) 4628 // The implicit object argument is ignored. 4629 Candidate.IgnoreObjectArgument = true; 4630 else { 4631 // Determine the implicit conversion sequence for the object 4632 // parameter. 4633 Candidate.Conversions[0] 4634 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 4635 Method, ActingContext); 4636 if (Candidate.Conversions[0].isBad()) { 4637 Candidate.Viable = false; 4638 Candidate.FailureKind = ovl_fail_bad_conversion; 4639 return; 4640 } 4641 } 4642 4643 // Determine the implicit conversion sequences for each of the 4644 // arguments. 4645 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4646 if (ArgIdx < NumArgsInProto) { 4647 // (C++ 13.3.2p3): for F to be a viable function, there shall 4648 // exist for each argument an implicit conversion sequence 4649 // (13.3.3.1) that converts that argument to the corresponding 4650 // parameter of F. 4651 QualType ParamType = Proto->getArgType(ArgIdx); 4652 Candidate.Conversions[ArgIdx + 1] 4653 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4654 SuppressUserConversions, 4655 /*InOverloadResolution=*/true, 4656 /*AllowObjCWritebackConversion=*/ 4657 getLangOptions().ObjCAutoRefCount); 4658 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4659 Candidate.Viable = false; 4660 Candidate.FailureKind = ovl_fail_bad_conversion; 4661 break; 4662 } 4663 } else { 4664 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4665 // argument for which there is no corresponding parameter is 4666 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4667 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4668 } 4669 } 4670} 4671 4672/// \brief Add a C++ member function template as a candidate to the candidate 4673/// set, using template argument deduction to produce an appropriate member 4674/// function template specialization. 4675void 4676Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 4677 DeclAccessPair FoundDecl, 4678 CXXRecordDecl *ActingContext, 4679 TemplateArgumentListInfo *ExplicitTemplateArgs, 4680 QualType ObjectType, 4681 Expr::Classification ObjectClassification, 4682 Expr **Args, unsigned NumArgs, 4683 OverloadCandidateSet& CandidateSet, 4684 bool SuppressUserConversions) { 4685 if (!CandidateSet.isNewCandidate(MethodTmpl)) 4686 return; 4687 4688 // C++ [over.match.funcs]p7: 4689 // In each case where a candidate is a function template, candidate 4690 // function template specializations are generated using template argument 4691 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4692 // candidate functions in the usual way.113) A given name can refer to one 4693 // or more function templates and also to a set of overloaded non-template 4694 // functions. In such a case, the candidate functions generated from each 4695 // function template are combined with the set of non-template candidate 4696 // functions. 4697 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4698 FunctionDecl *Specialization = 0; 4699 if (TemplateDeductionResult Result 4700 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 4701 Args, NumArgs, Specialization, Info)) { 4702 CandidateSet.push_back(OverloadCandidate()); 4703 OverloadCandidate &Candidate = CandidateSet.back(); 4704 Candidate.FoundDecl = FoundDecl; 4705 Candidate.Function = MethodTmpl->getTemplatedDecl(); 4706 Candidate.Viable = false; 4707 Candidate.FailureKind = ovl_fail_bad_deduction; 4708 Candidate.IsSurrogate = false; 4709 Candidate.IgnoreObjectArgument = false; 4710 Candidate.ExplicitCallArguments = NumArgs; 4711 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4712 Info); 4713 return; 4714 } 4715 4716 // Add the function template specialization produced by template argument 4717 // deduction as a candidate. 4718 assert(Specialization && "Missing member function template specialization?"); 4719 assert(isa<CXXMethodDecl>(Specialization) && 4720 "Specialization is not a member function?"); 4721 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 4722 ActingContext, ObjectType, ObjectClassification, 4723 Args, NumArgs, CandidateSet, SuppressUserConversions); 4724} 4725 4726/// \brief Add a C++ function template specialization as a candidate 4727/// in the candidate set, using template argument deduction to produce 4728/// an appropriate function template specialization. 4729void 4730Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 4731 DeclAccessPair FoundDecl, 4732 TemplateArgumentListInfo *ExplicitTemplateArgs, 4733 Expr **Args, unsigned NumArgs, 4734 OverloadCandidateSet& CandidateSet, 4735 bool SuppressUserConversions) { 4736 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4737 return; 4738 4739 // C++ [over.match.funcs]p7: 4740 // In each case where a candidate is a function template, candidate 4741 // function template specializations are generated using template argument 4742 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4743 // candidate functions in the usual way.113) A given name can refer to one 4744 // or more function templates and also to a set of overloaded non-template 4745 // functions. In such a case, the candidate functions generated from each 4746 // function template are combined with the set of non-template candidate 4747 // functions. 4748 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4749 FunctionDecl *Specialization = 0; 4750 if (TemplateDeductionResult Result 4751 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 4752 Args, NumArgs, Specialization, Info)) { 4753 CandidateSet.push_back(OverloadCandidate()); 4754 OverloadCandidate &Candidate = CandidateSet.back(); 4755 Candidate.FoundDecl = FoundDecl; 4756 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4757 Candidate.Viable = false; 4758 Candidate.FailureKind = ovl_fail_bad_deduction; 4759 Candidate.IsSurrogate = false; 4760 Candidate.IgnoreObjectArgument = false; 4761 Candidate.ExplicitCallArguments = NumArgs; 4762 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4763 Info); 4764 return; 4765 } 4766 4767 // Add the function template specialization produced by template argument 4768 // deduction as a candidate. 4769 assert(Specialization && "Missing function template specialization?"); 4770 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 4771 SuppressUserConversions); 4772} 4773 4774/// AddConversionCandidate - Add a C++ conversion function as a 4775/// candidate in the candidate set (C++ [over.match.conv], 4776/// C++ [over.match.copy]). From is the expression we're converting from, 4777/// and ToType is the type that we're eventually trying to convert to 4778/// (which may or may not be the same type as the type that the 4779/// conversion function produces). 4780void 4781Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 4782 DeclAccessPair FoundDecl, 4783 CXXRecordDecl *ActingContext, 4784 Expr *From, QualType ToType, 4785 OverloadCandidateSet& CandidateSet) { 4786 assert(!Conversion->getDescribedFunctionTemplate() && 4787 "Conversion function templates use AddTemplateConversionCandidate"); 4788 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 4789 if (!CandidateSet.isNewCandidate(Conversion)) 4790 return; 4791 4792 // Overload resolution is always an unevaluated context. 4793 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4794 4795 // Add this candidate 4796 CandidateSet.push_back(OverloadCandidate()); 4797 OverloadCandidate& Candidate = CandidateSet.back(); 4798 Candidate.FoundDecl = FoundDecl; 4799 Candidate.Function = Conversion; 4800 Candidate.IsSurrogate = false; 4801 Candidate.IgnoreObjectArgument = false; 4802 Candidate.FinalConversion.setAsIdentityConversion(); 4803 Candidate.FinalConversion.setFromType(ConvType); 4804 Candidate.FinalConversion.setAllToTypes(ToType); 4805 Candidate.Viable = true; 4806 Candidate.Conversions.resize(1); 4807 Candidate.ExplicitCallArguments = 1; 4808 4809 // C++ [over.match.funcs]p4: 4810 // For conversion functions, the function is considered to be a member of 4811 // the class of the implicit implied object argument for the purpose of 4812 // defining the type of the implicit object parameter. 4813 // 4814 // Determine the implicit conversion sequence for the implicit 4815 // object parameter. 4816 QualType ImplicitParamType = From->getType(); 4817 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 4818 ImplicitParamType = FromPtrType->getPointeeType(); 4819 CXXRecordDecl *ConversionContext 4820 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 4821 4822 Candidate.Conversions[0] 4823 = TryObjectArgumentInitialization(*this, From->getType(), 4824 From->Classify(Context), 4825 Conversion, ConversionContext); 4826 4827 if (Candidate.Conversions[0].isBad()) { 4828 Candidate.Viable = false; 4829 Candidate.FailureKind = ovl_fail_bad_conversion; 4830 return; 4831 } 4832 4833 // We won't go through a user-define type conversion function to convert a 4834 // derived to base as such conversions are given Conversion Rank. They only 4835 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 4836 QualType FromCanon 4837 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 4838 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 4839 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 4840 Candidate.Viable = false; 4841 Candidate.FailureKind = ovl_fail_trivial_conversion; 4842 return; 4843 } 4844 4845 // To determine what the conversion from the result of calling the 4846 // conversion function to the type we're eventually trying to 4847 // convert to (ToType), we need to synthesize a call to the 4848 // conversion function and attempt copy initialization from it. This 4849 // makes sure that we get the right semantics with respect to 4850 // lvalues/rvalues and the type. Fortunately, we can allocate this 4851 // call on the stack and we don't need its arguments to be 4852 // well-formed. 4853 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 4854 VK_LValue, From->getLocStart()); 4855 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 4856 Context.getPointerType(Conversion->getType()), 4857 CK_FunctionToPointerDecay, 4858 &ConversionRef, VK_RValue); 4859 4860 QualType ConversionType = Conversion->getConversionType(); 4861 if (RequireCompleteType(From->getLocStart(), ConversionType, 0)) { 4862 Candidate.Viable = false; 4863 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4864 return; 4865 } 4866 4867 ExprValueKind VK = Expr::getValueKindForType(ConversionType); 4868 4869 // Note that it is safe to allocate CallExpr on the stack here because 4870 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 4871 // allocator). 4872 QualType CallResultType = ConversionType.getNonLValueExprType(Context); 4873 CallExpr Call(Context, &ConversionFn, 0, 0, CallResultType, VK, 4874 From->getLocStart()); 4875 ImplicitConversionSequence ICS = 4876 TryCopyInitialization(*this, &Call, ToType, 4877 /*SuppressUserConversions=*/true, 4878 /*InOverloadResolution=*/false, 4879 /*AllowObjCWritebackConversion=*/false); 4880 4881 switch (ICS.getKind()) { 4882 case ImplicitConversionSequence::StandardConversion: 4883 Candidate.FinalConversion = ICS.Standard; 4884 4885 // C++ [over.ics.user]p3: 4886 // If the user-defined conversion is specified by a specialization of a 4887 // conversion function template, the second standard conversion sequence 4888 // shall have exact match rank. 4889 if (Conversion->getPrimaryTemplate() && 4890 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 4891 Candidate.Viable = false; 4892 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 4893 } 4894 4895 // C++0x [dcl.init.ref]p5: 4896 // In the second case, if the reference is an rvalue reference and 4897 // the second standard conversion sequence of the user-defined 4898 // conversion sequence includes an lvalue-to-rvalue conversion, the 4899 // program is ill-formed. 4900 if (ToType->isRValueReferenceType() && 4901 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 4902 Candidate.Viable = false; 4903 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4904 } 4905 break; 4906 4907 case ImplicitConversionSequence::BadConversion: 4908 Candidate.Viable = false; 4909 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4910 break; 4911 4912 default: 4913 llvm_unreachable( 4914 "Can only end up with a standard conversion sequence or failure"); 4915 } 4916} 4917 4918/// \brief Adds a conversion function template specialization 4919/// candidate to the overload set, using template argument deduction 4920/// to deduce the template arguments of the conversion function 4921/// template from the type that we are converting to (C++ 4922/// [temp.deduct.conv]). 4923void 4924Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 4925 DeclAccessPair FoundDecl, 4926 CXXRecordDecl *ActingDC, 4927 Expr *From, QualType ToType, 4928 OverloadCandidateSet &CandidateSet) { 4929 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 4930 "Only conversion function templates permitted here"); 4931 4932 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4933 return; 4934 4935 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4936 CXXConversionDecl *Specialization = 0; 4937 if (TemplateDeductionResult Result 4938 = DeduceTemplateArguments(FunctionTemplate, ToType, 4939 Specialization, Info)) { 4940 CandidateSet.push_back(OverloadCandidate()); 4941 OverloadCandidate &Candidate = CandidateSet.back(); 4942 Candidate.FoundDecl = FoundDecl; 4943 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4944 Candidate.Viable = false; 4945 Candidate.FailureKind = ovl_fail_bad_deduction; 4946 Candidate.IsSurrogate = false; 4947 Candidate.IgnoreObjectArgument = false; 4948 Candidate.ExplicitCallArguments = 1; 4949 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4950 Info); 4951 return; 4952 } 4953 4954 // Add the conversion function template specialization produced by 4955 // template argument deduction as a candidate. 4956 assert(Specialization && "Missing function template specialization?"); 4957 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 4958 CandidateSet); 4959} 4960 4961/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 4962/// converts the given @c Object to a function pointer via the 4963/// conversion function @c Conversion, and then attempts to call it 4964/// with the given arguments (C++ [over.call.object]p2-4). Proto is 4965/// the type of function that we'll eventually be calling. 4966void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 4967 DeclAccessPair FoundDecl, 4968 CXXRecordDecl *ActingContext, 4969 const FunctionProtoType *Proto, 4970 Expr *Object, 4971 Expr **Args, unsigned NumArgs, 4972 OverloadCandidateSet& CandidateSet) { 4973 if (!CandidateSet.isNewCandidate(Conversion)) 4974 return; 4975 4976 // Overload resolution is always an unevaluated context. 4977 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4978 4979 CandidateSet.push_back(OverloadCandidate()); 4980 OverloadCandidate& Candidate = CandidateSet.back(); 4981 Candidate.FoundDecl = FoundDecl; 4982 Candidate.Function = 0; 4983 Candidate.Surrogate = Conversion; 4984 Candidate.Viable = true; 4985 Candidate.IsSurrogate = true; 4986 Candidate.IgnoreObjectArgument = false; 4987 Candidate.Conversions.resize(NumArgs + 1); 4988 Candidate.ExplicitCallArguments = NumArgs; 4989 4990 // Determine the implicit conversion sequence for the implicit 4991 // object parameter. 4992 ImplicitConversionSequence ObjectInit 4993 = TryObjectArgumentInitialization(*this, Object->getType(), 4994 Object->Classify(Context), 4995 Conversion, ActingContext); 4996 if (ObjectInit.isBad()) { 4997 Candidate.Viable = false; 4998 Candidate.FailureKind = ovl_fail_bad_conversion; 4999 Candidate.Conversions[0] = ObjectInit; 5000 return; 5001 } 5002 5003 // The first conversion is actually a user-defined conversion whose 5004 // first conversion is ObjectInit's standard conversion (which is 5005 // effectively a reference binding). Record it as such. 5006 Candidate.Conversions[0].setUserDefined(); 5007 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 5008 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 5009 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false; 5010 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 5011 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl; 5012 Candidate.Conversions[0].UserDefined.After 5013 = Candidate.Conversions[0].UserDefined.Before; 5014 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 5015 5016 // Find the 5017 unsigned NumArgsInProto = Proto->getNumArgs(); 5018 5019 // (C++ 13.3.2p2): A candidate function having fewer than m 5020 // parameters is viable only if it has an ellipsis in its parameter 5021 // list (8.3.5). 5022 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 5023 Candidate.Viable = false; 5024 Candidate.FailureKind = ovl_fail_too_many_arguments; 5025 return; 5026 } 5027 5028 // Function types don't have any default arguments, so just check if 5029 // we have enough arguments. 5030 if (NumArgs < NumArgsInProto) { 5031 // Not enough arguments. 5032 Candidate.Viable = false; 5033 Candidate.FailureKind = ovl_fail_too_few_arguments; 5034 return; 5035 } 5036 5037 // Determine the implicit conversion sequences for each of the 5038 // arguments. 5039 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5040 if (ArgIdx < NumArgsInProto) { 5041 // (C++ 13.3.2p3): for F to be a viable function, there shall 5042 // exist for each argument an implicit conversion sequence 5043 // (13.3.3.1) that converts that argument to the corresponding 5044 // parameter of F. 5045 QualType ParamType = Proto->getArgType(ArgIdx); 5046 Candidate.Conversions[ArgIdx + 1] 5047 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5048 /*SuppressUserConversions=*/false, 5049 /*InOverloadResolution=*/false, 5050 /*AllowObjCWritebackConversion=*/ 5051 getLangOptions().ObjCAutoRefCount); 5052 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 5053 Candidate.Viable = false; 5054 Candidate.FailureKind = ovl_fail_bad_conversion; 5055 break; 5056 } 5057 } else { 5058 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5059 // argument for which there is no corresponding parameter is 5060 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5061 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 5062 } 5063 } 5064} 5065 5066/// \brief Add overload candidates for overloaded operators that are 5067/// member functions. 5068/// 5069/// Add the overloaded operator candidates that are member functions 5070/// for the operator Op that was used in an operator expression such 5071/// as "x Op y". , Args/NumArgs provides the operator arguments, and 5072/// CandidateSet will store the added overload candidates. (C++ 5073/// [over.match.oper]). 5074void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 5075 SourceLocation OpLoc, 5076 Expr **Args, unsigned NumArgs, 5077 OverloadCandidateSet& CandidateSet, 5078 SourceRange OpRange) { 5079 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5080 5081 // C++ [over.match.oper]p3: 5082 // For a unary operator @ with an operand of a type whose 5083 // cv-unqualified version is T1, and for a binary operator @ with 5084 // a left operand of a type whose cv-unqualified version is T1 and 5085 // a right operand of a type whose cv-unqualified version is T2, 5086 // three sets of candidate functions, designated member 5087 // candidates, non-member candidates and built-in candidates, are 5088 // constructed as follows: 5089 QualType T1 = Args[0]->getType(); 5090 5091 // -- If T1 is a class type, the set of member candidates is the 5092 // result of the qualified lookup of T1::operator@ 5093 // (13.3.1.1.1); otherwise, the set of member candidates is 5094 // empty. 5095 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 5096 // Complete the type if it can be completed. Otherwise, we're done. 5097 if (RequireCompleteType(OpLoc, T1, PDiag())) 5098 return; 5099 5100 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 5101 LookupQualifiedName(Operators, T1Rec->getDecl()); 5102 Operators.suppressDiagnostics(); 5103 5104 for (LookupResult::iterator Oper = Operators.begin(), 5105 OperEnd = Operators.end(); 5106 Oper != OperEnd; 5107 ++Oper) 5108 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 5109 Args[0]->Classify(Context), Args + 1, NumArgs - 1, 5110 CandidateSet, 5111 /* SuppressUserConversions = */ false); 5112 } 5113} 5114 5115/// AddBuiltinCandidate - Add a candidate for a built-in 5116/// operator. ResultTy and ParamTys are the result and parameter types 5117/// of the built-in candidate, respectively. Args and NumArgs are the 5118/// arguments being passed to the candidate. IsAssignmentOperator 5119/// should be true when this built-in candidate is an assignment 5120/// operator. NumContextualBoolArguments is the number of arguments 5121/// (at the beginning of the argument list) that will be contextually 5122/// converted to bool. 5123void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 5124 Expr **Args, unsigned NumArgs, 5125 OverloadCandidateSet& CandidateSet, 5126 bool IsAssignmentOperator, 5127 unsigned NumContextualBoolArguments) { 5128 // Overload resolution is always an unevaluated context. 5129 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5130 5131 // Add this candidate 5132 CandidateSet.push_back(OverloadCandidate()); 5133 OverloadCandidate& Candidate = CandidateSet.back(); 5134 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 5135 Candidate.Function = 0; 5136 Candidate.IsSurrogate = false; 5137 Candidate.IgnoreObjectArgument = false; 5138 Candidate.BuiltinTypes.ResultTy = ResultTy; 5139 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5140 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 5141 5142 // Determine the implicit conversion sequences for each of the 5143 // arguments. 5144 Candidate.Viable = true; 5145 Candidate.Conversions.resize(NumArgs); 5146 Candidate.ExplicitCallArguments = NumArgs; 5147 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5148 // C++ [over.match.oper]p4: 5149 // For the built-in assignment operators, conversions of the 5150 // left operand are restricted as follows: 5151 // -- no temporaries are introduced to hold the left operand, and 5152 // -- no user-defined conversions are applied to the left 5153 // operand to achieve a type match with the left-most 5154 // parameter of a built-in candidate. 5155 // 5156 // We block these conversions by turning off user-defined 5157 // conversions, since that is the only way that initialization of 5158 // a reference to a non-class type can occur from something that 5159 // is not of the same type. 5160 if (ArgIdx < NumContextualBoolArguments) { 5161 assert(ParamTys[ArgIdx] == Context.BoolTy && 5162 "Contextual conversion to bool requires bool type"); 5163 Candidate.Conversions[ArgIdx] 5164 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 5165 } else { 5166 Candidate.Conversions[ArgIdx] 5167 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 5168 ArgIdx == 0 && IsAssignmentOperator, 5169 /*InOverloadResolution=*/false, 5170 /*AllowObjCWritebackConversion=*/ 5171 getLangOptions().ObjCAutoRefCount); 5172 } 5173 if (Candidate.Conversions[ArgIdx].isBad()) { 5174 Candidate.Viable = false; 5175 Candidate.FailureKind = ovl_fail_bad_conversion; 5176 break; 5177 } 5178 } 5179} 5180 5181/// BuiltinCandidateTypeSet - A set of types that will be used for the 5182/// candidate operator functions for built-in operators (C++ 5183/// [over.built]). The types are separated into pointer types and 5184/// enumeration types. 5185class BuiltinCandidateTypeSet { 5186 /// TypeSet - A set of types. 5187 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 5188 5189 /// PointerTypes - The set of pointer types that will be used in the 5190 /// built-in candidates. 5191 TypeSet PointerTypes; 5192 5193 /// MemberPointerTypes - The set of member pointer types that will be 5194 /// used in the built-in candidates. 5195 TypeSet MemberPointerTypes; 5196 5197 /// EnumerationTypes - The set of enumeration types that will be 5198 /// used in the built-in candidates. 5199 TypeSet EnumerationTypes; 5200 5201 /// \brief The set of vector types that will be used in the built-in 5202 /// candidates. 5203 TypeSet VectorTypes; 5204 5205 /// \brief A flag indicating non-record types are viable candidates 5206 bool HasNonRecordTypes; 5207 5208 /// \brief A flag indicating whether either arithmetic or enumeration types 5209 /// were present in the candidate set. 5210 bool HasArithmeticOrEnumeralTypes; 5211 5212 /// \brief A flag indicating whether the nullptr type was present in the 5213 /// candidate set. 5214 bool HasNullPtrType; 5215 5216 /// Sema - The semantic analysis instance where we are building the 5217 /// candidate type set. 5218 Sema &SemaRef; 5219 5220 /// Context - The AST context in which we will build the type sets. 5221 ASTContext &Context; 5222 5223 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 5224 const Qualifiers &VisibleQuals); 5225 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 5226 5227public: 5228 /// iterator - Iterates through the types that are part of the set. 5229 typedef TypeSet::iterator iterator; 5230 5231 BuiltinCandidateTypeSet(Sema &SemaRef) 5232 : HasNonRecordTypes(false), 5233 HasArithmeticOrEnumeralTypes(false), 5234 HasNullPtrType(false), 5235 SemaRef(SemaRef), 5236 Context(SemaRef.Context) { } 5237 5238 void AddTypesConvertedFrom(QualType Ty, 5239 SourceLocation Loc, 5240 bool AllowUserConversions, 5241 bool AllowExplicitConversions, 5242 const Qualifiers &VisibleTypeConversionsQuals); 5243 5244 /// pointer_begin - First pointer type found; 5245 iterator pointer_begin() { return PointerTypes.begin(); } 5246 5247 /// pointer_end - Past the last pointer type found; 5248 iterator pointer_end() { return PointerTypes.end(); } 5249 5250 /// member_pointer_begin - First member pointer type found; 5251 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 5252 5253 /// member_pointer_end - Past the last member pointer type found; 5254 iterator member_pointer_end() { return MemberPointerTypes.end(); } 5255 5256 /// enumeration_begin - First enumeration type found; 5257 iterator enumeration_begin() { return EnumerationTypes.begin(); } 5258 5259 /// enumeration_end - Past the last enumeration type found; 5260 iterator enumeration_end() { return EnumerationTypes.end(); } 5261 5262 iterator vector_begin() { return VectorTypes.begin(); } 5263 iterator vector_end() { return VectorTypes.end(); } 5264 5265 bool hasNonRecordTypes() { return HasNonRecordTypes; } 5266 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 5267 bool hasNullPtrType() const { return HasNullPtrType; } 5268}; 5269 5270/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 5271/// the set of pointer types along with any more-qualified variants of 5272/// that type. For example, if @p Ty is "int const *", this routine 5273/// will add "int const *", "int const volatile *", "int const 5274/// restrict *", and "int const volatile restrict *" to the set of 5275/// pointer types. Returns true if the add of @p Ty itself succeeded, 5276/// false otherwise. 5277/// 5278/// FIXME: what to do about extended qualifiers? 5279bool 5280BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 5281 const Qualifiers &VisibleQuals) { 5282 5283 // Insert this type. 5284 if (!PointerTypes.insert(Ty)) 5285 return false; 5286 5287 QualType PointeeTy; 5288 const PointerType *PointerTy = Ty->getAs<PointerType>(); 5289 bool buildObjCPtr = false; 5290 if (!PointerTy) { 5291 if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) { 5292 PointeeTy = PTy->getPointeeType(); 5293 buildObjCPtr = true; 5294 } 5295 else 5296 llvm_unreachable("type was not a pointer type!"); 5297 } 5298 else 5299 PointeeTy = PointerTy->getPointeeType(); 5300 5301 // Don't add qualified variants of arrays. For one, they're not allowed 5302 // (the qualifier would sink to the element type), and for another, the 5303 // only overload situation where it matters is subscript or pointer +- int, 5304 // and those shouldn't have qualifier variants anyway. 5305 if (PointeeTy->isArrayType()) 5306 return true; 5307 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 5308 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 5309 BaseCVR = Array->getElementType().getCVRQualifiers(); 5310 bool hasVolatile = VisibleQuals.hasVolatile(); 5311 bool hasRestrict = VisibleQuals.hasRestrict(); 5312 5313 // Iterate through all strict supersets of BaseCVR. 5314 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 5315 if ((CVR | BaseCVR) != CVR) continue; 5316 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 5317 // in the types. 5318 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 5319 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 5320 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 5321 if (!buildObjCPtr) 5322 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 5323 else 5324 PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); 5325 } 5326 5327 return true; 5328} 5329 5330/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 5331/// to the set of pointer types along with any more-qualified variants of 5332/// that type. For example, if @p Ty is "int const *", this routine 5333/// will add "int const *", "int const volatile *", "int const 5334/// restrict *", and "int const volatile restrict *" to the set of 5335/// pointer types. Returns true if the add of @p Ty itself succeeded, 5336/// false otherwise. 5337/// 5338/// FIXME: what to do about extended qualifiers? 5339bool 5340BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 5341 QualType Ty) { 5342 // Insert this type. 5343 if (!MemberPointerTypes.insert(Ty)) 5344 return false; 5345 5346 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 5347 assert(PointerTy && "type was not a member pointer type!"); 5348 5349 QualType PointeeTy = PointerTy->getPointeeType(); 5350 // Don't add qualified variants of arrays. For one, they're not allowed 5351 // (the qualifier would sink to the element type), and for another, the 5352 // only overload situation where it matters is subscript or pointer +- int, 5353 // and those shouldn't have qualifier variants anyway. 5354 if (PointeeTy->isArrayType()) 5355 return true; 5356 const Type *ClassTy = PointerTy->getClass(); 5357 5358 // Iterate through all strict supersets of the pointee type's CVR 5359 // qualifiers. 5360 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 5361 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 5362 if ((CVR | BaseCVR) != CVR) continue; 5363 5364 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 5365 MemberPointerTypes.insert( 5366 Context.getMemberPointerType(QPointeeTy, ClassTy)); 5367 } 5368 5369 return true; 5370} 5371 5372/// AddTypesConvertedFrom - Add each of the types to which the type @p 5373/// Ty can be implicit converted to the given set of @p Types. We're 5374/// primarily interested in pointer types and enumeration types. We also 5375/// take member pointer types, for the conditional operator. 5376/// AllowUserConversions is true if we should look at the conversion 5377/// functions of a class type, and AllowExplicitConversions if we 5378/// should also include the explicit conversion functions of a class 5379/// type. 5380void 5381BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 5382 SourceLocation Loc, 5383 bool AllowUserConversions, 5384 bool AllowExplicitConversions, 5385 const Qualifiers &VisibleQuals) { 5386 // Only deal with canonical types. 5387 Ty = Context.getCanonicalType(Ty); 5388 5389 // Look through reference types; they aren't part of the type of an 5390 // expression for the purposes of conversions. 5391 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 5392 Ty = RefTy->getPointeeType(); 5393 5394 // If we're dealing with an array type, decay to the pointer. 5395 if (Ty->isArrayType()) 5396 Ty = SemaRef.Context.getArrayDecayedType(Ty); 5397 5398 // Otherwise, we don't care about qualifiers on the type. 5399 Ty = Ty.getLocalUnqualifiedType(); 5400 5401 // Flag if we ever add a non-record type. 5402 const RecordType *TyRec = Ty->getAs<RecordType>(); 5403 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 5404 5405 // Flag if we encounter an arithmetic type. 5406 HasArithmeticOrEnumeralTypes = 5407 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 5408 5409 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 5410 PointerTypes.insert(Ty); 5411 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 5412 // Insert our type, and its more-qualified variants, into the set 5413 // of types. 5414 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 5415 return; 5416 } else if (Ty->isMemberPointerType()) { 5417 // Member pointers are far easier, since the pointee can't be converted. 5418 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 5419 return; 5420 } else if (Ty->isEnumeralType()) { 5421 HasArithmeticOrEnumeralTypes = true; 5422 EnumerationTypes.insert(Ty); 5423 } else if (Ty->isVectorType()) { 5424 // We treat vector types as arithmetic types in many contexts as an 5425 // extension. 5426 HasArithmeticOrEnumeralTypes = true; 5427 VectorTypes.insert(Ty); 5428 } else if (Ty->isNullPtrType()) { 5429 HasNullPtrType = true; 5430 } else if (AllowUserConversions && TyRec) { 5431 // No conversion functions in incomplete types. 5432 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 5433 return; 5434 5435 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 5436 const UnresolvedSetImpl *Conversions 5437 = ClassDecl->getVisibleConversionFunctions(); 5438 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 5439 E = Conversions->end(); I != E; ++I) { 5440 NamedDecl *D = I.getDecl(); 5441 if (isa<UsingShadowDecl>(D)) 5442 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 5443 5444 // Skip conversion function templates; they don't tell us anything 5445 // about which builtin types we can convert to. 5446 if (isa<FunctionTemplateDecl>(D)) 5447 continue; 5448 5449 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 5450 if (AllowExplicitConversions || !Conv->isExplicit()) { 5451 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 5452 VisibleQuals); 5453 } 5454 } 5455 } 5456} 5457 5458/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 5459/// the volatile- and non-volatile-qualified assignment operators for the 5460/// given type to the candidate set. 5461static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 5462 QualType T, 5463 Expr **Args, 5464 unsigned NumArgs, 5465 OverloadCandidateSet &CandidateSet) { 5466 QualType ParamTypes[2]; 5467 5468 // T& operator=(T&, T) 5469 ParamTypes[0] = S.Context.getLValueReferenceType(T); 5470 ParamTypes[1] = T; 5471 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5472 /*IsAssignmentOperator=*/true); 5473 5474 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 5475 // volatile T& operator=(volatile T&, T) 5476 ParamTypes[0] 5477 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 5478 ParamTypes[1] = T; 5479 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5480 /*IsAssignmentOperator=*/true); 5481 } 5482} 5483 5484/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 5485/// if any, found in visible type conversion functions found in ArgExpr's type. 5486static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 5487 Qualifiers VRQuals; 5488 const RecordType *TyRec; 5489 if (const MemberPointerType *RHSMPType = 5490 ArgExpr->getType()->getAs<MemberPointerType>()) 5491 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 5492 else 5493 TyRec = ArgExpr->getType()->getAs<RecordType>(); 5494 if (!TyRec) { 5495 // Just to be safe, assume the worst case. 5496 VRQuals.addVolatile(); 5497 VRQuals.addRestrict(); 5498 return VRQuals; 5499 } 5500 5501 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 5502 if (!ClassDecl->hasDefinition()) 5503 return VRQuals; 5504 5505 const UnresolvedSetImpl *Conversions = 5506 ClassDecl->getVisibleConversionFunctions(); 5507 5508 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 5509 E = Conversions->end(); I != E; ++I) { 5510 NamedDecl *D = I.getDecl(); 5511 if (isa<UsingShadowDecl>(D)) 5512 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 5513 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 5514 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 5515 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 5516 CanTy = ResTypeRef->getPointeeType(); 5517 // Need to go down the pointer/mempointer chain and add qualifiers 5518 // as see them. 5519 bool done = false; 5520 while (!done) { 5521 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 5522 CanTy = ResTypePtr->getPointeeType(); 5523 else if (const MemberPointerType *ResTypeMPtr = 5524 CanTy->getAs<MemberPointerType>()) 5525 CanTy = ResTypeMPtr->getPointeeType(); 5526 else 5527 done = true; 5528 if (CanTy.isVolatileQualified()) 5529 VRQuals.addVolatile(); 5530 if (CanTy.isRestrictQualified()) 5531 VRQuals.addRestrict(); 5532 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 5533 return VRQuals; 5534 } 5535 } 5536 } 5537 return VRQuals; 5538} 5539 5540namespace { 5541 5542/// \brief Helper class to manage the addition of builtin operator overload 5543/// candidates. It provides shared state and utility methods used throughout 5544/// the process, as well as a helper method to add each group of builtin 5545/// operator overloads from the standard to a candidate set. 5546class BuiltinOperatorOverloadBuilder { 5547 // Common instance state available to all overload candidate addition methods. 5548 Sema &S; 5549 Expr **Args; 5550 unsigned NumArgs; 5551 Qualifiers VisibleTypeConversionsQuals; 5552 bool HasArithmeticOrEnumeralCandidateType; 5553 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 5554 OverloadCandidateSet &CandidateSet; 5555 5556 // Define some constants used to index and iterate over the arithemetic types 5557 // provided via the getArithmeticType() method below. 5558 // The "promoted arithmetic types" are the arithmetic 5559 // types are that preserved by promotion (C++ [over.built]p2). 5560 static const unsigned FirstIntegralType = 3; 5561 static const unsigned LastIntegralType = 18; 5562 static const unsigned FirstPromotedIntegralType = 3, 5563 LastPromotedIntegralType = 9; 5564 static const unsigned FirstPromotedArithmeticType = 0, 5565 LastPromotedArithmeticType = 9; 5566 static const unsigned NumArithmeticTypes = 18; 5567 5568 /// \brief Get the canonical type for a given arithmetic type index. 5569 CanQualType getArithmeticType(unsigned index) { 5570 assert(index < NumArithmeticTypes); 5571 static CanQualType ASTContext::* const 5572 ArithmeticTypes[NumArithmeticTypes] = { 5573 // Start of promoted types. 5574 &ASTContext::FloatTy, 5575 &ASTContext::DoubleTy, 5576 &ASTContext::LongDoubleTy, 5577 5578 // Start of integral types. 5579 &ASTContext::IntTy, 5580 &ASTContext::LongTy, 5581 &ASTContext::LongLongTy, 5582 &ASTContext::UnsignedIntTy, 5583 &ASTContext::UnsignedLongTy, 5584 &ASTContext::UnsignedLongLongTy, 5585 // End of promoted types. 5586 5587 &ASTContext::BoolTy, 5588 &ASTContext::CharTy, 5589 &ASTContext::WCharTy, 5590 &ASTContext::Char16Ty, 5591 &ASTContext::Char32Ty, 5592 &ASTContext::SignedCharTy, 5593 &ASTContext::ShortTy, 5594 &ASTContext::UnsignedCharTy, 5595 &ASTContext::UnsignedShortTy, 5596 // End of integral types. 5597 // FIXME: What about complex? 5598 }; 5599 return S.Context.*ArithmeticTypes[index]; 5600 } 5601 5602 /// \brief Gets the canonical type resulting from the usual arithemetic 5603 /// converions for the given arithmetic types. 5604 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 5605 // Accelerator table for performing the usual arithmetic conversions. 5606 // The rules are basically: 5607 // - if either is floating-point, use the wider floating-point 5608 // - if same signedness, use the higher rank 5609 // - if same size, use unsigned of the higher rank 5610 // - use the larger type 5611 // These rules, together with the axiom that higher ranks are 5612 // never smaller, are sufficient to precompute all of these results 5613 // *except* when dealing with signed types of higher rank. 5614 // (we could precompute SLL x UI for all known platforms, but it's 5615 // better not to make any assumptions). 5616 enum PromotedType { 5617 Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL, Dep=-1 5618 }; 5619 static PromotedType ConversionsTable[LastPromotedArithmeticType] 5620 [LastPromotedArithmeticType] = { 5621 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt }, 5622 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 5623 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 5624 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL }, 5625 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, Dep, UL, ULL }, 5626 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, Dep, Dep, ULL }, 5627 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, UI, UL, ULL }, 5628 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, UL, UL, ULL }, 5629 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, ULL, ULL, ULL }, 5630 }; 5631 5632 assert(L < LastPromotedArithmeticType); 5633 assert(R < LastPromotedArithmeticType); 5634 int Idx = ConversionsTable[L][R]; 5635 5636 // Fast path: the table gives us a concrete answer. 5637 if (Idx != Dep) return getArithmeticType(Idx); 5638 5639 // Slow path: we need to compare widths. 5640 // An invariant is that the signed type has higher rank. 5641 CanQualType LT = getArithmeticType(L), 5642 RT = getArithmeticType(R); 5643 unsigned LW = S.Context.getIntWidth(LT), 5644 RW = S.Context.getIntWidth(RT); 5645 5646 // If they're different widths, use the signed type. 5647 if (LW > RW) return LT; 5648 else if (LW < RW) return RT; 5649 5650 // Otherwise, use the unsigned type of the signed type's rank. 5651 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 5652 assert(L == SLL || R == SLL); 5653 return S.Context.UnsignedLongLongTy; 5654 } 5655 5656 /// \brief Helper method to factor out the common pattern of adding overloads 5657 /// for '++' and '--' builtin operators. 5658 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 5659 bool HasVolatile) { 5660 QualType ParamTypes[2] = { 5661 S.Context.getLValueReferenceType(CandidateTy), 5662 S.Context.IntTy 5663 }; 5664 5665 // Non-volatile version. 5666 if (NumArgs == 1) 5667 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5668 else 5669 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5670 5671 // Use a heuristic to reduce number of builtin candidates in the set: 5672 // add volatile version only if there are conversions to a volatile type. 5673 if (HasVolatile) { 5674 ParamTypes[0] = 5675 S.Context.getLValueReferenceType( 5676 S.Context.getVolatileType(CandidateTy)); 5677 if (NumArgs == 1) 5678 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5679 else 5680 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5681 } 5682 } 5683 5684public: 5685 BuiltinOperatorOverloadBuilder( 5686 Sema &S, Expr **Args, unsigned NumArgs, 5687 Qualifiers VisibleTypeConversionsQuals, 5688 bool HasArithmeticOrEnumeralCandidateType, 5689 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 5690 OverloadCandidateSet &CandidateSet) 5691 : S(S), Args(Args), NumArgs(NumArgs), 5692 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 5693 HasArithmeticOrEnumeralCandidateType( 5694 HasArithmeticOrEnumeralCandidateType), 5695 CandidateTypes(CandidateTypes), 5696 CandidateSet(CandidateSet) { 5697 // Validate some of our static helper constants in debug builds. 5698 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 5699 "Invalid first promoted integral type"); 5700 assert(getArithmeticType(LastPromotedIntegralType - 1) 5701 == S.Context.UnsignedLongLongTy && 5702 "Invalid last promoted integral type"); 5703 assert(getArithmeticType(FirstPromotedArithmeticType) 5704 == S.Context.FloatTy && 5705 "Invalid first promoted arithmetic type"); 5706 assert(getArithmeticType(LastPromotedArithmeticType - 1) 5707 == S.Context.UnsignedLongLongTy && 5708 "Invalid last promoted arithmetic type"); 5709 } 5710 5711 // C++ [over.built]p3: 5712 // 5713 // For every pair (T, VQ), where T is an arithmetic type, and VQ 5714 // is either volatile or empty, there exist candidate operator 5715 // functions of the form 5716 // 5717 // VQ T& operator++(VQ T&); 5718 // T operator++(VQ T&, int); 5719 // 5720 // C++ [over.built]p4: 5721 // 5722 // For every pair (T, VQ), where T is an arithmetic type other 5723 // than bool, and VQ is either volatile or empty, there exist 5724 // candidate operator functions of the form 5725 // 5726 // VQ T& operator--(VQ T&); 5727 // T operator--(VQ T&, int); 5728 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 5729 if (!HasArithmeticOrEnumeralCandidateType) 5730 return; 5731 5732 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 5733 Arith < NumArithmeticTypes; ++Arith) { 5734 addPlusPlusMinusMinusStyleOverloads( 5735 getArithmeticType(Arith), 5736 VisibleTypeConversionsQuals.hasVolatile()); 5737 } 5738 } 5739 5740 // C++ [over.built]p5: 5741 // 5742 // For every pair (T, VQ), where T is a cv-qualified or 5743 // cv-unqualified object type, and VQ is either volatile or 5744 // empty, there exist candidate operator functions of the form 5745 // 5746 // T*VQ& operator++(T*VQ&); 5747 // T*VQ& operator--(T*VQ&); 5748 // T* operator++(T*VQ&, int); 5749 // T* operator--(T*VQ&, int); 5750 void addPlusPlusMinusMinusPointerOverloads() { 5751 for (BuiltinCandidateTypeSet::iterator 5752 Ptr = CandidateTypes[0].pointer_begin(), 5753 PtrEnd = CandidateTypes[0].pointer_end(); 5754 Ptr != PtrEnd; ++Ptr) { 5755 // Skip pointer types that aren't pointers to object types. 5756 if (!(*Ptr)->getPointeeType()->isObjectType()) 5757 continue; 5758 5759 addPlusPlusMinusMinusStyleOverloads(*Ptr, 5760 (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5761 VisibleTypeConversionsQuals.hasVolatile())); 5762 } 5763 } 5764 5765 // C++ [over.built]p6: 5766 // For every cv-qualified or cv-unqualified object type T, there 5767 // exist candidate operator functions of the form 5768 // 5769 // T& operator*(T*); 5770 // 5771 // C++ [over.built]p7: 5772 // For every function type T that does not have cv-qualifiers or a 5773 // ref-qualifier, there exist candidate operator functions of the form 5774 // T& operator*(T*); 5775 void addUnaryStarPointerOverloads() { 5776 for (BuiltinCandidateTypeSet::iterator 5777 Ptr = CandidateTypes[0].pointer_begin(), 5778 PtrEnd = CandidateTypes[0].pointer_end(); 5779 Ptr != PtrEnd; ++Ptr) { 5780 QualType ParamTy = *Ptr; 5781 QualType PointeeTy = ParamTy->getPointeeType(); 5782 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 5783 continue; 5784 5785 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 5786 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 5787 continue; 5788 5789 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 5790 &ParamTy, Args, 1, CandidateSet); 5791 } 5792 } 5793 5794 // C++ [over.built]p9: 5795 // For every promoted arithmetic type T, there exist candidate 5796 // operator functions of the form 5797 // 5798 // T operator+(T); 5799 // T operator-(T); 5800 void addUnaryPlusOrMinusArithmeticOverloads() { 5801 if (!HasArithmeticOrEnumeralCandidateType) 5802 return; 5803 5804 for (unsigned Arith = FirstPromotedArithmeticType; 5805 Arith < LastPromotedArithmeticType; ++Arith) { 5806 QualType ArithTy = getArithmeticType(Arith); 5807 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 5808 } 5809 5810 // Extension: We also add these operators for vector types. 5811 for (BuiltinCandidateTypeSet::iterator 5812 Vec = CandidateTypes[0].vector_begin(), 5813 VecEnd = CandidateTypes[0].vector_end(); 5814 Vec != VecEnd; ++Vec) { 5815 QualType VecTy = *Vec; 5816 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5817 } 5818 } 5819 5820 // C++ [over.built]p8: 5821 // For every type T, there exist candidate operator functions of 5822 // the form 5823 // 5824 // T* operator+(T*); 5825 void addUnaryPlusPointerOverloads() { 5826 for (BuiltinCandidateTypeSet::iterator 5827 Ptr = CandidateTypes[0].pointer_begin(), 5828 PtrEnd = CandidateTypes[0].pointer_end(); 5829 Ptr != PtrEnd; ++Ptr) { 5830 QualType ParamTy = *Ptr; 5831 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 5832 } 5833 } 5834 5835 // C++ [over.built]p10: 5836 // For every promoted integral type T, there exist candidate 5837 // operator functions of the form 5838 // 5839 // T operator~(T); 5840 void addUnaryTildePromotedIntegralOverloads() { 5841 if (!HasArithmeticOrEnumeralCandidateType) 5842 return; 5843 5844 for (unsigned Int = FirstPromotedIntegralType; 5845 Int < LastPromotedIntegralType; ++Int) { 5846 QualType IntTy = getArithmeticType(Int); 5847 S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 5848 } 5849 5850 // Extension: We also add this operator for vector types. 5851 for (BuiltinCandidateTypeSet::iterator 5852 Vec = CandidateTypes[0].vector_begin(), 5853 VecEnd = CandidateTypes[0].vector_end(); 5854 Vec != VecEnd; ++Vec) { 5855 QualType VecTy = *Vec; 5856 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5857 } 5858 } 5859 5860 // C++ [over.match.oper]p16: 5861 // For every pointer to member type T, there exist candidate operator 5862 // functions of the form 5863 // 5864 // bool operator==(T,T); 5865 // bool operator!=(T,T); 5866 void addEqualEqualOrNotEqualMemberPointerOverloads() { 5867 /// Set of (canonical) types that we've already handled. 5868 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5869 5870 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5871 for (BuiltinCandidateTypeSet::iterator 5872 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5873 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5874 MemPtr != MemPtrEnd; 5875 ++MemPtr) { 5876 // Don't add the same builtin candidate twice. 5877 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5878 continue; 5879 5880 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5881 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5882 CandidateSet); 5883 } 5884 } 5885 } 5886 5887 // C++ [over.built]p15: 5888 // 5889 // For every T, where T is an enumeration type, a pointer type, or 5890 // std::nullptr_t, there exist candidate operator functions of the form 5891 // 5892 // bool operator<(T, T); 5893 // bool operator>(T, T); 5894 // bool operator<=(T, T); 5895 // bool operator>=(T, T); 5896 // bool operator==(T, T); 5897 // bool operator!=(T, T); 5898 void addRelationalPointerOrEnumeralOverloads() { 5899 // C++ [over.built]p1: 5900 // If there is a user-written candidate with the same name and parameter 5901 // types as a built-in candidate operator function, the built-in operator 5902 // function is hidden and is not included in the set of candidate 5903 // functions. 5904 // 5905 // The text is actually in a note, but if we don't implement it then we end 5906 // up with ambiguities when the user provides an overloaded operator for 5907 // an enumeration type. Note that only enumeration types have this problem, 5908 // so we track which enumeration types we've seen operators for. Also, the 5909 // only other overloaded operator with enumeration argumenst, operator=, 5910 // cannot be overloaded for enumeration types, so this is the only place 5911 // where we must suppress candidates like this. 5912 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 5913 UserDefinedBinaryOperators; 5914 5915 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5916 if (CandidateTypes[ArgIdx].enumeration_begin() != 5917 CandidateTypes[ArgIdx].enumeration_end()) { 5918 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 5919 CEnd = CandidateSet.end(); 5920 C != CEnd; ++C) { 5921 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 5922 continue; 5923 5924 QualType FirstParamType = 5925 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 5926 QualType SecondParamType = 5927 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 5928 5929 // Skip if either parameter isn't of enumeral type. 5930 if (!FirstParamType->isEnumeralType() || 5931 !SecondParamType->isEnumeralType()) 5932 continue; 5933 5934 // Add this operator to the set of known user-defined operators. 5935 UserDefinedBinaryOperators.insert( 5936 std::make_pair(S.Context.getCanonicalType(FirstParamType), 5937 S.Context.getCanonicalType(SecondParamType))); 5938 } 5939 } 5940 } 5941 5942 /// Set of (canonical) types that we've already handled. 5943 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5944 5945 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5946 for (BuiltinCandidateTypeSet::iterator 5947 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5948 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5949 Ptr != PtrEnd; ++Ptr) { 5950 // Don't add the same builtin candidate twice. 5951 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5952 continue; 5953 5954 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5955 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5956 CandidateSet); 5957 } 5958 for (BuiltinCandidateTypeSet::iterator 5959 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5960 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5961 Enum != EnumEnd; ++Enum) { 5962 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 5963 5964 // Don't add the same builtin candidate twice, or if a user defined 5965 // candidate exists. 5966 if (!AddedTypes.insert(CanonType) || 5967 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 5968 CanonType))) 5969 continue; 5970 5971 QualType ParamTypes[2] = { *Enum, *Enum }; 5972 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5973 CandidateSet); 5974 } 5975 5976 if (CandidateTypes[ArgIdx].hasNullPtrType()) { 5977 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy); 5978 if (AddedTypes.insert(NullPtrTy) && 5979 !UserDefinedBinaryOperators.count(std::make_pair(NullPtrTy, 5980 NullPtrTy))) { 5981 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy }; 5982 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5983 CandidateSet); 5984 } 5985 } 5986 } 5987 } 5988 5989 // C++ [over.built]p13: 5990 // 5991 // For every cv-qualified or cv-unqualified object type T 5992 // there exist candidate operator functions of the form 5993 // 5994 // T* operator+(T*, ptrdiff_t); 5995 // T& operator[](T*, ptrdiff_t); [BELOW] 5996 // T* operator-(T*, ptrdiff_t); 5997 // T* operator+(ptrdiff_t, T*); 5998 // T& operator[](ptrdiff_t, T*); [BELOW] 5999 // 6000 // C++ [over.built]p14: 6001 // 6002 // For every T, where T is a pointer to object type, there 6003 // exist candidate operator functions of the form 6004 // 6005 // ptrdiff_t operator-(T, T); 6006 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 6007 /// Set of (canonical) types that we've already handled. 6008 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6009 6010 for (int Arg = 0; Arg < 2; ++Arg) { 6011 QualType AsymetricParamTypes[2] = { 6012 S.Context.getPointerDiffType(), 6013 S.Context.getPointerDiffType(), 6014 }; 6015 for (BuiltinCandidateTypeSet::iterator 6016 Ptr = CandidateTypes[Arg].pointer_begin(), 6017 PtrEnd = CandidateTypes[Arg].pointer_end(); 6018 Ptr != PtrEnd; ++Ptr) { 6019 QualType PointeeTy = (*Ptr)->getPointeeType(); 6020 if (!PointeeTy->isObjectType()) 6021 continue; 6022 6023 AsymetricParamTypes[Arg] = *Ptr; 6024 if (Arg == 0 || Op == OO_Plus) { 6025 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 6026 // T* operator+(ptrdiff_t, T*); 6027 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, 6028 CandidateSet); 6029 } 6030 if (Op == OO_Minus) { 6031 // ptrdiff_t operator-(T, T); 6032 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6033 continue; 6034 6035 QualType ParamTypes[2] = { *Ptr, *Ptr }; 6036 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 6037 Args, 2, CandidateSet); 6038 } 6039 } 6040 } 6041 } 6042 6043 // C++ [over.built]p12: 6044 // 6045 // For every pair of promoted arithmetic types L and R, there 6046 // exist candidate operator functions of the form 6047 // 6048 // LR operator*(L, R); 6049 // LR operator/(L, R); 6050 // LR operator+(L, R); 6051 // LR operator-(L, R); 6052 // bool operator<(L, R); 6053 // bool operator>(L, R); 6054 // bool operator<=(L, R); 6055 // bool operator>=(L, R); 6056 // bool operator==(L, R); 6057 // bool operator!=(L, R); 6058 // 6059 // where LR is the result of the usual arithmetic conversions 6060 // between types L and R. 6061 // 6062 // C++ [over.built]p24: 6063 // 6064 // For every pair of promoted arithmetic types L and R, there exist 6065 // candidate operator functions of the form 6066 // 6067 // LR operator?(bool, L, R); 6068 // 6069 // where LR is the result of the usual arithmetic conversions 6070 // between types L and R. 6071 // Our candidates ignore the first parameter. 6072 void addGenericBinaryArithmeticOverloads(bool isComparison) { 6073 if (!HasArithmeticOrEnumeralCandidateType) 6074 return; 6075 6076 for (unsigned Left = FirstPromotedArithmeticType; 6077 Left < LastPromotedArithmeticType; ++Left) { 6078 for (unsigned Right = FirstPromotedArithmeticType; 6079 Right < LastPromotedArithmeticType; ++Right) { 6080 QualType LandR[2] = { getArithmeticType(Left), 6081 getArithmeticType(Right) }; 6082 QualType Result = 6083 isComparison ? S.Context.BoolTy 6084 : getUsualArithmeticConversions(Left, Right); 6085 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 6086 } 6087 } 6088 6089 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 6090 // conditional operator for vector types. 6091 for (BuiltinCandidateTypeSet::iterator 6092 Vec1 = CandidateTypes[0].vector_begin(), 6093 Vec1End = CandidateTypes[0].vector_end(); 6094 Vec1 != Vec1End; ++Vec1) { 6095 for (BuiltinCandidateTypeSet::iterator 6096 Vec2 = CandidateTypes[1].vector_begin(), 6097 Vec2End = CandidateTypes[1].vector_end(); 6098 Vec2 != Vec2End; ++Vec2) { 6099 QualType LandR[2] = { *Vec1, *Vec2 }; 6100 QualType Result = S.Context.BoolTy; 6101 if (!isComparison) { 6102 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 6103 Result = *Vec1; 6104 else 6105 Result = *Vec2; 6106 } 6107 6108 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 6109 } 6110 } 6111 } 6112 6113 // C++ [over.built]p17: 6114 // 6115 // For every pair of promoted integral types L and R, there 6116 // exist candidate operator functions of the form 6117 // 6118 // LR operator%(L, R); 6119 // LR operator&(L, R); 6120 // LR operator^(L, R); 6121 // LR operator|(L, R); 6122 // L operator<<(L, R); 6123 // L operator>>(L, R); 6124 // 6125 // where LR is the result of the usual arithmetic conversions 6126 // between types L and R. 6127 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 6128 if (!HasArithmeticOrEnumeralCandidateType) 6129 return; 6130 6131 for (unsigned Left = FirstPromotedIntegralType; 6132 Left < LastPromotedIntegralType; ++Left) { 6133 for (unsigned Right = FirstPromotedIntegralType; 6134 Right < LastPromotedIntegralType; ++Right) { 6135 QualType LandR[2] = { getArithmeticType(Left), 6136 getArithmeticType(Right) }; 6137 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 6138 ? LandR[0] 6139 : getUsualArithmeticConversions(Left, Right); 6140 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 6141 } 6142 } 6143 } 6144 6145 // C++ [over.built]p20: 6146 // 6147 // For every pair (T, VQ), where T is an enumeration or 6148 // pointer to member type and VQ is either volatile or 6149 // empty, there exist candidate operator functions of the form 6150 // 6151 // VQ T& operator=(VQ T&, T); 6152 void addAssignmentMemberPointerOrEnumeralOverloads() { 6153 /// Set of (canonical) types that we've already handled. 6154 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6155 6156 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 6157 for (BuiltinCandidateTypeSet::iterator 6158 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 6159 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 6160 Enum != EnumEnd; ++Enum) { 6161 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 6162 continue; 6163 6164 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, 6165 CandidateSet); 6166 } 6167 6168 for (BuiltinCandidateTypeSet::iterator 6169 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 6170 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 6171 MemPtr != MemPtrEnd; ++MemPtr) { 6172 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 6173 continue; 6174 6175 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, 6176 CandidateSet); 6177 } 6178 } 6179 } 6180 6181 // C++ [over.built]p19: 6182 // 6183 // For every pair (T, VQ), where T is any type and VQ is either 6184 // volatile or empty, there exist candidate operator functions 6185 // of the form 6186 // 6187 // T*VQ& operator=(T*VQ&, T*); 6188 // 6189 // C++ [over.built]p21: 6190 // 6191 // For every pair (T, VQ), where T is a cv-qualified or 6192 // cv-unqualified object type and VQ is either volatile or 6193 // empty, there exist candidate operator functions of the form 6194 // 6195 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 6196 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 6197 void addAssignmentPointerOverloads(bool isEqualOp) { 6198 /// Set of (canonical) types that we've already handled. 6199 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6200 6201 for (BuiltinCandidateTypeSet::iterator 6202 Ptr = CandidateTypes[0].pointer_begin(), 6203 PtrEnd = CandidateTypes[0].pointer_end(); 6204 Ptr != PtrEnd; ++Ptr) { 6205 // If this is operator=, keep track of the builtin candidates we added. 6206 if (isEqualOp) 6207 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 6208 else if (!(*Ptr)->getPointeeType()->isObjectType()) 6209 continue; 6210 6211 // non-volatile version 6212 QualType ParamTypes[2] = { 6213 S.Context.getLValueReferenceType(*Ptr), 6214 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 6215 }; 6216 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6217 /*IsAssigmentOperator=*/ isEqualOp); 6218 6219 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 6220 VisibleTypeConversionsQuals.hasVolatile()) { 6221 // volatile version 6222 ParamTypes[0] = 6223 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 6224 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6225 /*IsAssigmentOperator=*/isEqualOp); 6226 } 6227 } 6228 6229 if (isEqualOp) { 6230 for (BuiltinCandidateTypeSet::iterator 6231 Ptr = CandidateTypes[1].pointer_begin(), 6232 PtrEnd = CandidateTypes[1].pointer_end(); 6233 Ptr != PtrEnd; ++Ptr) { 6234 // Make sure we don't add the same candidate twice. 6235 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6236 continue; 6237 6238 QualType ParamTypes[2] = { 6239 S.Context.getLValueReferenceType(*Ptr), 6240 *Ptr, 6241 }; 6242 6243 // non-volatile version 6244 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6245 /*IsAssigmentOperator=*/true); 6246 6247 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 6248 VisibleTypeConversionsQuals.hasVolatile()) { 6249 // volatile version 6250 ParamTypes[0] = 6251 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 6252 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 6253 CandidateSet, /*IsAssigmentOperator=*/true); 6254 } 6255 } 6256 } 6257 } 6258 6259 // C++ [over.built]p18: 6260 // 6261 // For every triple (L, VQ, R), where L is an arithmetic type, 6262 // VQ is either volatile or empty, and R is a promoted 6263 // arithmetic type, there exist candidate operator functions of 6264 // the form 6265 // 6266 // VQ L& operator=(VQ L&, R); 6267 // VQ L& operator*=(VQ L&, R); 6268 // VQ L& operator/=(VQ L&, R); 6269 // VQ L& operator+=(VQ L&, R); 6270 // VQ L& operator-=(VQ L&, R); 6271 void addAssignmentArithmeticOverloads(bool isEqualOp) { 6272 if (!HasArithmeticOrEnumeralCandidateType) 6273 return; 6274 6275 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 6276 for (unsigned Right = FirstPromotedArithmeticType; 6277 Right < LastPromotedArithmeticType; ++Right) { 6278 QualType ParamTypes[2]; 6279 ParamTypes[1] = getArithmeticType(Right); 6280 6281 // Add this built-in operator as a candidate (VQ is empty). 6282 ParamTypes[0] = 6283 S.Context.getLValueReferenceType(getArithmeticType(Left)); 6284 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6285 /*IsAssigmentOperator=*/isEqualOp); 6286 6287 // Add this built-in operator as a candidate (VQ is 'volatile'). 6288 if (VisibleTypeConversionsQuals.hasVolatile()) { 6289 ParamTypes[0] = 6290 S.Context.getVolatileType(getArithmeticType(Left)); 6291 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 6292 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 6293 CandidateSet, 6294 /*IsAssigmentOperator=*/isEqualOp); 6295 } 6296 } 6297 } 6298 6299 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 6300 for (BuiltinCandidateTypeSet::iterator 6301 Vec1 = CandidateTypes[0].vector_begin(), 6302 Vec1End = CandidateTypes[0].vector_end(); 6303 Vec1 != Vec1End; ++Vec1) { 6304 for (BuiltinCandidateTypeSet::iterator 6305 Vec2 = CandidateTypes[1].vector_begin(), 6306 Vec2End = CandidateTypes[1].vector_end(); 6307 Vec2 != Vec2End; ++Vec2) { 6308 QualType ParamTypes[2]; 6309 ParamTypes[1] = *Vec2; 6310 // Add this built-in operator as a candidate (VQ is empty). 6311 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 6312 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6313 /*IsAssigmentOperator=*/isEqualOp); 6314 6315 // Add this built-in operator as a candidate (VQ is 'volatile'). 6316 if (VisibleTypeConversionsQuals.hasVolatile()) { 6317 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 6318 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 6319 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 6320 CandidateSet, 6321 /*IsAssigmentOperator=*/isEqualOp); 6322 } 6323 } 6324 } 6325 } 6326 6327 // C++ [over.built]p22: 6328 // 6329 // For every triple (L, VQ, R), where L is an integral type, VQ 6330 // is either volatile or empty, and R is a promoted integral 6331 // type, there exist candidate operator functions of the form 6332 // 6333 // VQ L& operator%=(VQ L&, R); 6334 // VQ L& operator<<=(VQ L&, R); 6335 // VQ L& operator>>=(VQ L&, R); 6336 // VQ L& operator&=(VQ L&, R); 6337 // VQ L& operator^=(VQ L&, R); 6338 // VQ L& operator|=(VQ L&, R); 6339 void addAssignmentIntegralOverloads() { 6340 if (!HasArithmeticOrEnumeralCandidateType) 6341 return; 6342 6343 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 6344 for (unsigned Right = FirstPromotedIntegralType; 6345 Right < LastPromotedIntegralType; ++Right) { 6346 QualType ParamTypes[2]; 6347 ParamTypes[1] = getArithmeticType(Right); 6348 6349 // Add this built-in operator as a candidate (VQ is empty). 6350 ParamTypes[0] = 6351 S.Context.getLValueReferenceType(getArithmeticType(Left)); 6352 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 6353 if (VisibleTypeConversionsQuals.hasVolatile()) { 6354 // Add this built-in operator as a candidate (VQ is 'volatile'). 6355 ParamTypes[0] = getArithmeticType(Left); 6356 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 6357 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 6358 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 6359 CandidateSet); 6360 } 6361 } 6362 } 6363 } 6364 6365 // C++ [over.operator]p23: 6366 // 6367 // There also exist candidate operator functions of the form 6368 // 6369 // bool operator!(bool); 6370 // bool operator&&(bool, bool); 6371 // bool operator||(bool, bool); 6372 void addExclaimOverload() { 6373 QualType ParamTy = S.Context.BoolTy; 6374 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 6375 /*IsAssignmentOperator=*/false, 6376 /*NumContextualBoolArguments=*/1); 6377 } 6378 void addAmpAmpOrPipePipeOverload() { 6379 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 6380 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 6381 /*IsAssignmentOperator=*/false, 6382 /*NumContextualBoolArguments=*/2); 6383 } 6384 6385 // C++ [over.built]p13: 6386 // 6387 // For every cv-qualified or cv-unqualified object type T there 6388 // exist candidate operator functions of the form 6389 // 6390 // T* operator+(T*, ptrdiff_t); [ABOVE] 6391 // T& operator[](T*, ptrdiff_t); 6392 // T* operator-(T*, ptrdiff_t); [ABOVE] 6393 // T* operator+(ptrdiff_t, T*); [ABOVE] 6394 // T& operator[](ptrdiff_t, T*); 6395 void addSubscriptOverloads() { 6396 for (BuiltinCandidateTypeSet::iterator 6397 Ptr = CandidateTypes[0].pointer_begin(), 6398 PtrEnd = CandidateTypes[0].pointer_end(); 6399 Ptr != PtrEnd; ++Ptr) { 6400 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 6401 QualType PointeeType = (*Ptr)->getPointeeType(); 6402 if (!PointeeType->isObjectType()) 6403 continue; 6404 6405 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 6406 6407 // T& operator[](T*, ptrdiff_t) 6408 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 6409 } 6410 6411 for (BuiltinCandidateTypeSet::iterator 6412 Ptr = CandidateTypes[1].pointer_begin(), 6413 PtrEnd = CandidateTypes[1].pointer_end(); 6414 Ptr != PtrEnd; ++Ptr) { 6415 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 6416 QualType PointeeType = (*Ptr)->getPointeeType(); 6417 if (!PointeeType->isObjectType()) 6418 continue; 6419 6420 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 6421 6422 // T& operator[](ptrdiff_t, T*) 6423 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 6424 } 6425 } 6426 6427 // C++ [over.built]p11: 6428 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 6429 // C1 is the same type as C2 or is a derived class of C2, T is an object 6430 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 6431 // there exist candidate operator functions of the form 6432 // 6433 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 6434 // 6435 // where CV12 is the union of CV1 and CV2. 6436 void addArrowStarOverloads() { 6437 for (BuiltinCandidateTypeSet::iterator 6438 Ptr = CandidateTypes[0].pointer_begin(), 6439 PtrEnd = CandidateTypes[0].pointer_end(); 6440 Ptr != PtrEnd; ++Ptr) { 6441 QualType C1Ty = (*Ptr); 6442 QualType C1; 6443 QualifierCollector Q1; 6444 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 6445 if (!isa<RecordType>(C1)) 6446 continue; 6447 // heuristic to reduce number of builtin candidates in the set. 6448 // Add volatile/restrict version only if there are conversions to a 6449 // volatile/restrict type. 6450 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 6451 continue; 6452 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 6453 continue; 6454 for (BuiltinCandidateTypeSet::iterator 6455 MemPtr = CandidateTypes[1].member_pointer_begin(), 6456 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 6457 MemPtr != MemPtrEnd; ++MemPtr) { 6458 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 6459 QualType C2 = QualType(mptr->getClass(), 0); 6460 C2 = C2.getUnqualifiedType(); 6461 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 6462 break; 6463 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 6464 // build CV12 T& 6465 QualType T = mptr->getPointeeType(); 6466 if (!VisibleTypeConversionsQuals.hasVolatile() && 6467 T.isVolatileQualified()) 6468 continue; 6469 if (!VisibleTypeConversionsQuals.hasRestrict() && 6470 T.isRestrictQualified()) 6471 continue; 6472 T = Q1.apply(S.Context, T); 6473 QualType ResultTy = S.Context.getLValueReferenceType(T); 6474 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 6475 } 6476 } 6477 } 6478 6479 // Note that we don't consider the first argument, since it has been 6480 // contextually converted to bool long ago. The candidates below are 6481 // therefore added as binary. 6482 // 6483 // C++ [over.built]p25: 6484 // For every type T, where T is a pointer, pointer-to-member, or scoped 6485 // enumeration type, there exist candidate operator functions of the form 6486 // 6487 // T operator?(bool, T, T); 6488 // 6489 void addConditionalOperatorOverloads() { 6490 /// Set of (canonical) types that we've already handled. 6491 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6492 6493 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 6494 for (BuiltinCandidateTypeSet::iterator 6495 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 6496 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 6497 Ptr != PtrEnd; ++Ptr) { 6498 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6499 continue; 6500 6501 QualType ParamTypes[2] = { *Ptr, *Ptr }; 6502 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 6503 } 6504 6505 for (BuiltinCandidateTypeSet::iterator 6506 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 6507 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 6508 MemPtr != MemPtrEnd; ++MemPtr) { 6509 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 6510 continue; 6511 6512 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 6513 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); 6514 } 6515 6516 if (S.getLangOptions().CPlusPlus0x) { 6517 for (BuiltinCandidateTypeSet::iterator 6518 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 6519 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 6520 Enum != EnumEnd; ++Enum) { 6521 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 6522 continue; 6523 6524 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 6525 continue; 6526 6527 QualType ParamTypes[2] = { *Enum, *Enum }; 6528 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); 6529 } 6530 } 6531 } 6532 } 6533}; 6534 6535} // end anonymous namespace 6536 6537/// AddBuiltinOperatorCandidates - Add the appropriate built-in 6538/// operator overloads to the candidate set (C++ [over.built]), based 6539/// on the operator @p Op and the arguments given. For example, if the 6540/// operator is a binary '+', this routine might add "int 6541/// operator+(int, int)" to cover integer addition. 6542void 6543Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 6544 SourceLocation OpLoc, 6545 Expr **Args, unsigned NumArgs, 6546 OverloadCandidateSet& CandidateSet) { 6547 // Find all of the types that the arguments can convert to, but only 6548 // if the operator we're looking at has built-in operator candidates 6549 // that make use of these types. Also record whether we encounter non-record 6550 // candidate types or either arithmetic or enumeral candidate types. 6551 Qualifiers VisibleTypeConversionsQuals; 6552 VisibleTypeConversionsQuals.addConst(); 6553 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6554 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 6555 6556 bool HasNonRecordCandidateType = false; 6557 bool HasArithmeticOrEnumeralCandidateType = false; 6558 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 6559 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6560 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 6561 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 6562 OpLoc, 6563 true, 6564 (Op == OO_Exclaim || 6565 Op == OO_AmpAmp || 6566 Op == OO_PipePipe), 6567 VisibleTypeConversionsQuals); 6568 HasNonRecordCandidateType = HasNonRecordCandidateType || 6569 CandidateTypes[ArgIdx].hasNonRecordTypes(); 6570 HasArithmeticOrEnumeralCandidateType = 6571 HasArithmeticOrEnumeralCandidateType || 6572 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 6573 } 6574 6575 // Exit early when no non-record types have been added to the candidate set 6576 // for any of the arguments to the operator. 6577 // 6578 // We can't exit early for !, ||, or &&, since there we have always have 6579 // 'bool' overloads. 6580 if (!HasNonRecordCandidateType && 6581 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe)) 6582 return; 6583 6584 // Setup an object to manage the common state for building overloads. 6585 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, 6586 VisibleTypeConversionsQuals, 6587 HasArithmeticOrEnumeralCandidateType, 6588 CandidateTypes, CandidateSet); 6589 6590 // Dispatch over the operation to add in only those overloads which apply. 6591 switch (Op) { 6592 case OO_None: 6593 case NUM_OVERLOADED_OPERATORS: 6594 llvm_unreachable("Expected an overloaded operator"); 6595 6596 case OO_New: 6597 case OO_Delete: 6598 case OO_Array_New: 6599 case OO_Array_Delete: 6600 case OO_Call: 6601 llvm_unreachable( 6602 "Special operators don't use AddBuiltinOperatorCandidates"); 6603 6604 case OO_Comma: 6605 case OO_Arrow: 6606 // C++ [over.match.oper]p3: 6607 // -- For the operator ',', the unary operator '&', or the 6608 // operator '->', the built-in candidates set is empty. 6609 break; 6610 6611 case OO_Plus: // '+' is either unary or binary 6612 if (NumArgs == 1) 6613 OpBuilder.addUnaryPlusPointerOverloads(); 6614 // Fall through. 6615 6616 case OO_Minus: // '-' is either unary or binary 6617 if (NumArgs == 1) { 6618 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 6619 } else { 6620 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 6621 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6622 } 6623 break; 6624 6625 case OO_Star: // '*' is either unary or binary 6626 if (NumArgs == 1) 6627 OpBuilder.addUnaryStarPointerOverloads(); 6628 else 6629 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6630 break; 6631 6632 case OO_Slash: 6633 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6634 break; 6635 6636 case OO_PlusPlus: 6637 case OO_MinusMinus: 6638 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 6639 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 6640 break; 6641 6642 case OO_EqualEqual: 6643 case OO_ExclaimEqual: 6644 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 6645 // Fall through. 6646 6647 case OO_Less: 6648 case OO_Greater: 6649 case OO_LessEqual: 6650 case OO_GreaterEqual: 6651 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 6652 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 6653 break; 6654 6655 case OO_Percent: 6656 case OO_Caret: 6657 case OO_Pipe: 6658 case OO_LessLess: 6659 case OO_GreaterGreater: 6660 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6661 break; 6662 6663 case OO_Amp: // '&' is either unary or binary 6664 if (NumArgs == 1) 6665 // C++ [over.match.oper]p3: 6666 // -- For the operator ',', the unary operator '&', or the 6667 // operator '->', the built-in candidates set is empty. 6668 break; 6669 6670 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6671 break; 6672 6673 case OO_Tilde: 6674 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 6675 break; 6676 6677 case OO_Equal: 6678 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 6679 // Fall through. 6680 6681 case OO_PlusEqual: 6682 case OO_MinusEqual: 6683 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 6684 // Fall through. 6685 6686 case OO_StarEqual: 6687 case OO_SlashEqual: 6688 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 6689 break; 6690 6691 case OO_PercentEqual: 6692 case OO_LessLessEqual: 6693 case OO_GreaterGreaterEqual: 6694 case OO_AmpEqual: 6695 case OO_CaretEqual: 6696 case OO_PipeEqual: 6697 OpBuilder.addAssignmentIntegralOverloads(); 6698 break; 6699 6700 case OO_Exclaim: 6701 OpBuilder.addExclaimOverload(); 6702 break; 6703 6704 case OO_AmpAmp: 6705 case OO_PipePipe: 6706 OpBuilder.addAmpAmpOrPipePipeOverload(); 6707 break; 6708 6709 case OO_Subscript: 6710 OpBuilder.addSubscriptOverloads(); 6711 break; 6712 6713 case OO_ArrowStar: 6714 OpBuilder.addArrowStarOverloads(); 6715 break; 6716 6717 case OO_Conditional: 6718 OpBuilder.addConditionalOperatorOverloads(); 6719 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6720 break; 6721 } 6722} 6723 6724/// \brief Add function candidates found via argument-dependent lookup 6725/// to the set of overloading candidates. 6726/// 6727/// This routine performs argument-dependent name lookup based on the 6728/// given function name (which may also be an operator name) and adds 6729/// all of the overload candidates found by ADL to the overload 6730/// candidate set (C++ [basic.lookup.argdep]). 6731void 6732Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 6733 bool Operator, 6734 Expr **Args, unsigned NumArgs, 6735 TemplateArgumentListInfo *ExplicitTemplateArgs, 6736 OverloadCandidateSet& CandidateSet, 6737 bool PartialOverloading, 6738 bool StdNamespaceIsAssociated) { 6739 ADLResult Fns; 6740 6741 // FIXME: This approach for uniquing ADL results (and removing 6742 // redundant candidates from the set) relies on pointer-equality, 6743 // which means we need to key off the canonical decl. However, 6744 // always going back to the canonical decl might not get us the 6745 // right set of default arguments. What default arguments are 6746 // we supposed to consider on ADL candidates, anyway? 6747 6748 // FIXME: Pass in the explicit template arguments? 6749 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns, 6750 StdNamespaceIsAssociated); 6751 6752 // Erase all of the candidates we already knew about. 6753 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 6754 CandEnd = CandidateSet.end(); 6755 Cand != CandEnd; ++Cand) 6756 if (Cand->Function) { 6757 Fns.erase(Cand->Function); 6758 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 6759 Fns.erase(FunTmpl); 6760 } 6761 6762 // For each of the ADL candidates we found, add it to the overload 6763 // set. 6764 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 6765 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 6766 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 6767 if (ExplicitTemplateArgs) 6768 continue; 6769 6770 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 6771 false, PartialOverloading); 6772 } else 6773 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 6774 FoundDecl, ExplicitTemplateArgs, 6775 Args, NumArgs, CandidateSet); 6776 } 6777} 6778 6779/// isBetterOverloadCandidate - Determines whether the first overload 6780/// candidate is a better candidate than the second (C++ 13.3.3p1). 6781bool 6782isBetterOverloadCandidate(Sema &S, 6783 const OverloadCandidate &Cand1, 6784 const OverloadCandidate &Cand2, 6785 SourceLocation Loc, 6786 bool UserDefinedConversion) { 6787 // Define viable functions to be better candidates than non-viable 6788 // functions. 6789 if (!Cand2.Viable) 6790 return Cand1.Viable; 6791 else if (!Cand1.Viable) 6792 return false; 6793 6794 // C++ [over.match.best]p1: 6795 // 6796 // -- if F is a static member function, ICS1(F) is defined such 6797 // that ICS1(F) is neither better nor worse than ICS1(G) for 6798 // any function G, and, symmetrically, ICS1(G) is neither 6799 // better nor worse than ICS1(F). 6800 unsigned StartArg = 0; 6801 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 6802 StartArg = 1; 6803 6804 // C++ [over.match.best]p1: 6805 // A viable function F1 is defined to be a better function than another 6806 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 6807 // conversion sequence than ICSi(F2), and then... 6808 unsigned NumArgs = Cand1.Conversions.size(); 6809 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 6810 bool HasBetterConversion = false; 6811 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 6812 switch (CompareImplicitConversionSequences(S, 6813 Cand1.Conversions[ArgIdx], 6814 Cand2.Conversions[ArgIdx])) { 6815 case ImplicitConversionSequence::Better: 6816 // Cand1 has a better conversion sequence. 6817 HasBetterConversion = true; 6818 break; 6819 6820 case ImplicitConversionSequence::Worse: 6821 // Cand1 can't be better than Cand2. 6822 return false; 6823 6824 case ImplicitConversionSequence::Indistinguishable: 6825 // Do nothing. 6826 break; 6827 } 6828 } 6829 6830 // -- for some argument j, ICSj(F1) is a better conversion sequence than 6831 // ICSj(F2), or, if not that, 6832 if (HasBetterConversion) 6833 return true; 6834 6835 // - F1 is a non-template function and F2 is a function template 6836 // specialization, or, if not that, 6837 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 6838 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 6839 return true; 6840 6841 // -- F1 and F2 are function template specializations, and the function 6842 // template for F1 is more specialized than the template for F2 6843 // according to the partial ordering rules described in 14.5.5.2, or, 6844 // if not that, 6845 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 6846 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 6847 if (FunctionTemplateDecl *BetterTemplate 6848 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 6849 Cand2.Function->getPrimaryTemplate(), 6850 Loc, 6851 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 6852 : TPOC_Call, 6853 Cand1.ExplicitCallArguments)) 6854 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 6855 } 6856 6857 // -- the context is an initialization by user-defined conversion 6858 // (see 8.5, 13.3.1.5) and the standard conversion sequence 6859 // from the return type of F1 to the destination type (i.e., 6860 // the type of the entity being initialized) is a better 6861 // conversion sequence than the standard conversion sequence 6862 // from the return type of F2 to the destination type. 6863 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 6864 isa<CXXConversionDecl>(Cand1.Function) && 6865 isa<CXXConversionDecl>(Cand2.Function)) { 6866 switch (CompareStandardConversionSequences(S, 6867 Cand1.FinalConversion, 6868 Cand2.FinalConversion)) { 6869 case ImplicitConversionSequence::Better: 6870 // Cand1 has a better conversion sequence. 6871 return true; 6872 6873 case ImplicitConversionSequence::Worse: 6874 // Cand1 can't be better than Cand2. 6875 return false; 6876 6877 case ImplicitConversionSequence::Indistinguishable: 6878 // Do nothing 6879 break; 6880 } 6881 } 6882 6883 return false; 6884} 6885 6886/// \brief Computes the best viable function (C++ 13.3.3) 6887/// within an overload candidate set. 6888/// 6889/// \param CandidateSet the set of candidate functions. 6890/// 6891/// \param Loc the location of the function name (or operator symbol) for 6892/// which overload resolution occurs. 6893/// 6894/// \param Best f overload resolution was successful or found a deleted 6895/// function, Best points to the candidate function found. 6896/// 6897/// \returns The result of overload resolution. 6898OverloadingResult 6899OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 6900 iterator &Best, 6901 bool UserDefinedConversion) { 6902 // Find the best viable function. 6903 Best = end(); 6904 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6905 if (Cand->Viable) 6906 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 6907 UserDefinedConversion)) 6908 Best = Cand; 6909 } 6910 6911 // If we didn't find any viable functions, abort. 6912 if (Best == end()) 6913 return OR_No_Viable_Function; 6914 6915 // Make sure that this function is better than every other viable 6916 // function. If not, we have an ambiguity. 6917 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6918 if (Cand->Viable && 6919 Cand != Best && 6920 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 6921 UserDefinedConversion)) { 6922 Best = end(); 6923 return OR_Ambiguous; 6924 } 6925 } 6926 6927 // Best is the best viable function. 6928 if (Best->Function && 6929 (Best->Function->isDeleted() || 6930 S.isFunctionConsideredUnavailable(Best->Function))) 6931 return OR_Deleted; 6932 6933 return OR_Success; 6934} 6935 6936namespace { 6937 6938enum OverloadCandidateKind { 6939 oc_function, 6940 oc_method, 6941 oc_constructor, 6942 oc_function_template, 6943 oc_method_template, 6944 oc_constructor_template, 6945 oc_implicit_default_constructor, 6946 oc_implicit_copy_constructor, 6947 oc_implicit_move_constructor, 6948 oc_implicit_copy_assignment, 6949 oc_implicit_move_assignment, 6950 oc_implicit_inherited_constructor 6951}; 6952 6953OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 6954 FunctionDecl *Fn, 6955 std::string &Description) { 6956 bool isTemplate = false; 6957 6958 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 6959 isTemplate = true; 6960 Description = S.getTemplateArgumentBindingsText( 6961 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 6962 } 6963 6964 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 6965 if (!Ctor->isImplicit()) 6966 return isTemplate ? oc_constructor_template : oc_constructor; 6967 6968 if (Ctor->getInheritedConstructor()) 6969 return oc_implicit_inherited_constructor; 6970 6971 if (Ctor->isDefaultConstructor()) 6972 return oc_implicit_default_constructor; 6973 6974 if (Ctor->isMoveConstructor()) 6975 return oc_implicit_move_constructor; 6976 6977 assert(Ctor->isCopyConstructor() && 6978 "unexpected sort of implicit constructor"); 6979 return oc_implicit_copy_constructor; 6980 } 6981 6982 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 6983 // This actually gets spelled 'candidate function' for now, but 6984 // it doesn't hurt to split it out. 6985 if (!Meth->isImplicit()) 6986 return isTemplate ? oc_method_template : oc_method; 6987 6988 if (Meth->isMoveAssignmentOperator()) 6989 return oc_implicit_move_assignment; 6990 6991 assert(Meth->isCopyAssignmentOperator() 6992 && "implicit method is not copy assignment operator?"); 6993 return oc_implicit_copy_assignment; 6994 } 6995 6996 return isTemplate ? oc_function_template : oc_function; 6997} 6998 6999void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { 7000 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 7001 if (!Ctor) return; 7002 7003 Ctor = Ctor->getInheritedConstructor(); 7004 if (!Ctor) return; 7005 7006 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 7007} 7008 7009} // end anonymous namespace 7010 7011// Notes the location of an overload candidate. 7012void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 7013 std::string FnDesc; 7014 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 7015 Diag(Fn->getLocation(), diag::note_ovl_candidate) 7016 << (unsigned) K << FnDesc; 7017 MaybeEmitInheritedConstructorNote(*this, Fn); 7018} 7019 7020//Notes the location of all overload candidates designated through 7021// OverloadedExpr 7022void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr) { 7023 assert(OverloadedExpr->getType() == Context.OverloadTy); 7024 7025 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); 7026 OverloadExpr *OvlExpr = Ovl.Expression; 7027 7028 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7029 IEnd = OvlExpr->decls_end(); 7030 I != IEnd; ++I) { 7031 if (FunctionTemplateDecl *FunTmpl = 7032 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) { 7033 NoteOverloadCandidate(FunTmpl->getTemplatedDecl()); 7034 } else if (FunctionDecl *Fun 7035 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) { 7036 NoteOverloadCandidate(Fun); 7037 } 7038 } 7039} 7040 7041/// Diagnoses an ambiguous conversion. The partial diagnostic is the 7042/// "lead" diagnostic; it will be given two arguments, the source and 7043/// target types of the conversion. 7044void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 7045 Sema &S, 7046 SourceLocation CaretLoc, 7047 const PartialDiagnostic &PDiag) const { 7048 S.Diag(CaretLoc, PDiag) 7049 << Ambiguous.getFromType() << Ambiguous.getToType(); 7050 for (AmbiguousConversionSequence::const_iterator 7051 I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 7052 S.NoteOverloadCandidate(*I); 7053 } 7054} 7055 7056namespace { 7057 7058void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 7059 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 7060 assert(Conv.isBad()); 7061 assert(Cand->Function && "for now, candidate must be a function"); 7062 FunctionDecl *Fn = Cand->Function; 7063 7064 // There's a conversion slot for the object argument if this is a 7065 // non-constructor method. Note that 'I' corresponds the 7066 // conversion-slot index. 7067 bool isObjectArgument = false; 7068 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 7069 if (I == 0) 7070 isObjectArgument = true; 7071 else 7072 I--; 7073 } 7074 7075 std::string FnDesc; 7076 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 7077 7078 Expr *FromExpr = Conv.Bad.FromExpr; 7079 QualType FromTy = Conv.Bad.getFromType(); 7080 QualType ToTy = Conv.Bad.getToType(); 7081 7082 if (FromTy == S.Context.OverloadTy) { 7083 assert(FromExpr && "overload set argument came from implicit argument?"); 7084 Expr *E = FromExpr->IgnoreParens(); 7085 if (isa<UnaryOperator>(E)) 7086 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 7087 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 7088 7089 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 7090 << (unsigned) FnKind << FnDesc 7091 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7092 << ToTy << Name << I+1; 7093 MaybeEmitInheritedConstructorNote(S, Fn); 7094 return; 7095 } 7096 7097 // Do some hand-waving analysis to see if the non-viability is due 7098 // to a qualifier mismatch. 7099 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 7100 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 7101 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 7102 CToTy = RT->getPointeeType(); 7103 else { 7104 // TODO: detect and diagnose the full richness of const mismatches. 7105 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 7106 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 7107 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 7108 } 7109 7110 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 7111 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 7112 // It is dumb that we have to do this here. 7113 while (isa<ArrayType>(CFromTy)) 7114 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 7115 while (isa<ArrayType>(CToTy)) 7116 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 7117 7118 Qualifiers FromQs = CFromTy.getQualifiers(); 7119 Qualifiers ToQs = CToTy.getQualifiers(); 7120 7121 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 7122 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 7123 << (unsigned) FnKind << FnDesc 7124 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7125 << FromTy 7126 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 7127 << (unsigned) isObjectArgument << I+1; 7128 MaybeEmitInheritedConstructorNote(S, Fn); 7129 return; 7130 } 7131 7132 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 7133 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership) 7134 << (unsigned) FnKind << FnDesc 7135 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7136 << FromTy 7137 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime() 7138 << (unsigned) isObjectArgument << I+1; 7139 MaybeEmitInheritedConstructorNote(S, Fn); 7140 return; 7141 } 7142 7143 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) { 7144 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc) 7145 << (unsigned) FnKind << FnDesc 7146 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7147 << FromTy 7148 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr() 7149 << (unsigned) isObjectArgument << I+1; 7150 MaybeEmitInheritedConstructorNote(S, Fn); 7151 return; 7152 } 7153 7154 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 7155 assert(CVR && "unexpected qualifiers mismatch"); 7156 7157 if (isObjectArgument) { 7158 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 7159 << (unsigned) FnKind << FnDesc 7160 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7161 << FromTy << (CVR - 1); 7162 } else { 7163 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 7164 << (unsigned) FnKind << FnDesc 7165 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7166 << FromTy << (CVR - 1) << I+1; 7167 } 7168 MaybeEmitInheritedConstructorNote(S, Fn); 7169 return; 7170 } 7171 7172 // Special diagnostic for failure to convert an initializer list, since 7173 // telling the user that it has type void is not useful. 7174 if (FromExpr && isa<InitListExpr>(FromExpr)) { 7175 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument) 7176 << (unsigned) FnKind << FnDesc 7177 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7178 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 7179 MaybeEmitInheritedConstructorNote(S, Fn); 7180 return; 7181 } 7182 7183 // Diagnose references or pointers to incomplete types differently, 7184 // since it's far from impossible that the incompleteness triggered 7185 // the failure. 7186 QualType TempFromTy = FromTy.getNonReferenceType(); 7187 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 7188 TempFromTy = PTy->getPointeeType(); 7189 if (TempFromTy->isIncompleteType()) { 7190 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 7191 << (unsigned) FnKind << FnDesc 7192 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7193 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 7194 MaybeEmitInheritedConstructorNote(S, Fn); 7195 return; 7196 } 7197 7198 // Diagnose base -> derived pointer conversions. 7199 unsigned BaseToDerivedConversion = 0; 7200 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 7201 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 7202 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 7203 FromPtrTy->getPointeeType()) && 7204 !FromPtrTy->getPointeeType()->isIncompleteType() && 7205 !ToPtrTy->getPointeeType()->isIncompleteType() && 7206 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 7207 FromPtrTy->getPointeeType())) 7208 BaseToDerivedConversion = 1; 7209 } 7210 } else if (const ObjCObjectPointerType *FromPtrTy 7211 = FromTy->getAs<ObjCObjectPointerType>()) { 7212 if (const ObjCObjectPointerType *ToPtrTy 7213 = ToTy->getAs<ObjCObjectPointerType>()) 7214 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 7215 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 7216 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 7217 FromPtrTy->getPointeeType()) && 7218 FromIface->isSuperClassOf(ToIface)) 7219 BaseToDerivedConversion = 2; 7220 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 7221 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 7222 !FromTy->isIncompleteType() && 7223 !ToRefTy->getPointeeType()->isIncompleteType() && 7224 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 7225 BaseToDerivedConversion = 3; 7226 } 7227 7228 if (BaseToDerivedConversion) { 7229 S.Diag(Fn->getLocation(), 7230 diag::note_ovl_candidate_bad_base_to_derived_conv) 7231 << (unsigned) FnKind << FnDesc 7232 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7233 << (BaseToDerivedConversion - 1) 7234 << FromTy << ToTy << I+1; 7235 MaybeEmitInheritedConstructorNote(S, Fn); 7236 return; 7237 } 7238 7239 if (isa<ObjCObjectPointerType>(CFromTy) && 7240 isa<PointerType>(CToTy)) { 7241 Qualifiers FromQs = CFromTy.getQualifiers(); 7242 Qualifiers ToQs = CToTy.getQualifiers(); 7243 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 7244 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv) 7245 << (unsigned) FnKind << FnDesc 7246 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7247 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 7248 MaybeEmitInheritedConstructorNote(S, Fn); 7249 return; 7250 } 7251 } 7252 7253 // Emit the generic diagnostic and, optionally, add the hints to it. 7254 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv); 7255 FDiag << (unsigned) FnKind << FnDesc 7256 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7257 << FromTy << ToTy << (unsigned) isObjectArgument << I + 1 7258 << (unsigned) (Cand->Fix.Kind); 7259 7260 // If we can fix the conversion, suggest the FixIts. 7261 for (SmallVector<FixItHint, 1>::iterator 7262 HI = Cand->Fix.Hints.begin(), HE = Cand->Fix.Hints.end(); 7263 HI != HE; ++HI) 7264 FDiag << *HI; 7265 S.Diag(Fn->getLocation(), FDiag); 7266 7267 MaybeEmitInheritedConstructorNote(S, Fn); 7268} 7269 7270void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 7271 unsigned NumFormalArgs) { 7272 // TODO: treat calls to a missing default constructor as a special case 7273 7274 FunctionDecl *Fn = Cand->Function; 7275 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 7276 7277 unsigned MinParams = Fn->getMinRequiredArguments(); 7278 7279 // With invalid overloaded operators, it's possible that we think we 7280 // have an arity mismatch when it fact it looks like we have the 7281 // right number of arguments, because only overloaded operators have 7282 // the weird behavior of overloading member and non-member functions. 7283 // Just don't report anything. 7284 if (Fn->isInvalidDecl() && 7285 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName) 7286 return; 7287 7288 // at least / at most / exactly 7289 unsigned mode, modeCount; 7290 if (NumFormalArgs < MinParams) { 7291 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 7292 (Cand->FailureKind == ovl_fail_bad_deduction && 7293 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 7294 if (MinParams != FnTy->getNumArgs() || 7295 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 7296 mode = 0; // "at least" 7297 else 7298 mode = 2; // "exactly" 7299 modeCount = MinParams; 7300 } else { 7301 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 7302 (Cand->FailureKind == ovl_fail_bad_deduction && 7303 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 7304 if (MinParams != FnTy->getNumArgs()) 7305 mode = 1; // "at most" 7306 else 7307 mode = 2; // "exactly" 7308 modeCount = FnTy->getNumArgs(); 7309 } 7310 7311 std::string Description; 7312 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 7313 7314 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 7315 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 7316 << modeCount << NumFormalArgs; 7317 MaybeEmitInheritedConstructorNote(S, Fn); 7318} 7319 7320/// Diagnose a failed template-argument deduction. 7321void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 7322 Expr **Args, unsigned NumArgs) { 7323 FunctionDecl *Fn = Cand->Function; // pattern 7324 7325 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 7326 NamedDecl *ParamD; 7327 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 7328 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 7329 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 7330 switch (Cand->DeductionFailure.Result) { 7331 case Sema::TDK_Success: 7332 llvm_unreachable("TDK_success while diagnosing bad deduction"); 7333 7334 case Sema::TDK_Incomplete: { 7335 assert(ParamD && "no parameter found for incomplete deduction result"); 7336 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 7337 << ParamD->getDeclName(); 7338 MaybeEmitInheritedConstructorNote(S, Fn); 7339 return; 7340 } 7341 7342 case Sema::TDK_Underqualified: { 7343 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 7344 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 7345 7346 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 7347 7348 // Param will have been canonicalized, but it should just be a 7349 // qualified version of ParamD, so move the qualifiers to that. 7350 QualifierCollector Qs; 7351 Qs.strip(Param); 7352 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 7353 assert(S.Context.hasSameType(Param, NonCanonParam)); 7354 7355 // Arg has also been canonicalized, but there's nothing we can do 7356 // about that. It also doesn't matter as much, because it won't 7357 // have any template parameters in it (because deduction isn't 7358 // done on dependent types). 7359 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 7360 7361 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 7362 << ParamD->getDeclName() << Arg << NonCanonParam; 7363 MaybeEmitInheritedConstructorNote(S, Fn); 7364 return; 7365 } 7366 7367 case Sema::TDK_Inconsistent: { 7368 assert(ParamD && "no parameter found for inconsistent deduction result"); 7369 int which = 0; 7370 if (isa<TemplateTypeParmDecl>(ParamD)) 7371 which = 0; 7372 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 7373 which = 1; 7374 else { 7375 which = 2; 7376 } 7377 7378 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 7379 << which << ParamD->getDeclName() 7380 << *Cand->DeductionFailure.getFirstArg() 7381 << *Cand->DeductionFailure.getSecondArg(); 7382 MaybeEmitInheritedConstructorNote(S, Fn); 7383 return; 7384 } 7385 7386 case Sema::TDK_InvalidExplicitArguments: 7387 assert(ParamD && "no parameter found for invalid explicit arguments"); 7388 if (ParamD->getDeclName()) 7389 S.Diag(Fn->getLocation(), 7390 diag::note_ovl_candidate_explicit_arg_mismatch_named) 7391 << ParamD->getDeclName(); 7392 else { 7393 int index = 0; 7394 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 7395 index = TTP->getIndex(); 7396 else if (NonTypeTemplateParmDecl *NTTP 7397 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 7398 index = NTTP->getIndex(); 7399 else 7400 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 7401 S.Diag(Fn->getLocation(), 7402 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 7403 << (index + 1); 7404 } 7405 MaybeEmitInheritedConstructorNote(S, Fn); 7406 return; 7407 7408 case Sema::TDK_TooManyArguments: 7409 case Sema::TDK_TooFewArguments: 7410 DiagnoseArityMismatch(S, Cand, NumArgs); 7411 return; 7412 7413 case Sema::TDK_InstantiationDepth: 7414 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 7415 MaybeEmitInheritedConstructorNote(S, Fn); 7416 return; 7417 7418 case Sema::TDK_SubstitutionFailure: { 7419 std::string ArgString; 7420 if (TemplateArgumentList *Args 7421 = Cand->DeductionFailure.getTemplateArgumentList()) 7422 ArgString = S.getTemplateArgumentBindingsText( 7423 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 7424 *Args); 7425 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 7426 << ArgString; 7427 MaybeEmitInheritedConstructorNote(S, Fn); 7428 return; 7429 } 7430 7431 // TODO: diagnose these individually, then kill off 7432 // note_ovl_candidate_bad_deduction, which is uselessly vague. 7433 case Sema::TDK_NonDeducedMismatch: 7434 case Sema::TDK_FailedOverloadResolution: 7435 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 7436 MaybeEmitInheritedConstructorNote(S, Fn); 7437 return; 7438 } 7439} 7440 7441/// CUDA: diagnose an invalid call across targets. 7442void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) { 7443 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext); 7444 FunctionDecl *Callee = Cand->Function; 7445 7446 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller), 7447 CalleeTarget = S.IdentifyCUDATarget(Callee); 7448 7449 std::string FnDesc; 7450 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Callee, FnDesc); 7451 7452 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target) 7453 << (unsigned) FnKind << CalleeTarget << CallerTarget; 7454} 7455 7456/// Generates a 'note' diagnostic for an overload candidate. We've 7457/// already generated a primary error at the call site. 7458/// 7459/// It really does need to be a single diagnostic with its caret 7460/// pointed at the candidate declaration. Yes, this creates some 7461/// major challenges of technical writing. Yes, this makes pointing 7462/// out problems with specific arguments quite awkward. It's still 7463/// better than generating twenty screens of text for every failed 7464/// overload. 7465/// 7466/// It would be great to be able to express per-candidate problems 7467/// more richly for those diagnostic clients that cared, but we'd 7468/// still have to be just as careful with the default diagnostics. 7469void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 7470 Expr **Args, unsigned NumArgs) { 7471 FunctionDecl *Fn = Cand->Function; 7472 7473 // Note deleted candidates, but only if they're viable. 7474 if (Cand->Viable && (Fn->isDeleted() || 7475 S.isFunctionConsideredUnavailable(Fn))) { 7476 std::string FnDesc; 7477 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 7478 7479 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 7480 << FnKind << FnDesc << Fn->isDeleted(); 7481 MaybeEmitInheritedConstructorNote(S, Fn); 7482 return; 7483 } 7484 7485 // We don't really have anything else to say about viable candidates. 7486 if (Cand->Viable) { 7487 S.NoteOverloadCandidate(Fn); 7488 return; 7489 } 7490 7491 switch (Cand->FailureKind) { 7492 case ovl_fail_too_many_arguments: 7493 case ovl_fail_too_few_arguments: 7494 return DiagnoseArityMismatch(S, Cand, NumArgs); 7495 7496 case ovl_fail_bad_deduction: 7497 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 7498 7499 case ovl_fail_trivial_conversion: 7500 case ovl_fail_bad_final_conversion: 7501 case ovl_fail_final_conversion_not_exact: 7502 return S.NoteOverloadCandidate(Fn); 7503 7504 case ovl_fail_bad_conversion: { 7505 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 7506 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 7507 if (Cand->Conversions[I].isBad()) 7508 return DiagnoseBadConversion(S, Cand, I); 7509 7510 // FIXME: this currently happens when we're called from SemaInit 7511 // when user-conversion overload fails. Figure out how to handle 7512 // those conditions and diagnose them well. 7513 return S.NoteOverloadCandidate(Fn); 7514 } 7515 7516 case ovl_fail_bad_target: 7517 return DiagnoseBadTarget(S, Cand); 7518 } 7519} 7520 7521void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 7522 // Desugar the type of the surrogate down to a function type, 7523 // retaining as many typedefs as possible while still showing 7524 // the function type (and, therefore, its parameter types). 7525 QualType FnType = Cand->Surrogate->getConversionType(); 7526 bool isLValueReference = false; 7527 bool isRValueReference = false; 7528 bool isPointer = false; 7529 if (const LValueReferenceType *FnTypeRef = 7530 FnType->getAs<LValueReferenceType>()) { 7531 FnType = FnTypeRef->getPointeeType(); 7532 isLValueReference = true; 7533 } else if (const RValueReferenceType *FnTypeRef = 7534 FnType->getAs<RValueReferenceType>()) { 7535 FnType = FnTypeRef->getPointeeType(); 7536 isRValueReference = true; 7537 } 7538 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 7539 FnType = FnTypePtr->getPointeeType(); 7540 isPointer = true; 7541 } 7542 // Desugar down to a function type. 7543 FnType = QualType(FnType->getAs<FunctionType>(), 0); 7544 // Reconstruct the pointer/reference as appropriate. 7545 if (isPointer) FnType = S.Context.getPointerType(FnType); 7546 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 7547 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 7548 7549 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 7550 << FnType; 7551 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 7552} 7553 7554void NoteBuiltinOperatorCandidate(Sema &S, 7555 const char *Opc, 7556 SourceLocation OpLoc, 7557 OverloadCandidate *Cand) { 7558 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 7559 std::string TypeStr("operator"); 7560 TypeStr += Opc; 7561 TypeStr += "("; 7562 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 7563 if (Cand->Conversions.size() == 1) { 7564 TypeStr += ")"; 7565 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 7566 } else { 7567 TypeStr += ", "; 7568 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 7569 TypeStr += ")"; 7570 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 7571 } 7572} 7573 7574void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 7575 OverloadCandidate *Cand) { 7576 unsigned NoOperands = Cand->Conversions.size(); 7577 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 7578 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 7579 if (ICS.isBad()) break; // all meaningless after first invalid 7580 if (!ICS.isAmbiguous()) continue; 7581 7582 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 7583 S.PDiag(diag::note_ambiguous_type_conversion)); 7584 } 7585} 7586 7587SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 7588 if (Cand->Function) 7589 return Cand->Function->getLocation(); 7590 if (Cand->IsSurrogate) 7591 return Cand->Surrogate->getLocation(); 7592 return SourceLocation(); 7593} 7594 7595static unsigned 7596RankDeductionFailure(const OverloadCandidate::DeductionFailureInfo &DFI) { 7597 switch ((Sema::TemplateDeductionResult)DFI.Result) { 7598 case Sema::TDK_Success: 7599 llvm_unreachable("TDK_success while diagnosing bad deduction"); 7600 7601 case Sema::TDK_Incomplete: 7602 return 1; 7603 7604 case Sema::TDK_Underqualified: 7605 case Sema::TDK_Inconsistent: 7606 return 2; 7607 7608 case Sema::TDK_SubstitutionFailure: 7609 case Sema::TDK_NonDeducedMismatch: 7610 return 3; 7611 7612 case Sema::TDK_InstantiationDepth: 7613 case Sema::TDK_FailedOverloadResolution: 7614 return 4; 7615 7616 case Sema::TDK_InvalidExplicitArguments: 7617 return 5; 7618 7619 case Sema::TDK_TooManyArguments: 7620 case Sema::TDK_TooFewArguments: 7621 return 6; 7622 } 7623 llvm_unreachable("Unhandled deduction result"); 7624} 7625 7626struct CompareOverloadCandidatesForDisplay { 7627 Sema &S; 7628 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 7629 7630 bool operator()(const OverloadCandidate *L, 7631 const OverloadCandidate *R) { 7632 // Fast-path this check. 7633 if (L == R) return false; 7634 7635 // Order first by viability. 7636 if (L->Viable) { 7637 if (!R->Viable) return true; 7638 7639 // TODO: introduce a tri-valued comparison for overload 7640 // candidates. Would be more worthwhile if we had a sort 7641 // that could exploit it. 7642 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 7643 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 7644 } else if (R->Viable) 7645 return false; 7646 7647 assert(L->Viable == R->Viable); 7648 7649 // Criteria by which we can sort non-viable candidates: 7650 if (!L->Viable) { 7651 // 1. Arity mismatches come after other candidates. 7652 if (L->FailureKind == ovl_fail_too_many_arguments || 7653 L->FailureKind == ovl_fail_too_few_arguments) 7654 return false; 7655 if (R->FailureKind == ovl_fail_too_many_arguments || 7656 R->FailureKind == ovl_fail_too_few_arguments) 7657 return true; 7658 7659 // 2. Bad conversions come first and are ordered by the number 7660 // of bad conversions and quality of good conversions. 7661 if (L->FailureKind == ovl_fail_bad_conversion) { 7662 if (R->FailureKind != ovl_fail_bad_conversion) 7663 return true; 7664 7665 // The conversion that can be fixed with a smaller number of changes, 7666 // comes first. 7667 unsigned numLFixes = L->Fix.NumConversionsFixed; 7668 unsigned numRFixes = R->Fix.NumConversionsFixed; 7669 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes; 7670 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes; 7671 if (numLFixes != numRFixes) { 7672 if (numLFixes < numRFixes) 7673 return true; 7674 else 7675 return false; 7676 } 7677 7678 // If there's any ordering between the defined conversions... 7679 // FIXME: this might not be transitive. 7680 assert(L->Conversions.size() == R->Conversions.size()); 7681 7682 int leftBetter = 0; 7683 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 7684 for (unsigned E = L->Conversions.size(); I != E; ++I) { 7685 switch (CompareImplicitConversionSequences(S, 7686 L->Conversions[I], 7687 R->Conversions[I])) { 7688 case ImplicitConversionSequence::Better: 7689 leftBetter++; 7690 break; 7691 7692 case ImplicitConversionSequence::Worse: 7693 leftBetter--; 7694 break; 7695 7696 case ImplicitConversionSequence::Indistinguishable: 7697 break; 7698 } 7699 } 7700 if (leftBetter > 0) return true; 7701 if (leftBetter < 0) return false; 7702 7703 } else if (R->FailureKind == ovl_fail_bad_conversion) 7704 return false; 7705 7706 if (L->FailureKind == ovl_fail_bad_deduction) { 7707 if (R->FailureKind != ovl_fail_bad_deduction) 7708 return true; 7709 7710 if (L->DeductionFailure.Result != R->DeductionFailure.Result) 7711 return RankDeductionFailure(L->DeductionFailure) 7712 < RankDeductionFailure(R->DeductionFailure); 7713 } else if (R->FailureKind == ovl_fail_bad_deduction) 7714 return false; 7715 7716 // TODO: others? 7717 } 7718 7719 // Sort everything else by location. 7720 SourceLocation LLoc = GetLocationForCandidate(L); 7721 SourceLocation RLoc = GetLocationForCandidate(R); 7722 7723 // Put candidates without locations (e.g. builtins) at the end. 7724 if (LLoc.isInvalid()) return false; 7725 if (RLoc.isInvalid()) return true; 7726 7727 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 7728 } 7729}; 7730 7731/// CompleteNonViableCandidate - Normally, overload resolution only 7732/// computes up to the first. Produces the FixIt set if possible. 7733void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 7734 Expr **Args, unsigned NumArgs) { 7735 assert(!Cand->Viable); 7736 7737 // Don't do anything on failures other than bad conversion. 7738 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 7739 7740 // We only want the FixIts if all the arguments can be corrected. 7741 bool Unfixable = false; 7742 // Use a implicit copy initialization to check conversion fixes. 7743 Cand->Fix.setConversionChecker(TryCopyInitialization); 7744 7745 // Skip forward to the first bad conversion. 7746 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 7747 unsigned ConvCount = Cand->Conversions.size(); 7748 while (true) { 7749 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 7750 ConvIdx++; 7751 if (Cand->Conversions[ConvIdx - 1].isBad()) { 7752 Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S); 7753 break; 7754 } 7755 } 7756 7757 if (ConvIdx == ConvCount) 7758 return; 7759 7760 assert(!Cand->Conversions[ConvIdx].isInitialized() && 7761 "remaining conversion is initialized?"); 7762 7763 // FIXME: this should probably be preserved from the overload 7764 // operation somehow. 7765 bool SuppressUserConversions = false; 7766 7767 const FunctionProtoType* Proto; 7768 unsigned ArgIdx = ConvIdx; 7769 7770 if (Cand->IsSurrogate) { 7771 QualType ConvType 7772 = Cand->Surrogate->getConversionType().getNonReferenceType(); 7773 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7774 ConvType = ConvPtrType->getPointeeType(); 7775 Proto = ConvType->getAs<FunctionProtoType>(); 7776 ArgIdx--; 7777 } else if (Cand->Function) { 7778 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 7779 if (isa<CXXMethodDecl>(Cand->Function) && 7780 !isa<CXXConstructorDecl>(Cand->Function)) 7781 ArgIdx--; 7782 } else { 7783 // Builtin binary operator with a bad first conversion. 7784 assert(ConvCount <= 3); 7785 for (; ConvIdx != ConvCount; ++ConvIdx) 7786 Cand->Conversions[ConvIdx] 7787 = TryCopyInitialization(S, Args[ConvIdx], 7788 Cand->BuiltinTypes.ParamTypes[ConvIdx], 7789 SuppressUserConversions, 7790 /*InOverloadResolution*/ true, 7791 /*AllowObjCWritebackConversion=*/ 7792 S.getLangOptions().ObjCAutoRefCount); 7793 return; 7794 } 7795 7796 // Fill in the rest of the conversions. 7797 unsigned NumArgsInProto = Proto->getNumArgs(); 7798 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 7799 if (ArgIdx < NumArgsInProto) { 7800 Cand->Conversions[ConvIdx] 7801 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 7802 SuppressUserConversions, 7803 /*InOverloadResolution=*/true, 7804 /*AllowObjCWritebackConversion=*/ 7805 S.getLangOptions().ObjCAutoRefCount); 7806 // Store the FixIt in the candidate if it exists. 7807 if (!Unfixable && Cand->Conversions[ConvIdx].isBad()) 7808 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S); 7809 } 7810 else 7811 Cand->Conversions[ConvIdx].setEllipsis(); 7812 } 7813} 7814 7815} // end anonymous namespace 7816 7817/// PrintOverloadCandidates - When overload resolution fails, prints 7818/// diagnostic messages containing the candidates in the candidate 7819/// set. 7820void OverloadCandidateSet::NoteCandidates(Sema &S, 7821 OverloadCandidateDisplayKind OCD, 7822 Expr **Args, unsigned NumArgs, 7823 const char *Opc, 7824 SourceLocation OpLoc) { 7825 // Sort the candidates by viability and position. Sorting directly would 7826 // be prohibitive, so we make a set of pointers and sort those. 7827 SmallVector<OverloadCandidate*, 32> Cands; 7828 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 7829 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 7830 if (Cand->Viable) 7831 Cands.push_back(Cand); 7832 else if (OCD == OCD_AllCandidates) { 7833 CompleteNonViableCandidate(S, Cand, Args, NumArgs); 7834 if (Cand->Function || Cand->IsSurrogate) 7835 Cands.push_back(Cand); 7836 // Otherwise, this a non-viable builtin candidate. We do not, in general, 7837 // want to list every possible builtin candidate. 7838 } 7839 } 7840 7841 std::sort(Cands.begin(), Cands.end(), 7842 CompareOverloadCandidatesForDisplay(S)); 7843 7844 bool ReportedAmbiguousConversions = false; 7845 7846 SmallVectorImpl<OverloadCandidate*>::iterator I, E; 7847 const DiagnosticsEngine::OverloadsShown ShowOverloads = 7848 S.Diags.getShowOverloads(); 7849 unsigned CandsShown = 0; 7850 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 7851 OverloadCandidate *Cand = *I; 7852 7853 // Set an arbitrary limit on the number of candidate functions we'll spam 7854 // the user with. FIXME: This limit should depend on details of the 7855 // candidate list. 7856 if (CandsShown >= 4 && ShowOverloads == DiagnosticsEngine::Ovl_Best) { 7857 break; 7858 } 7859 ++CandsShown; 7860 7861 if (Cand->Function) 7862 NoteFunctionCandidate(S, Cand, Args, NumArgs); 7863 else if (Cand->IsSurrogate) 7864 NoteSurrogateCandidate(S, Cand); 7865 else { 7866 assert(Cand->Viable && 7867 "Non-viable built-in candidates are not added to Cands."); 7868 // Generally we only see ambiguities including viable builtin 7869 // operators if overload resolution got screwed up by an 7870 // ambiguous user-defined conversion. 7871 // 7872 // FIXME: It's quite possible for different conversions to see 7873 // different ambiguities, though. 7874 if (!ReportedAmbiguousConversions) { 7875 NoteAmbiguousUserConversions(S, OpLoc, Cand); 7876 ReportedAmbiguousConversions = true; 7877 } 7878 7879 // If this is a viable builtin, print it. 7880 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 7881 } 7882 } 7883 7884 if (I != E) 7885 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 7886} 7887 7888// [PossiblyAFunctionType] --> [Return] 7889// NonFunctionType --> NonFunctionType 7890// R (A) --> R(A) 7891// R (*)(A) --> R (A) 7892// R (&)(A) --> R (A) 7893// R (S::*)(A) --> R (A) 7894QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { 7895 QualType Ret = PossiblyAFunctionType; 7896 if (const PointerType *ToTypePtr = 7897 PossiblyAFunctionType->getAs<PointerType>()) 7898 Ret = ToTypePtr->getPointeeType(); 7899 else if (const ReferenceType *ToTypeRef = 7900 PossiblyAFunctionType->getAs<ReferenceType>()) 7901 Ret = ToTypeRef->getPointeeType(); 7902 else if (const MemberPointerType *MemTypePtr = 7903 PossiblyAFunctionType->getAs<MemberPointerType>()) 7904 Ret = MemTypePtr->getPointeeType(); 7905 Ret = 7906 Context.getCanonicalType(Ret).getUnqualifiedType(); 7907 return Ret; 7908} 7909 7910// A helper class to help with address of function resolution 7911// - allows us to avoid passing around all those ugly parameters 7912class AddressOfFunctionResolver 7913{ 7914 Sema& S; 7915 Expr* SourceExpr; 7916 const QualType& TargetType; 7917 QualType TargetFunctionType; // Extracted function type from target type 7918 7919 bool Complain; 7920 //DeclAccessPair& ResultFunctionAccessPair; 7921 ASTContext& Context; 7922 7923 bool TargetTypeIsNonStaticMemberFunction; 7924 bool FoundNonTemplateFunction; 7925 7926 OverloadExpr::FindResult OvlExprInfo; 7927 OverloadExpr *OvlExpr; 7928 TemplateArgumentListInfo OvlExplicitTemplateArgs; 7929 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 7930 7931public: 7932 AddressOfFunctionResolver(Sema &S, Expr* SourceExpr, 7933 const QualType& TargetType, bool Complain) 7934 : S(S), SourceExpr(SourceExpr), TargetType(TargetType), 7935 Complain(Complain), Context(S.getASTContext()), 7936 TargetTypeIsNonStaticMemberFunction( 7937 !!TargetType->getAs<MemberPointerType>()), 7938 FoundNonTemplateFunction(false), 7939 OvlExprInfo(OverloadExpr::find(SourceExpr)), 7940 OvlExpr(OvlExprInfo.Expression) 7941 { 7942 ExtractUnqualifiedFunctionTypeFromTargetType(); 7943 7944 if (!TargetFunctionType->isFunctionType()) { 7945 if (OvlExpr->hasExplicitTemplateArgs()) { 7946 DeclAccessPair dap; 7947 if (FunctionDecl* Fn = S.ResolveSingleFunctionTemplateSpecialization( 7948 OvlExpr, false, &dap) ) { 7949 7950 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7951 if (!Method->isStatic()) { 7952 // If the target type is a non-function type and the function 7953 // found is a non-static member function, pretend as if that was 7954 // the target, it's the only possible type to end up with. 7955 TargetTypeIsNonStaticMemberFunction = true; 7956 7957 // And skip adding the function if its not in the proper form. 7958 // We'll diagnose this due to an empty set of functions. 7959 if (!OvlExprInfo.HasFormOfMemberPointer) 7960 return; 7961 } 7962 } 7963 7964 Matches.push_back(std::make_pair(dap,Fn)); 7965 } 7966 } 7967 return; 7968 } 7969 7970 if (OvlExpr->hasExplicitTemplateArgs()) 7971 OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); 7972 7973 if (FindAllFunctionsThatMatchTargetTypeExactly()) { 7974 // C++ [over.over]p4: 7975 // If more than one function is selected, [...] 7976 if (Matches.size() > 1) { 7977 if (FoundNonTemplateFunction) 7978 EliminateAllTemplateMatches(); 7979 else 7980 EliminateAllExceptMostSpecializedTemplate(); 7981 } 7982 } 7983 } 7984 7985private: 7986 bool isTargetTypeAFunction() const { 7987 return TargetFunctionType->isFunctionType(); 7988 } 7989 7990 // [ToType] [Return] 7991 7992 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false 7993 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false 7994 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true 7995 void inline ExtractUnqualifiedFunctionTypeFromTargetType() { 7996 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); 7997 } 7998 7999 // return true if any matching specializations were found 8000 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, 8001 const DeclAccessPair& CurAccessFunPair) { 8002 if (CXXMethodDecl *Method 8003 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 8004 // Skip non-static function templates when converting to pointer, and 8005 // static when converting to member pointer. 8006 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 8007 return false; 8008 } 8009 else if (TargetTypeIsNonStaticMemberFunction) 8010 return false; 8011 8012 // C++ [over.over]p2: 8013 // If the name is a function template, template argument deduction is 8014 // done (14.8.2.2), and if the argument deduction succeeds, the 8015 // resulting template argument list is used to generate a single 8016 // function template specialization, which is added to the set of 8017 // overloaded functions considered. 8018 FunctionDecl *Specialization = 0; 8019 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 8020 if (Sema::TemplateDeductionResult Result 8021 = S.DeduceTemplateArguments(FunctionTemplate, 8022 &OvlExplicitTemplateArgs, 8023 TargetFunctionType, Specialization, 8024 Info)) { 8025 // FIXME: make a note of the failed deduction for diagnostics. 8026 (void)Result; 8027 return false; 8028 } 8029 8030 // Template argument deduction ensures that we have an exact match. 8031 // This function template specicalization works. 8032 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 8033 assert(TargetFunctionType 8034 == Context.getCanonicalType(Specialization->getType())); 8035 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); 8036 return true; 8037 } 8038 8039 bool AddMatchingNonTemplateFunction(NamedDecl* Fn, 8040 const DeclAccessPair& CurAccessFunPair) { 8041 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 8042 // Skip non-static functions when converting to pointer, and static 8043 // when converting to member pointer. 8044 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 8045 return false; 8046 } 8047 else if (TargetTypeIsNonStaticMemberFunction) 8048 return false; 8049 8050 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 8051 if (S.getLangOptions().CUDA) 8052 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext)) 8053 if (S.CheckCUDATarget(Caller, FunDecl)) 8054 return false; 8055 8056 QualType ResultTy; 8057 if (Context.hasSameUnqualifiedType(TargetFunctionType, 8058 FunDecl->getType()) || 8059 S.IsNoReturnConversion(FunDecl->getType(), TargetFunctionType, 8060 ResultTy)) { 8061 Matches.push_back(std::make_pair(CurAccessFunPair, 8062 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 8063 FoundNonTemplateFunction = true; 8064 return true; 8065 } 8066 } 8067 8068 return false; 8069 } 8070 8071 bool FindAllFunctionsThatMatchTargetTypeExactly() { 8072 bool Ret = false; 8073 8074 // If the overload expression doesn't have the form of a pointer to 8075 // member, don't try to convert it to a pointer-to-member type. 8076 if (IsInvalidFormOfPointerToMemberFunction()) 8077 return false; 8078 8079 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 8080 E = OvlExpr->decls_end(); 8081 I != E; ++I) { 8082 // Look through any using declarations to find the underlying function. 8083 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 8084 8085 // C++ [over.over]p3: 8086 // Non-member functions and static member functions match 8087 // targets of type "pointer-to-function" or "reference-to-function." 8088 // Nonstatic member functions match targets of 8089 // type "pointer-to-member-function." 8090 // Note that according to DR 247, the containing class does not matter. 8091 if (FunctionTemplateDecl *FunctionTemplate 8092 = dyn_cast<FunctionTemplateDecl>(Fn)) { 8093 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) 8094 Ret = true; 8095 } 8096 // If we have explicit template arguments supplied, skip non-templates. 8097 else if (!OvlExpr->hasExplicitTemplateArgs() && 8098 AddMatchingNonTemplateFunction(Fn, I.getPair())) 8099 Ret = true; 8100 } 8101 assert(Ret || Matches.empty()); 8102 return Ret; 8103 } 8104 8105 void EliminateAllExceptMostSpecializedTemplate() { 8106 // [...] and any given function template specialization F1 is 8107 // eliminated if the set contains a second function template 8108 // specialization whose function template is more specialized 8109 // than the function template of F1 according to the partial 8110 // ordering rules of 14.5.5.2. 8111 8112 // The algorithm specified above is quadratic. We instead use a 8113 // two-pass algorithm (similar to the one used to identify the 8114 // best viable function in an overload set) that identifies the 8115 // best function template (if it exists). 8116 8117 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 8118 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 8119 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 8120 8121 UnresolvedSetIterator Result = 8122 S.getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 8123 TPOC_Other, 0, SourceExpr->getLocStart(), 8124 S.PDiag(), 8125 S.PDiag(diag::err_addr_ovl_ambiguous) 8126 << Matches[0].second->getDeclName(), 8127 S.PDiag(diag::note_ovl_candidate) 8128 << (unsigned) oc_function_template, 8129 Complain); 8130 8131 if (Result != MatchesCopy.end()) { 8132 // Make it the first and only element 8133 Matches[0].first = Matches[Result - MatchesCopy.begin()].first; 8134 Matches[0].second = cast<FunctionDecl>(*Result); 8135 Matches.resize(1); 8136 } 8137 } 8138 8139 void EliminateAllTemplateMatches() { 8140 // [...] any function template specializations in the set are 8141 // eliminated if the set also contains a non-template function, [...] 8142 for (unsigned I = 0, N = Matches.size(); I != N; ) { 8143 if (Matches[I].second->getPrimaryTemplate() == 0) 8144 ++I; 8145 else { 8146 Matches[I] = Matches[--N]; 8147 Matches.set_size(N); 8148 } 8149 } 8150 } 8151 8152public: 8153 void ComplainNoMatchesFound() const { 8154 assert(Matches.empty()); 8155 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) 8156 << OvlExpr->getName() << TargetFunctionType 8157 << OvlExpr->getSourceRange(); 8158 S.NoteAllOverloadCandidates(OvlExpr); 8159 } 8160 8161 bool IsInvalidFormOfPointerToMemberFunction() const { 8162 return TargetTypeIsNonStaticMemberFunction && 8163 !OvlExprInfo.HasFormOfMemberPointer; 8164 } 8165 8166 void ComplainIsInvalidFormOfPointerToMemberFunction() const { 8167 // TODO: Should we condition this on whether any functions might 8168 // have matched, or is it more appropriate to do that in callers? 8169 // TODO: a fixit wouldn't hurt. 8170 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 8171 << TargetType << OvlExpr->getSourceRange(); 8172 } 8173 8174 void ComplainOfInvalidConversion() const { 8175 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 8176 << OvlExpr->getName() << TargetType; 8177 } 8178 8179 void ComplainMultipleMatchesFound() const { 8180 assert(Matches.size() > 1); 8181 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) 8182 << OvlExpr->getName() 8183 << OvlExpr->getSourceRange(); 8184 S.NoteAllOverloadCandidates(OvlExpr); 8185 } 8186 8187 int getNumMatches() const { return Matches.size(); } 8188 8189 FunctionDecl* getMatchingFunctionDecl() const { 8190 if (Matches.size() != 1) return 0; 8191 return Matches[0].second; 8192 } 8193 8194 const DeclAccessPair* getMatchingFunctionAccessPair() const { 8195 if (Matches.size() != 1) return 0; 8196 return &Matches[0].first; 8197 } 8198}; 8199 8200/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 8201/// an overloaded function (C++ [over.over]), where @p From is an 8202/// expression with overloaded function type and @p ToType is the type 8203/// we're trying to resolve to. For example: 8204/// 8205/// @code 8206/// int f(double); 8207/// int f(int); 8208/// 8209/// int (*pfd)(double) = f; // selects f(double) 8210/// @endcode 8211/// 8212/// This routine returns the resulting FunctionDecl if it could be 8213/// resolved, and NULL otherwise. When @p Complain is true, this 8214/// routine will emit diagnostics if there is an error. 8215FunctionDecl * 8216Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, QualType TargetType, 8217 bool Complain, 8218 DeclAccessPair &FoundResult) { 8219 8220 assert(AddressOfExpr->getType() == Context.OverloadTy); 8221 8222 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, Complain); 8223 int NumMatches = Resolver.getNumMatches(); 8224 FunctionDecl* Fn = 0; 8225 if ( NumMatches == 0 && Complain) { 8226 if (Resolver.IsInvalidFormOfPointerToMemberFunction()) 8227 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); 8228 else 8229 Resolver.ComplainNoMatchesFound(); 8230 } 8231 else if (NumMatches > 1 && Complain) 8232 Resolver.ComplainMultipleMatchesFound(); 8233 else if (NumMatches == 1) { 8234 Fn = Resolver.getMatchingFunctionDecl(); 8235 assert(Fn); 8236 FoundResult = *Resolver.getMatchingFunctionAccessPair(); 8237 MarkDeclarationReferenced(AddressOfExpr->getLocStart(), Fn); 8238 if (Complain) 8239 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); 8240 } 8241 8242 return Fn; 8243} 8244 8245/// \brief Given an expression that refers to an overloaded function, try to 8246/// resolve that overloaded function expression down to a single function. 8247/// 8248/// This routine can only resolve template-ids that refer to a single function 8249/// template, where that template-id refers to a single template whose template 8250/// arguments are either provided by the template-id or have defaults, 8251/// as described in C++0x [temp.arg.explicit]p3. 8252FunctionDecl * 8253Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl, 8254 bool Complain, 8255 DeclAccessPair *FoundResult) { 8256 // C++ [over.over]p1: 8257 // [...] [Note: any redundant set of parentheses surrounding the 8258 // overloaded function name is ignored (5.1). ] 8259 // C++ [over.over]p1: 8260 // [...] The overloaded function name can be preceded by the & 8261 // operator. 8262 8263 // If we didn't actually find any template-ids, we're done. 8264 if (!ovl->hasExplicitTemplateArgs()) 8265 return 0; 8266 8267 TemplateArgumentListInfo ExplicitTemplateArgs; 8268 ovl->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 8269 8270 // Look through all of the overloaded functions, searching for one 8271 // whose type matches exactly. 8272 FunctionDecl *Matched = 0; 8273 for (UnresolvedSetIterator I = ovl->decls_begin(), 8274 E = ovl->decls_end(); I != E; ++I) { 8275 // C++0x [temp.arg.explicit]p3: 8276 // [...] In contexts where deduction is done and fails, or in contexts 8277 // where deduction is not done, if a template argument list is 8278 // specified and it, along with any default template arguments, 8279 // identifies a single function template specialization, then the 8280 // template-id is an lvalue for the function template specialization. 8281 FunctionTemplateDecl *FunctionTemplate 8282 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 8283 8284 // C++ [over.over]p2: 8285 // If the name is a function template, template argument deduction is 8286 // done (14.8.2.2), and if the argument deduction succeeds, the 8287 // resulting template argument list is used to generate a single 8288 // function template specialization, which is added to the set of 8289 // overloaded functions considered. 8290 FunctionDecl *Specialization = 0; 8291 TemplateDeductionInfo Info(Context, ovl->getNameLoc()); 8292 if (TemplateDeductionResult Result 8293 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 8294 Specialization, Info)) { 8295 // FIXME: make a note of the failed deduction for diagnostics. 8296 (void)Result; 8297 continue; 8298 } 8299 8300 assert(Specialization && "no specialization and no error?"); 8301 8302 // Multiple matches; we can't resolve to a single declaration. 8303 if (Matched) { 8304 if (Complain) { 8305 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous) 8306 << ovl->getName(); 8307 NoteAllOverloadCandidates(ovl); 8308 } 8309 return 0; 8310 } 8311 8312 Matched = Specialization; 8313 if (FoundResult) *FoundResult = I.getPair(); 8314 } 8315 8316 return Matched; 8317} 8318 8319 8320 8321 8322// Resolve and fix an overloaded expression that can be resolved 8323// because it identifies a single function template specialization. 8324// 8325// Last three arguments should only be supplied if Complain = true 8326// 8327// Return true if it was logically possible to so resolve the 8328// expression, regardless of whether or not it succeeded. Always 8329// returns true if 'complain' is set. 8330bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization( 8331 ExprResult &SrcExpr, bool doFunctionPointerConverion, 8332 bool complain, const SourceRange& OpRangeForComplaining, 8333 QualType DestTypeForComplaining, 8334 unsigned DiagIDForComplaining) { 8335 assert(SrcExpr.get()->getType() == Context.OverloadTy); 8336 8337 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get()); 8338 8339 DeclAccessPair found; 8340 ExprResult SingleFunctionExpression; 8341 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization( 8342 ovl.Expression, /*complain*/ false, &found)) { 8343 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getSourceRange().getBegin())) { 8344 SrcExpr = ExprError(); 8345 return true; 8346 } 8347 8348 // It is only correct to resolve to an instance method if we're 8349 // resolving a form that's permitted to be a pointer to member. 8350 // Otherwise we'll end up making a bound member expression, which 8351 // is illegal in all the contexts we resolve like this. 8352 if (!ovl.HasFormOfMemberPointer && 8353 isa<CXXMethodDecl>(fn) && 8354 cast<CXXMethodDecl>(fn)->isInstance()) { 8355 if (!complain) return false; 8356 8357 Diag(ovl.Expression->getExprLoc(), 8358 diag::err_bound_member_function) 8359 << 0 << ovl.Expression->getSourceRange(); 8360 8361 // TODO: I believe we only end up here if there's a mix of 8362 // static and non-static candidates (otherwise the expression 8363 // would have 'bound member' type, not 'overload' type). 8364 // Ideally we would note which candidate was chosen and why 8365 // the static candidates were rejected. 8366 SrcExpr = ExprError(); 8367 return true; 8368 } 8369 8370 // Fix the expresion to refer to 'fn'. 8371 SingleFunctionExpression = 8372 Owned(FixOverloadedFunctionReference(SrcExpr.take(), found, fn)); 8373 8374 // If desired, do function-to-pointer decay. 8375 if (doFunctionPointerConverion) { 8376 SingleFunctionExpression = 8377 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.take()); 8378 if (SingleFunctionExpression.isInvalid()) { 8379 SrcExpr = ExprError(); 8380 return true; 8381 } 8382 } 8383 } 8384 8385 if (!SingleFunctionExpression.isUsable()) { 8386 if (complain) { 8387 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) 8388 << ovl.Expression->getName() 8389 << DestTypeForComplaining 8390 << OpRangeForComplaining 8391 << ovl.Expression->getQualifierLoc().getSourceRange(); 8392 NoteAllOverloadCandidates(SrcExpr.get()); 8393 8394 SrcExpr = ExprError(); 8395 return true; 8396 } 8397 8398 return false; 8399 } 8400 8401 SrcExpr = SingleFunctionExpression; 8402 return true; 8403} 8404 8405/// \brief Add a single candidate to the overload set. 8406static void AddOverloadedCallCandidate(Sema &S, 8407 DeclAccessPair FoundDecl, 8408 TemplateArgumentListInfo *ExplicitTemplateArgs, 8409 Expr **Args, unsigned NumArgs, 8410 OverloadCandidateSet &CandidateSet, 8411 bool PartialOverloading, 8412 bool KnownValid) { 8413 NamedDecl *Callee = FoundDecl.getDecl(); 8414 if (isa<UsingShadowDecl>(Callee)) 8415 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 8416 8417 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 8418 if (ExplicitTemplateArgs) { 8419 assert(!KnownValid && "Explicit template arguments?"); 8420 return; 8421 } 8422 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 8423 false, PartialOverloading); 8424 return; 8425 } 8426 8427 if (FunctionTemplateDecl *FuncTemplate 8428 = dyn_cast<FunctionTemplateDecl>(Callee)) { 8429 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 8430 ExplicitTemplateArgs, 8431 Args, NumArgs, CandidateSet); 8432 return; 8433 } 8434 8435 assert(!KnownValid && "unhandled case in overloaded call candidate"); 8436} 8437 8438/// \brief Add the overload candidates named by callee and/or found by argument 8439/// dependent lookup to the given overload set. 8440void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 8441 Expr **Args, unsigned NumArgs, 8442 OverloadCandidateSet &CandidateSet, 8443 bool PartialOverloading) { 8444 8445#ifndef NDEBUG 8446 // Verify that ArgumentDependentLookup is consistent with the rules 8447 // in C++0x [basic.lookup.argdep]p3: 8448 // 8449 // Let X be the lookup set produced by unqualified lookup (3.4.1) 8450 // and let Y be the lookup set produced by argument dependent 8451 // lookup (defined as follows). If X contains 8452 // 8453 // -- a declaration of a class member, or 8454 // 8455 // -- a block-scope function declaration that is not a 8456 // using-declaration, or 8457 // 8458 // -- a declaration that is neither a function or a function 8459 // template 8460 // 8461 // then Y is empty. 8462 8463 if (ULE->requiresADL()) { 8464 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 8465 E = ULE->decls_end(); I != E; ++I) { 8466 assert(!(*I)->getDeclContext()->isRecord()); 8467 assert(isa<UsingShadowDecl>(*I) || 8468 !(*I)->getDeclContext()->isFunctionOrMethod()); 8469 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 8470 } 8471 } 8472#endif 8473 8474 // It would be nice to avoid this copy. 8475 TemplateArgumentListInfo TABuffer; 8476 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 8477 if (ULE->hasExplicitTemplateArgs()) { 8478 ULE->copyTemplateArgumentsInto(TABuffer); 8479 ExplicitTemplateArgs = &TABuffer; 8480 } 8481 8482 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 8483 E = ULE->decls_end(); I != E; ++I) 8484 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 8485 Args, NumArgs, CandidateSet, 8486 PartialOverloading, /*KnownValid*/ true); 8487 8488 if (ULE->requiresADL()) 8489 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 8490 Args, NumArgs, 8491 ExplicitTemplateArgs, 8492 CandidateSet, 8493 PartialOverloading, 8494 ULE->isStdAssociatedNamespace()); 8495} 8496 8497/// Attempt to recover from an ill-formed use of a non-dependent name in a 8498/// template, where the non-dependent name was declared after the template 8499/// was defined. This is common in code written for a compilers which do not 8500/// correctly implement two-stage name lookup. 8501/// 8502/// Returns true if a viable candidate was found and a diagnostic was issued. 8503static bool 8504DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc, 8505 const CXXScopeSpec &SS, LookupResult &R, 8506 TemplateArgumentListInfo *ExplicitTemplateArgs, 8507 Expr **Args, unsigned NumArgs) { 8508 if (SemaRef.ActiveTemplateInstantiations.empty() || !SS.isEmpty()) 8509 return false; 8510 8511 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) { 8512 SemaRef.LookupQualifiedName(R, DC); 8513 8514 if (!R.empty()) { 8515 R.suppressDiagnostics(); 8516 8517 if (isa<CXXRecordDecl>(DC)) { 8518 // Don't diagnose names we find in classes; we get much better 8519 // diagnostics for these from DiagnoseEmptyLookup. 8520 R.clear(); 8521 return false; 8522 } 8523 8524 OverloadCandidateSet Candidates(FnLoc); 8525 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 8526 AddOverloadedCallCandidate(SemaRef, I.getPair(), 8527 ExplicitTemplateArgs, Args, NumArgs, 8528 Candidates, false, /*KnownValid*/ false); 8529 8530 OverloadCandidateSet::iterator Best; 8531 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) { 8532 // No viable functions. Don't bother the user with notes for functions 8533 // which don't work and shouldn't be found anyway. 8534 R.clear(); 8535 return false; 8536 } 8537 8538 // Find the namespaces where ADL would have looked, and suggest 8539 // declaring the function there instead. 8540 Sema::AssociatedNamespaceSet AssociatedNamespaces; 8541 Sema::AssociatedClassSet AssociatedClasses; 8542 SemaRef.FindAssociatedClassesAndNamespaces(Args, NumArgs, 8543 AssociatedNamespaces, 8544 AssociatedClasses); 8545 // Never suggest declaring a function within namespace 'std'. 8546 Sema::AssociatedNamespaceSet SuggestedNamespaces; 8547 if (DeclContext *Std = SemaRef.getStdNamespace()) { 8548 for (Sema::AssociatedNamespaceSet::iterator 8549 it = AssociatedNamespaces.begin(), 8550 end = AssociatedNamespaces.end(); it != end; ++it) { 8551 if (!Std->Encloses(*it)) 8552 SuggestedNamespaces.insert(*it); 8553 } 8554 } else { 8555 // Lacking the 'std::' namespace, use all of the associated namespaces. 8556 SuggestedNamespaces = AssociatedNamespaces; 8557 } 8558 8559 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup) 8560 << R.getLookupName(); 8561 if (SuggestedNamespaces.empty()) { 8562 SemaRef.Diag(Best->Function->getLocation(), 8563 diag::note_not_found_by_two_phase_lookup) 8564 << R.getLookupName() << 0; 8565 } else if (SuggestedNamespaces.size() == 1) { 8566 SemaRef.Diag(Best->Function->getLocation(), 8567 diag::note_not_found_by_two_phase_lookup) 8568 << R.getLookupName() << 1 << *SuggestedNamespaces.begin(); 8569 } else { 8570 // FIXME: It would be useful to list the associated namespaces here, 8571 // but the diagnostics infrastructure doesn't provide a way to produce 8572 // a localized representation of a list of items. 8573 SemaRef.Diag(Best->Function->getLocation(), 8574 diag::note_not_found_by_two_phase_lookup) 8575 << R.getLookupName() << 2; 8576 } 8577 8578 // Try to recover by calling this function. 8579 return true; 8580 } 8581 8582 R.clear(); 8583 } 8584 8585 return false; 8586} 8587 8588/// Attempt to recover from ill-formed use of a non-dependent operator in a 8589/// template, where the non-dependent operator was declared after the template 8590/// was defined. 8591/// 8592/// Returns true if a viable candidate was found and a diagnostic was issued. 8593static bool 8594DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op, 8595 SourceLocation OpLoc, 8596 Expr **Args, unsigned NumArgs) { 8597 DeclarationName OpName = 8598 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op); 8599 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName); 8600 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R, 8601 /*ExplicitTemplateArgs=*/0, Args, NumArgs); 8602} 8603 8604/// Attempts to recover from a call where no functions were found. 8605/// 8606/// Returns true if new candidates were found. 8607static ExprResult 8608BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 8609 UnresolvedLookupExpr *ULE, 8610 SourceLocation LParenLoc, 8611 Expr **Args, unsigned NumArgs, 8612 SourceLocation RParenLoc, 8613 bool EmptyLookup) { 8614 8615 CXXScopeSpec SS; 8616 SS.Adopt(ULE->getQualifierLoc()); 8617 8618 TemplateArgumentListInfo TABuffer; 8619 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 8620 if (ULE->hasExplicitTemplateArgs()) { 8621 ULE->copyTemplateArgumentsInto(TABuffer); 8622 ExplicitTemplateArgs = &TABuffer; 8623 } 8624 8625 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 8626 Sema::LookupOrdinaryName); 8627 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R, 8628 ExplicitTemplateArgs, Args, NumArgs) && 8629 (!EmptyLookup || 8630 SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression, 8631 ExplicitTemplateArgs, Args, NumArgs))) 8632 return ExprError(); 8633 8634 assert(!R.empty() && "lookup results empty despite recovery"); 8635 8636 // Build an implicit member call if appropriate. Just drop the 8637 // casts and such from the call, we don't really care. 8638 ExprResult NewFn = ExprError(); 8639 if ((*R.begin())->isCXXClassMember()) 8640 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, 8641 ExplicitTemplateArgs); 8642 else if (ExplicitTemplateArgs) 8643 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 8644 else 8645 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 8646 8647 if (NewFn.isInvalid()) 8648 return ExprError(); 8649 8650 // This shouldn't cause an infinite loop because we're giving it 8651 // an expression with viable lookup results, which should never 8652 // end up here. 8653 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 8654 MultiExprArg(Args, NumArgs), RParenLoc); 8655} 8656 8657/// ResolveOverloadedCallFn - Given the call expression that calls Fn 8658/// (which eventually refers to the declaration Func) and the call 8659/// arguments Args/NumArgs, attempt to resolve the function call down 8660/// to a specific function. If overload resolution succeeds, returns 8661/// the function declaration produced by overload 8662/// resolution. Otherwise, emits diagnostics, deletes all of the 8663/// arguments and Fn, and returns NULL. 8664ExprResult 8665Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 8666 SourceLocation LParenLoc, 8667 Expr **Args, unsigned NumArgs, 8668 SourceLocation RParenLoc, 8669 Expr *ExecConfig) { 8670#ifndef NDEBUG 8671 if (ULE->requiresADL()) { 8672 // To do ADL, we must have found an unqualified name. 8673 assert(!ULE->getQualifier() && "qualified name with ADL"); 8674 8675 // We don't perform ADL for implicit declarations of builtins. 8676 // Verify that this was correctly set up. 8677 FunctionDecl *F; 8678 if (ULE->decls_begin() + 1 == ULE->decls_end() && 8679 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 8680 F->getBuiltinID() && F->isImplicit()) 8681 llvm_unreachable("performing ADL for builtin"); 8682 8683 // We don't perform ADL in C. 8684 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 8685 } else 8686 assert(!ULE->isStdAssociatedNamespace() && 8687 "std is associated namespace but not doing ADL"); 8688#endif 8689 8690 UnbridgedCastsSet UnbridgedCasts; 8691 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) 8692 return ExprError(); 8693 8694 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 8695 8696 // Add the functions denoted by the callee to the set of candidate 8697 // functions, including those from argument-dependent lookup. 8698 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 8699 8700 // If we found nothing, try to recover. 8701 // BuildRecoveryCallExpr diagnoses the error itself, so we just bail 8702 // out if it fails. 8703 if (CandidateSet.empty()) { 8704 // In Microsoft mode, if we are inside a template class member function then 8705 // create a type dependent CallExpr. The goal is to postpone name lookup 8706 // to instantiation time to be able to search into type dependent base 8707 // classes. 8708 if (getLangOptions().MicrosoftExt && CurContext->isDependentContext() && 8709 isa<CXXMethodDecl>(CurContext)) { 8710 CallExpr *CE = new (Context) CallExpr(Context, Fn, Args, NumArgs, 8711 Context.DependentTy, VK_RValue, 8712 RParenLoc); 8713 CE->setTypeDependent(true); 8714 return Owned(CE); 8715 } 8716 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 8717 RParenLoc, /*EmptyLookup=*/true); 8718 } 8719 8720 UnbridgedCasts.restore(); 8721 8722 OverloadCandidateSet::iterator Best; 8723 switch (CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best)) { 8724 case OR_Success: { 8725 FunctionDecl *FDecl = Best->Function; 8726 MarkDeclarationReferenced(Fn->getExprLoc(), FDecl); 8727 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 8728 DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()); 8729 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 8730 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc, 8731 ExecConfig); 8732 } 8733 8734 case OR_No_Viable_Function: { 8735 // Try to recover by looking for viable functions which the user might 8736 // have meant to call. 8737 ExprResult Recovery = BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, 8738 Args, NumArgs, RParenLoc, 8739 /*EmptyLookup=*/false); 8740 if (!Recovery.isInvalid()) 8741 return Recovery; 8742 8743 Diag(Fn->getSourceRange().getBegin(), 8744 diag::err_ovl_no_viable_function_in_call) 8745 << ULE->getName() << Fn->getSourceRange(); 8746 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8747 break; 8748 } 8749 8750 case OR_Ambiguous: 8751 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 8752 << ULE->getName() << Fn->getSourceRange(); 8753 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 8754 break; 8755 8756 case OR_Deleted: 8757 { 8758 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 8759 << Best->Function->isDeleted() 8760 << ULE->getName() 8761 << getDeletedOrUnavailableSuffix(Best->Function) 8762 << Fn->getSourceRange(); 8763 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8764 8765 // We emitted an error for the unvailable/deleted function call but keep 8766 // the call in the AST. 8767 FunctionDecl *FDecl = Best->Function; 8768 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 8769 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, 8770 RParenLoc, ExecConfig); 8771 } 8772 break; 8773 } 8774 8775 // Overload resolution failed. 8776 return ExprError(); 8777} 8778 8779static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 8780 return Functions.size() > 1 || 8781 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 8782} 8783 8784/// \brief Create a unary operation that may resolve to an overloaded 8785/// operator. 8786/// 8787/// \param OpLoc The location of the operator itself (e.g., '*'). 8788/// 8789/// \param OpcIn The UnaryOperator::Opcode that describes this 8790/// operator. 8791/// 8792/// \param Functions The set of non-member functions that will be 8793/// considered by overload resolution. The caller needs to build this 8794/// set based on the context using, e.g., 8795/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 8796/// set should not contain any member functions; those will be added 8797/// by CreateOverloadedUnaryOp(). 8798/// 8799/// \param input The input argument. 8800ExprResult 8801Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 8802 const UnresolvedSetImpl &Fns, 8803 Expr *Input) { 8804 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 8805 8806 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 8807 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 8808 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 8809 // TODO: provide better source location info. 8810 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 8811 8812 if (checkPlaceholderForOverload(*this, Input)) 8813 return ExprError(); 8814 8815 Expr *Args[2] = { Input, 0 }; 8816 unsigned NumArgs = 1; 8817 8818 // For post-increment and post-decrement, add the implicit '0' as 8819 // the second argument, so that we know this is a post-increment or 8820 // post-decrement. 8821 if (Opc == UO_PostInc || Opc == UO_PostDec) { 8822 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 8823 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 8824 SourceLocation()); 8825 NumArgs = 2; 8826 } 8827 8828 if (Input->isTypeDependent()) { 8829 if (Fns.empty()) 8830 return Owned(new (Context) UnaryOperator(Input, 8831 Opc, 8832 Context.DependentTy, 8833 VK_RValue, OK_Ordinary, 8834 OpLoc)); 8835 8836 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8837 UnresolvedLookupExpr *Fn 8838 = UnresolvedLookupExpr::Create(Context, NamingClass, 8839 NestedNameSpecifierLoc(), OpNameInfo, 8840 /*ADL*/ true, IsOverloaded(Fns), 8841 Fns.begin(), Fns.end()); 8842 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 8843 &Args[0], NumArgs, 8844 Context.DependentTy, 8845 VK_RValue, 8846 OpLoc)); 8847 } 8848 8849 // Build an empty overload set. 8850 OverloadCandidateSet CandidateSet(OpLoc); 8851 8852 // Add the candidates from the given function set. 8853 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 8854 8855 // Add operator candidates that are member functions. 8856 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 8857 8858 // Add candidates from ADL. 8859 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 8860 Args, NumArgs, 8861 /*ExplicitTemplateArgs*/ 0, 8862 CandidateSet); 8863 8864 // Add builtin operator candidates. 8865 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 8866 8867 bool HadMultipleCandidates = (CandidateSet.size() > 1); 8868 8869 // Perform overload resolution. 8870 OverloadCandidateSet::iterator Best; 8871 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8872 case OR_Success: { 8873 // We found a built-in operator or an overloaded operator. 8874 FunctionDecl *FnDecl = Best->Function; 8875 8876 if (FnDecl) { 8877 // We matched an overloaded operator. Build a call to that 8878 // operator. 8879 8880 MarkDeclarationReferenced(OpLoc, FnDecl); 8881 8882 // Convert the arguments. 8883 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 8884 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 8885 8886 ExprResult InputRes = 8887 PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 8888 Best->FoundDecl, Method); 8889 if (InputRes.isInvalid()) 8890 return ExprError(); 8891 Input = InputRes.take(); 8892 } else { 8893 // Convert the arguments. 8894 ExprResult InputInit 8895 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8896 Context, 8897 FnDecl->getParamDecl(0)), 8898 SourceLocation(), 8899 Input); 8900 if (InputInit.isInvalid()) 8901 return ExprError(); 8902 Input = InputInit.take(); 8903 } 8904 8905 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 8906 8907 // Determine the result type. 8908 QualType ResultTy = FnDecl->getResultType(); 8909 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8910 ResultTy = ResultTy.getNonLValueExprType(Context); 8911 8912 // Build the actual expression node. 8913 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 8914 HadMultipleCandidates); 8915 if (FnExpr.isInvalid()) 8916 return ExprError(); 8917 8918 Args[0] = Input; 8919 CallExpr *TheCall = 8920 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 8921 Args, NumArgs, ResultTy, VK, OpLoc); 8922 8923 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 8924 FnDecl)) 8925 return ExprError(); 8926 8927 return MaybeBindToTemporary(TheCall); 8928 } else { 8929 // We matched a built-in operator. Convert the arguments, then 8930 // break out so that we will build the appropriate built-in 8931 // operator node. 8932 ExprResult InputRes = 8933 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 8934 Best->Conversions[0], AA_Passing); 8935 if (InputRes.isInvalid()) 8936 return ExprError(); 8937 Input = InputRes.take(); 8938 break; 8939 } 8940 } 8941 8942 case OR_No_Viable_Function: 8943 // This is an erroneous use of an operator which can be overloaded by 8944 // a non-member function. Check for non-member operators which were 8945 // defined too late to be candidates. 8946 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args, NumArgs)) 8947 // FIXME: Recover by calling the found function. 8948 return ExprError(); 8949 8950 // No viable function; fall through to handling this as a 8951 // built-in operator, which will produce an error message for us. 8952 break; 8953 8954 case OR_Ambiguous: 8955 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 8956 << UnaryOperator::getOpcodeStr(Opc) 8957 << Input->getType() 8958 << Input->getSourceRange(); 8959 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs, 8960 UnaryOperator::getOpcodeStr(Opc), OpLoc); 8961 return ExprError(); 8962 8963 case OR_Deleted: 8964 Diag(OpLoc, diag::err_ovl_deleted_oper) 8965 << Best->Function->isDeleted() 8966 << UnaryOperator::getOpcodeStr(Opc) 8967 << getDeletedOrUnavailableSuffix(Best->Function) 8968 << Input->getSourceRange(); 8969 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs, 8970 UnaryOperator::getOpcodeStr(Opc), OpLoc); 8971 return ExprError(); 8972 } 8973 8974 // Either we found no viable overloaded operator or we matched a 8975 // built-in operator. In either case, fall through to trying to 8976 // build a built-in operation. 8977 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 8978} 8979 8980/// \brief Create a binary operation that may resolve to an overloaded 8981/// operator. 8982/// 8983/// \param OpLoc The location of the operator itself (e.g., '+'). 8984/// 8985/// \param OpcIn The BinaryOperator::Opcode that describes this 8986/// operator. 8987/// 8988/// \param Functions The set of non-member functions that will be 8989/// considered by overload resolution. The caller needs to build this 8990/// set based on the context using, e.g., 8991/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 8992/// set should not contain any member functions; those will be added 8993/// by CreateOverloadedBinOp(). 8994/// 8995/// \param LHS Left-hand argument. 8996/// \param RHS Right-hand argument. 8997ExprResult 8998Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 8999 unsigned OpcIn, 9000 const UnresolvedSetImpl &Fns, 9001 Expr *LHS, Expr *RHS) { 9002 Expr *Args[2] = { LHS, RHS }; 9003 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 9004 9005 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 9006 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 9007 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 9008 9009 // If either side is type-dependent, create an appropriate dependent 9010 // expression. 9011 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 9012 if (Fns.empty()) { 9013 // If there are no functions to store, just build a dependent 9014 // BinaryOperator or CompoundAssignment. 9015 if (Opc <= BO_Assign || Opc > BO_OrAssign) 9016 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 9017 Context.DependentTy, 9018 VK_RValue, OK_Ordinary, 9019 OpLoc)); 9020 9021 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 9022 Context.DependentTy, 9023 VK_LValue, 9024 OK_Ordinary, 9025 Context.DependentTy, 9026 Context.DependentTy, 9027 OpLoc)); 9028 } 9029 9030 // FIXME: save results of ADL from here? 9031 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 9032 // TODO: provide better source location info in DNLoc component. 9033 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 9034 UnresolvedLookupExpr *Fn 9035 = UnresolvedLookupExpr::Create(Context, NamingClass, 9036 NestedNameSpecifierLoc(), OpNameInfo, 9037 /*ADL*/ true, IsOverloaded(Fns), 9038 Fns.begin(), Fns.end()); 9039 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 9040 Args, 2, 9041 Context.DependentTy, 9042 VK_RValue, 9043 OpLoc)); 9044 } 9045 9046 // Always do placeholder-like conversions on the RHS. 9047 if (checkPlaceholderForOverload(*this, Args[1])) 9048 return ExprError(); 9049 9050 // Do placeholder-like conversion on the LHS; note that we should 9051 // not get here with a PseudoObject LHS. 9052 assert(Args[0]->getObjectKind() != OK_ObjCProperty); 9053 if (checkPlaceholderForOverload(*this, Args[0])) 9054 return ExprError(); 9055 9056 // If this is the assignment operator, we only perform overload resolution 9057 // if the left-hand side is a class or enumeration type. This is actually 9058 // a hack. The standard requires that we do overload resolution between the 9059 // various built-in candidates, but as DR507 points out, this can lead to 9060 // problems. So we do it this way, which pretty much follows what GCC does. 9061 // Note that we go the traditional code path for compound assignment forms. 9062 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 9063 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 9064 9065 // If this is the .* operator, which is not overloadable, just 9066 // create a built-in binary operator. 9067 if (Opc == BO_PtrMemD) 9068 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 9069 9070 // Build an empty overload set. 9071 OverloadCandidateSet CandidateSet(OpLoc); 9072 9073 // Add the candidates from the given function set. 9074 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 9075 9076 // Add operator candidates that are member functions. 9077 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 9078 9079 // Add candidates from ADL. 9080 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 9081 Args, 2, 9082 /*ExplicitTemplateArgs*/ 0, 9083 CandidateSet); 9084 9085 // Add builtin operator candidates. 9086 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 9087 9088 bool HadMultipleCandidates = (CandidateSet.size() > 1); 9089 9090 // Perform overload resolution. 9091 OverloadCandidateSet::iterator Best; 9092 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 9093 case OR_Success: { 9094 // We found a built-in operator or an overloaded operator. 9095 FunctionDecl *FnDecl = Best->Function; 9096 9097 if (FnDecl) { 9098 // We matched an overloaded operator. Build a call to that 9099 // operator. 9100 9101 MarkDeclarationReferenced(OpLoc, FnDecl); 9102 9103 // Convert the arguments. 9104 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 9105 // Best->Access is only meaningful for class members. 9106 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 9107 9108 ExprResult Arg1 = 9109 PerformCopyInitialization( 9110 InitializedEntity::InitializeParameter(Context, 9111 FnDecl->getParamDecl(0)), 9112 SourceLocation(), Owned(Args[1])); 9113 if (Arg1.isInvalid()) 9114 return ExprError(); 9115 9116 ExprResult Arg0 = 9117 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 9118 Best->FoundDecl, Method); 9119 if (Arg0.isInvalid()) 9120 return ExprError(); 9121 Args[0] = Arg0.takeAs<Expr>(); 9122 Args[1] = RHS = Arg1.takeAs<Expr>(); 9123 } else { 9124 // Convert the arguments. 9125 ExprResult Arg0 = PerformCopyInitialization( 9126 InitializedEntity::InitializeParameter(Context, 9127 FnDecl->getParamDecl(0)), 9128 SourceLocation(), Owned(Args[0])); 9129 if (Arg0.isInvalid()) 9130 return ExprError(); 9131 9132 ExprResult Arg1 = 9133 PerformCopyInitialization( 9134 InitializedEntity::InitializeParameter(Context, 9135 FnDecl->getParamDecl(1)), 9136 SourceLocation(), Owned(Args[1])); 9137 if (Arg1.isInvalid()) 9138 return ExprError(); 9139 Args[0] = LHS = Arg0.takeAs<Expr>(); 9140 Args[1] = RHS = Arg1.takeAs<Expr>(); 9141 } 9142 9143 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 9144 9145 // Determine the result type. 9146 QualType ResultTy = FnDecl->getResultType(); 9147 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 9148 ResultTy = ResultTy.getNonLValueExprType(Context); 9149 9150 // Build the actual expression node. 9151 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 9152 HadMultipleCandidates, OpLoc); 9153 if (FnExpr.isInvalid()) 9154 return ExprError(); 9155 9156 CXXOperatorCallExpr *TheCall = 9157 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 9158 Args, 2, ResultTy, VK, OpLoc); 9159 9160 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 9161 FnDecl)) 9162 return ExprError(); 9163 9164 return MaybeBindToTemporary(TheCall); 9165 } else { 9166 // We matched a built-in operator. Convert the arguments, then 9167 // break out so that we will build the appropriate built-in 9168 // operator node. 9169 ExprResult ArgsRes0 = 9170 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 9171 Best->Conversions[0], AA_Passing); 9172 if (ArgsRes0.isInvalid()) 9173 return ExprError(); 9174 Args[0] = ArgsRes0.take(); 9175 9176 ExprResult ArgsRes1 = 9177 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 9178 Best->Conversions[1], AA_Passing); 9179 if (ArgsRes1.isInvalid()) 9180 return ExprError(); 9181 Args[1] = ArgsRes1.take(); 9182 break; 9183 } 9184 } 9185 9186 case OR_No_Viable_Function: { 9187 // C++ [over.match.oper]p9: 9188 // If the operator is the operator , [...] and there are no 9189 // viable functions, then the operator is assumed to be the 9190 // built-in operator and interpreted according to clause 5. 9191 if (Opc == BO_Comma) 9192 break; 9193 9194 // For class as left operand for assignment or compound assigment 9195 // operator do not fall through to handling in built-in, but report that 9196 // no overloaded assignment operator found 9197 ExprResult Result = ExprError(); 9198 if (Args[0]->getType()->isRecordType() && 9199 Opc >= BO_Assign && Opc <= BO_OrAssign) { 9200 Diag(OpLoc, diag::err_ovl_no_viable_oper) 9201 << BinaryOperator::getOpcodeStr(Opc) 9202 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9203 } else { 9204 // This is an erroneous use of an operator which can be overloaded by 9205 // a non-member function. Check for non-member operators which were 9206 // defined too late to be candidates. 9207 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args, 2)) 9208 // FIXME: Recover by calling the found function. 9209 return ExprError(); 9210 9211 // No viable function; try to create a built-in operation, which will 9212 // produce an error. Then, show the non-viable candidates. 9213 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 9214 } 9215 assert(Result.isInvalid() && 9216 "C++ binary operator overloading is missing candidates!"); 9217 if (Result.isInvalid()) 9218 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 9219 BinaryOperator::getOpcodeStr(Opc), OpLoc); 9220 return move(Result); 9221 } 9222 9223 case OR_Ambiguous: 9224 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 9225 << BinaryOperator::getOpcodeStr(Opc) 9226 << Args[0]->getType() << Args[1]->getType() 9227 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9228 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 9229 BinaryOperator::getOpcodeStr(Opc), OpLoc); 9230 return ExprError(); 9231 9232 case OR_Deleted: 9233 Diag(OpLoc, diag::err_ovl_deleted_oper) 9234 << Best->Function->isDeleted() 9235 << BinaryOperator::getOpcodeStr(Opc) 9236 << getDeletedOrUnavailableSuffix(Best->Function) 9237 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9238 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 9239 BinaryOperator::getOpcodeStr(Opc), OpLoc); 9240 return ExprError(); 9241 } 9242 9243 // We matched a built-in operator; build it. 9244 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 9245} 9246 9247ExprResult 9248Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 9249 SourceLocation RLoc, 9250 Expr *Base, Expr *Idx) { 9251 Expr *Args[2] = { Base, Idx }; 9252 DeclarationName OpName = 9253 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 9254 9255 // If either side is type-dependent, create an appropriate dependent 9256 // expression. 9257 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 9258 9259 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 9260 // CHECKME: no 'operator' keyword? 9261 DeclarationNameInfo OpNameInfo(OpName, LLoc); 9262 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 9263 UnresolvedLookupExpr *Fn 9264 = UnresolvedLookupExpr::Create(Context, NamingClass, 9265 NestedNameSpecifierLoc(), OpNameInfo, 9266 /*ADL*/ true, /*Overloaded*/ false, 9267 UnresolvedSetIterator(), 9268 UnresolvedSetIterator()); 9269 // Can't add any actual overloads yet 9270 9271 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 9272 Args, 2, 9273 Context.DependentTy, 9274 VK_RValue, 9275 RLoc)); 9276 } 9277 9278 // Handle placeholders on both operands. 9279 if (checkPlaceholderForOverload(*this, Args[0])) 9280 return ExprError(); 9281 if (checkPlaceholderForOverload(*this, Args[1])) 9282 return ExprError(); 9283 9284 // Build an empty overload set. 9285 OverloadCandidateSet CandidateSet(LLoc); 9286 9287 // Subscript can only be overloaded as a member function. 9288 9289 // Add operator candidates that are member functions. 9290 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 9291 9292 // Add builtin operator candidates. 9293 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 9294 9295 bool HadMultipleCandidates = (CandidateSet.size() > 1); 9296 9297 // Perform overload resolution. 9298 OverloadCandidateSet::iterator Best; 9299 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 9300 case OR_Success: { 9301 // We found a built-in operator or an overloaded operator. 9302 FunctionDecl *FnDecl = Best->Function; 9303 9304 if (FnDecl) { 9305 // We matched an overloaded operator. Build a call to that 9306 // operator. 9307 9308 MarkDeclarationReferenced(LLoc, FnDecl); 9309 9310 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 9311 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 9312 9313 // Convert the arguments. 9314 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 9315 ExprResult Arg0 = 9316 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 9317 Best->FoundDecl, Method); 9318 if (Arg0.isInvalid()) 9319 return ExprError(); 9320 Args[0] = Arg0.take(); 9321 9322 // Convert the arguments. 9323 ExprResult InputInit 9324 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 9325 Context, 9326 FnDecl->getParamDecl(0)), 9327 SourceLocation(), 9328 Owned(Args[1])); 9329 if (InputInit.isInvalid()) 9330 return ExprError(); 9331 9332 Args[1] = InputInit.takeAs<Expr>(); 9333 9334 // Determine the result type 9335 QualType ResultTy = FnDecl->getResultType(); 9336 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 9337 ResultTy = ResultTy.getNonLValueExprType(Context); 9338 9339 // Build the actual expression node. 9340 DeclarationNameLoc LocInfo; 9341 LocInfo.CXXOperatorName.BeginOpNameLoc = LLoc.getRawEncoding(); 9342 LocInfo.CXXOperatorName.EndOpNameLoc = RLoc.getRawEncoding(); 9343 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 9344 HadMultipleCandidates, 9345 LLoc, LocInfo); 9346 if (FnExpr.isInvalid()) 9347 return ExprError(); 9348 9349 CXXOperatorCallExpr *TheCall = 9350 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 9351 FnExpr.take(), Args, 2, 9352 ResultTy, VK, RLoc); 9353 9354 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 9355 FnDecl)) 9356 return ExprError(); 9357 9358 return MaybeBindToTemporary(TheCall); 9359 } else { 9360 // We matched a built-in operator. Convert the arguments, then 9361 // break out so that we will build the appropriate built-in 9362 // operator node. 9363 ExprResult ArgsRes0 = 9364 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 9365 Best->Conversions[0], AA_Passing); 9366 if (ArgsRes0.isInvalid()) 9367 return ExprError(); 9368 Args[0] = ArgsRes0.take(); 9369 9370 ExprResult ArgsRes1 = 9371 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 9372 Best->Conversions[1], AA_Passing); 9373 if (ArgsRes1.isInvalid()) 9374 return ExprError(); 9375 Args[1] = ArgsRes1.take(); 9376 9377 break; 9378 } 9379 } 9380 9381 case OR_No_Viable_Function: { 9382 if (CandidateSet.empty()) 9383 Diag(LLoc, diag::err_ovl_no_oper) 9384 << Args[0]->getType() << /*subscript*/ 0 9385 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9386 else 9387 Diag(LLoc, diag::err_ovl_no_viable_subscript) 9388 << Args[0]->getType() 9389 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9390 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 9391 "[]", LLoc); 9392 return ExprError(); 9393 } 9394 9395 case OR_Ambiguous: 9396 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 9397 << "[]" 9398 << Args[0]->getType() << Args[1]->getType() 9399 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9400 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 9401 "[]", LLoc); 9402 return ExprError(); 9403 9404 case OR_Deleted: 9405 Diag(LLoc, diag::err_ovl_deleted_oper) 9406 << Best->Function->isDeleted() << "[]" 9407 << getDeletedOrUnavailableSuffix(Best->Function) 9408 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9409 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 9410 "[]", LLoc); 9411 return ExprError(); 9412 } 9413 9414 // We matched a built-in operator; build it. 9415 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 9416} 9417 9418/// BuildCallToMemberFunction - Build a call to a member 9419/// function. MemExpr is the expression that refers to the member 9420/// function (and includes the object parameter), Args/NumArgs are the 9421/// arguments to the function call (not including the object 9422/// parameter). The caller needs to validate that the member 9423/// expression refers to a non-static member function or an overloaded 9424/// member function. 9425ExprResult 9426Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 9427 SourceLocation LParenLoc, Expr **Args, 9428 unsigned NumArgs, SourceLocation RParenLoc) { 9429 assert(MemExprE->getType() == Context.BoundMemberTy || 9430 MemExprE->getType() == Context.OverloadTy); 9431 9432 // Dig out the member expression. This holds both the object 9433 // argument and the member function we're referring to. 9434 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 9435 9436 // Determine whether this is a call to a pointer-to-member function. 9437 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) { 9438 assert(op->getType() == Context.BoundMemberTy); 9439 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI); 9440 9441 QualType fnType = 9442 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType(); 9443 9444 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>(); 9445 QualType resultType = proto->getCallResultType(Context); 9446 ExprValueKind valueKind = Expr::getValueKindForType(proto->getResultType()); 9447 9448 // Check that the object type isn't more qualified than the 9449 // member function we're calling. 9450 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals()); 9451 9452 QualType objectType = op->getLHS()->getType(); 9453 if (op->getOpcode() == BO_PtrMemI) 9454 objectType = objectType->castAs<PointerType>()->getPointeeType(); 9455 Qualifiers objectQuals = objectType.getQualifiers(); 9456 9457 Qualifiers difference = objectQuals - funcQuals; 9458 difference.removeObjCGCAttr(); 9459 difference.removeAddressSpace(); 9460 if (difference) { 9461 std::string qualsString = difference.getAsString(); 9462 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals) 9463 << fnType.getUnqualifiedType() 9464 << qualsString 9465 << (qualsString.find(' ') == std::string::npos ? 1 : 2); 9466 } 9467 9468 CXXMemberCallExpr *call 9469 = new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 9470 resultType, valueKind, RParenLoc); 9471 9472 if (CheckCallReturnType(proto->getResultType(), 9473 op->getRHS()->getSourceRange().getBegin(), 9474 call, 0)) 9475 return ExprError(); 9476 9477 if (ConvertArgumentsForCall(call, op, 0, proto, Args, NumArgs, RParenLoc)) 9478 return ExprError(); 9479 9480 return MaybeBindToTemporary(call); 9481 } 9482 9483 UnbridgedCastsSet UnbridgedCasts; 9484 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) 9485 return ExprError(); 9486 9487 MemberExpr *MemExpr; 9488 CXXMethodDecl *Method = 0; 9489 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 9490 NestedNameSpecifier *Qualifier = 0; 9491 if (isa<MemberExpr>(NakedMemExpr)) { 9492 MemExpr = cast<MemberExpr>(NakedMemExpr); 9493 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 9494 FoundDecl = MemExpr->getFoundDecl(); 9495 Qualifier = MemExpr->getQualifier(); 9496 UnbridgedCasts.restore(); 9497 } else { 9498 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 9499 Qualifier = UnresExpr->getQualifier(); 9500 9501 QualType ObjectType = UnresExpr->getBaseType(); 9502 Expr::Classification ObjectClassification 9503 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 9504 : UnresExpr->getBase()->Classify(Context); 9505 9506 // Add overload candidates 9507 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 9508 9509 // FIXME: avoid copy. 9510 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 9511 if (UnresExpr->hasExplicitTemplateArgs()) { 9512 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 9513 TemplateArgs = &TemplateArgsBuffer; 9514 } 9515 9516 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 9517 E = UnresExpr->decls_end(); I != E; ++I) { 9518 9519 NamedDecl *Func = *I; 9520 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 9521 if (isa<UsingShadowDecl>(Func)) 9522 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 9523 9524 9525 // Microsoft supports direct constructor calls. 9526 if (getLangOptions().MicrosoftExt && isa<CXXConstructorDecl>(Func)) { 9527 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), Args, NumArgs, 9528 CandidateSet); 9529 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 9530 // If explicit template arguments were provided, we can't call a 9531 // non-template member function. 9532 if (TemplateArgs) 9533 continue; 9534 9535 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 9536 ObjectClassification, 9537 Args, NumArgs, CandidateSet, 9538 /*SuppressUserConversions=*/false); 9539 } else { 9540 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 9541 I.getPair(), ActingDC, TemplateArgs, 9542 ObjectType, ObjectClassification, 9543 Args, NumArgs, CandidateSet, 9544 /*SuppressUsedConversions=*/false); 9545 } 9546 } 9547 9548 DeclarationName DeclName = UnresExpr->getMemberName(); 9549 9550 UnbridgedCasts.restore(); 9551 9552 OverloadCandidateSet::iterator Best; 9553 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 9554 Best)) { 9555 case OR_Success: 9556 Method = cast<CXXMethodDecl>(Best->Function); 9557 MarkDeclarationReferenced(UnresExpr->getMemberLoc(), Method); 9558 FoundDecl = Best->FoundDecl; 9559 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 9560 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 9561 break; 9562 9563 case OR_No_Viable_Function: 9564 Diag(UnresExpr->getMemberLoc(), 9565 diag::err_ovl_no_viable_member_function_in_call) 9566 << DeclName << MemExprE->getSourceRange(); 9567 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9568 // FIXME: Leaking incoming expressions! 9569 return ExprError(); 9570 9571 case OR_Ambiguous: 9572 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 9573 << DeclName << MemExprE->getSourceRange(); 9574 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9575 // FIXME: Leaking incoming expressions! 9576 return ExprError(); 9577 9578 case OR_Deleted: 9579 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 9580 << Best->Function->isDeleted() 9581 << DeclName 9582 << getDeletedOrUnavailableSuffix(Best->Function) 9583 << MemExprE->getSourceRange(); 9584 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9585 // FIXME: Leaking incoming expressions! 9586 return ExprError(); 9587 } 9588 9589 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 9590 9591 // If overload resolution picked a static member, build a 9592 // non-member call based on that function. 9593 if (Method->isStatic()) { 9594 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 9595 Args, NumArgs, RParenLoc); 9596 } 9597 9598 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 9599 } 9600 9601 QualType ResultType = Method->getResultType(); 9602 ExprValueKind VK = Expr::getValueKindForType(ResultType); 9603 ResultType = ResultType.getNonLValueExprType(Context); 9604 9605 assert(Method && "Member call to something that isn't a method?"); 9606 CXXMemberCallExpr *TheCall = 9607 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 9608 ResultType, VK, RParenLoc); 9609 9610 // Check for a valid return type. 9611 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 9612 TheCall, Method)) 9613 return ExprError(); 9614 9615 // Convert the object argument (for a non-static member function call). 9616 // We only need to do this if there was actually an overload; otherwise 9617 // it was done at lookup. 9618 if (!Method->isStatic()) { 9619 ExprResult ObjectArg = 9620 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier, 9621 FoundDecl, Method); 9622 if (ObjectArg.isInvalid()) 9623 return ExprError(); 9624 MemExpr->setBase(ObjectArg.take()); 9625 } 9626 9627 // Convert the rest of the arguments 9628 const FunctionProtoType *Proto = 9629 Method->getType()->getAs<FunctionProtoType>(); 9630 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 9631 RParenLoc)) 9632 return ExprError(); 9633 9634 if (CheckFunctionCall(Method, TheCall)) 9635 return ExprError(); 9636 9637 if ((isa<CXXConstructorDecl>(CurContext) || 9638 isa<CXXDestructorDecl>(CurContext)) && 9639 TheCall->getMethodDecl()->isPure()) { 9640 const CXXMethodDecl *MD = TheCall->getMethodDecl(); 9641 9642 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts())) { 9643 Diag(MemExpr->getLocStart(), 9644 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor) 9645 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext) 9646 << MD->getParent()->getDeclName(); 9647 9648 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName(); 9649 } 9650 } 9651 return MaybeBindToTemporary(TheCall); 9652} 9653 9654/// BuildCallToObjectOfClassType - Build a call to an object of class 9655/// type (C++ [over.call.object]), which can end up invoking an 9656/// overloaded function call operator (@c operator()) or performing a 9657/// user-defined conversion on the object argument. 9658ExprResult 9659Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj, 9660 SourceLocation LParenLoc, 9661 Expr **Args, unsigned NumArgs, 9662 SourceLocation RParenLoc) { 9663 if (checkPlaceholderForOverload(*this, Obj)) 9664 return ExprError(); 9665 ExprResult Object = Owned(Obj); 9666 9667 UnbridgedCastsSet UnbridgedCasts; 9668 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) 9669 return ExprError(); 9670 9671 assert(Object.get()->getType()->isRecordType() && "Requires object type argument"); 9672 const RecordType *Record = Object.get()->getType()->getAs<RecordType>(); 9673 9674 // C++ [over.call.object]p1: 9675 // If the primary-expression E in the function call syntax 9676 // evaluates to a class object of type "cv T", then the set of 9677 // candidate functions includes at least the function call 9678 // operators of T. The function call operators of T are obtained by 9679 // ordinary lookup of the name operator() in the context of 9680 // (E).operator(). 9681 OverloadCandidateSet CandidateSet(LParenLoc); 9682 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 9683 9684 if (RequireCompleteType(LParenLoc, Object.get()->getType(), 9685 PDiag(diag::err_incomplete_object_call) 9686 << Object.get()->getSourceRange())) 9687 return true; 9688 9689 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 9690 LookupQualifiedName(R, Record->getDecl()); 9691 R.suppressDiagnostics(); 9692 9693 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 9694 Oper != OperEnd; ++Oper) { 9695 AddMethodCandidate(Oper.getPair(), Object.get()->getType(), 9696 Object.get()->Classify(Context), Args, NumArgs, CandidateSet, 9697 /*SuppressUserConversions=*/ false); 9698 } 9699 9700 // C++ [over.call.object]p2: 9701 // In addition, for each (non-explicit in C++0x) conversion function 9702 // declared in T of the form 9703 // 9704 // operator conversion-type-id () cv-qualifier; 9705 // 9706 // where cv-qualifier is the same cv-qualification as, or a 9707 // greater cv-qualification than, cv, and where conversion-type-id 9708 // denotes the type "pointer to function of (P1,...,Pn) returning 9709 // R", or the type "reference to pointer to function of 9710 // (P1,...,Pn) returning R", or the type "reference to function 9711 // of (P1,...,Pn) returning R", a surrogate call function [...] 9712 // is also considered as a candidate function. Similarly, 9713 // surrogate call functions are added to the set of candidate 9714 // functions for each conversion function declared in an 9715 // accessible base class provided the function is not hidden 9716 // within T by another intervening declaration. 9717 const UnresolvedSetImpl *Conversions 9718 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 9719 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 9720 E = Conversions->end(); I != E; ++I) { 9721 NamedDecl *D = *I; 9722 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 9723 if (isa<UsingShadowDecl>(D)) 9724 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 9725 9726 // Skip over templated conversion functions; they aren't 9727 // surrogates. 9728 if (isa<FunctionTemplateDecl>(D)) 9729 continue; 9730 9731 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 9732 if (!Conv->isExplicit()) { 9733 // Strip the reference type (if any) and then the pointer type (if 9734 // any) to get down to what might be a function type. 9735 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 9736 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 9737 ConvType = ConvPtrType->getPointeeType(); 9738 9739 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 9740 { 9741 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 9742 Object.get(), Args, NumArgs, CandidateSet); 9743 } 9744 } 9745 } 9746 9747 bool HadMultipleCandidates = (CandidateSet.size() > 1); 9748 9749 // Perform overload resolution. 9750 OverloadCandidateSet::iterator Best; 9751 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(), 9752 Best)) { 9753 case OR_Success: 9754 // Overload resolution succeeded; we'll build the appropriate call 9755 // below. 9756 break; 9757 9758 case OR_No_Viable_Function: 9759 if (CandidateSet.empty()) 9760 Diag(Object.get()->getSourceRange().getBegin(), diag::err_ovl_no_oper) 9761 << Object.get()->getType() << /*call*/ 1 9762 << Object.get()->getSourceRange(); 9763 else 9764 Diag(Object.get()->getSourceRange().getBegin(), 9765 diag::err_ovl_no_viable_object_call) 9766 << Object.get()->getType() << Object.get()->getSourceRange(); 9767 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9768 break; 9769 9770 case OR_Ambiguous: 9771 Diag(Object.get()->getSourceRange().getBegin(), 9772 diag::err_ovl_ambiguous_object_call) 9773 << Object.get()->getType() << Object.get()->getSourceRange(); 9774 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 9775 break; 9776 9777 case OR_Deleted: 9778 Diag(Object.get()->getSourceRange().getBegin(), 9779 diag::err_ovl_deleted_object_call) 9780 << Best->Function->isDeleted() 9781 << Object.get()->getType() 9782 << getDeletedOrUnavailableSuffix(Best->Function) 9783 << Object.get()->getSourceRange(); 9784 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9785 break; 9786 } 9787 9788 if (Best == CandidateSet.end()) 9789 return true; 9790 9791 UnbridgedCasts.restore(); 9792 9793 if (Best->Function == 0) { 9794 // Since there is no function declaration, this is one of the 9795 // surrogate candidates. Dig out the conversion function. 9796 CXXConversionDecl *Conv 9797 = cast<CXXConversionDecl>( 9798 Best->Conversions[0].UserDefined.ConversionFunction); 9799 9800 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 9801 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 9802 9803 // We selected one of the surrogate functions that converts the 9804 // object parameter to a function pointer. Perform the conversion 9805 // on the object argument, then let ActOnCallExpr finish the job. 9806 9807 // Create an implicit member expr to refer to the conversion operator. 9808 // and then call it. 9809 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl, 9810 Conv, HadMultipleCandidates); 9811 if (Call.isInvalid()) 9812 return ExprError(); 9813 9814 return ActOnCallExpr(S, Call.get(), LParenLoc, MultiExprArg(Args, NumArgs), 9815 RParenLoc); 9816 } 9817 9818 MarkDeclarationReferenced(LParenLoc, Best->Function); 9819 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 9820 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 9821 9822 // We found an overloaded operator(). Build a CXXOperatorCallExpr 9823 // that calls this method, using Object for the implicit object 9824 // parameter and passing along the remaining arguments. 9825 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 9826 const FunctionProtoType *Proto = 9827 Method->getType()->getAs<FunctionProtoType>(); 9828 9829 unsigned NumArgsInProto = Proto->getNumArgs(); 9830 unsigned NumArgsToCheck = NumArgs; 9831 9832 // Build the full argument list for the method call (the 9833 // implicit object parameter is placed at the beginning of the 9834 // list). 9835 Expr **MethodArgs; 9836 if (NumArgs < NumArgsInProto) { 9837 NumArgsToCheck = NumArgsInProto; 9838 MethodArgs = new Expr*[NumArgsInProto + 1]; 9839 } else { 9840 MethodArgs = new Expr*[NumArgs + 1]; 9841 } 9842 MethodArgs[0] = Object.get(); 9843 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 9844 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 9845 9846 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, 9847 HadMultipleCandidates); 9848 if (NewFn.isInvalid()) 9849 return true; 9850 9851 // Once we've built TheCall, all of the expressions are properly 9852 // owned. 9853 QualType ResultTy = Method->getResultType(); 9854 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 9855 ResultTy = ResultTy.getNonLValueExprType(Context); 9856 9857 CXXOperatorCallExpr *TheCall = 9858 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn.take(), 9859 MethodArgs, NumArgs + 1, 9860 ResultTy, VK, RParenLoc); 9861 delete [] MethodArgs; 9862 9863 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 9864 Method)) 9865 return true; 9866 9867 // We may have default arguments. If so, we need to allocate more 9868 // slots in the call for them. 9869 if (NumArgs < NumArgsInProto) 9870 TheCall->setNumArgs(Context, NumArgsInProto + 1); 9871 else if (NumArgs > NumArgsInProto) 9872 NumArgsToCheck = NumArgsInProto; 9873 9874 bool IsError = false; 9875 9876 // Initialize the implicit object parameter. 9877 ExprResult ObjRes = 9878 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/0, 9879 Best->FoundDecl, Method); 9880 if (ObjRes.isInvalid()) 9881 IsError = true; 9882 else 9883 Object = move(ObjRes); 9884 TheCall->setArg(0, Object.take()); 9885 9886 // Check the argument types. 9887 for (unsigned i = 0; i != NumArgsToCheck; i++) { 9888 Expr *Arg; 9889 if (i < NumArgs) { 9890 Arg = Args[i]; 9891 9892 // Pass the argument. 9893 9894 ExprResult InputInit 9895 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 9896 Context, 9897 Method->getParamDecl(i)), 9898 SourceLocation(), Arg); 9899 9900 IsError |= InputInit.isInvalid(); 9901 Arg = InputInit.takeAs<Expr>(); 9902 } else { 9903 ExprResult DefArg 9904 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 9905 if (DefArg.isInvalid()) { 9906 IsError = true; 9907 break; 9908 } 9909 9910 Arg = DefArg.takeAs<Expr>(); 9911 } 9912 9913 TheCall->setArg(i + 1, Arg); 9914 } 9915 9916 // If this is a variadic call, handle args passed through "...". 9917 if (Proto->isVariadic()) { 9918 // Promote the arguments (C99 6.5.2.2p7). 9919 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 9920 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod, 0); 9921 IsError |= Arg.isInvalid(); 9922 TheCall->setArg(i + 1, Arg.take()); 9923 } 9924 } 9925 9926 if (IsError) return true; 9927 9928 if (CheckFunctionCall(Method, TheCall)) 9929 return true; 9930 9931 return MaybeBindToTemporary(TheCall); 9932} 9933 9934/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 9935/// (if one exists), where @c Base is an expression of class type and 9936/// @c Member is the name of the member we're trying to find. 9937ExprResult 9938Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 9939 assert(Base->getType()->isRecordType() && 9940 "left-hand side must have class type"); 9941 9942 if (checkPlaceholderForOverload(*this, Base)) 9943 return ExprError(); 9944 9945 SourceLocation Loc = Base->getExprLoc(); 9946 9947 // C++ [over.ref]p1: 9948 // 9949 // [...] An expression x->m is interpreted as (x.operator->())->m 9950 // for a class object x of type T if T::operator->() exists and if 9951 // the operator is selected as the best match function by the 9952 // overload resolution mechanism (13.3). 9953 DeclarationName OpName = 9954 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 9955 OverloadCandidateSet CandidateSet(Loc); 9956 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 9957 9958 if (RequireCompleteType(Loc, Base->getType(), 9959 PDiag(diag::err_typecheck_incomplete_tag) 9960 << Base->getSourceRange())) 9961 return ExprError(); 9962 9963 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 9964 LookupQualifiedName(R, BaseRecord->getDecl()); 9965 R.suppressDiagnostics(); 9966 9967 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 9968 Oper != OperEnd; ++Oper) { 9969 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 9970 0, 0, CandidateSet, /*SuppressUserConversions=*/false); 9971 } 9972 9973 bool HadMultipleCandidates = (CandidateSet.size() > 1); 9974 9975 // Perform overload resolution. 9976 OverloadCandidateSet::iterator Best; 9977 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 9978 case OR_Success: 9979 // Overload resolution succeeded; we'll build the call below. 9980 break; 9981 9982 case OR_No_Viable_Function: 9983 if (CandidateSet.empty()) 9984 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 9985 << Base->getType() << Base->getSourceRange(); 9986 else 9987 Diag(OpLoc, diag::err_ovl_no_viable_oper) 9988 << "operator->" << Base->getSourceRange(); 9989 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 9990 return ExprError(); 9991 9992 case OR_Ambiguous: 9993 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 9994 << "->" << Base->getType() << Base->getSourceRange(); 9995 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, &Base, 1); 9996 return ExprError(); 9997 9998 case OR_Deleted: 9999 Diag(OpLoc, diag::err_ovl_deleted_oper) 10000 << Best->Function->isDeleted() 10001 << "->" 10002 << getDeletedOrUnavailableSuffix(Best->Function) 10003 << Base->getSourceRange(); 10004 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 10005 return ExprError(); 10006 } 10007 10008 MarkDeclarationReferenced(OpLoc, Best->Function); 10009 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 10010 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 10011 10012 // Convert the object parameter. 10013 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 10014 ExprResult BaseResult = 10015 PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 10016 Best->FoundDecl, Method); 10017 if (BaseResult.isInvalid()) 10018 return ExprError(); 10019 Base = BaseResult.take(); 10020 10021 // Build the operator call. 10022 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, 10023 HadMultipleCandidates); 10024 if (FnExpr.isInvalid()) 10025 return ExprError(); 10026 10027 QualType ResultTy = Method->getResultType(); 10028 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10029 ResultTy = ResultTy.getNonLValueExprType(Context); 10030 CXXOperatorCallExpr *TheCall = 10031 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.take(), 10032 &Base, 1, ResultTy, VK, OpLoc); 10033 10034 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 10035 Method)) 10036 return ExprError(); 10037 10038 return MaybeBindToTemporary(TheCall); 10039} 10040 10041/// FixOverloadedFunctionReference - E is an expression that refers to 10042/// a C++ overloaded function (possibly with some parentheses and 10043/// perhaps a '&' around it). We have resolved the overloaded function 10044/// to the function declaration Fn, so patch up the expression E to 10045/// refer (possibly indirectly) to Fn. Returns the new expr. 10046Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 10047 FunctionDecl *Fn) { 10048 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 10049 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 10050 Found, Fn); 10051 if (SubExpr == PE->getSubExpr()) 10052 return PE; 10053 10054 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 10055 } 10056 10057 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 10058 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 10059 Found, Fn); 10060 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 10061 SubExpr->getType()) && 10062 "Implicit cast type cannot be determined from overload"); 10063 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 10064 if (SubExpr == ICE->getSubExpr()) 10065 return ICE; 10066 10067 return ImplicitCastExpr::Create(Context, ICE->getType(), 10068 ICE->getCastKind(), 10069 SubExpr, 0, 10070 ICE->getValueKind()); 10071 } 10072 10073 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 10074 assert(UnOp->getOpcode() == UO_AddrOf && 10075 "Can only take the address of an overloaded function"); 10076 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 10077 if (Method->isStatic()) { 10078 // Do nothing: static member functions aren't any different 10079 // from non-member functions. 10080 } else { 10081 // Fix the sub expression, which really has to be an 10082 // UnresolvedLookupExpr holding an overloaded member function 10083 // or template. 10084 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 10085 Found, Fn); 10086 if (SubExpr == UnOp->getSubExpr()) 10087 return UnOp; 10088 10089 assert(isa<DeclRefExpr>(SubExpr) 10090 && "fixed to something other than a decl ref"); 10091 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 10092 && "fixed to a member ref with no nested name qualifier"); 10093 10094 // We have taken the address of a pointer to member 10095 // function. Perform the computation here so that we get the 10096 // appropriate pointer to member type. 10097 QualType ClassType 10098 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 10099 QualType MemPtrType 10100 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 10101 10102 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 10103 VK_RValue, OK_Ordinary, 10104 UnOp->getOperatorLoc()); 10105 } 10106 } 10107 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 10108 Found, Fn); 10109 if (SubExpr == UnOp->getSubExpr()) 10110 return UnOp; 10111 10112 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 10113 Context.getPointerType(SubExpr->getType()), 10114 VK_RValue, OK_Ordinary, 10115 UnOp->getOperatorLoc()); 10116 } 10117 10118 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 10119 // FIXME: avoid copy. 10120 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 10121 if (ULE->hasExplicitTemplateArgs()) { 10122 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 10123 TemplateArgs = &TemplateArgsBuffer; 10124 } 10125 10126 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 10127 ULE->getQualifierLoc(), 10128 Fn, 10129 ULE->getNameLoc(), 10130 Fn->getType(), 10131 VK_LValue, 10132 Found.getDecl(), 10133 TemplateArgs); 10134 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1); 10135 return DRE; 10136 } 10137 10138 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 10139 // FIXME: avoid copy. 10140 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 10141 if (MemExpr->hasExplicitTemplateArgs()) { 10142 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 10143 TemplateArgs = &TemplateArgsBuffer; 10144 } 10145 10146 Expr *Base; 10147 10148 // If we're filling in a static method where we used to have an 10149 // implicit member access, rewrite to a simple decl ref. 10150 if (MemExpr->isImplicitAccess()) { 10151 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 10152 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 10153 MemExpr->getQualifierLoc(), 10154 Fn, 10155 MemExpr->getMemberLoc(), 10156 Fn->getType(), 10157 VK_LValue, 10158 Found.getDecl(), 10159 TemplateArgs); 10160 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1); 10161 return DRE; 10162 } else { 10163 SourceLocation Loc = MemExpr->getMemberLoc(); 10164 if (MemExpr->getQualifier()) 10165 Loc = MemExpr->getQualifierLoc().getBeginLoc(); 10166 Base = new (Context) CXXThisExpr(Loc, 10167 MemExpr->getBaseType(), 10168 /*isImplicit=*/true); 10169 } 10170 } else 10171 Base = MemExpr->getBase(); 10172 10173 ExprValueKind valueKind; 10174 QualType type; 10175 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 10176 valueKind = VK_LValue; 10177 type = Fn->getType(); 10178 } else { 10179 valueKind = VK_RValue; 10180 type = Context.BoundMemberTy; 10181 } 10182 10183 MemberExpr *ME = MemberExpr::Create(Context, Base, 10184 MemExpr->isArrow(), 10185 MemExpr->getQualifierLoc(), 10186 Fn, 10187 Found, 10188 MemExpr->getMemberNameInfo(), 10189 TemplateArgs, 10190 type, valueKind, OK_Ordinary); 10191 ME->setHadMultipleCandidates(true); 10192 return ME; 10193 } 10194 10195 llvm_unreachable("Invalid reference to overloaded function"); 10196 return E; 10197} 10198 10199ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 10200 DeclAccessPair Found, 10201 FunctionDecl *Fn) { 10202 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 10203} 10204 10205} // end namespace clang 10206