SemaOverload.cpp revision fe5922809ec906390769a2cf0a765f395fa0c599
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 for (iterator i = begin(), e = end(); i != e; ++i) 545 for (unsigned ii = 0, ie = i->NumConversions; ii != ie; ++ii) 546 i->Conversions[ii].~ImplicitConversionSequence(); 547 NumInlineSequences = 0; 548 Candidates.clear(); 549 Functions.clear(); 550} 551 552namespace { 553 class UnbridgedCastsSet { 554 struct Entry { 555 Expr **Addr; 556 Expr *Saved; 557 }; 558 SmallVector<Entry, 2> Entries; 559 560 public: 561 void save(Sema &S, Expr *&E) { 562 assert(E->hasPlaceholderType(BuiltinType::ARCUnbridgedCast)); 563 Entry entry = { &E, E }; 564 Entries.push_back(entry); 565 E = S.stripARCUnbridgedCast(E); 566 } 567 568 void restore() { 569 for (SmallVectorImpl<Entry>::iterator 570 i = Entries.begin(), e = Entries.end(); i != e; ++i) 571 *i->Addr = i->Saved; 572 } 573 }; 574} 575 576/// checkPlaceholderForOverload - Do any interesting placeholder-like 577/// preprocessing on the given expression. 578/// 579/// \param unbridgedCasts a collection to which to add unbridged casts; 580/// without this, they will be immediately diagnosed as errors 581/// 582/// Return true on unrecoverable error. 583static bool checkPlaceholderForOverload(Sema &S, Expr *&E, 584 UnbridgedCastsSet *unbridgedCasts = 0) { 585 if (const BuiltinType *placeholder = E->getType()->getAsPlaceholderType()) { 586 // We can't handle overloaded expressions here because overload 587 // resolution might reasonably tweak them. 588 if (placeholder->getKind() == BuiltinType::Overload) return false; 589 590 // If the context potentially accepts unbridged ARC casts, strip 591 // the unbridged cast and add it to the collection for later restoration. 592 if (placeholder->getKind() == BuiltinType::ARCUnbridgedCast && 593 unbridgedCasts) { 594 unbridgedCasts->save(S, E); 595 return false; 596 } 597 598 // Go ahead and check everything else. 599 ExprResult result = S.CheckPlaceholderExpr(E); 600 if (result.isInvalid()) 601 return true; 602 603 E = result.take(); 604 return false; 605 } 606 607 // Nothing to do. 608 return false; 609} 610 611/// checkArgPlaceholdersForOverload - Check a set of call operands for 612/// placeholders. 613static bool checkArgPlaceholdersForOverload(Sema &S, Expr **args, 614 unsigned numArgs, 615 UnbridgedCastsSet &unbridged) { 616 for (unsigned i = 0; i != numArgs; ++i) 617 if (checkPlaceholderForOverload(S, args[i], &unbridged)) 618 return true; 619 620 return false; 621} 622 623// IsOverload - Determine whether the given New declaration is an 624// overload of the declarations in Old. This routine returns false if 625// New and Old cannot be overloaded, e.g., if New has the same 626// signature as some function in Old (C++ 1.3.10) or if the Old 627// declarations aren't functions (or function templates) at all. When 628// it does return false, MatchedDecl will point to the decl that New 629// cannot be overloaded with. This decl may be a UsingShadowDecl on 630// top of the underlying declaration. 631// 632// Example: Given the following input: 633// 634// void f(int, float); // #1 635// void f(int, int); // #2 636// int f(int, int); // #3 637// 638// When we process #1, there is no previous declaration of "f", 639// so IsOverload will not be used. 640// 641// When we process #2, Old contains only the FunctionDecl for #1. By 642// comparing the parameter types, we see that #1 and #2 are overloaded 643// (since they have different signatures), so this routine returns 644// false; MatchedDecl is unchanged. 645// 646// When we process #3, Old is an overload set containing #1 and #2. We 647// compare the signatures of #3 to #1 (they're overloaded, so we do 648// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 649// identical (return types of functions are not part of the 650// signature), IsOverload returns false and MatchedDecl will be set to 651// point to the FunctionDecl for #2. 652// 653// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 654// into a class by a using declaration. The rules for whether to hide 655// shadow declarations ignore some properties which otherwise figure 656// into a function template's signature. 657Sema::OverloadKind 658Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 659 NamedDecl *&Match, bool NewIsUsingDecl) { 660 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 661 I != E; ++I) { 662 NamedDecl *OldD = *I; 663 664 bool OldIsUsingDecl = false; 665 if (isa<UsingShadowDecl>(OldD)) { 666 OldIsUsingDecl = true; 667 668 // We can always introduce two using declarations into the same 669 // context, even if they have identical signatures. 670 if (NewIsUsingDecl) continue; 671 672 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 673 } 674 675 // If either declaration was introduced by a using declaration, 676 // we'll need to use slightly different rules for matching. 677 // Essentially, these rules are the normal rules, except that 678 // function templates hide function templates with different 679 // return types or template parameter lists. 680 bool UseMemberUsingDeclRules = 681 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 682 683 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 684 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 685 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 686 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 687 continue; 688 } 689 690 Match = *I; 691 return Ovl_Match; 692 } 693 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 694 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 695 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 696 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 697 continue; 698 } 699 700 Match = *I; 701 return Ovl_Match; 702 } 703 } else if (isa<UsingDecl>(OldD)) { 704 // We can overload with these, which can show up when doing 705 // redeclaration checks for UsingDecls. 706 assert(Old.getLookupKind() == LookupUsingDeclName); 707 } else if (isa<TagDecl>(OldD)) { 708 // We can always overload with tags by hiding them. 709 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 710 // Optimistically assume that an unresolved using decl will 711 // overload; if it doesn't, we'll have to diagnose during 712 // template instantiation. 713 } else { 714 // (C++ 13p1): 715 // Only function declarations can be overloaded; object and type 716 // declarations cannot be overloaded. 717 Match = *I; 718 return Ovl_NonFunction; 719 } 720 } 721 722 return Ovl_Overload; 723} 724 725bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 726 bool UseUsingDeclRules) { 727 // If both of the functions are extern "C", then they are not 728 // overloads. 729 if (Old->isExternC() && New->isExternC()) 730 return false; 731 732 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 733 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 734 735 // C++ [temp.fct]p2: 736 // A function template can be overloaded with other function templates 737 // and with normal (non-template) functions. 738 if ((OldTemplate == 0) != (NewTemplate == 0)) 739 return true; 740 741 // Is the function New an overload of the function Old? 742 QualType OldQType = Context.getCanonicalType(Old->getType()); 743 QualType NewQType = Context.getCanonicalType(New->getType()); 744 745 // Compare the signatures (C++ 1.3.10) of the two functions to 746 // determine whether they are overloads. If we find any mismatch 747 // in the signature, they are overloads. 748 749 // If either of these functions is a K&R-style function (no 750 // prototype), then we consider them to have matching signatures. 751 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 752 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 753 return false; 754 755 const FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 756 const FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 757 758 // The signature of a function includes the types of its 759 // parameters (C++ 1.3.10), which includes the presence or absence 760 // of the ellipsis; see C++ DR 357). 761 if (OldQType != NewQType && 762 (OldType->getNumArgs() != NewType->getNumArgs() || 763 OldType->isVariadic() != NewType->isVariadic() || 764 !FunctionArgTypesAreEqual(OldType, NewType))) 765 return true; 766 767 // C++ [temp.over.link]p4: 768 // The signature of a function template consists of its function 769 // signature, its return type and its template parameter list. The names 770 // of the template parameters are significant only for establishing the 771 // relationship between the template parameters and the rest of the 772 // signature. 773 // 774 // We check the return type and template parameter lists for function 775 // templates first; the remaining checks follow. 776 // 777 // However, we don't consider either of these when deciding whether 778 // a member introduced by a shadow declaration is hidden. 779 if (!UseUsingDeclRules && NewTemplate && 780 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 781 OldTemplate->getTemplateParameters(), 782 false, TPL_TemplateMatch) || 783 OldType->getResultType() != NewType->getResultType())) 784 return true; 785 786 // If the function is a class member, its signature includes the 787 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. 788 // 789 // As part of this, also check whether one of the member functions 790 // is static, in which case they are not overloads (C++ 791 // 13.1p2). While not part of the definition of the signature, 792 // this check is important to determine whether these functions 793 // can be overloaded. 794 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 795 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 796 if (OldMethod && NewMethod && 797 !OldMethod->isStatic() && !NewMethod->isStatic() && 798 (OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers() || 799 OldMethod->getRefQualifier() != NewMethod->getRefQualifier())) { 800 if (!UseUsingDeclRules && 801 OldMethod->getRefQualifier() != NewMethod->getRefQualifier() && 802 (OldMethod->getRefQualifier() == RQ_None || 803 NewMethod->getRefQualifier() == RQ_None)) { 804 // C++0x [over.load]p2: 805 // - Member function declarations with the same name and the same 806 // parameter-type-list as well as member function template 807 // declarations with the same name, the same parameter-type-list, and 808 // the same template parameter lists cannot be overloaded if any of 809 // them, but not all, have a ref-qualifier (8.3.5). 810 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) 811 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); 812 Diag(OldMethod->getLocation(), diag::note_previous_declaration); 813 } 814 815 return true; 816 } 817 818 // The signatures match; this is not an overload. 819 return false; 820} 821 822/// \brief Checks availability of the function depending on the current 823/// function context. Inside an unavailable function, unavailability is ignored. 824/// 825/// \returns true if \arg FD is unavailable and current context is inside 826/// an available function, false otherwise. 827bool Sema::isFunctionConsideredUnavailable(FunctionDecl *FD) { 828 return FD->isUnavailable() && !cast<Decl>(CurContext)->isUnavailable(); 829} 830 831/// \brief Tries a user-defined conversion from From to ToType. 832/// 833/// Produces an implicit conversion sequence for when a standard conversion 834/// is not an option. See TryImplicitConversion for more information. 835static ImplicitConversionSequence 836TryUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 837 bool SuppressUserConversions, 838 bool AllowExplicit, 839 bool InOverloadResolution, 840 bool CStyle, 841 bool AllowObjCWritebackConversion) { 842 ImplicitConversionSequence ICS; 843 844 if (SuppressUserConversions) { 845 // We're not in the case above, so there is no conversion that 846 // we can perform. 847 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 848 return ICS; 849 } 850 851 // Attempt user-defined conversion. 852 OverloadCandidateSet Conversions(From->getExprLoc()); 853 OverloadingResult UserDefResult 854 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 855 AllowExplicit); 856 857 if (UserDefResult == OR_Success) { 858 ICS.setUserDefined(); 859 // C++ [over.ics.user]p4: 860 // A conversion of an expression of class type to the same class 861 // type is given Exact Match rank, and a conversion of an 862 // expression of class type to a base class of that type is 863 // given Conversion rank, in spite of the fact that a copy 864 // constructor (i.e., a user-defined conversion function) is 865 // called for those cases. 866 if (CXXConstructorDecl *Constructor 867 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 868 QualType FromCanon 869 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 870 QualType ToCanon 871 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 872 if (Constructor->isCopyConstructor() && 873 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 874 // Turn this into a "standard" conversion sequence, so that it 875 // gets ranked with standard conversion sequences. 876 ICS.setStandard(); 877 ICS.Standard.setAsIdentityConversion(); 878 ICS.Standard.setFromType(From->getType()); 879 ICS.Standard.setAllToTypes(ToType); 880 ICS.Standard.CopyConstructor = Constructor; 881 if (ToCanon != FromCanon) 882 ICS.Standard.Second = ICK_Derived_To_Base; 883 } 884 } 885 886 // C++ [over.best.ics]p4: 887 // However, when considering the argument of a user-defined 888 // conversion function that is a candidate by 13.3.1.3 when 889 // invoked for the copying of the temporary in the second step 890 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 891 // 13.3.1.6 in all cases, only standard conversion sequences and 892 // ellipsis conversion sequences are allowed. 893 if (SuppressUserConversions && ICS.isUserDefined()) { 894 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 895 } 896 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 897 ICS.setAmbiguous(); 898 ICS.Ambiguous.setFromType(From->getType()); 899 ICS.Ambiguous.setToType(ToType); 900 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 901 Cand != Conversions.end(); ++Cand) 902 if (Cand->Viable) 903 ICS.Ambiguous.addConversion(Cand->Function); 904 } else { 905 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 906 } 907 908 return ICS; 909} 910 911/// TryImplicitConversion - Attempt to perform an implicit conversion 912/// from the given expression (Expr) to the given type (ToType). This 913/// function returns an implicit conversion sequence that can be used 914/// to perform the initialization. Given 915/// 916/// void f(float f); 917/// void g(int i) { f(i); } 918/// 919/// this routine would produce an implicit conversion sequence to 920/// describe the initialization of f from i, which will be a standard 921/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 922/// 4.1) followed by a floating-integral conversion (C++ 4.9). 923// 924/// Note that this routine only determines how the conversion can be 925/// performed; it does not actually perform the conversion. As such, 926/// it will not produce any diagnostics if no conversion is available, 927/// but will instead return an implicit conversion sequence of kind 928/// "BadConversion". 929/// 930/// If @p SuppressUserConversions, then user-defined conversions are 931/// not permitted. 932/// If @p AllowExplicit, then explicit user-defined conversions are 933/// permitted. 934/// 935/// \param AllowObjCWritebackConversion Whether we allow the Objective-C 936/// writeback conversion, which allows __autoreleasing id* parameters to 937/// be initialized with __strong id* or __weak id* arguments. 938static ImplicitConversionSequence 939TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 940 bool SuppressUserConversions, 941 bool AllowExplicit, 942 bool InOverloadResolution, 943 bool CStyle, 944 bool AllowObjCWritebackConversion) { 945 ImplicitConversionSequence ICS; 946 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 947 ICS.Standard, CStyle, AllowObjCWritebackConversion)){ 948 ICS.setStandard(); 949 return ICS; 950 } 951 952 if (!S.getLangOptions().CPlusPlus) { 953 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 954 return ICS; 955 } 956 957 // C++ [over.ics.user]p4: 958 // A conversion of an expression of class type to the same class 959 // type is given Exact Match rank, and a conversion of an 960 // expression of class type to a base class of that type is 961 // given Conversion rank, in spite of the fact that a copy/move 962 // constructor (i.e., a user-defined conversion function) is 963 // called for those cases. 964 QualType FromType = From->getType(); 965 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 966 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 967 S.IsDerivedFrom(FromType, ToType))) { 968 ICS.setStandard(); 969 ICS.Standard.setAsIdentityConversion(); 970 ICS.Standard.setFromType(FromType); 971 ICS.Standard.setAllToTypes(ToType); 972 973 // We don't actually check at this point whether there is a valid 974 // copy/move constructor, since overloading just assumes that it 975 // exists. When we actually perform initialization, we'll find the 976 // appropriate constructor to copy the returned object, if needed. 977 ICS.Standard.CopyConstructor = 0; 978 979 // Determine whether this is considered a derived-to-base conversion. 980 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 981 ICS.Standard.Second = ICK_Derived_To_Base; 982 983 return ICS; 984 } 985 986 return TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, 987 AllowExplicit, InOverloadResolution, CStyle, 988 AllowObjCWritebackConversion); 989} 990 991ImplicitConversionSequence 992Sema::TryImplicitConversion(Expr *From, QualType ToType, 993 bool SuppressUserConversions, 994 bool AllowExplicit, 995 bool InOverloadResolution, 996 bool CStyle, 997 bool AllowObjCWritebackConversion) { 998 return clang::TryImplicitConversion(*this, From, ToType, 999 SuppressUserConversions, AllowExplicit, 1000 InOverloadResolution, CStyle, 1001 AllowObjCWritebackConversion); 1002} 1003 1004/// PerformImplicitConversion - Perform an implicit conversion of the 1005/// expression From to the type ToType. Returns the 1006/// converted expression. Flavor is the kind of conversion we're 1007/// performing, used in the error message. If @p AllowExplicit, 1008/// explicit user-defined conversions are permitted. 1009ExprResult 1010Sema::PerformImplicitConversion(Expr *From, QualType ToType, 1011 AssignmentAction Action, bool AllowExplicit) { 1012 ImplicitConversionSequence ICS; 1013 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 1014} 1015 1016ExprResult 1017Sema::PerformImplicitConversion(Expr *From, QualType ToType, 1018 AssignmentAction Action, bool AllowExplicit, 1019 ImplicitConversionSequence& ICS) { 1020 if (checkPlaceholderForOverload(*this, From)) 1021 return ExprError(); 1022 1023 // Objective-C ARC: Determine whether we will allow the writeback conversion. 1024 bool AllowObjCWritebackConversion 1025 = getLangOptions().ObjCAutoRefCount && 1026 (Action == AA_Passing || Action == AA_Sending); 1027 1028 ICS = clang::TryImplicitConversion(*this, From, ToType, 1029 /*SuppressUserConversions=*/false, 1030 AllowExplicit, 1031 /*InOverloadResolution=*/false, 1032 /*CStyle=*/false, 1033 AllowObjCWritebackConversion); 1034 return PerformImplicitConversion(From, ToType, ICS, Action); 1035} 1036 1037/// \brief Determine whether the conversion from FromType to ToType is a valid 1038/// conversion that strips "noreturn" off the nested function type. 1039bool Sema::IsNoReturnConversion(QualType FromType, QualType ToType, 1040 QualType &ResultTy) { 1041 if (Context.hasSameUnqualifiedType(FromType, ToType)) 1042 return false; 1043 1044 // Permit the conversion F(t __attribute__((noreturn))) -> F(t) 1045 // where F adds one of the following at most once: 1046 // - a pointer 1047 // - a member pointer 1048 // - a block pointer 1049 CanQualType CanTo = Context.getCanonicalType(ToType); 1050 CanQualType CanFrom = Context.getCanonicalType(FromType); 1051 Type::TypeClass TyClass = CanTo->getTypeClass(); 1052 if (TyClass != CanFrom->getTypeClass()) return false; 1053 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { 1054 if (TyClass == Type::Pointer) { 1055 CanTo = CanTo.getAs<PointerType>()->getPointeeType(); 1056 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType(); 1057 } else if (TyClass == Type::BlockPointer) { 1058 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType(); 1059 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType(); 1060 } else if (TyClass == Type::MemberPointer) { 1061 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType(); 1062 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType(); 1063 } else { 1064 return false; 1065 } 1066 1067 TyClass = CanTo->getTypeClass(); 1068 if (TyClass != CanFrom->getTypeClass()) return false; 1069 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) 1070 return false; 1071 } 1072 1073 const FunctionType *FromFn = cast<FunctionType>(CanFrom); 1074 FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); 1075 if (!EInfo.getNoReturn()) return false; 1076 1077 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); 1078 assert(QualType(FromFn, 0).isCanonical()); 1079 if (QualType(FromFn, 0) != CanTo) return false; 1080 1081 ResultTy = ToType; 1082 return true; 1083} 1084 1085/// \brief Determine whether the conversion from FromType to ToType is a valid 1086/// vector conversion. 1087/// 1088/// \param ICK Will be set to the vector conversion kind, if this is a vector 1089/// conversion. 1090static bool IsVectorConversion(ASTContext &Context, QualType FromType, 1091 QualType ToType, ImplicitConversionKind &ICK) { 1092 // We need at least one of these types to be a vector type to have a vector 1093 // conversion. 1094 if (!ToType->isVectorType() && !FromType->isVectorType()) 1095 return false; 1096 1097 // Identical types require no conversions. 1098 if (Context.hasSameUnqualifiedType(FromType, ToType)) 1099 return false; 1100 1101 // There are no conversions between extended vector types, only identity. 1102 if (ToType->isExtVectorType()) { 1103 // There are no conversions between extended vector types other than the 1104 // identity conversion. 1105 if (FromType->isExtVectorType()) 1106 return false; 1107 1108 // Vector splat from any arithmetic type to a vector. 1109 if (FromType->isArithmeticType()) { 1110 ICK = ICK_Vector_Splat; 1111 return true; 1112 } 1113 } 1114 1115 // We can perform the conversion between vector types in the following cases: 1116 // 1)vector types are equivalent AltiVec and GCC vector types 1117 // 2)lax vector conversions are permitted and the vector types are of the 1118 // same size 1119 if (ToType->isVectorType() && FromType->isVectorType()) { 1120 if (Context.areCompatibleVectorTypes(FromType, ToType) || 1121 (Context.getLangOptions().LaxVectorConversions && 1122 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 1123 ICK = ICK_Vector_Conversion; 1124 return true; 1125 } 1126 } 1127 1128 return false; 1129} 1130 1131/// IsStandardConversion - Determines whether there is a standard 1132/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 1133/// expression From to the type ToType. Standard conversion sequences 1134/// only consider non-class types; for conversions that involve class 1135/// types, use TryImplicitConversion. If a conversion exists, SCS will 1136/// contain the standard conversion sequence required to perform this 1137/// conversion and this routine will return true. Otherwise, this 1138/// routine will return false and the value of SCS is unspecified. 1139static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 1140 bool InOverloadResolution, 1141 StandardConversionSequence &SCS, 1142 bool CStyle, 1143 bool AllowObjCWritebackConversion) { 1144 QualType FromType = From->getType(); 1145 1146 // Standard conversions (C++ [conv]) 1147 SCS.setAsIdentityConversion(); 1148 SCS.DeprecatedStringLiteralToCharPtr = false; 1149 SCS.IncompatibleObjC = false; 1150 SCS.setFromType(FromType); 1151 SCS.CopyConstructor = 0; 1152 1153 // There are no standard conversions for class types in C++, so 1154 // abort early. When overloading in C, however, we do permit 1155 if (FromType->isRecordType() || ToType->isRecordType()) { 1156 if (S.getLangOptions().CPlusPlus) 1157 return false; 1158 1159 // When we're overloading in C, we allow, as standard conversions, 1160 } 1161 1162 // The first conversion can be an lvalue-to-rvalue conversion, 1163 // array-to-pointer conversion, or function-to-pointer conversion 1164 // (C++ 4p1). 1165 1166 if (FromType == S.Context.OverloadTy) { 1167 DeclAccessPair AccessPair; 1168 if (FunctionDecl *Fn 1169 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 1170 AccessPair)) { 1171 // We were able to resolve the address of the overloaded function, 1172 // so we can convert to the type of that function. 1173 FromType = Fn->getType(); 1174 1175 // we can sometimes resolve &foo<int> regardless of ToType, so check 1176 // if the type matches (identity) or we are converting to bool 1177 if (!S.Context.hasSameUnqualifiedType( 1178 S.ExtractUnqualifiedFunctionType(ToType), FromType)) { 1179 QualType resultTy; 1180 // if the function type matches except for [[noreturn]], it's ok 1181 if (!S.IsNoReturnConversion(FromType, 1182 S.ExtractUnqualifiedFunctionType(ToType), resultTy)) 1183 // otherwise, only a boolean conversion is standard 1184 if (!ToType->isBooleanType()) 1185 return false; 1186 } 1187 1188 // Check if the "from" expression is taking the address of an overloaded 1189 // function and recompute the FromType accordingly. Take advantage of the 1190 // fact that non-static member functions *must* have such an address-of 1191 // expression. 1192 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn); 1193 if (Method && !Method->isStatic()) { 1194 assert(isa<UnaryOperator>(From->IgnoreParens()) && 1195 "Non-unary operator on non-static member address"); 1196 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() 1197 == UO_AddrOf && 1198 "Non-address-of operator on non-static member address"); 1199 const Type *ClassType 1200 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1201 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1202 } else if (isa<UnaryOperator>(From->IgnoreParens())) { 1203 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == 1204 UO_AddrOf && 1205 "Non-address-of operator for overloaded function expression"); 1206 FromType = S.Context.getPointerType(FromType); 1207 } 1208 1209 // Check that we've computed the proper type after overload resolution. 1210 assert(S.Context.hasSameType( 1211 FromType, 1212 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1213 } else { 1214 return false; 1215 } 1216 } 1217 // Lvalue-to-rvalue conversion (C++11 4.1): 1218 // A glvalue (3.10) of a non-function, non-array type T can 1219 // be converted to a prvalue. 1220 bool argIsLValue = From->isGLValue(); 1221 if (argIsLValue && 1222 !FromType->isFunctionType() && !FromType->isArrayType() && 1223 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1224 SCS.First = ICK_Lvalue_To_Rvalue; 1225 1226 // If T is a non-class type, the type of the rvalue is the 1227 // cv-unqualified version of T. Otherwise, the type of the rvalue 1228 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1229 // just strip the qualifiers because they don't matter. 1230 FromType = FromType.getUnqualifiedType(); 1231 } else if (FromType->isArrayType()) { 1232 // Array-to-pointer conversion (C++ 4.2) 1233 SCS.First = ICK_Array_To_Pointer; 1234 1235 // An lvalue or rvalue of type "array of N T" or "array of unknown 1236 // bound of T" can be converted to an rvalue of type "pointer to 1237 // T" (C++ 4.2p1). 1238 FromType = S.Context.getArrayDecayedType(FromType); 1239 1240 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1241 // This conversion is deprecated. (C++ D.4). 1242 SCS.DeprecatedStringLiteralToCharPtr = true; 1243 1244 // For the purpose of ranking in overload resolution 1245 // (13.3.3.1.1), this conversion is considered an 1246 // array-to-pointer conversion followed by a qualification 1247 // conversion (4.4). (C++ 4.2p2) 1248 SCS.Second = ICK_Identity; 1249 SCS.Third = ICK_Qualification; 1250 SCS.QualificationIncludesObjCLifetime = false; 1251 SCS.setAllToTypes(FromType); 1252 return true; 1253 } 1254 } else if (FromType->isFunctionType() && argIsLValue) { 1255 // Function-to-pointer conversion (C++ 4.3). 1256 SCS.First = ICK_Function_To_Pointer; 1257 1258 // An lvalue of function type T can be converted to an rvalue of 1259 // type "pointer to T." The result is a pointer to the 1260 // function. (C++ 4.3p1). 1261 FromType = S.Context.getPointerType(FromType); 1262 } else { 1263 // We don't require any conversions for the first step. 1264 SCS.First = ICK_Identity; 1265 } 1266 SCS.setToType(0, FromType); 1267 1268 // The second conversion can be an integral promotion, floating 1269 // point promotion, integral conversion, floating point conversion, 1270 // floating-integral conversion, pointer conversion, 1271 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1272 // For overloading in C, this can also be a "compatible-type" 1273 // conversion. 1274 bool IncompatibleObjC = false; 1275 ImplicitConversionKind SecondICK = ICK_Identity; 1276 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1277 // The unqualified versions of the types are the same: there's no 1278 // conversion to do. 1279 SCS.Second = ICK_Identity; 1280 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1281 // Integral promotion (C++ 4.5). 1282 SCS.Second = ICK_Integral_Promotion; 1283 FromType = ToType.getUnqualifiedType(); 1284 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1285 // Floating point promotion (C++ 4.6). 1286 SCS.Second = ICK_Floating_Promotion; 1287 FromType = ToType.getUnqualifiedType(); 1288 } else if (S.IsComplexPromotion(FromType, ToType)) { 1289 // Complex promotion (Clang extension) 1290 SCS.Second = ICK_Complex_Promotion; 1291 FromType = ToType.getUnqualifiedType(); 1292 } else if (ToType->isBooleanType() && 1293 (FromType->isArithmeticType() || 1294 FromType->isAnyPointerType() || 1295 FromType->isBlockPointerType() || 1296 FromType->isMemberPointerType() || 1297 FromType->isNullPtrType())) { 1298 // Boolean conversions (C++ 4.12). 1299 SCS.Second = ICK_Boolean_Conversion; 1300 FromType = S.Context.BoolTy; 1301 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1302 ToType->isIntegralType(S.Context)) { 1303 // Integral conversions (C++ 4.7). 1304 SCS.Second = ICK_Integral_Conversion; 1305 FromType = ToType.getUnqualifiedType(); 1306 } else if (FromType->isAnyComplexType() && ToType->isComplexType()) { 1307 // Complex conversions (C99 6.3.1.6) 1308 SCS.Second = ICK_Complex_Conversion; 1309 FromType = ToType.getUnqualifiedType(); 1310 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1311 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1312 // Complex-real conversions (C99 6.3.1.7) 1313 SCS.Second = ICK_Complex_Real; 1314 FromType = ToType.getUnqualifiedType(); 1315 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1316 // Floating point conversions (C++ 4.8). 1317 SCS.Second = ICK_Floating_Conversion; 1318 FromType = ToType.getUnqualifiedType(); 1319 } else if ((FromType->isRealFloatingType() && 1320 ToType->isIntegralType(S.Context)) || 1321 (FromType->isIntegralOrUnscopedEnumerationType() && 1322 ToType->isRealFloatingType())) { 1323 // Floating-integral conversions (C++ 4.9). 1324 SCS.Second = ICK_Floating_Integral; 1325 FromType = ToType.getUnqualifiedType(); 1326 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { 1327 SCS.Second = ICK_Block_Pointer_Conversion; 1328 } else if (AllowObjCWritebackConversion && 1329 S.isObjCWritebackConversion(FromType, ToType, FromType)) { 1330 SCS.Second = ICK_Writeback_Conversion; 1331 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1332 FromType, IncompatibleObjC)) { 1333 // Pointer conversions (C++ 4.10). 1334 SCS.Second = ICK_Pointer_Conversion; 1335 SCS.IncompatibleObjC = IncompatibleObjC; 1336 FromType = FromType.getUnqualifiedType(); 1337 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1338 InOverloadResolution, FromType)) { 1339 // Pointer to member conversions (4.11). 1340 SCS.Second = ICK_Pointer_Member; 1341 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1342 SCS.Second = SecondICK; 1343 FromType = ToType.getUnqualifiedType(); 1344 } else if (!S.getLangOptions().CPlusPlus && 1345 S.Context.typesAreCompatible(ToType, FromType)) { 1346 // Compatible conversions (Clang extension for C function overloading) 1347 SCS.Second = ICK_Compatible_Conversion; 1348 FromType = ToType.getUnqualifiedType(); 1349 } else if (S.IsNoReturnConversion(FromType, ToType, FromType)) { 1350 // Treat a conversion that strips "noreturn" as an identity conversion. 1351 SCS.Second = ICK_NoReturn_Adjustment; 1352 } else if (IsTransparentUnionStandardConversion(S, From, ToType, 1353 InOverloadResolution, 1354 SCS, CStyle)) { 1355 SCS.Second = ICK_TransparentUnionConversion; 1356 FromType = ToType; 1357 } else { 1358 // No second conversion required. 1359 SCS.Second = ICK_Identity; 1360 } 1361 SCS.setToType(1, FromType); 1362 1363 QualType CanonFrom; 1364 QualType CanonTo; 1365 // The third conversion can be a qualification conversion (C++ 4p1). 1366 bool ObjCLifetimeConversion; 1367 if (S.IsQualificationConversion(FromType, ToType, CStyle, 1368 ObjCLifetimeConversion)) { 1369 SCS.Third = ICK_Qualification; 1370 SCS.QualificationIncludesObjCLifetime = ObjCLifetimeConversion; 1371 FromType = ToType; 1372 CanonFrom = S.Context.getCanonicalType(FromType); 1373 CanonTo = S.Context.getCanonicalType(ToType); 1374 } else { 1375 // No conversion required 1376 SCS.Third = ICK_Identity; 1377 1378 // C++ [over.best.ics]p6: 1379 // [...] Any difference in top-level cv-qualification is 1380 // subsumed by the initialization itself and does not constitute 1381 // a conversion. [...] 1382 CanonFrom = S.Context.getCanonicalType(FromType); 1383 CanonTo = S.Context.getCanonicalType(ToType); 1384 if (CanonFrom.getLocalUnqualifiedType() 1385 == CanonTo.getLocalUnqualifiedType() && 1386 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1387 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr() 1388 || CanonFrom.getObjCLifetime() != CanonTo.getObjCLifetime())) { 1389 FromType = ToType; 1390 CanonFrom = CanonTo; 1391 } 1392 } 1393 SCS.setToType(2, FromType); 1394 1395 // If we have not converted the argument type to the parameter type, 1396 // this is a bad conversion sequence. 1397 if (CanonFrom != CanonTo) 1398 return false; 1399 1400 return true; 1401} 1402 1403static bool 1404IsTransparentUnionStandardConversion(Sema &S, Expr* From, 1405 QualType &ToType, 1406 bool InOverloadResolution, 1407 StandardConversionSequence &SCS, 1408 bool CStyle) { 1409 1410 const RecordType *UT = ToType->getAsUnionType(); 1411 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 1412 return false; 1413 // The field to initialize within the transparent union. 1414 RecordDecl *UD = UT->getDecl(); 1415 // It's compatible if the expression matches any of the fields. 1416 for (RecordDecl::field_iterator it = UD->field_begin(), 1417 itend = UD->field_end(); 1418 it != itend; ++it) { 1419 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, 1420 CStyle, /*ObjCWritebackConversion=*/false)) { 1421 ToType = it->getType(); 1422 return true; 1423 } 1424 } 1425 return false; 1426} 1427 1428/// IsIntegralPromotion - Determines whether the conversion from the 1429/// expression From (whose potentially-adjusted type is FromType) to 1430/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1431/// sets PromotedType to the promoted type. 1432bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1433 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1434 // All integers are built-in. 1435 if (!To) { 1436 return false; 1437 } 1438 1439 // An rvalue of type char, signed char, unsigned char, short int, or 1440 // unsigned short int can be converted to an rvalue of type int if 1441 // int can represent all the values of the source type; otherwise, 1442 // the source rvalue can be converted to an rvalue of type unsigned 1443 // int (C++ 4.5p1). 1444 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1445 !FromType->isEnumeralType()) { 1446 if (// We can promote any signed, promotable integer type to an int 1447 (FromType->isSignedIntegerType() || 1448 // We can promote any unsigned integer type whose size is 1449 // less than int to an int. 1450 (!FromType->isSignedIntegerType() && 1451 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1452 return To->getKind() == BuiltinType::Int; 1453 } 1454 1455 return To->getKind() == BuiltinType::UInt; 1456 } 1457 1458 // C++0x [conv.prom]p3: 1459 // A prvalue of an unscoped enumeration type whose underlying type is not 1460 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1461 // following types that can represent all the values of the enumeration 1462 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1463 // unsigned int, long int, unsigned long int, long long int, or unsigned 1464 // long long int. If none of the types in that list can represent all the 1465 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1466 // type can be converted to an rvalue a prvalue of the extended integer type 1467 // with lowest integer conversion rank (4.13) greater than the rank of long 1468 // long in which all the values of the enumeration can be represented. If 1469 // there are two such extended types, the signed one is chosen. 1470 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1471 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1472 // provided for a scoped enumeration. 1473 if (FromEnumType->getDecl()->isScoped()) 1474 return false; 1475 1476 // We have already pre-calculated the promotion type, so this is trivial. 1477 if (ToType->isIntegerType() && 1478 !RequireCompleteType(From->getLocStart(), FromType, PDiag())) 1479 return Context.hasSameUnqualifiedType(ToType, 1480 FromEnumType->getDecl()->getPromotionType()); 1481 } 1482 1483 // C++0x [conv.prom]p2: 1484 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1485 // to an rvalue a prvalue of the first of the following types that can 1486 // represent all the values of its underlying type: int, unsigned int, 1487 // long int, unsigned long int, long long int, or unsigned long long int. 1488 // If none of the types in that list can represent all the values of its 1489 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1490 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1491 // type. 1492 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1493 ToType->isIntegerType()) { 1494 // Determine whether the type we're converting from is signed or 1495 // unsigned. 1496 bool FromIsSigned = FromType->isSignedIntegerType(); 1497 uint64_t FromSize = Context.getTypeSize(FromType); 1498 1499 // The types we'll try to promote to, in the appropriate 1500 // order. Try each of these types. 1501 QualType PromoteTypes[6] = { 1502 Context.IntTy, Context.UnsignedIntTy, 1503 Context.LongTy, Context.UnsignedLongTy , 1504 Context.LongLongTy, Context.UnsignedLongLongTy 1505 }; 1506 for (int Idx = 0; Idx < 6; ++Idx) { 1507 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1508 if (FromSize < ToSize || 1509 (FromSize == ToSize && 1510 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1511 // We found the type that we can promote to. If this is the 1512 // type we wanted, we have a promotion. Otherwise, no 1513 // promotion. 1514 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1515 } 1516 } 1517 } 1518 1519 // An rvalue for an integral bit-field (9.6) can be converted to an 1520 // rvalue of type int if int can represent all the values of the 1521 // bit-field; otherwise, it can be converted to unsigned int if 1522 // unsigned int can represent all the values of the bit-field. If 1523 // the bit-field is larger yet, no integral promotion applies to 1524 // it. If the bit-field has an enumerated type, it is treated as any 1525 // other value of that type for promotion purposes (C++ 4.5p3). 1526 // FIXME: We should delay checking of bit-fields until we actually perform the 1527 // conversion. 1528 using llvm::APSInt; 1529 if (From) 1530 if (FieldDecl *MemberDecl = From->getBitField()) { 1531 APSInt BitWidth; 1532 if (FromType->isIntegralType(Context) && 1533 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1534 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1535 ToSize = Context.getTypeSize(ToType); 1536 1537 // Are we promoting to an int from a bitfield that fits in an int? 1538 if (BitWidth < ToSize || 1539 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1540 return To->getKind() == BuiltinType::Int; 1541 } 1542 1543 // Are we promoting to an unsigned int from an unsigned bitfield 1544 // that fits into an unsigned int? 1545 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1546 return To->getKind() == BuiltinType::UInt; 1547 } 1548 1549 return false; 1550 } 1551 } 1552 1553 // An rvalue of type bool can be converted to an rvalue of type int, 1554 // with false becoming zero and true becoming one (C++ 4.5p4). 1555 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1556 return true; 1557 } 1558 1559 return false; 1560} 1561 1562/// IsFloatingPointPromotion - Determines whether the conversion from 1563/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1564/// returns true and sets PromotedType to the promoted type. 1565bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1566 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1567 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1568 /// An rvalue of type float can be converted to an rvalue of type 1569 /// double. (C++ 4.6p1). 1570 if (FromBuiltin->getKind() == BuiltinType::Float && 1571 ToBuiltin->getKind() == BuiltinType::Double) 1572 return true; 1573 1574 // C99 6.3.1.5p1: 1575 // When a float is promoted to double or long double, or a 1576 // double is promoted to long double [...]. 1577 if (!getLangOptions().CPlusPlus && 1578 (FromBuiltin->getKind() == BuiltinType::Float || 1579 FromBuiltin->getKind() == BuiltinType::Double) && 1580 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1581 return true; 1582 1583 // Half can be promoted to float. 1584 if (FromBuiltin->getKind() == BuiltinType::Half && 1585 ToBuiltin->getKind() == BuiltinType::Float) 1586 return true; 1587 } 1588 1589 return false; 1590} 1591 1592/// \brief Determine if a conversion is a complex promotion. 1593/// 1594/// A complex promotion is defined as a complex -> complex conversion 1595/// where the conversion between the underlying real types is a 1596/// floating-point or integral promotion. 1597bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1598 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1599 if (!FromComplex) 1600 return false; 1601 1602 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1603 if (!ToComplex) 1604 return false; 1605 1606 return IsFloatingPointPromotion(FromComplex->getElementType(), 1607 ToComplex->getElementType()) || 1608 IsIntegralPromotion(0, FromComplex->getElementType(), 1609 ToComplex->getElementType()); 1610} 1611 1612/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1613/// the pointer type FromPtr to a pointer to type ToPointee, with the 1614/// same type qualifiers as FromPtr has on its pointee type. ToType, 1615/// if non-empty, will be a pointer to ToType that may or may not have 1616/// the right set of qualifiers on its pointee. 1617/// 1618static QualType 1619BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1620 QualType ToPointee, QualType ToType, 1621 ASTContext &Context, 1622 bool StripObjCLifetime = false) { 1623 assert((FromPtr->getTypeClass() == Type::Pointer || 1624 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1625 "Invalid similarly-qualified pointer type"); 1626 1627 /// Conversions to 'id' subsume cv-qualifier conversions. 1628 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1629 return ToType.getUnqualifiedType(); 1630 1631 QualType CanonFromPointee 1632 = Context.getCanonicalType(FromPtr->getPointeeType()); 1633 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1634 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1635 1636 if (StripObjCLifetime) 1637 Quals.removeObjCLifetime(); 1638 1639 // Exact qualifier match -> return the pointer type we're converting to. 1640 if (CanonToPointee.getLocalQualifiers() == Quals) { 1641 // ToType is exactly what we need. Return it. 1642 if (!ToType.isNull()) 1643 return ToType.getUnqualifiedType(); 1644 1645 // Build a pointer to ToPointee. It has the right qualifiers 1646 // already. 1647 if (isa<ObjCObjectPointerType>(ToType)) 1648 return Context.getObjCObjectPointerType(ToPointee); 1649 return Context.getPointerType(ToPointee); 1650 } 1651 1652 // Just build a canonical type that has the right qualifiers. 1653 QualType QualifiedCanonToPointee 1654 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1655 1656 if (isa<ObjCObjectPointerType>(ToType)) 1657 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1658 return Context.getPointerType(QualifiedCanonToPointee); 1659} 1660 1661static bool isNullPointerConstantForConversion(Expr *Expr, 1662 bool InOverloadResolution, 1663 ASTContext &Context) { 1664 // Handle value-dependent integral null pointer constants correctly. 1665 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1666 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1667 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1668 return !InOverloadResolution; 1669 1670 return Expr->isNullPointerConstant(Context, 1671 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1672 : Expr::NPC_ValueDependentIsNull); 1673} 1674 1675/// IsPointerConversion - Determines whether the conversion of the 1676/// expression From, which has the (possibly adjusted) type FromType, 1677/// can be converted to the type ToType via a pointer conversion (C++ 1678/// 4.10). If so, returns true and places the converted type (that 1679/// might differ from ToType in its cv-qualifiers at some level) into 1680/// ConvertedType. 1681/// 1682/// This routine also supports conversions to and from block pointers 1683/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1684/// pointers to interfaces. FIXME: Once we've determined the 1685/// appropriate overloading rules for Objective-C, we may want to 1686/// split the Objective-C checks into a different routine; however, 1687/// GCC seems to consider all of these conversions to be pointer 1688/// conversions, so for now they live here. IncompatibleObjC will be 1689/// set if the conversion is an allowed Objective-C conversion that 1690/// should result in a warning. 1691bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1692 bool InOverloadResolution, 1693 QualType& ConvertedType, 1694 bool &IncompatibleObjC) { 1695 IncompatibleObjC = false; 1696 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 1697 IncompatibleObjC)) 1698 return true; 1699 1700 // Conversion from a null pointer constant to any Objective-C pointer type. 1701 if (ToType->isObjCObjectPointerType() && 1702 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1703 ConvertedType = ToType; 1704 return true; 1705 } 1706 1707 // Blocks: Block pointers can be converted to void*. 1708 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1709 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1710 ConvertedType = ToType; 1711 return true; 1712 } 1713 // Blocks: A null pointer constant can be converted to a block 1714 // pointer type. 1715 if (ToType->isBlockPointerType() && 1716 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1717 ConvertedType = ToType; 1718 return true; 1719 } 1720 1721 // If the left-hand-side is nullptr_t, the right side can be a null 1722 // pointer constant. 1723 if (ToType->isNullPtrType() && 1724 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1725 ConvertedType = ToType; 1726 return true; 1727 } 1728 1729 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1730 if (!ToTypePtr) 1731 return false; 1732 1733 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1734 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1735 ConvertedType = ToType; 1736 return true; 1737 } 1738 1739 // Beyond this point, both types need to be pointers 1740 // , including objective-c pointers. 1741 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1742 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType() && 1743 !getLangOptions().ObjCAutoRefCount) { 1744 ConvertedType = BuildSimilarlyQualifiedPointerType( 1745 FromType->getAs<ObjCObjectPointerType>(), 1746 ToPointeeType, 1747 ToType, Context); 1748 return true; 1749 } 1750 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1751 if (!FromTypePtr) 1752 return false; 1753 1754 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1755 1756 // If the unqualified pointee types are the same, this can't be a 1757 // pointer conversion, so don't do all of the work below. 1758 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1759 return false; 1760 1761 // An rvalue of type "pointer to cv T," where T is an object type, 1762 // can be converted to an rvalue of type "pointer to cv void" (C++ 1763 // 4.10p2). 1764 if (FromPointeeType->isIncompleteOrObjectType() && 1765 ToPointeeType->isVoidType()) { 1766 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1767 ToPointeeType, 1768 ToType, Context, 1769 /*StripObjCLifetime=*/true); 1770 return true; 1771 } 1772 1773 // MSVC allows implicit function to void* type conversion. 1774 if (getLangOptions().MicrosoftExt && FromPointeeType->isFunctionType() && 1775 ToPointeeType->isVoidType()) { 1776 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1777 ToPointeeType, 1778 ToType, Context); 1779 return true; 1780 } 1781 1782 // When we're overloading in C, we allow a special kind of pointer 1783 // conversion for compatible-but-not-identical pointee types. 1784 if (!getLangOptions().CPlusPlus && 1785 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1786 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1787 ToPointeeType, 1788 ToType, Context); 1789 return true; 1790 } 1791 1792 // C++ [conv.ptr]p3: 1793 // 1794 // An rvalue of type "pointer to cv D," where D is a class type, 1795 // can be converted to an rvalue of type "pointer to cv B," where 1796 // B is a base class (clause 10) of D. If B is an inaccessible 1797 // (clause 11) or ambiguous (10.2) base class of D, a program that 1798 // necessitates this conversion is ill-formed. The result of the 1799 // conversion is a pointer to the base class sub-object of the 1800 // derived class object. The null pointer value is converted to 1801 // the null pointer value of the destination type. 1802 // 1803 // Note that we do not check for ambiguity or inaccessibility 1804 // here. That is handled by CheckPointerConversion. 1805 if (getLangOptions().CPlusPlus && 1806 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1807 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1808 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1809 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1810 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1811 ToPointeeType, 1812 ToType, Context); 1813 return true; 1814 } 1815 1816 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() && 1817 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) { 1818 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1819 ToPointeeType, 1820 ToType, Context); 1821 return true; 1822 } 1823 1824 return false; 1825} 1826 1827/// \brief Adopt the given qualifiers for the given type. 1828static QualType AdoptQualifiers(ASTContext &Context, QualType T, Qualifiers Qs){ 1829 Qualifiers TQs = T.getQualifiers(); 1830 1831 // Check whether qualifiers already match. 1832 if (TQs == Qs) 1833 return T; 1834 1835 if (Qs.compatiblyIncludes(TQs)) 1836 return Context.getQualifiedType(T, Qs); 1837 1838 return Context.getQualifiedType(T.getUnqualifiedType(), Qs); 1839} 1840 1841/// isObjCPointerConversion - Determines whether this is an 1842/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1843/// with the same arguments and return values. 1844bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1845 QualType& ConvertedType, 1846 bool &IncompatibleObjC) { 1847 if (!getLangOptions().ObjC1) 1848 return false; 1849 1850 // The set of qualifiers on the type we're converting from. 1851 Qualifiers FromQualifiers = FromType.getQualifiers(); 1852 1853 // First, we handle all conversions on ObjC object pointer types. 1854 const ObjCObjectPointerType* ToObjCPtr = 1855 ToType->getAs<ObjCObjectPointerType>(); 1856 const ObjCObjectPointerType *FromObjCPtr = 1857 FromType->getAs<ObjCObjectPointerType>(); 1858 1859 if (ToObjCPtr && FromObjCPtr) { 1860 // If the pointee types are the same (ignoring qualifications), 1861 // then this is not a pointer conversion. 1862 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 1863 FromObjCPtr->getPointeeType())) 1864 return false; 1865 1866 // Check for compatible 1867 // Objective C++: We're able to convert between "id" or "Class" and a 1868 // pointer to any interface (in both directions). 1869 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1870 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1871 return true; 1872 } 1873 // Conversions with Objective-C's id<...>. 1874 if ((FromObjCPtr->isObjCQualifiedIdType() || 1875 ToObjCPtr->isObjCQualifiedIdType()) && 1876 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1877 /*compare=*/false)) { 1878 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1879 return true; 1880 } 1881 // Objective C++: We're able to convert from a pointer to an 1882 // interface to a pointer to a different interface. 1883 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1884 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1885 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1886 if (getLangOptions().CPlusPlus && LHS && RHS && 1887 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1888 FromObjCPtr->getPointeeType())) 1889 return false; 1890 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1891 ToObjCPtr->getPointeeType(), 1892 ToType, Context); 1893 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 1894 return true; 1895 } 1896 1897 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1898 // Okay: this is some kind of implicit downcast of Objective-C 1899 // interfaces, which is permitted. However, we're going to 1900 // complain about it. 1901 IncompatibleObjC = true; 1902 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1903 ToObjCPtr->getPointeeType(), 1904 ToType, Context); 1905 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 1906 return true; 1907 } 1908 } 1909 // Beyond this point, both types need to be C pointers or block pointers. 1910 QualType ToPointeeType; 1911 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1912 ToPointeeType = ToCPtr->getPointeeType(); 1913 else if (const BlockPointerType *ToBlockPtr = 1914 ToType->getAs<BlockPointerType>()) { 1915 // Objective C++: We're able to convert from a pointer to any object 1916 // to a block pointer type. 1917 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1918 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1919 return true; 1920 } 1921 ToPointeeType = ToBlockPtr->getPointeeType(); 1922 } 1923 else if (FromType->getAs<BlockPointerType>() && 1924 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1925 // Objective C++: We're able to convert from a block pointer type to a 1926 // pointer to any object. 1927 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 1928 return true; 1929 } 1930 else 1931 return false; 1932 1933 QualType FromPointeeType; 1934 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1935 FromPointeeType = FromCPtr->getPointeeType(); 1936 else if (const BlockPointerType *FromBlockPtr = 1937 FromType->getAs<BlockPointerType>()) 1938 FromPointeeType = FromBlockPtr->getPointeeType(); 1939 else 1940 return false; 1941 1942 // If we have pointers to pointers, recursively check whether this 1943 // is an Objective-C conversion. 1944 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1945 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1946 IncompatibleObjC)) { 1947 // We always complain about this conversion. 1948 IncompatibleObjC = true; 1949 ConvertedType = Context.getPointerType(ConvertedType); 1950 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 1951 return true; 1952 } 1953 // Allow conversion of pointee being objective-c pointer to another one; 1954 // as in I* to id. 1955 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1956 ToPointeeType->getAs<ObjCObjectPointerType>() && 1957 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1958 IncompatibleObjC)) { 1959 1960 ConvertedType = Context.getPointerType(ConvertedType); 1961 ConvertedType = AdoptQualifiers(Context, ConvertedType, FromQualifiers); 1962 return true; 1963 } 1964 1965 // If we have pointers to functions or blocks, check whether the only 1966 // differences in the argument and result types are in Objective-C 1967 // pointer conversions. If so, we permit the conversion (but 1968 // complain about it). 1969 const FunctionProtoType *FromFunctionType 1970 = FromPointeeType->getAs<FunctionProtoType>(); 1971 const FunctionProtoType *ToFunctionType 1972 = ToPointeeType->getAs<FunctionProtoType>(); 1973 if (FromFunctionType && ToFunctionType) { 1974 // If the function types are exactly the same, this isn't an 1975 // Objective-C pointer conversion. 1976 if (Context.getCanonicalType(FromPointeeType) 1977 == Context.getCanonicalType(ToPointeeType)) 1978 return false; 1979 1980 // Perform the quick checks that will tell us whether these 1981 // function types are obviously different. 1982 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1983 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1984 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1985 return false; 1986 1987 bool HasObjCConversion = false; 1988 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1989 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1990 // Okay, the types match exactly. Nothing to do. 1991 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1992 ToFunctionType->getResultType(), 1993 ConvertedType, IncompatibleObjC)) { 1994 // Okay, we have an Objective-C pointer conversion. 1995 HasObjCConversion = true; 1996 } else { 1997 // Function types are too different. Abort. 1998 return false; 1999 } 2000 2001 // Check argument types. 2002 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 2003 ArgIdx != NumArgs; ++ArgIdx) { 2004 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 2005 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 2006 if (Context.getCanonicalType(FromArgType) 2007 == Context.getCanonicalType(ToArgType)) { 2008 // Okay, the types match exactly. Nothing to do. 2009 } else if (isObjCPointerConversion(FromArgType, ToArgType, 2010 ConvertedType, IncompatibleObjC)) { 2011 // Okay, we have an Objective-C pointer conversion. 2012 HasObjCConversion = true; 2013 } else { 2014 // Argument types are too different. Abort. 2015 return false; 2016 } 2017 } 2018 2019 if (HasObjCConversion) { 2020 // We had an Objective-C conversion. Allow this pointer 2021 // conversion, but complain about it. 2022 ConvertedType = AdoptQualifiers(Context, ToType, FromQualifiers); 2023 IncompatibleObjC = true; 2024 return true; 2025 } 2026 } 2027 2028 return false; 2029} 2030 2031/// \brief Determine whether this is an Objective-C writeback conversion, 2032/// used for parameter passing when performing automatic reference counting. 2033/// 2034/// \param FromType The type we're converting form. 2035/// 2036/// \param ToType The type we're converting to. 2037/// 2038/// \param ConvertedType The type that will be produced after applying 2039/// this conversion. 2040bool Sema::isObjCWritebackConversion(QualType FromType, QualType ToType, 2041 QualType &ConvertedType) { 2042 if (!getLangOptions().ObjCAutoRefCount || 2043 Context.hasSameUnqualifiedType(FromType, ToType)) 2044 return false; 2045 2046 // Parameter must be a pointer to __autoreleasing (with no other qualifiers). 2047 QualType ToPointee; 2048 if (const PointerType *ToPointer = ToType->getAs<PointerType>()) 2049 ToPointee = ToPointer->getPointeeType(); 2050 else 2051 return false; 2052 2053 Qualifiers ToQuals = ToPointee.getQualifiers(); 2054 if (!ToPointee->isObjCLifetimeType() || 2055 ToQuals.getObjCLifetime() != Qualifiers::OCL_Autoreleasing || 2056 !ToQuals.withoutObjCGLifetime().empty()) 2057 return false; 2058 2059 // Argument must be a pointer to __strong to __weak. 2060 QualType FromPointee; 2061 if (const PointerType *FromPointer = FromType->getAs<PointerType>()) 2062 FromPointee = FromPointer->getPointeeType(); 2063 else 2064 return false; 2065 2066 Qualifiers FromQuals = FromPointee.getQualifiers(); 2067 if (!FromPointee->isObjCLifetimeType() || 2068 (FromQuals.getObjCLifetime() != Qualifiers::OCL_Strong && 2069 FromQuals.getObjCLifetime() != Qualifiers::OCL_Weak)) 2070 return false; 2071 2072 // Make sure that we have compatible qualifiers. 2073 FromQuals.setObjCLifetime(Qualifiers::OCL_Autoreleasing); 2074 if (!ToQuals.compatiblyIncludes(FromQuals)) 2075 return false; 2076 2077 // Remove qualifiers from the pointee type we're converting from; they 2078 // aren't used in the compatibility check belong, and we'll be adding back 2079 // qualifiers (with __autoreleasing) if the compatibility check succeeds. 2080 FromPointee = FromPointee.getUnqualifiedType(); 2081 2082 // The unqualified form of the pointee types must be compatible. 2083 ToPointee = ToPointee.getUnqualifiedType(); 2084 bool IncompatibleObjC; 2085 if (Context.typesAreCompatible(FromPointee, ToPointee)) 2086 FromPointee = ToPointee; 2087 else if (!isObjCPointerConversion(FromPointee, ToPointee, FromPointee, 2088 IncompatibleObjC)) 2089 return false; 2090 2091 /// \brief Construct the type we're converting to, which is a pointer to 2092 /// __autoreleasing pointee. 2093 FromPointee = Context.getQualifiedType(FromPointee, FromQuals); 2094 ConvertedType = Context.getPointerType(FromPointee); 2095 return true; 2096} 2097 2098bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, 2099 QualType& ConvertedType) { 2100 QualType ToPointeeType; 2101 if (const BlockPointerType *ToBlockPtr = 2102 ToType->getAs<BlockPointerType>()) 2103 ToPointeeType = ToBlockPtr->getPointeeType(); 2104 else 2105 return false; 2106 2107 QualType FromPointeeType; 2108 if (const BlockPointerType *FromBlockPtr = 2109 FromType->getAs<BlockPointerType>()) 2110 FromPointeeType = FromBlockPtr->getPointeeType(); 2111 else 2112 return false; 2113 // We have pointer to blocks, check whether the only 2114 // differences in the argument and result types are in Objective-C 2115 // pointer conversions. If so, we permit the conversion. 2116 2117 const FunctionProtoType *FromFunctionType 2118 = FromPointeeType->getAs<FunctionProtoType>(); 2119 const FunctionProtoType *ToFunctionType 2120 = ToPointeeType->getAs<FunctionProtoType>(); 2121 2122 if (!FromFunctionType || !ToFunctionType) 2123 return false; 2124 2125 if (Context.hasSameType(FromPointeeType, ToPointeeType)) 2126 return true; 2127 2128 // Perform the quick checks that will tell us whether these 2129 // function types are obviously different. 2130 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 2131 FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) 2132 return false; 2133 2134 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); 2135 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); 2136 if (FromEInfo != ToEInfo) 2137 return false; 2138 2139 bool IncompatibleObjC = false; 2140 if (Context.hasSameType(FromFunctionType->getResultType(), 2141 ToFunctionType->getResultType())) { 2142 // Okay, the types match exactly. Nothing to do. 2143 } else { 2144 QualType RHS = FromFunctionType->getResultType(); 2145 QualType LHS = ToFunctionType->getResultType(); 2146 if ((!getLangOptions().CPlusPlus || !RHS->isRecordType()) && 2147 !RHS.hasQualifiers() && LHS.hasQualifiers()) 2148 LHS = LHS.getUnqualifiedType(); 2149 2150 if (Context.hasSameType(RHS,LHS)) { 2151 // OK exact match. 2152 } else if (isObjCPointerConversion(RHS, LHS, 2153 ConvertedType, IncompatibleObjC)) { 2154 if (IncompatibleObjC) 2155 return false; 2156 // Okay, we have an Objective-C pointer conversion. 2157 } 2158 else 2159 return false; 2160 } 2161 2162 // Check argument types. 2163 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 2164 ArgIdx != NumArgs; ++ArgIdx) { 2165 IncompatibleObjC = false; 2166 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 2167 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 2168 if (Context.hasSameType(FromArgType, ToArgType)) { 2169 // Okay, the types match exactly. Nothing to do. 2170 } else if (isObjCPointerConversion(ToArgType, FromArgType, 2171 ConvertedType, IncompatibleObjC)) { 2172 if (IncompatibleObjC) 2173 return false; 2174 // Okay, we have an Objective-C pointer conversion. 2175 } else 2176 // Argument types are too different. Abort. 2177 return false; 2178 } 2179 if (LangOpts.ObjCAutoRefCount && 2180 !Context.FunctionTypesMatchOnNSConsumedAttrs(FromFunctionType, 2181 ToFunctionType)) 2182 return false; 2183 2184 ConvertedType = ToType; 2185 return true; 2186} 2187 2188enum { 2189 ft_default, 2190 ft_different_class, 2191 ft_parameter_arity, 2192 ft_parameter_mismatch, 2193 ft_return_type, 2194 ft_qualifer_mismatch 2195}; 2196 2197/// HandleFunctionTypeMismatch - Gives diagnostic information for differeing 2198/// function types. Catches different number of parameter, mismatch in 2199/// parameter types, and different return types. 2200void Sema::HandleFunctionTypeMismatch(PartialDiagnostic &PDiag, 2201 QualType FromType, QualType ToType) { 2202 // If either type is not valid, include no extra info. 2203 if (FromType.isNull() || ToType.isNull()) { 2204 PDiag << ft_default; 2205 return; 2206 } 2207 2208 // Get the function type from the pointers. 2209 if (FromType->isMemberPointerType() && ToType->isMemberPointerType()) { 2210 const MemberPointerType *FromMember = FromType->getAs<MemberPointerType>(), 2211 *ToMember = ToType->getAs<MemberPointerType>(); 2212 if (FromMember->getClass() != ToMember->getClass()) { 2213 PDiag << ft_different_class << QualType(ToMember->getClass(), 0) 2214 << QualType(FromMember->getClass(), 0); 2215 return; 2216 } 2217 FromType = FromMember->getPointeeType(); 2218 ToType = ToMember->getPointeeType(); 2219 } 2220 2221 if (FromType->isPointerType()) 2222 FromType = FromType->getPointeeType(); 2223 if (ToType->isPointerType()) 2224 ToType = ToType->getPointeeType(); 2225 2226 // Remove references. 2227 FromType = FromType.getNonReferenceType(); 2228 ToType = ToType.getNonReferenceType(); 2229 2230 // Don't print extra info for non-specialized template functions. 2231 if (FromType->isInstantiationDependentType() && 2232 !FromType->getAs<TemplateSpecializationType>()) { 2233 PDiag << ft_default; 2234 return; 2235 } 2236 2237 // No extra info for same types. 2238 if (Context.hasSameType(FromType, ToType)) { 2239 PDiag << ft_default; 2240 return; 2241 } 2242 2243 const FunctionProtoType *FromFunction = FromType->getAs<FunctionProtoType>(), 2244 *ToFunction = ToType->getAs<FunctionProtoType>(); 2245 2246 // Both types need to be function types. 2247 if (!FromFunction || !ToFunction) { 2248 PDiag << ft_default; 2249 return; 2250 } 2251 2252 if (FromFunction->getNumArgs() != ToFunction->getNumArgs()) { 2253 PDiag << ft_parameter_arity << ToFunction->getNumArgs() 2254 << FromFunction->getNumArgs(); 2255 return; 2256 } 2257 2258 // Handle different parameter types. 2259 unsigned ArgPos; 2260 if (!FunctionArgTypesAreEqual(FromFunction, ToFunction, &ArgPos)) { 2261 PDiag << ft_parameter_mismatch << ArgPos + 1 2262 << ToFunction->getArgType(ArgPos) 2263 << FromFunction->getArgType(ArgPos); 2264 return; 2265 } 2266 2267 // Handle different return type. 2268 if (!Context.hasSameType(FromFunction->getResultType(), 2269 ToFunction->getResultType())) { 2270 PDiag << ft_return_type << ToFunction->getResultType() 2271 << FromFunction->getResultType(); 2272 return; 2273 } 2274 2275 unsigned FromQuals = FromFunction->getTypeQuals(), 2276 ToQuals = ToFunction->getTypeQuals(); 2277 if (FromQuals != ToQuals) { 2278 PDiag << ft_qualifer_mismatch << ToQuals << FromQuals; 2279 return; 2280 } 2281 2282 // Unable to find a difference, so add no extra info. 2283 PDiag << ft_default; 2284} 2285 2286/// FunctionArgTypesAreEqual - This routine checks two function proto types 2287/// for equality of their argument types. Caller has already checked that 2288/// they have same number of arguments. This routine assumes that Objective-C 2289/// pointer types which only differ in their protocol qualifiers are equal. 2290/// If the parameters are different, ArgPos will have the the parameter index 2291/// of the first different parameter. 2292bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, 2293 const FunctionProtoType *NewType, 2294 unsigned *ArgPos) { 2295 if (!getLangOptions().ObjC1) { 2296 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 2297 N = NewType->arg_type_begin(), 2298 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 2299 if (!Context.hasSameType(*O, *N)) { 2300 if (ArgPos) *ArgPos = O - OldType->arg_type_begin(); 2301 return false; 2302 } 2303 } 2304 return true; 2305 } 2306 2307 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 2308 N = NewType->arg_type_begin(), 2309 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 2310 QualType ToType = (*O); 2311 QualType FromType = (*N); 2312 if (!Context.hasSameType(ToType, FromType)) { 2313 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 2314 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 2315 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 2316 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 2317 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 2318 PTFr->getPointeeType()->isObjCQualifiedClassType())) 2319 continue; 2320 } 2321 else if (const ObjCObjectPointerType *PTTo = 2322 ToType->getAs<ObjCObjectPointerType>()) { 2323 if (const ObjCObjectPointerType *PTFr = 2324 FromType->getAs<ObjCObjectPointerType>()) 2325 if (Context.hasSameUnqualifiedType( 2326 PTTo->getObjectType()->getBaseType(), 2327 PTFr->getObjectType()->getBaseType())) 2328 continue; 2329 } 2330 if (ArgPos) *ArgPos = O - OldType->arg_type_begin(); 2331 return false; 2332 } 2333 } 2334 return true; 2335} 2336 2337/// CheckPointerConversion - Check the pointer conversion from the 2338/// expression From to the type ToType. This routine checks for 2339/// ambiguous or inaccessible derived-to-base pointer 2340/// conversions for which IsPointerConversion has already returned 2341/// true. It returns true and produces a diagnostic if there was an 2342/// error, or returns false otherwise. 2343bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 2344 CastKind &Kind, 2345 CXXCastPath& BasePath, 2346 bool IgnoreBaseAccess) { 2347 QualType FromType = From->getType(); 2348 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 2349 2350 Kind = CK_BitCast; 2351 2352 if (!IsCStyleOrFunctionalCast && 2353 Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy) && 2354 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 2355 DiagRuntimeBehavior(From->getExprLoc(), From, 2356 PDiag(diag::warn_impcast_bool_to_null_pointer) 2357 << ToType << From->getSourceRange()); 2358 2359 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 2360 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) { 2361 QualType FromPointeeType = FromPtrType->getPointeeType(), 2362 ToPointeeType = ToPtrType->getPointeeType(); 2363 2364 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 2365 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 2366 // We must have a derived-to-base conversion. Check an 2367 // ambiguous or inaccessible conversion. 2368 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 2369 From->getExprLoc(), 2370 From->getSourceRange(), &BasePath, 2371 IgnoreBaseAccess)) 2372 return true; 2373 2374 // The conversion was successful. 2375 Kind = CK_DerivedToBase; 2376 } 2377 } 2378 } else if (const ObjCObjectPointerType *ToPtrType = 2379 ToType->getAs<ObjCObjectPointerType>()) { 2380 if (const ObjCObjectPointerType *FromPtrType = 2381 FromType->getAs<ObjCObjectPointerType>()) { 2382 // Objective-C++ conversions are always okay. 2383 // FIXME: We should have a different class of conversions for the 2384 // Objective-C++ implicit conversions. 2385 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 2386 return false; 2387 } else if (FromType->isBlockPointerType()) { 2388 Kind = CK_BlockPointerToObjCPointerCast; 2389 } else { 2390 Kind = CK_CPointerToObjCPointerCast; 2391 } 2392 } else if (ToType->isBlockPointerType()) { 2393 if (!FromType->isBlockPointerType()) 2394 Kind = CK_AnyPointerToBlockPointerCast; 2395 } 2396 2397 // We shouldn't fall into this case unless it's valid for other 2398 // reasons. 2399 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 2400 Kind = CK_NullToPointer; 2401 2402 return false; 2403} 2404 2405/// IsMemberPointerConversion - Determines whether the conversion of the 2406/// expression From, which has the (possibly adjusted) type FromType, can be 2407/// converted to the type ToType via a member pointer conversion (C++ 4.11). 2408/// If so, returns true and places the converted type (that might differ from 2409/// ToType in its cv-qualifiers at some level) into ConvertedType. 2410bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 2411 QualType ToType, 2412 bool InOverloadResolution, 2413 QualType &ConvertedType) { 2414 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 2415 if (!ToTypePtr) 2416 return false; 2417 2418 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 2419 if (From->isNullPointerConstant(Context, 2420 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 2421 : Expr::NPC_ValueDependentIsNull)) { 2422 ConvertedType = ToType; 2423 return true; 2424 } 2425 2426 // Otherwise, both types have to be member pointers. 2427 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 2428 if (!FromTypePtr) 2429 return false; 2430 2431 // A pointer to member of B can be converted to a pointer to member of D, 2432 // where D is derived from B (C++ 4.11p2). 2433 QualType FromClass(FromTypePtr->getClass(), 0); 2434 QualType ToClass(ToTypePtr->getClass(), 0); 2435 2436 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && 2437 !RequireCompleteType(From->getLocStart(), ToClass, PDiag()) && 2438 IsDerivedFrom(ToClass, FromClass)) { 2439 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 2440 ToClass.getTypePtr()); 2441 return true; 2442 } 2443 2444 return false; 2445} 2446 2447/// CheckMemberPointerConversion - Check the member pointer conversion from the 2448/// expression From to the type ToType. This routine checks for ambiguous or 2449/// virtual or inaccessible base-to-derived member pointer conversions 2450/// for which IsMemberPointerConversion has already returned true. It returns 2451/// true and produces a diagnostic if there was an error, or returns false 2452/// otherwise. 2453bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 2454 CastKind &Kind, 2455 CXXCastPath &BasePath, 2456 bool IgnoreBaseAccess) { 2457 QualType FromType = From->getType(); 2458 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 2459 if (!FromPtrType) { 2460 // This must be a null pointer to member pointer conversion 2461 assert(From->isNullPointerConstant(Context, 2462 Expr::NPC_ValueDependentIsNull) && 2463 "Expr must be null pointer constant!"); 2464 Kind = CK_NullToMemberPointer; 2465 return false; 2466 } 2467 2468 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 2469 assert(ToPtrType && "No member pointer cast has a target type " 2470 "that is not a member pointer."); 2471 2472 QualType FromClass = QualType(FromPtrType->getClass(), 0); 2473 QualType ToClass = QualType(ToPtrType->getClass(), 0); 2474 2475 // FIXME: What about dependent types? 2476 assert(FromClass->isRecordType() && "Pointer into non-class."); 2477 assert(ToClass->isRecordType() && "Pointer into non-class."); 2478 2479 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 2480 /*DetectVirtual=*/true); 2481 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 2482 assert(DerivationOkay && 2483 "Should not have been called if derivation isn't OK."); 2484 (void)DerivationOkay; 2485 2486 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 2487 getUnqualifiedType())) { 2488 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 2489 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 2490 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 2491 return true; 2492 } 2493 2494 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 2495 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 2496 << FromClass << ToClass << QualType(VBase, 0) 2497 << From->getSourceRange(); 2498 return true; 2499 } 2500 2501 if (!IgnoreBaseAccess) 2502 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 2503 Paths.front(), 2504 diag::err_downcast_from_inaccessible_base); 2505 2506 // Must be a base to derived member conversion. 2507 BuildBasePathArray(Paths, BasePath); 2508 Kind = CK_BaseToDerivedMemberPointer; 2509 return false; 2510} 2511 2512/// IsQualificationConversion - Determines whether the conversion from 2513/// an rvalue of type FromType to ToType is a qualification conversion 2514/// (C++ 4.4). 2515/// 2516/// \param ObjCLifetimeConversion Output parameter that will be set to indicate 2517/// when the qualification conversion involves a change in the Objective-C 2518/// object lifetime. 2519bool 2520Sema::IsQualificationConversion(QualType FromType, QualType ToType, 2521 bool CStyle, bool &ObjCLifetimeConversion) { 2522 FromType = Context.getCanonicalType(FromType); 2523 ToType = Context.getCanonicalType(ToType); 2524 ObjCLifetimeConversion = false; 2525 2526 // If FromType and ToType are the same type, this is not a 2527 // qualification conversion. 2528 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 2529 return false; 2530 2531 // (C++ 4.4p4): 2532 // A conversion can add cv-qualifiers at levels other than the first 2533 // in multi-level pointers, subject to the following rules: [...] 2534 bool PreviousToQualsIncludeConst = true; 2535 bool UnwrappedAnyPointer = false; 2536 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 2537 // Within each iteration of the loop, we check the qualifiers to 2538 // determine if this still looks like a qualification 2539 // conversion. Then, if all is well, we unwrap one more level of 2540 // pointers or pointers-to-members and do it all again 2541 // until there are no more pointers or pointers-to-members left to 2542 // unwrap. 2543 UnwrappedAnyPointer = true; 2544 2545 Qualifiers FromQuals = FromType.getQualifiers(); 2546 Qualifiers ToQuals = ToType.getQualifiers(); 2547 2548 // Objective-C ARC: 2549 // Check Objective-C lifetime conversions. 2550 if (FromQuals.getObjCLifetime() != ToQuals.getObjCLifetime() && 2551 UnwrappedAnyPointer) { 2552 if (ToQuals.compatiblyIncludesObjCLifetime(FromQuals)) { 2553 ObjCLifetimeConversion = true; 2554 FromQuals.removeObjCLifetime(); 2555 ToQuals.removeObjCLifetime(); 2556 } else { 2557 // Qualification conversions cannot cast between different 2558 // Objective-C lifetime qualifiers. 2559 return false; 2560 } 2561 } 2562 2563 // Allow addition/removal of GC attributes but not changing GC attributes. 2564 if (FromQuals.getObjCGCAttr() != ToQuals.getObjCGCAttr() && 2565 (!FromQuals.hasObjCGCAttr() || !ToQuals.hasObjCGCAttr())) { 2566 FromQuals.removeObjCGCAttr(); 2567 ToQuals.removeObjCGCAttr(); 2568 } 2569 2570 // -- for every j > 0, if const is in cv 1,j then const is in cv 2571 // 2,j, and similarly for volatile. 2572 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals)) 2573 return false; 2574 2575 // -- if the cv 1,j and cv 2,j are different, then const is in 2576 // every cv for 0 < k < j. 2577 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers() 2578 && !PreviousToQualsIncludeConst) 2579 return false; 2580 2581 // Keep track of whether all prior cv-qualifiers in the "to" type 2582 // include const. 2583 PreviousToQualsIncludeConst 2584 = PreviousToQualsIncludeConst && ToQuals.hasConst(); 2585 } 2586 2587 // We are left with FromType and ToType being the pointee types 2588 // after unwrapping the original FromType and ToType the same number 2589 // of types. If we unwrapped any pointers, and if FromType and 2590 // ToType have the same unqualified type (since we checked 2591 // qualifiers above), then this is a qualification conversion. 2592 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2593} 2594 2595/// Determines whether there is a user-defined conversion sequence 2596/// (C++ [over.ics.user]) that converts expression From to the type 2597/// ToType. If such a conversion exists, User will contain the 2598/// user-defined conversion sequence that performs such a conversion 2599/// and this routine will return true. Otherwise, this routine returns 2600/// false and User is unspecified. 2601/// 2602/// \param AllowExplicit true if the conversion should consider C++0x 2603/// "explicit" conversion functions as well as non-explicit conversion 2604/// functions (C++0x [class.conv.fct]p2). 2605static OverloadingResult 2606IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 2607 UserDefinedConversionSequence& User, 2608 OverloadCandidateSet& CandidateSet, 2609 bool AllowExplicit) { 2610 // Whether we will only visit constructors. 2611 bool ConstructorsOnly = false; 2612 2613 // If the type we are conversion to is a class type, enumerate its 2614 // constructors. 2615 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 2616 // C++ [over.match.ctor]p1: 2617 // When objects of class type are direct-initialized (8.5), or 2618 // copy-initialized from an expression of the same or a 2619 // derived class type (8.5), overload resolution selects the 2620 // constructor. [...] For copy-initialization, the candidate 2621 // functions are all the converting constructors (12.3.1) of 2622 // that class. The argument list is the expression-list within 2623 // the parentheses of the initializer. 2624 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 2625 (From->getType()->getAs<RecordType>() && 2626 S.IsDerivedFrom(From->getType(), ToType))) 2627 ConstructorsOnly = true; 2628 2629 S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag()); 2630 // RequireCompleteType may have returned true due to some invalid decl 2631 // during template instantiation, but ToType may be complete enough now 2632 // to try to recover. 2633 if (ToType->isIncompleteType()) { 2634 // We're not going to find any constructors. 2635 } else if (CXXRecordDecl *ToRecordDecl 2636 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 2637 2638 Expr **Args = &From; 2639 unsigned NumArgs = 1; 2640 bool ListInitializing = false; 2641 // If we're list-initializing, we pass the individual elements as 2642 // arguments, not the entire list. 2643 if (InitListExpr *InitList = dyn_cast<InitListExpr>(From)) { 2644 Args = InitList->getInits(); 2645 NumArgs = InitList->getNumInits(); 2646 ListInitializing = true; 2647 } 2648 2649 DeclContext::lookup_iterator Con, ConEnd; 2650 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 2651 Con != ConEnd; ++Con) { 2652 NamedDecl *D = *Con; 2653 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2654 2655 // Find the constructor (which may be a template). 2656 CXXConstructorDecl *Constructor = 0; 2657 FunctionTemplateDecl *ConstructorTmpl 2658 = dyn_cast<FunctionTemplateDecl>(D); 2659 if (ConstructorTmpl) 2660 Constructor 2661 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2662 else 2663 Constructor = cast<CXXConstructorDecl>(D); 2664 2665 bool Usable = !Constructor->isInvalidDecl(); 2666 if (ListInitializing) 2667 Usable = Usable && (AllowExplicit || !Constructor->isExplicit()); 2668 else 2669 Usable = Usable &&Constructor->isConvertingConstructor(AllowExplicit); 2670 if (Usable) { 2671 if (ConstructorTmpl) 2672 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2673 /*ExplicitArgs*/ 0, 2674 Args, NumArgs, CandidateSet, 2675 /*SuppressUserConversions=*/ 2676 !ConstructorsOnly && 2677 !ListInitializing); 2678 else 2679 // Allow one user-defined conversion when user specifies a 2680 // From->ToType conversion via an static cast (c-style, etc). 2681 S.AddOverloadCandidate(Constructor, FoundDecl, 2682 Args, NumArgs, CandidateSet, 2683 /*SuppressUserConversions=*/ 2684 !ConstructorsOnly && !ListInitializing); 2685 } 2686 } 2687 } 2688 } 2689 2690 // Enumerate conversion functions, if we're allowed to. 2691 if (ConstructorsOnly || isa<InitListExpr>(From)) { 2692 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 2693 S.PDiag(0) << From->getSourceRange())) { 2694 // No conversion functions from incomplete types. 2695 } else if (const RecordType *FromRecordType 2696 = From->getType()->getAs<RecordType>()) { 2697 if (CXXRecordDecl *FromRecordDecl 2698 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 2699 // Add all of the conversion functions as candidates. 2700 const UnresolvedSetImpl *Conversions 2701 = FromRecordDecl->getVisibleConversionFunctions(); 2702 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2703 E = Conversions->end(); I != E; ++I) { 2704 DeclAccessPair FoundDecl = I.getPair(); 2705 NamedDecl *D = FoundDecl.getDecl(); 2706 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 2707 if (isa<UsingShadowDecl>(D)) 2708 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2709 2710 CXXConversionDecl *Conv; 2711 FunctionTemplateDecl *ConvTemplate; 2712 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 2713 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2714 else 2715 Conv = cast<CXXConversionDecl>(D); 2716 2717 if (AllowExplicit || !Conv->isExplicit()) { 2718 if (ConvTemplate) 2719 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 2720 ActingContext, From, ToType, 2721 CandidateSet); 2722 else 2723 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 2724 From, ToType, CandidateSet); 2725 } 2726 } 2727 } 2728 } 2729 2730 bool HadMultipleCandidates = (CandidateSet.size() > 1); 2731 2732 OverloadCandidateSet::iterator Best; 2733 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2734 case OR_Success: 2735 // Record the standard conversion we used and the conversion function. 2736 if (CXXConstructorDecl *Constructor 2737 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 2738 S.MarkDeclarationReferenced(From->getLocStart(), Constructor); 2739 2740 // C++ [over.ics.user]p1: 2741 // If the user-defined conversion is specified by a 2742 // constructor (12.3.1), the initial standard conversion 2743 // sequence converts the source type to the type required by 2744 // the argument of the constructor. 2745 // 2746 QualType ThisType = Constructor->getThisType(S.Context); 2747 if (isa<InitListExpr>(From)) { 2748 // Initializer lists don't have conversions as such. 2749 User.Before.setAsIdentityConversion(); 2750 } else { 2751 if (Best->Conversions[0].isEllipsis()) 2752 User.EllipsisConversion = true; 2753 else { 2754 User.Before = Best->Conversions[0].Standard; 2755 User.EllipsisConversion = false; 2756 } 2757 } 2758 User.HadMultipleCandidates = HadMultipleCandidates; 2759 User.ConversionFunction = Constructor; 2760 User.FoundConversionFunction = Best->FoundDecl; 2761 User.After.setAsIdentityConversion(); 2762 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2763 User.After.setAllToTypes(ToType); 2764 return OR_Success; 2765 } 2766 if (CXXConversionDecl *Conversion 2767 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2768 S.MarkDeclarationReferenced(From->getLocStart(), Conversion); 2769 2770 // C++ [over.ics.user]p1: 2771 // 2772 // [...] If the user-defined conversion is specified by a 2773 // conversion function (12.3.2), the initial standard 2774 // conversion sequence converts the source type to the 2775 // implicit object parameter of the conversion function. 2776 User.Before = Best->Conversions[0].Standard; 2777 User.HadMultipleCandidates = HadMultipleCandidates; 2778 User.ConversionFunction = Conversion; 2779 User.FoundConversionFunction = Best->FoundDecl; 2780 User.EllipsisConversion = false; 2781 2782 // C++ [over.ics.user]p2: 2783 // The second standard conversion sequence converts the 2784 // result of the user-defined conversion to the target type 2785 // for the sequence. Since an implicit conversion sequence 2786 // is an initialization, the special rules for 2787 // initialization by user-defined conversion apply when 2788 // selecting the best user-defined conversion for a 2789 // user-defined conversion sequence (see 13.3.3 and 2790 // 13.3.3.1). 2791 User.After = Best->FinalConversion; 2792 return OR_Success; 2793 } 2794 llvm_unreachable("Not a constructor or conversion function?"); 2795 2796 case OR_No_Viable_Function: 2797 return OR_No_Viable_Function; 2798 case OR_Deleted: 2799 // No conversion here! We're done. 2800 return OR_Deleted; 2801 2802 case OR_Ambiguous: 2803 return OR_Ambiguous; 2804 } 2805 2806 llvm_unreachable("Invalid OverloadResult!"); 2807} 2808 2809bool 2810Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2811 ImplicitConversionSequence ICS; 2812 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2813 OverloadingResult OvResult = 2814 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 2815 CandidateSet, false); 2816 if (OvResult == OR_Ambiguous) 2817 Diag(From->getSourceRange().getBegin(), 2818 diag::err_typecheck_ambiguous_condition) 2819 << From->getType() << ToType << From->getSourceRange(); 2820 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2821 Diag(From->getSourceRange().getBegin(), 2822 diag::err_typecheck_nonviable_condition) 2823 << From->getType() << ToType << From->getSourceRange(); 2824 else 2825 return false; 2826 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &From, 1); 2827 return true; 2828} 2829 2830/// CompareImplicitConversionSequences - Compare two implicit 2831/// conversion sequences to determine whether one is better than the 2832/// other or if they are indistinguishable (C++ 13.3.3.2). 2833static ImplicitConversionSequence::CompareKind 2834CompareImplicitConversionSequences(Sema &S, 2835 const ImplicitConversionSequence& ICS1, 2836 const ImplicitConversionSequence& ICS2) 2837{ 2838 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2839 // conversion sequences (as defined in 13.3.3.1) 2840 // -- a standard conversion sequence (13.3.3.1.1) is a better 2841 // conversion sequence than a user-defined conversion sequence or 2842 // an ellipsis conversion sequence, and 2843 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2844 // conversion sequence than an ellipsis conversion sequence 2845 // (13.3.3.1.3). 2846 // 2847 // C++0x [over.best.ics]p10: 2848 // For the purpose of ranking implicit conversion sequences as 2849 // described in 13.3.3.2, the ambiguous conversion sequence is 2850 // treated as a user-defined sequence that is indistinguishable 2851 // from any other user-defined conversion sequence. 2852 if (ICS1.getKindRank() < ICS2.getKindRank()) 2853 return ImplicitConversionSequence::Better; 2854 if (ICS2.getKindRank() < ICS1.getKindRank()) 2855 return ImplicitConversionSequence::Worse; 2856 2857 // The following checks require both conversion sequences to be of 2858 // the same kind. 2859 if (ICS1.getKind() != ICS2.getKind()) 2860 return ImplicitConversionSequence::Indistinguishable; 2861 2862 ImplicitConversionSequence::CompareKind Result = 2863 ImplicitConversionSequence::Indistinguishable; 2864 2865 // Two implicit conversion sequences of the same form are 2866 // indistinguishable conversion sequences unless one of the 2867 // following rules apply: (C++ 13.3.3.2p3): 2868 if (ICS1.isStandard()) 2869 Result = CompareStandardConversionSequences(S, 2870 ICS1.Standard, ICS2.Standard); 2871 else if (ICS1.isUserDefined()) { 2872 // User-defined conversion sequence U1 is a better conversion 2873 // sequence than another user-defined conversion sequence U2 if 2874 // they contain the same user-defined conversion function or 2875 // constructor and if the second standard conversion sequence of 2876 // U1 is better than the second standard conversion sequence of 2877 // U2 (C++ 13.3.3.2p3). 2878 if (ICS1.UserDefined.ConversionFunction == 2879 ICS2.UserDefined.ConversionFunction) 2880 Result = CompareStandardConversionSequences(S, 2881 ICS1.UserDefined.After, 2882 ICS2.UserDefined.After); 2883 } 2884 2885 // List-initialization sequence L1 is a better conversion sequence than 2886 // list-initialization sequence L2 if L1 converts to std::initializer_list<X> 2887 // for some X and L2 does not. 2888 if (Result == ImplicitConversionSequence::Indistinguishable && 2889 ICS1.isListInitializationSequence() && 2890 ICS2.isListInitializationSequence()) { 2891 // FIXME: Find out if ICS1 converts to initializer_list and ICS2 doesn't. 2892 } 2893 2894 return Result; 2895} 2896 2897static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2898 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2899 Qualifiers Quals; 2900 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2901 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2902 } 2903 2904 return Context.hasSameUnqualifiedType(T1, T2); 2905} 2906 2907// Per 13.3.3.2p3, compare the given standard conversion sequences to 2908// determine if one is a proper subset of the other. 2909static ImplicitConversionSequence::CompareKind 2910compareStandardConversionSubsets(ASTContext &Context, 2911 const StandardConversionSequence& SCS1, 2912 const StandardConversionSequence& SCS2) { 2913 ImplicitConversionSequence::CompareKind Result 2914 = ImplicitConversionSequence::Indistinguishable; 2915 2916 // the identity conversion sequence is considered to be a subsequence of 2917 // any non-identity conversion sequence 2918 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2919 return ImplicitConversionSequence::Better; 2920 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2921 return ImplicitConversionSequence::Worse; 2922 2923 if (SCS1.Second != SCS2.Second) { 2924 if (SCS1.Second == ICK_Identity) 2925 Result = ImplicitConversionSequence::Better; 2926 else if (SCS2.Second == ICK_Identity) 2927 Result = ImplicitConversionSequence::Worse; 2928 else 2929 return ImplicitConversionSequence::Indistinguishable; 2930 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2931 return ImplicitConversionSequence::Indistinguishable; 2932 2933 if (SCS1.Third == SCS2.Third) { 2934 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2935 : ImplicitConversionSequence::Indistinguishable; 2936 } 2937 2938 if (SCS1.Third == ICK_Identity) 2939 return Result == ImplicitConversionSequence::Worse 2940 ? ImplicitConversionSequence::Indistinguishable 2941 : ImplicitConversionSequence::Better; 2942 2943 if (SCS2.Third == ICK_Identity) 2944 return Result == ImplicitConversionSequence::Better 2945 ? ImplicitConversionSequence::Indistinguishable 2946 : ImplicitConversionSequence::Worse; 2947 2948 return ImplicitConversionSequence::Indistinguishable; 2949} 2950 2951/// \brief Determine whether one of the given reference bindings is better 2952/// than the other based on what kind of bindings they are. 2953static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 2954 const StandardConversionSequence &SCS2) { 2955 // C++0x [over.ics.rank]p3b4: 2956 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2957 // implicit object parameter of a non-static member function declared 2958 // without a ref-qualifier, and *either* S1 binds an rvalue reference 2959 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 2960 // lvalue reference to a function lvalue and S2 binds an rvalue 2961 // reference*. 2962 // 2963 // FIXME: Rvalue references. We're going rogue with the above edits, 2964 // because the semantics in the current C++0x working paper (N3225 at the 2965 // time of this writing) break the standard definition of std::forward 2966 // and std::reference_wrapper when dealing with references to functions. 2967 // Proposed wording changes submitted to CWG for consideration. 2968 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 2969 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 2970 return false; 2971 2972 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 2973 SCS2.IsLvalueReference) || 2974 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 2975 !SCS2.IsLvalueReference); 2976} 2977 2978/// CompareStandardConversionSequences - Compare two standard 2979/// conversion sequences to determine whether one is better than the 2980/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2981static ImplicitConversionSequence::CompareKind 2982CompareStandardConversionSequences(Sema &S, 2983 const StandardConversionSequence& SCS1, 2984 const StandardConversionSequence& SCS2) 2985{ 2986 // Standard conversion sequence S1 is a better conversion sequence 2987 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2988 2989 // -- S1 is a proper subsequence of S2 (comparing the conversion 2990 // sequences in the canonical form defined by 13.3.3.1.1, 2991 // excluding any Lvalue Transformation; the identity conversion 2992 // sequence is considered to be a subsequence of any 2993 // non-identity conversion sequence) or, if not that, 2994 if (ImplicitConversionSequence::CompareKind CK 2995 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 2996 return CK; 2997 2998 // -- the rank of S1 is better than the rank of S2 (by the rules 2999 // defined below), or, if not that, 3000 ImplicitConversionRank Rank1 = SCS1.getRank(); 3001 ImplicitConversionRank Rank2 = SCS2.getRank(); 3002 if (Rank1 < Rank2) 3003 return ImplicitConversionSequence::Better; 3004 else if (Rank2 < Rank1) 3005 return ImplicitConversionSequence::Worse; 3006 3007 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 3008 // are indistinguishable unless one of the following rules 3009 // applies: 3010 3011 // A conversion that is not a conversion of a pointer, or 3012 // pointer to member, to bool is better than another conversion 3013 // that is such a conversion. 3014 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 3015 return SCS2.isPointerConversionToBool() 3016 ? ImplicitConversionSequence::Better 3017 : ImplicitConversionSequence::Worse; 3018 3019 // C++ [over.ics.rank]p4b2: 3020 // 3021 // If class B is derived directly or indirectly from class A, 3022 // conversion of B* to A* is better than conversion of B* to 3023 // void*, and conversion of A* to void* is better than conversion 3024 // of B* to void*. 3025 bool SCS1ConvertsToVoid 3026 = SCS1.isPointerConversionToVoidPointer(S.Context); 3027 bool SCS2ConvertsToVoid 3028 = SCS2.isPointerConversionToVoidPointer(S.Context); 3029 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 3030 // Exactly one of the conversion sequences is a conversion to 3031 // a void pointer; it's the worse conversion. 3032 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 3033 : ImplicitConversionSequence::Worse; 3034 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 3035 // Neither conversion sequence converts to a void pointer; compare 3036 // their derived-to-base conversions. 3037 if (ImplicitConversionSequence::CompareKind DerivedCK 3038 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 3039 return DerivedCK; 3040 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid && 3041 !S.Context.hasSameType(SCS1.getFromType(), SCS2.getFromType())) { 3042 // Both conversion sequences are conversions to void 3043 // pointers. Compare the source types to determine if there's an 3044 // inheritance relationship in their sources. 3045 QualType FromType1 = SCS1.getFromType(); 3046 QualType FromType2 = SCS2.getFromType(); 3047 3048 // Adjust the types we're converting from via the array-to-pointer 3049 // conversion, if we need to. 3050 if (SCS1.First == ICK_Array_To_Pointer) 3051 FromType1 = S.Context.getArrayDecayedType(FromType1); 3052 if (SCS2.First == ICK_Array_To_Pointer) 3053 FromType2 = S.Context.getArrayDecayedType(FromType2); 3054 3055 QualType FromPointee1 = FromType1->getPointeeType().getUnqualifiedType(); 3056 QualType FromPointee2 = FromType2->getPointeeType().getUnqualifiedType(); 3057 3058 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3059 return ImplicitConversionSequence::Better; 3060 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3061 return ImplicitConversionSequence::Worse; 3062 3063 // Objective-C++: If one interface is more specific than the 3064 // other, it is the better one. 3065 const ObjCObjectPointerType* FromObjCPtr1 3066 = FromType1->getAs<ObjCObjectPointerType>(); 3067 const ObjCObjectPointerType* FromObjCPtr2 3068 = FromType2->getAs<ObjCObjectPointerType>(); 3069 if (FromObjCPtr1 && FromObjCPtr2) { 3070 bool AssignLeft = S.Context.canAssignObjCInterfaces(FromObjCPtr1, 3071 FromObjCPtr2); 3072 bool AssignRight = S.Context.canAssignObjCInterfaces(FromObjCPtr2, 3073 FromObjCPtr1); 3074 if (AssignLeft != AssignRight) { 3075 return AssignLeft? ImplicitConversionSequence::Better 3076 : ImplicitConversionSequence::Worse; 3077 } 3078 } 3079 } 3080 3081 // Compare based on qualification conversions (C++ 13.3.3.2p3, 3082 // bullet 3). 3083 if (ImplicitConversionSequence::CompareKind QualCK 3084 = CompareQualificationConversions(S, SCS1, SCS2)) 3085 return QualCK; 3086 3087 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 3088 // Check for a better reference binding based on the kind of bindings. 3089 if (isBetterReferenceBindingKind(SCS1, SCS2)) 3090 return ImplicitConversionSequence::Better; 3091 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 3092 return ImplicitConversionSequence::Worse; 3093 3094 // C++ [over.ics.rank]p3b4: 3095 // -- S1 and S2 are reference bindings (8.5.3), and the types to 3096 // which the references refer are the same type except for 3097 // top-level cv-qualifiers, and the type to which the reference 3098 // initialized by S2 refers is more cv-qualified than the type 3099 // to which the reference initialized by S1 refers. 3100 QualType T1 = SCS1.getToType(2); 3101 QualType T2 = SCS2.getToType(2); 3102 T1 = S.Context.getCanonicalType(T1); 3103 T2 = S.Context.getCanonicalType(T2); 3104 Qualifiers T1Quals, T2Quals; 3105 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3106 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3107 if (UnqualT1 == UnqualT2) { 3108 // Objective-C++ ARC: If the references refer to objects with different 3109 // lifetimes, prefer bindings that don't change lifetime. 3110 if (SCS1.ObjCLifetimeConversionBinding != 3111 SCS2.ObjCLifetimeConversionBinding) { 3112 return SCS1.ObjCLifetimeConversionBinding 3113 ? ImplicitConversionSequence::Worse 3114 : ImplicitConversionSequence::Better; 3115 } 3116 3117 // If the type is an array type, promote the element qualifiers to the 3118 // type for comparison. 3119 if (isa<ArrayType>(T1) && T1Quals) 3120 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3121 if (isa<ArrayType>(T2) && T2Quals) 3122 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3123 if (T2.isMoreQualifiedThan(T1)) 3124 return ImplicitConversionSequence::Better; 3125 else if (T1.isMoreQualifiedThan(T2)) 3126 return ImplicitConversionSequence::Worse; 3127 } 3128 } 3129 3130 // In Microsoft mode, prefer an integral conversion to a 3131 // floating-to-integral conversion if the integral conversion 3132 // is between types of the same size. 3133 // For example: 3134 // void f(float); 3135 // void f(int); 3136 // int main { 3137 // long a; 3138 // f(a); 3139 // } 3140 // Here, MSVC will call f(int) instead of generating a compile error 3141 // as clang will do in standard mode. 3142 if (S.getLangOptions().MicrosoftMode && 3143 SCS1.Second == ICK_Integral_Conversion && 3144 SCS2.Second == ICK_Floating_Integral && 3145 S.Context.getTypeSize(SCS1.getFromType()) == 3146 S.Context.getTypeSize(SCS1.getToType(2))) 3147 return ImplicitConversionSequence::Better; 3148 3149 return ImplicitConversionSequence::Indistinguishable; 3150} 3151 3152/// CompareQualificationConversions - Compares two standard conversion 3153/// sequences to determine whether they can be ranked based on their 3154/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 3155ImplicitConversionSequence::CompareKind 3156CompareQualificationConversions(Sema &S, 3157 const StandardConversionSequence& SCS1, 3158 const StandardConversionSequence& SCS2) { 3159 // C++ 13.3.3.2p3: 3160 // -- S1 and S2 differ only in their qualification conversion and 3161 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 3162 // cv-qualification signature of type T1 is a proper subset of 3163 // the cv-qualification signature of type T2, and S1 is not the 3164 // deprecated string literal array-to-pointer conversion (4.2). 3165 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 3166 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 3167 return ImplicitConversionSequence::Indistinguishable; 3168 3169 // FIXME: the example in the standard doesn't use a qualification 3170 // conversion (!) 3171 QualType T1 = SCS1.getToType(2); 3172 QualType T2 = SCS2.getToType(2); 3173 T1 = S.Context.getCanonicalType(T1); 3174 T2 = S.Context.getCanonicalType(T2); 3175 Qualifiers T1Quals, T2Quals; 3176 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 3177 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 3178 3179 // If the types are the same, we won't learn anything by unwrapped 3180 // them. 3181 if (UnqualT1 == UnqualT2) 3182 return ImplicitConversionSequence::Indistinguishable; 3183 3184 // If the type is an array type, promote the element qualifiers to the type 3185 // for comparison. 3186 if (isa<ArrayType>(T1) && T1Quals) 3187 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 3188 if (isa<ArrayType>(T2) && T2Quals) 3189 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 3190 3191 ImplicitConversionSequence::CompareKind Result 3192 = ImplicitConversionSequence::Indistinguishable; 3193 3194 // Objective-C++ ARC: 3195 // Prefer qualification conversions not involving a change in lifetime 3196 // to qualification conversions that do not change lifetime. 3197 if (SCS1.QualificationIncludesObjCLifetime != 3198 SCS2.QualificationIncludesObjCLifetime) { 3199 Result = SCS1.QualificationIncludesObjCLifetime 3200 ? ImplicitConversionSequence::Worse 3201 : ImplicitConversionSequence::Better; 3202 } 3203 3204 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 3205 // Within each iteration of the loop, we check the qualifiers to 3206 // determine if this still looks like a qualification 3207 // conversion. Then, if all is well, we unwrap one more level of 3208 // pointers or pointers-to-members and do it all again 3209 // until there are no more pointers or pointers-to-members left 3210 // to unwrap. This essentially mimics what 3211 // IsQualificationConversion does, but here we're checking for a 3212 // strict subset of qualifiers. 3213 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 3214 // The qualifiers are the same, so this doesn't tell us anything 3215 // about how the sequences rank. 3216 ; 3217 else if (T2.isMoreQualifiedThan(T1)) { 3218 // T1 has fewer qualifiers, so it could be the better sequence. 3219 if (Result == ImplicitConversionSequence::Worse) 3220 // Neither has qualifiers that are a subset of the other's 3221 // qualifiers. 3222 return ImplicitConversionSequence::Indistinguishable; 3223 3224 Result = ImplicitConversionSequence::Better; 3225 } else if (T1.isMoreQualifiedThan(T2)) { 3226 // T2 has fewer qualifiers, so it could be the better sequence. 3227 if (Result == ImplicitConversionSequence::Better) 3228 // Neither has qualifiers that are a subset of the other's 3229 // qualifiers. 3230 return ImplicitConversionSequence::Indistinguishable; 3231 3232 Result = ImplicitConversionSequence::Worse; 3233 } else { 3234 // Qualifiers are disjoint. 3235 return ImplicitConversionSequence::Indistinguishable; 3236 } 3237 3238 // If the types after this point are equivalent, we're done. 3239 if (S.Context.hasSameUnqualifiedType(T1, T2)) 3240 break; 3241 } 3242 3243 // Check that the winning standard conversion sequence isn't using 3244 // the deprecated string literal array to pointer conversion. 3245 switch (Result) { 3246 case ImplicitConversionSequence::Better: 3247 if (SCS1.DeprecatedStringLiteralToCharPtr) 3248 Result = ImplicitConversionSequence::Indistinguishable; 3249 break; 3250 3251 case ImplicitConversionSequence::Indistinguishable: 3252 break; 3253 3254 case ImplicitConversionSequence::Worse: 3255 if (SCS2.DeprecatedStringLiteralToCharPtr) 3256 Result = ImplicitConversionSequence::Indistinguishable; 3257 break; 3258 } 3259 3260 return Result; 3261} 3262 3263/// CompareDerivedToBaseConversions - Compares two standard conversion 3264/// sequences to determine whether they can be ranked based on their 3265/// various kinds of derived-to-base conversions (C++ 3266/// [over.ics.rank]p4b3). As part of these checks, we also look at 3267/// conversions between Objective-C interface types. 3268ImplicitConversionSequence::CompareKind 3269CompareDerivedToBaseConversions(Sema &S, 3270 const StandardConversionSequence& SCS1, 3271 const StandardConversionSequence& SCS2) { 3272 QualType FromType1 = SCS1.getFromType(); 3273 QualType ToType1 = SCS1.getToType(1); 3274 QualType FromType2 = SCS2.getFromType(); 3275 QualType ToType2 = SCS2.getToType(1); 3276 3277 // Adjust the types we're converting from via the array-to-pointer 3278 // conversion, if we need to. 3279 if (SCS1.First == ICK_Array_To_Pointer) 3280 FromType1 = S.Context.getArrayDecayedType(FromType1); 3281 if (SCS2.First == ICK_Array_To_Pointer) 3282 FromType2 = S.Context.getArrayDecayedType(FromType2); 3283 3284 // Canonicalize all of the types. 3285 FromType1 = S.Context.getCanonicalType(FromType1); 3286 ToType1 = S.Context.getCanonicalType(ToType1); 3287 FromType2 = S.Context.getCanonicalType(FromType2); 3288 ToType2 = S.Context.getCanonicalType(ToType2); 3289 3290 // C++ [over.ics.rank]p4b3: 3291 // 3292 // If class B is derived directly or indirectly from class A and 3293 // class C is derived directly or indirectly from B, 3294 // 3295 // Compare based on pointer conversions. 3296 if (SCS1.Second == ICK_Pointer_Conversion && 3297 SCS2.Second == ICK_Pointer_Conversion && 3298 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 3299 FromType1->isPointerType() && FromType2->isPointerType() && 3300 ToType1->isPointerType() && ToType2->isPointerType()) { 3301 QualType FromPointee1 3302 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3303 QualType ToPointee1 3304 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3305 QualType FromPointee2 3306 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3307 QualType ToPointee2 3308 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 3309 3310 // -- conversion of C* to B* is better than conversion of C* to A*, 3311 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3312 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3313 return ImplicitConversionSequence::Better; 3314 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3315 return ImplicitConversionSequence::Worse; 3316 } 3317 3318 // -- conversion of B* to A* is better than conversion of C* to A*, 3319 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 3320 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3321 return ImplicitConversionSequence::Better; 3322 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3323 return ImplicitConversionSequence::Worse; 3324 } 3325 } else if (SCS1.Second == ICK_Pointer_Conversion && 3326 SCS2.Second == ICK_Pointer_Conversion) { 3327 const ObjCObjectPointerType *FromPtr1 3328 = FromType1->getAs<ObjCObjectPointerType>(); 3329 const ObjCObjectPointerType *FromPtr2 3330 = FromType2->getAs<ObjCObjectPointerType>(); 3331 const ObjCObjectPointerType *ToPtr1 3332 = ToType1->getAs<ObjCObjectPointerType>(); 3333 const ObjCObjectPointerType *ToPtr2 3334 = ToType2->getAs<ObjCObjectPointerType>(); 3335 3336 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 3337 // Apply the same conversion ranking rules for Objective-C pointer types 3338 // that we do for C++ pointers to class types. However, we employ the 3339 // Objective-C pseudo-subtyping relationship used for assignment of 3340 // Objective-C pointer types. 3341 bool FromAssignLeft 3342 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 3343 bool FromAssignRight 3344 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 3345 bool ToAssignLeft 3346 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 3347 bool ToAssignRight 3348 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 3349 3350 // A conversion to an a non-id object pointer type or qualified 'id' 3351 // type is better than a conversion to 'id'. 3352 if (ToPtr1->isObjCIdType() && 3353 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 3354 return ImplicitConversionSequence::Worse; 3355 if (ToPtr2->isObjCIdType() && 3356 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 3357 return ImplicitConversionSequence::Better; 3358 3359 // A conversion to a non-id object pointer type is better than a 3360 // conversion to a qualified 'id' type 3361 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 3362 return ImplicitConversionSequence::Worse; 3363 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 3364 return ImplicitConversionSequence::Better; 3365 3366 // A conversion to an a non-Class object pointer type or qualified 'Class' 3367 // type is better than a conversion to 'Class'. 3368 if (ToPtr1->isObjCClassType() && 3369 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 3370 return ImplicitConversionSequence::Worse; 3371 if (ToPtr2->isObjCClassType() && 3372 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 3373 return ImplicitConversionSequence::Better; 3374 3375 // A conversion to a non-Class object pointer type is better than a 3376 // conversion to a qualified 'Class' type. 3377 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 3378 return ImplicitConversionSequence::Worse; 3379 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 3380 return ImplicitConversionSequence::Better; 3381 3382 // -- "conversion of C* to B* is better than conversion of C* to A*," 3383 if (S.Context.hasSameType(FromType1, FromType2) && 3384 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 3385 (ToAssignLeft != ToAssignRight)) 3386 return ToAssignLeft? ImplicitConversionSequence::Worse 3387 : ImplicitConversionSequence::Better; 3388 3389 // -- "conversion of B* to A* is better than conversion of C* to A*," 3390 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 3391 (FromAssignLeft != FromAssignRight)) 3392 return FromAssignLeft? ImplicitConversionSequence::Better 3393 : ImplicitConversionSequence::Worse; 3394 } 3395 } 3396 3397 // Ranking of member-pointer types. 3398 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 3399 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 3400 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 3401 const MemberPointerType * FromMemPointer1 = 3402 FromType1->getAs<MemberPointerType>(); 3403 const MemberPointerType * ToMemPointer1 = 3404 ToType1->getAs<MemberPointerType>(); 3405 const MemberPointerType * FromMemPointer2 = 3406 FromType2->getAs<MemberPointerType>(); 3407 const MemberPointerType * ToMemPointer2 = 3408 ToType2->getAs<MemberPointerType>(); 3409 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 3410 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 3411 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 3412 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 3413 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 3414 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 3415 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 3416 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 3417 // conversion of A::* to B::* is better than conversion of A::* to C::*, 3418 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 3419 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 3420 return ImplicitConversionSequence::Worse; 3421 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 3422 return ImplicitConversionSequence::Better; 3423 } 3424 // conversion of B::* to C::* is better than conversion of A::* to C::* 3425 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 3426 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 3427 return ImplicitConversionSequence::Better; 3428 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 3429 return ImplicitConversionSequence::Worse; 3430 } 3431 } 3432 3433 if (SCS1.Second == ICK_Derived_To_Base) { 3434 // -- conversion of C to B is better than conversion of C to A, 3435 // -- binding of an expression of type C to a reference of type 3436 // B& is better than binding an expression of type C to a 3437 // reference of type A&, 3438 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3439 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3440 if (S.IsDerivedFrom(ToType1, ToType2)) 3441 return ImplicitConversionSequence::Better; 3442 else if (S.IsDerivedFrom(ToType2, ToType1)) 3443 return ImplicitConversionSequence::Worse; 3444 } 3445 3446 // -- conversion of B to A is better than conversion of C to A. 3447 // -- binding of an expression of type B to a reference of type 3448 // A& is better than binding an expression of type C to a 3449 // reference of type A&, 3450 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 3451 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 3452 if (S.IsDerivedFrom(FromType2, FromType1)) 3453 return ImplicitConversionSequence::Better; 3454 else if (S.IsDerivedFrom(FromType1, FromType2)) 3455 return ImplicitConversionSequence::Worse; 3456 } 3457 } 3458 3459 return ImplicitConversionSequence::Indistinguishable; 3460} 3461 3462/// CompareReferenceRelationship - Compare the two types T1 and T2 to 3463/// determine whether they are reference-related, 3464/// reference-compatible, reference-compatible with added 3465/// qualification, or incompatible, for use in C++ initialization by 3466/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 3467/// type, and the first type (T1) is the pointee type of the reference 3468/// type being initialized. 3469Sema::ReferenceCompareResult 3470Sema::CompareReferenceRelationship(SourceLocation Loc, 3471 QualType OrigT1, QualType OrigT2, 3472 bool &DerivedToBase, 3473 bool &ObjCConversion, 3474 bool &ObjCLifetimeConversion) { 3475 assert(!OrigT1->isReferenceType() && 3476 "T1 must be the pointee type of the reference type"); 3477 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 3478 3479 QualType T1 = Context.getCanonicalType(OrigT1); 3480 QualType T2 = Context.getCanonicalType(OrigT2); 3481 Qualifiers T1Quals, T2Quals; 3482 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 3483 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 3484 3485 // C++ [dcl.init.ref]p4: 3486 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 3487 // reference-related to "cv2 T2" if T1 is the same type as T2, or 3488 // T1 is a base class of T2. 3489 DerivedToBase = false; 3490 ObjCConversion = false; 3491 ObjCLifetimeConversion = false; 3492 if (UnqualT1 == UnqualT2) { 3493 // Nothing to do. 3494 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 3495 IsDerivedFrom(UnqualT2, UnqualT1)) 3496 DerivedToBase = true; 3497 else if (UnqualT1->isObjCObjectOrInterfaceType() && 3498 UnqualT2->isObjCObjectOrInterfaceType() && 3499 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 3500 ObjCConversion = true; 3501 else 3502 return Ref_Incompatible; 3503 3504 // At this point, we know that T1 and T2 are reference-related (at 3505 // least). 3506 3507 // If the type is an array type, promote the element qualifiers to the type 3508 // for comparison. 3509 if (isa<ArrayType>(T1) && T1Quals) 3510 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 3511 if (isa<ArrayType>(T2) && T2Quals) 3512 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 3513 3514 // C++ [dcl.init.ref]p4: 3515 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 3516 // reference-related to T2 and cv1 is the same cv-qualification 3517 // as, or greater cv-qualification than, cv2. For purposes of 3518 // overload resolution, cases for which cv1 is greater 3519 // cv-qualification than cv2 are identified as 3520 // reference-compatible with added qualification (see 13.3.3.2). 3521 // 3522 // Note that we also require equivalence of Objective-C GC and address-space 3523 // qualifiers when performing these computations, so that e.g., an int in 3524 // address space 1 is not reference-compatible with an int in address 3525 // space 2. 3526 if (T1Quals.getObjCLifetime() != T2Quals.getObjCLifetime() && 3527 T1Quals.compatiblyIncludesObjCLifetime(T2Quals)) { 3528 T1Quals.removeObjCLifetime(); 3529 T2Quals.removeObjCLifetime(); 3530 ObjCLifetimeConversion = true; 3531 } 3532 3533 if (T1Quals == T2Quals) 3534 return Ref_Compatible; 3535 else if (T1Quals.compatiblyIncludes(T2Quals)) 3536 return Ref_Compatible_With_Added_Qualification; 3537 else 3538 return Ref_Related; 3539} 3540 3541/// \brief Look for a user-defined conversion to an value reference-compatible 3542/// with DeclType. Return true if something definite is found. 3543static bool 3544FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 3545 QualType DeclType, SourceLocation DeclLoc, 3546 Expr *Init, QualType T2, bool AllowRvalues, 3547 bool AllowExplicit) { 3548 assert(T2->isRecordType() && "Can only find conversions of record types."); 3549 CXXRecordDecl *T2RecordDecl 3550 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 3551 3552 OverloadCandidateSet CandidateSet(DeclLoc); 3553 const UnresolvedSetImpl *Conversions 3554 = T2RecordDecl->getVisibleConversionFunctions(); 3555 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3556 E = Conversions->end(); I != E; ++I) { 3557 NamedDecl *D = *I; 3558 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3559 if (isa<UsingShadowDecl>(D)) 3560 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3561 3562 FunctionTemplateDecl *ConvTemplate 3563 = dyn_cast<FunctionTemplateDecl>(D); 3564 CXXConversionDecl *Conv; 3565 if (ConvTemplate) 3566 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3567 else 3568 Conv = cast<CXXConversionDecl>(D); 3569 3570 // If this is an explicit conversion, and we're not allowed to consider 3571 // explicit conversions, skip it. 3572 if (!AllowExplicit && Conv->isExplicit()) 3573 continue; 3574 3575 if (AllowRvalues) { 3576 bool DerivedToBase = false; 3577 bool ObjCConversion = false; 3578 bool ObjCLifetimeConversion = false; 3579 3580 // If we are initializing an rvalue reference, don't permit conversion 3581 // functions that return lvalues. 3582 if (!ConvTemplate && DeclType->isRValueReferenceType()) { 3583 const ReferenceType *RefType 3584 = Conv->getConversionType()->getAs<LValueReferenceType>(); 3585 if (RefType && !RefType->getPointeeType()->isFunctionType()) 3586 continue; 3587 } 3588 3589 if (!ConvTemplate && 3590 S.CompareReferenceRelationship( 3591 DeclLoc, 3592 Conv->getConversionType().getNonReferenceType() 3593 .getUnqualifiedType(), 3594 DeclType.getNonReferenceType().getUnqualifiedType(), 3595 DerivedToBase, ObjCConversion, ObjCLifetimeConversion) == 3596 Sema::Ref_Incompatible) 3597 continue; 3598 } else { 3599 // If the conversion function doesn't return a reference type, 3600 // it can't be considered for this conversion. An rvalue reference 3601 // is only acceptable if its referencee is a function type. 3602 3603 const ReferenceType *RefType = 3604 Conv->getConversionType()->getAs<ReferenceType>(); 3605 if (!RefType || 3606 (!RefType->isLValueReferenceType() && 3607 !RefType->getPointeeType()->isFunctionType())) 3608 continue; 3609 } 3610 3611 if (ConvTemplate) 3612 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 3613 Init, DeclType, CandidateSet); 3614 else 3615 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 3616 DeclType, CandidateSet); 3617 } 3618 3619 bool HadMultipleCandidates = (CandidateSet.size() > 1); 3620 3621 OverloadCandidateSet::iterator Best; 3622 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 3623 case OR_Success: 3624 // C++ [over.ics.ref]p1: 3625 // 3626 // [...] If the parameter binds directly to the result of 3627 // applying a conversion function to the argument 3628 // expression, the implicit conversion sequence is a 3629 // user-defined conversion sequence (13.3.3.1.2), with the 3630 // second standard conversion sequence either an identity 3631 // conversion or, if the conversion function returns an 3632 // entity of a type that is a derived class of the parameter 3633 // type, a derived-to-base Conversion. 3634 if (!Best->FinalConversion.DirectBinding) 3635 return false; 3636 3637 if (Best->Function) 3638 S.MarkDeclarationReferenced(DeclLoc, Best->Function); 3639 ICS.setUserDefined(); 3640 ICS.UserDefined.Before = Best->Conversions[0].Standard; 3641 ICS.UserDefined.After = Best->FinalConversion; 3642 ICS.UserDefined.HadMultipleCandidates = HadMultipleCandidates; 3643 ICS.UserDefined.ConversionFunction = Best->Function; 3644 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl; 3645 ICS.UserDefined.EllipsisConversion = false; 3646 assert(ICS.UserDefined.After.ReferenceBinding && 3647 ICS.UserDefined.After.DirectBinding && 3648 "Expected a direct reference binding!"); 3649 return true; 3650 3651 case OR_Ambiguous: 3652 ICS.setAmbiguous(); 3653 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3654 Cand != CandidateSet.end(); ++Cand) 3655 if (Cand->Viable) 3656 ICS.Ambiguous.addConversion(Cand->Function); 3657 return true; 3658 3659 case OR_No_Viable_Function: 3660 case OR_Deleted: 3661 // There was no suitable conversion, or we found a deleted 3662 // conversion; continue with other checks. 3663 return false; 3664 } 3665 3666 llvm_unreachable("Invalid OverloadResult!"); 3667} 3668 3669/// \brief Compute an implicit conversion sequence for reference 3670/// initialization. 3671static ImplicitConversionSequence 3672TryReferenceInit(Sema &S, Expr *Init, QualType DeclType, 3673 SourceLocation DeclLoc, 3674 bool SuppressUserConversions, 3675 bool AllowExplicit) { 3676 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 3677 3678 // Most paths end in a failed conversion. 3679 ImplicitConversionSequence ICS; 3680 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3681 3682 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 3683 QualType T2 = Init->getType(); 3684 3685 // If the initializer is the address of an overloaded function, try 3686 // to resolve the overloaded function. If all goes well, T2 is the 3687 // type of the resulting function. 3688 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 3689 DeclAccessPair Found; 3690 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 3691 false, Found)) 3692 T2 = Fn->getType(); 3693 } 3694 3695 // Compute some basic properties of the types and the initializer. 3696 bool isRValRef = DeclType->isRValueReferenceType(); 3697 bool DerivedToBase = false; 3698 bool ObjCConversion = false; 3699 bool ObjCLifetimeConversion = false; 3700 Expr::Classification InitCategory = Init->Classify(S.Context); 3701 Sema::ReferenceCompareResult RefRelationship 3702 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 3703 ObjCConversion, ObjCLifetimeConversion); 3704 3705 3706 // C++0x [dcl.init.ref]p5: 3707 // A reference to type "cv1 T1" is initialized by an expression 3708 // of type "cv2 T2" as follows: 3709 3710 // -- If reference is an lvalue reference and the initializer expression 3711 if (!isRValRef) { 3712 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 3713 // reference-compatible with "cv2 T2," or 3714 // 3715 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 3716 if (InitCategory.isLValue() && 3717 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 3718 // C++ [over.ics.ref]p1: 3719 // When a parameter of reference type binds directly (8.5.3) 3720 // to an argument expression, the implicit conversion sequence 3721 // is the identity conversion, unless the argument expression 3722 // has a type that is a derived class of the parameter type, 3723 // in which case the implicit conversion sequence is a 3724 // derived-to-base Conversion (13.3.3.1). 3725 ICS.setStandard(); 3726 ICS.Standard.First = ICK_Identity; 3727 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3728 : ObjCConversion? ICK_Compatible_Conversion 3729 : ICK_Identity; 3730 ICS.Standard.Third = ICK_Identity; 3731 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3732 ICS.Standard.setToType(0, T2); 3733 ICS.Standard.setToType(1, T1); 3734 ICS.Standard.setToType(2, T1); 3735 ICS.Standard.ReferenceBinding = true; 3736 ICS.Standard.DirectBinding = true; 3737 ICS.Standard.IsLvalueReference = !isRValRef; 3738 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3739 ICS.Standard.BindsToRvalue = false; 3740 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3741 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 3742 ICS.Standard.CopyConstructor = 0; 3743 3744 // Nothing more to do: the inaccessibility/ambiguity check for 3745 // derived-to-base conversions is suppressed when we're 3746 // computing the implicit conversion sequence (C++ 3747 // [over.best.ics]p2). 3748 return ICS; 3749 } 3750 3751 // -- has a class type (i.e., T2 is a class type), where T1 is 3752 // not reference-related to T2, and can be implicitly 3753 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 3754 // is reference-compatible with "cv3 T3" 92) (this 3755 // conversion is selected by enumerating the applicable 3756 // conversion functions (13.3.1.6) and choosing the best 3757 // one through overload resolution (13.3)), 3758 if (!SuppressUserConversions && T2->isRecordType() && 3759 !S.RequireCompleteType(DeclLoc, T2, 0) && 3760 RefRelationship == Sema::Ref_Incompatible) { 3761 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3762 Init, T2, /*AllowRvalues=*/false, 3763 AllowExplicit)) 3764 return ICS; 3765 } 3766 } 3767 3768 // -- Otherwise, the reference shall be an lvalue reference to a 3769 // non-volatile const type (i.e., cv1 shall be const), or the reference 3770 // shall be an rvalue reference. 3771 // 3772 // We actually handle one oddity of C++ [over.ics.ref] at this 3773 // point, which is that, due to p2 (which short-circuits reference 3774 // binding by only attempting a simple conversion for non-direct 3775 // bindings) and p3's strange wording, we allow a const volatile 3776 // reference to bind to an rvalue. Hence the check for the presence 3777 // of "const" rather than checking for "const" being the only 3778 // qualifier. 3779 // This is also the point where rvalue references and lvalue inits no longer 3780 // go together. 3781 if (!isRValRef && !T1.isConstQualified()) 3782 return ICS; 3783 3784 // -- If the initializer expression 3785 // 3786 // -- is an xvalue, class prvalue, array prvalue or function 3787 // lvalue and "cv1 T1" is reference-compatible with "cv2 T2", or 3788 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 3789 (InitCategory.isXValue() || 3790 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 3791 (InitCategory.isLValue() && T2->isFunctionType()))) { 3792 ICS.setStandard(); 3793 ICS.Standard.First = ICK_Identity; 3794 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3795 : ObjCConversion? ICK_Compatible_Conversion 3796 : ICK_Identity; 3797 ICS.Standard.Third = ICK_Identity; 3798 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3799 ICS.Standard.setToType(0, T2); 3800 ICS.Standard.setToType(1, T1); 3801 ICS.Standard.setToType(2, T1); 3802 ICS.Standard.ReferenceBinding = true; 3803 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 3804 // binding unless we're binding to a class prvalue. 3805 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 3806 // allow the use of rvalue references in C++98/03 for the benefit of 3807 // standard library implementors; therefore, we need the xvalue check here. 3808 ICS.Standard.DirectBinding = 3809 S.getLangOptions().CPlusPlus0x || 3810 (InitCategory.isPRValue() && !T2->isRecordType()); 3811 ICS.Standard.IsLvalueReference = !isRValRef; 3812 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3813 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 3814 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3815 ICS.Standard.ObjCLifetimeConversionBinding = ObjCLifetimeConversion; 3816 ICS.Standard.CopyConstructor = 0; 3817 return ICS; 3818 } 3819 3820 // -- has a class type (i.e., T2 is a class type), where T1 is not 3821 // reference-related to T2, and can be implicitly converted to 3822 // an xvalue, class prvalue, or function lvalue of type 3823 // "cv3 T3", where "cv1 T1" is reference-compatible with 3824 // "cv3 T3", 3825 // 3826 // then the reference is bound to the value of the initializer 3827 // expression in the first case and to the result of the conversion 3828 // in the second case (or, in either case, to an appropriate base 3829 // class subobject). 3830 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3831 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 3832 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3833 Init, T2, /*AllowRvalues=*/true, 3834 AllowExplicit)) { 3835 // In the second case, if the reference is an rvalue reference 3836 // and the second standard conversion sequence of the 3837 // user-defined conversion sequence includes an lvalue-to-rvalue 3838 // conversion, the program is ill-formed. 3839 if (ICS.isUserDefined() && isRValRef && 3840 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 3841 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3842 3843 return ICS; 3844 } 3845 3846 // -- Otherwise, a temporary of type "cv1 T1" is created and 3847 // initialized from the initializer expression using the 3848 // rules for a non-reference copy initialization (8.5). The 3849 // reference is then bound to the temporary. If T1 is 3850 // reference-related to T2, cv1 must be the same 3851 // cv-qualification as, or greater cv-qualification than, 3852 // cv2; otherwise, the program is ill-formed. 3853 if (RefRelationship == Sema::Ref_Related) { 3854 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 3855 // we would be reference-compatible or reference-compatible with 3856 // added qualification. But that wasn't the case, so the reference 3857 // initialization fails. 3858 // 3859 // Note that we only want to check address spaces and cvr-qualifiers here. 3860 // ObjC GC and lifetime qualifiers aren't important. 3861 Qualifiers T1Quals = T1.getQualifiers(); 3862 Qualifiers T2Quals = T2.getQualifiers(); 3863 T1Quals.removeObjCGCAttr(); 3864 T1Quals.removeObjCLifetime(); 3865 T2Quals.removeObjCGCAttr(); 3866 T2Quals.removeObjCLifetime(); 3867 if (!T1Quals.compatiblyIncludes(T2Quals)) 3868 return ICS; 3869 } 3870 3871 // If at least one of the types is a class type, the types are not 3872 // related, and we aren't allowed any user conversions, the 3873 // reference binding fails. This case is important for breaking 3874 // recursion, since TryImplicitConversion below will attempt to 3875 // create a temporary through the use of a copy constructor. 3876 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3877 (T1->isRecordType() || T2->isRecordType())) 3878 return ICS; 3879 3880 // If T1 is reference-related to T2 and the reference is an rvalue 3881 // reference, the initializer expression shall not be an lvalue. 3882 if (RefRelationship >= Sema::Ref_Related && 3883 isRValRef && Init->Classify(S.Context).isLValue()) 3884 return ICS; 3885 3886 // C++ [over.ics.ref]p2: 3887 // When a parameter of reference type is not bound directly to 3888 // an argument expression, the conversion sequence is the one 3889 // required to convert the argument expression to the 3890 // underlying type of the reference according to 3891 // 13.3.3.1. Conceptually, this conversion sequence corresponds 3892 // to copy-initializing a temporary of the underlying type with 3893 // the argument expression. Any difference in top-level 3894 // cv-qualification is subsumed by the initialization itself 3895 // and does not constitute a conversion. 3896 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 3897 /*AllowExplicit=*/false, 3898 /*InOverloadResolution=*/false, 3899 /*CStyle=*/false, 3900 /*AllowObjCWritebackConversion=*/false); 3901 3902 // Of course, that's still a reference binding. 3903 if (ICS.isStandard()) { 3904 ICS.Standard.ReferenceBinding = true; 3905 ICS.Standard.IsLvalueReference = !isRValRef; 3906 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3907 ICS.Standard.BindsToRvalue = true; 3908 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3909 ICS.Standard.ObjCLifetimeConversionBinding = false; 3910 } else if (ICS.isUserDefined()) { 3911 // Don't allow rvalue references to bind to lvalues. 3912 if (DeclType->isRValueReferenceType()) { 3913 if (const ReferenceType *RefType 3914 = ICS.UserDefined.ConversionFunction->getResultType() 3915 ->getAs<LValueReferenceType>()) { 3916 if (!RefType->getPointeeType()->isFunctionType()) { 3917 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, Init, 3918 DeclType); 3919 return ICS; 3920 } 3921 } 3922 } 3923 3924 ICS.UserDefined.After.ReferenceBinding = true; 3925 ICS.UserDefined.After.IsLvalueReference = !isRValRef; 3926 ICS.UserDefined.After.BindsToFunctionLvalue = T2->isFunctionType(); 3927 ICS.UserDefined.After.BindsToRvalue = true; 3928 ICS.UserDefined.After.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3929 ICS.UserDefined.After.ObjCLifetimeConversionBinding = false; 3930 } 3931 3932 return ICS; 3933} 3934 3935static ImplicitConversionSequence 3936TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 3937 bool SuppressUserConversions, 3938 bool InOverloadResolution, 3939 bool AllowObjCWritebackConversion); 3940 3941/// TryListConversion - Try to copy-initialize a value of type ToType from the 3942/// initializer list From. 3943static ImplicitConversionSequence 3944TryListConversion(Sema &S, InitListExpr *From, QualType ToType, 3945 bool SuppressUserConversions, 3946 bool InOverloadResolution, 3947 bool AllowObjCWritebackConversion) { 3948 // C++11 [over.ics.list]p1: 3949 // When an argument is an initializer list, it is not an expression and 3950 // special rules apply for converting it to a parameter type. 3951 3952 ImplicitConversionSequence Result; 3953 Result.setBad(BadConversionSequence::no_conversion, From, ToType); 3954 Result.setListInitializationSequence(); 3955 3956 // We need a complete type for what follows. Incomplete types can bever be 3957 // initialized from init lists. 3958 if (S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag())) 3959 return Result; 3960 3961 // C++11 [over.ics.list]p2: 3962 // If the parameter type is std::initializer_list<X> or "array of X" and 3963 // all the elements can be implicitly converted to X, the implicit 3964 // conversion sequence is the worst conversion necessary to convert an 3965 // element of the list to X. 3966 QualType X; 3967 if (ToType->isArrayType()) 3968 X = S.Context.getBaseElementType(ToType); 3969 else 3970 (void)S.isStdInitializerList(ToType, &X); 3971 if (!X.isNull()) { 3972 for (unsigned i = 0, e = From->getNumInits(); i < e; ++i) { 3973 Expr *Init = From->getInit(i); 3974 ImplicitConversionSequence ICS = 3975 TryCopyInitialization(S, Init, X, SuppressUserConversions, 3976 InOverloadResolution, 3977 AllowObjCWritebackConversion); 3978 // If a single element isn't convertible, fail. 3979 if (ICS.isBad()) { 3980 Result = ICS; 3981 break; 3982 } 3983 // Otherwise, look for the worst conversion. 3984 if (Result.isBad() || 3985 CompareImplicitConversionSequences(S, ICS, Result) == 3986 ImplicitConversionSequence::Worse) 3987 Result = ICS; 3988 } 3989 Result.setListInitializationSequence(); 3990 return Result; 3991 } 3992 3993 // C++11 [over.ics.list]p3: 3994 // Otherwise, if the parameter is a non-aggregate class X and overload 3995 // resolution chooses a single best constructor [...] the implicit 3996 // conversion sequence is a user-defined conversion sequence. If multiple 3997 // constructors are viable but none is better than the others, the 3998 // implicit conversion sequence is a user-defined conversion sequence. 3999 if (ToType->isRecordType() && !ToType->isAggregateType()) { 4000 // This function can deal with initializer lists. 4001 Result = TryUserDefinedConversion(S, From, ToType, SuppressUserConversions, 4002 /*AllowExplicit=*/false, 4003 InOverloadResolution, /*CStyle=*/false, 4004 AllowObjCWritebackConversion); 4005 Result.setListInitializationSequence(); 4006 return Result; 4007 } 4008 4009 // C++11 [over.ics.list]p4: 4010 // Otherwise, if the parameter has an aggregate type which can be 4011 // initialized from the initializer list [...] the implicit conversion 4012 // sequence is a user-defined conversion sequence. 4013 if (ToType->isAggregateType()) { 4014 // Type is an aggregate, argument is an init list. At this point it comes 4015 // down to checking whether the initialization works. 4016 // FIXME: Find out whether this parameter is consumed or not. 4017 InitializedEntity Entity = 4018 InitializedEntity::InitializeParameter(S.Context, ToType, 4019 /*Consumed=*/false); 4020 if (S.CanPerformCopyInitialization(Entity, S.Owned(From))) { 4021 Result.setUserDefined(); 4022 Result.UserDefined.Before.setAsIdentityConversion(); 4023 // Initializer lists don't have a type. 4024 Result.UserDefined.Before.setFromType(QualType()); 4025 Result.UserDefined.Before.setAllToTypes(QualType()); 4026 4027 Result.UserDefined.After.setAsIdentityConversion(); 4028 Result.UserDefined.After.setFromType(ToType); 4029 Result.UserDefined.After.setAllToTypes(ToType); 4030 } 4031 return Result; 4032 } 4033 4034 // C++11 [over.ics.list]p5: 4035 // Otherwise, if the parameter is a reference, see 13.3.3.1.4. 4036 if (ToType->isReferenceType()) { 4037 // The standard is notoriously unclear here, since 13.3.3.1.4 doesn't 4038 // mention initializer lists in any way. So we go by what list- 4039 // initialization would do and try to extrapolate from that. 4040 4041 QualType T1 = ToType->getAs<ReferenceType>()->getPointeeType(); 4042 4043 // If the initializer list has a single element that is reference-related 4044 // to the parameter type, we initialize the reference from that. 4045 if (From->getNumInits() == 1) { 4046 Expr *Init = From->getInit(0); 4047 4048 QualType T2 = Init->getType(); 4049 4050 // If the initializer is the address of an overloaded function, try 4051 // to resolve the overloaded function. If all goes well, T2 is the 4052 // type of the resulting function. 4053 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 4054 DeclAccessPair Found; 4055 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction( 4056 Init, ToType, false, Found)) 4057 T2 = Fn->getType(); 4058 } 4059 4060 // Compute some basic properties of the types and the initializer. 4061 bool dummy1 = false; 4062 bool dummy2 = false; 4063 bool dummy3 = false; 4064 Sema::ReferenceCompareResult RefRelationship 4065 = S.CompareReferenceRelationship(From->getLocStart(), T1, T2, dummy1, 4066 dummy2, dummy3); 4067 4068 if (RefRelationship >= Sema::Ref_Related) 4069 return TryReferenceInit(S, Init, ToType, 4070 /*FIXME:*/From->getLocStart(), 4071 SuppressUserConversions, 4072 /*AllowExplicit=*/false); 4073 } 4074 4075 // Otherwise, we bind the reference to a temporary created from the 4076 // initializer list. 4077 Result = TryListConversion(S, From, T1, SuppressUserConversions, 4078 InOverloadResolution, 4079 AllowObjCWritebackConversion); 4080 if (Result.isFailure()) 4081 return Result; 4082 assert(!Result.isEllipsis() && 4083 "Sub-initialization cannot result in ellipsis conversion."); 4084 4085 // Can we even bind to a temporary? 4086 if (ToType->isRValueReferenceType() || 4087 (T1.isConstQualified() && !T1.isVolatileQualified())) { 4088 StandardConversionSequence &SCS = Result.isStandard() ? Result.Standard : 4089 Result.UserDefined.After; 4090 SCS.ReferenceBinding = true; 4091 SCS.IsLvalueReference = ToType->isLValueReferenceType(); 4092 SCS.BindsToRvalue = true; 4093 SCS.BindsToFunctionLvalue = false; 4094 SCS.BindsImplicitObjectArgumentWithoutRefQualifier = false; 4095 SCS.ObjCLifetimeConversionBinding = false; 4096 } else 4097 Result.setBad(BadConversionSequence::lvalue_ref_to_rvalue, 4098 From, ToType); 4099 return Result; 4100 } 4101 4102 // C++11 [over.ics.list]p6: 4103 // Otherwise, if the parameter type is not a class: 4104 if (!ToType->isRecordType()) { 4105 // - if the initializer list has one element, the implicit conversion 4106 // sequence is the one required to convert the element to the 4107 // parameter type. 4108 unsigned NumInits = From->getNumInits(); 4109 if (NumInits == 1) 4110 Result = TryCopyInitialization(S, From->getInit(0), ToType, 4111 SuppressUserConversions, 4112 InOverloadResolution, 4113 AllowObjCWritebackConversion); 4114 // - if the initializer list has no elements, the implicit conversion 4115 // sequence is the identity conversion. 4116 else if (NumInits == 0) { 4117 Result.setStandard(); 4118 Result.Standard.setAsIdentityConversion(); 4119 } 4120 return Result; 4121 } 4122 4123 // C++11 [over.ics.list]p7: 4124 // In all cases other than those enumerated above, no conversion is possible 4125 return Result; 4126} 4127 4128/// TryCopyInitialization - Try to copy-initialize a value of type 4129/// ToType from the expression From. Return the implicit conversion 4130/// sequence required to pass this argument, which may be a bad 4131/// conversion sequence (meaning that the argument cannot be passed to 4132/// a parameter of this type). If @p SuppressUserConversions, then we 4133/// do not permit any user-defined conversion sequences. 4134static ImplicitConversionSequence 4135TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 4136 bool SuppressUserConversions, 4137 bool InOverloadResolution, 4138 bool AllowObjCWritebackConversion) { 4139 if (InitListExpr *FromInitList = dyn_cast<InitListExpr>(From)) 4140 return TryListConversion(S, FromInitList, ToType, SuppressUserConversions, 4141 InOverloadResolution,AllowObjCWritebackConversion); 4142 4143 if (ToType->isReferenceType()) 4144 return TryReferenceInit(S, From, ToType, 4145 /*FIXME:*/From->getLocStart(), 4146 SuppressUserConversions, 4147 /*AllowExplicit=*/false); 4148 4149 return TryImplicitConversion(S, From, ToType, 4150 SuppressUserConversions, 4151 /*AllowExplicit=*/false, 4152 InOverloadResolution, 4153 /*CStyle=*/false, 4154 AllowObjCWritebackConversion); 4155} 4156 4157static bool TryCopyInitialization(const CanQualType FromQTy, 4158 const CanQualType ToQTy, 4159 Sema &S, 4160 SourceLocation Loc, 4161 ExprValueKind FromVK) { 4162 OpaqueValueExpr TmpExpr(Loc, FromQTy, FromVK); 4163 ImplicitConversionSequence ICS = 4164 TryCopyInitialization(S, &TmpExpr, ToQTy, true, true, false); 4165 4166 return !ICS.isBad(); 4167} 4168 4169/// TryObjectArgumentInitialization - Try to initialize the object 4170/// parameter of the given member function (@c Method) from the 4171/// expression @p From. 4172static ImplicitConversionSequence 4173TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 4174 Expr::Classification FromClassification, 4175 CXXMethodDecl *Method, 4176 CXXRecordDecl *ActingContext) { 4177 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 4178 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 4179 // const volatile object. 4180 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 4181 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 4182 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 4183 4184 // Set up the conversion sequence as a "bad" conversion, to allow us 4185 // to exit early. 4186 ImplicitConversionSequence ICS; 4187 4188 // We need to have an object of class type. 4189 QualType FromType = OrigFromType; 4190 if (const PointerType *PT = FromType->getAs<PointerType>()) { 4191 FromType = PT->getPointeeType(); 4192 4193 // When we had a pointer, it's implicitly dereferenced, so we 4194 // better have an lvalue. 4195 assert(FromClassification.isLValue()); 4196 } 4197 4198 assert(FromType->isRecordType()); 4199 4200 // C++0x [over.match.funcs]p4: 4201 // For non-static member functions, the type of the implicit object 4202 // parameter is 4203 // 4204 // - "lvalue reference to cv X" for functions declared without a 4205 // ref-qualifier or with the & ref-qualifier 4206 // - "rvalue reference to cv X" for functions declared with the && 4207 // ref-qualifier 4208 // 4209 // where X is the class of which the function is a member and cv is the 4210 // cv-qualification on the member function declaration. 4211 // 4212 // However, when finding an implicit conversion sequence for the argument, we 4213 // are not allowed to create temporaries or perform user-defined conversions 4214 // (C++ [over.match.funcs]p5). We perform a simplified version of 4215 // reference binding here, that allows class rvalues to bind to 4216 // non-constant references. 4217 4218 // First check the qualifiers. 4219 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 4220 if (ImplicitParamType.getCVRQualifiers() 4221 != FromTypeCanon.getLocalCVRQualifiers() && 4222 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 4223 ICS.setBad(BadConversionSequence::bad_qualifiers, 4224 OrigFromType, ImplicitParamType); 4225 return ICS; 4226 } 4227 4228 // Check that we have either the same type or a derived type. It 4229 // affects the conversion rank. 4230 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 4231 ImplicitConversionKind SecondKind; 4232 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 4233 SecondKind = ICK_Identity; 4234 } else if (S.IsDerivedFrom(FromType, ClassType)) 4235 SecondKind = ICK_Derived_To_Base; 4236 else { 4237 ICS.setBad(BadConversionSequence::unrelated_class, 4238 FromType, ImplicitParamType); 4239 return ICS; 4240 } 4241 4242 // Check the ref-qualifier. 4243 switch (Method->getRefQualifier()) { 4244 case RQ_None: 4245 // Do nothing; we don't care about lvalueness or rvalueness. 4246 break; 4247 4248 case RQ_LValue: 4249 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 4250 // non-const lvalue reference cannot bind to an rvalue 4251 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 4252 ImplicitParamType); 4253 return ICS; 4254 } 4255 break; 4256 4257 case RQ_RValue: 4258 if (!FromClassification.isRValue()) { 4259 // rvalue reference cannot bind to an lvalue 4260 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 4261 ImplicitParamType); 4262 return ICS; 4263 } 4264 break; 4265 } 4266 4267 // Success. Mark this as a reference binding. 4268 ICS.setStandard(); 4269 ICS.Standard.setAsIdentityConversion(); 4270 ICS.Standard.Second = SecondKind; 4271 ICS.Standard.setFromType(FromType); 4272 ICS.Standard.setAllToTypes(ImplicitParamType); 4273 ICS.Standard.ReferenceBinding = true; 4274 ICS.Standard.DirectBinding = true; 4275 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 4276 ICS.Standard.BindsToFunctionLvalue = false; 4277 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 4278 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 4279 = (Method->getRefQualifier() == RQ_None); 4280 return ICS; 4281} 4282 4283/// PerformObjectArgumentInitialization - Perform initialization of 4284/// the implicit object parameter for the given Method with the given 4285/// expression. 4286ExprResult 4287Sema::PerformObjectArgumentInitialization(Expr *From, 4288 NestedNameSpecifier *Qualifier, 4289 NamedDecl *FoundDecl, 4290 CXXMethodDecl *Method) { 4291 QualType FromRecordType, DestType; 4292 QualType ImplicitParamRecordType = 4293 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 4294 4295 Expr::Classification FromClassification; 4296 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 4297 FromRecordType = PT->getPointeeType(); 4298 DestType = Method->getThisType(Context); 4299 FromClassification = Expr::Classification::makeSimpleLValue(); 4300 } else { 4301 FromRecordType = From->getType(); 4302 DestType = ImplicitParamRecordType; 4303 FromClassification = From->Classify(Context); 4304 } 4305 4306 // Note that we always use the true parent context when performing 4307 // the actual argument initialization. 4308 ImplicitConversionSequence ICS 4309 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 4310 Method, Method->getParent()); 4311 if (ICS.isBad()) { 4312 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 4313 Qualifiers FromQs = FromRecordType.getQualifiers(); 4314 Qualifiers ToQs = DestType.getQualifiers(); 4315 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 4316 if (CVR) { 4317 Diag(From->getSourceRange().getBegin(), 4318 diag::err_member_function_call_bad_cvr) 4319 << Method->getDeclName() << FromRecordType << (CVR - 1) 4320 << From->getSourceRange(); 4321 Diag(Method->getLocation(), diag::note_previous_decl) 4322 << Method->getDeclName(); 4323 return ExprError(); 4324 } 4325 } 4326 4327 return Diag(From->getSourceRange().getBegin(), 4328 diag::err_implicit_object_parameter_init) 4329 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 4330 } 4331 4332 if (ICS.Standard.Second == ICK_Derived_To_Base) { 4333 ExprResult FromRes = 4334 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 4335 if (FromRes.isInvalid()) 4336 return ExprError(); 4337 From = FromRes.take(); 4338 } 4339 4340 if (!Context.hasSameType(From->getType(), DestType)) 4341 From = ImpCastExprToType(From, DestType, CK_NoOp, 4342 From->getValueKind()).take(); 4343 return Owned(From); 4344} 4345 4346/// TryContextuallyConvertToBool - Attempt to contextually convert the 4347/// expression From to bool (C++0x [conv]p3). 4348static ImplicitConversionSequence 4349TryContextuallyConvertToBool(Sema &S, Expr *From) { 4350 // FIXME: This is pretty broken. 4351 return TryImplicitConversion(S, From, S.Context.BoolTy, 4352 // FIXME: Are these flags correct? 4353 /*SuppressUserConversions=*/false, 4354 /*AllowExplicit=*/true, 4355 /*InOverloadResolution=*/false, 4356 /*CStyle=*/false, 4357 /*AllowObjCWritebackConversion=*/false); 4358} 4359 4360/// PerformContextuallyConvertToBool - Perform a contextual conversion 4361/// of the expression From to bool (C++0x [conv]p3). 4362ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) { 4363 if (checkPlaceholderForOverload(*this, From)) 4364 return ExprError(); 4365 4366 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 4367 if (!ICS.isBad()) 4368 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 4369 4370 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 4371 return Diag(From->getSourceRange().getBegin(), 4372 diag::err_typecheck_bool_condition) 4373 << From->getType() << From->getSourceRange(); 4374 return ExprError(); 4375} 4376 4377/// dropPointerConversions - If the given standard conversion sequence 4378/// involves any pointer conversions, remove them. This may change 4379/// the result type of the conversion sequence. 4380static void dropPointerConversion(StandardConversionSequence &SCS) { 4381 if (SCS.Second == ICK_Pointer_Conversion) { 4382 SCS.Second = ICK_Identity; 4383 SCS.Third = ICK_Identity; 4384 SCS.ToTypePtrs[2] = SCS.ToTypePtrs[1] = SCS.ToTypePtrs[0]; 4385 } 4386} 4387 4388/// TryContextuallyConvertToObjCPointer - Attempt to contextually 4389/// convert the expression From to an Objective-C pointer type. 4390static ImplicitConversionSequence 4391TryContextuallyConvertToObjCPointer(Sema &S, Expr *From) { 4392 // Do an implicit conversion to 'id'. 4393 QualType Ty = S.Context.getObjCIdType(); 4394 ImplicitConversionSequence ICS 4395 = TryImplicitConversion(S, From, Ty, 4396 // FIXME: Are these flags correct? 4397 /*SuppressUserConversions=*/false, 4398 /*AllowExplicit=*/true, 4399 /*InOverloadResolution=*/false, 4400 /*CStyle=*/false, 4401 /*AllowObjCWritebackConversion=*/false); 4402 4403 // Strip off any final conversions to 'id'. 4404 switch (ICS.getKind()) { 4405 case ImplicitConversionSequence::BadConversion: 4406 case ImplicitConversionSequence::AmbiguousConversion: 4407 case ImplicitConversionSequence::EllipsisConversion: 4408 break; 4409 4410 case ImplicitConversionSequence::UserDefinedConversion: 4411 dropPointerConversion(ICS.UserDefined.After); 4412 break; 4413 4414 case ImplicitConversionSequence::StandardConversion: 4415 dropPointerConversion(ICS.Standard); 4416 break; 4417 } 4418 4419 return ICS; 4420} 4421 4422/// PerformContextuallyConvertToObjCPointer - Perform a contextual 4423/// conversion of the expression From to an Objective-C pointer type. 4424ExprResult Sema::PerformContextuallyConvertToObjCPointer(Expr *From) { 4425 if (checkPlaceholderForOverload(*this, From)) 4426 return ExprError(); 4427 4428 QualType Ty = Context.getObjCIdType(); 4429 ImplicitConversionSequence ICS = 4430 TryContextuallyConvertToObjCPointer(*this, From); 4431 if (!ICS.isBad()) 4432 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 4433 return ExprError(); 4434} 4435 4436/// \brief Attempt to convert the given expression to an integral or 4437/// enumeration type. 4438/// 4439/// This routine will attempt to convert an expression of class type to an 4440/// integral or enumeration type, if that class type only has a single 4441/// conversion to an integral or enumeration type. 4442/// 4443/// \param Loc The source location of the construct that requires the 4444/// conversion. 4445/// 4446/// \param FromE The expression we're converting from. 4447/// 4448/// \param NotIntDiag The diagnostic to be emitted if the expression does not 4449/// have integral or enumeration type. 4450/// 4451/// \param IncompleteDiag The diagnostic to be emitted if the expression has 4452/// incomplete class type. 4453/// 4454/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 4455/// explicit conversion function (because no implicit conversion functions 4456/// were available). This is a recovery mode. 4457/// 4458/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 4459/// showing which conversion was picked. 4460/// 4461/// \param AmbigDiag The diagnostic to be emitted if there is more than one 4462/// conversion function that could convert to integral or enumeration type. 4463/// 4464/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 4465/// usable conversion function. 4466/// 4467/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 4468/// function, which may be an extension in this case. 4469/// 4470/// \returns The expression, converted to an integral or enumeration type if 4471/// successful. 4472ExprResult 4473Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 4474 const PartialDiagnostic &NotIntDiag, 4475 const PartialDiagnostic &IncompleteDiag, 4476 const PartialDiagnostic &ExplicitConvDiag, 4477 const PartialDiagnostic &ExplicitConvNote, 4478 const PartialDiagnostic &AmbigDiag, 4479 const PartialDiagnostic &AmbigNote, 4480 const PartialDiagnostic &ConvDiag) { 4481 // We can't perform any more checking for type-dependent expressions. 4482 if (From->isTypeDependent()) 4483 return Owned(From); 4484 4485 // If the expression already has integral or enumeration type, we're golden. 4486 QualType T = From->getType(); 4487 if (T->isIntegralOrEnumerationType()) 4488 return Owned(From); 4489 4490 // FIXME: Check for missing '()' if T is a function type? 4491 4492 // If we don't have a class type in C++, there's no way we can get an 4493 // expression of integral or enumeration type. 4494 const RecordType *RecordTy = T->getAs<RecordType>(); 4495 if (!RecordTy || !getLangOptions().CPlusPlus) { 4496 Diag(Loc, NotIntDiag) 4497 << T << From->getSourceRange(); 4498 return Owned(From); 4499 } 4500 4501 // We must have a complete class type. 4502 if (RequireCompleteType(Loc, T, IncompleteDiag)) 4503 return Owned(From); 4504 4505 // Look for a conversion to an integral or enumeration type. 4506 UnresolvedSet<4> ViableConversions; 4507 UnresolvedSet<4> ExplicitConversions; 4508 const UnresolvedSetImpl *Conversions 4509 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 4510 4511 bool HadMultipleCandidates = (Conversions->size() > 1); 4512 4513 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4514 E = Conversions->end(); 4515 I != E; 4516 ++I) { 4517 if (CXXConversionDecl *Conversion 4518 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 4519 if (Conversion->getConversionType().getNonReferenceType() 4520 ->isIntegralOrEnumerationType()) { 4521 if (Conversion->isExplicit()) 4522 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 4523 else 4524 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 4525 } 4526 } 4527 4528 switch (ViableConversions.size()) { 4529 case 0: 4530 if (ExplicitConversions.size() == 1) { 4531 DeclAccessPair Found = ExplicitConversions[0]; 4532 CXXConversionDecl *Conversion 4533 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 4534 4535 // The user probably meant to invoke the given explicit 4536 // conversion; use it. 4537 QualType ConvTy 4538 = Conversion->getConversionType().getNonReferenceType(); 4539 std::string TypeStr; 4540 ConvTy.getAsStringInternal(TypeStr, getPrintingPolicy()); 4541 4542 Diag(Loc, ExplicitConvDiag) 4543 << T << ConvTy 4544 << FixItHint::CreateInsertion(From->getLocStart(), 4545 "static_cast<" + TypeStr + ">(") 4546 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 4547 ")"); 4548 Diag(Conversion->getLocation(), ExplicitConvNote) 4549 << ConvTy->isEnumeralType() << ConvTy; 4550 4551 // If we aren't in a SFINAE context, build a call to the 4552 // explicit conversion function. 4553 if (isSFINAEContext()) 4554 return ExprError(); 4555 4556 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 4557 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion, 4558 HadMultipleCandidates); 4559 if (Result.isInvalid()) 4560 return ExprError(); 4561 // Record usage of conversion in an implicit cast. 4562 From = ImplicitCastExpr::Create(Context, Result.get()->getType(), 4563 CK_UserDefinedConversion, 4564 Result.get(), 0, 4565 Result.get()->getValueKind()); 4566 } 4567 4568 // We'll complain below about a non-integral condition type. 4569 break; 4570 4571 case 1: { 4572 // Apply this conversion. 4573 DeclAccessPair Found = ViableConversions[0]; 4574 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 4575 4576 CXXConversionDecl *Conversion 4577 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 4578 QualType ConvTy 4579 = Conversion->getConversionType().getNonReferenceType(); 4580 if (ConvDiag.getDiagID()) { 4581 if (isSFINAEContext()) 4582 return ExprError(); 4583 4584 Diag(Loc, ConvDiag) 4585 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 4586 } 4587 4588 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion, 4589 HadMultipleCandidates); 4590 if (Result.isInvalid()) 4591 return ExprError(); 4592 // Record usage of conversion in an implicit cast. 4593 From = ImplicitCastExpr::Create(Context, Result.get()->getType(), 4594 CK_UserDefinedConversion, 4595 Result.get(), 0, 4596 Result.get()->getValueKind()); 4597 break; 4598 } 4599 4600 default: 4601 Diag(Loc, AmbigDiag) 4602 << T << From->getSourceRange(); 4603 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 4604 CXXConversionDecl *Conv 4605 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 4606 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 4607 Diag(Conv->getLocation(), AmbigNote) 4608 << ConvTy->isEnumeralType() << ConvTy; 4609 } 4610 return Owned(From); 4611 } 4612 4613 if (!From->getType()->isIntegralOrEnumerationType()) 4614 Diag(Loc, NotIntDiag) 4615 << From->getType() << From->getSourceRange(); 4616 4617 return Owned(From); 4618} 4619 4620/// AddOverloadCandidate - Adds the given function to the set of 4621/// candidate functions, using the given function call arguments. If 4622/// @p SuppressUserConversions, then don't allow user-defined 4623/// conversions via constructors or conversion operators. 4624/// 4625/// \para PartialOverloading true if we are performing "partial" overloading 4626/// based on an incomplete set of function arguments. This feature is used by 4627/// code completion. 4628void 4629Sema::AddOverloadCandidate(FunctionDecl *Function, 4630 DeclAccessPair FoundDecl, 4631 Expr **Args, unsigned NumArgs, 4632 OverloadCandidateSet& CandidateSet, 4633 bool SuppressUserConversions, 4634 bool PartialOverloading) { 4635 const FunctionProtoType* Proto 4636 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 4637 assert(Proto && "Functions without a prototype cannot be overloaded"); 4638 assert(!Function->getDescribedFunctionTemplate() && 4639 "Use AddTemplateOverloadCandidate for function templates"); 4640 4641 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 4642 if (!isa<CXXConstructorDecl>(Method)) { 4643 // If we get here, it's because we're calling a member function 4644 // that is named without a member access expression (e.g., 4645 // "this->f") that was either written explicitly or created 4646 // implicitly. This can happen with a qualified call to a member 4647 // function, e.g., X::f(). We use an empty type for the implied 4648 // object argument (C++ [over.call.func]p3), and the acting context 4649 // is irrelevant. 4650 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 4651 QualType(), Expr::Classification::makeSimpleLValue(), 4652 Args, NumArgs, CandidateSet, 4653 SuppressUserConversions); 4654 return; 4655 } 4656 // We treat a constructor like a non-member function, since its object 4657 // argument doesn't participate in overload resolution. 4658 } 4659 4660 if (!CandidateSet.isNewCandidate(Function)) 4661 return; 4662 4663 // Overload resolution is always an unevaluated context. 4664 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4665 4666 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 4667 // C++ [class.copy]p3: 4668 // A member function template is never instantiated to perform the copy 4669 // of a class object to an object of its class type. 4670 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 4671 if (NumArgs == 1 && 4672 Constructor->isSpecializationCopyingObject() && 4673 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 4674 IsDerivedFrom(Args[0]->getType(), ClassType))) 4675 return; 4676 } 4677 4678 // Add this candidate 4679 OverloadCandidate &Candidate = CandidateSet.addCandidate(NumArgs); 4680 Candidate.FoundDecl = FoundDecl; 4681 Candidate.Function = Function; 4682 Candidate.Viable = true; 4683 Candidate.IsSurrogate = false; 4684 Candidate.IgnoreObjectArgument = false; 4685 Candidate.ExplicitCallArguments = NumArgs; 4686 4687 unsigned NumArgsInProto = Proto->getNumArgs(); 4688 4689 // (C++ 13.3.2p2): A candidate function having fewer than m 4690 // parameters is viable only if it has an ellipsis in its parameter 4691 // list (8.3.5). 4692 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 4693 !Proto->isVariadic()) { 4694 Candidate.Viable = false; 4695 Candidate.FailureKind = ovl_fail_too_many_arguments; 4696 return; 4697 } 4698 4699 // (C++ 13.3.2p2): A candidate function having more than m parameters 4700 // is viable only if the (m+1)st parameter has a default argument 4701 // (8.3.6). For the purposes of overload resolution, the 4702 // parameter list is truncated on the right, so that there are 4703 // exactly m parameters. 4704 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 4705 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 4706 // Not enough arguments. 4707 Candidate.Viable = false; 4708 Candidate.FailureKind = ovl_fail_too_few_arguments; 4709 return; 4710 } 4711 4712 // (CUDA B.1): Check for invalid calls between targets. 4713 if (getLangOptions().CUDA) 4714 if (const FunctionDecl *Caller = dyn_cast<FunctionDecl>(CurContext)) 4715 if (CheckCUDATarget(Caller, Function)) { 4716 Candidate.Viable = false; 4717 Candidate.FailureKind = ovl_fail_bad_target; 4718 return; 4719 } 4720 4721 // Determine the implicit conversion sequences for each of the 4722 // arguments. 4723 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4724 if (ArgIdx < NumArgsInProto) { 4725 // (C++ 13.3.2p3): for F to be a viable function, there shall 4726 // exist for each argument an implicit conversion sequence 4727 // (13.3.3.1) that converts that argument to the corresponding 4728 // parameter of F. 4729 QualType ParamType = Proto->getArgType(ArgIdx); 4730 Candidate.Conversions[ArgIdx] 4731 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4732 SuppressUserConversions, 4733 /*InOverloadResolution=*/true, 4734 /*AllowObjCWritebackConversion=*/ 4735 getLangOptions().ObjCAutoRefCount); 4736 if (Candidate.Conversions[ArgIdx].isBad()) { 4737 Candidate.Viable = false; 4738 Candidate.FailureKind = ovl_fail_bad_conversion; 4739 break; 4740 } 4741 } else { 4742 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4743 // argument for which there is no corresponding parameter is 4744 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4745 Candidate.Conversions[ArgIdx].setEllipsis(); 4746 } 4747 } 4748} 4749 4750/// \brief Add all of the function declarations in the given function set to 4751/// the overload canddiate set. 4752void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 4753 Expr **Args, unsigned NumArgs, 4754 OverloadCandidateSet& CandidateSet, 4755 bool SuppressUserConversions) { 4756 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 4757 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 4758 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 4759 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 4760 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 4761 cast<CXXMethodDecl>(FD)->getParent(), 4762 Args[0]->getType(), Args[0]->Classify(Context), 4763 Args + 1, NumArgs - 1, 4764 CandidateSet, SuppressUserConversions); 4765 else 4766 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 4767 SuppressUserConversions); 4768 } else { 4769 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 4770 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 4771 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 4772 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 4773 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 4774 /*FIXME: explicit args */ 0, 4775 Args[0]->getType(), 4776 Args[0]->Classify(Context), 4777 Args + 1, NumArgs - 1, 4778 CandidateSet, 4779 SuppressUserConversions); 4780 else 4781 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 4782 /*FIXME: explicit args */ 0, 4783 Args, NumArgs, CandidateSet, 4784 SuppressUserConversions); 4785 } 4786 } 4787} 4788 4789/// AddMethodCandidate - Adds a named decl (which is some kind of 4790/// method) as a method candidate to the given overload set. 4791void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 4792 QualType ObjectType, 4793 Expr::Classification ObjectClassification, 4794 Expr **Args, unsigned NumArgs, 4795 OverloadCandidateSet& CandidateSet, 4796 bool SuppressUserConversions) { 4797 NamedDecl *Decl = FoundDecl.getDecl(); 4798 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 4799 4800 if (isa<UsingShadowDecl>(Decl)) 4801 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 4802 4803 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 4804 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 4805 "Expected a member function template"); 4806 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 4807 /*ExplicitArgs*/ 0, 4808 ObjectType, ObjectClassification, Args, NumArgs, 4809 CandidateSet, 4810 SuppressUserConversions); 4811 } else { 4812 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 4813 ObjectType, ObjectClassification, Args, NumArgs, 4814 CandidateSet, SuppressUserConversions); 4815 } 4816} 4817 4818/// AddMethodCandidate - Adds the given C++ member function to the set 4819/// of candidate functions, using the given function call arguments 4820/// and the object argument (@c Object). For example, in a call 4821/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 4822/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 4823/// allow user-defined conversions via constructors or conversion 4824/// operators. 4825void 4826Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 4827 CXXRecordDecl *ActingContext, QualType ObjectType, 4828 Expr::Classification ObjectClassification, 4829 Expr **Args, unsigned NumArgs, 4830 OverloadCandidateSet& CandidateSet, 4831 bool SuppressUserConversions) { 4832 const FunctionProtoType* Proto 4833 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 4834 assert(Proto && "Methods without a prototype cannot be overloaded"); 4835 assert(!isa<CXXConstructorDecl>(Method) && 4836 "Use AddOverloadCandidate for constructors"); 4837 4838 if (!CandidateSet.isNewCandidate(Method)) 4839 return; 4840 4841 // Overload resolution is always an unevaluated context. 4842 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4843 4844 // Add this candidate 4845 OverloadCandidate &Candidate = CandidateSet.addCandidate(NumArgs + 1); 4846 Candidate.FoundDecl = FoundDecl; 4847 Candidate.Function = Method; 4848 Candidate.IsSurrogate = false; 4849 Candidate.IgnoreObjectArgument = false; 4850 Candidate.ExplicitCallArguments = NumArgs; 4851 4852 unsigned NumArgsInProto = Proto->getNumArgs(); 4853 4854 // (C++ 13.3.2p2): A candidate function having fewer than m 4855 // parameters is viable only if it has an ellipsis in its parameter 4856 // list (8.3.5). 4857 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4858 Candidate.Viable = false; 4859 Candidate.FailureKind = ovl_fail_too_many_arguments; 4860 return; 4861 } 4862 4863 // (C++ 13.3.2p2): A candidate function having more than m parameters 4864 // is viable only if the (m+1)st parameter has a default argument 4865 // (8.3.6). For the purposes of overload resolution, the 4866 // parameter list is truncated on the right, so that there are 4867 // exactly m parameters. 4868 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 4869 if (NumArgs < MinRequiredArgs) { 4870 // Not enough arguments. 4871 Candidate.Viable = false; 4872 Candidate.FailureKind = ovl_fail_too_few_arguments; 4873 return; 4874 } 4875 4876 Candidate.Viable = true; 4877 4878 if (Method->isStatic() || ObjectType.isNull()) 4879 // The implicit object argument is ignored. 4880 Candidate.IgnoreObjectArgument = true; 4881 else { 4882 // Determine the implicit conversion sequence for the object 4883 // parameter. 4884 Candidate.Conversions[0] 4885 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 4886 Method, ActingContext); 4887 if (Candidate.Conversions[0].isBad()) { 4888 Candidate.Viable = false; 4889 Candidate.FailureKind = ovl_fail_bad_conversion; 4890 return; 4891 } 4892 } 4893 4894 // Determine the implicit conversion sequences for each of the 4895 // arguments. 4896 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4897 if (ArgIdx < NumArgsInProto) { 4898 // (C++ 13.3.2p3): for F to be a viable function, there shall 4899 // exist for each argument an implicit conversion sequence 4900 // (13.3.3.1) that converts that argument to the corresponding 4901 // parameter of F. 4902 QualType ParamType = Proto->getArgType(ArgIdx); 4903 Candidate.Conversions[ArgIdx + 1] 4904 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4905 SuppressUserConversions, 4906 /*InOverloadResolution=*/true, 4907 /*AllowObjCWritebackConversion=*/ 4908 getLangOptions().ObjCAutoRefCount); 4909 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4910 Candidate.Viable = false; 4911 Candidate.FailureKind = ovl_fail_bad_conversion; 4912 break; 4913 } 4914 } else { 4915 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4916 // argument for which there is no corresponding parameter is 4917 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4918 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4919 } 4920 } 4921} 4922 4923/// \brief Add a C++ member function template as a candidate to the candidate 4924/// set, using template argument deduction to produce an appropriate member 4925/// function template specialization. 4926void 4927Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 4928 DeclAccessPair FoundDecl, 4929 CXXRecordDecl *ActingContext, 4930 TemplateArgumentListInfo *ExplicitTemplateArgs, 4931 QualType ObjectType, 4932 Expr::Classification ObjectClassification, 4933 Expr **Args, unsigned NumArgs, 4934 OverloadCandidateSet& CandidateSet, 4935 bool SuppressUserConversions) { 4936 if (!CandidateSet.isNewCandidate(MethodTmpl)) 4937 return; 4938 4939 // C++ [over.match.funcs]p7: 4940 // In each case where a candidate is a function template, candidate 4941 // function template specializations are generated using template argument 4942 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4943 // candidate functions in the usual way.113) A given name can refer to one 4944 // or more function templates and also to a set of overloaded non-template 4945 // functions. In such a case, the candidate functions generated from each 4946 // function template are combined with the set of non-template candidate 4947 // functions. 4948 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4949 FunctionDecl *Specialization = 0; 4950 if (TemplateDeductionResult Result 4951 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 4952 Args, NumArgs, Specialization, Info)) { 4953 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 4954 Candidate.FoundDecl = FoundDecl; 4955 Candidate.Function = MethodTmpl->getTemplatedDecl(); 4956 Candidate.Viable = false; 4957 Candidate.FailureKind = ovl_fail_bad_deduction; 4958 Candidate.IsSurrogate = false; 4959 Candidate.IgnoreObjectArgument = false; 4960 Candidate.ExplicitCallArguments = NumArgs; 4961 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4962 Info); 4963 return; 4964 } 4965 4966 // Add the function template specialization produced by template argument 4967 // deduction as a candidate. 4968 assert(Specialization && "Missing member function template specialization?"); 4969 assert(isa<CXXMethodDecl>(Specialization) && 4970 "Specialization is not a member function?"); 4971 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 4972 ActingContext, ObjectType, ObjectClassification, 4973 Args, NumArgs, CandidateSet, SuppressUserConversions); 4974} 4975 4976/// \brief Add a C++ function template specialization as a candidate 4977/// in the candidate set, using template argument deduction to produce 4978/// an appropriate function template specialization. 4979void 4980Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 4981 DeclAccessPair FoundDecl, 4982 TemplateArgumentListInfo *ExplicitTemplateArgs, 4983 Expr **Args, unsigned NumArgs, 4984 OverloadCandidateSet& CandidateSet, 4985 bool SuppressUserConversions) { 4986 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4987 return; 4988 4989 // C++ [over.match.funcs]p7: 4990 // In each case where a candidate is a function template, candidate 4991 // function template specializations are generated using template argument 4992 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4993 // candidate functions in the usual way.113) A given name can refer to one 4994 // or more function templates and also to a set of overloaded non-template 4995 // functions. In such a case, the candidate functions generated from each 4996 // function template are combined with the set of non-template candidate 4997 // functions. 4998 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4999 FunctionDecl *Specialization = 0; 5000 if (TemplateDeductionResult Result 5001 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5002 Args, NumArgs, Specialization, Info)) { 5003 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5004 Candidate.FoundDecl = FoundDecl; 5005 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 5006 Candidate.Viable = false; 5007 Candidate.FailureKind = ovl_fail_bad_deduction; 5008 Candidate.IsSurrogate = false; 5009 Candidate.IgnoreObjectArgument = false; 5010 Candidate.ExplicitCallArguments = NumArgs; 5011 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5012 Info); 5013 return; 5014 } 5015 5016 // Add the function template specialization produced by template argument 5017 // deduction as a candidate. 5018 assert(Specialization && "Missing function template specialization?"); 5019 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 5020 SuppressUserConversions); 5021} 5022 5023/// AddConversionCandidate - Add a C++ conversion function as a 5024/// candidate in the candidate set (C++ [over.match.conv], 5025/// C++ [over.match.copy]). From is the expression we're converting from, 5026/// and ToType is the type that we're eventually trying to convert to 5027/// (which may or may not be the same type as the type that the 5028/// conversion function produces). 5029void 5030Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 5031 DeclAccessPair FoundDecl, 5032 CXXRecordDecl *ActingContext, 5033 Expr *From, QualType ToType, 5034 OverloadCandidateSet& CandidateSet) { 5035 assert(!Conversion->getDescribedFunctionTemplate() && 5036 "Conversion function templates use AddTemplateConversionCandidate"); 5037 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 5038 if (!CandidateSet.isNewCandidate(Conversion)) 5039 return; 5040 5041 // Overload resolution is always an unevaluated context. 5042 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5043 5044 // Add this candidate 5045 OverloadCandidate &Candidate = CandidateSet.addCandidate(1); 5046 Candidate.FoundDecl = FoundDecl; 5047 Candidate.Function = Conversion; 5048 Candidate.IsSurrogate = false; 5049 Candidate.IgnoreObjectArgument = false; 5050 Candidate.FinalConversion.setAsIdentityConversion(); 5051 Candidate.FinalConversion.setFromType(ConvType); 5052 Candidate.FinalConversion.setAllToTypes(ToType); 5053 Candidate.Viable = true; 5054 Candidate.ExplicitCallArguments = 1; 5055 5056 // C++ [over.match.funcs]p4: 5057 // For conversion functions, the function is considered to be a member of 5058 // the class of the implicit implied object argument for the purpose of 5059 // defining the type of the implicit object parameter. 5060 // 5061 // Determine the implicit conversion sequence for the implicit 5062 // object parameter. 5063 QualType ImplicitParamType = From->getType(); 5064 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 5065 ImplicitParamType = FromPtrType->getPointeeType(); 5066 CXXRecordDecl *ConversionContext 5067 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 5068 5069 Candidate.Conversions[0] 5070 = TryObjectArgumentInitialization(*this, From->getType(), 5071 From->Classify(Context), 5072 Conversion, ConversionContext); 5073 5074 if (Candidate.Conversions[0].isBad()) { 5075 Candidate.Viable = false; 5076 Candidate.FailureKind = ovl_fail_bad_conversion; 5077 return; 5078 } 5079 5080 // We won't go through a user-define type conversion function to convert a 5081 // derived to base as such conversions are given Conversion Rank. They only 5082 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 5083 QualType FromCanon 5084 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 5085 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 5086 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 5087 Candidate.Viable = false; 5088 Candidate.FailureKind = ovl_fail_trivial_conversion; 5089 return; 5090 } 5091 5092 // To determine what the conversion from the result of calling the 5093 // conversion function to the type we're eventually trying to 5094 // convert to (ToType), we need to synthesize a call to the 5095 // conversion function and attempt copy initialization from it. This 5096 // makes sure that we get the right semantics with respect to 5097 // lvalues/rvalues and the type. Fortunately, we can allocate this 5098 // call on the stack and we don't need its arguments to be 5099 // well-formed. 5100 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 5101 VK_LValue, From->getLocStart()); 5102 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 5103 Context.getPointerType(Conversion->getType()), 5104 CK_FunctionToPointerDecay, 5105 &ConversionRef, VK_RValue); 5106 5107 QualType ConversionType = Conversion->getConversionType(); 5108 if (RequireCompleteType(From->getLocStart(), ConversionType, 0)) { 5109 Candidate.Viable = false; 5110 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5111 return; 5112 } 5113 5114 ExprValueKind VK = Expr::getValueKindForType(ConversionType); 5115 5116 // Note that it is safe to allocate CallExpr on the stack here because 5117 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 5118 // allocator). 5119 QualType CallResultType = ConversionType.getNonLValueExprType(Context); 5120 CallExpr Call(Context, &ConversionFn, 0, 0, CallResultType, VK, 5121 From->getLocStart()); 5122 ImplicitConversionSequence ICS = 5123 TryCopyInitialization(*this, &Call, ToType, 5124 /*SuppressUserConversions=*/true, 5125 /*InOverloadResolution=*/false, 5126 /*AllowObjCWritebackConversion=*/false); 5127 5128 switch (ICS.getKind()) { 5129 case ImplicitConversionSequence::StandardConversion: 5130 Candidate.FinalConversion = ICS.Standard; 5131 5132 // C++ [over.ics.user]p3: 5133 // If the user-defined conversion is specified by a specialization of a 5134 // conversion function template, the second standard conversion sequence 5135 // shall have exact match rank. 5136 if (Conversion->getPrimaryTemplate() && 5137 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 5138 Candidate.Viable = false; 5139 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 5140 } 5141 5142 // C++0x [dcl.init.ref]p5: 5143 // In the second case, if the reference is an rvalue reference and 5144 // the second standard conversion sequence of the user-defined 5145 // conversion sequence includes an lvalue-to-rvalue conversion, the 5146 // program is ill-formed. 5147 if (ToType->isRValueReferenceType() && 5148 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 5149 Candidate.Viable = false; 5150 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5151 } 5152 break; 5153 5154 case ImplicitConversionSequence::BadConversion: 5155 Candidate.Viable = false; 5156 Candidate.FailureKind = ovl_fail_bad_final_conversion; 5157 break; 5158 5159 default: 5160 llvm_unreachable( 5161 "Can only end up with a standard conversion sequence or failure"); 5162 } 5163} 5164 5165/// \brief Adds a conversion function template specialization 5166/// candidate to the overload set, using template argument deduction 5167/// to deduce the template arguments of the conversion function 5168/// template from the type that we are converting to (C++ 5169/// [temp.deduct.conv]). 5170void 5171Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 5172 DeclAccessPair FoundDecl, 5173 CXXRecordDecl *ActingDC, 5174 Expr *From, QualType ToType, 5175 OverloadCandidateSet &CandidateSet) { 5176 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 5177 "Only conversion function templates permitted here"); 5178 5179 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 5180 return; 5181 5182 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 5183 CXXConversionDecl *Specialization = 0; 5184 if (TemplateDeductionResult Result 5185 = DeduceTemplateArguments(FunctionTemplate, ToType, 5186 Specialization, Info)) { 5187 OverloadCandidate &Candidate = CandidateSet.addCandidate(); 5188 Candidate.FoundDecl = FoundDecl; 5189 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 5190 Candidate.Viable = false; 5191 Candidate.FailureKind = ovl_fail_bad_deduction; 5192 Candidate.IsSurrogate = false; 5193 Candidate.IgnoreObjectArgument = false; 5194 Candidate.ExplicitCallArguments = 1; 5195 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 5196 Info); 5197 return; 5198 } 5199 5200 // Add the conversion function template specialization produced by 5201 // template argument deduction as a candidate. 5202 assert(Specialization && "Missing function template specialization?"); 5203 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 5204 CandidateSet); 5205} 5206 5207/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 5208/// converts the given @c Object to a function pointer via the 5209/// conversion function @c Conversion, and then attempts to call it 5210/// with the given arguments (C++ [over.call.object]p2-4). Proto is 5211/// the type of function that we'll eventually be calling. 5212void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 5213 DeclAccessPair FoundDecl, 5214 CXXRecordDecl *ActingContext, 5215 const FunctionProtoType *Proto, 5216 Expr *Object, 5217 Expr **Args, unsigned NumArgs, 5218 OverloadCandidateSet& CandidateSet) { 5219 if (!CandidateSet.isNewCandidate(Conversion)) 5220 return; 5221 5222 // Overload resolution is always an unevaluated context. 5223 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5224 5225 OverloadCandidate &Candidate = CandidateSet.addCandidate(NumArgs + 1); 5226 Candidate.FoundDecl = FoundDecl; 5227 Candidate.Function = 0; 5228 Candidate.Surrogate = Conversion; 5229 Candidate.Viable = true; 5230 Candidate.IsSurrogate = true; 5231 Candidate.IgnoreObjectArgument = false; 5232 Candidate.ExplicitCallArguments = NumArgs; 5233 5234 // Determine the implicit conversion sequence for the implicit 5235 // object parameter. 5236 ImplicitConversionSequence ObjectInit 5237 = TryObjectArgumentInitialization(*this, Object->getType(), 5238 Object->Classify(Context), 5239 Conversion, ActingContext); 5240 if (ObjectInit.isBad()) { 5241 Candidate.Viable = false; 5242 Candidate.FailureKind = ovl_fail_bad_conversion; 5243 Candidate.Conversions[0] = ObjectInit; 5244 return; 5245 } 5246 5247 // The first conversion is actually a user-defined conversion whose 5248 // first conversion is ObjectInit's standard conversion (which is 5249 // effectively a reference binding). Record it as such. 5250 Candidate.Conversions[0].setUserDefined(); 5251 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 5252 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 5253 Candidate.Conversions[0].UserDefined.HadMultipleCandidates = false; 5254 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 5255 Candidate.Conversions[0].UserDefined.FoundConversionFunction = FoundDecl; 5256 Candidate.Conversions[0].UserDefined.After 5257 = Candidate.Conversions[0].UserDefined.Before; 5258 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 5259 5260 // Find the 5261 unsigned NumArgsInProto = Proto->getNumArgs(); 5262 5263 // (C++ 13.3.2p2): A candidate function having fewer than m 5264 // parameters is viable only if it has an ellipsis in its parameter 5265 // list (8.3.5). 5266 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 5267 Candidate.Viable = false; 5268 Candidate.FailureKind = ovl_fail_too_many_arguments; 5269 return; 5270 } 5271 5272 // Function types don't have any default arguments, so just check if 5273 // we have enough arguments. 5274 if (NumArgs < NumArgsInProto) { 5275 // Not enough arguments. 5276 Candidate.Viable = false; 5277 Candidate.FailureKind = ovl_fail_too_few_arguments; 5278 return; 5279 } 5280 5281 // Determine the implicit conversion sequences for each of the 5282 // arguments. 5283 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5284 if (ArgIdx < NumArgsInProto) { 5285 // (C++ 13.3.2p3): for F to be a viable function, there shall 5286 // exist for each argument an implicit conversion sequence 5287 // (13.3.3.1) that converts that argument to the corresponding 5288 // parameter of F. 5289 QualType ParamType = Proto->getArgType(ArgIdx); 5290 Candidate.Conversions[ArgIdx + 1] 5291 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 5292 /*SuppressUserConversions=*/false, 5293 /*InOverloadResolution=*/false, 5294 /*AllowObjCWritebackConversion=*/ 5295 getLangOptions().ObjCAutoRefCount); 5296 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 5297 Candidate.Viable = false; 5298 Candidate.FailureKind = ovl_fail_bad_conversion; 5299 break; 5300 } 5301 } else { 5302 // (C++ 13.3.2p2): For the purposes of overload resolution, any 5303 // argument for which there is no corresponding parameter is 5304 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 5305 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 5306 } 5307 } 5308} 5309 5310/// \brief Add overload candidates for overloaded operators that are 5311/// member functions. 5312/// 5313/// Add the overloaded operator candidates that are member functions 5314/// for the operator Op that was used in an operator expression such 5315/// as "x Op y". , Args/NumArgs provides the operator arguments, and 5316/// CandidateSet will store the added overload candidates. (C++ 5317/// [over.match.oper]). 5318void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 5319 SourceLocation OpLoc, 5320 Expr **Args, unsigned NumArgs, 5321 OverloadCandidateSet& CandidateSet, 5322 SourceRange OpRange) { 5323 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 5324 5325 // C++ [over.match.oper]p3: 5326 // For a unary operator @ with an operand of a type whose 5327 // cv-unqualified version is T1, and for a binary operator @ with 5328 // a left operand of a type whose cv-unqualified version is T1 and 5329 // a right operand of a type whose cv-unqualified version is T2, 5330 // three sets of candidate functions, designated member 5331 // candidates, non-member candidates and built-in candidates, are 5332 // constructed as follows: 5333 QualType T1 = Args[0]->getType(); 5334 5335 // -- If T1 is a class type, the set of member candidates is the 5336 // result of the qualified lookup of T1::operator@ 5337 // (13.3.1.1.1); otherwise, the set of member candidates is 5338 // empty. 5339 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 5340 // Complete the type if it can be completed. Otherwise, we're done. 5341 if (RequireCompleteType(OpLoc, T1, PDiag())) 5342 return; 5343 5344 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 5345 LookupQualifiedName(Operators, T1Rec->getDecl()); 5346 Operators.suppressDiagnostics(); 5347 5348 for (LookupResult::iterator Oper = Operators.begin(), 5349 OperEnd = Operators.end(); 5350 Oper != OperEnd; 5351 ++Oper) 5352 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 5353 Args[0]->Classify(Context), Args + 1, NumArgs - 1, 5354 CandidateSet, 5355 /* SuppressUserConversions = */ false); 5356 } 5357} 5358 5359/// AddBuiltinCandidate - Add a candidate for a built-in 5360/// operator. ResultTy and ParamTys are the result and parameter types 5361/// of the built-in candidate, respectively. Args and NumArgs are the 5362/// arguments being passed to the candidate. IsAssignmentOperator 5363/// should be true when this built-in candidate is an assignment 5364/// operator. NumContextualBoolArguments is the number of arguments 5365/// (at the beginning of the argument list) that will be contextually 5366/// converted to bool. 5367void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 5368 Expr **Args, unsigned NumArgs, 5369 OverloadCandidateSet& CandidateSet, 5370 bool IsAssignmentOperator, 5371 unsigned NumContextualBoolArguments) { 5372 // Overload resolution is always an unevaluated context. 5373 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 5374 5375 // Add this candidate 5376 OverloadCandidate &Candidate = CandidateSet.addCandidate(NumArgs); 5377 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 5378 Candidate.Function = 0; 5379 Candidate.IsSurrogate = false; 5380 Candidate.IgnoreObjectArgument = false; 5381 Candidate.BuiltinTypes.ResultTy = ResultTy; 5382 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5383 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 5384 5385 // Determine the implicit conversion sequences for each of the 5386 // arguments. 5387 Candidate.Viable = true; 5388 Candidate.ExplicitCallArguments = NumArgs; 5389 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5390 // C++ [over.match.oper]p4: 5391 // For the built-in assignment operators, conversions of the 5392 // left operand are restricted as follows: 5393 // -- no temporaries are introduced to hold the left operand, and 5394 // -- no user-defined conversions are applied to the left 5395 // operand to achieve a type match with the left-most 5396 // parameter of a built-in candidate. 5397 // 5398 // We block these conversions by turning off user-defined 5399 // conversions, since that is the only way that initialization of 5400 // a reference to a non-class type can occur from something that 5401 // is not of the same type. 5402 if (ArgIdx < NumContextualBoolArguments) { 5403 assert(ParamTys[ArgIdx] == Context.BoolTy && 5404 "Contextual conversion to bool requires bool type"); 5405 Candidate.Conversions[ArgIdx] 5406 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 5407 } else { 5408 Candidate.Conversions[ArgIdx] 5409 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 5410 ArgIdx == 0 && IsAssignmentOperator, 5411 /*InOverloadResolution=*/false, 5412 /*AllowObjCWritebackConversion=*/ 5413 getLangOptions().ObjCAutoRefCount); 5414 } 5415 if (Candidate.Conversions[ArgIdx].isBad()) { 5416 Candidate.Viable = false; 5417 Candidate.FailureKind = ovl_fail_bad_conversion; 5418 break; 5419 } 5420 } 5421} 5422 5423/// BuiltinCandidateTypeSet - A set of types that will be used for the 5424/// candidate operator functions for built-in operators (C++ 5425/// [over.built]). The types are separated into pointer types and 5426/// enumeration types. 5427class BuiltinCandidateTypeSet { 5428 /// TypeSet - A set of types. 5429 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 5430 5431 /// PointerTypes - The set of pointer types that will be used in the 5432 /// built-in candidates. 5433 TypeSet PointerTypes; 5434 5435 /// MemberPointerTypes - The set of member pointer types that will be 5436 /// used in the built-in candidates. 5437 TypeSet MemberPointerTypes; 5438 5439 /// EnumerationTypes - The set of enumeration types that will be 5440 /// used in the built-in candidates. 5441 TypeSet EnumerationTypes; 5442 5443 /// \brief The set of vector types that will be used in the built-in 5444 /// candidates. 5445 TypeSet VectorTypes; 5446 5447 /// \brief A flag indicating non-record types are viable candidates 5448 bool HasNonRecordTypes; 5449 5450 /// \brief A flag indicating whether either arithmetic or enumeration types 5451 /// were present in the candidate set. 5452 bool HasArithmeticOrEnumeralTypes; 5453 5454 /// \brief A flag indicating whether the nullptr type was present in the 5455 /// candidate set. 5456 bool HasNullPtrType; 5457 5458 /// Sema - The semantic analysis instance where we are building the 5459 /// candidate type set. 5460 Sema &SemaRef; 5461 5462 /// Context - The AST context in which we will build the type sets. 5463 ASTContext &Context; 5464 5465 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 5466 const Qualifiers &VisibleQuals); 5467 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 5468 5469public: 5470 /// iterator - Iterates through the types that are part of the set. 5471 typedef TypeSet::iterator iterator; 5472 5473 BuiltinCandidateTypeSet(Sema &SemaRef) 5474 : HasNonRecordTypes(false), 5475 HasArithmeticOrEnumeralTypes(false), 5476 HasNullPtrType(false), 5477 SemaRef(SemaRef), 5478 Context(SemaRef.Context) { } 5479 5480 void AddTypesConvertedFrom(QualType Ty, 5481 SourceLocation Loc, 5482 bool AllowUserConversions, 5483 bool AllowExplicitConversions, 5484 const Qualifiers &VisibleTypeConversionsQuals); 5485 5486 /// pointer_begin - First pointer type found; 5487 iterator pointer_begin() { return PointerTypes.begin(); } 5488 5489 /// pointer_end - Past the last pointer type found; 5490 iterator pointer_end() { return PointerTypes.end(); } 5491 5492 /// member_pointer_begin - First member pointer type found; 5493 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 5494 5495 /// member_pointer_end - Past the last member pointer type found; 5496 iterator member_pointer_end() { return MemberPointerTypes.end(); } 5497 5498 /// enumeration_begin - First enumeration type found; 5499 iterator enumeration_begin() { return EnumerationTypes.begin(); } 5500 5501 /// enumeration_end - Past the last enumeration type found; 5502 iterator enumeration_end() { return EnumerationTypes.end(); } 5503 5504 iterator vector_begin() { return VectorTypes.begin(); } 5505 iterator vector_end() { return VectorTypes.end(); } 5506 5507 bool hasNonRecordTypes() { return HasNonRecordTypes; } 5508 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 5509 bool hasNullPtrType() const { return HasNullPtrType; } 5510}; 5511 5512/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 5513/// the set of pointer types along with any more-qualified variants of 5514/// that type. For example, if @p Ty is "int const *", this routine 5515/// will add "int const *", "int const volatile *", "int const 5516/// restrict *", and "int const volatile restrict *" to the set of 5517/// pointer types. Returns true if the add of @p Ty itself succeeded, 5518/// false otherwise. 5519/// 5520/// FIXME: what to do about extended qualifiers? 5521bool 5522BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 5523 const Qualifiers &VisibleQuals) { 5524 5525 // Insert this type. 5526 if (!PointerTypes.insert(Ty)) 5527 return false; 5528 5529 QualType PointeeTy; 5530 const PointerType *PointerTy = Ty->getAs<PointerType>(); 5531 bool buildObjCPtr = false; 5532 if (!PointerTy) { 5533 if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) { 5534 PointeeTy = PTy->getPointeeType(); 5535 buildObjCPtr = true; 5536 } 5537 else 5538 llvm_unreachable("type was not a pointer type!"); 5539 } 5540 else 5541 PointeeTy = PointerTy->getPointeeType(); 5542 5543 // Don't add qualified variants of arrays. For one, they're not allowed 5544 // (the qualifier would sink to the element type), and for another, the 5545 // only overload situation where it matters is subscript or pointer +- int, 5546 // and those shouldn't have qualifier variants anyway. 5547 if (PointeeTy->isArrayType()) 5548 return true; 5549 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 5550 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 5551 BaseCVR = Array->getElementType().getCVRQualifiers(); 5552 bool hasVolatile = VisibleQuals.hasVolatile(); 5553 bool hasRestrict = VisibleQuals.hasRestrict(); 5554 5555 // Iterate through all strict supersets of BaseCVR. 5556 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 5557 if ((CVR | BaseCVR) != CVR) continue; 5558 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 5559 // in the types. 5560 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 5561 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 5562 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 5563 if (!buildObjCPtr) 5564 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 5565 else 5566 PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); 5567 } 5568 5569 return true; 5570} 5571 5572/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 5573/// to the set of pointer types along with any more-qualified variants of 5574/// that type. For example, if @p Ty is "int const *", this routine 5575/// will add "int const *", "int const volatile *", "int const 5576/// restrict *", and "int const volatile restrict *" to the set of 5577/// pointer types. Returns true if the add of @p Ty itself succeeded, 5578/// false otherwise. 5579/// 5580/// FIXME: what to do about extended qualifiers? 5581bool 5582BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 5583 QualType Ty) { 5584 // Insert this type. 5585 if (!MemberPointerTypes.insert(Ty)) 5586 return false; 5587 5588 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 5589 assert(PointerTy && "type was not a member pointer type!"); 5590 5591 QualType PointeeTy = PointerTy->getPointeeType(); 5592 // Don't add qualified variants of arrays. For one, they're not allowed 5593 // (the qualifier would sink to the element type), and for another, the 5594 // only overload situation where it matters is subscript or pointer +- int, 5595 // and those shouldn't have qualifier variants anyway. 5596 if (PointeeTy->isArrayType()) 5597 return true; 5598 const Type *ClassTy = PointerTy->getClass(); 5599 5600 // Iterate through all strict supersets of the pointee type's CVR 5601 // qualifiers. 5602 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 5603 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 5604 if ((CVR | BaseCVR) != CVR) continue; 5605 5606 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 5607 MemberPointerTypes.insert( 5608 Context.getMemberPointerType(QPointeeTy, ClassTy)); 5609 } 5610 5611 return true; 5612} 5613 5614/// AddTypesConvertedFrom - Add each of the types to which the type @p 5615/// Ty can be implicit converted to the given set of @p Types. We're 5616/// primarily interested in pointer types and enumeration types. We also 5617/// take member pointer types, for the conditional operator. 5618/// AllowUserConversions is true if we should look at the conversion 5619/// functions of a class type, and AllowExplicitConversions if we 5620/// should also include the explicit conversion functions of a class 5621/// type. 5622void 5623BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 5624 SourceLocation Loc, 5625 bool AllowUserConversions, 5626 bool AllowExplicitConversions, 5627 const Qualifiers &VisibleQuals) { 5628 // Only deal with canonical types. 5629 Ty = Context.getCanonicalType(Ty); 5630 5631 // Look through reference types; they aren't part of the type of an 5632 // expression for the purposes of conversions. 5633 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 5634 Ty = RefTy->getPointeeType(); 5635 5636 // If we're dealing with an array type, decay to the pointer. 5637 if (Ty->isArrayType()) 5638 Ty = SemaRef.Context.getArrayDecayedType(Ty); 5639 5640 // Otherwise, we don't care about qualifiers on the type. 5641 Ty = Ty.getLocalUnqualifiedType(); 5642 5643 // Flag if we ever add a non-record type. 5644 const RecordType *TyRec = Ty->getAs<RecordType>(); 5645 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 5646 5647 // Flag if we encounter an arithmetic type. 5648 HasArithmeticOrEnumeralTypes = 5649 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 5650 5651 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 5652 PointerTypes.insert(Ty); 5653 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 5654 // Insert our type, and its more-qualified variants, into the set 5655 // of types. 5656 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 5657 return; 5658 } else if (Ty->isMemberPointerType()) { 5659 // Member pointers are far easier, since the pointee can't be converted. 5660 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 5661 return; 5662 } else if (Ty->isEnumeralType()) { 5663 HasArithmeticOrEnumeralTypes = true; 5664 EnumerationTypes.insert(Ty); 5665 } else if (Ty->isVectorType()) { 5666 // We treat vector types as arithmetic types in many contexts as an 5667 // extension. 5668 HasArithmeticOrEnumeralTypes = true; 5669 VectorTypes.insert(Ty); 5670 } else if (Ty->isNullPtrType()) { 5671 HasNullPtrType = true; 5672 } else if (AllowUserConversions && TyRec) { 5673 // No conversion functions in incomplete types. 5674 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 5675 return; 5676 5677 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 5678 const UnresolvedSetImpl *Conversions 5679 = ClassDecl->getVisibleConversionFunctions(); 5680 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 5681 E = Conversions->end(); I != E; ++I) { 5682 NamedDecl *D = I.getDecl(); 5683 if (isa<UsingShadowDecl>(D)) 5684 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 5685 5686 // Skip conversion function templates; they don't tell us anything 5687 // about which builtin types we can convert to. 5688 if (isa<FunctionTemplateDecl>(D)) 5689 continue; 5690 5691 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 5692 if (AllowExplicitConversions || !Conv->isExplicit()) { 5693 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 5694 VisibleQuals); 5695 } 5696 } 5697 } 5698} 5699 5700/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 5701/// the volatile- and non-volatile-qualified assignment operators for the 5702/// given type to the candidate set. 5703static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 5704 QualType T, 5705 Expr **Args, 5706 unsigned NumArgs, 5707 OverloadCandidateSet &CandidateSet) { 5708 QualType ParamTypes[2]; 5709 5710 // T& operator=(T&, T) 5711 ParamTypes[0] = S.Context.getLValueReferenceType(T); 5712 ParamTypes[1] = T; 5713 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5714 /*IsAssignmentOperator=*/true); 5715 5716 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 5717 // volatile T& operator=(volatile T&, T) 5718 ParamTypes[0] 5719 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 5720 ParamTypes[1] = T; 5721 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5722 /*IsAssignmentOperator=*/true); 5723 } 5724} 5725 5726/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 5727/// if any, found in visible type conversion functions found in ArgExpr's type. 5728static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 5729 Qualifiers VRQuals; 5730 const RecordType *TyRec; 5731 if (const MemberPointerType *RHSMPType = 5732 ArgExpr->getType()->getAs<MemberPointerType>()) 5733 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 5734 else 5735 TyRec = ArgExpr->getType()->getAs<RecordType>(); 5736 if (!TyRec) { 5737 // Just to be safe, assume the worst case. 5738 VRQuals.addVolatile(); 5739 VRQuals.addRestrict(); 5740 return VRQuals; 5741 } 5742 5743 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 5744 if (!ClassDecl->hasDefinition()) 5745 return VRQuals; 5746 5747 const UnresolvedSetImpl *Conversions = 5748 ClassDecl->getVisibleConversionFunctions(); 5749 5750 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 5751 E = Conversions->end(); I != E; ++I) { 5752 NamedDecl *D = I.getDecl(); 5753 if (isa<UsingShadowDecl>(D)) 5754 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 5755 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 5756 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 5757 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 5758 CanTy = ResTypeRef->getPointeeType(); 5759 // Need to go down the pointer/mempointer chain and add qualifiers 5760 // as see them. 5761 bool done = false; 5762 while (!done) { 5763 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 5764 CanTy = ResTypePtr->getPointeeType(); 5765 else if (const MemberPointerType *ResTypeMPtr = 5766 CanTy->getAs<MemberPointerType>()) 5767 CanTy = ResTypeMPtr->getPointeeType(); 5768 else 5769 done = true; 5770 if (CanTy.isVolatileQualified()) 5771 VRQuals.addVolatile(); 5772 if (CanTy.isRestrictQualified()) 5773 VRQuals.addRestrict(); 5774 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 5775 return VRQuals; 5776 } 5777 } 5778 } 5779 return VRQuals; 5780} 5781 5782namespace { 5783 5784/// \brief Helper class to manage the addition of builtin operator overload 5785/// candidates. It provides shared state and utility methods used throughout 5786/// the process, as well as a helper method to add each group of builtin 5787/// operator overloads from the standard to a candidate set. 5788class BuiltinOperatorOverloadBuilder { 5789 // Common instance state available to all overload candidate addition methods. 5790 Sema &S; 5791 Expr **Args; 5792 unsigned NumArgs; 5793 Qualifiers VisibleTypeConversionsQuals; 5794 bool HasArithmeticOrEnumeralCandidateType; 5795 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 5796 OverloadCandidateSet &CandidateSet; 5797 5798 // Define some constants used to index and iterate over the arithemetic types 5799 // provided via the getArithmeticType() method below. 5800 // The "promoted arithmetic types" are the arithmetic 5801 // types are that preserved by promotion (C++ [over.built]p2). 5802 static const unsigned FirstIntegralType = 3; 5803 static const unsigned LastIntegralType = 18; 5804 static const unsigned FirstPromotedIntegralType = 3, 5805 LastPromotedIntegralType = 9; 5806 static const unsigned FirstPromotedArithmeticType = 0, 5807 LastPromotedArithmeticType = 9; 5808 static const unsigned NumArithmeticTypes = 18; 5809 5810 /// \brief Get the canonical type for a given arithmetic type index. 5811 CanQualType getArithmeticType(unsigned index) { 5812 assert(index < NumArithmeticTypes); 5813 static CanQualType ASTContext::* const 5814 ArithmeticTypes[NumArithmeticTypes] = { 5815 // Start of promoted types. 5816 &ASTContext::FloatTy, 5817 &ASTContext::DoubleTy, 5818 &ASTContext::LongDoubleTy, 5819 5820 // Start of integral types. 5821 &ASTContext::IntTy, 5822 &ASTContext::LongTy, 5823 &ASTContext::LongLongTy, 5824 &ASTContext::UnsignedIntTy, 5825 &ASTContext::UnsignedLongTy, 5826 &ASTContext::UnsignedLongLongTy, 5827 // End of promoted types. 5828 5829 &ASTContext::BoolTy, 5830 &ASTContext::CharTy, 5831 &ASTContext::WCharTy, 5832 &ASTContext::Char16Ty, 5833 &ASTContext::Char32Ty, 5834 &ASTContext::SignedCharTy, 5835 &ASTContext::ShortTy, 5836 &ASTContext::UnsignedCharTy, 5837 &ASTContext::UnsignedShortTy, 5838 // End of integral types. 5839 // FIXME: What about complex? 5840 }; 5841 return S.Context.*ArithmeticTypes[index]; 5842 } 5843 5844 /// \brief Gets the canonical type resulting from the usual arithemetic 5845 /// converions for the given arithmetic types. 5846 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 5847 // Accelerator table for performing the usual arithmetic conversions. 5848 // The rules are basically: 5849 // - if either is floating-point, use the wider floating-point 5850 // - if same signedness, use the higher rank 5851 // - if same size, use unsigned of the higher rank 5852 // - use the larger type 5853 // These rules, together with the axiom that higher ranks are 5854 // never smaller, are sufficient to precompute all of these results 5855 // *except* when dealing with signed types of higher rank. 5856 // (we could precompute SLL x UI for all known platforms, but it's 5857 // better not to make any assumptions). 5858 enum PromotedType { 5859 Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL, Dep=-1 5860 }; 5861 static PromotedType ConversionsTable[LastPromotedArithmeticType] 5862 [LastPromotedArithmeticType] = { 5863 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt }, 5864 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 5865 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 5866 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL }, 5867 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, Dep, UL, ULL }, 5868 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, Dep, Dep, ULL }, 5869 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, UI, UL, ULL }, 5870 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, UL, UL, ULL }, 5871 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, ULL, ULL, ULL }, 5872 }; 5873 5874 assert(L < LastPromotedArithmeticType); 5875 assert(R < LastPromotedArithmeticType); 5876 int Idx = ConversionsTable[L][R]; 5877 5878 // Fast path: the table gives us a concrete answer. 5879 if (Idx != Dep) return getArithmeticType(Idx); 5880 5881 // Slow path: we need to compare widths. 5882 // An invariant is that the signed type has higher rank. 5883 CanQualType LT = getArithmeticType(L), 5884 RT = getArithmeticType(R); 5885 unsigned LW = S.Context.getIntWidth(LT), 5886 RW = S.Context.getIntWidth(RT); 5887 5888 // If they're different widths, use the signed type. 5889 if (LW > RW) return LT; 5890 else if (LW < RW) return RT; 5891 5892 // Otherwise, use the unsigned type of the signed type's rank. 5893 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 5894 assert(L == SLL || R == SLL); 5895 return S.Context.UnsignedLongLongTy; 5896 } 5897 5898 /// \brief Helper method to factor out the common pattern of adding overloads 5899 /// for '++' and '--' builtin operators. 5900 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 5901 bool HasVolatile) { 5902 QualType ParamTypes[2] = { 5903 S.Context.getLValueReferenceType(CandidateTy), 5904 S.Context.IntTy 5905 }; 5906 5907 // Non-volatile version. 5908 if (NumArgs == 1) 5909 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5910 else 5911 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5912 5913 // Use a heuristic to reduce number of builtin candidates in the set: 5914 // add volatile version only if there are conversions to a volatile type. 5915 if (HasVolatile) { 5916 ParamTypes[0] = 5917 S.Context.getLValueReferenceType( 5918 S.Context.getVolatileType(CandidateTy)); 5919 if (NumArgs == 1) 5920 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5921 else 5922 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5923 } 5924 } 5925 5926public: 5927 BuiltinOperatorOverloadBuilder( 5928 Sema &S, Expr **Args, unsigned NumArgs, 5929 Qualifiers VisibleTypeConversionsQuals, 5930 bool HasArithmeticOrEnumeralCandidateType, 5931 SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 5932 OverloadCandidateSet &CandidateSet) 5933 : S(S), Args(Args), NumArgs(NumArgs), 5934 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 5935 HasArithmeticOrEnumeralCandidateType( 5936 HasArithmeticOrEnumeralCandidateType), 5937 CandidateTypes(CandidateTypes), 5938 CandidateSet(CandidateSet) { 5939 // Validate some of our static helper constants in debug builds. 5940 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 5941 "Invalid first promoted integral type"); 5942 assert(getArithmeticType(LastPromotedIntegralType - 1) 5943 == S.Context.UnsignedLongLongTy && 5944 "Invalid last promoted integral type"); 5945 assert(getArithmeticType(FirstPromotedArithmeticType) 5946 == S.Context.FloatTy && 5947 "Invalid first promoted arithmetic type"); 5948 assert(getArithmeticType(LastPromotedArithmeticType - 1) 5949 == S.Context.UnsignedLongLongTy && 5950 "Invalid last promoted arithmetic type"); 5951 } 5952 5953 // C++ [over.built]p3: 5954 // 5955 // For every pair (T, VQ), where T is an arithmetic type, and VQ 5956 // is either volatile or empty, there exist candidate operator 5957 // functions of the form 5958 // 5959 // VQ T& operator++(VQ T&); 5960 // T operator++(VQ T&, int); 5961 // 5962 // C++ [over.built]p4: 5963 // 5964 // For every pair (T, VQ), where T is an arithmetic type other 5965 // than bool, and VQ is either volatile or empty, there exist 5966 // candidate operator functions of the form 5967 // 5968 // VQ T& operator--(VQ T&); 5969 // T operator--(VQ T&, int); 5970 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 5971 if (!HasArithmeticOrEnumeralCandidateType) 5972 return; 5973 5974 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 5975 Arith < NumArithmeticTypes; ++Arith) { 5976 addPlusPlusMinusMinusStyleOverloads( 5977 getArithmeticType(Arith), 5978 VisibleTypeConversionsQuals.hasVolatile()); 5979 } 5980 } 5981 5982 // C++ [over.built]p5: 5983 // 5984 // For every pair (T, VQ), where T is a cv-qualified or 5985 // cv-unqualified object type, and VQ is either volatile or 5986 // empty, there exist candidate operator functions of the form 5987 // 5988 // T*VQ& operator++(T*VQ&); 5989 // T*VQ& operator--(T*VQ&); 5990 // T* operator++(T*VQ&, int); 5991 // T* operator--(T*VQ&, int); 5992 void addPlusPlusMinusMinusPointerOverloads() { 5993 for (BuiltinCandidateTypeSet::iterator 5994 Ptr = CandidateTypes[0].pointer_begin(), 5995 PtrEnd = CandidateTypes[0].pointer_end(); 5996 Ptr != PtrEnd; ++Ptr) { 5997 // Skip pointer types that aren't pointers to object types. 5998 if (!(*Ptr)->getPointeeType()->isObjectType()) 5999 continue; 6000 6001 addPlusPlusMinusMinusStyleOverloads(*Ptr, 6002 (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 6003 VisibleTypeConversionsQuals.hasVolatile())); 6004 } 6005 } 6006 6007 // C++ [over.built]p6: 6008 // For every cv-qualified or cv-unqualified object type T, there 6009 // exist candidate operator functions of the form 6010 // 6011 // T& operator*(T*); 6012 // 6013 // C++ [over.built]p7: 6014 // For every function type T that does not have cv-qualifiers or a 6015 // ref-qualifier, there exist candidate operator functions of the form 6016 // T& operator*(T*); 6017 void addUnaryStarPointerOverloads() { 6018 for (BuiltinCandidateTypeSet::iterator 6019 Ptr = CandidateTypes[0].pointer_begin(), 6020 PtrEnd = CandidateTypes[0].pointer_end(); 6021 Ptr != PtrEnd; ++Ptr) { 6022 QualType ParamTy = *Ptr; 6023 QualType PointeeTy = ParamTy->getPointeeType(); 6024 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 6025 continue; 6026 6027 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 6028 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 6029 continue; 6030 6031 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 6032 &ParamTy, Args, 1, CandidateSet); 6033 } 6034 } 6035 6036 // C++ [over.built]p9: 6037 // For every promoted arithmetic type T, there exist candidate 6038 // operator functions of the form 6039 // 6040 // T operator+(T); 6041 // T operator-(T); 6042 void addUnaryPlusOrMinusArithmeticOverloads() { 6043 if (!HasArithmeticOrEnumeralCandidateType) 6044 return; 6045 6046 for (unsigned Arith = FirstPromotedArithmeticType; 6047 Arith < LastPromotedArithmeticType; ++Arith) { 6048 QualType ArithTy = getArithmeticType(Arith); 6049 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 6050 } 6051 6052 // Extension: We also add these operators for vector types. 6053 for (BuiltinCandidateTypeSet::iterator 6054 Vec = CandidateTypes[0].vector_begin(), 6055 VecEnd = CandidateTypes[0].vector_end(); 6056 Vec != VecEnd; ++Vec) { 6057 QualType VecTy = *Vec; 6058 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 6059 } 6060 } 6061 6062 // C++ [over.built]p8: 6063 // For every type T, there exist candidate operator functions of 6064 // the form 6065 // 6066 // T* operator+(T*); 6067 void addUnaryPlusPointerOverloads() { 6068 for (BuiltinCandidateTypeSet::iterator 6069 Ptr = CandidateTypes[0].pointer_begin(), 6070 PtrEnd = CandidateTypes[0].pointer_end(); 6071 Ptr != PtrEnd; ++Ptr) { 6072 QualType ParamTy = *Ptr; 6073 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 6074 } 6075 } 6076 6077 // C++ [over.built]p10: 6078 // For every promoted integral type T, there exist candidate 6079 // operator functions of the form 6080 // 6081 // T operator~(T); 6082 void addUnaryTildePromotedIntegralOverloads() { 6083 if (!HasArithmeticOrEnumeralCandidateType) 6084 return; 6085 6086 for (unsigned Int = FirstPromotedIntegralType; 6087 Int < LastPromotedIntegralType; ++Int) { 6088 QualType IntTy = getArithmeticType(Int); 6089 S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 6090 } 6091 6092 // Extension: We also add this operator for vector types. 6093 for (BuiltinCandidateTypeSet::iterator 6094 Vec = CandidateTypes[0].vector_begin(), 6095 VecEnd = CandidateTypes[0].vector_end(); 6096 Vec != VecEnd; ++Vec) { 6097 QualType VecTy = *Vec; 6098 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 6099 } 6100 } 6101 6102 // C++ [over.match.oper]p16: 6103 // For every pointer to member type T, there exist candidate operator 6104 // functions of the form 6105 // 6106 // bool operator==(T,T); 6107 // bool operator!=(T,T); 6108 void addEqualEqualOrNotEqualMemberPointerOverloads() { 6109 /// Set of (canonical) types that we've already handled. 6110 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6111 6112 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6113 for (BuiltinCandidateTypeSet::iterator 6114 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 6115 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 6116 MemPtr != MemPtrEnd; 6117 ++MemPtr) { 6118 // Don't add the same builtin candidate twice. 6119 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 6120 continue; 6121 6122 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 6123 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6124 CandidateSet); 6125 } 6126 } 6127 } 6128 6129 // C++ [over.built]p15: 6130 // 6131 // For every T, where T is an enumeration type, a pointer type, or 6132 // std::nullptr_t, there exist candidate operator functions of the form 6133 // 6134 // bool operator<(T, T); 6135 // bool operator>(T, T); 6136 // bool operator<=(T, T); 6137 // bool operator>=(T, T); 6138 // bool operator==(T, T); 6139 // bool operator!=(T, T); 6140 void addRelationalPointerOrEnumeralOverloads() { 6141 // C++ [over.built]p1: 6142 // If there is a user-written candidate with the same name and parameter 6143 // types as a built-in candidate operator function, the built-in operator 6144 // function is hidden and is not included in the set of candidate 6145 // functions. 6146 // 6147 // The text is actually in a note, but if we don't implement it then we end 6148 // up with ambiguities when the user provides an overloaded operator for 6149 // an enumeration type. Note that only enumeration types have this problem, 6150 // so we track which enumeration types we've seen operators for. Also, the 6151 // only other overloaded operator with enumeration argumenst, operator=, 6152 // cannot be overloaded for enumeration types, so this is the only place 6153 // where we must suppress candidates like this. 6154 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 6155 UserDefinedBinaryOperators; 6156 6157 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6158 if (CandidateTypes[ArgIdx].enumeration_begin() != 6159 CandidateTypes[ArgIdx].enumeration_end()) { 6160 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 6161 CEnd = CandidateSet.end(); 6162 C != CEnd; ++C) { 6163 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 6164 continue; 6165 6166 QualType FirstParamType = 6167 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 6168 QualType SecondParamType = 6169 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 6170 6171 // Skip if either parameter isn't of enumeral type. 6172 if (!FirstParamType->isEnumeralType() || 6173 !SecondParamType->isEnumeralType()) 6174 continue; 6175 6176 // Add this operator to the set of known user-defined operators. 6177 UserDefinedBinaryOperators.insert( 6178 std::make_pair(S.Context.getCanonicalType(FirstParamType), 6179 S.Context.getCanonicalType(SecondParamType))); 6180 } 6181 } 6182 } 6183 6184 /// Set of (canonical) types that we've already handled. 6185 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6186 6187 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6188 for (BuiltinCandidateTypeSet::iterator 6189 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 6190 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 6191 Ptr != PtrEnd; ++Ptr) { 6192 // Don't add the same builtin candidate twice. 6193 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6194 continue; 6195 6196 QualType ParamTypes[2] = { *Ptr, *Ptr }; 6197 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6198 CandidateSet); 6199 } 6200 for (BuiltinCandidateTypeSet::iterator 6201 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 6202 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 6203 Enum != EnumEnd; ++Enum) { 6204 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 6205 6206 // Don't add the same builtin candidate twice, or if a user defined 6207 // candidate exists. 6208 if (!AddedTypes.insert(CanonType) || 6209 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 6210 CanonType))) 6211 continue; 6212 6213 QualType ParamTypes[2] = { *Enum, *Enum }; 6214 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6215 CandidateSet); 6216 } 6217 6218 if (CandidateTypes[ArgIdx].hasNullPtrType()) { 6219 CanQualType NullPtrTy = S.Context.getCanonicalType(S.Context.NullPtrTy); 6220 if (AddedTypes.insert(NullPtrTy) && 6221 !UserDefinedBinaryOperators.count(std::make_pair(NullPtrTy, 6222 NullPtrTy))) { 6223 QualType ParamTypes[2] = { NullPtrTy, NullPtrTy }; 6224 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 6225 CandidateSet); 6226 } 6227 } 6228 } 6229 } 6230 6231 // C++ [over.built]p13: 6232 // 6233 // For every cv-qualified or cv-unqualified object type T 6234 // there exist candidate operator functions of the form 6235 // 6236 // T* operator+(T*, ptrdiff_t); 6237 // T& operator[](T*, ptrdiff_t); [BELOW] 6238 // T* operator-(T*, ptrdiff_t); 6239 // T* operator+(ptrdiff_t, T*); 6240 // T& operator[](ptrdiff_t, T*); [BELOW] 6241 // 6242 // C++ [over.built]p14: 6243 // 6244 // For every T, where T is a pointer to object type, there 6245 // exist candidate operator functions of the form 6246 // 6247 // ptrdiff_t operator-(T, T); 6248 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 6249 /// Set of (canonical) types that we've already handled. 6250 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6251 6252 for (int Arg = 0; Arg < 2; ++Arg) { 6253 QualType AsymetricParamTypes[2] = { 6254 S.Context.getPointerDiffType(), 6255 S.Context.getPointerDiffType(), 6256 }; 6257 for (BuiltinCandidateTypeSet::iterator 6258 Ptr = CandidateTypes[Arg].pointer_begin(), 6259 PtrEnd = CandidateTypes[Arg].pointer_end(); 6260 Ptr != PtrEnd; ++Ptr) { 6261 QualType PointeeTy = (*Ptr)->getPointeeType(); 6262 if (!PointeeTy->isObjectType()) 6263 continue; 6264 6265 AsymetricParamTypes[Arg] = *Ptr; 6266 if (Arg == 0 || Op == OO_Plus) { 6267 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 6268 // T* operator+(ptrdiff_t, T*); 6269 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, 6270 CandidateSet); 6271 } 6272 if (Op == OO_Minus) { 6273 // ptrdiff_t operator-(T, T); 6274 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6275 continue; 6276 6277 QualType ParamTypes[2] = { *Ptr, *Ptr }; 6278 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 6279 Args, 2, CandidateSet); 6280 } 6281 } 6282 } 6283 } 6284 6285 // C++ [over.built]p12: 6286 // 6287 // For every pair of promoted arithmetic types L and R, there 6288 // exist candidate operator functions of the form 6289 // 6290 // LR operator*(L, R); 6291 // LR operator/(L, R); 6292 // LR operator+(L, R); 6293 // LR operator-(L, R); 6294 // bool operator<(L, R); 6295 // bool operator>(L, R); 6296 // bool operator<=(L, R); 6297 // bool operator>=(L, R); 6298 // bool operator==(L, R); 6299 // bool operator!=(L, R); 6300 // 6301 // where LR is the result of the usual arithmetic conversions 6302 // between types L and R. 6303 // 6304 // C++ [over.built]p24: 6305 // 6306 // For every pair of promoted arithmetic types L and R, there exist 6307 // candidate operator functions of the form 6308 // 6309 // LR operator?(bool, L, R); 6310 // 6311 // where LR is the result of the usual arithmetic conversions 6312 // between types L and R. 6313 // Our candidates ignore the first parameter. 6314 void addGenericBinaryArithmeticOverloads(bool isComparison) { 6315 if (!HasArithmeticOrEnumeralCandidateType) 6316 return; 6317 6318 for (unsigned Left = FirstPromotedArithmeticType; 6319 Left < LastPromotedArithmeticType; ++Left) { 6320 for (unsigned Right = FirstPromotedArithmeticType; 6321 Right < LastPromotedArithmeticType; ++Right) { 6322 QualType LandR[2] = { getArithmeticType(Left), 6323 getArithmeticType(Right) }; 6324 QualType Result = 6325 isComparison ? S.Context.BoolTy 6326 : getUsualArithmeticConversions(Left, Right); 6327 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 6328 } 6329 } 6330 6331 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 6332 // conditional operator for vector types. 6333 for (BuiltinCandidateTypeSet::iterator 6334 Vec1 = CandidateTypes[0].vector_begin(), 6335 Vec1End = CandidateTypes[0].vector_end(); 6336 Vec1 != Vec1End; ++Vec1) { 6337 for (BuiltinCandidateTypeSet::iterator 6338 Vec2 = CandidateTypes[1].vector_begin(), 6339 Vec2End = CandidateTypes[1].vector_end(); 6340 Vec2 != Vec2End; ++Vec2) { 6341 QualType LandR[2] = { *Vec1, *Vec2 }; 6342 QualType Result = S.Context.BoolTy; 6343 if (!isComparison) { 6344 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 6345 Result = *Vec1; 6346 else 6347 Result = *Vec2; 6348 } 6349 6350 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 6351 } 6352 } 6353 } 6354 6355 // C++ [over.built]p17: 6356 // 6357 // For every pair of promoted integral types L and R, there 6358 // exist candidate operator functions of the form 6359 // 6360 // LR operator%(L, R); 6361 // LR operator&(L, R); 6362 // LR operator^(L, R); 6363 // LR operator|(L, R); 6364 // L operator<<(L, R); 6365 // L operator>>(L, R); 6366 // 6367 // where LR is the result of the usual arithmetic conversions 6368 // between types L and R. 6369 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 6370 if (!HasArithmeticOrEnumeralCandidateType) 6371 return; 6372 6373 for (unsigned Left = FirstPromotedIntegralType; 6374 Left < LastPromotedIntegralType; ++Left) { 6375 for (unsigned Right = FirstPromotedIntegralType; 6376 Right < LastPromotedIntegralType; ++Right) { 6377 QualType LandR[2] = { getArithmeticType(Left), 6378 getArithmeticType(Right) }; 6379 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 6380 ? LandR[0] 6381 : getUsualArithmeticConversions(Left, Right); 6382 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 6383 } 6384 } 6385 } 6386 6387 // C++ [over.built]p20: 6388 // 6389 // For every pair (T, VQ), where T is an enumeration or 6390 // pointer to member type and VQ is either volatile or 6391 // empty, there exist candidate operator functions of the form 6392 // 6393 // VQ T& operator=(VQ T&, T); 6394 void addAssignmentMemberPointerOrEnumeralOverloads() { 6395 /// Set of (canonical) types that we've already handled. 6396 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6397 6398 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 6399 for (BuiltinCandidateTypeSet::iterator 6400 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 6401 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 6402 Enum != EnumEnd; ++Enum) { 6403 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 6404 continue; 6405 6406 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, 6407 CandidateSet); 6408 } 6409 6410 for (BuiltinCandidateTypeSet::iterator 6411 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 6412 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 6413 MemPtr != MemPtrEnd; ++MemPtr) { 6414 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 6415 continue; 6416 6417 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, 6418 CandidateSet); 6419 } 6420 } 6421 } 6422 6423 // C++ [over.built]p19: 6424 // 6425 // For every pair (T, VQ), where T is any type and VQ is either 6426 // volatile or empty, there exist candidate operator functions 6427 // of the form 6428 // 6429 // T*VQ& operator=(T*VQ&, T*); 6430 // 6431 // C++ [over.built]p21: 6432 // 6433 // For every pair (T, VQ), where T is a cv-qualified or 6434 // cv-unqualified object type and VQ is either volatile or 6435 // empty, there exist candidate operator functions of the form 6436 // 6437 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 6438 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 6439 void addAssignmentPointerOverloads(bool isEqualOp) { 6440 /// Set of (canonical) types that we've already handled. 6441 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6442 6443 for (BuiltinCandidateTypeSet::iterator 6444 Ptr = CandidateTypes[0].pointer_begin(), 6445 PtrEnd = CandidateTypes[0].pointer_end(); 6446 Ptr != PtrEnd; ++Ptr) { 6447 // If this is operator=, keep track of the builtin candidates we added. 6448 if (isEqualOp) 6449 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 6450 else if (!(*Ptr)->getPointeeType()->isObjectType()) 6451 continue; 6452 6453 // non-volatile version 6454 QualType ParamTypes[2] = { 6455 S.Context.getLValueReferenceType(*Ptr), 6456 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 6457 }; 6458 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6459 /*IsAssigmentOperator=*/ isEqualOp); 6460 6461 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 6462 VisibleTypeConversionsQuals.hasVolatile()) { 6463 // volatile version 6464 ParamTypes[0] = 6465 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 6466 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6467 /*IsAssigmentOperator=*/isEqualOp); 6468 } 6469 } 6470 6471 if (isEqualOp) { 6472 for (BuiltinCandidateTypeSet::iterator 6473 Ptr = CandidateTypes[1].pointer_begin(), 6474 PtrEnd = CandidateTypes[1].pointer_end(); 6475 Ptr != PtrEnd; ++Ptr) { 6476 // Make sure we don't add the same candidate twice. 6477 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6478 continue; 6479 6480 QualType ParamTypes[2] = { 6481 S.Context.getLValueReferenceType(*Ptr), 6482 *Ptr, 6483 }; 6484 6485 // non-volatile version 6486 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6487 /*IsAssigmentOperator=*/true); 6488 6489 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 6490 VisibleTypeConversionsQuals.hasVolatile()) { 6491 // volatile version 6492 ParamTypes[0] = 6493 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 6494 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 6495 CandidateSet, /*IsAssigmentOperator=*/true); 6496 } 6497 } 6498 } 6499 } 6500 6501 // C++ [over.built]p18: 6502 // 6503 // For every triple (L, VQ, R), where L is an arithmetic type, 6504 // VQ is either volatile or empty, and R is a promoted 6505 // arithmetic type, there exist candidate operator functions of 6506 // the form 6507 // 6508 // VQ L& operator=(VQ L&, R); 6509 // VQ L& operator*=(VQ L&, R); 6510 // VQ L& operator/=(VQ L&, R); 6511 // VQ L& operator+=(VQ L&, R); 6512 // VQ L& operator-=(VQ L&, R); 6513 void addAssignmentArithmeticOverloads(bool isEqualOp) { 6514 if (!HasArithmeticOrEnumeralCandidateType) 6515 return; 6516 6517 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 6518 for (unsigned Right = FirstPromotedArithmeticType; 6519 Right < LastPromotedArithmeticType; ++Right) { 6520 QualType ParamTypes[2]; 6521 ParamTypes[1] = getArithmeticType(Right); 6522 6523 // Add this built-in operator as a candidate (VQ is empty). 6524 ParamTypes[0] = 6525 S.Context.getLValueReferenceType(getArithmeticType(Left)); 6526 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6527 /*IsAssigmentOperator=*/isEqualOp); 6528 6529 // Add this built-in operator as a candidate (VQ is 'volatile'). 6530 if (VisibleTypeConversionsQuals.hasVolatile()) { 6531 ParamTypes[0] = 6532 S.Context.getVolatileType(getArithmeticType(Left)); 6533 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 6534 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 6535 CandidateSet, 6536 /*IsAssigmentOperator=*/isEqualOp); 6537 } 6538 } 6539 } 6540 6541 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 6542 for (BuiltinCandidateTypeSet::iterator 6543 Vec1 = CandidateTypes[0].vector_begin(), 6544 Vec1End = CandidateTypes[0].vector_end(); 6545 Vec1 != Vec1End; ++Vec1) { 6546 for (BuiltinCandidateTypeSet::iterator 6547 Vec2 = CandidateTypes[1].vector_begin(), 6548 Vec2End = CandidateTypes[1].vector_end(); 6549 Vec2 != Vec2End; ++Vec2) { 6550 QualType ParamTypes[2]; 6551 ParamTypes[1] = *Vec2; 6552 // Add this built-in operator as a candidate (VQ is empty). 6553 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 6554 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 6555 /*IsAssigmentOperator=*/isEqualOp); 6556 6557 // Add this built-in operator as a candidate (VQ is 'volatile'). 6558 if (VisibleTypeConversionsQuals.hasVolatile()) { 6559 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 6560 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 6561 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 6562 CandidateSet, 6563 /*IsAssigmentOperator=*/isEqualOp); 6564 } 6565 } 6566 } 6567 } 6568 6569 // C++ [over.built]p22: 6570 // 6571 // For every triple (L, VQ, R), where L is an integral type, VQ 6572 // is either volatile or empty, and R is a promoted integral 6573 // type, there exist candidate operator functions of the form 6574 // 6575 // VQ L& operator%=(VQ L&, R); 6576 // VQ L& operator<<=(VQ L&, R); 6577 // VQ L& operator>>=(VQ L&, R); 6578 // VQ L& operator&=(VQ L&, R); 6579 // VQ L& operator^=(VQ L&, R); 6580 // VQ L& operator|=(VQ L&, R); 6581 void addAssignmentIntegralOverloads() { 6582 if (!HasArithmeticOrEnumeralCandidateType) 6583 return; 6584 6585 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 6586 for (unsigned Right = FirstPromotedIntegralType; 6587 Right < LastPromotedIntegralType; ++Right) { 6588 QualType ParamTypes[2]; 6589 ParamTypes[1] = getArithmeticType(Right); 6590 6591 // Add this built-in operator as a candidate (VQ is empty). 6592 ParamTypes[0] = 6593 S.Context.getLValueReferenceType(getArithmeticType(Left)); 6594 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 6595 if (VisibleTypeConversionsQuals.hasVolatile()) { 6596 // Add this built-in operator as a candidate (VQ is 'volatile'). 6597 ParamTypes[0] = getArithmeticType(Left); 6598 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 6599 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 6600 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 6601 CandidateSet); 6602 } 6603 } 6604 } 6605 } 6606 6607 // C++ [over.operator]p23: 6608 // 6609 // There also exist candidate operator functions of the form 6610 // 6611 // bool operator!(bool); 6612 // bool operator&&(bool, bool); 6613 // bool operator||(bool, bool); 6614 void addExclaimOverload() { 6615 QualType ParamTy = S.Context.BoolTy; 6616 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 6617 /*IsAssignmentOperator=*/false, 6618 /*NumContextualBoolArguments=*/1); 6619 } 6620 void addAmpAmpOrPipePipeOverload() { 6621 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 6622 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 6623 /*IsAssignmentOperator=*/false, 6624 /*NumContextualBoolArguments=*/2); 6625 } 6626 6627 // C++ [over.built]p13: 6628 // 6629 // For every cv-qualified or cv-unqualified object type T there 6630 // exist candidate operator functions of the form 6631 // 6632 // T* operator+(T*, ptrdiff_t); [ABOVE] 6633 // T& operator[](T*, ptrdiff_t); 6634 // T* operator-(T*, ptrdiff_t); [ABOVE] 6635 // T* operator+(ptrdiff_t, T*); [ABOVE] 6636 // T& operator[](ptrdiff_t, T*); 6637 void addSubscriptOverloads() { 6638 for (BuiltinCandidateTypeSet::iterator 6639 Ptr = CandidateTypes[0].pointer_begin(), 6640 PtrEnd = CandidateTypes[0].pointer_end(); 6641 Ptr != PtrEnd; ++Ptr) { 6642 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 6643 QualType PointeeType = (*Ptr)->getPointeeType(); 6644 if (!PointeeType->isObjectType()) 6645 continue; 6646 6647 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 6648 6649 // T& operator[](T*, ptrdiff_t) 6650 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 6651 } 6652 6653 for (BuiltinCandidateTypeSet::iterator 6654 Ptr = CandidateTypes[1].pointer_begin(), 6655 PtrEnd = CandidateTypes[1].pointer_end(); 6656 Ptr != PtrEnd; ++Ptr) { 6657 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 6658 QualType PointeeType = (*Ptr)->getPointeeType(); 6659 if (!PointeeType->isObjectType()) 6660 continue; 6661 6662 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 6663 6664 // T& operator[](ptrdiff_t, T*) 6665 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 6666 } 6667 } 6668 6669 // C++ [over.built]p11: 6670 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 6671 // C1 is the same type as C2 or is a derived class of C2, T is an object 6672 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 6673 // there exist candidate operator functions of the form 6674 // 6675 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 6676 // 6677 // where CV12 is the union of CV1 and CV2. 6678 void addArrowStarOverloads() { 6679 for (BuiltinCandidateTypeSet::iterator 6680 Ptr = CandidateTypes[0].pointer_begin(), 6681 PtrEnd = CandidateTypes[0].pointer_end(); 6682 Ptr != PtrEnd; ++Ptr) { 6683 QualType C1Ty = (*Ptr); 6684 QualType C1; 6685 QualifierCollector Q1; 6686 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 6687 if (!isa<RecordType>(C1)) 6688 continue; 6689 // heuristic to reduce number of builtin candidates in the set. 6690 // Add volatile/restrict version only if there are conversions to a 6691 // volatile/restrict type. 6692 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 6693 continue; 6694 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 6695 continue; 6696 for (BuiltinCandidateTypeSet::iterator 6697 MemPtr = CandidateTypes[1].member_pointer_begin(), 6698 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 6699 MemPtr != MemPtrEnd; ++MemPtr) { 6700 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 6701 QualType C2 = QualType(mptr->getClass(), 0); 6702 C2 = C2.getUnqualifiedType(); 6703 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 6704 break; 6705 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 6706 // build CV12 T& 6707 QualType T = mptr->getPointeeType(); 6708 if (!VisibleTypeConversionsQuals.hasVolatile() && 6709 T.isVolatileQualified()) 6710 continue; 6711 if (!VisibleTypeConversionsQuals.hasRestrict() && 6712 T.isRestrictQualified()) 6713 continue; 6714 T = Q1.apply(S.Context, T); 6715 QualType ResultTy = S.Context.getLValueReferenceType(T); 6716 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 6717 } 6718 } 6719 } 6720 6721 // Note that we don't consider the first argument, since it has been 6722 // contextually converted to bool long ago. The candidates below are 6723 // therefore added as binary. 6724 // 6725 // C++ [over.built]p25: 6726 // For every type T, where T is a pointer, pointer-to-member, or scoped 6727 // enumeration type, there exist candidate operator functions of the form 6728 // 6729 // T operator?(bool, T, T); 6730 // 6731 void addConditionalOperatorOverloads() { 6732 /// Set of (canonical) types that we've already handled. 6733 llvm::SmallPtrSet<QualType, 8> AddedTypes; 6734 6735 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 6736 for (BuiltinCandidateTypeSet::iterator 6737 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 6738 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 6739 Ptr != PtrEnd; ++Ptr) { 6740 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 6741 continue; 6742 6743 QualType ParamTypes[2] = { *Ptr, *Ptr }; 6744 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 6745 } 6746 6747 for (BuiltinCandidateTypeSet::iterator 6748 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 6749 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 6750 MemPtr != MemPtrEnd; ++MemPtr) { 6751 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 6752 continue; 6753 6754 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 6755 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); 6756 } 6757 6758 if (S.getLangOptions().CPlusPlus0x) { 6759 for (BuiltinCandidateTypeSet::iterator 6760 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 6761 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 6762 Enum != EnumEnd; ++Enum) { 6763 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 6764 continue; 6765 6766 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 6767 continue; 6768 6769 QualType ParamTypes[2] = { *Enum, *Enum }; 6770 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); 6771 } 6772 } 6773 } 6774 } 6775}; 6776 6777} // end anonymous namespace 6778 6779/// AddBuiltinOperatorCandidates - Add the appropriate built-in 6780/// operator overloads to the candidate set (C++ [over.built]), based 6781/// on the operator @p Op and the arguments given. For example, if the 6782/// operator is a binary '+', this routine might add "int 6783/// operator+(int, int)" to cover integer addition. 6784void 6785Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 6786 SourceLocation OpLoc, 6787 Expr **Args, unsigned NumArgs, 6788 OverloadCandidateSet& CandidateSet) { 6789 // Find all of the types that the arguments can convert to, but only 6790 // if the operator we're looking at has built-in operator candidates 6791 // that make use of these types. Also record whether we encounter non-record 6792 // candidate types or either arithmetic or enumeral candidate types. 6793 Qualifiers VisibleTypeConversionsQuals; 6794 VisibleTypeConversionsQuals.addConst(); 6795 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 6796 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 6797 6798 bool HasNonRecordCandidateType = false; 6799 bool HasArithmeticOrEnumeralCandidateType = false; 6800 SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 6801 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 6802 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 6803 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 6804 OpLoc, 6805 true, 6806 (Op == OO_Exclaim || 6807 Op == OO_AmpAmp || 6808 Op == OO_PipePipe), 6809 VisibleTypeConversionsQuals); 6810 HasNonRecordCandidateType = HasNonRecordCandidateType || 6811 CandidateTypes[ArgIdx].hasNonRecordTypes(); 6812 HasArithmeticOrEnumeralCandidateType = 6813 HasArithmeticOrEnumeralCandidateType || 6814 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 6815 } 6816 6817 // Exit early when no non-record types have been added to the candidate set 6818 // for any of the arguments to the operator. 6819 // 6820 // We can't exit early for !, ||, or &&, since there we have always have 6821 // 'bool' overloads. 6822 if (!HasNonRecordCandidateType && 6823 !(Op == OO_Exclaim || Op == OO_AmpAmp || Op == OO_PipePipe)) 6824 return; 6825 6826 // Setup an object to manage the common state for building overloads. 6827 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, 6828 VisibleTypeConversionsQuals, 6829 HasArithmeticOrEnumeralCandidateType, 6830 CandidateTypes, CandidateSet); 6831 6832 // Dispatch over the operation to add in only those overloads which apply. 6833 switch (Op) { 6834 case OO_None: 6835 case NUM_OVERLOADED_OPERATORS: 6836 llvm_unreachable("Expected an overloaded operator"); 6837 6838 case OO_New: 6839 case OO_Delete: 6840 case OO_Array_New: 6841 case OO_Array_Delete: 6842 case OO_Call: 6843 llvm_unreachable( 6844 "Special operators don't use AddBuiltinOperatorCandidates"); 6845 6846 case OO_Comma: 6847 case OO_Arrow: 6848 // C++ [over.match.oper]p3: 6849 // -- For the operator ',', the unary operator '&', or the 6850 // operator '->', the built-in candidates set is empty. 6851 break; 6852 6853 case OO_Plus: // '+' is either unary or binary 6854 if (NumArgs == 1) 6855 OpBuilder.addUnaryPlusPointerOverloads(); 6856 // Fall through. 6857 6858 case OO_Minus: // '-' is either unary or binary 6859 if (NumArgs == 1) { 6860 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 6861 } else { 6862 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 6863 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6864 } 6865 break; 6866 6867 case OO_Star: // '*' is either unary or binary 6868 if (NumArgs == 1) 6869 OpBuilder.addUnaryStarPointerOverloads(); 6870 else 6871 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6872 break; 6873 6874 case OO_Slash: 6875 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6876 break; 6877 6878 case OO_PlusPlus: 6879 case OO_MinusMinus: 6880 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 6881 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 6882 break; 6883 6884 case OO_EqualEqual: 6885 case OO_ExclaimEqual: 6886 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 6887 // Fall through. 6888 6889 case OO_Less: 6890 case OO_Greater: 6891 case OO_LessEqual: 6892 case OO_GreaterEqual: 6893 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 6894 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 6895 break; 6896 6897 case OO_Percent: 6898 case OO_Caret: 6899 case OO_Pipe: 6900 case OO_LessLess: 6901 case OO_GreaterGreater: 6902 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6903 break; 6904 6905 case OO_Amp: // '&' is either unary or binary 6906 if (NumArgs == 1) 6907 // C++ [over.match.oper]p3: 6908 // -- For the operator ',', the unary operator '&', or the 6909 // operator '->', the built-in candidates set is empty. 6910 break; 6911 6912 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6913 break; 6914 6915 case OO_Tilde: 6916 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 6917 break; 6918 6919 case OO_Equal: 6920 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 6921 // Fall through. 6922 6923 case OO_PlusEqual: 6924 case OO_MinusEqual: 6925 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 6926 // Fall through. 6927 6928 case OO_StarEqual: 6929 case OO_SlashEqual: 6930 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 6931 break; 6932 6933 case OO_PercentEqual: 6934 case OO_LessLessEqual: 6935 case OO_GreaterGreaterEqual: 6936 case OO_AmpEqual: 6937 case OO_CaretEqual: 6938 case OO_PipeEqual: 6939 OpBuilder.addAssignmentIntegralOverloads(); 6940 break; 6941 6942 case OO_Exclaim: 6943 OpBuilder.addExclaimOverload(); 6944 break; 6945 6946 case OO_AmpAmp: 6947 case OO_PipePipe: 6948 OpBuilder.addAmpAmpOrPipePipeOverload(); 6949 break; 6950 6951 case OO_Subscript: 6952 OpBuilder.addSubscriptOverloads(); 6953 break; 6954 6955 case OO_ArrowStar: 6956 OpBuilder.addArrowStarOverloads(); 6957 break; 6958 6959 case OO_Conditional: 6960 OpBuilder.addConditionalOperatorOverloads(); 6961 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6962 break; 6963 } 6964} 6965 6966/// \brief Add function candidates found via argument-dependent lookup 6967/// to the set of overloading candidates. 6968/// 6969/// This routine performs argument-dependent name lookup based on the 6970/// given function name (which may also be an operator name) and adds 6971/// all of the overload candidates found by ADL to the overload 6972/// candidate set (C++ [basic.lookup.argdep]). 6973void 6974Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 6975 bool Operator, 6976 Expr **Args, unsigned NumArgs, 6977 TemplateArgumentListInfo *ExplicitTemplateArgs, 6978 OverloadCandidateSet& CandidateSet, 6979 bool PartialOverloading, 6980 bool StdNamespaceIsAssociated) { 6981 ADLResult Fns; 6982 6983 // FIXME: This approach for uniquing ADL results (and removing 6984 // redundant candidates from the set) relies on pointer-equality, 6985 // which means we need to key off the canonical decl. However, 6986 // always going back to the canonical decl might not get us the 6987 // right set of default arguments. What default arguments are 6988 // we supposed to consider on ADL candidates, anyway? 6989 6990 // FIXME: Pass in the explicit template arguments? 6991 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns, 6992 StdNamespaceIsAssociated); 6993 6994 // Erase all of the candidates we already knew about. 6995 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 6996 CandEnd = CandidateSet.end(); 6997 Cand != CandEnd; ++Cand) 6998 if (Cand->Function) { 6999 Fns.erase(Cand->Function); 7000 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 7001 Fns.erase(FunTmpl); 7002 } 7003 7004 // For each of the ADL candidates we found, add it to the overload 7005 // set. 7006 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 7007 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 7008 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 7009 if (ExplicitTemplateArgs) 7010 continue; 7011 7012 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 7013 false, PartialOverloading); 7014 } else 7015 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 7016 FoundDecl, ExplicitTemplateArgs, 7017 Args, NumArgs, CandidateSet); 7018 } 7019} 7020 7021/// isBetterOverloadCandidate - Determines whether the first overload 7022/// candidate is a better candidate than the second (C++ 13.3.3p1). 7023bool 7024isBetterOverloadCandidate(Sema &S, 7025 const OverloadCandidate &Cand1, 7026 const OverloadCandidate &Cand2, 7027 SourceLocation Loc, 7028 bool UserDefinedConversion) { 7029 // Define viable functions to be better candidates than non-viable 7030 // functions. 7031 if (!Cand2.Viable) 7032 return Cand1.Viable; 7033 else if (!Cand1.Viable) 7034 return false; 7035 7036 // C++ [over.match.best]p1: 7037 // 7038 // -- if F is a static member function, ICS1(F) is defined such 7039 // that ICS1(F) is neither better nor worse than ICS1(G) for 7040 // any function G, and, symmetrically, ICS1(G) is neither 7041 // better nor worse than ICS1(F). 7042 unsigned StartArg = 0; 7043 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 7044 StartArg = 1; 7045 7046 // C++ [over.match.best]p1: 7047 // A viable function F1 is defined to be a better function than another 7048 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 7049 // conversion sequence than ICSi(F2), and then... 7050 unsigned NumArgs = Cand1.NumConversions; 7051 assert(Cand2.NumConversions == NumArgs && "Overload candidate mismatch"); 7052 bool HasBetterConversion = false; 7053 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 7054 switch (CompareImplicitConversionSequences(S, 7055 Cand1.Conversions[ArgIdx], 7056 Cand2.Conversions[ArgIdx])) { 7057 case ImplicitConversionSequence::Better: 7058 // Cand1 has a better conversion sequence. 7059 HasBetterConversion = true; 7060 break; 7061 7062 case ImplicitConversionSequence::Worse: 7063 // Cand1 can't be better than Cand2. 7064 return false; 7065 7066 case ImplicitConversionSequence::Indistinguishable: 7067 // Do nothing. 7068 break; 7069 } 7070 } 7071 7072 // -- for some argument j, ICSj(F1) is a better conversion sequence than 7073 // ICSj(F2), or, if not that, 7074 if (HasBetterConversion) 7075 return true; 7076 7077 // - F1 is a non-template function and F2 is a function template 7078 // specialization, or, if not that, 7079 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 7080 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 7081 return true; 7082 7083 // -- F1 and F2 are function template specializations, and the function 7084 // template for F1 is more specialized than the template for F2 7085 // according to the partial ordering rules described in 14.5.5.2, or, 7086 // if not that, 7087 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 7088 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 7089 if (FunctionTemplateDecl *BetterTemplate 7090 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 7091 Cand2.Function->getPrimaryTemplate(), 7092 Loc, 7093 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 7094 : TPOC_Call, 7095 Cand1.ExplicitCallArguments)) 7096 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 7097 } 7098 7099 // -- the context is an initialization by user-defined conversion 7100 // (see 8.5, 13.3.1.5) and the standard conversion sequence 7101 // from the return type of F1 to the destination type (i.e., 7102 // the type of the entity being initialized) is a better 7103 // conversion sequence than the standard conversion sequence 7104 // from the return type of F2 to the destination type. 7105 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 7106 isa<CXXConversionDecl>(Cand1.Function) && 7107 isa<CXXConversionDecl>(Cand2.Function)) { 7108 switch (CompareStandardConversionSequences(S, 7109 Cand1.FinalConversion, 7110 Cand2.FinalConversion)) { 7111 case ImplicitConversionSequence::Better: 7112 // Cand1 has a better conversion sequence. 7113 return true; 7114 7115 case ImplicitConversionSequence::Worse: 7116 // Cand1 can't be better than Cand2. 7117 return false; 7118 7119 case ImplicitConversionSequence::Indistinguishable: 7120 // Do nothing 7121 break; 7122 } 7123 } 7124 7125 return false; 7126} 7127 7128/// \brief Computes the best viable function (C++ 13.3.3) 7129/// within an overload candidate set. 7130/// 7131/// \param CandidateSet the set of candidate functions. 7132/// 7133/// \param Loc the location of the function name (or operator symbol) for 7134/// which overload resolution occurs. 7135/// 7136/// \param Best f overload resolution was successful or found a deleted 7137/// function, Best points to the candidate function found. 7138/// 7139/// \returns The result of overload resolution. 7140OverloadingResult 7141OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 7142 iterator &Best, 7143 bool UserDefinedConversion) { 7144 // Find the best viable function. 7145 Best = end(); 7146 for (iterator Cand = begin(); Cand != end(); ++Cand) { 7147 if (Cand->Viable) 7148 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 7149 UserDefinedConversion)) 7150 Best = Cand; 7151 } 7152 7153 // If we didn't find any viable functions, abort. 7154 if (Best == end()) 7155 return OR_No_Viable_Function; 7156 7157 // Make sure that this function is better than every other viable 7158 // function. If not, we have an ambiguity. 7159 for (iterator Cand = begin(); Cand != end(); ++Cand) { 7160 if (Cand->Viable && 7161 Cand != Best && 7162 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 7163 UserDefinedConversion)) { 7164 Best = end(); 7165 return OR_Ambiguous; 7166 } 7167 } 7168 7169 // Best is the best viable function. 7170 if (Best->Function && 7171 (Best->Function->isDeleted() || 7172 S.isFunctionConsideredUnavailable(Best->Function))) 7173 return OR_Deleted; 7174 7175 return OR_Success; 7176} 7177 7178namespace { 7179 7180enum OverloadCandidateKind { 7181 oc_function, 7182 oc_method, 7183 oc_constructor, 7184 oc_function_template, 7185 oc_method_template, 7186 oc_constructor_template, 7187 oc_implicit_default_constructor, 7188 oc_implicit_copy_constructor, 7189 oc_implicit_move_constructor, 7190 oc_implicit_copy_assignment, 7191 oc_implicit_move_assignment, 7192 oc_implicit_inherited_constructor 7193}; 7194 7195OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 7196 FunctionDecl *Fn, 7197 std::string &Description) { 7198 bool isTemplate = false; 7199 7200 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 7201 isTemplate = true; 7202 Description = S.getTemplateArgumentBindingsText( 7203 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 7204 } 7205 7206 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 7207 if (!Ctor->isImplicit()) 7208 return isTemplate ? oc_constructor_template : oc_constructor; 7209 7210 if (Ctor->getInheritedConstructor()) 7211 return oc_implicit_inherited_constructor; 7212 7213 if (Ctor->isDefaultConstructor()) 7214 return oc_implicit_default_constructor; 7215 7216 if (Ctor->isMoveConstructor()) 7217 return oc_implicit_move_constructor; 7218 7219 assert(Ctor->isCopyConstructor() && 7220 "unexpected sort of implicit constructor"); 7221 return oc_implicit_copy_constructor; 7222 } 7223 7224 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 7225 // This actually gets spelled 'candidate function' for now, but 7226 // it doesn't hurt to split it out. 7227 if (!Meth->isImplicit()) 7228 return isTemplate ? oc_method_template : oc_method; 7229 7230 if (Meth->isMoveAssignmentOperator()) 7231 return oc_implicit_move_assignment; 7232 7233 assert(Meth->isCopyAssignmentOperator() 7234 && "implicit method is not copy assignment operator?"); 7235 return oc_implicit_copy_assignment; 7236 } 7237 7238 return isTemplate ? oc_function_template : oc_function; 7239} 7240 7241void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { 7242 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 7243 if (!Ctor) return; 7244 7245 Ctor = Ctor->getInheritedConstructor(); 7246 if (!Ctor) return; 7247 7248 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 7249} 7250 7251} // end anonymous namespace 7252 7253// Notes the location of an overload candidate. 7254void Sema::NoteOverloadCandidate(FunctionDecl *Fn, QualType DestType) { 7255 std::string FnDesc; 7256 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 7257 PartialDiagnostic PD = PDiag(diag::note_ovl_candidate) 7258 << (unsigned) K << FnDesc; 7259 HandleFunctionTypeMismatch(PD, Fn->getType(), DestType); 7260 Diag(Fn->getLocation(), PD); 7261 MaybeEmitInheritedConstructorNote(*this, Fn); 7262} 7263 7264//Notes the location of all overload candidates designated through 7265// OverloadedExpr 7266void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr, QualType DestType) { 7267 assert(OverloadedExpr->getType() == Context.OverloadTy); 7268 7269 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); 7270 OverloadExpr *OvlExpr = Ovl.Expression; 7271 7272 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7273 IEnd = OvlExpr->decls_end(); 7274 I != IEnd; ++I) { 7275 if (FunctionTemplateDecl *FunTmpl = 7276 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) { 7277 NoteOverloadCandidate(FunTmpl->getTemplatedDecl(), DestType); 7278 } else if (FunctionDecl *Fun 7279 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) { 7280 NoteOverloadCandidate(Fun, DestType); 7281 } 7282 } 7283} 7284 7285/// Diagnoses an ambiguous conversion. The partial diagnostic is the 7286/// "lead" diagnostic; it will be given two arguments, the source and 7287/// target types of the conversion. 7288void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 7289 Sema &S, 7290 SourceLocation CaretLoc, 7291 const PartialDiagnostic &PDiag) const { 7292 S.Diag(CaretLoc, PDiag) 7293 << Ambiguous.getFromType() << Ambiguous.getToType(); 7294 for (AmbiguousConversionSequence::const_iterator 7295 I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 7296 S.NoteOverloadCandidate(*I); 7297 } 7298} 7299 7300namespace { 7301 7302void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 7303 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 7304 assert(Conv.isBad()); 7305 assert(Cand->Function && "for now, candidate must be a function"); 7306 FunctionDecl *Fn = Cand->Function; 7307 7308 // There's a conversion slot for the object argument if this is a 7309 // non-constructor method. Note that 'I' corresponds the 7310 // conversion-slot index. 7311 bool isObjectArgument = false; 7312 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 7313 if (I == 0) 7314 isObjectArgument = true; 7315 else 7316 I--; 7317 } 7318 7319 std::string FnDesc; 7320 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 7321 7322 Expr *FromExpr = Conv.Bad.FromExpr; 7323 QualType FromTy = Conv.Bad.getFromType(); 7324 QualType ToTy = Conv.Bad.getToType(); 7325 7326 if (FromTy == S.Context.OverloadTy) { 7327 assert(FromExpr && "overload set argument came from implicit argument?"); 7328 Expr *E = FromExpr->IgnoreParens(); 7329 if (isa<UnaryOperator>(E)) 7330 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 7331 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 7332 7333 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 7334 << (unsigned) FnKind << FnDesc 7335 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7336 << ToTy << Name << I+1; 7337 MaybeEmitInheritedConstructorNote(S, Fn); 7338 return; 7339 } 7340 7341 // Do some hand-waving analysis to see if the non-viability is due 7342 // to a qualifier mismatch. 7343 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 7344 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 7345 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 7346 CToTy = RT->getPointeeType(); 7347 else { 7348 // TODO: detect and diagnose the full richness of const mismatches. 7349 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 7350 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 7351 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 7352 } 7353 7354 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 7355 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 7356 // It is dumb that we have to do this here. 7357 while (isa<ArrayType>(CFromTy)) 7358 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 7359 while (isa<ArrayType>(CToTy)) 7360 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 7361 7362 Qualifiers FromQs = CFromTy.getQualifiers(); 7363 Qualifiers ToQs = CToTy.getQualifiers(); 7364 7365 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 7366 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 7367 << (unsigned) FnKind << FnDesc 7368 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7369 << FromTy 7370 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 7371 << (unsigned) isObjectArgument << I+1; 7372 MaybeEmitInheritedConstructorNote(S, Fn); 7373 return; 7374 } 7375 7376 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 7377 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_ownership) 7378 << (unsigned) FnKind << FnDesc 7379 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7380 << FromTy 7381 << FromQs.getObjCLifetime() << ToQs.getObjCLifetime() 7382 << (unsigned) isObjectArgument << I+1; 7383 MaybeEmitInheritedConstructorNote(S, Fn); 7384 return; 7385 } 7386 7387 if (FromQs.getObjCGCAttr() != ToQs.getObjCGCAttr()) { 7388 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_gc) 7389 << (unsigned) FnKind << FnDesc 7390 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7391 << FromTy 7392 << FromQs.getObjCGCAttr() << ToQs.getObjCGCAttr() 7393 << (unsigned) isObjectArgument << I+1; 7394 MaybeEmitInheritedConstructorNote(S, Fn); 7395 return; 7396 } 7397 7398 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 7399 assert(CVR && "unexpected qualifiers mismatch"); 7400 7401 if (isObjectArgument) { 7402 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 7403 << (unsigned) FnKind << FnDesc 7404 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7405 << FromTy << (CVR - 1); 7406 } else { 7407 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 7408 << (unsigned) FnKind << FnDesc 7409 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7410 << FromTy << (CVR - 1) << I+1; 7411 } 7412 MaybeEmitInheritedConstructorNote(S, Fn); 7413 return; 7414 } 7415 7416 // Special diagnostic for failure to convert an initializer list, since 7417 // telling the user that it has type void is not useful. 7418 if (FromExpr && isa<InitListExpr>(FromExpr)) { 7419 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_list_argument) 7420 << (unsigned) FnKind << FnDesc 7421 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7422 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 7423 MaybeEmitInheritedConstructorNote(S, Fn); 7424 return; 7425 } 7426 7427 // Diagnose references or pointers to incomplete types differently, 7428 // since it's far from impossible that the incompleteness triggered 7429 // the failure. 7430 QualType TempFromTy = FromTy.getNonReferenceType(); 7431 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 7432 TempFromTy = PTy->getPointeeType(); 7433 if (TempFromTy->isIncompleteType()) { 7434 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 7435 << (unsigned) FnKind << FnDesc 7436 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7437 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 7438 MaybeEmitInheritedConstructorNote(S, Fn); 7439 return; 7440 } 7441 7442 // Diagnose base -> derived pointer conversions. 7443 unsigned BaseToDerivedConversion = 0; 7444 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 7445 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 7446 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 7447 FromPtrTy->getPointeeType()) && 7448 !FromPtrTy->getPointeeType()->isIncompleteType() && 7449 !ToPtrTy->getPointeeType()->isIncompleteType() && 7450 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 7451 FromPtrTy->getPointeeType())) 7452 BaseToDerivedConversion = 1; 7453 } 7454 } else if (const ObjCObjectPointerType *FromPtrTy 7455 = FromTy->getAs<ObjCObjectPointerType>()) { 7456 if (const ObjCObjectPointerType *ToPtrTy 7457 = ToTy->getAs<ObjCObjectPointerType>()) 7458 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 7459 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 7460 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 7461 FromPtrTy->getPointeeType()) && 7462 FromIface->isSuperClassOf(ToIface)) 7463 BaseToDerivedConversion = 2; 7464 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 7465 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 7466 !FromTy->isIncompleteType() && 7467 !ToRefTy->getPointeeType()->isIncompleteType() && 7468 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 7469 BaseToDerivedConversion = 3; 7470 } 7471 7472 if (BaseToDerivedConversion) { 7473 S.Diag(Fn->getLocation(), 7474 diag::note_ovl_candidate_bad_base_to_derived_conv) 7475 << (unsigned) FnKind << FnDesc 7476 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7477 << (BaseToDerivedConversion - 1) 7478 << FromTy << ToTy << I+1; 7479 MaybeEmitInheritedConstructorNote(S, Fn); 7480 return; 7481 } 7482 7483 if (isa<ObjCObjectPointerType>(CFromTy) && 7484 isa<PointerType>(CToTy)) { 7485 Qualifiers FromQs = CFromTy.getQualifiers(); 7486 Qualifiers ToQs = CToTy.getQualifiers(); 7487 if (FromQs.getObjCLifetime() != ToQs.getObjCLifetime()) { 7488 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_arc_conv) 7489 << (unsigned) FnKind << FnDesc 7490 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7491 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 7492 MaybeEmitInheritedConstructorNote(S, Fn); 7493 return; 7494 } 7495 } 7496 7497 // Emit the generic diagnostic and, optionally, add the hints to it. 7498 PartialDiagnostic FDiag = S.PDiag(diag::note_ovl_candidate_bad_conv); 7499 FDiag << (unsigned) FnKind << FnDesc 7500 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 7501 << FromTy << ToTy << (unsigned) isObjectArgument << I + 1 7502 << (unsigned) (Cand->Fix.Kind); 7503 7504 // If we can fix the conversion, suggest the FixIts. 7505 for (std::vector<FixItHint>::iterator HI = Cand->Fix.Hints.begin(), 7506 HE = Cand->Fix.Hints.end(); HI != HE; ++HI) 7507 FDiag << *HI; 7508 S.Diag(Fn->getLocation(), FDiag); 7509 7510 MaybeEmitInheritedConstructorNote(S, Fn); 7511} 7512 7513void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 7514 unsigned NumFormalArgs) { 7515 // TODO: treat calls to a missing default constructor as a special case 7516 7517 FunctionDecl *Fn = Cand->Function; 7518 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 7519 7520 unsigned MinParams = Fn->getMinRequiredArguments(); 7521 7522 // With invalid overloaded operators, it's possible that we think we 7523 // have an arity mismatch when it fact it looks like we have the 7524 // right number of arguments, because only overloaded operators have 7525 // the weird behavior of overloading member and non-member functions. 7526 // Just don't report anything. 7527 if (Fn->isInvalidDecl() && 7528 Fn->getDeclName().getNameKind() == DeclarationName::CXXOperatorName) 7529 return; 7530 7531 // at least / at most / exactly 7532 unsigned mode, modeCount; 7533 if (NumFormalArgs < MinParams) { 7534 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 7535 (Cand->FailureKind == ovl_fail_bad_deduction && 7536 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 7537 if (MinParams != FnTy->getNumArgs() || 7538 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 7539 mode = 0; // "at least" 7540 else 7541 mode = 2; // "exactly" 7542 modeCount = MinParams; 7543 } else { 7544 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 7545 (Cand->FailureKind == ovl_fail_bad_deduction && 7546 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 7547 if (MinParams != FnTy->getNumArgs()) 7548 mode = 1; // "at most" 7549 else 7550 mode = 2; // "exactly" 7551 modeCount = FnTy->getNumArgs(); 7552 } 7553 7554 std::string Description; 7555 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 7556 7557 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 7558 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 7559 << modeCount << NumFormalArgs; 7560 MaybeEmitInheritedConstructorNote(S, Fn); 7561} 7562 7563/// Diagnose a failed template-argument deduction. 7564void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 7565 Expr **Args, unsigned NumArgs) { 7566 FunctionDecl *Fn = Cand->Function; // pattern 7567 7568 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 7569 NamedDecl *ParamD; 7570 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 7571 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 7572 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 7573 switch (Cand->DeductionFailure.Result) { 7574 case Sema::TDK_Success: 7575 llvm_unreachable("TDK_success while diagnosing bad deduction"); 7576 7577 case Sema::TDK_Incomplete: { 7578 assert(ParamD && "no parameter found for incomplete deduction result"); 7579 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 7580 << ParamD->getDeclName(); 7581 MaybeEmitInheritedConstructorNote(S, Fn); 7582 return; 7583 } 7584 7585 case Sema::TDK_Underqualified: { 7586 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 7587 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 7588 7589 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 7590 7591 // Param will have been canonicalized, but it should just be a 7592 // qualified version of ParamD, so move the qualifiers to that. 7593 QualifierCollector Qs; 7594 Qs.strip(Param); 7595 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 7596 assert(S.Context.hasSameType(Param, NonCanonParam)); 7597 7598 // Arg has also been canonicalized, but there's nothing we can do 7599 // about that. It also doesn't matter as much, because it won't 7600 // have any template parameters in it (because deduction isn't 7601 // done on dependent types). 7602 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 7603 7604 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 7605 << ParamD->getDeclName() << Arg << NonCanonParam; 7606 MaybeEmitInheritedConstructorNote(S, Fn); 7607 return; 7608 } 7609 7610 case Sema::TDK_Inconsistent: { 7611 assert(ParamD && "no parameter found for inconsistent deduction result"); 7612 int which = 0; 7613 if (isa<TemplateTypeParmDecl>(ParamD)) 7614 which = 0; 7615 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 7616 which = 1; 7617 else { 7618 which = 2; 7619 } 7620 7621 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 7622 << which << ParamD->getDeclName() 7623 << *Cand->DeductionFailure.getFirstArg() 7624 << *Cand->DeductionFailure.getSecondArg(); 7625 MaybeEmitInheritedConstructorNote(S, Fn); 7626 return; 7627 } 7628 7629 case Sema::TDK_InvalidExplicitArguments: 7630 assert(ParamD && "no parameter found for invalid explicit arguments"); 7631 if (ParamD->getDeclName()) 7632 S.Diag(Fn->getLocation(), 7633 diag::note_ovl_candidate_explicit_arg_mismatch_named) 7634 << ParamD->getDeclName(); 7635 else { 7636 int index = 0; 7637 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 7638 index = TTP->getIndex(); 7639 else if (NonTypeTemplateParmDecl *NTTP 7640 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 7641 index = NTTP->getIndex(); 7642 else 7643 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 7644 S.Diag(Fn->getLocation(), 7645 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 7646 << (index + 1); 7647 } 7648 MaybeEmitInheritedConstructorNote(S, Fn); 7649 return; 7650 7651 case Sema::TDK_TooManyArguments: 7652 case Sema::TDK_TooFewArguments: 7653 DiagnoseArityMismatch(S, Cand, NumArgs); 7654 return; 7655 7656 case Sema::TDK_InstantiationDepth: 7657 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 7658 MaybeEmitInheritedConstructorNote(S, Fn); 7659 return; 7660 7661 case Sema::TDK_SubstitutionFailure: { 7662 std::string ArgString; 7663 if (TemplateArgumentList *Args 7664 = Cand->DeductionFailure.getTemplateArgumentList()) 7665 ArgString = S.getTemplateArgumentBindingsText( 7666 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 7667 *Args); 7668 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 7669 << ArgString; 7670 MaybeEmitInheritedConstructorNote(S, Fn); 7671 return; 7672 } 7673 7674 // TODO: diagnose these individually, then kill off 7675 // note_ovl_candidate_bad_deduction, which is uselessly vague. 7676 case Sema::TDK_NonDeducedMismatch: 7677 case Sema::TDK_FailedOverloadResolution: 7678 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 7679 MaybeEmitInheritedConstructorNote(S, Fn); 7680 return; 7681 } 7682} 7683 7684/// CUDA: diagnose an invalid call across targets. 7685void DiagnoseBadTarget(Sema &S, OverloadCandidate *Cand) { 7686 FunctionDecl *Caller = cast<FunctionDecl>(S.CurContext); 7687 FunctionDecl *Callee = Cand->Function; 7688 7689 Sema::CUDAFunctionTarget CallerTarget = S.IdentifyCUDATarget(Caller), 7690 CalleeTarget = S.IdentifyCUDATarget(Callee); 7691 7692 std::string FnDesc; 7693 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Callee, FnDesc); 7694 7695 S.Diag(Callee->getLocation(), diag::note_ovl_candidate_bad_target) 7696 << (unsigned) FnKind << CalleeTarget << CallerTarget; 7697} 7698 7699/// Generates a 'note' diagnostic for an overload candidate. We've 7700/// already generated a primary error at the call site. 7701/// 7702/// It really does need to be a single diagnostic with its caret 7703/// pointed at the candidate declaration. Yes, this creates some 7704/// major challenges of technical writing. Yes, this makes pointing 7705/// out problems with specific arguments quite awkward. It's still 7706/// better than generating twenty screens of text for every failed 7707/// overload. 7708/// 7709/// It would be great to be able to express per-candidate problems 7710/// more richly for those diagnostic clients that cared, but we'd 7711/// still have to be just as careful with the default diagnostics. 7712void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 7713 Expr **Args, unsigned NumArgs) { 7714 FunctionDecl *Fn = Cand->Function; 7715 7716 // Note deleted candidates, but only if they're viable. 7717 if (Cand->Viable && (Fn->isDeleted() || 7718 S.isFunctionConsideredUnavailable(Fn))) { 7719 std::string FnDesc; 7720 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 7721 7722 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 7723 << FnKind << FnDesc << Fn->isDeleted(); 7724 MaybeEmitInheritedConstructorNote(S, Fn); 7725 return; 7726 } 7727 7728 // We don't really have anything else to say about viable candidates. 7729 if (Cand->Viable) { 7730 S.NoteOverloadCandidate(Fn); 7731 return; 7732 } 7733 7734 switch (Cand->FailureKind) { 7735 case ovl_fail_too_many_arguments: 7736 case ovl_fail_too_few_arguments: 7737 return DiagnoseArityMismatch(S, Cand, NumArgs); 7738 7739 case ovl_fail_bad_deduction: 7740 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 7741 7742 case ovl_fail_trivial_conversion: 7743 case ovl_fail_bad_final_conversion: 7744 case ovl_fail_final_conversion_not_exact: 7745 return S.NoteOverloadCandidate(Fn); 7746 7747 case ovl_fail_bad_conversion: { 7748 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 7749 for (unsigned N = Cand->NumConversions; I != N; ++I) 7750 if (Cand->Conversions[I].isBad()) 7751 return DiagnoseBadConversion(S, Cand, I); 7752 7753 // FIXME: this currently happens when we're called from SemaInit 7754 // when user-conversion overload fails. Figure out how to handle 7755 // those conditions and diagnose them well. 7756 return S.NoteOverloadCandidate(Fn); 7757 } 7758 7759 case ovl_fail_bad_target: 7760 return DiagnoseBadTarget(S, Cand); 7761 } 7762} 7763 7764void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 7765 // Desugar the type of the surrogate down to a function type, 7766 // retaining as many typedefs as possible while still showing 7767 // the function type (and, therefore, its parameter types). 7768 QualType FnType = Cand->Surrogate->getConversionType(); 7769 bool isLValueReference = false; 7770 bool isRValueReference = false; 7771 bool isPointer = false; 7772 if (const LValueReferenceType *FnTypeRef = 7773 FnType->getAs<LValueReferenceType>()) { 7774 FnType = FnTypeRef->getPointeeType(); 7775 isLValueReference = true; 7776 } else if (const RValueReferenceType *FnTypeRef = 7777 FnType->getAs<RValueReferenceType>()) { 7778 FnType = FnTypeRef->getPointeeType(); 7779 isRValueReference = true; 7780 } 7781 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 7782 FnType = FnTypePtr->getPointeeType(); 7783 isPointer = true; 7784 } 7785 // Desugar down to a function type. 7786 FnType = QualType(FnType->getAs<FunctionType>(), 0); 7787 // Reconstruct the pointer/reference as appropriate. 7788 if (isPointer) FnType = S.Context.getPointerType(FnType); 7789 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 7790 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 7791 7792 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 7793 << FnType; 7794 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 7795} 7796 7797void NoteBuiltinOperatorCandidate(Sema &S, 7798 const char *Opc, 7799 SourceLocation OpLoc, 7800 OverloadCandidate *Cand) { 7801 assert(Cand->NumConversions <= 2 && "builtin operator is not binary"); 7802 std::string TypeStr("operator"); 7803 TypeStr += Opc; 7804 TypeStr += "("; 7805 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 7806 if (Cand->NumConversions == 1) { 7807 TypeStr += ")"; 7808 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 7809 } else { 7810 TypeStr += ", "; 7811 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 7812 TypeStr += ")"; 7813 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 7814 } 7815} 7816 7817void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 7818 OverloadCandidate *Cand) { 7819 unsigned NoOperands = Cand->NumConversions; 7820 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 7821 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 7822 if (ICS.isBad()) break; // all meaningless after first invalid 7823 if (!ICS.isAmbiguous()) continue; 7824 7825 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 7826 S.PDiag(diag::note_ambiguous_type_conversion)); 7827 } 7828} 7829 7830SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 7831 if (Cand->Function) 7832 return Cand->Function->getLocation(); 7833 if (Cand->IsSurrogate) 7834 return Cand->Surrogate->getLocation(); 7835 return SourceLocation(); 7836} 7837 7838static unsigned 7839RankDeductionFailure(const OverloadCandidate::DeductionFailureInfo &DFI) { 7840 switch ((Sema::TemplateDeductionResult)DFI.Result) { 7841 case Sema::TDK_Success: 7842 llvm_unreachable("TDK_success while diagnosing bad deduction"); 7843 7844 case Sema::TDK_Incomplete: 7845 return 1; 7846 7847 case Sema::TDK_Underqualified: 7848 case Sema::TDK_Inconsistent: 7849 return 2; 7850 7851 case Sema::TDK_SubstitutionFailure: 7852 case Sema::TDK_NonDeducedMismatch: 7853 return 3; 7854 7855 case Sema::TDK_InstantiationDepth: 7856 case Sema::TDK_FailedOverloadResolution: 7857 return 4; 7858 7859 case Sema::TDK_InvalidExplicitArguments: 7860 return 5; 7861 7862 case Sema::TDK_TooManyArguments: 7863 case Sema::TDK_TooFewArguments: 7864 return 6; 7865 } 7866 llvm_unreachable("Unhandled deduction result"); 7867} 7868 7869struct CompareOverloadCandidatesForDisplay { 7870 Sema &S; 7871 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 7872 7873 bool operator()(const OverloadCandidate *L, 7874 const OverloadCandidate *R) { 7875 // Fast-path this check. 7876 if (L == R) return false; 7877 7878 // Order first by viability. 7879 if (L->Viable) { 7880 if (!R->Viable) return true; 7881 7882 // TODO: introduce a tri-valued comparison for overload 7883 // candidates. Would be more worthwhile if we had a sort 7884 // that could exploit it. 7885 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 7886 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 7887 } else if (R->Viable) 7888 return false; 7889 7890 assert(L->Viable == R->Viable); 7891 7892 // Criteria by which we can sort non-viable candidates: 7893 if (!L->Viable) { 7894 // 1. Arity mismatches come after other candidates. 7895 if (L->FailureKind == ovl_fail_too_many_arguments || 7896 L->FailureKind == ovl_fail_too_few_arguments) 7897 return false; 7898 if (R->FailureKind == ovl_fail_too_many_arguments || 7899 R->FailureKind == ovl_fail_too_few_arguments) 7900 return true; 7901 7902 // 2. Bad conversions come first and are ordered by the number 7903 // of bad conversions and quality of good conversions. 7904 if (L->FailureKind == ovl_fail_bad_conversion) { 7905 if (R->FailureKind != ovl_fail_bad_conversion) 7906 return true; 7907 7908 // The conversion that can be fixed with a smaller number of changes, 7909 // comes first. 7910 unsigned numLFixes = L->Fix.NumConversionsFixed; 7911 unsigned numRFixes = R->Fix.NumConversionsFixed; 7912 numLFixes = (numLFixes == 0) ? UINT_MAX : numLFixes; 7913 numRFixes = (numRFixes == 0) ? UINT_MAX : numRFixes; 7914 if (numLFixes != numRFixes) { 7915 if (numLFixes < numRFixes) 7916 return true; 7917 else 7918 return false; 7919 } 7920 7921 // If there's any ordering between the defined conversions... 7922 // FIXME: this might not be transitive. 7923 assert(L->NumConversions == R->NumConversions); 7924 7925 int leftBetter = 0; 7926 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 7927 for (unsigned E = L->NumConversions; I != E; ++I) { 7928 switch (CompareImplicitConversionSequences(S, 7929 L->Conversions[I], 7930 R->Conversions[I])) { 7931 case ImplicitConversionSequence::Better: 7932 leftBetter++; 7933 break; 7934 7935 case ImplicitConversionSequence::Worse: 7936 leftBetter--; 7937 break; 7938 7939 case ImplicitConversionSequence::Indistinguishable: 7940 break; 7941 } 7942 } 7943 if (leftBetter > 0) return true; 7944 if (leftBetter < 0) return false; 7945 7946 } else if (R->FailureKind == ovl_fail_bad_conversion) 7947 return false; 7948 7949 if (L->FailureKind == ovl_fail_bad_deduction) { 7950 if (R->FailureKind != ovl_fail_bad_deduction) 7951 return true; 7952 7953 if (L->DeductionFailure.Result != R->DeductionFailure.Result) 7954 return RankDeductionFailure(L->DeductionFailure) 7955 < RankDeductionFailure(R->DeductionFailure); 7956 } else if (R->FailureKind == ovl_fail_bad_deduction) 7957 return false; 7958 7959 // TODO: others? 7960 } 7961 7962 // Sort everything else by location. 7963 SourceLocation LLoc = GetLocationForCandidate(L); 7964 SourceLocation RLoc = GetLocationForCandidate(R); 7965 7966 // Put candidates without locations (e.g. builtins) at the end. 7967 if (LLoc.isInvalid()) return false; 7968 if (RLoc.isInvalid()) return true; 7969 7970 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 7971 } 7972}; 7973 7974/// CompleteNonViableCandidate - Normally, overload resolution only 7975/// computes up to the first. Produces the FixIt set if possible. 7976void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 7977 Expr **Args, unsigned NumArgs) { 7978 assert(!Cand->Viable); 7979 7980 // Don't do anything on failures other than bad conversion. 7981 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 7982 7983 // We only want the FixIts if all the arguments can be corrected. 7984 bool Unfixable = false; 7985 // Use a implicit copy initialization to check conversion fixes. 7986 Cand->Fix.setConversionChecker(TryCopyInitialization); 7987 7988 // Skip forward to the first bad conversion. 7989 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 7990 unsigned ConvCount = Cand->NumConversions; 7991 while (true) { 7992 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 7993 ConvIdx++; 7994 if (Cand->Conversions[ConvIdx - 1].isBad()) { 7995 Unfixable = !Cand->TryToFixBadConversion(ConvIdx - 1, S); 7996 break; 7997 } 7998 } 7999 8000 if (ConvIdx == ConvCount) 8001 return; 8002 8003 assert(!Cand->Conversions[ConvIdx].isInitialized() && 8004 "remaining conversion is initialized?"); 8005 8006 // FIXME: this should probably be preserved from the overload 8007 // operation somehow. 8008 bool SuppressUserConversions = false; 8009 8010 const FunctionProtoType* Proto; 8011 unsigned ArgIdx = ConvIdx; 8012 8013 if (Cand->IsSurrogate) { 8014 QualType ConvType 8015 = Cand->Surrogate->getConversionType().getNonReferenceType(); 8016 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 8017 ConvType = ConvPtrType->getPointeeType(); 8018 Proto = ConvType->getAs<FunctionProtoType>(); 8019 ArgIdx--; 8020 } else if (Cand->Function) { 8021 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 8022 if (isa<CXXMethodDecl>(Cand->Function) && 8023 !isa<CXXConstructorDecl>(Cand->Function)) 8024 ArgIdx--; 8025 } else { 8026 // Builtin binary operator with a bad first conversion. 8027 assert(ConvCount <= 3); 8028 for (; ConvIdx != ConvCount; ++ConvIdx) 8029 Cand->Conversions[ConvIdx] 8030 = TryCopyInitialization(S, Args[ConvIdx], 8031 Cand->BuiltinTypes.ParamTypes[ConvIdx], 8032 SuppressUserConversions, 8033 /*InOverloadResolution*/ true, 8034 /*AllowObjCWritebackConversion=*/ 8035 S.getLangOptions().ObjCAutoRefCount); 8036 return; 8037 } 8038 8039 // Fill in the rest of the conversions. 8040 unsigned NumArgsInProto = Proto->getNumArgs(); 8041 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 8042 if (ArgIdx < NumArgsInProto) { 8043 Cand->Conversions[ConvIdx] 8044 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 8045 SuppressUserConversions, 8046 /*InOverloadResolution=*/true, 8047 /*AllowObjCWritebackConversion=*/ 8048 S.getLangOptions().ObjCAutoRefCount); 8049 // Store the FixIt in the candidate if it exists. 8050 if (!Unfixable && Cand->Conversions[ConvIdx].isBad()) 8051 Unfixable = !Cand->TryToFixBadConversion(ConvIdx, S); 8052 } 8053 else 8054 Cand->Conversions[ConvIdx].setEllipsis(); 8055 } 8056} 8057 8058} // end anonymous namespace 8059 8060/// PrintOverloadCandidates - When overload resolution fails, prints 8061/// diagnostic messages containing the candidates in the candidate 8062/// set. 8063void OverloadCandidateSet::NoteCandidates(Sema &S, 8064 OverloadCandidateDisplayKind OCD, 8065 Expr **Args, unsigned NumArgs, 8066 const char *Opc, 8067 SourceLocation OpLoc) { 8068 // Sort the candidates by viability and position. Sorting directly would 8069 // be prohibitive, so we make a set of pointers and sort those. 8070 SmallVector<OverloadCandidate*, 32> Cands; 8071 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 8072 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 8073 if (Cand->Viable) 8074 Cands.push_back(Cand); 8075 else if (OCD == OCD_AllCandidates) { 8076 CompleteNonViableCandidate(S, Cand, Args, NumArgs); 8077 if (Cand->Function || Cand->IsSurrogate) 8078 Cands.push_back(Cand); 8079 // Otherwise, this a non-viable builtin candidate. We do not, in general, 8080 // want to list every possible builtin candidate. 8081 } 8082 } 8083 8084 std::sort(Cands.begin(), Cands.end(), 8085 CompareOverloadCandidatesForDisplay(S)); 8086 8087 bool ReportedAmbiguousConversions = false; 8088 8089 SmallVectorImpl<OverloadCandidate*>::iterator I, E; 8090 const DiagnosticsEngine::OverloadsShown ShowOverloads = 8091 S.Diags.getShowOverloads(); 8092 unsigned CandsShown = 0; 8093 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 8094 OverloadCandidate *Cand = *I; 8095 8096 // Set an arbitrary limit on the number of candidate functions we'll spam 8097 // the user with. FIXME: This limit should depend on details of the 8098 // candidate list. 8099 if (CandsShown >= 4 && ShowOverloads == DiagnosticsEngine::Ovl_Best) { 8100 break; 8101 } 8102 ++CandsShown; 8103 8104 if (Cand->Function) 8105 NoteFunctionCandidate(S, Cand, Args, NumArgs); 8106 else if (Cand->IsSurrogate) 8107 NoteSurrogateCandidate(S, Cand); 8108 else { 8109 assert(Cand->Viable && 8110 "Non-viable built-in candidates are not added to Cands."); 8111 // Generally we only see ambiguities including viable builtin 8112 // operators if overload resolution got screwed up by an 8113 // ambiguous user-defined conversion. 8114 // 8115 // FIXME: It's quite possible for different conversions to see 8116 // different ambiguities, though. 8117 if (!ReportedAmbiguousConversions) { 8118 NoteAmbiguousUserConversions(S, OpLoc, Cand); 8119 ReportedAmbiguousConversions = true; 8120 } 8121 8122 // If this is a viable builtin, print it. 8123 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 8124 } 8125 } 8126 8127 if (I != E) 8128 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 8129} 8130 8131// [PossiblyAFunctionType] --> [Return] 8132// NonFunctionType --> NonFunctionType 8133// R (A) --> R(A) 8134// R (*)(A) --> R (A) 8135// R (&)(A) --> R (A) 8136// R (S::*)(A) --> R (A) 8137QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { 8138 QualType Ret = PossiblyAFunctionType; 8139 if (const PointerType *ToTypePtr = 8140 PossiblyAFunctionType->getAs<PointerType>()) 8141 Ret = ToTypePtr->getPointeeType(); 8142 else if (const ReferenceType *ToTypeRef = 8143 PossiblyAFunctionType->getAs<ReferenceType>()) 8144 Ret = ToTypeRef->getPointeeType(); 8145 else if (const MemberPointerType *MemTypePtr = 8146 PossiblyAFunctionType->getAs<MemberPointerType>()) 8147 Ret = MemTypePtr->getPointeeType(); 8148 Ret = 8149 Context.getCanonicalType(Ret).getUnqualifiedType(); 8150 return Ret; 8151} 8152 8153// A helper class to help with address of function resolution 8154// - allows us to avoid passing around all those ugly parameters 8155class AddressOfFunctionResolver 8156{ 8157 Sema& S; 8158 Expr* SourceExpr; 8159 const QualType& TargetType; 8160 QualType TargetFunctionType; // Extracted function type from target type 8161 8162 bool Complain; 8163 //DeclAccessPair& ResultFunctionAccessPair; 8164 ASTContext& Context; 8165 8166 bool TargetTypeIsNonStaticMemberFunction; 8167 bool FoundNonTemplateFunction; 8168 8169 OverloadExpr::FindResult OvlExprInfo; 8170 OverloadExpr *OvlExpr; 8171 TemplateArgumentListInfo OvlExplicitTemplateArgs; 8172 SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 8173 8174public: 8175 AddressOfFunctionResolver(Sema &S, Expr* SourceExpr, 8176 const QualType& TargetType, bool Complain) 8177 : S(S), SourceExpr(SourceExpr), TargetType(TargetType), 8178 Complain(Complain), Context(S.getASTContext()), 8179 TargetTypeIsNonStaticMemberFunction( 8180 !!TargetType->getAs<MemberPointerType>()), 8181 FoundNonTemplateFunction(false), 8182 OvlExprInfo(OverloadExpr::find(SourceExpr)), 8183 OvlExpr(OvlExprInfo.Expression) 8184 { 8185 ExtractUnqualifiedFunctionTypeFromTargetType(); 8186 8187 if (!TargetFunctionType->isFunctionType()) { 8188 if (OvlExpr->hasExplicitTemplateArgs()) { 8189 DeclAccessPair dap; 8190 if (FunctionDecl* Fn = S.ResolveSingleFunctionTemplateSpecialization( 8191 OvlExpr, false, &dap) ) { 8192 8193 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 8194 if (!Method->isStatic()) { 8195 // If the target type is a non-function type and the function 8196 // found is a non-static member function, pretend as if that was 8197 // the target, it's the only possible type to end up with. 8198 TargetTypeIsNonStaticMemberFunction = true; 8199 8200 // And skip adding the function if its not in the proper form. 8201 // We'll diagnose this due to an empty set of functions. 8202 if (!OvlExprInfo.HasFormOfMemberPointer) 8203 return; 8204 } 8205 } 8206 8207 Matches.push_back(std::make_pair(dap,Fn)); 8208 } 8209 } 8210 return; 8211 } 8212 8213 if (OvlExpr->hasExplicitTemplateArgs()) 8214 OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); 8215 8216 if (FindAllFunctionsThatMatchTargetTypeExactly()) { 8217 // C++ [over.over]p4: 8218 // If more than one function is selected, [...] 8219 if (Matches.size() > 1) { 8220 if (FoundNonTemplateFunction) 8221 EliminateAllTemplateMatches(); 8222 else 8223 EliminateAllExceptMostSpecializedTemplate(); 8224 } 8225 } 8226 } 8227 8228private: 8229 bool isTargetTypeAFunction() const { 8230 return TargetFunctionType->isFunctionType(); 8231 } 8232 8233 // [ToType] [Return] 8234 8235 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false 8236 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false 8237 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true 8238 void inline ExtractUnqualifiedFunctionTypeFromTargetType() { 8239 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); 8240 } 8241 8242 // return true if any matching specializations were found 8243 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, 8244 const DeclAccessPair& CurAccessFunPair) { 8245 if (CXXMethodDecl *Method 8246 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 8247 // Skip non-static function templates when converting to pointer, and 8248 // static when converting to member pointer. 8249 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 8250 return false; 8251 } 8252 else if (TargetTypeIsNonStaticMemberFunction) 8253 return false; 8254 8255 // C++ [over.over]p2: 8256 // If the name is a function template, template argument deduction is 8257 // done (14.8.2.2), and if the argument deduction succeeds, the 8258 // resulting template argument list is used to generate a single 8259 // function template specialization, which is added to the set of 8260 // overloaded functions considered. 8261 FunctionDecl *Specialization = 0; 8262 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 8263 if (Sema::TemplateDeductionResult Result 8264 = S.DeduceTemplateArguments(FunctionTemplate, 8265 &OvlExplicitTemplateArgs, 8266 TargetFunctionType, Specialization, 8267 Info)) { 8268 // FIXME: make a note of the failed deduction for diagnostics. 8269 (void)Result; 8270 return false; 8271 } 8272 8273 // Template argument deduction ensures that we have an exact match. 8274 // This function template specicalization works. 8275 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 8276 assert(TargetFunctionType 8277 == Context.getCanonicalType(Specialization->getType())); 8278 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); 8279 return true; 8280 } 8281 8282 bool AddMatchingNonTemplateFunction(NamedDecl* Fn, 8283 const DeclAccessPair& CurAccessFunPair) { 8284 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 8285 // Skip non-static functions when converting to pointer, and static 8286 // when converting to member pointer. 8287 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 8288 return false; 8289 } 8290 else if (TargetTypeIsNonStaticMemberFunction) 8291 return false; 8292 8293 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 8294 if (S.getLangOptions().CUDA) 8295 if (FunctionDecl *Caller = dyn_cast<FunctionDecl>(S.CurContext)) 8296 if (S.CheckCUDATarget(Caller, FunDecl)) 8297 return false; 8298 8299 QualType ResultTy; 8300 if (Context.hasSameUnqualifiedType(TargetFunctionType, 8301 FunDecl->getType()) || 8302 S.IsNoReturnConversion(FunDecl->getType(), TargetFunctionType, 8303 ResultTy)) { 8304 Matches.push_back(std::make_pair(CurAccessFunPair, 8305 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 8306 FoundNonTemplateFunction = true; 8307 return true; 8308 } 8309 } 8310 8311 return false; 8312 } 8313 8314 bool FindAllFunctionsThatMatchTargetTypeExactly() { 8315 bool Ret = false; 8316 8317 // If the overload expression doesn't have the form of a pointer to 8318 // member, don't try to convert it to a pointer-to-member type. 8319 if (IsInvalidFormOfPointerToMemberFunction()) 8320 return false; 8321 8322 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 8323 E = OvlExpr->decls_end(); 8324 I != E; ++I) { 8325 // Look through any using declarations to find the underlying function. 8326 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 8327 8328 // C++ [over.over]p3: 8329 // Non-member functions and static member functions match 8330 // targets of type "pointer-to-function" or "reference-to-function." 8331 // Nonstatic member functions match targets of 8332 // type "pointer-to-member-function." 8333 // Note that according to DR 247, the containing class does not matter. 8334 if (FunctionTemplateDecl *FunctionTemplate 8335 = dyn_cast<FunctionTemplateDecl>(Fn)) { 8336 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) 8337 Ret = true; 8338 } 8339 // If we have explicit template arguments supplied, skip non-templates. 8340 else if (!OvlExpr->hasExplicitTemplateArgs() && 8341 AddMatchingNonTemplateFunction(Fn, I.getPair())) 8342 Ret = true; 8343 } 8344 assert(Ret || Matches.empty()); 8345 return Ret; 8346 } 8347 8348 void EliminateAllExceptMostSpecializedTemplate() { 8349 // [...] and any given function template specialization F1 is 8350 // eliminated if the set contains a second function template 8351 // specialization whose function template is more specialized 8352 // than the function template of F1 according to the partial 8353 // ordering rules of 14.5.5.2. 8354 8355 // The algorithm specified above is quadratic. We instead use a 8356 // two-pass algorithm (similar to the one used to identify the 8357 // best viable function in an overload set) that identifies the 8358 // best function template (if it exists). 8359 8360 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 8361 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 8362 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 8363 8364 UnresolvedSetIterator Result = 8365 S.getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 8366 TPOC_Other, 0, SourceExpr->getLocStart(), 8367 S.PDiag(), 8368 S.PDiag(diag::err_addr_ovl_ambiguous) 8369 << Matches[0].second->getDeclName(), 8370 S.PDiag(diag::note_ovl_candidate) 8371 << (unsigned) oc_function_template, 8372 Complain, TargetFunctionType); 8373 8374 if (Result != MatchesCopy.end()) { 8375 // Make it the first and only element 8376 Matches[0].first = Matches[Result - MatchesCopy.begin()].first; 8377 Matches[0].second = cast<FunctionDecl>(*Result); 8378 Matches.resize(1); 8379 } 8380 } 8381 8382 void EliminateAllTemplateMatches() { 8383 // [...] any function template specializations in the set are 8384 // eliminated if the set also contains a non-template function, [...] 8385 for (unsigned I = 0, N = Matches.size(); I != N; ) { 8386 if (Matches[I].second->getPrimaryTemplate() == 0) 8387 ++I; 8388 else { 8389 Matches[I] = Matches[--N]; 8390 Matches.set_size(N); 8391 } 8392 } 8393 } 8394 8395public: 8396 void ComplainNoMatchesFound() const { 8397 assert(Matches.empty()); 8398 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) 8399 << OvlExpr->getName() << TargetFunctionType 8400 << OvlExpr->getSourceRange(); 8401 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); 8402 } 8403 8404 bool IsInvalidFormOfPointerToMemberFunction() const { 8405 return TargetTypeIsNonStaticMemberFunction && 8406 !OvlExprInfo.HasFormOfMemberPointer; 8407 } 8408 8409 void ComplainIsInvalidFormOfPointerToMemberFunction() const { 8410 // TODO: Should we condition this on whether any functions might 8411 // have matched, or is it more appropriate to do that in callers? 8412 // TODO: a fixit wouldn't hurt. 8413 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 8414 << TargetType << OvlExpr->getSourceRange(); 8415 } 8416 8417 void ComplainOfInvalidConversion() const { 8418 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 8419 << OvlExpr->getName() << TargetType; 8420 } 8421 8422 void ComplainMultipleMatchesFound() const { 8423 assert(Matches.size() > 1); 8424 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) 8425 << OvlExpr->getName() 8426 << OvlExpr->getSourceRange(); 8427 S.NoteAllOverloadCandidates(OvlExpr, TargetFunctionType); 8428 } 8429 8430 bool hadMultipleCandidates() const { return (OvlExpr->getNumDecls() > 1); } 8431 8432 int getNumMatches() const { return Matches.size(); } 8433 8434 FunctionDecl* getMatchingFunctionDecl() const { 8435 if (Matches.size() != 1) return 0; 8436 return Matches[0].second; 8437 } 8438 8439 const DeclAccessPair* getMatchingFunctionAccessPair() const { 8440 if (Matches.size() != 1) return 0; 8441 return &Matches[0].first; 8442 } 8443}; 8444 8445/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 8446/// an overloaded function (C++ [over.over]), where @p From is an 8447/// expression with overloaded function type and @p ToType is the type 8448/// we're trying to resolve to. For example: 8449/// 8450/// @code 8451/// int f(double); 8452/// int f(int); 8453/// 8454/// int (*pfd)(double) = f; // selects f(double) 8455/// @endcode 8456/// 8457/// This routine returns the resulting FunctionDecl if it could be 8458/// resolved, and NULL otherwise. When @p Complain is true, this 8459/// routine will emit diagnostics if there is an error. 8460FunctionDecl * 8461Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, 8462 QualType TargetType, 8463 bool Complain, 8464 DeclAccessPair &FoundResult, 8465 bool *pHadMultipleCandidates) { 8466 assert(AddressOfExpr->getType() == Context.OverloadTy); 8467 8468 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, 8469 Complain); 8470 int NumMatches = Resolver.getNumMatches(); 8471 FunctionDecl* Fn = 0; 8472 if (NumMatches == 0 && Complain) { 8473 if (Resolver.IsInvalidFormOfPointerToMemberFunction()) 8474 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); 8475 else 8476 Resolver.ComplainNoMatchesFound(); 8477 } 8478 else if (NumMatches > 1 && Complain) 8479 Resolver.ComplainMultipleMatchesFound(); 8480 else if (NumMatches == 1) { 8481 Fn = Resolver.getMatchingFunctionDecl(); 8482 assert(Fn); 8483 FoundResult = *Resolver.getMatchingFunctionAccessPair(); 8484 MarkDeclarationReferenced(AddressOfExpr->getLocStart(), Fn); 8485 if (Complain) 8486 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); 8487 } 8488 8489 if (pHadMultipleCandidates) 8490 *pHadMultipleCandidates = Resolver.hadMultipleCandidates(); 8491 return Fn; 8492} 8493 8494/// \brief Given an expression that refers to an overloaded function, try to 8495/// resolve that overloaded function expression down to a single function. 8496/// 8497/// This routine can only resolve template-ids that refer to a single function 8498/// template, where that template-id refers to a single template whose template 8499/// arguments are either provided by the template-id or have defaults, 8500/// as described in C++0x [temp.arg.explicit]p3. 8501FunctionDecl * 8502Sema::ResolveSingleFunctionTemplateSpecialization(OverloadExpr *ovl, 8503 bool Complain, 8504 DeclAccessPair *FoundResult) { 8505 // C++ [over.over]p1: 8506 // [...] [Note: any redundant set of parentheses surrounding the 8507 // overloaded function name is ignored (5.1). ] 8508 // C++ [over.over]p1: 8509 // [...] The overloaded function name can be preceded by the & 8510 // operator. 8511 8512 // If we didn't actually find any template-ids, we're done. 8513 if (!ovl->hasExplicitTemplateArgs()) 8514 return 0; 8515 8516 TemplateArgumentListInfo ExplicitTemplateArgs; 8517 ovl->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 8518 8519 // Look through all of the overloaded functions, searching for one 8520 // whose type matches exactly. 8521 FunctionDecl *Matched = 0; 8522 for (UnresolvedSetIterator I = ovl->decls_begin(), 8523 E = ovl->decls_end(); I != E; ++I) { 8524 // C++0x [temp.arg.explicit]p3: 8525 // [...] In contexts where deduction is done and fails, or in contexts 8526 // where deduction is not done, if a template argument list is 8527 // specified and it, along with any default template arguments, 8528 // identifies a single function template specialization, then the 8529 // template-id is an lvalue for the function template specialization. 8530 FunctionTemplateDecl *FunctionTemplate 8531 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 8532 8533 // C++ [over.over]p2: 8534 // If the name is a function template, template argument deduction is 8535 // done (14.8.2.2), and if the argument deduction succeeds, the 8536 // resulting template argument list is used to generate a single 8537 // function template specialization, which is added to the set of 8538 // overloaded functions considered. 8539 FunctionDecl *Specialization = 0; 8540 TemplateDeductionInfo Info(Context, ovl->getNameLoc()); 8541 if (TemplateDeductionResult Result 8542 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 8543 Specialization, Info)) { 8544 // FIXME: make a note of the failed deduction for diagnostics. 8545 (void)Result; 8546 continue; 8547 } 8548 8549 assert(Specialization && "no specialization and no error?"); 8550 8551 // Multiple matches; we can't resolve to a single declaration. 8552 if (Matched) { 8553 if (Complain) { 8554 Diag(ovl->getExprLoc(), diag::err_addr_ovl_ambiguous) 8555 << ovl->getName(); 8556 NoteAllOverloadCandidates(ovl); 8557 } 8558 return 0; 8559 } 8560 8561 Matched = Specialization; 8562 if (FoundResult) *FoundResult = I.getPair(); 8563 } 8564 8565 return Matched; 8566} 8567 8568 8569 8570 8571// Resolve and fix an overloaded expression that can be resolved 8572// because it identifies a single function template specialization. 8573// 8574// Last three arguments should only be supplied if Complain = true 8575// 8576// Return true if it was logically possible to so resolve the 8577// expression, regardless of whether or not it succeeded. Always 8578// returns true if 'complain' is set. 8579bool Sema::ResolveAndFixSingleFunctionTemplateSpecialization( 8580 ExprResult &SrcExpr, bool doFunctionPointerConverion, 8581 bool complain, const SourceRange& OpRangeForComplaining, 8582 QualType DestTypeForComplaining, 8583 unsigned DiagIDForComplaining) { 8584 assert(SrcExpr.get()->getType() == Context.OverloadTy); 8585 8586 OverloadExpr::FindResult ovl = OverloadExpr::find(SrcExpr.get()); 8587 8588 DeclAccessPair found; 8589 ExprResult SingleFunctionExpression; 8590 if (FunctionDecl *fn = ResolveSingleFunctionTemplateSpecialization( 8591 ovl.Expression, /*complain*/ false, &found)) { 8592 if (DiagnoseUseOfDecl(fn, SrcExpr.get()->getSourceRange().getBegin())) { 8593 SrcExpr = ExprError(); 8594 return true; 8595 } 8596 8597 // It is only correct to resolve to an instance method if we're 8598 // resolving a form that's permitted to be a pointer to member. 8599 // Otherwise we'll end up making a bound member expression, which 8600 // is illegal in all the contexts we resolve like this. 8601 if (!ovl.HasFormOfMemberPointer && 8602 isa<CXXMethodDecl>(fn) && 8603 cast<CXXMethodDecl>(fn)->isInstance()) { 8604 if (!complain) return false; 8605 8606 Diag(ovl.Expression->getExprLoc(), 8607 diag::err_bound_member_function) 8608 << 0 << ovl.Expression->getSourceRange(); 8609 8610 // TODO: I believe we only end up here if there's a mix of 8611 // static and non-static candidates (otherwise the expression 8612 // would have 'bound member' type, not 'overload' type). 8613 // Ideally we would note which candidate was chosen and why 8614 // the static candidates were rejected. 8615 SrcExpr = ExprError(); 8616 return true; 8617 } 8618 8619 // Fix the expresion to refer to 'fn'. 8620 SingleFunctionExpression = 8621 Owned(FixOverloadedFunctionReference(SrcExpr.take(), found, fn)); 8622 8623 // If desired, do function-to-pointer decay. 8624 if (doFunctionPointerConverion) { 8625 SingleFunctionExpression = 8626 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.take()); 8627 if (SingleFunctionExpression.isInvalid()) { 8628 SrcExpr = ExprError(); 8629 return true; 8630 } 8631 } 8632 } 8633 8634 if (!SingleFunctionExpression.isUsable()) { 8635 if (complain) { 8636 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) 8637 << ovl.Expression->getName() 8638 << DestTypeForComplaining 8639 << OpRangeForComplaining 8640 << ovl.Expression->getQualifierLoc().getSourceRange(); 8641 NoteAllOverloadCandidates(SrcExpr.get()); 8642 8643 SrcExpr = ExprError(); 8644 return true; 8645 } 8646 8647 return false; 8648 } 8649 8650 SrcExpr = SingleFunctionExpression; 8651 return true; 8652} 8653 8654/// \brief Add a single candidate to the overload set. 8655static void AddOverloadedCallCandidate(Sema &S, 8656 DeclAccessPair FoundDecl, 8657 TemplateArgumentListInfo *ExplicitTemplateArgs, 8658 Expr **Args, unsigned NumArgs, 8659 OverloadCandidateSet &CandidateSet, 8660 bool PartialOverloading, 8661 bool KnownValid) { 8662 NamedDecl *Callee = FoundDecl.getDecl(); 8663 if (isa<UsingShadowDecl>(Callee)) 8664 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 8665 8666 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 8667 if (ExplicitTemplateArgs) { 8668 assert(!KnownValid && "Explicit template arguments?"); 8669 return; 8670 } 8671 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 8672 false, PartialOverloading); 8673 return; 8674 } 8675 8676 if (FunctionTemplateDecl *FuncTemplate 8677 = dyn_cast<FunctionTemplateDecl>(Callee)) { 8678 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 8679 ExplicitTemplateArgs, 8680 Args, NumArgs, CandidateSet); 8681 return; 8682 } 8683 8684 assert(!KnownValid && "unhandled case in overloaded call candidate"); 8685} 8686 8687/// \brief Add the overload candidates named by callee and/or found by argument 8688/// dependent lookup to the given overload set. 8689void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 8690 Expr **Args, unsigned NumArgs, 8691 OverloadCandidateSet &CandidateSet, 8692 bool PartialOverloading) { 8693 8694#ifndef NDEBUG 8695 // Verify that ArgumentDependentLookup is consistent with the rules 8696 // in C++0x [basic.lookup.argdep]p3: 8697 // 8698 // Let X be the lookup set produced by unqualified lookup (3.4.1) 8699 // and let Y be the lookup set produced by argument dependent 8700 // lookup (defined as follows). If X contains 8701 // 8702 // -- a declaration of a class member, or 8703 // 8704 // -- a block-scope function declaration that is not a 8705 // using-declaration, or 8706 // 8707 // -- a declaration that is neither a function or a function 8708 // template 8709 // 8710 // then Y is empty. 8711 8712 if (ULE->requiresADL()) { 8713 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 8714 E = ULE->decls_end(); I != E; ++I) { 8715 assert(!(*I)->getDeclContext()->isRecord()); 8716 assert(isa<UsingShadowDecl>(*I) || 8717 !(*I)->getDeclContext()->isFunctionOrMethod()); 8718 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 8719 } 8720 } 8721#endif 8722 8723 // It would be nice to avoid this copy. 8724 TemplateArgumentListInfo TABuffer; 8725 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 8726 if (ULE->hasExplicitTemplateArgs()) { 8727 ULE->copyTemplateArgumentsInto(TABuffer); 8728 ExplicitTemplateArgs = &TABuffer; 8729 } 8730 8731 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 8732 E = ULE->decls_end(); I != E; ++I) 8733 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 8734 Args, NumArgs, CandidateSet, 8735 PartialOverloading, /*KnownValid*/ true); 8736 8737 if (ULE->requiresADL()) 8738 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 8739 Args, NumArgs, 8740 ExplicitTemplateArgs, 8741 CandidateSet, 8742 PartialOverloading, 8743 ULE->isStdAssociatedNamespace()); 8744} 8745 8746/// Attempt to recover from an ill-formed use of a non-dependent name in a 8747/// template, where the non-dependent name was declared after the template 8748/// was defined. This is common in code written for a compilers which do not 8749/// correctly implement two-stage name lookup. 8750/// 8751/// Returns true if a viable candidate was found and a diagnostic was issued. 8752static bool 8753DiagnoseTwoPhaseLookup(Sema &SemaRef, SourceLocation FnLoc, 8754 const CXXScopeSpec &SS, LookupResult &R, 8755 TemplateArgumentListInfo *ExplicitTemplateArgs, 8756 Expr **Args, unsigned NumArgs) { 8757 if (SemaRef.ActiveTemplateInstantiations.empty() || !SS.isEmpty()) 8758 return false; 8759 8760 for (DeclContext *DC = SemaRef.CurContext; DC; DC = DC->getParent()) { 8761 SemaRef.LookupQualifiedName(R, DC); 8762 8763 if (!R.empty()) { 8764 R.suppressDiagnostics(); 8765 8766 if (isa<CXXRecordDecl>(DC)) { 8767 // Don't diagnose names we find in classes; we get much better 8768 // diagnostics for these from DiagnoseEmptyLookup. 8769 R.clear(); 8770 return false; 8771 } 8772 8773 OverloadCandidateSet Candidates(FnLoc); 8774 for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) 8775 AddOverloadedCallCandidate(SemaRef, I.getPair(), 8776 ExplicitTemplateArgs, Args, NumArgs, 8777 Candidates, false, /*KnownValid*/ false); 8778 8779 OverloadCandidateSet::iterator Best; 8780 if (Candidates.BestViableFunction(SemaRef, FnLoc, Best) != OR_Success) { 8781 // No viable functions. Don't bother the user with notes for functions 8782 // which don't work and shouldn't be found anyway. 8783 R.clear(); 8784 return false; 8785 } 8786 8787 // Find the namespaces where ADL would have looked, and suggest 8788 // declaring the function there instead. 8789 Sema::AssociatedNamespaceSet AssociatedNamespaces; 8790 Sema::AssociatedClassSet AssociatedClasses; 8791 SemaRef.FindAssociatedClassesAndNamespaces(Args, NumArgs, 8792 AssociatedNamespaces, 8793 AssociatedClasses); 8794 // Never suggest declaring a function within namespace 'std'. 8795 Sema::AssociatedNamespaceSet SuggestedNamespaces; 8796 if (DeclContext *Std = SemaRef.getStdNamespace()) { 8797 for (Sema::AssociatedNamespaceSet::iterator 8798 it = AssociatedNamespaces.begin(), 8799 end = AssociatedNamespaces.end(); it != end; ++it) { 8800 if (!Std->Encloses(*it)) 8801 SuggestedNamespaces.insert(*it); 8802 } 8803 } else { 8804 // Lacking the 'std::' namespace, use all of the associated namespaces. 8805 SuggestedNamespaces = AssociatedNamespaces; 8806 } 8807 8808 SemaRef.Diag(R.getNameLoc(), diag::err_not_found_by_two_phase_lookup) 8809 << R.getLookupName(); 8810 if (SuggestedNamespaces.empty()) { 8811 SemaRef.Diag(Best->Function->getLocation(), 8812 diag::note_not_found_by_two_phase_lookup) 8813 << R.getLookupName() << 0; 8814 } else if (SuggestedNamespaces.size() == 1) { 8815 SemaRef.Diag(Best->Function->getLocation(), 8816 diag::note_not_found_by_two_phase_lookup) 8817 << R.getLookupName() << 1 << *SuggestedNamespaces.begin(); 8818 } else { 8819 // FIXME: It would be useful to list the associated namespaces here, 8820 // but the diagnostics infrastructure doesn't provide a way to produce 8821 // a localized representation of a list of items. 8822 SemaRef.Diag(Best->Function->getLocation(), 8823 diag::note_not_found_by_two_phase_lookup) 8824 << R.getLookupName() << 2; 8825 } 8826 8827 // Try to recover by calling this function. 8828 return true; 8829 } 8830 8831 R.clear(); 8832 } 8833 8834 return false; 8835} 8836 8837/// Attempt to recover from ill-formed use of a non-dependent operator in a 8838/// template, where the non-dependent operator was declared after the template 8839/// was defined. 8840/// 8841/// Returns true if a viable candidate was found and a diagnostic was issued. 8842static bool 8843DiagnoseTwoPhaseOperatorLookup(Sema &SemaRef, OverloadedOperatorKind Op, 8844 SourceLocation OpLoc, 8845 Expr **Args, unsigned NumArgs) { 8846 DeclarationName OpName = 8847 SemaRef.Context.DeclarationNames.getCXXOperatorName(Op); 8848 LookupResult R(SemaRef, OpName, OpLoc, Sema::LookupOperatorName); 8849 return DiagnoseTwoPhaseLookup(SemaRef, OpLoc, CXXScopeSpec(), R, 8850 /*ExplicitTemplateArgs=*/0, Args, NumArgs); 8851} 8852 8853/// Attempts to recover from a call where no functions were found. 8854/// 8855/// Returns true if new candidates were found. 8856static ExprResult 8857BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 8858 UnresolvedLookupExpr *ULE, 8859 SourceLocation LParenLoc, 8860 Expr **Args, unsigned NumArgs, 8861 SourceLocation RParenLoc, 8862 bool EmptyLookup) { 8863 8864 CXXScopeSpec SS; 8865 SS.Adopt(ULE->getQualifierLoc()); 8866 8867 TemplateArgumentListInfo TABuffer; 8868 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 8869 if (ULE->hasExplicitTemplateArgs()) { 8870 ULE->copyTemplateArgumentsInto(TABuffer); 8871 ExplicitTemplateArgs = &TABuffer; 8872 } 8873 8874 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 8875 Sema::LookupOrdinaryName); 8876 if (!DiagnoseTwoPhaseLookup(SemaRef, Fn->getExprLoc(), SS, R, 8877 ExplicitTemplateArgs, Args, NumArgs) && 8878 (!EmptyLookup || 8879 SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression, 8880 ExplicitTemplateArgs, Args, NumArgs))) 8881 return ExprError(); 8882 8883 assert(!R.empty() && "lookup results empty despite recovery"); 8884 8885 // Build an implicit member call if appropriate. Just drop the 8886 // casts and such from the call, we don't really care. 8887 ExprResult NewFn = ExprError(); 8888 if ((*R.begin())->isCXXClassMember()) 8889 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, 8890 ExplicitTemplateArgs); 8891 else if (ExplicitTemplateArgs) 8892 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 8893 else 8894 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 8895 8896 if (NewFn.isInvalid()) 8897 return ExprError(); 8898 8899 // This shouldn't cause an infinite loop because we're giving it 8900 // an expression with viable lookup results, which should never 8901 // end up here. 8902 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 8903 MultiExprArg(Args, NumArgs), RParenLoc); 8904} 8905 8906/// ResolveOverloadedCallFn - Given the call expression that calls Fn 8907/// (which eventually refers to the declaration Func) and the call 8908/// arguments Args/NumArgs, attempt to resolve the function call down 8909/// to a specific function. If overload resolution succeeds, returns 8910/// the function declaration produced by overload 8911/// resolution. Otherwise, emits diagnostics, deletes all of the 8912/// arguments and Fn, and returns NULL. 8913ExprResult 8914Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 8915 SourceLocation LParenLoc, 8916 Expr **Args, unsigned NumArgs, 8917 SourceLocation RParenLoc, 8918 Expr *ExecConfig) { 8919#ifndef NDEBUG 8920 if (ULE->requiresADL()) { 8921 // To do ADL, we must have found an unqualified name. 8922 assert(!ULE->getQualifier() && "qualified name with ADL"); 8923 8924 // We don't perform ADL for implicit declarations of builtins. 8925 // Verify that this was correctly set up. 8926 FunctionDecl *F; 8927 if (ULE->decls_begin() + 1 == ULE->decls_end() && 8928 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 8929 F->getBuiltinID() && F->isImplicit()) 8930 llvm_unreachable("performing ADL for builtin"); 8931 8932 // We don't perform ADL in C. 8933 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 8934 } else 8935 assert(!ULE->isStdAssociatedNamespace() && 8936 "std is associated namespace but not doing ADL"); 8937#endif 8938 8939 UnbridgedCastsSet UnbridgedCasts; 8940 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) 8941 return ExprError(); 8942 8943 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 8944 8945 // Add the functions denoted by the callee to the set of candidate 8946 // functions, including those from argument-dependent lookup. 8947 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 8948 8949 // If we found nothing, try to recover. 8950 // BuildRecoveryCallExpr diagnoses the error itself, so we just bail 8951 // out if it fails. 8952 if (CandidateSet.empty()) { 8953 // In Microsoft mode, if we are inside a template class member function then 8954 // create a type dependent CallExpr. The goal is to postpone name lookup 8955 // to instantiation time to be able to search into type dependent base 8956 // classes. 8957 if (getLangOptions().MicrosoftMode && CurContext->isDependentContext() && 8958 (isa<FunctionDecl>(CurContext) || isa<CXXRecordDecl>(CurContext))) { 8959 CallExpr *CE = new (Context) CallExpr(Context, Fn, Args, NumArgs, 8960 Context.DependentTy, VK_RValue, 8961 RParenLoc); 8962 CE->setTypeDependent(true); 8963 return Owned(CE); 8964 } 8965 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 8966 RParenLoc, /*EmptyLookup=*/true); 8967 } 8968 8969 UnbridgedCasts.restore(); 8970 8971 OverloadCandidateSet::iterator Best; 8972 switch (CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best)) { 8973 case OR_Success: { 8974 FunctionDecl *FDecl = Best->Function; 8975 MarkDeclarationReferenced(Fn->getExprLoc(), FDecl); 8976 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 8977 DiagnoseUseOfDecl(FDecl, ULE->getNameLoc()); 8978 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 8979 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc, 8980 ExecConfig); 8981 } 8982 8983 case OR_No_Viable_Function: { 8984 // Try to recover by looking for viable functions which the user might 8985 // have meant to call. 8986 ExprResult Recovery = BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, 8987 Args, NumArgs, RParenLoc, 8988 /*EmptyLookup=*/false); 8989 if (!Recovery.isInvalid()) 8990 return Recovery; 8991 8992 Diag(Fn->getSourceRange().getBegin(), 8993 diag::err_ovl_no_viable_function_in_call) 8994 << ULE->getName() << Fn->getSourceRange(); 8995 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8996 break; 8997 } 8998 8999 case OR_Ambiguous: 9000 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 9001 << ULE->getName() << Fn->getSourceRange(); 9002 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 9003 break; 9004 9005 case OR_Deleted: 9006 { 9007 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 9008 << Best->Function->isDeleted() 9009 << ULE->getName() 9010 << getDeletedOrUnavailableSuffix(Best->Function) 9011 << Fn->getSourceRange(); 9012 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9013 9014 // We emitted an error for the unvailable/deleted function call but keep 9015 // the call in the AST. 9016 FunctionDecl *FDecl = Best->Function; 9017 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 9018 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, 9019 RParenLoc, ExecConfig); 9020 } 9021 } 9022 9023 // Overload resolution failed. 9024 return ExprError(); 9025} 9026 9027static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 9028 return Functions.size() > 1 || 9029 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 9030} 9031 9032/// \brief Create a unary operation that may resolve to an overloaded 9033/// operator. 9034/// 9035/// \param OpLoc The location of the operator itself (e.g., '*'). 9036/// 9037/// \param OpcIn The UnaryOperator::Opcode that describes this 9038/// operator. 9039/// 9040/// \param Functions The set of non-member functions that will be 9041/// considered by overload resolution. The caller needs to build this 9042/// set based on the context using, e.g., 9043/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 9044/// set should not contain any member functions; those will be added 9045/// by CreateOverloadedUnaryOp(). 9046/// 9047/// \param input The input argument. 9048ExprResult 9049Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 9050 const UnresolvedSetImpl &Fns, 9051 Expr *Input) { 9052 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 9053 9054 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 9055 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 9056 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 9057 // TODO: provide better source location info. 9058 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 9059 9060 if (checkPlaceholderForOverload(*this, Input)) 9061 return ExprError(); 9062 9063 Expr *Args[2] = { Input, 0 }; 9064 unsigned NumArgs = 1; 9065 9066 // For post-increment and post-decrement, add the implicit '0' as 9067 // the second argument, so that we know this is a post-increment or 9068 // post-decrement. 9069 if (Opc == UO_PostInc || Opc == UO_PostDec) { 9070 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 9071 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 9072 SourceLocation()); 9073 NumArgs = 2; 9074 } 9075 9076 if (Input->isTypeDependent()) { 9077 if (Fns.empty()) 9078 return Owned(new (Context) UnaryOperator(Input, 9079 Opc, 9080 Context.DependentTy, 9081 VK_RValue, OK_Ordinary, 9082 OpLoc)); 9083 9084 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 9085 UnresolvedLookupExpr *Fn 9086 = UnresolvedLookupExpr::Create(Context, NamingClass, 9087 NestedNameSpecifierLoc(), OpNameInfo, 9088 /*ADL*/ true, IsOverloaded(Fns), 9089 Fns.begin(), Fns.end()); 9090 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 9091 &Args[0], NumArgs, 9092 Context.DependentTy, 9093 VK_RValue, 9094 OpLoc)); 9095 } 9096 9097 // Build an empty overload set. 9098 OverloadCandidateSet CandidateSet(OpLoc); 9099 9100 // Add the candidates from the given function set. 9101 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 9102 9103 // Add operator candidates that are member functions. 9104 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 9105 9106 // Add candidates from ADL. 9107 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 9108 Args, NumArgs, 9109 /*ExplicitTemplateArgs*/ 0, 9110 CandidateSet); 9111 9112 // Add builtin operator candidates. 9113 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 9114 9115 bool HadMultipleCandidates = (CandidateSet.size() > 1); 9116 9117 // Perform overload resolution. 9118 OverloadCandidateSet::iterator Best; 9119 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 9120 case OR_Success: { 9121 // We found a built-in operator or an overloaded operator. 9122 FunctionDecl *FnDecl = Best->Function; 9123 9124 if (FnDecl) { 9125 // We matched an overloaded operator. Build a call to that 9126 // operator. 9127 9128 MarkDeclarationReferenced(OpLoc, FnDecl); 9129 9130 // Convert the arguments. 9131 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 9132 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 9133 9134 ExprResult InputRes = 9135 PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 9136 Best->FoundDecl, Method); 9137 if (InputRes.isInvalid()) 9138 return ExprError(); 9139 Input = InputRes.take(); 9140 } else { 9141 // Convert the arguments. 9142 ExprResult InputInit 9143 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 9144 Context, 9145 FnDecl->getParamDecl(0)), 9146 SourceLocation(), 9147 Input); 9148 if (InputInit.isInvalid()) 9149 return ExprError(); 9150 Input = InputInit.take(); 9151 } 9152 9153 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 9154 9155 // Determine the result type. 9156 QualType ResultTy = FnDecl->getResultType(); 9157 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 9158 ResultTy = ResultTy.getNonLValueExprType(Context); 9159 9160 // Build the actual expression node. 9161 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 9162 HadMultipleCandidates); 9163 if (FnExpr.isInvalid()) 9164 return ExprError(); 9165 9166 Args[0] = Input; 9167 CallExpr *TheCall = 9168 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 9169 Args, NumArgs, ResultTy, VK, OpLoc); 9170 9171 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 9172 FnDecl)) 9173 return ExprError(); 9174 9175 return MaybeBindToTemporary(TheCall); 9176 } else { 9177 // We matched a built-in operator. Convert the arguments, then 9178 // break out so that we will build the appropriate built-in 9179 // operator node. 9180 ExprResult InputRes = 9181 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 9182 Best->Conversions[0], AA_Passing); 9183 if (InputRes.isInvalid()) 9184 return ExprError(); 9185 Input = InputRes.take(); 9186 break; 9187 } 9188 } 9189 9190 case OR_No_Viable_Function: 9191 // This is an erroneous use of an operator which can be overloaded by 9192 // a non-member function. Check for non-member operators which were 9193 // defined too late to be candidates. 9194 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args, NumArgs)) 9195 // FIXME: Recover by calling the found function. 9196 return ExprError(); 9197 9198 // No viable function; fall through to handling this as a 9199 // built-in operator, which will produce an error message for us. 9200 break; 9201 9202 case OR_Ambiguous: 9203 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 9204 << UnaryOperator::getOpcodeStr(Opc) 9205 << Input->getType() 9206 << Input->getSourceRange(); 9207 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs, 9208 UnaryOperator::getOpcodeStr(Opc), OpLoc); 9209 return ExprError(); 9210 9211 case OR_Deleted: 9212 Diag(OpLoc, diag::err_ovl_deleted_oper) 9213 << Best->Function->isDeleted() 9214 << UnaryOperator::getOpcodeStr(Opc) 9215 << getDeletedOrUnavailableSuffix(Best->Function) 9216 << Input->getSourceRange(); 9217 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs, 9218 UnaryOperator::getOpcodeStr(Opc), OpLoc); 9219 return ExprError(); 9220 } 9221 9222 // Either we found no viable overloaded operator or we matched a 9223 // built-in operator. In either case, fall through to trying to 9224 // build a built-in operation. 9225 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 9226} 9227 9228/// \brief Create a binary operation that may resolve to an overloaded 9229/// operator. 9230/// 9231/// \param OpLoc The location of the operator itself (e.g., '+'). 9232/// 9233/// \param OpcIn The BinaryOperator::Opcode that describes this 9234/// operator. 9235/// 9236/// \param Functions The set of non-member functions that will be 9237/// considered by overload resolution. The caller needs to build this 9238/// set based on the context using, e.g., 9239/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 9240/// set should not contain any member functions; those will be added 9241/// by CreateOverloadedBinOp(). 9242/// 9243/// \param LHS Left-hand argument. 9244/// \param RHS Right-hand argument. 9245ExprResult 9246Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 9247 unsigned OpcIn, 9248 const UnresolvedSetImpl &Fns, 9249 Expr *LHS, Expr *RHS) { 9250 Expr *Args[2] = { LHS, RHS }; 9251 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 9252 9253 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 9254 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 9255 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 9256 9257 // If either side is type-dependent, create an appropriate dependent 9258 // expression. 9259 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 9260 if (Fns.empty()) { 9261 // If there are no functions to store, just build a dependent 9262 // BinaryOperator or CompoundAssignment. 9263 if (Opc <= BO_Assign || Opc > BO_OrAssign) 9264 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 9265 Context.DependentTy, 9266 VK_RValue, OK_Ordinary, 9267 OpLoc)); 9268 9269 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 9270 Context.DependentTy, 9271 VK_LValue, 9272 OK_Ordinary, 9273 Context.DependentTy, 9274 Context.DependentTy, 9275 OpLoc)); 9276 } 9277 9278 // FIXME: save results of ADL from here? 9279 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 9280 // TODO: provide better source location info in DNLoc component. 9281 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 9282 UnresolvedLookupExpr *Fn 9283 = UnresolvedLookupExpr::Create(Context, NamingClass, 9284 NestedNameSpecifierLoc(), OpNameInfo, 9285 /*ADL*/ true, IsOverloaded(Fns), 9286 Fns.begin(), Fns.end()); 9287 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 9288 Args, 2, 9289 Context.DependentTy, 9290 VK_RValue, 9291 OpLoc)); 9292 } 9293 9294 // Always do placeholder-like conversions on the RHS. 9295 if (checkPlaceholderForOverload(*this, Args[1])) 9296 return ExprError(); 9297 9298 // Do placeholder-like conversion on the LHS; note that we should 9299 // not get here with a PseudoObject LHS. 9300 assert(Args[0]->getObjectKind() != OK_ObjCProperty); 9301 if (checkPlaceholderForOverload(*this, Args[0])) 9302 return ExprError(); 9303 9304 // If this is the assignment operator, we only perform overload resolution 9305 // if the left-hand side is a class or enumeration type. This is actually 9306 // a hack. The standard requires that we do overload resolution between the 9307 // various built-in candidates, but as DR507 points out, this can lead to 9308 // problems. So we do it this way, which pretty much follows what GCC does. 9309 // Note that we go the traditional code path for compound assignment forms. 9310 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 9311 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 9312 9313 // If this is the .* operator, which is not overloadable, just 9314 // create a built-in binary operator. 9315 if (Opc == BO_PtrMemD) 9316 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 9317 9318 // Build an empty overload set. 9319 OverloadCandidateSet CandidateSet(OpLoc); 9320 9321 // Add the candidates from the given function set. 9322 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 9323 9324 // Add operator candidates that are member functions. 9325 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 9326 9327 // Add candidates from ADL. 9328 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 9329 Args, 2, 9330 /*ExplicitTemplateArgs*/ 0, 9331 CandidateSet); 9332 9333 // Add builtin operator candidates. 9334 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 9335 9336 bool HadMultipleCandidates = (CandidateSet.size() > 1); 9337 9338 // Perform overload resolution. 9339 OverloadCandidateSet::iterator Best; 9340 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 9341 case OR_Success: { 9342 // We found a built-in operator or an overloaded operator. 9343 FunctionDecl *FnDecl = Best->Function; 9344 9345 if (FnDecl) { 9346 // We matched an overloaded operator. Build a call to that 9347 // operator. 9348 9349 MarkDeclarationReferenced(OpLoc, FnDecl); 9350 9351 // Convert the arguments. 9352 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 9353 // Best->Access is only meaningful for class members. 9354 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 9355 9356 ExprResult Arg1 = 9357 PerformCopyInitialization( 9358 InitializedEntity::InitializeParameter(Context, 9359 FnDecl->getParamDecl(0)), 9360 SourceLocation(), Owned(Args[1])); 9361 if (Arg1.isInvalid()) 9362 return ExprError(); 9363 9364 ExprResult Arg0 = 9365 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 9366 Best->FoundDecl, Method); 9367 if (Arg0.isInvalid()) 9368 return ExprError(); 9369 Args[0] = Arg0.takeAs<Expr>(); 9370 Args[1] = RHS = Arg1.takeAs<Expr>(); 9371 } else { 9372 // Convert the arguments. 9373 ExprResult Arg0 = PerformCopyInitialization( 9374 InitializedEntity::InitializeParameter(Context, 9375 FnDecl->getParamDecl(0)), 9376 SourceLocation(), Owned(Args[0])); 9377 if (Arg0.isInvalid()) 9378 return ExprError(); 9379 9380 ExprResult Arg1 = 9381 PerformCopyInitialization( 9382 InitializedEntity::InitializeParameter(Context, 9383 FnDecl->getParamDecl(1)), 9384 SourceLocation(), Owned(Args[1])); 9385 if (Arg1.isInvalid()) 9386 return ExprError(); 9387 Args[0] = LHS = Arg0.takeAs<Expr>(); 9388 Args[1] = RHS = Arg1.takeAs<Expr>(); 9389 } 9390 9391 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 9392 9393 // Determine the result type. 9394 QualType ResultTy = FnDecl->getResultType(); 9395 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 9396 ResultTy = ResultTy.getNonLValueExprType(Context); 9397 9398 // Build the actual expression node. 9399 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 9400 HadMultipleCandidates, OpLoc); 9401 if (FnExpr.isInvalid()) 9402 return ExprError(); 9403 9404 CXXOperatorCallExpr *TheCall = 9405 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 9406 Args, 2, ResultTy, VK, OpLoc); 9407 9408 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 9409 FnDecl)) 9410 return ExprError(); 9411 9412 return MaybeBindToTemporary(TheCall); 9413 } else { 9414 // We matched a built-in operator. Convert the arguments, then 9415 // break out so that we will build the appropriate built-in 9416 // operator node. 9417 ExprResult ArgsRes0 = 9418 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 9419 Best->Conversions[0], AA_Passing); 9420 if (ArgsRes0.isInvalid()) 9421 return ExprError(); 9422 Args[0] = ArgsRes0.take(); 9423 9424 ExprResult ArgsRes1 = 9425 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 9426 Best->Conversions[1], AA_Passing); 9427 if (ArgsRes1.isInvalid()) 9428 return ExprError(); 9429 Args[1] = ArgsRes1.take(); 9430 break; 9431 } 9432 } 9433 9434 case OR_No_Viable_Function: { 9435 // C++ [over.match.oper]p9: 9436 // If the operator is the operator , [...] and there are no 9437 // viable functions, then the operator is assumed to be the 9438 // built-in operator and interpreted according to clause 5. 9439 if (Opc == BO_Comma) 9440 break; 9441 9442 // For class as left operand for assignment or compound assigment 9443 // operator do not fall through to handling in built-in, but report that 9444 // no overloaded assignment operator found 9445 ExprResult Result = ExprError(); 9446 if (Args[0]->getType()->isRecordType() && 9447 Opc >= BO_Assign && Opc <= BO_OrAssign) { 9448 Diag(OpLoc, diag::err_ovl_no_viable_oper) 9449 << BinaryOperator::getOpcodeStr(Opc) 9450 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9451 } else { 9452 // This is an erroneous use of an operator which can be overloaded by 9453 // a non-member function. Check for non-member operators which were 9454 // defined too late to be candidates. 9455 if (DiagnoseTwoPhaseOperatorLookup(*this, Op, OpLoc, Args, 2)) 9456 // FIXME: Recover by calling the found function. 9457 return ExprError(); 9458 9459 // No viable function; try to create a built-in operation, which will 9460 // produce an error. Then, show the non-viable candidates. 9461 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 9462 } 9463 assert(Result.isInvalid() && 9464 "C++ binary operator overloading is missing candidates!"); 9465 if (Result.isInvalid()) 9466 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 9467 BinaryOperator::getOpcodeStr(Opc), OpLoc); 9468 return move(Result); 9469 } 9470 9471 case OR_Ambiguous: 9472 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 9473 << BinaryOperator::getOpcodeStr(Opc) 9474 << Args[0]->getType() << Args[1]->getType() 9475 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9476 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 9477 BinaryOperator::getOpcodeStr(Opc), OpLoc); 9478 return ExprError(); 9479 9480 case OR_Deleted: 9481 Diag(OpLoc, diag::err_ovl_deleted_oper) 9482 << Best->Function->isDeleted() 9483 << BinaryOperator::getOpcodeStr(Opc) 9484 << getDeletedOrUnavailableSuffix(Best->Function) 9485 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9486 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 9487 BinaryOperator::getOpcodeStr(Opc), OpLoc); 9488 return ExprError(); 9489 } 9490 9491 // We matched a built-in operator; build it. 9492 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 9493} 9494 9495ExprResult 9496Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 9497 SourceLocation RLoc, 9498 Expr *Base, Expr *Idx) { 9499 Expr *Args[2] = { Base, Idx }; 9500 DeclarationName OpName = 9501 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 9502 9503 // If either side is type-dependent, create an appropriate dependent 9504 // expression. 9505 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 9506 9507 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 9508 // CHECKME: no 'operator' keyword? 9509 DeclarationNameInfo OpNameInfo(OpName, LLoc); 9510 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 9511 UnresolvedLookupExpr *Fn 9512 = UnresolvedLookupExpr::Create(Context, NamingClass, 9513 NestedNameSpecifierLoc(), OpNameInfo, 9514 /*ADL*/ true, /*Overloaded*/ false, 9515 UnresolvedSetIterator(), 9516 UnresolvedSetIterator()); 9517 // Can't add any actual overloads yet 9518 9519 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 9520 Args, 2, 9521 Context.DependentTy, 9522 VK_RValue, 9523 RLoc)); 9524 } 9525 9526 // Handle placeholders on both operands. 9527 if (checkPlaceholderForOverload(*this, Args[0])) 9528 return ExprError(); 9529 if (checkPlaceholderForOverload(*this, Args[1])) 9530 return ExprError(); 9531 9532 // Build an empty overload set. 9533 OverloadCandidateSet CandidateSet(LLoc); 9534 9535 // Subscript can only be overloaded as a member function. 9536 9537 // Add operator candidates that are member functions. 9538 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 9539 9540 // Add builtin operator candidates. 9541 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 9542 9543 bool HadMultipleCandidates = (CandidateSet.size() > 1); 9544 9545 // Perform overload resolution. 9546 OverloadCandidateSet::iterator Best; 9547 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 9548 case OR_Success: { 9549 // We found a built-in operator or an overloaded operator. 9550 FunctionDecl *FnDecl = Best->Function; 9551 9552 if (FnDecl) { 9553 // We matched an overloaded operator. Build a call to that 9554 // operator. 9555 9556 MarkDeclarationReferenced(LLoc, FnDecl); 9557 9558 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 9559 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 9560 9561 // Convert the arguments. 9562 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 9563 ExprResult Arg0 = 9564 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 9565 Best->FoundDecl, Method); 9566 if (Arg0.isInvalid()) 9567 return ExprError(); 9568 Args[0] = Arg0.take(); 9569 9570 // Convert the arguments. 9571 ExprResult InputInit 9572 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 9573 Context, 9574 FnDecl->getParamDecl(0)), 9575 SourceLocation(), 9576 Owned(Args[1])); 9577 if (InputInit.isInvalid()) 9578 return ExprError(); 9579 9580 Args[1] = InputInit.takeAs<Expr>(); 9581 9582 // Determine the result type 9583 QualType ResultTy = FnDecl->getResultType(); 9584 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 9585 ResultTy = ResultTy.getNonLValueExprType(Context); 9586 9587 // Build the actual expression node. 9588 DeclarationNameLoc LocInfo; 9589 LocInfo.CXXOperatorName.BeginOpNameLoc = LLoc.getRawEncoding(); 9590 LocInfo.CXXOperatorName.EndOpNameLoc = RLoc.getRawEncoding(); 9591 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, 9592 HadMultipleCandidates, 9593 LLoc, LocInfo); 9594 if (FnExpr.isInvalid()) 9595 return ExprError(); 9596 9597 CXXOperatorCallExpr *TheCall = 9598 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 9599 FnExpr.take(), Args, 2, 9600 ResultTy, VK, RLoc); 9601 9602 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 9603 FnDecl)) 9604 return ExprError(); 9605 9606 return MaybeBindToTemporary(TheCall); 9607 } else { 9608 // We matched a built-in operator. Convert the arguments, then 9609 // break out so that we will build the appropriate built-in 9610 // operator node. 9611 ExprResult ArgsRes0 = 9612 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 9613 Best->Conversions[0], AA_Passing); 9614 if (ArgsRes0.isInvalid()) 9615 return ExprError(); 9616 Args[0] = ArgsRes0.take(); 9617 9618 ExprResult ArgsRes1 = 9619 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 9620 Best->Conversions[1], AA_Passing); 9621 if (ArgsRes1.isInvalid()) 9622 return ExprError(); 9623 Args[1] = ArgsRes1.take(); 9624 9625 break; 9626 } 9627 } 9628 9629 case OR_No_Viable_Function: { 9630 if (CandidateSet.empty()) 9631 Diag(LLoc, diag::err_ovl_no_oper) 9632 << Args[0]->getType() << /*subscript*/ 0 9633 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9634 else 9635 Diag(LLoc, diag::err_ovl_no_viable_subscript) 9636 << Args[0]->getType() 9637 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9638 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 9639 "[]", LLoc); 9640 return ExprError(); 9641 } 9642 9643 case OR_Ambiguous: 9644 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 9645 << "[]" 9646 << Args[0]->getType() << Args[1]->getType() 9647 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9648 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 9649 "[]", LLoc); 9650 return ExprError(); 9651 9652 case OR_Deleted: 9653 Diag(LLoc, diag::err_ovl_deleted_oper) 9654 << Best->Function->isDeleted() << "[]" 9655 << getDeletedOrUnavailableSuffix(Best->Function) 9656 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 9657 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 9658 "[]", LLoc); 9659 return ExprError(); 9660 } 9661 9662 // We matched a built-in operator; build it. 9663 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 9664} 9665 9666/// BuildCallToMemberFunction - Build a call to a member 9667/// function. MemExpr is the expression that refers to the member 9668/// function (and includes the object parameter), Args/NumArgs are the 9669/// arguments to the function call (not including the object 9670/// parameter). The caller needs to validate that the member 9671/// expression refers to a non-static member function or an overloaded 9672/// member function. 9673ExprResult 9674Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 9675 SourceLocation LParenLoc, Expr **Args, 9676 unsigned NumArgs, SourceLocation RParenLoc) { 9677 assert(MemExprE->getType() == Context.BoundMemberTy || 9678 MemExprE->getType() == Context.OverloadTy); 9679 9680 // Dig out the member expression. This holds both the object 9681 // argument and the member function we're referring to. 9682 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 9683 9684 // Determine whether this is a call to a pointer-to-member function. 9685 if (BinaryOperator *op = dyn_cast<BinaryOperator>(NakedMemExpr)) { 9686 assert(op->getType() == Context.BoundMemberTy); 9687 assert(op->getOpcode() == BO_PtrMemD || op->getOpcode() == BO_PtrMemI); 9688 9689 QualType fnType = 9690 op->getRHS()->getType()->castAs<MemberPointerType>()->getPointeeType(); 9691 9692 const FunctionProtoType *proto = fnType->castAs<FunctionProtoType>(); 9693 QualType resultType = proto->getCallResultType(Context); 9694 ExprValueKind valueKind = Expr::getValueKindForType(proto->getResultType()); 9695 9696 // Check that the object type isn't more qualified than the 9697 // member function we're calling. 9698 Qualifiers funcQuals = Qualifiers::fromCVRMask(proto->getTypeQuals()); 9699 9700 QualType objectType = op->getLHS()->getType(); 9701 if (op->getOpcode() == BO_PtrMemI) 9702 objectType = objectType->castAs<PointerType>()->getPointeeType(); 9703 Qualifiers objectQuals = objectType.getQualifiers(); 9704 9705 Qualifiers difference = objectQuals - funcQuals; 9706 difference.removeObjCGCAttr(); 9707 difference.removeAddressSpace(); 9708 if (difference) { 9709 std::string qualsString = difference.getAsString(); 9710 Diag(LParenLoc, diag::err_pointer_to_member_call_drops_quals) 9711 << fnType.getUnqualifiedType() 9712 << qualsString 9713 << (qualsString.find(' ') == std::string::npos ? 1 : 2); 9714 } 9715 9716 CXXMemberCallExpr *call 9717 = new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 9718 resultType, valueKind, RParenLoc); 9719 9720 if (CheckCallReturnType(proto->getResultType(), 9721 op->getRHS()->getSourceRange().getBegin(), 9722 call, 0)) 9723 return ExprError(); 9724 9725 if (ConvertArgumentsForCall(call, op, 0, proto, Args, NumArgs, RParenLoc)) 9726 return ExprError(); 9727 9728 return MaybeBindToTemporary(call); 9729 } 9730 9731 UnbridgedCastsSet UnbridgedCasts; 9732 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) 9733 return ExprError(); 9734 9735 MemberExpr *MemExpr; 9736 CXXMethodDecl *Method = 0; 9737 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 9738 NestedNameSpecifier *Qualifier = 0; 9739 if (isa<MemberExpr>(NakedMemExpr)) { 9740 MemExpr = cast<MemberExpr>(NakedMemExpr); 9741 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 9742 FoundDecl = MemExpr->getFoundDecl(); 9743 Qualifier = MemExpr->getQualifier(); 9744 UnbridgedCasts.restore(); 9745 } else { 9746 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 9747 Qualifier = UnresExpr->getQualifier(); 9748 9749 QualType ObjectType = UnresExpr->getBaseType(); 9750 Expr::Classification ObjectClassification 9751 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 9752 : UnresExpr->getBase()->Classify(Context); 9753 9754 // Add overload candidates 9755 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 9756 9757 // FIXME: avoid copy. 9758 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 9759 if (UnresExpr->hasExplicitTemplateArgs()) { 9760 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 9761 TemplateArgs = &TemplateArgsBuffer; 9762 } 9763 9764 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 9765 E = UnresExpr->decls_end(); I != E; ++I) { 9766 9767 NamedDecl *Func = *I; 9768 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 9769 if (isa<UsingShadowDecl>(Func)) 9770 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 9771 9772 9773 // Microsoft supports direct constructor calls. 9774 if (getLangOptions().MicrosoftExt && isa<CXXConstructorDecl>(Func)) { 9775 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), Args, NumArgs, 9776 CandidateSet); 9777 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 9778 // If explicit template arguments were provided, we can't call a 9779 // non-template member function. 9780 if (TemplateArgs) 9781 continue; 9782 9783 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 9784 ObjectClassification, 9785 Args, NumArgs, CandidateSet, 9786 /*SuppressUserConversions=*/false); 9787 } else { 9788 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 9789 I.getPair(), ActingDC, TemplateArgs, 9790 ObjectType, ObjectClassification, 9791 Args, NumArgs, CandidateSet, 9792 /*SuppressUsedConversions=*/false); 9793 } 9794 } 9795 9796 DeclarationName DeclName = UnresExpr->getMemberName(); 9797 9798 UnbridgedCasts.restore(); 9799 9800 OverloadCandidateSet::iterator Best; 9801 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 9802 Best)) { 9803 case OR_Success: 9804 Method = cast<CXXMethodDecl>(Best->Function); 9805 MarkDeclarationReferenced(UnresExpr->getMemberLoc(), Method); 9806 FoundDecl = Best->FoundDecl; 9807 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 9808 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 9809 break; 9810 9811 case OR_No_Viable_Function: 9812 Diag(UnresExpr->getMemberLoc(), 9813 diag::err_ovl_no_viable_member_function_in_call) 9814 << DeclName << MemExprE->getSourceRange(); 9815 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9816 // FIXME: Leaking incoming expressions! 9817 return ExprError(); 9818 9819 case OR_Ambiguous: 9820 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 9821 << DeclName << MemExprE->getSourceRange(); 9822 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9823 // FIXME: Leaking incoming expressions! 9824 return ExprError(); 9825 9826 case OR_Deleted: 9827 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 9828 << Best->Function->isDeleted() 9829 << DeclName 9830 << getDeletedOrUnavailableSuffix(Best->Function) 9831 << MemExprE->getSourceRange(); 9832 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 9833 // FIXME: Leaking incoming expressions! 9834 return ExprError(); 9835 } 9836 9837 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 9838 9839 // If overload resolution picked a static member, build a 9840 // non-member call based on that function. 9841 if (Method->isStatic()) { 9842 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 9843 Args, NumArgs, RParenLoc); 9844 } 9845 9846 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 9847 } 9848 9849 QualType ResultType = Method->getResultType(); 9850 ExprValueKind VK = Expr::getValueKindForType(ResultType); 9851 ResultType = ResultType.getNonLValueExprType(Context); 9852 9853 assert(Method && "Member call to something that isn't a method?"); 9854 CXXMemberCallExpr *TheCall = 9855 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 9856 ResultType, VK, RParenLoc); 9857 9858 // Check for a valid return type. 9859 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 9860 TheCall, Method)) 9861 return ExprError(); 9862 9863 // Convert the object argument (for a non-static member function call). 9864 // We only need to do this if there was actually an overload; otherwise 9865 // it was done at lookup. 9866 if (!Method->isStatic()) { 9867 ExprResult ObjectArg = 9868 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier, 9869 FoundDecl, Method); 9870 if (ObjectArg.isInvalid()) 9871 return ExprError(); 9872 MemExpr->setBase(ObjectArg.take()); 9873 } 9874 9875 // Convert the rest of the arguments 9876 const FunctionProtoType *Proto = 9877 Method->getType()->getAs<FunctionProtoType>(); 9878 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 9879 RParenLoc)) 9880 return ExprError(); 9881 9882 if (CheckFunctionCall(Method, TheCall)) 9883 return ExprError(); 9884 9885 if ((isa<CXXConstructorDecl>(CurContext) || 9886 isa<CXXDestructorDecl>(CurContext)) && 9887 TheCall->getMethodDecl()->isPure()) { 9888 const CXXMethodDecl *MD = TheCall->getMethodDecl(); 9889 9890 if (isa<CXXThisExpr>(MemExpr->getBase()->IgnoreParenCasts())) { 9891 Diag(MemExpr->getLocStart(), 9892 diag::warn_call_to_pure_virtual_member_function_from_ctor_dtor) 9893 << MD->getDeclName() << isa<CXXDestructorDecl>(CurContext) 9894 << MD->getParent()->getDeclName(); 9895 9896 Diag(MD->getLocStart(), diag::note_previous_decl) << MD->getDeclName(); 9897 } 9898 } 9899 return MaybeBindToTemporary(TheCall); 9900} 9901 9902/// BuildCallToObjectOfClassType - Build a call to an object of class 9903/// type (C++ [over.call.object]), which can end up invoking an 9904/// overloaded function call operator (@c operator()) or performing a 9905/// user-defined conversion on the object argument. 9906ExprResult 9907Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj, 9908 SourceLocation LParenLoc, 9909 Expr **Args, unsigned NumArgs, 9910 SourceLocation RParenLoc) { 9911 if (checkPlaceholderForOverload(*this, Obj)) 9912 return ExprError(); 9913 ExprResult Object = Owned(Obj); 9914 9915 UnbridgedCastsSet UnbridgedCasts; 9916 if (checkArgPlaceholdersForOverload(*this, Args, NumArgs, UnbridgedCasts)) 9917 return ExprError(); 9918 9919 assert(Object.get()->getType()->isRecordType() && "Requires object type argument"); 9920 const RecordType *Record = Object.get()->getType()->getAs<RecordType>(); 9921 9922 // C++ [over.call.object]p1: 9923 // If the primary-expression E in the function call syntax 9924 // evaluates to a class object of type "cv T", then the set of 9925 // candidate functions includes at least the function call 9926 // operators of T. The function call operators of T are obtained by 9927 // ordinary lookup of the name operator() in the context of 9928 // (E).operator(). 9929 OverloadCandidateSet CandidateSet(LParenLoc); 9930 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 9931 9932 if (RequireCompleteType(LParenLoc, Object.get()->getType(), 9933 PDiag(diag::err_incomplete_object_call) 9934 << Object.get()->getSourceRange())) 9935 return true; 9936 9937 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 9938 LookupQualifiedName(R, Record->getDecl()); 9939 R.suppressDiagnostics(); 9940 9941 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 9942 Oper != OperEnd; ++Oper) { 9943 AddMethodCandidate(Oper.getPair(), Object.get()->getType(), 9944 Object.get()->Classify(Context), Args, NumArgs, CandidateSet, 9945 /*SuppressUserConversions=*/ false); 9946 } 9947 9948 // C++ [over.call.object]p2: 9949 // In addition, for each (non-explicit in C++0x) conversion function 9950 // declared in T of the form 9951 // 9952 // operator conversion-type-id () cv-qualifier; 9953 // 9954 // where cv-qualifier is the same cv-qualification as, or a 9955 // greater cv-qualification than, cv, and where conversion-type-id 9956 // denotes the type "pointer to function of (P1,...,Pn) returning 9957 // R", or the type "reference to pointer to function of 9958 // (P1,...,Pn) returning R", or the type "reference to function 9959 // of (P1,...,Pn) returning R", a surrogate call function [...] 9960 // is also considered as a candidate function. Similarly, 9961 // surrogate call functions are added to the set of candidate 9962 // functions for each conversion function declared in an 9963 // accessible base class provided the function is not hidden 9964 // within T by another intervening declaration. 9965 const UnresolvedSetImpl *Conversions 9966 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 9967 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 9968 E = Conversions->end(); I != E; ++I) { 9969 NamedDecl *D = *I; 9970 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 9971 if (isa<UsingShadowDecl>(D)) 9972 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 9973 9974 // Skip over templated conversion functions; they aren't 9975 // surrogates. 9976 if (isa<FunctionTemplateDecl>(D)) 9977 continue; 9978 9979 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 9980 if (!Conv->isExplicit()) { 9981 // Strip the reference type (if any) and then the pointer type (if 9982 // any) to get down to what might be a function type. 9983 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 9984 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 9985 ConvType = ConvPtrType->getPointeeType(); 9986 9987 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 9988 { 9989 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 9990 Object.get(), Args, NumArgs, CandidateSet); 9991 } 9992 } 9993 } 9994 9995 bool HadMultipleCandidates = (CandidateSet.size() > 1); 9996 9997 // Perform overload resolution. 9998 OverloadCandidateSet::iterator Best; 9999 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(), 10000 Best)) { 10001 case OR_Success: 10002 // Overload resolution succeeded; we'll build the appropriate call 10003 // below. 10004 break; 10005 10006 case OR_No_Viable_Function: 10007 if (CandidateSet.empty()) 10008 Diag(Object.get()->getSourceRange().getBegin(), diag::err_ovl_no_oper) 10009 << Object.get()->getType() << /*call*/ 1 10010 << Object.get()->getSourceRange(); 10011 else 10012 Diag(Object.get()->getSourceRange().getBegin(), 10013 diag::err_ovl_no_viable_object_call) 10014 << Object.get()->getType() << Object.get()->getSourceRange(); 10015 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 10016 break; 10017 10018 case OR_Ambiguous: 10019 Diag(Object.get()->getSourceRange().getBegin(), 10020 diag::err_ovl_ambiguous_object_call) 10021 << Object.get()->getType() << Object.get()->getSourceRange(); 10022 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 10023 break; 10024 10025 case OR_Deleted: 10026 Diag(Object.get()->getSourceRange().getBegin(), 10027 diag::err_ovl_deleted_object_call) 10028 << Best->Function->isDeleted() 10029 << Object.get()->getType() 10030 << getDeletedOrUnavailableSuffix(Best->Function) 10031 << Object.get()->getSourceRange(); 10032 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 10033 break; 10034 } 10035 10036 if (Best == CandidateSet.end()) 10037 return true; 10038 10039 UnbridgedCasts.restore(); 10040 10041 if (Best->Function == 0) { 10042 // Since there is no function declaration, this is one of the 10043 // surrogate candidates. Dig out the conversion function. 10044 CXXConversionDecl *Conv 10045 = cast<CXXConversionDecl>( 10046 Best->Conversions[0].UserDefined.ConversionFunction); 10047 10048 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 10049 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 10050 10051 // We selected one of the surrogate functions that converts the 10052 // object parameter to a function pointer. Perform the conversion 10053 // on the object argument, then let ActOnCallExpr finish the job. 10054 10055 // Create an implicit member expr to refer to the conversion operator. 10056 // and then call it. 10057 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl, 10058 Conv, HadMultipleCandidates); 10059 if (Call.isInvalid()) 10060 return ExprError(); 10061 // Record usage of conversion in an implicit cast. 10062 Call = Owned(ImplicitCastExpr::Create(Context, Call.get()->getType(), 10063 CK_UserDefinedConversion, 10064 Call.get(), 0, VK_RValue)); 10065 10066 return ActOnCallExpr(S, Call.get(), LParenLoc, MultiExprArg(Args, NumArgs), 10067 RParenLoc); 10068 } 10069 10070 MarkDeclarationReferenced(LParenLoc, Best->Function); 10071 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 10072 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 10073 10074 // We found an overloaded operator(). Build a CXXOperatorCallExpr 10075 // that calls this method, using Object for the implicit object 10076 // parameter and passing along the remaining arguments. 10077 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 10078 const FunctionProtoType *Proto = 10079 Method->getType()->getAs<FunctionProtoType>(); 10080 10081 unsigned NumArgsInProto = Proto->getNumArgs(); 10082 unsigned NumArgsToCheck = NumArgs; 10083 10084 // Build the full argument list for the method call (the 10085 // implicit object parameter is placed at the beginning of the 10086 // list). 10087 Expr **MethodArgs; 10088 if (NumArgs < NumArgsInProto) { 10089 NumArgsToCheck = NumArgsInProto; 10090 MethodArgs = new Expr*[NumArgsInProto + 1]; 10091 } else { 10092 MethodArgs = new Expr*[NumArgs + 1]; 10093 } 10094 MethodArgs[0] = Object.get(); 10095 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 10096 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 10097 10098 ExprResult NewFn = CreateFunctionRefExpr(*this, Method, 10099 HadMultipleCandidates); 10100 if (NewFn.isInvalid()) 10101 return true; 10102 10103 // Once we've built TheCall, all of the expressions are properly 10104 // owned. 10105 QualType ResultTy = Method->getResultType(); 10106 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10107 ResultTy = ResultTy.getNonLValueExprType(Context); 10108 10109 CXXOperatorCallExpr *TheCall = 10110 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn.take(), 10111 MethodArgs, NumArgs + 1, 10112 ResultTy, VK, RParenLoc); 10113 delete [] MethodArgs; 10114 10115 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 10116 Method)) 10117 return true; 10118 10119 // We may have default arguments. If so, we need to allocate more 10120 // slots in the call for them. 10121 if (NumArgs < NumArgsInProto) 10122 TheCall->setNumArgs(Context, NumArgsInProto + 1); 10123 else if (NumArgs > NumArgsInProto) 10124 NumArgsToCheck = NumArgsInProto; 10125 10126 bool IsError = false; 10127 10128 // Initialize the implicit object parameter. 10129 ExprResult ObjRes = 10130 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/0, 10131 Best->FoundDecl, Method); 10132 if (ObjRes.isInvalid()) 10133 IsError = true; 10134 else 10135 Object = move(ObjRes); 10136 TheCall->setArg(0, Object.take()); 10137 10138 // Check the argument types. 10139 for (unsigned i = 0; i != NumArgsToCheck; i++) { 10140 Expr *Arg; 10141 if (i < NumArgs) { 10142 Arg = Args[i]; 10143 10144 // Pass the argument. 10145 10146 ExprResult InputInit 10147 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 10148 Context, 10149 Method->getParamDecl(i)), 10150 SourceLocation(), Arg); 10151 10152 IsError |= InputInit.isInvalid(); 10153 Arg = InputInit.takeAs<Expr>(); 10154 } else { 10155 ExprResult DefArg 10156 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 10157 if (DefArg.isInvalid()) { 10158 IsError = true; 10159 break; 10160 } 10161 10162 Arg = DefArg.takeAs<Expr>(); 10163 } 10164 10165 TheCall->setArg(i + 1, Arg); 10166 } 10167 10168 // If this is a variadic call, handle args passed through "...". 10169 if (Proto->isVariadic()) { 10170 // Promote the arguments (C99 6.5.2.2p7). 10171 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 10172 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod, 0); 10173 IsError |= Arg.isInvalid(); 10174 TheCall->setArg(i + 1, Arg.take()); 10175 } 10176 } 10177 10178 if (IsError) return true; 10179 10180 if (CheckFunctionCall(Method, TheCall)) 10181 return true; 10182 10183 return MaybeBindToTemporary(TheCall); 10184} 10185 10186/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 10187/// (if one exists), where @c Base is an expression of class type and 10188/// @c Member is the name of the member we're trying to find. 10189ExprResult 10190Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 10191 assert(Base->getType()->isRecordType() && 10192 "left-hand side must have class type"); 10193 10194 if (checkPlaceholderForOverload(*this, Base)) 10195 return ExprError(); 10196 10197 SourceLocation Loc = Base->getExprLoc(); 10198 10199 // C++ [over.ref]p1: 10200 // 10201 // [...] An expression x->m is interpreted as (x.operator->())->m 10202 // for a class object x of type T if T::operator->() exists and if 10203 // the operator is selected as the best match function by the 10204 // overload resolution mechanism (13.3). 10205 DeclarationName OpName = 10206 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 10207 OverloadCandidateSet CandidateSet(Loc); 10208 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 10209 10210 if (RequireCompleteType(Loc, Base->getType(), 10211 PDiag(diag::err_typecheck_incomplete_tag) 10212 << Base->getSourceRange())) 10213 return ExprError(); 10214 10215 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 10216 LookupQualifiedName(R, BaseRecord->getDecl()); 10217 R.suppressDiagnostics(); 10218 10219 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 10220 Oper != OperEnd; ++Oper) { 10221 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 10222 0, 0, CandidateSet, /*SuppressUserConversions=*/false); 10223 } 10224 10225 bool HadMultipleCandidates = (CandidateSet.size() > 1); 10226 10227 // Perform overload resolution. 10228 OverloadCandidateSet::iterator Best; 10229 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 10230 case OR_Success: 10231 // Overload resolution succeeded; we'll build the call below. 10232 break; 10233 10234 case OR_No_Viable_Function: 10235 if (CandidateSet.empty()) 10236 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 10237 << Base->getType() << Base->getSourceRange(); 10238 else 10239 Diag(OpLoc, diag::err_ovl_no_viable_oper) 10240 << "operator->" << Base->getSourceRange(); 10241 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 10242 return ExprError(); 10243 10244 case OR_Ambiguous: 10245 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 10246 << "->" << Base->getType() << Base->getSourceRange(); 10247 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, &Base, 1); 10248 return ExprError(); 10249 10250 case OR_Deleted: 10251 Diag(OpLoc, diag::err_ovl_deleted_oper) 10252 << Best->Function->isDeleted() 10253 << "->" 10254 << getDeletedOrUnavailableSuffix(Best->Function) 10255 << Base->getSourceRange(); 10256 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 10257 return ExprError(); 10258 } 10259 10260 MarkDeclarationReferenced(OpLoc, Best->Function); 10261 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 10262 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 10263 10264 // Convert the object parameter. 10265 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 10266 ExprResult BaseResult = 10267 PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 10268 Best->FoundDecl, Method); 10269 if (BaseResult.isInvalid()) 10270 return ExprError(); 10271 Base = BaseResult.take(); 10272 10273 // Build the operator call. 10274 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method, 10275 HadMultipleCandidates); 10276 if (FnExpr.isInvalid()) 10277 return ExprError(); 10278 10279 QualType ResultTy = Method->getResultType(); 10280 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 10281 ResultTy = ResultTy.getNonLValueExprType(Context); 10282 CXXOperatorCallExpr *TheCall = 10283 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.take(), 10284 &Base, 1, ResultTy, VK, OpLoc); 10285 10286 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 10287 Method)) 10288 return ExprError(); 10289 10290 return MaybeBindToTemporary(TheCall); 10291} 10292 10293/// FixOverloadedFunctionReference - E is an expression that refers to 10294/// a C++ overloaded function (possibly with some parentheses and 10295/// perhaps a '&' around it). We have resolved the overloaded function 10296/// to the function declaration Fn, so patch up the expression E to 10297/// refer (possibly indirectly) to Fn. Returns the new expr. 10298Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 10299 FunctionDecl *Fn) { 10300 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 10301 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 10302 Found, Fn); 10303 if (SubExpr == PE->getSubExpr()) 10304 return PE; 10305 10306 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 10307 } 10308 10309 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 10310 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 10311 Found, Fn); 10312 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 10313 SubExpr->getType()) && 10314 "Implicit cast type cannot be determined from overload"); 10315 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 10316 if (SubExpr == ICE->getSubExpr()) 10317 return ICE; 10318 10319 return ImplicitCastExpr::Create(Context, ICE->getType(), 10320 ICE->getCastKind(), 10321 SubExpr, 0, 10322 ICE->getValueKind()); 10323 } 10324 10325 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 10326 assert(UnOp->getOpcode() == UO_AddrOf && 10327 "Can only take the address of an overloaded function"); 10328 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 10329 if (Method->isStatic()) { 10330 // Do nothing: static member functions aren't any different 10331 // from non-member functions. 10332 } else { 10333 // Fix the sub expression, which really has to be an 10334 // UnresolvedLookupExpr holding an overloaded member function 10335 // or template. 10336 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 10337 Found, Fn); 10338 if (SubExpr == UnOp->getSubExpr()) 10339 return UnOp; 10340 10341 assert(isa<DeclRefExpr>(SubExpr) 10342 && "fixed to something other than a decl ref"); 10343 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 10344 && "fixed to a member ref with no nested name qualifier"); 10345 10346 // We have taken the address of a pointer to member 10347 // function. Perform the computation here so that we get the 10348 // appropriate pointer to member type. 10349 QualType ClassType 10350 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 10351 QualType MemPtrType 10352 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 10353 10354 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 10355 VK_RValue, OK_Ordinary, 10356 UnOp->getOperatorLoc()); 10357 } 10358 } 10359 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 10360 Found, Fn); 10361 if (SubExpr == UnOp->getSubExpr()) 10362 return UnOp; 10363 10364 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 10365 Context.getPointerType(SubExpr->getType()), 10366 VK_RValue, OK_Ordinary, 10367 UnOp->getOperatorLoc()); 10368 } 10369 10370 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 10371 // FIXME: avoid copy. 10372 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 10373 if (ULE->hasExplicitTemplateArgs()) { 10374 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 10375 TemplateArgs = &TemplateArgsBuffer; 10376 } 10377 10378 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 10379 ULE->getQualifierLoc(), 10380 Fn, 10381 ULE->getNameLoc(), 10382 Fn->getType(), 10383 VK_LValue, 10384 Found.getDecl(), 10385 TemplateArgs); 10386 DRE->setHadMultipleCandidates(ULE->getNumDecls() > 1); 10387 return DRE; 10388 } 10389 10390 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 10391 // FIXME: avoid copy. 10392 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 10393 if (MemExpr->hasExplicitTemplateArgs()) { 10394 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 10395 TemplateArgs = &TemplateArgsBuffer; 10396 } 10397 10398 Expr *Base; 10399 10400 // If we're filling in a static method where we used to have an 10401 // implicit member access, rewrite to a simple decl ref. 10402 if (MemExpr->isImplicitAccess()) { 10403 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 10404 DeclRefExpr *DRE = DeclRefExpr::Create(Context, 10405 MemExpr->getQualifierLoc(), 10406 Fn, 10407 MemExpr->getMemberLoc(), 10408 Fn->getType(), 10409 VK_LValue, 10410 Found.getDecl(), 10411 TemplateArgs); 10412 DRE->setHadMultipleCandidates(MemExpr->getNumDecls() > 1); 10413 return DRE; 10414 } else { 10415 SourceLocation Loc = MemExpr->getMemberLoc(); 10416 if (MemExpr->getQualifier()) 10417 Loc = MemExpr->getQualifierLoc().getBeginLoc(); 10418 CheckCXXThisCapture(Loc); 10419 Base = new (Context) CXXThisExpr(Loc, 10420 MemExpr->getBaseType(), 10421 /*isImplicit=*/true); 10422 } 10423 } else 10424 Base = MemExpr->getBase(); 10425 10426 ExprValueKind valueKind; 10427 QualType type; 10428 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 10429 valueKind = VK_LValue; 10430 type = Fn->getType(); 10431 } else { 10432 valueKind = VK_RValue; 10433 type = Context.BoundMemberTy; 10434 } 10435 10436 MemberExpr *ME = MemberExpr::Create(Context, Base, 10437 MemExpr->isArrow(), 10438 MemExpr->getQualifierLoc(), 10439 Fn, 10440 Found, 10441 MemExpr->getMemberNameInfo(), 10442 TemplateArgs, 10443 type, valueKind, OK_Ordinary); 10444 ME->setHadMultipleCandidates(true); 10445 return ME; 10446 } 10447 10448 llvm_unreachable("Invalid reference to overloaded function"); 10449} 10450 10451ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 10452 DeclAccessPair Found, 10453 FunctionDecl *Fn) { 10454 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 10455} 10456 10457} // end namespace clang 10458