SemaOverload.cpp revision 621c92a582546e2fa5ae28cf8b7e14d5a60fab11
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, 41 SourceLocation Loc = SourceLocation()) { 42 ExprResult E = S.Owned(new (S.Context) DeclRefExpr(Fn, Fn->getType(), VK_LValue, Loc)); 43 E = S.DefaultFunctionArrayConversion(E.take()); 44 if (E.isInvalid()) 45 return ExprError(); 46 return move(E); 47} 48 49static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 50 bool InOverloadResolution, 51 StandardConversionSequence &SCS, 52 bool CStyle); 53 54static bool IsTransparentUnionStandardConversion(Sema &S, Expr* From, 55 QualType &ToType, 56 bool InOverloadResolution, 57 StandardConversionSequence &SCS, 58 bool CStyle); 59static OverloadingResult 60IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 61 UserDefinedConversionSequence& User, 62 OverloadCandidateSet& Conversions, 63 bool AllowExplicit); 64 65 66static ImplicitConversionSequence::CompareKind 67CompareStandardConversionSequences(Sema &S, 68 const StandardConversionSequence& SCS1, 69 const StandardConversionSequence& SCS2); 70 71static ImplicitConversionSequence::CompareKind 72CompareQualificationConversions(Sema &S, 73 const StandardConversionSequence& SCS1, 74 const StandardConversionSequence& SCS2); 75 76static ImplicitConversionSequence::CompareKind 77CompareDerivedToBaseConversions(Sema &S, 78 const StandardConversionSequence& SCS1, 79 const StandardConversionSequence& SCS2); 80 81 82 83/// GetConversionCategory - Retrieve the implicit conversion 84/// category corresponding to the given implicit conversion kind. 85ImplicitConversionCategory 86GetConversionCategory(ImplicitConversionKind Kind) { 87 static const ImplicitConversionCategory 88 Category[(int)ICK_Num_Conversion_Kinds] = { 89 ICC_Identity, 90 ICC_Lvalue_Transformation, 91 ICC_Lvalue_Transformation, 92 ICC_Lvalue_Transformation, 93 ICC_Identity, 94 ICC_Qualification_Adjustment, 95 ICC_Promotion, 96 ICC_Promotion, 97 ICC_Promotion, 98 ICC_Conversion, 99 ICC_Conversion, 100 ICC_Conversion, 101 ICC_Conversion, 102 ICC_Conversion, 103 ICC_Conversion, 104 ICC_Conversion, 105 ICC_Conversion, 106 ICC_Conversion, 107 ICC_Conversion, 108 ICC_Conversion, 109 ICC_Conversion 110 }; 111 return Category[(int)Kind]; 112} 113 114/// GetConversionRank - Retrieve the implicit conversion rank 115/// corresponding to the given implicit conversion kind. 116ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 117 static const ImplicitConversionRank 118 Rank[(int)ICK_Num_Conversion_Kinds] = { 119 ICR_Exact_Match, 120 ICR_Exact_Match, 121 ICR_Exact_Match, 122 ICR_Exact_Match, 123 ICR_Exact_Match, 124 ICR_Exact_Match, 125 ICR_Promotion, 126 ICR_Promotion, 127 ICR_Promotion, 128 ICR_Conversion, 129 ICR_Conversion, 130 ICR_Conversion, 131 ICR_Conversion, 132 ICR_Conversion, 133 ICR_Conversion, 134 ICR_Conversion, 135 ICR_Conversion, 136 ICR_Conversion, 137 ICR_Conversion, 138 ICR_Conversion, 139 ICR_Complex_Real_Conversion, 140 ICR_Conversion, 141 ICR_Conversion 142 }; 143 return Rank[(int)Kind]; 144} 145 146/// GetImplicitConversionName - Return the name of this kind of 147/// implicit conversion. 148const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 149 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 150 "No conversion", 151 "Lvalue-to-rvalue", 152 "Array-to-pointer", 153 "Function-to-pointer", 154 "Noreturn adjustment", 155 "Qualification", 156 "Integral promotion", 157 "Floating point promotion", 158 "Complex promotion", 159 "Integral conversion", 160 "Floating conversion", 161 "Complex conversion", 162 "Floating-integral conversion", 163 "Pointer conversion", 164 "Pointer-to-member conversion", 165 "Boolean conversion", 166 "Compatible-types conversion", 167 "Derived-to-base conversion", 168 "Vector conversion", 169 "Vector splat", 170 "Complex-real conversion", 171 "Block Pointer conversion", 172 "Transparent Union Conversion" 173 }; 174 return Name[Kind]; 175} 176 177/// StandardConversionSequence - Set the standard conversion 178/// sequence to the identity conversion. 179void StandardConversionSequence::setAsIdentityConversion() { 180 First = ICK_Identity; 181 Second = ICK_Identity; 182 Third = ICK_Identity; 183 DeprecatedStringLiteralToCharPtr = false; 184 ReferenceBinding = false; 185 DirectBinding = false; 186 IsLvalueReference = true; 187 BindsToFunctionLvalue = false; 188 BindsToRvalue = false; 189 BindsImplicitObjectArgumentWithoutRefQualifier = false; 190 CopyConstructor = 0; 191} 192 193/// getRank - Retrieve the rank of this standard conversion sequence 194/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 195/// implicit conversions. 196ImplicitConversionRank StandardConversionSequence::getRank() const { 197 ImplicitConversionRank Rank = ICR_Exact_Match; 198 if (GetConversionRank(First) > Rank) 199 Rank = GetConversionRank(First); 200 if (GetConversionRank(Second) > Rank) 201 Rank = GetConversionRank(Second); 202 if (GetConversionRank(Third) > Rank) 203 Rank = GetConversionRank(Third); 204 return Rank; 205} 206 207/// isPointerConversionToBool - Determines whether this conversion is 208/// a conversion of a pointer or pointer-to-member to bool. This is 209/// used as part of the ranking of standard conversion sequences 210/// (C++ 13.3.3.2p4). 211bool StandardConversionSequence::isPointerConversionToBool() const { 212 // Note that FromType has not necessarily been transformed by the 213 // array-to-pointer or function-to-pointer implicit conversions, so 214 // check for their presence as well as checking whether FromType is 215 // a pointer. 216 if (getToType(1)->isBooleanType() && 217 (getFromType()->isPointerType() || 218 getFromType()->isObjCObjectPointerType() || 219 getFromType()->isBlockPointerType() || 220 getFromType()->isNullPtrType() || 221 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 222 return true; 223 224 return false; 225} 226 227/// isPointerConversionToVoidPointer - Determines whether this 228/// conversion is a conversion of a pointer to a void pointer. This is 229/// used as part of the ranking of standard conversion sequences (C++ 230/// 13.3.3.2p4). 231bool 232StandardConversionSequence:: 233isPointerConversionToVoidPointer(ASTContext& Context) const { 234 QualType FromType = getFromType(); 235 QualType ToType = getToType(1); 236 237 // Note that FromType has not necessarily been transformed by the 238 // array-to-pointer implicit conversion, so check for its presence 239 // and redo the conversion to get a pointer. 240 if (First == ICK_Array_To_Pointer) 241 FromType = Context.getArrayDecayedType(FromType); 242 243 if (Second == ICK_Pointer_Conversion && FromType->isAnyPointerType()) 244 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 245 return ToPtrType->getPointeeType()->isVoidType(); 246 247 return false; 248} 249 250/// DebugPrint - Print this standard conversion sequence to standard 251/// error. Useful for debugging overloading issues. 252void StandardConversionSequence::DebugPrint() const { 253 llvm::raw_ostream &OS = llvm::errs(); 254 bool PrintedSomething = false; 255 if (First != ICK_Identity) { 256 OS << GetImplicitConversionName(First); 257 PrintedSomething = true; 258 } 259 260 if (Second != ICK_Identity) { 261 if (PrintedSomething) { 262 OS << " -> "; 263 } 264 OS << GetImplicitConversionName(Second); 265 266 if (CopyConstructor) { 267 OS << " (by copy constructor)"; 268 } else if (DirectBinding) { 269 OS << " (direct reference binding)"; 270 } else if (ReferenceBinding) { 271 OS << " (reference binding)"; 272 } 273 PrintedSomething = true; 274 } 275 276 if (Third != ICK_Identity) { 277 if (PrintedSomething) { 278 OS << " -> "; 279 } 280 OS << GetImplicitConversionName(Third); 281 PrintedSomething = true; 282 } 283 284 if (!PrintedSomething) { 285 OS << "No conversions required"; 286 } 287} 288 289/// DebugPrint - Print this user-defined conversion sequence to standard 290/// error. Useful for debugging overloading issues. 291void UserDefinedConversionSequence::DebugPrint() const { 292 llvm::raw_ostream &OS = llvm::errs(); 293 if (Before.First || Before.Second || Before.Third) { 294 Before.DebugPrint(); 295 OS << " -> "; 296 } 297 OS << '\'' << ConversionFunction << '\''; 298 if (After.First || After.Second || After.Third) { 299 OS << " -> "; 300 After.DebugPrint(); 301 } 302} 303 304/// DebugPrint - Print this implicit conversion sequence to standard 305/// error. Useful for debugging overloading issues. 306void ImplicitConversionSequence::DebugPrint() const { 307 llvm::raw_ostream &OS = llvm::errs(); 308 switch (ConversionKind) { 309 case StandardConversion: 310 OS << "Standard conversion: "; 311 Standard.DebugPrint(); 312 break; 313 case UserDefinedConversion: 314 OS << "User-defined conversion: "; 315 UserDefined.DebugPrint(); 316 break; 317 case EllipsisConversion: 318 OS << "Ellipsis conversion"; 319 break; 320 case AmbiguousConversion: 321 OS << "Ambiguous conversion"; 322 break; 323 case BadConversion: 324 OS << "Bad conversion"; 325 break; 326 } 327 328 OS << "\n"; 329} 330 331void AmbiguousConversionSequence::construct() { 332 new (&conversions()) ConversionSet(); 333} 334 335void AmbiguousConversionSequence::destruct() { 336 conversions().~ConversionSet(); 337} 338 339void 340AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 341 FromTypePtr = O.FromTypePtr; 342 ToTypePtr = O.ToTypePtr; 343 new (&conversions()) ConversionSet(O.conversions()); 344} 345 346namespace { 347 // Structure used by OverloadCandidate::DeductionFailureInfo to store 348 // template parameter and template argument information. 349 struct DFIParamWithArguments { 350 TemplateParameter Param; 351 TemplateArgument FirstArg; 352 TemplateArgument SecondArg; 353 }; 354} 355 356/// \brief Convert from Sema's representation of template deduction information 357/// to the form used in overload-candidate information. 358OverloadCandidate::DeductionFailureInfo 359static MakeDeductionFailureInfo(ASTContext &Context, 360 Sema::TemplateDeductionResult TDK, 361 TemplateDeductionInfo &Info) { 362 OverloadCandidate::DeductionFailureInfo Result; 363 Result.Result = static_cast<unsigned>(TDK); 364 Result.Data = 0; 365 switch (TDK) { 366 case Sema::TDK_Success: 367 case Sema::TDK_InstantiationDepth: 368 case Sema::TDK_TooManyArguments: 369 case Sema::TDK_TooFewArguments: 370 break; 371 372 case Sema::TDK_Incomplete: 373 case Sema::TDK_InvalidExplicitArguments: 374 Result.Data = Info.Param.getOpaqueValue(); 375 break; 376 377 case Sema::TDK_Inconsistent: 378 case Sema::TDK_Underqualified: { 379 // FIXME: Should allocate from normal heap so that we can free this later. 380 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 381 Saved->Param = Info.Param; 382 Saved->FirstArg = Info.FirstArg; 383 Saved->SecondArg = Info.SecondArg; 384 Result.Data = Saved; 385 break; 386 } 387 388 case Sema::TDK_SubstitutionFailure: 389 Result.Data = Info.take(); 390 break; 391 392 case Sema::TDK_NonDeducedMismatch: 393 case Sema::TDK_FailedOverloadResolution: 394 break; 395 } 396 397 return Result; 398} 399 400void OverloadCandidate::DeductionFailureInfo::Destroy() { 401 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 402 case Sema::TDK_Success: 403 case Sema::TDK_InstantiationDepth: 404 case Sema::TDK_Incomplete: 405 case Sema::TDK_TooManyArguments: 406 case Sema::TDK_TooFewArguments: 407 case Sema::TDK_InvalidExplicitArguments: 408 break; 409 410 case Sema::TDK_Inconsistent: 411 case Sema::TDK_Underqualified: 412 // FIXME: Destroy the data? 413 Data = 0; 414 break; 415 416 case Sema::TDK_SubstitutionFailure: 417 // FIXME: Destroy the template arugment list? 418 Data = 0; 419 break; 420 421 // Unhandled 422 case Sema::TDK_NonDeducedMismatch: 423 case Sema::TDK_FailedOverloadResolution: 424 break; 425 } 426} 427 428TemplateParameter 429OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 430 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 431 case Sema::TDK_Success: 432 case Sema::TDK_InstantiationDepth: 433 case Sema::TDK_TooManyArguments: 434 case Sema::TDK_TooFewArguments: 435 case Sema::TDK_SubstitutionFailure: 436 return TemplateParameter(); 437 438 case Sema::TDK_Incomplete: 439 case Sema::TDK_InvalidExplicitArguments: 440 return TemplateParameter::getFromOpaqueValue(Data); 441 442 case Sema::TDK_Inconsistent: 443 case Sema::TDK_Underqualified: 444 return static_cast<DFIParamWithArguments*>(Data)->Param; 445 446 // Unhandled 447 case Sema::TDK_NonDeducedMismatch: 448 case Sema::TDK_FailedOverloadResolution: 449 break; 450 } 451 452 return TemplateParameter(); 453} 454 455TemplateArgumentList * 456OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 457 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 458 case Sema::TDK_Success: 459 case Sema::TDK_InstantiationDepth: 460 case Sema::TDK_TooManyArguments: 461 case Sema::TDK_TooFewArguments: 462 case Sema::TDK_Incomplete: 463 case Sema::TDK_InvalidExplicitArguments: 464 case Sema::TDK_Inconsistent: 465 case Sema::TDK_Underqualified: 466 return 0; 467 468 case Sema::TDK_SubstitutionFailure: 469 return static_cast<TemplateArgumentList*>(Data); 470 471 // Unhandled 472 case Sema::TDK_NonDeducedMismatch: 473 case Sema::TDK_FailedOverloadResolution: 474 break; 475 } 476 477 return 0; 478} 479 480const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 481 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 482 case Sema::TDK_Success: 483 case Sema::TDK_InstantiationDepth: 484 case Sema::TDK_Incomplete: 485 case Sema::TDK_TooManyArguments: 486 case Sema::TDK_TooFewArguments: 487 case Sema::TDK_InvalidExplicitArguments: 488 case Sema::TDK_SubstitutionFailure: 489 return 0; 490 491 case Sema::TDK_Inconsistent: 492 case Sema::TDK_Underqualified: 493 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 494 495 // Unhandled 496 case Sema::TDK_NonDeducedMismatch: 497 case Sema::TDK_FailedOverloadResolution: 498 break; 499 } 500 501 return 0; 502} 503 504const TemplateArgument * 505OverloadCandidate::DeductionFailureInfo::getSecondArg() { 506 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 507 case Sema::TDK_Success: 508 case Sema::TDK_InstantiationDepth: 509 case Sema::TDK_Incomplete: 510 case Sema::TDK_TooManyArguments: 511 case Sema::TDK_TooFewArguments: 512 case Sema::TDK_InvalidExplicitArguments: 513 case Sema::TDK_SubstitutionFailure: 514 return 0; 515 516 case Sema::TDK_Inconsistent: 517 case Sema::TDK_Underqualified: 518 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 519 520 // Unhandled 521 case Sema::TDK_NonDeducedMismatch: 522 case Sema::TDK_FailedOverloadResolution: 523 break; 524 } 525 526 return 0; 527} 528 529void OverloadCandidateSet::clear() { 530 inherited::clear(); 531 Functions.clear(); 532} 533 534// IsOverload - Determine whether the given New declaration is an 535// overload of the declarations in Old. This routine returns false if 536// New and Old cannot be overloaded, e.g., if New has the same 537// signature as some function in Old (C++ 1.3.10) or if the Old 538// declarations aren't functions (or function templates) at all. When 539// it does return false, MatchedDecl will point to the decl that New 540// cannot be overloaded with. This decl may be a UsingShadowDecl on 541// top of the underlying declaration. 542// 543// Example: Given the following input: 544// 545// void f(int, float); // #1 546// void f(int, int); // #2 547// int f(int, int); // #3 548// 549// When we process #1, there is no previous declaration of "f", 550// so IsOverload will not be used. 551// 552// When we process #2, Old contains only the FunctionDecl for #1. By 553// comparing the parameter types, we see that #1 and #2 are overloaded 554// (since they have different signatures), so this routine returns 555// false; MatchedDecl is unchanged. 556// 557// When we process #3, Old is an overload set containing #1 and #2. We 558// compare the signatures of #3 to #1 (they're overloaded, so we do 559// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 560// identical (return types of functions are not part of the 561// signature), IsOverload returns false and MatchedDecl will be set to 562// point to the FunctionDecl for #2. 563// 564// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 565// into a class by a using declaration. The rules for whether to hide 566// shadow declarations ignore some properties which otherwise figure 567// into a function template's signature. 568Sema::OverloadKind 569Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 570 NamedDecl *&Match, bool NewIsUsingDecl) { 571 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 572 I != E; ++I) { 573 NamedDecl *OldD = *I; 574 575 bool OldIsUsingDecl = false; 576 if (isa<UsingShadowDecl>(OldD)) { 577 OldIsUsingDecl = true; 578 579 // We can always introduce two using declarations into the same 580 // context, even if they have identical signatures. 581 if (NewIsUsingDecl) continue; 582 583 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 584 } 585 586 // If either declaration was introduced by a using declaration, 587 // we'll need to use slightly different rules for matching. 588 // Essentially, these rules are the normal rules, except that 589 // function templates hide function templates with different 590 // return types or template parameter lists. 591 bool UseMemberUsingDeclRules = 592 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 593 594 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 595 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 596 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 597 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 598 continue; 599 } 600 601 Match = *I; 602 return Ovl_Match; 603 } 604 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 605 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 606 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 607 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 608 continue; 609 } 610 611 Match = *I; 612 return Ovl_Match; 613 } 614 } else if (isa<UsingDecl>(OldD)) { 615 // We can overload with these, which can show up when doing 616 // redeclaration checks for UsingDecls. 617 assert(Old.getLookupKind() == LookupUsingDeclName); 618 } else if (isa<TagDecl>(OldD)) { 619 // We can always overload with tags by hiding them. 620 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 621 // Optimistically assume that an unresolved using decl will 622 // overload; if it doesn't, we'll have to diagnose during 623 // template instantiation. 624 } else { 625 // (C++ 13p1): 626 // Only function declarations can be overloaded; object and type 627 // declarations cannot be overloaded. 628 Match = *I; 629 return Ovl_NonFunction; 630 } 631 } 632 633 return Ovl_Overload; 634} 635 636bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 637 bool UseUsingDeclRules) { 638 // If both of the functions are extern "C", then they are not 639 // overloads. 640 if (Old->isExternC() && New->isExternC()) 641 return false; 642 643 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 644 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 645 646 // C++ [temp.fct]p2: 647 // A function template can be overloaded with other function templates 648 // and with normal (non-template) functions. 649 if ((OldTemplate == 0) != (NewTemplate == 0)) 650 return true; 651 652 // Is the function New an overload of the function Old? 653 QualType OldQType = Context.getCanonicalType(Old->getType()); 654 QualType NewQType = Context.getCanonicalType(New->getType()); 655 656 // Compare the signatures (C++ 1.3.10) of the two functions to 657 // determine whether they are overloads. If we find any mismatch 658 // in the signature, they are overloads. 659 660 // If either of these functions is a K&R-style function (no 661 // prototype), then we consider them to have matching signatures. 662 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 663 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 664 return false; 665 666 const FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 667 const FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 668 669 // The signature of a function includes the types of its 670 // parameters (C++ 1.3.10), which includes the presence or absence 671 // of the ellipsis; see C++ DR 357). 672 if (OldQType != NewQType && 673 (OldType->getNumArgs() != NewType->getNumArgs() || 674 OldType->isVariadic() != NewType->isVariadic() || 675 !FunctionArgTypesAreEqual(OldType, NewType))) 676 return true; 677 678 // C++ [temp.over.link]p4: 679 // The signature of a function template consists of its function 680 // signature, its return type and its template parameter list. The names 681 // of the template parameters are significant only for establishing the 682 // relationship between the template parameters and the rest of the 683 // signature. 684 // 685 // We check the return type and template parameter lists for function 686 // templates first; the remaining checks follow. 687 // 688 // However, we don't consider either of these when deciding whether 689 // a member introduced by a shadow declaration is hidden. 690 if (!UseUsingDeclRules && NewTemplate && 691 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 692 OldTemplate->getTemplateParameters(), 693 false, TPL_TemplateMatch) || 694 OldType->getResultType() != NewType->getResultType())) 695 return true; 696 697 // If the function is a class member, its signature includes the 698 // cv-qualifiers (if any) and ref-qualifier (if any) on the function itself. 699 // 700 // As part of this, also check whether one of the member functions 701 // is static, in which case they are not overloads (C++ 702 // 13.1p2). While not part of the definition of the signature, 703 // this check is important to determine whether these functions 704 // can be overloaded. 705 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 706 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 707 if (OldMethod && NewMethod && 708 !OldMethod->isStatic() && !NewMethod->isStatic() && 709 (OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers() || 710 OldMethod->getRefQualifier() != NewMethod->getRefQualifier())) { 711 if (!UseUsingDeclRules && 712 OldMethod->getRefQualifier() != NewMethod->getRefQualifier() && 713 (OldMethod->getRefQualifier() == RQ_None || 714 NewMethod->getRefQualifier() == RQ_None)) { 715 // C++0x [over.load]p2: 716 // - Member function declarations with the same name and the same 717 // parameter-type-list as well as member function template 718 // declarations with the same name, the same parameter-type-list, and 719 // the same template parameter lists cannot be overloaded if any of 720 // them, but not all, have a ref-qualifier (8.3.5). 721 Diag(NewMethod->getLocation(), diag::err_ref_qualifier_overload) 722 << NewMethod->getRefQualifier() << OldMethod->getRefQualifier(); 723 Diag(OldMethod->getLocation(), diag::note_previous_declaration); 724 } 725 726 return true; 727 } 728 729 // The signatures match; this is not an overload. 730 return false; 731} 732 733/// TryImplicitConversion - Attempt to perform an implicit conversion 734/// from the given expression (Expr) to the given type (ToType). This 735/// function returns an implicit conversion sequence that can be used 736/// to perform the initialization. Given 737/// 738/// void f(float f); 739/// void g(int i) { f(i); } 740/// 741/// this routine would produce an implicit conversion sequence to 742/// describe the initialization of f from i, which will be a standard 743/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 744/// 4.1) followed by a floating-integral conversion (C++ 4.9). 745// 746/// Note that this routine only determines how the conversion can be 747/// performed; it does not actually perform the conversion. As such, 748/// it will not produce any diagnostics if no conversion is available, 749/// but will instead return an implicit conversion sequence of kind 750/// "BadConversion". 751/// 752/// If @p SuppressUserConversions, then user-defined conversions are 753/// not permitted. 754/// If @p AllowExplicit, then explicit user-defined conversions are 755/// permitted. 756static ImplicitConversionSequence 757TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 758 bool SuppressUserConversions, 759 bool AllowExplicit, 760 bool InOverloadResolution, 761 bool CStyle) { 762 ImplicitConversionSequence ICS; 763 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 764 ICS.Standard, CStyle)) { 765 ICS.setStandard(); 766 return ICS; 767 } 768 769 if (!S.getLangOptions().CPlusPlus) { 770 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 771 return ICS; 772 } 773 774 // C++ [over.ics.user]p4: 775 // A conversion of an expression of class type to the same class 776 // type is given Exact Match rank, and a conversion of an 777 // expression of class type to a base class of that type is 778 // given Conversion rank, in spite of the fact that a copy/move 779 // constructor (i.e., a user-defined conversion function) is 780 // called for those cases. 781 QualType FromType = From->getType(); 782 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 783 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 784 S.IsDerivedFrom(FromType, ToType))) { 785 ICS.setStandard(); 786 ICS.Standard.setAsIdentityConversion(); 787 ICS.Standard.setFromType(FromType); 788 ICS.Standard.setAllToTypes(ToType); 789 790 // We don't actually check at this point whether there is a valid 791 // copy/move constructor, since overloading just assumes that it 792 // exists. When we actually perform initialization, we'll find the 793 // appropriate constructor to copy the returned object, if needed. 794 ICS.Standard.CopyConstructor = 0; 795 796 // Determine whether this is considered a derived-to-base conversion. 797 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 798 ICS.Standard.Second = ICK_Derived_To_Base; 799 800 return ICS; 801 } 802 803 if (SuppressUserConversions) { 804 // We're not in the case above, so there is no conversion that 805 // we can perform. 806 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 807 return ICS; 808 } 809 810 // Attempt user-defined conversion. 811 OverloadCandidateSet Conversions(From->getExprLoc()); 812 OverloadingResult UserDefResult 813 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 814 AllowExplicit); 815 816 if (UserDefResult == OR_Success) { 817 ICS.setUserDefined(); 818 // C++ [over.ics.user]p4: 819 // A conversion of an expression of class type to the same class 820 // type is given Exact Match rank, and a conversion of an 821 // expression of class type to a base class of that type is 822 // given Conversion rank, in spite of the fact that a copy 823 // constructor (i.e., a user-defined conversion function) is 824 // called for those cases. 825 if (CXXConstructorDecl *Constructor 826 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 827 QualType FromCanon 828 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 829 QualType ToCanon 830 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 831 if (Constructor->isCopyConstructor() && 832 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 833 // Turn this into a "standard" conversion sequence, so that it 834 // gets ranked with standard conversion sequences. 835 ICS.setStandard(); 836 ICS.Standard.setAsIdentityConversion(); 837 ICS.Standard.setFromType(From->getType()); 838 ICS.Standard.setAllToTypes(ToType); 839 ICS.Standard.CopyConstructor = Constructor; 840 if (ToCanon != FromCanon) 841 ICS.Standard.Second = ICK_Derived_To_Base; 842 } 843 } 844 845 // C++ [over.best.ics]p4: 846 // However, when considering the argument of a user-defined 847 // conversion function that is a candidate by 13.3.1.3 when 848 // invoked for the copying of the temporary in the second step 849 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 850 // 13.3.1.6 in all cases, only standard conversion sequences and 851 // ellipsis conversion sequences are allowed. 852 if (SuppressUserConversions && ICS.isUserDefined()) { 853 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 854 } 855 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 856 ICS.setAmbiguous(); 857 ICS.Ambiguous.setFromType(From->getType()); 858 ICS.Ambiguous.setToType(ToType); 859 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 860 Cand != Conversions.end(); ++Cand) 861 if (Cand->Viable) 862 ICS.Ambiguous.addConversion(Cand->Function); 863 } else { 864 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 865 } 866 867 return ICS; 868} 869 870bool Sema::TryImplicitConversion(InitializationSequence &Sequence, 871 const InitializedEntity &Entity, 872 Expr *Initializer, 873 bool SuppressUserConversions, 874 bool AllowExplicitConversions, 875 bool InOverloadResolution, 876 bool CStyle) { 877 ImplicitConversionSequence ICS 878 = clang::TryImplicitConversion(*this, Initializer, Entity.getType(), 879 SuppressUserConversions, 880 AllowExplicitConversions, 881 InOverloadResolution, 882 CStyle); 883 if (ICS.isBad()) return true; 884 885 // Perform the actual conversion. 886 Sequence.AddConversionSequenceStep(ICS, Entity.getType()); 887 return false; 888} 889 890/// PerformImplicitConversion - Perform an implicit conversion of the 891/// expression From to the type ToType. Returns the 892/// converted expression. Flavor is the kind of conversion we're 893/// performing, used in the error message. If @p AllowExplicit, 894/// explicit user-defined conversions are permitted. 895ExprResult 896Sema::PerformImplicitConversion(Expr *From, QualType ToType, 897 AssignmentAction Action, bool AllowExplicit) { 898 ImplicitConversionSequence ICS; 899 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 900} 901 902ExprResult 903Sema::PerformImplicitConversion(Expr *From, QualType ToType, 904 AssignmentAction Action, bool AllowExplicit, 905 ImplicitConversionSequence& ICS) { 906 ICS = clang::TryImplicitConversion(*this, From, ToType, 907 /*SuppressUserConversions=*/false, 908 AllowExplicit, 909 /*InOverloadResolution=*/false, 910 /*CStyle=*/false); 911 return PerformImplicitConversion(From, ToType, ICS, Action); 912} 913 914/// \brief Determine whether the conversion from FromType to ToType is a valid 915/// conversion that strips "noreturn" off the nested function type. 916static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 917 QualType ToType, QualType &ResultTy) { 918 if (Context.hasSameUnqualifiedType(FromType, ToType)) 919 return false; 920 921 // Permit the conversion F(t __attribute__((noreturn))) -> F(t) 922 // where F adds one of the following at most once: 923 // - a pointer 924 // - a member pointer 925 // - a block pointer 926 CanQualType CanTo = Context.getCanonicalType(ToType); 927 CanQualType CanFrom = Context.getCanonicalType(FromType); 928 Type::TypeClass TyClass = CanTo->getTypeClass(); 929 if (TyClass != CanFrom->getTypeClass()) return false; 930 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) { 931 if (TyClass == Type::Pointer) { 932 CanTo = CanTo.getAs<PointerType>()->getPointeeType(); 933 CanFrom = CanFrom.getAs<PointerType>()->getPointeeType(); 934 } else if (TyClass == Type::BlockPointer) { 935 CanTo = CanTo.getAs<BlockPointerType>()->getPointeeType(); 936 CanFrom = CanFrom.getAs<BlockPointerType>()->getPointeeType(); 937 } else if (TyClass == Type::MemberPointer) { 938 CanTo = CanTo.getAs<MemberPointerType>()->getPointeeType(); 939 CanFrom = CanFrom.getAs<MemberPointerType>()->getPointeeType(); 940 } else { 941 return false; 942 } 943 944 TyClass = CanTo->getTypeClass(); 945 if (TyClass != CanFrom->getTypeClass()) return false; 946 if (TyClass != Type::FunctionProto && TyClass != Type::FunctionNoProto) 947 return false; 948 } 949 950 const FunctionType *FromFn = cast<FunctionType>(CanFrom); 951 FunctionType::ExtInfo EInfo = FromFn->getExtInfo(); 952 if (!EInfo.getNoReturn()) return false; 953 954 FromFn = Context.adjustFunctionType(FromFn, EInfo.withNoReturn(false)); 955 assert(QualType(FromFn, 0).isCanonical()); 956 if (QualType(FromFn, 0) != CanTo) return false; 957 958 ResultTy = ToType; 959 return true; 960} 961 962/// \brief Determine whether the conversion from FromType to ToType is a valid 963/// vector conversion. 964/// 965/// \param ICK Will be set to the vector conversion kind, if this is a vector 966/// conversion. 967static bool IsVectorConversion(ASTContext &Context, QualType FromType, 968 QualType ToType, ImplicitConversionKind &ICK) { 969 // We need at least one of these types to be a vector type to have a vector 970 // conversion. 971 if (!ToType->isVectorType() && !FromType->isVectorType()) 972 return false; 973 974 // Identical types require no conversions. 975 if (Context.hasSameUnqualifiedType(FromType, ToType)) 976 return false; 977 978 // There are no conversions between extended vector types, only identity. 979 if (ToType->isExtVectorType()) { 980 // There are no conversions between extended vector types other than the 981 // identity conversion. 982 if (FromType->isExtVectorType()) 983 return false; 984 985 // Vector splat from any arithmetic type to a vector. 986 if (FromType->isArithmeticType()) { 987 ICK = ICK_Vector_Splat; 988 return true; 989 } 990 } 991 992 // We can perform the conversion between vector types in the following cases: 993 // 1)vector types are equivalent AltiVec and GCC vector types 994 // 2)lax vector conversions are permitted and the vector types are of the 995 // same size 996 if (ToType->isVectorType() && FromType->isVectorType()) { 997 if (Context.areCompatibleVectorTypes(FromType, ToType) || 998 (Context.getLangOptions().LaxVectorConversions && 999 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 1000 ICK = ICK_Vector_Conversion; 1001 return true; 1002 } 1003 } 1004 1005 return false; 1006} 1007 1008/// IsStandardConversion - Determines whether there is a standard 1009/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 1010/// expression From to the type ToType. Standard conversion sequences 1011/// only consider non-class types; for conversions that involve class 1012/// types, use TryImplicitConversion. If a conversion exists, SCS will 1013/// contain the standard conversion sequence required to perform this 1014/// conversion and this routine will return true. Otherwise, this 1015/// routine will return false and the value of SCS is unspecified. 1016static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 1017 bool InOverloadResolution, 1018 StandardConversionSequence &SCS, 1019 bool CStyle) { 1020 QualType FromType = From->getType(); 1021 1022 // Standard conversions (C++ [conv]) 1023 SCS.setAsIdentityConversion(); 1024 SCS.DeprecatedStringLiteralToCharPtr = false; 1025 SCS.IncompatibleObjC = false; 1026 SCS.setFromType(FromType); 1027 SCS.CopyConstructor = 0; 1028 1029 // There are no standard conversions for class types in C++, so 1030 // abort early. When overloading in C, however, we do permit 1031 if (FromType->isRecordType() || ToType->isRecordType()) { 1032 if (S.getLangOptions().CPlusPlus) 1033 return false; 1034 1035 // When we're overloading in C, we allow, as standard conversions, 1036 } 1037 1038 // The first conversion can be an lvalue-to-rvalue conversion, 1039 // array-to-pointer conversion, or function-to-pointer conversion 1040 // (C++ 4p1). 1041 1042 if (FromType == S.Context.OverloadTy) { 1043 DeclAccessPair AccessPair; 1044 if (FunctionDecl *Fn 1045 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 1046 AccessPair)) { 1047 // We were able to resolve the address of the overloaded function, 1048 // so we can convert to the type of that function. 1049 FromType = Fn->getType(); 1050 1051 // we can sometimes resolve &foo<int> regardless of ToType, so check 1052 // if the type matches (identity) or we are converting to bool 1053 if (!S.Context.hasSameUnqualifiedType( 1054 S.ExtractUnqualifiedFunctionType(ToType), FromType)) { 1055 QualType resultTy; 1056 // if the function type matches except for [[noreturn]], it's ok 1057 if (!IsNoReturnConversion(S.Context, FromType, 1058 S.ExtractUnqualifiedFunctionType(ToType), resultTy)) 1059 // otherwise, only a boolean conversion is standard 1060 if (!ToType->isBooleanType()) 1061 return false; 1062 } 1063 1064 // Check if the "from" expression is taking the address of an overloaded 1065 // function and recompute the FromType accordingly. Take advantage of the 1066 // fact that non-static member functions *must* have such an address-of 1067 // expression. 1068 CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn); 1069 if (Method && !Method->isStatic()) { 1070 assert(isa<UnaryOperator>(From->IgnoreParens()) && 1071 "Non-unary operator on non-static member address"); 1072 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() 1073 == UO_AddrOf && 1074 "Non-address-of operator on non-static member address"); 1075 const Type *ClassType 1076 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 1077 FromType = S.Context.getMemberPointerType(FromType, ClassType); 1078 } else if (isa<UnaryOperator>(From->IgnoreParens())) { 1079 assert(cast<UnaryOperator>(From->IgnoreParens())->getOpcode() == 1080 UO_AddrOf && 1081 "Non-address-of operator for overloaded function expression"); 1082 FromType = S.Context.getPointerType(FromType); 1083 } 1084 1085 // Check that we've computed the proper type after overload resolution. 1086 assert(S.Context.hasSameType( 1087 FromType, 1088 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 1089 } else { 1090 return false; 1091 } 1092 } 1093 // Lvalue-to-rvalue conversion (C++ 4.1): 1094 // An lvalue (3.10) of a non-function, non-array type T can be 1095 // converted to an rvalue. 1096 bool argIsLValue = From->isLValue(); 1097 if (argIsLValue && 1098 !FromType->isFunctionType() && !FromType->isArrayType() && 1099 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 1100 SCS.First = ICK_Lvalue_To_Rvalue; 1101 1102 // If T is a non-class type, the type of the rvalue is the 1103 // cv-unqualified version of T. Otherwise, the type of the rvalue 1104 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1105 // just strip the qualifiers because they don't matter. 1106 FromType = FromType.getUnqualifiedType(); 1107 } else if (FromType->isArrayType()) { 1108 // Array-to-pointer conversion (C++ 4.2) 1109 SCS.First = ICK_Array_To_Pointer; 1110 1111 // An lvalue or rvalue of type "array of N T" or "array of unknown 1112 // bound of T" can be converted to an rvalue of type "pointer to 1113 // T" (C++ 4.2p1). 1114 FromType = S.Context.getArrayDecayedType(FromType); 1115 1116 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1117 // This conversion is deprecated. (C++ D.4). 1118 SCS.DeprecatedStringLiteralToCharPtr = true; 1119 1120 // For the purpose of ranking in overload resolution 1121 // (13.3.3.1.1), this conversion is considered an 1122 // array-to-pointer conversion followed by a qualification 1123 // conversion (4.4). (C++ 4.2p2) 1124 SCS.Second = ICK_Identity; 1125 SCS.Third = ICK_Qualification; 1126 SCS.setAllToTypes(FromType); 1127 return true; 1128 } 1129 } else if (FromType->isFunctionType() && argIsLValue) { 1130 // Function-to-pointer conversion (C++ 4.3). 1131 SCS.First = ICK_Function_To_Pointer; 1132 1133 // An lvalue of function type T can be converted to an rvalue of 1134 // type "pointer to T." The result is a pointer to the 1135 // function. (C++ 4.3p1). 1136 FromType = S.Context.getPointerType(FromType); 1137 } else { 1138 // We don't require any conversions for the first step. 1139 SCS.First = ICK_Identity; 1140 } 1141 SCS.setToType(0, FromType); 1142 1143 // The second conversion can be an integral promotion, floating 1144 // point promotion, integral conversion, floating point conversion, 1145 // floating-integral conversion, pointer conversion, 1146 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1147 // For overloading in C, this can also be a "compatible-type" 1148 // conversion. 1149 bool IncompatibleObjC = false; 1150 ImplicitConversionKind SecondICK = ICK_Identity; 1151 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1152 // The unqualified versions of the types are the same: there's no 1153 // conversion to do. 1154 SCS.Second = ICK_Identity; 1155 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1156 // Integral promotion (C++ 4.5). 1157 SCS.Second = ICK_Integral_Promotion; 1158 FromType = ToType.getUnqualifiedType(); 1159 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1160 // Floating point promotion (C++ 4.6). 1161 SCS.Second = ICK_Floating_Promotion; 1162 FromType = ToType.getUnqualifiedType(); 1163 } else if (S.IsComplexPromotion(FromType, ToType)) { 1164 // Complex promotion (Clang extension) 1165 SCS.Second = ICK_Complex_Promotion; 1166 FromType = ToType.getUnqualifiedType(); 1167 } else if (ToType->isBooleanType() && 1168 (FromType->isArithmeticType() || 1169 FromType->isAnyPointerType() || 1170 FromType->isBlockPointerType() || 1171 FromType->isMemberPointerType() || 1172 FromType->isNullPtrType())) { 1173 // Boolean conversions (C++ 4.12). 1174 SCS.Second = ICK_Boolean_Conversion; 1175 FromType = S.Context.BoolTy; 1176 } else if (FromType->isIntegralOrUnscopedEnumerationType() && 1177 ToType->isIntegralType(S.Context)) { 1178 // Integral conversions (C++ 4.7). 1179 SCS.Second = ICK_Integral_Conversion; 1180 FromType = ToType.getUnqualifiedType(); 1181 } else if (FromType->isAnyComplexType() && ToType->isComplexType()) { 1182 // Complex conversions (C99 6.3.1.6) 1183 SCS.Second = ICK_Complex_Conversion; 1184 FromType = ToType.getUnqualifiedType(); 1185 } else if ((FromType->isAnyComplexType() && ToType->isArithmeticType()) || 1186 (ToType->isAnyComplexType() && FromType->isArithmeticType())) { 1187 // Complex-real conversions (C99 6.3.1.7) 1188 SCS.Second = ICK_Complex_Real; 1189 FromType = ToType.getUnqualifiedType(); 1190 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1191 // Floating point conversions (C++ 4.8). 1192 SCS.Second = ICK_Floating_Conversion; 1193 FromType = ToType.getUnqualifiedType(); 1194 } else if ((FromType->isRealFloatingType() && 1195 ToType->isIntegralType(S.Context)) || 1196 (FromType->isIntegralOrUnscopedEnumerationType() && 1197 ToType->isRealFloatingType())) { 1198 // Floating-integral conversions (C++ 4.9). 1199 SCS.Second = ICK_Floating_Integral; 1200 FromType = ToType.getUnqualifiedType(); 1201 } else if (S.IsBlockPointerConversion(FromType, ToType, FromType)) { 1202 SCS.Second = ICK_Block_Pointer_Conversion; 1203 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1204 FromType, IncompatibleObjC)) { 1205 // Pointer conversions (C++ 4.10). 1206 SCS.Second = ICK_Pointer_Conversion; 1207 SCS.IncompatibleObjC = IncompatibleObjC; 1208 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1209 InOverloadResolution, FromType)) { 1210 // Pointer to member conversions (4.11). 1211 SCS.Second = ICK_Pointer_Member; 1212 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1213 SCS.Second = SecondICK; 1214 FromType = ToType.getUnqualifiedType(); 1215 } else if (!S.getLangOptions().CPlusPlus && 1216 S.Context.typesAreCompatible(ToType, FromType)) { 1217 // Compatible conversions (Clang extension for C function overloading) 1218 SCS.Second = ICK_Compatible_Conversion; 1219 FromType = ToType.getUnqualifiedType(); 1220 } else if (IsNoReturnConversion(S.Context, FromType, ToType, FromType)) { 1221 // Treat a conversion that strips "noreturn" as an identity conversion. 1222 SCS.Second = ICK_NoReturn_Adjustment; 1223 } else if (IsTransparentUnionStandardConversion(S, From, ToType, 1224 InOverloadResolution, 1225 SCS, CStyle)) { 1226 SCS.Second = ICK_TransparentUnionConversion; 1227 FromType = ToType; 1228 } else { 1229 // No second conversion required. 1230 SCS.Second = ICK_Identity; 1231 } 1232 SCS.setToType(1, FromType); 1233 1234 QualType CanonFrom; 1235 QualType CanonTo; 1236 // The third conversion can be a qualification conversion (C++ 4p1). 1237 if (S.IsQualificationConversion(FromType, ToType, CStyle)) { 1238 SCS.Third = ICK_Qualification; 1239 FromType = ToType; 1240 CanonFrom = S.Context.getCanonicalType(FromType); 1241 CanonTo = S.Context.getCanonicalType(ToType); 1242 } else { 1243 // No conversion required 1244 SCS.Third = ICK_Identity; 1245 1246 // C++ [over.best.ics]p6: 1247 // [...] Any difference in top-level cv-qualification is 1248 // subsumed by the initialization itself and does not constitute 1249 // a conversion. [...] 1250 CanonFrom = S.Context.getCanonicalType(FromType); 1251 CanonTo = S.Context.getCanonicalType(ToType); 1252 if (CanonFrom.getLocalUnqualifiedType() 1253 == CanonTo.getLocalUnqualifiedType() && 1254 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1255 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1256 FromType = ToType; 1257 CanonFrom = CanonTo; 1258 } 1259 } 1260 SCS.setToType(2, FromType); 1261 1262 // If we have not converted the argument type to the parameter type, 1263 // this is a bad conversion sequence. 1264 if (CanonFrom != CanonTo) 1265 return false; 1266 1267 return true; 1268} 1269 1270static bool 1271IsTransparentUnionStandardConversion(Sema &S, Expr* From, 1272 QualType &ToType, 1273 bool InOverloadResolution, 1274 StandardConversionSequence &SCS, 1275 bool CStyle) { 1276 1277 const RecordType *UT = ToType->getAsUnionType(); 1278 if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) 1279 return false; 1280 // The field to initialize within the transparent union. 1281 RecordDecl *UD = UT->getDecl(); 1282 // It's compatible if the expression matches any of the fields. 1283 for (RecordDecl::field_iterator it = UD->field_begin(), 1284 itend = UD->field_end(); 1285 it != itend; ++it) { 1286 if (IsStandardConversion(S, From, it->getType(), InOverloadResolution, SCS, CStyle)) { 1287 ToType = it->getType(); 1288 return true; 1289 } 1290 } 1291 return false; 1292} 1293 1294/// IsIntegralPromotion - Determines whether the conversion from the 1295/// expression From (whose potentially-adjusted type is FromType) to 1296/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1297/// sets PromotedType to the promoted type. 1298bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1299 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1300 // All integers are built-in. 1301 if (!To) { 1302 return false; 1303 } 1304 1305 // An rvalue of type char, signed char, unsigned char, short int, or 1306 // unsigned short int can be converted to an rvalue of type int if 1307 // int can represent all the values of the source type; otherwise, 1308 // the source rvalue can be converted to an rvalue of type unsigned 1309 // int (C++ 4.5p1). 1310 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1311 !FromType->isEnumeralType()) { 1312 if (// We can promote any signed, promotable integer type to an int 1313 (FromType->isSignedIntegerType() || 1314 // We can promote any unsigned integer type whose size is 1315 // less than int to an int. 1316 (!FromType->isSignedIntegerType() && 1317 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1318 return To->getKind() == BuiltinType::Int; 1319 } 1320 1321 return To->getKind() == BuiltinType::UInt; 1322 } 1323 1324 // C++0x [conv.prom]p3: 1325 // A prvalue of an unscoped enumeration type whose underlying type is not 1326 // fixed (7.2) can be converted to an rvalue a prvalue of the first of the 1327 // following types that can represent all the values of the enumeration 1328 // (i.e., the values in the range bmin to bmax as described in 7.2): int, 1329 // unsigned int, long int, unsigned long int, long long int, or unsigned 1330 // long long int. If none of the types in that list can represent all the 1331 // values of the enumeration, an rvalue a prvalue of an unscoped enumeration 1332 // type can be converted to an rvalue a prvalue of the extended integer type 1333 // with lowest integer conversion rank (4.13) greater than the rank of long 1334 // long in which all the values of the enumeration can be represented. If 1335 // there are two such extended types, the signed one is chosen. 1336 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) { 1337 // C++0x 7.2p9: Note that this implicit enum to int conversion is not 1338 // provided for a scoped enumeration. 1339 if (FromEnumType->getDecl()->isScoped()) 1340 return false; 1341 1342 // We have already pre-calculated the promotion type, so this is trivial. 1343 if (ToType->isIntegerType() && 1344 !RequireCompleteType(From->getLocStart(), FromType, PDiag())) 1345 return Context.hasSameUnqualifiedType(ToType, 1346 FromEnumType->getDecl()->getPromotionType()); 1347 } 1348 1349 // C++0x [conv.prom]p2: 1350 // A prvalue of type char16_t, char32_t, or wchar_t (3.9.1) can be converted 1351 // to an rvalue a prvalue of the first of the following types that can 1352 // represent all the values of its underlying type: int, unsigned int, 1353 // long int, unsigned long int, long long int, or unsigned long long int. 1354 // If none of the types in that list can represent all the values of its 1355 // underlying type, an rvalue a prvalue of type char16_t, char32_t, 1356 // or wchar_t can be converted to an rvalue a prvalue of its underlying 1357 // type. 1358 if (FromType->isAnyCharacterType() && !FromType->isCharType() && 1359 ToType->isIntegerType()) { 1360 // Determine whether the type we're converting from is signed or 1361 // unsigned. 1362 bool FromIsSigned; 1363 uint64_t FromSize = Context.getTypeSize(FromType); 1364 1365 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1366 FromIsSigned = true; 1367 1368 // The types we'll try to promote to, in the appropriate 1369 // order. Try each of these types. 1370 QualType PromoteTypes[6] = { 1371 Context.IntTy, Context.UnsignedIntTy, 1372 Context.LongTy, Context.UnsignedLongTy , 1373 Context.LongLongTy, Context.UnsignedLongLongTy 1374 }; 1375 for (int Idx = 0; Idx < 6; ++Idx) { 1376 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1377 if (FromSize < ToSize || 1378 (FromSize == ToSize && 1379 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1380 // We found the type that we can promote to. If this is the 1381 // type we wanted, we have a promotion. Otherwise, no 1382 // promotion. 1383 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1384 } 1385 } 1386 } 1387 1388 // An rvalue for an integral bit-field (9.6) can be converted to an 1389 // rvalue of type int if int can represent all the values of the 1390 // bit-field; otherwise, it can be converted to unsigned int if 1391 // unsigned int can represent all the values of the bit-field. If 1392 // the bit-field is larger yet, no integral promotion applies to 1393 // it. If the bit-field has an enumerated type, it is treated as any 1394 // other value of that type for promotion purposes (C++ 4.5p3). 1395 // FIXME: We should delay checking of bit-fields until we actually perform the 1396 // conversion. 1397 using llvm::APSInt; 1398 if (From) 1399 if (FieldDecl *MemberDecl = From->getBitField()) { 1400 APSInt BitWidth; 1401 if (FromType->isIntegralType(Context) && 1402 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1403 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1404 ToSize = Context.getTypeSize(ToType); 1405 1406 // Are we promoting to an int from a bitfield that fits in an int? 1407 if (BitWidth < ToSize || 1408 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1409 return To->getKind() == BuiltinType::Int; 1410 } 1411 1412 // Are we promoting to an unsigned int from an unsigned bitfield 1413 // that fits into an unsigned int? 1414 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1415 return To->getKind() == BuiltinType::UInt; 1416 } 1417 1418 return false; 1419 } 1420 } 1421 1422 // An rvalue of type bool can be converted to an rvalue of type int, 1423 // with false becoming zero and true becoming one (C++ 4.5p4). 1424 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1425 return true; 1426 } 1427 1428 return false; 1429} 1430 1431/// IsFloatingPointPromotion - Determines whether the conversion from 1432/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1433/// returns true and sets PromotedType to the promoted type. 1434bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1435 /// An rvalue of type float can be converted to an rvalue of type 1436 /// double. (C++ 4.6p1). 1437 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1438 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1439 if (FromBuiltin->getKind() == BuiltinType::Float && 1440 ToBuiltin->getKind() == BuiltinType::Double) 1441 return true; 1442 1443 // C99 6.3.1.5p1: 1444 // When a float is promoted to double or long double, or a 1445 // double is promoted to long double [...]. 1446 if (!getLangOptions().CPlusPlus && 1447 (FromBuiltin->getKind() == BuiltinType::Float || 1448 FromBuiltin->getKind() == BuiltinType::Double) && 1449 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1450 return true; 1451 } 1452 1453 return false; 1454} 1455 1456/// \brief Determine if a conversion is a complex promotion. 1457/// 1458/// A complex promotion is defined as a complex -> complex conversion 1459/// where the conversion between the underlying real types is a 1460/// floating-point or integral promotion. 1461bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1462 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1463 if (!FromComplex) 1464 return false; 1465 1466 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1467 if (!ToComplex) 1468 return false; 1469 1470 return IsFloatingPointPromotion(FromComplex->getElementType(), 1471 ToComplex->getElementType()) || 1472 IsIntegralPromotion(0, FromComplex->getElementType(), 1473 ToComplex->getElementType()); 1474} 1475 1476/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1477/// the pointer type FromPtr to a pointer to type ToPointee, with the 1478/// same type qualifiers as FromPtr has on its pointee type. ToType, 1479/// if non-empty, will be a pointer to ToType that may or may not have 1480/// the right set of qualifiers on its pointee. 1481static QualType 1482BuildSimilarlyQualifiedPointerType(const Type *FromPtr, 1483 QualType ToPointee, QualType ToType, 1484 ASTContext &Context) { 1485 assert((FromPtr->getTypeClass() == Type::Pointer || 1486 FromPtr->getTypeClass() == Type::ObjCObjectPointer) && 1487 "Invalid similarly-qualified pointer type"); 1488 1489 /// \brief Conversions to 'id' subsume cv-qualifier conversions. 1490 if (ToType->isObjCIdType() || ToType->isObjCQualifiedIdType()) 1491 return ToType.getUnqualifiedType(); 1492 1493 QualType CanonFromPointee 1494 = Context.getCanonicalType(FromPtr->getPointeeType()); 1495 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1496 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1497 1498 // Exact qualifier match -> return the pointer type we're converting to. 1499 if (CanonToPointee.getLocalQualifiers() == Quals) { 1500 // ToType is exactly what we need. Return it. 1501 if (!ToType.isNull()) 1502 return ToType.getUnqualifiedType(); 1503 1504 // Build a pointer to ToPointee. It has the right qualifiers 1505 // already. 1506 if (isa<ObjCObjectPointerType>(ToType)) 1507 return Context.getObjCObjectPointerType(ToPointee); 1508 return Context.getPointerType(ToPointee); 1509 } 1510 1511 // Just build a canonical type that has the right qualifiers. 1512 QualType QualifiedCanonToPointee 1513 = Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), Quals); 1514 1515 if (isa<ObjCObjectPointerType>(ToType)) 1516 return Context.getObjCObjectPointerType(QualifiedCanonToPointee); 1517 return Context.getPointerType(QualifiedCanonToPointee); 1518} 1519 1520static bool isNullPointerConstantForConversion(Expr *Expr, 1521 bool InOverloadResolution, 1522 ASTContext &Context) { 1523 // Handle value-dependent integral null pointer constants correctly. 1524 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1525 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1526 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1527 return !InOverloadResolution; 1528 1529 return Expr->isNullPointerConstant(Context, 1530 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1531 : Expr::NPC_ValueDependentIsNull); 1532} 1533 1534/// IsPointerConversion - Determines whether the conversion of the 1535/// expression From, which has the (possibly adjusted) type FromType, 1536/// can be converted to the type ToType via a pointer conversion (C++ 1537/// 4.10). If so, returns true and places the converted type (that 1538/// might differ from ToType in its cv-qualifiers at some level) into 1539/// ConvertedType. 1540/// 1541/// This routine also supports conversions to and from block pointers 1542/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1543/// pointers to interfaces. FIXME: Once we've determined the 1544/// appropriate overloading rules for Objective-C, we may want to 1545/// split the Objective-C checks into a different routine; however, 1546/// GCC seems to consider all of these conversions to be pointer 1547/// conversions, so for now they live here. IncompatibleObjC will be 1548/// set if the conversion is an allowed Objective-C conversion that 1549/// should result in a warning. 1550bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1551 bool InOverloadResolution, 1552 QualType& ConvertedType, 1553 bool &IncompatibleObjC) { 1554 IncompatibleObjC = false; 1555 if (isObjCPointerConversion(FromType, ToType, ConvertedType, 1556 IncompatibleObjC)) 1557 return true; 1558 1559 // Conversion from a null pointer constant to any Objective-C pointer type. 1560 if (ToType->isObjCObjectPointerType() && 1561 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1562 ConvertedType = ToType; 1563 return true; 1564 } 1565 1566 // Blocks: Block pointers can be converted to void*. 1567 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1568 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1569 ConvertedType = ToType; 1570 return true; 1571 } 1572 // Blocks: A null pointer constant can be converted to a block 1573 // pointer type. 1574 if (ToType->isBlockPointerType() && 1575 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1576 ConvertedType = ToType; 1577 return true; 1578 } 1579 1580 // If the left-hand-side is nullptr_t, the right side can be a null 1581 // pointer constant. 1582 if (ToType->isNullPtrType() && 1583 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1584 ConvertedType = ToType; 1585 return true; 1586 } 1587 1588 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1589 if (!ToTypePtr) 1590 return false; 1591 1592 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1593 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1594 ConvertedType = ToType; 1595 return true; 1596 } 1597 1598 // Beyond this point, both types need to be pointers 1599 // , including objective-c pointers. 1600 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1601 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1602 ConvertedType = BuildSimilarlyQualifiedPointerType( 1603 FromType->getAs<ObjCObjectPointerType>(), 1604 ToPointeeType, 1605 ToType, Context); 1606 return true; 1607 } 1608 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1609 if (!FromTypePtr) 1610 return false; 1611 1612 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1613 1614 // If the unqualified pointee types are the same, this can't be a 1615 // pointer conversion, so don't do all of the work below. 1616 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1617 return false; 1618 1619 // An rvalue of type "pointer to cv T," where T is an object type, 1620 // can be converted to an rvalue of type "pointer to cv void" (C++ 1621 // 4.10p2). 1622 if (FromPointeeType->isIncompleteOrObjectType() && 1623 ToPointeeType->isVoidType()) { 1624 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1625 ToPointeeType, 1626 ToType, Context); 1627 return true; 1628 } 1629 1630 // When we're overloading in C, we allow a special kind of pointer 1631 // conversion for compatible-but-not-identical pointee types. 1632 if (!getLangOptions().CPlusPlus && 1633 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1634 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1635 ToPointeeType, 1636 ToType, Context); 1637 return true; 1638 } 1639 1640 // C++ [conv.ptr]p3: 1641 // 1642 // An rvalue of type "pointer to cv D," where D is a class type, 1643 // can be converted to an rvalue of type "pointer to cv B," where 1644 // B is a base class (clause 10) of D. If B is an inaccessible 1645 // (clause 11) or ambiguous (10.2) base class of D, a program that 1646 // necessitates this conversion is ill-formed. The result of the 1647 // conversion is a pointer to the base class sub-object of the 1648 // derived class object. The null pointer value is converted to 1649 // the null pointer value of the destination type. 1650 // 1651 // Note that we do not check for ambiguity or inaccessibility 1652 // here. That is handled by CheckPointerConversion. 1653 if (getLangOptions().CPlusPlus && 1654 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1655 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1656 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1657 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1658 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1659 ToPointeeType, 1660 ToType, Context); 1661 return true; 1662 } 1663 1664 if (FromPointeeType->isVectorType() && ToPointeeType->isVectorType() && 1665 Context.areCompatibleVectorTypes(FromPointeeType, ToPointeeType)) { 1666 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1667 ToPointeeType, 1668 ToType, Context); 1669 return true; 1670 } 1671 1672 return false; 1673} 1674 1675/// isObjCPointerConversion - Determines whether this is an 1676/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1677/// with the same arguments and return values. 1678bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1679 QualType& ConvertedType, 1680 bool &IncompatibleObjC) { 1681 if (!getLangOptions().ObjC1) 1682 return false; 1683 1684 // First, we handle all conversions on ObjC object pointer types. 1685 const ObjCObjectPointerType* ToObjCPtr = 1686 ToType->getAs<ObjCObjectPointerType>(); 1687 const ObjCObjectPointerType *FromObjCPtr = 1688 FromType->getAs<ObjCObjectPointerType>(); 1689 1690 if (ToObjCPtr && FromObjCPtr) { 1691 // If the pointee types are the same (ignoring qualifications), 1692 // then this is not a pointer conversion. 1693 if (Context.hasSameUnqualifiedType(ToObjCPtr->getPointeeType(), 1694 FromObjCPtr->getPointeeType())) 1695 return false; 1696 1697 // Objective C++: We're able to convert between "id" or "Class" and a 1698 // pointer to any interface (in both directions). 1699 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1700 ConvertedType = ToType; 1701 return true; 1702 } 1703 // Conversions with Objective-C's id<...>. 1704 if ((FromObjCPtr->isObjCQualifiedIdType() || 1705 ToObjCPtr->isObjCQualifiedIdType()) && 1706 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1707 /*compare=*/false)) { 1708 ConvertedType = ToType; 1709 return true; 1710 } 1711 // Objective C++: We're able to convert from a pointer to an 1712 // interface to a pointer to a different interface. 1713 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1714 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1715 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1716 if (getLangOptions().CPlusPlus && LHS && RHS && 1717 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1718 FromObjCPtr->getPointeeType())) 1719 return false; 1720 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1721 ToObjCPtr->getPointeeType(), 1722 ToType, Context); 1723 return true; 1724 } 1725 1726 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1727 // Okay: this is some kind of implicit downcast of Objective-C 1728 // interfaces, which is permitted. However, we're going to 1729 // complain about it. 1730 IncompatibleObjC = true; 1731 ConvertedType = BuildSimilarlyQualifiedPointerType(FromObjCPtr, 1732 ToObjCPtr->getPointeeType(), 1733 ToType, Context); 1734 return true; 1735 } 1736 } 1737 // Beyond this point, both types need to be C pointers or block pointers. 1738 QualType ToPointeeType; 1739 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1740 ToPointeeType = ToCPtr->getPointeeType(); 1741 else if (const BlockPointerType *ToBlockPtr = 1742 ToType->getAs<BlockPointerType>()) { 1743 // Objective C++: We're able to convert from a pointer to any object 1744 // to a block pointer type. 1745 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1746 ConvertedType = ToType; 1747 return true; 1748 } 1749 ToPointeeType = ToBlockPtr->getPointeeType(); 1750 } 1751 else if (FromType->getAs<BlockPointerType>() && 1752 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1753 // Objective C++: We're able to convert from a block pointer type to a 1754 // pointer to any object. 1755 ConvertedType = ToType; 1756 return true; 1757 } 1758 else 1759 return false; 1760 1761 QualType FromPointeeType; 1762 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1763 FromPointeeType = FromCPtr->getPointeeType(); 1764 else if (const BlockPointerType *FromBlockPtr = 1765 FromType->getAs<BlockPointerType>()) 1766 FromPointeeType = FromBlockPtr->getPointeeType(); 1767 else 1768 return false; 1769 1770 // If we have pointers to pointers, recursively check whether this 1771 // is an Objective-C conversion. 1772 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1773 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1774 IncompatibleObjC)) { 1775 // We always complain about this conversion. 1776 IncompatibleObjC = true; 1777 ConvertedType = Context.getPointerType(ConvertedType); 1778 return true; 1779 } 1780 // Allow conversion of pointee being objective-c pointer to another one; 1781 // as in I* to id. 1782 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1783 ToPointeeType->getAs<ObjCObjectPointerType>() && 1784 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1785 IncompatibleObjC)) { 1786 ConvertedType = Context.getPointerType(ConvertedType); 1787 return true; 1788 } 1789 1790 // If we have pointers to functions or blocks, check whether the only 1791 // differences in the argument and result types are in Objective-C 1792 // pointer conversions. If so, we permit the conversion (but 1793 // complain about it). 1794 const FunctionProtoType *FromFunctionType 1795 = FromPointeeType->getAs<FunctionProtoType>(); 1796 const FunctionProtoType *ToFunctionType 1797 = ToPointeeType->getAs<FunctionProtoType>(); 1798 if (FromFunctionType && ToFunctionType) { 1799 // If the function types are exactly the same, this isn't an 1800 // Objective-C pointer conversion. 1801 if (Context.getCanonicalType(FromPointeeType) 1802 == Context.getCanonicalType(ToPointeeType)) 1803 return false; 1804 1805 // Perform the quick checks that will tell us whether these 1806 // function types are obviously different. 1807 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1808 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1809 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1810 return false; 1811 1812 bool HasObjCConversion = false; 1813 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1814 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1815 // Okay, the types match exactly. Nothing to do. 1816 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1817 ToFunctionType->getResultType(), 1818 ConvertedType, IncompatibleObjC)) { 1819 // Okay, we have an Objective-C pointer conversion. 1820 HasObjCConversion = true; 1821 } else { 1822 // Function types are too different. Abort. 1823 return false; 1824 } 1825 1826 // Check argument types. 1827 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1828 ArgIdx != NumArgs; ++ArgIdx) { 1829 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1830 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1831 if (Context.getCanonicalType(FromArgType) 1832 == Context.getCanonicalType(ToArgType)) { 1833 // Okay, the types match exactly. Nothing to do. 1834 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1835 ConvertedType, IncompatibleObjC)) { 1836 // Okay, we have an Objective-C pointer conversion. 1837 HasObjCConversion = true; 1838 } else { 1839 // Argument types are too different. Abort. 1840 return false; 1841 } 1842 } 1843 1844 if (HasObjCConversion) { 1845 // We had an Objective-C conversion. Allow this pointer 1846 // conversion, but complain about it. 1847 ConvertedType = ToType; 1848 IncompatibleObjC = true; 1849 return true; 1850 } 1851 } 1852 1853 return false; 1854} 1855 1856bool Sema::IsBlockPointerConversion(QualType FromType, QualType ToType, 1857 QualType& ConvertedType) { 1858 QualType ToPointeeType; 1859 if (const BlockPointerType *ToBlockPtr = 1860 ToType->getAs<BlockPointerType>()) 1861 ToPointeeType = ToBlockPtr->getPointeeType(); 1862 else 1863 return false; 1864 1865 QualType FromPointeeType; 1866 if (const BlockPointerType *FromBlockPtr = 1867 FromType->getAs<BlockPointerType>()) 1868 FromPointeeType = FromBlockPtr->getPointeeType(); 1869 else 1870 return false; 1871 // We have pointer to blocks, check whether the only 1872 // differences in the argument and result types are in Objective-C 1873 // pointer conversions. If so, we permit the conversion. 1874 1875 const FunctionProtoType *FromFunctionType 1876 = FromPointeeType->getAs<FunctionProtoType>(); 1877 const FunctionProtoType *ToFunctionType 1878 = ToPointeeType->getAs<FunctionProtoType>(); 1879 1880 if (!FromFunctionType || !ToFunctionType) 1881 return false; 1882 1883 if (Context.hasSameType(FromPointeeType, ToPointeeType)) 1884 return true; 1885 1886 // Perform the quick checks that will tell us whether these 1887 // function types are obviously different. 1888 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1889 FromFunctionType->isVariadic() != ToFunctionType->isVariadic()) 1890 return false; 1891 1892 FunctionType::ExtInfo FromEInfo = FromFunctionType->getExtInfo(); 1893 FunctionType::ExtInfo ToEInfo = ToFunctionType->getExtInfo(); 1894 if (FromEInfo != ToEInfo) 1895 return false; 1896 1897 bool IncompatibleObjC = false; 1898 if (Context.hasSameType(FromFunctionType->getResultType(), 1899 ToFunctionType->getResultType())) { 1900 // Okay, the types match exactly. Nothing to do. 1901 } else { 1902 QualType RHS = FromFunctionType->getResultType(); 1903 QualType LHS = ToFunctionType->getResultType(); 1904 if ((!getLangOptions().CPlusPlus || !RHS->isRecordType()) && 1905 !RHS.hasQualifiers() && LHS.hasQualifiers()) 1906 LHS = LHS.getUnqualifiedType(); 1907 1908 if (Context.hasSameType(RHS,LHS)) { 1909 // OK exact match. 1910 } else if (isObjCPointerConversion(RHS, LHS, 1911 ConvertedType, IncompatibleObjC)) { 1912 if (IncompatibleObjC) 1913 return false; 1914 // Okay, we have an Objective-C pointer conversion. 1915 } 1916 else 1917 return false; 1918 } 1919 1920 // Check argument types. 1921 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1922 ArgIdx != NumArgs; ++ArgIdx) { 1923 IncompatibleObjC = false; 1924 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1925 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1926 if (Context.hasSameType(FromArgType, ToArgType)) { 1927 // Okay, the types match exactly. Nothing to do. 1928 } else if (isObjCPointerConversion(ToArgType, FromArgType, 1929 ConvertedType, IncompatibleObjC)) { 1930 if (IncompatibleObjC) 1931 return false; 1932 // Okay, we have an Objective-C pointer conversion. 1933 } else 1934 // Argument types are too different. Abort. 1935 return false; 1936 } 1937 ConvertedType = ToType; 1938 return true; 1939} 1940 1941/// FunctionArgTypesAreEqual - This routine checks two function proto types 1942/// for equlity of their argument types. Caller has already checked that 1943/// they have same number of arguments. This routine assumes that Objective-C 1944/// pointer types which only differ in their protocol qualifiers are equal. 1945bool Sema::FunctionArgTypesAreEqual(const FunctionProtoType *OldType, 1946 const FunctionProtoType *NewType) { 1947 if (!getLangOptions().ObjC1) 1948 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1949 NewType->arg_type_begin()); 1950 1951 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1952 N = NewType->arg_type_begin(), 1953 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1954 QualType ToType = (*O); 1955 QualType FromType = (*N); 1956 if (ToType != FromType) { 1957 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1958 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1959 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1960 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1961 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1962 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1963 continue; 1964 } 1965 else if (const ObjCObjectPointerType *PTTo = 1966 ToType->getAs<ObjCObjectPointerType>()) { 1967 if (const ObjCObjectPointerType *PTFr = 1968 FromType->getAs<ObjCObjectPointerType>()) 1969 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1970 continue; 1971 } 1972 return false; 1973 } 1974 } 1975 return true; 1976} 1977 1978/// CheckPointerConversion - Check the pointer conversion from the 1979/// expression From to the type ToType. This routine checks for 1980/// ambiguous or inaccessible derived-to-base pointer 1981/// conversions for which IsPointerConversion has already returned 1982/// true. It returns true and produces a diagnostic if there was an 1983/// error, or returns false otherwise. 1984bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1985 CastKind &Kind, 1986 CXXCastPath& BasePath, 1987 bool IgnoreBaseAccess) { 1988 QualType FromType = From->getType(); 1989 bool IsCStyleOrFunctionalCast = IgnoreBaseAccess; 1990 1991 Kind = CK_BitCast; 1992 1993 if (!IsCStyleOrFunctionalCast && 1994 Context.hasSameUnqualifiedType(From->getType(), Context.BoolTy) && 1995 From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) 1996 DiagRuntimeBehavior(From->getExprLoc(), From, 1997 PDiag(diag::warn_impcast_bool_to_null_pointer) 1998 << ToType << From->getSourceRange()); 1999 2000 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 2001 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 2002 QualType FromPointeeType = FromPtrType->getPointeeType(), 2003 ToPointeeType = ToPtrType->getPointeeType(); 2004 2005 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 2006 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 2007 // We must have a derived-to-base conversion. Check an 2008 // ambiguous or inaccessible conversion. 2009 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 2010 From->getExprLoc(), 2011 From->getSourceRange(), &BasePath, 2012 IgnoreBaseAccess)) 2013 return true; 2014 2015 // The conversion was successful. 2016 Kind = CK_DerivedToBase; 2017 } 2018 } 2019 if (const ObjCObjectPointerType *FromPtrType = 2020 FromType->getAs<ObjCObjectPointerType>()) { 2021 if (const ObjCObjectPointerType *ToPtrType = 2022 ToType->getAs<ObjCObjectPointerType>()) { 2023 // Objective-C++ conversions are always okay. 2024 // FIXME: We should have a different class of conversions for the 2025 // Objective-C++ implicit conversions. 2026 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 2027 return false; 2028 } 2029 } 2030 2031 // We shouldn't fall into this case unless it's valid for other 2032 // reasons. 2033 if (From->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) 2034 Kind = CK_NullToPointer; 2035 2036 return false; 2037} 2038 2039/// IsMemberPointerConversion - Determines whether the conversion of the 2040/// expression From, which has the (possibly adjusted) type FromType, can be 2041/// converted to the type ToType via a member pointer conversion (C++ 4.11). 2042/// If so, returns true and places the converted type (that might differ from 2043/// ToType in its cv-qualifiers at some level) into ConvertedType. 2044bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 2045 QualType ToType, 2046 bool InOverloadResolution, 2047 QualType &ConvertedType) { 2048 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 2049 if (!ToTypePtr) 2050 return false; 2051 2052 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 2053 if (From->isNullPointerConstant(Context, 2054 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 2055 : Expr::NPC_ValueDependentIsNull)) { 2056 ConvertedType = ToType; 2057 return true; 2058 } 2059 2060 // Otherwise, both types have to be member pointers. 2061 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 2062 if (!FromTypePtr) 2063 return false; 2064 2065 // A pointer to member of B can be converted to a pointer to member of D, 2066 // where D is derived from B (C++ 4.11p2). 2067 QualType FromClass(FromTypePtr->getClass(), 0); 2068 QualType ToClass(ToTypePtr->getClass(), 0); 2069 2070 if (!Context.hasSameUnqualifiedType(FromClass, ToClass) && 2071 !RequireCompleteType(From->getLocStart(), ToClass, PDiag()) && 2072 IsDerivedFrom(ToClass, FromClass)) { 2073 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 2074 ToClass.getTypePtr()); 2075 return true; 2076 } 2077 2078 return false; 2079} 2080 2081/// CheckMemberPointerConversion - Check the member pointer conversion from the 2082/// expression From to the type ToType. This routine checks for ambiguous or 2083/// virtual or inaccessible base-to-derived member pointer conversions 2084/// for which IsMemberPointerConversion has already returned true. It returns 2085/// true and produces a diagnostic if there was an error, or returns false 2086/// otherwise. 2087bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 2088 CastKind &Kind, 2089 CXXCastPath &BasePath, 2090 bool IgnoreBaseAccess) { 2091 QualType FromType = From->getType(); 2092 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 2093 if (!FromPtrType) { 2094 // This must be a null pointer to member pointer conversion 2095 assert(From->isNullPointerConstant(Context, 2096 Expr::NPC_ValueDependentIsNull) && 2097 "Expr must be null pointer constant!"); 2098 Kind = CK_NullToMemberPointer; 2099 return false; 2100 } 2101 2102 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 2103 assert(ToPtrType && "No member pointer cast has a target type " 2104 "that is not a member pointer."); 2105 2106 QualType FromClass = QualType(FromPtrType->getClass(), 0); 2107 QualType ToClass = QualType(ToPtrType->getClass(), 0); 2108 2109 // FIXME: What about dependent types? 2110 assert(FromClass->isRecordType() && "Pointer into non-class."); 2111 assert(ToClass->isRecordType() && "Pointer into non-class."); 2112 2113 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 2114 /*DetectVirtual=*/true); 2115 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 2116 assert(DerivationOkay && 2117 "Should not have been called if derivation isn't OK."); 2118 (void)DerivationOkay; 2119 2120 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 2121 getUnqualifiedType())) { 2122 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 2123 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 2124 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 2125 return true; 2126 } 2127 2128 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 2129 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 2130 << FromClass << ToClass << QualType(VBase, 0) 2131 << From->getSourceRange(); 2132 return true; 2133 } 2134 2135 if (!IgnoreBaseAccess) 2136 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 2137 Paths.front(), 2138 diag::err_downcast_from_inaccessible_base); 2139 2140 // Must be a base to derived member conversion. 2141 BuildBasePathArray(Paths, BasePath); 2142 Kind = CK_BaseToDerivedMemberPointer; 2143 return false; 2144} 2145 2146/// IsQualificationConversion - Determines whether the conversion from 2147/// an rvalue of type FromType to ToType is a qualification conversion 2148/// (C++ 4.4). 2149bool 2150Sema::IsQualificationConversion(QualType FromType, QualType ToType, 2151 bool CStyle) { 2152 FromType = Context.getCanonicalType(FromType); 2153 ToType = Context.getCanonicalType(ToType); 2154 2155 // If FromType and ToType are the same type, this is not a 2156 // qualification conversion. 2157 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 2158 return false; 2159 2160 // (C++ 4.4p4): 2161 // A conversion can add cv-qualifiers at levels other than the first 2162 // in multi-level pointers, subject to the following rules: [...] 2163 bool PreviousToQualsIncludeConst = true; 2164 bool UnwrappedAnyPointer = false; 2165 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 2166 // Within each iteration of the loop, we check the qualifiers to 2167 // determine if this still looks like a qualification 2168 // conversion. Then, if all is well, we unwrap one more level of 2169 // pointers or pointers-to-members and do it all again 2170 // until there are no more pointers or pointers-to-members left to 2171 // unwrap. 2172 UnwrappedAnyPointer = true; 2173 2174 Qualifiers FromQuals = FromType.getQualifiers(); 2175 Qualifiers ToQuals = ToType.getQualifiers(); 2176 2177 // -- for every j > 0, if const is in cv 1,j then const is in cv 2178 // 2,j, and similarly for volatile. 2179 if (!CStyle && !ToQuals.compatiblyIncludes(FromQuals)) 2180 return false; 2181 2182 // -- if the cv 1,j and cv 2,j are different, then const is in 2183 // every cv for 0 < k < j. 2184 if (!CStyle && FromQuals.getCVRQualifiers() != ToQuals.getCVRQualifiers() 2185 && !PreviousToQualsIncludeConst) 2186 return false; 2187 2188 // Keep track of whether all prior cv-qualifiers in the "to" type 2189 // include const. 2190 PreviousToQualsIncludeConst 2191 = PreviousToQualsIncludeConst && ToQuals.hasConst(); 2192 } 2193 2194 // We are left with FromType and ToType being the pointee types 2195 // after unwrapping the original FromType and ToType the same number 2196 // of types. If we unwrapped any pointers, and if FromType and 2197 // ToType have the same unqualified type (since we checked 2198 // qualifiers above), then this is a qualification conversion. 2199 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 2200} 2201 2202/// Determines whether there is a user-defined conversion sequence 2203/// (C++ [over.ics.user]) that converts expression From to the type 2204/// ToType. If such a conversion exists, User will contain the 2205/// user-defined conversion sequence that performs such a conversion 2206/// and this routine will return true. Otherwise, this routine returns 2207/// false and User is unspecified. 2208/// 2209/// \param AllowExplicit true if the conversion should consider C++0x 2210/// "explicit" conversion functions as well as non-explicit conversion 2211/// functions (C++0x [class.conv.fct]p2). 2212static OverloadingResult 2213IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 2214 UserDefinedConversionSequence& User, 2215 OverloadCandidateSet& CandidateSet, 2216 bool AllowExplicit) { 2217 // Whether we will only visit constructors. 2218 bool ConstructorsOnly = false; 2219 2220 // If the type we are conversion to is a class type, enumerate its 2221 // constructors. 2222 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 2223 // C++ [over.match.ctor]p1: 2224 // When objects of class type are direct-initialized (8.5), or 2225 // copy-initialized from an expression of the same or a 2226 // derived class type (8.5), overload resolution selects the 2227 // constructor. [...] For copy-initialization, the candidate 2228 // functions are all the converting constructors (12.3.1) of 2229 // that class. The argument list is the expression-list within 2230 // the parentheses of the initializer. 2231 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 2232 (From->getType()->getAs<RecordType>() && 2233 S.IsDerivedFrom(From->getType(), ToType))) 2234 ConstructorsOnly = true; 2235 2236 S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag()); 2237 // RequireCompleteType may have returned true due to some invalid decl 2238 // during template instantiation, but ToType may be complete enough now 2239 // to try to recover. 2240 if (ToType->isIncompleteType()) { 2241 // We're not going to find any constructors. 2242 } else if (CXXRecordDecl *ToRecordDecl 2243 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 2244 DeclContext::lookup_iterator Con, ConEnd; 2245 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 2246 Con != ConEnd; ++Con) { 2247 NamedDecl *D = *Con; 2248 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 2249 2250 // Find the constructor (which may be a template). 2251 CXXConstructorDecl *Constructor = 0; 2252 FunctionTemplateDecl *ConstructorTmpl 2253 = dyn_cast<FunctionTemplateDecl>(D); 2254 if (ConstructorTmpl) 2255 Constructor 2256 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 2257 else 2258 Constructor = cast<CXXConstructorDecl>(D); 2259 2260 if (!Constructor->isInvalidDecl() && 2261 Constructor->isConvertingConstructor(AllowExplicit)) { 2262 if (ConstructorTmpl) 2263 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 2264 /*ExplicitArgs*/ 0, 2265 &From, 1, CandidateSet, 2266 /*SuppressUserConversions=*/ 2267 !ConstructorsOnly); 2268 else 2269 // Allow one user-defined conversion when user specifies a 2270 // From->ToType conversion via an static cast (c-style, etc). 2271 S.AddOverloadCandidate(Constructor, FoundDecl, 2272 &From, 1, CandidateSet, 2273 /*SuppressUserConversions=*/ 2274 !ConstructorsOnly); 2275 } 2276 } 2277 } 2278 } 2279 2280 // Enumerate conversion functions, if we're allowed to. 2281 if (ConstructorsOnly) { 2282 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 2283 S.PDiag(0) << From->getSourceRange())) { 2284 // No conversion functions from incomplete types. 2285 } else if (const RecordType *FromRecordType 2286 = From->getType()->getAs<RecordType>()) { 2287 if (CXXRecordDecl *FromRecordDecl 2288 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 2289 // Add all of the conversion functions as candidates. 2290 const UnresolvedSetImpl *Conversions 2291 = FromRecordDecl->getVisibleConversionFunctions(); 2292 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2293 E = Conversions->end(); I != E; ++I) { 2294 DeclAccessPair FoundDecl = I.getPair(); 2295 NamedDecl *D = FoundDecl.getDecl(); 2296 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 2297 if (isa<UsingShadowDecl>(D)) 2298 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2299 2300 CXXConversionDecl *Conv; 2301 FunctionTemplateDecl *ConvTemplate; 2302 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 2303 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2304 else 2305 Conv = cast<CXXConversionDecl>(D); 2306 2307 if (AllowExplicit || !Conv->isExplicit()) { 2308 if (ConvTemplate) 2309 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 2310 ActingContext, From, ToType, 2311 CandidateSet); 2312 else 2313 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 2314 From, ToType, CandidateSet); 2315 } 2316 } 2317 } 2318 } 2319 2320 OverloadCandidateSet::iterator Best; 2321 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best, true)) { 2322 case OR_Success: 2323 // Record the standard conversion we used and the conversion function. 2324 if (CXXConstructorDecl *Constructor 2325 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 2326 S.MarkDeclarationReferenced(From->getLocStart(), Constructor); 2327 2328 // C++ [over.ics.user]p1: 2329 // If the user-defined conversion is specified by a 2330 // constructor (12.3.1), the initial standard conversion 2331 // sequence converts the source type to the type required by 2332 // the argument of the constructor. 2333 // 2334 QualType ThisType = Constructor->getThisType(S.Context); 2335 if (Best->Conversions[0].isEllipsis()) 2336 User.EllipsisConversion = true; 2337 else { 2338 User.Before = Best->Conversions[0].Standard; 2339 User.EllipsisConversion = false; 2340 } 2341 User.ConversionFunction = Constructor; 2342 User.FoundConversionFunction = Best->FoundDecl.getDecl(); 2343 User.After.setAsIdentityConversion(); 2344 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2345 User.After.setAllToTypes(ToType); 2346 return OR_Success; 2347 } else if (CXXConversionDecl *Conversion 2348 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2349 S.MarkDeclarationReferenced(From->getLocStart(), Conversion); 2350 2351 // C++ [over.ics.user]p1: 2352 // 2353 // [...] If the user-defined conversion is specified by a 2354 // conversion function (12.3.2), the initial standard 2355 // conversion sequence converts the source type to the 2356 // implicit object parameter of the conversion function. 2357 User.Before = Best->Conversions[0].Standard; 2358 User.ConversionFunction = Conversion; 2359 User.FoundConversionFunction = Best->FoundDecl.getDecl(); 2360 User.EllipsisConversion = false; 2361 2362 // C++ [over.ics.user]p2: 2363 // The second standard conversion sequence converts the 2364 // result of the user-defined conversion to the target type 2365 // for the sequence. Since an implicit conversion sequence 2366 // is an initialization, the special rules for 2367 // initialization by user-defined conversion apply when 2368 // selecting the best user-defined conversion for a 2369 // user-defined conversion sequence (see 13.3.3 and 2370 // 13.3.3.1). 2371 User.After = Best->FinalConversion; 2372 return OR_Success; 2373 } else { 2374 llvm_unreachable("Not a constructor or conversion function?"); 2375 return OR_No_Viable_Function; 2376 } 2377 2378 case OR_No_Viable_Function: 2379 return OR_No_Viable_Function; 2380 case OR_Deleted: 2381 // No conversion here! We're done. 2382 return OR_Deleted; 2383 2384 case OR_Ambiguous: 2385 return OR_Ambiguous; 2386 } 2387 2388 return OR_No_Viable_Function; 2389} 2390 2391bool 2392Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2393 ImplicitConversionSequence ICS; 2394 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2395 OverloadingResult OvResult = 2396 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 2397 CandidateSet, false); 2398 if (OvResult == OR_Ambiguous) 2399 Diag(From->getSourceRange().getBegin(), 2400 diag::err_typecheck_ambiguous_condition) 2401 << From->getType() << ToType << From->getSourceRange(); 2402 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2403 Diag(From->getSourceRange().getBegin(), 2404 diag::err_typecheck_nonviable_condition) 2405 << From->getType() << ToType << From->getSourceRange(); 2406 else 2407 return false; 2408 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &From, 1); 2409 return true; 2410} 2411 2412/// CompareImplicitConversionSequences - Compare two implicit 2413/// conversion sequences to determine whether one is better than the 2414/// other or if they are indistinguishable (C++ 13.3.3.2). 2415static ImplicitConversionSequence::CompareKind 2416CompareImplicitConversionSequences(Sema &S, 2417 const ImplicitConversionSequence& ICS1, 2418 const ImplicitConversionSequence& ICS2) 2419{ 2420 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2421 // conversion sequences (as defined in 13.3.3.1) 2422 // -- a standard conversion sequence (13.3.3.1.1) is a better 2423 // conversion sequence than a user-defined conversion sequence or 2424 // an ellipsis conversion sequence, and 2425 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2426 // conversion sequence than an ellipsis conversion sequence 2427 // (13.3.3.1.3). 2428 // 2429 // C++0x [over.best.ics]p10: 2430 // For the purpose of ranking implicit conversion sequences as 2431 // described in 13.3.3.2, the ambiguous conversion sequence is 2432 // treated as a user-defined sequence that is indistinguishable 2433 // from any other user-defined conversion sequence. 2434 if (ICS1.getKindRank() < ICS2.getKindRank()) 2435 return ImplicitConversionSequence::Better; 2436 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2437 return ImplicitConversionSequence::Worse; 2438 2439 // The following checks require both conversion sequences to be of 2440 // the same kind. 2441 if (ICS1.getKind() != ICS2.getKind()) 2442 return ImplicitConversionSequence::Indistinguishable; 2443 2444 // Two implicit conversion sequences of the same form are 2445 // indistinguishable conversion sequences unless one of the 2446 // following rules apply: (C++ 13.3.3.2p3): 2447 if (ICS1.isStandard()) 2448 return CompareStandardConversionSequences(S, ICS1.Standard, ICS2.Standard); 2449 else if (ICS1.isUserDefined()) { 2450 // User-defined conversion sequence U1 is a better conversion 2451 // sequence than another user-defined conversion sequence U2 if 2452 // they contain the same user-defined conversion function or 2453 // constructor and if the second standard conversion sequence of 2454 // U1 is better than the second standard conversion sequence of 2455 // U2 (C++ 13.3.3.2p3). 2456 if (ICS1.UserDefined.ConversionFunction == 2457 ICS2.UserDefined.ConversionFunction) 2458 return CompareStandardConversionSequences(S, 2459 ICS1.UserDefined.After, 2460 ICS2.UserDefined.After); 2461 } 2462 2463 return ImplicitConversionSequence::Indistinguishable; 2464} 2465 2466static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2467 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2468 Qualifiers Quals; 2469 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2470 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2471 } 2472 2473 return Context.hasSameUnqualifiedType(T1, T2); 2474} 2475 2476// Per 13.3.3.2p3, compare the given standard conversion sequences to 2477// determine if one is a proper subset of the other. 2478static ImplicitConversionSequence::CompareKind 2479compareStandardConversionSubsets(ASTContext &Context, 2480 const StandardConversionSequence& SCS1, 2481 const StandardConversionSequence& SCS2) { 2482 ImplicitConversionSequence::CompareKind Result 2483 = ImplicitConversionSequence::Indistinguishable; 2484 2485 // the identity conversion sequence is considered to be a subsequence of 2486 // any non-identity conversion sequence 2487 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2488 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2489 return ImplicitConversionSequence::Better; 2490 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2491 return ImplicitConversionSequence::Worse; 2492 } 2493 2494 if (SCS1.Second != SCS2.Second) { 2495 if (SCS1.Second == ICK_Identity) 2496 Result = ImplicitConversionSequence::Better; 2497 else if (SCS2.Second == ICK_Identity) 2498 Result = ImplicitConversionSequence::Worse; 2499 else 2500 return ImplicitConversionSequence::Indistinguishable; 2501 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2502 return ImplicitConversionSequence::Indistinguishable; 2503 2504 if (SCS1.Third == SCS2.Third) { 2505 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2506 : ImplicitConversionSequence::Indistinguishable; 2507 } 2508 2509 if (SCS1.Third == ICK_Identity) 2510 return Result == ImplicitConversionSequence::Worse 2511 ? ImplicitConversionSequence::Indistinguishable 2512 : ImplicitConversionSequence::Better; 2513 2514 if (SCS2.Third == ICK_Identity) 2515 return Result == ImplicitConversionSequence::Better 2516 ? ImplicitConversionSequence::Indistinguishable 2517 : ImplicitConversionSequence::Worse; 2518 2519 return ImplicitConversionSequence::Indistinguishable; 2520} 2521 2522/// \brief Determine whether one of the given reference bindings is better 2523/// than the other based on what kind of bindings they are. 2524static bool isBetterReferenceBindingKind(const StandardConversionSequence &SCS1, 2525 const StandardConversionSequence &SCS2) { 2526 // C++0x [over.ics.rank]p3b4: 2527 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2528 // implicit object parameter of a non-static member function declared 2529 // without a ref-qualifier, and *either* S1 binds an rvalue reference 2530 // to an rvalue and S2 binds an lvalue reference *or S1 binds an 2531 // lvalue reference to a function lvalue and S2 binds an rvalue 2532 // reference*. 2533 // 2534 // FIXME: Rvalue references. We're going rogue with the above edits, 2535 // because the semantics in the current C++0x working paper (N3225 at the 2536 // time of this writing) break the standard definition of std::forward 2537 // and std::reference_wrapper when dealing with references to functions. 2538 // Proposed wording changes submitted to CWG for consideration. 2539 if (SCS1.BindsImplicitObjectArgumentWithoutRefQualifier || 2540 SCS2.BindsImplicitObjectArgumentWithoutRefQualifier) 2541 return false; 2542 2543 return (!SCS1.IsLvalueReference && SCS1.BindsToRvalue && 2544 SCS2.IsLvalueReference) || 2545 (SCS1.IsLvalueReference && SCS1.BindsToFunctionLvalue && 2546 !SCS2.IsLvalueReference); 2547} 2548 2549/// CompareStandardConversionSequences - Compare two standard 2550/// conversion sequences to determine whether one is better than the 2551/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2552static ImplicitConversionSequence::CompareKind 2553CompareStandardConversionSequences(Sema &S, 2554 const StandardConversionSequence& SCS1, 2555 const StandardConversionSequence& SCS2) 2556{ 2557 // Standard conversion sequence S1 is a better conversion sequence 2558 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2559 2560 // -- S1 is a proper subsequence of S2 (comparing the conversion 2561 // sequences in the canonical form defined by 13.3.3.1.1, 2562 // excluding any Lvalue Transformation; the identity conversion 2563 // sequence is considered to be a subsequence of any 2564 // non-identity conversion sequence) or, if not that, 2565 if (ImplicitConversionSequence::CompareKind CK 2566 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 2567 return CK; 2568 2569 // -- the rank of S1 is better than the rank of S2 (by the rules 2570 // defined below), or, if not that, 2571 ImplicitConversionRank Rank1 = SCS1.getRank(); 2572 ImplicitConversionRank Rank2 = SCS2.getRank(); 2573 if (Rank1 < Rank2) 2574 return ImplicitConversionSequence::Better; 2575 else if (Rank2 < Rank1) 2576 return ImplicitConversionSequence::Worse; 2577 2578 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2579 // are indistinguishable unless one of the following rules 2580 // applies: 2581 2582 // A conversion that is not a conversion of a pointer, or 2583 // pointer to member, to bool is better than another conversion 2584 // that is such a conversion. 2585 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2586 return SCS2.isPointerConversionToBool() 2587 ? ImplicitConversionSequence::Better 2588 : ImplicitConversionSequence::Worse; 2589 2590 // C++ [over.ics.rank]p4b2: 2591 // 2592 // If class B is derived directly or indirectly from class A, 2593 // conversion of B* to A* is better than conversion of B* to 2594 // void*, and conversion of A* to void* is better than conversion 2595 // of B* to void*. 2596 bool SCS1ConvertsToVoid 2597 = SCS1.isPointerConversionToVoidPointer(S.Context); 2598 bool SCS2ConvertsToVoid 2599 = SCS2.isPointerConversionToVoidPointer(S.Context); 2600 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2601 // Exactly one of the conversion sequences is a conversion to 2602 // a void pointer; it's the worse conversion. 2603 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2604 : ImplicitConversionSequence::Worse; 2605 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2606 // Neither conversion sequence converts to a void pointer; compare 2607 // their derived-to-base conversions. 2608 if (ImplicitConversionSequence::CompareKind DerivedCK 2609 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 2610 return DerivedCK; 2611 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2612 // Both conversion sequences are conversions to void 2613 // pointers. Compare the source types to determine if there's an 2614 // inheritance relationship in their sources. 2615 QualType FromType1 = SCS1.getFromType(); 2616 QualType FromType2 = SCS2.getFromType(); 2617 2618 // Adjust the types we're converting from via the array-to-pointer 2619 // conversion, if we need to. 2620 if (SCS1.First == ICK_Array_To_Pointer) 2621 FromType1 = S.Context.getArrayDecayedType(FromType1); 2622 if (SCS2.First == ICK_Array_To_Pointer) 2623 FromType2 = S.Context.getArrayDecayedType(FromType2); 2624 2625 QualType FromPointee1 2626 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2627 QualType FromPointee2 2628 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2629 2630 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2631 return ImplicitConversionSequence::Better; 2632 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2633 return ImplicitConversionSequence::Worse; 2634 2635 // Objective-C++: If one interface is more specific than the 2636 // other, it is the better one. 2637 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2638 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2639 if (FromIface1 && FromIface1) { 2640 if (S.Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2641 return ImplicitConversionSequence::Better; 2642 else if (S.Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2643 return ImplicitConversionSequence::Worse; 2644 } 2645 } 2646 2647 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2648 // bullet 3). 2649 if (ImplicitConversionSequence::CompareKind QualCK 2650 = CompareQualificationConversions(S, SCS1, SCS2)) 2651 return QualCK; 2652 2653 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2654 // Check for a better reference binding based on the kind of bindings. 2655 if (isBetterReferenceBindingKind(SCS1, SCS2)) 2656 return ImplicitConversionSequence::Better; 2657 else if (isBetterReferenceBindingKind(SCS2, SCS1)) 2658 return ImplicitConversionSequence::Worse; 2659 2660 // C++ [over.ics.rank]p3b4: 2661 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2662 // which the references refer are the same type except for 2663 // top-level cv-qualifiers, and the type to which the reference 2664 // initialized by S2 refers is more cv-qualified than the type 2665 // to which the reference initialized by S1 refers. 2666 QualType T1 = SCS1.getToType(2); 2667 QualType T2 = SCS2.getToType(2); 2668 T1 = S.Context.getCanonicalType(T1); 2669 T2 = S.Context.getCanonicalType(T2); 2670 Qualifiers T1Quals, T2Quals; 2671 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2672 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2673 if (UnqualT1 == UnqualT2) { 2674 // If the type is an array type, promote the element qualifiers to the 2675 // type for comparison. 2676 if (isa<ArrayType>(T1) && T1Quals) 2677 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2678 if (isa<ArrayType>(T2) && T2Quals) 2679 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2680 if (T2.isMoreQualifiedThan(T1)) 2681 return ImplicitConversionSequence::Better; 2682 else if (T1.isMoreQualifiedThan(T2)) 2683 return ImplicitConversionSequence::Worse; 2684 } 2685 } 2686 2687 return ImplicitConversionSequence::Indistinguishable; 2688} 2689 2690/// CompareQualificationConversions - Compares two standard conversion 2691/// sequences to determine whether they can be ranked based on their 2692/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2693ImplicitConversionSequence::CompareKind 2694CompareQualificationConversions(Sema &S, 2695 const StandardConversionSequence& SCS1, 2696 const StandardConversionSequence& SCS2) { 2697 // C++ 13.3.3.2p3: 2698 // -- S1 and S2 differ only in their qualification conversion and 2699 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2700 // cv-qualification signature of type T1 is a proper subset of 2701 // the cv-qualification signature of type T2, and S1 is not the 2702 // deprecated string literal array-to-pointer conversion (4.2). 2703 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2704 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2705 return ImplicitConversionSequence::Indistinguishable; 2706 2707 // FIXME: the example in the standard doesn't use a qualification 2708 // conversion (!) 2709 QualType T1 = SCS1.getToType(2); 2710 QualType T2 = SCS2.getToType(2); 2711 T1 = S.Context.getCanonicalType(T1); 2712 T2 = S.Context.getCanonicalType(T2); 2713 Qualifiers T1Quals, T2Quals; 2714 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2715 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2716 2717 // If the types are the same, we won't learn anything by unwrapped 2718 // them. 2719 if (UnqualT1 == UnqualT2) 2720 return ImplicitConversionSequence::Indistinguishable; 2721 2722 // If the type is an array type, promote the element qualifiers to the type 2723 // for comparison. 2724 if (isa<ArrayType>(T1) && T1Quals) 2725 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2726 if (isa<ArrayType>(T2) && T2Quals) 2727 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2728 2729 ImplicitConversionSequence::CompareKind Result 2730 = ImplicitConversionSequence::Indistinguishable; 2731 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 2732 // Within each iteration of the loop, we check the qualifiers to 2733 // determine if this still looks like a qualification 2734 // conversion. Then, if all is well, we unwrap one more level of 2735 // pointers or pointers-to-members and do it all again 2736 // until there are no more pointers or pointers-to-members left 2737 // to unwrap. This essentially mimics what 2738 // IsQualificationConversion does, but here we're checking for a 2739 // strict subset of qualifiers. 2740 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2741 // The qualifiers are the same, so this doesn't tell us anything 2742 // about how the sequences rank. 2743 ; 2744 else if (T2.isMoreQualifiedThan(T1)) { 2745 // T1 has fewer qualifiers, so it could be the better sequence. 2746 if (Result == ImplicitConversionSequence::Worse) 2747 // Neither has qualifiers that are a subset of the other's 2748 // qualifiers. 2749 return ImplicitConversionSequence::Indistinguishable; 2750 2751 Result = ImplicitConversionSequence::Better; 2752 } else if (T1.isMoreQualifiedThan(T2)) { 2753 // T2 has fewer qualifiers, so it could be the better sequence. 2754 if (Result == ImplicitConversionSequence::Better) 2755 // Neither has qualifiers that are a subset of the other's 2756 // qualifiers. 2757 return ImplicitConversionSequence::Indistinguishable; 2758 2759 Result = ImplicitConversionSequence::Worse; 2760 } else { 2761 // Qualifiers are disjoint. 2762 return ImplicitConversionSequence::Indistinguishable; 2763 } 2764 2765 // If the types after this point are equivalent, we're done. 2766 if (S.Context.hasSameUnqualifiedType(T1, T2)) 2767 break; 2768 } 2769 2770 // Check that the winning standard conversion sequence isn't using 2771 // the deprecated string literal array to pointer conversion. 2772 switch (Result) { 2773 case ImplicitConversionSequence::Better: 2774 if (SCS1.DeprecatedStringLiteralToCharPtr) 2775 Result = ImplicitConversionSequence::Indistinguishable; 2776 break; 2777 2778 case ImplicitConversionSequence::Indistinguishable: 2779 break; 2780 2781 case ImplicitConversionSequence::Worse: 2782 if (SCS2.DeprecatedStringLiteralToCharPtr) 2783 Result = ImplicitConversionSequence::Indistinguishable; 2784 break; 2785 } 2786 2787 return Result; 2788} 2789 2790/// CompareDerivedToBaseConversions - Compares two standard conversion 2791/// sequences to determine whether they can be ranked based on their 2792/// various kinds of derived-to-base conversions (C++ 2793/// [over.ics.rank]p4b3). As part of these checks, we also look at 2794/// conversions between Objective-C interface types. 2795ImplicitConversionSequence::CompareKind 2796CompareDerivedToBaseConversions(Sema &S, 2797 const StandardConversionSequence& SCS1, 2798 const StandardConversionSequence& SCS2) { 2799 QualType FromType1 = SCS1.getFromType(); 2800 QualType ToType1 = SCS1.getToType(1); 2801 QualType FromType2 = SCS2.getFromType(); 2802 QualType ToType2 = SCS2.getToType(1); 2803 2804 // Adjust the types we're converting from via the array-to-pointer 2805 // conversion, if we need to. 2806 if (SCS1.First == ICK_Array_To_Pointer) 2807 FromType1 = S.Context.getArrayDecayedType(FromType1); 2808 if (SCS2.First == ICK_Array_To_Pointer) 2809 FromType2 = S.Context.getArrayDecayedType(FromType2); 2810 2811 // Canonicalize all of the types. 2812 FromType1 = S.Context.getCanonicalType(FromType1); 2813 ToType1 = S.Context.getCanonicalType(ToType1); 2814 FromType2 = S.Context.getCanonicalType(FromType2); 2815 ToType2 = S.Context.getCanonicalType(ToType2); 2816 2817 // C++ [over.ics.rank]p4b3: 2818 // 2819 // If class B is derived directly or indirectly from class A and 2820 // class C is derived directly or indirectly from B, 2821 // 2822 // Compare based on pointer conversions. 2823 if (SCS1.Second == ICK_Pointer_Conversion && 2824 SCS2.Second == ICK_Pointer_Conversion && 2825 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2826 FromType1->isPointerType() && FromType2->isPointerType() && 2827 ToType1->isPointerType() && ToType2->isPointerType()) { 2828 QualType FromPointee1 2829 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2830 QualType ToPointee1 2831 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2832 QualType FromPointee2 2833 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2834 QualType ToPointee2 2835 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2836 2837 // -- conversion of C* to B* is better than conversion of C* to A*, 2838 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2839 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2840 return ImplicitConversionSequence::Better; 2841 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2842 return ImplicitConversionSequence::Worse; 2843 } 2844 2845 // -- conversion of B* to A* is better than conversion of C* to A*, 2846 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2847 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2848 return ImplicitConversionSequence::Better; 2849 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2850 return ImplicitConversionSequence::Worse; 2851 } 2852 } else if (SCS1.Second == ICK_Pointer_Conversion && 2853 SCS2.Second == ICK_Pointer_Conversion) { 2854 const ObjCObjectPointerType *FromPtr1 2855 = FromType1->getAs<ObjCObjectPointerType>(); 2856 const ObjCObjectPointerType *FromPtr2 2857 = FromType2->getAs<ObjCObjectPointerType>(); 2858 const ObjCObjectPointerType *ToPtr1 2859 = ToType1->getAs<ObjCObjectPointerType>(); 2860 const ObjCObjectPointerType *ToPtr2 2861 = ToType2->getAs<ObjCObjectPointerType>(); 2862 2863 if (FromPtr1 && FromPtr2 && ToPtr1 && ToPtr2) { 2864 // Apply the same conversion ranking rules for Objective-C pointer types 2865 // that we do for C++ pointers to class types. However, we employ the 2866 // Objective-C pseudo-subtyping relationship used for assignment of 2867 // Objective-C pointer types. 2868 bool FromAssignLeft 2869 = S.Context.canAssignObjCInterfaces(FromPtr1, FromPtr2); 2870 bool FromAssignRight 2871 = S.Context.canAssignObjCInterfaces(FromPtr2, FromPtr1); 2872 bool ToAssignLeft 2873 = S.Context.canAssignObjCInterfaces(ToPtr1, ToPtr2); 2874 bool ToAssignRight 2875 = S.Context.canAssignObjCInterfaces(ToPtr2, ToPtr1); 2876 2877 // A conversion to an a non-id object pointer type or qualified 'id' 2878 // type is better than a conversion to 'id'. 2879 if (ToPtr1->isObjCIdType() && 2880 (ToPtr2->isObjCQualifiedIdType() || ToPtr2->getInterfaceDecl())) 2881 return ImplicitConversionSequence::Worse; 2882 if (ToPtr2->isObjCIdType() && 2883 (ToPtr1->isObjCQualifiedIdType() || ToPtr1->getInterfaceDecl())) 2884 return ImplicitConversionSequence::Better; 2885 2886 // A conversion to a non-id object pointer type is better than a 2887 // conversion to a qualified 'id' type 2888 if (ToPtr1->isObjCQualifiedIdType() && ToPtr2->getInterfaceDecl()) 2889 return ImplicitConversionSequence::Worse; 2890 if (ToPtr2->isObjCQualifiedIdType() && ToPtr1->getInterfaceDecl()) 2891 return ImplicitConversionSequence::Better; 2892 2893 // A conversion to an a non-Class object pointer type or qualified 'Class' 2894 // type is better than a conversion to 'Class'. 2895 if (ToPtr1->isObjCClassType() && 2896 (ToPtr2->isObjCQualifiedClassType() || ToPtr2->getInterfaceDecl())) 2897 return ImplicitConversionSequence::Worse; 2898 if (ToPtr2->isObjCClassType() && 2899 (ToPtr1->isObjCQualifiedClassType() || ToPtr1->getInterfaceDecl())) 2900 return ImplicitConversionSequence::Better; 2901 2902 // A conversion to a non-Class object pointer type is better than a 2903 // conversion to a qualified 'Class' type. 2904 if (ToPtr1->isObjCQualifiedClassType() && ToPtr2->getInterfaceDecl()) 2905 return ImplicitConversionSequence::Worse; 2906 if (ToPtr2->isObjCQualifiedClassType() && ToPtr1->getInterfaceDecl()) 2907 return ImplicitConversionSequence::Better; 2908 2909 // -- "conversion of C* to B* is better than conversion of C* to A*," 2910 if (S.Context.hasSameType(FromType1, FromType2) && 2911 !FromPtr1->isObjCIdType() && !FromPtr1->isObjCClassType() && 2912 (ToAssignLeft != ToAssignRight)) 2913 return ToAssignLeft? ImplicitConversionSequence::Worse 2914 : ImplicitConversionSequence::Better; 2915 2916 // -- "conversion of B* to A* is better than conversion of C* to A*," 2917 if (S.Context.hasSameUnqualifiedType(ToType1, ToType2) && 2918 (FromAssignLeft != FromAssignRight)) 2919 return FromAssignLeft? ImplicitConversionSequence::Better 2920 : ImplicitConversionSequence::Worse; 2921 } 2922 } 2923 2924 // Ranking of member-pointer types. 2925 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2926 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2927 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2928 const MemberPointerType * FromMemPointer1 = 2929 FromType1->getAs<MemberPointerType>(); 2930 const MemberPointerType * ToMemPointer1 = 2931 ToType1->getAs<MemberPointerType>(); 2932 const MemberPointerType * FromMemPointer2 = 2933 FromType2->getAs<MemberPointerType>(); 2934 const MemberPointerType * ToMemPointer2 = 2935 ToType2->getAs<MemberPointerType>(); 2936 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2937 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2938 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2939 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2940 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2941 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2942 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2943 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2944 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2945 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2946 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2947 return ImplicitConversionSequence::Worse; 2948 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2949 return ImplicitConversionSequence::Better; 2950 } 2951 // conversion of B::* to C::* is better than conversion of A::* to C::* 2952 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2953 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2954 return ImplicitConversionSequence::Better; 2955 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2956 return ImplicitConversionSequence::Worse; 2957 } 2958 } 2959 2960 if (SCS1.Second == ICK_Derived_To_Base) { 2961 // -- conversion of C to B is better than conversion of C to A, 2962 // -- binding of an expression of type C to a reference of type 2963 // B& is better than binding an expression of type C to a 2964 // reference of type A&, 2965 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2966 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2967 if (S.IsDerivedFrom(ToType1, ToType2)) 2968 return ImplicitConversionSequence::Better; 2969 else if (S.IsDerivedFrom(ToType2, ToType1)) 2970 return ImplicitConversionSequence::Worse; 2971 } 2972 2973 // -- conversion of B to A is better than conversion of C to A. 2974 // -- binding of an expression of type B to a reference of type 2975 // A& is better than binding an expression of type C to a 2976 // reference of type A&, 2977 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2978 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2979 if (S.IsDerivedFrom(FromType2, FromType1)) 2980 return ImplicitConversionSequence::Better; 2981 else if (S.IsDerivedFrom(FromType1, FromType2)) 2982 return ImplicitConversionSequence::Worse; 2983 } 2984 } 2985 2986 return ImplicitConversionSequence::Indistinguishable; 2987} 2988 2989/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2990/// determine whether they are reference-related, 2991/// reference-compatible, reference-compatible with added 2992/// qualification, or incompatible, for use in C++ initialization by 2993/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2994/// type, and the first type (T1) is the pointee type of the reference 2995/// type being initialized. 2996Sema::ReferenceCompareResult 2997Sema::CompareReferenceRelationship(SourceLocation Loc, 2998 QualType OrigT1, QualType OrigT2, 2999 bool &DerivedToBase, 3000 bool &ObjCConversion) { 3001 assert(!OrigT1->isReferenceType() && 3002 "T1 must be the pointee type of the reference type"); 3003 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 3004 3005 QualType T1 = Context.getCanonicalType(OrigT1); 3006 QualType T2 = Context.getCanonicalType(OrigT2); 3007 Qualifiers T1Quals, T2Quals; 3008 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 3009 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 3010 3011 // C++ [dcl.init.ref]p4: 3012 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 3013 // reference-related to "cv2 T2" if T1 is the same type as T2, or 3014 // T1 is a base class of T2. 3015 DerivedToBase = false; 3016 ObjCConversion = false; 3017 if (UnqualT1 == UnqualT2) { 3018 // Nothing to do. 3019 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 3020 IsDerivedFrom(UnqualT2, UnqualT1)) 3021 DerivedToBase = true; 3022 else if (UnqualT1->isObjCObjectOrInterfaceType() && 3023 UnqualT2->isObjCObjectOrInterfaceType() && 3024 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 3025 ObjCConversion = true; 3026 else 3027 return Ref_Incompatible; 3028 3029 // At this point, we know that T1 and T2 are reference-related (at 3030 // least). 3031 3032 // If the type is an array type, promote the element qualifiers to the type 3033 // for comparison. 3034 if (isa<ArrayType>(T1) && T1Quals) 3035 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 3036 if (isa<ArrayType>(T2) && T2Quals) 3037 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 3038 3039 // C++ [dcl.init.ref]p4: 3040 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 3041 // reference-related to T2 and cv1 is the same cv-qualification 3042 // as, or greater cv-qualification than, cv2. For purposes of 3043 // overload resolution, cases for which cv1 is greater 3044 // cv-qualification than cv2 are identified as 3045 // reference-compatible with added qualification (see 13.3.3.2). 3046 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 3047 return Ref_Compatible; 3048 else if (T1.isMoreQualifiedThan(T2)) 3049 return Ref_Compatible_With_Added_Qualification; 3050 else 3051 return Ref_Related; 3052} 3053 3054/// \brief Look for a user-defined conversion to an value reference-compatible 3055/// with DeclType. Return true if something definite is found. 3056static bool 3057FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 3058 QualType DeclType, SourceLocation DeclLoc, 3059 Expr *Init, QualType T2, bool AllowRvalues, 3060 bool AllowExplicit) { 3061 assert(T2->isRecordType() && "Can only find conversions of record types."); 3062 CXXRecordDecl *T2RecordDecl 3063 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 3064 3065 OverloadCandidateSet CandidateSet(DeclLoc); 3066 const UnresolvedSetImpl *Conversions 3067 = T2RecordDecl->getVisibleConversionFunctions(); 3068 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3069 E = Conversions->end(); I != E; ++I) { 3070 NamedDecl *D = *I; 3071 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 3072 if (isa<UsingShadowDecl>(D)) 3073 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 3074 3075 FunctionTemplateDecl *ConvTemplate 3076 = dyn_cast<FunctionTemplateDecl>(D); 3077 CXXConversionDecl *Conv; 3078 if (ConvTemplate) 3079 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 3080 else 3081 Conv = cast<CXXConversionDecl>(D); 3082 3083 // If this is an explicit conversion, and we're not allowed to consider 3084 // explicit conversions, skip it. 3085 if (!AllowExplicit && Conv->isExplicit()) 3086 continue; 3087 3088 if (AllowRvalues) { 3089 bool DerivedToBase = false; 3090 bool ObjCConversion = false; 3091 if (!ConvTemplate && 3092 S.CompareReferenceRelationship( 3093 DeclLoc, 3094 Conv->getConversionType().getNonReferenceType() 3095 .getUnqualifiedType(), 3096 DeclType.getNonReferenceType().getUnqualifiedType(), 3097 DerivedToBase, ObjCConversion) == 3098 Sema::Ref_Incompatible) 3099 continue; 3100 } else { 3101 // If the conversion function doesn't return a reference type, 3102 // it can't be considered for this conversion. An rvalue reference 3103 // is only acceptable if its referencee is a function type. 3104 3105 const ReferenceType *RefType = 3106 Conv->getConversionType()->getAs<ReferenceType>(); 3107 if (!RefType || 3108 (!RefType->isLValueReferenceType() && 3109 !RefType->getPointeeType()->isFunctionType())) 3110 continue; 3111 } 3112 3113 if (ConvTemplate) 3114 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 3115 Init, DeclType, CandidateSet); 3116 else 3117 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 3118 DeclType, CandidateSet); 3119 } 3120 3121 OverloadCandidateSet::iterator Best; 3122 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best, true)) { 3123 case OR_Success: 3124 // C++ [over.ics.ref]p1: 3125 // 3126 // [...] If the parameter binds directly to the result of 3127 // applying a conversion function to the argument 3128 // expression, the implicit conversion sequence is a 3129 // user-defined conversion sequence (13.3.3.1.2), with the 3130 // second standard conversion sequence either an identity 3131 // conversion or, if the conversion function returns an 3132 // entity of a type that is a derived class of the parameter 3133 // type, a derived-to-base Conversion. 3134 if (!Best->FinalConversion.DirectBinding) 3135 return false; 3136 3137 if (Best->Function) 3138 S.MarkDeclarationReferenced(DeclLoc, Best->Function); 3139 ICS.setUserDefined(); 3140 ICS.UserDefined.Before = Best->Conversions[0].Standard; 3141 ICS.UserDefined.After = Best->FinalConversion; 3142 ICS.UserDefined.ConversionFunction = Best->Function; 3143 ICS.UserDefined.FoundConversionFunction = Best->FoundDecl.getDecl(); 3144 ICS.UserDefined.EllipsisConversion = false; 3145 assert(ICS.UserDefined.After.ReferenceBinding && 3146 ICS.UserDefined.After.DirectBinding && 3147 "Expected a direct reference binding!"); 3148 return true; 3149 3150 case OR_Ambiguous: 3151 ICS.setAmbiguous(); 3152 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 3153 Cand != CandidateSet.end(); ++Cand) 3154 if (Cand->Viable) 3155 ICS.Ambiguous.addConversion(Cand->Function); 3156 return true; 3157 3158 case OR_No_Viable_Function: 3159 case OR_Deleted: 3160 // There was no suitable conversion, or we found a deleted 3161 // conversion; continue with other checks. 3162 return false; 3163 } 3164 3165 return false; 3166} 3167 3168/// \brief Compute an implicit conversion sequence for reference 3169/// initialization. 3170static ImplicitConversionSequence 3171TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 3172 SourceLocation DeclLoc, 3173 bool SuppressUserConversions, 3174 bool AllowExplicit) { 3175 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 3176 3177 // Most paths end in a failed conversion. 3178 ImplicitConversionSequence ICS; 3179 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3180 3181 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 3182 QualType T2 = Init->getType(); 3183 3184 // If the initializer is the address of an overloaded function, try 3185 // to resolve the overloaded function. If all goes well, T2 is the 3186 // type of the resulting function. 3187 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 3188 DeclAccessPair Found; 3189 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 3190 false, Found)) 3191 T2 = Fn->getType(); 3192 } 3193 3194 // Compute some basic properties of the types and the initializer. 3195 bool isRValRef = DeclType->isRValueReferenceType(); 3196 bool DerivedToBase = false; 3197 bool ObjCConversion = false; 3198 Expr::Classification InitCategory = Init->Classify(S.Context); 3199 Sema::ReferenceCompareResult RefRelationship 3200 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 3201 ObjCConversion); 3202 3203 3204 // C++0x [dcl.init.ref]p5: 3205 // A reference to type "cv1 T1" is initialized by an expression 3206 // of type "cv2 T2" as follows: 3207 3208 // -- If reference is an lvalue reference and the initializer expression 3209 if (!isRValRef) { 3210 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 3211 // reference-compatible with "cv2 T2," or 3212 // 3213 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 3214 if (InitCategory.isLValue() && 3215 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 3216 // C++ [over.ics.ref]p1: 3217 // When a parameter of reference type binds directly (8.5.3) 3218 // to an argument expression, the implicit conversion sequence 3219 // is the identity conversion, unless the argument expression 3220 // has a type that is a derived class of the parameter type, 3221 // in which case the implicit conversion sequence is a 3222 // derived-to-base Conversion (13.3.3.1). 3223 ICS.setStandard(); 3224 ICS.Standard.First = ICK_Identity; 3225 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3226 : ObjCConversion? ICK_Compatible_Conversion 3227 : ICK_Identity; 3228 ICS.Standard.Third = ICK_Identity; 3229 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3230 ICS.Standard.setToType(0, T2); 3231 ICS.Standard.setToType(1, T1); 3232 ICS.Standard.setToType(2, T1); 3233 ICS.Standard.ReferenceBinding = true; 3234 ICS.Standard.DirectBinding = true; 3235 ICS.Standard.IsLvalueReference = !isRValRef; 3236 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3237 ICS.Standard.BindsToRvalue = false; 3238 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3239 ICS.Standard.CopyConstructor = 0; 3240 3241 // Nothing more to do: the inaccessibility/ambiguity check for 3242 // derived-to-base conversions is suppressed when we're 3243 // computing the implicit conversion sequence (C++ 3244 // [over.best.ics]p2). 3245 return ICS; 3246 } 3247 3248 // -- has a class type (i.e., T2 is a class type), where T1 is 3249 // not reference-related to T2, and can be implicitly 3250 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 3251 // is reference-compatible with "cv3 T3" 92) (this 3252 // conversion is selected by enumerating the applicable 3253 // conversion functions (13.3.1.6) and choosing the best 3254 // one through overload resolution (13.3)), 3255 if (!SuppressUserConversions && T2->isRecordType() && 3256 !S.RequireCompleteType(DeclLoc, T2, 0) && 3257 RefRelationship == Sema::Ref_Incompatible) { 3258 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3259 Init, T2, /*AllowRvalues=*/false, 3260 AllowExplicit)) 3261 return ICS; 3262 } 3263 } 3264 3265 // -- Otherwise, the reference shall be an lvalue reference to a 3266 // non-volatile const type (i.e., cv1 shall be const), or the reference 3267 // shall be an rvalue reference. 3268 // 3269 // We actually handle one oddity of C++ [over.ics.ref] at this 3270 // point, which is that, due to p2 (which short-circuits reference 3271 // binding by only attempting a simple conversion for non-direct 3272 // bindings) and p3's strange wording, we allow a const volatile 3273 // reference to bind to an rvalue. Hence the check for the presence 3274 // of "const" rather than checking for "const" being the only 3275 // qualifier. 3276 // This is also the point where rvalue references and lvalue inits no longer 3277 // go together. 3278 if (!isRValRef && !T1.isConstQualified()) 3279 return ICS; 3280 3281 // -- If the initializer expression 3282 // 3283 // -- is an xvalue, class prvalue, array prvalue or function 3284 // lvalue and "cv1T1" is reference-compatible with "cv2 T2", or 3285 if (RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification && 3286 (InitCategory.isXValue() || 3287 (InitCategory.isPRValue() && (T2->isRecordType() || T2->isArrayType())) || 3288 (InitCategory.isLValue() && T2->isFunctionType()))) { 3289 ICS.setStandard(); 3290 ICS.Standard.First = ICK_Identity; 3291 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 3292 : ObjCConversion? ICK_Compatible_Conversion 3293 : ICK_Identity; 3294 ICS.Standard.Third = ICK_Identity; 3295 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 3296 ICS.Standard.setToType(0, T2); 3297 ICS.Standard.setToType(1, T1); 3298 ICS.Standard.setToType(2, T1); 3299 ICS.Standard.ReferenceBinding = true; 3300 // In C++0x, this is always a direct binding. In C++98/03, it's a direct 3301 // binding unless we're binding to a class prvalue. 3302 // Note: Although xvalues wouldn't normally show up in C++98/03 code, we 3303 // allow the use of rvalue references in C++98/03 for the benefit of 3304 // standard library implementors; therefore, we need the xvalue check here. 3305 ICS.Standard.DirectBinding = 3306 S.getLangOptions().CPlusPlus0x || 3307 (InitCategory.isPRValue() && !T2->isRecordType()); 3308 ICS.Standard.IsLvalueReference = !isRValRef; 3309 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3310 ICS.Standard.BindsToRvalue = InitCategory.isRValue(); 3311 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3312 ICS.Standard.CopyConstructor = 0; 3313 return ICS; 3314 } 3315 3316 // -- has a class type (i.e., T2 is a class type), where T1 is not 3317 // reference-related to T2, and can be implicitly converted to 3318 // an xvalue, class prvalue, or function lvalue of type 3319 // "cv3 T3", where "cv1 T1" is reference-compatible with 3320 // "cv3 T3", 3321 // 3322 // then the reference is bound to the value of the initializer 3323 // expression in the first case and to the result of the conversion 3324 // in the second case (or, in either case, to an appropriate base 3325 // class subobject). 3326 if (!SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3327 T2->isRecordType() && !S.RequireCompleteType(DeclLoc, T2, 0) && 3328 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 3329 Init, T2, /*AllowRvalues=*/true, 3330 AllowExplicit)) { 3331 // In the second case, if the reference is an rvalue reference 3332 // and the second standard conversion sequence of the 3333 // user-defined conversion sequence includes an lvalue-to-rvalue 3334 // conversion, the program is ill-formed. 3335 if (ICS.isUserDefined() && isRValRef && 3336 ICS.UserDefined.After.First == ICK_Lvalue_To_Rvalue) 3337 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 3338 3339 return ICS; 3340 } 3341 3342 // -- Otherwise, a temporary of type "cv1 T1" is created and 3343 // initialized from the initializer expression using the 3344 // rules for a non-reference copy initialization (8.5). The 3345 // reference is then bound to the temporary. If T1 is 3346 // reference-related to T2, cv1 must be the same 3347 // cv-qualification as, or greater cv-qualification than, 3348 // cv2; otherwise, the program is ill-formed. 3349 if (RefRelationship == Sema::Ref_Related) { 3350 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 3351 // we would be reference-compatible or reference-compatible with 3352 // added qualification. But that wasn't the case, so the reference 3353 // initialization fails. 3354 return ICS; 3355 } 3356 3357 // If at least one of the types is a class type, the types are not 3358 // related, and we aren't allowed any user conversions, the 3359 // reference binding fails. This case is important for breaking 3360 // recursion, since TryImplicitConversion below will attempt to 3361 // create a temporary through the use of a copy constructor. 3362 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3363 (T1->isRecordType() || T2->isRecordType())) 3364 return ICS; 3365 3366 // If T1 is reference-related to T2 and the reference is an rvalue 3367 // reference, the initializer expression shall not be an lvalue. 3368 if (RefRelationship >= Sema::Ref_Related && 3369 isRValRef && Init->Classify(S.Context).isLValue()) 3370 return ICS; 3371 3372 // C++ [over.ics.ref]p2: 3373 // When a parameter of reference type is not bound directly to 3374 // an argument expression, the conversion sequence is the one 3375 // required to convert the argument expression to the 3376 // underlying type of the reference according to 3377 // 13.3.3.1. Conceptually, this conversion sequence corresponds 3378 // to copy-initializing a temporary of the underlying type with 3379 // the argument expression. Any difference in top-level 3380 // cv-qualification is subsumed by the initialization itself 3381 // and does not constitute a conversion. 3382 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 3383 /*AllowExplicit=*/false, 3384 /*InOverloadResolution=*/false, 3385 /*CStyle=*/false); 3386 3387 // Of course, that's still a reference binding. 3388 if (ICS.isStandard()) { 3389 ICS.Standard.ReferenceBinding = true; 3390 ICS.Standard.IsLvalueReference = !isRValRef; 3391 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3392 ICS.Standard.BindsToRvalue = true; 3393 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3394 } else if (ICS.isUserDefined()) { 3395 ICS.UserDefined.After.ReferenceBinding = true; 3396 ICS.Standard.IsLvalueReference = !isRValRef; 3397 ICS.Standard.BindsToFunctionLvalue = T2->isFunctionType(); 3398 ICS.Standard.BindsToRvalue = true; 3399 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier = false; 3400 } 3401 3402 return ICS; 3403} 3404 3405/// TryCopyInitialization - Try to copy-initialize a value of type 3406/// ToType from the expression From. Return the implicit conversion 3407/// sequence required to pass this argument, which may be a bad 3408/// conversion sequence (meaning that the argument cannot be passed to 3409/// a parameter of this type). If @p SuppressUserConversions, then we 3410/// do not permit any user-defined conversion sequences. 3411static ImplicitConversionSequence 3412TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 3413 bool SuppressUserConversions, 3414 bool InOverloadResolution) { 3415 if (ToType->isReferenceType()) 3416 return TryReferenceInit(S, From, ToType, 3417 /*FIXME:*/From->getLocStart(), 3418 SuppressUserConversions, 3419 /*AllowExplicit=*/false); 3420 3421 return TryImplicitConversion(S, From, ToType, 3422 SuppressUserConversions, 3423 /*AllowExplicit=*/false, 3424 InOverloadResolution, 3425 /*CStyle=*/false); 3426} 3427 3428/// TryObjectArgumentInitialization - Try to initialize the object 3429/// parameter of the given member function (@c Method) from the 3430/// expression @p From. 3431static ImplicitConversionSequence 3432TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 3433 Expr::Classification FromClassification, 3434 CXXMethodDecl *Method, 3435 CXXRecordDecl *ActingContext) { 3436 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 3437 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 3438 // const volatile object. 3439 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 3440 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 3441 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 3442 3443 // Set up the conversion sequence as a "bad" conversion, to allow us 3444 // to exit early. 3445 ImplicitConversionSequence ICS; 3446 3447 // We need to have an object of class type. 3448 QualType FromType = OrigFromType; 3449 if (const PointerType *PT = FromType->getAs<PointerType>()) { 3450 FromType = PT->getPointeeType(); 3451 3452 // When we had a pointer, it's implicitly dereferenced, so we 3453 // better have an lvalue. 3454 assert(FromClassification.isLValue()); 3455 } 3456 3457 assert(FromType->isRecordType()); 3458 3459 // C++0x [over.match.funcs]p4: 3460 // For non-static member functions, the type of the implicit object 3461 // parameter is 3462 // 3463 // - "lvalue reference to cv X" for functions declared without a 3464 // ref-qualifier or with the & ref-qualifier 3465 // - "rvalue reference to cv X" for functions declared with the && 3466 // ref-qualifier 3467 // 3468 // where X is the class of which the function is a member and cv is the 3469 // cv-qualification on the member function declaration. 3470 // 3471 // However, when finding an implicit conversion sequence for the argument, we 3472 // are not allowed to create temporaries or perform user-defined conversions 3473 // (C++ [over.match.funcs]p5). We perform a simplified version of 3474 // reference binding here, that allows class rvalues to bind to 3475 // non-constant references. 3476 3477 // First check the qualifiers. 3478 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 3479 if (ImplicitParamType.getCVRQualifiers() 3480 != FromTypeCanon.getLocalCVRQualifiers() && 3481 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 3482 ICS.setBad(BadConversionSequence::bad_qualifiers, 3483 OrigFromType, ImplicitParamType); 3484 return ICS; 3485 } 3486 3487 // Check that we have either the same type or a derived type. It 3488 // affects the conversion rank. 3489 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 3490 ImplicitConversionKind SecondKind; 3491 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 3492 SecondKind = ICK_Identity; 3493 } else if (S.IsDerivedFrom(FromType, ClassType)) 3494 SecondKind = ICK_Derived_To_Base; 3495 else { 3496 ICS.setBad(BadConversionSequence::unrelated_class, 3497 FromType, ImplicitParamType); 3498 return ICS; 3499 } 3500 3501 // Check the ref-qualifier. 3502 switch (Method->getRefQualifier()) { 3503 case RQ_None: 3504 // Do nothing; we don't care about lvalueness or rvalueness. 3505 break; 3506 3507 case RQ_LValue: 3508 if (!FromClassification.isLValue() && Quals != Qualifiers::Const) { 3509 // non-const lvalue reference cannot bind to an rvalue 3510 ICS.setBad(BadConversionSequence::lvalue_ref_to_rvalue, FromType, 3511 ImplicitParamType); 3512 return ICS; 3513 } 3514 break; 3515 3516 case RQ_RValue: 3517 if (!FromClassification.isRValue()) { 3518 // rvalue reference cannot bind to an lvalue 3519 ICS.setBad(BadConversionSequence::rvalue_ref_to_lvalue, FromType, 3520 ImplicitParamType); 3521 return ICS; 3522 } 3523 break; 3524 } 3525 3526 // Success. Mark this as a reference binding. 3527 ICS.setStandard(); 3528 ICS.Standard.setAsIdentityConversion(); 3529 ICS.Standard.Second = SecondKind; 3530 ICS.Standard.setFromType(FromType); 3531 ICS.Standard.setAllToTypes(ImplicitParamType); 3532 ICS.Standard.ReferenceBinding = true; 3533 ICS.Standard.DirectBinding = true; 3534 ICS.Standard.IsLvalueReference = Method->getRefQualifier() != RQ_RValue; 3535 ICS.Standard.BindsToFunctionLvalue = false; 3536 ICS.Standard.BindsToRvalue = FromClassification.isRValue(); 3537 ICS.Standard.BindsImplicitObjectArgumentWithoutRefQualifier 3538 = (Method->getRefQualifier() == RQ_None); 3539 return ICS; 3540} 3541 3542/// PerformObjectArgumentInitialization - Perform initialization of 3543/// the implicit object parameter for the given Method with the given 3544/// expression. 3545ExprResult 3546Sema::PerformObjectArgumentInitialization(Expr *From, 3547 NestedNameSpecifier *Qualifier, 3548 NamedDecl *FoundDecl, 3549 CXXMethodDecl *Method) { 3550 QualType FromRecordType, DestType; 3551 QualType ImplicitParamRecordType = 3552 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3553 3554 Expr::Classification FromClassification; 3555 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3556 FromRecordType = PT->getPointeeType(); 3557 DestType = Method->getThisType(Context); 3558 FromClassification = Expr::Classification::makeSimpleLValue(); 3559 } else { 3560 FromRecordType = From->getType(); 3561 DestType = ImplicitParamRecordType; 3562 FromClassification = From->Classify(Context); 3563 } 3564 3565 // Note that we always use the true parent context when performing 3566 // the actual argument initialization. 3567 ImplicitConversionSequence ICS 3568 = TryObjectArgumentInitialization(*this, From->getType(), FromClassification, 3569 Method, Method->getParent()); 3570 if (ICS.isBad()) { 3571 if (ICS.Bad.Kind == BadConversionSequence::bad_qualifiers) { 3572 Qualifiers FromQs = FromRecordType.getQualifiers(); 3573 Qualifiers ToQs = DestType.getQualifiers(); 3574 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 3575 if (CVR) { 3576 Diag(From->getSourceRange().getBegin(), 3577 diag::err_member_function_call_bad_cvr) 3578 << Method->getDeclName() << FromRecordType << (CVR - 1) 3579 << From->getSourceRange(); 3580 Diag(Method->getLocation(), diag::note_previous_decl) 3581 << Method->getDeclName(); 3582 return ExprError(); 3583 } 3584 } 3585 3586 return Diag(From->getSourceRange().getBegin(), 3587 diag::err_implicit_object_parameter_init) 3588 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3589 } 3590 3591 if (ICS.Standard.Second == ICK_Derived_To_Base) { 3592 ExprResult FromRes = 3593 PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3594 if (FromRes.isInvalid()) 3595 return ExprError(); 3596 From = FromRes.take(); 3597 } 3598 3599 if (!Context.hasSameType(From->getType(), DestType)) 3600 From = ImpCastExprToType(From, DestType, CK_NoOp, 3601 From->getType()->isPointerType() ? VK_RValue : VK_LValue).take(); 3602 return Owned(From); 3603} 3604 3605/// TryContextuallyConvertToBool - Attempt to contextually convert the 3606/// expression From to bool (C++0x [conv]p3). 3607static ImplicitConversionSequence 3608TryContextuallyConvertToBool(Sema &S, Expr *From) { 3609 // FIXME: This is pretty broken. 3610 return TryImplicitConversion(S, From, S.Context.BoolTy, 3611 // FIXME: Are these flags correct? 3612 /*SuppressUserConversions=*/false, 3613 /*AllowExplicit=*/true, 3614 /*InOverloadResolution=*/false, 3615 /*CStyle=*/false); 3616} 3617 3618/// PerformContextuallyConvertToBool - Perform a contextual conversion 3619/// of the expression From to bool (C++0x [conv]p3). 3620ExprResult Sema::PerformContextuallyConvertToBool(Expr *From) { 3621 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 3622 if (!ICS.isBad()) 3623 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3624 3625 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3626 return Diag(From->getSourceRange().getBegin(), 3627 diag::err_typecheck_bool_condition) 3628 << From->getType() << From->getSourceRange(); 3629 return ExprError(); 3630} 3631 3632/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3633/// expression From to 'id'. 3634static ImplicitConversionSequence 3635TryContextuallyConvertToObjCId(Sema &S, Expr *From) { 3636 QualType Ty = S.Context.getObjCIdType(); 3637 return TryImplicitConversion(S, From, Ty, 3638 // FIXME: Are these flags correct? 3639 /*SuppressUserConversions=*/false, 3640 /*AllowExplicit=*/true, 3641 /*InOverloadResolution=*/false, 3642 /*CStyle=*/false); 3643} 3644 3645/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3646/// of the expression From to 'id'. 3647ExprResult Sema::PerformContextuallyConvertToObjCId(Expr *From) { 3648 QualType Ty = Context.getObjCIdType(); 3649 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(*this, From); 3650 if (!ICS.isBad()) 3651 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3652 return ExprError(); 3653} 3654 3655/// \brief Attempt to convert the given expression to an integral or 3656/// enumeration type. 3657/// 3658/// This routine will attempt to convert an expression of class type to an 3659/// integral or enumeration type, if that class type only has a single 3660/// conversion to an integral or enumeration type. 3661/// 3662/// \param Loc The source location of the construct that requires the 3663/// conversion. 3664/// 3665/// \param FromE The expression we're converting from. 3666/// 3667/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3668/// have integral or enumeration type. 3669/// 3670/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3671/// incomplete class type. 3672/// 3673/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3674/// explicit conversion function (because no implicit conversion functions 3675/// were available). This is a recovery mode. 3676/// 3677/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3678/// showing which conversion was picked. 3679/// 3680/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3681/// conversion function that could convert to integral or enumeration type. 3682/// 3683/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3684/// usable conversion function. 3685/// 3686/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3687/// function, which may be an extension in this case. 3688/// 3689/// \returns The expression, converted to an integral or enumeration type if 3690/// successful. 3691ExprResult 3692Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 3693 const PartialDiagnostic &NotIntDiag, 3694 const PartialDiagnostic &IncompleteDiag, 3695 const PartialDiagnostic &ExplicitConvDiag, 3696 const PartialDiagnostic &ExplicitConvNote, 3697 const PartialDiagnostic &AmbigDiag, 3698 const PartialDiagnostic &AmbigNote, 3699 const PartialDiagnostic &ConvDiag) { 3700 // We can't perform any more checking for type-dependent expressions. 3701 if (From->isTypeDependent()) 3702 return Owned(From); 3703 3704 // If the expression already has integral or enumeration type, we're golden. 3705 QualType T = From->getType(); 3706 if (T->isIntegralOrEnumerationType()) 3707 return Owned(From); 3708 3709 // FIXME: Check for missing '()' if T is a function type? 3710 3711 // If we don't have a class type in C++, there's no way we can get an 3712 // expression of integral or enumeration type. 3713 const RecordType *RecordTy = T->getAs<RecordType>(); 3714 if (!RecordTy || !getLangOptions().CPlusPlus) { 3715 Diag(Loc, NotIntDiag) 3716 << T << From->getSourceRange(); 3717 return Owned(From); 3718 } 3719 3720 // We must have a complete class type. 3721 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3722 return Owned(From); 3723 3724 // Look for a conversion to an integral or enumeration type. 3725 UnresolvedSet<4> ViableConversions; 3726 UnresolvedSet<4> ExplicitConversions; 3727 const UnresolvedSetImpl *Conversions 3728 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3729 3730 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3731 E = Conversions->end(); 3732 I != E; 3733 ++I) { 3734 if (CXXConversionDecl *Conversion 3735 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3736 if (Conversion->getConversionType().getNonReferenceType() 3737 ->isIntegralOrEnumerationType()) { 3738 if (Conversion->isExplicit()) 3739 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3740 else 3741 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3742 } 3743 } 3744 3745 switch (ViableConversions.size()) { 3746 case 0: 3747 if (ExplicitConversions.size() == 1) { 3748 DeclAccessPair Found = ExplicitConversions[0]; 3749 CXXConversionDecl *Conversion 3750 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3751 3752 // The user probably meant to invoke the given explicit 3753 // conversion; use it. 3754 QualType ConvTy 3755 = Conversion->getConversionType().getNonReferenceType(); 3756 std::string TypeStr; 3757 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3758 3759 Diag(Loc, ExplicitConvDiag) 3760 << T << ConvTy 3761 << FixItHint::CreateInsertion(From->getLocStart(), 3762 "static_cast<" + TypeStr + ">(") 3763 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3764 ")"); 3765 Diag(Conversion->getLocation(), ExplicitConvNote) 3766 << ConvTy->isEnumeralType() << ConvTy; 3767 3768 // If we aren't in a SFINAE context, build a call to the 3769 // explicit conversion function. 3770 if (isSFINAEContext()) 3771 return ExprError(); 3772 3773 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3774 ExprResult Result = BuildCXXMemberCallExpr(From, Found, Conversion); 3775 if (Result.isInvalid()) 3776 return ExprError(); 3777 3778 From = Result.get(); 3779 } 3780 3781 // We'll complain below about a non-integral condition type. 3782 break; 3783 3784 case 1: { 3785 // Apply this conversion. 3786 DeclAccessPair Found = ViableConversions[0]; 3787 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3788 3789 CXXConversionDecl *Conversion 3790 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3791 QualType ConvTy 3792 = Conversion->getConversionType().getNonReferenceType(); 3793 if (ConvDiag.getDiagID()) { 3794 if (isSFINAEContext()) 3795 return ExprError(); 3796 3797 Diag(Loc, ConvDiag) 3798 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 3799 } 3800 3801 ExprResult Result = BuildCXXMemberCallExpr(From, Found, 3802 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3803 if (Result.isInvalid()) 3804 return ExprError(); 3805 3806 From = Result.get(); 3807 break; 3808 } 3809 3810 default: 3811 Diag(Loc, AmbigDiag) 3812 << T << From->getSourceRange(); 3813 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3814 CXXConversionDecl *Conv 3815 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3816 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3817 Diag(Conv->getLocation(), AmbigNote) 3818 << ConvTy->isEnumeralType() << ConvTy; 3819 } 3820 return Owned(From); 3821 } 3822 3823 if (!From->getType()->isIntegralOrEnumerationType()) 3824 Diag(Loc, NotIntDiag) 3825 << From->getType() << From->getSourceRange(); 3826 3827 return Owned(From); 3828} 3829 3830/// AddOverloadCandidate - Adds the given function to the set of 3831/// candidate functions, using the given function call arguments. If 3832/// @p SuppressUserConversions, then don't allow user-defined 3833/// conversions via constructors or conversion operators. 3834/// 3835/// \para PartialOverloading true if we are performing "partial" overloading 3836/// based on an incomplete set of function arguments. This feature is used by 3837/// code completion. 3838void 3839Sema::AddOverloadCandidate(FunctionDecl *Function, 3840 DeclAccessPair FoundDecl, 3841 Expr **Args, unsigned NumArgs, 3842 OverloadCandidateSet& CandidateSet, 3843 bool SuppressUserConversions, 3844 bool PartialOverloading) { 3845 const FunctionProtoType* Proto 3846 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3847 assert(Proto && "Functions without a prototype cannot be overloaded"); 3848 assert(!Function->getDescribedFunctionTemplate() && 3849 "Use AddTemplateOverloadCandidate for function templates"); 3850 3851 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3852 if (!isa<CXXConstructorDecl>(Method)) { 3853 // If we get here, it's because we're calling a member function 3854 // that is named without a member access expression (e.g., 3855 // "this->f") that was either written explicitly or created 3856 // implicitly. This can happen with a qualified call to a member 3857 // function, e.g., X::f(). We use an empty type for the implied 3858 // object argument (C++ [over.call.func]p3), and the acting context 3859 // is irrelevant. 3860 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3861 QualType(), Expr::Classification::makeSimpleLValue(), 3862 Args, NumArgs, CandidateSet, 3863 SuppressUserConversions); 3864 return; 3865 } 3866 // We treat a constructor like a non-member function, since its object 3867 // argument doesn't participate in overload resolution. 3868 } 3869 3870 if (!CandidateSet.isNewCandidate(Function)) 3871 return; 3872 3873 // Overload resolution is always an unevaluated context. 3874 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 3875 3876 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3877 // C++ [class.copy]p3: 3878 // A member function template is never instantiated to perform the copy 3879 // of a class object to an object of its class type. 3880 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3881 if (NumArgs == 1 && 3882 Constructor->isSpecializationCopyingObject() && 3883 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3884 IsDerivedFrom(Args[0]->getType(), ClassType))) 3885 return; 3886 } 3887 3888 // Add this candidate 3889 CandidateSet.push_back(OverloadCandidate()); 3890 OverloadCandidate& Candidate = CandidateSet.back(); 3891 Candidate.FoundDecl = FoundDecl; 3892 Candidate.Function = Function; 3893 Candidate.Viable = true; 3894 Candidate.IsSurrogate = false; 3895 Candidate.IgnoreObjectArgument = false; 3896 Candidate.ExplicitCallArguments = NumArgs; 3897 3898 unsigned NumArgsInProto = Proto->getNumArgs(); 3899 3900 // (C++ 13.3.2p2): A candidate function having fewer than m 3901 // parameters is viable only if it has an ellipsis in its parameter 3902 // list (8.3.5). 3903 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3904 !Proto->isVariadic()) { 3905 Candidate.Viable = false; 3906 Candidate.FailureKind = ovl_fail_too_many_arguments; 3907 return; 3908 } 3909 3910 // (C++ 13.3.2p2): A candidate function having more than m parameters 3911 // is viable only if the (m+1)st parameter has a default argument 3912 // (8.3.6). For the purposes of overload resolution, the 3913 // parameter list is truncated on the right, so that there are 3914 // exactly m parameters. 3915 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3916 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3917 // Not enough arguments. 3918 Candidate.Viable = false; 3919 Candidate.FailureKind = ovl_fail_too_few_arguments; 3920 return; 3921 } 3922 3923 // Determine the implicit conversion sequences for each of the 3924 // arguments. 3925 Candidate.Conversions.resize(NumArgs); 3926 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3927 if (ArgIdx < NumArgsInProto) { 3928 // (C++ 13.3.2p3): for F to be a viable function, there shall 3929 // exist for each argument an implicit conversion sequence 3930 // (13.3.3.1) that converts that argument to the corresponding 3931 // parameter of F. 3932 QualType ParamType = Proto->getArgType(ArgIdx); 3933 Candidate.Conversions[ArgIdx] 3934 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3935 SuppressUserConversions, 3936 /*InOverloadResolution=*/true); 3937 if (Candidate.Conversions[ArgIdx].isBad()) { 3938 Candidate.Viable = false; 3939 Candidate.FailureKind = ovl_fail_bad_conversion; 3940 break; 3941 } 3942 } else { 3943 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3944 // argument for which there is no corresponding parameter is 3945 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3946 Candidate.Conversions[ArgIdx].setEllipsis(); 3947 } 3948 } 3949} 3950 3951/// \brief Add all of the function declarations in the given function set to 3952/// the overload canddiate set. 3953void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3954 Expr **Args, unsigned NumArgs, 3955 OverloadCandidateSet& CandidateSet, 3956 bool SuppressUserConversions) { 3957 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3958 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3959 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3960 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3961 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3962 cast<CXXMethodDecl>(FD)->getParent(), 3963 Args[0]->getType(), Args[0]->Classify(Context), 3964 Args + 1, NumArgs - 1, 3965 CandidateSet, SuppressUserConversions); 3966 else 3967 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3968 SuppressUserConversions); 3969 } else { 3970 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3971 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3972 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3973 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3974 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3975 /*FIXME: explicit args */ 0, 3976 Args[0]->getType(), 3977 Args[0]->Classify(Context), 3978 Args + 1, NumArgs - 1, 3979 CandidateSet, 3980 SuppressUserConversions); 3981 else 3982 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3983 /*FIXME: explicit args */ 0, 3984 Args, NumArgs, CandidateSet, 3985 SuppressUserConversions); 3986 } 3987 } 3988} 3989 3990/// AddMethodCandidate - Adds a named decl (which is some kind of 3991/// method) as a method candidate to the given overload set. 3992void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3993 QualType ObjectType, 3994 Expr::Classification ObjectClassification, 3995 Expr **Args, unsigned NumArgs, 3996 OverloadCandidateSet& CandidateSet, 3997 bool SuppressUserConversions) { 3998 NamedDecl *Decl = FoundDecl.getDecl(); 3999 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 4000 4001 if (isa<UsingShadowDecl>(Decl)) 4002 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 4003 4004 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 4005 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 4006 "Expected a member function template"); 4007 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 4008 /*ExplicitArgs*/ 0, 4009 ObjectType, ObjectClassification, Args, NumArgs, 4010 CandidateSet, 4011 SuppressUserConversions); 4012 } else { 4013 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 4014 ObjectType, ObjectClassification, Args, NumArgs, 4015 CandidateSet, SuppressUserConversions); 4016 } 4017} 4018 4019/// AddMethodCandidate - Adds the given C++ member function to the set 4020/// of candidate functions, using the given function call arguments 4021/// and the object argument (@c Object). For example, in a call 4022/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 4023/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 4024/// allow user-defined conversions via constructors or conversion 4025/// operators. 4026void 4027Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 4028 CXXRecordDecl *ActingContext, QualType ObjectType, 4029 Expr::Classification ObjectClassification, 4030 Expr **Args, unsigned NumArgs, 4031 OverloadCandidateSet& CandidateSet, 4032 bool SuppressUserConversions) { 4033 const FunctionProtoType* Proto 4034 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 4035 assert(Proto && "Methods without a prototype cannot be overloaded"); 4036 assert(!isa<CXXConstructorDecl>(Method) && 4037 "Use AddOverloadCandidate for constructors"); 4038 4039 if (!CandidateSet.isNewCandidate(Method)) 4040 return; 4041 4042 // Overload resolution is always an unevaluated context. 4043 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4044 4045 // Add this candidate 4046 CandidateSet.push_back(OverloadCandidate()); 4047 OverloadCandidate& Candidate = CandidateSet.back(); 4048 Candidate.FoundDecl = FoundDecl; 4049 Candidate.Function = Method; 4050 Candidate.IsSurrogate = false; 4051 Candidate.IgnoreObjectArgument = false; 4052 Candidate.ExplicitCallArguments = NumArgs; 4053 4054 unsigned NumArgsInProto = Proto->getNumArgs(); 4055 4056 // (C++ 13.3.2p2): A candidate function having fewer than m 4057 // parameters is viable only if it has an ellipsis in its parameter 4058 // list (8.3.5). 4059 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4060 Candidate.Viable = false; 4061 Candidate.FailureKind = ovl_fail_too_many_arguments; 4062 return; 4063 } 4064 4065 // (C++ 13.3.2p2): A candidate function having more than m parameters 4066 // is viable only if the (m+1)st parameter has a default argument 4067 // (8.3.6). For the purposes of overload resolution, the 4068 // parameter list is truncated on the right, so that there are 4069 // exactly m parameters. 4070 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 4071 if (NumArgs < MinRequiredArgs) { 4072 // Not enough arguments. 4073 Candidate.Viable = false; 4074 Candidate.FailureKind = ovl_fail_too_few_arguments; 4075 return; 4076 } 4077 4078 Candidate.Viable = true; 4079 Candidate.Conversions.resize(NumArgs + 1); 4080 4081 if (Method->isStatic() || ObjectType.isNull()) 4082 // The implicit object argument is ignored. 4083 Candidate.IgnoreObjectArgument = true; 4084 else { 4085 // Determine the implicit conversion sequence for the object 4086 // parameter. 4087 Candidate.Conversions[0] 4088 = TryObjectArgumentInitialization(*this, ObjectType, ObjectClassification, 4089 Method, ActingContext); 4090 if (Candidate.Conversions[0].isBad()) { 4091 Candidate.Viable = false; 4092 Candidate.FailureKind = ovl_fail_bad_conversion; 4093 return; 4094 } 4095 } 4096 4097 // Determine the implicit conversion sequences for each of the 4098 // arguments. 4099 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4100 if (ArgIdx < NumArgsInProto) { 4101 // (C++ 13.3.2p3): for F to be a viable function, there shall 4102 // exist for each argument an implicit conversion sequence 4103 // (13.3.3.1) that converts that argument to the corresponding 4104 // parameter of F. 4105 QualType ParamType = Proto->getArgType(ArgIdx); 4106 Candidate.Conversions[ArgIdx + 1] 4107 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4108 SuppressUserConversions, 4109 /*InOverloadResolution=*/true); 4110 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4111 Candidate.Viable = false; 4112 Candidate.FailureKind = ovl_fail_bad_conversion; 4113 break; 4114 } 4115 } else { 4116 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4117 // argument for which there is no corresponding parameter is 4118 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4119 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4120 } 4121 } 4122} 4123 4124/// \brief Add a C++ member function template as a candidate to the candidate 4125/// set, using template argument deduction to produce an appropriate member 4126/// function template specialization. 4127void 4128Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 4129 DeclAccessPair FoundDecl, 4130 CXXRecordDecl *ActingContext, 4131 TemplateArgumentListInfo *ExplicitTemplateArgs, 4132 QualType ObjectType, 4133 Expr::Classification ObjectClassification, 4134 Expr **Args, unsigned NumArgs, 4135 OverloadCandidateSet& CandidateSet, 4136 bool SuppressUserConversions) { 4137 if (!CandidateSet.isNewCandidate(MethodTmpl)) 4138 return; 4139 4140 // C++ [over.match.funcs]p7: 4141 // In each case where a candidate is a function template, candidate 4142 // function template specializations are generated using template argument 4143 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4144 // candidate functions in the usual way.113) A given name can refer to one 4145 // or more function templates and also to a set of overloaded non-template 4146 // functions. In such a case, the candidate functions generated from each 4147 // function template are combined with the set of non-template candidate 4148 // functions. 4149 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4150 FunctionDecl *Specialization = 0; 4151 if (TemplateDeductionResult Result 4152 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 4153 Args, NumArgs, Specialization, Info)) { 4154 CandidateSet.push_back(OverloadCandidate()); 4155 OverloadCandidate &Candidate = CandidateSet.back(); 4156 Candidate.FoundDecl = FoundDecl; 4157 Candidate.Function = MethodTmpl->getTemplatedDecl(); 4158 Candidate.Viable = false; 4159 Candidate.FailureKind = ovl_fail_bad_deduction; 4160 Candidate.IsSurrogate = false; 4161 Candidate.IgnoreObjectArgument = false; 4162 Candidate.ExplicitCallArguments = NumArgs; 4163 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4164 Info); 4165 return; 4166 } 4167 4168 // Add the function template specialization produced by template argument 4169 // deduction as a candidate. 4170 assert(Specialization && "Missing member function template specialization?"); 4171 assert(isa<CXXMethodDecl>(Specialization) && 4172 "Specialization is not a member function?"); 4173 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 4174 ActingContext, ObjectType, ObjectClassification, 4175 Args, NumArgs, CandidateSet, SuppressUserConversions); 4176} 4177 4178/// \brief Add a C++ function template specialization as a candidate 4179/// in the candidate set, using template argument deduction to produce 4180/// an appropriate function template specialization. 4181void 4182Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 4183 DeclAccessPair FoundDecl, 4184 TemplateArgumentListInfo *ExplicitTemplateArgs, 4185 Expr **Args, unsigned NumArgs, 4186 OverloadCandidateSet& CandidateSet, 4187 bool SuppressUserConversions) { 4188 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4189 return; 4190 4191 // C++ [over.match.funcs]p7: 4192 // In each case where a candidate is a function template, candidate 4193 // function template specializations are generated using template argument 4194 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 4195 // candidate functions in the usual way.113) A given name can refer to one 4196 // or more function templates and also to a set of overloaded non-template 4197 // functions. In such a case, the candidate functions generated from each 4198 // function template are combined with the set of non-template candidate 4199 // functions. 4200 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4201 FunctionDecl *Specialization = 0; 4202 if (TemplateDeductionResult Result 4203 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 4204 Args, NumArgs, Specialization, Info)) { 4205 CandidateSet.push_back(OverloadCandidate()); 4206 OverloadCandidate &Candidate = CandidateSet.back(); 4207 Candidate.FoundDecl = FoundDecl; 4208 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4209 Candidate.Viable = false; 4210 Candidate.FailureKind = ovl_fail_bad_deduction; 4211 Candidate.IsSurrogate = false; 4212 Candidate.IgnoreObjectArgument = false; 4213 Candidate.ExplicitCallArguments = NumArgs; 4214 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4215 Info); 4216 return; 4217 } 4218 4219 // Add the function template specialization produced by template argument 4220 // deduction as a candidate. 4221 assert(Specialization && "Missing function template specialization?"); 4222 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 4223 SuppressUserConversions); 4224} 4225 4226/// AddConversionCandidate - Add a C++ conversion function as a 4227/// candidate in the candidate set (C++ [over.match.conv], 4228/// C++ [over.match.copy]). From is the expression we're converting from, 4229/// and ToType is the type that we're eventually trying to convert to 4230/// (which may or may not be the same type as the type that the 4231/// conversion function produces). 4232void 4233Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 4234 DeclAccessPair FoundDecl, 4235 CXXRecordDecl *ActingContext, 4236 Expr *From, QualType ToType, 4237 OverloadCandidateSet& CandidateSet) { 4238 assert(!Conversion->getDescribedFunctionTemplate() && 4239 "Conversion function templates use AddTemplateConversionCandidate"); 4240 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 4241 if (!CandidateSet.isNewCandidate(Conversion)) 4242 return; 4243 4244 // Overload resolution is always an unevaluated context. 4245 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4246 4247 // Add this candidate 4248 CandidateSet.push_back(OverloadCandidate()); 4249 OverloadCandidate& Candidate = CandidateSet.back(); 4250 Candidate.FoundDecl = FoundDecl; 4251 Candidate.Function = Conversion; 4252 Candidate.IsSurrogate = false; 4253 Candidate.IgnoreObjectArgument = false; 4254 Candidate.FinalConversion.setAsIdentityConversion(); 4255 Candidate.FinalConversion.setFromType(ConvType); 4256 Candidate.FinalConversion.setAllToTypes(ToType); 4257 Candidate.Viable = true; 4258 Candidate.Conversions.resize(1); 4259 Candidate.ExplicitCallArguments = 1; 4260 4261 // C++ [over.match.funcs]p4: 4262 // For conversion functions, the function is considered to be a member of 4263 // the class of the implicit implied object argument for the purpose of 4264 // defining the type of the implicit object parameter. 4265 // 4266 // Determine the implicit conversion sequence for the implicit 4267 // object parameter. 4268 QualType ImplicitParamType = From->getType(); 4269 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 4270 ImplicitParamType = FromPtrType->getPointeeType(); 4271 CXXRecordDecl *ConversionContext 4272 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 4273 4274 Candidate.Conversions[0] 4275 = TryObjectArgumentInitialization(*this, From->getType(), 4276 From->Classify(Context), 4277 Conversion, ConversionContext); 4278 4279 if (Candidate.Conversions[0].isBad()) { 4280 Candidate.Viable = false; 4281 Candidate.FailureKind = ovl_fail_bad_conversion; 4282 return; 4283 } 4284 4285 // We won't go through a user-define type conversion function to convert a 4286 // derived to base as such conversions are given Conversion Rank. They only 4287 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 4288 QualType FromCanon 4289 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 4290 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 4291 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 4292 Candidate.Viable = false; 4293 Candidate.FailureKind = ovl_fail_trivial_conversion; 4294 return; 4295 } 4296 4297 // To determine what the conversion from the result of calling the 4298 // conversion function to the type we're eventually trying to 4299 // convert to (ToType), we need to synthesize a call to the 4300 // conversion function and attempt copy initialization from it. This 4301 // makes sure that we get the right semantics with respect to 4302 // lvalues/rvalues and the type. Fortunately, we can allocate this 4303 // call on the stack and we don't need its arguments to be 4304 // well-formed. 4305 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 4306 VK_LValue, From->getLocStart()); 4307 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 4308 Context.getPointerType(Conversion->getType()), 4309 CK_FunctionToPointerDecay, 4310 &ConversionRef, VK_RValue); 4311 4312 QualType CallResultType 4313 = Conversion->getConversionType().getNonLValueExprType(Context); 4314 if (RequireCompleteType(From->getLocStart(), CallResultType, 0)) { 4315 Candidate.Viable = false; 4316 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4317 return; 4318 } 4319 4320 ExprValueKind VK = Expr::getValueKindForType(Conversion->getConversionType()); 4321 4322 // Note that it is safe to allocate CallExpr on the stack here because 4323 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 4324 // allocator). 4325 CallExpr Call(Context, &ConversionFn, 0, 0, CallResultType, VK, 4326 From->getLocStart()); 4327 ImplicitConversionSequence ICS = 4328 TryCopyInitialization(*this, &Call, ToType, 4329 /*SuppressUserConversions=*/true, 4330 /*InOverloadResolution=*/false); 4331 4332 switch (ICS.getKind()) { 4333 case ImplicitConversionSequence::StandardConversion: 4334 Candidate.FinalConversion = ICS.Standard; 4335 4336 // C++ [over.ics.user]p3: 4337 // If the user-defined conversion is specified by a specialization of a 4338 // conversion function template, the second standard conversion sequence 4339 // shall have exact match rank. 4340 if (Conversion->getPrimaryTemplate() && 4341 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 4342 Candidate.Viable = false; 4343 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 4344 } 4345 4346 // C++0x [dcl.init.ref]p5: 4347 // In the second case, if the reference is an rvalue reference and 4348 // the second standard conversion sequence of the user-defined 4349 // conversion sequence includes an lvalue-to-rvalue conversion, the 4350 // program is ill-formed. 4351 if (ToType->isRValueReferenceType() && 4352 ICS.Standard.First == ICK_Lvalue_To_Rvalue) { 4353 Candidate.Viable = false; 4354 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4355 } 4356 break; 4357 4358 case ImplicitConversionSequence::BadConversion: 4359 Candidate.Viable = false; 4360 Candidate.FailureKind = ovl_fail_bad_final_conversion; 4361 break; 4362 4363 default: 4364 assert(false && 4365 "Can only end up with a standard conversion sequence or failure"); 4366 } 4367} 4368 4369/// \brief Adds a conversion function template specialization 4370/// candidate to the overload set, using template argument deduction 4371/// to deduce the template arguments of the conversion function 4372/// template from the type that we are converting to (C++ 4373/// [temp.deduct.conv]). 4374void 4375Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 4376 DeclAccessPair FoundDecl, 4377 CXXRecordDecl *ActingDC, 4378 Expr *From, QualType ToType, 4379 OverloadCandidateSet &CandidateSet) { 4380 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 4381 "Only conversion function templates permitted here"); 4382 4383 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 4384 return; 4385 4386 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 4387 CXXConversionDecl *Specialization = 0; 4388 if (TemplateDeductionResult Result 4389 = DeduceTemplateArguments(FunctionTemplate, ToType, 4390 Specialization, Info)) { 4391 CandidateSet.push_back(OverloadCandidate()); 4392 OverloadCandidate &Candidate = CandidateSet.back(); 4393 Candidate.FoundDecl = FoundDecl; 4394 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 4395 Candidate.Viable = false; 4396 Candidate.FailureKind = ovl_fail_bad_deduction; 4397 Candidate.IsSurrogate = false; 4398 Candidate.IgnoreObjectArgument = false; 4399 Candidate.ExplicitCallArguments = 1; 4400 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 4401 Info); 4402 return; 4403 } 4404 4405 // Add the conversion function template specialization produced by 4406 // template argument deduction as a candidate. 4407 assert(Specialization && "Missing function template specialization?"); 4408 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 4409 CandidateSet); 4410} 4411 4412/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 4413/// converts the given @c Object to a function pointer via the 4414/// conversion function @c Conversion, and then attempts to call it 4415/// with the given arguments (C++ [over.call.object]p2-4). Proto is 4416/// the type of function that we'll eventually be calling. 4417void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 4418 DeclAccessPair FoundDecl, 4419 CXXRecordDecl *ActingContext, 4420 const FunctionProtoType *Proto, 4421 Expr *Object, 4422 Expr **Args, unsigned NumArgs, 4423 OverloadCandidateSet& CandidateSet) { 4424 if (!CandidateSet.isNewCandidate(Conversion)) 4425 return; 4426 4427 // Overload resolution is always an unevaluated context. 4428 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4429 4430 CandidateSet.push_back(OverloadCandidate()); 4431 OverloadCandidate& Candidate = CandidateSet.back(); 4432 Candidate.FoundDecl = FoundDecl; 4433 Candidate.Function = 0; 4434 Candidate.Surrogate = Conversion; 4435 Candidate.Viable = true; 4436 Candidate.IsSurrogate = true; 4437 Candidate.IgnoreObjectArgument = false; 4438 Candidate.Conversions.resize(NumArgs + 1); 4439 Candidate.ExplicitCallArguments = NumArgs; 4440 4441 // Determine the implicit conversion sequence for the implicit 4442 // object parameter. 4443 ImplicitConversionSequence ObjectInit 4444 = TryObjectArgumentInitialization(*this, Object->getType(), 4445 Object->Classify(Context), 4446 Conversion, ActingContext); 4447 if (ObjectInit.isBad()) { 4448 Candidate.Viable = false; 4449 Candidate.FailureKind = ovl_fail_bad_conversion; 4450 Candidate.Conversions[0] = ObjectInit; 4451 return; 4452 } 4453 4454 // The first conversion is actually a user-defined conversion whose 4455 // first conversion is ObjectInit's standard conversion (which is 4456 // effectively a reference binding). Record it as such. 4457 Candidate.Conversions[0].setUserDefined(); 4458 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 4459 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 4460 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 4461 Candidate.Conversions[0].UserDefined.FoundConversionFunction 4462 = FoundDecl.getDecl(); 4463 Candidate.Conversions[0].UserDefined.After 4464 = Candidate.Conversions[0].UserDefined.Before; 4465 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 4466 4467 // Find the 4468 unsigned NumArgsInProto = Proto->getNumArgs(); 4469 4470 // (C++ 13.3.2p2): A candidate function having fewer than m 4471 // parameters is viable only if it has an ellipsis in its parameter 4472 // list (8.3.5). 4473 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 4474 Candidate.Viable = false; 4475 Candidate.FailureKind = ovl_fail_too_many_arguments; 4476 return; 4477 } 4478 4479 // Function types don't have any default arguments, so just check if 4480 // we have enough arguments. 4481 if (NumArgs < NumArgsInProto) { 4482 // Not enough arguments. 4483 Candidate.Viable = false; 4484 Candidate.FailureKind = ovl_fail_too_few_arguments; 4485 return; 4486 } 4487 4488 // Determine the implicit conversion sequences for each of the 4489 // arguments. 4490 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4491 if (ArgIdx < NumArgsInProto) { 4492 // (C++ 13.3.2p3): for F to be a viable function, there shall 4493 // exist for each argument an implicit conversion sequence 4494 // (13.3.3.1) that converts that argument to the corresponding 4495 // parameter of F. 4496 QualType ParamType = Proto->getArgType(ArgIdx); 4497 Candidate.Conversions[ArgIdx + 1] 4498 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4499 /*SuppressUserConversions=*/false, 4500 /*InOverloadResolution=*/false); 4501 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4502 Candidate.Viable = false; 4503 Candidate.FailureKind = ovl_fail_bad_conversion; 4504 break; 4505 } 4506 } else { 4507 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4508 // argument for which there is no corresponding parameter is 4509 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4510 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4511 } 4512 } 4513} 4514 4515/// \brief Add overload candidates for overloaded operators that are 4516/// member functions. 4517/// 4518/// Add the overloaded operator candidates that are member functions 4519/// for the operator Op that was used in an operator expression such 4520/// as "x Op y". , Args/NumArgs provides the operator arguments, and 4521/// CandidateSet will store the added overload candidates. (C++ 4522/// [over.match.oper]). 4523void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 4524 SourceLocation OpLoc, 4525 Expr **Args, unsigned NumArgs, 4526 OverloadCandidateSet& CandidateSet, 4527 SourceRange OpRange) { 4528 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4529 4530 // C++ [over.match.oper]p3: 4531 // For a unary operator @ with an operand of a type whose 4532 // cv-unqualified version is T1, and for a binary operator @ with 4533 // a left operand of a type whose cv-unqualified version is T1 and 4534 // a right operand of a type whose cv-unqualified version is T2, 4535 // three sets of candidate functions, designated member 4536 // candidates, non-member candidates and built-in candidates, are 4537 // constructed as follows: 4538 QualType T1 = Args[0]->getType(); 4539 4540 // -- If T1 is a class type, the set of member candidates is the 4541 // result of the qualified lookup of T1::operator@ 4542 // (13.3.1.1.1); otherwise, the set of member candidates is 4543 // empty. 4544 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 4545 // Complete the type if it can be completed. Otherwise, we're done. 4546 if (RequireCompleteType(OpLoc, T1, PDiag())) 4547 return; 4548 4549 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 4550 LookupQualifiedName(Operators, T1Rec->getDecl()); 4551 Operators.suppressDiagnostics(); 4552 4553 for (LookupResult::iterator Oper = Operators.begin(), 4554 OperEnd = Operators.end(); 4555 Oper != OperEnd; 4556 ++Oper) 4557 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 4558 Args[0]->Classify(Context), Args + 1, NumArgs - 1, 4559 CandidateSet, 4560 /* SuppressUserConversions = */ false); 4561 } 4562} 4563 4564/// AddBuiltinCandidate - Add a candidate for a built-in 4565/// operator. ResultTy and ParamTys are the result and parameter types 4566/// of the built-in candidate, respectively. Args and NumArgs are the 4567/// arguments being passed to the candidate. IsAssignmentOperator 4568/// should be true when this built-in candidate is an assignment 4569/// operator. NumContextualBoolArguments is the number of arguments 4570/// (at the beginning of the argument list) that will be contextually 4571/// converted to bool. 4572void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 4573 Expr **Args, unsigned NumArgs, 4574 OverloadCandidateSet& CandidateSet, 4575 bool IsAssignmentOperator, 4576 unsigned NumContextualBoolArguments) { 4577 // Overload resolution is always an unevaluated context. 4578 EnterExpressionEvaluationContext Unevaluated(*this, Sema::Unevaluated); 4579 4580 // Add this candidate 4581 CandidateSet.push_back(OverloadCandidate()); 4582 OverloadCandidate& Candidate = CandidateSet.back(); 4583 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 4584 Candidate.Function = 0; 4585 Candidate.IsSurrogate = false; 4586 Candidate.IgnoreObjectArgument = false; 4587 Candidate.BuiltinTypes.ResultTy = ResultTy; 4588 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4589 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 4590 4591 // Determine the implicit conversion sequences for each of the 4592 // arguments. 4593 Candidate.Viable = true; 4594 Candidate.Conversions.resize(NumArgs); 4595 Candidate.ExplicitCallArguments = NumArgs; 4596 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4597 // C++ [over.match.oper]p4: 4598 // For the built-in assignment operators, conversions of the 4599 // left operand are restricted as follows: 4600 // -- no temporaries are introduced to hold the left operand, and 4601 // -- no user-defined conversions are applied to the left 4602 // operand to achieve a type match with the left-most 4603 // parameter of a built-in candidate. 4604 // 4605 // We block these conversions by turning off user-defined 4606 // conversions, since that is the only way that initialization of 4607 // a reference to a non-class type can occur from something that 4608 // is not of the same type. 4609 if (ArgIdx < NumContextualBoolArguments) { 4610 assert(ParamTys[ArgIdx] == Context.BoolTy && 4611 "Contextual conversion to bool requires bool type"); 4612 Candidate.Conversions[ArgIdx] 4613 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 4614 } else { 4615 Candidate.Conversions[ArgIdx] 4616 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4617 ArgIdx == 0 && IsAssignmentOperator, 4618 /*InOverloadResolution=*/false); 4619 } 4620 if (Candidate.Conversions[ArgIdx].isBad()) { 4621 Candidate.Viable = false; 4622 Candidate.FailureKind = ovl_fail_bad_conversion; 4623 break; 4624 } 4625 } 4626} 4627 4628/// BuiltinCandidateTypeSet - A set of types that will be used for the 4629/// candidate operator functions for built-in operators (C++ 4630/// [over.built]). The types are separated into pointer types and 4631/// enumeration types. 4632class BuiltinCandidateTypeSet { 4633 /// TypeSet - A set of types. 4634 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4635 4636 /// PointerTypes - The set of pointer types that will be used in the 4637 /// built-in candidates. 4638 TypeSet PointerTypes; 4639 4640 /// MemberPointerTypes - The set of member pointer types that will be 4641 /// used in the built-in candidates. 4642 TypeSet MemberPointerTypes; 4643 4644 /// EnumerationTypes - The set of enumeration types that will be 4645 /// used in the built-in candidates. 4646 TypeSet EnumerationTypes; 4647 4648 /// \brief The set of vector types that will be used in the built-in 4649 /// candidates. 4650 TypeSet VectorTypes; 4651 4652 /// \brief A flag indicating non-record types are viable candidates 4653 bool HasNonRecordTypes; 4654 4655 /// \brief A flag indicating whether either arithmetic or enumeration types 4656 /// were present in the candidate set. 4657 bool HasArithmeticOrEnumeralTypes; 4658 4659 /// Sema - The semantic analysis instance where we are building the 4660 /// candidate type set. 4661 Sema &SemaRef; 4662 4663 /// Context - The AST context in which we will build the type sets. 4664 ASTContext &Context; 4665 4666 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4667 const Qualifiers &VisibleQuals); 4668 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4669 4670public: 4671 /// iterator - Iterates through the types that are part of the set. 4672 typedef TypeSet::iterator iterator; 4673 4674 BuiltinCandidateTypeSet(Sema &SemaRef) 4675 : HasNonRecordTypes(false), 4676 HasArithmeticOrEnumeralTypes(false), 4677 SemaRef(SemaRef), 4678 Context(SemaRef.Context) { } 4679 4680 void AddTypesConvertedFrom(QualType Ty, 4681 SourceLocation Loc, 4682 bool AllowUserConversions, 4683 bool AllowExplicitConversions, 4684 const Qualifiers &VisibleTypeConversionsQuals); 4685 4686 /// pointer_begin - First pointer type found; 4687 iterator pointer_begin() { return PointerTypes.begin(); } 4688 4689 /// pointer_end - Past the last pointer type found; 4690 iterator pointer_end() { return PointerTypes.end(); } 4691 4692 /// member_pointer_begin - First member pointer type found; 4693 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4694 4695 /// member_pointer_end - Past the last member pointer type found; 4696 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4697 4698 /// enumeration_begin - First enumeration type found; 4699 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4700 4701 /// enumeration_end - Past the last enumeration type found; 4702 iterator enumeration_end() { return EnumerationTypes.end(); } 4703 4704 iterator vector_begin() { return VectorTypes.begin(); } 4705 iterator vector_end() { return VectorTypes.end(); } 4706 4707 bool hasNonRecordTypes() { return HasNonRecordTypes; } 4708 bool hasArithmeticOrEnumeralTypes() { return HasArithmeticOrEnumeralTypes; } 4709}; 4710 4711/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4712/// the set of pointer types along with any more-qualified variants of 4713/// that type. For example, if @p Ty is "int const *", this routine 4714/// will add "int const *", "int const volatile *", "int const 4715/// restrict *", and "int const volatile restrict *" to the set of 4716/// pointer types. Returns true if the add of @p Ty itself succeeded, 4717/// false otherwise. 4718/// 4719/// FIXME: what to do about extended qualifiers? 4720bool 4721BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4722 const Qualifiers &VisibleQuals) { 4723 4724 // Insert this type. 4725 if (!PointerTypes.insert(Ty)) 4726 return false; 4727 4728 QualType PointeeTy; 4729 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4730 bool buildObjCPtr = false; 4731 if (!PointerTy) { 4732 if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) { 4733 PointeeTy = PTy->getPointeeType(); 4734 buildObjCPtr = true; 4735 } 4736 else 4737 assert(false && "type was not a pointer type!"); 4738 } 4739 else 4740 PointeeTy = PointerTy->getPointeeType(); 4741 4742 // Don't add qualified variants of arrays. For one, they're not allowed 4743 // (the qualifier would sink to the element type), and for another, the 4744 // only overload situation where it matters is subscript or pointer +- int, 4745 // and those shouldn't have qualifier variants anyway. 4746 if (PointeeTy->isArrayType()) 4747 return true; 4748 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4749 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4750 BaseCVR = Array->getElementType().getCVRQualifiers(); 4751 bool hasVolatile = VisibleQuals.hasVolatile(); 4752 bool hasRestrict = VisibleQuals.hasRestrict(); 4753 4754 // Iterate through all strict supersets of BaseCVR. 4755 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4756 if ((CVR | BaseCVR) != CVR) continue; 4757 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4758 // in the types. 4759 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4760 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4761 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4762 if (!buildObjCPtr) 4763 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4764 else 4765 PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); 4766 } 4767 4768 return true; 4769} 4770 4771/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4772/// to the set of pointer types along with any more-qualified variants of 4773/// that type. For example, if @p Ty is "int const *", this routine 4774/// will add "int const *", "int const volatile *", "int const 4775/// restrict *", and "int const volatile restrict *" to the set of 4776/// pointer types. Returns true if the add of @p Ty itself succeeded, 4777/// false otherwise. 4778/// 4779/// FIXME: what to do about extended qualifiers? 4780bool 4781BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4782 QualType Ty) { 4783 // Insert this type. 4784 if (!MemberPointerTypes.insert(Ty)) 4785 return false; 4786 4787 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4788 assert(PointerTy && "type was not a member pointer type!"); 4789 4790 QualType PointeeTy = PointerTy->getPointeeType(); 4791 // Don't add qualified variants of arrays. For one, they're not allowed 4792 // (the qualifier would sink to the element type), and for another, the 4793 // only overload situation where it matters is subscript or pointer +- int, 4794 // and those shouldn't have qualifier variants anyway. 4795 if (PointeeTy->isArrayType()) 4796 return true; 4797 const Type *ClassTy = PointerTy->getClass(); 4798 4799 // Iterate through all strict supersets of the pointee type's CVR 4800 // qualifiers. 4801 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4802 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4803 if ((CVR | BaseCVR) != CVR) continue; 4804 4805 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4806 MemberPointerTypes.insert( 4807 Context.getMemberPointerType(QPointeeTy, ClassTy)); 4808 } 4809 4810 return true; 4811} 4812 4813/// AddTypesConvertedFrom - Add each of the types to which the type @p 4814/// Ty can be implicit converted to the given set of @p Types. We're 4815/// primarily interested in pointer types and enumeration types. We also 4816/// take member pointer types, for the conditional operator. 4817/// AllowUserConversions is true if we should look at the conversion 4818/// functions of a class type, and AllowExplicitConversions if we 4819/// should also include the explicit conversion functions of a class 4820/// type. 4821void 4822BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4823 SourceLocation Loc, 4824 bool AllowUserConversions, 4825 bool AllowExplicitConversions, 4826 const Qualifiers &VisibleQuals) { 4827 // Only deal with canonical types. 4828 Ty = Context.getCanonicalType(Ty); 4829 4830 // Look through reference types; they aren't part of the type of an 4831 // expression for the purposes of conversions. 4832 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4833 Ty = RefTy->getPointeeType(); 4834 4835 // If we're dealing with an array type, decay to the pointer. 4836 if (Ty->isArrayType()) 4837 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4838 4839 // Otherwise, we don't care about qualifiers on the type. 4840 Ty = Ty.getLocalUnqualifiedType(); 4841 4842 // Flag if we ever add a non-record type. 4843 const RecordType *TyRec = Ty->getAs<RecordType>(); 4844 HasNonRecordTypes = HasNonRecordTypes || !TyRec; 4845 4846 // Flag if we encounter an arithmetic type. 4847 HasArithmeticOrEnumeralTypes = 4848 HasArithmeticOrEnumeralTypes || Ty->isArithmeticType(); 4849 4850 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 4851 PointerTypes.insert(Ty); 4852 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 4853 // Insert our type, and its more-qualified variants, into the set 4854 // of types. 4855 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4856 return; 4857 } else if (Ty->isMemberPointerType()) { 4858 // Member pointers are far easier, since the pointee can't be converted. 4859 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4860 return; 4861 } else if (Ty->isEnumeralType()) { 4862 HasArithmeticOrEnumeralTypes = true; 4863 EnumerationTypes.insert(Ty); 4864 } else if (Ty->isVectorType()) { 4865 // We treat vector types as arithmetic types in many contexts as an 4866 // extension. 4867 HasArithmeticOrEnumeralTypes = true; 4868 VectorTypes.insert(Ty); 4869 } else if (AllowUserConversions && TyRec) { 4870 // No conversion functions in incomplete types. 4871 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) 4872 return; 4873 4874 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4875 const UnresolvedSetImpl *Conversions 4876 = ClassDecl->getVisibleConversionFunctions(); 4877 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4878 E = Conversions->end(); I != E; ++I) { 4879 NamedDecl *D = I.getDecl(); 4880 if (isa<UsingShadowDecl>(D)) 4881 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4882 4883 // Skip conversion function templates; they don't tell us anything 4884 // about which builtin types we can convert to. 4885 if (isa<FunctionTemplateDecl>(D)) 4886 continue; 4887 4888 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4889 if (AllowExplicitConversions || !Conv->isExplicit()) { 4890 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4891 VisibleQuals); 4892 } 4893 } 4894 } 4895} 4896 4897/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4898/// the volatile- and non-volatile-qualified assignment operators for the 4899/// given type to the candidate set. 4900static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4901 QualType T, 4902 Expr **Args, 4903 unsigned NumArgs, 4904 OverloadCandidateSet &CandidateSet) { 4905 QualType ParamTypes[2]; 4906 4907 // T& operator=(T&, T) 4908 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4909 ParamTypes[1] = T; 4910 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4911 /*IsAssignmentOperator=*/true); 4912 4913 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4914 // volatile T& operator=(volatile T&, T) 4915 ParamTypes[0] 4916 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4917 ParamTypes[1] = T; 4918 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4919 /*IsAssignmentOperator=*/true); 4920 } 4921} 4922 4923/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4924/// if any, found in visible type conversion functions found in ArgExpr's type. 4925static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4926 Qualifiers VRQuals; 4927 const RecordType *TyRec; 4928 if (const MemberPointerType *RHSMPType = 4929 ArgExpr->getType()->getAs<MemberPointerType>()) 4930 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4931 else 4932 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4933 if (!TyRec) { 4934 // Just to be safe, assume the worst case. 4935 VRQuals.addVolatile(); 4936 VRQuals.addRestrict(); 4937 return VRQuals; 4938 } 4939 4940 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4941 if (!ClassDecl->hasDefinition()) 4942 return VRQuals; 4943 4944 const UnresolvedSetImpl *Conversions = 4945 ClassDecl->getVisibleConversionFunctions(); 4946 4947 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4948 E = Conversions->end(); I != E; ++I) { 4949 NamedDecl *D = I.getDecl(); 4950 if (isa<UsingShadowDecl>(D)) 4951 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4952 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4953 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4954 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4955 CanTy = ResTypeRef->getPointeeType(); 4956 // Need to go down the pointer/mempointer chain and add qualifiers 4957 // as see them. 4958 bool done = false; 4959 while (!done) { 4960 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4961 CanTy = ResTypePtr->getPointeeType(); 4962 else if (const MemberPointerType *ResTypeMPtr = 4963 CanTy->getAs<MemberPointerType>()) 4964 CanTy = ResTypeMPtr->getPointeeType(); 4965 else 4966 done = true; 4967 if (CanTy.isVolatileQualified()) 4968 VRQuals.addVolatile(); 4969 if (CanTy.isRestrictQualified()) 4970 VRQuals.addRestrict(); 4971 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4972 return VRQuals; 4973 } 4974 } 4975 } 4976 return VRQuals; 4977} 4978 4979namespace { 4980 4981/// \brief Helper class to manage the addition of builtin operator overload 4982/// candidates. It provides shared state and utility methods used throughout 4983/// the process, as well as a helper method to add each group of builtin 4984/// operator overloads from the standard to a candidate set. 4985class BuiltinOperatorOverloadBuilder { 4986 // Common instance state available to all overload candidate addition methods. 4987 Sema &S; 4988 Expr **Args; 4989 unsigned NumArgs; 4990 Qualifiers VisibleTypeConversionsQuals; 4991 bool HasArithmeticOrEnumeralCandidateType; 4992 llvm::SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes; 4993 OverloadCandidateSet &CandidateSet; 4994 4995 // Define some constants used to index and iterate over the arithemetic types 4996 // provided via the getArithmeticType() method below. 4997 // The "promoted arithmetic types" are the arithmetic 4998 // types are that preserved by promotion (C++ [over.built]p2). 4999 static const unsigned FirstIntegralType = 3; 5000 static const unsigned LastIntegralType = 18; 5001 static const unsigned FirstPromotedIntegralType = 3, 5002 LastPromotedIntegralType = 9; 5003 static const unsigned FirstPromotedArithmeticType = 0, 5004 LastPromotedArithmeticType = 9; 5005 static const unsigned NumArithmeticTypes = 18; 5006 5007 /// \brief Get the canonical type for a given arithmetic type index. 5008 CanQualType getArithmeticType(unsigned index) { 5009 assert(index < NumArithmeticTypes); 5010 static CanQualType ASTContext::* const 5011 ArithmeticTypes[NumArithmeticTypes] = { 5012 // Start of promoted types. 5013 &ASTContext::FloatTy, 5014 &ASTContext::DoubleTy, 5015 &ASTContext::LongDoubleTy, 5016 5017 // Start of integral types. 5018 &ASTContext::IntTy, 5019 &ASTContext::LongTy, 5020 &ASTContext::LongLongTy, 5021 &ASTContext::UnsignedIntTy, 5022 &ASTContext::UnsignedLongTy, 5023 &ASTContext::UnsignedLongLongTy, 5024 // End of promoted types. 5025 5026 &ASTContext::BoolTy, 5027 &ASTContext::CharTy, 5028 &ASTContext::WCharTy, 5029 &ASTContext::Char16Ty, 5030 &ASTContext::Char32Ty, 5031 &ASTContext::SignedCharTy, 5032 &ASTContext::ShortTy, 5033 &ASTContext::UnsignedCharTy, 5034 &ASTContext::UnsignedShortTy, 5035 // End of integral types. 5036 // FIXME: What about complex? 5037 }; 5038 return S.Context.*ArithmeticTypes[index]; 5039 } 5040 5041 /// \brief Gets the canonical type resulting from the usual arithemetic 5042 /// converions for the given arithmetic types. 5043 CanQualType getUsualArithmeticConversions(unsigned L, unsigned R) { 5044 // Accelerator table for performing the usual arithmetic conversions. 5045 // The rules are basically: 5046 // - if either is floating-point, use the wider floating-point 5047 // - if same signedness, use the higher rank 5048 // - if same size, use unsigned of the higher rank 5049 // - use the larger type 5050 // These rules, together with the axiom that higher ranks are 5051 // never smaller, are sufficient to precompute all of these results 5052 // *except* when dealing with signed types of higher rank. 5053 // (we could precompute SLL x UI for all known platforms, but it's 5054 // better not to make any assumptions). 5055 enum PromotedType { 5056 Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL, Dep=-1 5057 }; 5058 static PromotedType ConversionsTable[LastPromotedArithmeticType] 5059 [LastPromotedArithmeticType] = { 5060 /* Flt*/ { Flt, Dbl, LDbl, Flt, Flt, Flt, Flt, Flt, Flt }, 5061 /* Dbl*/ { Dbl, Dbl, LDbl, Dbl, Dbl, Dbl, Dbl, Dbl, Dbl }, 5062 /*LDbl*/ { LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl, LDbl }, 5063 /* SI*/ { Flt, Dbl, LDbl, SI, SL, SLL, UI, UL, ULL }, 5064 /* SL*/ { Flt, Dbl, LDbl, SL, SL, SLL, Dep, UL, ULL }, 5065 /* SLL*/ { Flt, Dbl, LDbl, SLL, SLL, SLL, Dep, Dep, ULL }, 5066 /* UI*/ { Flt, Dbl, LDbl, UI, Dep, Dep, UI, UL, ULL }, 5067 /* UL*/ { Flt, Dbl, LDbl, UL, UL, Dep, UL, UL, ULL }, 5068 /* ULL*/ { Flt, Dbl, LDbl, ULL, ULL, ULL, ULL, ULL, ULL }, 5069 }; 5070 5071 assert(L < LastPromotedArithmeticType); 5072 assert(R < LastPromotedArithmeticType); 5073 int Idx = ConversionsTable[L][R]; 5074 5075 // Fast path: the table gives us a concrete answer. 5076 if (Idx != Dep) return getArithmeticType(Idx); 5077 5078 // Slow path: we need to compare widths. 5079 // An invariant is that the signed type has higher rank. 5080 CanQualType LT = getArithmeticType(L), 5081 RT = getArithmeticType(R); 5082 unsigned LW = S.Context.getIntWidth(LT), 5083 RW = S.Context.getIntWidth(RT); 5084 5085 // If they're different widths, use the signed type. 5086 if (LW > RW) return LT; 5087 else if (LW < RW) return RT; 5088 5089 // Otherwise, use the unsigned type of the signed type's rank. 5090 if (L == SL || R == SL) return S.Context.UnsignedLongTy; 5091 assert(L == SLL || R == SLL); 5092 return S.Context.UnsignedLongLongTy; 5093 } 5094 5095 /// \brief Helper method to factor out the common pattern of adding overloads 5096 /// for '++' and '--' builtin operators. 5097 void addPlusPlusMinusMinusStyleOverloads(QualType CandidateTy, 5098 bool HasVolatile) { 5099 QualType ParamTypes[2] = { 5100 S.Context.getLValueReferenceType(CandidateTy), 5101 S.Context.IntTy 5102 }; 5103 5104 // Non-volatile version. 5105 if (NumArgs == 1) 5106 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5107 else 5108 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5109 5110 // Use a heuristic to reduce number of builtin candidates in the set: 5111 // add volatile version only if there are conversions to a volatile type. 5112 if (HasVolatile) { 5113 ParamTypes[0] = 5114 S.Context.getLValueReferenceType( 5115 S.Context.getVolatileType(CandidateTy)); 5116 if (NumArgs == 1) 5117 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 5118 else 5119 S.AddBuiltinCandidate(CandidateTy, ParamTypes, Args, 2, CandidateSet); 5120 } 5121 } 5122 5123public: 5124 BuiltinOperatorOverloadBuilder( 5125 Sema &S, Expr **Args, unsigned NumArgs, 5126 Qualifiers VisibleTypeConversionsQuals, 5127 bool HasArithmeticOrEnumeralCandidateType, 5128 llvm::SmallVectorImpl<BuiltinCandidateTypeSet> &CandidateTypes, 5129 OverloadCandidateSet &CandidateSet) 5130 : S(S), Args(Args), NumArgs(NumArgs), 5131 VisibleTypeConversionsQuals(VisibleTypeConversionsQuals), 5132 HasArithmeticOrEnumeralCandidateType( 5133 HasArithmeticOrEnumeralCandidateType), 5134 CandidateTypes(CandidateTypes), 5135 CandidateSet(CandidateSet) { 5136 // Validate some of our static helper constants in debug builds. 5137 assert(getArithmeticType(FirstPromotedIntegralType) == S.Context.IntTy && 5138 "Invalid first promoted integral type"); 5139 assert(getArithmeticType(LastPromotedIntegralType - 1) 5140 == S.Context.UnsignedLongLongTy && 5141 "Invalid last promoted integral type"); 5142 assert(getArithmeticType(FirstPromotedArithmeticType) 5143 == S.Context.FloatTy && 5144 "Invalid first promoted arithmetic type"); 5145 assert(getArithmeticType(LastPromotedArithmeticType - 1) 5146 == S.Context.UnsignedLongLongTy && 5147 "Invalid last promoted arithmetic type"); 5148 } 5149 5150 // C++ [over.built]p3: 5151 // 5152 // For every pair (T, VQ), where T is an arithmetic type, and VQ 5153 // is either volatile or empty, there exist candidate operator 5154 // functions of the form 5155 // 5156 // VQ T& operator++(VQ T&); 5157 // T operator++(VQ T&, int); 5158 // 5159 // C++ [over.built]p4: 5160 // 5161 // For every pair (T, VQ), where T is an arithmetic type other 5162 // than bool, and VQ is either volatile or empty, there exist 5163 // candidate operator functions of the form 5164 // 5165 // VQ T& operator--(VQ T&); 5166 // T operator--(VQ T&, int); 5167 void addPlusPlusMinusMinusArithmeticOverloads(OverloadedOperatorKind Op) { 5168 if (!HasArithmeticOrEnumeralCandidateType) 5169 return; 5170 5171 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 5172 Arith < NumArithmeticTypes; ++Arith) { 5173 addPlusPlusMinusMinusStyleOverloads( 5174 getArithmeticType(Arith), 5175 VisibleTypeConversionsQuals.hasVolatile()); 5176 } 5177 } 5178 5179 // C++ [over.built]p5: 5180 // 5181 // For every pair (T, VQ), where T is a cv-qualified or 5182 // cv-unqualified object type, and VQ is either volatile or 5183 // empty, there exist candidate operator functions of the form 5184 // 5185 // T*VQ& operator++(T*VQ&); 5186 // T*VQ& operator--(T*VQ&); 5187 // T* operator++(T*VQ&, int); 5188 // T* operator--(T*VQ&, int); 5189 void addPlusPlusMinusMinusPointerOverloads() { 5190 for (BuiltinCandidateTypeSet::iterator 5191 Ptr = CandidateTypes[0].pointer_begin(), 5192 PtrEnd = CandidateTypes[0].pointer_end(); 5193 Ptr != PtrEnd; ++Ptr) { 5194 // Skip pointer types that aren't pointers to object types. 5195 if (!(*Ptr)->getPointeeType()->isObjectType()) 5196 continue; 5197 5198 addPlusPlusMinusMinusStyleOverloads(*Ptr, 5199 (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5200 VisibleTypeConversionsQuals.hasVolatile())); 5201 } 5202 } 5203 5204 // C++ [over.built]p6: 5205 // For every cv-qualified or cv-unqualified object type T, there 5206 // exist candidate operator functions of the form 5207 // 5208 // T& operator*(T*); 5209 // 5210 // C++ [over.built]p7: 5211 // For every function type T that does not have cv-qualifiers or a 5212 // ref-qualifier, there exist candidate operator functions of the form 5213 // T& operator*(T*); 5214 void addUnaryStarPointerOverloads() { 5215 for (BuiltinCandidateTypeSet::iterator 5216 Ptr = CandidateTypes[0].pointer_begin(), 5217 PtrEnd = CandidateTypes[0].pointer_end(); 5218 Ptr != PtrEnd; ++Ptr) { 5219 QualType ParamTy = *Ptr; 5220 QualType PointeeTy = ParamTy->getPointeeType(); 5221 if (!PointeeTy->isObjectType() && !PointeeTy->isFunctionType()) 5222 continue; 5223 5224 if (const FunctionProtoType *Proto =PointeeTy->getAs<FunctionProtoType>()) 5225 if (Proto->getTypeQuals() || Proto->getRefQualifier()) 5226 continue; 5227 5228 S.AddBuiltinCandidate(S.Context.getLValueReferenceType(PointeeTy), 5229 &ParamTy, Args, 1, CandidateSet); 5230 } 5231 } 5232 5233 // C++ [over.built]p9: 5234 // For every promoted arithmetic type T, there exist candidate 5235 // operator functions of the form 5236 // 5237 // T operator+(T); 5238 // T operator-(T); 5239 void addUnaryPlusOrMinusArithmeticOverloads() { 5240 if (!HasArithmeticOrEnumeralCandidateType) 5241 return; 5242 5243 for (unsigned Arith = FirstPromotedArithmeticType; 5244 Arith < LastPromotedArithmeticType; ++Arith) { 5245 QualType ArithTy = getArithmeticType(Arith); 5246 S.AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 5247 } 5248 5249 // Extension: We also add these operators for vector types. 5250 for (BuiltinCandidateTypeSet::iterator 5251 Vec = CandidateTypes[0].vector_begin(), 5252 VecEnd = CandidateTypes[0].vector_end(); 5253 Vec != VecEnd; ++Vec) { 5254 QualType VecTy = *Vec; 5255 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5256 } 5257 } 5258 5259 // C++ [over.built]p8: 5260 // For every type T, there exist candidate operator functions of 5261 // the form 5262 // 5263 // T* operator+(T*); 5264 void addUnaryPlusPointerOverloads() { 5265 for (BuiltinCandidateTypeSet::iterator 5266 Ptr = CandidateTypes[0].pointer_begin(), 5267 PtrEnd = CandidateTypes[0].pointer_end(); 5268 Ptr != PtrEnd; ++Ptr) { 5269 QualType ParamTy = *Ptr; 5270 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 5271 } 5272 } 5273 5274 // C++ [over.built]p10: 5275 // For every promoted integral type T, there exist candidate 5276 // operator functions of the form 5277 // 5278 // T operator~(T); 5279 void addUnaryTildePromotedIntegralOverloads() { 5280 if (!HasArithmeticOrEnumeralCandidateType) 5281 return; 5282 5283 for (unsigned Int = FirstPromotedIntegralType; 5284 Int < LastPromotedIntegralType; ++Int) { 5285 QualType IntTy = getArithmeticType(Int); 5286 S.AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 5287 } 5288 5289 // Extension: We also add this operator for vector types. 5290 for (BuiltinCandidateTypeSet::iterator 5291 Vec = CandidateTypes[0].vector_begin(), 5292 VecEnd = CandidateTypes[0].vector_end(); 5293 Vec != VecEnd; ++Vec) { 5294 QualType VecTy = *Vec; 5295 S.AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 5296 } 5297 } 5298 5299 // C++ [over.match.oper]p16: 5300 // For every pointer to member type T, there exist candidate operator 5301 // functions of the form 5302 // 5303 // bool operator==(T,T); 5304 // bool operator!=(T,T); 5305 void addEqualEqualOrNotEqualMemberPointerOverloads() { 5306 /// Set of (canonical) types that we've already handled. 5307 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5308 5309 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5310 for (BuiltinCandidateTypeSet::iterator 5311 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5312 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5313 MemPtr != MemPtrEnd; 5314 ++MemPtr) { 5315 // Don't add the same builtin candidate twice. 5316 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5317 continue; 5318 5319 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5320 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5321 CandidateSet); 5322 } 5323 } 5324 } 5325 5326 // C++ [over.built]p15: 5327 // 5328 // For every pointer or enumeration type T, there exist 5329 // candidate operator functions of the form 5330 // 5331 // bool operator<(T, T); 5332 // bool operator>(T, T); 5333 // bool operator<=(T, T); 5334 // bool operator>=(T, T); 5335 // bool operator==(T, T); 5336 // bool operator!=(T, T); 5337 void addRelationalPointerOrEnumeralOverloads() { 5338 // C++ [over.built]p1: 5339 // If there is a user-written candidate with the same name and parameter 5340 // types as a built-in candidate operator function, the built-in operator 5341 // function is hidden and is not included in the set of candidate 5342 // functions. 5343 // 5344 // The text is actually in a note, but if we don't implement it then we end 5345 // up with ambiguities when the user provides an overloaded operator for 5346 // an enumeration type. Note that only enumeration types have this problem, 5347 // so we track which enumeration types we've seen operators for. Also, the 5348 // only other overloaded operator with enumeration argumenst, operator=, 5349 // cannot be overloaded for enumeration types, so this is the only place 5350 // where we must suppress candidates like this. 5351 llvm::DenseSet<std::pair<CanQualType, CanQualType> > 5352 UserDefinedBinaryOperators; 5353 5354 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5355 if (CandidateTypes[ArgIdx].enumeration_begin() != 5356 CandidateTypes[ArgIdx].enumeration_end()) { 5357 for (OverloadCandidateSet::iterator C = CandidateSet.begin(), 5358 CEnd = CandidateSet.end(); 5359 C != CEnd; ++C) { 5360 if (!C->Viable || !C->Function || C->Function->getNumParams() != 2) 5361 continue; 5362 5363 QualType FirstParamType = 5364 C->Function->getParamDecl(0)->getType().getUnqualifiedType(); 5365 QualType SecondParamType = 5366 C->Function->getParamDecl(1)->getType().getUnqualifiedType(); 5367 5368 // Skip if either parameter isn't of enumeral type. 5369 if (!FirstParamType->isEnumeralType() || 5370 !SecondParamType->isEnumeralType()) 5371 continue; 5372 5373 // Add this operator to the set of known user-defined operators. 5374 UserDefinedBinaryOperators.insert( 5375 std::make_pair(S.Context.getCanonicalType(FirstParamType), 5376 S.Context.getCanonicalType(SecondParamType))); 5377 } 5378 } 5379 } 5380 5381 /// Set of (canonical) types that we've already handled. 5382 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5383 5384 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5385 for (BuiltinCandidateTypeSet::iterator 5386 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5387 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5388 Ptr != PtrEnd; ++Ptr) { 5389 // Don't add the same builtin candidate twice. 5390 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5391 continue; 5392 5393 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5394 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5395 CandidateSet); 5396 } 5397 for (BuiltinCandidateTypeSet::iterator 5398 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5399 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5400 Enum != EnumEnd; ++Enum) { 5401 CanQualType CanonType = S.Context.getCanonicalType(*Enum); 5402 5403 // Don't add the same builtin candidate twice, or if a user defined 5404 // candidate exists. 5405 if (!AddedTypes.insert(CanonType) || 5406 UserDefinedBinaryOperators.count(std::make_pair(CanonType, 5407 CanonType))) 5408 continue; 5409 5410 QualType ParamTypes[2] = { *Enum, *Enum }; 5411 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, 5412 CandidateSet); 5413 } 5414 } 5415 } 5416 5417 // C++ [over.built]p13: 5418 // 5419 // For every cv-qualified or cv-unqualified object type T 5420 // there exist candidate operator functions of the form 5421 // 5422 // T* operator+(T*, ptrdiff_t); 5423 // T& operator[](T*, ptrdiff_t); [BELOW] 5424 // T* operator-(T*, ptrdiff_t); 5425 // T* operator+(ptrdiff_t, T*); 5426 // T& operator[](ptrdiff_t, T*); [BELOW] 5427 // 5428 // C++ [over.built]p14: 5429 // 5430 // For every T, where T is a pointer to object type, there 5431 // exist candidate operator functions of the form 5432 // 5433 // ptrdiff_t operator-(T, T); 5434 void addBinaryPlusOrMinusPointerOverloads(OverloadedOperatorKind Op) { 5435 /// Set of (canonical) types that we've already handled. 5436 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5437 5438 for (int Arg = 0; Arg < 2; ++Arg) { 5439 QualType AsymetricParamTypes[2] = { 5440 S.Context.getPointerDiffType(), 5441 S.Context.getPointerDiffType(), 5442 }; 5443 for (BuiltinCandidateTypeSet::iterator 5444 Ptr = CandidateTypes[Arg].pointer_begin(), 5445 PtrEnd = CandidateTypes[Arg].pointer_end(); 5446 Ptr != PtrEnd; ++Ptr) { 5447 QualType PointeeTy = (*Ptr)->getPointeeType(); 5448 if (!PointeeTy->isObjectType()) 5449 continue; 5450 5451 AsymetricParamTypes[Arg] = *Ptr; 5452 if (Arg == 0 || Op == OO_Plus) { 5453 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 5454 // T* operator+(ptrdiff_t, T*); 5455 S.AddBuiltinCandidate(*Ptr, AsymetricParamTypes, Args, 2, 5456 CandidateSet); 5457 } 5458 if (Op == OO_Minus) { 5459 // ptrdiff_t operator-(T, T); 5460 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5461 continue; 5462 5463 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5464 S.AddBuiltinCandidate(S.Context.getPointerDiffType(), ParamTypes, 5465 Args, 2, CandidateSet); 5466 } 5467 } 5468 } 5469 } 5470 5471 // C++ [over.built]p12: 5472 // 5473 // For every pair of promoted arithmetic types L and R, there 5474 // exist candidate operator functions of the form 5475 // 5476 // LR operator*(L, R); 5477 // LR operator/(L, R); 5478 // LR operator+(L, R); 5479 // LR operator-(L, R); 5480 // bool operator<(L, R); 5481 // bool operator>(L, R); 5482 // bool operator<=(L, R); 5483 // bool operator>=(L, R); 5484 // bool operator==(L, R); 5485 // bool operator!=(L, R); 5486 // 5487 // where LR is the result of the usual arithmetic conversions 5488 // between types L and R. 5489 // 5490 // C++ [over.built]p24: 5491 // 5492 // For every pair of promoted arithmetic types L and R, there exist 5493 // candidate operator functions of the form 5494 // 5495 // LR operator?(bool, L, R); 5496 // 5497 // where LR is the result of the usual arithmetic conversions 5498 // between types L and R. 5499 // Our candidates ignore the first parameter. 5500 void addGenericBinaryArithmeticOverloads(bool isComparison) { 5501 if (!HasArithmeticOrEnumeralCandidateType) 5502 return; 5503 5504 for (unsigned Left = FirstPromotedArithmeticType; 5505 Left < LastPromotedArithmeticType; ++Left) { 5506 for (unsigned Right = FirstPromotedArithmeticType; 5507 Right < LastPromotedArithmeticType; ++Right) { 5508 QualType LandR[2] = { getArithmeticType(Left), 5509 getArithmeticType(Right) }; 5510 QualType Result = 5511 isComparison ? S.Context.BoolTy 5512 : getUsualArithmeticConversions(Left, Right); 5513 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5514 } 5515 } 5516 5517 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 5518 // conditional operator for vector types. 5519 for (BuiltinCandidateTypeSet::iterator 5520 Vec1 = CandidateTypes[0].vector_begin(), 5521 Vec1End = CandidateTypes[0].vector_end(); 5522 Vec1 != Vec1End; ++Vec1) { 5523 for (BuiltinCandidateTypeSet::iterator 5524 Vec2 = CandidateTypes[1].vector_begin(), 5525 Vec2End = CandidateTypes[1].vector_end(); 5526 Vec2 != Vec2End; ++Vec2) { 5527 QualType LandR[2] = { *Vec1, *Vec2 }; 5528 QualType Result = S.Context.BoolTy; 5529 if (!isComparison) { 5530 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 5531 Result = *Vec1; 5532 else 5533 Result = *Vec2; 5534 } 5535 5536 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5537 } 5538 } 5539 } 5540 5541 // C++ [over.built]p17: 5542 // 5543 // For every pair of promoted integral types L and R, there 5544 // exist candidate operator functions of the form 5545 // 5546 // LR operator%(L, R); 5547 // LR operator&(L, R); 5548 // LR operator^(L, R); 5549 // LR operator|(L, R); 5550 // L operator<<(L, R); 5551 // L operator>>(L, R); 5552 // 5553 // where LR is the result of the usual arithmetic conversions 5554 // between types L and R. 5555 void addBinaryBitwiseArithmeticOverloads(OverloadedOperatorKind Op) { 5556 if (!HasArithmeticOrEnumeralCandidateType) 5557 return; 5558 5559 for (unsigned Left = FirstPromotedIntegralType; 5560 Left < LastPromotedIntegralType; ++Left) { 5561 for (unsigned Right = FirstPromotedIntegralType; 5562 Right < LastPromotedIntegralType; ++Right) { 5563 QualType LandR[2] = { getArithmeticType(Left), 5564 getArithmeticType(Right) }; 5565 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 5566 ? LandR[0] 5567 : getUsualArithmeticConversions(Left, Right); 5568 S.AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 5569 } 5570 } 5571 } 5572 5573 // C++ [over.built]p20: 5574 // 5575 // For every pair (T, VQ), where T is an enumeration or 5576 // pointer to member type and VQ is either volatile or 5577 // empty, there exist candidate operator functions of the form 5578 // 5579 // VQ T& operator=(VQ T&, T); 5580 void addAssignmentMemberPointerOrEnumeralOverloads() { 5581 /// Set of (canonical) types that we've already handled. 5582 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5583 5584 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5585 for (BuiltinCandidateTypeSet::iterator 5586 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5587 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5588 Enum != EnumEnd; ++Enum) { 5589 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5590 continue; 5591 5592 AddBuiltinAssignmentOperatorCandidates(S, *Enum, Args, 2, 5593 CandidateSet); 5594 } 5595 5596 for (BuiltinCandidateTypeSet::iterator 5597 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5598 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5599 MemPtr != MemPtrEnd; ++MemPtr) { 5600 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5601 continue; 5602 5603 AddBuiltinAssignmentOperatorCandidates(S, *MemPtr, Args, 2, 5604 CandidateSet); 5605 } 5606 } 5607 } 5608 5609 // C++ [over.built]p19: 5610 // 5611 // For every pair (T, VQ), where T is any type and VQ is either 5612 // volatile or empty, there exist candidate operator functions 5613 // of the form 5614 // 5615 // T*VQ& operator=(T*VQ&, T*); 5616 // 5617 // C++ [over.built]p21: 5618 // 5619 // For every pair (T, VQ), where T is a cv-qualified or 5620 // cv-unqualified object type and VQ is either volatile or 5621 // empty, there exist candidate operator functions of the form 5622 // 5623 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 5624 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 5625 void addAssignmentPointerOverloads(bool isEqualOp) { 5626 /// Set of (canonical) types that we've already handled. 5627 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5628 5629 for (BuiltinCandidateTypeSet::iterator 5630 Ptr = CandidateTypes[0].pointer_begin(), 5631 PtrEnd = CandidateTypes[0].pointer_end(); 5632 Ptr != PtrEnd; ++Ptr) { 5633 // If this is operator=, keep track of the builtin candidates we added. 5634 if (isEqualOp) 5635 AddedTypes.insert(S.Context.getCanonicalType(*Ptr)); 5636 else if (!(*Ptr)->getPointeeType()->isObjectType()) 5637 continue; 5638 5639 // non-volatile version 5640 QualType ParamTypes[2] = { 5641 S.Context.getLValueReferenceType(*Ptr), 5642 isEqualOp ? *Ptr : S.Context.getPointerDiffType(), 5643 }; 5644 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5645 /*IsAssigmentOperator=*/ isEqualOp); 5646 5647 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5648 VisibleTypeConversionsQuals.hasVolatile()) { 5649 // volatile version 5650 ParamTypes[0] = 5651 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5652 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5653 /*IsAssigmentOperator=*/isEqualOp); 5654 } 5655 } 5656 5657 if (isEqualOp) { 5658 for (BuiltinCandidateTypeSet::iterator 5659 Ptr = CandidateTypes[1].pointer_begin(), 5660 PtrEnd = CandidateTypes[1].pointer_end(); 5661 Ptr != PtrEnd; ++Ptr) { 5662 // Make sure we don't add the same candidate twice. 5663 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5664 continue; 5665 5666 QualType ParamTypes[2] = { 5667 S.Context.getLValueReferenceType(*Ptr), 5668 *Ptr, 5669 }; 5670 5671 // non-volatile version 5672 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5673 /*IsAssigmentOperator=*/true); 5674 5675 if (!S.Context.getCanonicalType(*Ptr).isVolatileQualified() && 5676 VisibleTypeConversionsQuals.hasVolatile()) { 5677 // volatile version 5678 ParamTypes[0] = 5679 S.Context.getLValueReferenceType(S.Context.getVolatileType(*Ptr)); 5680 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5681 CandidateSet, /*IsAssigmentOperator=*/true); 5682 } 5683 } 5684 } 5685 } 5686 5687 // C++ [over.built]p18: 5688 // 5689 // For every triple (L, VQ, R), where L is an arithmetic type, 5690 // VQ is either volatile or empty, and R is a promoted 5691 // arithmetic type, there exist candidate operator functions of 5692 // the form 5693 // 5694 // VQ L& operator=(VQ L&, R); 5695 // VQ L& operator*=(VQ L&, R); 5696 // VQ L& operator/=(VQ L&, R); 5697 // VQ L& operator+=(VQ L&, R); 5698 // VQ L& operator-=(VQ L&, R); 5699 void addAssignmentArithmeticOverloads(bool isEqualOp) { 5700 if (!HasArithmeticOrEnumeralCandidateType) 5701 return; 5702 5703 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 5704 for (unsigned Right = FirstPromotedArithmeticType; 5705 Right < LastPromotedArithmeticType; ++Right) { 5706 QualType ParamTypes[2]; 5707 ParamTypes[1] = getArithmeticType(Right); 5708 5709 // Add this built-in operator as a candidate (VQ is empty). 5710 ParamTypes[0] = 5711 S.Context.getLValueReferenceType(getArithmeticType(Left)); 5712 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5713 /*IsAssigmentOperator=*/isEqualOp); 5714 5715 // Add this built-in operator as a candidate (VQ is 'volatile'). 5716 if (VisibleTypeConversionsQuals.hasVolatile()) { 5717 ParamTypes[0] = 5718 S.Context.getVolatileType(getArithmeticType(Left)); 5719 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5720 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5721 CandidateSet, 5722 /*IsAssigmentOperator=*/isEqualOp); 5723 } 5724 } 5725 } 5726 5727 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 5728 for (BuiltinCandidateTypeSet::iterator 5729 Vec1 = CandidateTypes[0].vector_begin(), 5730 Vec1End = CandidateTypes[0].vector_end(); 5731 Vec1 != Vec1End; ++Vec1) { 5732 for (BuiltinCandidateTypeSet::iterator 5733 Vec2 = CandidateTypes[1].vector_begin(), 5734 Vec2End = CandidateTypes[1].vector_end(); 5735 Vec2 != Vec2End; ++Vec2) { 5736 QualType ParamTypes[2]; 5737 ParamTypes[1] = *Vec2; 5738 // Add this built-in operator as a candidate (VQ is empty). 5739 ParamTypes[0] = S.Context.getLValueReferenceType(*Vec1); 5740 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5741 /*IsAssigmentOperator=*/isEqualOp); 5742 5743 // Add this built-in operator as a candidate (VQ is 'volatile'). 5744 if (VisibleTypeConversionsQuals.hasVolatile()) { 5745 ParamTypes[0] = S.Context.getVolatileType(*Vec1); 5746 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5747 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5748 CandidateSet, 5749 /*IsAssigmentOperator=*/isEqualOp); 5750 } 5751 } 5752 } 5753 } 5754 5755 // C++ [over.built]p22: 5756 // 5757 // For every triple (L, VQ, R), where L is an integral type, VQ 5758 // is either volatile or empty, and R is a promoted integral 5759 // type, there exist candidate operator functions of the form 5760 // 5761 // VQ L& operator%=(VQ L&, R); 5762 // VQ L& operator<<=(VQ L&, R); 5763 // VQ L& operator>>=(VQ L&, R); 5764 // VQ L& operator&=(VQ L&, R); 5765 // VQ L& operator^=(VQ L&, R); 5766 // VQ L& operator|=(VQ L&, R); 5767 void addAssignmentIntegralOverloads() { 5768 if (!HasArithmeticOrEnumeralCandidateType) 5769 return; 5770 5771 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 5772 for (unsigned Right = FirstPromotedIntegralType; 5773 Right < LastPromotedIntegralType; ++Right) { 5774 QualType ParamTypes[2]; 5775 ParamTypes[1] = getArithmeticType(Right); 5776 5777 // Add this built-in operator as a candidate (VQ is empty). 5778 ParamTypes[0] = 5779 S.Context.getLValueReferenceType(getArithmeticType(Left)); 5780 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5781 if (VisibleTypeConversionsQuals.hasVolatile()) { 5782 // Add this built-in operator as a candidate (VQ is 'volatile'). 5783 ParamTypes[0] = getArithmeticType(Left); 5784 ParamTypes[0] = S.Context.getVolatileType(ParamTypes[0]); 5785 ParamTypes[0] = S.Context.getLValueReferenceType(ParamTypes[0]); 5786 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, 5787 CandidateSet); 5788 } 5789 } 5790 } 5791 } 5792 5793 // C++ [over.operator]p23: 5794 // 5795 // There also exist candidate operator functions of the form 5796 // 5797 // bool operator!(bool); 5798 // bool operator&&(bool, bool); 5799 // bool operator||(bool, bool); 5800 void addExclaimOverload() { 5801 QualType ParamTy = S.Context.BoolTy; 5802 S.AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 5803 /*IsAssignmentOperator=*/false, 5804 /*NumContextualBoolArguments=*/1); 5805 } 5806 void addAmpAmpOrPipePipeOverload() { 5807 QualType ParamTypes[2] = { S.Context.BoolTy, S.Context.BoolTy }; 5808 S.AddBuiltinCandidate(S.Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 5809 /*IsAssignmentOperator=*/false, 5810 /*NumContextualBoolArguments=*/2); 5811 } 5812 5813 // C++ [over.built]p13: 5814 // 5815 // For every cv-qualified or cv-unqualified object type T there 5816 // exist candidate operator functions of the form 5817 // 5818 // T* operator+(T*, ptrdiff_t); [ABOVE] 5819 // T& operator[](T*, ptrdiff_t); 5820 // T* operator-(T*, ptrdiff_t); [ABOVE] 5821 // T* operator+(ptrdiff_t, T*); [ABOVE] 5822 // T& operator[](ptrdiff_t, T*); 5823 void addSubscriptOverloads() { 5824 for (BuiltinCandidateTypeSet::iterator 5825 Ptr = CandidateTypes[0].pointer_begin(), 5826 PtrEnd = CandidateTypes[0].pointer_end(); 5827 Ptr != PtrEnd; ++Ptr) { 5828 QualType ParamTypes[2] = { *Ptr, S.Context.getPointerDiffType() }; 5829 QualType PointeeType = (*Ptr)->getPointeeType(); 5830 if (!PointeeType->isObjectType()) 5831 continue; 5832 5833 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 5834 5835 // T& operator[](T*, ptrdiff_t) 5836 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5837 } 5838 5839 for (BuiltinCandidateTypeSet::iterator 5840 Ptr = CandidateTypes[1].pointer_begin(), 5841 PtrEnd = CandidateTypes[1].pointer_end(); 5842 Ptr != PtrEnd; ++Ptr) { 5843 QualType ParamTypes[2] = { S.Context.getPointerDiffType(), *Ptr }; 5844 QualType PointeeType = (*Ptr)->getPointeeType(); 5845 if (!PointeeType->isObjectType()) 5846 continue; 5847 5848 QualType ResultTy = S.Context.getLValueReferenceType(PointeeType); 5849 5850 // T& operator[](ptrdiff_t, T*) 5851 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5852 } 5853 } 5854 5855 // C++ [over.built]p11: 5856 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 5857 // C1 is the same type as C2 or is a derived class of C2, T is an object 5858 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 5859 // there exist candidate operator functions of the form 5860 // 5861 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 5862 // 5863 // where CV12 is the union of CV1 and CV2. 5864 void addArrowStarOverloads() { 5865 for (BuiltinCandidateTypeSet::iterator 5866 Ptr = CandidateTypes[0].pointer_begin(), 5867 PtrEnd = CandidateTypes[0].pointer_end(); 5868 Ptr != PtrEnd; ++Ptr) { 5869 QualType C1Ty = (*Ptr); 5870 QualType C1; 5871 QualifierCollector Q1; 5872 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 5873 if (!isa<RecordType>(C1)) 5874 continue; 5875 // heuristic to reduce number of builtin candidates in the set. 5876 // Add volatile/restrict version only if there are conversions to a 5877 // volatile/restrict type. 5878 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 5879 continue; 5880 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 5881 continue; 5882 for (BuiltinCandidateTypeSet::iterator 5883 MemPtr = CandidateTypes[1].member_pointer_begin(), 5884 MemPtrEnd = CandidateTypes[1].member_pointer_end(); 5885 MemPtr != MemPtrEnd; ++MemPtr) { 5886 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 5887 QualType C2 = QualType(mptr->getClass(), 0); 5888 C2 = C2.getUnqualifiedType(); 5889 if (C1 != C2 && !S.IsDerivedFrom(C1, C2)) 5890 break; 5891 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 5892 // build CV12 T& 5893 QualType T = mptr->getPointeeType(); 5894 if (!VisibleTypeConversionsQuals.hasVolatile() && 5895 T.isVolatileQualified()) 5896 continue; 5897 if (!VisibleTypeConversionsQuals.hasRestrict() && 5898 T.isRestrictQualified()) 5899 continue; 5900 T = Q1.apply(S.Context, T); 5901 QualType ResultTy = S.Context.getLValueReferenceType(T); 5902 S.AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5903 } 5904 } 5905 } 5906 5907 // Note that we don't consider the first argument, since it has been 5908 // contextually converted to bool long ago. The candidates below are 5909 // therefore added as binary. 5910 // 5911 // C++ [over.built]p25: 5912 // For every type T, where T is a pointer, pointer-to-member, or scoped 5913 // enumeration type, there exist candidate operator functions of the form 5914 // 5915 // T operator?(bool, T, T); 5916 // 5917 void addConditionalOperatorOverloads() { 5918 /// Set of (canonical) types that we've already handled. 5919 llvm::SmallPtrSet<QualType, 8> AddedTypes; 5920 5921 for (unsigned ArgIdx = 0; ArgIdx < 2; ++ArgIdx) { 5922 for (BuiltinCandidateTypeSet::iterator 5923 Ptr = CandidateTypes[ArgIdx].pointer_begin(), 5924 PtrEnd = CandidateTypes[ArgIdx].pointer_end(); 5925 Ptr != PtrEnd; ++Ptr) { 5926 if (!AddedTypes.insert(S.Context.getCanonicalType(*Ptr))) 5927 continue; 5928 5929 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5930 S.AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5931 } 5932 5933 for (BuiltinCandidateTypeSet::iterator 5934 MemPtr = CandidateTypes[ArgIdx].member_pointer_begin(), 5935 MemPtrEnd = CandidateTypes[ArgIdx].member_pointer_end(); 5936 MemPtr != MemPtrEnd; ++MemPtr) { 5937 if (!AddedTypes.insert(S.Context.getCanonicalType(*MemPtr))) 5938 continue; 5939 5940 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 5941 S.AddBuiltinCandidate(*MemPtr, ParamTypes, Args, 2, CandidateSet); 5942 } 5943 5944 if (S.getLangOptions().CPlusPlus0x) { 5945 for (BuiltinCandidateTypeSet::iterator 5946 Enum = CandidateTypes[ArgIdx].enumeration_begin(), 5947 EnumEnd = CandidateTypes[ArgIdx].enumeration_end(); 5948 Enum != EnumEnd; ++Enum) { 5949 if (!(*Enum)->getAs<EnumType>()->getDecl()->isScoped()) 5950 continue; 5951 5952 if (!AddedTypes.insert(S.Context.getCanonicalType(*Enum))) 5953 continue; 5954 5955 QualType ParamTypes[2] = { *Enum, *Enum }; 5956 S.AddBuiltinCandidate(*Enum, ParamTypes, Args, 2, CandidateSet); 5957 } 5958 } 5959 } 5960 } 5961}; 5962 5963} // end anonymous namespace 5964 5965/// AddBuiltinOperatorCandidates - Add the appropriate built-in 5966/// operator overloads to the candidate set (C++ [over.built]), based 5967/// on the operator @p Op and the arguments given. For example, if the 5968/// operator is a binary '+', this routine might add "int 5969/// operator+(int, int)" to cover integer addition. 5970void 5971Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 5972 SourceLocation OpLoc, 5973 Expr **Args, unsigned NumArgs, 5974 OverloadCandidateSet& CandidateSet) { 5975 // Find all of the types that the arguments can convert to, but only 5976 // if the operator we're looking at has built-in operator candidates 5977 // that make use of these types. Also record whether we encounter non-record 5978 // candidate types or either arithmetic or enumeral candidate types. 5979 Qualifiers VisibleTypeConversionsQuals; 5980 VisibleTypeConversionsQuals.addConst(); 5981 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 5982 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 5983 5984 bool HasNonRecordCandidateType = false; 5985 bool HasArithmeticOrEnumeralCandidateType = false; 5986 llvm::SmallVector<BuiltinCandidateTypeSet, 2> CandidateTypes; 5987 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 5988 CandidateTypes.push_back(BuiltinCandidateTypeSet(*this)); 5989 CandidateTypes[ArgIdx].AddTypesConvertedFrom(Args[ArgIdx]->getType(), 5990 OpLoc, 5991 true, 5992 (Op == OO_Exclaim || 5993 Op == OO_AmpAmp || 5994 Op == OO_PipePipe), 5995 VisibleTypeConversionsQuals); 5996 HasNonRecordCandidateType = HasNonRecordCandidateType || 5997 CandidateTypes[ArgIdx].hasNonRecordTypes(); 5998 HasArithmeticOrEnumeralCandidateType = 5999 HasArithmeticOrEnumeralCandidateType || 6000 CandidateTypes[ArgIdx].hasArithmeticOrEnumeralTypes(); 6001 } 6002 6003 // Exit early when no non-record types have been added to the candidate set 6004 // for any of the arguments to the operator. 6005 if (!HasNonRecordCandidateType) 6006 return; 6007 6008 // Setup an object to manage the common state for building overloads. 6009 BuiltinOperatorOverloadBuilder OpBuilder(*this, Args, NumArgs, 6010 VisibleTypeConversionsQuals, 6011 HasArithmeticOrEnumeralCandidateType, 6012 CandidateTypes, CandidateSet); 6013 6014 // Dispatch over the operation to add in only those overloads which apply. 6015 switch (Op) { 6016 case OO_None: 6017 case NUM_OVERLOADED_OPERATORS: 6018 assert(false && "Expected an overloaded operator"); 6019 break; 6020 6021 case OO_New: 6022 case OO_Delete: 6023 case OO_Array_New: 6024 case OO_Array_Delete: 6025 case OO_Call: 6026 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 6027 break; 6028 6029 case OO_Comma: 6030 case OO_Arrow: 6031 // C++ [over.match.oper]p3: 6032 // -- For the operator ',', the unary operator '&', or the 6033 // operator '->', the built-in candidates set is empty. 6034 break; 6035 6036 case OO_Plus: // '+' is either unary or binary 6037 if (NumArgs == 1) 6038 OpBuilder.addUnaryPlusPointerOverloads(); 6039 // Fall through. 6040 6041 case OO_Minus: // '-' is either unary or binary 6042 if (NumArgs == 1) { 6043 OpBuilder.addUnaryPlusOrMinusArithmeticOverloads(); 6044 } else { 6045 OpBuilder.addBinaryPlusOrMinusPointerOverloads(Op); 6046 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6047 } 6048 break; 6049 6050 case OO_Star: // '*' is either unary or binary 6051 if (NumArgs == 1) 6052 OpBuilder.addUnaryStarPointerOverloads(); 6053 else 6054 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6055 break; 6056 6057 case OO_Slash: 6058 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6059 break; 6060 6061 case OO_PlusPlus: 6062 case OO_MinusMinus: 6063 OpBuilder.addPlusPlusMinusMinusArithmeticOverloads(Op); 6064 OpBuilder.addPlusPlusMinusMinusPointerOverloads(); 6065 break; 6066 6067 case OO_EqualEqual: 6068 case OO_ExclaimEqual: 6069 OpBuilder.addEqualEqualOrNotEqualMemberPointerOverloads(); 6070 // Fall through. 6071 6072 case OO_Less: 6073 case OO_Greater: 6074 case OO_LessEqual: 6075 case OO_GreaterEqual: 6076 OpBuilder.addRelationalPointerOrEnumeralOverloads(); 6077 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/true); 6078 break; 6079 6080 case OO_Percent: 6081 case OO_Caret: 6082 case OO_Pipe: 6083 case OO_LessLess: 6084 case OO_GreaterGreater: 6085 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6086 break; 6087 6088 case OO_Amp: // '&' is either unary or binary 6089 if (NumArgs == 1) 6090 // C++ [over.match.oper]p3: 6091 // -- For the operator ',', the unary operator '&', or the 6092 // operator '->', the built-in candidates set is empty. 6093 break; 6094 6095 OpBuilder.addBinaryBitwiseArithmeticOverloads(Op); 6096 break; 6097 6098 case OO_Tilde: 6099 OpBuilder.addUnaryTildePromotedIntegralOverloads(); 6100 break; 6101 6102 case OO_Equal: 6103 OpBuilder.addAssignmentMemberPointerOrEnumeralOverloads(); 6104 // Fall through. 6105 6106 case OO_PlusEqual: 6107 case OO_MinusEqual: 6108 OpBuilder.addAssignmentPointerOverloads(Op == OO_Equal); 6109 // Fall through. 6110 6111 case OO_StarEqual: 6112 case OO_SlashEqual: 6113 OpBuilder.addAssignmentArithmeticOverloads(Op == OO_Equal); 6114 break; 6115 6116 case OO_PercentEqual: 6117 case OO_LessLessEqual: 6118 case OO_GreaterGreaterEqual: 6119 case OO_AmpEqual: 6120 case OO_CaretEqual: 6121 case OO_PipeEqual: 6122 OpBuilder.addAssignmentIntegralOverloads(); 6123 break; 6124 6125 case OO_Exclaim: 6126 OpBuilder.addExclaimOverload(); 6127 break; 6128 6129 case OO_AmpAmp: 6130 case OO_PipePipe: 6131 OpBuilder.addAmpAmpOrPipePipeOverload(); 6132 break; 6133 6134 case OO_Subscript: 6135 OpBuilder.addSubscriptOverloads(); 6136 break; 6137 6138 case OO_ArrowStar: 6139 OpBuilder.addArrowStarOverloads(); 6140 break; 6141 6142 case OO_Conditional: 6143 OpBuilder.addConditionalOperatorOverloads(); 6144 OpBuilder.addGenericBinaryArithmeticOverloads(/*isComparison=*/false); 6145 break; 6146 } 6147} 6148 6149/// \brief Add function candidates found via argument-dependent lookup 6150/// to the set of overloading candidates. 6151/// 6152/// This routine performs argument-dependent name lookup based on the 6153/// given function name (which may also be an operator name) and adds 6154/// all of the overload candidates found by ADL to the overload 6155/// candidate set (C++ [basic.lookup.argdep]). 6156void 6157Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 6158 bool Operator, 6159 Expr **Args, unsigned NumArgs, 6160 TemplateArgumentListInfo *ExplicitTemplateArgs, 6161 OverloadCandidateSet& CandidateSet, 6162 bool PartialOverloading, 6163 bool StdNamespaceIsAssociated) { 6164 ADLResult Fns; 6165 6166 // FIXME: This approach for uniquing ADL results (and removing 6167 // redundant candidates from the set) relies on pointer-equality, 6168 // which means we need to key off the canonical decl. However, 6169 // always going back to the canonical decl might not get us the 6170 // right set of default arguments. What default arguments are 6171 // we supposed to consider on ADL candidates, anyway? 6172 6173 // FIXME: Pass in the explicit template arguments? 6174 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns, 6175 StdNamespaceIsAssociated); 6176 6177 // Erase all of the candidates we already knew about. 6178 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 6179 CandEnd = CandidateSet.end(); 6180 Cand != CandEnd; ++Cand) 6181 if (Cand->Function) { 6182 Fns.erase(Cand->Function); 6183 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 6184 Fns.erase(FunTmpl); 6185 } 6186 6187 // For each of the ADL candidates we found, add it to the overload 6188 // set. 6189 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 6190 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 6191 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 6192 if (ExplicitTemplateArgs) 6193 continue; 6194 6195 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 6196 false, PartialOverloading); 6197 } else 6198 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 6199 FoundDecl, ExplicitTemplateArgs, 6200 Args, NumArgs, CandidateSet); 6201 } 6202} 6203 6204/// isBetterOverloadCandidate - Determines whether the first overload 6205/// candidate is a better candidate than the second (C++ 13.3.3p1). 6206bool 6207isBetterOverloadCandidate(Sema &S, 6208 const OverloadCandidate &Cand1, 6209 const OverloadCandidate &Cand2, 6210 SourceLocation Loc, 6211 bool UserDefinedConversion) { 6212 // Define viable functions to be better candidates than non-viable 6213 // functions. 6214 if (!Cand2.Viable) 6215 return Cand1.Viable; 6216 else if (!Cand1.Viable) 6217 return false; 6218 6219 // C++ [over.match.best]p1: 6220 // 6221 // -- if F is a static member function, ICS1(F) is defined such 6222 // that ICS1(F) is neither better nor worse than ICS1(G) for 6223 // any function G, and, symmetrically, ICS1(G) is neither 6224 // better nor worse than ICS1(F). 6225 unsigned StartArg = 0; 6226 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 6227 StartArg = 1; 6228 6229 // C++ [over.match.best]p1: 6230 // A viable function F1 is defined to be a better function than another 6231 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 6232 // conversion sequence than ICSi(F2), and then... 6233 unsigned NumArgs = Cand1.Conversions.size(); 6234 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 6235 bool HasBetterConversion = false; 6236 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 6237 switch (CompareImplicitConversionSequences(S, 6238 Cand1.Conversions[ArgIdx], 6239 Cand2.Conversions[ArgIdx])) { 6240 case ImplicitConversionSequence::Better: 6241 // Cand1 has a better conversion sequence. 6242 HasBetterConversion = true; 6243 break; 6244 6245 case ImplicitConversionSequence::Worse: 6246 // Cand1 can't be better than Cand2. 6247 return false; 6248 6249 case ImplicitConversionSequence::Indistinguishable: 6250 // Do nothing. 6251 break; 6252 } 6253 } 6254 6255 // -- for some argument j, ICSj(F1) is a better conversion sequence than 6256 // ICSj(F2), or, if not that, 6257 if (HasBetterConversion) 6258 return true; 6259 6260 // - F1 is a non-template function and F2 is a function template 6261 // specialization, or, if not that, 6262 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 6263 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 6264 return true; 6265 6266 // -- F1 and F2 are function template specializations, and the function 6267 // template for F1 is more specialized than the template for F2 6268 // according to the partial ordering rules described in 14.5.5.2, or, 6269 // if not that, 6270 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 6271 Cand2.Function && Cand2.Function->getPrimaryTemplate()) { 6272 if (FunctionTemplateDecl *BetterTemplate 6273 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 6274 Cand2.Function->getPrimaryTemplate(), 6275 Loc, 6276 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 6277 : TPOC_Call, 6278 Cand1.ExplicitCallArguments)) 6279 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 6280 } 6281 6282 // -- the context is an initialization by user-defined conversion 6283 // (see 8.5, 13.3.1.5) and the standard conversion sequence 6284 // from the return type of F1 to the destination type (i.e., 6285 // the type of the entity being initialized) is a better 6286 // conversion sequence than the standard conversion sequence 6287 // from the return type of F2 to the destination type. 6288 if (UserDefinedConversion && Cand1.Function && Cand2.Function && 6289 isa<CXXConversionDecl>(Cand1.Function) && 6290 isa<CXXConversionDecl>(Cand2.Function)) { 6291 switch (CompareStandardConversionSequences(S, 6292 Cand1.FinalConversion, 6293 Cand2.FinalConversion)) { 6294 case ImplicitConversionSequence::Better: 6295 // Cand1 has a better conversion sequence. 6296 return true; 6297 6298 case ImplicitConversionSequence::Worse: 6299 // Cand1 can't be better than Cand2. 6300 return false; 6301 6302 case ImplicitConversionSequence::Indistinguishable: 6303 // Do nothing 6304 break; 6305 } 6306 } 6307 6308 return false; 6309} 6310 6311/// \brief Computes the best viable function (C++ 13.3.3) 6312/// within an overload candidate set. 6313/// 6314/// \param CandidateSet the set of candidate functions. 6315/// 6316/// \param Loc the location of the function name (or operator symbol) for 6317/// which overload resolution occurs. 6318/// 6319/// \param Best f overload resolution was successful or found a deleted 6320/// function, Best points to the candidate function found. 6321/// 6322/// \returns The result of overload resolution. 6323OverloadingResult 6324OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 6325 iterator &Best, 6326 bool UserDefinedConversion) { 6327 // Find the best viable function. 6328 Best = end(); 6329 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6330 if (Cand->Viable) 6331 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc, 6332 UserDefinedConversion)) 6333 Best = Cand; 6334 } 6335 6336 // If we didn't find any viable functions, abort. 6337 if (Best == end()) 6338 return OR_No_Viable_Function; 6339 6340 // Make sure that this function is better than every other viable 6341 // function. If not, we have an ambiguity. 6342 for (iterator Cand = begin(); Cand != end(); ++Cand) { 6343 if (Cand->Viable && 6344 Cand != Best && 6345 !isBetterOverloadCandidate(S, *Best, *Cand, Loc, 6346 UserDefinedConversion)) { 6347 Best = end(); 6348 return OR_Ambiguous; 6349 } 6350 } 6351 6352 // Best is the best viable function. 6353 if (Best->Function && 6354 (Best->Function->isDeleted() || Best->Function->isUnavailable())) 6355 return OR_Deleted; 6356 6357 return OR_Success; 6358} 6359 6360namespace { 6361 6362enum OverloadCandidateKind { 6363 oc_function, 6364 oc_method, 6365 oc_constructor, 6366 oc_function_template, 6367 oc_method_template, 6368 oc_constructor_template, 6369 oc_implicit_default_constructor, 6370 oc_implicit_copy_constructor, 6371 oc_implicit_copy_assignment, 6372 oc_implicit_inherited_constructor 6373}; 6374 6375OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 6376 FunctionDecl *Fn, 6377 std::string &Description) { 6378 bool isTemplate = false; 6379 6380 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 6381 isTemplate = true; 6382 Description = S.getTemplateArgumentBindingsText( 6383 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 6384 } 6385 6386 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 6387 if (!Ctor->isImplicit()) 6388 return isTemplate ? oc_constructor_template : oc_constructor; 6389 6390 if (Ctor->getInheritedConstructor()) 6391 return oc_implicit_inherited_constructor; 6392 6393 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 6394 : oc_implicit_default_constructor; 6395 } 6396 6397 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 6398 // This actually gets spelled 'candidate function' for now, but 6399 // it doesn't hurt to split it out. 6400 if (!Meth->isImplicit()) 6401 return isTemplate ? oc_method_template : oc_method; 6402 6403 assert(Meth->isCopyAssignmentOperator() 6404 && "implicit method is not copy assignment operator?"); 6405 return oc_implicit_copy_assignment; 6406 } 6407 6408 return isTemplate ? oc_function_template : oc_function; 6409} 6410 6411void MaybeEmitInheritedConstructorNote(Sema &S, FunctionDecl *Fn) { 6412 const CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn); 6413 if (!Ctor) return; 6414 6415 Ctor = Ctor->getInheritedConstructor(); 6416 if (!Ctor) return; 6417 6418 S.Diag(Ctor->getLocation(), diag::note_ovl_candidate_inherited_constructor); 6419} 6420 6421} // end anonymous namespace 6422 6423// Notes the location of an overload candidate. 6424void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 6425 std::string FnDesc; 6426 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 6427 Diag(Fn->getLocation(), diag::note_ovl_candidate) 6428 << (unsigned) K << FnDesc; 6429 MaybeEmitInheritedConstructorNote(*this, Fn); 6430} 6431 6432//Notes the location of all overload candidates designated through 6433// OverloadedExpr 6434void Sema::NoteAllOverloadCandidates(Expr* OverloadedExpr) { 6435 assert(OverloadedExpr->getType() == Context.OverloadTy); 6436 6437 OverloadExpr::FindResult Ovl = OverloadExpr::find(OverloadedExpr); 6438 OverloadExpr *OvlExpr = Ovl.Expression; 6439 6440 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6441 IEnd = OvlExpr->decls_end(); 6442 I != IEnd; ++I) { 6443 if (FunctionTemplateDecl *FunTmpl = 6444 dyn_cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()) ) { 6445 NoteOverloadCandidate(FunTmpl->getTemplatedDecl()); 6446 } else if (FunctionDecl *Fun 6447 = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl()) ) { 6448 NoteOverloadCandidate(Fun); 6449 } 6450 } 6451} 6452 6453/// Diagnoses an ambiguous conversion. The partial diagnostic is the 6454/// "lead" diagnostic; it will be given two arguments, the source and 6455/// target types of the conversion. 6456void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 6457 Sema &S, 6458 SourceLocation CaretLoc, 6459 const PartialDiagnostic &PDiag) const { 6460 S.Diag(CaretLoc, PDiag) 6461 << Ambiguous.getFromType() << Ambiguous.getToType(); 6462 for (AmbiguousConversionSequence::const_iterator 6463 I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 6464 S.NoteOverloadCandidate(*I); 6465 } 6466} 6467 6468namespace { 6469 6470void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 6471 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 6472 assert(Conv.isBad()); 6473 assert(Cand->Function && "for now, candidate must be a function"); 6474 FunctionDecl *Fn = Cand->Function; 6475 6476 // There's a conversion slot for the object argument if this is a 6477 // non-constructor method. Note that 'I' corresponds the 6478 // conversion-slot index. 6479 bool isObjectArgument = false; 6480 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 6481 if (I == 0) 6482 isObjectArgument = true; 6483 else 6484 I--; 6485 } 6486 6487 std::string FnDesc; 6488 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6489 6490 Expr *FromExpr = Conv.Bad.FromExpr; 6491 QualType FromTy = Conv.Bad.getFromType(); 6492 QualType ToTy = Conv.Bad.getToType(); 6493 6494 if (FromTy == S.Context.OverloadTy) { 6495 assert(FromExpr && "overload set argument came from implicit argument?"); 6496 Expr *E = FromExpr->IgnoreParens(); 6497 if (isa<UnaryOperator>(E)) 6498 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 6499 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 6500 6501 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 6502 << (unsigned) FnKind << FnDesc 6503 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6504 << ToTy << Name << I+1; 6505 MaybeEmitInheritedConstructorNote(S, Fn); 6506 return; 6507 } 6508 6509 // Do some hand-waving analysis to see if the non-viability is due 6510 // to a qualifier mismatch. 6511 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 6512 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 6513 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 6514 CToTy = RT->getPointeeType(); 6515 else { 6516 // TODO: detect and diagnose the full richness of const mismatches. 6517 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 6518 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 6519 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 6520 } 6521 6522 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 6523 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 6524 // It is dumb that we have to do this here. 6525 while (isa<ArrayType>(CFromTy)) 6526 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 6527 while (isa<ArrayType>(CToTy)) 6528 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 6529 6530 Qualifiers FromQs = CFromTy.getQualifiers(); 6531 Qualifiers ToQs = CToTy.getQualifiers(); 6532 6533 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 6534 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 6535 << (unsigned) FnKind << FnDesc 6536 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6537 << FromTy 6538 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 6539 << (unsigned) isObjectArgument << I+1; 6540 MaybeEmitInheritedConstructorNote(S, Fn); 6541 return; 6542 } 6543 6544 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 6545 assert(CVR && "unexpected qualifiers mismatch"); 6546 6547 if (isObjectArgument) { 6548 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 6549 << (unsigned) FnKind << FnDesc 6550 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6551 << FromTy << (CVR - 1); 6552 } else { 6553 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 6554 << (unsigned) FnKind << FnDesc 6555 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6556 << FromTy << (CVR - 1) << I+1; 6557 } 6558 MaybeEmitInheritedConstructorNote(S, Fn); 6559 return; 6560 } 6561 6562 // Diagnose references or pointers to incomplete types differently, 6563 // since it's far from impossible that the incompleteness triggered 6564 // the failure. 6565 QualType TempFromTy = FromTy.getNonReferenceType(); 6566 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 6567 TempFromTy = PTy->getPointeeType(); 6568 if (TempFromTy->isIncompleteType()) { 6569 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 6570 << (unsigned) FnKind << FnDesc 6571 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6572 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6573 MaybeEmitInheritedConstructorNote(S, Fn); 6574 return; 6575 } 6576 6577 // Diagnose base -> derived pointer conversions. 6578 unsigned BaseToDerivedConversion = 0; 6579 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 6580 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 6581 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6582 FromPtrTy->getPointeeType()) && 6583 !FromPtrTy->getPointeeType()->isIncompleteType() && 6584 !ToPtrTy->getPointeeType()->isIncompleteType() && 6585 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 6586 FromPtrTy->getPointeeType())) 6587 BaseToDerivedConversion = 1; 6588 } 6589 } else if (const ObjCObjectPointerType *FromPtrTy 6590 = FromTy->getAs<ObjCObjectPointerType>()) { 6591 if (const ObjCObjectPointerType *ToPtrTy 6592 = ToTy->getAs<ObjCObjectPointerType>()) 6593 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 6594 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 6595 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 6596 FromPtrTy->getPointeeType()) && 6597 FromIface->isSuperClassOf(ToIface)) 6598 BaseToDerivedConversion = 2; 6599 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 6600 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 6601 !FromTy->isIncompleteType() && 6602 !ToRefTy->getPointeeType()->isIncompleteType() && 6603 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 6604 BaseToDerivedConversion = 3; 6605 } 6606 6607 if (BaseToDerivedConversion) { 6608 S.Diag(Fn->getLocation(), 6609 diag::note_ovl_candidate_bad_base_to_derived_conv) 6610 << (unsigned) FnKind << FnDesc 6611 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6612 << (BaseToDerivedConversion - 1) 6613 << FromTy << ToTy << I+1; 6614 MaybeEmitInheritedConstructorNote(S, Fn); 6615 return; 6616 } 6617 6618 // TODO: specialize more based on the kind of mismatch 6619 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 6620 << (unsigned) FnKind << FnDesc 6621 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 6622 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 6623 MaybeEmitInheritedConstructorNote(S, Fn); 6624} 6625 6626void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 6627 unsigned NumFormalArgs) { 6628 // TODO: treat calls to a missing default constructor as a special case 6629 6630 FunctionDecl *Fn = Cand->Function; 6631 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 6632 6633 unsigned MinParams = Fn->getMinRequiredArguments(); 6634 6635 // at least / at most / exactly 6636 unsigned mode, modeCount; 6637 if (NumFormalArgs < MinParams) { 6638 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 6639 (Cand->FailureKind == ovl_fail_bad_deduction && 6640 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 6641 if (MinParams != FnTy->getNumArgs() || 6642 FnTy->isVariadic() || FnTy->isTemplateVariadic()) 6643 mode = 0; // "at least" 6644 else 6645 mode = 2; // "exactly" 6646 modeCount = MinParams; 6647 } else { 6648 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 6649 (Cand->FailureKind == ovl_fail_bad_deduction && 6650 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 6651 if (MinParams != FnTy->getNumArgs()) 6652 mode = 1; // "at most" 6653 else 6654 mode = 2; // "exactly" 6655 modeCount = FnTy->getNumArgs(); 6656 } 6657 6658 std::string Description; 6659 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 6660 6661 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 6662 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 6663 << modeCount << NumFormalArgs; 6664 MaybeEmitInheritedConstructorNote(S, Fn); 6665} 6666 6667/// Diagnose a failed template-argument deduction. 6668void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 6669 Expr **Args, unsigned NumArgs) { 6670 FunctionDecl *Fn = Cand->Function; // pattern 6671 6672 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 6673 NamedDecl *ParamD; 6674 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 6675 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 6676 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 6677 switch (Cand->DeductionFailure.Result) { 6678 case Sema::TDK_Success: 6679 llvm_unreachable("TDK_success while diagnosing bad deduction"); 6680 6681 case Sema::TDK_Incomplete: { 6682 assert(ParamD && "no parameter found for incomplete deduction result"); 6683 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 6684 << ParamD->getDeclName(); 6685 MaybeEmitInheritedConstructorNote(S, Fn); 6686 return; 6687 } 6688 6689 case Sema::TDK_Underqualified: { 6690 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 6691 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 6692 6693 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 6694 6695 // Param will have been canonicalized, but it should just be a 6696 // qualified version of ParamD, so move the qualifiers to that. 6697 QualifierCollector Qs; 6698 Qs.strip(Param); 6699 QualType NonCanonParam = Qs.apply(S.Context, TParam->getTypeForDecl()); 6700 assert(S.Context.hasSameType(Param, NonCanonParam)); 6701 6702 // Arg has also been canonicalized, but there's nothing we can do 6703 // about that. It also doesn't matter as much, because it won't 6704 // have any template parameters in it (because deduction isn't 6705 // done on dependent types). 6706 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 6707 6708 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 6709 << ParamD->getDeclName() << Arg << NonCanonParam; 6710 MaybeEmitInheritedConstructorNote(S, Fn); 6711 return; 6712 } 6713 6714 case Sema::TDK_Inconsistent: { 6715 assert(ParamD && "no parameter found for inconsistent deduction result"); 6716 int which = 0; 6717 if (isa<TemplateTypeParmDecl>(ParamD)) 6718 which = 0; 6719 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 6720 which = 1; 6721 else { 6722 which = 2; 6723 } 6724 6725 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 6726 << which << ParamD->getDeclName() 6727 << *Cand->DeductionFailure.getFirstArg() 6728 << *Cand->DeductionFailure.getSecondArg(); 6729 MaybeEmitInheritedConstructorNote(S, Fn); 6730 return; 6731 } 6732 6733 case Sema::TDK_InvalidExplicitArguments: 6734 assert(ParamD && "no parameter found for invalid explicit arguments"); 6735 if (ParamD->getDeclName()) 6736 S.Diag(Fn->getLocation(), 6737 diag::note_ovl_candidate_explicit_arg_mismatch_named) 6738 << ParamD->getDeclName(); 6739 else { 6740 int index = 0; 6741 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 6742 index = TTP->getIndex(); 6743 else if (NonTypeTemplateParmDecl *NTTP 6744 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 6745 index = NTTP->getIndex(); 6746 else 6747 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 6748 S.Diag(Fn->getLocation(), 6749 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 6750 << (index + 1); 6751 } 6752 MaybeEmitInheritedConstructorNote(S, Fn); 6753 return; 6754 6755 case Sema::TDK_TooManyArguments: 6756 case Sema::TDK_TooFewArguments: 6757 DiagnoseArityMismatch(S, Cand, NumArgs); 6758 return; 6759 6760 case Sema::TDK_InstantiationDepth: 6761 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 6762 MaybeEmitInheritedConstructorNote(S, Fn); 6763 return; 6764 6765 case Sema::TDK_SubstitutionFailure: { 6766 std::string ArgString; 6767 if (TemplateArgumentList *Args 6768 = Cand->DeductionFailure.getTemplateArgumentList()) 6769 ArgString = S.getTemplateArgumentBindingsText( 6770 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 6771 *Args); 6772 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 6773 << ArgString; 6774 MaybeEmitInheritedConstructorNote(S, Fn); 6775 return; 6776 } 6777 6778 // TODO: diagnose these individually, then kill off 6779 // note_ovl_candidate_bad_deduction, which is uselessly vague. 6780 case Sema::TDK_NonDeducedMismatch: 6781 case Sema::TDK_FailedOverloadResolution: 6782 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 6783 MaybeEmitInheritedConstructorNote(S, Fn); 6784 return; 6785 } 6786} 6787 6788/// Generates a 'note' diagnostic for an overload candidate. We've 6789/// already generated a primary error at the call site. 6790/// 6791/// It really does need to be a single diagnostic with its caret 6792/// pointed at the candidate declaration. Yes, this creates some 6793/// major challenges of technical writing. Yes, this makes pointing 6794/// out problems with specific arguments quite awkward. It's still 6795/// better than generating twenty screens of text for every failed 6796/// overload. 6797/// 6798/// It would be great to be able to express per-candidate problems 6799/// more richly for those diagnostic clients that cared, but we'd 6800/// still have to be just as careful with the default diagnostics. 6801void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 6802 Expr **Args, unsigned NumArgs) { 6803 FunctionDecl *Fn = Cand->Function; 6804 6805 // Note deleted candidates, but only if they're viable. 6806 if (Cand->Viable && (Fn->isDeleted() || Fn->isUnavailable())) { 6807 std::string FnDesc; 6808 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 6809 6810 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 6811 << FnKind << FnDesc << Fn->isDeleted(); 6812 MaybeEmitInheritedConstructorNote(S, Fn); 6813 return; 6814 } 6815 6816 // We don't really have anything else to say about viable candidates. 6817 if (Cand->Viable) { 6818 S.NoteOverloadCandidate(Fn); 6819 return; 6820 } 6821 6822 switch (Cand->FailureKind) { 6823 case ovl_fail_too_many_arguments: 6824 case ovl_fail_too_few_arguments: 6825 return DiagnoseArityMismatch(S, Cand, NumArgs); 6826 6827 case ovl_fail_bad_deduction: 6828 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 6829 6830 case ovl_fail_trivial_conversion: 6831 case ovl_fail_bad_final_conversion: 6832 case ovl_fail_final_conversion_not_exact: 6833 return S.NoteOverloadCandidate(Fn); 6834 6835 case ovl_fail_bad_conversion: { 6836 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 6837 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 6838 if (Cand->Conversions[I].isBad()) 6839 return DiagnoseBadConversion(S, Cand, I); 6840 6841 // FIXME: this currently happens when we're called from SemaInit 6842 // when user-conversion overload fails. Figure out how to handle 6843 // those conditions and diagnose them well. 6844 return S.NoteOverloadCandidate(Fn); 6845 } 6846 } 6847} 6848 6849void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 6850 // Desugar the type of the surrogate down to a function type, 6851 // retaining as many typedefs as possible while still showing 6852 // the function type (and, therefore, its parameter types). 6853 QualType FnType = Cand->Surrogate->getConversionType(); 6854 bool isLValueReference = false; 6855 bool isRValueReference = false; 6856 bool isPointer = false; 6857 if (const LValueReferenceType *FnTypeRef = 6858 FnType->getAs<LValueReferenceType>()) { 6859 FnType = FnTypeRef->getPointeeType(); 6860 isLValueReference = true; 6861 } else if (const RValueReferenceType *FnTypeRef = 6862 FnType->getAs<RValueReferenceType>()) { 6863 FnType = FnTypeRef->getPointeeType(); 6864 isRValueReference = true; 6865 } 6866 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 6867 FnType = FnTypePtr->getPointeeType(); 6868 isPointer = true; 6869 } 6870 // Desugar down to a function type. 6871 FnType = QualType(FnType->getAs<FunctionType>(), 0); 6872 // Reconstruct the pointer/reference as appropriate. 6873 if (isPointer) FnType = S.Context.getPointerType(FnType); 6874 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 6875 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 6876 6877 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 6878 << FnType; 6879 MaybeEmitInheritedConstructorNote(S, Cand->Surrogate); 6880} 6881 6882void NoteBuiltinOperatorCandidate(Sema &S, 6883 const char *Opc, 6884 SourceLocation OpLoc, 6885 OverloadCandidate *Cand) { 6886 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 6887 std::string TypeStr("operator"); 6888 TypeStr += Opc; 6889 TypeStr += "("; 6890 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 6891 if (Cand->Conversions.size() == 1) { 6892 TypeStr += ")"; 6893 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 6894 } else { 6895 TypeStr += ", "; 6896 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 6897 TypeStr += ")"; 6898 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 6899 } 6900} 6901 6902void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 6903 OverloadCandidate *Cand) { 6904 unsigned NoOperands = Cand->Conversions.size(); 6905 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 6906 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 6907 if (ICS.isBad()) break; // all meaningless after first invalid 6908 if (!ICS.isAmbiguous()) continue; 6909 6910 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 6911 S.PDiag(diag::note_ambiguous_type_conversion)); 6912 } 6913} 6914 6915SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 6916 if (Cand->Function) 6917 return Cand->Function->getLocation(); 6918 if (Cand->IsSurrogate) 6919 return Cand->Surrogate->getLocation(); 6920 return SourceLocation(); 6921} 6922 6923struct CompareOverloadCandidatesForDisplay { 6924 Sema &S; 6925 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 6926 6927 bool operator()(const OverloadCandidate *L, 6928 const OverloadCandidate *R) { 6929 // Fast-path this check. 6930 if (L == R) return false; 6931 6932 // Order first by viability. 6933 if (L->Viable) { 6934 if (!R->Viable) return true; 6935 6936 // TODO: introduce a tri-valued comparison for overload 6937 // candidates. Would be more worthwhile if we had a sort 6938 // that could exploit it. 6939 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 6940 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 6941 } else if (R->Viable) 6942 return false; 6943 6944 assert(L->Viable == R->Viable); 6945 6946 // Criteria by which we can sort non-viable candidates: 6947 if (!L->Viable) { 6948 // 1. Arity mismatches come after other candidates. 6949 if (L->FailureKind == ovl_fail_too_many_arguments || 6950 L->FailureKind == ovl_fail_too_few_arguments) 6951 return false; 6952 if (R->FailureKind == ovl_fail_too_many_arguments || 6953 R->FailureKind == ovl_fail_too_few_arguments) 6954 return true; 6955 6956 // 2. Bad conversions come first and are ordered by the number 6957 // of bad conversions and quality of good conversions. 6958 if (L->FailureKind == ovl_fail_bad_conversion) { 6959 if (R->FailureKind != ovl_fail_bad_conversion) 6960 return true; 6961 6962 // If there's any ordering between the defined conversions... 6963 // FIXME: this might not be transitive. 6964 assert(L->Conversions.size() == R->Conversions.size()); 6965 6966 int leftBetter = 0; 6967 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 6968 for (unsigned E = L->Conversions.size(); I != E; ++I) { 6969 switch (CompareImplicitConversionSequences(S, 6970 L->Conversions[I], 6971 R->Conversions[I])) { 6972 case ImplicitConversionSequence::Better: 6973 leftBetter++; 6974 break; 6975 6976 case ImplicitConversionSequence::Worse: 6977 leftBetter--; 6978 break; 6979 6980 case ImplicitConversionSequence::Indistinguishable: 6981 break; 6982 } 6983 } 6984 if (leftBetter > 0) return true; 6985 if (leftBetter < 0) return false; 6986 6987 } else if (R->FailureKind == ovl_fail_bad_conversion) 6988 return false; 6989 6990 // TODO: others? 6991 } 6992 6993 // Sort everything else by location. 6994 SourceLocation LLoc = GetLocationForCandidate(L); 6995 SourceLocation RLoc = GetLocationForCandidate(R); 6996 6997 // Put candidates without locations (e.g. builtins) at the end. 6998 if (LLoc.isInvalid()) return false; 6999 if (RLoc.isInvalid()) return true; 7000 7001 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 7002 } 7003}; 7004 7005/// CompleteNonViableCandidate - Normally, overload resolution only 7006/// computes up to the first 7007void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 7008 Expr **Args, unsigned NumArgs) { 7009 assert(!Cand->Viable); 7010 7011 // Don't do anything on failures other than bad conversion. 7012 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 7013 7014 // Skip forward to the first bad conversion. 7015 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 7016 unsigned ConvCount = Cand->Conversions.size(); 7017 while (true) { 7018 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 7019 ConvIdx++; 7020 if (Cand->Conversions[ConvIdx - 1].isBad()) 7021 break; 7022 } 7023 7024 if (ConvIdx == ConvCount) 7025 return; 7026 7027 assert(!Cand->Conversions[ConvIdx].isInitialized() && 7028 "remaining conversion is initialized?"); 7029 7030 // FIXME: this should probably be preserved from the overload 7031 // operation somehow. 7032 bool SuppressUserConversions = false; 7033 7034 const FunctionProtoType* Proto; 7035 unsigned ArgIdx = ConvIdx; 7036 7037 if (Cand->IsSurrogate) { 7038 QualType ConvType 7039 = Cand->Surrogate->getConversionType().getNonReferenceType(); 7040 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7041 ConvType = ConvPtrType->getPointeeType(); 7042 Proto = ConvType->getAs<FunctionProtoType>(); 7043 ArgIdx--; 7044 } else if (Cand->Function) { 7045 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 7046 if (isa<CXXMethodDecl>(Cand->Function) && 7047 !isa<CXXConstructorDecl>(Cand->Function)) 7048 ArgIdx--; 7049 } else { 7050 // Builtin binary operator with a bad first conversion. 7051 assert(ConvCount <= 3); 7052 for (; ConvIdx != ConvCount; ++ConvIdx) 7053 Cand->Conversions[ConvIdx] 7054 = TryCopyInitialization(S, Args[ConvIdx], 7055 Cand->BuiltinTypes.ParamTypes[ConvIdx], 7056 SuppressUserConversions, 7057 /*InOverloadResolution*/ true); 7058 return; 7059 } 7060 7061 // Fill in the rest of the conversions. 7062 unsigned NumArgsInProto = Proto->getNumArgs(); 7063 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 7064 if (ArgIdx < NumArgsInProto) 7065 Cand->Conversions[ConvIdx] 7066 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 7067 SuppressUserConversions, 7068 /*InOverloadResolution=*/true); 7069 else 7070 Cand->Conversions[ConvIdx].setEllipsis(); 7071 } 7072} 7073 7074} // end anonymous namespace 7075 7076/// PrintOverloadCandidates - When overload resolution fails, prints 7077/// diagnostic messages containing the candidates in the candidate 7078/// set. 7079void OverloadCandidateSet::NoteCandidates(Sema &S, 7080 OverloadCandidateDisplayKind OCD, 7081 Expr **Args, unsigned NumArgs, 7082 const char *Opc, 7083 SourceLocation OpLoc) { 7084 // Sort the candidates by viability and position. Sorting directly would 7085 // be prohibitive, so we make a set of pointers and sort those. 7086 llvm::SmallVector<OverloadCandidate*, 32> Cands; 7087 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 7088 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 7089 if (Cand->Viable) 7090 Cands.push_back(Cand); 7091 else if (OCD == OCD_AllCandidates) { 7092 CompleteNonViableCandidate(S, Cand, Args, NumArgs); 7093 if (Cand->Function || Cand->IsSurrogate) 7094 Cands.push_back(Cand); 7095 // Otherwise, this a non-viable builtin candidate. We do not, in general, 7096 // want to list every possible builtin candidate. 7097 } 7098 } 7099 7100 std::sort(Cands.begin(), Cands.end(), 7101 CompareOverloadCandidatesForDisplay(S)); 7102 7103 bool ReportedAmbiguousConversions = false; 7104 7105 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 7106 const Diagnostic::OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 7107 unsigned CandsShown = 0; 7108 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 7109 OverloadCandidate *Cand = *I; 7110 7111 // Set an arbitrary limit on the number of candidate functions we'll spam 7112 // the user with. FIXME: This limit should depend on details of the 7113 // candidate list. 7114 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 7115 break; 7116 } 7117 ++CandsShown; 7118 7119 if (Cand->Function) 7120 NoteFunctionCandidate(S, Cand, Args, NumArgs); 7121 else if (Cand->IsSurrogate) 7122 NoteSurrogateCandidate(S, Cand); 7123 else { 7124 assert(Cand->Viable && 7125 "Non-viable built-in candidates are not added to Cands."); 7126 // Generally we only see ambiguities including viable builtin 7127 // operators if overload resolution got screwed up by an 7128 // ambiguous user-defined conversion. 7129 // 7130 // FIXME: It's quite possible for different conversions to see 7131 // different ambiguities, though. 7132 if (!ReportedAmbiguousConversions) { 7133 NoteAmbiguousUserConversions(S, OpLoc, Cand); 7134 ReportedAmbiguousConversions = true; 7135 } 7136 7137 // If this is a viable builtin, print it. 7138 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 7139 } 7140 } 7141 7142 if (I != E) 7143 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 7144} 7145 7146// [PossiblyAFunctionType] --> [Return] 7147// NonFunctionType --> NonFunctionType 7148// R (A) --> R(A) 7149// R (*)(A) --> R (A) 7150// R (&)(A) --> R (A) 7151// R (S::*)(A) --> R (A) 7152QualType Sema::ExtractUnqualifiedFunctionType(QualType PossiblyAFunctionType) { 7153 QualType Ret = PossiblyAFunctionType; 7154 if (const PointerType *ToTypePtr = 7155 PossiblyAFunctionType->getAs<PointerType>()) 7156 Ret = ToTypePtr->getPointeeType(); 7157 else if (const ReferenceType *ToTypeRef = 7158 PossiblyAFunctionType->getAs<ReferenceType>()) 7159 Ret = ToTypeRef->getPointeeType(); 7160 else if (const MemberPointerType *MemTypePtr = 7161 PossiblyAFunctionType->getAs<MemberPointerType>()) 7162 Ret = MemTypePtr->getPointeeType(); 7163 Ret = 7164 Context.getCanonicalType(Ret).getUnqualifiedType(); 7165 return Ret; 7166} 7167 7168// A helper class to help with address of function resolution 7169// - allows us to avoid passing around all those ugly parameters 7170class AddressOfFunctionResolver 7171{ 7172 Sema& S; 7173 Expr* SourceExpr; 7174 const QualType& TargetType; 7175 QualType TargetFunctionType; // Extracted function type from target type 7176 7177 bool Complain; 7178 //DeclAccessPair& ResultFunctionAccessPair; 7179 ASTContext& Context; 7180 7181 bool TargetTypeIsNonStaticMemberFunction; 7182 bool FoundNonTemplateFunction; 7183 7184 OverloadExpr::FindResult OvlExprInfo; 7185 OverloadExpr *OvlExpr; 7186 TemplateArgumentListInfo OvlExplicitTemplateArgs; 7187 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 7188 7189public: 7190 AddressOfFunctionResolver(Sema &S, Expr* SourceExpr, 7191 const QualType& TargetType, bool Complain) 7192 : S(S), SourceExpr(SourceExpr), TargetType(TargetType), 7193 Complain(Complain), Context(S.getASTContext()), 7194 TargetTypeIsNonStaticMemberFunction( 7195 !!TargetType->getAs<MemberPointerType>()), 7196 FoundNonTemplateFunction(false), 7197 OvlExprInfo(OverloadExpr::find(SourceExpr)), 7198 OvlExpr(OvlExprInfo.Expression) 7199 { 7200 ExtractUnqualifiedFunctionTypeFromTargetType(); 7201 7202 if (!TargetFunctionType->isFunctionType()) { 7203 if (OvlExpr->hasExplicitTemplateArgs()) { 7204 DeclAccessPair dap; 7205 if( FunctionDecl* Fn = S.ResolveSingleFunctionTemplateSpecialization( 7206 OvlExpr, false, &dap) ) { 7207 7208 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7209 if (!Method->isStatic()) { 7210 // If the target type is a non-function type and the function 7211 // found is a non-static member function, pretend as if that was 7212 // the target, it's the only possible type to end up with. 7213 TargetTypeIsNonStaticMemberFunction = true; 7214 7215 // And skip adding the function if its not in the proper form. 7216 // We'll diagnose this due to an empty set of functions. 7217 if (!OvlExprInfo.HasFormOfMemberPointer) 7218 return; 7219 } 7220 } 7221 7222 Matches.push_back(std::make_pair(dap,Fn)); 7223 } 7224 } 7225 return; 7226 } 7227 7228 if (OvlExpr->hasExplicitTemplateArgs()) 7229 OvlExpr->getExplicitTemplateArgs().copyInto(OvlExplicitTemplateArgs); 7230 7231 if (FindAllFunctionsThatMatchTargetTypeExactly()) { 7232 // C++ [over.over]p4: 7233 // If more than one function is selected, [...] 7234 if (Matches.size() > 1) { 7235 if (FoundNonTemplateFunction) 7236 EliminateAllTemplateMatches(); 7237 else 7238 EliminateAllExceptMostSpecializedTemplate(); 7239 } 7240 } 7241 } 7242 7243private: 7244 bool isTargetTypeAFunction() const { 7245 return TargetFunctionType->isFunctionType(); 7246 } 7247 7248 // [ToType] [Return] 7249 7250 // R (*)(A) --> R (A), IsNonStaticMemberFunction = false 7251 // R (&)(A) --> R (A), IsNonStaticMemberFunction = false 7252 // R (S::*)(A) --> R (A), IsNonStaticMemberFunction = true 7253 void inline ExtractUnqualifiedFunctionTypeFromTargetType() { 7254 TargetFunctionType = S.ExtractUnqualifiedFunctionType(TargetType); 7255 } 7256 7257 // return true if any matching specializations were found 7258 bool AddMatchingTemplateFunction(FunctionTemplateDecl* FunctionTemplate, 7259 const DeclAccessPair& CurAccessFunPair) { 7260 if (CXXMethodDecl *Method 7261 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 7262 // Skip non-static function templates when converting to pointer, and 7263 // static when converting to member pointer. 7264 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 7265 return false; 7266 } 7267 else if (TargetTypeIsNonStaticMemberFunction) 7268 return false; 7269 7270 // C++ [over.over]p2: 7271 // If the name is a function template, template argument deduction is 7272 // done (14.8.2.2), and if the argument deduction succeeds, the 7273 // resulting template argument list is used to generate a single 7274 // function template specialization, which is added to the set of 7275 // overloaded functions considered. 7276 FunctionDecl *Specialization = 0; 7277 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 7278 if (Sema::TemplateDeductionResult Result 7279 = S.DeduceTemplateArguments(FunctionTemplate, 7280 &OvlExplicitTemplateArgs, 7281 TargetFunctionType, Specialization, 7282 Info)) { 7283 // FIXME: make a note of the failed deduction for diagnostics. 7284 (void)Result; 7285 return false; 7286 } 7287 7288 // Template argument deduction ensures that we have an exact match. 7289 // This function template specicalization works. 7290 Specialization = cast<FunctionDecl>(Specialization->getCanonicalDecl()); 7291 assert(TargetFunctionType 7292 == Context.getCanonicalType(Specialization->getType())); 7293 Matches.push_back(std::make_pair(CurAccessFunPair, Specialization)); 7294 return true; 7295 } 7296 7297 bool AddMatchingNonTemplateFunction(NamedDecl* Fn, 7298 const DeclAccessPair& CurAccessFunPair) { 7299 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7300 // Skip non-static functions when converting to pointer, and static 7301 // when converting to member pointer. 7302 if (Method->isStatic() == TargetTypeIsNonStaticMemberFunction) 7303 return false; 7304 } 7305 else if (TargetTypeIsNonStaticMemberFunction) 7306 return false; 7307 7308 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 7309 QualType ResultTy; 7310 if (Context.hasSameUnqualifiedType(TargetFunctionType, 7311 FunDecl->getType()) || 7312 IsNoReturnConversion(Context, FunDecl->getType(), TargetFunctionType, 7313 ResultTy)) { 7314 Matches.push_back(std::make_pair(CurAccessFunPair, 7315 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 7316 FoundNonTemplateFunction = true; 7317 return true; 7318 } 7319 } 7320 7321 return false; 7322 } 7323 7324 bool FindAllFunctionsThatMatchTargetTypeExactly() { 7325 bool Ret = false; 7326 7327 // If the overload expression doesn't have the form of a pointer to 7328 // member, don't try to convert it to a pointer-to-member type. 7329 if (IsInvalidFormOfPointerToMemberFunction()) 7330 return false; 7331 7332 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7333 E = OvlExpr->decls_end(); 7334 I != E; ++I) { 7335 // Look through any using declarations to find the underlying function. 7336 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 7337 7338 // C++ [over.over]p3: 7339 // Non-member functions and static member functions match 7340 // targets of type "pointer-to-function" or "reference-to-function." 7341 // Nonstatic member functions match targets of 7342 // type "pointer-to-member-function." 7343 // Note that according to DR 247, the containing class does not matter. 7344 if (FunctionTemplateDecl *FunctionTemplate 7345 = dyn_cast<FunctionTemplateDecl>(Fn)) { 7346 if (AddMatchingTemplateFunction(FunctionTemplate, I.getPair())) 7347 Ret = true; 7348 } 7349 // If we have explicit template arguments supplied, skip non-templates. 7350 else if (!OvlExpr->hasExplicitTemplateArgs() && 7351 AddMatchingNonTemplateFunction(Fn, I.getPair())) 7352 Ret = true; 7353 } 7354 assert(Ret || Matches.empty()); 7355 return Ret; 7356 } 7357 7358 void EliminateAllExceptMostSpecializedTemplate() { 7359 // [...] and any given function template specialization F1 is 7360 // eliminated if the set contains a second function template 7361 // specialization whose function template is more specialized 7362 // than the function template of F1 according to the partial 7363 // ordering rules of 14.5.5.2. 7364 7365 // The algorithm specified above is quadratic. We instead use a 7366 // two-pass algorithm (similar to the one used to identify the 7367 // best viable function in an overload set) that identifies the 7368 // best function template (if it exists). 7369 7370 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 7371 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 7372 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 7373 7374 UnresolvedSetIterator Result = 7375 S.getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 7376 TPOC_Other, 0, SourceExpr->getLocStart(), 7377 S.PDiag(), 7378 S.PDiag(diag::err_addr_ovl_ambiguous) 7379 << Matches[0].second->getDeclName(), 7380 S.PDiag(diag::note_ovl_candidate) 7381 << (unsigned) oc_function_template, 7382 Complain); 7383 7384 if (Result != MatchesCopy.end()) { 7385 // Make it the first and only element 7386 Matches[0].first = Matches[Result - MatchesCopy.begin()].first; 7387 Matches[0].second = cast<FunctionDecl>(*Result); 7388 Matches.resize(1); 7389 } 7390 } 7391 7392 void EliminateAllTemplateMatches() { 7393 // [...] any function template specializations in the set are 7394 // eliminated if the set also contains a non-template function, [...] 7395 for (unsigned I = 0, N = Matches.size(); I != N; ) { 7396 if (Matches[I].second->getPrimaryTemplate() == 0) 7397 ++I; 7398 else { 7399 Matches[I] = Matches[--N]; 7400 Matches.set_size(N); 7401 } 7402 } 7403 } 7404 7405public: 7406 void ComplainNoMatchesFound() const { 7407 assert(Matches.empty()); 7408 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_no_viable) 7409 << OvlExpr->getName() << TargetFunctionType 7410 << OvlExpr->getSourceRange(); 7411 S.NoteAllOverloadCandidates(OvlExpr); 7412 } 7413 7414 bool IsInvalidFormOfPointerToMemberFunction() const { 7415 return TargetTypeIsNonStaticMemberFunction && 7416 !OvlExprInfo.HasFormOfMemberPointer; 7417 } 7418 7419 void ComplainIsInvalidFormOfPointerToMemberFunction() const { 7420 // TODO: Should we condition this on whether any functions might 7421 // have matched, or is it more appropriate to do that in callers? 7422 // TODO: a fixit wouldn't hurt. 7423 S.Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 7424 << TargetType << OvlExpr->getSourceRange(); 7425 } 7426 7427 void ComplainOfInvalidConversion() const { 7428 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 7429 << OvlExpr->getName() << TargetType; 7430 } 7431 7432 void ComplainMultipleMatchesFound() const { 7433 assert(Matches.size() > 1); 7434 S.Diag(OvlExpr->getLocStart(), diag::err_addr_ovl_ambiguous) 7435 << OvlExpr->getName() 7436 << OvlExpr->getSourceRange(); 7437 S.NoteAllOverloadCandidates(OvlExpr); 7438 } 7439 7440 int getNumMatches() const { return Matches.size(); } 7441 7442 FunctionDecl* getMatchingFunctionDecl() const { 7443 if (Matches.size() != 1) return 0; 7444 return Matches[0].second; 7445 } 7446 7447 const DeclAccessPair* getMatchingFunctionAccessPair() const { 7448 if (Matches.size() != 1) return 0; 7449 return &Matches[0].first; 7450 } 7451}; 7452 7453/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 7454/// an overloaded function (C++ [over.over]), where @p From is an 7455/// expression with overloaded function type and @p ToType is the type 7456/// we're trying to resolve to. For example: 7457/// 7458/// @code 7459/// int f(double); 7460/// int f(int); 7461/// 7462/// int (*pfd)(double) = f; // selects f(double) 7463/// @endcode 7464/// 7465/// This routine returns the resulting FunctionDecl if it could be 7466/// resolved, and NULL otherwise. When @p Complain is true, this 7467/// routine will emit diagnostics if there is an error. 7468FunctionDecl * 7469Sema::ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, QualType TargetType, 7470 bool Complain, 7471 DeclAccessPair &FoundResult) { 7472 7473 assert(AddressOfExpr->getType() == Context.OverloadTy); 7474 7475 AddressOfFunctionResolver Resolver(*this, AddressOfExpr, TargetType, Complain); 7476 int NumMatches = Resolver.getNumMatches(); 7477 FunctionDecl* Fn = 0; 7478 if ( NumMatches == 0 && Complain) { 7479 if (Resolver.IsInvalidFormOfPointerToMemberFunction()) 7480 Resolver.ComplainIsInvalidFormOfPointerToMemberFunction(); 7481 else 7482 Resolver.ComplainNoMatchesFound(); 7483 } 7484 else if (NumMatches > 1 && Complain) 7485 Resolver.ComplainMultipleMatchesFound(); 7486 else if (NumMatches == 1) { 7487 Fn = Resolver.getMatchingFunctionDecl(); 7488 assert(Fn); 7489 FoundResult = *Resolver.getMatchingFunctionAccessPair(); 7490 MarkDeclarationReferenced(AddressOfExpr->getLocStart(), Fn); 7491 if (Complain) 7492 CheckAddressOfMemberAccess(AddressOfExpr, FoundResult); 7493 } 7494 7495 return Fn; 7496} 7497 7498/// \brief Given an expression that refers to an overloaded function, try to 7499/// resolve that overloaded function expression down to a single function. 7500/// 7501/// This routine can only resolve template-ids that refer to a single function 7502/// template, where that template-id refers to a single template whose template 7503/// arguments are either provided by the template-id or have defaults, 7504/// as described in C++0x [temp.arg.explicit]p3. 7505FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From, 7506 bool Complain, 7507 DeclAccessPair* FoundResult) { 7508 // C++ [over.over]p1: 7509 // [...] [Note: any redundant set of parentheses surrounding the 7510 // overloaded function name is ignored (5.1). ] 7511 // C++ [over.over]p1: 7512 // [...] The overloaded function name can be preceded by the & 7513 // operator. 7514 if (From->getType() != Context.OverloadTy) 7515 return 0; 7516 7517 OverloadExpr *OvlExpr = OverloadExpr::find(From).Expression; 7518 7519 // If we didn't actually find any template-ids, we're done. 7520 if (!OvlExpr->hasExplicitTemplateArgs()) 7521 return 0; 7522 7523 TemplateArgumentListInfo ExplicitTemplateArgs; 7524 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 7525 7526 // Look through all of the overloaded functions, searching for one 7527 // whose type matches exactly. 7528 FunctionDecl *Matched = 0; 7529 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 7530 E = OvlExpr->decls_end(); I != E; ++I) { 7531 // C++0x [temp.arg.explicit]p3: 7532 // [...] In contexts where deduction is done and fails, or in contexts 7533 // where deduction is not done, if a template argument list is 7534 // specified and it, along with any default template arguments, 7535 // identifies a single function template specialization, then the 7536 // template-id is an lvalue for the function template specialization. 7537 FunctionTemplateDecl *FunctionTemplate 7538 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 7539 7540 // C++ [over.over]p2: 7541 // If the name is a function template, template argument deduction is 7542 // done (14.8.2.2), and if the argument deduction succeeds, the 7543 // resulting template argument list is used to generate a single 7544 // function template specialization, which is added to the set of 7545 // overloaded functions considered. 7546 FunctionDecl *Specialization = 0; 7547 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 7548 if (TemplateDeductionResult Result 7549 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 7550 Specialization, Info)) { 7551 // FIXME: make a note of the failed deduction for diagnostics. 7552 (void)Result; 7553 continue; 7554 } 7555 7556 // Multiple matches; we can't resolve to a single declaration. 7557 if (Matched) { 7558 if (FoundResult) 7559 *FoundResult = DeclAccessPair(); 7560 7561 if (Complain) { 7562 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 7563 << OvlExpr->getName(); 7564 NoteAllOverloadCandidates(OvlExpr); 7565 } 7566 return 0; 7567 } 7568 7569 if ((Matched = Specialization) && FoundResult) 7570 *FoundResult = I.getPair(); 7571 } 7572 7573 return Matched; 7574} 7575 7576 7577 7578 7579// Resolve and fix an overloaded expression that 7580// can be resolved because it identifies a single function 7581// template specialization 7582// Last three arguments should only be supplied if Complain = true 7583ExprResult Sema::ResolveAndFixSingleFunctionTemplateSpecialization( 7584 Expr *SrcExpr, bool DoFunctionPointerConverion, bool Complain, 7585 const SourceRange& OpRangeForComplaining, 7586 QualType DestTypeForComplaining, 7587 unsigned DiagIDForComplaining ) { 7588 7589 assert(SrcExpr->getType() == Context.OverloadTy); 7590 7591 DeclAccessPair Found; 7592 ExprResult SingleFunctionExpression; 7593 if (FunctionDecl* Fn = ResolveSingleFunctionTemplateSpecialization( 7594 SrcExpr, false, // false -> Complain 7595 &Found)) { 7596 if (!DiagnoseUseOfDecl(Fn, SrcExpr->getSourceRange().getBegin())) { 7597 // mark the expression as resolved to Fn 7598 SingleFunctionExpression = Owned(FixOverloadedFunctionReference(SrcExpr, 7599 Found, Fn)); 7600 if (DoFunctionPointerConverion) 7601 SingleFunctionExpression = 7602 DefaultFunctionArrayLvalueConversion(SingleFunctionExpression.take()); 7603 } 7604 } 7605 if (!SingleFunctionExpression.isUsable()) { 7606 if (Complain) { 7607 OverloadExpr* oe = OverloadExpr::find(SrcExpr).Expression; 7608 Diag(OpRangeForComplaining.getBegin(), DiagIDForComplaining) 7609 << oe->getName() << DestTypeForComplaining << OpRangeForComplaining 7610 << oe->getQualifierLoc().getSourceRange(); 7611 NoteAllOverloadCandidates(SrcExpr); 7612 } 7613 return ExprError(); 7614 } 7615 7616 return SingleFunctionExpression; 7617} 7618 7619/// \brief Add a single candidate to the overload set. 7620static void AddOverloadedCallCandidate(Sema &S, 7621 DeclAccessPair FoundDecl, 7622 TemplateArgumentListInfo *ExplicitTemplateArgs, 7623 Expr **Args, unsigned NumArgs, 7624 OverloadCandidateSet &CandidateSet, 7625 bool PartialOverloading) { 7626 NamedDecl *Callee = FoundDecl.getDecl(); 7627 if (isa<UsingShadowDecl>(Callee)) 7628 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 7629 7630 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 7631 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 7632 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 7633 false, PartialOverloading); 7634 return; 7635 } 7636 7637 if (FunctionTemplateDecl *FuncTemplate 7638 = dyn_cast<FunctionTemplateDecl>(Callee)) { 7639 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 7640 ExplicitTemplateArgs, 7641 Args, NumArgs, CandidateSet); 7642 return; 7643 } 7644 7645 assert(false && "unhandled case in overloaded call candidate"); 7646 7647 // do nothing? 7648} 7649 7650/// \brief Add the overload candidates named by callee and/or found by argument 7651/// dependent lookup to the given overload set. 7652void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 7653 Expr **Args, unsigned NumArgs, 7654 OverloadCandidateSet &CandidateSet, 7655 bool PartialOverloading) { 7656 7657#ifndef NDEBUG 7658 // Verify that ArgumentDependentLookup is consistent with the rules 7659 // in C++0x [basic.lookup.argdep]p3: 7660 // 7661 // Let X be the lookup set produced by unqualified lookup (3.4.1) 7662 // and let Y be the lookup set produced by argument dependent 7663 // lookup (defined as follows). If X contains 7664 // 7665 // -- a declaration of a class member, or 7666 // 7667 // -- a block-scope function declaration that is not a 7668 // using-declaration, or 7669 // 7670 // -- a declaration that is neither a function or a function 7671 // template 7672 // 7673 // then Y is empty. 7674 7675 if (ULE->requiresADL()) { 7676 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 7677 E = ULE->decls_end(); I != E; ++I) { 7678 assert(!(*I)->getDeclContext()->isRecord()); 7679 assert(isa<UsingShadowDecl>(*I) || 7680 !(*I)->getDeclContext()->isFunctionOrMethod()); 7681 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 7682 } 7683 } 7684#endif 7685 7686 // It would be nice to avoid this copy. 7687 TemplateArgumentListInfo TABuffer; 7688 TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 7689 if (ULE->hasExplicitTemplateArgs()) { 7690 ULE->copyTemplateArgumentsInto(TABuffer); 7691 ExplicitTemplateArgs = &TABuffer; 7692 } 7693 7694 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 7695 E = ULE->decls_end(); I != E; ++I) 7696 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 7697 Args, NumArgs, CandidateSet, 7698 PartialOverloading); 7699 7700 if (ULE->requiresADL()) 7701 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 7702 Args, NumArgs, 7703 ExplicitTemplateArgs, 7704 CandidateSet, 7705 PartialOverloading, 7706 ULE->isStdAssociatedNamespace()); 7707} 7708 7709/// Attempts to recover from a call where no functions were found. 7710/// 7711/// Returns true if new candidates were found. 7712static ExprResult 7713BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 7714 UnresolvedLookupExpr *ULE, 7715 SourceLocation LParenLoc, 7716 Expr **Args, unsigned NumArgs, 7717 SourceLocation RParenLoc) { 7718 7719 CXXScopeSpec SS; 7720 SS.Adopt(ULE->getQualifierLoc()); 7721 7722 TemplateArgumentListInfo TABuffer; 7723 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 7724 if (ULE->hasExplicitTemplateArgs()) { 7725 ULE->copyTemplateArgumentsInto(TABuffer); 7726 ExplicitTemplateArgs = &TABuffer; 7727 } 7728 7729 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 7730 Sema::LookupOrdinaryName); 7731 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 7732 return ExprError(); 7733 7734 assert(!R.empty() && "lookup results empty despite recovery"); 7735 7736 // Build an implicit member call if appropriate. Just drop the 7737 // casts and such from the call, we don't really care. 7738 ExprResult NewFn = ExprError(); 7739 if ((*R.begin())->isCXXClassMember()) 7740 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, 7741 ExplicitTemplateArgs); 7742 else if (ExplicitTemplateArgs) 7743 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 7744 else 7745 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 7746 7747 if (NewFn.isInvalid()) 7748 return ExprError(); 7749 7750 // This shouldn't cause an infinite loop because we're giving it 7751 // an expression with non-empty lookup results, which should never 7752 // end up here. 7753 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 7754 MultiExprArg(Args, NumArgs), RParenLoc); 7755} 7756 7757/// ResolveOverloadedCallFn - Given the call expression that calls Fn 7758/// (which eventually refers to the declaration Func) and the call 7759/// arguments Args/NumArgs, attempt to resolve the function call down 7760/// to a specific function. If overload resolution succeeds, returns 7761/// the function declaration produced by overload 7762/// resolution. Otherwise, emits diagnostics, deletes all of the 7763/// arguments and Fn, and returns NULL. 7764ExprResult 7765Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 7766 SourceLocation LParenLoc, 7767 Expr **Args, unsigned NumArgs, 7768 SourceLocation RParenLoc, 7769 Expr *ExecConfig) { 7770#ifndef NDEBUG 7771 if (ULE->requiresADL()) { 7772 // To do ADL, we must have found an unqualified name. 7773 assert(!ULE->getQualifier() && "qualified name with ADL"); 7774 7775 // We don't perform ADL for implicit declarations of builtins. 7776 // Verify that this was correctly set up. 7777 FunctionDecl *F; 7778 if (ULE->decls_begin() + 1 == ULE->decls_end() && 7779 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 7780 F->getBuiltinID() && F->isImplicit()) 7781 assert(0 && "performing ADL for builtin"); 7782 7783 // We don't perform ADL in C. 7784 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 7785 } else 7786 assert(!ULE->isStdAssociatedNamespace() && 7787 "std is associated namespace but not doing ADL"); 7788#endif 7789 7790 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 7791 7792 // Add the functions denoted by the callee to the set of candidate 7793 // functions, including those from argument-dependent lookup. 7794 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 7795 7796 // If we found nothing, try to recover. 7797 // AddRecoveryCallCandidates diagnoses the error itself, so we just 7798 // bailout out if it fails. 7799 if (CandidateSet.empty()) 7800 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 7801 RParenLoc); 7802 7803 OverloadCandidateSet::iterator Best; 7804 switch (CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best)) { 7805 case OR_Success: { 7806 FunctionDecl *FDecl = Best->Function; 7807 MarkDeclarationReferenced(Fn->getExprLoc(), FDecl); 7808 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 7809 DiagnoseUseOfDecl(FDecl? FDecl : Best->FoundDecl.getDecl(), 7810 ULE->getNameLoc()); 7811 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 7812 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc, 7813 ExecConfig); 7814 } 7815 7816 case OR_No_Viable_Function: 7817 Diag(Fn->getSourceRange().getBegin(), 7818 diag::err_ovl_no_viable_function_in_call) 7819 << ULE->getName() << Fn->getSourceRange(); 7820 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7821 break; 7822 7823 case OR_Ambiguous: 7824 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 7825 << ULE->getName() << Fn->getSourceRange(); 7826 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 7827 break; 7828 7829 case OR_Deleted: 7830 { 7831 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 7832 << Best->Function->isDeleted() 7833 << ULE->getName() 7834 << getDeletedOrUnavailableSuffix(Best->Function) 7835 << Fn->getSourceRange(); 7836 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7837 } 7838 break; 7839 } 7840 7841 // Overload resolution failed. 7842 return ExprError(); 7843} 7844 7845static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 7846 return Functions.size() > 1 || 7847 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 7848} 7849 7850/// \brief Create a unary operation that may resolve to an overloaded 7851/// operator. 7852/// 7853/// \param OpLoc The location of the operator itself (e.g., '*'). 7854/// 7855/// \param OpcIn The UnaryOperator::Opcode that describes this 7856/// operator. 7857/// 7858/// \param Functions The set of non-member functions that will be 7859/// considered by overload resolution. The caller needs to build this 7860/// set based on the context using, e.g., 7861/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 7862/// set should not contain any member functions; those will be added 7863/// by CreateOverloadedUnaryOp(). 7864/// 7865/// \param input The input argument. 7866ExprResult 7867Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 7868 const UnresolvedSetImpl &Fns, 7869 Expr *Input) { 7870 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 7871 7872 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 7873 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 7874 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 7875 // TODO: provide better source location info. 7876 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 7877 7878 if (Input->getObjectKind() == OK_ObjCProperty) { 7879 ExprResult Result = ConvertPropertyForRValue(Input); 7880 if (Result.isInvalid()) 7881 return ExprError(); 7882 Input = Result.take(); 7883 } 7884 7885 Expr *Args[2] = { Input, 0 }; 7886 unsigned NumArgs = 1; 7887 7888 // For post-increment and post-decrement, add the implicit '0' as 7889 // the second argument, so that we know this is a post-increment or 7890 // post-decrement. 7891 if (Opc == UO_PostInc || Opc == UO_PostDec) { 7892 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 7893 Args[1] = IntegerLiteral::Create(Context, Zero, Context.IntTy, 7894 SourceLocation()); 7895 NumArgs = 2; 7896 } 7897 7898 if (Input->isTypeDependent()) { 7899 if (Fns.empty()) 7900 return Owned(new (Context) UnaryOperator(Input, 7901 Opc, 7902 Context.DependentTy, 7903 VK_RValue, OK_Ordinary, 7904 OpLoc)); 7905 7906 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7907 UnresolvedLookupExpr *Fn 7908 = UnresolvedLookupExpr::Create(Context, NamingClass, 7909 NestedNameSpecifierLoc(), OpNameInfo, 7910 /*ADL*/ true, IsOverloaded(Fns), 7911 Fns.begin(), Fns.end()); 7912 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 7913 &Args[0], NumArgs, 7914 Context.DependentTy, 7915 VK_RValue, 7916 OpLoc)); 7917 } 7918 7919 // Build an empty overload set. 7920 OverloadCandidateSet CandidateSet(OpLoc); 7921 7922 // Add the candidates from the given function set. 7923 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 7924 7925 // Add operator candidates that are member functions. 7926 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 7927 7928 // Add candidates from ADL. 7929 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 7930 Args, NumArgs, 7931 /*ExplicitTemplateArgs*/ 0, 7932 CandidateSet); 7933 7934 // Add builtin operator candidates. 7935 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 7936 7937 // Perform overload resolution. 7938 OverloadCandidateSet::iterator Best; 7939 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 7940 case OR_Success: { 7941 // We found a built-in operator or an overloaded operator. 7942 FunctionDecl *FnDecl = Best->Function; 7943 7944 if (FnDecl) { 7945 // We matched an overloaded operator. Build a call to that 7946 // operator. 7947 7948 MarkDeclarationReferenced(OpLoc, FnDecl); 7949 7950 // Convert the arguments. 7951 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 7952 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 7953 7954 ExprResult InputRes = 7955 PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 7956 Best->FoundDecl, Method); 7957 if (InputRes.isInvalid()) 7958 return ExprError(); 7959 Input = InputRes.take(); 7960 } else { 7961 // Convert the arguments. 7962 ExprResult InputInit 7963 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7964 Context, 7965 FnDecl->getParamDecl(0)), 7966 SourceLocation(), 7967 Input); 7968 if (InputInit.isInvalid()) 7969 return ExprError(); 7970 Input = InputInit.take(); 7971 } 7972 7973 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7974 7975 // Determine the result type. 7976 QualType ResultTy = FnDecl->getResultType(); 7977 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 7978 ResultTy = ResultTy.getNonLValueExprType(Context); 7979 7980 // Build the actual expression node. 7981 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl); 7982 if (FnExpr.isInvalid()) 7983 return ExprError(); 7984 7985 Args[0] = Input; 7986 CallExpr *TheCall = 7987 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 7988 Args, NumArgs, ResultTy, VK, OpLoc); 7989 7990 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 7991 FnDecl)) 7992 return ExprError(); 7993 7994 return MaybeBindToTemporary(TheCall); 7995 } else { 7996 // We matched a built-in operator. Convert the arguments, then 7997 // break out so that we will build the appropriate built-in 7998 // operator node. 7999 ExprResult InputRes = 8000 PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 8001 Best->Conversions[0], AA_Passing); 8002 if (InputRes.isInvalid()) 8003 return ExprError(); 8004 Input = InputRes.take(); 8005 break; 8006 } 8007 } 8008 8009 case OR_No_Viable_Function: 8010 // No viable function; fall through to handling this as a 8011 // built-in operator, which will produce an error message for us. 8012 break; 8013 8014 case OR_Ambiguous: 8015 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 8016 << UnaryOperator::getOpcodeStr(Opc) 8017 << Input->getType() 8018 << Input->getSourceRange(); 8019 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 8020 Args, NumArgs, 8021 UnaryOperator::getOpcodeStr(Opc), OpLoc); 8022 return ExprError(); 8023 8024 case OR_Deleted: 8025 Diag(OpLoc, diag::err_ovl_deleted_oper) 8026 << Best->Function->isDeleted() 8027 << UnaryOperator::getOpcodeStr(Opc) 8028 << getDeletedOrUnavailableSuffix(Best->Function) 8029 << Input->getSourceRange(); 8030 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8031 return ExprError(); 8032 } 8033 8034 // Either we found no viable overloaded operator or we matched a 8035 // built-in operator. In either case, fall through to trying to 8036 // build a built-in operation. 8037 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 8038} 8039 8040/// \brief Create a binary operation that may resolve to an overloaded 8041/// operator. 8042/// 8043/// \param OpLoc The location of the operator itself (e.g., '+'). 8044/// 8045/// \param OpcIn The BinaryOperator::Opcode that describes this 8046/// operator. 8047/// 8048/// \param Functions The set of non-member functions that will be 8049/// considered by overload resolution. The caller needs to build this 8050/// set based on the context using, e.g., 8051/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 8052/// set should not contain any member functions; those will be added 8053/// by CreateOverloadedBinOp(). 8054/// 8055/// \param LHS Left-hand argument. 8056/// \param RHS Right-hand argument. 8057ExprResult 8058Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 8059 unsigned OpcIn, 8060 const UnresolvedSetImpl &Fns, 8061 Expr *LHS, Expr *RHS) { 8062 Expr *Args[2] = { LHS, RHS }; 8063 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 8064 8065 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 8066 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 8067 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 8068 8069 // If either side is type-dependent, create an appropriate dependent 8070 // expression. 8071 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 8072 if (Fns.empty()) { 8073 // If there are no functions to store, just build a dependent 8074 // BinaryOperator or CompoundAssignment. 8075 if (Opc <= BO_Assign || Opc > BO_OrAssign) 8076 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 8077 Context.DependentTy, 8078 VK_RValue, OK_Ordinary, 8079 OpLoc)); 8080 8081 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 8082 Context.DependentTy, 8083 VK_LValue, 8084 OK_Ordinary, 8085 Context.DependentTy, 8086 Context.DependentTy, 8087 OpLoc)); 8088 } 8089 8090 // FIXME: save results of ADL from here? 8091 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8092 // TODO: provide better source location info in DNLoc component. 8093 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 8094 UnresolvedLookupExpr *Fn 8095 = UnresolvedLookupExpr::Create(Context, NamingClass, 8096 NestedNameSpecifierLoc(), OpNameInfo, 8097 /*ADL*/ true, IsOverloaded(Fns), 8098 Fns.begin(), Fns.end()); 8099 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 8100 Args, 2, 8101 Context.DependentTy, 8102 VK_RValue, 8103 OpLoc)); 8104 } 8105 8106 // Always do property rvalue conversions on the RHS. 8107 if (Args[1]->getObjectKind() == OK_ObjCProperty) { 8108 ExprResult Result = ConvertPropertyForRValue(Args[1]); 8109 if (Result.isInvalid()) 8110 return ExprError(); 8111 Args[1] = Result.take(); 8112 } 8113 8114 // The LHS is more complicated. 8115 if (Args[0]->getObjectKind() == OK_ObjCProperty) { 8116 8117 // There's a tension for assignment operators between primitive 8118 // property assignment and the overloaded operators. 8119 if (BinaryOperator::isAssignmentOp(Opc)) { 8120 const ObjCPropertyRefExpr *PRE = LHS->getObjCProperty(); 8121 8122 // Is the property "logically" settable? 8123 bool Settable = (PRE->isExplicitProperty() || 8124 PRE->getImplicitPropertySetter()); 8125 8126 // To avoid gratuitously inventing semantics, use the primitive 8127 // unless it isn't. Thoughts in case we ever really care: 8128 // - If the property isn't logically settable, we have to 8129 // load and hope. 8130 // - If the property is settable and this is simple assignment, 8131 // we really should use the primitive. 8132 // - If the property is settable, then we could try overloading 8133 // on a generic lvalue of the appropriate type; if it works 8134 // out to a builtin candidate, we would do that same operation 8135 // on the property, and otherwise just error. 8136 if (Settable) 8137 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8138 } 8139 8140 ExprResult Result = ConvertPropertyForRValue(Args[0]); 8141 if (Result.isInvalid()) 8142 return ExprError(); 8143 Args[0] = Result.take(); 8144 } 8145 8146 // If this is the assignment operator, we only perform overload resolution 8147 // if the left-hand side is a class or enumeration type. This is actually 8148 // a hack. The standard requires that we do overload resolution between the 8149 // various built-in candidates, but as DR507 points out, this can lead to 8150 // problems. So we do it this way, which pretty much follows what GCC does. 8151 // Note that we go the traditional code path for compound assignment forms. 8152 if (Opc == BO_Assign && !Args[0]->getType()->isOverloadableType()) 8153 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8154 8155 // If this is the .* operator, which is not overloadable, just 8156 // create a built-in binary operator. 8157 if (Opc == BO_PtrMemD) 8158 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8159 8160 // Build an empty overload set. 8161 OverloadCandidateSet CandidateSet(OpLoc); 8162 8163 // Add the candidates from the given function set. 8164 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 8165 8166 // Add operator candidates that are member functions. 8167 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 8168 8169 // Add candidates from ADL. 8170 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 8171 Args, 2, 8172 /*ExplicitTemplateArgs*/ 0, 8173 CandidateSet); 8174 8175 // Add builtin operator candidates. 8176 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 8177 8178 // Perform overload resolution. 8179 OverloadCandidateSet::iterator Best; 8180 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8181 case OR_Success: { 8182 // We found a built-in operator or an overloaded operator. 8183 FunctionDecl *FnDecl = Best->Function; 8184 8185 if (FnDecl) { 8186 // We matched an overloaded operator. Build a call to that 8187 // operator. 8188 8189 MarkDeclarationReferenced(OpLoc, FnDecl); 8190 8191 // Convert the arguments. 8192 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 8193 // Best->Access is only meaningful for class members. 8194 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 8195 8196 ExprResult Arg1 = 8197 PerformCopyInitialization( 8198 InitializedEntity::InitializeParameter(Context, 8199 FnDecl->getParamDecl(0)), 8200 SourceLocation(), Owned(Args[1])); 8201 if (Arg1.isInvalid()) 8202 return ExprError(); 8203 8204 ExprResult Arg0 = 8205 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 8206 Best->FoundDecl, Method); 8207 if (Arg0.isInvalid()) 8208 return ExprError(); 8209 Args[0] = Arg0.takeAs<Expr>(); 8210 Args[1] = RHS = Arg1.takeAs<Expr>(); 8211 } else { 8212 // Convert the arguments. 8213 ExprResult Arg0 = PerformCopyInitialization( 8214 InitializedEntity::InitializeParameter(Context, 8215 FnDecl->getParamDecl(0)), 8216 SourceLocation(), Owned(Args[0])); 8217 if (Arg0.isInvalid()) 8218 return ExprError(); 8219 8220 ExprResult Arg1 = 8221 PerformCopyInitialization( 8222 InitializedEntity::InitializeParameter(Context, 8223 FnDecl->getParamDecl(1)), 8224 SourceLocation(), Owned(Args[1])); 8225 if (Arg1.isInvalid()) 8226 return ExprError(); 8227 Args[0] = LHS = Arg0.takeAs<Expr>(); 8228 Args[1] = RHS = Arg1.takeAs<Expr>(); 8229 } 8230 8231 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 8232 8233 // Determine the result type. 8234 QualType ResultTy = FnDecl->getResultType(); 8235 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8236 ResultTy = ResultTy.getNonLValueExprType(Context); 8237 8238 // Build the actual expression node. 8239 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, OpLoc); 8240 if (FnExpr.isInvalid()) 8241 return ExprError(); 8242 8243 CXXOperatorCallExpr *TheCall = 8244 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr.take(), 8245 Args, 2, ResultTy, VK, OpLoc); 8246 8247 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 8248 FnDecl)) 8249 return ExprError(); 8250 8251 return MaybeBindToTemporary(TheCall); 8252 } else { 8253 // We matched a built-in operator. Convert the arguments, then 8254 // break out so that we will build the appropriate built-in 8255 // operator node. 8256 ExprResult ArgsRes0 = 8257 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 8258 Best->Conversions[0], AA_Passing); 8259 if (ArgsRes0.isInvalid()) 8260 return ExprError(); 8261 Args[0] = ArgsRes0.take(); 8262 8263 ExprResult ArgsRes1 = 8264 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 8265 Best->Conversions[1], AA_Passing); 8266 if (ArgsRes1.isInvalid()) 8267 return ExprError(); 8268 Args[1] = ArgsRes1.take(); 8269 break; 8270 } 8271 } 8272 8273 case OR_No_Viable_Function: { 8274 // C++ [over.match.oper]p9: 8275 // If the operator is the operator , [...] and there are no 8276 // viable functions, then the operator is assumed to be the 8277 // built-in operator and interpreted according to clause 5. 8278 if (Opc == BO_Comma) 8279 break; 8280 8281 // For class as left operand for assignment or compound assigment 8282 // operator do not fall through to handling in built-in, but report that 8283 // no overloaded assignment operator found 8284 ExprResult Result = ExprError(); 8285 if (Args[0]->getType()->isRecordType() && 8286 Opc >= BO_Assign && Opc <= BO_OrAssign) { 8287 Diag(OpLoc, diag::err_ovl_no_viable_oper) 8288 << BinaryOperator::getOpcodeStr(Opc) 8289 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8290 } else { 8291 // No viable function; try to create a built-in operation, which will 8292 // produce an error. Then, show the non-viable candidates. 8293 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8294 } 8295 assert(Result.isInvalid() && 8296 "C++ binary operator overloading is missing candidates!"); 8297 if (Result.isInvalid()) 8298 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8299 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8300 return move(Result); 8301 } 8302 8303 case OR_Ambiguous: 8304 Diag(OpLoc, diag::err_ovl_ambiguous_oper_binary) 8305 << BinaryOperator::getOpcodeStr(Opc) 8306 << Args[0]->getType() << Args[1]->getType() 8307 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8308 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 8309 BinaryOperator::getOpcodeStr(Opc), OpLoc); 8310 return ExprError(); 8311 8312 case OR_Deleted: 8313 Diag(OpLoc, diag::err_ovl_deleted_oper) 8314 << Best->Function->isDeleted() 8315 << BinaryOperator::getOpcodeStr(Opc) 8316 << getDeletedOrUnavailableSuffix(Best->Function) 8317 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8318 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2); 8319 return ExprError(); 8320 } 8321 8322 // We matched a built-in operator; build it. 8323 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 8324} 8325 8326ExprResult 8327Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 8328 SourceLocation RLoc, 8329 Expr *Base, Expr *Idx) { 8330 Expr *Args[2] = { Base, Idx }; 8331 DeclarationName OpName = 8332 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 8333 8334 // If either side is type-dependent, create an appropriate dependent 8335 // expression. 8336 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 8337 8338 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 8339 // CHECKME: no 'operator' keyword? 8340 DeclarationNameInfo OpNameInfo(OpName, LLoc); 8341 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 8342 UnresolvedLookupExpr *Fn 8343 = UnresolvedLookupExpr::Create(Context, NamingClass, 8344 NestedNameSpecifierLoc(), OpNameInfo, 8345 /*ADL*/ true, /*Overloaded*/ false, 8346 UnresolvedSetIterator(), 8347 UnresolvedSetIterator()); 8348 // Can't add any actual overloads yet 8349 8350 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 8351 Args, 2, 8352 Context.DependentTy, 8353 VK_RValue, 8354 RLoc)); 8355 } 8356 8357 if (Args[0]->getObjectKind() == OK_ObjCProperty) { 8358 ExprResult Result = ConvertPropertyForRValue(Args[0]); 8359 if (Result.isInvalid()) 8360 return ExprError(); 8361 Args[0] = Result.take(); 8362 } 8363 if (Args[1]->getObjectKind() == OK_ObjCProperty) { 8364 ExprResult Result = ConvertPropertyForRValue(Args[1]); 8365 if (Result.isInvalid()) 8366 return ExprError(); 8367 Args[1] = Result.take(); 8368 } 8369 8370 // Build an empty overload set. 8371 OverloadCandidateSet CandidateSet(LLoc); 8372 8373 // Subscript can only be overloaded as a member function. 8374 8375 // Add operator candidates that are member functions. 8376 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 8377 8378 // Add builtin operator candidates. 8379 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 8380 8381 // Perform overload resolution. 8382 OverloadCandidateSet::iterator Best; 8383 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 8384 case OR_Success: { 8385 // We found a built-in operator or an overloaded operator. 8386 FunctionDecl *FnDecl = Best->Function; 8387 8388 if (FnDecl) { 8389 // We matched an overloaded operator. Build a call to that 8390 // operator. 8391 8392 MarkDeclarationReferenced(LLoc, FnDecl); 8393 8394 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 8395 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 8396 8397 // Convert the arguments. 8398 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 8399 ExprResult Arg0 = 8400 PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 8401 Best->FoundDecl, Method); 8402 if (Arg0.isInvalid()) 8403 return ExprError(); 8404 Args[0] = Arg0.take(); 8405 8406 // Convert the arguments. 8407 ExprResult InputInit 8408 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8409 Context, 8410 FnDecl->getParamDecl(0)), 8411 SourceLocation(), 8412 Owned(Args[1])); 8413 if (InputInit.isInvalid()) 8414 return ExprError(); 8415 8416 Args[1] = InputInit.takeAs<Expr>(); 8417 8418 // Determine the result type 8419 QualType ResultTy = FnDecl->getResultType(); 8420 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8421 ResultTy = ResultTy.getNonLValueExprType(Context); 8422 8423 // Build the actual expression node. 8424 ExprResult FnExpr = CreateFunctionRefExpr(*this, FnDecl, LLoc); 8425 if (FnExpr.isInvalid()) 8426 return ExprError(); 8427 8428 CXXOperatorCallExpr *TheCall = 8429 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 8430 FnExpr.take(), Args, 2, 8431 ResultTy, VK, RLoc); 8432 8433 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 8434 FnDecl)) 8435 return ExprError(); 8436 8437 return MaybeBindToTemporary(TheCall); 8438 } else { 8439 // We matched a built-in operator. Convert the arguments, then 8440 // break out so that we will build the appropriate built-in 8441 // operator node. 8442 ExprResult ArgsRes0 = 8443 PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 8444 Best->Conversions[0], AA_Passing); 8445 if (ArgsRes0.isInvalid()) 8446 return ExprError(); 8447 Args[0] = ArgsRes0.take(); 8448 8449 ExprResult ArgsRes1 = 8450 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 8451 Best->Conversions[1], AA_Passing); 8452 if (ArgsRes1.isInvalid()) 8453 return ExprError(); 8454 Args[1] = ArgsRes1.take(); 8455 8456 break; 8457 } 8458 } 8459 8460 case OR_No_Viable_Function: { 8461 if (CandidateSet.empty()) 8462 Diag(LLoc, diag::err_ovl_no_oper) 8463 << Args[0]->getType() << /*subscript*/ 0 8464 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8465 else 8466 Diag(LLoc, diag::err_ovl_no_viable_subscript) 8467 << Args[0]->getType() 8468 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8469 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8470 "[]", LLoc); 8471 return ExprError(); 8472 } 8473 8474 case OR_Ambiguous: 8475 Diag(LLoc, diag::err_ovl_ambiguous_oper_binary) 8476 << "[]" 8477 << Args[0]->getType() << Args[1]->getType() 8478 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8479 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 8480 "[]", LLoc); 8481 return ExprError(); 8482 8483 case OR_Deleted: 8484 Diag(LLoc, diag::err_ovl_deleted_oper) 8485 << Best->Function->isDeleted() << "[]" 8486 << getDeletedOrUnavailableSuffix(Best->Function) 8487 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 8488 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 8489 "[]", LLoc); 8490 return ExprError(); 8491 } 8492 8493 // We matched a built-in operator; build it. 8494 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 8495} 8496 8497/// BuildCallToMemberFunction - Build a call to a member 8498/// function. MemExpr is the expression that refers to the member 8499/// function (and includes the object parameter), Args/NumArgs are the 8500/// arguments to the function call (not including the object 8501/// parameter). The caller needs to validate that the member 8502/// expression refers to a member function or an overloaded member 8503/// function. 8504ExprResult 8505Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 8506 SourceLocation LParenLoc, Expr **Args, 8507 unsigned NumArgs, SourceLocation RParenLoc) { 8508 // Dig out the member expression. This holds both the object 8509 // argument and the member function we're referring to. 8510 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 8511 8512 MemberExpr *MemExpr; 8513 CXXMethodDecl *Method = 0; 8514 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 8515 NestedNameSpecifier *Qualifier = 0; 8516 if (isa<MemberExpr>(NakedMemExpr)) { 8517 MemExpr = cast<MemberExpr>(NakedMemExpr); 8518 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 8519 FoundDecl = MemExpr->getFoundDecl(); 8520 Qualifier = MemExpr->getQualifier(); 8521 } else { 8522 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 8523 Qualifier = UnresExpr->getQualifier(); 8524 8525 QualType ObjectType = UnresExpr->getBaseType(); 8526 Expr::Classification ObjectClassification 8527 = UnresExpr->isArrow()? Expr::Classification::makeSimpleLValue() 8528 : UnresExpr->getBase()->Classify(Context); 8529 8530 // Add overload candidates 8531 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 8532 8533 // FIXME: avoid copy. 8534 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 8535 if (UnresExpr->hasExplicitTemplateArgs()) { 8536 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 8537 TemplateArgs = &TemplateArgsBuffer; 8538 } 8539 8540 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 8541 E = UnresExpr->decls_end(); I != E; ++I) { 8542 8543 NamedDecl *Func = *I; 8544 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 8545 if (isa<UsingShadowDecl>(Func)) 8546 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 8547 8548 8549 // Microsoft supports direct constructor calls. 8550 if (getLangOptions().Microsoft && isa<CXXConstructorDecl>(Func)) { 8551 AddOverloadCandidate(cast<CXXConstructorDecl>(Func), I.getPair(), Args, NumArgs, 8552 CandidateSet); 8553 } else if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 8554 // If explicit template arguments were provided, we can't call a 8555 // non-template member function. 8556 if (TemplateArgs) 8557 continue; 8558 8559 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 8560 ObjectClassification, 8561 Args, NumArgs, CandidateSet, 8562 /*SuppressUserConversions=*/false); 8563 } else { 8564 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 8565 I.getPair(), ActingDC, TemplateArgs, 8566 ObjectType, ObjectClassification, 8567 Args, NumArgs, CandidateSet, 8568 /*SuppressUsedConversions=*/false); 8569 } 8570 } 8571 8572 DeclarationName DeclName = UnresExpr->getMemberName(); 8573 8574 OverloadCandidateSet::iterator Best; 8575 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 8576 Best)) { 8577 case OR_Success: 8578 Method = cast<CXXMethodDecl>(Best->Function); 8579 MarkDeclarationReferenced(UnresExpr->getMemberLoc(), Method); 8580 FoundDecl = Best->FoundDecl; 8581 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 8582 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 8583 break; 8584 8585 case OR_No_Viable_Function: 8586 Diag(UnresExpr->getMemberLoc(), 8587 diag::err_ovl_no_viable_member_function_in_call) 8588 << DeclName << MemExprE->getSourceRange(); 8589 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8590 // FIXME: Leaking incoming expressions! 8591 return ExprError(); 8592 8593 case OR_Ambiguous: 8594 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 8595 << DeclName << MemExprE->getSourceRange(); 8596 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8597 // FIXME: Leaking incoming expressions! 8598 return ExprError(); 8599 8600 case OR_Deleted: 8601 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 8602 << Best->Function->isDeleted() 8603 << DeclName 8604 << getDeletedOrUnavailableSuffix(Best->Function) 8605 << MemExprE->getSourceRange(); 8606 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8607 // FIXME: Leaking incoming expressions! 8608 return ExprError(); 8609 } 8610 8611 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 8612 8613 // If overload resolution picked a static member, build a 8614 // non-member call based on that function. 8615 if (Method->isStatic()) { 8616 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 8617 Args, NumArgs, RParenLoc); 8618 } 8619 8620 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 8621 } 8622 8623 QualType ResultType = Method->getResultType(); 8624 ExprValueKind VK = Expr::getValueKindForType(ResultType); 8625 ResultType = ResultType.getNonLValueExprType(Context); 8626 8627 assert(Method && "Member call to something that isn't a method?"); 8628 CXXMemberCallExpr *TheCall = 8629 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 8630 ResultType, VK, RParenLoc); 8631 8632 // Check for a valid return type. 8633 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 8634 TheCall, Method)) 8635 return ExprError(); 8636 8637 // Convert the object argument (for a non-static member function call). 8638 // We only need to do this if there was actually an overload; otherwise 8639 // it was done at lookup. 8640 if (!Method->isStatic()) { 8641 ExprResult ObjectArg = 8642 PerformObjectArgumentInitialization(MemExpr->getBase(), Qualifier, 8643 FoundDecl, Method); 8644 if (ObjectArg.isInvalid()) 8645 return ExprError(); 8646 MemExpr->setBase(ObjectArg.take()); 8647 } 8648 8649 // Convert the rest of the arguments 8650 const FunctionProtoType *Proto = 8651 Method->getType()->getAs<FunctionProtoType>(); 8652 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 8653 RParenLoc)) 8654 return ExprError(); 8655 8656 if (CheckFunctionCall(Method, TheCall)) 8657 return ExprError(); 8658 8659 return MaybeBindToTemporary(TheCall); 8660} 8661 8662/// BuildCallToObjectOfClassType - Build a call to an object of class 8663/// type (C++ [over.call.object]), which can end up invoking an 8664/// overloaded function call operator (@c operator()) or performing a 8665/// user-defined conversion on the object argument. 8666ExprResult 8667Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Obj, 8668 SourceLocation LParenLoc, 8669 Expr **Args, unsigned NumArgs, 8670 SourceLocation RParenLoc) { 8671 ExprResult Object = Owned(Obj); 8672 if (Object.get()->getObjectKind() == OK_ObjCProperty) { 8673 Object = ConvertPropertyForRValue(Object.take()); 8674 if (Object.isInvalid()) 8675 return ExprError(); 8676 } 8677 8678 assert(Object.get()->getType()->isRecordType() && "Requires object type argument"); 8679 const RecordType *Record = Object.get()->getType()->getAs<RecordType>(); 8680 8681 // C++ [over.call.object]p1: 8682 // If the primary-expression E in the function call syntax 8683 // evaluates to a class object of type "cv T", then the set of 8684 // candidate functions includes at least the function call 8685 // operators of T. The function call operators of T are obtained by 8686 // ordinary lookup of the name operator() in the context of 8687 // (E).operator(). 8688 OverloadCandidateSet CandidateSet(LParenLoc); 8689 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 8690 8691 if (RequireCompleteType(LParenLoc, Object.get()->getType(), 8692 PDiag(diag::err_incomplete_object_call) 8693 << Object.get()->getSourceRange())) 8694 return true; 8695 8696 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 8697 LookupQualifiedName(R, Record->getDecl()); 8698 R.suppressDiagnostics(); 8699 8700 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 8701 Oper != OperEnd; ++Oper) { 8702 AddMethodCandidate(Oper.getPair(), Object.get()->getType(), 8703 Object.get()->Classify(Context), Args, NumArgs, CandidateSet, 8704 /*SuppressUserConversions=*/ false); 8705 } 8706 8707 // C++ [over.call.object]p2: 8708 // In addition, for each conversion function declared in T of the 8709 // form 8710 // 8711 // operator conversion-type-id () cv-qualifier; 8712 // 8713 // where cv-qualifier is the same cv-qualification as, or a 8714 // greater cv-qualification than, cv, and where conversion-type-id 8715 // denotes the type "pointer to function of (P1,...,Pn) returning 8716 // R", or the type "reference to pointer to function of 8717 // (P1,...,Pn) returning R", or the type "reference to function 8718 // of (P1,...,Pn) returning R", a surrogate call function [...] 8719 // is also considered as a candidate function. Similarly, 8720 // surrogate call functions are added to the set of candidate 8721 // functions for each conversion function declared in an 8722 // accessible base class provided the function is not hidden 8723 // within T by another intervening declaration. 8724 const UnresolvedSetImpl *Conversions 8725 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 8726 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 8727 E = Conversions->end(); I != E; ++I) { 8728 NamedDecl *D = *I; 8729 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 8730 if (isa<UsingShadowDecl>(D)) 8731 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 8732 8733 // Skip over templated conversion functions; they aren't 8734 // surrogates. 8735 if (isa<FunctionTemplateDecl>(D)) 8736 continue; 8737 8738 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 8739 8740 // Strip the reference type (if any) and then the pointer type (if 8741 // any) to get down to what might be a function type. 8742 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 8743 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 8744 ConvType = ConvPtrType->getPointeeType(); 8745 8746 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 8747 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 8748 Object.get(), Args, NumArgs, CandidateSet); 8749 } 8750 8751 // Perform overload resolution. 8752 OverloadCandidateSet::iterator Best; 8753 switch (CandidateSet.BestViableFunction(*this, Object.get()->getLocStart(), 8754 Best)) { 8755 case OR_Success: 8756 // Overload resolution succeeded; we'll build the appropriate call 8757 // below. 8758 break; 8759 8760 case OR_No_Viable_Function: 8761 if (CandidateSet.empty()) 8762 Diag(Object.get()->getSourceRange().getBegin(), diag::err_ovl_no_oper) 8763 << Object.get()->getType() << /*call*/ 1 8764 << Object.get()->getSourceRange(); 8765 else 8766 Diag(Object.get()->getSourceRange().getBegin(), 8767 diag::err_ovl_no_viable_object_call) 8768 << Object.get()->getType() << Object.get()->getSourceRange(); 8769 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8770 break; 8771 8772 case OR_Ambiguous: 8773 Diag(Object.get()->getSourceRange().getBegin(), 8774 diag::err_ovl_ambiguous_object_call) 8775 << Object.get()->getType() << Object.get()->getSourceRange(); 8776 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 8777 break; 8778 8779 case OR_Deleted: 8780 Diag(Object.get()->getSourceRange().getBegin(), 8781 diag::err_ovl_deleted_object_call) 8782 << Best->Function->isDeleted() 8783 << Object.get()->getType() 8784 << getDeletedOrUnavailableSuffix(Best->Function) 8785 << Object.get()->getSourceRange(); 8786 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 8787 break; 8788 } 8789 8790 if (Best == CandidateSet.end()) 8791 return true; 8792 8793 if (Best->Function == 0) { 8794 // Since there is no function declaration, this is one of the 8795 // surrogate candidates. Dig out the conversion function. 8796 CXXConversionDecl *Conv 8797 = cast<CXXConversionDecl>( 8798 Best->Conversions[0].UserDefined.ConversionFunction); 8799 8800 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 8801 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 8802 8803 // We selected one of the surrogate functions that converts the 8804 // object parameter to a function pointer. Perform the conversion 8805 // on the object argument, then let ActOnCallExpr finish the job. 8806 8807 // Create an implicit member expr to refer to the conversion operator. 8808 // and then call it. 8809 ExprResult Call = BuildCXXMemberCallExpr(Object.get(), Best->FoundDecl, Conv); 8810 if (Call.isInvalid()) 8811 return ExprError(); 8812 8813 return ActOnCallExpr(S, Call.get(), LParenLoc, MultiExprArg(Args, NumArgs), 8814 RParenLoc); 8815 } 8816 8817 MarkDeclarationReferenced(LParenLoc, Best->Function); 8818 CheckMemberOperatorAccess(LParenLoc, Object.get(), 0, Best->FoundDecl); 8819 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 8820 8821 // We found an overloaded operator(). Build a CXXOperatorCallExpr 8822 // that calls this method, using Object for the implicit object 8823 // parameter and passing along the remaining arguments. 8824 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 8825 const FunctionProtoType *Proto = 8826 Method->getType()->getAs<FunctionProtoType>(); 8827 8828 unsigned NumArgsInProto = Proto->getNumArgs(); 8829 unsigned NumArgsToCheck = NumArgs; 8830 8831 // Build the full argument list for the method call (the 8832 // implicit object parameter is placed at the beginning of the 8833 // list). 8834 Expr **MethodArgs; 8835 if (NumArgs < NumArgsInProto) { 8836 NumArgsToCheck = NumArgsInProto; 8837 MethodArgs = new Expr*[NumArgsInProto + 1]; 8838 } else { 8839 MethodArgs = new Expr*[NumArgs + 1]; 8840 } 8841 MethodArgs[0] = Object.get(); 8842 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 8843 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 8844 8845 ExprResult NewFn = CreateFunctionRefExpr(*this, Method); 8846 if (NewFn.isInvalid()) 8847 return true; 8848 8849 // Once we've built TheCall, all of the expressions are properly 8850 // owned. 8851 QualType ResultTy = Method->getResultType(); 8852 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 8853 ResultTy = ResultTy.getNonLValueExprType(Context); 8854 8855 CXXOperatorCallExpr *TheCall = 8856 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn.take(), 8857 MethodArgs, NumArgs + 1, 8858 ResultTy, VK, RParenLoc); 8859 delete [] MethodArgs; 8860 8861 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 8862 Method)) 8863 return true; 8864 8865 // We may have default arguments. If so, we need to allocate more 8866 // slots in the call for them. 8867 if (NumArgs < NumArgsInProto) 8868 TheCall->setNumArgs(Context, NumArgsInProto + 1); 8869 else if (NumArgs > NumArgsInProto) 8870 NumArgsToCheck = NumArgsInProto; 8871 8872 bool IsError = false; 8873 8874 // Initialize the implicit object parameter. 8875 ExprResult ObjRes = 8876 PerformObjectArgumentInitialization(Object.get(), /*Qualifier=*/0, 8877 Best->FoundDecl, Method); 8878 if (ObjRes.isInvalid()) 8879 IsError = true; 8880 else 8881 Object = move(ObjRes); 8882 TheCall->setArg(0, Object.take()); 8883 8884 // Check the argument types. 8885 for (unsigned i = 0; i != NumArgsToCheck; i++) { 8886 Expr *Arg; 8887 if (i < NumArgs) { 8888 Arg = Args[i]; 8889 8890 // Pass the argument. 8891 8892 ExprResult InputInit 8893 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 8894 Context, 8895 Method->getParamDecl(i)), 8896 SourceLocation(), Arg); 8897 8898 IsError |= InputInit.isInvalid(); 8899 Arg = InputInit.takeAs<Expr>(); 8900 } else { 8901 ExprResult DefArg 8902 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 8903 if (DefArg.isInvalid()) { 8904 IsError = true; 8905 break; 8906 } 8907 8908 Arg = DefArg.takeAs<Expr>(); 8909 } 8910 8911 TheCall->setArg(i + 1, Arg); 8912 } 8913 8914 // If this is a variadic call, handle args passed through "...". 8915 if (Proto->isVariadic()) { 8916 // Promote the arguments (C99 6.5.2.2p7). 8917 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 8918 ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], VariadicMethod, 0); 8919 IsError |= Arg.isInvalid(); 8920 TheCall->setArg(i + 1, Arg.take()); 8921 } 8922 } 8923 8924 if (IsError) return true; 8925 8926 if (CheckFunctionCall(Method, TheCall)) 8927 return true; 8928 8929 return MaybeBindToTemporary(TheCall); 8930} 8931 8932/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 8933/// (if one exists), where @c Base is an expression of class type and 8934/// @c Member is the name of the member we're trying to find. 8935ExprResult 8936Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 8937 assert(Base->getType()->isRecordType() && 8938 "left-hand side must have class type"); 8939 8940 if (Base->getObjectKind() == OK_ObjCProperty) { 8941 ExprResult Result = ConvertPropertyForRValue(Base); 8942 if (Result.isInvalid()) 8943 return ExprError(); 8944 Base = Result.take(); 8945 } 8946 8947 SourceLocation Loc = Base->getExprLoc(); 8948 8949 // C++ [over.ref]p1: 8950 // 8951 // [...] An expression x->m is interpreted as (x.operator->())->m 8952 // for a class object x of type T if T::operator->() exists and if 8953 // the operator is selected as the best match function by the 8954 // overload resolution mechanism (13.3). 8955 DeclarationName OpName = 8956 Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 8957 OverloadCandidateSet CandidateSet(Loc); 8958 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 8959 8960 if (RequireCompleteType(Loc, Base->getType(), 8961 PDiag(diag::err_typecheck_incomplete_tag) 8962 << Base->getSourceRange())) 8963 return ExprError(); 8964 8965 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 8966 LookupQualifiedName(R, BaseRecord->getDecl()); 8967 R.suppressDiagnostics(); 8968 8969 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 8970 Oper != OperEnd; ++Oper) { 8971 AddMethodCandidate(Oper.getPair(), Base->getType(), Base->Classify(Context), 8972 0, 0, CandidateSet, /*SuppressUserConversions=*/false); 8973 } 8974 8975 // Perform overload resolution. 8976 OverloadCandidateSet::iterator Best; 8977 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 8978 case OR_Success: 8979 // Overload resolution succeeded; we'll build the call below. 8980 break; 8981 8982 case OR_No_Viable_Function: 8983 if (CandidateSet.empty()) 8984 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 8985 << Base->getType() << Base->getSourceRange(); 8986 else 8987 Diag(OpLoc, diag::err_ovl_no_viable_oper) 8988 << "operator->" << Base->getSourceRange(); 8989 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 8990 return ExprError(); 8991 8992 case OR_Ambiguous: 8993 Diag(OpLoc, diag::err_ovl_ambiguous_oper_unary) 8994 << "->" << Base->getType() << Base->getSourceRange(); 8995 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, &Base, 1); 8996 return ExprError(); 8997 8998 case OR_Deleted: 8999 Diag(OpLoc, diag::err_ovl_deleted_oper) 9000 << Best->Function->isDeleted() 9001 << "->" 9002 << getDeletedOrUnavailableSuffix(Best->Function) 9003 << Base->getSourceRange(); 9004 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 9005 return ExprError(); 9006 } 9007 9008 MarkDeclarationReferenced(OpLoc, Best->Function); 9009 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 9010 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 9011 9012 // Convert the object parameter. 9013 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 9014 ExprResult BaseResult = 9015 PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 9016 Best->FoundDecl, Method); 9017 if (BaseResult.isInvalid()) 9018 return ExprError(); 9019 Base = BaseResult.take(); 9020 9021 // Build the operator call. 9022 ExprResult FnExpr = CreateFunctionRefExpr(*this, Method); 9023 if (FnExpr.isInvalid()) 9024 return ExprError(); 9025 9026 QualType ResultTy = Method->getResultType(); 9027 ExprValueKind VK = Expr::getValueKindForType(ResultTy); 9028 ResultTy = ResultTy.getNonLValueExprType(Context); 9029 CXXOperatorCallExpr *TheCall = 9030 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr.take(), 9031 &Base, 1, ResultTy, VK, OpLoc); 9032 9033 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 9034 Method)) 9035 return ExprError(); 9036 9037 return MaybeBindToTemporary(TheCall); 9038} 9039 9040/// FixOverloadedFunctionReference - E is an expression that refers to 9041/// a C++ overloaded function (possibly with some parentheses and 9042/// perhaps a '&' around it). We have resolved the overloaded function 9043/// to the function declaration Fn, so patch up the expression E to 9044/// refer (possibly indirectly) to Fn. Returns the new expr. 9045Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 9046 FunctionDecl *Fn) { 9047 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 9048 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 9049 Found, Fn); 9050 if (SubExpr == PE->getSubExpr()) 9051 return PE; 9052 9053 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 9054 } 9055 9056 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 9057 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 9058 Found, Fn); 9059 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 9060 SubExpr->getType()) && 9061 "Implicit cast type cannot be determined from overload"); 9062 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 9063 if (SubExpr == ICE->getSubExpr()) 9064 return ICE; 9065 9066 return ImplicitCastExpr::Create(Context, ICE->getType(), 9067 ICE->getCastKind(), 9068 SubExpr, 0, 9069 ICE->getValueKind()); 9070 } 9071 9072 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 9073 assert(UnOp->getOpcode() == UO_AddrOf && 9074 "Can only take the address of an overloaded function"); 9075 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 9076 if (Method->isStatic()) { 9077 // Do nothing: static member functions aren't any different 9078 // from non-member functions. 9079 } else { 9080 // Fix the sub expression, which really has to be an 9081 // UnresolvedLookupExpr holding an overloaded member function 9082 // or template. 9083 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 9084 Found, Fn); 9085 if (SubExpr == UnOp->getSubExpr()) 9086 return UnOp; 9087 9088 assert(isa<DeclRefExpr>(SubExpr) 9089 && "fixed to something other than a decl ref"); 9090 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 9091 && "fixed to a member ref with no nested name qualifier"); 9092 9093 // We have taken the address of a pointer to member 9094 // function. Perform the computation here so that we get the 9095 // appropriate pointer to member type. 9096 QualType ClassType 9097 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 9098 QualType MemPtrType 9099 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 9100 9101 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, MemPtrType, 9102 VK_RValue, OK_Ordinary, 9103 UnOp->getOperatorLoc()); 9104 } 9105 } 9106 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 9107 Found, Fn); 9108 if (SubExpr == UnOp->getSubExpr()) 9109 return UnOp; 9110 9111 return new (Context) UnaryOperator(SubExpr, UO_AddrOf, 9112 Context.getPointerType(SubExpr->getType()), 9113 VK_RValue, OK_Ordinary, 9114 UnOp->getOperatorLoc()); 9115 } 9116 9117 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 9118 // FIXME: avoid copy. 9119 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 9120 if (ULE->hasExplicitTemplateArgs()) { 9121 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 9122 TemplateArgs = &TemplateArgsBuffer; 9123 } 9124 9125 return DeclRefExpr::Create(Context, 9126 ULE->getQualifierLoc(), 9127 Fn, 9128 ULE->getNameLoc(), 9129 Fn->getType(), 9130 VK_LValue, 9131 TemplateArgs); 9132 } 9133 9134 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 9135 // FIXME: avoid copy. 9136 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 9137 if (MemExpr->hasExplicitTemplateArgs()) { 9138 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 9139 TemplateArgs = &TemplateArgsBuffer; 9140 } 9141 9142 Expr *Base; 9143 9144 // If we're filling in a static method where we used to have an 9145 // implicit member access, rewrite to a simple decl ref. 9146 if (MemExpr->isImplicitAccess()) { 9147 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 9148 return DeclRefExpr::Create(Context, 9149 MemExpr->getQualifierLoc(), 9150 Fn, 9151 MemExpr->getMemberLoc(), 9152 Fn->getType(), 9153 VK_LValue, 9154 TemplateArgs); 9155 } else { 9156 SourceLocation Loc = MemExpr->getMemberLoc(); 9157 if (MemExpr->getQualifier()) 9158 Loc = MemExpr->getQualifierLoc().getBeginLoc(); 9159 Base = new (Context) CXXThisExpr(Loc, 9160 MemExpr->getBaseType(), 9161 /*isImplicit=*/true); 9162 } 9163 } else 9164 Base = MemExpr->getBase(); 9165 9166 return MemberExpr::Create(Context, Base, 9167 MemExpr->isArrow(), 9168 MemExpr->getQualifierLoc(), 9169 Fn, 9170 Found, 9171 MemExpr->getMemberNameInfo(), 9172 TemplateArgs, 9173 Fn->getType(), 9174 cast<CXXMethodDecl>(Fn)->isStatic() 9175 ? VK_LValue : VK_RValue, 9176 OK_Ordinary); 9177 } 9178 9179 llvm_unreachable("Invalid reference to overloaded function"); 9180 return E; 9181} 9182 9183ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 9184 DeclAccessPair Found, 9185 FunctionDecl *Fn) { 9186 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 9187} 9188 9189} // end namespace clang 9190