SemaOverload.cpp revision 2a7fb27913999d132cf9e10e03dc5271faa2e9d3
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/Sema.h" 15#include "clang/Sema/Lookup.h" 16#include "clang/Sema/Initialization.h" 17#include "clang/Sema/Template.h" 18#include "clang/Sema/TemplateDeduction.h" 19#include "clang/Basic/Diagnostic.h" 20#include "clang/Lex/Preprocessor.h" 21#include "clang/AST/ASTContext.h" 22#include "clang/AST/CXXInheritance.h" 23#include "clang/AST/DeclObjC.h" 24#include "clang/AST/Expr.h" 25#include "clang/AST/ExprCXX.h" 26#include "clang/AST/TypeOrdering.h" 27#include "clang/Basic/PartialDiagnostic.h" 28#include "llvm/ADT/SmallPtrSet.h" 29#include "llvm/ADT/STLExtras.h" 30#include <algorithm> 31 32namespace clang { 33using namespace sema; 34 35static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 36 bool InOverloadResolution, 37 StandardConversionSequence &SCS); 38static OverloadingResult 39IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 40 UserDefinedConversionSequence& User, 41 OverloadCandidateSet& Conversions, 42 bool AllowExplicit); 43 44 45static ImplicitConversionSequence::CompareKind 46CompareStandardConversionSequences(Sema &S, 47 const StandardConversionSequence& SCS1, 48 const StandardConversionSequence& SCS2); 49 50static ImplicitConversionSequence::CompareKind 51CompareQualificationConversions(Sema &S, 52 const StandardConversionSequence& SCS1, 53 const StandardConversionSequence& SCS2); 54 55static ImplicitConversionSequence::CompareKind 56CompareDerivedToBaseConversions(Sema &S, 57 const StandardConversionSequence& SCS1, 58 const StandardConversionSequence& SCS2); 59 60 61 62/// GetConversionCategory - Retrieve the implicit conversion 63/// category corresponding to the given implicit conversion kind. 64ImplicitConversionCategory 65GetConversionCategory(ImplicitConversionKind Kind) { 66 static const ImplicitConversionCategory 67 Category[(int)ICK_Num_Conversion_Kinds] = { 68 ICC_Identity, 69 ICC_Lvalue_Transformation, 70 ICC_Lvalue_Transformation, 71 ICC_Lvalue_Transformation, 72 ICC_Identity, 73 ICC_Qualification_Adjustment, 74 ICC_Promotion, 75 ICC_Promotion, 76 ICC_Promotion, 77 ICC_Conversion, 78 ICC_Conversion, 79 ICC_Conversion, 80 ICC_Conversion, 81 ICC_Conversion, 82 ICC_Conversion, 83 ICC_Conversion, 84 ICC_Conversion, 85 ICC_Conversion, 86 ICC_Conversion, 87 ICC_Conversion, 88 ICC_Conversion 89 }; 90 return Category[(int)Kind]; 91} 92 93/// GetConversionRank - Retrieve the implicit conversion rank 94/// corresponding to the given implicit conversion kind. 95ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 96 static const ImplicitConversionRank 97 Rank[(int)ICK_Num_Conversion_Kinds] = { 98 ICR_Exact_Match, 99 ICR_Exact_Match, 100 ICR_Exact_Match, 101 ICR_Exact_Match, 102 ICR_Exact_Match, 103 ICR_Exact_Match, 104 ICR_Promotion, 105 ICR_Promotion, 106 ICR_Promotion, 107 ICR_Conversion, 108 ICR_Conversion, 109 ICR_Conversion, 110 ICR_Conversion, 111 ICR_Conversion, 112 ICR_Conversion, 113 ICR_Conversion, 114 ICR_Conversion, 115 ICR_Conversion, 116 ICR_Conversion, 117 ICR_Conversion, 118 ICR_Complex_Real_Conversion 119 }; 120 return Rank[(int)Kind]; 121} 122 123/// GetImplicitConversionName - Return the name of this kind of 124/// implicit conversion. 125const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 126 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 127 "No conversion", 128 "Lvalue-to-rvalue", 129 "Array-to-pointer", 130 "Function-to-pointer", 131 "Noreturn adjustment", 132 "Qualification", 133 "Integral promotion", 134 "Floating point promotion", 135 "Complex promotion", 136 "Integral conversion", 137 "Floating conversion", 138 "Complex conversion", 139 "Floating-integral conversion", 140 "Pointer conversion", 141 "Pointer-to-member conversion", 142 "Boolean conversion", 143 "Compatible-types conversion", 144 "Derived-to-base conversion", 145 "Vector conversion", 146 "Vector splat", 147 "Complex-real conversion" 148 }; 149 return Name[Kind]; 150} 151 152/// StandardConversionSequence - Set the standard conversion 153/// sequence to the identity conversion. 154void StandardConversionSequence::setAsIdentityConversion() { 155 First = ICK_Identity; 156 Second = ICK_Identity; 157 Third = ICK_Identity; 158 DeprecatedStringLiteralToCharPtr = false; 159 ReferenceBinding = false; 160 DirectBinding = false; 161 RRefBinding = false; 162 CopyConstructor = 0; 163} 164 165/// getRank - Retrieve the rank of this standard conversion sequence 166/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 167/// implicit conversions. 168ImplicitConversionRank StandardConversionSequence::getRank() const { 169 ImplicitConversionRank Rank = ICR_Exact_Match; 170 if (GetConversionRank(First) > Rank) 171 Rank = GetConversionRank(First); 172 if (GetConversionRank(Second) > Rank) 173 Rank = GetConversionRank(Second); 174 if (GetConversionRank(Third) > Rank) 175 Rank = GetConversionRank(Third); 176 return Rank; 177} 178 179/// isPointerConversionToBool - Determines whether this conversion is 180/// a conversion of a pointer or pointer-to-member to bool. This is 181/// used as part of the ranking of standard conversion sequences 182/// (C++ 13.3.3.2p4). 183bool StandardConversionSequence::isPointerConversionToBool() const { 184 // Note that FromType has not necessarily been transformed by the 185 // array-to-pointer or function-to-pointer implicit conversions, so 186 // check for their presence as well as checking whether FromType is 187 // a pointer. 188 if (getToType(1)->isBooleanType() && 189 (getFromType()->isPointerType() || 190 getFromType()->isObjCObjectPointerType() || 191 getFromType()->isBlockPointerType() || 192 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 193 return true; 194 195 return false; 196} 197 198/// isPointerConversionToVoidPointer - Determines whether this 199/// conversion is a conversion of a pointer to a void pointer. This is 200/// used as part of the ranking of standard conversion sequences (C++ 201/// 13.3.3.2p4). 202bool 203StandardConversionSequence:: 204isPointerConversionToVoidPointer(ASTContext& Context) const { 205 QualType FromType = getFromType(); 206 QualType ToType = getToType(1); 207 208 // Note that FromType has not necessarily been transformed by the 209 // array-to-pointer implicit conversion, so check for its presence 210 // and redo the conversion to get a pointer. 211 if (First == ICK_Array_To_Pointer) 212 FromType = Context.getArrayDecayedType(FromType); 213 214 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 215 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 216 return ToPtrType->getPointeeType()->isVoidType(); 217 218 return false; 219} 220 221/// DebugPrint - Print this standard conversion sequence to standard 222/// error. Useful for debugging overloading issues. 223void StandardConversionSequence::DebugPrint() const { 224 llvm::raw_ostream &OS = llvm::errs(); 225 bool PrintedSomething = false; 226 if (First != ICK_Identity) { 227 OS << GetImplicitConversionName(First); 228 PrintedSomething = true; 229 } 230 231 if (Second != ICK_Identity) { 232 if (PrintedSomething) { 233 OS << " -> "; 234 } 235 OS << GetImplicitConversionName(Second); 236 237 if (CopyConstructor) { 238 OS << " (by copy constructor)"; 239 } else if (DirectBinding) { 240 OS << " (direct reference binding)"; 241 } else if (ReferenceBinding) { 242 OS << " (reference binding)"; 243 } 244 PrintedSomething = true; 245 } 246 247 if (Third != ICK_Identity) { 248 if (PrintedSomething) { 249 OS << " -> "; 250 } 251 OS << GetImplicitConversionName(Third); 252 PrintedSomething = true; 253 } 254 255 if (!PrintedSomething) { 256 OS << "No conversions required"; 257 } 258} 259 260/// DebugPrint - Print this user-defined conversion sequence to standard 261/// error. Useful for debugging overloading issues. 262void UserDefinedConversionSequence::DebugPrint() const { 263 llvm::raw_ostream &OS = llvm::errs(); 264 if (Before.First || Before.Second || Before.Third) { 265 Before.DebugPrint(); 266 OS << " -> "; 267 } 268 OS << '\'' << ConversionFunction << '\''; 269 if (After.First || After.Second || After.Third) { 270 OS << " -> "; 271 After.DebugPrint(); 272 } 273} 274 275/// DebugPrint - Print this implicit conversion sequence to standard 276/// error. Useful for debugging overloading issues. 277void ImplicitConversionSequence::DebugPrint() const { 278 llvm::raw_ostream &OS = llvm::errs(); 279 switch (ConversionKind) { 280 case StandardConversion: 281 OS << "Standard conversion: "; 282 Standard.DebugPrint(); 283 break; 284 case UserDefinedConversion: 285 OS << "User-defined conversion: "; 286 UserDefined.DebugPrint(); 287 break; 288 case EllipsisConversion: 289 OS << "Ellipsis conversion"; 290 break; 291 case AmbiguousConversion: 292 OS << "Ambiguous conversion"; 293 break; 294 case BadConversion: 295 OS << "Bad conversion"; 296 break; 297 } 298 299 OS << "\n"; 300} 301 302void AmbiguousConversionSequence::construct() { 303 new (&conversions()) ConversionSet(); 304} 305 306void AmbiguousConversionSequence::destruct() { 307 conversions().~ConversionSet(); 308} 309 310void 311AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 312 FromTypePtr = O.FromTypePtr; 313 ToTypePtr = O.ToTypePtr; 314 new (&conversions()) ConversionSet(O.conversions()); 315} 316 317namespace { 318 // Structure used by OverloadCandidate::DeductionFailureInfo to store 319 // template parameter and template argument information. 320 struct DFIParamWithArguments { 321 TemplateParameter Param; 322 TemplateArgument FirstArg; 323 TemplateArgument SecondArg; 324 }; 325} 326 327/// \brief Convert from Sema's representation of template deduction information 328/// to the form used in overload-candidate information. 329OverloadCandidate::DeductionFailureInfo 330static MakeDeductionFailureInfo(ASTContext &Context, 331 Sema::TemplateDeductionResult TDK, 332 TemplateDeductionInfo &Info) { 333 OverloadCandidate::DeductionFailureInfo Result; 334 Result.Result = static_cast<unsigned>(TDK); 335 Result.Data = 0; 336 switch (TDK) { 337 case Sema::TDK_Success: 338 case Sema::TDK_InstantiationDepth: 339 case Sema::TDK_TooManyArguments: 340 case Sema::TDK_TooFewArguments: 341 break; 342 343 case Sema::TDK_Incomplete: 344 case Sema::TDK_InvalidExplicitArguments: 345 Result.Data = Info.Param.getOpaqueValue(); 346 break; 347 348 case Sema::TDK_Inconsistent: 349 case Sema::TDK_Underqualified: { 350 // FIXME: Should allocate from normal heap so that we can free this later. 351 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 352 Saved->Param = Info.Param; 353 Saved->FirstArg = Info.FirstArg; 354 Saved->SecondArg = Info.SecondArg; 355 Result.Data = Saved; 356 break; 357 } 358 359 case Sema::TDK_SubstitutionFailure: 360 Result.Data = Info.take(); 361 break; 362 363 case Sema::TDK_NonDeducedMismatch: 364 case Sema::TDK_FailedOverloadResolution: 365 break; 366 } 367 368 return Result; 369} 370 371void OverloadCandidate::DeductionFailureInfo::Destroy() { 372 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 373 case Sema::TDK_Success: 374 case Sema::TDK_InstantiationDepth: 375 case Sema::TDK_Incomplete: 376 case Sema::TDK_TooManyArguments: 377 case Sema::TDK_TooFewArguments: 378 case Sema::TDK_InvalidExplicitArguments: 379 break; 380 381 case Sema::TDK_Inconsistent: 382 case Sema::TDK_Underqualified: 383 // FIXME: Destroy the data? 384 Data = 0; 385 break; 386 387 case Sema::TDK_SubstitutionFailure: 388 // FIXME: Destroy the template arugment list? 389 Data = 0; 390 break; 391 392 // Unhandled 393 case Sema::TDK_NonDeducedMismatch: 394 case Sema::TDK_FailedOverloadResolution: 395 break; 396 } 397} 398 399TemplateParameter 400OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 401 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 402 case Sema::TDK_Success: 403 case Sema::TDK_InstantiationDepth: 404 case Sema::TDK_TooManyArguments: 405 case Sema::TDK_TooFewArguments: 406 case Sema::TDK_SubstitutionFailure: 407 return TemplateParameter(); 408 409 case Sema::TDK_Incomplete: 410 case Sema::TDK_InvalidExplicitArguments: 411 return TemplateParameter::getFromOpaqueValue(Data); 412 413 case Sema::TDK_Inconsistent: 414 case Sema::TDK_Underqualified: 415 return static_cast<DFIParamWithArguments*>(Data)->Param; 416 417 // Unhandled 418 case Sema::TDK_NonDeducedMismatch: 419 case Sema::TDK_FailedOverloadResolution: 420 break; 421 } 422 423 return TemplateParameter(); 424} 425 426TemplateArgumentList * 427OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 428 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 429 case Sema::TDK_Success: 430 case Sema::TDK_InstantiationDepth: 431 case Sema::TDK_TooManyArguments: 432 case Sema::TDK_TooFewArguments: 433 case Sema::TDK_Incomplete: 434 case Sema::TDK_InvalidExplicitArguments: 435 case Sema::TDK_Inconsistent: 436 case Sema::TDK_Underqualified: 437 return 0; 438 439 case Sema::TDK_SubstitutionFailure: 440 return static_cast<TemplateArgumentList*>(Data); 441 442 // Unhandled 443 case Sema::TDK_NonDeducedMismatch: 444 case Sema::TDK_FailedOverloadResolution: 445 break; 446 } 447 448 return 0; 449} 450 451const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 452 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 453 case Sema::TDK_Success: 454 case Sema::TDK_InstantiationDepth: 455 case Sema::TDK_Incomplete: 456 case Sema::TDK_TooManyArguments: 457 case Sema::TDK_TooFewArguments: 458 case Sema::TDK_InvalidExplicitArguments: 459 case Sema::TDK_SubstitutionFailure: 460 return 0; 461 462 case Sema::TDK_Inconsistent: 463 case Sema::TDK_Underqualified: 464 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 465 466 // Unhandled 467 case Sema::TDK_NonDeducedMismatch: 468 case Sema::TDK_FailedOverloadResolution: 469 break; 470 } 471 472 return 0; 473} 474 475const TemplateArgument * 476OverloadCandidate::DeductionFailureInfo::getSecondArg() { 477 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 478 case Sema::TDK_Success: 479 case Sema::TDK_InstantiationDepth: 480 case Sema::TDK_Incomplete: 481 case Sema::TDK_TooManyArguments: 482 case Sema::TDK_TooFewArguments: 483 case Sema::TDK_InvalidExplicitArguments: 484 case Sema::TDK_SubstitutionFailure: 485 return 0; 486 487 case Sema::TDK_Inconsistent: 488 case Sema::TDK_Underqualified: 489 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 490 491 // Unhandled 492 case Sema::TDK_NonDeducedMismatch: 493 case Sema::TDK_FailedOverloadResolution: 494 break; 495 } 496 497 return 0; 498} 499 500void OverloadCandidateSet::clear() { 501 inherited::clear(); 502 Functions.clear(); 503} 504 505// IsOverload - Determine whether the given New declaration is an 506// overload of the declarations in Old. This routine returns false if 507// New and Old cannot be overloaded, e.g., if New has the same 508// signature as some function in Old (C++ 1.3.10) or if the Old 509// declarations aren't functions (or function templates) at all. When 510// it does return false, MatchedDecl will point to the decl that New 511// cannot be overloaded with. This decl may be a UsingShadowDecl on 512// top of the underlying declaration. 513// 514// Example: Given the following input: 515// 516// void f(int, float); // #1 517// void f(int, int); // #2 518// int f(int, int); // #3 519// 520// When we process #1, there is no previous declaration of "f", 521// so IsOverload will not be used. 522// 523// When we process #2, Old contains only the FunctionDecl for #1. By 524// comparing the parameter types, we see that #1 and #2 are overloaded 525// (since they have different signatures), so this routine returns 526// false; MatchedDecl is unchanged. 527// 528// When we process #3, Old is an overload set containing #1 and #2. We 529// compare the signatures of #3 to #1 (they're overloaded, so we do 530// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 531// identical (return types of functions are not part of the 532// signature), IsOverload returns false and MatchedDecl will be set to 533// point to the FunctionDecl for #2. 534// 535// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 536// into a class by a using declaration. The rules for whether to hide 537// shadow declarations ignore some properties which otherwise figure 538// into a function template's signature. 539Sema::OverloadKind 540Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 541 NamedDecl *&Match, bool NewIsUsingDecl) { 542 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 543 I != E; ++I) { 544 NamedDecl *OldD = *I; 545 546 bool OldIsUsingDecl = false; 547 if (isa<UsingShadowDecl>(OldD)) { 548 OldIsUsingDecl = true; 549 550 // We can always introduce two using declarations into the same 551 // context, even if they have identical signatures. 552 if (NewIsUsingDecl) continue; 553 554 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 555 } 556 557 // If either declaration was introduced by a using declaration, 558 // we'll need to use slightly different rules for matching. 559 // Essentially, these rules are the normal rules, except that 560 // function templates hide function templates with different 561 // return types or template parameter lists. 562 bool UseMemberUsingDeclRules = 563 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 564 565 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 566 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 567 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 568 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 569 continue; 570 } 571 572 Match = *I; 573 return Ovl_Match; 574 } 575 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 576 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 577 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 578 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 579 continue; 580 } 581 582 Match = *I; 583 return Ovl_Match; 584 } 585 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 586 // We can overload with these, which can show up when doing 587 // redeclaration checks for UsingDecls. 588 assert(Old.getLookupKind() == LookupUsingDeclName); 589 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 590 // Optimistically assume that an unresolved using decl will 591 // overload; if it doesn't, we'll have to diagnose during 592 // template instantiation. 593 } else { 594 // (C++ 13p1): 595 // Only function declarations can be overloaded; object and type 596 // declarations cannot be overloaded. 597 Match = *I; 598 return Ovl_NonFunction; 599 } 600 } 601 602 return Ovl_Overload; 603} 604 605bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 606 bool UseUsingDeclRules) { 607 // If both of the functions are extern "C", then they are not 608 // overloads. 609 if (Old->isExternC() && New->isExternC()) 610 return false; 611 612 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 613 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 614 615 // C++ [temp.fct]p2: 616 // A function template can be overloaded with other function templates 617 // and with normal (non-template) functions. 618 if ((OldTemplate == 0) != (NewTemplate == 0)) 619 return true; 620 621 // Is the function New an overload of the function Old? 622 QualType OldQType = Context.getCanonicalType(Old->getType()); 623 QualType NewQType = Context.getCanonicalType(New->getType()); 624 625 // Compare the signatures (C++ 1.3.10) of the two functions to 626 // determine whether they are overloads. If we find any mismatch 627 // in the signature, they are overloads. 628 629 // If either of these functions is a K&R-style function (no 630 // prototype), then we consider them to have matching signatures. 631 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 632 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 633 return false; 634 635 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 636 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 637 638 // The signature of a function includes the types of its 639 // parameters (C++ 1.3.10), which includes the presence or absence 640 // of the ellipsis; see C++ DR 357). 641 if (OldQType != NewQType && 642 (OldType->getNumArgs() != NewType->getNumArgs() || 643 OldType->isVariadic() != NewType->isVariadic() || 644 !FunctionArgTypesAreEqual(OldType, NewType))) 645 return true; 646 647 // C++ [temp.over.link]p4: 648 // The signature of a function template consists of its function 649 // signature, its return type and its template parameter list. The names 650 // of the template parameters are significant only for establishing the 651 // relationship between the template parameters and the rest of the 652 // signature. 653 // 654 // We check the return type and template parameter lists for function 655 // templates first; the remaining checks follow. 656 // 657 // However, we don't consider either of these when deciding whether 658 // a member introduced by a shadow declaration is hidden. 659 if (!UseUsingDeclRules && NewTemplate && 660 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 661 OldTemplate->getTemplateParameters(), 662 false, TPL_TemplateMatch) || 663 OldType->getResultType() != NewType->getResultType())) 664 return true; 665 666 // If the function is a class member, its signature includes the 667 // cv-qualifiers (if any) on the function itself. 668 // 669 // As part of this, also check whether one of the member functions 670 // is static, in which case they are not overloads (C++ 671 // 13.1p2). While not part of the definition of the signature, 672 // this check is important to determine whether these functions 673 // can be overloaded. 674 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 675 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 676 if (OldMethod && NewMethod && 677 !OldMethod->isStatic() && !NewMethod->isStatic() && 678 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 679 return true; 680 681 // The signatures match; this is not an overload. 682 return false; 683} 684 685/// TryImplicitConversion - Attempt to perform an implicit conversion 686/// from the given expression (Expr) to the given type (ToType). This 687/// function returns an implicit conversion sequence that can be used 688/// to perform the initialization. Given 689/// 690/// void f(float f); 691/// void g(int i) { f(i); } 692/// 693/// this routine would produce an implicit conversion sequence to 694/// describe the initialization of f from i, which will be a standard 695/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 696/// 4.1) followed by a floating-integral conversion (C++ 4.9). 697// 698/// Note that this routine only determines how the conversion can be 699/// performed; it does not actually perform the conversion. As such, 700/// it will not produce any diagnostics if no conversion is available, 701/// but will instead return an implicit conversion sequence of kind 702/// "BadConversion". 703/// 704/// If @p SuppressUserConversions, then user-defined conversions are 705/// not permitted. 706/// If @p AllowExplicit, then explicit user-defined conversions are 707/// permitted. 708static ImplicitConversionSequence 709TryImplicitConversion(Sema &S, Expr *From, QualType ToType, 710 bool SuppressUserConversions, 711 bool AllowExplicit, 712 bool InOverloadResolution) { 713 ImplicitConversionSequence ICS; 714 if (IsStandardConversion(S, From, ToType, InOverloadResolution, 715 ICS.Standard)) { 716 ICS.setStandard(); 717 return ICS; 718 } 719 720 if (!S.getLangOptions().CPlusPlus) { 721 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 722 return ICS; 723 } 724 725 // C++ [over.ics.user]p4: 726 // A conversion of an expression of class type to the same class 727 // type is given Exact Match rank, and a conversion of an 728 // expression of class type to a base class of that type is 729 // given Conversion rank, in spite of the fact that a copy/move 730 // constructor (i.e., a user-defined conversion function) is 731 // called for those cases. 732 QualType FromType = From->getType(); 733 if (ToType->getAs<RecordType>() && FromType->getAs<RecordType>() && 734 (S.Context.hasSameUnqualifiedType(FromType, ToType) || 735 S.IsDerivedFrom(FromType, ToType))) { 736 ICS.setStandard(); 737 ICS.Standard.setAsIdentityConversion(); 738 ICS.Standard.setFromType(FromType); 739 ICS.Standard.setAllToTypes(ToType); 740 741 // We don't actually check at this point whether there is a valid 742 // copy/move constructor, since overloading just assumes that it 743 // exists. When we actually perform initialization, we'll find the 744 // appropriate constructor to copy the returned object, if needed. 745 ICS.Standard.CopyConstructor = 0; 746 747 // Determine whether this is considered a derived-to-base conversion. 748 if (!S.Context.hasSameUnqualifiedType(FromType, ToType)) 749 ICS.Standard.Second = ICK_Derived_To_Base; 750 751 return ICS; 752 } 753 754 if (SuppressUserConversions) { 755 // We're not in the case above, so there is no conversion that 756 // we can perform. 757 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 758 return ICS; 759 } 760 761 // Attempt user-defined conversion. 762 OverloadCandidateSet Conversions(From->getExprLoc()); 763 OverloadingResult UserDefResult 764 = IsUserDefinedConversion(S, From, ToType, ICS.UserDefined, Conversions, 765 AllowExplicit); 766 767 if (UserDefResult == OR_Success) { 768 ICS.setUserDefined(); 769 // C++ [over.ics.user]p4: 770 // A conversion of an expression of class type to the same class 771 // type is given Exact Match rank, and a conversion of an 772 // expression of class type to a base class of that type is 773 // given Conversion rank, in spite of the fact that a copy 774 // constructor (i.e., a user-defined conversion function) is 775 // called for those cases. 776 if (CXXConstructorDecl *Constructor 777 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 778 QualType FromCanon 779 = S.Context.getCanonicalType(From->getType().getUnqualifiedType()); 780 QualType ToCanon 781 = S.Context.getCanonicalType(ToType).getUnqualifiedType(); 782 if (Constructor->isCopyConstructor() && 783 (FromCanon == ToCanon || S.IsDerivedFrom(FromCanon, ToCanon))) { 784 // Turn this into a "standard" conversion sequence, so that it 785 // gets ranked with standard conversion sequences. 786 ICS.setStandard(); 787 ICS.Standard.setAsIdentityConversion(); 788 ICS.Standard.setFromType(From->getType()); 789 ICS.Standard.setAllToTypes(ToType); 790 ICS.Standard.CopyConstructor = Constructor; 791 if (ToCanon != FromCanon) 792 ICS.Standard.Second = ICK_Derived_To_Base; 793 } 794 } 795 796 // C++ [over.best.ics]p4: 797 // However, when considering the argument of a user-defined 798 // conversion function that is a candidate by 13.3.1.3 when 799 // invoked for the copying of the temporary in the second step 800 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 801 // 13.3.1.6 in all cases, only standard conversion sequences and 802 // ellipsis conversion sequences are allowed. 803 if (SuppressUserConversions && ICS.isUserDefined()) { 804 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 805 } 806 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 807 ICS.setAmbiguous(); 808 ICS.Ambiguous.setFromType(From->getType()); 809 ICS.Ambiguous.setToType(ToType); 810 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 811 Cand != Conversions.end(); ++Cand) 812 if (Cand->Viable) 813 ICS.Ambiguous.addConversion(Cand->Function); 814 } else { 815 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 816 } 817 818 return ICS; 819} 820 821bool Sema::TryImplicitConversion(InitializationSequence &Sequence, 822 const InitializedEntity &Entity, 823 Expr *Initializer, 824 bool SuppressUserConversions, 825 bool AllowExplicitConversions, 826 bool InOverloadResolution) { 827 ImplicitConversionSequence ICS 828 = clang::TryImplicitConversion(*this, Initializer, Entity.getType(), 829 SuppressUserConversions, 830 AllowExplicitConversions, 831 InOverloadResolution); 832 if (ICS.isBad()) return true; 833 834 // Perform the actual conversion. 835 Sequence.AddConversionSequenceStep(ICS, Entity.getType()); 836 return false; 837} 838 839/// PerformImplicitConversion - Perform an implicit conversion of the 840/// expression From to the type ToType. Returns true if there was an 841/// error, false otherwise. The expression From is replaced with the 842/// converted expression. Flavor is the kind of conversion we're 843/// performing, used in the error message. If @p AllowExplicit, 844/// explicit user-defined conversions are permitted. 845bool 846Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 847 AssignmentAction Action, bool AllowExplicit) { 848 ImplicitConversionSequence ICS; 849 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 850} 851 852bool 853Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 854 AssignmentAction Action, bool AllowExplicit, 855 ImplicitConversionSequence& ICS) { 856 ICS = clang::TryImplicitConversion(*this, From, ToType, 857 /*SuppressUserConversions=*/false, 858 AllowExplicit, 859 /*InOverloadResolution=*/false); 860 return PerformImplicitConversion(From, ToType, ICS, Action); 861} 862 863/// \brief Determine whether the conversion from FromType to ToType is a valid 864/// conversion that strips "noreturn" off the nested function type. 865static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 866 QualType ToType, QualType &ResultTy) { 867 if (Context.hasSameUnqualifiedType(FromType, ToType)) 868 return false; 869 870 // Strip the noreturn off the type we're converting from; noreturn can 871 // safely be removed. 872 FromType = Context.getNoReturnType(FromType, false); 873 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 874 return false; 875 876 ResultTy = FromType; 877 return true; 878} 879 880/// \brief Determine whether the conversion from FromType to ToType is a valid 881/// vector conversion. 882/// 883/// \param ICK Will be set to the vector conversion kind, if this is a vector 884/// conversion. 885static bool IsVectorConversion(ASTContext &Context, QualType FromType, 886 QualType ToType, ImplicitConversionKind &ICK) { 887 // We need at least one of these types to be a vector type to have a vector 888 // conversion. 889 if (!ToType->isVectorType() && !FromType->isVectorType()) 890 return false; 891 892 // Identical types require no conversions. 893 if (Context.hasSameUnqualifiedType(FromType, ToType)) 894 return false; 895 896 // There are no conversions between extended vector types, only identity. 897 if (ToType->isExtVectorType()) { 898 // There are no conversions between extended vector types other than the 899 // identity conversion. 900 if (FromType->isExtVectorType()) 901 return false; 902 903 // Vector splat from any arithmetic type to a vector. 904 if (FromType->isArithmeticType()) { 905 ICK = ICK_Vector_Splat; 906 return true; 907 } 908 } 909 910 // We can perform the conversion between vector types in the following cases: 911 // 1)vector types are equivalent AltiVec and GCC vector types 912 // 2)lax vector conversions are permitted and the vector types are of the 913 // same size 914 if (ToType->isVectorType() && FromType->isVectorType()) { 915 if (Context.areCompatibleVectorTypes(FromType, ToType) || 916 (Context.getLangOptions().LaxVectorConversions && 917 (Context.getTypeSize(FromType) == Context.getTypeSize(ToType)))) { 918 ICK = ICK_Vector_Conversion; 919 return true; 920 } 921 } 922 923 return false; 924} 925 926/// IsStandardConversion - Determines whether there is a standard 927/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 928/// expression From to the type ToType. Standard conversion sequences 929/// only consider non-class types; for conversions that involve class 930/// types, use TryImplicitConversion. If a conversion exists, SCS will 931/// contain the standard conversion sequence required to perform this 932/// conversion and this routine will return true. Otherwise, this 933/// routine will return false and the value of SCS is unspecified. 934static bool IsStandardConversion(Sema &S, Expr* From, QualType ToType, 935 bool InOverloadResolution, 936 StandardConversionSequence &SCS) { 937 QualType FromType = From->getType(); 938 939 // Standard conversions (C++ [conv]) 940 SCS.setAsIdentityConversion(); 941 SCS.DeprecatedStringLiteralToCharPtr = false; 942 SCS.IncompatibleObjC = false; 943 SCS.setFromType(FromType); 944 SCS.CopyConstructor = 0; 945 946 // There are no standard conversions for class types in C++, so 947 // abort early. When overloading in C, however, we do permit 948 if (FromType->isRecordType() || ToType->isRecordType()) { 949 if (S.getLangOptions().CPlusPlus) 950 return false; 951 952 // When we're overloading in C, we allow, as standard conversions, 953 } 954 955 // The first conversion can be an lvalue-to-rvalue conversion, 956 // array-to-pointer conversion, or function-to-pointer conversion 957 // (C++ 4p1). 958 959 if (FromType == S.Context.OverloadTy) { 960 DeclAccessPair AccessPair; 961 if (FunctionDecl *Fn 962 = S.ResolveAddressOfOverloadedFunction(From, ToType, false, 963 AccessPair)) { 964 // We were able to resolve the address of the overloaded function, 965 // so we can convert to the type of that function. 966 FromType = Fn->getType(); 967 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 968 if (!Method->isStatic()) { 969 Type *ClassType 970 = S.Context.getTypeDeclType(Method->getParent()).getTypePtr(); 971 FromType = S.Context.getMemberPointerType(FromType, ClassType); 972 } 973 } 974 975 // If the "from" expression takes the address of the overloaded 976 // function, update the type of the resulting expression accordingly. 977 if (FromType->getAs<FunctionType>()) 978 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens())) 979 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 980 FromType = S.Context.getPointerType(FromType); 981 982 // Check that we've computed the proper type after overload resolution. 983 assert(S.Context.hasSameType(FromType, 984 S.FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 985 } else { 986 return false; 987 } 988 } 989 // Lvalue-to-rvalue conversion (C++ 4.1): 990 // An lvalue (3.10) of a non-function, non-array type T can be 991 // converted to an rvalue. 992 Expr::isLvalueResult argIsLvalue = From->isLvalue(S.Context); 993 if (argIsLvalue == Expr::LV_Valid && 994 !FromType->isFunctionType() && !FromType->isArrayType() && 995 S.Context.getCanonicalType(FromType) != S.Context.OverloadTy) { 996 SCS.First = ICK_Lvalue_To_Rvalue; 997 998 // If T is a non-class type, the type of the rvalue is the 999 // cv-unqualified version of T. Otherwise, the type of the rvalue 1000 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 1001 // just strip the qualifiers because they don't matter. 1002 FromType = FromType.getUnqualifiedType(); 1003 } else if (FromType->isArrayType()) { 1004 // Array-to-pointer conversion (C++ 4.2) 1005 SCS.First = ICK_Array_To_Pointer; 1006 1007 // An lvalue or rvalue of type "array of N T" or "array of unknown 1008 // bound of T" can be converted to an rvalue of type "pointer to 1009 // T" (C++ 4.2p1). 1010 FromType = S.Context.getArrayDecayedType(FromType); 1011 1012 if (S.IsStringLiteralToNonConstPointerConversion(From, ToType)) { 1013 // This conversion is deprecated. (C++ D.4). 1014 SCS.DeprecatedStringLiteralToCharPtr = true; 1015 1016 // For the purpose of ranking in overload resolution 1017 // (13.3.3.1.1), this conversion is considered an 1018 // array-to-pointer conversion followed by a qualification 1019 // conversion (4.4). (C++ 4.2p2) 1020 SCS.Second = ICK_Identity; 1021 SCS.Third = ICK_Qualification; 1022 SCS.setAllToTypes(FromType); 1023 return true; 1024 } 1025 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 1026 // Function-to-pointer conversion (C++ 4.3). 1027 SCS.First = ICK_Function_To_Pointer; 1028 1029 // An lvalue of function type T can be converted to an rvalue of 1030 // type "pointer to T." The result is a pointer to the 1031 // function. (C++ 4.3p1). 1032 FromType = S.Context.getPointerType(FromType); 1033 } else { 1034 // We don't require any conversions for the first step. 1035 SCS.First = ICK_Identity; 1036 } 1037 SCS.setToType(0, FromType); 1038 1039 // The second conversion can be an integral promotion, floating 1040 // point promotion, integral conversion, floating point conversion, 1041 // floating-integral conversion, pointer conversion, 1042 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 1043 // For overloading in C, this can also be a "compatible-type" 1044 // conversion. 1045 bool IncompatibleObjC = false; 1046 ImplicitConversionKind SecondICK = ICK_Identity; 1047 if (S.Context.hasSameUnqualifiedType(FromType, ToType)) { 1048 // The unqualified versions of the types are the same: there's no 1049 // conversion to do. 1050 SCS.Second = ICK_Identity; 1051 } else if (S.IsIntegralPromotion(From, FromType, ToType)) { 1052 // Integral promotion (C++ 4.5). 1053 SCS.Second = ICK_Integral_Promotion; 1054 FromType = ToType.getUnqualifiedType(); 1055 } else if (S.IsFloatingPointPromotion(FromType, ToType)) { 1056 // Floating point promotion (C++ 4.6). 1057 SCS.Second = ICK_Floating_Promotion; 1058 FromType = ToType.getUnqualifiedType(); 1059 } else if (S.IsComplexPromotion(FromType, ToType)) { 1060 // Complex promotion (Clang extension) 1061 SCS.Second = ICK_Complex_Promotion; 1062 FromType = ToType.getUnqualifiedType(); 1063 } else if (FromType->isIntegralOrEnumerationType() && 1064 ToType->isIntegralType(S.Context)) { 1065 // Integral conversions (C++ 4.7). 1066 SCS.Second = ICK_Integral_Conversion; 1067 FromType = ToType.getUnqualifiedType(); 1068 } else if (FromType->isComplexType() && ToType->isComplexType()) { 1069 // Complex conversions (C99 6.3.1.6) 1070 SCS.Second = ICK_Complex_Conversion; 1071 FromType = ToType.getUnqualifiedType(); 1072 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 1073 (ToType->isComplexType() && FromType->isArithmeticType())) { 1074 // Complex-real conversions (C99 6.3.1.7) 1075 SCS.Second = ICK_Complex_Real; 1076 FromType = ToType.getUnqualifiedType(); 1077 } else if (FromType->isRealFloatingType() && ToType->isRealFloatingType()) { 1078 // Floating point conversions (C++ 4.8). 1079 SCS.Second = ICK_Floating_Conversion; 1080 FromType = ToType.getUnqualifiedType(); 1081 } else if ((FromType->isRealFloatingType() && 1082 ToType->isIntegralType(S.Context) && !ToType->isBooleanType()) || 1083 (FromType->isIntegralOrEnumerationType() && 1084 ToType->isRealFloatingType())) { 1085 // Floating-integral conversions (C++ 4.9). 1086 SCS.Second = ICK_Floating_Integral; 1087 FromType = ToType.getUnqualifiedType(); 1088 } else if (S.IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1089 FromType, IncompatibleObjC)) { 1090 // Pointer conversions (C++ 4.10). 1091 SCS.Second = ICK_Pointer_Conversion; 1092 SCS.IncompatibleObjC = IncompatibleObjC; 1093 } else if (S.IsMemberPointerConversion(From, FromType, ToType, 1094 InOverloadResolution, FromType)) { 1095 // Pointer to member conversions (4.11). 1096 SCS.Second = ICK_Pointer_Member; 1097 } else if (ToType->isBooleanType() && 1098 (FromType->isArithmeticType() || 1099 FromType->isEnumeralType() || 1100 FromType->isAnyPointerType() || 1101 FromType->isBlockPointerType() || 1102 FromType->isMemberPointerType() || 1103 FromType->isNullPtrType())) { 1104 // Boolean conversions (C++ 4.12). 1105 SCS.Second = ICK_Boolean_Conversion; 1106 FromType = S.Context.BoolTy; 1107 } else if (IsVectorConversion(S.Context, FromType, ToType, SecondICK)) { 1108 SCS.Second = SecondICK; 1109 FromType = ToType.getUnqualifiedType(); 1110 } else if (!S.getLangOptions().CPlusPlus && 1111 S.Context.typesAreCompatible(ToType, FromType)) { 1112 // Compatible conversions (Clang extension for C function overloading) 1113 SCS.Second = ICK_Compatible_Conversion; 1114 FromType = ToType.getUnqualifiedType(); 1115 } else if (IsNoReturnConversion(S.Context, FromType, ToType, FromType)) { 1116 // Treat a conversion that strips "noreturn" as an identity conversion. 1117 SCS.Second = ICK_NoReturn_Adjustment; 1118 } else { 1119 // No second conversion required. 1120 SCS.Second = ICK_Identity; 1121 } 1122 SCS.setToType(1, FromType); 1123 1124 QualType CanonFrom; 1125 QualType CanonTo; 1126 // The third conversion can be a qualification conversion (C++ 4p1). 1127 if (S.IsQualificationConversion(FromType, ToType)) { 1128 SCS.Third = ICK_Qualification; 1129 FromType = ToType; 1130 CanonFrom = S.Context.getCanonicalType(FromType); 1131 CanonTo = S.Context.getCanonicalType(ToType); 1132 } else { 1133 // No conversion required 1134 SCS.Third = ICK_Identity; 1135 1136 // C++ [over.best.ics]p6: 1137 // [...] Any difference in top-level cv-qualification is 1138 // subsumed by the initialization itself and does not constitute 1139 // a conversion. [...] 1140 CanonFrom = S.Context.getCanonicalType(FromType); 1141 CanonTo = S.Context.getCanonicalType(ToType); 1142 if (CanonFrom.getLocalUnqualifiedType() 1143 == CanonTo.getLocalUnqualifiedType() && 1144 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1145 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1146 FromType = ToType; 1147 CanonFrom = CanonTo; 1148 } 1149 } 1150 SCS.setToType(2, FromType); 1151 1152 // If we have not converted the argument type to the parameter type, 1153 // this is a bad conversion sequence. 1154 if (CanonFrom != CanonTo) 1155 return false; 1156 1157 return true; 1158} 1159 1160/// IsIntegralPromotion - Determines whether the conversion from the 1161/// expression From (whose potentially-adjusted type is FromType) to 1162/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1163/// sets PromotedType to the promoted type. 1164bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1165 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1166 // All integers are built-in. 1167 if (!To) { 1168 return false; 1169 } 1170 1171 // An rvalue of type char, signed char, unsigned char, short int, or 1172 // unsigned short int can be converted to an rvalue of type int if 1173 // int can represent all the values of the source type; otherwise, 1174 // the source rvalue can be converted to an rvalue of type unsigned 1175 // int (C++ 4.5p1). 1176 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1177 !FromType->isEnumeralType()) { 1178 if (// We can promote any signed, promotable integer type to an int 1179 (FromType->isSignedIntegerType() || 1180 // We can promote any unsigned integer type whose size is 1181 // less than int to an int. 1182 (!FromType->isSignedIntegerType() && 1183 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1184 return To->getKind() == BuiltinType::Int; 1185 } 1186 1187 return To->getKind() == BuiltinType::UInt; 1188 } 1189 1190 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 1191 // can be converted to an rvalue of the first of the following types 1192 // that can represent all the values of its underlying type: int, 1193 // unsigned int, long, or unsigned long (C++ 4.5p2). 1194 1195 // We pre-calculate the promotion type for enum types. 1196 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 1197 if (ToType->isIntegerType()) 1198 return Context.hasSameUnqualifiedType(ToType, 1199 FromEnumType->getDecl()->getPromotionType()); 1200 1201 if (FromType->isWideCharType() && ToType->isIntegerType()) { 1202 // Determine whether the type we're converting from is signed or 1203 // unsigned. 1204 bool FromIsSigned; 1205 uint64_t FromSize = Context.getTypeSize(FromType); 1206 1207 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1208 FromIsSigned = true; 1209 1210 // The types we'll try to promote to, in the appropriate 1211 // order. Try each of these types. 1212 QualType PromoteTypes[6] = { 1213 Context.IntTy, Context.UnsignedIntTy, 1214 Context.LongTy, Context.UnsignedLongTy , 1215 Context.LongLongTy, Context.UnsignedLongLongTy 1216 }; 1217 for (int Idx = 0; Idx < 6; ++Idx) { 1218 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1219 if (FromSize < ToSize || 1220 (FromSize == ToSize && 1221 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1222 // We found the type that we can promote to. If this is the 1223 // type we wanted, we have a promotion. Otherwise, no 1224 // promotion. 1225 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1226 } 1227 } 1228 } 1229 1230 // An rvalue for an integral bit-field (9.6) can be converted to an 1231 // rvalue of type int if int can represent all the values of the 1232 // bit-field; otherwise, it can be converted to unsigned int if 1233 // unsigned int can represent all the values of the bit-field. If 1234 // the bit-field is larger yet, no integral promotion applies to 1235 // it. If the bit-field has an enumerated type, it is treated as any 1236 // other value of that type for promotion purposes (C++ 4.5p3). 1237 // FIXME: We should delay checking of bit-fields until we actually perform the 1238 // conversion. 1239 using llvm::APSInt; 1240 if (From) 1241 if (FieldDecl *MemberDecl = From->getBitField()) { 1242 APSInt BitWidth; 1243 if (FromType->isIntegralType(Context) && 1244 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1245 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1246 ToSize = Context.getTypeSize(ToType); 1247 1248 // Are we promoting to an int from a bitfield that fits in an int? 1249 if (BitWidth < ToSize || 1250 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1251 return To->getKind() == BuiltinType::Int; 1252 } 1253 1254 // Are we promoting to an unsigned int from an unsigned bitfield 1255 // that fits into an unsigned int? 1256 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1257 return To->getKind() == BuiltinType::UInt; 1258 } 1259 1260 return false; 1261 } 1262 } 1263 1264 // An rvalue of type bool can be converted to an rvalue of type int, 1265 // with false becoming zero and true becoming one (C++ 4.5p4). 1266 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1267 return true; 1268 } 1269 1270 return false; 1271} 1272 1273/// IsFloatingPointPromotion - Determines whether the conversion from 1274/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1275/// returns true and sets PromotedType to the promoted type. 1276bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1277 /// An rvalue of type float can be converted to an rvalue of type 1278 /// double. (C++ 4.6p1). 1279 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1280 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1281 if (FromBuiltin->getKind() == BuiltinType::Float && 1282 ToBuiltin->getKind() == BuiltinType::Double) 1283 return true; 1284 1285 // C99 6.3.1.5p1: 1286 // When a float is promoted to double or long double, or a 1287 // double is promoted to long double [...]. 1288 if (!getLangOptions().CPlusPlus && 1289 (FromBuiltin->getKind() == BuiltinType::Float || 1290 FromBuiltin->getKind() == BuiltinType::Double) && 1291 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1292 return true; 1293 } 1294 1295 return false; 1296} 1297 1298/// \brief Determine if a conversion is a complex promotion. 1299/// 1300/// A complex promotion is defined as a complex -> complex conversion 1301/// where the conversion between the underlying real types is a 1302/// floating-point or integral promotion. 1303bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1304 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1305 if (!FromComplex) 1306 return false; 1307 1308 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1309 if (!ToComplex) 1310 return false; 1311 1312 return IsFloatingPointPromotion(FromComplex->getElementType(), 1313 ToComplex->getElementType()) || 1314 IsIntegralPromotion(0, FromComplex->getElementType(), 1315 ToComplex->getElementType()); 1316} 1317 1318/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1319/// the pointer type FromPtr to a pointer to type ToPointee, with the 1320/// same type qualifiers as FromPtr has on its pointee type. ToType, 1321/// if non-empty, will be a pointer to ToType that may or may not have 1322/// the right set of qualifiers on its pointee. 1323static QualType 1324BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 1325 QualType ToPointee, QualType ToType, 1326 ASTContext &Context) { 1327 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 1328 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1329 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1330 1331 // Exact qualifier match -> return the pointer type we're converting to. 1332 if (CanonToPointee.getLocalQualifiers() == Quals) { 1333 // ToType is exactly what we need. Return it. 1334 if (!ToType.isNull()) 1335 return ToType.getUnqualifiedType(); 1336 1337 // Build a pointer to ToPointee. It has the right qualifiers 1338 // already. 1339 return Context.getPointerType(ToPointee); 1340 } 1341 1342 // Just build a canonical type that has the right qualifiers. 1343 return Context.getPointerType( 1344 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 1345 Quals)); 1346} 1347 1348/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 1349/// the FromType, which is an objective-c pointer, to ToType, which may or may 1350/// not have the right set of qualifiers. 1351static QualType 1352BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 1353 QualType ToType, 1354 ASTContext &Context) { 1355 QualType CanonFromType = Context.getCanonicalType(FromType); 1356 QualType CanonToType = Context.getCanonicalType(ToType); 1357 Qualifiers Quals = CanonFromType.getQualifiers(); 1358 1359 // Exact qualifier match -> return the pointer type we're converting to. 1360 if (CanonToType.getLocalQualifiers() == Quals) 1361 return ToType; 1362 1363 // Just build a canonical type that has the right qualifiers. 1364 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 1365} 1366 1367static bool isNullPointerConstantForConversion(Expr *Expr, 1368 bool InOverloadResolution, 1369 ASTContext &Context) { 1370 // Handle value-dependent integral null pointer constants correctly. 1371 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1372 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1373 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1374 return !InOverloadResolution; 1375 1376 return Expr->isNullPointerConstant(Context, 1377 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1378 : Expr::NPC_ValueDependentIsNull); 1379} 1380 1381/// IsPointerConversion - Determines whether the conversion of the 1382/// expression From, which has the (possibly adjusted) type FromType, 1383/// can be converted to the type ToType via a pointer conversion (C++ 1384/// 4.10). If so, returns true and places the converted type (that 1385/// might differ from ToType in its cv-qualifiers at some level) into 1386/// ConvertedType. 1387/// 1388/// This routine also supports conversions to and from block pointers 1389/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1390/// pointers to interfaces. FIXME: Once we've determined the 1391/// appropriate overloading rules for Objective-C, we may want to 1392/// split the Objective-C checks into a different routine; however, 1393/// GCC seems to consider all of these conversions to be pointer 1394/// conversions, so for now they live here. IncompatibleObjC will be 1395/// set if the conversion is an allowed Objective-C conversion that 1396/// should result in a warning. 1397bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1398 bool InOverloadResolution, 1399 QualType& ConvertedType, 1400 bool &IncompatibleObjC) { 1401 IncompatibleObjC = false; 1402 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1403 return true; 1404 1405 // Conversion from a null pointer constant to any Objective-C pointer type. 1406 if (ToType->isObjCObjectPointerType() && 1407 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1408 ConvertedType = ToType; 1409 return true; 1410 } 1411 1412 // Blocks: Block pointers can be converted to void*. 1413 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1414 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1415 ConvertedType = ToType; 1416 return true; 1417 } 1418 // Blocks: A null pointer constant can be converted to a block 1419 // pointer type. 1420 if (ToType->isBlockPointerType() && 1421 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1422 ConvertedType = ToType; 1423 return true; 1424 } 1425 1426 // If the left-hand-side is nullptr_t, the right side can be a null 1427 // pointer constant. 1428 if (ToType->isNullPtrType() && 1429 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1430 ConvertedType = ToType; 1431 return true; 1432 } 1433 1434 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1435 if (!ToTypePtr) 1436 return false; 1437 1438 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1439 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1440 ConvertedType = ToType; 1441 return true; 1442 } 1443 1444 // Beyond this point, both types need to be pointers 1445 // , including objective-c pointers. 1446 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1447 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1448 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1449 ToType, Context); 1450 return true; 1451 1452 } 1453 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1454 if (!FromTypePtr) 1455 return false; 1456 1457 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1458 1459 // If the unqualified pointee types are the same, this can't be a 1460 // pointer conversion, so don't do all of the work below. 1461 if (Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) 1462 return false; 1463 1464 // An rvalue of type "pointer to cv T," where T is an object type, 1465 // can be converted to an rvalue of type "pointer to cv void" (C++ 1466 // 4.10p2). 1467 if (FromPointeeType->isIncompleteOrObjectType() && 1468 ToPointeeType->isVoidType()) { 1469 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1470 ToPointeeType, 1471 ToType, Context); 1472 return true; 1473 } 1474 1475 // When we're overloading in C, we allow a special kind of pointer 1476 // conversion for compatible-but-not-identical pointee types. 1477 if (!getLangOptions().CPlusPlus && 1478 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1479 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1480 ToPointeeType, 1481 ToType, Context); 1482 return true; 1483 } 1484 1485 // C++ [conv.ptr]p3: 1486 // 1487 // An rvalue of type "pointer to cv D," where D is a class type, 1488 // can be converted to an rvalue of type "pointer to cv B," where 1489 // B is a base class (clause 10) of D. If B is an inaccessible 1490 // (clause 11) or ambiguous (10.2) base class of D, a program that 1491 // necessitates this conversion is ill-formed. The result of the 1492 // conversion is a pointer to the base class sub-object of the 1493 // derived class object. The null pointer value is converted to 1494 // the null pointer value of the destination type. 1495 // 1496 // Note that we do not check for ambiguity or inaccessibility 1497 // here. That is handled by CheckPointerConversion. 1498 if (getLangOptions().CPlusPlus && 1499 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1500 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1501 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1502 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1503 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1504 ToPointeeType, 1505 ToType, Context); 1506 return true; 1507 } 1508 1509 return false; 1510} 1511 1512/// isObjCPointerConversion - Determines whether this is an 1513/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1514/// with the same arguments and return values. 1515bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1516 QualType& ConvertedType, 1517 bool &IncompatibleObjC) { 1518 if (!getLangOptions().ObjC1) 1519 return false; 1520 1521 // First, we handle all conversions on ObjC object pointer types. 1522 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1523 const ObjCObjectPointerType *FromObjCPtr = 1524 FromType->getAs<ObjCObjectPointerType>(); 1525 1526 if (ToObjCPtr && FromObjCPtr) { 1527 // Objective C++: We're able to convert between "id" or "Class" and a 1528 // pointer to any interface (in both directions). 1529 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1530 ConvertedType = ToType; 1531 return true; 1532 } 1533 // Conversions with Objective-C's id<...>. 1534 if ((FromObjCPtr->isObjCQualifiedIdType() || 1535 ToObjCPtr->isObjCQualifiedIdType()) && 1536 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1537 /*compare=*/false)) { 1538 ConvertedType = ToType; 1539 return true; 1540 } 1541 // Objective C++: We're able to convert from a pointer to an 1542 // interface to a pointer to a different interface. 1543 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1544 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1545 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1546 if (getLangOptions().CPlusPlus && LHS && RHS && 1547 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1548 FromObjCPtr->getPointeeType())) 1549 return false; 1550 ConvertedType = ToType; 1551 return true; 1552 } 1553 1554 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1555 // Okay: this is some kind of implicit downcast of Objective-C 1556 // interfaces, which is permitted. However, we're going to 1557 // complain about it. 1558 IncompatibleObjC = true; 1559 ConvertedType = FromType; 1560 return true; 1561 } 1562 } 1563 // Beyond this point, both types need to be C pointers or block pointers. 1564 QualType ToPointeeType; 1565 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1566 ToPointeeType = ToCPtr->getPointeeType(); 1567 else if (const BlockPointerType *ToBlockPtr = 1568 ToType->getAs<BlockPointerType>()) { 1569 // Objective C++: We're able to convert from a pointer to any object 1570 // to a block pointer type. 1571 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1572 ConvertedType = ToType; 1573 return true; 1574 } 1575 ToPointeeType = ToBlockPtr->getPointeeType(); 1576 } 1577 else if (FromType->getAs<BlockPointerType>() && 1578 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1579 // Objective C++: We're able to convert from a block pointer type to a 1580 // pointer to any object. 1581 ConvertedType = ToType; 1582 return true; 1583 } 1584 else 1585 return false; 1586 1587 QualType FromPointeeType; 1588 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1589 FromPointeeType = FromCPtr->getPointeeType(); 1590 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1591 FromPointeeType = FromBlockPtr->getPointeeType(); 1592 else 1593 return false; 1594 1595 // If we have pointers to pointers, recursively check whether this 1596 // is an Objective-C conversion. 1597 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1598 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1599 IncompatibleObjC)) { 1600 // We always complain about this conversion. 1601 IncompatibleObjC = true; 1602 ConvertedType = ToType; 1603 return true; 1604 } 1605 // Allow conversion of pointee being objective-c pointer to another one; 1606 // as in I* to id. 1607 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1608 ToPointeeType->getAs<ObjCObjectPointerType>() && 1609 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1610 IncompatibleObjC)) { 1611 ConvertedType = ToType; 1612 return true; 1613 } 1614 1615 // If we have pointers to functions or blocks, check whether the only 1616 // differences in the argument and result types are in Objective-C 1617 // pointer conversions. If so, we permit the conversion (but 1618 // complain about it). 1619 const FunctionProtoType *FromFunctionType 1620 = FromPointeeType->getAs<FunctionProtoType>(); 1621 const FunctionProtoType *ToFunctionType 1622 = ToPointeeType->getAs<FunctionProtoType>(); 1623 if (FromFunctionType && ToFunctionType) { 1624 // If the function types are exactly the same, this isn't an 1625 // Objective-C pointer conversion. 1626 if (Context.getCanonicalType(FromPointeeType) 1627 == Context.getCanonicalType(ToPointeeType)) 1628 return false; 1629 1630 // Perform the quick checks that will tell us whether these 1631 // function types are obviously different. 1632 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1633 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1634 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1635 return false; 1636 1637 bool HasObjCConversion = false; 1638 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1639 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1640 // Okay, the types match exactly. Nothing to do. 1641 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1642 ToFunctionType->getResultType(), 1643 ConvertedType, IncompatibleObjC)) { 1644 // Okay, we have an Objective-C pointer conversion. 1645 HasObjCConversion = true; 1646 } else { 1647 // Function types are too different. Abort. 1648 return false; 1649 } 1650 1651 // Check argument types. 1652 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1653 ArgIdx != NumArgs; ++ArgIdx) { 1654 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1655 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1656 if (Context.getCanonicalType(FromArgType) 1657 == Context.getCanonicalType(ToArgType)) { 1658 // Okay, the types match exactly. Nothing to do. 1659 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1660 ConvertedType, IncompatibleObjC)) { 1661 // Okay, we have an Objective-C pointer conversion. 1662 HasObjCConversion = true; 1663 } else { 1664 // Argument types are too different. Abort. 1665 return false; 1666 } 1667 } 1668 1669 if (HasObjCConversion) { 1670 // We had an Objective-C conversion. Allow this pointer 1671 // conversion, but complain about it. 1672 ConvertedType = ToType; 1673 IncompatibleObjC = true; 1674 return true; 1675 } 1676 } 1677 1678 return false; 1679} 1680 1681/// FunctionArgTypesAreEqual - This routine checks two function proto types 1682/// for equlity of their argument types. Caller has already checked that 1683/// they have same number of arguments. This routine assumes that Objective-C 1684/// pointer types which only differ in their protocol qualifiers are equal. 1685bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, 1686 FunctionProtoType* NewType){ 1687 if (!getLangOptions().ObjC1) 1688 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1689 NewType->arg_type_begin()); 1690 1691 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1692 N = NewType->arg_type_begin(), 1693 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1694 QualType ToType = (*O); 1695 QualType FromType = (*N); 1696 if (ToType != FromType) { 1697 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1698 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1699 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1700 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1701 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1702 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1703 continue; 1704 } 1705 else if (const ObjCObjectPointerType *PTTo = 1706 ToType->getAs<ObjCObjectPointerType>()) { 1707 if (const ObjCObjectPointerType *PTFr = 1708 FromType->getAs<ObjCObjectPointerType>()) 1709 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1710 continue; 1711 } 1712 return false; 1713 } 1714 } 1715 return true; 1716} 1717 1718/// CheckPointerConversion - Check the pointer conversion from the 1719/// expression From to the type ToType. This routine checks for 1720/// ambiguous or inaccessible derived-to-base pointer 1721/// conversions for which IsPointerConversion has already returned 1722/// true. It returns true and produces a diagnostic if there was an 1723/// error, or returns false otherwise. 1724bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1725 CastExpr::CastKind &Kind, 1726 CXXCastPath& BasePath, 1727 bool IgnoreBaseAccess) { 1728 QualType FromType = From->getType(); 1729 1730 if (CXXBoolLiteralExpr* LitBool 1731 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1732 if (LitBool->getValue() == false) 1733 Diag(LitBool->getExprLoc(), diag::warn_init_pointer_from_false) 1734 << ToType; 1735 1736 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1737 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1738 QualType FromPointeeType = FromPtrType->getPointeeType(), 1739 ToPointeeType = ToPtrType->getPointeeType(); 1740 1741 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1742 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1743 // We must have a derived-to-base conversion. Check an 1744 // ambiguous or inaccessible conversion. 1745 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1746 From->getExprLoc(), 1747 From->getSourceRange(), &BasePath, 1748 IgnoreBaseAccess)) 1749 return true; 1750 1751 // The conversion was successful. 1752 Kind = CastExpr::CK_DerivedToBase; 1753 } 1754 } 1755 if (const ObjCObjectPointerType *FromPtrType = 1756 FromType->getAs<ObjCObjectPointerType>()) 1757 if (const ObjCObjectPointerType *ToPtrType = 1758 ToType->getAs<ObjCObjectPointerType>()) { 1759 // Objective-C++ conversions are always okay. 1760 // FIXME: We should have a different class of conversions for the 1761 // Objective-C++ implicit conversions. 1762 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1763 return false; 1764 1765 } 1766 return false; 1767} 1768 1769/// IsMemberPointerConversion - Determines whether the conversion of the 1770/// expression From, which has the (possibly adjusted) type FromType, can be 1771/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1772/// If so, returns true and places the converted type (that might differ from 1773/// ToType in its cv-qualifiers at some level) into ConvertedType. 1774bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1775 QualType ToType, 1776 bool InOverloadResolution, 1777 QualType &ConvertedType) { 1778 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1779 if (!ToTypePtr) 1780 return false; 1781 1782 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1783 if (From->isNullPointerConstant(Context, 1784 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1785 : Expr::NPC_ValueDependentIsNull)) { 1786 ConvertedType = ToType; 1787 return true; 1788 } 1789 1790 // Otherwise, both types have to be member pointers. 1791 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1792 if (!FromTypePtr) 1793 return false; 1794 1795 // A pointer to member of B can be converted to a pointer to member of D, 1796 // where D is derived from B (C++ 4.11p2). 1797 QualType FromClass(FromTypePtr->getClass(), 0); 1798 QualType ToClass(ToTypePtr->getClass(), 0); 1799 // FIXME: What happens when these are dependent? Is this function even called? 1800 1801 if (IsDerivedFrom(ToClass, FromClass)) { 1802 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1803 ToClass.getTypePtr()); 1804 return true; 1805 } 1806 1807 return false; 1808} 1809 1810/// CheckMemberPointerConversion - Check the member pointer conversion from the 1811/// expression From to the type ToType. This routine checks for ambiguous or 1812/// virtual or inaccessible base-to-derived member pointer conversions 1813/// for which IsMemberPointerConversion has already returned true. It returns 1814/// true and produces a diagnostic if there was an error, or returns false 1815/// otherwise. 1816bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1817 CastExpr::CastKind &Kind, 1818 CXXCastPath &BasePath, 1819 bool IgnoreBaseAccess) { 1820 QualType FromType = From->getType(); 1821 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1822 if (!FromPtrType) { 1823 // This must be a null pointer to member pointer conversion 1824 assert(From->isNullPointerConstant(Context, 1825 Expr::NPC_ValueDependentIsNull) && 1826 "Expr must be null pointer constant!"); 1827 Kind = CastExpr::CK_NullToMemberPointer; 1828 return false; 1829 } 1830 1831 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1832 assert(ToPtrType && "No member pointer cast has a target type " 1833 "that is not a member pointer."); 1834 1835 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1836 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1837 1838 // FIXME: What about dependent types? 1839 assert(FromClass->isRecordType() && "Pointer into non-class."); 1840 assert(ToClass->isRecordType() && "Pointer into non-class."); 1841 1842 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1843 /*DetectVirtual=*/true); 1844 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1845 assert(DerivationOkay && 1846 "Should not have been called if derivation isn't OK."); 1847 (void)DerivationOkay; 1848 1849 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1850 getUnqualifiedType())) { 1851 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1852 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1853 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1854 return true; 1855 } 1856 1857 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1858 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1859 << FromClass << ToClass << QualType(VBase, 0) 1860 << From->getSourceRange(); 1861 return true; 1862 } 1863 1864 if (!IgnoreBaseAccess) 1865 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1866 Paths.front(), 1867 diag::err_downcast_from_inaccessible_base); 1868 1869 // Must be a base to derived member conversion. 1870 BuildBasePathArray(Paths, BasePath); 1871 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1872 return false; 1873} 1874 1875/// IsQualificationConversion - Determines whether the conversion from 1876/// an rvalue of type FromType to ToType is a qualification conversion 1877/// (C++ 4.4). 1878bool 1879Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1880 FromType = Context.getCanonicalType(FromType); 1881 ToType = Context.getCanonicalType(ToType); 1882 1883 // If FromType and ToType are the same type, this is not a 1884 // qualification conversion. 1885 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1886 return false; 1887 1888 // (C++ 4.4p4): 1889 // A conversion can add cv-qualifiers at levels other than the first 1890 // in multi-level pointers, subject to the following rules: [...] 1891 bool PreviousToQualsIncludeConst = true; 1892 bool UnwrappedAnyPointer = false; 1893 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 1894 // Within each iteration of the loop, we check the qualifiers to 1895 // determine if this still looks like a qualification 1896 // conversion. Then, if all is well, we unwrap one more level of 1897 // pointers or pointers-to-members and do it all again 1898 // until there are no more pointers or pointers-to-members left to 1899 // unwrap. 1900 UnwrappedAnyPointer = true; 1901 1902 // -- for every j > 0, if const is in cv 1,j then const is in cv 1903 // 2,j, and similarly for volatile. 1904 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1905 return false; 1906 1907 // -- if the cv 1,j and cv 2,j are different, then const is in 1908 // every cv for 0 < k < j. 1909 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1910 && !PreviousToQualsIncludeConst) 1911 return false; 1912 1913 // Keep track of whether all prior cv-qualifiers in the "to" type 1914 // include const. 1915 PreviousToQualsIncludeConst 1916 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1917 } 1918 1919 // We are left with FromType and ToType being the pointee types 1920 // after unwrapping the original FromType and ToType the same number 1921 // of types. If we unwrapped any pointers, and if FromType and 1922 // ToType have the same unqualified type (since we checked 1923 // qualifiers above), then this is a qualification conversion. 1924 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1925} 1926 1927/// Determines whether there is a user-defined conversion sequence 1928/// (C++ [over.ics.user]) that converts expression From to the type 1929/// ToType. If such a conversion exists, User will contain the 1930/// user-defined conversion sequence that performs such a conversion 1931/// and this routine will return true. Otherwise, this routine returns 1932/// false and User is unspecified. 1933/// 1934/// \param AllowExplicit true if the conversion should consider C++0x 1935/// "explicit" conversion functions as well as non-explicit conversion 1936/// functions (C++0x [class.conv.fct]p2). 1937static OverloadingResult 1938IsUserDefinedConversion(Sema &S, Expr *From, QualType ToType, 1939 UserDefinedConversionSequence& User, 1940 OverloadCandidateSet& CandidateSet, 1941 bool AllowExplicit) { 1942 // Whether we will only visit constructors. 1943 bool ConstructorsOnly = false; 1944 1945 // If the type we are conversion to is a class type, enumerate its 1946 // constructors. 1947 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1948 // C++ [over.match.ctor]p1: 1949 // When objects of class type are direct-initialized (8.5), or 1950 // copy-initialized from an expression of the same or a 1951 // derived class type (8.5), overload resolution selects the 1952 // constructor. [...] For copy-initialization, the candidate 1953 // functions are all the converting constructors (12.3.1) of 1954 // that class. The argument list is the expression-list within 1955 // the parentheses of the initializer. 1956 if (S.Context.hasSameUnqualifiedType(ToType, From->getType()) || 1957 (From->getType()->getAs<RecordType>() && 1958 S.IsDerivedFrom(From->getType(), ToType))) 1959 ConstructorsOnly = true; 1960 1961 if (S.RequireCompleteType(From->getLocStart(), ToType, S.PDiag())) { 1962 // We're not going to find any constructors. 1963 } else if (CXXRecordDecl *ToRecordDecl 1964 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1965 DeclContext::lookup_iterator Con, ConEnd; 1966 for (llvm::tie(Con, ConEnd) = S.LookupConstructors(ToRecordDecl); 1967 Con != ConEnd; ++Con) { 1968 NamedDecl *D = *Con; 1969 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1970 1971 // Find the constructor (which may be a template). 1972 CXXConstructorDecl *Constructor = 0; 1973 FunctionTemplateDecl *ConstructorTmpl 1974 = dyn_cast<FunctionTemplateDecl>(D); 1975 if (ConstructorTmpl) 1976 Constructor 1977 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1978 else 1979 Constructor = cast<CXXConstructorDecl>(D); 1980 1981 if (!Constructor->isInvalidDecl() && 1982 Constructor->isConvertingConstructor(AllowExplicit)) { 1983 if (ConstructorTmpl) 1984 S.AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1985 /*ExplicitArgs*/ 0, 1986 &From, 1, CandidateSet, 1987 /*SuppressUserConversions=*/ 1988 !ConstructorsOnly); 1989 else 1990 // Allow one user-defined conversion when user specifies a 1991 // From->ToType conversion via an static cast (c-style, etc). 1992 S.AddOverloadCandidate(Constructor, FoundDecl, 1993 &From, 1, CandidateSet, 1994 /*SuppressUserConversions=*/ 1995 !ConstructorsOnly); 1996 } 1997 } 1998 } 1999 } 2000 2001 // Enumerate conversion functions, if we're allowed to. 2002 if (ConstructorsOnly) { 2003 } else if (S.RequireCompleteType(From->getLocStart(), From->getType(), 2004 S.PDiag(0) << From->getSourceRange())) { 2005 // No conversion functions from incomplete types. 2006 } else if (const RecordType *FromRecordType 2007 = From->getType()->getAs<RecordType>()) { 2008 if (CXXRecordDecl *FromRecordDecl 2009 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 2010 // Add all of the conversion functions as candidates. 2011 const UnresolvedSetImpl *Conversions 2012 = FromRecordDecl->getVisibleConversionFunctions(); 2013 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2014 E = Conversions->end(); I != E; ++I) { 2015 DeclAccessPair FoundDecl = I.getPair(); 2016 NamedDecl *D = FoundDecl.getDecl(); 2017 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 2018 if (isa<UsingShadowDecl>(D)) 2019 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2020 2021 CXXConversionDecl *Conv; 2022 FunctionTemplateDecl *ConvTemplate; 2023 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 2024 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2025 else 2026 Conv = cast<CXXConversionDecl>(D); 2027 2028 if (AllowExplicit || !Conv->isExplicit()) { 2029 if (ConvTemplate) 2030 S.AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 2031 ActingContext, From, ToType, 2032 CandidateSet); 2033 else 2034 S.AddConversionCandidate(Conv, FoundDecl, ActingContext, 2035 From, ToType, CandidateSet); 2036 } 2037 } 2038 } 2039 } 2040 2041 OverloadCandidateSet::iterator Best; 2042 switch (CandidateSet.BestViableFunction(S, From->getLocStart(), Best)) { 2043 case OR_Success: 2044 // Record the standard conversion we used and the conversion function. 2045 if (CXXConstructorDecl *Constructor 2046 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 2047 // C++ [over.ics.user]p1: 2048 // If the user-defined conversion is specified by a 2049 // constructor (12.3.1), the initial standard conversion 2050 // sequence converts the source type to the type required by 2051 // the argument of the constructor. 2052 // 2053 QualType ThisType = Constructor->getThisType(S.Context); 2054 if (Best->Conversions[0].isEllipsis()) 2055 User.EllipsisConversion = true; 2056 else { 2057 User.Before = Best->Conversions[0].Standard; 2058 User.EllipsisConversion = false; 2059 } 2060 User.ConversionFunction = Constructor; 2061 User.After.setAsIdentityConversion(); 2062 User.After.setFromType(ThisType->getAs<PointerType>()->getPointeeType()); 2063 User.After.setAllToTypes(ToType); 2064 return OR_Success; 2065 } else if (CXXConversionDecl *Conversion 2066 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2067 // C++ [over.ics.user]p1: 2068 // 2069 // [...] If the user-defined conversion is specified by a 2070 // conversion function (12.3.2), the initial standard 2071 // conversion sequence converts the source type to the 2072 // implicit object parameter of the conversion function. 2073 User.Before = Best->Conversions[0].Standard; 2074 User.ConversionFunction = Conversion; 2075 User.EllipsisConversion = false; 2076 2077 // C++ [over.ics.user]p2: 2078 // The second standard conversion sequence converts the 2079 // result of the user-defined conversion to the target type 2080 // for the sequence. Since an implicit conversion sequence 2081 // is an initialization, the special rules for 2082 // initialization by user-defined conversion apply when 2083 // selecting the best user-defined conversion for a 2084 // user-defined conversion sequence (see 13.3.3 and 2085 // 13.3.3.1). 2086 User.After = Best->FinalConversion; 2087 return OR_Success; 2088 } else { 2089 llvm_unreachable("Not a constructor or conversion function?"); 2090 return OR_No_Viable_Function; 2091 } 2092 2093 case OR_No_Viable_Function: 2094 return OR_No_Viable_Function; 2095 case OR_Deleted: 2096 // No conversion here! We're done. 2097 return OR_Deleted; 2098 2099 case OR_Ambiguous: 2100 return OR_Ambiguous; 2101 } 2102 2103 return OR_No_Viable_Function; 2104} 2105 2106bool 2107Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2108 ImplicitConversionSequence ICS; 2109 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2110 OverloadingResult OvResult = 2111 IsUserDefinedConversion(*this, From, ToType, ICS.UserDefined, 2112 CandidateSet, false); 2113 if (OvResult == OR_Ambiguous) 2114 Diag(From->getSourceRange().getBegin(), 2115 diag::err_typecheck_ambiguous_condition) 2116 << From->getType() << ToType << From->getSourceRange(); 2117 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2118 Diag(From->getSourceRange().getBegin(), 2119 diag::err_typecheck_nonviable_condition) 2120 << From->getType() << ToType << From->getSourceRange(); 2121 else 2122 return false; 2123 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &From, 1); 2124 return true; 2125} 2126 2127/// CompareImplicitConversionSequences - Compare two implicit 2128/// conversion sequences to determine whether one is better than the 2129/// other or if they are indistinguishable (C++ 13.3.3.2). 2130static ImplicitConversionSequence::CompareKind 2131CompareImplicitConversionSequences(Sema &S, 2132 const ImplicitConversionSequence& ICS1, 2133 const ImplicitConversionSequence& ICS2) 2134{ 2135 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2136 // conversion sequences (as defined in 13.3.3.1) 2137 // -- a standard conversion sequence (13.3.3.1.1) is a better 2138 // conversion sequence than a user-defined conversion sequence or 2139 // an ellipsis conversion sequence, and 2140 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2141 // conversion sequence than an ellipsis conversion sequence 2142 // (13.3.3.1.3). 2143 // 2144 // C++0x [over.best.ics]p10: 2145 // For the purpose of ranking implicit conversion sequences as 2146 // described in 13.3.3.2, the ambiguous conversion sequence is 2147 // treated as a user-defined sequence that is indistinguishable 2148 // from any other user-defined conversion sequence. 2149 if (ICS1.getKindRank() < ICS2.getKindRank()) 2150 return ImplicitConversionSequence::Better; 2151 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2152 return ImplicitConversionSequence::Worse; 2153 2154 // The following checks require both conversion sequences to be of 2155 // the same kind. 2156 if (ICS1.getKind() != ICS2.getKind()) 2157 return ImplicitConversionSequence::Indistinguishable; 2158 2159 // Two implicit conversion sequences of the same form are 2160 // indistinguishable conversion sequences unless one of the 2161 // following rules apply: (C++ 13.3.3.2p3): 2162 if (ICS1.isStandard()) 2163 return CompareStandardConversionSequences(S, ICS1.Standard, ICS2.Standard); 2164 else if (ICS1.isUserDefined()) { 2165 // User-defined conversion sequence U1 is a better conversion 2166 // sequence than another user-defined conversion sequence U2 if 2167 // they contain the same user-defined conversion function or 2168 // constructor and if the second standard conversion sequence of 2169 // U1 is better than the second standard conversion sequence of 2170 // U2 (C++ 13.3.3.2p3). 2171 if (ICS1.UserDefined.ConversionFunction == 2172 ICS2.UserDefined.ConversionFunction) 2173 return CompareStandardConversionSequences(S, 2174 ICS1.UserDefined.After, 2175 ICS2.UserDefined.After); 2176 } 2177 2178 return ImplicitConversionSequence::Indistinguishable; 2179} 2180 2181static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2182 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2183 Qualifiers Quals; 2184 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2185 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2186 } 2187 2188 return Context.hasSameUnqualifiedType(T1, T2); 2189} 2190 2191// Per 13.3.3.2p3, compare the given standard conversion sequences to 2192// determine if one is a proper subset of the other. 2193static ImplicitConversionSequence::CompareKind 2194compareStandardConversionSubsets(ASTContext &Context, 2195 const StandardConversionSequence& SCS1, 2196 const StandardConversionSequence& SCS2) { 2197 ImplicitConversionSequence::CompareKind Result 2198 = ImplicitConversionSequence::Indistinguishable; 2199 2200 // the identity conversion sequence is considered to be a subsequence of 2201 // any non-identity conversion sequence 2202 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2203 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2204 return ImplicitConversionSequence::Better; 2205 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2206 return ImplicitConversionSequence::Worse; 2207 } 2208 2209 if (SCS1.Second != SCS2.Second) { 2210 if (SCS1.Second == ICK_Identity) 2211 Result = ImplicitConversionSequence::Better; 2212 else if (SCS2.Second == ICK_Identity) 2213 Result = ImplicitConversionSequence::Worse; 2214 else 2215 return ImplicitConversionSequence::Indistinguishable; 2216 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2217 return ImplicitConversionSequence::Indistinguishable; 2218 2219 if (SCS1.Third == SCS2.Third) { 2220 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2221 : ImplicitConversionSequence::Indistinguishable; 2222 } 2223 2224 if (SCS1.Third == ICK_Identity) 2225 return Result == ImplicitConversionSequence::Worse 2226 ? ImplicitConversionSequence::Indistinguishable 2227 : ImplicitConversionSequence::Better; 2228 2229 if (SCS2.Third == ICK_Identity) 2230 return Result == ImplicitConversionSequence::Better 2231 ? ImplicitConversionSequence::Indistinguishable 2232 : ImplicitConversionSequence::Worse; 2233 2234 return ImplicitConversionSequence::Indistinguishable; 2235} 2236 2237/// CompareStandardConversionSequences - Compare two standard 2238/// conversion sequences to determine whether one is better than the 2239/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2240static ImplicitConversionSequence::CompareKind 2241CompareStandardConversionSequences(Sema &S, 2242 const StandardConversionSequence& SCS1, 2243 const StandardConversionSequence& SCS2) 2244{ 2245 // Standard conversion sequence S1 is a better conversion sequence 2246 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2247 2248 // -- S1 is a proper subsequence of S2 (comparing the conversion 2249 // sequences in the canonical form defined by 13.3.3.1.1, 2250 // excluding any Lvalue Transformation; the identity conversion 2251 // sequence is considered to be a subsequence of any 2252 // non-identity conversion sequence) or, if not that, 2253 if (ImplicitConversionSequence::CompareKind CK 2254 = compareStandardConversionSubsets(S.Context, SCS1, SCS2)) 2255 return CK; 2256 2257 // -- the rank of S1 is better than the rank of S2 (by the rules 2258 // defined below), or, if not that, 2259 ImplicitConversionRank Rank1 = SCS1.getRank(); 2260 ImplicitConversionRank Rank2 = SCS2.getRank(); 2261 if (Rank1 < Rank2) 2262 return ImplicitConversionSequence::Better; 2263 else if (Rank2 < Rank1) 2264 return ImplicitConversionSequence::Worse; 2265 2266 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2267 // are indistinguishable unless one of the following rules 2268 // applies: 2269 2270 // A conversion that is not a conversion of a pointer, or 2271 // pointer to member, to bool is better than another conversion 2272 // that is such a conversion. 2273 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2274 return SCS2.isPointerConversionToBool() 2275 ? ImplicitConversionSequence::Better 2276 : ImplicitConversionSequence::Worse; 2277 2278 // C++ [over.ics.rank]p4b2: 2279 // 2280 // If class B is derived directly or indirectly from class A, 2281 // conversion of B* to A* is better than conversion of B* to 2282 // void*, and conversion of A* to void* is better than conversion 2283 // of B* to void*. 2284 bool SCS1ConvertsToVoid 2285 = SCS1.isPointerConversionToVoidPointer(S.Context); 2286 bool SCS2ConvertsToVoid 2287 = SCS2.isPointerConversionToVoidPointer(S.Context); 2288 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2289 // Exactly one of the conversion sequences is a conversion to 2290 // a void pointer; it's the worse conversion. 2291 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2292 : ImplicitConversionSequence::Worse; 2293 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2294 // Neither conversion sequence converts to a void pointer; compare 2295 // their derived-to-base conversions. 2296 if (ImplicitConversionSequence::CompareKind DerivedCK 2297 = CompareDerivedToBaseConversions(S, SCS1, SCS2)) 2298 return DerivedCK; 2299 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2300 // Both conversion sequences are conversions to void 2301 // pointers. Compare the source types to determine if there's an 2302 // inheritance relationship in their sources. 2303 QualType FromType1 = SCS1.getFromType(); 2304 QualType FromType2 = SCS2.getFromType(); 2305 2306 // Adjust the types we're converting from via the array-to-pointer 2307 // conversion, if we need to. 2308 if (SCS1.First == ICK_Array_To_Pointer) 2309 FromType1 = S.Context.getArrayDecayedType(FromType1); 2310 if (SCS2.First == ICK_Array_To_Pointer) 2311 FromType2 = S.Context.getArrayDecayedType(FromType2); 2312 2313 QualType FromPointee1 2314 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2315 QualType FromPointee2 2316 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2317 2318 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2319 return ImplicitConversionSequence::Better; 2320 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2321 return ImplicitConversionSequence::Worse; 2322 2323 // Objective-C++: If one interface is more specific than the 2324 // other, it is the better one. 2325 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2326 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2327 if (FromIface1 && FromIface1) { 2328 if (S.Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2329 return ImplicitConversionSequence::Better; 2330 else if (S.Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2331 return ImplicitConversionSequence::Worse; 2332 } 2333 } 2334 2335 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2336 // bullet 3). 2337 if (ImplicitConversionSequence::CompareKind QualCK 2338 = CompareQualificationConversions(S, SCS1, SCS2)) 2339 return QualCK; 2340 2341 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2342 // C++0x [over.ics.rank]p3b4: 2343 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2344 // implicit object parameter of a non-static member function declared 2345 // without a ref-qualifier, and S1 binds an rvalue reference to an 2346 // rvalue and S2 binds an lvalue reference. 2347 // FIXME: We don't know if we're dealing with the implicit object parameter, 2348 // or if the member function in this case has a ref qualifier. 2349 // (Of course, we don't have ref qualifiers yet.) 2350 if (SCS1.RRefBinding != SCS2.RRefBinding) 2351 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 2352 : ImplicitConversionSequence::Worse; 2353 2354 // C++ [over.ics.rank]p3b4: 2355 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2356 // which the references refer are the same type except for 2357 // top-level cv-qualifiers, and the type to which the reference 2358 // initialized by S2 refers is more cv-qualified than the type 2359 // to which the reference initialized by S1 refers. 2360 QualType T1 = SCS1.getToType(2); 2361 QualType T2 = SCS2.getToType(2); 2362 T1 = S.Context.getCanonicalType(T1); 2363 T2 = S.Context.getCanonicalType(T2); 2364 Qualifiers T1Quals, T2Quals; 2365 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2366 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2367 if (UnqualT1 == UnqualT2) { 2368 // If the type is an array type, promote the element qualifiers to the type 2369 // for comparison. 2370 if (isa<ArrayType>(T1) && T1Quals) 2371 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2372 if (isa<ArrayType>(T2) && T2Quals) 2373 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2374 if (T2.isMoreQualifiedThan(T1)) 2375 return ImplicitConversionSequence::Better; 2376 else if (T1.isMoreQualifiedThan(T2)) 2377 return ImplicitConversionSequence::Worse; 2378 } 2379 } 2380 2381 return ImplicitConversionSequence::Indistinguishable; 2382} 2383 2384/// CompareQualificationConversions - Compares two standard conversion 2385/// sequences to determine whether they can be ranked based on their 2386/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2387ImplicitConversionSequence::CompareKind 2388CompareQualificationConversions(Sema &S, 2389 const StandardConversionSequence& SCS1, 2390 const StandardConversionSequence& SCS2) { 2391 // C++ 13.3.3.2p3: 2392 // -- S1 and S2 differ only in their qualification conversion and 2393 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2394 // cv-qualification signature of type T1 is a proper subset of 2395 // the cv-qualification signature of type T2, and S1 is not the 2396 // deprecated string literal array-to-pointer conversion (4.2). 2397 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2398 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2399 return ImplicitConversionSequence::Indistinguishable; 2400 2401 // FIXME: the example in the standard doesn't use a qualification 2402 // conversion (!) 2403 QualType T1 = SCS1.getToType(2); 2404 QualType T2 = SCS2.getToType(2); 2405 T1 = S.Context.getCanonicalType(T1); 2406 T2 = S.Context.getCanonicalType(T2); 2407 Qualifiers T1Quals, T2Quals; 2408 QualType UnqualT1 = S.Context.getUnqualifiedArrayType(T1, T1Quals); 2409 QualType UnqualT2 = S.Context.getUnqualifiedArrayType(T2, T2Quals); 2410 2411 // If the types are the same, we won't learn anything by unwrapped 2412 // them. 2413 if (UnqualT1 == UnqualT2) 2414 return ImplicitConversionSequence::Indistinguishable; 2415 2416 // If the type is an array type, promote the element qualifiers to the type 2417 // for comparison. 2418 if (isa<ArrayType>(T1) && T1Quals) 2419 T1 = S.Context.getQualifiedType(UnqualT1, T1Quals); 2420 if (isa<ArrayType>(T2) && T2Quals) 2421 T2 = S.Context.getQualifiedType(UnqualT2, T2Quals); 2422 2423 ImplicitConversionSequence::CompareKind Result 2424 = ImplicitConversionSequence::Indistinguishable; 2425 while (S.Context.UnwrapSimilarPointerTypes(T1, T2)) { 2426 // Within each iteration of the loop, we check the qualifiers to 2427 // determine if this still looks like a qualification 2428 // conversion. Then, if all is well, we unwrap one more level of 2429 // pointers or pointers-to-members and do it all again 2430 // until there are no more pointers or pointers-to-members left 2431 // to unwrap. This essentially mimics what 2432 // IsQualificationConversion does, but here we're checking for a 2433 // strict subset of qualifiers. 2434 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2435 // The qualifiers are the same, so this doesn't tell us anything 2436 // about how the sequences rank. 2437 ; 2438 else if (T2.isMoreQualifiedThan(T1)) { 2439 // T1 has fewer qualifiers, so it could be the better sequence. 2440 if (Result == ImplicitConversionSequence::Worse) 2441 // Neither has qualifiers that are a subset of the other's 2442 // qualifiers. 2443 return ImplicitConversionSequence::Indistinguishable; 2444 2445 Result = ImplicitConversionSequence::Better; 2446 } else if (T1.isMoreQualifiedThan(T2)) { 2447 // T2 has fewer qualifiers, so it could be the better sequence. 2448 if (Result == ImplicitConversionSequence::Better) 2449 // Neither has qualifiers that are a subset of the other's 2450 // qualifiers. 2451 return ImplicitConversionSequence::Indistinguishable; 2452 2453 Result = ImplicitConversionSequence::Worse; 2454 } else { 2455 // Qualifiers are disjoint. 2456 return ImplicitConversionSequence::Indistinguishable; 2457 } 2458 2459 // If the types after this point are equivalent, we're done. 2460 if (S.Context.hasSameUnqualifiedType(T1, T2)) 2461 break; 2462 } 2463 2464 // Check that the winning standard conversion sequence isn't using 2465 // the deprecated string literal array to pointer conversion. 2466 switch (Result) { 2467 case ImplicitConversionSequence::Better: 2468 if (SCS1.DeprecatedStringLiteralToCharPtr) 2469 Result = ImplicitConversionSequence::Indistinguishable; 2470 break; 2471 2472 case ImplicitConversionSequence::Indistinguishable: 2473 break; 2474 2475 case ImplicitConversionSequence::Worse: 2476 if (SCS2.DeprecatedStringLiteralToCharPtr) 2477 Result = ImplicitConversionSequence::Indistinguishable; 2478 break; 2479 } 2480 2481 return Result; 2482} 2483 2484/// CompareDerivedToBaseConversions - Compares two standard conversion 2485/// sequences to determine whether they can be ranked based on their 2486/// various kinds of derived-to-base conversions (C++ 2487/// [over.ics.rank]p4b3). As part of these checks, we also look at 2488/// conversions between Objective-C interface types. 2489ImplicitConversionSequence::CompareKind 2490CompareDerivedToBaseConversions(Sema &S, 2491 const StandardConversionSequence& SCS1, 2492 const StandardConversionSequence& SCS2) { 2493 QualType FromType1 = SCS1.getFromType(); 2494 QualType ToType1 = SCS1.getToType(1); 2495 QualType FromType2 = SCS2.getFromType(); 2496 QualType ToType2 = SCS2.getToType(1); 2497 2498 // Adjust the types we're converting from via the array-to-pointer 2499 // conversion, if we need to. 2500 if (SCS1.First == ICK_Array_To_Pointer) 2501 FromType1 = S.Context.getArrayDecayedType(FromType1); 2502 if (SCS2.First == ICK_Array_To_Pointer) 2503 FromType2 = S.Context.getArrayDecayedType(FromType2); 2504 2505 // Canonicalize all of the types. 2506 FromType1 = S.Context.getCanonicalType(FromType1); 2507 ToType1 = S.Context.getCanonicalType(ToType1); 2508 FromType2 = S.Context.getCanonicalType(FromType2); 2509 ToType2 = S.Context.getCanonicalType(ToType2); 2510 2511 // C++ [over.ics.rank]p4b3: 2512 // 2513 // If class B is derived directly or indirectly from class A and 2514 // class C is derived directly or indirectly from B, 2515 // 2516 // For Objective-C, we let A, B, and C also be Objective-C 2517 // interfaces. 2518 2519 // Compare based on pointer conversions. 2520 if (SCS1.Second == ICK_Pointer_Conversion && 2521 SCS2.Second == ICK_Pointer_Conversion && 2522 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2523 FromType1->isPointerType() && FromType2->isPointerType() && 2524 ToType1->isPointerType() && ToType2->isPointerType()) { 2525 QualType FromPointee1 2526 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2527 QualType ToPointee1 2528 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2529 QualType FromPointee2 2530 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2531 QualType ToPointee2 2532 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2533 2534 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2535 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2536 const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>(); 2537 const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>(); 2538 2539 // -- conversion of C* to B* is better than conversion of C* to A*, 2540 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2541 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2542 return ImplicitConversionSequence::Better; 2543 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2544 return ImplicitConversionSequence::Worse; 2545 2546 if (ToIface1 && ToIface2) { 2547 if (S.Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2548 return ImplicitConversionSequence::Better; 2549 else if (S.Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2550 return ImplicitConversionSequence::Worse; 2551 } 2552 } 2553 2554 // -- conversion of B* to A* is better than conversion of C* to A*, 2555 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2556 if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2557 return ImplicitConversionSequence::Better; 2558 else if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2559 return ImplicitConversionSequence::Worse; 2560 2561 if (FromIface1 && FromIface2) { 2562 if (S.Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2563 return ImplicitConversionSequence::Better; 2564 else if (S.Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2565 return ImplicitConversionSequence::Worse; 2566 } 2567 } 2568 } 2569 2570 // Ranking of member-pointer types. 2571 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2572 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2573 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2574 const MemberPointerType * FromMemPointer1 = 2575 FromType1->getAs<MemberPointerType>(); 2576 const MemberPointerType * ToMemPointer1 = 2577 ToType1->getAs<MemberPointerType>(); 2578 const MemberPointerType * FromMemPointer2 = 2579 FromType2->getAs<MemberPointerType>(); 2580 const MemberPointerType * ToMemPointer2 = 2581 ToType2->getAs<MemberPointerType>(); 2582 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2583 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2584 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2585 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2586 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2587 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2588 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2589 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2590 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2591 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2592 if (S.IsDerivedFrom(ToPointee1, ToPointee2)) 2593 return ImplicitConversionSequence::Worse; 2594 else if (S.IsDerivedFrom(ToPointee2, ToPointee1)) 2595 return ImplicitConversionSequence::Better; 2596 } 2597 // conversion of B::* to C::* is better than conversion of A::* to C::* 2598 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2599 if (S.IsDerivedFrom(FromPointee1, FromPointee2)) 2600 return ImplicitConversionSequence::Better; 2601 else if (S.IsDerivedFrom(FromPointee2, FromPointee1)) 2602 return ImplicitConversionSequence::Worse; 2603 } 2604 } 2605 2606 if (SCS1.Second == ICK_Derived_To_Base) { 2607 // -- conversion of C to B is better than conversion of C to A, 2608 // -- binding of an expression of type C to a reference of type 2609 // B& is better than binding an expression of type C to a 2610 // reference of type A&, 2611 if (S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2612 !S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2613 if (S.IsDerivedFrom(ToType1, ToType2)) 2614 return ImplicitConversionSequence::Better; 2615 else if (S.IsDerivedFrom(ToType2, ToType1)) 2616 return ImplicitConversionSequence::Worse; 2617 } 2618 2619 // -- conversion of B to A is better than conversion of C to A. 2620 // -- binding of an expression of type B to a reference of type 2621 // A& is better than binding an expression of type C to a 2622 // reference of type A&, 2623 if (!S.Context.hasSameUnqualifiedType(FromType1, FromType2) && 2624 S.Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2625 if (S.IsDerivedFrom(FromType2, FromType1)) 2626 return ImplicitConversionSequence::Better; 2627 else if (S.IsDerivedFrom(FromType1, FromType2)) 2628 return ImplicitConversionSequence::Worse; 2629 } 2630 } 2631 2632 return ImplicitConversionSequence::Indistinguishable; 2633} 2634 2635/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2636/// determine whether they are reference-related, 2637/// reference-compatible, reference-compatible with added 2638/// qualification, or incompatible, for use in C++ initialization by 2639/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2640/// type, and the first type (T1) is the pointee type of the reference 2641/// type being initialized. 2642Sema::ReferenceCompareResult 2643Sema::CompareReferenceRelationship(SourceLocation Loc, 2644 QualType OrigT1, QualType OrigT2, 2645 bool &DerivedToBase, 2646 bool &ObjCConversion) { 2647 assert(!OrigT1->isReferenceType() && 2648 "T1 must be the pointee type of the reference type"); 2649 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2650 2651 QualType T1 = Context.getCanonicalType(OrigT1); 2652 QualType T2 = Context.getCanonicalType(OrigT2); 2653 Qualifiers T1Quals, T2Quals; 2654 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2655 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2656 2657 // C++ [dcl.init.ref]p4: 2658 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2659 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2660 // T1 is a base class of T2. 2661 DerivedToBase = false; 2662 ObjCConversion = false; 2663 if (UnqualT1 == UnqualT2) { 2664 // Nothing to do. 2665 } else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2666 IsDerivedFrom(UnqualT2, UnqualT1)) 2667 DerivedToBase = true; 2668 else if (UnqualT1->isObjCObjectOrInterfaceType() && 2669 UnqualT2->isObjCObjectOrInterfaceType() && 2670 Context.canBindObjCObjectType(UnqualT1, UnqualT2)) 2671 ObjCConversion = true; 2672 else 2673 return Ref_Incompatible; 2674 2675 // At this point, we know that T1 and T2 are reference-related (at 2676 // least). 2677 2678 // If the type is an array type, promote the element qualifiers to the type 2679 // for comparison. 2680 if (isa<ArrayType>(T1) && T1Quals) 2681 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2682 if (isa<ArrayType>(T2) && T2Quals) 2683 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2684 2685 // C++ [dcl.init.ref]p4: 2686 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2687 // reference-related to T2 and cv1 is the same cv-qualification 2688 // as, or greater cv-qualification than, cv2. For purposes of 2689 // overload resolution, cases for which cv1 is greater 2690 // cv-qualification than cv2 are identified as 2691 // reference-compatible with added qualification (see 13.3.3.2). 2692 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2693 return Ref_Compatible; 2694 else if (T1.isMoreQualifiedThan(T2)) 2695 return Ref_Compatible_With_Added_Qualification; 2696 else 2697 return Ref_Related; 2698} 2699 2700/// \brief Look for a user-defined conversion to an value reference-compatible 2701/// with DeclType. Return true if something definite is found. 2702static bool 2703FindConversionForRefInit(Sema &S, ImplicitConversionSequence &ICS, 2704 QualType DeclType, SourceLocation DeclLoc, 2705 Expr *Init, QualType T2, bool AllowRvalues, 2706 bool AllowExplicit) { 2707 assert(T2->isRecordType() && "Can only find conversions of record types."); 2708 CXXRecordDecl *T2RecordDecl 2709 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2710 2711 QualType ToType 2712 = AllowRvalues? DeclType->getAs<ReferenceType>()->getPointeeType() 2713 : DeclType; 2714 2715 OverloadCandidateSet CandidateSet(DeclLoc); 2716 const UnresolvedSetImpl *Conversions 2717 = T2RecordDecl->getVisibleConversionFunctions(); 2718 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2719 E = Conversions->end(); I != E; ++I) { 2720 NamedDecl *D = *I; 2721 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2722 if (isa<UsingShadowDecl>(D)) 2723 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2724 2725 FunctionTemplateDecl *ConvTemplate 2726 = dyn_cast<FunctionTemplateDecl>(D); 2727 CXXConversionDecl *Conv; 2728 if (ConvTemplate) 2729 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2730 else 2731 Conv = cast<CXXConversionDecl>(D); 2732 2733 // If this is an explicit conversion, and we're not allowed to consider 2734 // explicit conversions, skip it. 2735 if (!AllowExplicit && Conv->isExplicit()) 2736 continue; 2737 2738 if (AllowRvalues) { 2739 bool DerivedToBase = false; 2740 bool ObjCConversion = false; 2741 if (!ConvTemplate && 2742 S.CompareReferenceRelationship(DeclLoc, 2743 Conv->getConversionType().getNonReferenceType().getUnqualifiedType(), 2744 DeclType.getNonReferenceType().getUnqualifiedType(), 2745 DerivedToBase, ObjCConversion) 2746 == Sema::Ref_Incompatible) 2747 continue; 2748 } else { 2749 // If the conversion function doesn't return a reference type, 2750 // it can't be considered for this conversion. An rvalue reference 2751 // is only acceptable if its referencee is a function type. 2752 2753 const ReferenceType *RefType = 2754 Conv->getConversionType()->getAs<ReferenceType>(); 2755 if (!RefType || 2756 (!RefType->isLValueReferenceType() && 2757 !RefType->getPointeeType()->isFunctionType())) 2758 continue; 2759 } 2760 2761 if (ConvTemplate) 2762 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2763 Init, ToType, CandidateSet); 2764 else 2765 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2766 ToType, CandidateSet); 2767 } 2768 2769 OverloadCandidateSet::iterator Best; 2770 switch (CandidateSet.BestViableFunction(S, DeclLoc, Best)) { 2771 case OR_Success: 2772 // C++ [over.ics.ref]p1: 2773 // 2774 // [...] If the parameter binds directly to the result of 2775 // applying a conversion function to the argument 2776 // expression, the implicit conversion sequence is a 2777 // user-defined conversion sequence (13.3.3.1.2), with the 2778 // second standard conversion sequence either an identity 2779 // conversion or, if the conversion function returns an 2780 // entity of a type that is a derived class of the parameter 2781 // type, a derived-to-base Conversion. 2782 if (!Best->FinalConversion.DirectBinding) 2783 return false; 2784 2785 ICS.setUserDefined(); 2786 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2787 ICS.UserDefined.After = Best->FinalConversion; 2788 ICS.UserDefined.ConversionFunction = Best->Function; 2789 ICS.UserDefined.EllipsisConversion = false; 2790 assert(ICS.UserDefined.After.ReferenceBinding && 2791 ICS.UserDefined.After.DirectBinding && 2792 "Expected a direct reference binding!"); 2793 return true; 2794 2795 case OR_Ambiguous: 2796 ICS.setAmbiguous(); 2797 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2798 Cand != CandidateSet.end(); ++Cand) 2799 if (Cand->Viable) 2800 ICS.Ambiguous.addConversion(Cand->Function); 2801 return true; 2802 2803 case OR_No_Viable_Function: 2804 case OR_Deleted: 2805 // There was no suitable conversion, or we found a deleted 2806 // conversion; continue with other checks. 2807 return false; 2808 } 2809 2810 return false; 2811} 2812 2813/// \brief Compute an implicit conversion sequence for reference 2814/// initialization. 2815static ImplicitConversionSequence 2816TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2817 SourceLocation DeclLoc, 2818 bool SuppressUserConversions, 2819 bool AllowExplicit) { 2820 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2821 2822 // Most paths end in a failed conversion. 2823 ImplicitConversionSequence ICS; 2824 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2825 2826 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2827 QualType T2 = Init->getType(); 2828 2829 // If the initializer is the address of an overloaded function, try 2830 // to resolve the overloaded function. If all goes well, T2 is the 2831 // type of the resulting function. 2832 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2833 DeclAccessPair Found; 2834 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2835 false, Found)) 2836 T2 = Fn->getType(); 2837 } 2838 2839 // Compute some basic properties of the types and the initializer. 2840 bool isRValRef = DeclType->isRValueReferenceType(); 2841 bool DerivedToBase = false; 2842 bool ObjCConversion = false; 2843 Expr::Classification InitCategory = Init->Classify(S.Context); 2844 Sema::ReferenceCompareResult RefRelationship 2845 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase, 2846 ObjCConversion); 2847 2848 2849 // C++0x [dcl.init.ref]p5: 2850 // A reference to type "cv1 T1" is initialized by an expression 2851 // of type "cv2 T2" as follows: 2852 2853 // -- If reference is an lvalue reference and the initializer expression 2854 // The next bullet point (T1 is a function) is pretty much equivalent to this 2855 // one, so it's handled here. 2856 if (!isRValRef || T1->isFunctionType()) { 2857 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2858 // reference-compatible with "cv2 T2," or 2859 // 2860 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2861 if (InitCategory.isLValue() && 2862 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2863 // C++ [over.ics.ref]p1: 2864 // When a parameter of reference type binds directly (8.5.3) 2865 // to an argument expression, the implicit conversion sequence 2866 // is the identity conversion, unless the argument expression 2867 // has a type that is a derived class of the parameter type, 2868 // in which case the implicit conversion sequence is a 2869 // derived-to-base Conversion (13.3.3.1). 2870 ICS.setStandard(); 2871 ICS.Standard.First = ICK_Identity; 2872 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 2873 : ObjCConversion? ICK_Compatible_Conversion 2874 : ICK_Identity; 2875 ICS.Standard.Third = ICK_Identity; 2876 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2877 ICS.Standard.setToType(0, T2); 2878 ICS.Standard.setToType(1, T1); 2879 ICS.Standard.setToType(2, T1); 2880 ICS.Standard.ReferenceBinding = true; 2881 ICS.Standard.DirectBinding = true; 2882 ICS.Standard.RRefBinding = isRValRef; 2883 ICS.Standard.CopyConstructor = 0; 2884 2885 // Nothing more to do: the inaccessibility/ambiguity check for 2886 // derived-to-base conversions is suppressed when we're 2887 // computing the implicit conversion sequence (C++ 2888 // [over.best.ics]p2). 2889 return ICS; 2890 } 2891 2892 // -- has a class type (i.e., T2 is a class type), where T1 is 2893 // not reference-related to T2, and can be implicitly 2894 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2895 // is reference-compatible with "cv3 T3" 92) (this 2896 // conversion is selected by enumerating the applicable 2897 // conversion functions (13.3.1.6) and choosing the best 2898 // one through overload resolution (13.3)), 2899 if (!SuppressUserConversions && T2->isRecordType() && 2900 !S.RequireCompleteType(DeclLoc, T2, 0) && 2901 RefRelationship == Sema::Ref_Incompatible) { 2902 if (FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 2903 Init, T2, /*AllowRvalues=*/false, 2904 AllowExplicit)) 2905 return ICS; 2906 } 2907 } 2908 2909 // -- Otherwise, the reference shall be an lvalue reference to a 2910 // non-volatile const type (i.e., cv1 shall be const), or the reference 2911 // shall be an rvalue reference and the initializer expression shall be 2912 // an rvalue or have a function type. 2913 // 2914 // We actually handle one oddity of C++ [over.ics.ref] at this 2915 // point, which is that, due to p2 (which short-circuits reference 2916 // binding by only attempting a simple conversion for non-direct 2917 // bindings) and p3's strange wording, we allow a const volatile 2918 // reference to bind to an rvalue. Hence the check for the presence 2919 // of "const" rather than checking for "const" being the only 2920 // qualifier. 2921 // This is also the point where rvalue references and lvalue inits no longer 2922 // go together. 2923 if ((!isRValRef && !T1.isConstQualified()) || 2924 (isRValRef && InitCategory.isLValue())) 2925 return ICS; 2926 2927 // -- If T1 is a function type, then 2928 // -- if T2 is the same type as T1, the reference is bound to the 2929 // initializer expression lvalue; 2930 // -- if T2 is a class type and the initializer expression can be 2931 // implicitly converted to an lvalue of type T1 [...], the 2932 // reference is bound to the function lvalue that is the result 2933 // of the conversion; 2934 // This is the same as for the lvalue case above, so it was handled there. 2935 // -- otherwise, the program is ill-formed. 2936 // This is the one difference to the lvalue case. 2937 if (T1->isFunctionType()) 2938 return ICS; 2939 2940 // -- Otherwise, if T2 is a class type and 2941 // -- the initializer expression is an rvalue and "cv1 T1" 2942 // is reference-compatible with "cv2 T2," or 2943 // 2944 // -- T1 is not reference-related to T2 and the initializer 2945 // expression can be implicitly converted to an rvalue 2946 // of type "cv3 T3" (this conversion is selected by 2947 // enumerating the applicable conversion functions 2948 // (13.3.1.6) and choosing the best one through overload 2949 // resolution (13.3)), 2950 // 2951 // then the reference is bound to the initializer 2952 // expression rvalue in the first case and to the object 2953 // that is the result of the conversion in the second case 2954 // (or, in either case, to the appropriate base class 2955 // subobject of the object). 2956 if (T2->isRecordType()) { 2957 // First case: "cv1 T1" is reference-compatible with "cv2 T2". This is a 2958 // direct binding in C++0x but not in C++03. 2959 if (InitCategory.isRValue() && 2960 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2961 ICS.setStandard(); 2962 ICS.Standard.First = ICK_Identity; 2963 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base 2964 : ObjCConversion? ICK_Compatible_Conversion 2965 : ICK_Identity; 2966 ICS.Standard.Third = ICK_Identity; 2967 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2968 ICS.Standard.setToType(0, T2); 2969 ICS.Standard.setToType(1, T1); 2970 ICS.Standard.setToType(2, T1); 2971 ICS.Standard.ReferenceBinding = true; 2972 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 2973 ICS.Standard.RRefBinding = isRValRef; 2974 ICS.Standard.CopyConstructor = 0; 2975 return ICS; 2976 } 2977 2978 // Second case: not reference-related. 2979 if (RefRelationship == Sema::Ref_Incompatible && 2980 !S.RequireCompleteType(DeclLoc, T2, 0) && 2981 FindConversionForRefInit(S, ICS, DeclType, DeclLoc, 2982 Init, T2, /*AllowRvalues=*/true, 2983 AllowExplicit)) 2984 return ICS; 2985 } 2986 2987 // -- Otherwise, a temporary of type "cv1 T1" is created and 2988 // initialized from the initializer expression using the 2989 // rules for a non-reference copy initialization (8.5). The 2990 // reference is then bound to the temporary. If T1 is 2991 // reference-related to T2, cv1 must be the same 2992 // cv-qualification as, or greater cv-qualification than, 2993 // cv2; otherwise, the program is ill-formed. 2994 if (RefRelationship == Sema::Ref_Related) { 2995 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2996 // we would be reference-compatible or reference-compatible with 2997 // added qualification. But that wasn't the case, so the reference 2998 // initialization fails. 2999 return ICS; 3000 } 3001 3002 // If at least one of the types is a class type, the types are not 3003 // related, and we aren't allowed any user conversions, the 3004 // reference binding fails. This case is important for breaking 3005 // recursion, since TryImplicitConversion below will attempt to 3006 // create a temporary through the use of a copy constructor. 3007 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 3008 (T1->isRecordType() || T2->isRecordType())) 3009 return ICS; 3010 3011 // C++ [over.ics.ref]p2: 3012 // When a parameter of reference type is not bound directly to 3013 // an argument expression, the conversion sequence is the one 3014 // required to convert the argument expression to the 3015 // underlying type of the reference according to 3016 // 13.3.3.1. Conceptually, this conversion sequence corresponds 3017 // to copy-initializing a temporary of the underlying type with 3018 // the argument expression. Any difference in top-level 3019 // cv-qualification is subsumed by the initialization itself 3020 // and does not constitute a conversion. 3021 ICS = TryImplicitConversion(S, Init, T1, SuppressUserConversions, 3022 /*AllowExplicit=*/false, 3023 /*InOverloadResolution=*/false); 3024 3025 // Of course, that's still a reference binding. 3026 if (ICS.isStandard()) { 3027 ICS.Standard.ReferenceBinding = true; 3028 ICS.Standard.RRefBinding = isRValRef; 3029 } else if (ICS.isUserDefined()) { 3030 ICS.UserDefined.After.ReferenceBinding = true; 3031 ICS.UserDefined.After.RRefBinding = isRValRef; 3032 } 3033 return ICS; 3034} 3035 3036/// TryCopyInitialization - Try to copy-initialize a value of type 3037/// ToType from the expression From. Return the implicit conversion 3038/// sequence required to pass this argument, which may be a bad 3039/// conversion sequence (meaning that the argument cannot be passed to 3040/// a parameter of this type). If @p SuppressUserConversions, then we 3041/// do not permit any user-defined conversion sequences. 3042static ImplicitConversionSequence 3043TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 3044 bool SuppressUserConversions, 3045 bool InOverloadResolution) { 3046 if (ToType->isReferenceType()) 3047 return TryReferenceInit(S, From, ToType, 3048 /*FIXME:*/From->getLocStart(), 3049 SuppressUserConversions, 3050 /*AllowExplicit=*/false); 3051 3052 return TryImplicitConversion(S, From, ToType, 3053 SuppressUserConversions, 3054 /*AllowExplicit=*/false, 3055 InOverloadResolution); 3056} 3057 3058/// TryObjectArgumentInitialization - Try to initialize the object 3059/// parameter of the given member function (@c Method) from the 3060/// expression @p From. 3061static ImplicitConversionSequence 3062TryObjectArgumentInitialization(Sema &S, QualType OrigFromType, 3063 CXXMethodDecl *Method, 3064 CXXRecordDecl *ActingContext) { 3065 QualType ClassType = S.Context.getTypeDeclType(ActingContext); 3066 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 3067 // const volatile object. 3068 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 3069 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 3070 QualType ImplicitParamType = S.Context.getCVRQualifiedType(ClassType, Quals); 3071 3072 // Set up the conversion sequence as a "bad" conversion, to allow us 3073 // to exit early. 3074 ImplicitConversionSequence ICS; 3075 3076 // We need to have an object of class type. 3077 QualType FromType = OrigFromType; 3078 if (const PointerType *PT = FromType->getAs<PointerType>()) 3079 FromType = PT->getPointeeType(); 3080 3081 assert(FromType->isRecordType()); 3082 3083 // The implicit object parameter is has the type "reference to cv X", 3084 // where X is the class of which the function is a member 3085 // (C++ [over.match.funcs]p4). However, when finding an implicit 3086 // conversion sequence for the argument, we are not allowed to 3087 // create temporaries or perform user-defined conversions 3088 // (C++ [over.match.funcs]p5). We perform a simplified version of 3089 // reference binding here, that allows class rvalues to bind to 3090 // non-constant references. 3091 3092 // First check the qualifiers. We don't care about lvalue-vs-rvalue 3093 // with the implicit object parameter (C++ [over.match.funcs]p5). 3094 QualType FromTypeCanon = S.Context.getCanonicalType(FromType); 3095 if (ImplicitParamType.getCVRQualifiers() 3096 != FromTypeCanon.getLocalCVRQualifiers() && 3097 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 3098 ICS.setBad(BadConversionSequence::bad_qualifiers, 3099 OrigFromType, ImplicitParamType); 3100 return ICS; 3101 } 3102 3103 // Check that we have either the same type or a derived type. It 3104 // affects the conversion rank. 3105 QualType ClassTypeCanon = S.Context.getCanonicalType(ClassType); 3106 ImplicitConversionKind SecondKind; 3107 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 3108 SecondKind = ICK_Identity; 3109 } else if (S.IsDerivedFrom(FromType, ClassType)) 3110 SecondKind = ICK_Derived_To_Base; 3111 else { 3112 ICS.setBad(BadConversionSequence::unrelated_class, 3113 FromType, ImplicitParamType); 3114 return ICS; 3115 } 3116 3117 // Success. Mark this as a reference binding. 3118 ICS.setStandard(); 3119 ICS.Standard.setAsIdentityConversion(); 3120 ICS.Standard.Second = SecondKind; 3121 ICS.Standard.setFromType(FromType); 3122 ICS.Standard.setAllToTypes(ImplicitParamType); 3123 ICS.Standard.ReferenceBinding = true; 3124 ICS.Standard.DirectBinding = true; 3125 ICS.Standard.RRefBinding = false; 3126 return ICS; 3127} 3128 3129/// PerformObjectArgumentInitialization - Perform initialization of 3130/// the implicit object parameter for the given Method with the given 3131/// expression. 3132bool 3133Sema::PerformObjectArgumentInitialization(Expr *&From, 3134 NestedNameSpecifier *Qualifier, 3135 NamedDecl *FoundDecl, 3136 CXXMethodDecl *Method) { 3137 QualType FromRecordType, DestType; 3138 QualType ImplicitParamRecordType = 3139 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3140 3141 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3142 FromRecordType = PT->getPointeeType(); 3143 DestType = Method->getThisType(Context); 3144 } else { 3145 FromRecordType = From->getType(); 3146 DestType = ImplicitParamRecordType; 3147 } 3148 3149 // Note that we always use the true parent context when performing 3150 // the actual argument initialization. 3151 ImplicitConversionSequence ICS 3152 = TryObjectArgumentInitialization(*this, From->getType(), Method, 3153 Method->getParent()); 3154 if (ICS.isBad()) 3155 return Diag(From->getSourceRange().getBegin(), 3156 diag::err_implicit_object_parameter_init) 3157 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3158 3159 if (ICS.Standard.Second == ICK_Derived_To_Base) 3160 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3161 3162 if (!Context.hasSameType(From->getType(), DestType)) 3163 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 3164 From->getType()->isPointerType() ? 3165 ImplicitCastExpr::RValue : ImplicitCastExpr::LValue); 3166 return false; 3167} 3168 3169/// TryContextuallyConvertToBool - Attempt to contextually convert the 3170/// expression From to bool (C++0x [conv]p3). 3171static ImplicitConversionSequence 3172TryContextuallyConvertToBool(Sema &S, Expr *From) { 3173 // FIXME: This is pretty broken. 3174 return TryImplicitConversion(S, From, S.Context.BoolTy, 3175 // FIXME: Are these flags correct? 3176 /*SuppressUserConversions=*/false, 3177 /*AllowExplicit=*/true, 3178 /*InOverloadResolution=*/false); 3179} 3180 3181/// PerformContextuallyConvertToBool - Perform a contextual conversion 3182/// of the expression From to bool (C++0x [conv]p3). 3183bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3184 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(*this, From); 3185 if (!ICS.isBad()) 3186 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3187 3188 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3189 return Diag(From->getSourceRange().getBegin(), 3190 diag::err_typecheck_bool_condition) 3191 << From->getType() << From->getSourceRange(); 3192 return true; 3193} 3194 3195/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3196/// expression From to 'id'. 3197static ImplicitConversionSequence 3198TryContextuallyConvertToObjCId(Sema &S, Expr *From) { 3199 QualType Ty = S.Context.getObjCIdType(); 3200 return TryImplicitConversion(S, From, Ty, 3201 // FIXME: Are these flags correct? 3202 /*SuppressUserConversions=*/false, 3203 /*AllowExplicit=*/true, 3204 /*InOverloadResolution=*/false); 3205} 3206 3207/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3208/// of the expression From to 'id'. 3209bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3210 QualType Ty = Context.getObjCIdType(); 3211 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(*this, From); 3212 if (!ICS.isBad()) 3213 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3214 return true; 3215} 3216 3217/// \brief Attempt to convert the given expression to an integral or 3218/// enumeration type. 3219/// 3220/// This routine will attempt to convert an expression of class type to an 3221/// integral or enumeration type, if that class type only has a single 3222/// conversion to an integral or enumeration type. 3223/// 3224/// \param Loc The source location of the construct that requires the 3225/// conversion. 3226/// 3227/// \param FromE The expression we're converting from. 3228/// 3229/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3230/// have integral or enumeration type. 3231/// 3232/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3233/// incomplete class type. 3234/// 3235/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3236/// explicit conversion function (because no implicit conversion functions 3237/// were available). This is a recovery mode. 3238/// 3239/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3240/// showing which conversion was picked. 3241/// 3242/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3243/// conversion function that could convert to integral or enumeration type. 3244/// 3245/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3246/// usable conversion function. 3247/// 3248/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3249/// function, which may be an extension in this case. 3250/// 3251/// \returns The expression, converted to an integral or enumeration type if 3252/// successful. 3253ExprResult 3254Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, Expr *From, 3255 const PartialDiagnostic &NotIntDiag, 3256 const PartialDiagnostic &IncompleteDiag, 3257 const PartialDiagnostic &ExplicitConvDiag, 3258 const PartialDiagnostic &ExplicitConvNote, 3259 const PartialDiagnostic &AmbigDiag, 3260 const PartialDiagnostic &AmbigNote, 3261 const PartialDiagnostic &ConvDiag) { 3262 // We can't perform any more checking for type-dependent expressions. 3263 if (From->isTypeDependent()) 3264 return Owned(From); 3265 3266 // If the expression already has integral or enumeration type, we're golden. 3267 QualType T = From->getType(); 3268 if (T->isIntegralOrEnumerationType()) 3269 return Owned(From); 3270 3271 // FIXME: Check for missing '()' if T is a function type? 3272 3273 // If we don't have a class type in C++, there's no way we can get an 3274 // expression of integral or enumeration type. 3275 const RecordType *RecordTy = T->getAs<RecordType>(); 3276 if (!RecordTy || !getLangOptions().CPlusPlus) { 3277 Diag(Loc, NotIntDiag) 3278 << T << From->getSourceRange(); 3279 return Owned(From); 3280 } 3281 3282 // We must have a complete class type. 3283 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3284 return Owned(From); 3285 3286 // Look for a conversion to an integral or enumeration type. 3287 UnresolvedSet<4> ViableConversions; 3288 UnresolvedSet<4> ExplicitConversions; 3289 const UnresolvedSetImpl *Conversions 3290 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3291 3292 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3293 E = Conversions->end(); 3294 I != E; 3295 ++I) { 3296 if (CXXConversionDecl *Conversion 3297 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3298 if (Conversion->getConversionType().getNonReferenceType() 3299 ->isIntegralOrEnumerationType()) { 3300 if (Conversion->isExplicit()) 3301 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3302 else 3303 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3304 } 3305 } 3306 3307 switch (ViableConversions.size()) { 3308 case 0: 3309 if (ExplicitConversions.size() == 1) { 3310 DeclAccessPair Found = ExplicitConversions[0]; 3311 CXXConversionDecl *Conversion 3312 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3313 3314 // The user probably meant to invoke the given explicit 3315 // conversion; use it. 3316 QualType ConvTy 3317 = Conversion->getConversionType().getNonReferenceType(); 3318 std::string TypeStr; 3319 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3320 3321 Diag(Loc, ExplicitConvDiag) 3322 << T << ConvTy 3323 << FixItHint::CreateInsertion(From->getLocStart(), 3324 "static_cast<" + TypeStr + ">(") 3325 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3326 ")"); 3327 Diag(Conversion->getLocation(), ExplicitConvNote) 3328 << ConvTy->isEnumeralType() << ConvTy; 3329 3330 // If we aren't in a SFINAE context, build a call to the 3331 // explicit conversion function. 3332 if (isSFINAEContext()) 3333 return ExprError(); 3334 3335 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3336 From = BuildCXXMemberCallExpr(From, Found, Conversion); 3337 } 3338 3339 // We'll complain below about a non-integral condition type. 3340 break; 3341 3342 case 1: { 3343 // Apply this conversion. 3344 DeclAccessPair Found = ViableConversions[0]; 3345 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3346 3347 CXXConversionDecl *Conversion 3348 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3349 QualType ConvTy 3350 = Conversion->getConversionType().getNonReferenceType(); 3351 if (ConvDiag.getDiagID()) { 3352 if (isSFINAEContext()) 3353 return ExprError(); 3354 3355 Diag(Loc, ConvDiag) 3356 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 3357 } 3358 3359 From = BuildCXXMemberCallExpr(From, Found, 3360 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3361 break; 3362 } 3363 3364 default: 3365 Diag(Loc, AmbigDiag) 3366 << T << From->getSourceRange(); 3367 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3368 CXXConversionDecl *Conv 3369 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3370 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3371 Diag(Conv->getLocation(), AmbigNote) 3372 << ConvTy->isEnumeralType() << ConvTy; 3373 } 3374 return Owned(From); 3375 } 3376 3377 if (!From->getType()->isIntegralOrEnumerationType()) 3378 Diag(Loc, NotIntDiag) 3379 << From->getType() << From->getSourceRange(); 3380 3381 return Owned(From); 3382} 3383 3384/// AddOverloadCandidate - Adds the given function to the set of 3385/// candidate functions, using the given function call arguments. If 3386/// @p SuppressUserConversions, then don't allow user-defined 3387/// conversions via constructors or conversion operators. 3388/// 3389/// \para PartialOverloading true if we are performing "partial" overloading 3390/// based on an incomplete set of function arguments. This feature is used by 3391/// code completion. 3392void 3393Sema::AddOverloadCandidate(FunctionDecl *Function, 3394 DeclAccessPair FoundDecl, 3395 Expr **Args, unsigned NumArgs, 3396 OverloadCandidateSet& CandidateSet, 3397 bool SuppressUserConversions, 3398 bool PartialOverloading) { 3399 const FunctionProtoType* Proto 3400 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3401 assert(Proto && "Functions without a prototype cannot be overloaded"); 3402 assert(!Function->getDescribedFunctionTemplate() && 3403 "Use AddTemplateOverloadCandidate for function templates"); 3404 3405 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3406 if (!isa<CXXConstructorDecl>(Method)) { 3407 // If we get here, it's because we're calling a member function 3408 // that is named without a member access expression (e.g., 3409 // "this->f") that was either written explicitly or created 3410 // implicitly. This can happen with a qualified call to a member 3411 // function, e.g., X::f(). We use an empty type for the implied 3412 // object argument (C++ [over.call.func]p3), and the acting context 3413 // is irrelevant. 3414 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3415 QualType(), Args, NumArgs, CandidateSet, 3416 SuppressUserConversions); 3417 return; 3418 } 3419 // We treat a constructor like a non-member function, since its object 3420 // argument doesn't participate in overload resolution. 3421 } 3422 3423 if (!CandidateSet.isNewCandidate(Function)) 3424 return; 3425 3426 // Overload resolution is always an unevaluated context. 3427 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3428 3429 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3430 // C++ [class.copy]p3: 3431 // A member function template is never instantiated to perform the copy 3432 // of a class object to an object of its class type. 3433 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3434 if (NumArgs == 1 && 3435 Constructor->isCopyConstructorLikeSpecialization() && 3436 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3437 IsDerivedFrom(Args[0]->getType(), ClassType))) 3438 return; 3439 } 3440 3441 // Add this candidate 3442 CandidateSet.push_back(OverloadCandidate()); 3443 OverloadCandidate& Candidate = CandidateSet.back(); 3444 Candidate.FoundDecl = FoundDecl; 3445 Candidate.Function = Function; 3446 Candidate.Viable = true; 3447 Candidate.IsSurrogate = false; 3448 Candidate.IgnoreObjectArgument = false; 3449 3450 unsigned NumArgsInProto = Proto->getNumArgs(); 3451 3452 // (C++ 13.3.2p2): A candidate function having fewer than m 3453 // parameters is viable only if it has an ellipsis in its parameter 3454 // list (8.3.5). 3455 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3456 !Proto->isVariadic()) { 3457 Candidate.Viable = false; 3458 Candidate.FailureKind = ovl_fail_too_many_arguments; 3459 return; 3460 } 3461 3462 // (C++ 13.3.2p2): A candidate function having more than m parameters 3463 // is viable only if the (m+1)st parameter has a default argument 3464 // (8.3.6). For the purposes of overload resolution, the 3465 // parameter list is truncated on the right, so that there are 3466 // exactly m parameters. 3467 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3468 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3469 // Not enough arguments. 3470 Candidate.Viable = false; 3471 Candidate.FailureKind = ovl_fail_too_few_arguments; 3472 return; 3473 } 3474 3475 // Determine the implicit conversion sequences for each of the 3476 // arguments. 3477 Candidate.Conversions.resize(NumArgs); 3478 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3479 if (ArgIdx < NumArgsInProto) { 3480 // (C++ 13.3.2p3): for F to be a viable function, there shall 3481 // exist for each argument an implicit conversion sequence 3482 // (13.3.3.1) that converts that argument to the corresponding 3483 // parameter of F. 3484 QualType ParamType = Proto->getArgType(ArgIdx); 3485 Candidate.Conversions[ArgIdx] 3486 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3487 SuppressUserConversions, 3488 /*InOverloadResolution=*/true); 3489 if (Candidate.Conversions[ArgIdx].isBad()) { 3490 Candidate.Viable = false; 3491 Candidate.FailureKind = ovl_fail_bad_conversion; 3492 break; 3493 } 3494 } else { 3495 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3496 // argument for which there is no corresponding parameter is 3497 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3498 Candidate.Conversions[ArgIdx].setEllipsis(); 3499 } 3500 } 3501} 3502 3503/// \brief Add all of the function declarations in the given function set to 3504/// the overload canddiate set. 3505void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3506 Expr **Args, unsigned NumArgs, 3507 OverloadCandidateSet& CandidateSet, 3508 bool SuppressUserConversions) { 3509 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3510 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3511 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3512 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3513 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3514 cast<CXXMethodDecl>(FD)->getParent(), 3515 Args[0]->getType(), Args + 1, NumArgs - 1, 3516 CandidateSet, SuppressUserConversions); 3517 else 3518 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3519 SuppressUserConversions); 3520 } else { 3521 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3522 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3523 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3524 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3525 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3526 /*FIXME: explicit args */ 0, 3527 Args[0]->getType(), Args + 1, NumArgs - 1, 3528 CandidateSet, 3529 SuppressUserConversions); 3530 else 3531 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3532 /*FIXME: explicit args */ 0, 3533 Args, NumArgs, CandidateSet, 3534 SuppressUserConversions); 3535 } 3536 } 3537} 3538 3539/// AddMethodCandidate - Adds a named decl (which is some kind of 3540/// method) as a method candidate to the given overload set. 3541void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3542 QualType ObjectType, 3543 Expr **Args, unsigned NumArgs, 3544 OverloadCandidateSet& CandidateSet, 3545 bool SuppressUserConversions) { 3546 NamedDecl *Decl = FoundDecl.getDecl(); 3547 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3548 3549 if (isa<UsingShadowDecl>(Decl)) 3550 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3551 3552 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3553 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3554 "Expected a member function template"); 3555 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3556 /*ExplicitArgs*/ 0, 3557 ObjectType, Args, NumArgs, 3558 CandidateSet, 3559 SuppressUserConversions); 3560 } else { 3561 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3562 ObjectType, Args, NumArgs, 3563 CandidateSet, SuppressUserConversions); 3564 } 3565} 3566 3567/// AddMethodCandidate - Adds the given C++ member function to the set 3568/// of candidate functions, using the given function call arguments 3569/// and the object argument (@c Object). For example, in a call 3570/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3571/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3572/// allow user-defined conversions via constructors or conversion 3573/// operators. 3574void 3575Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3576 CXXRecordDecl *ActingContext, QualType ObjectType, 3577 Expr **Args, unsigned NumArgs, 3578 OverloadCandidateSet& CandidateSet, 3579 bool SuppressUserConversions) { 3580 const FunctionProtoType* Proto 3581 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3582 assert(Proto && "Methods without a prototype cannot be overloaded"); 3583 assert(!isa<CXXConstructorDecl>(Method) && 3584 "Use AddOverloadCandidate for constructors"); 3585 3586 if (!CandidateSet.isNewCandidate(Method)) 3587 return; 3588 3589 // Overload resolution is always an unevaluated context. 3590 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3591 3592 // Add this candidate 3593 CandidateSet.push_back(OverloadCandidate()); 3594 OverloadCandidate& Candidate = CandidateSet.back(); 3595 Candidate.FoundDecl = FoundDecl; 3596 Candidate.Function = Method; 3597 Candidate.IsSurrogate = false; 3598 Candidate.IgnoreObjectArgument = false; 3599 3600 unsigned NumArgsInProto = Proto->getNumArgs(); 3601 3602 // (C++ 13.3.2p2): A candidate function having fewer than m 3603 // parameters is viable only if it has an ellipsis in its parameter 3604 // list (8.3.5). 3605 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3606 Candidate.Viable = false; 3607 Candidate.FailureKind = ovl_fail_too_many_arguments; 3608 return; 3609 } 3610 3611 // (C++ 13.3.2p2): A candidate function having more than m parameters 3612 // is viable only if the (m+1)st parameter has a default argument 3613 // (8.3.6). For the purposes of overload resolution, the 3614 // parameter list is truncated on the right, so that there are 3615 // exactly m parameters. 3616 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3617 if (NumArgs < MinRequiredArgs) { 3618 // Not enough arguments. 3619 Candidate.Viable = false; 3620 Candidate.FailureKind = ovl_fail_too_few_arguments; 3621 return; 3622 } 3623 3624 Candidate.Viable = true; 3625 Candidate.Conversions.resize(NumArgs + 1); 3626 3627 if (Method->isStatic() || ObjectType.isNull()) 3628 // The implicit object argument is ignored. 3629 Candidate.IgnoreObjectArgument = true; 3630 else { 3631 // Determine the implicit conversion sequence for the object 3632 // parameter. 3633 Candidate.Conversions[0] 3634 = TryObjectArgumentInitialization(*this, ObjectType, Method, 3635 ActingContext); 3636 if (Candidate.Conversions[0].isBad()) { 3637 Candidate.Viable = false; 3638 Candidate.FailureKind = ovl_fail_bad_conversion; 3639 return; 3640 } 3641 } 3642 3643 // Determine the implicit conversion sequences for each of the 3644 // arguments. 3645 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3646 if (ArgIdx < NumArgsInProto) { 3647 // (C++ 13.3.2p3): for F to be a viable function, there shall 3648 // exist for each argument an implicit conversion sequence 3649 // (13.3.3.1) that converts that argument to the corresponding 3650 // parameter of F. 3651 QualType ParamType = Proto->getArgType(ArgIdx); 3652 Candidate.Conversions[ArgIdx + 1] 3653 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3654 SuppressUserConversions, 3655 /*InOverloadResolution=*/true); 3656 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3657 Candidate.Viable = false; 3658 Candidate.FailureKind = ovl_fail_bad_conversion; 3659 break; 3660 } 3661 } else { 3662 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3663 // argument for which there is no corresponding parameter is 3664 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3665 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3666 } 3667 } 3668} 3669 3670/// \brief Add a C++ member function template as a candidate to the candidate 3671/// set, using template argument deduction to produce an appropriate member 3672/// function template specialization. 3673void 3674Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3675 DeclAccessPair FoundDecl, 3676 CXXRecordDecl *ActingContext, 3677 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3678 QualType ObjectType, 3679 Expr **Args, unsigned NumArgs, 3680 OverloadCandidateSet& CandidateSet, 3681 bool SuppressUserConversions) { 3682 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3683 return; 3684 3685 // C++ [over.match.funcs]p7: 3686 // In each case where a candidate is a function template, candidate 3687 // function template specializations are generated using template argument 3688 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3689 // candidate functions in the usual way.113) A given name can refer to one 3690 // or more function templates and also to a set of overloaded non-template 3691 // functions. In such a case, the candidate functions generated from each 3692 // function template are combined with the set of non-template candidate 3693 // functions. 3694 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3695 FunctionDecl *Specialization = 0; 3696 if (TemplateDeductionResult Result 3697 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3698 Args, NumArgs, Specialization, Info)) { 3699 CandidateSet.push_back(OverloadCandidate()); 3700 OverloadCandidate &Candidate = CandidateSet.back(); 3701 Candidate.FoundDecl = FoundDecl; 3702 Candidate.Function = MethodTmpl->getTemplatedDecl(); 3703 Candidate.Viable = false; 3704 Candidate.FailureKind = ovl_fail_bad_deduction; 3705 Candidate.IsSurrogate = false; 3706 Candidate.IgnoreObjectArgument = false; 3707 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3708 Info); 3709 return; 3710 } 3711 3712 // Add the function template specialization produced by template argument 3713 // deduction as a candidate. 3714 assert(Specialization && "Missing member function template specialization?"); 3715 assert(isa<CXXMethodDecl>(Specialization) && 3716 "Specialization is not a member function?"); 3717 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3718 ActingContext, ObjectType, Args, NumArgs, 3719 CandidateSet, SuppressUserConversions); 3720} 3721 3722/// \brief Add a C++ function template specialization as a candidate 3723/// in the candidate set, using template argument deduction to produce 3724/// an appropriate function template specialization. 3725void 3726Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3727 DeclAccessPair FoundDecl, 3728 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3729 Expr **Args, unsigned NumArgs, 3730 OverloadCandidateSet& CandidateSet, 3731 bool SuppressUserConversions) { 3732 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3733 return; 3734 3735 // C++ [over.match.funcs]p7: 3736 // In each case where a candidate is a function template, candidate 3737 // function template specializations are generated using template argument 3738 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3739 // candidate functions in the usual way.113) A given name can refer to one 3740 // or more function templates and also to a set of overloaded non-template 3741 // functions. In such a case, the candidate functions generated from each 3742 // function template are combined with the set of non-template candidate 3743 // functions. 3744 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3745 FunctionDecl *Specialization = 0; 3746 if (TemplateDeductionResult Result 3747 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3748 Args, NumArgs, Specialization, Info)) { 3749 CandidateSet.push_back(OverloadCandidate()); 3750 OverloadCandidate &Candidate = CandidateSet.back(); 3751 Candidate.FoundDecl = FoundDecl; 3752 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3753 Candidate.Viable = false; 3754 Candidate.FailureKind = ovl_fail_bad_deduction; 3755 Candidate.IsSurrogate = false; 3756 Candidate.IgnoreObjectArgument = false; 3757 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3758 Info); 3759 return; 3760 } 3761 3762 // Add the function template specialization produced by template argument 3763 // deduction as a candidate. 3764 assert(Specialization && "Missing function template specialization?"); 3765 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3766 SuppressUserConversions); 3767} 3768 3769/// AddConversionCandidate - Add a C++ conversion function as a 3770/// candidate in the candidate set (C++ [over.match.conv], 3771/// C++ [over.match.copy]). From is the expression we're converting from, 3772/// and ToType is the type that we're eventually trying to convert to 3773/// (which may or may not be the same type as the type that the 3774/// conversion function produces). 3775void 3776Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3777 DeclAccessPair FoundDecl, 3778 CXXRecordDecl *ActingContext, 3779 Expr *From, QualType ToType, 3780 OverloadCandidateSet& CandidateSet) { 3781 assert(!Conversion->getDescribedFunctionTemplate() && 3782 "Conversion function templates use AddTemplateConversionCandidate"); 3783 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3784 if (!CandidateSet.isNewCandidate(Conversion)) 3785 return; 3786 3787 // Overload resolution is always an unevaluated context. 3788 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3789 3790 // Add this candidate 3791 CandidateSet.push_back(OverloadCandidate()); 3792 OverloadCandidate& Candidate = CandidateSet.back(); 3793 Candidate.FoundDecl = FoundDecl; 3794 Candidate.Function = Conversion; 3795 Candidate.IsSurrogate = false; 3796 Candidate.IgnoreObjectArgument = false; 3797 Candidate.FinalConversion.setAsIdentityConversion(); 3798 Candidate.FinalConversion.setFromType(ConvType); 3799 Candidate.FinalConversion.setAllToTypes(ToType); 3800 Candidate.Viable = true; 3801 Candidate.Conversions.resize(1); 3802 3803 // C++ [over.match.funcs]p4: 3804 // For conversion functions, the function is considered to be a member of 3805 // the class of the implicit implied object argument for the purpose of 3806 // defining the type of the implicit object parameter. 3807 // 3808 // Determine the implicit conversion sequence for the implicit 3809 // object parameter. 3810 QualType ImplicitParamType = From->getType(); 3811 if (const PointerType *FromPtrType = ImplicitParamType->getAs<PointerType>()) 3812 ImplicitParamType = FromPtrType->getPointeeType(); 3813 CXXRecordDecl *ConversionContext 3814 = cast<CXXRecordDecl>(ImplicitParamType->getAs<RecordType>()->getDecl()); 3815 3816 Candidate.Conversions[0] 3817 = TryObjectArgumentInitialization(*this, From->getType(), Conversion, 3818 ConversionContext); 3819 3820 if (Candidate.Conversions[0].isBad()) { 3821 Candidate.Viable = false; 3822 Candidate.FailureKind = ovl_fail_bad_conversion; 3823 return; 3824 } 3825 3826 // We won't go through a user-define type conversion function to convert a 3827 // derived to base as such conversions are given Conversion Rank. They only 3828 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3829 QualType FromCanon 3830 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3831 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3832 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3833 Candidate.Viable = false; 3834 Candidate.FailureKind = ovl_fail_trivial_conversion; 3835 return; 3836 } 3837 3838 // To determine what the conversion from the result of calling the 3839 // conversion function to the type we're eventually trying to 3840 // convert to (ToType), we need to synthesize a call to the 3841 // conversion function and attempt copy initialization from it. This 3842 // makes sure that we get the right semantics with respect to 3843 // lvalues/rvalues and the type. Fortunately, we can allocate this 3844 // call on the stack and we don't need its arguments to be 3845 // well-formed. 3846 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3847 From->getLocStart()); 3848 ImplicitCastExpr ConversionFn(ImplicitCastExpr::OnStack, 3849 Context.getPointerType(Conversion->getType()), 3850 CastExpr::CK_FunctionToPointerDecay, 3851 &ConversionRef, ImplicitCastExpr::RValue); 3852 3853 // Note that it is safe to allocate CallExpr on the stack here because 3854 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3855 // allocator). 3856 CallExpr Call(Context, &ConversionFn, 0, 0, 3857 Conversion->getConversionType().getNonLValueExprType(Context), 3858 From->getLocStart()); 3859 ImplicitConversionSequence ICS = 3860 TryCopyInitialization(*this, &Call, ToType, 3861 /*SuppressUserConversions=*/true, 3862 /*InOverloadResolution=*/false); 3863 3864 switch (ICS.getKind()) { 3865 case ImplicitConversionSequence::StandardConversion: 3866 Candidate.FinalConversion = ICS.Standard; 3867 3868 // C++ [over.ics.user]p3: 3869 // If the user-defined conversion is specified by a specialization of a 3870 // conversion function template, the second standard conversion sequence 3871 // shall have exact match rank. 3872 if (Conversion->getPrimaryTemplate() && 3873 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3874 Candidate.Viable = false; 3875 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3876 } 3877 3878 break; 3879 3880 case ImplicitConversionSequence::BadConversion: 3881 Candidate.Viable = false; 3882 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3883 break; 3884 3885 default: 3886 assert(false && 3887 "Can only end up with a standard conversion sequence or failure"); 3888 } 3889} 3890 3891/// \brief Adds a conversion function template specialization 3892/// candidate to the overload set, using template argument deduction 3893/// to deduce the template arguments of the conversion function 3894/// template from the type that we are converting to (C++ 3895/// [temp.deduct.conv]). 3896void 3897Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3898 DeclAccessPair FoundDecl, 3899 CXXRecordDecl *ActingDC, 3900 Expr *From, QualType ToType, 3901 OverloadCandidateSet &CandidateSet) { 3902 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3903 "Only conversion function templates permitted here"); 3904 3905 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3906 return; 3907 3908 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3909 CXXConversionDecl *Specialization = 0; 3910 if (TemplateDeductionResult Result 3911 = DeduceTemplateArguments(FunctionTemplate, ToType, 3912 Specialization, Info)) { 3913 CandidateSet.push_back(OverloadCandidate()); 3914 OverloadCandidate &Candidate = CandidateSet.back(); 3915 Candidate.FoundDecl = FoundDecl; 3916 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3917 Candidate.Viable = false; 3918 Candidate.FailureKind = ovl_fail_bad_deduction; 3919 Candidate.IsSurrogate = false; 3920 Candidate.IgnoreObjectArgument = false; 3921 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3922 Info); 3923 return; 3924 } 3925 3926 // Add the conversion function template specialization produced by 3927 // template argument deduction as a candidate. 3928 assert(Specialization && "Missing function template specialization?"); 3929 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3930 CandidateSet); 3931} 3932 3933/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3934/// converts the given @c Object to a function pointer via the 3935/// conversion function @c Conversion, and then attempts to call it 3936/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3937/// the type of function that we'll eventually be calling. 3938void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3939 DeclAccessPair FoundDecl, 3940 CXXRecordDecl *ActingContext, 3941 const FunctionProtoType *Proto, 3942 QualType ObjectType, 3943 Expr **Args, unsigned NumArgs, 3944 OverloadCandidateSet& CandidateSet) { 3945 if (!CandidateSet.isNewCandidate(Conversion)) 3946 return; 3947 3948 // Overload resolution is always an unevaluated context. 3949 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3950 3951 CandidateSet.push_back(OverloadCandidate()); 3952 OverloadCandidate& Candidate = CandidateSet.back(); 3953 Candidate.FoundDecl = FoundDecl; 3954 Candidate.Function = 0; 3955 Candidate.Surrogate = Conversion; 3956 Candidate.Viable = true; 3957 Candidate.IsSurrogate = true; 3958 Candidate.IgnoreObjectArgument = false; 3959 Candidate.Conversions.resize(NumArgs + 1); 3960 3961 // Determine the implicit conversion sequence for the implicit 3962 // object parameter. 3963 ImplicitConversionSequence ObjectInit 3964 = TryObjectArgumentInitialization(*this, ObjectType, Conversion, 3965 ActingContext); 3966 if (ObjectInit.isBad()) { 3967 Candidate.Viable = false; 3968 Candidate.FailureKind = ovl_fail_bad_conversion; 3969 Candidate.Conversions[0] = ObjectInit; 3970 return; 3971 } 3972 3973 // The first conversion is actually a user-defined conversion whose 3974 // first conversion is ObjectInit's standard conversion (which is 3975 // effectively a reference binding). Record it as such. 3976 Candidate.Conversions[0].setUserDefined(); 3977 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3978 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3979 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3980 Candidate.Conversions[0].UserDefined.After 3981 = Candidate.Conversions[0].UserDefined.Before; 3982 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3983 3984 // Find the 3985 unsigned NumArgsInProto = Proto->getNumArgs(); 3986 3987 // (C++ 13.3.2p2): A candidate function having fewer than m 3988 // parameters is viable only if it has an ellipsis in its parameter 3989 // list (8.3.5). 3990 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3991 Candidate.Viable = false; 3992 Candidate.FailureKind = ovl_fail_too_many_arguments; 3993 return; 3994 } 3995 3996 // Function types don't have any default arguments, so just check if 3997 // we have enough arguments. 3998 if (NumArgs < NumArgsInProto) { 3999 // Not enough arguments. 4000 Candidate.Viable = false; 4001 Candidate.FailureKind = ovl_fail_too_few_arguments; 4002 return; 4003 } 4004 4005 // Determine the implicit conversion sequences for each of the 4006 // arguments. 4007 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4008 if (ArgIdx < NumArgsInProto) { 4009 // (C++ 13.3.2p3): for F to be a viable function, there shall 4010 // exist for each argument an implicit conversion sequence 4011 // (13.3.3.1) that converts that argument to the corresponding 4012 // parameter of F. 4013 QualType ParamType = Proto->getArgType(ArgIdx); 4014 Candidate.Conversions[ArgIdx + 1] 4015 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 4016 /*SuppressUserConversions=*/false, 4017 /*InOverloadResolution=*/false); 4018 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 4019 Candidate.Viable = false; 4020 Candidate.FailureKind = ovl_fail_bad_conversion; 4021 break; 4022 } 4023 } else { 4024 // (C++ 13.3.2p2): For the purposes of overload resolution, any 4025 // argument for which there is no corresponding parameter is 4026 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 4027 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 4028 } 4029 } 4030} 4031 4032/// \brief Add overload candidates for overloaded operators that are 4033/// member functions. 4034/// 4035/// Add the overloaded operator candidates that are member functions 4036/// for the operator Op that was used in an operator expression such 4037/// as "x Op y". , Args/NumArgs provides the operator arguments, and 4038/// CandidateSet will store the added overload candidates. (C++ 4039/// [over.match.oper]). 4040void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 4041 SourceLocation OpLoc, 4042 Expr **Args, unsigned NumArgs, 4043 OverloadCandidateSet& CandidateSet, 4044 SourceRange OpRange) { 4045 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 4046 4047 // C++ [over.match.oper]p3: 4048 // For a unary operator @ with an operand of a type whose 4049 // cv-unqualified version is T1, and for a binary operator @ with 4050 // a left operand of a type whose cv-unqualified version is T1 and 4051 // a right operand of a type whose cv-unqualified version is T2, 4052 // three sets of candidate functions, designated member 4053 // candidates, non-member candidates and built-in candidates, are 4054 // constructed as follows: 4055 QualType T1 = Args[0]->getType(); 4056 4057 // -- If T1 is a class type, the set of member candidates is the 4058 // result of the qualified lookup of T1::operator@ 4059 // (13.3.1.1.1); otherwise, the set of member candidates is 4060 // empty. 4061 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 4062 // Complete the type if it can be completed. Otherwise, we're done. 4063 if (RequireCompleteType(OpLoc, T1, PDiag())) 4064 return; 4065 4066 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 4067 LookupQualifiedName(Operators, T1Rec->getDecl()); 4068 Operators.suppressDiagnostics(); 4069 4070 for (LookupResult::iterator Oper = Operators.begin(), 4071 OperEnd = Operators.end(); 4072 Oper != OperEnd; 4073 ++Oper) 4074 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 4075 Args + 1, NumArgs - 1, CandidateSet, 4076 /* SuppressUserConversions = */ false); 4077 } 4078} 4079 4080/// AddBuiltinCandidate - Add a candidate for a built-in 4081/// operator. ResultTy and ParamTys are the result and parameter types 4082/// of the built-in candidate, respectively. Args and NumArgs are the 4083/// arguments being passed to the candidate. IsAssignmentOperator 4084/// should be true when this built-in candidate is an assignment 4085/// operator. NumContextualBoolArguments is the number of arguments 4086/// (at the beginning of the argument list) that will be contextually 4087/// converted to bool. 4088void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 4089 Expr **Args, unsigned NumArgs, 4090 OverloadCandidateSet& CandidateSet, 4091 bool IsAssignmentOperator, 4092 unsigned NumContextualBoolArguments) { 4093 // Overload resolution is always an unevaluated context. 4094 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 4095 4096 // Add this candidate 4097 CandidateSet.push_back(OverloadCandidate()); 4098 OverloadCandidate& Candidate = CandidateSet.back(); 4099 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 4100 Candidate.Function = 0; 4101 Candidate.IsSurrogate = false; 4102 Candidate.IgnoreObjectArgument = false; 4103 Candidate.BuiltinTypes.ResultTy = ResultTy; 4104 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4105 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 4106 4107 // Determine the implicit conversion sequences for each of the 4108 // arguments. 4109 Candidate.Viable = true; 4110 Candidate.Conversions.resize(NumArgs); 4111 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 4112 // C++ [over.match.oper]p4: 4113 // For the built-in assignment operators, conversions of the 4114 // left operand are restricted as follows: 4115 // -- no temporaries are introduced to hold the left operand, and 4116 // -- no user-defined conversions are applied to the left 4117 // operand to achieve a type match with the left-most 4118 // parameter of a built-in candidate. 4119 // 4120 // We block these conversions by turning off user-defined 4121 // conversions, since that is the only way that initialization of 4122 // a reference to a non-class type can occur from something that 4123 // is not of the same type. 4124 if (ArgIdx < NumContextualBoolArguments) { 4125 assert(ParamTys[ArgIdx] == Context.BoolTy && 4126 "Contextual conversion to bool requires bool type"); 4127 Candidate.Conversions[ArgIdx] 4128 = TryContextuallyConvertToBool(*this, Args[ArgIdx]); 4129 } else { 4130 Candidate.Conversions[ArgIdx] 4131 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4132 ArgIdx == 0 && IsAssignmentOperator, 4133 /*InOverloadResolution=*/false); 4134 } 4135 if (Candidate.Conversions[ArgIdx].isBad()) { 4136 Candidate.Viable = false; 4137 Candidate.FailureKind = ovl_fail_bad_conversion; 4138 break; 4139 } 4140 } 4141} 4142 4143/// BuiltinCandidateTypeSet - A set of types that will be used for the 4144/// candidate operator functions for built-in operators (C++ 4145/// [over.built]). The types are separated into pointer types and 4146/// enumeration types. 4147class BuiltinCandidateTypeSet { 4148 /// TypeSet - A set of types. 4149 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4150 4151 /// PointerTypes - The set of pointer types that will be used in the 4152 /// built-in candidates. 4153 TypeSet PointerTypes; 4154 4155 /// MemberPointerTypes - The set of member pointer types that will be 4156 /// used in the built-in candidates. 4157 TypeSet MemberPointerTypes; 4158 4159 /// EnumerationTypes - The set of enumeration types that will be 4160 /// used in the built-in candidates. 4161 TypeSet EnumerationTypes; 4162 4163 /// \brief The set of vector types that will be used in the built-in 4164 /// candidates. 4165 TypeSet VectorTypes; 4166 4167 /// Sema - The semantic analysis instance where we are building the 4168 /// candidate type set. 4169 Sema &SemaRef; 4170 4171 /// Context - The AST context in which we will build the type sets. 4172 ASTContext &Context; 4173 4174 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4175 const Qualifiers &VisibleQuals); 4176 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4177 4178public: 4179 /// iterator - Iterates through the types that are part of the set. 4180 typedef TypeSet::iterator iterator; 4181 4182 BuiltinCandidateTypeSet(Sema &SemaRef) 4183 : SemaRef(SemaRef), Context(SemaRef.Context) { } 4184 4185 void AddTypesConvertedFrom(QualType Ty, 4186 SourceLocation Loc, 4187 bool AllowUserConversions, 4188 bool AllowExplicitConversions, 4189 const Qualifiers &VisibleTypeConversionsQuals); 4190 4191 /// pointer_begin - First pointer type found; 4192 iterator pointer_begin() { return PointerTypes.begin(); } 4193 4194 /// pointer_end - Past the last pointer type found; 4195 iterator pointer_end() { return PointerTypes.end(); } 4196 4197 /// member_pointer_begin - First member pointer type found; 4198 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4199 4200 /// member_pointer_end - Past the last member pointer type found; 4201 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4202 4203 /// enumeration_begin - First enumeration type found; 4204 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4205 4206 /// enumeration_end - Past the last enumeration type found; 4207 iterator enumeration_end() { return EnumerationTypes.end(); } 4208 4209 iterator vector_begin() { return VectorTypes.begin(); } 4210 iterator vector_end() { return VectorTypes.end(); } 4211}; 4212 4213/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4214/// the set of pointer types along with any more-qualified variants of 4215/// that type. For example, if @p Ty is "int const *", this routine 4216/// will add "int const *", "int const volatile *", "int const 4217/// restrict *", and "int const volatile restrict *" to the set of 4218/// pointer types. Returns true if the add of @p Ty itself succeeded, 4219/// false otherwise. 4220/// 4221/// FIXME: what to do about extended qualifiers? 4222bool 4223BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4224 const Qualifiers &VisibleQuals) { 4225 4226 // Insert this type. 4227 if (!PointerTypes.insert(Ty)) 4228 return false; 4229 4230 QualType PointeeTy; 4231 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4232 bool buildObjCPtr = false; 4233 if (!PointerTy) { 4234 if (const ObjCObjectPointerType *PTy = Ty->getAs<ObjCObjectPointerType>()) { 4235 PointeeTy = PTy->getPointeeType(); 4236 buildObjCPtr = true; 4237 } 4238 else 4239 assert(false && "type was not a pointer type!"); 4240 } 4241 else 4242 PointeeTy = PointerTy->getPointeeType(); 4243 4244 // Don't add qualified variants of arrays. For one, they're not allowed 4245 // (the qualifier would sink to the element type), and for another, the 4246 // only overload situation where it matters is subscript or pointer +- int, 4247 // and those shouldn't have qualifier variants anyway. 4248 if (PointeeTy->isArrayType()) 4249 return true; 4250 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4251 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4252 BaseCVR = Array->getElementType().getCVRQualifiers(); 4253 bool hasVolatile = VisibleQuals.hasVolatile(); 4254 bool hasRestrict = VisibleQuals.hasRestrict(); 4255 4256 // Iterate through all strict supersets of BaseCVR. 4257 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4258 if ((CVR | BaseCVR) != CVR) continue; 4259 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4260 // in the types. 4261 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4262 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4263 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4264 if (!buildObjCPtr) 4265 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4266 else 4267 PointerTypes.insert(Context.getObjCObjectPointerType(QPointeeTy)); 4268 } 4269 4270 return true; 4271} 4272 4273/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4274/// to the set of pointer types along with any more-qualified variants of 4275/// that type. For example, if @p Ty is "int const *", this routine 4276/// will add "int const *", "int const volatile *", "int const 4277/// restrict *", and "int const volatile restrict *" to the set of 4278/// pointer types. Returns true if the add of @p Ty itself succeeded, 4279/// false otherwise. 4280/// 4281/// FIXME: what to do about extended qualifiers? 4282bool 4283BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4284 QualType Ty) { 4285 // Insert this type. 4286 if (!MemberPointerTypes.insert(Ty)) 4287 return false; 4288 4289 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4290 assert(PointerTy && "type was not a member pointer type!"); 4291 4292 QualType PointeeTy = PointerTy->getPointeeType(); 4293 // Don't add qualified variants of arrays. For one, they're not allowed 4294 // (the qualifier would sink to the element type), and for another, the 4295 // only overload situation where it matters is subscript or pointer +- int, 4296 // and those shouldn't have qualifier variants anyway. 4297 if (PointeeTy->isArrayType()) 4298 return true; 4299 const Type *ClassTy = PointerTy->getClass(); 4300 4301 // Iterate through all strict supersets of the pointee type's CVR 4302 // qualifiers. 4303 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4304 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4305 if ((CVR | BaseCVR) != CVR) continue; 4306 4307 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4308 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 4309 } 4310 4311 return true; 4312} 4313 4314/// AddTypesConvertedFrom - Add each of the types to which the type @p 4315/// Ty can be implicit converted to the given set of @p Types. We're 4316/// primarily interested in pointer types and enumeration types. We also 4317/// take member pointer types, for the conditional operator. 4318/// AllowUserConversions is true if we should look at the conversion 4319/// functions of a class type, and AllowExplicitConversions if we 4320/// should also include the explicit conversion functions of a class 4321/// type. 4322void 4323BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4324 SourceLocation Loc, 4325 bool AllowUserConversions, 4326 bool AllowExplicitConversions, 4327 const Qualifiers &VisibleQuals) { 4328 // Only deal with canonical types. 4329 Ty = Context.getCanonicalType(Ty); 4330 4331 // Look through reference types; they aren't part of the type of an 4332 // expression for the purposes of conversions. 4333 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4334 Ty = RefTy->getPointeeType(); 4335 4336 // We don't care about qualifiers on the type. 4337 Ty = Ty.getLocalUnqualifiedType(); 4338 4339 // If we're dealing with an array type, decay to the pointer. 4340 if (Ty->isArrayType()) 4341 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4342 if (Ty->isObjCIdType() || Ty->isObjCClassType()) 4343 PointerTypes.insert(Ty); 4344 else if (Ty->getAs<PointerType>() || Ty->getAs<ObjCObjectPointerType>()) { 4345 // Insert our type, and its more-qualified variants, into the set 4346 // of types. 4347 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4348 return; 4349 } else if (Ty->isMemberPointerType()) { 4350 // Member pointers are far easier, since the pointee can't be converted. 4351 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4352 return; 4353 } else if (Ty->isEnumeralType()) { 4354 EnumerationTypes.insert(Ty); 4355 } else if (Ty->isVectorType()) { 4356 VectorTypes.insert(Ty); 4357 } else if (AllowUserConversions) { 4358 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 4359 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 4360 // No conversion functions in incomplete types. 4361 return; 4362 } 4363 4364 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4365 const UnresolvedSetImpl *Conversions 4366 = ClassDecl->getVisibleConversionFunctions(); 4367 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4368 E = Conversions->end(); I != E; ++I) { 4369 NamedDecl *D = I.getDecl(); 4370 if (isa<UsingShadowDecl>(D)) 4371 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4372 4373 // Skip conversion function templates; they don't tell us anything 4374 // about which builtin types we can convert to. 4375 if (isa<FunctionTemplateDecl>(D)) 4376 continue; 4377 4378 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4379 if (AllowExplicitConversions || !Conv->isExplicit()) { 4380 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4381 VisibleQuals); 4382 } 4383 } 4384 } 4385 } 4386} 4387 4388/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4389/// the volatile- and non-volatile-qualified assignment operators for the 4390/// given type to the candidate set. 4391static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4392 QualType T, 4393 Expr **Args, 4394 unsigned NumArgs, 4395 OverloadCandidateSet &CandidateSet) { 4396 QualType ParamTypes[2]; 4397 4398 // T& operator=(T&, T) 4399 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4400 ParamTypes[1] = T; 4401 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4402 /*IsAssignmentOperator=*/true); 4403 4404 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4405 // volatile T& operator=(volatile T&, T) 4406 ParamTypes[0] 4407 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4408 ParamTypes[1] = T; 4409 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4410 /*IsAssignmentOperator=*/true); 4411 } 4412} 4413 4414/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4415/// if any, found in visible type conversion functions found in ArgExpr's type. 4416static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4417 Qualifiers VRQuals; 4418 const RecordType *TyRec; 4419 if (const MemberPointerType *RHSMPType = 4420 ArgExpr->getType()->getAs<MemberPointerType>()) 4421 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4422 else 4423 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4424 if (!TyRec) { 4425 // Just to be safe, assume the worst case. 4426 VRQuals.addVolatile(); 4427 VRQuals.addRestrict(); 4428 return VRQuals; 4429 } 4430 4431 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4432 if (!ClassDecl->hasDefinition()) 4433 return VRQuals; 4434 4435 const UnresolvedSetImpl *Conversions = 4436 ClassDecl->getVisibleConversionFunctions(); 4437 4438 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4439 E = Conversions->end(); I != E; ++I) { 4440 NamedDecl *D = I.getDecl(); 4441 if (isa<UsingShadowDecl>(D)) 4442 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4443 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4444 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4445 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4446 CanTy = ResTypeRef->getPointeeType(); 4447 // Need to go down the pointer/mempointer chain and add qualifiers 4448 // as see them. 4449 bool done = false; 4450 while (!done) { 4451 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4452 CanTy = ResTypePtr->getPointeeType(); 4453 else if (const MemberPointerType *ResTypeMPtr = 4454 CanTy->getAs<MemberPointerType>()) 4455 CanTy = ResTypeMPtr->getPointeeType(); 4456 else 4457 done = true; 4458 if (CanTy.isVolatileQualified()) 4459 VRQuals.addVolatile(); 4460 if (CanTy.isRestrictQualified()) 4461 VRQuals.addRestrict(); 4462 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4463 return VRQuals; 4464 } 4465 } 4466 } 4467 return VRQuals; 4468} 4469 4470/// AddBuiltinOperatorCandidates - Add the appropriate built-in 4471/// operator overloads to the candidate set (C++ [over.built]), based 4472/// on the operator @p Op and the arguments given. For example, if the 4473/// operator is a binary '+', this routine might add "int 4474/// operator+(int, int)" to cover integer addition. 4475void 4476Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 4477 SourceLocation OpLoc, 4478 Expr **Args, unsigned NumArgs, 4479 OverloadCandidateSet& CandidateSet) { 4480 // The set of "promoted arithmetic types", which are the arithmetic 4481 // types are that preserved by promotion (C++ [over.built]p2). Note 4482 // that the first few of these types are the promoted integral 4483 // types; these types need to be first. 4484 // FIXME: What about complex? 4485 const unsigned FirstIntegralType = 0; 4486 const unsigned LastIntegralType = 13; 4487 const unsigned FirstPromotedIntegralType = 7, 4488 LastPromotedIntegralType = 13; 4489 const unsigned FirstPromotedArithmeticType = 7, 4490 LastPromotedArithmeticType = 16; 4491 const unsigned NumArithmeticTypes = 16; 4492 QualType ArithmeticTypes[NumArithmeticTypes] = { 4493 Context.BoolTy, Context.CharTy, Context.WCharTy, 4494// FIXME: Context.Char16Ty, Context.Char32Ty, 4495 Context.SignedCharTy, Context.ShortTy, 4496 Context.UnsignedCharTy, Context.UnsignedShortTy, 4497 Context.IntTy, Context.LongTy, Context.LongLongTy, 4498 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 4499 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 4500 }; 4501 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 4502 "Invalid first promoted integral type"); 4503 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 4504 == Context.UnsignedLongLongTy && 4505 "Invalid last promoted integral type"); 4506 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 4507 "Invalid first promoted arithmetic type"); 4508 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 4509 == Context.LongDoubleTy && 4510 "Invalid last promoted arithmetic type"); 4511 4512 // Find all of the types that the arguments can convert to, but only 4513 // if the operator we're looking at has built-in operator candidates 4514 // that make use of these types. 4515 Qualifiers VisibleTypeConversionsQuals; 4516 VisibleTypeConversionsQuals.addConst(); 4517 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4518 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 4519 4520 BuiltinCandidateTypeSet CandidateTypes(*this); 4521 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4522 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 4523 OpLoc, 4524 true, 4525 (Op == OO_Exclaim || 4526 Op == OO_AmpAmp || 4527 Op == OO_PipePipe), 4528 VisibleTypeConversionsQuals); 4529 4530 bool isComparison = false; 4531 switch (Op) { 4532 case OO_None: 4533 case NUM_OVERLOADED_OPERATORS: 4534 assert(false && "Expected an overloaded operator"); 4535 break; 4536 4537 case OO_Star: // '*' is either unary or binary 4538 if (NumArgs == 1) 4539 goto UnaryStar; 4540 else 4541 goto BinaryStar; 4542 break; 4543 4544 case OO_Plus: // '+' is either unary or binary 4545 if (NumArgs == 1) 4546 goto UnaryPlus; 4547 else 4548 goto BinaryPlus; 4549 break; 4550 4551 case OO_Minus: // '-' is either unary or binary 4552 if (NumArgs == 1) 4553 goto UnaryMinus; 4554 else 4555 goto BinaryMinus; 4556 break; 4557 4558 case OO_Amp: // '&' is either unary or binary 4559 if (NumArgs == 1) 4560 goto UnaryAmp; 4561 else 4562 goto BinaryAmp; 4563 4564 case OO_PlusPlus: 4565 case OO_MinusMinus: 4566 // C++ [over.built]p3: 4567 // 4568 // For every pair (T, VQ), where T is an arithmetic type, and VQ 4569 // is either volatile or empty, there exist candidate operator 4570 // functions of the form 4571 // 4572 // VQ T& operator++(VQ T&); 4573 // T operator++(VQ T&, int); 4574 // 4575 // C++ [over.built]p4: 4576 // 4577 // For every pair (T, VQ), where T is an arithmetic type other 4578 // than bool, and VQ is either volatile or empty, there exist 4579 // candidate operator functions of the form 4580 // 4581 // VQ T& operator--(VQ T&); 4582 // T operator--(VQ T&, int); 4583 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 4584 Arith < NumArithmeticTypes; ++Arith) { 4585 QualType ArithTy = ArithmeticTypes[Arith]; 4586 QualType ParamTypes[2] 4587 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 4588 4589 // Non-volatile version. 4590 if (NumArgs == 1) 4591 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4592 else 4593 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4594 // heuristic to reduce number of builtin candidates in the set. 4595 // Add volatile version only if there are conversions to a volatile type. 4596 if (VisibleTypeConversionsQuals.hasVolatile()) { 4597 // Volatile version 4598 ParamTypes[0] 4599 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 4600 if (NumArgs == 1) 4601 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4602 else 4603 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4604 } 4605 } 4606 4607 // C++ [over.built]p5: 4608 // 4609 // For every pair (T, VQ), where T is a cv-qualified or 4610 // cv-unqualified object type, and VQ is either volatile or 4611 // empty, there exist candidate operator functions of the form 4612 // 4613 // T*VQ& operator++(T*VQ&); 4614 // T*VQ& operator--(T*VQ&); 4615 // T* operator++(T*VQ&, int); 4616 // T* operator--(T*VQ&, int); 4617 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4618 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4619 // Skip pointer types that aren't pointers to object types. 4620 if (!(*Ptr)->getPointeeType()->isIncompleteOrObjectType()) 4621 continue; 4622 4623 QualType ParamTypes[2] = { 4624 Context.getLValueReferenceType(*Ptr), Context.IntTy 4625 }; 4626 4627 // Without volatile 4628 if (NumArgs == 1) 4629 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4630 else 4631 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4632 4633 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4634 VisibleTypeConversionsQuals.hasVolatile()) { 4635 // With volatile 4636 ParamTypes[0] 4637 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4638 if (NumArgs == 1) 4639 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4640 else 4641 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4642 } 4643 } 4644 break; 4645 4646 UnaryStar: 4647 // C++ [over.built]p6: 4648 // For every cv-qualified or cv-unqualified object type T, there 4649 // exist candidate operator functions of the form 4650 // 4651 // T& operator*(T*); 4652 // 4653 // C++ [over.built]p7: 4654 // For every function type T, there exist candidate operator 4655 // functions of the form 4656 // T& operator*(T*); 4657 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4658 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4659 QualType ParamTy = *Ptr; 4660 QualType PointeeTy = ParamTy->getPointeeType(); 4661 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 4662 &ParamTy, Args, 1, CandidateSet); 4663 } 4664 break; 4665 4666 UnaryPlus: 4667 // C++ [over.built]p8: 4668 // For every type T, there exist candidate operator functions of 4669 // the form 4670 // 4671 // T* operator+(T*); 4672 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4673 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4674 QualType ParamTy = *Ptr; 4675 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4676 } 4677 4678 // Fall through 4679 4680 UnaryMinus: 4681 // C++ [over.built]p9: 4682 // For every promoted arithmetic type T, there exist candidate 4683 // operator functions of the form 4684 // 4685 // T operator+(T); 4686 // T operator-(T); 4687 for (unsigned Arith = FirstPromotedArithmeticType; 4688 Arith < LastPromotedArithmeticType; ++Arith) { 4689 QualType ArithTy = ArithmeticTypes[Arith]; 4690 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4691 } 4692 4693 // Extension: We also add these operators for vector types. 4694 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4695 VecEnd = CandidateTypes.vector_end(); 4696 Vec != VecEnd; ++Vec) { 4697 QualType VecTy = *Vec; 4698 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4699 } 4700 break; 4701 4702 case OO_Tilde: 4703 // C++ [over.built]p10: 4704 // For every promoted integral type T, there exist candidate 4705 // operator functions of the form 4706 // 4707 // T operator~(T); 4708 for (unsigned Int = FirstPromotedIntegralType; 4709 Int < LastPromotedIntegralType; ++Int) { 4710 QualType IntTy = ArithmeticTypes[Int]; 4711 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4712 } 4713 4714 // Extension: We also add this operator for vector types. 4715 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4716 VecEnd = CandidateTypes.vector_end(); 4717 Vec != VecEnd; ++Vec) { 4718 QualType VecTy = *Vec; 4719 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4720 } 4721 break; 4722 4723 case OO_New: 4724 case OO_Delete: 4725 case OO_Array_New: 4726 case OO_Array_Delete: 4727 case OO_Call: 4728 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 4729 break; 4730 4731 case OO_Comma: 4732 UnaryAmp: 4733 case OO_Arrow: 4734 // C++ [over.match.oper]p3: 4735 // -- For the operator ',', the unary operator '&', or the 4736 // operator '->', the built-in candidates set is empty. 4737 break; 4738 4739 case OO_EqualEqual: 4740 case OO_ExclaimEqual: 4741 // C++ [over.match.oper]p16: 4742 // For every pointer to member type T, there exist candidate operator 4743 // functions of the form 4744 // 4745 // bool operator==(T,T); 4746 // bool operator!=(T,T); 4747 for (BuiltinCandidateTypeSet::iterator 4748 MemPtr = CandidateTypes.member_pointer_begin(), 4749 MemPtrEnd = CandidateTypes.member_pointer_end(); 4750 MemPtr != MemPtrEnd; 4751 ++MemPtr) { 4752 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4753 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4754 } 4755 4756 // Fall through 4757 4758 case OO_Less: 4759 case OO_Greater: 4760 case OO_LessEqual: 4761 case OO_GreaterEqual: 4762 // C++ [over.built]p15: 4763 // 4764 // For every pointer or enumeration type T, there exist 4765 // candidate operator functions of the form 4766 // 4767 // bool operator<(T, T); 4768 // bool operator>(T, T); 4769 // bool operator<=(T, T); 4770 // bool operator>=(T, T); 4771 // bool operator==(T, T); 4772 // bool operator!=(T, T); 4773 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4774 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4775 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4776 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4777 } 4778 for (BuiltinCandidateTypeSet::iterator Enum 4779 = CandidateTypes.enumeration_begin(); 4780 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4781 QualType ParamTypes[2] = { *Enum, *Enum }; 4782 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4783 } 4784 4785 // Fall through. 4786 isComparison = true; 4787 4788 BinaryPlus: 4789 BinaryMinus: 4790 if (!isComparison) { 4791 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4792 4793 // C++ [over.built]p13: 4794 // 4795 // For every cv-qualified or cv-unqualified object type T 4796 // there exist candidate operator functions of the form 4797 // 4798 // T* operator+(T*, ptrdiff_t); 4799 // T& operator[](T*, ptrdiff_t); [BELOW] 4800 // T* operator-(T*, ptrdiff_t); 4801 // T* operator+(ptrdiff_t, T*); 4802 // T& operator[](ptrdiff_t, T*); [BELOW] 4803 // 4804 // C++ [over.built]p14: 4805 // 4806 // For every T, where T is a pointer to object type, there 4807 // exist candidate operator functions of the form 4808 // 4809 // ptrdiff_t operator-(T, T); 4810 for (BuiltinCandidateTypeSet::iterator Ptr 4811 = CandidateTypes.pointer_begin(); 4812 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4813 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4814 4815 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4816 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4817 4818 if (Op == OO_Plus) { 4819 // T* operator+(ptrdiff_t, T*); 4820 ParamTypes[0] = ParamTypes[1]; 4821 ParamTypes[1] = *Ptr; 4822 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4823 } else { 4824 // ptrdiff_t operator-(T, T); 4825 ParamTypes[1] = *Ptr; 4826 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4827 Args, 2, CandidateSet); 4828 } 4829 } 4830 } 4831 // Fall through 4832 4833 case OO_Slash: 4834 BinaryStar: 4835 Conditional: 4836 // C++ [over.built]p12: 4837 // 4838 // For every pair of promoted arithmetic types L and R, there 4839 // exist candidate operator functions of the form 4840 // 4841 // LR operator*(L, R); 4842 // LR operator/(L, R); 4843 // LR operator+(L, R); 4844 // LR operator-(L, R); 4845 // bool operator<(L, R); 4846 // bool operator>(L, R); 4847 // bool operator<=(L, R); 4848 // bool operator>=(L, R); 4849 // bool operator==(L, R); 4850 // bool operator!=(L, R); 4851 // 4852 // where LR is the result of the usual arithmetic conversions 4853 // between types L and R. 4854 // 4855 // C++ [over.built]p24: 4856 // 4857 // For every pair of promoted arithmetic types L and R, there exist 4858 // candidate operator functions of the form 4859 // 4860 // LR operator?(bool, L, R); 4861 // 4862 // where LR is the result of the usual arithmetic conversions 4863 // between types L and R. 4864 // Our candidates ignore the first parameter. 4865 for (unsigned Left = FirstPromotedArithmeticType; 4866 Left < LastPromotedArithmeticType; ++Left) { 4867 for (unsigned Right = FirstPromotedArithmeticType; 4868 Right < LastPromotedArithmeticType; ++Right) { 4869 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4870 QualType Result 4871 = isComparison 4872 ? Context.BoolTy 4873 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4874 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4875 } 4876 } 4877 4878 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 4879 // conditional operator for vector types. 4880 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4881 Vec1End = CandidateTypes.vector_end(); 4882 Vec1 != Vec1End; ++Vec1) 4883 for (BuiltinCandidateTypeSet::iterator 4884 Vec2 = CandidateTypes.vector_begin(), 4885 Vec2End = CandidateTypes.vector_end(); 4886 Vec2 != Vec2End; ++Vec2) { 4887 QualType LandR[2] = { *Vec1, *Vec2 }; 4888 QualType Result; 4889 if (isComparison) 4890 Result = Context.BoolTy; 4891 else { 4892 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 4893 Result = *Vec1; 4894 else 4895 Result = *Vec2; 4896 } 4897 4898 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4899 } 4900 4901 break; 4902 4903 case OO_Percent: 4904 BinaryAmp: 4905 case OO_Caret: 4906 case OO_Pipe: 4907 case OO_LessLess: 4908 case OO_GreaterGreater: 4909 // C++ [over.built]p17: 4910 // 4911 // For every pair of promoted integral types L and R, there 4912 // exist candidate operator functions of the form 4913 // 4914 // LR operator%(L, R); 4915 // LR operator&(L, R); 4916 // LR operator^(L, R); 4917 // LR operator|(L, R); 4918 // L operator<<(L, R); 4919 // L operator>>(L, R); 4920 // 4921 // where LR is the result of the usual arithmetic conversions 4922 // between types L and R. 4923 for (unsigned Left = FirstPromotedIntegralType; 4924 Left < LastPromotedIntegralType; ++Left) { 4925 for (unsigned Right = FirstPromotedIntegralType; 4926 Right < LastPromotedIntegralType; ++Right) { 4927 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4928 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4929 ? LandR[0] 4930 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4931 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4932 } 4933 } 4934 break; 4935 4936 case OO_Equal: 4937 // C++ [over.built]p20: 4938 // 4939 // For every pair (T, VQ), where T is an enumeration or 4940 // pointer to member type and VQ is either volatile or 4941 // empty, there exist candidate operator functions of the form 4942 // 4943 // VQ T& operator=(VQ T&, T); 4944 for (BuiltinCandidateTypeSet::iterator 4945 Enum = CandidateTypes.enumeration_begin(), 4946 EnumEnd = CandidateTypes.enumeration_end(); 4947 Enum != EnumEnd; ++Enum) 4948 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4949 CandidateSet); 4950 for (BuiltinCandidateTypeSet::iterator 4951 MemPtr = CandidateTypes.member_pointer_begin(), 4952 MemPtrEnd = CandidateTypes.member_pointer_end(); 4953 MemPtr != MemPtrEnd; ++MemPtr) 4954 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4955 CandidateSet); 4956 4957 // Fall through. 4958 4959 case OO_PlusEqual: 4960 case OO_MinusEqual: 4961 // C++ [over.built]p19: 4962 // 4963 // For every pair (T, VQ), where T is any type and VQ is either 4964 // volatile or empty, there exist candidate operator functions 4965 // of the form 4966 // 4967 // T*VQ& operator=(T*VQ&, T*); 4968 // 4969 // C++ [over.built]p21: 4970 // 4971 // For every pair (T, VQ), where T is a cv-qualified or 4972 // cv-unqualified object type and VQ is either volatile or 4973 // empty, there exist candidate operator functions of the form 4974 // 4975 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4976 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4977 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4978 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4979 QualType ParamTypes[2]; 4980 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4981 4982 // non-volatile version 4983 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4984 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4985 /*IsAssigmentOperator=*/Op == OO_Equal); 4986 4987 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4988 VisibleTypeConversionsQuals.hasVolatile()) { 4989 // volatile version 4990 ParamTypes[0] 4991 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4992 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4993 /*IsAssigmentOperator=*/Op == OO_Equal); 4994 } 4995 } 4996 // Fall through. 4997 4998 case OO_StarEqual: 4999 case OO_SlashEqual: 5000 // C++ [over.built]p18: 5001 // 5002 // For every triple (L, VQ, R), where L is an arithmetic type, 5003 // VQ is either volatile or empty, and R is a promoted 5004 // arithmetic type, there exist candidate operator functions of 5005 // the form 5006 // 5007 // VQ L& operator=(VQ L&, R); 5008 // VQ L& operator*=(VQ L&, R); 5009 // VQ L& operator/=(VQ L&, R); 5010 // VQ L& operator+=(VQ L&, R); 5011 // VQ L& operator-=(VQ L&, R); 5012 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 5013 for (unsigned Right = FirstPromotedArithmeticType; 5014 Right < LastPromotedArithmeticType; ++Right) { 5015 QualType ParamTypes[2]; 5016 ParamTypes[1] = ArithmeticTypes[Right]; 5017 5018 // Add this built-in operator as a candidate (VQ is empty). 5019 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 5020 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5021 /*IsAssigmentOperator=*/Op == OO_Equal); 5022 5023 // Add this built-in operator as a candidate (VQ is 'volatile'). 5024 if (VisibleTypeConversionsQuals.hasVolatile()) { 5025 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 5026 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 5027 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5028 /*IsAssigmentOperator=*/Op == OO_Equal); 5029 } 5030 } 5031 } 5032 5033 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 5034 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 5035 Vec1End = CandidateTypes.vector_end(); 5036 Vec1 != Vec1End; ++Vec1) 5037 for (BuiltinCandidateTypeSet::iterator 5038 Vec2 = CandidateTypes.vector_begin(), 5039 Vec2End = CandidateTypes.vector_end(); 5040 Vec2 != Vec2End; ++Vec2) { 5041 QualType ParamTypes[2]; 5042 ParamTypes[1] = *Vec2; 5043 // Add this built-in operator as a candidate (VQ is empty). 5044 ParamTypes[0] = Context.getLValueReferenceType(*Vec1); 5045 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5046 /*IsAssigmentOperator=*/Op == OO_Equal); 5047 5048 // Add this built-in operator as a candidate (VQ is 'volatile'). 5049 if (VisibleTypeConversionsQuals.hasVolatile()) { 5050 ParamTypes[0] = Context.getVolatileType(*Vec1); 5051 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 5052 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 5053 /*IsAssigmentOperator=*/Op == OO_Equal); 5054 } 5055 } 5056 break; 5057 5058 case OO_PercentEqual: 5059 case OO_LessLessEqual: 5060 case OO_GreaterGreaterEqual: 5061 case OO_AmpEqual: 5062 case OO_CaretEqual: 5063 case OO_PipeEqual: 5064 // C++ [over.built]p22: 5065 // 5066 // For every triple (L, VQ, R), where L is an integral type, VQ 5067 // is either volatile or empty, and R is a promoted integral 5068 // type, there exist candidate operator functions of the form 5069 // 5070 // VQ L& operator%=(VQ L&, R); 5071 // VQ L& operator<<=(VQ L&, R); 5072 // VQ L& operator>>=(VQ L&, R); 5073 // VQ L& operator&=(VQ L&, R); 5074 // VQ L& operator^=(VQ L&, R); 5075 // VQ L& operator|=(VQ L&, R); 5076 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 5077 for (unsigned Right = FirstPromotedIntegralType; 5078 Right < LastPromotedIntegralType; ++Right) { 5079 QualType ParamTypes[2]; 5080 ParamTypes[1] = ArithmeticTypes[Right]; 5081 5082 // Add this built-in operator as a candidate (VQ is empty). 5083 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 5084 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5085 if (VisibleTypeConversionsQuals.hasVolatile()) { 5086 // Add this built-in operator as a candidate (VQ is 'volatile'). 5087 ParamTypes[0] = ArithmeticTypes[Left]; 5088 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 5089 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 5090 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 5091 } 5092 } 5093 } 5094 break; 5095 5096 case OO_Exclaim: { 5097 // C++ [over.operator]p23: 5098 // 5099 // There also exist candidate operator functions of the form 5100 // 5101 // bool operator!(bool); 5102 // bool operator&&(bool, bool); [BELOW] 5103 // bool operator||(bool, bool); [BELOW] 5104 QualType ParamTy = Context.BoolTy; 5105 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 5106 /*IsAssignmentOperator=*/false, 5107 /*NumContextualBoolArguments=*/1); 5108 break; 5109 } 5110 5111 case OO_AmpAmp: 5112 case OO_PipePipe: { 5113 // C++ [over.operator]p23: 5114 // 5115 // There also exist candidate operator functions of the form 5116 // 5117 // bool operator!(bool); [ABOVE] 5118 // bool operator&&(bool, bool); 5119 // bool operator||(bool, bool); 5120 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 5121 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 5122 /*IsAssignmentOperator=*/false, 5123 /*NumContextualBoolArguments=*/2); 5124 break; 5125 } 5126 5127 case OO_Subscript: 5128 // C++ [over.built]p13: 5129 // 5130 // For every cv-qualified or cv-unqualified object type T there 5131 // exist candidate operator functions of the form 5132 // 5133 // T* operator+(T*, ptrdiff_t); [ABOVE] 5134 // T& operator[](T*, ptrdiff_t); 5135 // T* operator-(T*, ptrdiff_t); [ABOVE] 5136 // T* operator+(ptrdiff_t, T*); [ABOVE] 5137 // T& operator[](ptrdiff_t, T*); 5138 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 5139 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 5140 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 5141 QualType PointeeType = (*Ptr)->getPointeeType(); 5142 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 5143 5144 // T& operator[](T*, ptrdiff_t) 5145 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5146 5147 // T& operator[](ptrdiff_t, T*); 5148 ParamTypes[0] = ParamTypes[1]; 5149 ParamTypes[1] = *Ptr; 5150 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5151 } 5152 break; 5153 5154 case OO_ArrowStar: 5155 // C++ [over.built]p11: 5156 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 5157 // C1 is the same type as C2 or is a derived class of C2, T is an object 5158 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 5159 // there exist candidate operator functions of the form 5160 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 5161 // where CV12 is the union of CV1 and CV2. 5162 { 5163 for (BuiltinCandidateTypeSet::iterator Ptr = 5164 CandidateTypes.pointer_begin(); 5165 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 5166 QualType C1Ty = (*Ptr); 5167 QualType C1; 5168 QualifierCollector Q1; 5169 C1 = QualType(Q1.strip(C1Ty->getPointeeType()), 0); 5170 if (!isa<RecordType>(C1)) 5171 continue; 5172 // heuristic to reduce number of builtin candidates in the set. 5173 // Add volatile/restrict version only if there are conversions to a 5174 // volatile/restrict type. 5175 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 5176 continue; 5177 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 5178 continue; 5179 for (BuiltinCandidateTypeSet::iterator 5180 MemPtr = CandidateTypes.member_pointer_begin(), 5181 MemPtrEnd = CandidateTypes.member_pointer_end(); 5182 MemPtr != MemPtrEnd; ++MemPtr) { 5183 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 5184 QualType C2 = QualType(mptr->getClass(), 0); 5185 C2 = C2.getUnqualifiedType(); 5186 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 5187 break; 5188 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 5189 // build CV12 T& 5190 QualType T = mptr->getPointeeType(); 5191 if (!VisibleTypeConversionsQuals.hasVolatile() && 5192 T.isVolatileQualified()) 5193 continue; 5194 if (!VisibleTypeConversionsQuals.hasRestrict() && 5195 T.isRestrictQualified()) 5196 continue; 5197 T = Q1.apply(T); 5198 QualType ResultTy = Context.getLValueReferenceType(T); 5199 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5200 } 5201 } 5202 } 5203 break; 5204 5205 case OO_Conditional: 5206 // Note that we don't consider the first argument, since it has been 5207 // contextually converted to bool long ago. The candidates below are 5208 // therefore added as binary. 5209 // 5210 // C++ [over.built]p24: 5211 // For every type T, where T is a pointer or pointer-to-member type, 5212 // there exist candidate operator functions of the form 5213 // 5214 // T operator?(bool, T, T); 5215 // 5216 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 5217 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 5218 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5219 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5220 } 5221 for (BuiltinCandidateTypeSet::iterator Ptr = 5222 CandidateTypes.member_pointer_begin(), 5223 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 5224 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5225 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5226 } 5227 goto Conditional; 5228 } 5229} 5230 5231/// \brief Add function candidates found via argument-dependent lookup 5232/// to the set of overloading candidates. 5233/// 5234/// This routine performs argument-dependent name lookup based on the 5235/// given function name (which may also be an operator name) and adds 5236/// all of the overload candidates found by ADL to the overload 5237/// candidate set (C++ [basic.lookup.argdep]). 5238void 5239Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 5240 bool Operator, 5241 Expr **Args, unsigned NumArgs, 5242 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5243 OverloadCandidateSet& CandidateSet, 5244 bool PartialOverloading) { 5245 ADLResult Fns; 5246 5247 // FIXME: This approach for uniquing ADL results (and removing 5248 // redundant candidates from the set) relies on pointer-equality, 5249 // which means we need to key off the canonical decl. However, 5250 // always going back to the canonical decl might not get us the 5251 // right set of default arguments. What default arguments are 5252 // we supposed to consider on ADL candidates, anyway? 5253 5254 // FIXME: Pass in the explicit template arguments? 5255 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 5256 5257 // Erase all of the candidates we already knew about. 5258 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5259 CandEnd = CandidateSet.end(); 5260 Cand != CandEnd; ++Cand) 5261 if (Cand->Function) { 5262 Fns.erase(Cand->Function); 5263 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 5264 Fns.erase(FunTmpl); 5265 } 5266 5267 // For each of the ADL candidates we found, add it to the overload 5268 // set. 5269 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 5270 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 5271 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 5272 if (ExplicitTemplateArgs) 5273 continue; 5274 5275 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 5276 false, PartialOverloading); 5277 } else 5278 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 5279 FoundDecl, ExplicitTemplateArgs, 5280 Args, NumArgs, CandidateSet); 5281 } 5282} 5283 5284/// isBetterOverloadCandidate - Determines whether the first overload 5285/// candidate is a better candidate than the second (C++ 13.3.3p1). 5286bool 5287isBetterOverloadCandidate(Sema &S, 5288 const OverloadCandidate& Cand1, 5289 const OverloadCandidate& Cand2, 5290 SourceLocation Loc) { 5291 // Define viable functions to be better candidates than non-viable 5292 // functions. 5293 if (!Cand2.Viable) 5294 return Cand1.Viable; 5295 else if (!Cand1.Viable) 5296 return false; 5297 5298 // C++ [over.match.best]p1: 5299 // 5300 // -- if F is a static member function, ICS1(F) is defined such 5301 // that ICS1(F) is neither better nor worse than ICS1(G) for 5302 // any function G, and, symmetrically, ICS1(G) is neither 5303 // better nor worse than ICS1(F). 5304 unsigned StartArg = 0; 5305 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 5306 StartArg = 1; 5307 5308 // C++ [over.match.best]p1: 5309 // A viable function F1 is defined to be a better function than another 5310 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 5311 // conversion sequence than ICSi(F2), and then... 5312 unsigned NumArgs = Cand1.Conversions.size(); 5313 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 5314 bool HasBetterConversion = false; 5315 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 5316 switch (CompareImplicitConversionSequences(S, 5317 Cand1.Conversions[ArgIdx], 5318 Cand2.Conversions[ArgIdx])) { 5319 case ImplicitConversionSequence::Better: 5320 // Cand1 has a better conversion sequence. 5321 HasBetterConversion = true; 5322 break; 5323 5324 case ImplicitConversionSequence::Worse: 5325 // Cand1 can't be better than Cand2. 5326 return false; 5327 5328 case ImplicitConversionSequence::Indistinguishable: 5329 // Do nothing. 5330 break; 5331 } 5332 } 5333 5334 // -- for some argument j, ICSj(F1) is a better conversion sequence than 5335 // ICSj(F2), or, if not that, 5336 if (HasBetterConversion) 5337 return true; 5338 5339 // - F1 is a non-template function and F2 is a function template 5340 // specialization, or, if not that, 5341 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 5342 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5343 return true; 5344 5345 // -- F1 and F2 are function template specializations, and the function 5346 // template for F1 is more specialized than the template for F2 5347 // according to the partial ordering rules described in 14.5.5.2, or, 5348 // if not that, 5349 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 5350 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5351 if (FunctionTemplateDecl *BetterTemplate 5352 = S.getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 5353 Cand2.Function->getPrimaryTemplate(), 5354 Loc, 5355 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 5356 : TPOC_Call)) 5357 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 5358 5359 // -- the context is an initialization by user-defined conversion 5360 // (see 8.5, 13.3.1.5) and the standard conversion sequence 5361 // from the return type of F1 to the destination type (i.e., 5362 // the type of the entity being initialized) is a better 5363 // conversion sequence than the standard conversion sequence 5364 // from the return type of F2 to the destination type. 5365 if (Cand1.Function && Cand2.Function && 5366 isa<CXXConversionDecl>(Cand1.Function) && 5367 isa<CXXConversionDecl>(Cand2.Function)) { 5368 switch (CompareStandardConversionSequences(S, 5369 Cand1.FinalConversion, 5370 Cand2.FinalConversion)) { 5371 case ImplicitConversionSequence::Better: 5372 // Cand1 has a better conversion sequence. 5373 return true; 5374 5375 case ImplicitConversionSequence::Worse: 5376 // Cand1 can't be better than Cand2. 5377 return false; 5378 5379 case ImplicitConversionSequence::Indistinguishable: 5380 // Do nothing 5381 break; 5382 } 5383 } 5384 5385 return false; 5386} 5387 5388/// \brief Computes the best viable function (C++ 13.3.3) 5389/// within an overload candidate set. 5390/// 5391/// \param CandidateSet the set of candidate functions. 5392/// 5393/// \param Loc the location of the function name (or operator symbol) for 5394/// which overload resolution occurs. 5395/// 5396/// \param Best f overload resolution was successful or found a deleted 5397/// function, Best points to the candidate function found. 5398/// 5399/// \returns The result of overload resolution. 5400OverloadingResult 5401OverloadCandidateSet::BestViableFunction(Sema &S, SourceLocation Loc, 5402 iterator& Best) { 5403 // Find the best viable function. 5404 Best = end(); 5405 for (iterator Cand = begin(); Cand != end(); ++Cand) { 5406 if (Cand->Viable) 5407 if (Best == end() || isBetterOverloadCandidate(S, *Cand, *Best, Loc)) 5408 Best = Cand; 5409 } 5410 5411 // If we didn't find any viable functions, abort. 5412 if (Best == end()) 5413 return OR_No_Viable_Function; 5414 5415 // Make sure that this function is better than every other viable 5416 // function. If not, we have an ambiguity. 5417 for (iterator Cand = begin(); Cand != end(); ++Cand) { 5418 if (Cand->Viable && 5419 Cand != Best && 5420 !isBetterOverloadCandidate(S, *Best, *Cand, Loc)) { 5421 Best = end(); 5422 return OR_Ambiguous; 5423 } 5424 } 5425 5426 // Best is the best viable function. 5427 if (Best->Function && 5428 (Best->Function->isDeleted() || 5429 Best->Function->getAttr<UnavailableAttr>())) 5430 return OR_Deleted; 5431 5432 // C++ [basic.def.odr]p2: 5433 // An overloaded function is used if it is selected by overload resolution 5434 // when referred to from a potentially-evaluated expression. [Note: this 5435 // covers calls to named functions (5.2.2), operator overloading 5436 // (clause 13), user-defined conversions (12.3.2), allocation function for 5437 // placement new (5.3.4), as well as non-default initialization (8.5). 5438 if (Best->Function) 5439 S.MarkDeclarationReferenced(Loc, Best->Function); 5440 return OR_Success; 5441} 5442 5443namespace { 5444 5445enum OverloadCandidateKind { 5446 oc_function, 5447 oc_method, 5448 oc_constructor, 5449 oc_function_template, 5450 oc_method_template, 5451 oc_constructor_template, 5452 oc_implicit_default_constructor, 5453 oc_implicit_copy_constructor, 5454 oc_implicit_copy_assignment 5455}; 5456 5457OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 5458 FunctionDecl *Fn, 5459 std::string &Description) { 5460 bool isTemplate = false; 5461 5462 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 5463 isTemplate = true; 5464 Description = S.getTemplateArgumentBindingsText( 5465 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 5466 } 5467 5468 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 5469 if (!Ctor->isImplicit()) 5470 return isTemplate ? oc_constructor_template : oc_constructor; 5471 5472 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 5473 : oc_implicit_default_constructor; 5474 } 5475 5476 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 5477 // This actually gets spelled 'candidate function' for now, but 5478 // it doesn't hurt to split it out. 5479 if (!Meth->isImplicit()) 5480 return isTemplate ? oc_method_template : oc_method; 5481 5482 assert(Meth->isCopyAssignment() 5483 && "implicit method is not copy assignment operator?"); 5484 return oc_implicit_copy_assignment; 5485 } 5486 5487 return isTemplate ? oc_function_template : oc_function; 5488} 5489 5490} // end anonymous namespace 5491 5492// Notes the location of an overload candidate. 5493void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 5494 std::string FnDesc; 5495 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 5496 Diag(Fn->getLocation(), diag::note_ovl_candidate) 5497 << (unsigned) K << FnDesc; 5498} 5499 5500/// Diagnoses an ambiguous conversion. The partial diagnostic is the 5501/// "lead" diagnostic; it will be given two arguments, the source and 5502/// target types of the conversion. 5503void ImplicitConversionSequence::DiagnoseAmbiguousConversion( 5504 Sema &S, 5505 SourceLocation CaretLoc, 5506 const PartialDiagnostic &PDiag) const { 5507 S.Diag(CaretLoc, PDiag) 5508 << Ambiguous.getFromType() << Ambiguous.getToType(); 5509 for (AmbiguousConversionSequence::const_iterator 5510 I = Ambiguous.begin(), E = Ambiguous.end(); I != E; ++I) { 5511 S.NoteOverloadCandidate(*I); 5512 } 5513} 5514 5515namespace { 5516 5517void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 5518 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 5519 assert(Conv.isBad()); 5520 assert(Cand->Function && "for now, candidate must be a function"); 5521 FunctionDecl *Fn = Cand->Function; 5522 5523 // There's a conversion slot for the object argument if this is a 5524 // non-constructor method. Note that 'I' corresponds the 5525 // conversion-slot index. 5526 bool isObjectArgument = false; 5527 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 5528 if (I == 0) 5529 isObjectArgument = true; 5530 else 5531 I--; 5532 } 5533 5534 std::string FnDesc; 5535 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5536 5537 Expr *FromExpr = Conv.Bad.FromExpr; 5538 QualType FromTy = Conv.Bad.getFromType(); 5539 QualType ToTy = Conv.Bad.getToType(); 5540 5541 if (FromTy == S.Context.OverloadTy) { 5542 assert(FromExpr && "overload set argument came from implicit argument?"); 5543 Expr *E = FromExpr->IgnoreParens(); 5544 if (isa<UnaryOperator>(E)) 5545 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 5546 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 5547 5548 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 5549 << (unsigned) FnKind << FnDesc 5550 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5551 << ToTy << Name << I+1; 5552 return; 5553 } 5554 5555 // Do some hand-waving analysis to see if the non-viability is due 5556 // to a qualifier mismatch. 5557 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 5558 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 5559 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 5560 CToTy = RT->getPointeeType(); 5561 else { 5562 // TODO: detect and diagnose the full richness of const mismatches. 5563 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 5564 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 5565 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 5566 } 5567 5568 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 5569 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 5570 // It is dumb that we have to do this here. 5571 while (isa<ArrayType>(CFromTy)) 5572 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 5573 while (isa<ArrayType>(CToTy)) 5574 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 5575 5576 Qualifiers FromQs = CFromTy.getQualifiers(); 5577 Qualifiers ToQs = CToTy.getQualifiers(); 5578 5579 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 5580 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 5581 << (unsigned) FnKind << FnDesc 5582 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5583 << FromTy 5584 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 5585 << (unsigned) isObjectArgument << I+1; 5586 return; 5587 } 5588 5589 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 5590 assert(CVR && "unexpected qualifiers mismatch"); 5591 5592 if (isObjectArgument) { 5593 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 5594 << (unsigned) FnKind << FnDesc 5595 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5596 << FromTy << (CVR - 1); 5597 } else { 5598 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 5599 << (unsigned) FnKind << FnDesc 5600 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5601 << FromTy << (CVR - 1) << I+1; 5602 } 5603 return; 5604 } 5605 5606 // Diagnose references or pointers to incomplete types differently, 5607 // since it's far from impossible that the incompleteness triggered 5608 // the failure. 5609 QualType TempFromTy = FromTy.getNonReferenceType(); 5610 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 5611 TempFromTy = PTy->getPointeeType(); 5612 if (TempFromTy->isIncompleteType()) { 5613 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 5614 << (unsigned) FnKind << FnDesc 5615 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5616 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5617 return; 5618 } 5619 5620 // Diagnose base -> derived pointer conversions. 5621 unsigned BaseToDerivedConversion = 0; 5622 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 5623 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 5624 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 5625 FromPtrTy->getPointeeType()) && 5626 !FromPtrTy->getPointeeType()->isIncompleteType() && 5627 !ToPtrTy->getPointeeType()->isIncompleteType() && 5628 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 5629 FromPtrTy->getPointeeType())) 5630 BaseToDerivedConversion = 1; 5631 } 5632 } else if (const ObjCObjectPointerType *FromPtrTy 5633 = FromTy->getAs<ObjCObjectPointerType>()) { 5634 if (const ObjCObjectPointerType *ToPtrTy 5635 = ToTy->getAs<ObjCObjectPointerType>()) 5636 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 5637 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 5638 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 5639 FromPtrTy->getPointeeType()) && 5640 FromIface->isSuperClassOf(ToIface)) 5641 BaseToDerivedConversion = 2; 5642 } else if (const ReferenceType *ToRefTy = ToTy->getAs<ReferenceType>()) { 5643 if (ToRefTy->getPointeeType().isAtLeastAsQualifiedAs(FromTy) && 5644 !FromTy->isIncompleteType() && 5645 !ToRefTy->getPointeeType()->isIncompleteType() && 5646 S.IsDerivedFrom(ToRefTy->getPointeeType(), FromTy)) 5647 BaseToDerivedConversion = 3; 5648 } 5649 5650 if (BaseToDerivedConversion) { 5651 S.Diag(Fn->getLocation(), 5652 diag::note_ovl_candidate_bad_base_to_derived_conv) 5653 << (unsigned) FnKind << FnDesc 5654 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5655 << (BaseToDerivedConversion - 1) 5656 << FromTy << ToTy << I+1; 5657 return; 5658 } 5659 5660 // TODO: specialize more based on the kind of mismatch 5661 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 5662 << (unsigned) FnKind << FnDesc 5663 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5664 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5665} 5666 5667void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 5668 unsigned NumFormalArgs) { 5669 // TODO: treat calls to a missing default constructor as a special case 5670 5671 FunctionDecl *Fn = Cand->Function; 5672 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 5673 5674 unsigned MinParams = Fn->getMinRequiredArguments(); 5675 5676 // at least / at most / exactly 5677 // FIXME: variadic templates "at most" should account for parameter packs 5678 unsigned mode, modeCount; 5679 if (NumFormalArgs < MinParams) { 5680 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 5681 (Cand->FailureKind == ovl_fail_bad_deduction && 5682 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 5683 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 5684 mode = 0; // "at least" 5685 else 5686 mode = 2; // "exactly" 5687 modeCount = MinParams; 5688 } else { 5689 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 5690 (Cand->FailureKind == ovl_fail_bad_deduction && 5691 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 5692 if (MinParams != FnTy->getNumArgs()) 5693 mode = 1; // "at most" 5694 else 5695 mode = 2; // "exactly" 5696 modeCount = FnTy->getNumArgs(); 5697 } 5698 5699 std::string Description; 5700 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 5701 5702 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 5703 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 5704 << modeCount << NumFormalArgs; 5705} 5706 5707/// Diagnose a failed template-argument deduction. 5708void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 5709 Expr **Args, unsigned NumArgs) { 5710 FunctionDecl *Fn = Cand->Function; // pattern 5711 5712 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 5713 NamedDecl *ParamD; 5714 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 5715 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 5716 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 5717 switch (Cand->DeductionFailure.Result) { 5718 case Sema::TDK_Success: 5719 llvm_unreachable("TDK_success while diagnosing bad deduction"); 5720 5721 case Sema::TDK_Incomplete: { 5722 assert(ParamD && "no parameter found for incomplete deduction result"); 5723 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 5724 << ParamD->getDeclName(); 5725 return; 5726 } 5727 5728 case Sema::TDK_Underqualified: { 5729 assert(ParamD && "no parameter found for bad qualifiers deduction result"); 5730 TemplateTypeParmDecl *TParam = cast<TemplateTypeParmDecl>(ParamD); 5731 5732 QualType Param = Cand->DeductionFailure.getFirstArg()->getAsType(); 5733 5734 // Param will have been canonicalized, but it should just be a 5735 // qualified version of ParamD, so move the qualifiers to that. 5736 QualifierCollector Qs(S.Context); 5737 Qs.strip(Param); 5738 QualType NonCanonParam = Qs.apply(TParam->getTypeForDecl()); 5739 assert(S.Context.hasSameType(Param, NonCanonParam)); 5740 5741 // Arg has also been canonicalized, but there's nothing we can do 5742 // about that. It also doesn't matter as much, because it won't 5743 // have any template parameters in it (because deduction isn't 5744 // done on dependent types). 5745 QualType Arg = Cand->DeductionFailure.getSecondArg()->getAsType(); 5746 5747 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_underqualified) 5748 << ParamD->getDeclName() << Arg << NonCanonParam; 5749 return; 5750 } 5751 5752 case Sema::TDK_Inconsistent: { 5753 assert(ParamD && "no parameter found for inconsistent deduction result"); 5754 int which = 0; 5755 if (isa<TemplateTypeParmDecl>(ParamD)) 5756 which = 0; 5757 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 5758 which = 1; 5759 else { 5760 which = 2; 5761 } 5762 5763 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 5764 << which << ParamD->getDeclName() 5765 << *Cand->DeductionFailure.getFirstArg() 5766 << *Cand->DeductionFailure.getSecondArg(); 5767 return; 5768 } 5769 5770 case Sema::TDK_InvalidExplicitArguments: 5771 assert(ParamD && "no parameter found for invalid explicit arguments"); 5772 if (ParamD->getDeclName()) 5773 S.Diag(Fn->getLocation(), 5774 diag::note_ovl_candidate_explicit_arg_mismatch_named) 5775 << ParamD->getDeclName(); 5776 else { 5777 int index = 0; 5778 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 5779 index = TTP->getIndex(); 5780 else if (NonTypeTemplateParmDecl *NTTP 5781 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 5782 index = NTTP->getIndex(); 5783 else 5784 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 5785 S.Diag(Fn->getLocation(), 5786 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 5787 << (index + 1); 5788 } 5789 return; 5790 5791 case Sema::TDK_TooManyArguments: 5792 case Sema::TDK_TooFewArguments: 5793 DiagnoseArityMismatch(S, Cand, NumArgs); 5794 return; 5795 5796 case Sema::TDK_InstantiationDepth: 5797 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 5798 return; 5799 5800 case Sema::TDK_SubstitutionFailure: { 5801 std::string ArgString; 5802 if (TemplateArgumentList *Args 5803 = Cand->DeductionFailure.getTemplateArgumentList()) 5804 ArgString = S.getTemplateArgumentBindingsText( 5805 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 5806 *Args); 5807 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 5808 << ArgString; 5809 return; 5810 } 5811 5812 // TODO: diagnose these individually, then kill off 5813 // note_ovl_candidate_bad_deduction, which is uselessly vague. 5814 case Sema::TDK_NonDeducedMismatch: 5815 case Sema::TDK_FailedOverloadResolution: 5816 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 5817 return; 5818 } 5819} 5820 5821/// Generates a 'note' diagnostic for an overload candidate. We've 5822/// already generated a primary error at the call site. 5823/// 5824/// It really does need to be a single diagnostic with its caret 5825/// pointed at the candidate declaration. Yes, this creates some 5826/// major challenges of technical writing. Yes, this makes pointing 5827/// out problems with specific arguments quite awkward. It's still 5828/// better than generating twenty screens of text for every failed 5829/// overload. 5830/// 5831/// It would be great to be able to express per-candidate problems 5832/// more richly for those diagnostic clients that cared, but we'd 5833/// still have to be just as careful with the default diagnostics. 5834void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 5835 Expr **Args, unsigned NumArgs) { 5836 FunctionDecl *Fn = Cand->Function; 5837 5838 // Note deleted candidates, but only if they're viable. 5839 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 5840 std::string FnDesc; 5841 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5842 5843 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 5844 << FnKind << FnDesc << Fn->isDeleted(); 5845 return; 5846 } 5847 5848 // We don't really have anything else to say about viable candidates. 5849 if (Cand->Viable) { 5850 S.NoteOverloadCandidate(Fn); 5851 return; 5852 } 5853 5854 switch (Cand->FailureKind) { 5855 case ovl_fail_too_many_arguments: 5856 case ovl_fail_too_few_arguments: 5857 return DiagnoseArityMismatch(S, Cand, NumArgs); 5858 5859 case ovl_fail_bad_deduction: 5860 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 5861 5862 case ovl_fail_trivial_conversion: 5863 case ovl_fail_bad_final_conversion: 5864 case ovl_fail_final_conversion_not_exact: 5865 return S.NoteOverloadCandidate(Fn); 5866 5867 case ovl_fail_bad_conversion: { 5868 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 5869 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 5870 if (Cand->Conversions[I].isBad()) 5871 return DiagnoseBadConversion(S, Cand, I); 5872 5873 // FIXME: this currently happens when we're called from SemaInit 5874 // when user-conversion overload fails. Figure out how to handle 5875 // those conditions and diagnose them well. 5876 return S.NoteOverloadCandidate(Fn); 5877 } 5878 } 5879} 5880 5881void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 5882 // Desugar the type of the surrogate down to a function type, 5883 // retaining as many typedefs as possible while still showing 5884 // the function type (and, therefore, its parameter types). 5885 QualType FnType = Cand->Surrogate->getConversionType(); 5886 bool isLValueReference = false; 5887 bool isRValueReference = false; 5888 bool isPointer = false; 5889 if (const LValueReferenceType *FnTypeRef = 5890 FnType->getAs<LValueReferenceType>()) { 5891 FnType = FnTypeRef->getPointeeType(); 5892 isLValueReference = true; 5893 } else if (const RValueReferenceType *FnTypeRef = 5894 FnType->getAs<RValueReferenceType>()) { 5895 FnType = FnTypeRef->getPointeeType(); 5896 isRValueReference = true; 5897 } 5898 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 5899 FnType = FnTypePtr->getPointeeType(); 5900 isPointer = true; 5901 } 5902 // Desugar down to a function type. 5903 FnType = QualType(FnType->getAs<FunctionType>(), 0); 5904 // Reconstruct the pointer/reference as appropriate. 5905 if (isPointer) FnType = S.Context.getPointerType(FnType); 5906 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5907 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5908 5909 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5910 << FnType; 5911} 5912 5913void NoteBuiltinOperatorCandidate(Sema &S, 5914 const char *Opc, 5915 SourceLocation OpLoc, 5916 OverloadCandidate *Cand) { 5917 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5918 std::string TypeStr("operator"); 5919 TypeStr += Opc; 5920 TypeStr += "("; 5921 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5922 if (Cand->Conversions.size() == 1) { 5923 TypeStr += ")"; 5924 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5925 } else { 5926 TypeStr += ", "; 5927 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5928 TypeStr += ")"; 5929 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5930 } 5931} 5932 5933void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5934 OverloadCandidate *Cand) { 5935 unsigned NoOperands = Cand->Conversions.size(); 5936 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5937 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5938 if (ICS.isBad()) break; // all meaningless after first invalid 5939 if (!ICS.isAmbiguous()) continue; 5940 5941 ICS.DiagnoseAmbiguousConversion(S, OpLoc, 5942 S.PDiag(diag::note_ambiguous_type_conversion)); 5943 } 5944} 5945 5946SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5947 if (Cand->Function) 5948 return Cand->Function->getLocation(); 5949 if (Cand->IsSurrogate) 5950 return Cand->Surrogate->getLocation(); 5951 return SourceLocation(); 5952} 5953 5954struct CompareOverloadCandidatesForDisplay { 5955 Sema &S; 5956 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5957 5958 bool operator()(const OverloadCandidate *L, 5959 const OverloadCandidate *R) { 5960 // Fast-path this check. 5961 if (L == R) return false; 5962 5963 // Order first by viability. 5964 if (L->Viable) { 5965 if (!R->Viable) return true; 5966 5967 // TODO: introduce a tri-valued comparison for overload 5968 // candidates. Would be more worthwhile if we had a sort 5969 // that could exploit it. 5970 if (isBetterOverloadCandidate(S, *L, *R, SourceLocation())) return true; 5971 if (isBetterOverloadCandidate(S, *R, *L, SourceLocation())) return false; 5972 } else if (R->Viable) 5973 return false; 5974 5975 assert(L->Viable == R->Viable); 5976 5977 // Criteria by which we can sort non-viable candidates: 5978 if (!L->Viable) { 5979 // 1. Arity mismatches come after other candidates. 5980 if (L->FailureKind == ovl_fail_too_many_arguments || 5981 L->FailureKind == ovl_fail_too_few_arguments) 5982 return false; 5983 if (R->FailureKind == ovl_fail_too_many_arguments || 5984 R->FailureKind == ovl_fail_too_few_arguments) 5985 return true; 5986 5987 // 2. Bad conversions come first and are ordered by the number 5988 // of bad conversions and quality of good conversions. 5989 if (L->FailureKind == ovl_fail_bad_conversion) { 5990 if (R->FailureKind != ovl_fail_bad_conversion) 5991 return true; 5992 5993 // If there's any ordering between the defined conversions... 5994 // FIXME: this might not be transitive. 5995 assert(L->Conversions.size() == R->Conversions.size()); 5996 5997 int leftBetter = 0; 5998 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5999 for (unsigned E = L->Conversions.size(); I != E; ++I) { 6000 switch (CompareImplicitConversionSequences(S, 6001 L->Conversions[I], 6002 R->Conversions[I])) { 6003 case ImplicitConversionSequence::Better: 6004 leftBetter++; 6005 break; 6006 6007 case ImplicitConversionSequence::Worse: 6008 leftBetter--; 6009 break; 6010 6011 case ImplicitConversionSequence::Indistinguishable: 6012 break; 6013 } 6014 } 6015 if (leftBetter > 0) return true; 6016 if (leftBetter < 0) return false; 6017 6018 } else if (R->FailureKind == ovl_fail_bad_conversion) 6019 return false; 6020 6021 // TODO: others? 6022 } 6023 6024 // Sort everything else by location. 6025 SourceLocation LLoc = GetLocationForCandidate(L); 6026 SourceLocation RLoc = GetLocationForCandidate(R); 6027 6028 // Put candidates without locations (e.g. builtins) at the end. 6029 if (LLoc.isInvalid()) return false; 6030 if (RLoc.isInvalid()) return true; 6031 6032 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 6033 } 6034}; 6035 6036/// CompleteNonViableCandidate - Normally, overload resolution only 6037/// computes up to the first 6038void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 6039 Expr **Args, unsigned NumArgs) { 6040 assert(!Cand->Viable); 6041 6042 // Don't do anything on failures other than bad conversion. 6043 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 6044 6045 // Skip forward to the first bad conversion. 6046 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 6047 unsigned ConvCount = Cand->Conversions.size(); 6048 while (true) { 6049 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 6050 ConvIdx++; 6051 if (Cand->Conversions[ConvIdx - 1].isBad()) 6052 break; 6053 } 6054 6055 if (ConvIdx == ConvCount) 6056 return; 6057 6058 assert(!Cand->Conversions[ConvIdx].isInitialized() && 6059 "remaining conversion is initialized?"); 6060 6061 // FIXME: this should probably be preserved from the overload 6062 // operation somehow. 6063 bool SuppressUserConversions = false; 6064 6065 const FunctionProtoType* Proto; 6066 unsigned ArgIdx = ConvIdx; 6067 6068 if (Cand->IsSurrogate) { 6069 QualType ConvType 6070 = Cand->Surrogate->getConversionType().getNonReferenceType(); 6071 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 6072 ConvType = ConvPtrType->getPointeeType(); 6073 Proto = ConvType->getAs<FunctionProtoType>(); 6074 ArgIdx--; 6075 } else if (Cand->Function) { 6076 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 6077 if (isa<CXXMethodDecl>(Cand->Function) && 6078 !isa<CXXConstructorDecl>(Cand->Function)) 6079 ArgIdx--; 6080 } else { 6081 // Builtin binary operator with a bad first conversion. 6082 assert(ConvCount <= 3); 6083 for (; ConvIdx != ConvCount; ++ConvIdx) 6084 Cand->Conversions[ConvIdx] 6085 = TryCopyInitialization(S, Args[ConvIdx], 6086 Cand->BuiltinTypes.ParamTypes[ConvIdx], 6087 SuppressUserConversions, 6088 /*InOverloadResolution*/ true); 6089 return; 6090 } 6091 6092 // Fill in the rest of the conversions. 6093 unsigned NumArgsInProto = Proto->getNumArgs(); 6094 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 6095 if (ArgIdx < NumArgsInProto) 6096 Cand->Conversions[ConvIdx] 6097 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 6098 SuppressUserConversions, 6099 /*InOverloadResolution=*/true); 6100 else 6101 Cand->Conversions[ConvIdx].setEllipsis(); 6102 } 6103} 6104 6105} // end anonymous namespace 6106 6107/// PrintOverloadCandidates - When overload resolution fails, prints 6108/// diagnostic messages containing the candidates in the candidate 6109/// set. 6110void OverloadCandidateSet::NoteCandidates(Sema &S, 6111 OverloadCandidateDisplayKind OCD, 6112 Expr **Args, unsigned NumArgs, 6113 const char *Opc, 6114 SourceLocation OpLoc) { 6115 // Sort the candidates by viability and position. Sorting directly would 6116 // be prohibitive, so we make a set of pointers and sort those. 6117 llvm::SmallVector<OverloadCandidate*, 32> Cands; 6118 if (OCD == OCD_AllCandidates) Cands.reserve(size()); 6119 for (iterator Cand = begin(), LastCand = end(); Cand != LastCand; ++Cand) { 6120 if (Cand->Viable) 6121 Cands.push_back(Cand); 6122 else if (OCD == OCD_AllCandidates) { 6123 CompleteNonViableCandidate(S, Cand, Args, NumArgs); 6124 if (Cand->Function || Cand->IsSurrogate) 6125 Cands.push_back(Cand); 6126 // Otherwise, this a non-viable builtin candidate. We do not, in general, 6127 // want to list every possible builtin candidate. 6128 } 6129 } 6130 6131 std::sort(Cands.begin(), Cands.end(), 6132 CompareOverloadCandidatesForDisplay(S)); 6133 6134 bool ReportedAmbiguousConversions = false; 6135 6136 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 6137 const Diagnostic::OverloadsShown ShowOverloads = S.Diags.getShowOverloads(); 6138 unsigned CandsShown = 0; 6139 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 6140 OverloadCandidate *Cand = *I; 6141 6142 // Set an arbitrary limit on the number of candidate functions we'll spam 6143 // the user with. FIXME: This limit should depend on details of the 6144 // candidate list. 6145 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 6146 break; 6147 } 6148 ++CandsShown; 6149 6150 if (Cand->Function) 6151 NoteFunctionCandidate(S, Cand, Args, NumArgs); 6152 else if (Cand->IsSurrogate) 6153 NoteSurrogateCandidate(S, Cand); 6154 else { 6155 assert(Cand->Viable && 6156 "Non-viable built-in candidates are not added to Cands."); 6157 // Generally we only see ambiguities including viable builtin 6158 // operators if overload resolution got screwed up by an 6159 // ambiguous user-defined conversion. 6160 // 6161 // FIXME: It's quite possible for different conversions to see 6162 // different ambiguities, though. 6163 if (!ReportedAmbiguousConversions) { 6164 NoteAmbiguousUserConversions(S, OpLoc, Cand); 6165 ReportedAmbiguousConversions = true; 6166 } 6167 6168 // If this is a viable builtin, print it. 6169 NoteBuiltinOperatorCandidate(S, Opc, OpLoc, Cand); 6170 } 6171 } 6172 6173 if (I != E) 6174 S.Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 6175} 6176 6177static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 6178 if (isa<UnresolvedLookupExpr>(E)) 6179 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 6180 6181 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 6182} 6183 6184/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 6185/// an overloaded function (C++ [over.over]), where @p From is an 6186/// expression with overloaded function type and @p ToType is the type 6187/// we're trying to resolve to. For example: 6188/// 6189/// @code 6190/// int f(double); 6191/// int f(int); 6192/// 6193/// int (*pfd)(double) = f; // selects f(double) 6194/// @endcode 6195/// 6196/// This routine returns the resulting FunctionDecl if it could be 6197/// resolved, and NULL otherwise. When @p Complain is true, this 6198/// routine will emit diagnostics if there is an error. 6199FunctionDecl * 6200Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 6201 bool Complain, 6202 DeclAccessPair &FoundResult) { 6203 QualType FunctionType = ToType; 6204 bool IsMember = false; 6205 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 6206 FunctionType = ToTypePtr->getPointeeType(); 6207 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 6208 FunctionType = ToTypeRef->getPointeeType(); 6209 else if (const MemberPointerType *MemTypePtr = 6210 ToType->getAs<MemberPointerType>()) { 6211 FunctionType = MemTypePtr->getPointeeType(); 6212 IsMember = true; 6213 } 6214 6215 // C++ [over.over]p1: 6216 // [...] [Note: any redundant set of parentheses surrounding the 6217 // overloaded function name is ignored (5.1). ] 6218 // C++ [over.over]p1: 6219 // [...] The overloaded function name can be preceded by the & 6220 // operator. 6221 // However, remember whether the expression has member-pointer form: 6222 // C++ [expr.unary.op]p4: 6223 // A pointer to member is only formed when an explicit & is used 6224 // and its operand is a qualified-id not enclosed in 6225 // parentheses. 6226 bool HasFormOfMemberPointer = false; 6227 OverloadExpr *OvlExpr; 6228 { 6229 Expr *Tmp = From->IgnoreParens(); 6230 if (isa<UnaryOperator>(Tmp)) { 6231 Tmp = cast<UnaryOperator>(Tmp)->getSubExpr(); 6232 OvlExpr = cast<OverloadExpr>(Tmp->IgnoreParens()); 6233 HasFormOfMemberPointer = (Tmp == OvlExpr && OvlExpr->getQualifier()); 6234 } else { 6235 OvlExpr = cast<OverloadExpr>(Tmp); 6236 } 6237 } 6238 6239 // We expect a pointer or reference to function, or a function pointer. 6240 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 6241 if (!FunctionType->isFunctionType()) { 6242 if (Complain) 6243 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 6244 << OvlExpr->getName() << ToType; 6245 6246 return 0; 6247 } 6248 6249 // If the overload expression doesn't have the form of a pointer to 6250 // member, don't try to convert it to a pointer-to-member type. 6251 if (IsMember && !HasFormOfMemberPointer) { 6252 if (!Complain) return 0; 6253 6254 // TODO: Should we condition this on whether any functions might 6255 // have matched, or is it more appropriate to do that in callers? 6256 // TODO: a fixit wouldn't hurt. 6257 Diag(OvlExpr->getNameLoc(), diag::err_addr_ovl_no_qualifier) 6258 << ToType << OvlExpr->getSourceRange(); 6259 return 0; 6260 } 6261 6262 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 6263 if (OvlExpr->hasExplicitTemplateArgs()) { 6264 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 6265 ExplicitTemplateArgs = &ETABuffer; 6266 } 6267 6268 assert(From->getType() == Context.OverloadTy); 6269 6270 // Look through all of the overloaded functions, searching for one 6271 // whose type matches exactly. 6272 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 6273 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 6274 6275 bool FoundNonTemplateFunction = false; 6276 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6277 E = OvlExpr->decls_end(); I != E; ++I) { 6278 // Look through any using declarations to find the underlying function. 6279 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 6280 6281 // C++ [over.over]p3: 6282 // Non-member functions and static member functions match 6283 // targets of type "pointer-to-function" or "reference-to-function." 6284 // Nonstatic member functions match targets of 6285 // type "pointer-to-member-function." 6286 // Note that according to DR 247, the containing class does not matter. 6287 6288 if (FunctionTemplateDecl *FunctionTemplate 6289 = dyn_cast<FunctionTemplateDecl>(Fn)) { 6290 if (CXXMethodDecl *Method 6291 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 6292 // Skip non-static function templates when converting to pointer, and 6293 // static when converting to member pointer. 6294 if (Method->isStatic() == IsMember) 6295 continue; 6296 } else if (IsMember) 6297 continue; 6298 6299 // C++ [over.over]p2: 6300 // If the name is a function template, template argument deduction is 6301 // done (14.8.2.2), and if the argument deduction succeeds, the 6302 // resulting template argument list is used to generate a single 6303 // function template specialization, which is added to the set of 6304 // overloaded functions considered. 6305 // FIXME: We don't really want to build the specialization here, do we? 6306 FunctionDecl *Specialization = 0; 6307 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6308 if (TemplateDeductionResult Result 6309 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 6310 FunctionType, Specialization, Info)) { 6311 // FIXME: make a note of the failed deduction for diagnostics. 6312 (void)Result; 6313 } else { 6314 // FIXME: If the match isn't exact, shouldn't we just drop this as 6315 // a candidate? Find a testcase before changing the code. 6316 assert(FunctionType 6317 == Context.getCanonicalType(Specialization->getType())); 6318 Matches.push_back(std::make_pair(I.getPair(), 6319 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 6320 } 6321 6322 continue; 6323 } 6324 6325 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6326 // Skip non-static functions when converting to pointer, and static 6327 // when converting to member pointer. 6328 if (Method->isStatic() == IsMember) 6329 continue; 6330 6331 // If we have explicit template arguments, skip non-templates. 6332 if (OvlExpr->hasExplicitTemplateArgs()) 6333 continue; 6334 } else if (IsMember) 6335 continue; 6336 6337 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 6338 QualType ResultTy; 6339 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 6340 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 6341 ResultTy)) { 6342 Matches.push_back(std::make_pair(I.getPair(), 6343 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 6344 FoundNonTemplateFunction = true; 6345 } 6346 } 6347 } 6348 6349 // If there were 0 or 1 matches, we're done. 6350 if (Matches.empty()) { 6351 if (Complain) { 6352 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 6353 << OvlExpr->getName() << FunctionType; 6354 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6355 E = OvlExpr->decls_end(); 6356 I != E; ++I) 6357 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 6358 NoteOverloadCandidate(F); 6359 } 6360 6361 return 0; 6362 } else if (Matches.size() == 1) { 6363 FunctionDecl *Result = Matches[0].second; 6364 FoundResult = Matches[0].first; 6365 MarkDeclarationReferenced(From->getLocStart(), Result); 6366 if (Complain) 6367 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 6368 return Result; 6369 } 6370 6371 // C++ [over.over]p4: 6372 // If more than one function is selected, [...] 6373 if (!FoundNonTemplateFunction) { 6374 // [...] and any given function template specialization F1 is 6375 // eliminated if the set contains a second function template 6376 // specialization whose function template is more specialized 6377 // than the function template of F1 according to the partial 6378 // ordering rules of 14.5.5.2. 6379 6380 // The algorithm specified above is quadratic. We instead use a 6381 // two-pass algorithm (similar to the one used to identify the 6382 // best viable function in an overload set) that identifies the 6383 // best function template (if it exists). 6384 6385 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 6386 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6387 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 6388 6389 UnresolvedSetIterator Result = 6390 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 6391 TPOC_Other, From->getLocStart(), 6392 PDiag(), 6393 PDiag(diag::err_addr_ovl_ambiguous) 6394 << Matches[0].second->getDeclName(), 6395 PDiag(diag::note_ovl_candidate) 6396 << (unsigned) oc_function_template); 6397 assert(Result != MatchesCopy.end() && "no most-specialized template"); 6398 MarkDeclarationReferenced(From->getLocStart(), *Result); 6399 FoundResult = Matches[Result - MatchesCopy.begin()].first; 6400 if (Complain) { 6401 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 6402 DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc()); 6403 } 6404 return cast<FunctionDecl>(*Result); 6405 } 6406 6407 // [...] any function template specializations in the set are 6408 // eliminated if the set also contains a non-template function, [...] 6409 for (unsigned I = 0, N = Matches.size(); I != N; ) { 6410 if (Matches[I].second->getPrimaryTemplate() == 0) 6411 ++I; 6412 else { 6413 Matches[I] = Matches[--N]; 6414 Matches.set_size(N); 6415 } 6416 } 6417 6418 // [...] After such eliminations, if any, there shall remain exactly one 6419 // selected function. 6420 if (Matches.size() == 1) { 6421 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 6422 FoundResult = Matches[0].first; 6423 if (Complain) { 6424 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 6425 DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc()); 6426 } 6427 return cast<FunctionDecl>(Matches[0].second); 6428 } 6429 6430 // FIXME: We should probably return the same thing that BestViableFunction 6431 // returns (even if we issue the diagnostics here). 6432 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 6433 << Matches[0].second->getDeclName(); 6434 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6435 NoteOverloadCandidate(Matches[I].second); 6436 return 0; 6437} 6438 6439/// \brief Given an expression that refers to an overloaded function, try to 6440/// resolve that overloaded function expression down to a single function. 6441/// 6442/// This routine can only resolve template-ids that refer to a single function 6443/// template, where that template-id refers to a single template whose template 6444/// arguments are either provided by the template-id or have defaults, 6445/// as described in C++0x [temp.arg.explicit]p3. 6446FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 6447 // C++ [over.over]p1: 6448 // [...] [Note: any redundant set of parentheses surrounding the 6449 // overloaded function name is ignored (5.1). ] 6450 // C++ [over.over]p1: 6451 // [...] The overloaded function name can be preceded by the & 6452 // operator. 6453 6454 if (From->getType() != Context.OverloadTy) 6455 return 0; 6456 6457 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6458 6459 // If we didn't actually find any template-ids, we're done. 6460 if (!OvlExpr->hasExplicitTemplateArgs()) 6461 return 0; 6462 6463 TemplateArgumentListInfo ExplicitTemplateArgs; 6464 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 6465 6466 // Look through all of the overloaded functions, searching for one 6467 // whose type matches exactly. 6468 FunctionDecl *Matched = 0; 6469 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6470 E = OvlExpr->decls_end(); I != E; ++I) { 6471 // C++0x [temp.arg.explicit]p3: 6472 // [...] In contexts where deduction is done and fails, or in contexts 6473 // where deduction is not done, if a template argument list is 6474 // specified and it, along with any default template arguments, 6475 // identifies a single function template specialization, then the 6476 // template-id is an lvalue for the function template specialization. 6477 FunctionTemplateDecl *FunctionTemplate 6478 = cast<FunctionTemplateDecl>((*I)->getUnderlyingDecl()); 6479 6480 // C++ [over.over]p2: 6481 // If the name is a function template, template argument deduction is 6482 // done (14.8.2.2), and if the argument deduction succeeds, the 6483 // resulting template argument list is used to generate a single 6484 // function template specialization, which is added to the set of 6485 // overloaded functions considered. 6486 FunctionDecl *Specialization = 0; 6487 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6488 if (TemplateDeductionResult Result 6489 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 6490 Specialization, Info)) { 6491 // FIXME: make a note of the failed deduction for diagnostics. 6492 (void)Result; 6493 continue; 6494 } 6495 6496 // Multiple matches; we can't resolve to a single declaration. 6497 if (Matched) 6498 return 0; 6499 6500 Matched = Specialization; 6501 } 6502 6503 return Matched; 6504} 6505 6506/// \brief Add a single candidate to the overload set. 6507static void AddOverloadedCallCandidate(Sema &S, 6508 DeclAccessPair FoundDecl, 6509 const TemplateArgumentListInfo *ExplicitTemplateArgs, 6510 Expr **Args, unsigned NumArgs, 6511 OverloadCandidateSet &CandidateSet, 6512 bool PartialOverloading) { 6513 NamedDecl *Callee = FoundDecl.getDecl(); 6514 if (isa<UsingShadowDecl>(Callee)) 6515 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 6516 6517 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 6518 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 6519 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 6520 false, PartialOverloading); 6521 return; 6522 } 6523 6524 if (FunctionTemplateDecl *FuncTemplate 6525 = dyn_cast<FunctionTemplateDecl>(Callee)) { 6526 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 6527 ExplicitTemplateArgs, 6528 Args, NumArgs, CandidateSet); 6529 return; 6530 } 6531 6532 assert(false && "unhandled case in overloaded call candidate"); 6533 6534 // do nothing? 6535} 6536 6537/// \brief Add the overload candidates named by callee and/or found by argument 6538/// dependent lookup to the given overload set. 6539void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 6540 Expr **Args, unsigned NumArgs, 6541 OverloadCandidateSet &CandidateSet, 6542 bool PartialOverloading) { 6543 6544#ifndef NDEBUG 6545 // Verify that ArgumentDependentLookup is consistent with the rules 6546 // in C++0x [basic.lookup.argdep]p3: 6547 // 6548 // Let X be the lookup set produced by unqualified lookup (3.4.1) 6549 // and let Y be the lookup set produced by argument dependent 6550 // lookup (defined as follows). If X contains 6551 // 6552 // -- a declaration of a class member, or 6553 // 6554 // -- a block-scope function declaration that is not a 6555 // using-declaration, or 6556 // 6557 // -- a declaration that is neither a function or a function 6558 // template 6559 // 6560 // then Y is empty. 6561 6562 if (ULE->requiresADL()) { 6563 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6564 E = ULE->decls_end(); I != E; ++I) { 6565 assert(!(*I)->getDeclContext()->isRecord()); 6566 assert(isa<UsingShadowDecl>(*I) || 6567 !(*I)->getDeclContext()->isFunctionOrMethod()); 6568 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 6569 } 6570 } 6571#endif 6572 6573 // It would be nice to avoid this copy. 6574 TemplateArgumentListInfo TABuffer; 6575 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6576 if (ULE->hasExplicitTemplateArgs()) { 6577 ULE->copyTemplateArgumentsInto(TABuffer); 6578 ExplicitTemplateArgs = &TABuffer; 6579 } 6580 6581 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6582 E = ULE->decls_end(); I != E; ++I) 6583 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 6584 Args, NumArgs, CandidateSet, 6585 PartialOverloading); 6586 6587 if (ULE->requiresADL()) 6588 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 6589 Args, NumArgs, 6590 ExplicitTemplateArgs, 6591 CandidateSet, 6592 PartialOverloading); 6593} 6594 6595/// Attempts to recover from a call where no functions were found. 6596/// 6597/// Returns true if new candidates were found. 6598static ExprResult 6599BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 6600 UnresolvedLookupExpr *ULE, 6601 SourceLocation LParenLoc, 6602 Expr **Args, unsigned NumArgs, 6603 SourceLocation *CommaLocs, 6604 SourceLocation RParenLoc) { 6605 6606 CXXScopeSpec SS; 6607 if (ULE->getQualifier()) { 6608 SS.setScopeRep(ULE->getQualifier()); 6609 SS.setRange(ULE->getQualifierRange()); 6610 } 6611 6612 TemplateArgumentListInfo TABuffer; 6613 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6614 if (ULE->hasExplicitTemplateArgs()) { 6615 ULE->copyTemplateArgumentsInto(TABuffer); 6616 ExplicitTemplateArgs = &TABuffer; 6617 } 6618 6619 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 6620 Sema::LookupOrdinaryName); 6621 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 6622 return SemaRef.ExprError(); 6623 6624 assert(!R.empty() && "lookup results empty despite recovery"); 6625 6626 // Build an implicit member call if appropriate. Just drop the 6627 // casts and such from the call, we don't really care. 6628 ExprResult NewFn = SemaRef.ExprError(); 6629 if ((*R.begin())->isCXXClassMember()) 6630 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 6631 else if (ExplicitTemplateArgs) 6632 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 6633 else 6634 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 6635 6636 if (NewFn.isInvalid()) 6637 return SemaRef.ExprError(); 6638 6639 // This shouldn't cause an infinite loop because we're giving it 6640 // an expression with non-empty lookup results, which should never 6641 // end up here. 6642 return SemaRef.ActOnCallExpr(/*Scope*/ 0, NewFn.take(), LParenLoc, 6643 Sema::MultiExprArg(SemaRef, Args, NumArgs), 6644 CommaLocs, RParenLoc); 6645} 6646 6647/// ResolveOverloadedCallFn - Given the call expression that calls Fn 6648/// (which eventually refers to the declaration Func) and the call 6649/// arguments Args/NumArgs, attempt to resolve the function call down 6650/// to a specific function. If overload resolution succeeds, returns 6651/// the function declaration produced by overload 6652/// resolution. Otherwise, emits diagnostics, deletes all of the 6653/// arguments and Fn, and returns NULL. 6654ExprResult 6655Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 6656 SourceLocation LParenLoc, 6657 Expr **Args, unsigned NumArgs, 6658 SourceLocation *CommaLocs, 6659 SourceLocation RParenLoc) { 6660#ifndef NDEBUG 6661 if (ULE->requiresADL()) { 6662 // To do ADL, we must have found an unqualified name. 6663 assert(!ULE->getQualifier() && "qualified name with ADL"); 6664 6665 // We don't perform ADL for implicit declarations of builtins. 6666 // Verify that this was correctly set up. 6667 FunctionDecl *F; 6668 if (ULE->decls_begin() + 1 == ULE->decls_end() && 6669 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 6670 F->getBuiltinID() && F->isImplicit()) 6671 assert(0 && "performing ADL for builtin"); 6672 6673 // We don't perform ADL in C. 6674 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 6675 } 6676#endif 6677 6678 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 6679 6680 // Add the functions denoted by the callee to the set of candidate 6681 // functions, including those from argument-dependent lookup. 6682 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 6683 6684 // If we found nothing, try to recover. 6685 // AddRecoveryCallCandidates diagnoses the error itself, so we just 6686 // bailout out if it fails. 6687 if (CandidateSet.empty()) 6688 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 6689 CommaLocs, RParenLoc); 6690 6691 OverloadCandidateSet::iterator Best; 6692 switch (CandidateSet.BestViableFunction(*this, Fn->getLocStart(), Best)) { 6693 case OR_Success: { 6694 FunctionDecl *FDecl = Best->Function; 6695 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 6696 DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc()); 6697 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 6698 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 6699 } 6700 6701 case OR_No_Viable_Function: 6702 Diag(Fn->getSourceRange().getBegin(), 6703 diag::err_ovl_no_viable_function_in_call) 6704 << ULE->getName() << Fn->getSourceRange(); 6705 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 6706 break; 6707 6708 case OR_Ambiguous: 6709 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 6710 << ULE->getName() << Fn->getSourceRange(); 6711 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 6712 break; 6713 6714 case OR_Deleted: 6715 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 6716 << Best->Function->isDeleted() 6717 << ULE->getName() 6718 << Fn->getSourceRange(); 6719 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 6720 break; 6721 } 6722 6723 // Overload resolution failed. 6724 return ExprError(); 6725} 6726 6727static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 6728 return Functions.size() > 1 || 6729 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 6730} 6731 6732/// \brief Create a unary operation that may resolve to an overloaded 6733/// operator. 6734/// 6735/// \param OpLoc The location of the operator itself (e.g., '*'). 6736/// 6737/// \param OpcIn The UnaryOperator::Opcode that describes this 6738/// operator. 6739/// 6740/// \param Functions The set of non-member functions that will be 6741/// considered by overload resolution. The caller needs to build this 6742/// set based on the context using, e.g., 6743/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6744/// set should not contain any member functions; those will be added 6745/// by CreateOverloadedUnaryOp(). 6746/// 6747/// \param input The input argument. 6748ExprResult 6749Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 6750 const UnresolvedSetImpl &Fns, 6751 Expr *Input) { 6752 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6753 6754 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 6755 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 6756 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6757 // TODO: provide better source location info. 6758 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 6759 6760 Expr *Args[2] = { Input, 0 }; 6761 unsigned NumArgs = 1; 6762 6763 // For post-increment and post-decrement, add the implicit '0' as 6764 // the second argument, so that we know this is a post-increment or 6765 // post-decrement. 6766 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 6767 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 6768 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 6769 SourceLocation()); 6770 NumArgs = 2; 6771 } 6772 6773 if (Input->isTypeDependent()) { 6774 if (Fns.empty()) 6775 return Owned(new (Context) UnaryOperator(Input, 6776 Opc, 6777 Context.DependentTy, 6778 OpLoc)); 6779 6780 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6781 UnresolvedLookupExpr *Fn 6782 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6783 0, SourceRange(), OpNameInfo, 6784 /*ADL*/ true, IsOverloaded(Fns), 6785 Fns.begin(), Fns.end()); 6786 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6787 &Args[0], NumArgs, 6788 Context.DependentTy, 6789 OpLoc)); 6790 } 6791 6792 // Build an empty overload set. 6793 OverloadCandidateSet CandidateSet(OpLoc); 6794 6795 // Add the candidates from the given function set. 6796 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 6797 6798 // Add operator candidates that are member functions. 6799 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6800 6801 // Add candidates from ADL. 6802 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6803 Args, NumArgs, 6804 /*ExplicitTemplateArgs*/ 0, 6805 CandidateSet); 6806 6807 // Add builtin operator candidates. 6808 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6809 6810 // Perform overload resolution. 6811 OverloadCandidateSet::iterator Best; 6812 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 6813 case OR_Success: { 6814 // We found a built-in operator or an overloaded operator. 6815 FunctionDecl *FnDecl = Best->Function; 6816 6817 if (FnDecl) { 6818 // We matched an overloaded operator. Build a call to that 6819 // operator. 6820 6821 // Convert the arguments. 6822 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6823 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 6824 6825 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 6826 Best->FoundDecl, Method)) 6827 return ExprError(); 6828 } else { 6829 // Convert the arguments. 6830 ExprResult InputInit 6831 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6832 FnDecl->getParamDecl(0)), 6833 SourceLocation(), 6834 Input); 6835 if (InputInit.isInvalid()) 6836 return ExprError(); 6837 Input = InputInit.take(); 6838 } 6839 6840 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6841 6842 // Determine the result type 6843 QualType ResultTy = FnDecl->getCallResultType(); 6844 6845 // Build the actual expression node. 6846 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6847 SourceLocation()); 6848 UsualUnaryConversions(FnExpr); 6849 6850 Args[0] = Input; 6851 CallExpr *TheCall = 6852 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6853 Args, NumArgs, ResultTy, OpLoc); 6854 6855 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 6856 FnDecl)) 6857 return ExprError(); 6858 6859 return MaybeBindToTemporary(TheCall); 6860 } else { 6861 // We matched a built-in operator. Convert the arguments, then 6862 // break out so that we will build the appropriate built-in 6863 // operator node. 6864 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 6865 Best->Conversions[0], AA_Passing)) 6866 return ExprError(); 6867 6868 break; 6869 } 6870 } 6871 6872 case OR_No_Viable_Function: 6873 // No viable function; fall through to handling this as a 6874 // built-in operator, which will produce an error message for us. 6875 break; 6876 6877 case OR_Ambiguous: 6878 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6879 << UnaryOperator::getOpcodeStr(Opc) 6880 << Input->getSourceRange(); 6881 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, 6882 Args, NumArgs, 6883 UnaryOperator::getOpcodeStr(Opc), OpLoc); 6884 return ExprError(); 6885 6886 case OR_Deleted: 6887 Diag(OpLoc, diag::err_ovl_deleted_oper) 6888 << Best->Function->isDeleted() 6889 << UnaryOperator::getOpcodeStr(Opc) 6890 << Input->getSourceRange(); 6891 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 6892 return ExprError(); 6893 } 6894 6895 // Either we found no viable overloaded operator or we matched a 6896 // built-in operator. In either case, fall through to trying to 6897 // build a built-in operation. 6898 return CreateBuiltinUnaryOp(OpLoc, Opc, Input); 6899} 6900 6901/// \brief Create a binary operation that may resolve to an overloaded 6902/// operator. 6903/// 6904/// \param OpLoc The location of the operator itself (e.g., '+'). 6905/// 6906/// \param OpcIn The BinaryOperator::Opcode that describes this 6907/// operator. 6908/// 6909/// \param Functions The set of non-member functions that will be 6910/// considered by overload resolution. The caller needs to build this 6911/// set based on the context using, e.g., 6912/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6913/// set should not contain any member functions; those will be added 6914/// by CreateOverloadedBinOp(). 6915/// 6916/// \param LHS Left-hand argument. 6917/// \param RHS Right-hand argument. 6918ExprResult 6919Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 6920 unsigned OpcIn, 6921 const UnresolvedSetImpl &Fns, 6922 Expr *LHS, Expr *RHS) { 6923 Expr *Args[2] = { LHS, RHS }; 6924 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 6925 6926 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 6927 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 6928 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6929 6930 // If either side is type-dependent, create an appropriate dependent 6931 // expression. 6932 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6933 if (Fns.empty()) { 6934 // If there are no functions to store, just build a dependent 6935 // BinaryOperator or CompoundAssignment. 6936 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 6937 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 6938 Context.DependentTy, OpLoc)); 6939 6940 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 6941 Context.DependentTy, 6942 Context.DependentTy, 6943 Context.DependentTy, 6944 OpLoc)); 6945 } 6946 6947 // FIXME: save results of ADL from here? 6948 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6949 // TODO: provide better source location info in DNLoc component. 6950 DeclarationNameInfo OpNameInfo(OpName, OpLoc); 6951 UnresolvedLookupExpr *Fn 6952 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6953 0, SourceRange(), OpNameInfo, 6954 /*ADL*/ true, IsOverloaded(Fns), 6955 Fns.begin(), Fns.end()); 6956 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6957 Args, 2, 6958 Context.DependentTy, 6959 OpLoc)); 6960 } 6961 6962 // If this is the .* operator, which is not overloadable, just 6963 // create a built-in binary operator. 6964 if (Opc == BinaryOperator::PtrMemD) 6965 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6966 6967 // If this is the assignment operator, we only perform overload resolution 6968 // if the left-hand side is a class or enumeration type. This is actually 6969 // a hack. The standard requires that we do overload resolution between the 6970 // various built-in candidates, but as DR507 points out, this can lead to 6971 // problems. So we do it this way, which pretty much follows what GCC does. 6972 // Note that we go the traditional code path for compound assignment forms. 6973 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6974 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6975 6976 // Build an empty overload set. 6977 OverloadCandidateSet CandidateSet(OpLoc); 6978 6979 // Add the candidates from the given function set. 6980 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6981 6982 // Add operator candidates that are member functions. 6983 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6984 6985 // Add candidates from ADL. 6986 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6987 Args, 2, 6988 /*ExplicitTemplateArgs*/ 0, 6989 CandidateSet); 6990 6991 // Add builtin operator candidates. 6992 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6993 6994 // Perform overload resolution. 6995 OverloadCandidateSet::iterator Best; 6996 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 6997 case OR_Success: { 6998 // We found a built-in operator or an overloaded operator. 6999 FunctionDecl *FnDecl = Best->Function; 7000 7001 if (FnDecl) { 7002 // We matched an overloaded operator. Build a call to that 7003 // operator. 7004 7005 // Convert the arguments. 7006 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 7007 // Best->Access is only meaningful for class members. 7008 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 7009 7010 ExprResult Arg1 7011 = PerformCopyInitialization( 7012 InitializedEntity::InitializeParameter( 7013 FnDecl->getParamDecl(0)), 7014 SourceLocation(), 7015 Owned(Args[1])); 7016 if (Arg1.isInvalid()) 7017 return ExprError(); 7018 7019 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 7020 Best->FoundDecl, Method)) 7021 return ExprError(); 7022 7023 Args[1] = RHS = Arg1.takeAs<Expr>(); 7024 } else { 7025 // Convert the arguments. 7026 ExprResult Arg0 7027 = PerformCopyInitialization( 7028 InitializedEntity::InitializeParameter( 7029 FnDecl->getParamDecl(0)), 7030 SourceLocation(), 7031 Owned(Args[0])); 7032 if (Arg0.isInvalid()) 7033 return ExprError(); 7034 7035 ExprResult Arg1 7036 = PerformCopyInitialization( 7037 InitializedEntity::InitializeParameter( 7038 FnDecl->getParamDecl(1)), 7039 SourceLocation(), 7040 Owned(Args[1])); 7041 if (Arg1.isInvalid()) 7042 return ExprError(); 7043 Args[0] = LHS = Arg0.takeAs<Expr>(); 7044 Args[1] = RHS = Arg1.takeAs<Expr>(); 7045 } 7046 7047 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7048 7049 // Determine the result type 7050 QualType ResultTy 7051 = FnDecl->getType()->getAs<FunctionType>() 7052 ->getCallResultType(Context); 7053 7054 // Build the actual expression node. 7055 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 7056 OpLoc); 7057 UsualUnaryConversions(FnExpr); 7058 7059 CXXOperatorCallExpr *TheCall = 7060 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 7061 Args, 2, ResultTy, OpLoc); 7062 7063 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall, 7064 FnDecl)) 7065 return ExprError(); 7066 7067 return MaybeBindToTemporary(TheCall); 7068 } else { 7069 // We matched a built-in operator. Convert the arguments, then 7070 // break out so that we will build the appropriate built-in 7071 // operator node. 7072 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 7073 Best->Conversions[0], AA_Passing) || 7074 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 7075 Best->Conversions[1], AA_Passing)) 7076 return ExprError(); 7077 7078 break; 7079 } 7080 } 7081 7082 case OR_No_Viable_Function: { 7083 // C++ [over.match.oper]p9: 7084 // If the operator is the operator , [...] and there are no 7085 // viable functions, then the operator is assumed to be the 7086 // built-in operator and interpreted according to clause 5. 7087 if (Opc == BinaryOperator::Comma) 7088 break; 7089 7090 // For class as left operand for assignment or compound assigment operator 7091 // do not fall through to handling in built-in, but report that no overloaded 7092 // assignment operator found 7093 ExprResult Result = ExprError(); 7094 if (Args[0]->getType()->isRecordType() && 7095 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 7096 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7097 << BinaryOperator::getOpcodeStr(Opc) 7098 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7099 } else { 7100 // No viable function; try to create a built-in operation, which will 7101 // produce an error. Then, show the non-viable candidates. 7102 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7103 } 7104 assert(Result.isInvalid() && 7105 "C++ binary operator overloading is missing candidates!"); 7106 if (Result.isInvalid()) 7107 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 7108 BinaryOperator::getOpcodeStr(Opc), OpLoc); 7109 return move(Result); 7110 } 7111 7112 case OR_Ambiguous: 7113 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7114 << BinaryOperator::getOpcodeStr(Opc) 7115 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7116 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 7117 BinaryOperator::getOpcodeStr(Opc), OpLoc); 7118 return ExprError(); 7119 7120 case OR_Deleted: 7121 Diag(OpLoc, diag::err_ovl_deleted_oper) 7122 << Best->Function->isDeleted() 7123 << BinaryOperator::getOpcodeStr(Opc) 7124 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7125 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2); 7126 return ExprError(); 7127 } 7128 7129 // We matched a built-in operator; build it. 7130 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 7131} 7132 7133ExprResult 7134Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 7135 SourceLocation RLoc, 7136 Expr *Base, Expr *Idx) { 7137 Expr *Args[2] = { Base, Idx }; 7138 DeclarationName OpName = 7139 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 7140 7141 // If either side is type-dependent, create an appropriate dependent 7142 // expression. 7143 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 7144 7145 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 7146 // CHECKME: no 'operator' keyword? 7147 DeclarationNameInfo OpNameInfo(OpName, LLoc); 7148 OpNameInfo.setCXXOperatorNameRange(SourceRange(LLoc, RLoc)); 7149 UnresolvedLookupExpr *Fn 7150 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 7151 0, SourceRange(), OpNameInfo, 7152 /*ADL*/ true, /*Overloaded*/ false, 7153 UnresolvedSetIterator(), 7154 UnresolvedSetIterator()); 7155 // Can't add any actual overloads yet 7156 7157 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 7158 Args, 2, 7159 Context.DependentTy, 7160 RLoc)); 7161 } 7162 7163 // Build an empty overload set. 7164 OverloadCandidateSet CandidateSet(LLoc); 7165 7166 // Subscript can only be overloaded as a member function. 7167 7168 // Add operator candidates that are member functions. 7169 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 7170 7171 // Add builtin operator candidates. 7172 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 7173 7174 // Perform overload resolution. 7175 OverloadCandidateSet::iterator Best; 7176 switch (CandidateSet.BestViableFunction(*this, LLoc, Best)) { 7177 case OR_Success: { 7178 // We found a built-in operator or an overloaded operator. 7179 FunctionDecl *FnDecl = Best->Function; 7180 7181 if (FnDecl) { 7182 // We matched an overloaded operator. Build a call to that 7183 // operator. 7184 7185 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 7186 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 7187 7188 // Convert the arguments. 7189 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 7190 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 7191 Best->FoundDecl, Method)) 7192 return ExprError(); 7193 7194 // Convert the arguments. 7195 ExprResult InputInit 7196 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7197 FnDecl->getParamDecl(0)), 7198 SourceLocation(), 7199 Owned(Args[1])); 7200 if (InputInit.isInvalid()) 7201 return ExprError(); 7202 7203 Args[1] = InputInit.takeAs<Expr>(); 7204 7205 // Determine the result type 7206 QualType ResultTy 7207 = FnDecl->getType()->getAs<FunctionType>() 7208 ->getCallResultType(Context); 7209 7210 // Build the actual expression node. 7211 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 7212 LLoc); 7213 UsualUnaryConversions(FnExpr); 7214 7215 CXXOperatorCallExpr *TheCall = 7216 new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 7217 FnExpr, Args, 2, 7218 ResultTy, RLoc); 7219 7220 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall, 7221 FnDecl)) 7222 return ExprError(); 7223 7224 return MaybeBindToTemporary(TheCall); 7225 } else { 7226 // We matched a built-in operator. Convert the arguments, then 7227 // break out so that we will build the appropriate built-in 7228 // operator node. 7229 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 7230 Best->Conversions[0], AA_Passing) || 7231 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 7232 Best->Conversions[1], AA_Passing)) 7233 return ExprError(); 7234 7235 break; 7236 } 7237 } 7238 7239 case OR_No_Viable_Function: { 7240 if (CandidateSet.empty()) 7241 Diag(LLoc, diag::err_ovl_no_oper) 7242 << Args[0]->getType() << /*subscript*/ 0 7243 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7244 else 7245 Diag(LLoc, diag::err_ovl_no_viable_subscript) 7246 << Args[0]->getType() 7247 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7248 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 7249 "[]", LLoc); 7250 return ExprError(); 7251 } 7252 7253 case OR_Ambiguous: 7254 Diag(LLoc, diag::err_ovl_ambiguous_oper) 7255 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7256 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, 2, 7257 "[]", LLoc); 7258 return ExprError(); 7259 7260 case OR_Deleted: 7261 Diag(LLoc, diag::err_ovl_deleted_oper) 7262 << Best->Function->isDeleted() << "[]" 7263 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7264 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, 2, 7265 "[]", LLoc); 7266 return ExprError(); 7267 } 7268 7269 // We matched a built-in operator; build it. 7270 return CreateBuiltinArraySubscriptExpr(Args[0], LLoc, Args[1], RLoc); 7271} 7272 7273/// BuildCallToMemberFunction - Build a call to a member 7274/// function. MemExpr is the expression that refers to the member 7275/// function (and includes the object parameter), Args/NumArgs are the 7276/// arguments to the function call (not including the object 7277/// parameter). The caller needs to validate that the member 7278/// expression refers to a member function or an overloaded member 7279/// function. 7280ExprResult 7281Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 7282 SourceLocation LParenLoc, Expr **Args, 7283 unsigned NumArgs, SourceLocation *CommaLocs, 7284 SourceLocation RParenLoc) { 7285 // Dig out the member expression. This holds both the object 7286 // argument and the member function we're referring to. 7287 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 7288 7289 MemberExpr *MemExpr; 7290 CXXMethodDecl *Method = 0; 7291 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 7292 NestedNameSpecifier *Qualifier = 0; 7293 if (isa<MemberExpr>(NakedMemExpr)) { 7294 MemExpr = cast<MemberExpr>(NakedMemExpr); 7295 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 7296 FoundDecl = MemExpr->getFoundDecl(); 7297 Qualifier = MemExpr->getQualifier(); 7298 } else { 7299 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 7300 Qualifier = UnresExpr->getQualifier(); 7301 7302 QualType ObjectType = UnresExpr->getBaseType(); 7303 7304 // Add overload candidates 7305 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 7306 7307 // FIXME: avoid copy. 7308 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7309 if (UnresExpr->hasExplicitTemplateArgs()) { 7310 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7311 TemplateArgs = &TemplateArgsBuffer; 7312 } 7313 7314 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 7315 E = UnresExpr->decls_end(); I != E; ++I) { 7316 7317 NamedDecl *Func = *I; 7318 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 7319 if (isa<UsingShadowDecl>(Func)) 7320 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 7321 7322 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 7323 // If explicit template arguments were provided, we can't call a 7324 // non-template member function. 7325 if (TemplateArgs) 7326 continue; 7327 7328 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 7329 Args, NumArgs, 7330 CandidateSet, /*SuppressUserConversions=*/false); 7331 } else { 7332 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 7333 I.getPair(), ActingDC, TemplateArgs, 7334 ObjectType, Args, NumArgs, 7335 CandidateSet, 7336 /*SuppressUsedConversions=*/false); 7337 } 7338 } 7339 7340 DeclarationName DeclName = UnresExpr->getMemberName(); 7341 7342 OverloadCandidateSet::iterator Best; 7343 switch (CandidateSet.BestViableFunction(*this, UnresExpr->getLocStart(), 7344 Best)) { 7345 case OR_Success: 7346 Method = cast<CXXMethodDecl>(Best->Function); 7347 FoundDecl = Best->FoundDecl; 7348 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 7349 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 7350 break; 7351 7352 case OR_No_Viable_Function: 7353 Diag(UnresExpr->getMemberLoc(), 7354 diag::err_ovl_no_viable_member_function_in_call) 7355 << DeclName << MemExprE->getSourceRange(); 7356 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7357 // FIXME: Leaking incoming expressions! 7358 return ExprError(); 7359 7360 case OR_Ambiguous: 7361 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 7362 << DeclName << MemExprE->getSourceRange(); 7363 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7364 // FIXME: Leaking incoming expressions! 7365 return ExprError(); 7366 7367 case OR_Deleted: 7368 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 7369 << Best->Function->isDeleted() 7370 << DeclName << MemExprE->getSourceRange(); 7371 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7372 // FIXME: Leaking incoming expressions! 7373 return ExprError(); 7374 } 7375 7376 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 7377 7378 // If overload resolution picked a static member, build a 7379 // non-member call based on that function. 7380 if (Method->isStatic()) { 7381 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 7382 Args, NumArgs, RParenLoc); 7383 } 7384 7385 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 7386 } 7387 7388 assert(Method && "Member call to something that isn't a method?"); 7389 CXXMemberCallExpr *TheCall = 7390 new (Context) CXXMemberCallExpr(Context, MemExprE, Args, NumArgs, 7391 Method->getCallResultType(), 7392 RParenLoc); 7393 7394 // Check for a valid return type. 7395 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 7396 TheCall, Method)) 7397 return ExprError(); 7398 7399 // Convert the object argument (for a non-static member function call). 7400 // We only need to do this if there was actually an overload; otherwise 7401 // it was done at lookup. 7402 Expr *ObjectArg = MemExpr->getBase(); 7403 if (!Method->isStatic() && 7404 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 7405 FoundDecl, Method)) 7406 return ExprError(); 7407 MemExpr->setBase(ObjectArg); 7408 7409 // Convert the rest of the arguments 7410 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7411 if (ConvertArgumentsForCall(TheCall, MemExpr, Method, Proto, Args, NumArgs, 7412 RParenLoc)) 7413 return ExprError(); 7414 7415 if (CheckFunctionCall(Method, TheCall)) 7416 return ExprError(); 7417 7418 return MaybeBindToTemporary(TheCall); 7419} 7420 7421/// BuildCallToObjectOfClassType - Build a call to an object of class 7422/// type (C++ [over.call.object]), which can end up invoking an 7423/// overloaded function call operator (@c operator()) or performing a 7424/// user-defined conversion on the object argument. 7425Sema::ExprResult 7426Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 7427 SourceLocation LParenLoc, 7428 Expr **Args, unsigned NumArgs, 7429 SourceLocation *CommaLocs, 7430 SourceLocation RParenLoc) { 7431 assert(Object->getType()->isRecordType() && "Requires object type argument"); 7432 const RecordType *Record = Object->getType()->getAs<RecordType>(); 7433 7434 // C++ [over.call.object]p1: 7435 // If the primary-expression E in the function call syntax 7436 // evaluates to a class object of type "cv T", then the set of 7437 // candidate functions includes at least the function call 7438 // operators of T. The function call operators of T are obtained by 7439 // ordinary lookup of the name operator() in the context of 7440 // (E).operator(). 7441 OverloadCandidateSet CandidateSet(LParenLoc); 7442 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 7443 7444 if (RequireCompleteType(LParenLoc, Object->getType(), 7445 PDiag(diag::err_incomplete_object_call) 7446 << Object->getSourceRange())) 7447 return true; 7448 7449 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 7450 LookupQualifiedName(R, Record->getDecl()); 7451 R.suppressDiagnostics(); 7452 7453 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7454 Oper != OperEnd; ++Oper) { 7455 AddMethodCandidate(Oper.getPair(), Object->getType(), 7456 Args, NumArgs, CandidateSet, 7457 /*SuppressUserConversions=*/ false); 7458 } 7459 7460 // C++ [over.call.object]p2: 7461 // In addition, for each conversion function declared in T of the 7462 // form 7463 // 7464 // operator conversion-type-id () cv-qualifier; 7465 // 7466 // where cv-qualifier is the same cv-qualification as, or a 7467 // greater cv-qualification than, cv, and where conversion-type-id 7468 // denotes the type "pointer to function of (P1,...,Pn) returning 7469 // R", or the type "reference to pointer to function of 7470 // (P1,...,Pn) returning R", or the type "reference to function 7471 // of (P1,...,Pn) returning R", a surrogate call function [...] 7472 // is also considered as a candidate function. Similarly, 7473 // surrogate call functions are added to the set of candidate 7474 // functions for each conversion function declared in an 7475 // accessible base class provided the function is not hidden 7476 // within T by another intervening declaration. 7477 const UnresolvedSetImpl *Conversions 7478 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 7479 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 7480 E = Conversions->end(); I != E; ++I) { 7481 NamedDecl *D = *I; 7482 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 7483 if (isa<UsingShadowDecl>(D)) 7484 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 7485 7486 // Skip over templated conversion functions; they aren't 7487 // surrogates. 7488 if (isa<FunctionTemplateDecl>(D)) 7489 continue; 7490 7491 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 7492 7493 // Strip the reference type (if any) and then the pointer type (if 7494 // any) to get down to what might be a function type. 7495 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 7496 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7497 ConvType = ConvPtrType->getPointeeType(); 7498 7499 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 7500 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 7501 Object->getType(), Args, NumArgs, 7502 CandidateSet); 7503 } 7504 7505 // Perform overload resolution. 7506 OverloadCandidateSet::iterator Best; 7507 switch (CandidateSet.BestViableFunction(*this, Object->getLocStart(), 7508 Best)) { 7509 case OR_Success: 7510 // Overload resolution succeeded; we'll build the appropriate call 7511 // below. 7512 break; 7513 7514 case OR_No_Viable_Function: 7515 if (CandidateSet.empty()) 7516 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 7517 << Object->getType() << /*call*/ 1 7518 << Object->getSourceRange(); 7519 else 7520 Diag(Object->getSourceRange().getBegin(), 7521 diag::err_ovl_no_viable_object_call) 7522 << Object->getType() << Object->getSourceRange(); 7523 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7524 break; 7525 7526 case OR_Ambiguous: 7527 Diag(Object->getSourceRange().getBegin(), 7528 diag::err_ovl_ambiguous_object_call) 7529 << Object->getType() << Object->getSourceRange(); 7530 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, Args, NumArgs); 7531 break; 7532 7533 case OR_Deleted: 7534 Diag(Object->getSourceRange().getBegin(), 7535 diag::err_ovl_deleted_object_call) 7536 << Best->Function->isDeleted() 7537 << Object->getType() << Object->getSourceRange(); 7538 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Args, NumArgs); 7539 break; 7540 } 7541 7542 if (Best == CandidateSet.end()) 7543 return true; 7544 7545 if (Best->Function == 0) { 7546 // Since there is no function declaration, this is one of the 7547 // surrogate candidates. Dig out the conversion function. 7548 CXXConversionDecl *Conv 7549 = cast<CXXConversionDecl>( 7550 Best->Conversions[0].UserDefined.ConversionFunction); 7551 7552 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7553 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7554 7555 // We selected one of the surrogate functions that converts the 7556 // object parameter to a function pointer. Perform the conversion 7557 // on the object argument, then let ActOnCallExpr finish the job. 7558 7559 // Create an implicit member expr to refer to the conversion operator. 7560 // and then call it. 7561 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 7562 Conv); 7563 7564 return ActOnCallExpr(S, CE, LParenLoc, 7565 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 7566 CommaLocs, RParenLoc); 7567 } 7568 7569 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7570 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7571 7572 // We found an overloaded operator(). Build a CXXOperatorCallExpr 7573 // that calls this method, using Object for the implicit object 7574 // parameter and passing along the remaining arguments. 7575 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7576 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7577 7578 unsigned NumArgsInProto = Proto->getNumArgs(); 7579 unsigned NumArgsToCheck = NumArgs; 7580 7581 // Build the full argument list for the method call (the 7582 // implicit object parameter is placed at the beginning of the 7583 // list). 7584 Expr **MethodArgs; 7585 if (NumArgs < NumArgsInProto) { 7586 NumArgsToCheck = NumArgsInProto; 7587 MethodArgs = new Expr*[NumArgsInProto + 1]; 7588 } else { 7589 MethodArgs = new Expr*[NumArgs + 1]; 7590 } 7591 MethodArgs[0] = Object; 7592 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7593 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 7594 7595 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 7596 SourceLocation()); 7597 UsualUnaryConversions(NewFn); 7598 7599 // Once we've built TheCall, all of the expressions are properly 7600 // owned. 7601 QualType ResultTy = Method->getCallResultType(); 7602 CXXOperatorCallExpr *TheCall = 7603 new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 7604 MethodArgs, NumArgs + 1, 7605 ResultTy, RParenLoc); 7606 delete [] MethodArgs; 7607 7608 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall, 7609 Method)) 7610 return true; 7611 7612 // We may have default arguments. If so, we need to allocate more 7613 // slots in the call for them. 7614 if (NumArgs < NumArgsInProto) 7615 TheCall->setNumArgs(Context, NumArgsInProto + 1); 7616 else if (NumArgs > NumArgsInProto) 7617 NumArgsToCheck = NumArgsInProto; 7618 7619 bool IsError = false; 7620 7621 // Initialize the implicit object parameter. 7622 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 7623 Best->FoundDecl, Method); 7624 TheCall->setArg(0, Object); 7625 7626 7627 // Check the argument types. 7628 for (unsigned i = 0; i != NumArgsToCheck; i++) { 7629 Expr *Arg; 7630 if (i < NumArgs) { 7631 Arg = Args[i]; 7632 7633 // Pass the argument. 7634 7635 ExprResult InputInit 7636 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7637 Method->getParamDecl(i)), 7638 SourceLocation(), Arg); 7639 7640 IsError |= InputInit.isInvalid(); 7641 Arg = InputInit.takeAs<Expr>(); 7642 } else { 7643 ExprResult DefArg 7644 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 7645 if (DefArg.isInvalid()) { 7646 IsError = true; 7647 break; 7648 } 7649 7650 Arg = DefArg.takeAs<Expr>(); 7651 } 7652 7653 TheCall->setArg(i + 1, Arg); 7654 } 7655 7656 // If this is a variadic call, handle args passed through "...". 7657 if (Proto->isVariadic()) { 7658 // Promote the arguments (C99 6.5.2.2p7). 7659 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 7660 Expr *Arg = Args[i]; 7661 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 7662 TheCall->setArg(i + 1, Arg); 7663 } 7664 } 7665 7666 if (IsError) return true; 7667 7668 if (CheckFunctionCall(Method, TheCall)) 7669 return true; 7670 7671 return MaybeBindToTemporary(TheCall); 7672} 7673 7674/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 7675/// (if one exists), where @c Base is an expression of class type and 7676/// @c Member is the name of the member we're trying to find. 7677ExprResult 7678Sema::BuildOverloadedArrowExpr(Scope *S, Expr *Base, SourceLocation OpLoc) { 7679 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 7680 7681 SourceLocation Loc = Base->getExprLoc(); 7682 7683 // C++ [over.ref]p1: 7684 // 7685 // [...] An expression x->m is interpreted as (x.operator->())->m 7686 // for a class object x of type T if T::operator->() exists and if 7687 // the operator is selected as the best match function by the 7688 // overload resolution mechanism (13.3). 7689 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 7690 OverloadCandidateSet CandidateSet(Loc); 7691 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 7692 7693 if (RequireCompleteType(Loc, Base->getType(), 7694 PDiag(diag::err_typecheck_incomplete_tag) 7695 << Base->getSourceRange())) 7696 return ExprError(); 7697 7698 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 7699 LookupQualifiedName(R, BaseRecord->getDecl()); 7700 R.suppressDiagnostics(); 7701 7702 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7703 Oper != OperEnd; ++Oper) { 7704 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 7705 /*SuppressUserConversions=*/false); 7706 } 7707 7708 // Perform overload resolution. 7709 OverloadCandidateSet::iterator Best; 7710 switch (CandidateSet.BestViableFunction(*this, OpLoc, Best)) { 7711 case OR_Success: 7712 // Overload resolution succeeded; we'll build the call below. 7713 break; 7714 7715 case OR_No_Viable_Function: 7716 if (CandidateSet.empty()) 7717 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 7718 << Base->getType() << Base->getSourceRange(); 7719 else 7720 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7721 << "operator->" << Base->getSourceRange(); 7722 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 7723 return ExprError(); 7724 7725 case OR_Ambiguous: 7726 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7727 << "->" << Base->getSourceRange(); 7728 CandidateSet.NoteCandidates(*this, OCD_ViableCandidates, &Base, 1); 7729 return ExprError(); 7730 7731 case OR_Deleted: 7732 Diag(OpLoc, diag::err_ovl_deleted_oper) 7733 << Best->Function->isDeleted() 7734 << "->" << Base->getSourceRange(); 7735 CandidateSet.NoteCandidates(*this, OCD_AllCandidates, &Base, 1); 7736 return ExprError(); 7737 } 7738 7739 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 7740 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7741 7742 // Convert the object parameter. 7743 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7744 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 7745 Best->FoundDecl, Method)) 7746 return ExprError(); 7747 7748 // Build the operator call. 7749 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 7750 SourceLocation()); 7751 UsualUnaryConversions(FnExpr); 7752 7753 QualType ResultTy = Method->getCallResultType(); 7754 CXXOperatorCallExpr *TheCall = 7755 new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 7756 &Base, 1, ResultTy, OpLoc); 7757 7758 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall, 7759 Method)) 7760 return ExprError(); 7761 return Owned(TheCall); 7762} 7763 7764/// FixOverloadedFunctionReference - E is an expression that refers to 7765/// a C++ overloaded function (possibly with some parentheses and 7766/// perhaps a '&' around it). We have resolved the overloaded function 7767/// to the function declaration Fn, so patch up the expression E to 7768/// refer (possibly indirectly) to Fn. Returns the new expr. 7769Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 7770 FunctionDecl *Fn) { 7771 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 7772 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 7773 Found, Fn); 7774 if (SubExpr == PE->getSubExpr()) 7775 return PE->Retain(); 7776 7777 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 7778 } 7779 7780 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 7781 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 7782 Found, Fn); 7783 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 7784 SubExpr->getType()) && 7785 "Implicit cast type cannot be determined from overload"); 7786 assert(ICE->path_empty() && "fixing up hierarchy conversion?"); 7787 if (SubExpr == ICE->getSubExpr()) 7788 return ICE->Retain(); 7789 7790 return ImplicitCastExpr::Create(Context, ICE->getType(), 7791 ICE->getCastKind(), 7792 SubExpr, 0, 7793 ICE->getCategory()); 7794 } 7795 7796 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 7797 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 7798 "Can only take the address of an overloaded function"); 7799 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7800 if (Method->isStatic()) { 7801 // Do nothing: static member functions aren't any different 7802 // from non-member functions. 7803 } else { 7804 // Fix the sub expression, which really has to be an 7805 // UnresolvedLookupExpr holding an overloaded member function 7806 // or template. 7807 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7808 Found, Fn); 7809 if (SubExpr == UnOp->getSubExpr()) 7810 return UnOp->Retain(); 7811 7812 assert(isa<DeclRefExpr>(SubExpr) 7813 && "fixed to something other than a decl ref"); 7814 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 7815 && "fixed to a member ref with no nested name qualifier"); 7816 7817 // We have taken the address of a pointer to member 7818 // function. Perform the computation here so that we get the 7819 // appropriate pointer to member type. 7820 QualType ClassType 7821 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 7822 QualType MemPtrType 7823 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 7824 7825 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7826 MemPtrType, UnOp->getOperatorLoc()); 7827 } 7828 } 7829 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7830 Found, Fn); 7831 if (SubExpr == UnOp->getSubExpr()) 7832 return UnOp->Retain(); 7833 7834 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7835 Context.getPointerType(SubExpr->getType()), 7836 UnOp->getOperatorLoc()); 7837 } 7838 7839 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 7840 // FIXME: avoid copy. 7841 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7842 if (ULE->hasExplicitTemplateArgs()) { 7843 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 7844 TemplateArgs = &TemplateArgsBuffer; 7845 } 7846 7847 return DeclRefExpr::Create(Context, 7848 ULE->getQualifier(), 7849 ULE->getQualifierRange(), 7850 Fn, 7851 ULE->getNameLoc(), 7852 Fn->getType(), 7853 TemplateArgs); 7854 } 7855 7856 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 7857 // FIXME: avoid copy. 7858 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7859 if (MemExpr->hasExplicitTemplateArgs()) { 7860 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7861 TemplateArgs = &TemplateArgsBuffer; 7862 } 7863 7864 Expr *Base; 7865 7866 // If we're filling in 7867 if (MemExpr->isImplicitAccess()) { 7868 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 7869 return DeclRefExpr::Create(Context, 7870 MemExpr->getQualifier(), 7871 MemExpr->getQualifierRange(), 7872 Fn, 7873 MemExpr->getMemberLoc(), 7874 Fn->getType(), 7875 TemplateArgs); 7876 } else { 7877 SourceLocation Loc = MemExpr->getMemberLoc(); 7878 if (MemExpr->getQualifier()) 7879 Loc = MemExpr->getQualifierRange().getBegin(); 7880 Base = new (Context) CXXThisExpr(Loc, 7881 MemExpr->getBaseType(), 7882 /*isImplicit=*/true); 7883 } 7884 } else 7885 Base = MemExpr->getBase()->Retain(); 7886 7887 return MemberExpr::Create(Context, Base, 7888 MemExpr->isArrow(), 7889 MemExpr->getQualifier(), 7890 MemExpr->getQualifierRange(), 7891 Fn, 7892 Found, 7893 MemExpr->getMemberNameInfo(), 7894 TemplateArgs, 7895 Fn->getType()); 7896 } 7897 7898 assert(false && "Invalid reference to overloaded function"); 7899 return E->Retain(); 7900} 7901 7902ExprResult Sema::FixOverloadedFunctionReference(ExprResult E, 7903 DeclAccessPair Found, 7904 FunctionDecl *Fn) { 7905 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 7906} 7907 7908} // end namespace clang 7909