SemaOverload.cpp revision 1ec8ef7cd60e9615979e618ec39ab88305917949
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 "Sema.h" 15#include "Lookup.h" 16#include "SemaInit.h" 17#include "clang/Basic/Diagnostic.h" 18#include "clang/Lex/Preprocessor.h" 19#include "clang/AST/ASTContext.h" 20#include "clang/AST/CXXInheritance.h" 21#include "clang/AST/Expr.h" 22#include "clang/AST/ExprCXX.h" 23#include "clang/AST/TypeOrdering.h" 24#include "clang/Basic/PartialDiagnostic.h" 25#include "llvm/ADT/SmallPtrSet.h" 26#include "llvm/ADT/STLExtras.h" 27#include <algorithm> 28 29namespace clang { 30 31/// GetConversionCategory - Retrieve the implicit conversion 32/// category corresponding to the given implicit conversion kind. 33ImplicitConversionCategory 34GetConversionCategory(ImplicitConversionKind Kind) { 35 static const ImplicitConversionCategory 36 Category[(int)ICK_Num_Conversion_Kinds] = { 37 ICC_Identity, 38 ICC_Lvalue_Transformation, 39 ICC_Lvalue_Transformation, 40 ICC_Lvalue_Transformation, 41 ICC_Identity, 42 ICC_Qualification_Adjustment, 43 ICC_Promotion, 44 ICC_Promotion, 45 ICC_Promotion, 46 ICC_Conversion, 47 ICC_Conversion, 48 ICC_Conversion, 49 ICC_Conversion, 50 ICC_Conversion, 51 ICC_Conversion, 52 ICC_Conversion, 53 ICC_Conversion, 54 ICC_Conversion, 55 ICC_Conversion, 56 ICC_Conversion, 57 ICC_Conversion 58 }; 59 return Category[(int)Kind]; 60} 61 62/// GetConversionRank - Retrieve the implicit conversion rank 63/// corresponding to the given implicit conversion kind. 64ImplicitConversionRank GetConversionRank(ImplicitConversionKind Kind) { 65 static const ImplicitConversionRank 66 Rank[(int)ICK_Num_Conversion_Kinds] = { 67 ICR_Exact_Match, 68 ICR_Exact_Match, 69 ICR_Exact_Match, 70 ICR_Exact_Match, 71 ICR_Exact_Match, 72 ICR_Exact_Match, 73 ICR_Promotion, 74 ICR_Promotion, 75 ICR_Promotion, 76 ICR_Conversion, 77 ICR_Conversion, 78 ICR_Conversion, 79 ICR_Conversion, 80 ICR_Conversion, 81 ICR_Conversion, 82 ICR_Conversion, 83 ICR_Conversion, 84 ICR_Conversion, 85 ICR_Conversion, 86 ICR_Conversion, 87 ICR_Complex_Real_Conversion 88 }; 89 return Rank[(int)Kind]; 90} 91 92/// GetImplicitConversionName - Return the name of this kind of 93/// implicit conversion. 94const char* GetImplicitConversionName(ImplicitConversionKind Kind) { 95 static const char* const Name[(int)ICK_Num_Conversion_Kinds] = { 96 "No conversion", 97 "Lvalue-to-rvalue", 98 "Array-to-pointer", 99 "Function-to-pointer", 100 "Noreturn adjustment", 101 "Qualification", 102 "Integral promotion", 103 "Floating point promotion", 104 "Complex promotion", 105 "Integral conversion", 106 "Floating conversion", 107 "Complex conversion", 108 "Floating-integral conversion", 109 "Pointer conversion", 110 "Pointer-to-member conversion", 111 "Boolean conversion", 112 "Compatible-types conversion", 113 "Derived-to-base conversion", 114 "Vector conversion", 115 "Vector splat", 116 "Complex-real conversion" 117 }; 118 return Name[Kind]; 119} 120 121/// StandardConversionSequence - Set the standard conversion 122/// sequence to the identity conversion. 123void StandardConversionSequence::setAsIdentityConversion() { 124 First = ICK_Identity; 125 Second = ICK_Identity; 126 Third = ICK_Identity; 127 DeprecatedStringLiteralToCharPtr = false; 128 ReferenceBinding = false; 129 DirectBinding = false; 130 RRefBinding = false; 131 CopyConstructor = 0; 132} 133 134/// getRank - Retrieve the rank of this standard conversion sequence 135/// (C++ 13.3.3.1.1p3). The rank is the largest rank of each of the 136/// implicit conversions. 137ImplicitConversionRank StandardConversionSequence::getRank() const { 138 ImplicitConversionRank Rank = ICR_Exact_Match; 139 if (GetConversionRank(First) > Rank) 140 Rank = GetConversionRank(First); 141 if (GetConversionRank(Second) > Rank) 142 Rank = GetConversionRank(Second); 143 if (GetConversionRank(Third) > Rank) 144 Rank = GetConversionRank(Third); 145 return Rank; 146} 147 148/// isPointerConversionToBool - Determines whether this conversion is 149/// a conversion of a pointer or pointer-to-member to bool. This is 150/// used as part of the ranking of standard conversion sequences 151/// (C++ 13.3.3.2p4). 152bool StandardConversionSequence::isPointerConversionToBool() const { 153 // Note that FromType has not necessarily been transformed by the 154 // array-to-pointer or function-to-pointer implicit conversions, so 155 // check for their presence as well as checking whether FromType is 156 // a pointer. 157 if (getToType(1)->isBooleanType() && 158 (getFromType()->isPointerType() || 159 getFromType()->isObjCObjectPointerType() || 160 getFromType()->isBlockPointerType() || 161 First == ICK_Array_To_Pointer || First == ICK_Function_To_Pointer)) 162 return true; 163 164 return false; 165} 166 167/// isPointerConversionToVoidPointer - Determines whether this 168/// conversion is a conversion of a pointer to a void pointer. This is 169/// used as part of the ranking of standard conversion sequences (C++ 170/// 13.3.3.2p4). 171bool 172StandardConversionSequence:: 173isPointerConversionToVoidPointer(ASTContext& Context) const { 174 QualType FromType = getFromType(); 175 QualType ToType = getToType(1); 176 177 // Note that FromType has not necessarily been transformed by the 178 // array-to-pointer implicit conversion, so check for its presence 179 // and redo the conversion to get a pointer. 180 if (First == ICK_Array_To_Pointer) 181 FromType = Context.getArrayDecayedType(FromType); 182 183 if (Second == ICK_Pointer_Conversion && FromType->isPointerType()) 184 if (const PointerType* ToPtrType = ToType->getAs<PointerType>()) 185 return ToPtrType->getPointeeType()->isVoidType(); 186 187 return false; 188} 189 190/// DebugPrint - Print this standard conversion sequence to standard 191/// error. Useful for debugging overloading issues. 192void StandardConversionSequence::DebugPrint() const { 193 llvm::raw_ostream &OS = llvm::errs(); 194 bool PrintedSomething = false; 195 if (First != ICK_Identity) { 196 OS << GetImplicitConversionName(First); 197 PrintedSomething = true; 198 } 199 200 if (Second != ICK_Identity) { 201 if (PrintedSomething) { 202 OS << " -> "; 203 } 204 OS << GetImplicitConversionName(Second); 205 206 if (CopyConstructor) { 207 OS << " (by copy constructor)"; 208 } else if (DirectBinding) { 209 OS << " (direct reference binding)"; 210 } else if (ReferenceBinding) { 211 OS << " (reference binding)"; 212 } 213 PrintedSomething = true; 214 } 215 216 if (Third != ICK_Identity) { 217 if (PrintedSomething) { 218 OS << " -> "; 219 } 220 OS << GetImplicitConversionName(Third); 221 PrintedSomething = true; 222 } 223 224 if (!PrintedSomething) { 225 OS << "No conversions required"; 226 } 227} 228 229/// DebugPrint - Print this user-defined conversion sequence to standard 230/// error. Useful for debugging overloading issues. 231void UserDefinedConversionSequence::DebugPrint() const { 232 llvm::raw_ostream &OS = llvm::errs(); 233 if (Before.First || Before.Second || Before.Third) { 234 Before.DebugPrint(); 235 OS << " -> "; 236 } 237 OS << '\'' << ConversionFunction << '\''; 238 if (After.First || After.Second || After.Third) { 239 OS << " -> "; 240 After.DebugPrint(); 241 } 242} 243 244/// DebugPrint - Print this implicit conversion sequence to standard 245/// error. Useful for debugging overloading issues. 246void ImplicitConversionSequence::DebugPrint() const { 247 llvm::raw_ostream &OS = llvm::errs(); 248 switch (ConversionKind) { 249 case StandardConversion: 250 OS << "Standard conversion: "; 251 Standard.DebugPrint(); 252 break; 253 case UserDefinedConversion: 254 OS << "User-defined conversion: "; 255 UserDefined.DebugPrint(); 256 break; 257 case EllipsisConversion: 258 OS << "Ellipsis conversion"; 259 break; 260 case AmbiguousConversion: 261 OS << "Ambiguous conversion"; 262 break; 263 case BadConversion: 264 OS << "Bad conversion"; 265 break; 266 } 267 268 OS << "\n"; 269} 270 271void AmbiguousConversionSequence::construct() { 272 new (&conversions()) ConversionSet(); 273} 274 275void AmbiguousConversionSequence::destruct() { 276 conversions().~ConversionSet(); 277} 278 279void 280AmbiguousConversionSequence::copyFrom(const AmbiguousConversionSequence &O) { 281 FromTypePtr = O.FromTypePtr; 282 ToTypePtr = O.ToTypePtr; 283 new (&conversions()) ConversionSet(O.conversions()); 284} 285 286namespace { 287 // Structure used by OverloadCandidate::DeductionFailureInfo to store 288 // template parameter and template argument information. 289 struct DFIParamWithArguments { 290 TemplateParameter Param; 291 TemplateArgument FirstArg; 292 TemplateArgument SecondArg; 293 }; 294} 295 296/// \brief Convert from Sema's representation of template deduction information 297/// to the form used in overload-candidate information. 298OverloadCandidate::DeductionFailureInfo 299static MakeDeductionFailureInfo(ASTContext &Context, 300 Sema::TemplateDeductionResult TDK, 301 Sema::TemplateDeductionInfo &Info) { 302 OverloadCandidate::DeductionFailureInfo Result; 303 Result.Result = static_cast<unsigned>(TDK); 304 Result.Data = 0; 305 switch (TDK) { 306 case Sema::TDK_Success: 307 case Sema::TDK_InstantiationDepth: 308 case Sema::TDK_TooManyArguments: 309 case Sema::TDK_TooFewArguments: 310 break; 311 312 case Sema::TDK_Incomplete: 313 case Sema::TDK_InvalidExplicitArguments: 314 Result.Data = Info.Param.getOpaqueValue(); 315 break; 316 317 case Sema::TDK_Inconsistent: 318 case Sema::TDK_InconsistentQuals: { 319 // FIXME: Should allocate from normal heap so that we can free this later. 320 DFIParamWithArguments *Saved = new (Context) DFIParamWithArguments; 321 Saved->Param = Info.Param; 322 Saved->FirstArg = Info.FirstArg; 323 Saved->SecondArg = Info.SecondArg; 324 Result.Data = Saved; 325 break; 326 } 327 328 case Sema::TDK_SubstitutionFailure: 329 Result.Data = Info.take(); 330 break; 331 332 case Sema::TDK_NonDeducedMismatch: 333 case Sema::TDK_FailedOverloadResolution: 334 break; 335 } 336 337 return Result; 338} 339 340void OverloadCandidate::DeductionFailureInfo::Destroy() { 341 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 342 case Sema::TDK_Success: 343 case Sema::TDK_InstantiationDepth: 344 case Sema::TDK_Incomplete: 345 case Sema::TDK_TooManyArguments: 346 case Sema::TDK_TooFewArguments: 347 case Sema::TDK_InvalidExplicitArguments: 348 break; 349 350 case Sema::TDK_Inconsistent: 351 case Sema::TDK_InconsistentQuals: 352 // FIXME: Destroy the data? 353 Data = 0; 354 break; 355 356 case Sema::TDK_SubstitutionFailure: 357 // FIXME: Destroy the template arugment list? 358 Data = 0; 359 break; 360 361 // Unhandled 362 case Sema::TDK_NonDeducedMismatch: 363 case Sema::TDK_FailedOverloadResolution: 364 break; 365 } 366} 367 368TemplateParameter 369OverloadCandidate::DeductionFailureInfo::getTemplateParameter() { 370 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 371 case Sema::TDK_Success: 372 case Sema::TDK_InstantiationDepth: 373 case Sema::TDK_TooManyArguments: 374 case Sema::TDK_TooFewArguments: 375 case Sema::TDK_SubstitutionFailure: 376 return TemplateParameter(); 377 378 case Sema::TDK_Incomplete: 379 case Sema::TDK_InvalidExplicitArguments: 380 return TemplateParameter::getFromOpaqueValue(Data); 381 382 case Sema::TDK_Inconsistent: 383 case Sema::TDK_InconsistentQuals: 384 return static_cast<DFIParamWithArguments*>(Data)->Param; 385 386 // Unhandled 387 case Sema::TDK_NonDeducedMismatch: 388 case Sema::TDK_FailedOverloadResolution: 389 break; 390 } 391 392 return TemplateParameter(); 393} 394 395TemplateArgumentList * 396OverloadCandidate::DeductionFailureInfo::getTemplateArgumentList() { 397 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 398 case Sema::TDK_Success: 399 case Sema::TDK_InstantiationDepth: 400 case Sema::TDK_TooManyArguments: 401 case Sema::TDK_TooFewArguments: 402 case Sema::TDK_Incomplete: 403 case Sema::TDK_InvalidExplicitArguments: 404 case Sema::TDK_Inconsistent: 405 case Sema::TDK_InconsistentQuals: 406 return 0; 407 408 case Sema::TDK_SubstitutionFailure: 409 return static_cast<TemplateArgumentList*>(Data); 410 411 // Unhandled 412 case Sema::TDK_NonDeducedMismatch: 413 case Sema::TDK_FailedOverloadResolution: 414 break; 415 } 416 417 return 0; 418} 419 420const TemplateArgument *OverloadCandidate::DeductionFailureInfo::getFirstArg() { 421 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 422 case Sema::TDK_Success: 423 case Sema::TDK_InstantiationDepth: 424 case Sema::TDK_Incomplete: 425 case Sema::TDK_TooManyArguments: 426 case Sema::TDK_TooFewArguments: 427 case Sema::TDK_InvalidExplicitArguments: 428 case Sema::TDK_SubstitutionFailure: 429 return 0; 430 431 case Sema::TDK_Inconsistent: 432 case Sema::TDK_InconsistentQuals: 433 return &static_cast<DFIParamWithArguments*>(Data)->FirstArg; 434 435 // Unhandled 436 case Sema::TDK_NonDeducedMismatch: 437 case Sema::TDK_FailedOverloadResolution: 438 break; 439 } 440 441 return 0; 442} 443 444const TemplateArgument * 445OverloadCandidate::DeductionFailureInfo::getSecondArg() { 446 switch (static_cast<Sema::TemplateDeductionResult>(Result)) { 447 case Sema::TDK_Success: 448 case Sema::TDK_InstantiationDepth: 449 case Sema::TDK_Incomplete: 450 case Sema::TDK_TooManyArguments: 451 case Sema::TDK_TooFewArguments: 452 case Sema::TDK_InvalidExplicitArguments: 453 case Sema::TDK_SubstitutionFailure: 454 return 0; 455 456 case Sema::TDK_Inconsistent: 457 case Sema::TDK_InconsistentQuals: 458 return &static_cast<DFIParamWithArguments*>(Data)->SecondArg; 459 460 // Unhandled 461 case Sema::TDK_NonDeducedMismatch: 462 case Sema::TDK_FailedOverloadResolution: 463 break; 464 } 465 466 return 0; 467} 468 469void OverloadCandidateSet::clear() { 470 inherited::clear(); 471 Functions.clear(); 472} 473 474// IsOverload - Determine whether the given New declaration is an 475// overload of the declarations in Old. This routine returns false if 476// New and Old cannot be overloaded, e.g., if New has the same 477// signature as some function in Old (C++ 1.3.10) or if the Old 478// declarations aren't functions (or function templates) at all. When 479// it does return false, MatchedDecl will point to the decl that New 480// cannot be overloaded with. This decl may be a UsingShadowDecl on 481// top of the underlying declaration. 482// 483// Example: Given the following input: 484// 485// void f(int, float); // #1 486// void f(int, int); // #2 487// int f(int, int); // #3 488// 489// When we process #1, there is no previous declaration of "f", 490// so IsOverload will not be used. 491// 492// When we process #2, Old contains only the FunctionDecl for #1. By 493// comparing the parameter types, we see that #1 and #2 are overloaded 494// (since they have different signatures), so this routine returns 495// false; MatchedDecl is unchanged. 496// 497// When we process #3, Old is an overload set containing #1 and #2. We 498// compare the signatures of #3 to #1 (they're overloaded, so we do 499// nothing) and then #3 to #2. Since the signatures of #3 and #2 are 500// identical (return types of functions are not part of the 501// signature), IsOverload returns false and MatchedDecl will be set to 502// point to the FunctionDecl for #2. 503// 504// 'NewIsUsingShadowDecl' indicates that 'New' is being introduced 505// into a class by a using declaration. The rules for whether to hide 506// shadow declarations ignore some properties which otherwise figure 507// into a function template's signature. 508Sema::OverloadKind 509Sema::CheckOverload(Scope *S, FunctionDecl *New, const LookupResult &Old, 510 NamedDecl *&Match, bool NewIsUsingDecl) { 511 for (LookupResult::iterator I = Old.begin(), E = Old.end(); 512 I != E; ++I) { 513 NamedDecl *OldD = *I; 514 515 bool OldIsUsingDecl = false; 516 if (isa<UsingShadowDecl>(OldD)) { 517 OldIsUsingDecl = true; 518 519 // We can always introduce two using declarations into the same 520 // context, even if they have identical signatures. 521 if (NewIsUsingDecl) continue; 522 523 OldD = cast<UsingShadowDecl>(OldD)->getTargetDecl(); 524 } 525 526 // If either declaration was introduced by a using declaration, 527 // we'll need to use slightly different rules for matching. 528 // Essentially, these rules are the normal rules, except that 529 // function templates hide function templates with different 530 // return types or template parameter lists. 531 bool UseMemberUsingDeclRules = 532 (OldIsUsingDecl || NewIsUsingDecl) && CurContext->isRecord(); 533 534 if (FunctionTemplateDecl *OldT = dyn_cast<FunctionTemplateDecl>(OldD)) { 535 if (!IsOverload(New, OldT->getTemplatedDecl(), UseMemberUsingDeclRules)) { 536 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 537 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 538 continue; 539 } 540 541 Match = *I; 542 return Ovl_Match; 543 } 544 } else if (FunctionDecl *OldF = dyn_cast<FunctionDecl>(OldD)) { 545 if (!IsOverload(New, OldF, UseMemberUsingDeclRules)) { 546 if (UseMemberUsingDeclRules && OldIsUsingDecl) { 547 HideUsingShadowDecl(S, cast<UsingShadowDecl>(*I)); 548 continue; 549 } 550 551 Match = *I; 552 return Ovl_Match; 553 } 554 } else if (isa<UsingDecl>(OldD) || isa<TagDecl>(OldD)) { 555 // We can overload with these, which can show up when doing 556 // redeclaration checks for UsingDecls. 557 assert(Old.getLookupKind() == LookupUsingDeclName); 558 } else if (isa<UnresolvedUsingValueDecl>(OldD)) { 559 // Optimistically assume that an unresolved using decl will 560 // overload; if it doesn't, we'll have to diagnose during 561 // template instantiation. 562 } else { 563 // (C++ 13p1): 564 // Only function declarations can be overloaded; object and type 565 // declarations cannot be overloaded. 566 Match = *I; 567 return Ovl_NonFunction; 568 } 569 } 570 571 return Ovl_Overload; 572} 573 574bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old, 575 bool UseUsingDeclRules) { 576 FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate(); 577 FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate(); 578 579 // C++ [temp.fct]p2: 580 // A function template can be overloaded with other function templates 581 // and with normal (non-template) functions. 582 if ((OldTemplate == 0) != (NewTemplate == 0)) 583 return true; 584 585 // Is the function New an overload of the function Old? 586 QualType OldQType = Context.getCanonicalType(Old->getType()); 587 QualType NewQType = Context.getCanonicalType(New->getType()); 588 589 // Compare the signatures (C++ 1.3.10) of the two functions to 590 // determine whether they are overloads. If we find any mismatch 591 // in the signature, they are overloads. 592 593 // If either of these functions is a K&R-style function (no 594 // prototype), then we consider them to have matching signatures. 595 if (isa<FunctionNoProtoType>(OldQType.getTypePtr()) || 596 isa<FunctionNoProtoType>(NewQType.getTypePtr())) 597 return false; 598 599 FunctionProtoType* OldType = cast<FunctionProtoType>(OldQType); 600 FunctionProtoType* NewType = cast<FunctionProtoType>(NewQType); 601 602 // The signature of a function includes the types of its 603 // parameters (C++ 1.3.10), which includes the presence or absence 604 // of the ellipsis; see C++ DR 357). 605 if (OldQType != NewQType && 606 (OldType->getNumArgs() != NewType->getNumArgs() || 607 OldType->isVariadic() != NewType->isVariadic() || 608 !FunctionArgTypesAreEqual(OldType, NewType))) 609 return true; 610 611 // C++ [temp.over.link]p4: 612 // The signature of a function template consists of its function 613 // signature, its return type and its template parameter list. The names 614 // of the template parameters are significant only for establishing the 615 // relationship between the template parameters and the rest of the 616 // signature. 617 // 618 // We check the return type and template parameter lists for function 619 // templates first; the remaining checks follow. 620 // 621 // However, we don't consider either of these when deciding whether 622 // a member introduced by a shadow declaration is hidden. 623 if (!UseUsingDeclRules && NewTemplate && 624 (!TemplateParameterListsAreEqual(NewTemplate->getTemplateParameters(), 625 OldTemplate->getTemplateParameters(), 626 false, TPL_TemplateMatch) || 627 OldType->getResultType() != NewType->getResultType())) 628 return true; 629 630 // If the function is a class member, its signature includes the 631 // cv-qualifiers (if any) on the function itself. 632 // 633 // As part of this, also check whether one of the member functions 634 // is static, in which case they are not overloads (C++ 635 // 13.1p2). While not part of the definition of the signature, 636 // this check is important to determine whether these functions 637 // can be overloaded. 638 CXXMethodDecl* OldMethod = dyn_cast<CXXMethodDecl>(Old); 639 CXXMethodDecl* NewMethod = dyn_cast<CXXMethodDecl>(New); 640 if (OldMethod && NewMethod && 641 !OldMethod->isStatic() && !NewMethod->isStatic() && 642 OldMethod->getTypeQualifiers() != NewMethod->getTypeQualifiers()) 643 return true; 644 645 // The signatures match; this is not an overload. 646 return false; 647} 648 649/// TryImplicitConversion - Attempt to perform an implicit conversion 650/// from the given expression (Expr) to the given type (ToType). This 651/// function returns an implicit conversion sequence that can be used 652/// to perform the initialization. Given 653/// 654/// void f(float f); 655/// void g(int i) { f(i); } 656/// 657/// this routine would produce an implicit conversion sequence to 658/// describe the initialization of f from i, which will be a standard 659/// conversion sequence containing an lvalue-to-rvalue conversion (C++ 660/// 4.1) followed by a floating-integral conversion (C++ 4.9). 661// 662/// Note that this routine only determines how the conversion can be 663/// performed; it does not actually perform the conversion. As such, 664/// it will not produce any diagnostics if no conversion is available, 665/// but will instead return an implicit conversion sequence of kind 666/// "BadConversion". 667/// 668/// If @p SuppressUserConversions, then user-defined conversions are 669/// not permitted. 670/// If @p AllowExplicit, then explicit user-defined conversions are 671/// permitted. 672ImplicitConversionSequence 673Sema::TryImplicitConversion(Expr* From, QualType ToType, 674 bool SuppressUserConversions, 675 bool AllowExplicit, 676 bool InOverloadResolution) { 677 ImplicitConversionSequence ICS; 678 if (IsStandardConversion(From, ToType, InOverloadResolution, ICS.Standard)) { 679 ICS.setStandard(); 680 return ICS; 681 } 682 683 if (!getLangOptions().CPlusPlus) { 684 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 685 return ICS; 686 } 687 688 if (SuppressUserConversions) { 689 // C++ [over.ics.user]p4: 690 // A conversion of an expression of class type to the same class 691 // type is given Exact Match rank, and a conversion of an 692 // expression of class type to a base class of that type is 693 // given Conversion rank, in spite of the fact that a copy/move 694 // constructor (i.e., a user-defined conversion function) is 695 // called for those cases. 696 QualType FromType = From->getType(); 697 if (!ToType->getAs<RecordType>() || !FromType->getAs<RecordType>() || 698 !(Context.hasSameUnqualifiedType(FromType, ToType) || 699 IsDerivedFrom(FromType, ToType))) { 700 // We're not in the case above, so there is no conversion that 701 // we can perform. 702 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 703 return ICS; 704 } 705 706 ICS.setStandard(); 707 ICS.Standard.setAsIdentityConversion(); 708 ICS.Standard.setFromType(FromType); 709 ICS.Standard.setAllToTypes(ToType); 710 711 // We don't actually check at this point whether there is a valid 712 // copy/move constructor, since overloading just assumes that it 713 // exists. When we actually perform initialization, we'll find the 714 // appropriate constructor to copy the returned object, if needed. 715 ICS.Standard.CopyConstructor = 0; 716 717 // Determine whether this is considered a derived-to-base conversion. 718 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 719 ICS.Standard.Second = ICK_Derived_To_Base; 720 721 return ICS; 722 } 723 724 // Attempt user-defined conversion. 725 OverloadCandidateSet Conversions(From->getExprLoc()); 726 OverloadingResult UserDefResult 727 = IsUserDefinedConversion(From, ToType, ICS.UserDefined, Conversions, 728 AllowExplicit); 729 730 if (UserDefResult == OR_Success) { 731 ICS.setUserDefined(); 732 // C++ [over.ics.user]p4: 733 // A conversion of an expression of class type to the same class 734 // type is given Exact Match rank, and a conversion of an 735 // expression of class type to a base class of that type is 736 // given Conversion rank, in spite of the fact that a copy 737 // constructor (i.e., a user-defined conversion function) is 738 // called for those cases. 739 if (CXXConstructorDecl *Constructor 740 = dyn_cast<CXXConstructorDecl>(ICS.UserDefined.ConversionFunction)) { 741 QualType FromCanon 742 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 743 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 744 if (Constructor->isCopyConstructor() && 745 (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon))) { 746 // Turn this into a "standard" conversion sequence, so that it 747 // gets ranked with standard conversion sequences. 748 ICS.setStandard(); 749 ICS.Standard.setAsIdentityConversion(); 750 ICS.Standard.setFromType(From->getType()); 751 ICS.Standard.setAllToTypes(ToType); 752 ICS.Standard.CopyConstructor = Constructor; 753 if (ToCanon != FromCanon) 754 ICS.Standard.Second = ICK_Derived_To_Base; 755 } 756 } 757 758 // C++ [over.best.ics]p4: 759 // However, when considering the argument of a user-defined 760 // conversion function that is a candidate by 13.3.1.3 when 761 // invoked for the copying of the temporary in the second step 762 // of a class copy-initialization, or by 13.3.1.4, 13.3.1.5, or 763 // 13.3.1.6 in all cases, only standard conversion sequences and 764 // ellipsis conversion sequences are allowed. 765 if (SuppressUserConversions && ICS.isUserDefined()) { 766 ICS.setBad(BadConversionSequence::suppressed_user, From, ToType); 767 } 768 } else if (UserDefResult == OR_Ambiguous && !SuppressUserConversions) { 769 ICS.setAmbiguous(); 770 ICS.Ambiguous.setFromType(From->getType()); 771 ICS.Ambiguous.setToType(ToType); 772 for (OverloadCandidateSet::iterator Cand = Conversions.begin(); 773 Cand != Conversions.end(); ++Cand) 774 if (Cand->Viable) 775 ICS.Ambiguous.addConversion(Cand->Function); 776 } else { 777 ICS.setBad(BadConversionSequence::no_conversion, From, ToType); 778 } 779 780 return ICS; 781} 782 783/// PerformImplicitConversion - Perform an implicit conversion of the 784/// expression From to the type ToType. Returns true if there was an 785/// error, false otherwise. The expression From is replaced with the 786/// converted expression. Flavor is the kind of conversion we're 787/// performing, used in the error message. If @p AllowExplicit, 788/// explicit user-defined conversions are permitted. 789bool 790Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 791 AssignmentAction Action, bool AllowExplicit) { 792 ImplicitConversionSequence ICS; 793 return PerformImplicitConversion(From, ToType, Action, AllowExplicit, ICS); 794} 795 796bool 797Sema::PerformImplicitConversion(Expr *&From, QualType ToType, 798 AssignmentAction Action, bool AllowExplicit, 799 ImplicitConversionSequence& ICS) { 800 ICS = TryImplicitConversion(From, ToType, 801 /*SuppressUserConversions=*/false, 802 AllowExplicit, 803 /*InOverloadResolution=*/false); 804 return PerformImplicitConversion(From, ToType, ICS, Action); 805} 806 807/// \brief Determine whether the conversion from FromType to ToType is a valid 808/// conversion that strips "noreturn" off the nested function type. 809static bool IsNoReturnConversion(ASTContext &Context, QualType FromType, 810 QualType ToType, QualType &ResultTy) { 811 if (Context.hasSameUnqualifiedType(FromType, ToType)) 812 return false; 813 814 // Strip the noreturn off the type we're converting from; noreturn can 815 // safely be removed. 816 FromType = Context.getNoReturnType(FromType, false); 817 if (!Context.hasSameUnqualifiedType(FromType, ToType)) 818 return false; 819 820 ResultTy = FromType; 821 return true; 822} 823 824/// \brief Determine whether the conversion from FromType to ToType is a valid 825/// vector conversion. 826/// 827/// \param ICK Will be set to the vector conversion kind, if this is a vector 828/// conversion. 829static bool IsVectorConversion(ASTContext &Context, QualType FromType, 830 QualType ToType, ImplicitConversionKind &ICK) { 831 // We need at least one of these types to be a vector type to have a vector 832 // conversion. 833 if (!ToType->isVectorType() && !FromType->isVectorType()) 834 return false; 835 836 // Identical types require no conversions. 837 if (Context.hasSameUnqualifiedType(FromType, ToType)) 838 return false; 839 840 // There are no conversions between extended vector types, only identity. 841 if (ToType->isExtVectorType()) { 842 // There are no conversions between extended vector types other than the 843 // identity conversion. 844 if (FromType->isExtVectorType()) 845 return false; 846 847 // Vector splat from any arithmetic type to a vector. 848 if (!FromType->isVectorType() && FromType->isArithmeticType()) { 849 ICK = ICK_Vector_Splat; 850 return true; 851 } 852 } 853 854 // If lax vector conversions are permitted and the vector types are of the 855 // same size, we can perform the conversion. 856 if (Context.getLangOptions().LaxVectorConversions && 857 FromType->isVectorType() && ToType->isVectorType() && 858 Context.getTypeSize(FromType) == Context.getTypeSize(ToType)) { 859 ICK = ICK_Vector_Conversion; 860 return true; 861 } 862 863 return false; 864} 865 866/// IsStandardConversion - Determines whether there is a standard 867/// conversion sequence (C++ [conv], C++ [over.ics.scs]) from the 868/// expression From to the type ToType. Standard conversion sequences 869/// only consider non-class types; for conversions that involve class 870/// types, use TryImplicitConversion. If a conversion exists, SCS will 871/// contain the standard conversion sequence required to perform this 872/// conversion and this routine will return true. Otherwise, this 873/// routine will return false and the value of SCS is unspecified. 874bool 875Sema::IsStandardConversion(Expr* From, QualType ToType, 876 bool InOverloadResolution, 877 StandardConversionSequence &SCS) { 878 QualType FromType = From->getType(); 879 880 // Standard conversions (C++ [conv]) 881 SCS.setAsIdentityConversion(); 882 SCS.DeprecatedStringLiteralToCharPtr = false; 883 SCS.IncompatibleObjC = false; 884 SCS.setFromType(FromType); 885 SCS.CopyConstructor = 0; 886 887 // There are no standard conversions for class types in C++, so 888 // abort early. When overloading in C, however, we do permit 889 if (FromType->isRecordType() || ToType->isRecordType()) { 890 if (getLangOptions().CPlusPlus) 891 return false; 892 893 // When we're overloading in C, we allow, as standard conversions, 894 } 895 896 // The first conversion can be an lvalue-to-rvalue conversion, 897 // array-to-pointer conversion, or function-to-pointer conversion 898 // (C++ 4p1). 899 900 if (FromType == Context.OverloadTy) { 901 DeclAccessPair AccessPair; 902 if (FunctionDecl *Fn 903 = ResolveAddressOfOverloadedFunction(From, ToType, false, 904 AccessPair)) { 905 // We were able to resolve the address of the overloaded function, 906 // so we can convert to the type of that function. 907 FromType = Fn->getType(); 908 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 909 if (!Method->isStatic()) { 910 Type *ClassType 911 = Context.getTypeDeclType(Method->getParent()).getTypePtr(); 912 FromType = Context.getMemberPointerType(FromType, ClassType); 913 } 914 } 915 916 // If the "from" expression takes the address of the overloaded 917 // function, update the type of the resulting expression accordingly. 918 if (FromType->getAs<FunctionType>()) 919 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(From->IgnoreParens())) 920 if (UnOp->getOpcode() == UnaryOperator::AddrOf) 921 FromType = Context.getPointerType(FromType); 922 923 // Check that we've computed the proper type after overload resolution. 924 assert(Context.hasSameType(FromType, 925 FixOverloadedFunctionReference(From, AccessPair, Fn)->getType())); 926 } else { 927 return false; 928 } 929 } 930 // Lvalue-to-rvalue conversion (C++ 4.1): 931 // An lvalue (3.10) of a non-function, non-array type T can be 932 // converted to an rvalue. 933 Expr::isLvalueResult argIsLvalue = From->isLvalue(Context); 934 if (argIsLvalue == Expr::LV_Valid && 935 !FromType->isFunctionType() && !FromType->isArrayType() && 936 Context.getCanonicalType(FromType) != Context.OverloadTy) { 937 SCS.First = ICK_Lvalue_To_Rvalue; 938 939 // If T is a non-class type, the type of the rvalue is the 940 // cv-unqualified version of T. Otherwise, the type of the rvalue 941 // is T (C++ 4.1p1). C++ can't get here with class types; in C, we 942 // just strip the qualifiers because they don't matter. 943 FromType = FromType.getUnqualifiedType(); 944 } else if (FromType->isArrayType()) { 945 // Array-to-pointer conversion (C++ 4.2) 946 SCS.First = ICK_Array_To_Pointer; 947 948 // An lvalue or rvalue of type "array of N T" or "array of unknown 949 // bound of T" can be converted to an rvalue of type "pointer to 950 // T" (C++ 4.2p1). 951 FromType = Context.getArrayDecayedType(FromType); 952 953 if (IsStringLiteralToNonConstPointerConversion(From, ToType)) { 954 // This conversion is deprecated. (C++ D.4). 955 SCS.DeprecatedStringLiteralToCharPtr = true; 956 957 // For the purpose of ranking in overload resolution 958 // (13.3.3.1.1), this conversion is considered an 959 // array-to-pointer conversion followed by a qualification 960 // conversion (4.4). (C++ 4.2p2) 961 SCS.Second = ICK_Identity; 962 SCS.Third = ICK_Qualification; 963 SCS.setAllToTypes(FromType); 964 return true; 965 } 966 } else if (FromType->isFunctionType() && argIsLvalue == Expr::LV_Valid) { 967 // Function-to-pointer conversion (C++ 4.3). 968 SCS.First = ICK_Function_To_Pointer; 969 970 // An lvalue of function type T can be converted to an rvalue of 971 // type "pointer to T." The result is a pointer to the 972 // function. (C++ 4.3p1). 973 FromType = Context.getPointerType(FromType); 974 } else { 975 // We don't require any conversions for the first step. 976 SCS.First = ICK_Identity; 977 } 978 SCS.setToType(0, FromType); 979 980 // The second conversion can be an integral promotion, floating 981 // point promotion, integral conversion, floating point conversion, 982 // floating-integral conversion, pointer conversion, 983 // pointer-to-member conversion, or boolean conversion (C++ 4p1). 984 // For overloading in C, this can also be a "compatible-type" 985 // conversion. 986 bool IncompatibleObjC = false; 987 ImplicitConversionKind SecondICK = ICK_Identity; 988 if (Context.hasSameUnqualifiedType(FromType, ToType)) { 989 // The unqualified versions of the types are the same: there's no 990 // conversion to do. 991 SCS.Second = ICK_Identity; 992 } else if (IsIntegralPromotion(From, FromType, ToType)) { 993 // Integral promotion (C++ 4.5). 994 SCS.Second = ICK_Integral_Promotion; 995 FromType = ToType.getUnqualifiedType(); 996 } else if (IsFloatingPointPromotion(FromType, ToType)) { 997 // Floating point promotion (C++ 4.6). 998 SCS.Second = ICK_Floating_Promotion; 999 FromType = ToType.getUnqualifiedType(); 1000 } else if (IsComplexPromotion(FromType, ToType)) { 1001 // Complex promotion (Clang extension) 1002 SCS.Second = ICK_Complex_Promotion; 1003 FromType = ToType.getUnqualifiedType(); 1004 } else if (FromType->isIntegralOrEnumerationType() && 1005 ToType->isIntegralType(Context)) { 1006 // Integral conversions (C++ 4.7). 1007 SCS.Second = ICK_Integral_Conversion; 1008 FromType = ToType.getUnqualifiedType(); 1009 } else if (FromType->isComplexType() && ToType->isComplexType()) { 1010 // Complex conversions (C99 6.3.1.6) 1011 SCS.Second = ICK_Complex_Conversion; 1012 FromType = ToType.getUnqualifiedType(); 1013 } else if ((FromType->isComplexType() && ToType->isArithmeticType()) || 1014 (ToType->isComplexType() && FromType->isArithmeticType())) { 1015 // Complex-real conversions (C99 6.3.1.7) 1016 SCS.Second = ICK_Complex_Real; 1017 FromType = ToType.getUnqualifiedType(); 1018 } else if (FromType->isFloatingType() && ToType->isFloatingType()) { 1019 // Floating point conversions (C++ 4.8). 1020 SCS.Second = ICK_Floating_Conversion; 1021 FromType = ToType.getUnqualifiedType(); 1022 } else if ((FromType->isFloatingType() && 1023 ToType->isIntegralType(Context) && !ToType->isBooleanType()) || 1024 (FromType->isIntegralOrEnumerationType() && 1025 ToType->isFloatingType())) { 1026 // Floating-integral conversions (C++ 4.9). 1027 SCS.Second = ICK_Floating_Integral; 1028 FromType = ToType.getUnqualifiedType(); 1029 } else if (IsPointerConversion(From, FromType, ToType, InOverloadResolution, 1030 FromType, IncompatibleObjC)) { 1031 // Pointer conversions (C++ 4.10). 1032 SCS.Second = ICK_Pointer_Conversion; 1033 SCS.IncompatibleObjC = IncompatibleObjC; 1034 } else if (IsMemberPointerConversion(From, FromType, ToType, 1035 InOverloadResolution, FromType)) { 1036 // Pointer to member conversions (4.11). 1037 SCS.Second = ICK_Pointer_Member; 1038 } else if (ToType->isBooleanType() && 1039 (FromType->isArithmeticType() || 1040 FromType->isEnumeralType() || 1041 FromType->isAnyPointerType() || 1042 FromType->isBlockPointerType() || 1043 FromType->isMemberPointerType() || 1044 FromType->isNullPtrType())) { 1045 // Boolean conversions (C++ 4.12). 1046 SCS.Second = ICK_Boolean_Conversion; 1047 FromType = Context.BoolTy; 1048 } else if (IsVectorConversion(Context, FromType, ToType, SecondICK)) { 1049 SCS.Second = SecondICK; 1050 FromType = ToType.getUnqualifiedType(); 1051 } else if (!getLangOptions().CPlusPlus && 1052 Context.typesAreCompatible(ToType, FromType)) { 1053 // Compatible conversions (Clang extension for C function overloading) 1054 SCS.Second = ICK_Compatible_Conversion; 1055 FromType = ToType.getUnqualifiedType(); 1056 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 1057 // Treat a conversion that strips "noreturn" as an identity conversion. 1058 SCS.Second = ICK_NoReturn_Adjustment; 1059 } else { 1060 // No second conversion required. 1061 SCS.Second = ICK_Identity; 1062 } 1063 SCS.setToType(1, FromType); 1064 1065 QualType CanonFrom; 1066 QualType CanonTo; 1067 // The third conversion can be a qualification conversion (C++ 4p1). 1068 if (IsQualificationConversion(FromType, ToType)) { 1069 SCS.Third = ICK_Qualification; 1070 FromType = ToType; 1071 CanonFrom = Context.getCanonicalType(FromType); 1072 CanonTo = Context.getCanonicalType(ToType); 1073 } else { 1074 // No conversion required 1075 SCS.Third = ICK_Identity; 1076 1077 // C++ [over.best.ics]p6: 1078 // [...] Any difference in top-level cv-qualification is 1079 // subsumed by the initialization itself and does not constitute 1080 // a conversion. [...] 1081 CanonFrom = Context.getCanonicalType(FromType); 1082 CanonTo = Context.getCanonicalType(ToType); 1083 if (CanonFrom.getLocalUnqualifiedType() 1084 == CanonTo.getLocalUnqualifiedType() && 1085 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1086 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1087 FromType = ToType; 1088 CanonFrom = CanonTo; 1089 } 1090 } 1091 SCS.setToType(2, FromType); 1092 1093 // If we have not converted the argument type to the parameter type, 1094 // this is a bad conversion sequence. 1095 if (CanonFrom != CanonTo) 1096 return false; 1097 1098 return true; 1099} 1100 1101/// IsIntegralPromotion - Determines whether the conversion from the 1102/// expression From (whose potentially-adjusted type is FromType) to 1103/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1104/// sets PromotedType to the promoted type. 1105bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1106 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1107 // All integers are built-in. 1108 if (!To) { 1109 return false; 1110 } 1111 1112 // An rvalue of type char, signed char, unsigned char, short int, or 1113 // unsigned short int can be converted to an rvalue of type int if 1114 // int can represent all the values of the source type; otherwise, 1115 // the source rvalue can be converted to an rvalue of type unsigned 1116 // int (C++ 4.5p1). 1117 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1118 !FromType->isEnumeralType()) { 1119 if (// We can promote any signed, promotable integer type to an int 1120 (FromType->isSignedIntegerType() || 1121 // We can promote any unsigned integer type whose size is 1122 // less than int to an int. 1123 (!FromType->isSignedIntegerType() && 1124 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1125 return To->getKind() == BuiltinType::Int; 1126 } 1127 1128 return To->getKind() == BuiltinType::UInt; 1129 } 1130 1131 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 1132 // can be converted to an rvalue of the first of the following types 1133 // that can represent all the values of its underlying type: int, 1134 // unsigned int, long, or unsigned long (C++ 4.5p2). 1135 1136 // We pre-calculate the promotion type for enum types. 1137 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 1138 if (ToType->isIntegerType()) 1139 return Context.hasSameUnqualifiedType(ToType, 1140 FromEnumType->getDecl()->getPromotionType()); 1141 1142 if (FromType->isWideCharType() && ToType->isIntegerType()) { 1143 // Determine whether the type we're converting from is signed or 1144 // unsigned. 1145 bool FromIsSigned; 1146 uint64_t FromSize = Context.getTypeSize(FromType); 1147 1148 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1149 FromIsSigned = true; 1150 1151 // The types we'll try to promote to, in the appropriate 1152 // order. Try each of these types. 1153 QualType PromoteTypes[6] = { 1154 Context.IntTy, Context.UnsignedIntTy, 1155 Context.LongTy, Context.UnsignedLongTy , 1156 Context.LongLongTy, Context.UnsignedLongLongTy 1157 }; 1158 for (int Idx = 0; Idx < 6; ++Idx) { 1159 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1160 if (FromSize < ToSize || 1161 (FromSize == ToSize && 1162 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1163 // We found the type that we can promote to. If this is the 1164 // type we wanted, we have a promotion. Otherwise, no 1165 // promotion. 1166 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1167 } 1168 } 1169 } 1170 1171 // An rvalue for an integral bit-field (9.6) can be converted to an 1172 // rvalue of type int if int can represent all the values of the 1173 // bit-field; otherwise, it can be converted to unsigned int if 1174 // unsigned int can represent all the values of the bit-field. If 1175 // the bit-field is larger yet, no integral promotion applies to 1176 // it. If the bit-field has an enumerated type, it is treated as any 1177 // other value of that type for promotion purposes (C++ 4.5p3). 1178 // FIXME: We should delay checking of bit-fields until we actually perform the 1179 // conversion. 1180 using llvm::APSInt; 1181 if (From) 1182 if (FieldDecl *MemberDecl = From->getBitField()) { 1183 APSInt BitWidth; 1184 if (FromType->isIntegralType(Context) && 1185 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1186 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1187 ToSize = Context.getTypeSize(ToType); 1188 1189 // Are we promoting to an int from a bitfield that fits in an int? 1190 if (BitWidth < ToSize || 1191 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1192 return To->getKind() == BuiltinType::Int; 1193 } 1194 1195 // Are we promoting to an unsigned int from an unsigned bitfield 1196 // that fits into an unsigned int? 1197 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1198 return To->getKind() == BuiltinType::UInt; 1199 } 1200 1201 return false; 1202 } 1203 } 1204 1205 // An rvalue of type bool can be converted to an rvalue of type int, 1206 // with false becoming zero and true becoming one (C++ 4.5p4). 1207 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1208 return true; 1209 } 1210 1211 return false; 1212} 1213 1214/// IsFloatingPointPromotion - Determines whether the conversion from 1215/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1216/// returns true and sets PromotedType to the promoted type. 1217bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1218 /// An rvalue of type float can be converted to an rvalue of type 1219 /// double. (C++ 4.6p1). 1220 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1221 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1222 if (FromBuiltin->getKind() == BuiltinType::Float && 1223 ToBuiltin->getKind() == BuiltinType::Double) 1224 return true; 1225 1226 // C99 6.3.1.5p1: 1227 // When a float is promoted to double or long double, or a 1228 // double is promoted to long double [...]. 1229 if (!getLangOptions().CPlusPlus && 1230 (FromBuiltin->getKind() == BuiltinType::Float || 1231 FromBuiltin->getKind() == BuiltinType::Double) && 1232 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1233 return true; 1234 } 1235 1236 return false; 1237} 1238 1239/// \brief Determine if a conversion is a complex promotion. 1240/// 1241/// A complex promotion is defined as a complex -> complex conversion 1242/// where the conversion between the underlying real types is a 1243/// floating-point or integral promotion. 1244bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1245 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1246 if (!FromComplex) 1247 return false; 1248 1249 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1250 if (!ToComplex) 1251 return false; 1252 1253 return IsFloatingPointPromotion(FromComplex->getElementType(), 1254 ToComplex->getElementType()) || 1255 IsIntegralPromotion(0, FromComplex->getElementType(), 1256 ToComplex->getElementType()); 1257} 1258 1259/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1260/// the pointer type FromPtr to a pointer to type ToPointee, with the 1261/// same type qualifiers as FromPtr has on its pointee type. ToType, 1262/// if non-empty, will be a pointer to ToType that may or may not have 1263/// the right set of qualifiers on its pointee. 1264static QualType 1265BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 1266 QualType ToPointee, QualType ToType, 1267 ASTContext &Context) { 1268 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 1269 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1270 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1271 1272 // Exact qualifier match -> return the pointer type we're converting to. 1273 if (CanonToPointee.getLocalQualifiers() == Quals) { 1274 // ToType is exactly what we need. Return it. 1275 if (!ToType.isNull()) 1276 return ToType.getUnqualifiedType(); 1277 1278 // Build a pointer to ToPointee. It has the right qualifiers 1279 // already. 1280 return Context.getPointerType(ToPointee); 1281 } 1282 1283 // Just build a canonical type that has the right qualifiers. 1284 return Context.getPointerType( 1285 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 1286 Quals)); 1287} 1288 1289/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 1290/// the FromType, which is an objective-c pointer, to ToType, which may or may 1291/// not have the right set of qualifiers. 1292static QualType 1293BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 1294 QualType ToType, 1295 ASTContext &Context) { 1296 QualType CanonFromType = Context.getCanonicalType(FromType); 1297 QualType CanonToType = Context.getCanonicalType(ToType); 1298 Qualifiers Quals = CanonFromType.getQualifiers(); 1299 1300 // Exact qualifier match -> return the pointer type we're converting to. 1301 if (CanonToType.getLocalQualifiers() == Quals) 1302 return ToType; 1303 1304 // Just build a canonical type that has the right qualifiers. 1305 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 1306} 1307 1308static bool isNullPointerConstantForConversion(Expr *Expr, 1309 bool InOverloadResolution, 1310 ASTContext &Context) { 1311 // Handle value-dependent integral null pointer constants correctly. 1312 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1313 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1314 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1315 return !InOverloadResolution; 1316 1317 return Expr->isNullPointerConstant(Context, 1318 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1319 : Expr::NPC_ValueDependentIsNull); 1320} 1321 1322/// IsPointerConversion - Determines whether the conversion of the 1323/// expression From, which has the (possibly adjusted) type FromType, 1324/// can be converted to the type ToType via a pointer conversion (C++ 1325/// 4.10). If so, returns true and places the converted type (that 1326/// might differ from ToType in its cv-qualifiers at some level) into 1327/// ConvertedType. 1328/// 1329/// This routine also supports conversions to and from block pointers 1330/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1331/// pointers to interfaces. FIXME: Once we've determined the 1332/// appropriate overloading rules for Objective-C, we may want to 1333/// split the Objective-C checks into a different routine; however, 1334/// GCC seems to consider all of these conversions to be pointer 1335/// conversions, so for now they live here. IncompatibleObjC will be 1336/// set if the conversion is an allowed Objective-C conversion that 1337/// should result in a warning. 1338bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1339 bool InOverloadResolution, 1340 QualType& ConvertedType, 1341 bool &IncompatibleObjC) { 1342 IncompatibleObjC = false; 1343 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1344 return true; 1345 1346 // Conversion from a null pointer constant to any Objective-C pointer type. 1347 if (ToType->isObjCObjectPointerType() && 1348 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1349 ConvertedType = ToType; 1350 return true; 1351 } 1352 1353 // Blocks: Block pointers can be converted to void*. 1354 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1355 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1356 ConvertedType = ToType; 1357 return true; 1358 } 1359 // Blocks: A null pointer constant can be converted to a block 1360 // pointer type. 1361 if (ToType->isBlockPointerType() && 1362 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1363 ConvertedType = ToType; 1364 return true; 1365 } 1366 1367 // If the left-hand-side is nullptr_t, the right side can be a null 1368 // pointer constant. 1369 if (ToType->isNullPtrType() && 1370 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1371 ConvertedType = ToType; 1372 return true; 1373 } 1374 1375 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1376 if (!ToTypePtr) 1377 return false; 1378 1379 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1380 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1381 ConvertedType = ToType; 1382 return true; 1383 } 1384 1385 // Beyond this point, both types need to be pointers 1386 // , including objective-c pointers. 1387 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1388 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1389 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1390 ToType, Context); 1391 return true; 1392 1393 } 1394 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1395 if (!FromTypePtr) 1396 return false; 1397 1398 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1399 1400 // An rvalue of type "pointer to cv T," where T is an object type, 1401 // can be converted to an rvalue of type "pointer to cv void" (C++ 1402 // 4.10p2). 1403 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1404 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1405 ToPointeeType, 1406 ToType, Context); 1407 return true; 1408 } 1409 1410 // When we're overloading in C, we allow a special kind of pointer 1411 // conversion for compatible-but-not-identical pointee types. 1412 if (!getLangOptions().CPlusPlus && 1413 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1414 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1415 ToPointeeType, 1416 ToType, Context); 1417 return true; 1418 } 1419 1420 // C++ [conv.ptr]p3: 1421 // 1422 // An rvalue of type "pointer to cv D," where D is a class type, 1423 // can be converted to an rvalue of type "pointer to cv B," where 1424 // B is a base class (clause 10) of D. If B is an inaccessible 1425 // (clause 11) or ambiguous (10.2) base class of D, a program that 1426 // necessitates this conversion is ill-formed. The result of the 1427 // conversion is a pointer to the base class sub-object of the 1428 // derived class object. The null pointer value is converted to 1429 // the null pointer value of the destination type. 1430 // 1431 // Note that we do not check for ambiguity or inaccessibility 1432 // here. That is handled by CheckPointerConversion. 1433 if (getLangOptions().CPlusPlus && 1434 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1435 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1436 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1437 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1438 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1439 ToPointeeType, 1440 ToType, Context); 1441 return true; 1442 } 1443 1444 return false; 1445} 1446 1447/// isObjCPointerConversion - Determines whether this is an 1448/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1449/// with the same arguments and return values. 1450bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1451 QualType& ConvertedType, 1452 bool &IncompatibleObjC) { 1453 if (!getLangOptions().ObjC1) 1454 return false; 1455 1456 // First, we handle all conversions on ObjC object pointer types. 1457 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1458 const ObjCObjectPointerType *FromObjCPtr = 1459 FromType->getAs<ObjCObjectPointerType>(); 1460 1461 if (ToObjCPtr && FromObjCPtr) { 1462 // Objective C++: We're able to convert between "id" or "Class" and a 1463 // pointer to any interface (in both directions). 1464 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1465 ConvertedType = ToType; 1466 return true; 1467 } 1468 // Conversions with Objective-C's id<...>. 1469 if ((FromObjCPtr->isObjCQualifiedIdType() || 1470 ToObjCPtr->isObjCQualifiedIdType()) && 1471 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1472 /*compare=*/false)) { 1473 ConvertedType = ToType; 1474 return true; 1475 } 1476 // Objective C++: We're able to convert from a pointer to an 1477 // interface to a pointer to a different interface. 1478 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1479 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1480 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1481 if (getLangOptions().CPlusPlus && LHS && RHS && 1482 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1483 FromObjCPtr->getPointeeType())) 1484 return false; 1485 ConvertedType = ToType; 1486 return true; 1487 } 1488 1489 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1490 // Okay: this is some kind of implicit downcast of Objective-C 1491 // interfaces, which is permitted. However, we're going to 1492 // complain about it. 1493 IncompatibleObjC = true; 1494 ConvertedType = FromType; 1495 return true; 1496 } 1497 } 1498 // Beyond this point, both types need to be C pointers or block pointers. 1499 QualType ToPointeeType; 1500 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1501 ToPointeeType = ToCPtr->getPointeeType(); 1502 else if (const BlockPointerType *ToBlockPtr = 1503 ToType->getAs<BlockPointerType>()) { 1504 // Objective C++: We're able to convert from a pointer to any object 1505 // to a block pointer type. 1506 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1507 ConvertedType = ToType; 1508 return true; 1509 } 1510 ToPointeeType = ToBlockPtr->getPointeeType(); 1511 } 1512 else if (FromType->getAs<BlockPointerType>() && 1513 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1514 // Objective C++: We're able to convert from a block pointer type to a 1515 // pointer to any object. 1516 ConvertedType = ToType; 1517 return true; 1518 } 1519 else 1520 return false; 1521 1522 QualType FromPointeeType; 1523 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1524 FromPointeeType = FromCPtr->getPointeeType(); 1525 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1526 FromPointeeType = FromBlockPtr->getPointeeType(); 1527 else 1528 return false; 1529 1530 // If we have pointers to pointers, recursively check whether this 1531 // is an Objective-C conversion. 1532 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1533 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1534 IncompatibleObjC)) { 1535 // We always complain about this conversion. 1536 IncompatibleObjC = true; 1537 ConvertedType = ToType; 1538 return true; 1539 } 1540 // Allow conversion of pointee being objective-c pointer to another one; 1541 // as in I* to id. 1542 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1543 ToPointeeType->getAs<ObjCObjectPointerType>() && 1544 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1545 IncompatibleObjC)) { 1546 ConvertedType = ToType; 1547 return true; 1548 } 1549 1550 // If we have pointers to functions or blocks, check whether the only 1551 // differences in the argument and result types are in Objective-C 1552 // pointer conversions. If so, we permit the conversion (but 1553 // complain about it). 1554 const FunctionProtoType *FromFunctionType 1555 = FromPointeeType->getAs<FunctionProtoType>(); 1556 const FunctionProtoType *ToFunctionType 1557 = ToPointeeType->getAs<FunctionProtoType>(); 1558 if (FromFunctionType && ToFunctionType) { 1559 // If the function types are exactly the same, this isn't an 1560 // Objective-C pointer conversion. 1561 if (Context.getCanonicalType(FromPointeeType) 1562 == Context.getCanonicalType(ToPointeeType)) 1563 return false; 1564 1565 // Perform the quick checks that will tell us whether these 1566 // function types are obviously different. 1567 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1568 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1569 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1570 return false; 1571 1572 bool HasObjCConversion = false; 1573 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1574 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1575 // Okay, the types match exactly. Nothing to do. 1576 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1577 ToFunctionType->getResultType(), 1578 ConvertedType, IncompatibleObjC)) { 1579 // Okay, we have an Objective-C pointer conversion. 1580 HasObjCConversion = true; 1581 } else { 1582 // Function types are too different. Abort. 1583 return false; 1584 } 1585 1586 // Check argument types. 1587 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1588 ArgIdx != NumArgs; ++ArgIdx) { 1589 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1590 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1591 if (Context.getCanonicalType(FromArgType) 1592 == Context.getCanonicalType(ToArgType)) { 1593 // Okay, the types match exactly. Nothing to do. 1594 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1595 ConvertedType, IncompatibleObjC)) { 1596 // Okay, we have an Objective-C pointer conversion. 1597 HasObjCConversion = true; 1598 } else { 1599 // Argument types are too different. Abort. 1600 return false; 1601 } 1602 } 1603 1604 if (HasObjCConversion) { 1605 // We had an Objective-C conversion. Allow this pointer 1606 // conversion, but complain about it. 1607 ConvertedType = ToType; 1608 IncompatibleObjC = true; 1609 return true; 1610 } 1611 } 1612 1613 return false; 1614} 1615 1616/// FunctionArgTypesAreEqual - This routine checks two function proto types 1617/// for equlity of their argument types. Caller has already checked that 1618/// they have same number of arguments. This routine assumes that Objective-C 1619/// pointer types which only differ in their protocol qualifiers are equal. 1620bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, 1621 FunctionProtoType* NewType){ 1622 if (!getLangOptions().ObjC1) 1623 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1624 NewType->arg_type_begin()); 1625 1626 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1627 N = NewType->arg_type_begin(), 1628 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1629 QualType ToType = (*O); 1630 QualType FromType = (*N); 1631 if (ToType != FromType) { 1632 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1633 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1634 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1635 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1636 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1637 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1638 continue; 1639 } 1640 else if (const ObjCObjectPointerType *PTTo = 1641 ToType->getAs<ObjCObjectPointerType>()) { 1642 if (const ObjCObjectPointerType *PTFr = 1643 FromType->getAs<ObjCObjectPointerType>()) 1644 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1645 continue; 1646 } 1647 return false; 1648 } 1649 } 1650 return true; 1651} 1652 1653/// CheckPointerConversion - Check the pointer conversion from the 1654/// expression From to the type ToType. This routine checks for 1655/// ambiguous or inaccessible derived-to-base pointer 1656/// conversions for which IsPointerConversion has already returned 1657/// true. It returns true and produces a diagnostic if there was an 1658/// error, or returns false otherwise. 1659bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1660 CastExpr::CastKind &Kind, 1661 CXXBaseSpecifierArray& BasePath, 1662 bool IgnoreBaseAccess) { 1663 QualType FromType = From->getType(); 1664 1665 if (CXXBoolLiteralExpr* LitBool 1666 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1667 if (LitBool->getValue() == false) 1668 Diag(LitBool->getExprLoc(), diag::warn_init_pointer_from_false) 1669 << ToType; 1670 1671 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1672 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1673 QualType FromPointeeType = FromPtrType->getPointeeType(), 1674 ToPointeeType = ToPtrType->getPointeeType(); 1675 1676 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1677 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1678 // We must have a derived-to-base conversion. Check an 1679 // ambiguous or inaccessible conversion. 1680 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1681 From->getExprLoc(), 1682 From->getSourceRange(), &BasePath, 1683 IgnoreBaseAccess)) 1684 return true; 1685 1686 // The conversion was successful. 1687 Kind = CastExpr::CK_DerivedToBase; 1688 } 1689 } 1690 if (const ObjCObjectPointerType *FromPtrType = 1691 FromType->getAs<ObjCObjectPointerType>()) 1692 if (const ObjCObjectPointerType *ToPtrType = 1693 ToType->getAs<ObjCObjectPointerType>()) { 1694 // Objective-C++ conversions are always okay. 1695 // FIXME: We should have a different class of conversions for the 1696 // Objective-C++ implicit conversions. 1697 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1698 return false; 1699 1700 } 1701 return false; 1702} 1703 1704/// IsMemberPointerConversion - Determines whether the conversion of the 1705/// expression From, which has the (possibly adjusted) type FromType, can be 1706/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1707/// If so, returns true and places the converted type (that might differ from 1708/// ToType in its cv-qualifiers at some level) into ConvertedType. 1709bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1710 QualType ToType, 1711 bool InOverloadResolution, 1712 QualType &ConvertedType) { 1713 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1714 if (!ToTypePtr) 1715 return false; 1716 1717 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1718 if (From->isNullPointerConstant(Context, 1719 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1720 : Expr::NPC_ValueDependentIsNull)) { 1721 ConvertedType = ToType; 1722 return true; 1723 } 1724 1725 // Otherwise, both types have to be member pointers. 1726 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1727 if (!FromTypePtr) 1728 return false; 1729 1730 // A pointer to member of B can be converted to a pointer to member of D, 1731 // where D is derived from B (C++ 4.11p2). 1732 QualType FromClass(FromTypePtr->getClass(), 0); 1733 QualType ToClass(ToTypePtr->getClass(), 0); 1734 // FIXME: What happens when these are dependent? Is this function even called? 1735 1736 if (IsDerivedFrom(ToClass, FromClass)) { 1737 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1738 ToClass.getTypePtr()); 1739 return true; 1740 } 1741 1742 return false; 1743} 1744 1745/// CheckMemberPointerConversion - Check the member pointer conversion from the 1746/// expression From to the type ToType. This routine checks for ambiguous or 1747/// virtual or inaccessible base-to-derived member pointer conversions 1748/// for which IsMemberPointerConversion has already returned true. It returns 1749/// true and produces a diagnostic if there was an error, or returns false 1750/// otherwise. 1751bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1752 CastExpr::CastKind &Kind, 1753 CXXBaseSpecifierArray &BasePath, 1754 bool IgnoreBaseAccess) { 1755 QualType FromType = From->getType(); 1756 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1757 if (!FromPtrType) { 1758 // This must be a null pointer to member pointer conversion 1759 assert(From->isNullPointerConstant(Context, 1760 Expr::NPC_ValueDependentIsNull) && 1761 "Expr must be null pointer constant!"); 1762 Kind = CastExpr::CK_NullToMemberPointer; 1763 return false; 1764 } 1765 1766 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1767 assert(ToPtrType && "No member pointer cast has a target type " 1768 "that is not a member pointer."); 1769 1770 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1771 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1772 1773 // FIXME: What about dependent types? 1774 assert(FromClass->isRecordType() && "Pointer into non-class."); 1775 assert(ToClass->isRecordType() && "Pointer into non-class."); 1776 1777 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1778 /*DetectVirtual=*/true); 1779 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1780 assert(DerivationOkay && 1781 "Should not have been called if derivation isn't OK."); 1782 (void)DerivationOkay; 1783 1784 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1785 getUnqualifiedType())) { 1786 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1787 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1788 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1789 return true; 1790 } 1791 1792 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1793 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1794 << FromClass << ToClass << QualType(VBase, 0) 1795 << From->getSourceRange(); 1796 return true; 1797 } 1798 1799 if (!IgnoreBaseAccess) 1800 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1801 Paths.front(), 1802 diag::err_downcast_from_inaccessible_base); 1803 1804 // Must be a base to derived member conversion. 1805 BuildBasePathArray(Paths, BasePath); 1806 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1807 return false; 1808} 1809 1810/// IsQualificationConversion - Determines whether the conversion from 1811/// an rvalue of type FromType to ToType is a qualification conversion 1812/// (C++ 4.4). 1813bool 1814Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1815 FromType = Context.getCanonicalType(FromType); 1816 ToType = Context.getCanonicalType(ToType); 1817 1818 // If FromType and ToType are the same type, this is not a 1819 // qualification conversion. 1820 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1821 return false; 1822 1823 // (C++ 4.4p4): 1824 // A conversion can add cv-qualifiers at levels other than the first 1825 // in multi-level pointers, subject to the following rules: [...] 1826 bool PreviousToQualsIncludeConst = true; 1827 bool UnwrappedAnyPointer = false; 1828 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 1829 // Within each iteration of the loop, we check the qualifiers to 1830 // determine if this still looks like a qualification 1831 // conversion. Then, if all is well, we unwrap one more level of 1832 // pointers or pointers-to-members and do it all again 1833 // until there are no more pointers or pointers-to-members left to 1834 // unwrap. 1835 UnwrappedAnyPointer = true; 1836 1837 // -- for every j > 0, if const is in cv 1,j then const is in cv 1838 // 2,j, and similarly for volatile. 1839 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1840 return false; 1841 1842 // -- if the cv 1,j and cv 2,j are different, then const is in 1843 // every cv for 0 < k < j. 1844 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1845 && !PreviousToQualsIncludeConst) 1846 return false; 1847 1848 // Keep track of whether all prior cv-qualifiers in the "to" type 1849 // include const. 1850 PreviousToQualsIncludeConst 1851 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1852 } 1853 1854 // We are left with FromType and ToType being the pointee types 1855 // after unwrapping the original FromType and ToType the same number 1856 // of types. If we unwrapped any pointers, and if FromType and 1857 // ToType have the same unqualified type (since we checked 1858 // qualifiers above), then this is a qualification conversion. 1859 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1860} 1861 1862/// Determines whether there is a user-defined conversion sequence 1863/// (C++ [over.ics.user]) that converts expression From to the type 1864/// ToType. If such a conversion exists, User will contain the 1865/// user-defined conversion sequence that performs such a conversion 1866/// and this routine will return true. Otherwise, this routine returns 1867/// false and User is unspecified. 1868/// 1869/// \param AllowExplicit true if the conversion should consider C++0x 1870/// "explicit" conversion functions as well as non-explicit conversion 1871/// functions (C++0x [class.conv.fct]p2). 1872OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1873 UserDefinedConversionSequence& User, 1874 OverloadCandidateSet& CandidateSet, 1875 bool AllowExplicit) { 1876 // Whether we will only visit constructors. 1877 bool ConstructorsOnly = false; 1878 1879 // If the type we are conversion to is a class type, enumerate its 1880 // constructors. 1881 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1882 // C++ [over.match.ctor]p1: 1883 // When objects of class type are direct-initialized (8.5), or 1884 // copy-initialized from an expression of the same or a 1885 // derived class type (8.5), overload resolution selects the 1886 // constructor. [...] For copy-initialization, the candidate 1887 // functions are all the converting constructors (12.3.1) of 1888 // that class. The argument list is the expression-list within 1889 // the parentheses of the initializer. 1890 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1891 (From->getType()->getAs<RecordType>() && 1892 IsDerivedFrom(From->getType(), ToType))) 1893 ConstructorsOnly = true; 1894 1895 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1896 // We're not going to find any constructors. 1897 } else if (CXXRecordDecl *ToRecordDecl 1898 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1899 DeclarationName ConstructorName 1900 = Context.DeclarationNames.getCXXConstructorName( 1901 Context.getCanonicalType(ToType).getUnqualifiedType()); 1902 DeclContext::lookup_iterator Con, ConEnd; 1903 for (llvm::tie(Con, ConEnd) 1904 = ToRecordDecl->lookup(ConstructorName); 1905 Con != ConEnd; ++Con) { 1906 NamedDecl *D = *Con; 1907 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1908 1909 // Find the constructor (which may be a template). 1910 CXXConstructorDecl *Constructor = 0; 1911 FunctionTemplateDecl *ConstructorTmpl 1912 = dyn_cast<FunctionTemplateDecl>(D); 1913 if (ConstructorTmpl) 1914 Constructor 1915 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1916 else 1917 Constructor = cast<CXXConstructorDecl>(D); 1918 1919 if (!Constructor->isInvalidDecl() && 1920 Constructor->isConvertingConstructor(AllowExplicit)) { 1921 if (ConstructorTmpl) 1922 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1923 /*ExplicitArgs*/ 0, 1924 &From, 1, CandidateSet, 1925 /*SuppressUserConversions=*/!ConstructorsOnly); 1926 else 1927 // Allow one user-defined conversion when user specifies a 1928 // From->ToType conversion via an static cast (c-style, etc). 1929 AddOverloadCandidate(Constructor, FoundDecl, 1930 &From, 1, CandidateSet, 1931 /*SuppressUserConversions=*/!ConstructorsOnly); 1932 } 1933 } 1934 } 1935 } 1936 1937 // Enumerate conversion functions, if we're allowed to. 1938 if (ConstructorsOnly) { 1939 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1940 PDiag(0) << From->getSourceRange())) { 1941 // No conversion functions from incomplete types. 1942 } else if (const RecordType *FromRecordType 1943 = From->getType()->getAs<RecordType>()) { 1944 if (CXXRecordDecl *FromRecordDecl 1945 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1946 // Add all of the conversion functions as candidates. 1947 const UnresolvedSetImpl *Conversions 1948 = FromRecordDecl->getVisibleConversionFunctions(); 1949 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1950 E = Conversions->end(); I != E; ++I) { 1951 DeclAccessPair FoundDecl = I.getPair(); 1952 NamedDecl *D = FoundDecl.getDecl(); 1953 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1954 if (isa<UsingShadowDecl>(D)) 1955 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1956 1957 CXXConversionDecl *Conv; 1958 FunctionTemplateDecl *ConvTemplate; 1959 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1960 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1961 else 1962 Conv = cast<CXXConversionDecl>(D); 1963 1964 if (AllowExplicit || !Conv->isExplicit()) { 1965 if (ConvTemplate) 1966 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1967 ActingContext, From, ToType, 1968 CandidateSet); 1969 else 1970 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1971 From, ToType, CandidateSet); 1972 } 1973 } 1974 } 1975 } 1976 1977 OverloadCandidateSet::iterator Best; 1978 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1979 case OR_Success: 1980 // Record the standard conversion we used and the conversion function. 1981 if (CXXConstructorDecl *Constructor 1982 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1983 // C++ [over.ics.user]p1: 1984 // If the user-defined conversion is specified by a 1985 // constructor (12.3.1), the initial standard conversion 1986 // sequence converts the source type to the type required by 1987 // the argument of the constructor. 1988 // 1989 QualType ThisType = Constructor->getThisType(Context); 1990 if (Best->Conversions[0].isEllipsis()) 1991 User.EllipsisConversion = true; 1992 else { 1993 User.Before = Best->Conversions[0].Standard; 1994 User.EllipsisConversion = false; 1995 } 1996 User.ConversionFunction = Constructor; 1997 User.After.setAsIdentityConversion(); 1998 User.After.setFromType( 1999 ThisType->getAs<PointerType>()->getPointeeType()); 2000 User.After.setAllToTypes(ToType); 2001 return OR_Success; 2002 } else if (CXXConversionDecl *Conversion 2003 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2004 // C++ [over.ics.user]p1: 2005 // 2006 // [...] If the user-defined conversion is specified by a 2007 // conversion function (12.3.2), the initial standard 2008 // conversion sequence converts the source type to the 2009 // implicit object parameter of the conversion function. 2010 User.Before = Best->Conversions[0].Standard; 2011 User.ConversionFunction = Conversion; 2012 User.EllipsisConversion = false; 2013 2014 // C++ [over.ics.user]p2: 2015 // The second standard conversion sequence converts the 2016 // result of the user-defined conversion to the target type 2017 // for the sequence. Since an implicit conversion sequence 2018 // is an initialization, the special rules for 2019 // initialization by user-defined conversion apply when 2020 // selecting the best user-defined conversion for a 2021 // user-defined conversion sequence (see 13.3.3 and 2022 // 13.3.3.1). 2023 User.After = Best->FinalConversion; 2024 return OR_Success; 2025 } else { 2026 assert(false && "Not a constructor or conversion function?"); 2027 return OR_No_Viable_Function; 2028 } 2029 2030 case OR_No_Viable_Function: 2031 return OR_No_Viable_Function; 2032 case OR_Deleted: 2033 // No conversion here! We're done. 2034 return OR_Deleted; 2035 2036 case OR_Ambiguous: 2037 return OR_Ambiguous; 2038 } 2039 2040 return OR_No_Viable_Function; 2041} 2042 2043bool 2044Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2045 ImplicitConversionSequence ICS; 2046 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2047 OverloadingResult OvResult = 2048 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 2049 CandidateSet, false); 2050 if (OvResult == OR_Ambiguous) 2051 Diag(From->getSourceRange().getBegin(), 2052 diag::err_typecheck_ambiguous_condition) 2053 << From->getType() << ToType << From->getSourceRange(); 2054 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2055 Diag(From->getSourceRange().getBegin(), 2056 diag::err_typecheck_nonviable_condition) 2057 << From->getType() << ToType << From->getSourceRange(); 2058 else 2059 return false; 2060 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 2061 return true; 2062} 2063 2064/// CompareImplicitConversionSequences - Compare two implicit 2065/// conversion sequences to determine whether one is better than the 2066/// other or if they are indistinguishable (C++ 13.3.3.2). 2067ImplicitConversionSequence::CompareKind 2068Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 2069 const ImplicitConversionSequence& ICS2) 2070{ 2071 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2072 // conversion sequences (as defined in 13.3.3.1) 2073 // -- a standard conversion sequence (13.3.3.1.1) is a better 2074 // conversion sequence than a user-defined conversion sequence or 2075 // an ellipsis conversion sequence, and 2076 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2077 // conversion sequence than an ellipsis conversion sequence 2078 // (13.3.3.1.3). 2079 // 2080 // C++0x [over.best.ics]p10: 2081 // For the purpose of ranking implicit conversion sequences as 2082 // described in 13.3.3.2, the ambiguous conversion sequence is 2083 // treated as a user-defined sequence that is indistinguishable 2084 // from any other user-defined conversion sequence. 2085 if (ICS1.getKindRank() < ICS2.getKindRank()) 2086 return ImplicitConversionSequence::Better; 2087 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2088 return ImplicitConversionSequence::Worse; 2089 2090 // The following checks require both conversion sequences to be of 2091 // the same kind. 2092 if (ICS1.getKind() != ICS2.getKind()) 2093 return ImplicitConversionSequence::Indistinguishable; 2094 2095 // Two implicit conversion sequences of the same form are 2096 // indistinguishable conversion sequences unless one of the 2097 // following rules apply: (C++ 13.3.3.2p3): 2098 if (ICS1.isStandard()) 2099 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 2100 else if (ICS1.isUserDefined()) { 2101 // User-defined conversion sequence U1 is a better conversion 2102 // sequence than another user-defined conversion sequence U2 if 2103 // they contain the same user-defined conversion function or 2104 // constructor and if the second standard conversion sequence of 2105 // U1 is better than the second standard conversion sequence of 2106 // U2 (C++ 13.3.3.2p3). 2107 if (ICS1.UserDefined.ConversionFunction == 2108 ICS2.UserDefined.ConversionFunction) 2109 return CompareStandardConversionSequences(ICS1.UserDefined.After, 2110 ICS2.UserDefined.After); 2111 } 2112 2113 return ImplicitConversionSequence::Indistinguishable; 2114} 2115 2116static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2117 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2118 Qualifiers Quals; 2119 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2120 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2121 } 2122 2123 return Context.hasSameUnqualifiedType(T1, T2); 2124} 2125 2126// Per 13.3.3.2p3, compare the given standard conversion sequences to 2127// determine if one is a proper subset of the other. 2128static ImplicitConversionSequence::CompareKind 2129compareStandardConversionSubsets(ASTContext &Context, 2130 const StandardConversionSequence& SCS1, 2131 const StandardConversionSequence& SCS2) { 2132 ImplicitConversionSequence::CompareKind Result 2133 = ImplicitConversionSequence::Indistinguishable; 2134 2135 // the identity conversion sequence is considered to be a subsequence of 2136 // any non-identity conversion sequence 2137 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2138 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2139 return ImplicitConversionSequence::Better; 2140 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2141 return ImplicitConversionSequence::Worse; 2142 } 2143 2144 if (SCS1.Second != SCS2.Second) { 2145 if (SCS1.Second == ICK_Identity) 2146 Result = ImplicitConversionSequence::Better; 2147 else if (SCS2.Second == ICK_Identity) 2148 Result = ImplicitConversionSequence::Worse; 2149 else 2150 return ImplicitConversionSequence::Indistinguishable; 2151 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2152 return ImplicitConversionSequence::Indistinguishable; 2153 2154 if (SCS1.Third == SCS2.Third) { 2155 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2156 : ImplicitConversionSequence::Indistinguishable; 2157 } 2158 2159 if (SCS1.Third == ICK_Identity) 2160 return Result == ImplicitConversionSequence::Worse 2161 ? ImplicitConversionSequence::Indistinguishable 2162 : ImplicitConversionSequence::Better; 2163 2164 if (SCS2.Third == ICK_Identity) 2165 return Result == ImplicitConversionSequence::Better 2166 ? ImplicitConversionSequence::Indistinguishable 2167 : ImplicitConversionSequence::Worse; 2168 2169 return ImplicitConversionSequence::Indistinguishable; 2170} 2171 2172/// CompareStandardConversionSequences - Compare two standard 2173/// conversion sequences to determine whether one is better than the 2174/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2175ImplicitConversionSequence::CompareKind 2176Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 2177 const StandardConversionSequence& SCS2) 2178{ 2179 // Standard conversion sequence S1 is a better conversion sequence 2180 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2181 2182 // -- S1 is a proper subsequence of S2 (comparing the conversion 2183 // sequences in the canonical form defined by 13.3.3.1.1, 2184 // excluding any Lvalue Transformation; the identity conversion 2185 // sequence is considered to be a subsequence of any 2186 // non-identity conversion sequence) or, if not that, 2187 if (ImplicitConversionSequence::CompareKind CK 2188 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 2189 return CK; 2190 2191 // -- the rank of S1 is better than the rank of S2 (by the rules 2192 // defined below), or, if not that, 2193 ImplicitConversionRank Rank1 = SCS1.getRank(); 2194 ImplicitConversionRank Rank2 = SCS2.getRank(); 2195 if (Rank1 < Rank2) 2196 return ImplicitConversionSequence::Better; 2197 else if (Rank2 < Rank1) 2198 return ImplicitConversionSequence::Worse; 2199 2200 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2201 // are indistinguishable unless one of the following rules 2202 // applies: 2203 2204 // A conversion that is not a conversion of a pointer, or 2205 // pointer to member, to bool is better than another conversion 2206 // that is such a conversion. 2207 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2208 return SCS2.isPointerConversionToBool() 2209 ? ImplicitConversionSequence::Better 2210 : ImplicitConversionSequence::Worse; 2211 2212 // C++ [over.ics.rank]p4b2: 2213 // 2214 // If class B is derived directly or indirectly from class A, 2215 // conversion of B* to A* is better than conversion of B* to 2216 // void*, and conversion of A* to void* is better than conversion 2217 // of B* to void*. 2218 bool SCS1ConvertsToVoid 2219 = SCS1.isPointerConversionToVoidPointer(Context); 2220 bool SCS2ConvertsToVoid 2221 = SCS2.isPointerConversionToVoidPointer(Context); 2222 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2223 // Exactly one of the conversion sequences is a conversion to 2224 // a void pointer; it's the worse conversion. 2225 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2226 : ImplicitConversionSequence::Worse; 2227 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2228 // Neither conversion sequence converts to a void pointer; compare 2229 // their derived-to-base conversions. 2230 if (ImplicitConversionSequence::CompareKind DerivedCK 2231 = CompareDerivedToBaseConversions(SCS1, SCS2)) 2232 return DerivedCK; 2233 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2234 // Both conversion sequences are conversions to void 2235 // pointers. Compare the source types to determine if there's an 2236 // inheritance relationship in their sources. 2237 QualType FromType1 = SCS1.getFromType(); 2238 QualType FromType2 = SCS2.getFromType(); 2239 2240 // Adjust the types we're converting from via the array-to-pointer 2241 // conversion, if we need to. 2242 if (SCS1.First == ICK_Array_To_Pointer) 2243 FromType1 = Context.getArrayDecayedType(FromType1); 2244 if (SCS2.First == ICK_Array_To_Pointer) 2245 FromType2 = Context.getArrayDecayedType(FromType2); 2246 2247 QualType FromPointee1 2248 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2249 QualType FromPointee2 2250 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2251 2252 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2253 return ImplicitConversionSequence::Better; 2254 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2255 return ImplicitConversionSequence::Worse; 2256 2257 // Objective-C++: If one interface is more specific than the 2258 // other, it is the better one. 2259 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2260 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2261 if (FromIface1 && FromIface1) { 2262 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2263 return ImplicitConversionSequence::Better; 2264 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2265 return ImplicitConversionSequence::Worse; 2266 } 2267 } 2268 2269 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2270 // bullet 3). 2271 if (ImplicitConversionSequence::CompareKind QualCK 2272 = CompareQualificationConversions(SCS1, SCS2)) 2273 return QualCK; 2274 2275 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2276 // C++0x [over.ics.rank]p3b4: 2277 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2278 // implicit object parameter of a non-static member function declared 2279 // without a ref-qualifier, and S1 binds an rvalue reference to an 2280 // rvalue and S2 binds an lvalue reference. 2281 // FIXME: We don't know if we're dealing with the implicit object parameter, 2282 // or if the member function in this case has a ref qualifier. 2283 // (Of course, we don't have ref qualifiers yet.) 2284 if (SCS1.RRefBinding != SCS2.RRefBinding) 2285 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 2286 : ImplicitConversionSequence::Worse; 2287 2288 // C++ [over.ics.rank]p3b4: 2289 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2290 // which the references refer are the same type except for 2291 // top-level cv-qualifiers, and the type to which the reference 2292 // initialized by S2 refers is more cv-qualified than the type 2293 // to which the reference initialized by S1 refers. 2294 QualType T1 = SCS1.getToType(2); 2295 QualType T2 = SCS2.getToType(2); 2296 T1 = Context.getCanonicalType(T1); 2297 T2 = Context.getCanonicalType(T2); 2298 Qualifiers T1Quals, T2Quals; 2299 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2300 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2301 if (UnqualT1 == UnqualT2) { 2302 // If the type is an array type, promote the element qualifiers to the type 2303 // for comparison. 2304 if (isa<ArrayType>(T1) && T1Quals) 2305 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2306 if (isa<ArrayType>(T2) && T2Quals) 2307 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2308 if (T2.isMoreQualifiedThan(T1)) 2309 return ImplicitConversionSequence::Better; 2310 else if (T1.isMoreQualifiedThan(T2)) 2311 return ImplicitConversionSequence::Worse; 2312 } 2313 } 2314 2315 return ImplicitConversionSequence::Indistinguishable; 2316} 2317 2318/// CompareQualificationConversions - Compares two standard conversion 2319/// sequences to determine whether they can be ranked based on their 2320/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2321ImplicitConversionSequence::CompareKind 2322Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 2323 const StandardConversionSequence& SCS2) { 2324 // C++ 13.3.3.2p3: 2325 // -- S1 and S2 differ only in their qualification conversion and 2326 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2327 // cv-qualification signature of type T1 is a proper subset of 2328 // the cv-qualification signature of type T2, and S1 is not the 2329 // deprecated string literal array-to-pointer conversion (4.2). 2330 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2331 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2332 return ImplicitConversionSequence::Indistinguishable; 2333 2334 // FIXME: the example in the standard doesn't use a qualification 2335 // conversion (!) 2336 QualType T1 = SCS1.getToType(2); 2337 QualType T2 = SCS2.getToType(2); 2338 T1 = Context.getCanonicalType(T1); 2339 T2 = Context.getCanonicalType(T2); 2340 Qualifiers T1Quals, T2Quals; 2341 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2342 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2343 2344 // If the types are the same, we won't learn anything by unwrapped 2345 // them. 2346 if (UnqualT1 == UnqualT2) 2347 return ImplicitConversionSequence::Indistinguishable; 2348 2349 // If the type is an array type, promote the element qualifiers to the type 2350 // for comparison. 2351 if (isa<ArrayType>(T1) && T1Quals) 2352 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2353 if (isa<ArrayType>(T2) && T2Quals) 2354 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2355 2356 ImplicitConversionSequence::CompareKind Result 2357 = ImplicitConversionSequence::Indistinguishable; 2358 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2359 // Within each iteration of the loop, we check the qualifiers to 2360 // determine if this still looks like a qualification 2361 // conversion. Then, if all is well, we unwrap one more level of 2362 // pointers or pointers-to-members and do it all again 2363 // until there are no more pointers or pointers-to-members left 2364 // to unwrap. This essentially mimics what 2365 // IsQualificationConversion does, but here we're checking for a 2366 // strict subset of qualifiers. 2367 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2368 // The qualifiers are the same, so this doesn't tell us anything 2369 // about how the sequences rank. 2370 ; 2371 else if (T2.isMoreQualifiedThan(T1)) { 2372 // T1 has fewer qualifiers, so it could be the better sequence. 2373 if (Result == ImplicitConversionSequence::Worse) 2374 // Neither has qualifiers that are a subset of the other's 2375 // qualifiers. 2376 return ImplicitConversionSequence::Indistinguishable; 2377 2378 Result = ImplicitConversionSequence::Better; 2379 } else if (T1.isMoreQualifiedThan(T2)) { 2380 // T2 has fewer qualifiers, so it could be the better sequence. 2381 if (Result == ImplicitConversionSequence::Better) 2382 // Neither has qualifiers that are a subset of the other's 2383 // qualifiers. 2384 return ImplicitConversionSequence::Indistinguishable; 2385 2386 Result = ImplicitConversionSequence::Worse; 2387 } else { 2388 // Qualifiers are disjoint. 2389 return ImplicitConversionSequence::Indistinguishable; 2390 } 2391 2392 // If the types after this point are equivalent, we're done. 2393 if (Context.hasSameUnqualifiedType(T1, T2)) 2394 break; 2395 } 2396 2397 // Check that the winning standard conversion sequence isn't using 2398 // the deprecated string literal array to pointer conversion. 2399 switch (Result) { 2400 case ImplicitConversionSequence::Better: 2401 if (SCS1.DeprecatedStringLiteralToCharPtr) 2402 Result = ImplicitConversionSequence::Indistinguishable; 2403 break; 2404 2405 case ImplicitConversionSequence::Indistinguishable: 2406 break; 2407 2408 case ImplicitConversionSequence::Worse: 2409 if (SCS2.DeprecatedStringLiteralToCharPtr) 2410 Result = ImplicitConversionSequence::Indistinguishable; 2411 break; 2412 } 2413 2414 return Result; 2415} 2416 2417/// CompareDerivedToBaseConversions - Compares two standard conversion 2418/// sequences to determine whether they can be ranked based on their 2419/// various kinds of derived-to-base conversions (C++ 2420/// [over.ics.rank]p4b3). As part of these checks, we also look at 2421/// conversions between Objective-C interface types. 2422ImplicitConversionSequence::CompareKind 2423Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2424 const StandardConversionSequence& SCS2) { 2425 QualType FromType1 = SCS1.getFromType(); 2426 QualType ToType1 = SCS1.getToType(1); 2427 QualType FromType2 = SCS2.getFromType(); 2428 QualType ToType2 = SCS2.getToType(1); 2429 2430 // Adjust the types we're converting from via the array-to-pointer 2431 // conversion, if we need to. 2432 if (SCS1.First == ICK_Array_To_Pointer) 2433 FromType1 = Context.getArrayDecayedType(FromType1); 2434 if (SCS2.First == ICK_Array_To_Pointer) 2435 FromType2 = Context.getArrayDecayedType(FromType2); 2436 2437 // Canonicalize all of the types. 2438 FromType1 = Context.getCanonicalType(FromType1); 2439 ToType1 = Context.getCanonicalType(ToType1); 2440 FromType2 = Context.getCanonicalType(FromType2); 2441 ToType2 = Context.getCanonicalType(ToType2); 2442 2443 // C++ [over.ics.rank]p4b3: 2444 // 2445 // If class B is derived directly or indirectly from class A and 2446 // class C is derived directly or indirectly from B, 2447 // 2448 // For Objective-C, we let A, B, and C also be Objective-C 2449 // interfaces. 2450 2451 // Compare based on pointer conversions. 2452 if (SCS1.Second == ICK_Pointer_Conversion && 2453 SCS2.Second == ICK_Pointer_Conversion && 2454 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2455 FromType1->isPointerType() && FromType2->isPointerType() && 2456 ToType1->isPointerType() && ToType2->isPointerType()) { 2457 QualType FromPointee1 2458 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2459 QualType ToPointee1 2460 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2461 QualType FromPointee2 2462 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2463 QualType ToPointee2 2464 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2465 2466 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2467 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2468 const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>(); 2469 const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>(); 2470 2471 // -- conversion of C* to B* is better than conversion of C* to A*, 2472 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2473 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2474 return ImplicitConversionSequence::Better; 2475 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2476 return ImplicitConversionSequence::Worse; 2477 2478 if (ToIface1 && ToIface2) { 2479 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2480 return ImplicitConversionSequence::Better; 2481 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2482 return ImplicitConversionSequence::Worse; 2483 } 2484 } 2485 2486 // -- conversion of B* to A* is better than conversion of C* to A*, 2487 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2488 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2489 return ImplicitConversionSequence::Better; 2490 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2491 return ImplicitConversionSequence::Worse; 2492 2493 if (FromIface1 && FromIface2) { 2494 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2495 return ImplicitConversionSequence::Better; 2496 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2497 return ImplicitConversionSequence::Worse; 2498 } 2499 } 2500 } 2501 2502 // Ranking of member-pointer types. 2503 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2504 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2505 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2506 const MemberPointerType * FromMemPointer1 = 2507 FromType1->getAs<MemberPointerType>(); 2508 const MemberPointerType * ToMemPointer1 = 2509 ToType1->getAs<MemberPointerType>(); 2510 const MemberPointerType * FromMemPointer2 = 2511 FromType2->getAs<MemberPointerType>(); 2512 const MemberPointerType * ToMemPointer2 = 2513 ToType2->getAs<MemberPointerType>(); 2514 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2515 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2516 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2517 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2518 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2519 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2520 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2521 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2522 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2523 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2524 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2525 return ImplicitConversionSequence::Worse; 2526 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2527 return ImplicitConversionSequence::Better; 2528 } 2529 // conversion of B::* to C::* is better than conversion of A::* to C::* 2530 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2531 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2532 return ImplicitConversionSequence::Better; 2533 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2534 return ImplicitConversionSequence::Worse; 2535 } 2536 } 2537 2538 if (SCS1.Second == ICK_Derived_To_Base) { 2539 // -- conversion of C to B is better than conversion of C to A, 2540 // -- binding of an expression of type C to a reference of type 2541 // B& is better than binding an expression of type C to a 2542 // reference of type A&, 2543 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2544 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2545 if (IsDerivedFrom(ToType1, ToType2)) 2546 return ImplicitConversionSequence::Better; 2547 else if (IsDerivedFrom(ToType2, ToType1)) 2548 return ImplicitConversionSequence::Worse; 2549 } 2550 2551 // -- conversion of B to A is better than conversion of C to A. 2552 // -- binding of an expression of type B to a reference of type 2553 // A& is better than binding an expression of type C to a 2554 // reference of type A&, 2555 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2556 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2557 if (IsDerivedFrom(FromType2, FromType1)) 2558 return ImplicitConversionSequence::Better; 2559 else if (IsDerivedFrom(FromType1, FromType2)) 2560 return ImplicitConversionSequence::Worse; 2561 } 2562 } 2563 2564 return ImplicitConversionSequence::Indistinguishable; 2565} 2566 2567/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2568/// determine whether they are reference-related, 2569/// reference-compatible, reference-compatible with added 2570/// qualification, or incompatible, for use in C++ initialization by 2571/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2572/// type, and the first type (T1) is the pointee type of the reference 2573/// type being initialized. 2574Sema::ReferenceCompareResult 2575Sema::CompareReferenceRelationship(SourceLocation Loc, 2576 QualType OrigT1, QualType OrigT2, 2577 bool& DerivedToBase) { 2578 assert(!OrigT1->isReferenceType() && 2579 "T1 must be the pointee type of the reference type"); 2580 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2581 2582 QualType T1 = Context.getCanonicalType(OrigT1); 2583 QualType T2 = Context.getCanonicalType(OrigT2); 2584 Qualifiers T1Quals, T2Quals; 2585 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2586 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2587 2588 // C++ [dcl.init.ref]p4: 2589 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2590 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2591 // T1 is a base class of T2. 2592 if (UnqualT1 == UnqualT2) 2593 DerivedToBase = false; 2594 else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2595 IsDerivedFrom(UnqualT2, UnqualT1)) 2596 DerivedToBase = true; 2597 else 2598 return Ref_Incompatible; 2599 2600 // At this point, we know that T1 and T2 are reference-related (at 2601 // least). 2602 2603 // If the type is an array type, promote the element qualifiers to the type 2604 // for comparison. 2605 if (isa<ArrayType>(T1) && T1Quals) 2606 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2607 if (isa<ArrayType>(T2) && T2Quals) 2608 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2609 2610 // C++ [dcl.init.ref]p4: 2611 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2612 // reference-related to T2 and cv1 is the same cv-qualification 2613 // as, or greater cv-qualification than, cv2. For purposes of 2614 // overload resolution, cases for which cv1 is greater 2615 // cv-qualification than cv2 are identified as 2616 // reference-compatible with added qualification (see 13.3.3.2). 2617 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2618 return Ref_Compatible; 2619 else if (T1.isMoreQualifiedThan(T2)) 2620 return Ref_Compatible_With_Added_Qualification; 2621 else 2622 return Ref_Related; 2623} 2624 2625/// \brief Compute an implicit conversion sequence for reference 2626/// initialization. 2627static ImplicitConversionSequence 2628TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2629 SourceLocation DeclLoc, 2630 bool SuppressUserConversions, 2631 bool AllowExplicit) { 2632 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2633 2634 // Most paths end in a failed conversion. 2635 ImplicitConversionSequence ICS; 2636 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2637 2638 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2639 QualType T2 = Init->getType(); 2640 2641 // If the initializer is the address of an overloaded function, try 2642 // to resolve the overloaded function. If all goes well, T2 is the 2643 // type of the resulting function. 2644 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2645 DeclAccessPair Found; 2646 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2647 false, Found)) 2648 T2 = Fn->getType(); 2649 } 2650 2651 // Compute some basic properties of the types and the initializer. 2652 bool isRValRef = DeclType->isRValueReferenceType(); 2653 bool DerivedToBase = false; 2654 Expr::isLvalueResult InitLvalue = Init->isLvalue(S.Context); 2655 Sema::ReferenceCompareResult RefRelationship 2656 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); 2657 2658 2659 // C++ [over.ics.ref]p3: 2660 // Except for an implicit object parameter, for which see 13.3.1, 2661 // a standard conversion sequence cannot be formed if it requires 2662 // binding an lvalue reference to non-const to an rvalue or 2663 // binding an rvalue reference to an lvalue. 2664 // 2665 // FIXME: DPG doesn't trust this code. It seems far too early to 2666 // abort because of a binding of an rvalue reference to an lvalue. 2667 if (isRValRef && InitLvalue == Expr::LV_Valid) 2668 return ICS; 2669 2670 // C++0x [dcl.init.ref]p16: 2671 // A reference to type "cv1 T1" is initialized by an expression 2672 // of type "cv2 T2" as follows: 2673 2674 // -- If the initializer expression 2675 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2676 // reference-compatible with "cv2 T2," or 2677 // 2678 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2679 if (InitLvalue == Expr::LV_Valid && 2680 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2681 // C++ [over.ics.ref]p1: 2682 // When a parameter of reference type binds directly (8.5.3) 2683 // to an argument expression, the implicit conversion sequence 2684 // is the identity conversion, unless the argument expression 2685 // has a type that is a derived class of the parameter type, 2686 // in which case the implicit conversion sequence is a 2687 // derived-to-base Conversion (13.3.3.1). 2688 ICS.setStandard(); 2689 ICS.Standard.First = ICK_Identity; 2690 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2691 ICS.Standard.Third = ICK_Identity; 2692 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2693 ICS.Standard.setToType(0, T2); 2694 ICS.Standard.setToType(1, T1); 2695 ICS.Standard.setToType(2, T1); 2696 ICS.Standard.ReferenceBinding = true; 2697 ICS.Standard.DirectBinding = true; 2698 ICS.Standard.RRefBinding = false; 2699 ICS.Standard.CopyConstructor = 0; 2700 2701 // Nothing more to do: the inaccessibility/ambiguity check for 2702 // derived-to-base conversions is suppressed when we're 2703 // computing the implicit conversion sequence (C++ 2704 // [over.best.ics]p2). 2705 return ICS; 2706 } 2707 2708 // -- has a class type (i.e., T2 is a class type), where T1 is 2709 // not reference-related to T2, and can be implicitly 2710 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2711 // is reference-compatible with "cv3 T3" 92) (this 2712 // conversion is selected by enumerating the applicable 2713 // conversion functions (13.3.1.6) and choosing the best 2714 // one through overload resolution (13.3)), 2715 if (!isRValRef && !SuppressUserConversions && T2->isRecordType() && 2716 !S.RequireCompleteType(DeclLoc, T2, 0) && 2717 RefRelationship == Sema::Ref_Incompatible) { 2718 CXXRecordDecl *T2RecordDecl 2719 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2720 2721 OverloadCandidateSet CandidateSet(DeclLoc); 2722 const UnresolvedSetImpl *Conversions 2723 = T2RecordDecl->getVisibleConversionFunctions(); 2724 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2725 E = Conversions->end(); I != E; ++I) { 2726 NamedDecl *D = *I; 2727 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2728 if (isa<UsingShadowDecl>(D)) 2729 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2730 2731 FunctionTemplateDecl *ConvTemplate 2732 = dyn_cast<FunctionTemplateDecl>(D); 2733 CXXConversionDecl *Conv; 2734 if (ConvTemplate) 2735 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2736 else 2737 Conv = cast<CXXConversionDecl>(D); 2738 2739 // If the conversion function doesn't return a reference type, 2740 // it can't be considered for this conversion. 2741 if (Conv->getConversionType()->isLValueReferenceType() && 2742 (AllowExplicit || !Conv->isExplicit())) { 2743 if (ConvTemplate) 2744 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2745 Init, DeclType, CandidateSet); 2746 else 2747 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2748 DeclType, CandidateSet); 2749 } 2750 } 2751 2752 OverloadCandidateSet::iterator Best; 2753 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2754 case OR_Success: 2755 // C++ [over.ics.ref]p1: 2756 // 2757 // [...] If the parameter binds directly to the result of 2758 // applying a conversion function to the argument 2759 // expression, the implicit conversion sequence is a 2760 // user-defined conversion sequence (13.3.3.1.2), with the 2761 // second standard conversion sequence either an identity 2762 // conversion or, if the conversion function returns an 2763 // entity of a type that is a derived class of the parameter 2764 // type, a derived-to-base Conversion. 2765 if (!Best->FinalConversion.DirectBinding) 2766 break; 2767 2768 ICS.setUserDefined(); 2769 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2770 ICS.UserDefined.After = Best->FinalConversion; 2771 ICS.UserDefined.ConversionFunction = Best->Function; 2772 ICS.UserDefined.EllipsisConversion = false; 2773 assert(ICS.UserDefined.After.ReferenceBinding && 2774 ICS.UserDefined.After.DirectBinding && 2775 "Expected a direct reference binding!"); 2776 return ICS; 2777 2778 case OR_Ambiguous: 2779 ICS.setAmbiguous(); 2780 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2781 Cand != CandidateSet.end(); ++Cand) 2782 if (Cand->Viable) 2783 ICS.Ambiguous.addConversion(Cand->Function); 2784 return ICS; 2785 2786 case OR_No_Viable_Function: 2787 case OR_Deleted: 2788 // There was no suitable conversion, or we found a deleted 2789 // conversion; continue with other checks. 2790 break; 2791 } 2792 } 2793 2794 // -- Otherwise, the reference shall be to a non-volatile const 2795 // type (i.e., cv1 shall be const), or the reference shall be an 2796 // rvalue reference and the initializer expression shall be an rvalue. 2797 // 2798 // We actually handle one oddity of C++ [over.ics.ref] at this 2799 // point, which is that, due to p2 (which short-circuits reference 2800 // binding by only attempting a simple conversion for non-direct 2801 // bindings) and p3's strange wording, we allow a const volatile 2802 // reference to bind to an rvalue. Hence the check for the presence 2803 // of "const" rather than checking for "const" being the only 2804 // qualifier. 2805 if (!isRValRef && !T1.isConstQualified()) 2806 return ICS; 2807 2808 // -- if T2 is a class type and 2809 // -- the initializer expression is an rvalue and "cv1 T1" 2810 // is reference-compatible with "cv2 T2," or 2811 // 2812 // -- T1 is not reference-related to T2 and the initializer 2813 // expression can be implicitly converted to an rvalue 2814 // of type "cv3 T3" (this conversion is selected by 2815 // enumerating the applicable conversion functions 2816 // (13.3.1.6) and choosing the best one through overload 2817 // resolution (13.3)), 2818 // 2819 // then the reference is bound to the initializer 2820 // expression rvalue in the first case and to the object 2821 // that is the result of the conversion in the second case 2822 // (or, in either case, to the appropriate base class 2823 // subobject of the object). 2824 // 2825 // We're only checking the first case here, which is a direct 2826 // binding in C++0x but not in C++03. 2827 if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && 2828 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2829 ICS.setStandard(); 2830 ICS.Standard.First = ICK_Identity; 2831 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2832 ICS.Standard.Third = ICK_Identity; 2833 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2834 ICS.Standard.setToType(0, T2); 2835 ICS.Standard.setToType(1, T1); 2836 ICS.Standard.setToType(2, T1); 2837 ICS.Standard.ReferenceBinding = true; 2838 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 2839 ICS.Standard.RRefBinding = isRValRef; 2840 ICS.Standard.CopyConstructor = 0; 2841 return ICS; 2842 } 2843 2844 // -- Otherwise, a temporary of type "cv1 T1" is created and 2845 // initialized from the initializer expression using the 2846 // rules for a non-reference copy initialization (8.5). The 2847 // reference is then bound to the temporary. If T1 is 2848 // reference-related to T2, cv1 must be the same 2849 // cv-qualification as, or greater cv-qualification than, 2850 // cv2; otherwise, the program is ill-formed. 2851 if (RefRelationship == Sema::Ref_Related) { 2852 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2853 // we would be reference-compatible or reference-compatible with 2854 // added qualification. But that wasn't the case, so the reference 2855 // initialization fails. 2856 return ICS; 2857 } 2858 2859 // If at least one of the types is a class type, the types are not 2860 // related, and we aren't allowed any user conversions, the 2861 // reference binding fails. This case is important for breaking 2862 // recursion, since TryImplicitConversion below will attempt to 2863 // create a temporary through the use of a copy constructor. 2864 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2865 (T1->isRecordType() || T2->isRecordType())) 2866 return ICS; 2867 2868 // C++ [over.ics.ref]p2: 2869 // When a parameter of reference type is not bound directly to 2870 // an argument expression, the conversion sequence is the one 2871 // required to convert the argument expression to the 2872 // underlying type of the reference according to 2873 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2874 // to copy-initializing a temporary of the underlying type with 2875 // the argument expression. Any difference in top-level 2876 // cv-qualification is subsumed by the initialization itself 2877 // and does not constitute a conversion. 2878 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2879 /*AllowExplicit=*/false, 2880 /*InOverloadResolution=*/false); 2881 2882 // Of course, that's still a reference binding. 2883 if (ICS.isStandard()) { 2884 ICS.Standard.ReferenceBinding = true; 2885 ICS.Standard.RRefBinding = isRValRef; 2886 } else if (ICS.isUserDefined()) { 2887 ICS.UserDefined.After.ReferenceBinding = true; 2888 ICS.UserDefined.After.RRefBinding = isRValRef; 2889 } 2890 return ICS; 2891} 2892 2893/// TryCopyInitialization - Try to copy-initialize a value of type 2894/// ToType from the expression From. Return the implicit conversion 2895/// sequence required to pass this argument, which may be a bad 2896/// conversion sequence (meaning that the argument cannot be passed to 2897/// a parameter of this type). If @p SuppressUserConversions, then we 2898/// do not permit any user-defined conversion sequences. 2899static ImplicitConversionSequence 2900TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 2901 bool SuppressUserConversions, 2902 bool InOverloadResolution) { 2903 if (ToType->isReferenceType()) 2904 return TryReferenceInit(S, From, ToType, 2905 /*FIXME:*/From->getLocStart(), 2906 SuppressUserConversions, 2907 /*AllowExplicit=*/false); 2908 2909 return S.TryImplicitConversion(From, ToType, 2910 SuppressUserConversions, 2911 /*AllowExplicit=*/false, 2912 InOverloadResolution); 2913} 2914 2915/// TryObjectArgumentInitialization - Try to initialize the object 2916/// parameter of the given member function (@c Method) from the 2917/// expression @p From. 2918ImplicitConversionSequence 2919Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2920 CXXMethodDecl *Method, 2921 CXXRecordDecl *ActingContext) { 2922 QualType ClassType = Context.getTypeDeclType(ActingContext); 2923 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2924 // const volatile object. 2925 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2926 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2927 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2928 2929 // Set up the conversion sequence as a "bad" conversion, to allow us 2930 // to exit early. 2931 ImplicitConversionSequence ICS; 2932 2933 // We need to have an object of class type. 2934 QualType FromType = OrigFromType; 2935 if (const PointerType *PT = FromType->getAs<PointerType>()) 2936 FromType = PT->getPointeeType(); 2937 2938 assert(FromType->isRecordType()); 2939 2940 // The implicit object parameter is has the type "reference to cv X", 2941 // where X is the class of which the function is a member 2942 // (C++ [over.match.funcs]p4). However, when finding an implicit 2943 // conversion sequence for the argument, we are not allowed to 2944 // create temporaries or perform user-defined conversions 2945 // (C++ [over.match.funcs]p5). We perform a simplified version of 2946 // reference binding here, that allows class rvalues to bind to 2947 // non-constant references. 2948 2949 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2950 // with the implicit object parameter (C++ [over.match.funcs]p5). 2951 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2952 if (ImplicitParamType.getCVRQualifiers() 2953 != FromTypeCanon.getLocalCVRQualifiers() && 2954 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2955 ICS.setBad(BadConversionSequence::bad_qualifiers, 2956 OrigFromType, ImplicitParamType); 2957 return ICS; 2958 } 2959 2960 // Check that we have either the same type or a derived type. It 2961 // affects the conversion rank. 2962 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2963 ImplicitConversionKind SecondKind; 2964 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2965 SecondKind = ICK_Identity; 2966 } else if (IsDerivedFrom(FromType, ClassType)) 2967 SecondKind = ICK_Derived_To_Base; 2968 else { 2969 ICS.setBad(BadConversionSequence::unrelated_class, 2970 FromType, ImplicitParamType); 2971 return ICS; 2972 } 2973 2974 // Success. Mark this as a reference binding. 2975 ICS.setStandard(); 2976 ICS.Standard.setAsIdentityConversion(); 2977 ICS.Standard.Second = SecondKind; 2978 ICS.Standard.setFromType(FromType); 2979 ICS.Standard.setAllToTypes(ImplicitParamType); 2980 ICS.Standard.ReferenceBinding = true; 2981 ICS.Standard.DirectBinding = true; 2982 ICS.Standard.RRefBinding = false; 2983 return ICS; 2984} 2985 2986/// PerformObjectArgumentInitialization - Perform initialization of 2987/// the implicit object parameter for the given Method with the given 2988/// expression. 2989bool 2990Sema::PerformObjectArgumentInitialization(Expr *&From, 2991 NestedNameSpecifier *Qualifier, 2992 NamedDecl *FoundDecl, 2993 CXXMethodDecl *Method) { 2994 QualType FromRecordType, DestType; 2995 QualType ImplicitParamRecordType = 2996 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2997 2998 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 2999 FromRecordType = PT->getPointeeType(); 3000 DestType = Method->getThisType(Context); 3001 } else { 3002 FromRecordType = From->getType(); 3003 DestType = ImplicitParamRecordType; 3004 } 3005 3006 // Note that we always use the true parent context when performing 3007 // the actual argument initialization. 3008 ImplicitConversionSequence ICS 3009 = TryObjectArgumentInitialization(From->getType(), Method, 3010 Method->getParent()); 3011 if (ICS.isBad()) 3012 return Diag(From->getSourceRange().getBegin(), 3013 diag::err_implicit_object_parameter_init) 3014 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3015 3016 if (ICS.Standard.Second == ICK_Derived_To_Base) 3017 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3018 3019 if (!Context.hasSameType(From->getType(), DestType)) 3020 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 3021 /*isLvalue=*/!From->getType()->isPointerType()); 3022 return false; 3023} 3024 3025/// TryContextuallyConvertToBool - Attempt to contextually convert the 3026/// expression From to bool (C++0x [conv]p3). 3027ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 3028 // FIXME: This is pretty broken. 3029 return TryImplicitConversion(From, Context.BoolTy, 3030 // FIXME: Are these flags correct? 3031 /*SuppressUserConversions=*/false, 3032 /*AllowExplicit=*/true, 3033 /*InOverloadResolution=*/false); 3034} 3035 3036/// PerformContextuallyConvertToBool - Perform a contextual conversion 3037/// of the expression From to bool (C++0x [conv]p3). 3038bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3039 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 3040 if (!ICS.isBad()) 3041 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3042 3043 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3044 return Diag(From->getSourceRange().getBegin(), 3045 diag::err_typecheck_bool_condition) 3046 << From->getType() << From->getSourceRange(); 3047 return true; 3048} 3049 3050/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3051/// expression From to 'id'. 3052ImplicitConversionSequence Sema::TryContextuallyConvertToObjCId(Expr *From) { 3053 QualType Ty = Context.getObjCIdType(); 3054 return TryImplicitConversion(From, Ty, 3055 // FIXME: Are these flags correct? 3056 /*SuppressUserConversions=*/false, 3057 /*AllowExplicit=*/true, 3058 /*InOverloadResolution=*/false); 3059} 3060 3061/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3062/// of the expression From to 'id'. 3063bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3064 QualType Ty = Context.getObjCIdType(); 3065 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(From); 3066 if (!ICS.isBad()) 3067 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3068 return true; 3069} 3070 3071/// AddOverloadCandidate - Adds the given function to the set of 3072/// candidate functions, using the given function call arguments. If 3073/// @p SuppressUserConversions, then don't allow user-defined 3074/// conversions via constructors or conversion operators. 3075/// 3076/// \para PartialOverloading true if we are performing "partial" overloading 3077/// based on an incomplete set of function arguments. This feature is used by 3078/// code completion. 3079void 3080Sema::AddOverloadCandidate(FunctionDecl *Function, 3081 DeclAccessPair FoundDecl, 3082 Expr **Args, unsigned NumArgs, 3083 OverloadCandidateSet& CandidateSet, 3084 bool SuppressUserConversions, 3085 bool PartialOverloading) { 3086 const FunctionProtoType* Proto 3087 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3088 assert(Proto && "Functions without a prototype cannot be overloaded"); 3089 assert(!Function->getDescribedFunctionTemplate() && 3090 "Use AddTemplateOverloadCandidate for function templates"); 3091 3092 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3093 if (!isa<CXXConstructorDecl>(Method)) { 3094 // If we get here, it's because we're calling a member function 3095 // that is named without a member access expression (e.g., 3096 // "this->f") that was either written explicitly or created 3097 // implicitly. This can happen with a qualified call to a member 3098 // function, e.g., X::f(). We use an empty type for the implied 3099 // object argument (C++ [over.call.func]p3), and the acting context 3100 // is irrelevant. 3101 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3102 QualType(), Args, NumArgs, CandidateSet, 3103 SuppressUserConversions); 3104 return; 3105 } 3106 // We treat a constructor like a non-member function, since its object 3107 // argument doesn't participate in overload resolution. 3108 } 3109 3110 if (!CandidateSet.isNewCandidate(Function)) 3111 return; 3112 3113 // Overload resolution is always an unevaluated context. 3114 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3115 3116 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3117 // C++ [class.copy]p3: 3118 // A member function template is never instantiated to perform the copy 3119 // of a class object to an object of its class type. 3120 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3121 if (NumArgs == 1 && 3122 Constructor->isCopyConstructorLikeSpecialization() && 3123 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3124 IsDerivedFrom(Args[0]->getType(), ClassType))) 3125 return; 3126 } 3127 3128 // Add this candidate 3129 CandidateSet.push_back(OverloadCandidate()); 3130 OverloadCandidate& Candidate = CandidateSet.back(); 3131 Candidate.FoundDecl = FoundDecl; 3132 Candidate.Function = Function; 3133 Candidate.Viable = true; 3134 Candidate.IsSurrogate = false; 3135 Candidate.IgnoreObjectArgument = false; 3136 3137 unsigned NumArgsInProto = Proto->getNumArgs(); 3138 3139 // (C++ 13.3.2p2): A candidate function having fewer than m 3140 // parameters is viable only if it has an ellipsis in its parameter 3141 // list (8.3.5). 3142 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3143 !Proto->isVariadic()) { 3144 Candidate.Viable = false; 3145 Candidate.FailureKind = ovl_fail_too_many_arguments; 3146 return; 3147 } 3148 3149 // (C++ 13.3.2p2): A candidate function having more than m parameters 3150 // is viable only if the (m+1)st parameter has a default argument 3151 // (8.3.6). For the purposes of overload resolution, the 3152 // parameter list is truncated on the right, so that there are 3153 // exactly m parameters. 3154 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3155 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3156 // Not enough arguments. 3157 Candidate.Viable = false; 3158 Candidate.FailureKind = ovl_fail_too_few_arguments; 3159 return; 3160 } 3161 3162 // Determine the implicit conversion sequences for each of the 3163 // arguments. 3164 Candidate.Conversions.resize(NumArgs); 3165 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3166 if (ArgIdx < NumArgsInProto) { 3167 // (C++ 13.3.2p3): for F to be a viable function, there shall 3168 // exist for each argument an implicit conversion sequence 3169 // (13.3.3.1) that converts that argument to the corresponding 3170 // parameter of F. 3171 QualType ParamType = Proto->getArgType(ArgIdx); 3172 Candidate.Conversions[ArgIdx] 3173 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3174 SuppressUserConversions, 3175 /*InOverloadResolution=*/true); 3176 if (Candidate.Conversions[ArgIdx].isBad()) { 3177 Candidate.Viable = false; 3178 Candidate.FailureKind = ovl_fail_bad_conversion; 3179 break; 3180 } 3181 } else { 3182 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3183 // argument for which there is no corresponding parameter is 3184 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3185 Candidate.Conversions[ArgIdx].setEllipsis(); 3186 } 3187 } 3188} 3189 3190/// \brief Add all of the function declarations in the given function set to 3191/// the overload canddiate set. 3192void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3193 Expr **Args, unsigned NumArgs, 3194 OverloadCandidateSet& CandidateSet, 3195 bool SuppressUserConversions) { 3196 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3197 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3198 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3199 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3200 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3201 cast<CXXMethodDecl>(FD)->getParent(), 3202 Args[0]->getType(), Args + 1, NumArgs - 1, 3203 CandidateSet, SuppressUserConversions); 3204 else 3205 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3206 SuppressUserConversions); 3207 } else { 3208 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3209 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3210 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3211 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3212 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3213 /*FIXME: explicit args */ 0, 3214 Args[0]->getType(), Args + 1, NumArgs - 1, 3215 CandidateSet, 3216 SuppressUserConversions); 3217 else 3218 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3219 /*FIXME: explicit args */ 0, 3220 Args, NumArgs, CandidateSet, 3221 SuppressUserConversions); 3222 } 3223 } 3224} 3225 3226/// AddMethodCandidate - Adds a named decl (which is some kind of 3227/// method) as a method candidate to the given overload set. 3228void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3229 QualType ObjectType, 3230 Expr **Args, unsigned NumArgs, 3231 OverloadCandidateSet& CandidateSet, 3232 bool SuppressUserConversions) { 3233 NamedDecl *Decl = FoundDecl.getDecl(); 3234 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3235 3236 if (isa<UsingShadowDecl>(Decl)) 3237 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3238 3239 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3240 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3241 "Expected a member function template"); 3242 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3243 /*ExplicitArgs*/ 0, 3244 ObjectType, Args, NumArgs, 3245 CandidateSet, 3246 SuppressUserConversions); 3247 } else { 3248 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3249 ObjectType, Args, NumArgs, 3250 CandidateSet, SuppressUserConversions); 3251 } 3252} 3253 3254/// AddMethodCandidate - Adds the given C++ member function to the set 3255/// of candidate functions, using the given function call arguments 3256/// and the object argument (@c Object). For example, in a call 3257/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3258/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3259/// allow user-defined conversions via constructors or conversion 3260/// operators. 3261void 3262Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3263 CXXRecordDecl *ActingContext, QualType ObjectType, 3264 Expr **Args, unsigned NumArgs, 3265 OverloadCandidateSet& CandidateSet, 3266 bool SuppressUserConversions) { 3267 const FunctionProtoType* Proto 3268 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3269 assert(Proto && "Methods without a prototype cannot be overloaded"); 3270 assert(!isa<CXXConstructorDecl>(Method) && 3271 "Use AddOverloadCandidate for constructors"); 3272 3273 if (!CandidateSet.isNewCandidate(Method)) 3274 return; 3275 3276 // Overload resolution is always an unevaluated context. 3277 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3278 3279 // Add this candidate 3280 CandidateSet.push_back(OverloadCandidate()); 3281 OverloadCandidate& Candidate = CandidateSet.back(); 3282 Candidate.FoundDecl = FoundDecl; 3283 Candidate.Function = Method; 3284 Candidate.IsSurrogate = false; 3285 Candidate.IgnoreObjectArgument = false; 3286 3287 unsigned NumArgsInProto = Proto->getNumArgs(); 3288 3289 // (C++ 13.3.2p2): A candidate function having fewer than m 3290 // parameters is viable only if it has an ellipsis in its parameter 3291 // list (8.3.5). 3292 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3293 Candidate.Viable = false; 3294 Candidate.FailureKind = ovl_fail_too_many_arguments; 3295 return; 3296 } 3297 3298 // (C++ 13.3.2p2): A candidate function having more than m parameters 3299 // is viable only if the (m+1)st parameter has a default argument 3300 // (8.3.6). For the purposes of overload resolution, the 3301 // parameter list is truncated on the right, so that there are 3302 // exactly m parameters. 3303 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3304 if (NumArgs < MinRequiredArgs) { 3305 // Not enough arguments. 3306 Candidate.Viable = false; 3307 Candidate.FailureKind = ovl_fail_too_few_arguments; 3308 return; 3309 } 3310 3311 Candidate.Viable = true; 3312 Candidate.Conversions.resize(NumArgs + 1); 3313 3314 if (Method->isStatic() || ObjectType.isNull()) 3315 // The implicit object argument is ignored. 3316 Candidate.IgnoreObjectArgument = true; 3317 else { 3318 // Determine the implicit conversion sequence for the object 3319 // parameter. 3320 Candidate.Conversions[0] 3321 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 3322 if (Candidate.Conversions[0].isBad()) { 3323 Candidate.Viable = false; 3324 Candidate.FailureKind = ovl_fail_bad_conversion; 3325 return; 3326 } 3327 } 3328 3329 // Determine the implicit conversion sequences for each of the 3330 // arguments. 3331 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3332 if (ArgIdx < NumArgsInProto) { 3333 // (C++ 13.3.2p3): for F to be a viable function, there shall 3334 // exist for each argument an implicit conversion sequence 3335 // (13.3.3.1) that converts that argument to the corresponding 3336 // parameter of F. 3337 QualType ParamType = Proto->getArgType(ArgIdx); 3338 Candidate.Conversions[ArgIdx + 1] 3339 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3340 SuppressUserConversions, 3341 /*InOverloadResolution=*/true); 3342 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3343 Candidate.Viable = false; 3344 Candidate.FailureKind = ovl_fail_bad_conversion; 3345 break; 3346 } 3347 } else { 3348 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3349 // argument for which there is no corresponding parameter is 3350 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3351 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3352 } 3353 } 3354} 3355 3356/// \brief Add a C++ member function template as a candidate to the candidate 3357/// set, using template argument deduction to produce an appropriate member 3358/// function template specialization. 3359void 3360Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3361 DeclAccessPair FoundDecl, 3362 CXXRecordDecl *ActingContext, 3363 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3364 QualType ObjectType, 3365 Expr **Args, unsigned NumArgs, 3366 OverloadCandidateSet& CandidateSet, 3367 bool SuppressUserConversions) { 3368 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3369 return; 3370 3371 // C++ [over.match.funcs]p7: 3372 // In each case where a candidate is a function template, candidate 3373 // function template specializations are generated using template argument 3374 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3375 // candidate functions in the usual way.113) A given name can refer to one 3376 // or more function templates and also to a set of overloaded non-template 3377 // functions. In such a case, the candidate functions generated from each 3378 // function template are combined with the set of non-template candidate 3379 // functions. 3380 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3381 FunctionDecl *Specialization = 0; 3382 if (TemplateDeductionResult Result 3383 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3384 Args, NumArgs, Specialization, Info)) { 3385 CandidateSet.push_back(OverloadCandidate()); 3386 OverloadCandidate &Candidate = CandidateSet.back(); 3387 Candidate.FoundDecl = FoundDecl; 3388 Candidate.Function = MethodTmpl->getTemplatedDecl(); 3389 Candidate.Viable = false; 3390 Candidate.FailureKind = ovl_fail_bad_deduction; 3391 Candidate.IsSurrogate = false; 3392 Candidate.IgnoreObjectArgument = false; 3393 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3394 Info); 3395 return; 3396 } 3397 3398 // Add the function template specialization produced by template argument 3399 // deduction as a candidate. 3400 assert(Specialization && "Missing member function template specialization?"); 3401 assert(isa<CXXMethodDecl>(Specialization) && 3402 "Specialization is not a member function?"); 3403 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3404 ActingContext, ObjectType, Args, NumArgs, 3405 CandidateSet, SuppressUserConversions); 3406} 3407 3408/// \brief Add a C++ function template specialization as a candidate 3409/// in the candidate set, using template argument deduction to produce 3410/// an appropriate function template specialization. 3411void 3412Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3413 DeclAccessPair FoundDecl, 3414 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3415 Expr **Args, unsigned NumArgs, 3416 OverloadCandidateSet& CandidateSet, 3417 bool SuppressUserConversions) { 3418 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3419 return; 3420 3421 // C++ [over.match.funcs]p7: 3422 // In each case where a candidate is a function template, candidate 3423 // function template specializations are generated using template argument 3424 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3425 // candidate functions in the usual way.113) A given name can refer to one 3426 // or more function templates and also to a set of overloaded non-template 3427 // functions. In such a case, the candidate functions generated from each 3428 // function template are combined with the set of non-template candidate 3429 // functions. 3430 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3431 FunctionDecl *Specialization = 0; 3432 if (TemplateDeductionResult Result 3433 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3434 Args, NumArgs, Specialization, Info)) { 3435 CandidateSet.push_back(OverloadCandidate()); 3436 OverloadCandidate &Candidate = CandidateSet.back(); 3437 Candidate.FoundDecl = FoundDecl; 3438 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3439 Candidate.Viable = false; 3440 Candidate.FailureKind = ovl_fail_bad_deduction; 3441 Candidate.IsSurrogate = false; 3442 Candidate.IgnoreObjectArgument = false; 3443 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3444 Info); 3445 return; 3446 } 3447 3448 // Add the function template specialization produced by template argument 3449 // deduction as a candidate. 3450 assert(Specialization && "Missing function template specialization?"); 3451 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3452 SuppressUserConversions); 3453} 3454 3455/// AddConversionCandidate - Add a C++ conversion function as a 3456/// candidate in the candidate set (C++ [over.match.conv], 3457/// C++ [over.match.copy]). From is the expression we're converting from, 3458/// and ToType is the type that we're eventually trying to convert to 3459/// (which may or may not be the same type as the type that the 3460/// conversion function produces). 3461void 3462Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3463 DeclAccessPair FoundDecl, 3464 CXXRecordDecl *ActingContext, 3465 Expr *From, QualType ToType, 3466 OverloadCandidateSet& CandidateSet) { 3467 assert(!Conversion->getDescribedFunctionTemplate() && 3468 "Conversion function templates use AddTemplateConversionCandidate"); 3469 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3470 if (!CandidateSet.isNewCandidate(Conversion)) 3471 return; 3472 3473 // Overload resolution is always an unevaluated context. 3474 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3475 3476 // Add this candidate 3477 CandidateSet.push_back(OverloadCandidate()); 3478 OverloadCandidate& Candidate = CandidateSet.back(); 3479 Candidate.FoundDecl = FoundDecl; 3480 Candidate.Function = Conversion; 3481 Candidate.IsSurrogate = false; 3482 Candidate.IgnoreObjectArgument = false; 3483 Candidate.FinalConversion.setAsIdentityConversion(); 3484 Candidate.FinalConversion.setFromType(ConvType); 3485 Candidate.FinalConversion.setAllToTypes(ToType); 3486 3487 // Determine the implicit conversion sequence for the implicit 3488 // object parameter. 3489 Candidate.Viable = true; 3490 Candidate.Conversions.resize(1); 3491 Candidate.Conversions[0] 3492 = TryObjectArgumentInitialization(From->getType(), Conversion, 3493 ActingContext); 3494 // Conversion functions to a different type in the base class is visible in 3495 // the derived class. So, a derived to base conversion should not participate 3496 // in overload resolution. 3497 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3498 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3499 if (Candidate.Conversions[0].isBad()) { 3500 Candidate.Viable = false; 3501 Candidate.FailureKind = ovl_fail_bad_conversion; 3502 return; 3503 } 3504 3505 // We won't go through a user-define type conversion function to convert a 3506 // derived to base as such conversions are given Conversion Rank. They only 3507 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3508 QualType FromCanon 3509 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3510 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3511 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3512 Candidate.Viable = false; 3513 Candidate.FailureKind = ovl_fail_trivial_conversion; 3514 return; 3515 } 3516 3517 // To determine what the conversion from the result of calling the 3518 // conversion function to the type we're eventually trying to 3519 // convert to (ToType), we need to synthesize a call to the 3520 // conversion function and attempt copy initialization from it. This 3521 // makes sure that we get the right semantics with respect to 3522 // lvalues/rvalues and the type. Fortunately, we can allocate this 3523 // call on the stack and we don't need its arguments to be 3524 // well-formed. 3525 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3526 From->getLocStart()); 3527 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 3528 CastExpr::CK_FunctionToPointerDecay, 3529 &ConversionRef, CXXBaseSpecifierArray(), false); 3530 3531 // Note that it is safe to allocate CallExpr on the stack here because 3532 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3533 // allocator). 3534 CallExpr Call(Context, &ConversionFn, 0, 0, 3535 Conversion->getConversionType().getNonReferenceType(), 3536 From->getLocStart()); 3537 ImplicitConversionSequence ICS = 3538 TryCopyInitialization(*this, &Call, ToType, 3539 /*SuppressUserConversions=*/true, 3540 /*InOverloadResolution=*/false); 3541 3542 switch (ICS.getKind()) { 3543 case ImplicitConversionSequence::StandardConversion: 3544 Candidate.FinalConversion = ICS.Standard; 3545 3546 // C++ [over.ics.user]p3: 3547 // If the user-defined conversion is specified by a specialization of a 3548 // conversion function template, the second standard conversion sequence 3549 // shall have exact match rank. 3550 if (Conversion->getPrimaryTemplate() && 3551 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3552 Candidate.Viable = false; 3553 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3554 } 3555 3556 break; 3557 3558 case ImplicitConversionSequence::BadConversion: 3559 Candidate.Viable = false; 3560 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3561 break; 3562 3563 default: 3564 assert(false && 3565 "Can only end up with a standard conversion sequence or failure"); 3566 } 3567} 3568 3569/// \brief Adds a conversion function template specialization 3570/// candidate to the overload set, using template argument deduction 3571/// to deduce the template arguments of the conversion function 3572/// template from the type that we are converting to (C++ 3573/// [temp.deduct.conv]). 3574void 3575Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3576 DeclAccessPair FoundDecl, 3577 CXXRecordDecl *ActingDC, 3578 Expr *From, QualType ToType, 3579 OverloadCandidateSet &CandidateSet) { 3580 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3581 "Only conversion function templates permitted here"); 3582 3583 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3584 return; 3585 3586 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3587 CXXConversionDecl *Specialization = 0; 3588 if (TemplateDeductionResult Result 3589 = DeduceTemplateArguments(FunctionTemplate, ToType, 3590 Specialization, Info)) { 3591 CandidateSet.push_back(OverloadCandidate()); 3592 OverloadCandidate &Candidate = CandidateSet.back(); 3593 Candidate.FoundDecl = FoundDecl; 3594 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3595 Candidate.Viable = false; 3596 Candidate.FailureKind = ovl_fail_bad_deduction; 3597 Candidate.IsSurrogate = false; 3598 Candidate.IgnoreObjectArgument = false; 3599 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3600 Info); 3601 return; 3602 } 3603 3604 // Add the conversion function template specialization produced by 3605 // template argument deduction as a candidate. 3606 assert(Specialization && "Missing function template specialization?"); 3607 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3608 CandidateSet); 3609} 3610 3611/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3612/// converts the given @c Object to a function pointer via the 3613/// conversion function @c Conversion, and then attempts to call it 3614/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3615/// the type of function that we'll eventually be calling. 3616void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3617 DeclAccessPair FoundDecl, 3618 CXXRecordDecl *ActingContext, 3619 const FunctionProtoType *Proto, 3620 QualType ObjectType, 3621 Expr **Args, unsigned NumArgs, 3622 OverloadCandidateSet& CandidateSet) { 3623 if (!CandidateSet.isNewCandidate(Conversion)) 3624 return; 3625 3626 // Overload resolution is always an unevaluated context. 3627 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3628 3629 CandidateSet.push_back(OverloadCandidate()); 3630 OverloadCandidate& Candidate = CandidateSet.back(); 3631 Candidate.FoundDecl = FoundDecl; 3632 Candidate.Function = 0; 3633 Candidate.Surrogate = Conversion; 3634 Candidate.Viable = true; 3635 Candidate.IsSurrogate = true; 3636 Candidate.IgnoreObjectArgument = false; 3637 Candidate.Conversions.resize(NumArgs + 1); 3638 3639 // Determine the implicit conversion sequence for the implicit 3640 // object parameter. 3641 ImplicitConversionSequence ObjectInit 3642 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3643 if (ObjectInit.isBad()) { 3644 Candidate.Viable = false; 3645 Candidate.FailureKind = ovl_fail_bad_conversion; 3646 Candidate.Conversions[0] = ObjectInit; 3647 return; 3648 } 3649 3650 // The first conversion is actually a user-defined conversion whose 3651 // first conversion is ObjectInit's standard conversion (which is 3652 // effectively a reference binding). Record it as such. 3653 Candidate.Conversions[0].setUserDefined(); 3654 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3655 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3656 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3657 Candidate.Conversions[0].UserDefined.After 3658 = Candidate.Conversions[0].UserDefined.Before; 3659 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3660 3661 // Find the 3662 unsigned NumArgsInProto = Proto->getNumArgs(); 3663 3664 // (C++ 13.3.2p2): A candidate function having fewer than m 3665 // parameters is viable only if it has an ellipsis in its parameter 3666 // list (8.3.5). 3667 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3668 Candidate.Viable = false; 3669 Candidate.FailureKind = ovl_fail_too_many_arguments; 3670 return; 3671 } 3672 3673 // Function types don't have any default arguments, so just check if 3674 // we have enough arguments. 3675 if (NumArgs < NumArgsInProto) { 3676 // Not enough arguments. 3677 Candidate.Viable = false; 3678 Candidate.FailureKind = ovl_fail_too_few_arguments; 3679 return; 3680 } 3681 3682 // Determine the implicit conversion sequences for each of the 3683 // arguments. 3684 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3685 if (ArgIdx < NumArgsInProto) { 3686 // (C++ 13.3.2p3): for F to be a viable function, there shall 3687 // exist for each argument an implicit conversion sequence 3688 // (13.3.3.1) that converts that argument to the corresponding 3689 // parameter of F. 3690 QualType ParamType = Proto->getArgType(ArgIdx); 3691 Candidate.Conversions[ArgIdx + 1] 3692 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3693 /*SuppressUserConversions=*/false, 3694 /*InOverloadResolution=*/false); 3695 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3696 Candidate.Viable = false; 3697 Candidate.FailureKind = ovl_fail_bad_conversion; 3698 break; 3699 } 3700 } else { 3701 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3702 // argument for which there is no corresponding parameter is 3703 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3704 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3705 } 3706 } 3707} 3708 3709/// \brief Add overload candidates for overloaded operators that are 3710/// member functions. 3711/// 3712/// Add the overloaded operator candidates that are member functions 3713/// for the operator Op that was used in an operator expression such 3714/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3715/// CandidateSet will store the added overload candidates. (C++ 3716/// [over.match.oper]). 3717void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3718 SourceLocation OpLoc, 3719 Expr **Args, unsigned NumArgs, 3720 OverloadCandidateSet& CandidateSet, 3721 SourceRange OpRange) { 3722 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3723 3724 // C++ [over.match.oper]p3: 3725 // For a unary operator @ with an operand of a type whose 3726 // cv-unqualified version is T1, and for a binary operator @ with 3727 // a left operand of a type whose cv-unqualified version is T1 and 3728 // a right operand of a type whose cv-unqualified version is T2, 3729 // three sets of candidate functions, designated member 3730 // candidates, non-member candidates and built-in candidates, are 3731 // constructed as follows: 3732 QualType T1 = Args[0]->getType(); 3733 QualType T2; 3734 if (NumArgs > 1) 3735 T2 = Args[1]->getType(); 3736 3737 // -- If T1 is a class type, the set of member candidates is the 3738 // result of the qualified lookup of T1::operator@ 3739 // (13.3.1.1.1); otherwise, the set of member candidates is 3740 // empty. 3741 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3742 // Complete the type if it can be completed. Otherwise, we're done. 3743 if (RequireCompleteType(OpLoc, T1, PDiag())) 3744 return; 3745 3746 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3747 LookupQualifiedName(Operators, T1Rec->getDecl()); 3748 Operators.suppressDiagnostics(); 3749 3750 for (LookupResult::iterator Oper = Operators.begin(), 3751 OperEnd = Operators.end(); 3752 Oper != OperEnd; 3753 ++Oper) 3754 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3755 Args + 1, NumArgs - 1, CandidateSet, 3756 /* SuppressUserConversions = */ false); 3757 } 3758} 3759 3760/// AddBuiltinCandidate - Add a candidate for a built-in 3761/// operator. ResultTy and ParamTys are the result and parameter types 3762/// of the built-in candidate, respectively. Args and NumArgs are the 3763/// arguments being passed to the candidate. IsAssignmentOperator 3764/// should be true when this built-in candidate is an assignment 3765/// operator. NumContextualBoolArguments is the number of arguments 3766/// (at the beginning of the argument list) that will be contextually 3767/// converted to bool. 3768void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3769 Expr **Args, unsigned NumArgs, 3770 OverloadCandidateSet& CandidateSet, 3771 bool IsAssignmentOperator, 3772 unsigned NumContextualBoolArguments) { 3773 // Overload resolution is always an unevaluated context. 3774 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3775 3776 // Add this candidate 3777 CandidateSet.push_back(OverloadCandidate()); 3778 OverloadCandidate& Candidate = CandidateSet.back(); 3779 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3780 Candidate.Function = 0; 3781 Candidate.IsSurrogate = false; 3782 Candidate.IgnoreObjectArgument = false; 3783 Candidate.BuiltinTypes.ResultTy = ResultTy; 3784 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3785 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3786 3787 // Determine the implicit conversion sequences for each of the 3788 // arguments. 3789 Candidate.Viable = true; 3790 Candidate.Conversions.resize(NumArgs); 3791 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3792 // C++ [over.match.oper]p4: 3793 // For the built-in assignment operators, conversions of the 3794 // left operand are restricted as follows: 3795 // -- no temporaries are introduced to hold the left operand, and 3796 // -- no user-defined conversions are applied to the left 3797 // operand to achieve a type match with the left-most 3798 // parameter of a built-in candidate. 3799 // 3800 // We block these conversions by turning off user-defined 3801 // conversions, since that is the only way that initialization of 3802 // a reference to a non-class type can occur from something that 3803 // is not of the same type. 3804 if (ArgIdx < NumContextualBoolArguments) { 3805 assert(ParamTys[ArgIdx] == Context.BoolTy && 3806 "Contextual conversion to bool requires bool type"); 3807 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3808 } else { 3809 Candidate.Conversions[ArgIdx] 3810 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 3811 ArgIdx == 0 && IsAssignmentOperator, 3812 /*InOverloadResolution=*/false); 3813 } 3814 if (Candidate.Conversions[ArgIdx].isBad()) { 3815 Candidate.Viable = false; 3816 Candidate.FailureKind = ovl_fail_bad_conversion; 3817 break; 3818 } 3819 } 3820} 3821 3822/// BuiltinCandidateTypeSet - A set of types that will be used for the 3823/// candidate operator functions for built-in operators (C++ 3824/// [over.built]). The types are separated into pointer types and 3825/// enumeration types. 3826class BuiltinCandidateTypeSet { 3827 /// TypeSet - A set of types. 3828 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3829 3830 /// PointerTypes - The set of pointer types that will be used in the 3831 /// built-in candidates. 3832 TypeSet PointerTypes; 3833 3834 /// MemberPointerTypes - The set of member pointer types that will be 3835 /// used in the built-in candidates. 3836 TypeSet MemberPointerTypes; 3837 3838 /// EnumerationTypes - The set of enumeration types that will be 3839 /// used in the built-in candidates. 3840 TypeSet EnumerationTypes; 3841 3842 /// \brief The set of vector types that will be used in the built-in 3843 /// candidates. 3844 TypeSet VectorTypes; 3845 3846 /// Sema - The semantic analysis instance where we are building the 3847 /// candidate type set. 3848 Sema &SemaRef; 3849 3850 /// Context - The AST context in which we will build the type sets. 3851 ASTContext &Context; 3852 3853 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3854 const Qualifiers &VisibleQuals); 3855 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3856 3857public: 3858 /// iterator - Iterates through the types that are part of the set. 3859 typedef TypeSet::iterator iterator; 3860 3861 BuiltinCandidateTypeSet(Sema &SemaRef) 3862 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3863 3864 void AddTypesConvertedFrom(QualType Ty, 3865 SourceLocation Loc, 3866 bool AllowUserConversions, 3867 bool AllowExplicitConversions, 3868 const Qualifiers &VisibleTypeConversionsQuals); 3869 3870 /// pointer_begin - First pointer type found; 3871 iterator pointer_begin() { return PointerTypes.begin(); } 3872 3873 /// pointer_end - Past the last pointer type found; 3874 iterator pointer_end() { return PointerTypes.end(); } 3875 3876 /// member_pointer_begin - First member pointer type found; 3877 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3878 3879 /// member_pointer_end - Past the last member pointer type found; 3880 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3881 3882 /// enumeration_begin - First enumeration type found; 3883 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3884 3885 /// enumeration_end - Past the last enumeration type found; 3886 iterator enumeration_end() { return EnumerationTypes.end(); } 3887 3888 iterator vector_begin() { return VectorTypes.begin(); } 3889 iterator vector_end() { return VectorTypes.end(); } 3890}; 3891 3892/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3893/// the set of pointer types along with any more-qualified variants of 3894/// that type. For example, if @p Ty is "int const *", this routine 3895/// will add "int const *", "int const volatile *", "int const 3896/// restrict *", and "int const volatile restrict *" to the set of 3897/// pointer types. Returns true if the add of @p Ty itself succeeded, 3898/// false otherwise. 3899/// 3900/// FIXME: what to do about extended qualifiers? 3901bool 3902BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3903 const Qualifiers &VisibleQuals) { 3904 3905 // Insert this type. 3906 if (!PointerTypes.insert(Ty)) 3907 return false; 3908 3909 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3910 assert(PointerTy && "type was not a pointer type!"); 3911 3912 QualType PointeeTy = PointerTy->getPointeeType(); 3913 // Don't add qualified variants of arrays. For one, they're not allowed 3914 // (the qualifier would sink to the element type), and for another, the 3915 // only overload situation where it matters is subscript or pointer +- int, 3916 // and those shouldn't have qualifier variants anyway. 3917 if (PointeeTy->isArrayType()) 3918 return true; 3919 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3920 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3921 BaseCVR = Array->getElementType().getCVRQualifiers(); 3922 bool hasVolatile = VisibleQuals.hasVolatile(); 3923 bool hasRestrict = VisibleQuals.hasRestrict(); 3924 3925 // Iterate through all strict supersets of BaseCVR. 3926 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3927 if ((CVR | BaseCVR) != CVR) continue; 3928 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3929 // in the types. 3930 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3931 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3932 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3933 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3934 } 3935 3936 return true; 3937} 3938 3939/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3940/// to the set of pointer types along with any more-qualified variants of 3941/// that type. For example, if @p Ty is "int const *", this routine 3942/// will add "int const *", "int const volatile *", "int const 3943/// restrict *", and "int const volatile restrict *" to the set of 3944/// pointer types. Returns true if the add of @p Ty itself succeeded, 3945/// false otherwise. 3946/// 3947/// FIXME: what to do about extended qualifiers? 3948bool 3949BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3950 QualType Ty) { 3951 // Insert this type. 3952 if (!MemberPointerTypes.insert(Ty)) 3953 return false; 3954 3955 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3956 assert(PointerTy && "type was not a member pointer type!"); 3957 3958 QualType PointeeTy = PointerTy->getPointeeType(); 3959 // Don't add qualified variants of arrays. For one, they're not allowed 3960 // (the qualifier would sink to the element type), and for another, the 3961 // only overload situation where it matters is subscript or pointer +- int, 3962 // and those shouldn't have qualifier variants anyway. 3963 if (PointeeTy->isArrayType()) 3964 return true; 3965 const Type *ClassTy = PointerTy->getClass(); 3966 3967 // Iterate through all strict supersets of the pointee type's CVR 3968 // qualifiers. 3969 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3970 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3971 if ((CVR | BaseCVR) != CVR) continue; 3972 3973 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3974 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3975 } 3976 3977 return true; 3978} 3979 3980/// AddTypesConvertedFrom - Add each of the types to which the type @p 3981/// Ty can be implicit converted to the given set of @p Types. We're 3982/// primarily interested in pointer types and enumeration types. We also 3983/// take member pointer types, for the conditional operator. 3984/// AllowUserConversions is true if we should look at the conversion 3985/// functions of a class type, and AllowExplicitConversions if we 3986/// should also include the explicit conversion functions of a class 3987/// type. 3988void 3989BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3990 SourceLocation Loc, 3991 bool AllowUserConversions, 3992 bool AllowExplicitConversions, 3993 const Qualifiers &VisibleQuals) { 3994 // Only deal with canonical types. 3995 Ty = Context.getCanonicalType(Ty); 3996 3997 // Look through reference types; they aren't part of the type of an 3998 // expression for the purposes of conversions. 3999 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4000 Ty = RefTy->getPointeeType(); 4001 4002 // We don't care about qualifiers on the type. 4003 Ty = Ty.getLocalUnqualifiedType(); 4004 4005 // If we're dealing with an array type, decay to the pointer. 4006 if (Ty->isArrayType()) 4007 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4008 4009 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 4010 QualType PointeeTy = PointerTy->getPointeeType(); 4011 4012 // Insert our type, and its more-qualified variants, into the set 4013 // of types. 4014 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4015 return; 4016 } else if (Ty->isMemberPointerType()) { 4017 // Member pointers are far easier, since the pointee can't be converted. 4018 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4019 return; 4020 } else if (Ty->isEnumeralType()) { 4021 EnumerationTypes.insert(Ty); 4022 } else if (Ty->isVectorType()) { 4023 VectorTypes.insert(Ty); 4024 } else if (AllowUserConversions) { 4025 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 4026 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 4027 // No conversion functions in incomplete types. 4028 return; 4029 } 4030 4031 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4032 const UnresolvedSetImpl *Conversions 4033 = ClassDecl->getVisibleConversionFunctions(); 4034 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4035 E = Conversions->end(); I != E; ++I) { 4036 NamedDecl *D = I.getDecl(); 4037 if (isa<UsingShadowDecl>(D)) 4038 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4039 4040 // Skip conversion function templates; they don't tell us anything 4041 // about which builtin types we can convert to. 4042 if (isa<FunctionTemplateDecl>(D)) 4043 continue; 4044 4045 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4046 if (AllowExplicitConversions || !Conv->isExplicit()) { 4047 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4048 VisibleQuals); 4049 } 4050 } 4051 } 4052 } 4053} 4054 4055/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4056/// the volatile- and non-volatile-qualified assignment operators for the 4057/// given type to the candidate set. 4058static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4059 QualType T, 4060 Expr **Args, 4061 unsigned NumArgs, 4062 OverloadCandidateSet &CandidateSet) { 4063 QualType ParamTypes[2]; 4064 4065 // T& operator=(T&, T) 4066 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4067 ParamTypes[1] = T; 4068 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4069 /*IsAssignmentOperator=*/true); 4070 4071 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4072 // volatile T& operator=(volatile T&, T) 4073 ParamTypes[0] 4074 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4075 ParamTypes[1] = T; 4076 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4077 /*IsAssignmentOperator=*/true); 4078 } 4079} 4080 4081/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4082/// if any, found in visible type conversion functions found in ArgExpr's type. 4083static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4084 Qualifiers VRQuals; 4085 const RecordType *TyRec; 4086 if (const MemberPointerType *RHSMPType = 4087 ArgExpr->getType()->getAs<MemberPointerType>()) 4088 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4089 else 4090 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4091 if (!TyRec) { 4092 // Just to be safe, assume the worst case. 4093 VRQuals.addVolatile(); 4094 VRQuals.addRestrict(); 4095 return VRQuals; 4096 } 4097 4098 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4099 if (!ClassDecl->hasDefinition()) 4100 return VRQuals; 4101 4102 const UnresolvedSetImpl *Conversions = 4103 ClassDecl->getVisibleConversionFunctions(); 4104 4105 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4106 E = Conversions->end(); I != E; ++I) { 4107 NamedDecl *D = I.getDecl(); 4108 if (isa<UsingShadowDecl>(D)) 4109 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4110 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4111 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4112 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4113 CanTy = ResTypeRef->getPointeeType(); 4114 // Need to go down the pointer/mempointer chain and add qualifiers 4115 // as see them. 4116 bool done = false; 4117 while (!done) { 4118 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4119 CanTy = ResTypePtr->getPointeeType(); 4120 else if (const MemberPointerType *ResTypeMPtr = 4121 CanTy->getAs<MemberPointerType>()) 4122 CanTy = ResTypeMPtr->getPointeeType(); 4123 else 4124 done = true; 4125 if (CanTy.isVolatileQualified()) 4126 VRQuals.addVolatile(); 4127 if (CanTy.isRestrictQualified()) 4128 VRQuals.addRestrict(); 4129 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4130 return VRQuals; 4131 } 4132 } 4133 } 4134 return VRQuals; 4135} 4136 4137/// AddBuiltinOperatorCandidates - Add the appropriate built-in 4138/// operator overloads to the candidate set (C++ [over.built]), based 4139/// on the operator @p Op and the arguments given. For example, if the 4140/// operator is a binary '+', this routine might add "int 4141/// operator+(int, int)" to cover integer addition. 4142void 4143Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 4144 SourceLocation OpLoc, 4145 Expr **Args, unsigned NumArgs, 4146 OverloadCandidateSet& CandidateSet) { 4147 // The set of "promoted arithmetic types", which are the arithmetic 4148 // types are that preserved by promotion (C++ [over.built]p2). Note 4149 // that the first few of these types are the promoted integral 4150 // types; these types need to be first. 4151 // FIXME: What about complex? 4152 const unsigned FirstIntegralType = 0; 4153 const unsigned LastIntegralType = 13; 4154 const unsigned FirstPromotedIntegralType = 7, 4155 LastPromotedIntegralType = 13; 4156 const unsigned FirstPromotedArithmeticType = 7, 4157 LastPromotedArithmeticType = 16; 4158 const unsigned NumArithmeticTypes = 16; 4159 QualType ArithmeticTypes[NumArithmeticTypes] = { 4160 Context.BoolTy, Context.CharTy, Context.WCharTy, 4161// FIXME: Context.Char16Ty, Context.Char32Ty, 4162 Context.SignedCharTy, Context.ShortTy, 4163 Context.UnsignedCharTy, Context.UnsignedShortTy, 4164 Context.IntTy, Context.LongTy, Context.LongLongTy, 4165 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 4166 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 4167 }; 4168 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 4169 "Invalid first promoted integral type"); 4170 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 4171 == Context.UnsignedLongLongTy && 4172 "Invalid last promoted integral type"); 4173 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 4174 "Invalid first promoted arithmetic type"); 4175 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 4176 == Context.LongDoubleTy && 4177 "Invalid last promoted arithmetic type"); 4178 4179 // Find all of the types that the arguments can convert to, but only 4180 // if the operator we're looking at has built-in operator candidates 4181 // that make use of these types. 4182 Qualifiers VisibleTypeConversionsQuals; 4183 VisibleTypeConversionsQuals.addConst(); 4184 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4185 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 4186 4187 BuiltinCandidateTypeSet CandidateTypes(*this); 4188 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4189 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 4190 OpLoc, 4191 true, 4192 (Op == OO_Exclaim || 4193 Op == OO_AmpAmp || 4194 Op == OO_PipePipe), 4195 VisibleTypeConversionsQuals); 4196 4197 bool isComparison = false; 4198 switch (Op) { 4199 case OO_None: 4200 case NUM_OVERLOADED_OPERATORS: 4201 assert(false && "Expected an overloaded operator"); 4202 break; 4203 4204 case OO_Star: // '*' is either unary or binary 4205 if (NumArgs == 1) 4206 goto UnaryStar; 4207 else 4208 goto BinaryStar; 4209 break; 4210 4211 case OO_Plus: // '+' is either unary or binary 4212 if (NumArgs == 1) 4213 goto UnaryPlus; 4214 else 4215 goto BinaryPlus; 4216 break; 4217 4218 case OO_Minus: // '-' is either unary or binary 4219 if (NumArgs == 1) 4220 goto UnaryMinus; 4221 else 4222 goto BinaryMinus; 4223 break; 4224 4225 case OO_Amp: // '&' is either unary or binary 4226 if (NumArgs == 1) 4227 goto UnaryAmp; 4228 else 4229 goto BinaryAmp; 4230 4231 case OO_PlusPlus: 4232 case OO_MinusMinus: 4233 // C++ [over.built]p3: 4234 // 4235 // For every pair (T, VQ), where T is an arithmetic type, and VQ 4236 // is either volatile or empty, there exist candidate operator 4237 // functions of the form 4238 // 4239 // VQ T& operator++(VQ T&); 4240 // T operator++(VQ T&, int); 4241 // 4242 // C++ [over.built]p4: 4243 // 4244 // For every pair (T, VQ), where T is an arithmetic type other 4245 // than bool, and VQ is either volatile or empty, there exist 4246 // candidate operator functions of the form 4247 // 4248 // VQ T& operator--(VQ T&); 4249 // T operator--(VQ T&, int); 4250 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 4251 Arith < NumArithmeticTypes; ++Arith) { 4252 QualType ArithTy = ArithmeticTypes[Arith]; 4253 QualType ParamTypes[2] 4254 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 4255 4256 // Non-volatile version. 4257 if (NumArgs == 1) 4258 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4259 else 4260 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4261 // heuristic to reduce number of builtin candidates in the set. 4262 // Add volatile version only if there are conversions to a volatile type. 4263 if (VisibleTypeConversionsQuals.hasVolatile()) { 4264 // Volatile version 4265 ParamTypes[0] 4266 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 4267 if (NumArgs == 1) 4268 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4269 else 4270 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4271 } 4272 } 4273 4274 // C++ [over.built]p5: 4275 // 4276 // For every pair (T, VQ), where T is a cv-qualified or 4277 // cv-unqualified object type, and VQ is either volatile or 4278 // empty, there exist candidate operator functions of the form 4279 // 4280 // T*VQ& operator++(T*VQ&); 4281 // T*VQ& operator--(T*VQ&); 4282 // T* operator++(T*VQ&, int); 4283 // T* operator--(T*VQ&, int); 4284 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4285 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4286 // Skip pointer types that aren't pointers to object types. 4287 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 4288 continue; 4289 4290 QualType ParamTypes[2] = { 4291 Context.getLValueReferenceType(*Ptr), Context.IntTy 4292 }; 4293 4294 // Without volatile 4295 if (NumArgs == 1) 4296 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4297 else 4298 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4299 4300 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4301 VisibleTypeConversionsQuals.hasVolatile()) { 4302 // With volatile 4303 ParamTypes[0] 4304 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4305 if (NumArgs == 1) 4306 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4307 else 4308 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4309 } 4310 } 4311 break; 4312 4313 UnaryStar: 4314 // C++ [over.built]p6: 4315 // For every cv-qualified or cv-unqualified object type T, there 4316 // exist candidate operator functions of the form 4317 // 4318 // T& operator*(T*); 4319 // 4320 // C++ [over.built]p7: 4321 // For every function type T, there exist candidate operator 4322 // functions of the form 4323 // T& operator*(T*); 4324 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4325 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4326 QualType ParamTy = *Ptr; 4327 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 4328 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 4329 &ParamTy, Args, 1, CandidateSet); 4330 } 4331 break; 4332 4333 UnaryPlus: 4334 // C++ [over.built]p8: 4335 // For every type T, there exist candidate operator functions of 4336 // the form 4337 // 4338 // T* operator+(T*); 4339 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4340 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4341 QualType ParamTy = *Ptr; 4342 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4343 } 4344 4345 // Fall through 4346 4347 UnaryMinus: 4348 // C++ [over.built]p9: 4349 // For every promoted arithmetic type T, there exist candidate 4350 // operator functions of the form 4351 // 4352 // T operator+(T); 4353 // T operator-(T); 4354 for (unsigned Arith = FirstPromotedArithmeticType; 4355 Arith < LastPromotedArithmeticType; ++Arith) { 4356 QualType ArithTy = ArithmeticTypes[Arith]; 4357 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4358 } 4359 4360 // Extension: We also add these operators for vector types. 4361 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4362 VecEnd = CandidateTypes.vector_end(); 4363 Vec != VecEnd; ++Vec) { 4364 QualType VecTy = *Vec; 4365 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4366 } 4367 break; 4368 4369 case OO_Tilde: 4370 // C++ [over.built]p10: 4371 // For every promoted integral type T, there exist candidate 4372 // operator functions of the form 4373 // 4374 // T operator~(T); 4375 for (unsigned Int = FirstPromotedIntegralType; 4376 Int < LastPromotedIntegralType; ++Int) { 4377 QualType IntTy = ArithmeticTypes[Int]; 4378 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4379 } 4380 4381 // Extension: We also add this operator for vector types. 4382 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4383 VecEnd = CandidateTypes.vector_end(); 4384 Vec != VecEnd; ++Vec) { 4385 QualType VecTy = *Vec; 4386 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4387 } 4388 break; 4389 4390 case OO_New: 4391 case OO_Delete: 4392 case OO_Array_New: 4393 case OO_Array_Delete: 4394 case OO_Call: 4395 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 4396 break; 4397 4398 case OO_Comma: 4399 UnaryAmp: 4400 case OO_Arrow: 4401 // C++ [over.match.oper]p3: 4402 // -- For the operator ',', the unary operator '&', or the 4403 // operator '->', the built-in candidates set is empty. 4404 break; 4405 4406 case OO_EqualEqual: 4407 case OO_ExclaimEqual: 4408 // C++ [over.match.oper]p16: 4409 // For every pointer to member type T, there exist candidate operator 4410 // functions of the form 4411 // 4412 // bool operator==(T,T); 4413 // bool operator!=(T,T); 4414 for (BuiltinCandidateTypeSet::iterator 4415 MemPtr = CandidateTypes.member_pointer_begin(), 4416 MemPtrEnd = CandidateTypes.member_pointer_end(); 4417 MemPtr != MemPtrEnd; 4418 ++MemPtr) { 4419 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4420 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4421 } 4422 4423 // Fall through 4424 4425 case OO_Less: 4426 case OO_Greater: 4427 case OO_LessEqual: 4428 case OO_GreaterEqual: 4429 // C++ [over.built]p15: 4430 // 4431 // For every pointer or enumeration type T, there exist 4432 // candidate operator functions of the form 4433 // 4434 // bool operator<(T, T); 4435 // bool operator>(T, T); 4436 // bool operator<=(T, T); 4437 // bool operator>=(T, T); 4438 // bool operator==(T, T); 4439 // bool operator!=(T, T); 4440 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4441 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4442 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4443 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4444 } 4445 for (BuiltinCandidateTypeSet::iterator Enum 4446 = CandidateTypes.enumeration_begin(); 4447 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4448 QualType ParamTypes[2] = { *Enum, *Enum }; 4449 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4450 } 4451 4452 // Fall through. 4453 isComparison = true; 4454 4455 BinaryPlus: 4456 BinaryMinus: 4457 if (!isComparison) { 4458 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4459 4460 // C++ [over.built]p13: 4461 // 4462 // For every cv-qualified or cv-unqualified object type T 4463 // there exist candidate operator functions of the form 4464 // 4465 // T* operator+(T*, ptrdiff_t); 4466 // T& operator[](T*, ptrdiff_t); [BELOW] 4467 // T* operator-(T*, ptrdiff_t); 4468 // T* operator+(ptrdiff_t, T*); 4469 // T& operator[](ptrdiff_t, T*); [BELOW] 4470 // 4471 // C++ [over.built]p14: 4472 // 4473 // For every T, where T is a pointer to object type, there 4474 // exist candidate operator functions of the form 4475 // 4476 // ptrdiff_t operator-(T, T); 4477 for (BuiltinCandidateTypeSet::iterator Ptr 4478 = CandidateTypes.pointer_begin(); 4479 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4480 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4481 4482 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4483 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4484 4485 if (Op == OO_Plus) { 4486 // T* operator+(ptrdiff_t, T*); 4487 ParamTypes[0] = ParamTypes[1]; 4488 ParamTypes[1] = *Ptr; 4489 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4490 } else { 4491 // ptrdiff_t operator-(T, T); 4492 ParamTypes[1] = *Ptr; 4493 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4494 Args, 2, CandidateSet); 4495 } 4496 } 4497 } 4498 // Fall through 4499 4500 case OO_Slash: 4501 BinaryStar: 4502 Conditional: 4503 // C++ [over.built]p12: 4504 // 4505 // For every pair of promoted arithmetic types L and R, there 4506 // exist candidate operator functions of the form 4507 // 4508 // LR operator*(L, R); 4509 // LR operator/(L, R); 4510 // LR operator+(L, R); 4511 // LR operator-(L, R); 4512 // bool operator<(L, R); 4513 // bool operator>(L, R); 4514 // bool operator<=(L, R); 4515 // bool operator>=(L, R); 4516 // bool operator==(L, R); 4517 // bool operator!=(L, R); 4518 // 4519 // where LR is the result of the usual arithmetic conversions 4520 // between types L and R. 4521 // 4522 // C++ [over.built]p24: 4523 // 4524 // For every pair of promoted arithmetic types L and R, there exist 4525 // candidate operator functions of the form 4526 // 4527 // LR operator?(bool, L, R); 4528 // 4529 // where LR is the result of the usual arithmetic conversions 4530 // between types L and R. 4531 // Our candidates ignore the first parameter. 4532 for (unsigned Left = FirstPromotedArithmeticType; 4533 Left < LastPromotedArithmeticType; ++Left) { 4534 for (unsigned Right = FirstPromotedArithmeticType; 4535 Right < LastPromotedArithmeticType; ++Right) { 4536 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4537 QualType Result 4538 = isComparison 4539 ? Context.BoolTy 4540 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4541 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4542 } 4543 } 4544 4545 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 4546 // conditional operator for vector types. 4547 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4548 Vec1End = CandidateTypes.vector_end(); 4549 Vec1 != Vec1End; ++Vec1) 4550 for (BuiltinCandidateTypeSet::iterator 4551 Vec2 = CandidateTypes.vector_begin(), 4552 Vec2End = CandidateTypes.vector_end(); 4553 Vec2 != Vec2End; ++Vec2) { 4554 QualType LandR[2] = { *Vec1, *Vec2 }; 4555 QualType Result; 4556 if (isComparison) 4557 Result = Context.BoolTy; 4558 else { 4559 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 4560 Result = *Vec1; 4561 else 4562 Result = *Vec2; 4563 } 4564 4565 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4566 } 4567 4568 break; 4569 4570 case OO_Percent: 4571 BinaryAmp: 4572 case OO_Caret: 4573 case OO_Pipe: 4574 case OO_LessLess: 4575 case OO_GreaterGreater: 4576 // C++ [over.built]p17: 4577 // 4578 // For every pair of promoted integral types L and R, there 4579 // exist candidate operator functions of the form 4580 // 4581 // LR operator%(L, R); 4582 // LR operator&(L, R); 4583 // LR operator^(L, R); 4584 // LR operator|(L, R); 4585 // L operator<<(L, R); 4586 // L operator>>(L, R); 4587 // 4588 // where LR is the result of the usual arithmetic conversions 4589 // between types L and R. 4590 for (unsigned Left = FirstPromotedIntegralType; 4591 Left < LastPromotedIntegralType; ++Left) { 4592 for (unsigned Right = FirstPromotedIntegralType; 4593 Right < LastPromotedIntegralType; ++Right) { 4594 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4595 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4596 ? LandR[0] 4597 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4598 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4599 } 4600 } 4601 break; 4602 4603 case OO_Equal: 4604 // C++ [over.built]p20: 4605 // 4606 // For every pair (T, VQ), where T is an enumeration or 4607 // pointer to member type and VQ is either volatile or 4608 // empty, there exist candidate operator functions of the form 4609 // 4610 // VQ T& operator=(VQ T&, T); 4611 for (BuiltinCandidateTypeSet::iterator 4612 Enum = CandidateTypes.enumeration_begin(), 4613 EnumEnd = CandidateTypes.enumeration_end(); 4614 Enum != EnumEnd; ++Enum) 4615 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4616 CandidateSet); 4617 for (BuiltinCandidateTypeSet::iterator 4618 MemPtr = CandidateTypes.member_pointer_begin(), 4619 MemPtrEnd = CandidateTypes.member_pointer_end(); 4620 MemPtr != MemPtrEnd; ++MemPtr) 4621 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4622 CandidateSet); 4623 4624 // Fall through. 4625 4626 case OO_PlusEqual: 4627 case OO_MinusEqual: 4628 // C++ [over.built]p19: 4629 // 4630 // For every pair (T, VQ), where T is any type and VQ is either 4631 // volatile or empty, there exist candidate operator functions 4632 // of the form 4633 // 4634 // T*VQ& operator=(T*VQ&, T*); 4635 // 4636 // C++ [over.built]p21: 4637 // 4638 // For every pair (T, VQ), where T is a cv-qualified or 4639 // cv-unqualified object type and VQ is either volatile or 4640 // empty, there exist candidate operator functions of the form 4641 // 4642 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4643 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4644 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4645 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4646 QualType ParamTypes[2]; 4647 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4648 4649 // non-volatile version 4650 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4651 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4652 /*IsAssigmentOperator=*/Op == OO_Equal); 4653 4654 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4655 VisibleTypeConversionsQuals.hasVolatile()) { 4656 // volatile version 4657 ParamTypes[0] 4658 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4659 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4660 /*IsAssigmentOperator=*/Op == OO_Equal); 4661 } 4662 } 4663 // Fall through. 4664 4665 case OO_StarEqual: 4666 case OO_SlashEqual: 4667 // C++ [over.built]p18: 4668 // 4669 // For every triple (L, VQ, R), where L is an arithmetic type, 4670 // VQ is either volatile or empty, and R is a promoted 4671 // arithmetic type, there exist candidate operator functions of 4672 // the form 4673 // 4674 // VQ L& operator=(VQ L&, R); 4675 // VQ L& operator*=(VQ L&, R); 4676 // VQ L& operator/=(VQ L&, R); 4677 // VQ L& operator+=(VQ L&, R); 4678 // VQ L& operator-=(VQ L&, R); 4679 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4680 for (unsigned Right = FirstPromotedArithmeticType; 4681 Right < LastPromotedArithmeticType; ++Right) { 4682 QualType ParamTypes[2]; 4683 ParamTypes[1] = ArithmeticTypes[Right]; 4684 4685 // Add this built-in operator as a candidate (VQ is empty). 4686 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4687 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4688 /*IsAssigmentOperator=*/Op == OO_Equal); 4689 4690 // Add this built-in operator as a candidate (VQ is 'volatile'). 4691 if (VisibleTypeConversionsQuals.hasVolatile()) { 4692 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4693 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4694 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4695 /*IsAssigmentOperator=*/Op == OO_Equal); 4696 } 4697 } 4698 } 4699 4700 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 4701 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4702 Vec1End = CandidateTypes.vector_end(); 4703 Vec1 != Vec1End; ++Vec1) 4704 for (BuiltinCandidateTypeSet::iterator 4705 Vec2 = CandidateTypes.vector_begin(), 4706 Vec2End = CandidateTypes.vector_end(); 4707 Vec2 != Vec2End; ++Vec2) { 4708 QualType ParamTypes[2]; 4709 ParamTypes[1] = *Vec2; 4710 // Add this built-in operator as a candidate (VQ is empty). 4711 ParamTypes[0] = Context.getLValueReferenceType(*Vec1); 4712 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4713 /*IsAssigmentOperator=*/Op == OO_Equal); 4714 4715 // Add this built-in operator as a candidate (VQ is 'volatile'). 4716 if (VisibleTypeConversionsQuals.hasVolatile()) { 4717 ParamTypes[0] = Context.getVolatileType(*Vec1); 4718 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4719 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4720 /*IsAssigmentOperator=*/Op == OO_Equal); 4721 } 4722 } 4723 break; 4724 4725 case OO_PercentEqual: 4726 case OO_LessLessEqual: 4727 case OO_GreaterGreaterEqual: 4728 case OO_AmpEqual: 4729 case OO_CaretEqual: 4730 case OO_PipeEqual: 4731 // C++ [over.built]p22: 4732 // 4733 // For every triple (L, VQ, R), where L is an integral type, VQ 4734 // is either volatile or empty, and R is a promoted integral 4735 // type, there exist candidate operator functions of the form 4736 // 4737 // VQ L& operator%=(VQ L&, R); 4738 // VQ L& operator<<=(VQ L&, R); 4739 // VQ L& operator>>=(VQ L&, R); 4740 // VQ L& operator&=(VQ L&, R); 4741 // VQ L& operator^=(VQ L&, R); 4742 // VQ L& operator|=(VQ L&, R); 4743 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4744 for (unsigned Right = FirstPromotedIntegralType; 4745 Right < LastPromotedIntegralType; ++Right) { 4746 QualType ParamTypes[2]; 4747 ParamTypes[1] = ArithmeticTypes[Right]; 4748 4749 // Add this built-in operator as a candidate (VQ is empty). 4750 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4751 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4752 if (VisibleTypeConversionsQuals.hasVolatile()) { 4753 // Add this built-in operator as a candidate (VQ is 'volatile'). 4754 ParamTypes[0] = ArithmeticTypes[Left]; 4755 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4756 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4757 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4758 } 4759 } 4760 } 4761 break; 4762 4763 case OO_Exclaim: { 4764 // C++ [over.operator]p23: 4765 // 4766 // There also exist candidate operator functions of the form 4767 // 4768 // bool operator!(bool); 4769 // bool operator&&(bool, bool); [BELOW] 4770 // bool operator||(bool, bool); [BELOW] 4771 QualType ParamTy = Context.BoolTy; 4772 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4773 /*IsAssignmentOperator=*/false, 4774 /*NumContextualBoolArguments=*/1); 4775 break; 4776 } 4777 4778 case OO_AmpAmp: 4779 case OO_PipePipe: { 4780 // C++ [over.operator]p23: 4781 // 4782 // There also exist candidate operator functions of the form 4783 // 4784 // bool operator!(bool); [ABOVE] 4785 // bool operator&&(bool, bool); 4786 // bool operator||(bool, bool); 4787 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4788 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4789 /*IsAssignmentOperator=*/false, 4790 /*NumContextualBoolArguments=*/2); 4791 break; 4792 } 4793 4794 case OO_Subscript: 4795 // C++ [over.built]p13: 4796 // 4797 // For every cv-qualified or cv-unqualified object type T there 4798 // exist candidate operator functions of the form 4799 // 4800 // T* operator+(T*, ptrdiff_t); [ABOVE] 4801 // T& operator[](T*, ptrdiff_t); 4802 // T* operator-(T*, ptrdiff_t); [ABOVE] 4803 // T* operator+(ptrdiff_t, T*); [ABOVE] 4804 // T& operator[](ptrdiff_t, T*); 4805 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4806 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4807 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4808 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4809 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4810 4811 // T& operator[](T*, ptrdiff_t) 4812 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4813 4814 // T& operator[](ptrdiff_t, T*); 4815 ParamTypes[0] = ParamTypes[1]; 4816 ParamTypes[1] = *Ptr; 4817 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4818 } 4819 break; 4820 4821 case OO_ArrowStar: 4822 // C++ [over.built]p11: 4823 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4824 // C1 is the same type as C2 or is a derived class of C2, T is an object 4825 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4826 // there exist candidate operator functions of the form 4827 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4828 // where CV12 is the union of CV1 and CV2. 4829 { 4830 for (BuiltinCandidateTypeSet::iterator Ptr = 4831 CandidateTypes.pointer_begin(); 4832 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4833 QualType C1Ty = (*Ptr); 4834 QualType C1; 4835 QualifierCollector Q1; 4836 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4837 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4838 if (!isa<RecordType>(C1)) 4839 continue; 4840 // heuristic to reduce number of builtin candidates in the set. 4841 // Add volatile/restrict version only if there are conversions to a 4842 // volatile/restrict type. 4843 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4844 continue; 4845 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4846 continue; 4847 } 4848 for (BuiltinCandidateTypeSet::iterator 4849 MemPtr = CandidateTypes.member_pointer_begin(), 4850 MemPtrEnd = CandidateTypes.member_pointer_end(); 4851 MemPtr != MemPtrEnd; ++MemPtr) { 4852 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4853 QualType C2 = QualType(mptr->getClass(), 0); 4854 C2 = C2.getUnqualifiedType(); 4855 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4856 break; 4857 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4858 // build CV12 T& 4859 QualType T = mptr->getPointeeType(); 4860 if (!VisibleTypeConversionsQuals.hasVolatile() && 4861 T.isVolatileQualified()) 4862 continue; 4863 if (!VisibleTypeConversionsQuals.hasRestrict() && 4864 T.isRestrictQualified()) 4865 continue; 4866 T = Q1.apply(T); 4867 QualType ResultTy = Context.getLValueReferenceType(T); 4868 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4869 } 4870 } 4871 } 4872 break; 4873 4874 case OO_Conditional: 4875 // Note that we don't consider the first argument, since it has been 4876 // contextually converted to bool long ago. The candidates below are 4877 // therefore added as binary. 4878 // 4879 // C++ [over.built]p24: 4880 // For every type T, where T is a pointer or pointer-to-member type, 4881 // there exist candidate operator functions of the form 4882 // 4883 // T operator?(bool, T, T); 4884 // 4885 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4886 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4887 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4888 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4889 } 4890 for (BuiltinCandidateTypeSet::iterator Ptr = 4891 CandidateTypes.member_pointer_begin(), 4892 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4893 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4894 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4895 } 4896 goto Conditional; 4897 } 4898} 4899 4900/// \brief Add function candidates found via argument-dependent lookup 4901/// to the set of overloading candidates. 4902/// 4903/// This routine performs argument-dependent name lookup based on the 4904/// given function name (which may also be an operator name) and adds 4905/// all of the overload candidates found by ADL to the overload 4906/// candidate set (C++ [basic.lookup.argdep]). 4907void 4908Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4909 bool Operator, 4910 Expr **Args, unsigned NumArgs, 4911 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4912 OverloadCandidateSet& CandidateSet, 4913 bool PartialOverloading) { 4914 ADLResult Fns; 4915 4916 // FIXME: This approach for uniquing ADL results (and removing 4917 // redundant candidates from the set) relies on pointer-equality, 4918 // which means we need to key off the canonical decl. However, 4919 // always going back to the canonical decl might not get us the 4920 // right set of default arguments. What default arguments are 4921 // we supposed to consider on ADL candidates, anyway? 4922 4923 // FIXME: Pass in the explicit template arguments? 4924 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4925 4926 // Erase all of the candidates we already knew about. 4927 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4928 CandEnd = CandidateSet.end(); 4929 Cand != CandEnd; ++Cand) 4930 if (Cand->Function) { 4931 Fns.erase(Cand->Function); 4932 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4933 Fns.erase(FunTmpl); 4934 } 4935 4936 // For each of the ADL candidates we found, add it to the overload 4937 // set. 4938 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4939 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 4940 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4941 if (ExplicitTemplateArgs) 4942 continue; 4943 4944 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 4945 false, PartialOverloading); 4946 } else 4947 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4948 FoundDecl, ExplicitTemplateArgs, 4949 Args, NumArgs, CandidateSet); 4950 } 4951} 4952 4953/// isBetterOverloadCandidate - Determines whether the first overload 4954/// candidate is a better candidate than the second (C++ 13.3.3p1). 4955bool 4956Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4957 const OverloadCandidate& Cand2, 4958 SourceLocation Loc) { 4959 // Define viable functions to be better candidates than non-viable 4960 // functions. 4961 if (!Cand2.Viable) 4962 return Cand1.Viable; 4963 else if (!Cand1.Viable) 4964 return false; 4965 4966 // C++ [over.match.best]p1: 4967 // 4968 // -- if F is a static member function, ICS1(F) is defined such 4969 // that ICS1(F) is neither better nor worse than ICS1(G) for 4970 // any function G, and, symmetrically, ICS1(G) is neither 4971 // better nor worse than ICS1(F). 4972 unsigned StartArg = 0; 4973 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4974 StartArg = 1; 4975 4976 // C++ [over.match.best]p1: 4977 // A viable function F1 is defined to be a better function than another 4978 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4979 // conversion sequence than ICSi(F2), and then... 4980 unsigned NumArgs = Cand1.Conversions.size(); 4981 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4982 bool HasBetterConversion = false; 4983 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4984 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4985 Cand2.Conversions[ArgIdx])) { 4986 case ImplicitConversionSequence::Better: 4987 // Cand1 has a better conversion sequence. 4988 HasBetterConversion = true; 4989 break; 4990 4991 case ImplicitConversionSequence::Worse: 4992 // Cand1 can't be better than Cand2. 4993 return false; 4994 4995 case ImplicitConversionSequence::Indistinguishable: 4996 // Do nothing. 4997 break; 4998 } 4999 } 5000 5001 // -- for some argument j, ICSj(F1) is a better conversion sequence than 5002 // ICSj(F2), or, if not that, 5003 if (HasBetterConversion) 5004 return true; 5005 5006 // - F1 is a non-template function and F2 is a function template 5007 // specialization, or, if not that, 5008 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 5009 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5010 return true; 5011 5012 // -- F1 and F2 are function template specializations, and the function 5013 // template for F1 is more specialized than the template for F2 5014 // according to the partial ordering rules described in 14.5.5.2, or, 5015 // if not that, 5016 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 5017 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5018 if (FunctionTemplateDecl *BetterTemplate 5019 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 5020 Cand2.Function->getPrimaryTemplate(), 5021 Loc, 5022 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 5023 : TPOC_Call)) 5024 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 5025 5026 // -- the context is an initialization by user-defined conversion 5027 // (see 8.5, 13.3.1.5) and the standard conversion sequence 5028 // from the return type of F1 to the destination type (i.e., 5029 // the type of the entity being initialized) is a better 5030 // conversion sequence than the standard conversion sequence 5031 // from the return type of F2 to the destination type. 5032 if (Cand1.Function && Cand2.Function && 5033 isa<CXXConversionDecl>(Cand1.Function) && 5034 isa<CXXConversionDecl>(Cand2.Function)) { 5035 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 5036 Cand2.FinalConversion)) { 5037 case ImplicitConversionSequence::Better: 5038 // Cand1 has a better conversion sequence. 5039 return true; 5040 5041 case ImplicitConversionSequence::Worse: 5042 // Cand1 can't be better than Cand2. 5043 return false; 5044 5045 case ImplicitConversionSequence::Indistinguishable: 5046 // Do nothing 5047 break; 5048 } 5049 } 5050 5051 return false; 5052} 5053 5054/// \brief Computes the best viable function (C++ 13.3.3) 5055/// within an overload candidate set. 5056/// 5057/// \param CandidateSet the set of candidate functions. 5058/// 5059/// \param Loc the location of the function name (or operator symbol) for 5060/// which overload resolution occurs. 5061/// 5062/// \param Best f overload resolution was successful or found a deleted 5063/// function, Best points to the candidate function found. 5064/// 5065/// \returns The result of overload resolution. 5066OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 5067 SourceLocation Loc, 5068 OverloadCandidateSet::iterator& Best) { 5069 // Find the best viable function. 5070 Best = CandidateSet.end(); 5071 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5072 Cand != CandidateSet.end(); ++Cand) { 5073 if (Cand->Viable) { 5074 if (Best == CandidateSet.end() || 5075 isBetterOverloadCandidate(*Cand, *Best, Loc)) 5076 Best = Cand; 5077 } 5078 } 5079 5080 // If we didn't find any viable functions, abort. 5081 if (Best == CandidateSet.end()) 5082 return OR_No_Viable_Function; 5083 5084 // Make sure that this function is better than every other viable 5085 // function. If not, we have an ambiguity. 5086 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5087 Cand != CandidateSet.end(); ++Cand) { 5088 if (Cand->Viable && 5089 Cand != Best && 5090 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 5091 Best = CandidateSet.end(); 5092 return OR_Ambiguous; 5093 } 5094 } 5095 5096 // Best is the best viable function. 5097 if (Best->Function && 5098 (Best->Function->isDeleted() || 5099 Best->Function->getAttr<UnavailableAttr>())) 5100 return OR_Deleted; 5101 5102 // C++ [basic.def.odr]p2: 5103 // An overloaded function is used if it is selected by overload resolution 5104 // when referred to from a potentially-evaluated expression. [Note: this 5105 // covers calls to named functions (5.2.2), operator overloading 5106 // (clause 13), user-defined conversions (12.3.2), allocation function for 5107 // placement new (5.3.4), as well as non-default initialization (8.5). 5108 if (Best->Function) 5109 MarkDeclarationReferenced(Loc, Best->Function); 5110 return OR_Success; 5111} 5112 5113namespace { 5114 5115enum OverloadCandidateKind { 5116 oc_function, 5117 oc_method, 5118 oc_constructor, 5119 oc_function_template, 5120 oc_method_template, 5121 oc_constructor_template, 5122 oc_implicit_default_constructor, 5123 oc_implicit_copy_constructor, 5124 oc_implicit_copy_assignment 5125}; 5126 5127OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 5128 FunctionDecl *Fn, 5129 std::string &Description) { 5130 bool isTemplate = false; 5131 5132 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 5133 isTemplate = true; 5134 Description = S.getTemplateArgumentBindingsText( 5135 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 5136 } 5137 5138 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 5139 if (!Ctor->isImplicit()) 5140 return isTemplate ? oc_constructor_template : oc_constructor; 5141 5142 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 5143 : oc_implicit_default_constructor; 5144 } 5145 5146 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 5147 // This actually gets spelled 'candidate function' for now, but 5148 // it doesn't hurt to split it out. 5149 if (!Meth->isImplicit()) 5150 return isTemplate ? oc_method_template : oc_method; 5151 5152 assert(Meth->isCopyAssignment() 5153 && "implicit method is not copy assignment operator?"); 5154 return oc_implicit_copy_assignment; 5155 } 5156 5157 return isTemplate ? oc_function_template : oc_function; 5158} 5159 5160} // end anonymous namespace 5161 5162// Notes the location of an overload candidate. 5163void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 5164 std::string FnDesc; 5165 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 5166 Diag(Fn->getLocation(), diag::note_ovl_candidate) 5167 << (unsigned) K << FnDesc; 5168} 5169 5170/// Diagnoses an ambiguous conversion. The partial diagnostic is the 5171/// "lead" diagnostic; it will be given two arguments, the source and 5172/// target types of the conversion. 5173void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 5174 SourceLocation CaretLoc, 5175 const PartialDiagnostic &PDiag) { 5176 Diag(CaretLoc, PDiag) 5177 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 5178 for (AmbiguousConversionSequence::const_iterator 5179 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 5180 NoteOverloadCandidate(*I); 5181 } 5182} 5183 5184namespace { 5185 5186void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 5187 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 5188 assert(Conv.isBad()); 5189 assert(Cand->Function && "for now, candidate must be a function"); 5190 FunctionDecl *Fn = Cand->Function; 5191 5192 // There's a conversion slot for the object argument if this is a 5193 // non-constructor method. Note that 'I' corresponds the 5194 // conversion-slot index. 5195 bool isObjectArgument = false; 5196 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 5197 if (I == 0) 5198 isObjectArgument = true; 5199 else 5200 I--; 5201 } 5202 5203 std::string FnDesc; 5204 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5205 5206 Expr *FromExpr = Conv.Bad.FromExpr; 5207 QualType FromTy = Conv.Bad.getFromType(); 5208 QualType ToTy = Conv.Bad.getToType(); 5209 5210 if (FromTy == S.Context.OverloadTy) { 5211 assert(FromExpr && "overload set argument came from implicit argument?"); 5212 Expr *E = FromExpr->IgnoreParens(); 5213 if (isa<UnaryOperator>(E)) 5214 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 5215 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 5216 5217 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 5218 << (unsigned) FnKind << FnDesc 5219 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5220 << ToTy << Name << I+1; 5221 return; 5222 } 5223 5224 // Do some hand-waving analysis to see if the non-viability is due 5225 // to a qualifier mismatch. 5226 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 5227 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 5228 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 5229 CToTy = RT->getPointeeType(); 5230 else { 5231 // TODO: detect and diagnose the full richness of const mismatches. 5232 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 5233 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 5234 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 5235 } 5236 5237 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 5238 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 5239 // It is dumb that we have to do this here. 5240 while (isa<ArrayType>(CFromTy)) 5241 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 5242 while (isa<ArrayType>(CToTy)) 5243 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 5244 5245 Qualifiers FromQs = CFromTy.getQualifiers(); 5246 Qualifiers ToQs = CToTy.getQualifiers(); 5247 5248 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 5249 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 5250 << (unsigned) FnKind << FnDesc 5251 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5252 << FromTy 5253 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 5254 << (unsigned) isObjectArgument << I+1; 5255 return; 5256 } 5257 5258 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 5259 assert(CVR && "unexpected qualifiers mismatch"); 5260 5261 if (isObjectArgument) { 5262 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 5263 << (unsigned) FnKind << FnDesc 5264 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5265 << FromTy << (CVR - 1); 5266 } else { 5267 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 5268 << (unsigned) FnKind << FnDesc 5269 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5270 << FromTy << (CVR - 1) << I+1; 5271 } 5272 return; 5273 } 5274 5275 // Diagnose references or pointers to incomplete types differently, 5276 // since it's far from impossible that the incompleteness triggered 5277 // the failure. 5278 QualType TempFromTy = FromTy.getNonReferenceType(); 5279 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 5280 TempFromTy = PTy->getPointeeType(); 5281 if (TempFromTy->isIncompleteType()) { 5282 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 5283 << (unsigned) FnKind << FnDesc 5284 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5285 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5286 return; 5287 } 5288 5289 // TODO: specialize more based on the kind of mismatch 5290 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 5291 << (unsigned) FnKind << FnDesc 5292 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5293 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5294} 5295 5296void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 5297 unsigned NumFormalArgs) { 5298 // TODO: treat calls to a missing default constructor as a special case 5299 5300 FunctionDecl *Fn = Cand->Function; 5301 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 5302 5303 unsigned MinParams = Fn->getMinRequiredArguments(); 5304 5305 // at least / at most / exactly 5306 // FIXME: variadic templates "at most" should account for parameter packs 5307 unsigned mode, modeCount; 5308 if (NumFormalArgs < MinParams) { 5309 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 5310 (Cand->FailureKind == ovl_fail_bad_deduction && 5311 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 5312 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 5313 mode = 0; // "at least" 5314 else 5315 mode = 2; // "exactly" 5316 modeCount = MinParams; 5317 } else { 5318 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 5319 (Cand->FailureKind == ovl_fail_bad_deduction && 5320 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 5321 if (MinParams != FnTy->getNumArgs()) 5322 mode = 1; // "at most" 5323 else 5324 mode = 2; // "exactly" 5325 modeCount = FnTy->getNumArgs(); 5326 } 5327 5328 std::string Description; 5329 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 5330 5331 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 5332 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 5333 << modeCount << NumFormalArgs; 5334} 5335 5336/// Diagnose a failed template-argument deduction. 5337void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 5338 Expr **Args, unsigned NumArgs) { 5339 FunctionDecl *Fn = Cand->Function; // pattern 5340 5341 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 5342 NamedDecl *ParamD; 5343 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 5344 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 5345 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 5346 switch (Cand->DeductionFailure.Result) { 5347 case Sema::TDK_Success: 5348 llvm_unreachable("TDK_success while diagnosing bad deduction"); 5349 5350 case Sema::TDK_Incomplete: { 5351 assert(ParamD && "no parameter found for incomplete deduction result"); 5352 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 5353 << ParamD->getDeclName(); 5354 return; 5355 } 5356 5357 case Sema::TDK_Inconsistent: 5358 case Sema::TDK_InconsistentQuals: { 5359 assert(ParamD && "no parameter found for inconsistent deduction result"); 5360 int which = 0; 5361 if (isa<TemplateTypeParmDecl>(ParamD)) 5362 which = 0; 5363 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 5364 which = 1; 5365 else { 5366 which = 2; 5367 } 5368 5369 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 5370 << which << ParamD->getDeclName() 5371 << *Cand->DeductionFailure.getFirstArg() 5372 << *Cand->DeductionFailure.getSecondArg(); 5373 return; 5374 } 5375 5376 case Sema::TDK_InvalidExplicitArguments: 5377 assert(ParamD && "no parameter found for invalid explicit arguments"); 5378 if (ParamD->getDeclName()) 5379 S.Diag(Fn->getLocation(), 5380 diag::note_ovl_candidate_explicit_arg_mismatch_named) 5381 << ParamD->getDeclName(); 5382 else { 5383 int index = 0; 5384 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 5385 index = TTP->getIndex(); 5386 else if (NonTypeTemplateParmDecl *NTTP 5387 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 5388 index = NTTP->getIndex(); 5389 else 5390 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 5391 S.Diag(Fn->getLocation(), 5392 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 5393 << (index + 1); 5394 } 5395 return; 5396 5397 case Sema::TDK_TooManyArguments: 5398 case Sema::TDK_TooFewArguments: 5399 DiagnoseArityMismatch(S, Cand, NumArgs); 5400 return; 5401 5402 case Sema::TDK_InstantiationDepth: 5403 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 5404 return; 5405 5406 case Sema::TDK_SubstitutionFailure: { 5407 std::string ArgString; 5408 if (TemplateArgumentList *Args 5409 = Cand->DeductionFailure.getTemplateArgumentList()) 5410 ArgString = S.getTemplateArgumentBindingsText( 5411 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 5412 *Args); 5413 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 5414 << ArgString; 5415 return; 5416 } 5417 5418 // TODO: diagnose these individually, then kill off 5419 // note_ovl_candidate_bad_deduction, which is uselessly vague. 5420 case Sema::TDK_NonDeducedMismatch: 5421 case Sema::TDK_FailedOverloadResolution: 5422 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 5423 return; 5424 } 5425} 5426 5427/// Generates a 'note' diagnostic for an overload candidate. We've 5428/// already generated a primary error at the call site. 5429/// 5430/// It really does need to be a single diagnostic with its caret 5431/// pointed at the candidate declaration. Yes, this creates some 5432/// major challenges of technical writing. Yes, this makes pointing 5433/// out problems with specific arguments quite awkward. It's still 5434/// better than generating twenty screens of text for every failed 5435/// overload. 5436/// 5437/// It would be great to be able to express per-candidate problems 5438/// more richly for those diagnostic clients that cared, but we'd 5439/// still have to be just as careful with the default diagnostics. 5440void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 5441 Expr **Args, unsigned NumArgs) { 5442 FunctionDecl *Fn = Cand->Function; 5443 5444 // Note deleted candidates, but only if they're viable. 5445 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 5446 std::string FnDesc; 5447 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5448 5449 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 5450 << FnKind << FnDesc << Fn->isDeleted(); 5451 return; 5452 } 5453 5454 // We don't really have anything else to say about viable candidates. 5455 if (Cand->Viable) { 5456 S.NoteOverloadCandidate(Fn); 5457 return; 5458 } 5459 5460 switch (Cand->FailureKind) { 5461 case ovl_fail_too_many_arguments: 5462 case ovl_fail_too_few_arguments: 5463 return DiagnoseArityMismatch(S, Cand, NumArgs); 5464 5465 case ovl_fail_bad_deduction: 5466 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 5467 5468 case ovl_fail_trivial_conversion: 5469 case ovl_fail_bad_final_conversion: 5470 case ovl_fail_final_conversion_not_exact: 5471 return S.NoteOverloadCandidate(Fn); 5472 5473 case ovl_fail_bad_conversion: { 5474 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 5475 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 5476 if (Cand->Conversions[I].isBad()) 5477 return DiagnoseBadConversion(S, Cand, I); 5478 5479 // FIXME: this currently happens when we're called from SemaInit 5480 // when user-conversion overload fails. Figure out how to handle 5481 // those conditions and diagnose them well. 5482 return S.NoteOverloadCandidate(Fn); 5483 } 5484 } 5485} 5486 5487void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 5488 // Desugar the type of the surrogate down to a function type, 5489 // retaining as many typedefs as possible while still showing 5490 // the function type (and, therefore, its parameter types). 5491 QualType FnType = Cand->Surrogate->getConversionType(); 5492 bool isLValueReference = false; 5493 bool isRValueReference = false; 5494 bool isPointer = false; 5495 if (const LValueReferenceType *FnTypeRef = 5496 FnType->getAs<LValueReferenceType>()) { 5497 FnType = FnTypeRef->getPointeeType(); 5498 isLValueReference = true; 5499 } else if (const RValueReferenceType *FnTypeRef = 5500 FnType->getAs<RValueReferenceType>()) { 5501 FnType = FnTypeRef->getPointeeType(); 5502 isRValueReference = true; 5503 } 5504 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 5505 FnType = FnTypePtr->getPointeeType(); 5506 isPointer = true; 5507 } 5508 // Desugar down to a function type. 5509 FnType = QualType(FnType->getAs<FunctionType>(), 0); 5510 // Reconstruct the pointer/reference as appropriate. 5511 if (isPointer) FnType = S.Context.getPointerType(FnType); 5512 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5513 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5514 5515 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5516 << FnType; 5517} 5518 5519void NoteBuiltinOperatorCandidate(Sema &S, 5520 const char *Opc, 5521 SourceLocation OpLoc, 5522 OverloadCandidate *Cand) { 5523 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5524 std::string TypeStr("operator"); 5525 TypeStr += Opc; 5526 TypeStr += "("; 5527 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5528 if (Cand->Conversions.size() == 1) { 5529 TypeStr += ")"; 5530 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5531 } else { 5532 TypeStr += ", "; 5533 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5534 TypeStr += ")"; 5535 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5536 } 5537} 5538 5539void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5540 OverloadCandidate *Cand) { 5541 unsigned NoOperands = Cand->Conversions.size(); 5542 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5543 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5544 if (ICS.isBad()) break; // all meaningless after first invalid 5545 if (!ICS.isAmbiguous()) continue; 5546 5547 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5548 S.PDiag(diag::note_ambiguous_type_conversion)); 5549 } 5550} 5551 5552SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5553 if (Cand->Function) 5554 return Cand->Function->getLocation(); 5555 if (Cand->IsSurrogate) 5556 return Cand->Surrogate->getLocation(); 5557 return SourceLocation(); 5558} 5559 5560struct CompareOverloadCandidatesForDisplay { 5561 Sema &S; 5562 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5563 5564 bool operator()(const OverloadCandidate *L, 5565 const OverloadCandidate *R) { 5566 // Fast-path this check. 5567 if (L == R) return false; 5568 5569 // Order first by viability. 5570 if (L->Viable) { 5571 if (!R->Viable) return true; 5572 5573 // TODO: introduce a tri-valued comparison for overload 5574 // candidates. Would be more worthwhile if we had a sort 5575 // that could exploit it. 5576 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5577 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5578 } else if (R->Viable) 5579 return false; 5580 5581 assert(L->Viable == R->Viable); 5582 5583 // Criteria by which we can sort non-viable candidates: 5584 if (!L->Viable) { 5585 // 1. Arity mismatches come after other candidates. 5586 if (L->FailureKind == ovl_fail_too_many_arguments || 5587 L->FailureKind == ovl_fail_too_few_arguments) 5588 return false; 5589 if (R->FailureKind == ovl_fail_too_many_arguments || 5590 R->FailureKind == ovl_fail_too_few_arguments) 5591 return true; 5592 5593 // 2. Bad conversions come first and are ordered by the number 5594 // of bad conversions and quality of good conversions. 5595 if (L->FailureKind == ovl_fail_bad_conversion) { 5596 if (R->FailureKind != ovl_fail_bad_conversion) 5597 return true; 5598 5599 // If there's any ordering between the defined conversions... 5600 // FIXME: this might not be transitive. 5601 assert(L->Conversions.size() == R->Conversions.size()); 5602 5603 int leftBetter = 0; 5604 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5605 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5606 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5607 R->Conversions[I])) { 5608 case ImplicitConversionSequence::Better: 5609 leftBetter++; 5610 break; 5611 5612 case ImplicitConversionSequence::Worse: 5613 leftBetter--; 5614 break; 5615 5616 case ImplicitConversionSequence::Indistinguishable: 5617 break; 5618 } 5619 } 5620 if (leftBetter > 0) return true; 5621 if (leftBetter < 0) return false; 5622 5623 } else if (R->FailureKind == ovl_fail_bad_conversion) 5624 return false; 5625 5626 // TODO: others? 5627 } 5628 5629 // Sort everything else by location. 5630 SourceLocation LLoc = GetLocationForCandidate(L); 5631 SourceLocation RLoc = GetLocationForCandidate(R); 5632 5633 // Put candidates without locations (e.g. builtins) at the end. 5634 if (LLoc.isInvalid()) return false; 5635 if (RLoc.isInvalid()) return true; 5636 5637 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5638 } 5639}; 5640 5641/// CompleteNonViableCandidate - Normally, overload resolution only 5642/// computes up to the first 5643void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5644 Expr **Args, unsigned NumArgs) { 5645 assert(!Cand->Viable); 5646 5647 // Don't do anything on failures other than bad conversion. 5648 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5649 5650 // Skip forward to the first bad conversion. 5651 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5652 unsigned ConvCount = Cand->Conversions.size(); 5653 while (true) { 5654 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5655 ConvIdx++; 5656 if (Cand->Conversions[ConvIdx - 1].isBad()) 5657 break; 5658 } 5659 5660 if (ConvIdx == ConvCount) 5661 return; 5662 5663 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5664 "remaining conversion is initialized?"); 5665 5666 // FIXME: this should probably be preserved from the overload 5667 // operation somehow. 5668 bool SuppressUserConversions = false; 5669 5670 const FunctionProtoType* Proto; 5671 unsigned ArgIdx = ConvIdx; 5672 5673 if (Cand->IsSurrogate) { 5674 QualType ConvType 5675 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5676 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5677 ConvType = ConvPtrType->getPointeeType(); 5678 Proto = ConvType->getAs<FunctionProtoType>(); 5679 ArgIdx--; 5680 } else if (Cand->Function) { 5681 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5682 if (isa<CXXMethodDecl>(Cand->Function) && 5683 !isa<CXXConstructorDecl>(Cand->Function)) 5684 ArgIdx--; 5685 } else { 5686 // Builtin binary operator with a bad first conversion. 5687 assert(ConvCount <= 3); 5688 for (; ConvIdx != ConvCount; ++ConvIdx) 5689 Cand->Conversions[ConvIdx] 5690 = TryCopyInitialization(S, Args[ConvIdx], 5691 Cand->BuiltinTypes.ParamTypes[ConvIdx], 5692 SuppressUserConversions, 5693 /*InOverloadResolution*/ true); 5694 return; 5695 } 5696 5697 // Fill in the rest of the conversions. 5698 unsigned NumArgsInProto = Proto->getNumArgs(); 5699 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 5700 if (ArgIdx < NumArgsInProto) 5701 Cand->Conversions[ConvIdx] 5702 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 5703 SuppressUserConversions, 5704 /*InOverloadResolution=*/true); 5705 else 5706 Cand->Conversions[ConvIdx].setEllipsis(); 5707 } 5708} 5709 5710} // end anonymous namespace 5711 5712/// PrintOverloadCandidates - When overload resolution fails, prints 5713/// diagnostic messages containing the candidates in the candidate 5714/// set. 5715void 5716Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 5717 OverloadCandidateDisplayKind OCD, 5718 Expr **Args, unsigned NumArgs, 5719 const char *Opc, 5720 SourceLocation OpLoc) { 5721 // Sort the candidates by viability and position. Sorting directly would 5722 // be prohibitive, so we make a set of pointers and sort those. 5723 llvm::SmallVector<OverloadCandidate*, 32> Cands; 5724 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 5725 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5726 LastCand = CandidateSet.end(); 5727 Cand != LastCand; ++Cand) { 5728 if (Cand->Viable) 5729 Cands.push_back(Cand); 5730 else if (OCD == OCD_AllCandidates) { 5731 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 5732 if (Cand->Function || Cand->IsSurrogate) 5733 Cands.push_back(Cand); 5734 // Otherwise, this a non-viable builtin candidate. We do not, in general, 5735 // want to list every possible builtin candidate. 5736 } 5737 } 5738 5739 std::sort(Cands.begin(), Cands.end(), 5740 CompareOverloadCandidatesForDisplay(*this)); 5741 5742 bool ReportedAmbiguousConversions = false; 5743 5744 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 5745 const Diagnostic::OverloadsShown ShowOverloads = Diags.getShowOverloads(); 5746 unsigned CandsShown = 0; 5747 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 5748 OverloadCandidate *Cand = *I; 5749 5750 // Set an arbitrary limit on the number of candidate functions we'll spam 5751 // the user with. FIXME: This limit should depend on details of the 5752 // candidate list. 5753 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 5754 break; 5755 } 5756 ++CandsShown; 5757 5758 if (Cand->Function) 5759 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 5760 else if (Cand->IsSurrogate) 5761 NoteSurrogateCandidate(*this, Cand); 5762 else { 5763 assert(Cand->Viable && 5764 "Non-viable built-in candidates are not added to Cands."); 5765 // Generally we only see ambiguities including viable builtin 5766 // operators if overload resolution got screwed up by an 5767 // ambiguous user-defined conversion. 5768 // 5769 // FIXME: It's quite possible for different conversions to see 5770 // different ambiguities, though. 5771 if (!ReportedAmbiguousConversions) { 5772 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 5773 ReportedAmbiguousConversions = true; 5774 } 5775 5776 // If this is a viable builtin, print it. 5777 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 5778 } 5779 } 5780 5781 if (I != E) 5782 Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 5783} 5784 5785static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 5786 if (isa<UnresolvedLookupExpr>(E)) 5787 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 5788 5789 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 5790} 5791 5792/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 5793/// an overloaded function (C++ [over.over]), where @p From is an 5794/// expression with overloaded function type and @p ToType is the type 5795/// we're trying to resolve to. For example: 5796/// 5797/// @code 5798/// int f(double); 5799/// int f(int); 5800/// 5801/// int (*pfd)(double) = f; // selects f(double) 5802/// @endcode 5803/// 5804/// This routine returns the resulting FunctionDecl if it could be 5805/// resolved, and NULL otherwise. When @p Complain is true, this 5806/// routine will emit diagnostics if there is an error. 5807FunctionDecl * 5808Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 5809 bool Complain, 5810 DeclAccessPair &FoundResult) { 5811 QualType FunctionType = ToType; 5812 bool IsMember = false; 5813 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 5814 FunctionType = ToTypePtr->getPointeeType(); 5815 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 5816 FunctionType = ToTypeRef->getPointeeType(); 5817 else if (const MemberPointerType *MemTypePtr = 5818 ToType->getAs<MemberPointerType>()) { 5819 FunctionType = MemTypePtr->getPointeeType(); 5820 IsMember = true; 5821 } 5822 5823 // C++ [over.over]p1: 5824 // [...] [Note: any redundant set of parentheses surrounding the 5825 // overloaded function name is ignored (5.1). ] 5826 // C++ [over.over]p1: 5827 // [...] The overloaded function name can be preceded by the & 5828 // operator. 5829 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5830 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5831 if (OvlExpr->hasExplicitTemplateArgs()) { 5832 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5833 ExplicitTemplateArgs = &ETABuffer; 5834 } 5835 5836 // We expect a pointer or reference to function, or a function pointer. 5837 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 5838 if (!FunctionType->isFunctionType()) { 5839 if (Complain) 5840 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 5841 << OvlExpr->getName() << ToType; 5842 5843 return 0; 5844 } 5845 5846 assert(From->getType() == Context.OverloadTy); 5847 5848 // Look through all of the overloaded functions, searching for one 5849 // whose type matches exactly. 5850 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 5851 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 5852 5853 bool FoundNonTemplateFunction = false; 5854 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5855 E = OvlExpr->decls_end(); I != E; ++I) { 5856 // Look through any using declarations to find the underlying function. 5857 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5858 5859 // C++ [over.over]p3: 5860 // Non-member functions and static member functions match 5861 // targets of type "pointer-to-function" or "reference-to-function." 5862 // Nonstatic member functions match targets of 5863 // type "pointer-to-member-function." 5864 // Note that according to DR 247, the containing class does not matter. 5865 5866 if (FunctionTemplateDecl *FunctionTemplate 5867 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5868 if (CXXMethodDecl *Method 5869 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5870 // Skip non-static function templates when converting to pointer, and 5871 // static when converting to member pointer. 5872 if (Method->isStatic() == IsMember) 5873 continue; 5874 } else if (IsMember) 5875 continue; 5876 5877 // C++ [over.over]p2: 5878 // If the name is a function template, template argument deduction is 5879 // done (14.8.2.2), and if the argument deduction succeeds, the 5880 // resulting template argument list is used to generate a single 5881 // function template specialization, which is added to the set of 5882 // overloaded functions considered. 5883 // FIXME: We don't really want to build the specialization here, do we? 5884 FunctionDecl *Specialization = 0; 5885 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5886 if (TemplateDeductionResult Result 5887 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5888 FunctionType, Specialization, Info)) { 5889 // FIXME: make a note of the failed deduction for diagnostics. 5890 (void)Result; 5891 } else { 5892 // FIXME: If the match isn't exact, shouldn't we just drop this as 5893 // a candidate? Find a testcase before changing the code. 5894 assert(FunctionType 5895 == Context.getCanonicalType(Specialization->getType())); 5896 Matches.push_back(std::make_pair(I.getPair(), 5897 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 5898 } 5899 5900 continue; 5901 } 5902 5903 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5904 // Skip non-static functions when converting to pointer, and static 5905 // when converting to member pointer. 5906 if (Method->isStatic() == IsMember) 5907 continue; 5908 5909 // If we have explicit template arguments, skip non-templates. 5910 if (OvlExpr->hasExplicitTemplateArgs()) 5911 continue; 5912 } else if (IsMember) 5913 continue; 5914 5915 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5916 QualType ResultTy; 5917 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5918 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5919 ResultTy)) { 5920 Matches.push_back(std::make_pair(I.getPair(), 5921 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 5922 FoundNonTemplateFunction = true; 5923 } 5924 } 5925 } 5926 5927 // If there were 0 or 1 matches, we're done. 5928 if (Matches.empty()) { 5929 if (Complain) { 5930 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 5931 << OvlExpr->getName() << FunctionType; 5932 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5933 E = OvlExpr->decls_end(); 5934 I != E; ++I) 5935 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 5936 NoteOverloadCandidate(F); 5937 } 5938 5939 return 0; 5940 } else if (Matches.size() == 1) { 5941 FunctionDecl *Result = Matches[0].second; 5942 FoundResult = Matches[0].first; 5943 MarkDeclarationReferenced(From->getLocStart(), Result); 5944 if (Complain) 5945 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 5946 return Result; 5947 } 5948 5949 // C++ [over.over]p4: 5950 // If more than one function is selected, [...] 5951 if (!FoundNonTemplateFunction) { 5952 // [...] and any given function template specialization F1 is 5953 // eliminated if the set contains a second function template 5954 // specialization whose function template is more specialized 5955 // than the function template of F1 according to the partial 5956 // ordering rules of 14.5.5.2. 5957 5958 // The algorithm specified above is quadratic. We instead use a 5959 // two-pass algorithm (similar to the one used to identify the 5960 // best viable function in an overload set) that identifies the 5961 // best function template (if it exists). 5962 5963 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 5964 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5965 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 5966 5967 UnresolvedSetIterator Result = 5968 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 5969 TPOC_Other, From->getLocStart(), 5970 PDiag(), 5971 PDiag(diag::err_addr_ovl_ambiguous) 5972 << Matches[0].second->getDeclName(), 5973 PDiag(diag::note_ovl_candidate) 5974 << (unsigned) oc_function_template); 5975 assert(Result != MatchesCopy.end() && "no most-specialized template"); 5976 MarkDeclarationReferenced(From->getLocStart(), *Result); 5977 FoundResult = Matches[Result - MatchesCopy.begin()].first; 5978 if (Complain) { 5979 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 5980 DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc()); 5981 } 5982 return cast<FunctionDecl>(*Result); 5983 } 5984 5985 // [...] any function template specializations in the set are 5986 // eliminated if the set also contains a non-template function, [...] 5987 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5988 if (Matches[I].second->getPrimaryTemplate() == 0) 5989 ++I; 5990 else { 5991 Matches[I] = Matches[--N]; 5992 Matches.set_size(N); 5993 } 5994 } 5995 5996 // [...] After such eliminations, if any, there shall remain exactly one 5997 // selected function. 5998 if (Matches.size() == 1) { 5999 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 6000 FoundResult = Matches[0].first; 6001 if (Complain) { 6002 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 6003 DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc()); 6004 } 6005 return cast<FunctionDecl>(Matches[0].second); 6006 } 6007 6008 // FIXME: We should probably return the same thing that BestViableFunction 6009 // returns (even if we issue the diagnostics here). 6010 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 6011 << Matches[0].second->getDeclName(); 6012 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6013 NoteOverloadCandidate(Matches[I].second); 6014 return 0; 6015} 6016 6017/// \brief Given an expression that refers to an overloaded function, try to 6018/// resolve that overloaded function expression down to a single function. 6019/// 6020/// This routine can only resolve template-ids that refer to a single function 6021/// template, where that template-id refers to a single template whose template 6022/// arguments are either provided by the template-id or have defaults, 6023/// as described in C++0x [temp.arg.explicit]p3. 6024FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 6025 // C++ [over.over]p1: 6026 // [...] [Note: any redundant set of parentheses surrounding the 6027 // overloaded function name is ignored (5.1). ] 6028 // C++ [over.over]p1: 6029 // [...] The overloaded function name can be preceded by the & 6030 // operator. 6031 6032 if (From->getType() != Context.OverloadTy) 6033 return 0; 6034 6035 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6036 6037 // If we didn't actually find any template-ids, we're done. 6038 if (!OvlExpr->hasExplicitTemplateArgs()) 6039 return 0; 6040 6041 TemplateArgumentListInfo ExplicitTemplateArgs; 6042 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 6043 6044 // Look through all of the overloaded functions, searching for one 6045 // whose type matches exactly. 6046 FunctionDecl *Matched = 0; 6047 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6048 E = OvlExpr->decls_end(); I != E; ++I) { 6049 // C++0x [temp.arg.explicit]p3: 6050 // [...] In contexts where deduction is done and fails, or in contexts 6051 // where deduction is not done, if a template argument list is 6052 // specified and it, along with any default template arguments, 6053 // identifies a single function template specialization, then the 6054 // template-id is an lvalue for the function template specialization. 6055 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 6056 6057 // C++ [over.over]p2: 6058 // If the name is a function template, template argument deduction is 6059 // done (14.8.2.2), and if the argument deduction succeeds, the 6060 // resulting template argument list is used to generate a single 6061 // function template specialization, which is added to the set of 6062 // overloaded functions considered. 6063 FunctionDecl *Specialization = 0; 6064 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6065 if (TemplateDeductionResult Result 6066 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 6067 Specialization, Info)) { 6068 // FIXME: make a note of the failed deduction for diagnostics. 6069 (void)Result; 6070 continue; 6071 } 6072 6073 // Multiple matches; we can't resolve to a single declaration. 6074 if (Matched) 6075 return 0; 6076 6077 Matched = Specialization; 6078 } 6079 6080 return Matched; 6081} 6082 6083/// \brief Add a single candidate to the overload set. 6084static void AddOverloadedCallCandidate(Sema &S, 6085 DeclAccessPair FoundDecl, 6086 const TemplateArgumentListInfo *ExplicitTemplateArgs, 6087 Expr **Args, unsigned NumArgs, 6088 OverloadCandidateSet &CandidateSet, 6089 bool PartialOverloading) { 6090 NamedDecl *Callee = FoundDecl.getDecl(); 6091 if (isa<UsingShadowDecl>(Callee)) 6092 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 6093 6094 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 6095 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 6096 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 6097 false, PartialOverloading); 6098 return; 6099 } 6100 6101 if (FunctionTemplateDecl *FuncTemplate 6102 = dyn_cast<FunctionTemplateDecl>(Callee)) { 6103 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 6104 ExplicitTemplateArgs, 6105 Args, NumArgs, CandidateSet); 6106 return; 6107 } 6108 6109 assert(false && "unhandled case in overloaded call candidate"); 6110 6111 // do nothing? 6112} 6113 6114/// \brief Add the overload candidates named by callee and/or found by argument 6115/// dependent lookup to the given overload set. 6116void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 6117 Expr **Args, unsigned NumArgs, 6118 OverloadCandidateSet &CandidateSet, 6119 bool PartialOverloading) { 6120 6121#ifndef NDEBUG 6122 // Verify that ArgumentDependentLookup is consistent with the rules 6123 // in C++0x [basic.lookup.argdep]p3: 6124 // 6125 // Let X be the lookup set produced by unqualified lookup (3.4.1) 6126 // and let Y be the lookup set produced by argument dependent 6127 // lookup (defined as follows). If X contains 6128 // 6129 // -- a declaration of a class member, or 6130 // 6131 // -- a block-scope function declaration that is not a 6132 // using-declaration, or 6133 // 6134 // -- a declaration that is neither a function or a function 6135 // template 6136 // 6137 // then Y is empty. 6138 6139 if (ULE->requiresADL()) { 6140 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6141 E = ULE->decls_end(); I != E; ++I) { 6142 assert(!(*I)->getDeclContext()->isRecord()); 6143 assert(isa<UsingShadowDecl>(*I) || 6144 !(*I)->getDeclContext()->isFunctionOrMethod()); 6145 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 6146 } 6147 } 6148#endif 6149 6150 // It would be nice to avoid this copy. 6151 TemplateArgumentListInfo TABuffer; 6152 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6153 if (ULE->hasExplicitTemplateArgs()) { 6154 ULE->copyTemplateArgumentsInto(TABuffer); 6155 ExplicitTemplateArgs = &TABuffer; 6156 } 6157 6158 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6159 E = ULE->decls_end(); I != E; ++I) 6160 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 6161 Args, NumArgs, CandidateSet, 6162 PartialOverloading); 6163 6164 if (ULE->requiresADL()) 6165 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 6166 Args, NumArgs, 6167 ExplicitTemplateArgs, 6168 CandidateSet, 6169 PartialOverloading); 6170} 6171 6172static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 6173 Expr **Args, unsigned NumArgs) { 6174 Fn->Destroy(SemaRef.Context); 6175 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 6176 Args[Arg]->Destroy(SemaRef.Context); 6177 return SemaRef.ExprError(); 6178} 6179 6180/// Attempts to recover from a call where no functions were found. 6181/// 6182/// Returns true if new candidates were found. 6183static Sema::OwningExprResult 6184BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 6185 UnresolvedLookupExpr *ULE, 6186 SourceLocation LParenLoc, 6187 Expr **Args, unsigned NumArgs, 6188 SourceLocation *CommaLocs, 6189 SourceLocation RParenLoc) { 6190 6191 CXXScopeSpec SS; 6192 if (ULE->getQualifier()) { 6193 SS.setScopeRep(ULE->getQualifier()); 6194 SS.setRange(ULE->getQualifierRange()); 6195 } 6196 6197 TemplateArgumentListInfo TABuffer; 6198 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6199 if (ULE->hasExplicitTemplateArgs()) { 6200 ULE->copyTemplateArgumentsInto(TABuffer); 6201 ExplicitTemplateArgs = &TABuffer; 6202 } 6203 6204 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 6205 Sema::LookupOrdinaryName); 6206 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 6207 return Destroy(SemaRef, Fn, Args, NumArgs); 6208 6209 assert(!R.empty() && "lookup results empty despite recovery"); 6210 6211 // Build an implicit member call if appropriate. Just drop the 6212 // casts and such from the call, we don't really care. 6213 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 6214 if ((*R.begin())->isCXXClassMember()) 6215 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 6216 else if (ExplicitTemplateArgs) 6217 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 6218 else 6219 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 6220 6221 if (NewFn.isInvalid()) 6222 return Destroy(SemaRef, Fn, Args, NumArgs); 6223 6224 Fn->Destroy(SemaRef.Context); 6225 6226 // This shouldn't cause an infinite loop because we're giving it 6227 // an expression with non-empty lookup results, which should never 6228 // end up here. 6229 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 6230 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 6231 CommaLocs, RParenLoc); 6232} 6233 6234/// ResolveOverloadedCallFn - Given the call expression that calls Fn 6235/// (which eventually refers to the declaration Func) and the call 6236/// arguments Args/NumArgs, attempt to resolve the function call down 6237/// to a specific function. If overload resolution succeeds, returns 6238/// the function declaration produced by overload 6239/// resolution. Otherwise, emits diagnostics, deletes all of the 6240/// arguments and Fn, and returns NULL. 6241Sema::OwningExprResult 6242Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 6243 SourceLocation LParenLoc, 6244 Expr **Args, unsigned NumArgs, 6245 SourceLocation *CommaLocs, 6246 SourceLocation RParenLoc) { 6247#ifndef NDEBUG 6248 if (ULE->requiresADL()) { 6249 // To do ADL, we must have found an unqualified name. 6250 assert(!ULE->getQualifier() && "qualified name with ADL"); 6251 6252 // We don't perform ADL for implicit declarations of builtins. 6253 // Verify that this was correctly set up. 6254 FunctionDecl *F; 6255 if (ULE->decls_begin() + 1 == ULE->decls_end() && 6256 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 6257 F->getBuiltinID() && F->isImplicit()) 6258 assert(0 && "performing ADL for builtin"); 6259 6260 // We don't perform ADL in C. 6261 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 6262 } 6263#endif 6264 6265 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 6266 6267 // Add the functions denoted by the callee to the set of candidate 6268 // functions, including those from argument-dependent lookup. 6269 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 6270 6271 // If we found nothing, try to recover. 6272 // AddRecoveryCallCandidates diagnoses the error itself, so we just 6273 // bailout out if it fails. 6274 if (CandidateSet.empty()) 6275 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 6276 CommaLocs, RParenLoc); 6277 6278 OverloadCandidateSet::iterator Best; 6279 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 6280 case OR_Success: { 6281 FunctionDecl *FDecl = Best->Function; 6282 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 6283 DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc()); 6284 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 6285 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 6286 } 6287 6288 case OR_No_Viable_Function: 6289 Diag(Fn->getSourceRange().getBegin(), 6290 diag::err_ovl_no_viable_function_in_call) 6291 << ULE->getName() << Fn->getSourceRange(); 6292 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6293 break; 6294 6295 case OR_Ambiguous: 6296 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 6297 << ULE->getName() << Fn->getSourceRange(); 6298 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6299 break; 6300 6301 case OR_Deleted: 6302 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 6303 << Best->Function->isDeleted() 6304 << ULE->getName() 6305 << Fn->getSourceRange(); 6306 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6307 break; 6308 } 6309 6310 // Overload resolution failed. Destroy all of the subexpressions and 6311 // return NULL. 6312 Fn->Destroy(Context); 6313 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 6314 Args[Arg]->Destroy(Context); 6315 return ExprError(); 6316} 6317 6318static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 6319 return Functions.size() > 1 || 6320 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 6321} 6322 6323/// \brief Create a unary operation that may resolve to an overloaded 6324/// operator. 6325/// 6326/// \param OpLoc The location of the operator itself (e.g., '*'). 6327/// 6328/// \param OpcIn The UnaryOperator::Opcode that describes this 6329/// operator. 6330/// 6331/// \param Functions The set of non-member functions that will be 6332/// considered by overload resolution. The caller needs to build this 6333/// set based on the context using, e.g., 6334/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6335/// set should not contain any member functions; those will be added 6336/// by CreateOverloadedUnaryOp(). 6337/// 6338/// \param input The input argument. 6339Sema::OwningExprResult 6340Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 6341 const UnresolvedSetImpl &Fns, 6342 ExprArg input) { 6343 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6344 Expr *Input = (Expr *)input.get(); 6345 6346 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 6347 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 6348 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6349 6350 Expr *Args[2] = { Input, 0 }; 6351 unsigned NumArgs = 1; 6352 6353 // For post-increment and post-decrement, add the implicit '0' as 6354 // the second argument, so that we know this is a post-increment or 6355 // post-decrement. 6356 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 6357 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 6358 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 6359 SourceLocation()); 6360 NumArgs = 2; 6361 } 6362 6363 if (Input->isTypeDependent()) { 6364 if (Fns.empty()) 6365 return Owned(new (Context) UnaryOperator(input.takeAs<Expr>(), 6366 Opc, 6367 Context.DependentTy, 6368 OpLoc)); 6369 6370 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6371 UnresolvedLookupExpr *Fn 6372 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6373 0, SourceRange(), OpName, OpLoc, 6374 /*ADL*/ true, IsOverloaded(Fns), 6375 Fns.begin(), Fns.end()); 6376 input.release(); 6377 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6378 &Args[0], NumArgs, 6379 Context.DependentTy, 6380 OpLoc)); 6381 } 6382 6383 // Build an empty overload set. 6384 OverloadCandidateSet CandidateSet(OpLoc); 6385 6386 // Add the candidates from the given function set. 6387 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 6388 6389 // Add operator candidates that are member functions. 6390 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6391 6392 // Add candidates from ADL. 6393 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6394 Args, NumArgs, 6395 /*ExplicitTemplateArgs*/ 0, 6396 CandidateSet); 6397 6398 // Add builtin operator candidates. 6399 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6400 6401 // Perform overload resolution. 6402 OverloadCandidateSet::iterator Best; 6403 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6404 case OR_Success: { 6405 // We found a built-in operator or an overloaded operator. 6406 FunctionDecl *FnDecl = Best->Function; 6407 6408 if (FnDecl) { 6409 // We matched an overloaded operator. Build a call to that 6410 // operator. 6411 6412 // Convert the arguments. 6413 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6414 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 6415 6416 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 6417 Best->FoundDecl, Method)) 6418 return ExprError(); 6419 } else { 6420 // Convert the arguments. 6421 OwningExprResult InputInit 6422 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6423 FnDecl->getParamDecl(0)), 6424 SourceLocation(), 6425 move(input)); 6426 if (InputInit.isInvalid()) 6427 return ExprError(); 6428 6429 input = move(InputInit); 6430 Input = (Expr *)input.get(); 6431 } 6432 6433 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6434 6435 // Determine the result type 6436 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 6437 6438 // Build the actual expression node. 6439 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6440 SourceLocation()); 6441 UsualUnaryConversions(FnExpr); 6442 6443 input.release(); 6444 Args[0] = Input; 6445 ExprOwningPtr<CallExpr> TheCall(this, 6446 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6447 Args, NumArgs, ResultTy, OpLoc)); 6448 6449 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6450 FnDecl)) 6451 return ExprError(); 6452 6453 return MaybeBindToTemporary(TheCall.release()); 6454 } else { 6455 // We matched a built-in operator. Convert the arguments, then 6456 // break out so that we will build the appropriate built-in 6457 // operator node. 6458 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 6459 Best->Conversions[0], AA_Passing)) 6460 return ExprError(); 6461 6462 break; 6463 } 6464 } 6465 6466 case OR_No_Viable_Function: 6467 // No viable function; fall through to handling this as a 6468 // built-in operator, which will produce an error message for us. 6469 break; 6470 6471 case OR_Ambiguous: 6472 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6473 << UnaryOperator::getOpcodeStr(Opc) 6474 << Input->getSourceRange(); 6475 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 6476 UnaryOperator::getOpcodeStr(Opc), OpLoc); 6477 return ExprError(); 6478 6479 case OR_Deleted: 6480 Diag(OpLoc, diag::err_ovl_deleted_oper) 6481 << Best->Function->isDeleted() 6482 << UnaryOperator::getOpcodeStr(Opc) 6483 << Input->getSourceRange(); 6484 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6485 return ExprError(); 6486 } 6487 6488 // Either we found no viable overloaded operator or we matched a 6489 // built-in operator. In either case, fall through to trying to 6490 // build a built-in operation. 6491 input.release(); 6492 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 6493} 6494 6495/// \brief Create a binary operation that may resolve to an overloaded 6496/// operator. 6497/// 6498/// \param OpLoc The location of the operator itself (e.g., '+'). 6499/// 6500/// \param OpcIn The BinaryOperator::Opcode that describes this 6501/// operator. 6502/// 6503/// \param Functions The set of non-member functions that will be 6504/// considered by overload resolution. The caller needs to build this 6505/// set based on the context using, e.g., 6506/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6507/// set should not contain any member functions; those will be added 6508/// by CreateOverloadedBinOp(). 6509/// 6510/// \param LHS Left-hand argument. 6511/// \param RHS Right-hand argument. 6512Sema::OwningExprResult 6513Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 6514 unsigned OpcIn, 6515 const UnresolvedSetImpl &Fns, 6516 Expr *LHS, Expr *RHS) { 6517 Expr *Args[2] = { LHS, RHS }; 6518 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 6519 6520 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 6521 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 6522 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6523 6524 // If either side is type-dependent, create an appropriate dependent 6525 // expression. 6526 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6527 if (Fns.empty()) { 6528 // If there are no functions to store, just build a dependent 6529 // BinaryOperator or CompoundAssignment. 6530 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 6531 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 6532 Context.DependentTy, OpLoc)); 6533 6534 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 6535 Context.DependentTy, 6536 Context.DependentTy, 6537 Context.DependentTy, 6538 OpLoc)); 6539 } 6540 6541 // FIXME: save results of ADL from here? 6542 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6543 UnresolvedLookupExpr *Fn 6544 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6545 0, SourceRange(), OpName, OpLoc, 6546 /*ADL*/ true, IsOverloaded(Fns), 6547 Fns.begin(), Fns.end()); 6548 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6549 Args, 2, 6550 Context.DependentTy, 6551 OpLoc)); 6552 } 6553 6554 // If this is the .* operator, which is not overloadable, just 6555 // create a built-in binary operator. 6556 if (Opc == BinaryOperator::PtrMemD) 6557 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6558 6559 // If this is the assignment operator, we only perform overload resolution 6560 // if the left-hand side is a class or enumeration type. This is actually 6561 // a hack. The standard requires that we do overload resolution between the 6562 // various built-in candidates, but as DR507 points out, this can lead to 6563 // problems. So we do it this way, which pretty much follows what GCC does. 6564 // Note that we go the traditional code path for compound assignment forms. 6565 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6566 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6567 6568 // Build an empty overload set. 6569 OverloadCandidateSet CandidateSet(OpLoc); 6570 6571 // Add the candidates from the given function set. 6572 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6573 6574 // Add operator candidates that are member functions. 6575 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6576 6577 // Add candidates from ADL. 6578 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6579 Args, 2, 6580 /*ExplicitTemplateArgs*/ 0, 6581 CandidateSet); 6582 6583 // Add builtin operator candidates. 6584 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6585 6586 // Perform overload resolution. 6587 OverloadCandidateSet::iterator Best; 6588 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6589 case OR_Success: { 6590 // We found a built-in operator or an overloaded operator. 6591 FunctionDecl *FnDecl = Best->Function; 6592 6593 if (FnDecl) { 6594 // We matched an overloaded operator. Build a call to that 6595 // operator. 6596 6597 // Convert the arguments. 6598 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6599 // Best->Access is only meaningful for class members. 6600 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6601 6602 OwningExprResult Arg1 6603 = PerformCopyInitialization( 6604 InitializedEntity::InitializeParameter( 6605 FnDecl->getParamDecl(0)), 6606 SourceLocation(), 6607 Owned(Args[1])); 6608 if (Arg1.isInvalid()) 6609 return ExprError(); 6610 6611 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6612 Best->FoundDecl, Method)) 6613 return ExprError(); 6614 6615 Args[1] = RHS = Arg1.takeAs<Expr>(); 6616 } else { 6617 // Convert the arguments. 6618 OwningExprResult Arg0 6619 = PerformCopyInitialization( 6620 InitializedEntity::InitializeParameter( 6621 FnDecl->getParamDecl(0)), 6622 SourceLocation(), 6623 Owned(Args[0])); 6624 if (Arg0.isInvalid()) 6625 return ExprError(); 6626 6627 OwningExprResult Arg1 6628 = PerformCopyInitialization( 6629 InitializedEntity::InitializeParameter( 6630 FnDecl->getParamDecl(1)), 6631 SourceLocation(), 6632 Owned(Args[1])); 6633 if (Arg1.isInvalid()) 6634 return ExprError(); 6635 Args[0] = LHS = Arg0.takeAs<Expr>(); 6636 Args[1] = RHS = Arg1.takeAs<Expr>(); 6637 } 6638 6639 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6640 6641 // Determine the result type 6642 QualType ResultTy 6643 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6644 ResultTy = ResultTy.getNonReferenceType(); 6645 6646 // Build the actual expression node. 6647 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6648 OpLoc); 6649 UsualUnaryConversions(FnExpr); 6650 6651 ExprOwningPtr<CXXOperatorCallExpr> 6652 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6653 Args, 2, ResultTy, 6654 OpLoc)); 6655 6656 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6657 FnDecl)) 6658 return ExprError(); 6659 6660 return MaybeBindToTemporary(TheCall.release()); 6661 } else { 6662 // We matched a built-in operator. Convert the arguments, then 6663 // break out so that we will build the appropriate built-in 6664 // operator node. 6665 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6666 Best->Conversions[0], AA_Passing) || 6667 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6668 Best->Conversions[1], AA_Passing)) 6669 return ExprError(); 6670 6671 break; 6672 } 6673 } 6674 6675 case OR_No_Viable_Function: { 6676 // C++ [over.match.oper]p9: 6677 // If the operator is the operator , [...] and there are no 6678 // viable functions, then the operator is assumed to be the 6679 // built-in operator and interpreted according to clause 5. 6680 if (Opc == BinaryOperator::Comma) 6681 break; 6682 6683 // For class as left operand for assignment or compound assigment operator 6684 // do not fall through to handling in built-in, but report that no overloaded 6685 // assignment operator found 6686 OwningExprResult Result = ExprError(); 6687 if (Args[0]->getType()->isRecordType() && 6688 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6689 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6690 << BinaryOperator::getOpcodeStr(Opc) 6691 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6692 } else { 6693 // No viable function; try to create a built-in operation, which will 6694 // produce an error. Then, show the non-viable candidates. 6695 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6696 } 6697 assert(Result.isInvalid() && 6698 "C++ binary operator overloading is missing candidates!"); 6699 if (Result.isInvalid()) 6700 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6701 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6702 return move(Result); 6703 } 6704 6705 case OR_Ambiguous: 6706 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6707 << BinaryOperator::getOpcodeStr(Opc) 6708 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6709 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6710 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6711 return ExprError(); 6712 6713 case OR_Deleted: 6714 Diag(OpLoc, diag::err_ovl_deleted_oper) 6715 << Best->Function->isDeleted() 6716 << BinaryOperator::getOpcodeStr(Opc) 6717 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6718 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 6719 return ExprError(); 6720 } 6721 6722 // We matched a built-in operator; build it. 6723 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6724} 6725 6726Action::OwningExprResult 6727Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 6728 SourceLocation RLoc, 6729 ExprArg Base, ExprArg Idx) { 6730 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 6731 static_cast<Expr*>(Idx.get()) }; 6732 DeclarationName OpName = 6733 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 6734 6735 // If either side is type-dependent, create an appropriate dependent 6736 // expression. 6737 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6738 6739 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6740 UnresolvedLookupExpr *Fn 6741 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6742 0, SourceRange(), OpName, LLoc, 6743 /*ADL*/ true, /*Overloaded*/ false, 6744 UnresolvedSetIterator(), 6745 UnresolvedSetIterator()); 6746 // Can't add any actual overloads yet 6747 6748 Base.release(); 6749 Idx.release(); 6750 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 6751 Args, 2, 6752 Context.DependentTy, 6753 RLoc)); 6754 } 6755 6756 // Build an empty overload set. 6757 OverloadCandidateSet CandidateSet(LLoc); 6758 6759 // Subscript can only be overloaded as a member function. 6760 6761 // Add operator candidates that are member functions. 6762 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6763 6764 // Add builtin operator candidates. 6765 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6766 6767 // Perform overload resolution. 6768 OverloadCandidateSet::iterator Best; 6769 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 6770 case OR_Success: { 6771 // We found a built-in operator or an overloaded operator. 6772 FunctionDecl *FnDecl = Best->Function; 6773 6774 if (FnDecl) { 6775 // We matched an overloaded operator. Build a call to that 6776 // operator. 6777 6778 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 6779 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 6780 6781 // Convert the arguments. 6782 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 6783 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6784 Best->FoundDecl, Method)) 6785 return ExprError(); 6786 6787 // Convert the arguments. 6788 OwningExprResult InputInit 6789 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6790 FnDecl->getParamDecl(0)), 6791 SourceLocation(), 6792 Owned(Args[1])); 6793 if (InputInit.isInvalid()) 6794 return ExprError(); 6795 6796 Args[1] = InputInit.takeAs<Expr>(); 6797 6798 // Determine the result type 6799 QualType ResultTy 6800 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6801 ResultTy = ResultTy.getNonReferenceType(); 6802 6803 // Build the actual expression node. 6804 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6805 LLoc); 6806 UsualUnaryConversions(FnExpr); 6807 6808 Base.release(); 6809 Idx.release(); 6810 ExprOwningPtr<CXXOperatorCallExpr> 6811 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 6812 FnExpr, Args, 2, 6813 ResultTy, RLoc)); 6814 6815 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 6816 FnDecl)) 6817 return ExprError(); 6818 6819 return MaybeBindToTemporary(TheCall.release()); 6820 } else { 6821 // We matched a built-in operator. Convert the arguments, then 6822 // break out so that we will build the appropriate built-in 6823 // operator node. 6824 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6825 Best->Conversions[0], AA_Passing) || 6826 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6827 Best->Conversions[1], AA_Passing)) 6828 return ExprError(); 6829 6830 break; 6831 } 6832 } 6833 6834 case OR_No_Viable_Function: { 6835 if (CandidateSet.empty()) 6836 Diag(LLoc, diag::err_ovl_no_oper) 6837 << Args[0]->getType() << /*subscript*/ 0 6838 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6839 else 6840 Diag(LLoc, diag::err_ovl_no_viable_subscript) 6841 << Args[0]->getType() 6842 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6843 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6844 "[]", LLoc); 6845 return ExprError(); 6846 } 6847 6848 case OR_Ambiguous: 6849 Diag(LLoc, diag::err_ovl_ambiguous_oper) 6850 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6851 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6852 "[]", LLoc); 6853 return ExprError(); 6854 6855 case OR_Deleted: 6856 Diag(LLoc, diag::err_ovl_deleted_oper) 6857 << Best->Function->isDeleted() << "[]" 6858 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6859 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6860 "[]", LLoc); 6861 return ExprError(); 6862 } 6863 6864 // We matched a built-in operator; build it. 6865 Base.release(); 6866 Idx.release(); 6867 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 6868 Owned(Args[1]), RLoc); 6869} 6870 6871/// BuildCallToMemberFunction - Build a call to a member 6872/// function. MemExpr is the expression that refers to the member 6873/// function (and includes the object parameter), Args/NumArgs are the 6874/// arguments to the function call (not including the object 6875/// parameter). The caller needs to validate that the member 6876/// expression refers to a member function or an overloaded member 6877/// function. 6878Sema::OwningExprResult 6879Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6880 SourceLocation LParenLoc, Expr **Args, 6881 unsigned NumArgs, SourceLocation *CommaLocs, 6882 SourceLocation RParenLoc) { 6883 // Dig out the member expression. This holds both the object 6884 // argument and the member function we're referring to. 6885 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6886 6887 MemberExpr *MemExpr; 6888 CXXMethodDecl *Method = 0; 6889 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 6890 NestedNameSpecifier *Qualifier = 0; 6891 if (isa<MemberExpr>(NakedMemExpr)) { 6892 MemExpr = cast<MemberExpr>(NakedMemExpr); 6893 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6894 FoundDecl = MemExpr->getFoundDecl(); 6895 Qualifier = MemExpr->getQualifier(); 6896 } else { 6897 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6898 Qualifier = UnresExpr->getQualifier(); 6899 6900 QualType ObjectType = UnresExpr->getBaseType(); 6901 6902 // Add overload candidates 6903 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6904 6905 // FIXME: avoid copy. 6906 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6907 if (UnresExpr->hasExplicitTemplateArgs()) { 6908 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6909 TemplateArgs = &TemplateArgsBuffer; 6910 } 6911 6912 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6913 E = UnresExpr->decls_end(); I != E; ++I) { 6914 6915 NamedDecl *Func = *I; 6916 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6917 if (isa<UsingShadowDecl>(Func)) 6918 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6919 6920 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6921 // If explicit template arguments were provided, we can't call a 6922 // non-template member function. 6923 if (TemplateArgs) 6924 continue; 6925 6926 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 6927 Args, NumArgs, 6928 CandidateSet, /*SuppressUserConversions=*/false); 6929 } else { 6930 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6931 I.getPair(), ActingDC, TemplateArgs, 6932 ObjectType, Args, NumArgs, 6933 CandidateSet, 6934 /*SuppressUsedConversions=*/false); 6935 } 6936 } 6937 6938 DeclarationName DeclName = UnresExpr->getMemberName(); 6939 6940 OverloadCandidateSet::iterator Best; 6941 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6942 case OR_Success: 6943 Method = cast<CXXMethodDecl>(Best->Function); 6944 FoundDecl = Best->FoundDecl; 6945 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 6946 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 6947 break; 6948 6949 case OR_No_Viable_Function: 6950 Diag(UnresExpr->getMemberLoc(), 6951 diag::err_ovl_no_viable_member_function_in_call) 6952 << DeclName << MemExprE->getSourceRange(); 6953 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6954 // FIXME: Leaking incoming expressions! 6955 return ExprError(); 6956 6957 case OR_Ambiguous: 6958 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6959 << DeclName << MemExprE->getSourceRange(); 6960 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6961 // FIXME: Leaking incoming expressions! 6962 return ExprError(); 6963 6964 case OR_Deleted: 6965 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6966 << Best->Function->isDeleted() 6967 << DeclName << MemExprE->getSourceRange(); 6968 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6969 // FIXME: Leaking incoming expressions! 6970 return ExprError(); 6971 } 6972 6973 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 6974 6975 // If overload resolution picked a static member, build a 6976 // non-member call based on that function. 6977 if (Method->isStatic()) { 6978 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6979 Args, NumArgs, RParenLoc); 6980 } 6981 6982 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6983 } 6984 6985 assert(Method && "Member call to something that isn't a method?"); 6986 ExprOwningPtr<CXXMemberCallExpr> 6987 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6988 NumArgs, 6989 Method->getResultType().getNonReferenceType(), 6990 RParenLoc)); 6991 6992 // Check for a valid return type. 6993 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6994 TheCall.get(), Method)) 6995 return ExprError(); 6996 6997 // Convert the object argument (for a non-static member function call). 6998 // We only need to do this if there was actually an overload; otherwise 6999 // it was done at lookup. 7000 Expr *ObjectArg = MemExpr->getBase(); 7001 if (!Method->isStatic() && 7002 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 7003 FoundDecl, Method)) 7004 return ExprError(); 7005 MemExpr->setBase(ObjectArg); 7006 7007 // Convert the rest of the arguments 7008 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7009 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 7010 RParenLoc)) 7011 return ExprError(); 7012 7013 if (CheckFunctionCall(Method, TheCall.get())) 7014 return ExprError(); 7015 7016 return MaybeBindToTemporary(TheCall.release()); 7017} 7018 7019/// BuildCallToObjectOfClassType - Build a call to an object of class 7020/// type (C++ [over.call.object]), which can end up invoking an 7021/// overloaded function call operator (@c operator()) or performing a 7022/// user-defined conversion on the object argument. 7023Sema::ExprResult 7024Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 7025 SourceLocation LParenLoc, 7026 Expr **Args, unsigned NumArgs, 7027 SourceLocation *CommaLocs, 7028 SourceLocation RParenLoc) { 7029 assert(Object->getType()->isRecordType() && "Requires object type argument"); 7030 const RecordType *Record = Object->getType()->getAs<RecordType>(); 7031 7032 // C++ [over.call.object]p1: 7033 // If the primary-expression E in the function call syntax 7034 // evaluates to a class object of type "cv T", then the set of 7035 // candidate functions includes at least the function call 7036 // operators of T. The function call operators of T are obtained by 7037 // ordinary lookup of the name operator() in the context of 7038 // (E).operator(). 7039 OverloadCandidateSet CandidateSet(LParenLoc); 7040 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 7041 7042 if (RequireCompleteType(LParenLoc, Object->getType(), 7043 PDiag(diag::err_incomplete_object_call) 7044 << Object->getSourceRange())) 7045 return true; 7046 7047 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 7048 LookupQualifiedName(R, Record->getDecl()); 7049 R.suppressDiagnostics(); 7050 7051 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7052 Oper != OperEnd; ++Oper) { 7053 AddMethodCandidate(Oper.getPair(), Object->getType(), 7054 Args, NumArgs, CandidateSet, 7055 /*SuppressUserConversions=*/ false); 7056 } 7057 7058 // C++ [over.call.object]p2: 7059 // In addition, for each conversion function declared in T of the 7060 // form 7061 // 7062 // operator conversion-type-id () cv-qualifier; 7063 // 7064 // where cv-qualifier is the same cv-qualification as, or a 7065 // greater cv-qualification than, cv, and where conversion-type-id 7066 // denotes the type "pointer to function of (P1,...,Pn) returning 7067 // R", or the type "reference to pointer to function of 7068 // (P1,...,Pn) returning R", or the type "reference to function 7069 // of (P1,...,Pn) returning R", a surrogate call function [...] 7070 // is also considered as a candidate function. Similarly, 7071 // surrogate call functions are added to the set of candidate 7072 // functions for each conversion function declared in an 7073 // accessible base class provided the function is not hidden 7074 // within T by another intervening declaration. 7075 const UnresolvedSetImpl *Conversions 7076 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 7077 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 7078 E = Conversions->end(); I != E; ++I) { 7079 NamedDecl *D = *I; 7080 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 7081 if (isa<UsingShadowDecl>(D)) 7082 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 7083 7084 // Skip over templated conversion functions; they aren't 7085 // surrogates. 7086 if (isa<FunctionTemplateDecl>(D)) 7087 continue; 7088 7089 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 7090 7091 // Strip the reference type (if any) and then the pointer type (if 7092 // any) to get down to what might be a function type. 7093 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 7094 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7095 ConvType = ConvPtrType->getPointeeType(); 7096 7097 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 7098 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 7099 Object->getType(), Args, NumArgs, 7100 CandidateSet); 7101 } 7102 7103 // Perform overload resolution. 7104 OverloadCandidateSet::iterator Best; 7105 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 7106 case OR_Success: 7107 // Overload resolution succeeded; we'll build the appropriate call 7108 // below. 7109 break; 7110 7111 case OR_No_Viable_Function: 7112 if (CandidateSet.empty()) 7113 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 7114 << Object->getType() << /*call*/ 1 7115 << Object->getSourceRange(); 7116 else 7117 Diag(Object->getSourceRange().getBegin(), 7118 diag::err_ovl_no_viable_object_call) 7119 << Object->getType() << Object->getSourceRange(); 7120 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7121 break; 7122 7123 case OR_Ambiguous: 7124 Diag(Object->getSourceRange().getBegin(), 7125 diag::err_ovl_ambiguous_object_call) 7126 << Object->getType() << Object->getSourceRange(); 7127 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 7128 break; 7129 7130 case OR_Deleted: 7131 Diag(Object->getSourceRange().getBegin(), 7132 diag::err_ovl_deleted_object_call) 7133 << Best->Function->isDeleted() 7134 << Object->getType() << Object->getSourceRange(); 7135 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7136 break; 7137 } 7138 7139 if (Best == CandidateSet.end()) { 7140 // We had an error; delete all of the subexpressions and return 7141 // the error. 7142 Object->Destroy(Context); 7143 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7144 Args[ArgIdx]->Destroy(Context); 7145 return true; 7146 } 7147 7148 if (Best->Function == 0) { 7149 // Since there is no function declaration, this is one of the 7150 // surrogate candidates. Dig out the conversion function. 7151 CXXConversionDecl *Conv 7152 = cast<CXXConversionDecl>( 7153 Best->Conversions[0].UserDefined.ConversionFunction); 7154 7155 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7156 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7157 7158 // We selected one of the surrogate functions that converts the 7159 // object parameter to a function pointer. Perform the conversion 7160 // on the object argument, then let ActOnCallExpr finish the job. 7161 7162 // Create an implicit member expr to refer to the conversion operator. 7163 // and then call it. 7164 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 7165 Conv); 7166 7167 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 7168 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 7169 CommaLocs, RParenLoc).result(); 7170 } 7171 7172 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7173 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7174 7175 // We found an overloaded operator(). Build a CXXOperatorCallExpr 7176 // that calls this method, using Object for the implicit object 7177 // parameter and passing along the remaining arguments. 7178 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7179 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7180 7181 unsigned NumArgsInProto = Proto->getNumArgs(); 7182 unsigned NumArgsToCheck = NumArgs; 7183 7184 // Build the full argument list for the method call (the 7185 // implicit object parameter is placed at the beginning of the 7186 // list). 7187 Expr **MethodArgs; 7188 if (NumArgs < NumArgsInProto) { 7189 NumArgsToCheck = NumArgsInProto; 7190 MethodArgs = new Expr*[NumArgsInProto + 1]; 7191 } else { 7192 MethodArgs = new Expr*[NumArgs + 1]; 7193 } 7194 MethodArgs[0] = Object; 7195 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7196 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 7197 7198 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 7199 SourceLocation()); 7200 UsualUnaryConversions(NewFn); 7201 7202 // Once we've built TheCall, all of the expressions are properly 7203 // owned. 7204 QualType ResultTy = Method->getResultType().getNonReferenceType(); 7205 ExprOwningPtr<CXXOperatorCallExpr> 7206 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 7207 MethodArgs, NumArgs + 1, 7208 ResultTy, RParenLoc)); 7209 delete [] MethodArgs; 7210 7211 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 7212 Method)) 7213 return true; 7214 7215 // We may have default arguments. If so, we need to allocate more 7216 // slots in the call for them. 7217 if (NumArgs < NumArgsInProto) 7218 TheCall->setNumArgs(Context, NumArgsInProto + 1); 7219 else if (NumArgs > NumArgsInProto) 7220 NumArgsToCheck = NumArgsInProto; 7221 7222 bool IsError = false; 7223 7224 // Initialize the implicit object parameter. 7225 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 7226 Best->FoundDecl, Method); 7227 TheCall->setArg(0, Object); 7228 7229 7230 // Check the argument types. 7231 for (unsigned i = 0; i != NumArgsToCheck; i++) { 7232 Expr *Arg; 7233 if (i < NumArgs) { 7234 Arg = Args[i]; 7235 7236 // Pass the argument. 7237 7238 OwningExprResult InputInit 7239 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7240 Method->getParamDecl(i)), 7241 SourceLocation(), Owned(Arg)); 7242 7243 IsError |= InputInit.isInvalid(); 7244 Arg = InputInit.takeAs<Expr>(); 7245 } else { 7246 OwningExprResult DefArg 7247 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 7248 if (DefArg.isInvalid()) { 7249 IsError = true; 7250 break; 7251 } 7252 7253 Arg = DefArg.takeAs<Expr>(); 7254 } 7255 7256 TheCall->setArg(i + 1, Arg); 7257 } 7258 7259 // If this is a variadic call, handle args passed through "...". 7260 if (Proto->isVariadic()) { 7261 // Promote the arguments (C99 6.5.2.2p7). 7262 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 7263 Expr *Arg = Args[i]; 7264 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 7265 TheCall->setArg(i + 1, Arg); 7266 } 7267 } 7268 7269 if (IsError) return true; 7270 7271 if (CheckFunctionCall(Method, TheCall.get())) 7272 return true; 7273 7274 return MaybeBindToTemporary(TheCall.release()).result(); 7275} 7276 7277/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 7278/// (if one exists), where @c Base is an expression of class type and 7279/// @c Member is the name of the member we're trying to find. 7280Sema::OwningExprResult 7281Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 7282 Expr *Base = static_cast<Expr *>(BaseIn.get()); 7283 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 7284 7285 SourceLocation Loc = Base->getExprLoc(); 7286 7287 // C++ [over.ref]p1: 7288 // 7289 // [...] An expression x->m is interpreted as (x.operator->())->m 7290 // for a class object x of type T if T::operator->() exists and if 7291 // the operator is selected as the best match function by the 7292 // overload resolution mechanism (13.3). 7293 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 7294 OverloadCandidateSet CandidateSet(Loc); 7295 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 7296 7297 if (RequireCompleteType(Loc, Base->getType(), 7298 PDiag(diag::err_typecheck_incomplete_tag) 7299 << Base->getSourceRange())) 7300 return ExprError(); 7301 7302 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 7303 LookupQualifiedName(R, BaseRecord->getDecl()); 7304 R.suppressDiagnostics(); 7305 7306 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7307 Oper != OperEnd; ++Oper) { 7308 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 7309 /*SuppressUserConversions=*/false); 7310 } 7311 7312 // Perform overload resolution. 7313 OverloadCandidateSet::iterator Best; 7314 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 7315 case OR_Success: 7316 // Overload resolution succeeded; we'll build the call below. 7317 break; 7318 7319 case OR_No_Viable_Function: 7320 if (CandidateSet.empty()) 7321 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 7322 << Base->getType() << Base->getSourceRange(); 7323 else 7324 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7325 << "operator->" << Base->getSourceRange(); 7326 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7327 return ExprError(); 7328 7329 case OR_Ambiguous: 7330 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7331 << "->" << Base->getSourceRange(); 7332 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 7333 return ExprError(); 7334 7335 case OR_Deleted: 7336 Diag(OpLoc, diag::err_ovl_deleted_oper) 7337 << Best->Function->isDeleted() 7338 << "->" << Base->getSourceRange(); 7339 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7340 return ExprError(); 7341 } 7342 7343 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 7344 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7345 7346 // Convert the object parameter. 7347 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7348 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 7349 Best->FoundDecl, Method)) 7350 return ExprError(); 7351 7352 // No concerns about early exits now. 7353 BaseIn.release(); 7354 7355 // Build the operator call. 7356 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 7357 SourceLocation()); 7358 UsualUnaryConversions(FnExpr); 7359 7360 QualType ResultTy = Method->getResultType().getNonReferenceType(); 7361 ExprOwningPtr<CXXOperatorCallExpr> 7362 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 7363 &Base, 1, ResultTy, OpLoc)); 7364 7365 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 7366 Method)) 7367 return ExprError(); 7368 return move(TheCall); 7369} 7370 7371/// FixOverloadedFunctionReference - E is an expression that refers to 7372/// a C++ overloaded function (possibly with some parentheses and 7373/// perhaps a '&' around it). We have resolved the overloaded function 7374/// to the function declaration Fn, so patch up the expression E to 7375/// refer (possibly indirectly) to Fn. Returns the new expr. 7376Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 7377 FunctionDecl *Fn) { 7378 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 7379 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 7380 Found, Fn); 7381 if (SubExpr == PE->getSubExpr()) 7382 return PE->Retain(); 7383 7384 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 7385 } 7386 7387 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 7388 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 7389 Found, Fn); 7390 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 7391 SubExpr->getType()) && 7392 "Implicit cast type cannot be determined from overload"); 7393 if (SubExpr == ICE->getSubExpr()) 7394 return ICE->Retain(); 7395 7396 return new (Context) ImplicitCastExpr(ICE->getType(), 7397 ICE->getCastKind(), 7398 SubExpr, CXXBaseSpecifierArray(), 7399 ICE->isLvalueCast()); 7400 } 7401 7402 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 7403 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 7404 "Can only take the address of an overloaded function"); 7405 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7406 if (Method->isStatic()) { 7407 // Do nothing: static member functions aren't any different 7408 // from non-member functions. 7409 } else { 7410 // Fix the sub expression, which really has to be an 7411 // UnresolvedLookupExpr holding an overloaded member function 7412 // or template. 7413 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7414 Found, Fn); 7415 if (SubExpr == UnOp->getSubExpr()) 7416 return UnOp->Retain(); 7417 7418 assert(isa<DeclRefExpr>(SubExpr) 7419 && "fixed to something other than a decl ref"); 7420 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 7421 && "fixed to a member ref with no nested name qualifier"); 7422 7423 // We have taken the address of a pointer to member 7424 // function. Perform the computation here so that we get the 7425 // appropriate pointer to member type. 7426 QualType ClassType 7427 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 7428 QualType MemPtrType 7429 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 7430 7431 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7432 MemPtrType, UnOp->getOperatorLoc()); 7433 } 7434 } 7435 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7436 Found, Fn); 7437 if (SubExpr == UnOp->getSubExpr()) 7438 return UnOp->Retain(); 7439 7440 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7441 Context.getPointerType(SubExpr->getType()), 7442 UnOp->getOperatorLoc()); 7443 } 7444 7445 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 7446 // FIXME: avoid copy. 7447 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7448 if (ULE->hasExplicitTemplateArgs()) { 7449 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 7450 TemplateArgs = &TemplateArgsBuffer; 7451 } 7452 7453 return DeclRefExpr::Create(Context, 7454 ULE->getQualifier(), 7455 ULE->getQualifierRange(), 7456 Fn, 7457 ULE->getNameLoc(), 7458 Fn->getType(), 7459 TemplateArgs); 7460 } 7461 7462 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 7463 // FIXME: avoid copy. 7464 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7465 if (MemExpr->hasExplicitTemplateArgs()) { 7466 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7467 TemplateArgs = &TemplateArgsBuffer; 7468 } 7469 7470 Expr *Base; 7471 7472 // If we're filling in 7473 if (MemExpr->isImplicitAccess()) { 7474 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 7475 return DeclRefExpr::Create(Context, 7476 MemExpr->getQualifier(), 7477 MemExpr->getQualifierRange(), 7478 Fn, 7479 MemExpr->getMemberLoc(), 7480 Fn->getType(), 7481 TemplateArgs); 7482 } else { 7483 SourceLocation Loc = MemExpr->getMemberLoc(); 7484 if (MemExpr->getQualifier()) 7485 Loc = MemExpr->getQualifierRange().getBegin(); 7486 Base = new (Context) CXXThisExpr(Loc, 7487 MemExpr->getBaseType(), 7488 /*isImplicit=*/true); 7489 } 7490 } else 7491 Base = MemExpr->getBase()->Retain(); 7492 7493 return MemberExpr::Create(Context, Base, 7494 MemExpr->isArrow(), 7495 MemExpr->getQualifier(), 7496 MemExpr->getQualifierRange(), 7497 Fn, 7498 Found, 7499 MemExpr->getMemberLoc(), 7500 TemplateArgs, 7501 Fn->getType()); 7502 } 7503 7504 assert(false && "Invalid reference to overloaded function"); 7505 return E->Retain(); 7506} 7507 7508Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 7509 DeclAccessPair Found, 7510 FunctionDecl *Fn) { 7511 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 7512} 7513 7514} // end namespace clang 7515