SemaOverload.cpp revision 0c293ea13d452c1a47a05ada5a5ee9acc69c66cc
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->isRealFloatingType() && ToType->isRealFloatingType()) { 1019 // Floating point conversions (C++ 4.8). 1020 SCS.Second = ICK_Floating_Conversion; 1021 FromType = ToType.getUnqualifiedType(); 1022 } else if ((FromType->isRealFloatingType() && 1023 ToType->isIntegralType(Context) && !ToType->isBooleanType()) || 1024 (FromType->isIntegralOrEnumerationType() && 1025 ToType->isRealFloatingType())) { 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 /*FIXME*/!FromType->isVectorType()) { 1046 // Boolean conversions (C++ 4.12). 1047 SCS.Second = ICK_Boolean_Conversion; 1048 FromType = Context.BoolTy; 1049 } else if (IsVectorConversion(Context, FromType, ToType, SecondICK)) { 1050 SCS.Second = SecondICK; 1051 FromType = ToType.getUnqualifiedType(); 1052 } else if (!getLangOptions().CPlusPlus && 1053 Context.typesAreCompatible(ToType, FromType)) { 1054 // Compatible conversions (Clang extension for C function overloading) 1055 SCS.Second = ICK_Compatible_Conversion; 1056 FromType = ToType.getUnqualifiedType(); 1057 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 1058 // Treat a conversion that strips "noreturn" as an identity conversion. 1059 SCS.Second = ICK_NoReturn_Adjustment; 1060 } else { 1061 // No second conversion required. 1062 SCS.Second = ICK_Identity; 1063 } 1064 SCS.setToType(1, FromType); 1065 1066 QualType CanonFrom; 1067 QualType CanonTo; 1068 // The third conversion can be a qualification conversion (C++ 4p1). 1069 if (IsQualificationConversion(FromType, ToType)) { 1070 SCS.Third = ICK_Qualification; 1071 FromType = ToType; 1072 CanonFrom = Context.getCanonicalType(FromType); 1073 CanonTo = Context.getCanonicalType(ToType); 1074 } else { 1075 // No conversion required 1076 SCS.Third = ICK_Identity; 1077 1078 // C++ [over.best.ics]p6: 1079 // [...] Any difference in top-level cv-qualification is 1080 // subsumed by the initialization itself and does not constitute 1081 // a conversion. [...] 1082 CanonFrom = Context.getCanonicalType(FromType); 1083 CanonTo = Context.getCanonicalType(ToType); 1084 if (CanonFrom.getLocalUnqualifiedType() 1085 == CanonTo.getLocalUnqualifiedType() && 1086 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1087 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1088 FromType = ToType; 1089 CanonFrom = CanonTo; 1090 } 1091 } 1092 SCS.setToType(2, FromType); 1093 1094 // If we have not converted the argument type to the parameter type, 1095 // this is a bad conversion sequence. 1096 if (CanonFrom != CanonTo) 1097 return false; 1098 1099 return true; 1100} 1101 1102/// IsIntegralPromotion - Determines whether the conversion from the 1103/// expression From (whose potentially-adjusted type is FromType) to 1104/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1105/// sets PromotedType to the promoted type. 1106bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1107 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1108 // All integers are built-in. 1109 if (!To) { 1110 return false; 1111 } 1112 1113 // An rvalue of type char, signed char, unsigned char, short int, or 1114 // unsigned short int can be converted to an rvalue of type int if 1115 // int can represent all the values of the source type; otherwise, 1116 // the source rvalue can be converted to an rvalue of type unsigned 1117 // int (C++ 4.5p1). 1118 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1119 !FromType->isEnumeralType()) { 1120 if (// We can promote any signed, promotable integer type to an int 1121 (FromType->isSignedIntegerType() || 1122 // We can promote any unsigned integer type whose size is 1123 // less than int to an int. 1124 (!FromType->isSignedIntegerType() && 1125 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1126 return To->getKind() == BuiltinType::Int; 1127 } 1128 1129 return To->getKind() == BuiltinType::UInt; 1130 } 1131 1132 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 1133 // can be converted to an rvalue of the first of the following types 1134 // that can represent all the values of its underlying type: int, 1135 // unsigned int, long, or unsigned long (C++ 4.5p2). 1136 1137 // We pre-calculate the promotion type for enum types. 1138 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 1139 if (ToType->isIntegerType()) 1140 return Context.hasSameUnqualifiedType(ToType, 1141 FromEnumType->getDecl()->getPromotionType()); 1142 1143 if (FromType->isWideCharType() && ToType->isIntegerType()) { 1144 // Determine whether the type we're converting from is signed or 1145 // unsigned. 1146 bool FromIsSigned; 1147 uint64_t FromSize = Context.getTypeSize(FromType); 1148 1149 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1150 FromIsSigned = true; 1151 1152 // The types we'll try to promote to, in the appropriate 1153 // order. Try each of these types. 1154 QualType PromoteTypes[6] = { 1155 Context.IntTy, Context.UnsignedIntTy, 1156 Context.LongTy, Context.UnsignedLongTy , 1157 Context.LongLongTy, Context.UnsignedLongLongTy 1158 }; 1159 for (int Idx = 0; Idx < 6; ++Idx) { 1160 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1161 if (FromSize < ToSize || 1162 (FromSize == ToSize && 1163 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1164 // We found the type that we can promote to. If this is the 1165 // type we wanted, we have a promotion. Otherwise, no 1166 // promotion. 1167 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1168 } 1169 } 1170 } 1171 1172 // An rvalue for an integral bit-field (9.6) can be converted to an 1173 // rvalue of type int if int can represent all the values of the 1174 // bit-field; otherwise, it can be converted to unsigned int if 1175 // unsigned int can represent all the values of the bit-field. If 1176 // the bit-field is larger yet, no integral promotion applies to 1177 // it. If the bit-field has an enumerated type, it is treated as any 1178 // other value of that type for promotion purposes (C++ 4.5p3). 1179 // FIXME: We should delay checking of bit-fields until we actually perform the 1180 // conversion. 1181 using llvm::APSInt; 1182 if (From) 1183 if (FieldDecl *MemberDecl = From->getBitField()) { 1184 APSInt BitWidth; 1185 if (FromType->isIntegralType(Context) && 1186 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1187 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1188 ToSize = Context.getTypeSize(ToType); 1189 1190 // Are we promoting to an int from a bitfield that fits in an int? 1191 if (BitWidth < ToSize || 1192 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1193 return To->getKind() == BuiltinType::Int; 1194 } 1195 1196 // Are we promoting to an unsigned int from an unsigned bitfield 1197 // that fits into an unsigned int? 1198 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1199 return To->getKind() == BuiltinType::UInt; 1200 } 1201 1202 return false; 1203 } 1204 } 1205 1206 // An rvalue of type bool can be converted to an rvalue of type int, 1207 // with false becoming zero and true becoming one (C++ 4.5p4). 1208 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1209 return true; 1210 } 1211 1212 return false; 1213} 1214 1215/// IsFloatingPointPromotion - Determines whether the conversion from 1216/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1217/// returns true and sets PromotedType to the promoted type. 1218bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1219 /// An rvalue of type float can be converted to an rvalue of type 1220 /// double. (C++ 4.6p1). 1221 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1222 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1223 if (FromBuiltin->getKind() == BuiltinType::Float && 1224 ToBuiltin->getKind() == BuiltinType::Double) 1225 return true; 1226 1227 // C99 6.3.1.5p1: 1228 // When a float is promoted to double or long double, or a 1229 // double is promoted to long double [...]. 1230 if (!getLangOptions().CPlusPlus && 1231 (FromBuiltin->getKind() == BuiltinType::Float || 1232 FromBuiltin->getKind() == BuiltinType::Double) && 1233 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1234 return true; 1235 } 1236 1237 return false; 1238} 1239 1240/// \brief Determine if a conversion is a complex promotion. 1241/// 1242/// A complex promotion is defined as a complex -> complex conversion 1243/// where the conversion between the underlying real types is a 1244/// floating-point or integral promotion. 1245bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1246 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1247 if (!FromComplex) 1248 return false; 1249 1250 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1251 if (!ToComplex) 1252 return false; 1253 1254 return IsFloatingPointPromotion(FromComplex->getElementType(), 1255 ToComplex->getElementType()) || 1256 IsIntegralPromotion(0, FromComplex->getElementType(), 1257 ToComplex->getElementType()); 1258} 1259 1260/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1261/// the pointer type FromPtr to a pointer to type ToPointee, with the 1262/// same type qualifiers as FromPtr has on its pointee type. ToType, 1263/// if non-empty, will be a pointer to ToType that may or may not have 1264/// the right set of qualifiers on its pointee. 1265static QualType 1266BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 1267 QualType ToPointee, QualType ToType, 1268 ASTContext &Context) { 1269 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 1270 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1271 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1272 1273 // Exact qualifier match -> return the pointer type we're converting to. 1274 if (CanonToPointee.getLocalQualifiers() == Quals) { 1275 // ToType is exactly what we need. Return it. 1276 if (!ToType.isNull()) 1277 return ToType.getUnqualifiedType(); 1278 1279 // Build a pointer to ToPointee. It has the right qualifiers 1280 // already. 1281 return Context.getPointerType(ToPointee); 1282 } 1283 1284 // Just build a canonical type that has the right qualifiers. 1285 return Context.getPointerType( 1286 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 1287 Quals)); 1288} 1289 1290/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 1291/// the FromType, which is an objective-c pointer, to ToType, which may or may 1292/// not have the right set of qualifiers. 1293static QualType 1294BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 1295 QualType ToType, 1296 ASTContext &Context) { 1297 QualType CanonFromType = Context.getCanonicalType(FromType); 1298 QualType CanonToType = Context.getCanonicalType(ToType); 1299 Qualifiers Quals = CanonFromType.getQualifiers(); 1300 1301 // Exact qualifier match -> return the pointer type we're converting to. 1302 if (CanonToType.getLocalQualifiers() == Quals) 1303 return ToType; 1304 1305 // Just build a canonical type that has the right qualifiers. 1306 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 1307} 1308 1309static bool isNullPointerConstantForConversion(Expr *Expr, 1310 bool InOverloadResolution, 1311 ASTContext &Context) { 1312 // Handle value-dependent integral null pointer constants correctly. 1313 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1314 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1315 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1316 return !InOverloadResolution; 1317 1318 return Expr->isNullPointerConstant(Context, 1319 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1320 : Expr::NPC_ValueDependentIsNull); 1321} 1322 1323/// IsPointerConversion - Determines whether the conversion of the 1324/// expression From, which has the (possibly adjusted) type FromType, 1325/// can be converted to the type ToType via a pointer conversion (C++ 1326/// 4.10). If so, returns true and places the converted type (that 1327/// might differ from ToType in its cv-qualifiers at some level) into 1328/// ConvertedType. 1329/// 1330/// This routine also supports conversions to and from block pointers 1331/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1332/// pointers to interfaces. FIXME: Once we've determined the 1333/// appropriate overloading rules for Objective-C, we may want to 1334/// split the Objective-C checks into a different routine; however, 1335/// GCC seems to consider all of these conversions to be pointer 1336/// conversions, so for now they live here. IncompatibleObjC will be 1337/// set if the conversion is an allowed Objective-C conversion that 1338/// should result in a warning. 1339bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1340 bool InOverloadResolution, 1341 QualType& ConvertedType, 1342 bool &IncompatibleObjC) { 1343 IncompatibleObjC = false; 1344 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1345 return true; 1346 1347 // Conversion from a null pointer constant to any Objective-C pointer type. 1348 if (ToType->isObjCObjectPointerType() && 1349 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1350 ConvertedType = ToType; 1351 return true; 1352 } 1353 1354 // Blocks: Block pointers can be converted to void*. 1355 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1356 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1357 ConvertedType = ToType; 1358 return true; 1359 } 1360 // Blocks: A null pointer constant can be converted to a block 1361 // pointer type. 1362 if (ToType->isBlockPointerType() && 1363 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1364 ConvertedType = ToType; 1365 return true; 1366 } 1367 1368 // If the left-hand-side is nullptr_t, the right side can be a null 1369 // pointer constant. 1370 if (ToType->isNullPtrType() && 1371 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1372 ConvertedType = ToType; 1373 return true; 1374 } 1375 1376 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1377 if (!ToTypePtr) 1378 return false; 1379 1380 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1381 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1382 ConvertedType = ToType; 1383 return true; 1384 } 1385 1386 // Beyond this point, both types need to be pointers 1387 // , including objective-c pointers. 1388 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1389 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1390 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1391 ToType, Context); 1392 return true; 1393 1394 } 1395 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1396 if (!FromTypePtr) 1397 return false; 1398 1399 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1400 1401 // An rvalue of type "pointer to cv T," where T is an object type, 1402 // can be converted to an rvalue of type "pointer to cv void" (C++ 1403 // 4.10p2). 1404 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1405 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1406 ToPointeeType, 1407 ToType, Context); 1408 return true; 1409 } 1410 1411 // When we're overloading in C, we allow a special kind of pointer 1412 // conversion for compatible-but-not-identical pointee types. 1413 if (!getLangOptions().CPlusPlus && 1414 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1415 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1416 ToPointeeType, 1417 ToType, Context); 1418 return true; 1419 } 1420 1421 // C++ [conv.ptr]p3: 1422 // 1423 // An rvalue of type "pointer to cv D," where D is a class type, 1424 // can be converted to an rvalue of type "pointer to cv B," where 1425 // B is a base class (clause 10) of D. If B is an inaccessible 1426 // (clause 11) or ambiguous (10.2) base class of D, a program that 1427 // necessitates this conversion is ill-formed. The result of the 1428 // conversion is a pointer to the base class sub-object of the 1429 // derived class object. The null pointer value is converted to 1430 // the null pointer value of the destination type. 1431 // 1432 // Note that we do not check for ambiguity or inaccessibility 1433 // here. That is handled by CheckPointerConversion. 1434 if (getLangOptions().CPlusPlus && 1435 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1436 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1437 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1438 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1439 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1440 ToPointeeType, 1441 ToType, Context); 1442 return true; 1443 } 1444 1445 return false; 1446} 1447 1448/// isObjCPointerConversion - Determines whether this is an 1449/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1450/// with the same arguments and return values. 1451bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1452 QualType& ConvertedType, 1453 bool &IncompatibleObjC) { 1454 if (!getLangOptions().ObjC1) 1455 return false; 1456 1457 // First, we handle all conversions on ObjC object pointer types. 1458 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1459 const ObjCObjectPointerType *FromObjCPtr = 1460 FromType->getAs<ObjCObjectPointerType>(); 1461 1462 if (ToObjCPtr && FromObjCPtr) { 1463 // Objective C++: We're able to convert between "id" or "Class" and a 1464 // pointer to any interface (in both directions). 1465 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1466 ConvertedType = ToType; 1467 return true; 1468 } 1469 // Conversions with Objective-C's id<...>. 1470 if ((FromObjCPtr->isObjCQualifiedIdType() || 1471 ToObjCPtr->isObjCQualifiedIdType()) && 1472 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1473 /*compare=*/false)) { 1474 ConvertedType = ToType; 1475 return true; 1476 } 1477 // Objective C++: We're able to convert from a pointer to an 1478 // interface to a pointer to a different interface. 1479 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1480 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1481 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1482 if (getLangOptions().CPlusPlus && LHS && RHS && 1483 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1484 FromObjCPtr->getPointeeType())) 1485 return false; 1486 ConvertedType = ToType; 1487 return true; 1488 } 1489 1490 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1491 // Okay: this is some kind of implicit downcast of Objective-C 1492 // interfaces, which is permitted. However, we're going to 1493 // complain about it. 1494 IncompatibleObjC = true; 1495 ConvertedType = FromType; 1496 return true; 1497 } 1498 } 1499 // Beyond this point, both types need to be C pointers or block pointers. 1500 QualType ToPointeeType; 1501 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1502 ToPointeeType = ToCPtr->getPointeeType(); 1503 else if (const BlockPointerType *ToBlockPtr = 1504 ToType->getAs<BlockPointerType>()) { 1505 // Objective C++: We're able to convert from a pointer to any object 1506 // to a block pointer type. 1507 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1508 ConvertedType = ToType; 1509 return true; 1510 } 1511 ToPointeeType = ToBlockPtr->getPointeeType(); 1512 } 1513 else if (FromType->getAs<BlockPointerType>() && 1514 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1515 // Objective C++: We're able to convert from a block pointer type to a 1516 // pointer to any object. 1517 ConvertedType = ToType; 1518 return true; 1519 } 1520 else 1521 return false; 1522 1523 QualType FromPointeeType; 1524 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1525 FromPointeeType = FromCPtr->getPointeeType(); 1526 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1527 FromPointeeType = FromBlockPtr->getPointeeType(); 1528 else 1529 return false; 1530 1531 // If we have pointers to pointers, recursively check whether this 1532 // is an Objective-C conversion. 1533 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1534 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1535 IncompatibleObjC)) { 1536 // We always complain about this conversion. 1537 IncompatibleObjC = true; 1538 ConvertedType = ToType; 1539 return true; 1540 } 1541 // Allow conversion of pointee being objective-c pointer to another one; 1542 // as in I* to id. 1543 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1544 ToPointeeType->getAs<ObjCObjectPointerType>() && 1545 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1546 IncompatibleObjC)) { 1547 ConvertedType = ToType; 1548 return true; 1549 } 1550 1551 // If we have pointers to functions or blocks, check whether the only 1552 // differences in the argument and result types are in Objective-C 1553 // pointer conversions. If so, we permit the conversion (but 1554 // complain about it). 1555 const FunctionProtoType *FromFunctionType 1556 = FromPointeeType->getAs<FunctionProtoType>(); 1557 const FunctionProtoType *ToFunctionType 1558 = ToPointeeType->getAs<FunctionProtoType>(); 1559 if (FromFunctionType && ToFunctionType) { 1560 // If the function types are exactly the same, this isn't an 1561 // Objective-C pointer conversion. 1562 if (Context.getCanonicalType(FromPointeeType) 1563 == Context.getCanonicalType(ToPointeeType)) 1564 return false; 1565 1566 // Perform the quick checks that will tell us whether these 1567 // function types are obviously different. 1568 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1569 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1570 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1571 return false; 1572 1573 bool HasObjCConversion = false; 1574 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1575 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1576 // Okay, the types match exactly. Nothing to do. 1577 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1578 ToFunctionType->getResultType(), 1579 ConvertedType, IncompatibleObjC)) { 1580 // Okay, we have an Objective-C pointer conversion. 1581 HasObjCConversion = true; 1582 } else { 1583 // Function types are too different. Abort. 1584 return false; 1585 } 1586 1587 // Check argument types. 1588 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1589 ArgIdx != NumArgs; ++ArgIdx) { 1590 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1591 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1592 if (Context.getCanonicalType(FromArgType) 1593 == Context.getCanonicalType(ToArgType)) { 1594 // Okay, the types match exactly. Nothing to do. 1595 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1596 ConvertedType, IncompatibleObjC)) { 1597 // Okay, we have an Objective-C pointer conversion. 1598 HasObjCConversion = true; 1599 } else { 1600 // Argument types are too different. Abort. 1601 return false; 1602 } 1603 } 1604 1605 if (HasObjCConversion) { 1606 // We had an Objective-C conversion. Allow this pointer 1607 // conversion, but complain about it. 1608 ConvertedType = ToType; 1609 IncompatibleObjC = true; 1610 return true; 1611 } 1612 } 1613 1614 return false; 1615} 1616 1617/// FunctionArgTypesAreEqual - This routine checks two function proto types 1618/// for equlity of their argument types. Caller has already checked that 1619/// they have same number of arguments. This routine assumes that Objective-C 1620/// pointer types which only differ in their protocol qualifiers are equal. 1621bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, 1622 FunctionProtoType* NewType){ 1623 if (!getLangOptions().ObjC1) 1624 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1625 NewType->arg_type_begin()); 1626 1627 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1628 N = NewType->arg_type_begin(), 1629 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1630 QualType ToType = (*O); 1631 QualType FromType = (*N); 1632 if (ToType != FromType) { 1633 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1634 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1635 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1636 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1637 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1638 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1639 continue; 1640 } 1641 else if (const ObjCObjectPointerType *PTTo = 1642 ToType->getAs<ObjCObjectPointerType>()) { 1643 if (const ObjCObjectPointerType *PTFr = 1644 FromType->getAs<ObjCObjectPointerType>()) 1645 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1646 continue; 1647 } 1648 return false; 1649 } 1650 } 1651 return true; 1652} 1653 1654/// CheckPointerConversion - Check the pointer conversion from the 1655/// expression From to the type ToType. This routine checks for 1656/// ambiguous or inaccessible derived-to-base pointer 1657/// conversions for which IsPointerConversion has already returned 1658/// true. It returns true and produces a diagnostic if there was an 1659/// error, or returns false otherwise. 1660bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1661 CastExpr::CastKind &Kind, 1662 CXXBaseSpecifierArray& BasePath, 1663 bool IgnoreBaseAccess) { 1664 QualType FromType = From->getType(); 1665 1666 if (CXXBoolLiteralExpr* LitBool 1667 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1668 if (LitBool->getValue() == false) 1669 Diag(LitBool->getExprLoc(), diag::warn_init_pointer_from_false) 1670 << ToType; 1671 1672 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1673 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1674 QualType FromPointeeType = FromPtrType->getPointeeType(), 1675 ToPointeeType = ToPtrType->getPointeeType(); 1676 1677 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1678 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1679 // We must have a derived-to-base conversion. Check an 1680 // ambiguous or inaccessible conversion. 1681 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1682 From->getExprLoc(), 1683 From->getSourceRange(), &BasePath, 1684 IgnoreBaseAccess)) 1685 return true; 1686 1687 // The conversion was successful. 1688 Kind = CastExpr::CK_DerivedToBase; 1689 } 1690 } 1691 if (const ObjCObjectPointerType *FromPtrType = 1692 FromType->getAs<ObjCObjectPointerType>()) 1693 if (const ObjCObjectPointerType *ToPtrType = 1694 ToType->getAs<ObjCObjectPointerType>()) { 1695 // Objective-C++ conversions are always okay. 1696 // FIXME: We should have a different class of conversions for the 1697 // Objective-C++ implicit conversions. 1698 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1699 return false; 1700 1701 } 1702 return false; 1703} 1704 1705/// IsMemberPointerConversion - Determines whether the conversion of the 1706/// expression From, which has the (possibly adjusted) type FromType, can be 1707/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1708/// If so, returns true and places the converted type (that might differ from 1709/// ToType in its cv-qualifiers at some level) into ConvertedType. 1710bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1711 QualType ToType, 1712 bool InOverloadResolution, 1713 QualType &ConvertedType) { 1714 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1715 if (!ToTypePtr) 1716 return false; 1717 1718 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1719 if (From->isNullPointerConstant(Context, 1720 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1721 : Expr::NPC_ValueDependentIsNull)) { 1722 ConvertedType = ToType; 1723 return true; 1724 } 1725 1726 // Otherwise, both types have to be member pointers. 1727 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1728 if (!FromTypePtr) 1729 return false; 1730 1731 // A pointer to member of B can be converted to a pointer to member of D, 1732 // where D is derived from B (C++ 4.11p2). 1733 QualType FromClass(FromTypePtr->getClass(), 0); 1734 QualType ToClass(ToTypePtr->getClass(), 0); 1735 // FIXME: What happens when these are dependent? Is this function even called? 1736 1737 if (IsDerivedFrom(ToClass, FromClass)) { 1738 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1739 ToClass.getTypePtr()); 1740 return true; 1741 } 1742 1743 return false; 1744} 1745 1746/// CheckMemberPointerConversion - Check the member pointer conversion from the 1747/// expression From to the type ToType. This routine checks for ambiguous or 1748/// virtual or inaccessible base-to-derived member pointer conversions 1749/// for which IsMemberPointerConversion has already returned true. It returns 1750/// true and produces a diagnostic if there was an error, or returns false 1751/// otherwise. 1752bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1753 CastExpr::CastKind &Kind, 1754 CXXBaseSpecifierArray &BasePath, 1755 bool IgnoreBaseAccess) { 1756 QualType FromType = From->getType(); 1757 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1758 if (!FromPtrType) { 1759 // This must be a null pointer to member pointer conversion 1760 assert(From->isNullPointerConstant(Context, 1761 Expr::NPC_ValueDependentIsNull) && 1762 "Expr must be null pointer constant!"); 1763 Kind = CastExpr::CK_NullToMemberPointer; 1764 return false; 1765 } 1766 1767 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1768 assert(ToPtrType && "No member pointer cast has a target type " 1769 "that is not a member pointer."); 1770 1771 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1772 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1773 1774 // FIXME: What about dependent types? 1775 assert(FromClass->isRecordType() && "Pointer into non-class."); 1776 assert(ToClass->isRecordType() && "Pointer into non-class."); 1777 1778 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1779 /*DetectVirtual=*/true); 1780 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1781 assert(DerivationOkay && 1782 "Should not have been called if derivation isn't OK."); 1783 (void)DerivationOkay; 1784 1785 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1786 getUnqualifiedType())) { 1787 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1788 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1789 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1790 return true; 1791 } 1792 1793 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1794 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1795 << FromClass << ToClass << QualType(VBase, 0) 1796 << From->getSourceRange(); 1797 return true; 1798 } 1799 1800 if (!IgnoreBaseAccess) 1801 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1802 Paths.front(), 1803 diag::err_downcast_from_inaccessible_base); 1804 1805 // Must be a base to derived member conversion. 1806 BuildBasePathArray(Paths, BasePath); 1807 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1808 return false; 1809} 1810 1811/// IsQualificationConversion - Determines whether the conversion from 1812/// an rvalue of type FromType to ToType is a qualification conversion 1813/// (C++ 4.4). 1814bool 1815Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1816 FromType = Context.getCanonicalType(FromType); 1817 ToType = Context.getCanonicalType(ToType); 1818 1819 // If FromType and ToType are the same type, this is not a 1820 // qualification conversion. 1821 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1822 return false; 1823 1824 // (C++ 4.4p4): 1825 // A conversion can add cv-qualifiers at levels other than the first 1826 // in multi-level pointers, subject to the following rules: [...] 1827 bool PreviousToQualsIncludeConst = true; 1828 bool UnwrappedAnyPointer = false; 1829 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 1830 // Within each iteration of the loop, we check the qualifiers to 1831 // determine if this still looks like a qualification 1832 // conversion. Then, if all is well, we unwrap one more level of 1833 // pointers or pointers-to-members and do it all again 1834 // until there are no more pointers or pointers-to-members left to 1835 // unwrap. 1836 UnwrappedAnyPointer = true; 1837 1838 // -- for every j > 0, if const is in cv 1,j then const is in cv 1839 // 2,j, and similarly for volatile. 1840 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1841 return false; 1842 1843 // -- if the cv 1,j and cv 2,j are different, then const is in 1844 // every cv for 0 < k < j. 1845 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1846 && !PreviousToQualsIncludeConst) 1847 return false; 1848 1849 // Keep track of whether all prior cv-qualifiers in the "to" type 1850 // include const. 1851 PreviousToQualsIncludeConst 1852 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1853 } 1854 1855 // We are left with FromType and ToType being the pointee types 1856 // after unwrapping the original FromType and ToType the same number 1857 // of types. If we unwrapped any pointers, and if FromType and 1858 // ToType have the same unqualified type (since we checked 1859 // qualifiers above), then this is a qualification conversion. 1860 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1861} 1862 1863/// Determines whether there is a user-defined conversion sequence 1864/// (C++ [over.ics.user]) that converts expression From to the type 1865/// ToType. If such a conversion exists, User will contain the 1866/// user-defined conversion sequence that performs such a conversion 1867/// and this routine will return true. Otherwise, this routine returns 1868/// false and User is unspecified. 1869/// 1870/// \param AllowExplicit true if the conversion should consider C++0x 1871/// "explicit" conversion functions as well as non-explicit conversion 1872/// functions (C++0x [class.conv.fct]p2). 1873OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1874 UserDefinedConversionSequence& User, 1875 OverloadCandidateSet& CandidateSet, 1876 bool AllowExplicit) { 1877 // Whether we will only visit constructors. 1878 bool ConstructorsOnly = false; 1879 1880 // If the type we are conversion to is a class type, enumerate its 1881 // constructors. 1882 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1883 // C++ [over.match.ctor]p1: 1884 // When objects of class type are direct-initialized (8.5), or 1885 // copy-initialized from an expression of the same or a 1886 // derived class type (8.5), overload resolution selects the 1887 // constructor. [...] For copy-initialization, the candidate 1888 // functions are all the converting constructors (12.3.1) of 1889 // that class. The argument list is the expression-list within 1890 // the parentheses of the initializer. 1891 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1892 (From->getType()->getAs<RecordType>() && 1893 IsDerivedFrom(From->getType(), ToType))) 1894 ConstructorsOnly = true; 1895 1896 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1897 // We're not going to find any constructors. 1898 } else if (CXXRecordDecl *ToRecordDecl 1899 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1900 DeclarationName ConstructorName 1901 = Context.DeclarationNames.getCXXConstructorName( 1902 Context.getCanonicalType(ToType).getUnqualifiedType()); 1903 DeclContext::lookup_iterator Con, ConEnd; 1904 for (llvm::tie(Con, ConEnd) 1905 = ToRecordDecl->lookup(ConstructorName); 1906 Con != ConEnd; ++Con) { 1907 NamedDecl *D = *Con; 1908 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1909 1910 // Find the constructor (which may be a template). 1911 CXXConstructorDecl *Constructor = 0; 1912 FunctionTemplateDecl *ConstructorTmpl 1913 = dyn_cast<FunctionTemplateDecl>(D); 1914 if (ConstructorTmpl) 1915 Constructor 1916 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1917 else 1918 Constructor = cast<CXXConstructorDecl>(D); 1919 1920 if (!Constructor->isInvalidDecl() && 1921 Constructor->isConvertingConstructor(AllowExplicit)) { 1922 if (ConstructorTmpl) 1923 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1924 /*ExplicitArgs*/ 0, 1925 &From, 1, CandidateSet, 1926 /*SuppressUserConversions=*/!ConstructorsOnly); 1927 else 1928 // Allow one user-defined conversion when user specifies a 1929 // From->ToType conversion via an static cast (c-style, etc). 1930 AddOverloadCandidate(Constructor, FoundDecl, 1931 &From, 1, CandidateSet, 1932 /*SuppressUserConversions=*/!ConstructorsOnly); 1933 } 1934 } 1935 } 1936 } 1937 1938 // Enumerate conversion functions, if we're allowed to. 1939 if (ConstructorsOnly) { 1940 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1941 PDiag(0) << From->getSourceRange())) { 1942 // No conversion functions from incomplete types. 1943 } else if (const RecordType *FromRecordType 1944 = From->getType()->getAs<RecordType>()) { 1945 if (CXXRecordDecl *FromRecordDecl 1946 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1947 // Add all of the conversion functions as candidates. 1948 const UnresolvedSetImpl *Conversions 1949 = FromRecordDecl->getVisibleConversionFunctions(); 1950 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1951 E = Conversions->end(); I != E; ++I) { 1952 DeclAccessPair FoundDecl = I.getPair(); 1953 NamedDecl *D = FoundDecl.getDecl(); 1954 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1955 if (isa<UsingShadowDecl>(D)) 1956 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1957 1958 CXXConversionDecl *Conv; 1959 FunctionTemplateDecl *ConvTemplate; 1960 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1961 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1962 else 1963 Conv = cast<CXXConversionDecl>(D); 1964 1965 if (AllowExplicit || !Conv->isExplicit()) { 1966 if (ConvTemplate) 1967 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1968 ActingContext, From, ToType, 1969 CandidateSet); 1970 else 1971 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1972 From, ToType, CandidateSet); 1973 } 1974 } 1975 } 1976 } 1977 1978 OverloadCandidateSet::iterator Best; 1979 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1980 case OR_Success: 1981 // Record the standard conversion we used and the conversion function. 1982 if (CXXConstructorDecl *Constructor 1983 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1984 // C++ [over.ics.user]p1: 1985 // If the user-defined conversion is specified by a 1986 // constructor (12.3.1), the initial standard conversion 1987 // sequence converts the source type to the type required by 1988 // the argument of the constructor. 1989 // 1990 QualType ThisType = Constructor->getThisType(Context); 1991 if (Best->Conversions[0].isEllipsis()) 1992 User.EllipsisConversion = true; 1993 else { 1994 User.Before = Best->Conversions[0].Standard; 1995 User.EllipsisConversion = false; 1996 } 1997 User.ConversionFunction = Constructor; 1998 User.After.setAsIdentityConversion(); 1999 User.After.setFromType( 2000 ThisType->getAs<PointerType>()->getPointeeType()); 2001 User.After.setAllToTypes(ToType); 2002 return OR_Success; 2003 } else if (CXXConversionDecl *Conversion 2004 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2005 // C++ [over.ics.user]p1: 2006 // 2007 // [...] If the user-defined conversion is specified by a 2008 // conversion function (12.3.2), the initial standard 2009 // conversion sequence converts the source type to the 2010 // implicit object parameter of the conversion function. 2011 User.Before = Best->Conversions[0].Standard; 2012 User.ConversionFunction = Conversion; 2013 User.EllipsisConversion = false; 2014 2015 // C++ [over.ics.user]p2: 2016 // The second standard conversion sequence converts the 2017 // result of the user-defined conversion to the target type 2018 // for the sequence. Since an implicit conversion sequence 2019 // is an initialization, the special rules for 2020 // initialization by user-defined conversion apply when 2021 // selecting the best user-defined conversion for a 2022 // user-defined conversion sequence (see 13.3.3 and 2023 // 13.3.3.1). 2024 User.After = Best->FinalConversion; 2025 return OR_Success; 2026 } else { 2027 assert(false && "Not a constructor or conversion function?"); 2028 return OR_No_Viable_Function; 2029 } 2030 2031 case OR_No_Viable_Function: 2032 return OR_No_Viable_Function; 2033 case OR_Deleted: 2034 // No conversion here! We're done. 2035 return OR_Deleted; 2036 2037 case OR_Ambiguous: 2038 return OR_Ambiguous; 2039 } 2040 2041 return OR_No_Viable_Function; 2042} 2043 2044bool 2045Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2046 ImplicitConversionSequence ICS; 2047 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2048 OverloadingResult OvResult = 2049 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 2050 CandidateSet, false); 2051 if (OvResult == OR_Ambiguous) 2052 Diag(From->getSourceRange().getBegin(), 2053 diag::err_typecheck_ambiguous_condition) 2054 << From->getType() << ToType << From->getSourceRange(); 2055 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2056 Diag(From->getSourceRange().getBegin(), 2057 diag::err_typecheck_nonviable_condition) 2058 << From->getType() << ToType << From->getSourceRange(); 2059 else 2060 return false; 2061 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 2062 return true; 2063} 2064 2065/// CompareImplicitConversionSequences - Compare two implicit 2066/// conversion sequences to determine whether one is better than the 2067/// other or if they are indistinguishable (C++ 13.3.3.2). 2068ImplicitConversionSequence::CompareKind 2069Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 2070 const ImplicitConversionSequence& ICS2) 2071{ 2072 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2073 // conversion sequences (as defined in 13.3.3.1) 2074 // -- a standard conversion sequence (13.3.3.1.1) is a better 2075 // conversion sequence than a user-defined conversion sequence or 2076 // an ellipsis conversion sequence, and 2077 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2078 // conversion sequence than an ellipsis conversion sequence 2079 // (13.3.3.1.3). 2080 // 2081 // C++0x [over.best.ics]p10: 2082 // For the purpose of ranking implicit conversion sequences as 2083 // described in 13.3.3.2, the ambiguous conversion sequence is 2084 // treated as a user-defined sequence that is indistinguishable 2085 // from any other user-defined conversion sequence. 2086 if (ICS1.getKindRank() < ICS2.getKindRank()) 2087 return ImplicitConversionSequence::Better; 2088 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2089 return ImplicitConversionSequence::Worse; 2090 2091 // The following checks require both conversion sequences to be of 2092 // the same kind. 2093 if (ICS1.getKind() != ICS2.getKind()) 2094 return ImplicitConversionSequence::Indistinguishable; 2095 2096 // Two implicit conversion sequences of the same form are 2097 // indistinguishable conversion sequences unless one of the 2098 // following rules apply: (C++ 13.3.3.2p3): 2099 if (ICS1.isStandard()) 2100 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 2101 else if (ICS1.isUserDefined()) { 2102 // User-defined conversion sequence U1 is a better conversion 2103 // sequence than another user-defined conversion sequence U2 if 2104 // they contain the same user-defined conversion function or 2105 // constructor and if the second standard conversion sequence of 2106 // U1 is better than the second standard conversion sequence of 2107 // U2 (C++ 13.3.3.2p3). 2108 if (ICS1.UserDefined.ConversionFunction == 2109 ICS2.UserDefined.ConversionFunction) 2110 return CompareStandardConversionSequences(ICS1.UserDefined.After, 2111 ICS2.UserDefined.After); 2112 } 2113 2114 return ImplicitConversionSequence::Indistinguishable; 2115} 2116 2117static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2118 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2119 Qualifiers Quals; 2120 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2121 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2122 } 2123 2124 return Context.hasSameUnqualifiedType(T1, T2); 2125} 2126 2127// Per 13.3.3.2p3, compare the given standard conversion sequences to 2128// determine if one is a proper subset of the other. 2129static ImplicitConversionSequence::CompareKind 2130compareStandardConversionSubsets(ASTContext &Context, 2131 const StandardConversionSequence& SCS1, 2132 const StandardConversionSequence& SCS2) { 2133 ImplicitConversionSequence::CompareKind Result 2134 = ImplicitConversionSequence::Indistinguishable; 2135 2136 // the identity conversion sequence is considered to be a subsequence of 2137 // any non-identity conversion sequence 2138 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2139 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2140 return ImplicitConversionSequence::Better; 2141 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2142 return ImplicitConversionSequence::Worse; 2143 } 2144 2145 if (SCS1.Second != SCS2.Second) { 2146 if (SCS1.Second == ICK_Identity) 2147 Result = ImplicitConversionSequence::Better; 2148 else if (SCS2.Second == ICK_Identity) 2149 Result = ImplicitConversionSequence::Worse; 2150 else 2151 return ImplicitConversionSequence::Indistinguishable; 2152 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2153 return ImplicitConversionSequence::Indistinguishable; 2154 2155 if (SCS1.Third == SCS2.Third) { 2156 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2157 : ImplicitConversionSequence::Indistinguishable; 2158 } 2159 2160 if (SCS1.Third == ICK_Identity) 2161 return Result == ImplicitConversionSequence::Worse 2162 ? ImplicitConversionSequence::Indistinguishable 2163 : ImplicitConversionSequence::Better; 2164 2165 if (SCS2.Third == ICK_Identity) 2166 return Result == ImplicitConversionSequence::Better 2167 ? ImplicitConversionSequence::Indistinguishable 2168 : ImplicitConversionSequence::Worse; 2169 2170 return ImplicitConversionSequence::Indistinguishable; 2171} 2172 2173/// CompareStandardConversionSequences - Compare two standard 2174/// conversion sequences to determine whether one is better than the 2175/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2176ImplicitConversionSequence::CompareKind 2177Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 2178 const StandardConversionSequence& SCS2) 2179{ 2180 // Standard conversion sequence S1 is a better conversion sequence 2181 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2182 2183 // -- S1 is a proper subsequence of S2 (comparing the conversion 2184 // sequences in the canonical form defined by 13.3.3.1.1, 2185 // excluding any Lvalue Transformation; the identity conversion 2186 // sequence is considered to be a subsequence of any 2187 // non-identity conversion sequence) or, if not that, 2188 if (ImplicitConversionSequence::CompareKind CK 2189 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 2190 return CK; 2191 2192 // -- the rank of S1 is better than the rank of S2 (by the rules 2193 // defined below), or, if not that, 2194 ImplicitConversionRank Rank1 = SCS1.getRank(); 2195 ImplicitConversionRank Rank2 = SCS2.getRank(); 2196 if (Rank1 < Rank2) 2197 return ImplicitConversionSequence::Better; 2198 else if (Rank2 < Rank1) 2199 return ImplicitConversionSequence::Worse; 2200 2201 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2202 // are indistinguishable unless one of the following rules 2203 // applies: 2204 2205 // A conversion that is not a conversion of a pointer, or 2206 // pointer to member, to bool is better than another conversion 2207 // that is such a conversion. 2208 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2209 return SCS2.isPointerConversionToBool() 2210 ? ImplicitConversionSequence::Better 2211 : ImplicitConversionSequence::Worse; 2212 2213 // C++ [over.ics.rank]p4b2: 2214 // 2215 // If class B is derived directly or indirectly from class A, 2216 // conversion of B* to A* is better than conversion of B* to 2217 // void*, and conversion of A* to void* is better than conversion 2218 // of B* to void*. 2219 bool SCS1ConvertsToVoid 2220 = SCS1.isPointerConversionToVoidPointer(Context); 2221 bool SCS2ConvertsToVoid 2222 = SCS2.isPointerConversionToVoidPointer(Context); 2223 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2224 // Exactly one of the conversion sequences is a conversion to 2225 // a void pointer; it's the worse conversion. 2226 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2227 : ImplicitConversionSequence::Worse; 2228 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2229 // Neither conversion sequence converts to a void pointer; compare 2230 // their derived-to-base conversions. 2231 if (ImplicitConversionSequence::CompareKind DerivedCK 2232 = CompareDerivedToBaseConversions(SCS1, SCS2)) 2233 return DerivedCK; 2234 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2235 // Both conversion sequences are conversions to void 2236 // pointers. Compare the source types to determine if there's an 2237 // inheritance relationship in their sources. 2238 QualType FromType1 = SCS1.getFromType(); 2239 QualType FromType2 = SCS2.getFromType(); 2240 2241 // Adjust the types we're converting from via the array-to-pointer 2242 // conversion, if we need to. 2243 if (SCS1.First == ICK_Array_To_Pointer) 2244 FromType1 = Context.getArrayDecayedType(FromType1); 2245 if (SCS2.First == ICK_Array_To_Pointer) 2246 FromType2 = Context.getArrayDecayedType(FromType2); 2247 2248 QualType FromPointee1 2249 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2250 QualType FromPointee2 2251 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2252 2253 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2254 return ImplicitConversionSequence::Better; 2255 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2256 return ImplicitConversionSequence::Worse; 2257 2258 // Objective-C++: If one interface is more specific than the 2259 // other, it is the better one. 2260 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2261 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2262 if (FromIface1 && FromIface1) { 2263 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2264 return ImplicitConversionSequence::Better; 2265 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2266 return ImplicitConversionSequence::Worse; 2267 } 2268 } 2269 2270 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2271 // bullet 3). 2272 if (ImplicitConversionSequence::CompareKind QualCK 2273 = CompareQualificationConversions(SCS1, SCS2)) 2274 return QualCK; 2275 2276 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2277 // C++0x [over.ics.rank]p3b4: 2278 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2279 // implicit object parameter of a non-static member function declared 2280 // without a ref-qualifier, and S1 binds an rvalue reference to an 2281 // rvalue and S2 binds an lvalue reference. 2282 // FIXME: We don't know if we're dealing with the implicit object parameter, 2283 // or if the member function in this case has a ref qualifier. 2284 // (Of course, we don't have ref qualifiers yet.) 2285 if (SCS1.RRefBinding != SCS2.RRefBinding) 2286 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 2287 : ImplicitConversionSequence::Worse; 2288 2289 // C++ [over.ics.rank]p3b4: 2290 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2291 // which the references refer are the same type except for 2292 // top-level cv-qualifiers, and the type to which the reference 2293 // initialized by S2 refers is more cv-qualified than the type 2294 // to which the reference initialized by S1 refers. 2295 QualType T1 = SCS1.getToType(2); 2296 QualType T2 = SCS2.getToType(2); 2297 T1 = Context.getCanonicalType(T1); 2298 T2 = Context.getCanonicalType(T2); 2299 Qualifiers T1Quals, T2Quals; 2300 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2301 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2302 if (UnqualT1 == UnqualT2) { 2303 // If the type is an array type, promote the element qualifiers to the type 2304 // for comparison. 2305 if (isa<ArrayType>(T1) && T1Quals) 2306 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2307 if (isa<ArrayType>(T2) && T2Quals) 2308 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2309 if (T2.isMoreQualifiedThan(T1)) 2310 return ImplicitConversionSequence::Better; 2311 else if (T1.isMoreQualifiedThan(T2)) 2312 return ImplicitConversionSequence::Worse; 2313 } 2314 } 2315 2316 return ImplicitConversionSequence::Indistinguishable; 2317} 2318 2319/// CompareQualificationConversions - Compares two standard conversion 2320/// sequences to determine whether they can be ranked based on their 2321/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2322ImplicitConversionSequence::CompareKind 2323Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 2324 const StandardConversionSequence& SCS2) { 2325 // C++ 13.3.3.2p3: 2326 // -- S1 and S2 differ only in their qualification conversion and 2327 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2328 // cv-qualification signature of type T1 is a proper subset of 2329 // the cv-qualification signature of type T2, and S1 is not the 2330 // deprecated string literal array-to-pointer conversion (4.2). 2331 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2332 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2333 return ImplicitConversionSequence::Indistinguishable; 2334 2335 // FIXME: the example in the standard doesn't use a qualification 2336 // conversion (!) 2337 QualType T1 = SCS1.getToType(2); 2338 QualType T2 = SCS2.getToType(2); 2339 T1 = Context.getCanonicalType(T1); 2340 T2 = Context.getCanonicalType(T2); 2341 Qualifiers T1Quals, T2Quals; 2342 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2343 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2344 2345 // If the types are the same, we won't learn anything by unwrapped 2346 // them. 2347 if (UnqualT1 == UnqualT2) 2348 return ImplicitConversionSequence::Indistinguishable; 2349 2350 // If the type is an array type, promote the element qualifiers to the type 2351 // for comparison. 2352 if (isa<ArrayType>(T1) && T1Quals) 2353 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2354 if (isa<ArrayType>(T2) && T2Quals) 2355 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2356 2357 ImplicitConversionSequence::CompareKind Result 2358 = ImplicitConversionSequence::Indistinguishable; 2359 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2360 // Within each iteration of the loop, we check the qualifiers to 2361 // determine if this still looks like a qualification 2362 // conversion. Then, if all is well, we unwrap one more level of 2363 // pointers or pointers-to-members and do it all again 2364 // until there are no more pointers or pointers-to-members left 2365 // to unwrap. This essentially mimics what 2366 // IsQualificationConversion does, but here we're checking for a 2367 // strict subset of qualifiers. 2368 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2369 // The qualifiers are the same, so this doesn't tell us anything 2370 // about how the sequences rank. 2371 ; 2372 else if (T2.isMoreQualifiedThan(T1)) { 2373 // T1 has fewer qualifiers, so it could be the better sequence. 2374 if (Result == ImplicitConversionSequence::Worse) 2375 // Neither has qualifiers that are a subset of the other's 2376 // qualifiers. 2377 return ImplicitConversionSequence::Indistinguishable; 2378 2379 Result = ImplicitConversionSequence::Better; 2380 } else if (T1.isMoreQualifiedThan(T2)) { 2381 // T2 has fewer qualifiers, so it could be the better sequence. 2382 if (Result == ImplicitConversionSequence::Better) 2383 // Neither has qualifiers that are a subset of the other's 2384 // qualifiers. 2385 return ImplicitConversionSequence::Indistinguishable; 2386 2387 Result = ImplicitConversionSequence::Worse; 2388 } else { 2389 // Qualifiers are disjoint. 2390 return ImplicitConversionSequence::Indistinguishable; 2391 } 2392 2393 // If the types after this point are equivalent, we're done. 2394 if (Context.hasSameUnqualifiedType(T1, T2)) 2395 break; 2396 } 2397 2398 // Check that the winning standard conversion sequence isn't using 2399 // the deprecated string literal array to pointer conversion. 2400 switch (Result) { 2401 case ImplicitConversionSequence::Better: 2402 if (SCS1.DeprecatedStringLiteralToCharPtr) 2403 Result = ImplicitConversionSequence::Indistinguishable; 2404 break; 2405 2406 case ImplicitConversionSequence::Indistinguishable: 2407 break; 2408 2409 case ImplicitConversionSequence::Worse: 2410 if (SCS2.DeprecatedStringLiteralToCharPtr) 2411 Result = ImplicitConversionSequence::Indistinguishable; 2412 break; 2413 } 2414 2415 return Result; 2416} 2417 2418/// CompareDerivedToBaseConversions - Compares two standard conversion 2419/// sequences to determine whether they can be ranked based on their 2420/// various kinds of derived-to-base conversions (C++ 2421/// [over.ics.rank]p4b3). As part of these checks, we also look at 2422/// conversions between Objective-C interface types. 2423ImplicitConversionSequence::CompareKind 2424Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2425 const StandardConversionSequence& SCS2) { 2426 QualType FromType1 = SCS1.getFromType(); 2427 QualType ToType1 = SCS1.getToType(1); 2428 QualType FromType2 = SCS2.getFromType(); 2429 QualType ToType2 = SCS2.getToType(1); 2430 2431 // Adjust the types we're converting from via the array-to-pointer 2432 // conversion, if we need to. 2433 if (SCS1.First == ICK_Array_To_Pointer) 2434 FromType1 = Context.getArrayDecayedType(FromType1); 2435 if (SCS2.First == ICK_Array_To_Pointer) 2436 FromType2 = Context.getArrayDecayedType(FromType2); 2437 2438 // Canonicalize all of the types. 2439 FromType1 = Context.getCanonicalType(FromType1); 2440 ToType1 = Context.getCanonicalType(ToType1); 2441 FromType2 = Context.getCanonicalType(FromType2); 2442 ToType2 = Context.getCanonicalType(ToType2); 2443 2444 // C++ [over.ics.rank]p4b3: 2445 // 2446 // If class B is derived directly or indirectly from class A and 2447 // class C is derived directly or indirectly from B, 2448 // 2449 // For Objective-C, we let A, B, and C also be Objective-C 2450 // interfaces. 2451 2452 // Compare based on pointer conversions. 2453 if (SCS1.Second == ICK_Pointer_Conversion && 2454 SCS2.Second == ICK_Pointer_Conversion && 2455 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2456 FromType1->isPointerType() && FromType2->isPointerType() && 2457 ToType1->isPointerType() && ToType2->isPointerType()) { 2458 QualType FromPointee1 2459 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2460 QualType ToPointee1 2461 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2462 QualType FromPointee2 2463 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2464 QualType ToPointee2 2465 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2466 2467 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2468 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2469 const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>(); 2470 const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>(); 2471 2472 // -- conversion of C* to B* is better than conversion of C* to A*, 2473 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2474 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2475 return ImplicitConversionSequence::Better; 2476 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2477 return ImplicitConversionSequence::Worse; 2478 2479 if (ToIface1 && ToIface2) { 2480 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2481 return ImplicitConversionSequence::Better; 2482 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2483 return ImplicitConversionSequence::Worse; 2484 } 2485 } 2486 2487 // -- conversion of B* to A* is better than conversion of C* to A*, 2488 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2489 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2490 return ImplicitConversionSequence::Better; 2491 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2492 return ImplicitConversionSequence::Worse; 2493 2494 if (FromIface1 && FromIface2) { 2495 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2496 return ImplicitConversionSequence::Better; 2497 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2498 return ImplicitConversionSequence::Worse; 2499 } 2500 } 2501 } 2502 2503 // Ranking of member-pointer types. 2504 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2505 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2506 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2507 const MemberPointerType * FromMemPointer1 = 2508 FromType1->getAs<MemberPointerType>(); 2509 const MemberPointerType * ToMemPointer1 = 2510 ToType1->getAs<MemberPointerType>(); 2511 const MemberPointerType * FromMemPointer2 = 2512 FromType2->getAs<MemberPointerType>(); 2513 const MemberPointerType * ToMemPointer2 = 2514 ToType2->getAs<MemberPointerType>(); 2515 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2516 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2517 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2518 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2519 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2520 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2521 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2522 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2523 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2524 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2525 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2526 return ImplicitConversionSequence::Worse; 2527 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2528 return ImplicitConversionSequence::Better; 2529 } 2530 // conversion of B::* to C::* is better than conversion of A::* to C::* 2531 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2532 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2533 return ImplicitConversionSequence::Better; 2534 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2535 return ImplicitConversionSequence::Worse; 2536 } 2537 } 2538 2539 if (SCS1.Second == ICK_Derived_To_Base) { 2540 // -- conversion of C to B is better than conversion of C to A, 2541 // -- binding of an expression of type C to a reference of type 2542 // B& is better than binding an expression of type C to a 2543 // reference of type A&, 2544 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2545 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2546 if (IsDerivedFrom(ToType1, ToType2)) 2547 return ImplicitConversionSequence::Better; 2548 else if (IsDerivedFrom(ToType2, ToType1)) 2549 return ImplicitConversionSequence::Worse; 2550 } 2551 2552 // -- conversion of B to A is better than conversion of C to A. 2553 // -- binding of an expression of type B to a reference of type 2554 // A& is better than binding an expression of type C to a 2555 // reference of type A&, 2556 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2557 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2558 if (IsDerivedFrom(FromType2, FromType1)) 2559 return ImplicitConversionSequence::Better; 2560 else if (IsDerivedFrom(FromType1, FromType2)) 2561 return ImplicitConversionSequence::Worse; 2562 } 2563 } 2564 2565 return ImplicitConversionSequence::Indistinguishable; 2566} 2567 2568/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2569/// determine whether they are reference-related, 2570/// reference-compatible, reference-compatible with added 2571/// qualification, or incompatible, for use in C++ initialization by 2572/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2573/// type, and the first type (T1) is the pointee type of the reference 2574/// type being initialized. 2575Sema::ReferenceCompareResult 2576Sema::CompareReferenceRelationship(SourceLocation Loc, 2577 QualType OrigT1, QualType OrigT2, 2578 bool& DerivedToBase) { 2579 assert(!OrigT1->isReferenceType() && 2580 "T1 must be the pointee type of the reference type"); 2581 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2582 2583 QualType T1 = Context.getCanonicalType(OrigT1); 2584 QualType T2 = Context.getCanonicalType(OrigT2); 2585 Qualifiers T1Quals, T2Quals; 2586 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2587 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2588 2589 // C++ [dcl.init.ref]p4: 2590 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2591 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2592 // T1 is a base class of T2. 2593 if (UnqualT1 == UnqualT2) 2594 DerivedToBase = false; 2595 else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2596 IsDerivedFrom(UnqualT2, UnqualT1)) 2597 DerivedToBase = true; 2598 else 2599 return Ref_Incompatible; 2600 2601 // At this point, we know that T1 and T2 are reference-related (at 2602 // least). 2603 2604 // If the type is an array type, promote the element qualifiers to the type 2605 // for comparison. 2606 if (isa<ArrayType>(T1) && T1Quals) 2607 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2608 if (isa<ArrayType>(T2) && T2Quals) 2609 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2610 2611 // C++ [dcl.init.ref]p4: 2612 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2613 // reference-related to T2 and cv1 is the same cv-qualification 2614 // as, or greater cv-qualification than, cv2. For purposes of 2615 // overload resolution, cases for which cv1 is greater 2616 // cv-qualification than cv2 are identified as 2617 // reference-compatible with added qualification (see 13.3.3.2). 2618 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2619 return Ref_Compatible; 2620 else if (T1.isMoreQualifiedThan(T2)) 2621 return Ref_Compatible_With_Added_Qualification; 2622 else 2623 return Ref_Related; 2624} 2625 2626/// \brief Compute an implicit conversion sequence for reference 2627/// initialization. 2628static ImplicitConversionSequence 2629TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2630 SourceLocation DeclLoc, 2631 bool SuppressUserConversions, 2632 bool AllowExplicit) { 2633 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2634 2635 // Most paths end in a failed conversion. 2636 ImplicitConversionSequence ICS; 2637 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2638 2639 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2640 QualType T2 = Init->getType(); 2641 2642 // If the initializer is the address of an overloaded function, try 2643 // to resolve the overloaded function. If all goes well, T2 is the 2644 // type of the resulting function. 2645 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2646 DeclAccessPair Found; 2647 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2648 false, Found)) 2649 T2 = Fn->getType(); 2650 } 2651 2652 // Compute some basic properties of the types and the initializer. 2653 bool isRValRef = DeclType->isRValueReferenceType(); 2654 bool DerivedToBase = false; 2655 Expr::isLvalueResult InitLvalue = Init->isLvalue(S.Context); 2656 Sema::ReferenceCompareResult RefRelationship 2657 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); 2658 2659 2660 // C++ [over.ics.ref]p3: 2661 // Except for an implicit object parameter, for which see 13.3.1, 2662 // a standard conversion sequence cannot be formed if it requires 2663 // binding an lvalue reference to non-const to an rvalue or 2664 // binding an rvalue reference to an lvalue. 2665 // 2666 // FIXME: DPG doesn't trust this code. It seems far too early to 2667 // abort because of a binding of an rvalue reference to an lvalue. 2668 if (isRValRef && InitLvalue == Expr::LV_Valid) 2669 return ICS; 2670 2671 // C++0x [dcl.init.ref]p16: 2672 // A reference to type "cv1 T1" is initialized by an expression 2673 // of type "cv2 T2" as follows: 2674 2675 // -- If the initializer expression 2676 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2677 // reference-compatible with "cv2 T2," or 2678 // 2679 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2680 if (InitLvalue == Expr::LV_Valid && 2681 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2682 // C++ [over.ics.ref]p1: 2683 // When a parameter of reference type binds directly (8.5.3) 2684 // to an argument expression, the implicit conversion sequence 2685 // is the identity conversion, unless the argument expression 2686 // has a type that is a derived class of the parameter type, 2687 // in which case the implicit conversion sequence is a 2688 // derived-to-base Conversion (13.3.3.1). 2689 ICS.setStandard(); 2690 ICS.Standard.First = ICK_Identity; 2691 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2692 ICS.Standard.Third = ICK_Identity; 2693 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2694 ICS.Standard.setToType(0, T2); 2695 ICS.Standard.setToType(1, T1); 2696 ICS.Standard.setToType(2, T1); 2697 ICS.Standard.ReferenceBinding = true; 2698 ICS.Standard.DirectBinding = true; 2699 ICS.Standard.RRefBinding = false; 2700 ICS.Standard.CopyConstructor = 0; 2701 2702 // Nothing more to do: the inaccessibility/ambiguity check for 2703 // derived-to-base conversions is suppressed when we're 2704 // computing the implicit conversion sequence (C++ 2705 // [over.best.ics]p2). 2706 return ICS; 2707 } 2708 2709 // -- has a class type (i.e., T2 is a class type), where T1 is 2710 // not reference-related to T2, and can be implicitly 2711 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2712 // is reference-compatible with "cv3 T3" 92) (this 2713 // conversion is selected by enumerating the applicable 2714 // conversion functions (13.3.1.6) and choosing the best 2715 // one through overload resolution (13.3)), 2716 if (!isRValRef && !SuppressUserConversions && T2->isRecordType() && 2717 !S.RequireCompleteType(DeclLoc, T2, 0) && 2718 RefRelationship == Sema::Ref_Incompatible) { 2719 CXXRecordDecl *T2RecordDecl 2720 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2721 2722 OverloadCandidateSet CandidateSet(DeclLoc); 2723 const UnresolvedSetImpl *Conversions 2724 = T2RecordDecl->getVisibleConversionFunctions(); 2725 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2726 E = Conversions->end(); I != E; ++I) { 2727 NamedDecl *D = *I; 2728 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2729 if (isa<UsingShadowDecl>(D)) 2730 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2731 2732 FunctionTemplateDecl *ConvTemplate 2733 = dyn_cast<FunctionTemplateDecl>(D); 2734 CXXConversionDecl *Conv; 2735 if (ConvTemplate) 2736 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2737 else 2738 Conv = cast<CXXConversionDecl>(D); 2739 2740 // If the conversion function doesn't return a reference type, 2741 // it can't be considered for this conversion. 2742 if (Conv->getConversionType()->isLValueReferenceType() && 2743 (AllowExplicit || !Conv->isExplicit())) { 2744 if (ConvTemplate) 2745 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2746 Init, DeclType, CandidateSet); 2747 else 2748 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2749 DeclType, CandidateSet); 2750 } 2751 } 2752 2753 OverloadCandidateSet::iterator Best; 2754 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2755 case OR_Success: 2756 // C++ [over.ics.ref]p1: 2757 // 2758 // [...] If the parameter binds directly to the result of 2759 // applying a conversion function to the argument 2760 // expression, the implicit conversion sequence is a 2761 // user-defined conversion sequence (13.3.3.1.2), with the 2762 // second standard conversion sequence either an identity 2763 // conversion or, if the conversion function returns an 2764 // entity of a type that is a derived class of the parameter 2765 // type, a derived-to-base Conversion. 2766 if (!Best->FinalConversion.DirectBinding) 2767 break; 2768 2769 ICS.setUserDefined(); 2770 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2771 ICS.UserDefined.After = Best->FinalConversion; 2772 ICS.UserDefined.ConversionFunction = Best->Function; 2773 ICS.UserDefined.EllipsisConversion = false; 2774 assert(ICS.UserDefined.After.ReferenceBinding && 2775 ICS.UserDefined.After.DirectBinding && 2776 "Expected a direct reference binding!"); 2777 return ICS; 2778 2779 case OR_Ambiguous: 2780 ICS.setAmbiguous(); 2781 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2782 Cand != CandidateSet.end(); ++Cand) 2783 if (Cand->Viable) 2784 ICS.Ambiguous.addConversion(Cand->Function); 2785 return ICS; 2786 2787 case OR_No_Viable_Function: 2788 case OR_Deleted: 2789 // There was no suitable conversion, or we found a deleted 2790 // conversion; continue with other checks. 2791 break; 2792 } 2793 } 2794 2795 // -- Otherwise, the reference shall be to a non-volatile const 2796 // type (i.e., cv1 shall be const), or the reference shall be an 2797 // rvalue reference and the initializer expression shall be an rvalue. 2798 // 2799 // We actually handle one oddity of C++ [over.ics.ref] at this 2800 // point, which is that, due to p2 (which short-circuits reference 2801 // binding by only attempting a simple conversion for non-direct 2802 // bindings) and p3's strange wording, we allow a const volatile 2803 // reference to bind to an rvalue. Hence the check for the presence 2804 // of "const" rather than checking for "const" being the only 2805 // qualifier. 2806 if (!isRValRef && !T1.isConstQualified()) 2807 return ICS; 2808 2809 // -- if T2 is a class type and 2810 // -- the initializer expression is an rvalue and "cv1 T1" 2811 // is reference-compatible with "cv2 T2," or 2812 // 2813 // -- T1 is not reference-related to T2 and the initializer 2814 // expression can be implicitly converted to an rvalue 2815 // of type "cv3 T3" (this conversion is selected by 2816 // enumerating the applicable conversion functions 2817 // (13.3.1.6) and choosing the best one through overload 2818 // resolution (13.3)), 2819 // 2820 // then the reference is bound to the initializer 2821 // expression rvalue in the first case and to the object 2822 // that is the result of the conversion in the second case 2823 // (or, in either case, to the appropriate base class 2824 // subobject of the object). 2825 // 2826 // We're only checking the first case here, which is a direct 2827 // binding in C++0x but not in C++03. 2828 if (InitLvalue != Expr::LV_Valid && T2->isRecordType() && 2829 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2830 ICS.setStandard(); 2831 ICS.Standard.First = ICK_Identity; 2832 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2833 ICS.Standard.Third = ICK_Identity; 2834 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2835 ICS.Standard.setToType(0, T2); 2836 ICS.Standard.setToType(1, T1); 2837 ICS.Standard.setToType(2, T1); 2838 ICS.Standard.ReferenceBinding = true; 2839 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 2840 ICS.Standard.RRefBinding = isRValRef; 2841 ICS.Standard.CopyConstructor = 0; 2842 return ICS; 2843 } 2844 2845 // -- Otherwise, a temporary of type "cv1 T1" is created and 2846 // initialized from the initializer expression using the 2847 // rules for a non-reference copy initialization (8.5). The 2848 // reference is then bound to the temporary. If T1 is 2849 // reference-related to T2, cv1 must be the same 2850 // cv-qualification as, or greater cv-qualification than, 2851 // cv2; otherwise, the program is ill-formed. 2852 if (RefRelationship == Sema::Ref_Related) { 2853 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2854 // we would be reference-compatible or reference-compatible with 2855 // added qualification. But that wasn't the case, so the reference 2856 // initialization fails. 2857 return ICS; 2858 } 2859 2860 // If at least one of the types is a class type, the types are not 2861 // related, and we aren't allowed any user conversions, the 2862 // reference binding fails. This case is important for breaking 2863 // recursion, since TryImplicitConversion below will attempt to 2864 // create a temporary through the use of a copy constructor. 2865 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2866 (T1->isRecordType() || T2->isRecordType())) 2867 return ICS; 2868 2869 // C++ [over.ics.ref]p2: 2870 // When a parameter of reference type is not bound directly to 2871 // an argument expression, the conversion sequence is the one 2872 // required to convert the argument expression to the 2873 // underlying type of the reference according to 2874 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2875 // to copy-initializing a temporary of the underlying type with 2876 // the argument expression. Any difference in top-level 2877 // cv-qualification is subsumed by the initialization itself 2878 // and does not constitute a conversion. 2879 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2880 /*AllowExplicit=*/false, 2881 /*InOverloadResolution=*/false); 2882 2883 // Of course, that's still a reference binding. 2884 if (ICS.isStandard()) { 2885 ICS.Standard.ReferenceBinding = true; 2886 ICS.Standard.RRefBinding = isRValRef; 2887 } else if (ICS.isUserDefined()) { 2888 ICS.UserDefined.After.ReferenceBinding = true; 2889 ICS.UserDefined.After.RRefBinding = isRValRef; 2890 } 2891 return ICS; 2892} 2893 2894/// TryCopyInitialization - Try to copy-initialize a value of type 2895/// ToType from the expression From. Return the implicit conversion 2896/// sequence required to pass this argument, which may be a bad 2897/// conversion sequence (meaning that the argument cannot be passed to 2898/// a parameter of this type). If @p SuppressUserConversions, then we 2899/// do not permit any user-defined conversion sequences. 2900static ImplicitConversionSequence 2901TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 2902 bool SuppressUserConversions, 2903 bool InOverloadResolution) { 2904 if (ToType->isReferenceType()) 2905 return TryReferenceInit(S, From, ToType, 2906 /*FIXME:*/From->getLocStart(), 2907 SuppressUserConversions, 2908 /*AllowExplicit=*/false); 2909 2910 return S.TryImplicitConversion(From, ToType, 2911 SuppressUserConversions, 2912 /*AllowExplicit=*/false, 2913 InOverloadResolution); 2914} 2915 2916/// TryObjectArgumentInitialization - Try to initialize the object 2917/// parameter of the given member function (@c Method) from the 2918/// expression @p From. 2919ImplicitConversionSequence 2920Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2921 CXXMethodDecl *Method, 2922 CXXRecordDecl *ActingContext) { 2923 QualType ClassType = Context.getTypeDeclType(ActingContext); 2924 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2925 // const volatile object. 2926 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2927 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2928 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2929 2930 // Set up the conversion sequence as a "bad" conversion, to allow us 2931 // to exit early. 2932 ImplicitConversionSequence ICS; 2933 2934 // We need to have an object of class type. 2935 QualType FromType = OrigFromType; 2936 if (const PointerType *PT = FromType->getAs<PointerType>()) 2937 FromType = PT->getPointeeType(); 2938 2939 assert(FromType->isRecordType()); 2940 2941 // The implicit object parameter is has the type "reference to cv X", 2942 // where X is the class of which the function is a member 2943 // (C++ [over.match.funcs]p4). However, when finding an implicit 2944 // conversion sequence for the argument, we are not allowed to 2945 // create temporaries or perform user-defined conversions 2946 // (C++ [over.match.funcs]p5). We perform a simplified version of 2947 // reference binding here, that allows class rvalues to bind to 2948 // non-constant references. 2949 2950 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2951 // with the implicit object parameter (C++ [over.match.funcs]p5). 2952 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2953 if (ImplicitParamType.getCVRQualifiers() 2954 != FromTypeCanon.getLocalCVRQualifiers() && 2955 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2956 ICS.setBad(BadConversionSequence::bad_qualifiers, 2957 OrigFromType, ImplicitParamType); 2958 return ICS; 2959 } 2960 2961 // Check that we have either the same type or a derived type. It 2962 // affects the conversion rank. 2963 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2964 ImplicitConversionKind SecondKind; 2965 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2966 SecondKind = ICK_Identity; 2967 } else if (IsDerivedFrom(FromType, ClassType)) 2968 SecondKind = ICK_Derived_To_Base; 2969 else { 2970 ICS.setBad(BadConversionSequence::unrelated_class, 2971 FromType, ImplicitParamType); 2972 return ICS; 2973 } 2974 2975 // Success. Mark this as a reference binding. 2976 ICS.setStandard(); 2977 ICS.Standard.setAsIdentityConversion(); 2978 ICS.Standard.Second = SecondKind; 2979 ICS.Standard.setFromType(FromType); 2980 ICS.Standard.setAllToTypes(ImplicitParamType); 2981 ICS.Standard.ReferenceBinding = true; 2982 ICS.Standard.DirectBinding = true; 2983 ICS.Standard.RRefBinding = false; 2984 return ICS; 2985} 2986 2987/// PerformObjectArgumentInitialization - Perform initialization of 2988/// the implicit object parameter for the given Method with the given 2989/// expression. 2990bool 2991Sema::PerformObjectArgumentInitialization(Expr *&From, 2992 NestedNameSpecifier *Qualifier, 2993 NamedDecl *FoundDecl, 2994 CXXMethodDecl *Method) { 2995 QualType FromRecordType, DestType; 2996 QualType ImplicitParamRecordType = 2997 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 2998 2999 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3000 FromRecordType = PT->getPointeeType(); 3001 DestType = Method->getThisType(Context); 3002 } else { 3003 FromRecordType = From->getType(); 3004 DestType = ImplicitParamRecordType; 3005 } 3006 3007 // Note that we always use the true parent context when performing 3008 // the actual argument initialization. 3009 ImplicitConversionSequence ICS 3010 = TryObjectArgumentInitialization(From->getType(), Method, 3011 Method->getParent()); 3012 if (ICS.isBad()) 3013 return Diag(From->getSourceRange().getBegin(), 3014 diag::err_implicit_object_parameter_init) 3015 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3016 3017 if (ICS.Standard.Second == ICK_Derived_To_Base) 3018 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3019 3020 if (!Context.hasSameType(From->getType(), DestType)) 3021 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 3022 /*isLvalue=*/!From->getType()->isPointerType()); 3023 return false; 3024} 3025 3026/// TryContextuallyConvertToBool - Attempt to contextually convert the 3027/// expression From to bool (C++0x [conv]p3). 3028ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 3029 // FIXME: This is pretty broken. 3030 return TryImplicitConversion(From, Context.BoolTy, 3031 // FIXME: Are these flags correct? 3032 /*SuppressUserConversions=*/false, 3033 /*AllowExplicit=*/true, 3034 /*InOverloadResolution=*/false); 3035} 3036 3037/// PerformContextuallyConvertToBool - Perform a contextual conversion 3038/// of the expression From to bool (C++0x [conv]p3). 3039bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3040 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 3041 if (!ICS.isBad()) 3042 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3043 3044 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3045 return Diag(From->getSourceRange().getBegin(), 3046 diag::err_typecheck_bool_condition) 3047 << From->getType() << From->getSourceRange(); 3048 return true; 3049} 3050 3051/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3052/// expression From to 'id'. 3053ImplicitConversionSequence Sema::TryContextuallyConvertToObjCId(Expr *From) { 3054 QualType Ty = Context.getObjCIdType(); 3055 return TryImplicitConversion(From, Ty, 3056 // FIXME: Are these flags correct? 3057 /*SuppressUserConversions=*/false, 3058 /*AllowExplicit=*/true, 3059 /*InOverloadResolution=*/false); 3060} 3061 3062/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3063/// of the expression From to 'id'. 3064bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3065 QualType Ty = Context.getObjCIdType(); 3066 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(From); 3067 if (!ICS.isBad()) 3068 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3069 return true; 3070} 3071 3072/// AddOverloadCandidate - Adds the given function to the set of 3073/// candidate functions, using the given function call arguments. If 3074/// @p SuppressUserConversions, then don't allow user-defined 3075/// conversions via constructors or conversion operators. 3076/// 3077/// \para PartialOverloading true if we are performing "partial" overloading 3078/// based on an incomplete set of function arguments. This feature is used by 3079/// code completion. 3080void 3081Sema::AddOverloadCandidate(FunctionDecl *Function, 3082 DeclAccessPair FoundDecl, 3083 Expr **Args, unsigned NumArgs, 3084 OverloadCandidateSet& CandidateSet, 3085 bool SuppressUserConversions, 3086 bool PartialOverloading) { 3087 const FunctionProtoType* Proto 3088 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3089 assert(Proto && "Functions without a prototype cannot be overloaded"); 3090 assert(!Function->getDescribedFunctionTemplate() && 3091 "Use AddTemplateOverloadCandidate for function templates"); 3092 3093 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3094 if (!isa<CXXConstructorDecl>(Method)) { 3095 // If we get here, it's because we're calling a member function 3096 // that is named without a member access expression (e.g., 3097 // "this->f") that was either written explicitly or created 3098 // implicitly. This can happen with a qualified call to a member 3099 // function, e.g., X::f(). We use an empty type for the implied 3100 // object argument (C++ [over.call.func]p3), and the acting context 3101 // is irrelevant. 3102 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3103 QualType(), Args, NumArgs, CandidateSet, 3104 SuppressUserConversions); 3105 return; 3106 } 3107 // We treat a constructor like a non-member function, since its object 3108 // argument doesn't participate in overload resolution. 3109 } 3110 3111 if (!CandidateSet.isNewCandidate(Function)) 3112 return; 3113 3114 // Overload resolution is always an unevaluated context. 3115 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3116 3117 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3118 // C++ [class.copy]p3: 3119 // A member function template is never instantiated to perform the copy 3120 // of a class object to an object of its class type. 3121 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3122 if (NumArgs == 1 && 3123 Constructor->isCopyConstructorLikeSpecialization() && 3124 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3125 IsDerivedFrom(Args[0]->getType(), ClassType))) 3126 return; 3127 } 3128 3129 // Add this candidate 3130 CandidateSet.push_back(OverloadCandidate()); 3131 OverloadCandidate& Candidate = CandidateSet.back(); 3132 Candidate.FoundDecl = FoundDecl; 3133 Candidate.Function = Function; 3134 Candidate.Viable = true; 3135 Candidate.IsSurrogate = false; 3136 Candidate.IgnoreObjectArgument = false; 3137 3138 unsigned NumArgsInProto = Proto->getNumArgs(); 3139 3140 // (C++ 13.3.2p2): A candidate function having fewer than m 3141 // parameters is viable only if it has an ellipsis in its parameter 3142 // list (8.3.5). 3143 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3144 !Proto->isVariadic()) { 3145 Candidate.Viable = false; 3146 Candidate.FailureKind = ovl_fail_too_many_arguments; 3147 return; 3148 } 3149 3150 // (C++ 13.3.2p2): A candidate function having more than m parameters 3151 // is viable only if the (m+1)st parameter has a default argument 3152 // (8.3.6). For the purposes of overload resolution, the 3153 // parameter list is truncated on the right, so that there are 3154 // exactly m parameters. 3155 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3156 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3157 // Not enough arguments. 3158 Candidate.Viable = false; 3159 Candidate.FailureKind = ovl_fail_too_few_arguments; 3160 return; 3161 } 3162 3163 // Determine the implicit conversion sequences for each of the 3164 // arguments. 3165 Candidate.Conversions.resize(NumArgs); 3166 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3167 if (ArgIdx < NumArgsInProto) { 3168 // (C++ 13.3.2p3): for F to be a viable function, there shall 3169 // exist for each argument an implicit conversion sequence 3170 // (13.3.3.1) that converts that argument to the corresponding 3171 // parameter of F. 3172 QualType ParamType = Proto->getArgType(ArgIdx); 3173 Candidate.Conversions[ArgIdx] 3174 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3175 SuppressUserConversions, 3176 /*InOverloadResolution=*/true); 3177 if (Candidate.Conversions[ArgIdx].isBad()) { 3178 Candidate.Viable = false; 3179 Candidate.FailureKind = ovl_fail_bad_conversion; 3180 break; 3181 } 3182 } else { 3183 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3184 // argument for which there is no corresponding parameter is 3185 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3186 Candidate.Conversions[ArgIdx].setEllipsis(); 3187 } 3188 } 3189} 3190 3191/// \brief Add all of the function declarations in the given function set to 3192/// the overload canddiate set. 3193void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3194 Expr **Args, unsigned NumArgs, 3195 OverloadCandidateSet& CandidateSet, 3196 bool SuppressUserConversions) { 3197 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3198 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3199 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3200 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3201 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3202 cast<CXXMethodDecl>(FD)->getParent(), 3203 Args[0]->getType(), Args + 1, NumArgs - 1, 3204 CandidateSet, SuppressUserConversions); 3205 else 3206 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3207 SuppressUserConversions); 3208 } else { 3209 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3210 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3211 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3212 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3213 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3214 /*FIXME: explicit args */ 0, 3215 Args[0]->getType(), Args + 1, NumArgs - 1, 3216 CandidateSet, 3217 SuppressUserConversions); 3218 else 3219 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3220 /*FIXME: explicit args */ 0, 3221 Args, NumArgs, CandidateSet, 3222 SuppressUserConversions); 3223 } 3224 } 3225} 3226 3227/// AddMethodCandidate - Adds a named decl (which is some kind of 3228/// method) as a method candidate to the given overload set. 3229void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3230 QualType ObjectType, 3231 Expr **Args, unsigned NumArgs, 3232 OverloadCandidateSet& CandidateSet, 3233 bool SuppressUserConversions) { 3234 NamedDecl *Decl = FoundDecl.getDecl(); 3235 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3236 3237 if (isa<UsingShadowDecl>(Decl)) 3238 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3239 3240 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3241 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3242 "Expected a member function template"); 3243 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3244 /*ExplicitArgs*/ 0, 3245 ObjectType, Args, NumArgs, 3246 CandidateSet, 3247 SuppressUserConversions); 3248 } else { 3249 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3250 ObjectType, Args, NumArgs, 3251 CandidateSet, SuppressUserConversions); 3252 } 3253} 3254 3255/// AddMethodCandidate - Adds the given C++ member function to the set 3256/// of candidate functions, using the given function call arguments 3257/// and the object argument (@c Object). For example, in a call 3258/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3259/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3260/// allow user-defined conversions via constructors or conversion 3261/// operators. 3262void 3263Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3264 CXXRecordDecl *ActingContext, QualType ObjectType, 3265 Expr **Args, unsigned NumArgs, 3266 OverloadCandidateSet& CandidateSet, 3267 bool SuppressUserConversions) { 3268 const FunctionProtoType* Proto 3269 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3270 assert(Proto && "Methods without a prototype cannot be overloaded"); 3271 assert(!isa<CXXConstructorDecl>(Method) && 3272 "Use AddOverloadCandidate for constructors"); 3273 3274 if (!CandidateSet.isNewCandidate(Method)) 3275 return; 3276 3277 // Overload resolution is always an unevaluated context. 3278 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3279 3280 // Add this candidate 3281 CandidateSet.push_back(OverloadCandidate()); 3282 OverloadCandidate& Candidate = CandidateSet.back(); 3283 Candidate.FoundDecl = FoundDecl; 3284 Candidate.Function = Method; 3285 Candidate.IsSurrogate = false; 3286 Candidate.IgnoreObjectArgument = false; 3287 3288 unsigned NumArgsInProto = Proto->getNumArgs(); 3289 3290 // (C++ 13.3.2p2): A candidate function having fewer than m 3291 // parameters is viable only if it has an ellipsis in its parameter 3292 // list (8.3.5). 3293 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3294 Candidate.Viable = false; 3295 Candidate.FailureKind = ovl_fail_too_many_arguments; 3296 return; 3297 } 3298 3299 // (C++ 13.3.2p2): A candidate function having more than m parameters 3300 // is viable only if the (m+1)st parameter has a default argument 3301 // (8.3.6). For the purposes of overload resolution, the 3302 // parameter list is truncated on the right, so that there are 3303 // exactly m parameters. 3304 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3305 if (NumArgs < MinRequiredArgs) { 3306 // Not enough arguments. 3307 Candidate.Viable = false; 3308 Candidate.FailureKind = ovl_fail_too_few_arguments; 3309 return; 3310 } 3311 3312 Candidate.Viable = true; 3313 Candidate.Conversions.resize(NumArgs + 1); 3314 3315 if (Method->isStatic() || ObjectType.isNull()) 3316 // The implicit object argument is ignored. 3317 Candidate.IgnoreObjectArgument = true; 3318 else { 3319 // Determine the implicit conversion sequence for the object 3320 // parameter. 3321 Candidate.Conversions[0] 3322 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 3323 if (Candidate.Conversions[0].isBad()) { 3324 Candidate.Viable = false; 3325 Candidate.FailureKind = ovl_fail_bad_conversion; 3326 return; 3327 } 3328 } 3329 3330 // Determine the implicit conversion sequences for each of the 3331 // arguments. 3332 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3333 if (ArgIdx < NumArgsInProto) { 3334 // (C++ 13.3.2p3): for F to be a viable function, there shall 3335 // exist for each argument an implicit conversion sequence 3336 // (13.3.3.1) that converts that argument to the corresponding 3337 // parameter of F. 3338 QualType ParamType = Proto->getArgType(ArgIdx); 3339 Candidate.Conversions[ArgIdx + 1] 3340 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3341 SuppressUserConversions, 3342 /*InOverloadResolution=*/true); 3343 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3344 Candidate.Viable = false; 3345 Candidate.FailureKind = ovl_fail_bad_conversion; 3346 break; 3347 } 3348 } else { 3349 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3350 // argument for which there is no corresponding parameter is 3351 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3352 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3353 } 3354 } 3355} 3356 3357/// \brief Add a C++ member function template as a candidate to the candidate 3358/// set, using template argument deduction to produce an appropriate member 3359/// function template specialization. 3360void 3361Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3362 DeclAccessPair FoundDecl, 3363 CXXRecordDecl *ActingContext, 3364 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3365 QualType ObjectType, 3366 Expr **Args, unsigned NumArgs, 3367 OverloadCandidateSet& CandidateSet, 3368 bool SuppressUserConversions) { 3369 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3370 return; 3371 3372 // C++ [over.match.funcs]p7: 3373 // In each case where a candidate is a function template, candidate 3374 // function template specializations are generated using template argument 3375 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3376 // candidate functions in the usual way.113) A given name can refer to one 3377 // or more function templates and also to a set of overloaded non-template 3378 // functions. In such a case, the candidate functions generated from each 3379 // function template are combined with the set of non-template candidate 3380 // functions. 3381 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3382 FunctionDecl *Specialization = 0; 3383 if (TemplateDeductionResult Result 3384 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3385 Args, NumArgs, Specialization, Info)) { 3386 CandidateSet.push_back(OverloadCandidate()); 3387 OverloadCandidate &Candidate = CandidateSet.back(); 3388 Candidate.FoundDecl = FoundDecl; 3389 Candidate.Function = MethodTmpl->getTemplatedDecl(); 3390 Candidate.Viable = false; 3391 Candidate.FailureKind = ovl_fail_bad_deduction; 3392 Candidate.IsSurrogate = false; 3393 Candidate.IgnoreObjectArgument = false; 3394 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3395 Info); 3396 return; 3397 } 3398 3399 // Add the function template specialization produced by template argument 3400 // deduction as a candidate. 3401 assert(Specialization && "Missing member function template specialization?"); 3402 assert(isa<CXXMethodDecl>(Specialization) && 3403 "Specialization is not a member function?"); 3404 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3405 ActingContext, ObjectType, Args, NumArgs, 3406 CandidateSet, SuppressUserConversions); 3407} 3408 3409/// \brief Add a C++ function template specialization as a candidate 3410/// in the candidate set, using template argument deduction to produce 3411/// an appropriate function template specialization. 3412void 3413Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3414 DeclAccessPair FoundDecl, 3415 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3416 Expr **Args, unsigned NumArgs, 3417 OverloadCandidateSet& CandidateSet, 3418 bool SuppressUserConversions) { 3419 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3420 return; 3421 3422 // C++ [over.match.funcs]p7: 3423 // In each case where a candidate is a function template, candidate 3424 // function template specializations are generated using template argument 3425 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3426 // candidate functions in the usual way.113) A given name can refer to one 3427 // or more function templates and also to a set of overloaded non-template 3428 // functions. In such a case, the candidate functions generated from each 3429 // function template are combined with the set of non-template candidate 3430 // functions. 3431 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3432 FunctionDecl *Specialization = 0; 3433 if (TemplateDeductionResult Result 3434 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3435 Args, NumArgs, Specialization, Info)) { 3436 CandidateSet.push_back(OverloadCandidate()); 3437 OverloadCandidate &Candidate = CandidateSet.back(); 3438 Candidate.FoundDecl = FoundDecl; 3439 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3440 Candidate.Viable = false; 3441 Candidate.FailureKind = ovl_fail_bad_deduction; 3442 Candidate.IsSurrogate = false; 3443 Candidate.IgnoreObjectArgument = false; 3444 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3445 Info); 3446 return; 3447 } 3448 3449 // Add the function template specialization produced by template argument 3450 // deduction as a candidate. 3451 assert(Specialization && "Missing function template specialization?"); 3452 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3453 SuppressUserConversions); 3454} 3455 3456/// AddConversionCandidate - Add a C++ conversion function as a 3457/// candidate in the candidate set (C++ [over.match.conv], 3458/// C++ [over.match.copy]). From is the expression we're converting from, 3459/// and ToType is the type that we're eventually trying to convert to 3460/// (which may or may not be the same type as the type that the 3461/// conversion function produces). 3462void 3463Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3464 DeclAccessPair FoundDecl, 3465 CXXRecordDecl *ActingContext, 3466 Expr *From, QualType ToType, 3467 OverloadCandidateSet& CandidateSet) { 3468 assert(!Conversion->getDescribedFunctionTemplate() && 3469 "Conversion function templates use AddTemplateConversionCandidate"); 3470 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3471 if (!CandidateSet.isNewCandidate(Conversion)) 3472 return; 3473 3474 // Overload resolution is always an unevaluated context. 3475 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3476 3477 // Add this candidate 3478 CandidateSet.push_back(OverloadCandidate()); 3479 OverloadCandidate& Candidate = CandidateSet.back(); 3480 Candidate.FoundDecl = FoundDecl; 3481 Candidate.Function = Conversion; 3482 Candidate.IsSurrogate = false; 3483 Candidate.IgnoreObjectArgument = false; 3484 Candidate.FinalConversion.setAsIdentityConversion(); 3485 Candidate.FinalConversion.setFromType(ConvType); 3486 Candidate.FinalConversion.setAllToTypes(ToType); 3487 3488 // Determine the implicit conversion sequence for the implicit 3489 // object parameter. 3490 Candidate.Viable = true; 3491 Candidate.Conversions.resize(1); 3492 Candidate.Conversions[0] 3493 = TryObjectArgumentInitialization(From->getType(), Conversion, 3494 ActingContext); 3495 // Conversion functions to a different type in the base class is visible in 3496 // the derived class. So, a derived to base conversion should not participate 3497 // in overload resolution. 3498 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3499 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3500 if (Candidate.Conversions[0].isBad()) { 3501 Candidate.Viable = false; 3502 Candidate.FailureKind = ovl_fail_bad_conversion; 3503 return; 3504 } 3505 3506 // We won't go through a user-define type conversion function to convert a 3507 // derived to base as such conversions are given Conversion Rank. They only 3508 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3509 QualType FromCanon 3510 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3511 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3512 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3513 Candidate.Viable = false; 3514 Candidate.FailureKind = ovl_fail_trivial_conversion; 3515 return; 3516 } 3517 3518 // To determine what the conversion from the result of calling the 3519 // conversion function to the type we're eventually trying to 3520 // convert to (ToType), we need to synthesize a call to the 3521 // conversion function and attempt copy initialization from it. This 3522 // makes sure that we get the right semantics with respect to 3523 // lvalues/rvalues and the type. Fortunately, we can allocate this 3524 // call on the stack and we don't need its arguments to be 3525 // well-formed. 3526 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3527 From->getLocStart()); 3528 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 3529 CastExpr::CK_FunctionToPointerDecay, 3530 &ConversionRef, CXXBaseSpecifierArray(), false); 3531 3532 // Note that it is safe to allocate CallExpr on the stack here because 3533 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3534 // allocator). 3535 CallExpr Call(Context, &ConversionFn, 0, 0, 3536 Conversion->getConversionType().getNonReferenceType(), 3537 From->getLocStart()); 3538 ImplicitConversionSequence ICS = 3539 TryCopyInitialization(*this, &Call, ToType, 3540 /*SuppressUserConversions=*/true, 3541 /*InOverloadResolution=*/false); 3542 3543 switch (ICS.getKind()) { 3544 case ImplicitConversionSequence::StandardConversion: 3545 Candidate.FinalConversion = ICS.Standard; 3546 3547 // C++ [over.ics.user]p3: 3548 // If the user-defined conversion is specified by a specialization of a 3549 // conversion function template, the second standard conversion sequence 3550 // shall have exact match rank. 3551 if (Conversion->getPrimaryTemplate() && 3552 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3553 Candidate.Viable = false; 3554 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3555 } 3556 3557 break; 3558 3559 case ImplicitConversionSequence::BadConversion: 3560 Candidate.Viable = false; 3561 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3562 break; 3563 3564 default: 3565 assert(false && 3566 "Can only end up with a standard conversion sequence or failure"); 3567 } 3568} 3569 3570/// \brief Adds a conversion function template specialization 3571/// candidate to the overload set, using template argument deduction 3572/// to deduce the template arguments of the conversion function 3573/// template from the type that we are converting to (C++ 3574/// [temp.deduct.conv]). 3575void 3576Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3577 DeclAccessPair FoundDecl, 3578 CXXRecordDecl *ActingDC, 3579 Expr *From, QualType ToType, 3580 OverloadCandidateSet &CandidateSet) { 3581 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3582 "Only conversion function templates permitted here"); 3583 3584 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3585 return; 3586 3587 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3588 CXXConversionDecl *Specialization = 0; 3589 if (TemplateDeductionResult Result 3590 = DeduceTemplateArguments(FunctionTemplate, ToType, 3591 Specialization, Info)) { 3592 CandidateSet.push_back(OverloadCandidate()); 3593 OverloadCandidate &Candidate = CandidateSet.back(); 3594 Candidate.FoundDecl = FoundDecl; 3595 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3596 Candidate.Viable = false; 3597 Candidate.FailureKind = ovl_fail_bad_deduction; 3598 Candidate.IsSurrogate = false; 3599 Candidate.IgnoreObjectArgument = false; 3600 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3601 Info); 3602 return; 3603 } 3604 3605 // Add the conversion function template specialization produced by 3606 // template argument deduction as a candidate. 3607 assert(Specialization && "Missing function template specialization?"); 3608 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3609 CandidateSet); 3610} 3611 3612/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3613/// converts the given @c Object to a function pointer via the 3614/// conversion function @c Conversion, and then attempts to call it 3615/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3616/// the type of function that we'll eventually be calling. 3617void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3618 DeclAccessPair FoundDecl, 3619 CXXRecordDecl *ActingContext, 3620 const FunctionProtoType *Proto, 3621 QualType ObjectType, 3622 Expr **Args, unsigned NumArgs, 3623 OverloadCandidateSet& CandidateSet) { 3624 if (!CandidateSet.isNewCandidate(Conversion)) 3625 return; 3626 3627 // Overload resolution is always an unevaluated context. 3628 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3629 3630 CandidateSet.push_back(OverloadCandidate()); 3631 OverloadCandidate& Candidate = CandidateSet.back(); 3632 Candidate.FoundDecl = FoundDecl; 3633 Candidate.Function = 0; 3634 Candidate.Surrogate = Conversion; 3635 Candidate.Viable = true; 3636 Candidate.IsSurrogate = true; 3637 Candidate.IgnoreObjectArgument = false; 3638 Candidate.Conversions.resize(NumArgs + 1); 3639 3640 // Determine the implicit conversion sequence for the implicit 3641 // object parameter. 3642 ImplicitConversionSequence ObjectInit 3643 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3644 if (ObjectInit.isBad()) { 3645 Candidate.Viable = false; 3646 Candidate.FailureKind = ovl_fail_bad_conversion; 3647 Candidate.Conversions[0] = ObjectInit; 3648 return; 3649 } 3650 3651 // The first conversion is actually a user-defined conversion whose 3652 // first conversion is ObjectInit's standard conversion (which is 3653 // effectively a reference binding). Record it as such. 3654 Candidate.Conversions[0].setUserDefined(); 3655 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3656 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3657 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3658 Candidate.Conversions[0].UserDefined.After 3659 = Candidate.Conversions[0].UserDefined.Before; 3660 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3661 3662 // Find the 3663 unsigned NumArgsInProto = Proto->getNumArgs(); 3664 3665 // (C++ 13.3.2p2): A candidate function having fewer than m 3666 // parameters is viable only if it has an ellipsis in its parameter 3667 // list (8.3.5). 3668 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3669 Candidate.Viable = false; 3670 Candidate.FailureKind = ovl_fail_too_many_arguments; 3671 return; 3672 } 3673 3674 // Function types don't have any default arguments, so just check if 3675 // we have enough arguments. 3676 if (NumArgs < NumArgsInProto) { 3677 // Not enough arguments. 3678 Candidate.Viable = false; 3679 Candidate.FailureKind = ovl_fail_too_few_arguments; 3680 return; 3681 } 3682 3683 // Determine the implicit conversion sequences for each of the 3684 // arguments. 3685 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3686 if (ArgIdx < NumArgsInProto) { 3687 // (C++ 13.3.2p3): for F to be a viable function, there shall 3688 // exist for each argument an implicit conversion sequence 3689 // (13.3.3.1) that converts that argument to the corresponding 3690 // parameter of F. 3691 QualType ParamType = Proto->getArgType(ArgIdx); 3692 Candidate.Conversions[ArgIdx + 1] 3693 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3694 /*SuppressUserConversions=*/false, 3695 /*InOverloadResolution=*/false); 3696 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3697 Candidate.Viable = false; 3698 Candidate.FailureKind = ovl_fail_bad_conversion; 3699 break; 3700 } 3701 } else { 3702 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3703 // argument for which there is no corresponding parameter is 3704 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3705 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3706 } 3707 } 3708} 3709 3710/// \brief Add overload candidates for overloaded operators that are 3711/// member functions. 3712/// 3713/// Add the overloaded operator candidates that are member functions 3714/// for the operator Op that was used in an operator expression such 3715/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3716/// CandidateSet will store the added overload candidates. (C++ 3717/// [over.match.oper]). 3718void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3719 SourceLocation OpLoc, 3720 Expr **Args, unsigned NumArgs, 3721 OverloadCandidateSet& CandidateSet, 3722 SourceRange OpRange) { 3723 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3724 3725 // C++ [over.match.oper]p3: 3726 // For a unary operator @ with an operand of a type whose 3727 // cv-unqualified version is T1, and for a binary operator @ with 3728 // a left operand of a type whose cv-unqualified version is T1 and 3729 // a right operand of a type whose cv-unqualified version is T2, 3730 // three sets of candidate functions, designated member 3731 // candidates, non-member candidates and built-in candidates, are 3732 // constructed as follows: 3733 QualType T1 = Args[0]->getType(); 3734 QualType T2; 3735 if (NumArgs > 1) 3736 T2 = Args[1]->getType(); 3737 3738 // -- If T1 is a class type, the set of member candidates is the 3739 // result of the qualified lookup of T1::operator@ 3740 // (13.3.1.1.1); otherwise, the set of member candidates is 3741 // empty. 3742 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3743 // Complete the type if it can be completed. Otherwise, we're done. 3744 if (RequireCompleteType(OpLoc, T1, PDiag())) 3745 return; 3746 3747 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3748 LookupQualifiedName(Operators, T1Rec->getDecl()); 3749 Operators.suppressDiagnostics(); 3750 3751 for (LookupResult::iterator Oper = Operators.begin(), 3752 OperEnd = Operators.end(); 3753 Oper != OperEnd; 3754 ++Oper) 3755 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3756 Args + 1, NumArgs - 1, CandidateSet, 3757 /* SuppressUserConversions = */ false); 3758 } 3759} 3760 3761/// AddBuiltinCandidate - Add a candidate for a built-in 3762/// operator. ResultTy and ParamTys are the result and parameter types 3763/// of the built-in candidate, respectively. Args and NumArgs are the 3764/// arguments being passed to the candidate. IsAssignmentOperator 3765/// should be true when this built-in candidate is an assignment 3766/// operator. NumContextualBoolArguments is the number of arguments 3767/// (at the beginning of the argument list) that will be contextually 3768/// converted to bool. 3769void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3770 Expr **Args, unsigned NumArgs, 3771 OverloadCandidateSet& CandidateSet, 3772 bool IsAssignmentOperator, 3773 unsigned NumContextualBoolArguments) { 3774 // Overload resolution is always an unevaluated context. 3775 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3776 3777 // Add this candidate 3778 CandidateSet.push_back(OverloadCandidate()); 3779 OverloadCandidate& Candidate = CandidateSet.back(); 3780 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3781 Candidate.Function = 0; 3782 Candidate.IsSurrogate = false; 3783 Candidate.IgnoreObjectArgument = false; 3784 Candidate.BuiltinTypes.ResultTy = ResultTy; 3785 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3786 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3787 3788 // Determine the implicit conversion sequences for each of the 3789 // arguments. 3790 Candidate.Viable = true; 3791 Candidate.Conversions.resize(NumArgs); 3792 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3793 // C++ [over.match.oper]p4: 3794 // For the built-in assignment operators, conversions of the 3795 // left operand are restricted as follows: 3796 // -- no temporaries are introduced to hold the left operand, and 3797 // -- no user-defined conversions are applied to the left 3798 // operand to achieve a type match with the left-most 3799 // parameter of a built-in candidate. 3800 // 3801 // We block these conversions by turning off user-defined 3802 // conversions, since that is the only way that initialization of 3803 // a reference to a non-class type can occur from something that 3804 // is not of the same type. 3805 if (ArgIdx < NumContextualBoolArguments) { 3806 assert(ParamTys[ArgIdx] == Context.BoolTy && 3807 "Contextual conversion to bool requires bool type"); 3808 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 3809 } else { 3810 Candidate.Conversions[ArgIdx] 3811 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 3812 ArgIdx == 0 && IsAssignmentOperator, 3813 /*InOverloadResolution=*/false); 3814 } 3815 if (Candidate.Conversions[ArgIdx].isBad()) { 3816 Candidate.Viable = false; 3817 Candidate.FailureKind = ovl_fail_bad_conversion; 3818 break; 3819 } 3820 } 3821} 3822 3823/// BuiltinCandidateTypeSet - A set of types that will be used for the 3824/// candidate operator functions for built-in operators (C++ 3825/// [over.built]). The types are separated into pointer types and 3826/// enumeration types. 3827class BuiltinCandidateTypeSet { 3828 /// TypeSet - A set of types. 3829 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 3830 3831 /// PointerTypes - The set of pointer types that will be used in the 3832 /// built-in candidates. 3833 TypeSet PointerTypes; 3834 3835 /// MemberPointerTypes - The set of member pointer types that will be 3836 /// used in the built-in candidates. 3837 TypeSet MemberPointerTypes; 3838 3839 /// EnumerationTypes - The set of enumeration types that will be 3840 /// used in the built-in candidates. 3841 TypeSet EnumerationTypes; 3842 3843 /// \brief The set of vector types that will be used in the built-in 3844 /// candidates. 3845 TypeSet VectorTypes; 3846 3847 /// Sema - The semantic analysis instance where we are building the 3848 /// candidate type set. 3849 Sema &SemaRef; 3850 3851 /// Context - The AST context in which we will build the type sets. 3852 ASTContext &Context; 3853 3854 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3855 const Qualifiers &VisibleQuals); 3856 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 3857 3858public: 3859 /// iterator - Iterates through the types that are part of the set. 3860 typedef TypeSet::iterator iterator; 3861 3862 BuiltinCandidateTypeSet(Sema &SemaRef) 3863 : SemaRef(SemaRef), Context(SemaRef.Context) { } 3864 3865 void AddTypesConvertedFrom(QualType Ty, 3866 SourceLocation Loc, 3867 bool AllowUserConversions, 3868 bool AllowExplicitConversions, 3869 const Qualifiers &VisibleTypeConversionsQuals); 3870 3871 /// pointer_begin - First pointer type found; 3872 iterator pointer_begin() { return PointerTypes.begin(); } 3873 3874 /// pointer_end - Past the last pointer type found; 3875 iterator pointer_end() { return PointerTypes.end(); } 3876 3877 /// member_pointer_begin - First member pointer type found; 3878 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 3879 3880 /// member_pointer_end - Past the last member pointer type found; 3881 iterator member_pointer_end() { return MemberPointerTypes.end(); } 3882 3883 /// enumeration_begin - First enumeration type found; 3884 iterator enumeration_begin() { return EnumerationTypes.begin(); } 3885 3886 /// enumeration_end - Past the last enumeration type found; 3887 iterator enumeration_end() { return EnumerationTypes.end(); } 3888 3889 iterator vector_begin() { return VectorTypes.begin(); } 3890 iterator vector_end() { return VectorTypes.end(); } 3891}; 3892 3893/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 3894/// the set of pointer types along with any more-qualified variants of 3895/// that type. For example, if @p Ty is "int const *", this routine 3896/// will add "int const *", "int const volatile *", "int const 3897/// restrict *", and "int const volatile restrict *" to the set of 3898/// pointer types. Returns true if the add of @p Ty itself succeeded, 3899/// false otherwise. 3900/// 3901/// FIXME: what to do about extended qualifiers? 3902bool 3903BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 3904 const Qualifiers &VisibleQuals) { 3905 3906 // Insert this type. 3907 if (!PointerTypes.insert(Ty)) 3908 return false; 3909 3910 const PointerType *PointerTy = Ty->getAs<PointerType>(); 3911 assert(PointerTy && "type was not a pointer type!"); 3912 3913 QualType PointeeTy = PointerTy->getPointeeType(); 3914 // Don't add qualified variants of arrays. For one, they're not allowed 3915 // (the qualifier would sink to the element type), and for another, the 3916 // only overload situation where it matters is subscript or pointer +- int, 3917 // and those shouldn't have qualifier variants anyway. 3918 if (PointeeTy->isArrayType()) 3919 return true; 3920 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3921 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 3922 BaseCVR = Array->getElementType().getCVRQualifiers(); 3923 bool hasVolatile = VisibleQuals.hasVolatile(); 3924 bool hasRestrict = VisibleQuals.hasRestrict(); 3925 3926 // Iterate through all strict supersets of BaseCVR. 3927 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3928 if ((CVR | BaseCVR) != CVR) continue; 3929 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 3930 // in the types. 3931 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 3932 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 3933 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3934 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 3935 } 3936 3937 return true; 3938} 3939 3940/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 3941/// to the set of pointer types along with any more-qualified variants of 3942/// that type. For example, if @p Ty is "int const *", this routine 3943/// will add "int const *", "int const volatile *", "int const 3944/// restrict *", and "int const volatile restrict *" to the set of 3945/// pointer types. Returns true if the add of @p Ty itself succeeded, 3946/// false otherwise. 3947/// 3948/// FIXME: what to do about extended qualifiers? 3949bool 3950BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 3951 QualType Ty) { 3952 // Insert this type. 3953 if (!MemberPointerTypes.insert(Ty)) 3954 return false; 3955 3956 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 3957 assert(PointerTy && "type was not a member pointer type!"); 3958 3959 QualType PointeeTy = PointerTy->getPointeeType(); 3960 // Don't add qualified variants of arrays. For one, they're not allowed 3961 // (the qualifier would sink to the element type), and for another, the 3962 // only overload situation where it matters is subscript or pointer +- int, 3963 // and those shouldn't have qualifier variants anyway. 3964 if (PointeeTy->isArrayType()) 3965 return true; 3966 const Type *ClassTy = PointerTy->getClass(); 3967 3968 // Iterate through all strict supersets of the pointee type's CVR 3969 // qualifiers. 3970 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 3971 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 3972 if ((CVR | BaseCVR) != CVR) continue; 3973 3974 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 3975 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 3976 } 3977 3978 return true; 3979} 3980 3981/// AddTypesConvertedFrom - Add each of the types to which the type @p 3982/// Ty can be implicit converted to the given set of @p Types. We're 3983/// primarily interested in pointer types and enumeration types. We also 3984/// take member pointer types, for the conditional operator. 3985/// AllowUserConversions is true if we should look at the conversion 3986/// functions of a class type, and AllowExplicitConversions if we 3987/// should also include the explicit conversion functions of a class 3988/// type. 3989void 3990BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 3991 SourceLocation Loc, 3992 bool AllowUserConversions, 3993 bool AllowExplicitConversions, 3994 const Qualifiers &VisibleQuals) { 3995 // Only deal with canonical types. 3996 Ty = Context.getCanonicalType(Ty); 3997 3998 // Look through reference types; they aren't part of the type of an 3999 // expression for the purposes of conversions. 4000 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4001 Ty = RefTy->getPointeeType(); 4002 4003 // We don't care about qualifiers on the type. 4004 Ty = Ty.getLocalUnqualifiedType(); 4005 4006 // If we're dealing with an array type, decay to the pointer. 4007 if (Ty->isArrayType()) 4008 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4009 4010 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 4011 QualType PointeeTy = PointerTy->getPointeeType(); 4012 4013 // Insert our type, and its more-qualified variants, into the set 4014 // of types. 4015 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4016 return; 4017 } else if (Ty->isMemberPointerType()) { 4018 // Member pointers are far easier, since the pointee can't be converted. 4019 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4020 return; 4021 } else if (Ty->isEnumeralType()) { 4022 EnumerationTypes.insert(Ty); 4023 } else if (Ty->isVectorType()) { 4024 VectorTypes.insert(Ty); 4025 } else if (AllowUserConversions) { 4026 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 4027 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 4028 // No conversion functions in incomplete types. 4029 return; 4030 } 4031 4032 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4033 const UnresolvedSetImpl *Conversions 4034 = ClassDecl->getVisibleConversionFunctions(); 4035 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4036 E = Conversions->end(); I != E; ++I) { 4037 NamedDecl *D = I.getDecl(); 4038 if (isa<UsingShadowDecl>(D)) 4039 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4040 4041 // Skip conversion function templates; they don't tell us anything 4042 // about which builtin types we can convert to. 4043 if (isa<FunctionTemplateDecl>(D)) 4044 continue; 4045 4046 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4047 if (AllowExplicitConversions || !Conv->isExplicit()) { 4048 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4049 VisibleQuals); 4050 } 4051 } 4052 } 4053 } 4054} 4055 4056/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4057/// the volatile- and non-volatile-qualified assignment operators for the 4058/// given type to the candidate set. 4059static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4060 QualType T, 4061 Expr **Args, 4062 unsigned NumArgs, 4063 OverloadCandidateSet &CandidateSet) { 4064 QualType ParamTypes[2]; 4065 4066 // T& operator=(T&, T) 4067 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4068 ParamTypes[1] = T; 4069 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4070 /*IsAssignmentOperator=*/true); 4071 4072 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4073 // volatile T& operator=(volatile T&, T) 4074 ParamTypes[0] 4075 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4076 ParamTypes[1] = T; 4077 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4078 /*IsAssignmentOperator=*/true); 4079 } 4080} 4081 4082/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4083/// if any, found in visible type conversion functions found in ArgExpr's type. 4084static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4085 Qualifiers VRQuals; 4086 const RecordType *TyRec; 4087 if (const MemberPointerType *RHSMPType = 4088 ArgExpr->getType()->getAs<MemberPointerType>()) 4089 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4090 else 4091 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4092 if (!TyRec) { 4093 // Just to be safe, assume the worst case. 4094 VRQuals.addVolatile(); 4095 VRQuals.addRestrict(); 4096 return VRQuals; 4097 } 4098 4099 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4100 if (!ClassDecl->hasDefinition()) 4101 return VRQuals; 4102 4103 const UnresolvedSetImpl *Conversions = 4104 ClassDecl->getVisibleConversionFunctions(); 4105 4106 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4107 E = Conversions->end(); I != E; ++I) { 4108 NamedDecl *D = I.getDecl(); 4109 if (isa<UsingShadowDecl>(D)) 4110 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4111 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4112 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4113 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4114 CanTy = ResTypeRef->getPointeeType(); 4115 // Need to go down the pointer/mempointer chain and add qualifiers 4116 // as see them. 4117 bool done = false; 4118 while (!done) { 4119 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4120 CanTy = ResTypePtr->getPointeeType(); 4121 else if (const MemberPointerType *ResTypeMPtr = 4122 CanTy->getAs<MemberPointerType>()) 4123 CanTy = ResTypeMPtr->getPointeeType(); 4124 else 4125 done = true; 4126 if (CanTy.isVolatileQualified()) 4127 VRQuals.addVolatile(); 4128 if (CanTy.isRestrictQualified()) 4129 VRQuals.addRestrict(); 4130 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4131 return VRQuals; 4132 } 4133 } 4134 } 4135 return VRQuals; 4136} 4137 4138/// AddBuiltinOperatorCandidates - Add the appropriate built-in 4139/// operator overloads to the candidate set (C++ [over.built]), based 4140/// on the operator @p Op and the arguments given. For example, if the 4141/// operator is a binary '+', this routine might add "int 4142/// operator+(int, int)" to cover integer addition. 4143void 4144Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 4145 SourceLocation OpLoc, 4146 Expr **Args, unsigned NumArgs, 4147 OverloadCandidateSet& CandidateSet) { 4148 // The set of "promoted arithmetic types", which are the arithmetic 4149 // types are that preserved by promotion (C++ [over.built]p2). Note 4150 // that the first few of these types are the promoted integral 4151 // types; these types need to be first. 4152 // FIXME: What about complex? 4153 const unsigned FirstIntegralType = 0; 4154 const unsigned LastIntegralType = 13; 4155 const unsigned FirstPromotedIntegralType = 7, 4156 LastPromotedIntegralType = 13; 4157 const unsigned FirstPromotedArithmeticType = 7, 4158 LastPromotedArithmeticType = 16; 4159 const unsigned NumArithmeticTypes = 16; 4160 QualType ArithmeticTypes[NumArithmeticTypes] = { 4161 Context.BoolTy, Context.CharTy, Context.WCharTy, 4162// FIXME: Context.Char16Ty, Context.Char32Ty, 4163 Context.SignedCharTy, Context.ShortTy, 4164 Context.UnsignedCharTy, Context.UnsignedShortTy, 4165 Context.IntTy, Context.LongTy, Context.LongLongTy, 4166 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 4167 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 4168 }; 4169 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 4170 "Invalid first promoted integral type"); 4171 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 4172 == Context.UnsignedLongLongTy && 4173 "Invalid last promoted integral type"); 4174 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 4175 "Invalid first promoted arithmetic type"); 4176 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 4177 == Context.LongDoubleTy && 4178 "Invalid last promoted arithmetic type"); 4179 4180 // Find all of the types that the arguments can convert to, but only 4181 // if the operator we're looking at has built-in operator candidates 4182 // that make use of these types. 4183 Qualifiers VisibleTypeConversionsQuals; 4184 VisibleTypeConversionsQuals.addConst(); 4185 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4186 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 4187 4188 BuiltinCandidateTypeSet CandidateTypes(*this); 4189 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4190 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 4191 OpLoc, 4192 true, 4193 (Op == OO_Exclaim || 4194 Op == OO_AmpAmp || 4195 Op == OO_PipePipe), 4196 VisibleTypeConversionsQuals); 4197 4198 bool isComparison = false; 4199 switch (Op) { 4200 case OO_None: 4201 case NUM_OVERLOADED_OPERATORS: 4202 assert(false && "Expected an overloaded operator"); 4203 break; 4204 4205 case OO_Star: // '*' is either unary or binary 4206 if (NumArgs == 1) 4207 goto UnaryStar; 4208 else 4209 goto BinaryStar; 4210 break; 4211 4212 case OO_Plus: // '+' is either unary or binary 4213 if (NumArgs == 1) 4214 goto UnaryPlus; 4215 else 4216 goto BinaryPlus; 4217 break; 4218 4219 case OO_Minus: // '-' is either unary or binary 4220 if (NumArgs == 1) 4221 goto UnaryMinus; 4222 else 4223 goto BinaryMinus; 4224 break; 4225 4226 case OO_Amp: // '&' is either unary or binary 4227 if (NumArgs == 1) 4228 goto UnaryAmp; 4229 else 4230 goto BinaryAmp; 4231 4232 case OO_PlusPlus: 4233 case OO_MinusMinus: 4234 // C++ [over.built]p3: 4235 // 4236 // For every pair (T, VQ), where T is an arithmetic type, and VQ 4237 // is either volatile or empty, there exist candidate operator 4238 // functions of the form 4239 // 4240 // VQ T& operator++(VQ T&); 4241 // T operator++(VQ T&, int); 4242 // 4243 // C++ [over.built]p4: 4244 // 4245 // For every pair (T, VQ), where T is an arithmetic type other 4246 // than bool, and VQ is either volatile or empty, there exist 4247 // candidate operator functions of the form 4248 // 4249 // VQ T& operator--(VQ T&); 4250 // T operator--(VQ T&, int); 4251 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 4252 Arith < NumArithmeticTypes; ++Arith) { 4253 QualType ArithTy = ArithmeticTypes[Arith]; 4254 QualType ParamTypes[2] 4255 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 4256 4257 // Non-volatile version. 4258 if (NumArgs == 1) 4259 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4260 else 4261 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4262 // heuristic to reduce number of builtin candidates in the set. 4263 // Add volatile version only if there are conversions to a volatile type. 4264 if (VisibleTypeConversionsQuals.hasVolatile()) { 4265 // Volatile version 4266 ParamTypes[0] 4267 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 4268 if (NumArgs == 1) 4269 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4270 else 4271 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4272 } 4273 } 4274 4275 // C++ [over.built]p5: 4276 // 4277 // For every pair (T, VQ), where T is a cv-qualified or 4278 // cv-unqualified object type, and VQ is either volatile or 4279 // empty, there exist candidate operator functions of the form 4280 // 4281 // T*VQ& operator++(T*VQ&); 4282 // T*VQ& operator--(T*VQ&); 4283 // T* operator++(T*VQ&, int); 4284 // T* operator--(T*VQ&, int); 4285 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4286 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4287 // Skip pointer types that aren't pointers to object types. 4288 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 4289 continue; 4290 4291 QualType ParamTypes[2] = { 4292 Context.getLValueReferenceType(*Ptr), Context.IntTy 4293 }; 4294 4295 // Without volatile 4296 if (NumArgs == 1) 4297 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4298 else 4299 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4300 4301 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4302 VisibleTypeConversionsQuals.hasVolatile()) { 4303 // With volatile 4304 ParamTypes[0] 4305 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4306 if (NumArgs == 1) 4307 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4308 else 4309 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4310 } 4311 } 4312 break; 4313 4314 UnaryStar: 4315 // C++ [over.built]p6: 4316 // For every cv-qualified or cv-unqualified object type T, there 4317 // exist candidate operator functions of the form 4318 // 4319 // T& operator*(T*); 4320 // 4321 // C++ [over.built]p7: 4322 // For every function type T, there exist candidate operator 4323 // functions of the form 4324 // T& operator*(T*); 4325 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4326 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4327 QualType ParamTy = *Ptr; 4328 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 4329 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 4330 &ParamTy, Args, 1, CandidateSet); 4331 } 4332 break; 4333 4334 UnaryPlus: 4335 // C++ [over.built]p8: 4336 // For every type T, there exist candidate operator functions of 4337 // the form 4338 // 4339 // T* operator+(T*); 4340 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4341 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4342 QualType ParamTy = *Ptr; 4343 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4344 } 4345 4346 // Fall through 4347 4348 UnaryMinus: 4349 // C++ [over.built]p9: 4350 // For every promoted arithmetic type T, there exist candidate 4351 // operator functions of the form 4352 // 4353 // T operator+(T); 4354 // T operator-(T); 4355 for (unsigned Arith = FirstPromotedArithmeticType; 4356 Arith < LastPromotedArithmeticType; ++Arith) { 4357 QualType ArithTy = ArithmeticTypes[Arith]; 4358 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4359 } 4360 4361 // Extension: We also add these operators for vector types. 4362 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4363 VecEnd = CandidateTypes.vector_end(); 4364 Vec != VecEnd; ++Vec) { 4365 QualType VecTy = *Vec; 4366 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4367 } 4368 break; 4369 4370 case OO_Tilde: 4371 // C++ [over.built]p10: 4372 // For every promoted integral type T, there exist candidate 4373 // operator functions of the form 4374 // 4375 // T operator~(T); 4376 for (unsigned Int = FirstPromotedIntegralType; 4377 Int < LastPromotedIntegralType; ++Int) { 4378 QualType IntTy = ArithmeticTypes[Int]; 4379 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4380 } 4381 4382 // Extension: We also add this operator for vector types. 4383 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4384 VecEnd = CandidateTypes.vector_end(); 4385 Vec != VecEnd; ++Vec) { 4386 QualType VecTy = *Vec; 4387 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4388 } 4389 break; 4390 4391 case OO_New: 4392 case OO_Delete: 4393 case OO_Array_New: 4394 case OO_Array_Delete: 4395 case OO_Call: 4396 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 4397 break; 4398 4399 case OO_Comma: 4400 UnaryAmp: 4401 case OO_Arrow: 4402 // C++ [over.match.oper]p3: 4403 // -- For the operator ',', the unary operator '&', or the 4404 // operator '->', the built-in candidates set is empty. 4405 break; 4406 4407 case OO_EqualEqual: 4408 case OO_ExclaimEqual: 4409 // C++ [over.match.oper]p16: 4410 // For every pointer to member type T, there exist candidate operator 4411 // functions of the form 4412 // 4413 // bool operator==(T,T); 4414 // bool operator!=(T,T); 4415 for (BuiltinCandidateTypeSet::iterator 4416 MemPtr = CandidateTypes.member_pointer_begin(), 4417 MemPtrEnd = CandidateTypes.member_pointer_end(); 4418 MemPtr != MemPtrEnd; 4419 ++MemPtr) { 4420 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4421 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4422 } 4423 4424 // Fall through 4425 4426 case OO_Less: 4427 case OO_Greater: 4428 case OO_LessEqual: 4429 case OO_GreaterEqual: 4430 // C++ [over.built]p15: 4431 // 4432 // For every pointer or enumeration type T, there exist 4433 // candidate operator functions of the form 4434 // 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 // bool operator!=(T, T); 4441 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4442 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4443 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4444 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4445 } 4446 for (BuiltinCandidateTypeSet::iterator Enum 4447 = CandidateTypes.enumeration_begin(); 4448 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4449 QualType ParamTypes[2] = { *Enum, *Enum }; 4450 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4451 } 4452 4453 // Fall through. 4454 isComparison = true; 4455 4456 BinaryPlus: 4457 BinaryMinus: 4458 if (!isComparison) { 4459 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4460 4461 // C++ [over.built]p13: 4462 // 4463 // For every cv-qualified or cv-unqualified object type T 4464 // there exist candidate operator functions of the form 4465 // 4466 // T* operator+(T*, ptrdiff_t); 4467 // T& operator[](T*, ptrdiff_t); [BELOW] 4468 // T* operator-(T*, ptrdiff_t); 4469 // T* operator+(ptrdiff_t, T*); 4470 // T& operator[](ptrdiff_t, T*); [BELOW] 4471 // 4472 // C++ [over.built]p14: 4473 // 4474 // For every T, where T is a pointer to object type, there 4475 // exist candidate operator functions of the form 4476 // 4477 // ptrdiff_t operator-(T, T); 4478 for (BuiltinCandidateTypeSet::iterator Ptr 4479 = CandidateTypes.pointer_begin(); 4480 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4481 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4482 4483 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4484 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4485 4486 if (Op == OO_Plus) { 4487 // T* operator+(ptrdiff_t, T*); 4488 ParamTypes[0] = ParamTypes[1]; 4489 ParamTypes[1] = *Ptr; 4490 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4491 } else { 4492 // ptrdiff_t operator-(T, T); 4493 ParamTypes[1] = *Ptr; 4494 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4495 Args, 2, CandidateSet); 4496 } 4497 } 4498 } 4499 // Fall through 4500 4501 case OO_Slash: 4502 BinaryStar: 4503 Conditional: 4504 // C++ [over.built]p12: 4505 // 4506 // For every pair of promoted arithmetic types L and R, there 4507 // exist candidate operator functions of the form 4508 // 4509 // LR operator*(L, R); 4510 // LR operator/(L, R); 4511 // LR operator+(L, R); 4512 // LR 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 // bool operator!=(L, R); 4519 // 4520 // where LR is the result of the usual arithmetic conversions 4521 // between types L and R. 4522 // 4523 // C++ [over.built]p24: 4524 // 4525 // For every pair of promoted arithmetic types L and R, there exist 4526 // candidate operator functions of the form 4527 // 4528 // LR operator?(bool, L, R); 4529 // 4530 // where LR is the result of the usual arithmetic conversions 4531 // between types L and R. 4532 // Our candidates ignore the first parameter. 4533 for (unsigned Left = FirstPromotedArithmeticType; 4534 Left < LastPromotedArithmeticType; ++Left) { 4535 for (unsigned Right = FirstPromotedArithmeticType; 4536 Right < LastPromotedArithmeticType; ++Right) { 4537 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4538 QualType Result 4539 = isComparison 4540 ? Context.BoolTy 4541 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4542 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4543 } 4544 } 4545 4546 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 4547 // conditional operator for vector types. 4548 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4549 Vec1End = CandidateTypes.vector_end(); 4550 Vec1 != Vec1End; ++Vec1) 4551 for (BuiltinCandidateTypeSet::iterator 4552 Vec2 = CandidateTypes.vector_begin(), 4553 Vec2End = CandidateTypes.vector_end(); 4554 Vec2 != Vec2End; ++Vec2) { 4555 QualType LandR[2] = { *Vec1, *Vec2 }; 4556 QualType Result; 4557 if (isComparison) 4558 Result = Context.BoolTy; 4559 else { 4560 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 4561 Result = *Vec1; 4562 else 4563 Result = *Vec2; 4564 } 4565 4566 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4567 } 4568 4569 break; 4570 4571 case OO_Percent: 4572 BinaryAmp: 4573 case OO_Caret: 4574 case OO_Pipe: 4575 case OO_LessLess: 4576 case OO_GreaterGreater: 4577 // C++ [over.built]p17: 4578 // 4579 // For every pair of promoted integral types L and R, there 4580 // exist candidate operator functions of the form 4581 // 4582 // LR operator%(L, R); 4583 // LR operator&(L, R); 4584 // LR operator^(L, R); 4585 // LR operator|(L, R); 4586 // L operator<<(L, R); 4587 // L operator>>(L, R); 4588 // 4589 // where LR is the result of the usual arithmetic conversions 4590 // between types L and R. 4591 for (unsigned Left = FirstPromotedIntegralType; 4592 Left < LastPromotedIntegralType; ++Left) { 4593 for (unsigned Right = FirstPromotedIntegralType; 4594 Right < LastPromotedIntegralType; ++Right) { 4595 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4596 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4597 ? LandR[0] 4598 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4599 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4600 } 4601 } 4602 break; 4603 4604 case OO_Equal: 4605 // C++ [over.built]p20: 4606 // 4607 // For every pair (T, VQ), where T is an enumeration or 4608 // pointer to member type and VQ is either volatile or 4609 // empty, there exist candidate operator functions of the form 4610 // 4611 // VQ T& operator=(VQ T&, T); 4612 for (BuiltinCandidateTypeSet::iterator 4613 Enum = CandidateTypes.enumeration_begin(), 4614 EnumEnd = CandidateTypes.enumeration_end(); 4615 Enum != EnumEnd; ++Enum) 4616 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4617 CandidateSet); 4618 for (BuiltinCandidateTypeSet::iterator 4619 MemPtr = CandidateTypes.member_pointer_begin(), 4620 MemPtrEnd = CandidateTypes.member_pointer_end(); 4621 MemPtr != MemPtrEnd; ++MemPtr) 4622 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4623 CandidateSet); 4624 4625 // Fall through. 4626 4627 case OO_PlusEqual: 4628 case OO_MinusEqual: 4629 // C++ [over.built]p19: 4630 // 4631 // For every pair (T, VQ), where T is any type and VQ is either 4632 // volatile or empty, there exist candidate operator functions 4633 // of the form 4634 // 4635 // T*VQ& operator=(T*VQ&, T*); 4636 // 4637 // C++ [over.built]p21: 4638 // 4639 // For every pair (T, VQ), where T is a cv-qualified or 4640 // cv-unqualified object type and VQ is either volatile or 4641 // empty, there exist candidate operator functions of the form 4642 // 4643 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4644 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4645 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4646 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4647 QualType ParamTypes[2]; 4648 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4649 4650 // non-volatile version 4651 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4652 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4653 /*IsAssigmentOperator=*/Op == OO_Equal); 4654 4655 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4656 VisibleTypeConversionsQuals.hasVolatile()) { 4657 // volatile version 4658 ParamTypes[0] 4659 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4660 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4661 /*IsAssigmentOperator=*/Op == OO_Equal); 4662 } 4663 } 4664 // Fall through. 4665 4666 case OO_StarEqual: 4667 case OO_SlashEqual: 4668 // C++ [over.built]p18: 4669 // 4670 // For every triple (L, VQ, R), where L is an arithmetic type, 4671 // VQ is either volatile or empty, and R is a promoted 4672 // arithmetic type, there exist candidate operator functions of 4673 // the form 4674 // 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 // VQ L& operator-=(VQ L&, R); 4680 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4681 for (unsigned Right = FirstPromotedArithmeticType; 4682 Right < LastPromotedArithmeticType; ++Right) { 4683 QualType ParamTypes[2]; 4684 ParamTypes[1] = ArithmeticTypes[Right]; 4685 4686 // Add this built-in operator as a candidate (VQ is empty). 4687 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4688 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4689 /*IsAssigmentOperator=*/Op == OO_Equal); 4690 4691 // Add this built-in operator as a candidate (VQ is 'volatile'). 4692 if (VisibleTypeConversionsQuals.hasVolatile()) { 4693 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4694 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4695 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4696 /*IsAssigmentOperator=*/Op == OO_Equal); 4697 } 4698 } 4699 } 4700 4701 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 4702 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4703 Vec1End = CandidateTypes.vector_end(); 4704 Vec1 != Vec1End; ++Vec1) 4705 for (BuiltinCandidateTypeSet::iterator 4706 Vec2 = CandidateTypes.vector_begin(), 4707 Vec2End = CandidateTypes.vector_end(); 4708 Vec2 != Vec2End; ++Vec2) { 4709 QualType ParamTypes[2]; 4710 ParamTypes[1] = *Vec2; 4711 // Add this built-in operator as a candidate (VQ is empty). 4712 ParamTypes[0] = Context.getLValueReferenceType(*Vec1); 4713 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4714 /*IsAssigmentOperator=*/Op == OO_Equal); 4715 4716 // Add this built-in operator as a candidate (VQ is 'volatile'). 4717 if (VisibleTypeConversionsQuals.hasVolatile()) { 4718 ParamTypes[0] = Context.getVolatileType(*Vec1); 4719 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4720 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4721 /*IsAssigmentOperator=*/Op == OO_Equal); 4722 } 4723 } 4724 break; 4725 4726 case OO_PercentEqual: 4727 case OO_LessLessEqual: 4728 case OO_GreaterGreaterEqual: 4729 case OO_AmpEqual: 4730 case OO_CaretEqual: 4731 case OO_PipeEqual: 4732 // C++ [over.built]p22: 4733 // 4734 // For every triple (L, VQ, R), where L is an integral type, VQ 4735 // is either volatile or empty, and R is a promoted integral 4736 // type, there exist candidate operator functions of the form 4737 // 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 // VQ L& operator|=(VQ L&, R); 4744 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4745 for (unsigned Right = FirstPromotedIntegralType; 4746 Right < LastPromotedIntegralType; ++Right) { 4747 QualType ParamTypes[2]; 4748 ParamTypes[1] = ArithmeticTypes[Right]; 4749 4750 // Add this built-in operator as a candidate (VQ is empty). 4751 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4752 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4753 if (VisibleTypeConversionsQuals.hasVolatile()) { 4754 // Add this built-in operator as a candidate (VQ is 'volatile'). 4755 ParamTypes[0] = ArithmeticTypes[Left]; 4756 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4757 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4758 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4759 } 4760 } 4761 } 4762 break; 4763 4764 case OO_Exclaim: { 4765 // C++ [over.operator]p23: 4766 // 4767 // There also exist candidate operator functions of the form 4768 // 4769 // bool operator!(bool); 4770 // bool operator&&(bool, bool); [BELOW] 4771 // bool operator||(bool, bool); [BELOW] 4772 QualType ParamTy = Context.BoolTy; 4773 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4774 /*IsAssignmentOperator=*/false, 4775 /*NumContextualBoolArguments=*/1); 4776 break; 4777 } 4778 4779 case OO_AmpAmp: 4780 case OO_PipePipe: { 4781 // C++ [over.operator]p23: 4782 // 4783 // There also exist candidate operator functions of the form 4784 // 4785 // bool operator!(bool); [ABOVE] 4786 // bool operator&&(bool, bool); 4787 // bool operator||(bool, bool); 4788 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4789 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4790 /*IsAssignmentOperator=*/false, 4791 /*NumContextualBoolArguments=*/2); 4792 break; 4793 } 4794 4795 case OO_Subscript: 4796 // C++ [over.built]p13: 4797 // 4798 // For every cv-qualified or cv-unqualified object type T there 4799 // exist candidate operator functions of the form 4800 // 4801 // T* operator+(T*, ptrdiff_t); [ABOVE] 4802 // T& operator[](T*, ptrdiff_t); 4803 // T* operator-(T*, ptrdiff_t); [ABOVE] 4804 // T* operator+(ptrdiff_t, T*); [ABOVE] 4805 // T& operator[](ptrdiff_t, T*); 4806 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4807 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4808 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4809 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 4810 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 4811 4812 // T& operator[](T*, ptrdiff_t) 4813 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4814 4815 // T& operator[](ptrdiff_t, T*); 4816 ParamTypes[0] = ParamTypes[1]; 4817 ParamTypes[1] = *Ptr; 4818 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4819 } 4820 break; 4821 4822 case OO_ArrowStar: 4823 // C++ [over.built]p11: 4824 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 4825 // C1 is the same type as C2 or is a derived class of C2, T is an object 4826 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 4827 // there exist candidate operator functions of the form 4828 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 4829 // where CV12 is the union of CV1 and CV2. 4830 { 4831 for (BuiltinCandidateTypeSet::iterator Ptr = 4832 CandidateTypes.pointer_begin(); 4833 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4834 QualType C1Ty = (*Ptr); 4835 QualType C1; 4836 QualifierCollector Q1; 4837 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 4838 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 4839 if (!isa<RecordType>(C1)) 4840 continue; 4841 // heuristic to reduce number of builtin candidates in the set. 4842 // Add volatile/restrict version only if there are conversions to a 4843 // volatile/restrict type. 4844 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 4845 continue; 4846 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 4847 continue; 4848 } 4849 for (BuiltinCandidateTypeSet::iterator 4850 MemPtr = CandidateTypes.member_pointer_begin(), 4851 MemPtrEnd = CandidateTypes.member_pointer_end(); 4852 MemPtr != MemPtrEnd; ++MemPtr) { 4853 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 4854 QualType C2 = QualType(mptr->getClass(), 0); 4855 C2 = C2.getUnqualifiedType(); 4856 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 4857 break; 4858 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 4859 // build CV12 T& 4860 QualType T = mptr->getPointeeType(); 4861 if (!VisibleTypeConversionsQuals.hasVolatile() && 4862 T.isVolatileQualified()) 4863 continue; 4864 if (!VisibleTypeConversionsQuals.hasRestrict() && 4865 T.isRestrictQualified()) 4866 continue; 4867 T = Q1.apply(T); 4868 QualType ResultTy = Context.getLValueReferenceType(T); 4869 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 4870 } 4871 } 4872 } 4873 break; 4874 4875 case OO_Conditional: 4876 // Note that we don't consider the first argument, since it has been 4877 // contextually converted to bool long ago. The candidates below are 4878 // therefore added as binary. 4879 // 4880 // C++ [over.built]p24: 4881 // For every type T, where T is a pointer or pointer-to-member type, 4882 // there exist candidate operator functions of the form 4883 // 4884 // T operator?(bool, T, T); 4885 // 4886 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 4887 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 4888 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4889 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4890 } 4891 for (BuiltinCandidateTypeSet::iterator Ptr = 4892 CandidateTypes.member_pointer_begin(), 4893 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 4894 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4895 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4896 } 4897 goto Conditional; 4898 } 4899} 4900 4901/// \brief Add function candidates found via argument-dependent lookup 4902/// to the set of overloading candidates. 4903/// 4904/// This routine performs argument-dependent name lookup based on the 4905/// given function name (which may also be an operator name) and adds 4906/// all of the overload candidates found by ADL to the overload 4907/// candidate set (C++ [basic.lookup.argdep]). 4908void 4909Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 4910 bool Operator, 4911 Expr **Args, unsigned NumArgs, 4912 const TemplateArgumentListInfo *ExplicitTemplateArgs, 4913 OverloadCandidateSet& CandidateSet, 4914 bool PartialOverloading) { 4915 ADLResult Fns; 4916 4917 // FIXME: This approach for uniquing ADL results (and removing 4918 // redundant candidates from the set) relies on pointer-equality, 4919 // which means we need to key off the canonical decl. However, 4920 // always going back to the canonical decl might not get us the 4921 // right set of default arguments. What default arguments are 4922 // we supposed to consider on ADL candidates, anyway? 4923 4924 // FIXME: Pass in the explicit template arguments? 4925 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 4926 4927 // Erase all of the candidates we already knew about. 4928 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 4929 CandEnd = CandidateSet.end(); 4930 Cand != CandEnd; ++Cand) 4931 if (Cand->Function) { 4932 Fns.erase(Cand->Function); 4933 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 4934 Fns.erase(FunTmpl); 4935 } 4936 4937 // For each of the ADL candidates we found, add it to the overload 4938 // set. 4939 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 4940 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 4941 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 4942 if (ExplicitTemplateArgs) 4943 continue; 4944 4945 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 4946 false, PartialOverloading); 4947 } else 4948 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 4949 FoundDecl, ExplicitTemplateArgs, 4950 Args, NumArgs, CandidateSet); 4951 } 4952} 4953 4954/// isBetterOverloadCandidate - Determines whether the first overload 4955/// candidate is a better candidate than the second (C++ 13.3.3p1). 4956bool 4957Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 4958 const OverloadCandidate& Cand2, 4959 SourceLocation Loc) { 4960 // Define viable functions to be better candidates than non-viable 4961 // functions. 4962 if (!Cand2.Viable) 4963 return Cand1.Viable; 4964 else if (!Cand1.Viable) 4965 return false; 4966 4967 // C++ [over.match.best]p1: 4968 // 4969 // -- if F is a static member function, ICS1(F) is defined such 4970 // that ICS1(F) is neither better nor worse than ICS1(G) for 4971 // any function G, and, symmetrically, ICS1(G) is neither 4972 // better nor worse than ICS1(F). 4973 unsigned StartArg = 0; 4974 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 4975 StartArg = 1; 4976 4977 // C++ [over.match.best]p1: 4978 // A viable function F1 is defined to be a better function than another 4979 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 4980 // conversion sequence than ICSi(F2), and then... 4981 unsigned NumArgs = Cand1.Conversions.size(); 4982 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 4983 bool HasBetterConversion = false; 4984 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 4985 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 4986 Cand2.Conversions[ArgIdx])) { 4987 case ImplicitConversionSequence::Better: 4988 // Cand1 has a better conversion sequence. 4989 HasBetterConversion = true; 4990 break; 4991 4992 case ImplicitConversionSequence::Worse: 4993 // Cand1 can't be better than Cand2. 4994 return false; 4995 4996 case ImplicitConversionSequence::Indistinguishable: 4997 // Do nothing. 4998 break; 4999 } 5000 } 5001 5002 // -- for some argument j, ICSj(F1) is a better conversion sequence than 5003 // ICSj(F2), or, if not that, 5004 if (HasBetterConversion) 5005 return true; 5006 5007 // - F1 is a non-template function and F2 is a function template 5008 // specialization, or, if not that, 5009 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 5010 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5011 return true; 5012 5013 // -- F1 and F2 are function template specializations, and the function 5014 // template for F1 is more specialized than the template for F2 5015 // according to the partial ordering rules described in 14.5.5.2, or, 5016 // if not that, 5017 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 5018 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5019 if (FunctionTemplateDecl *BetterTemplate 5020 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 5021 Cand2.Function->getPrimaryTemplate(), 5022 Loc, 5023 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 5024 : TPOC_Call)) 5025 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 5026 5027 // -- the context is an initialization by user-defined conversion 5028 // (see 8.5, 13.3.1.5) and the standard conversion sequence 5029 // from the return type of F1 to the destination type (i.e., 5030 // the type of the entity being initialized) is a better 5031 // conversion sequence than the standard conversion sequence 5032 // from the return type of F2 to the destination type. 5033 if (Cand1.Function && Cand2.Function && 5034 isa<CXXConversionDecl>(Cand1.Function) && 5035 isa<CXXConversionDecl>(Cand2.Function)) { 5036 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 5037 Cand2.FinalConversion)) { 5038 case ImplicitConversionSequence::Better: 5039 // Cand1 has a better conversion sequence. 5040 return true; 5041 5042 case ImplicitConversionSequence::Worse: 5043 // Cand1 can't be better than Cand2. 5044 return false; 5045 5046 case ImplicitConversionSequence::Indistinguishable: 5047 // Do nothing 5048 break; 5049 } 5050 } 5051 5052 return false; 5053} 5054 5055/// \brief Computes the best viable function (C++ 13.3.3) 5056/// within an overload candidate set. 5057/// 5058/// \param CandidateSet the set of candidate functions. 5059/// 5060/// \param Loc the location of the function name (or operator symbol) for 5061/// which overload resolution occurs. 5062/// 5063/// \param Best f overload resolution was successful or found a deleted 5064/// function, Best points to the candidate function found. 5065/// 5066/// \returns The result of overload resolution. 5067OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 5068 SourceLocation Loc, 5069 OverloadCandidateSet::iterator& Best) { 5070 // Find the best viable function. 5071 Best = CandidateSet.end(); 5072 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5073 Cand != CandidateSet.end(); ++Cand) { 5074 if (Cand->Viable) { 5075 if (Best == CandidateSet.end() || 5076 isBetterOverloadCandidate(*Cand, *Best, Loc)) 5077 Best = Cand; 5078 } 5079 } 5080 5081 // If we didn't find any viable functions, abort. 5082 if (Best == CandidateSet.end()) 5083 return OR_No_Viable_Function; 5084 5085 // Make sure that this function is better than every other viable 5086 // function. If not, we have an ambiguity. 5087 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5088 Cand != CandidateSet.end(); ++Cand) { 5089 if (Cand->Viable && 5090 Cand != Best && 5091 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 5092 Best = CandidateSet.end(); 5093 return OR_Ambiguous; 5094 } 5095 } 5096 5097 // Best is the best viable function. 5098 if (Best->Function && 5099 (Best->Function->isDeleted() || 5100 Best->Function->getAttr<UnavailableAttr>())) 5101 return OR_Deleted; 5102 5103 // C++ [basic.def.odr]p2: 5104 // An overloaded function is used if it is selected by overload resolution 5105 // when referred to from a potentially-evaluated expression. [Note: this 5106 // covers calls to named functions (5.2.2), operator overloading 5107 // (clause 13), user-defined conversions (12.3.2), allocation function for 5108 // placement new (5.3.4), as well as non-default initialization (8.5). 5109 if (Best->Function) 5110 MarkDeclarationReferenced(Loc, Best->Function); 5111 return OR_Success; 5112} 5113 5114namespace { 5115 5116enum OverloadCandidateKind { 5117 oc_function, 5118 oc_method, 5119 oc_constructor, 5120 oc_function_template, 5121 oc_method_template, 5122 oc_constructor_template, 5123 oc_implicit_default_constructor, 5124 oc_implicit_copy_constructor, 5125 oc_implicit_copy_assignment 5126}; 5127 5128OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 5129 FunctionDecl *Fn, 5130 std::string &Description) { 5131 bool isTemplate = false; 5132 5133 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 5134 isTemplate = true; 5135 Description = S.getTemplateArgumentBindingsText( 5136 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 5137 } 5138 5139 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 5140 if (!Ctor->isImplicit()) 5141 return isTemplate ? oc_constructor_template : oc_constructor; 5142 5143 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 5144 : oc_implicit_default_constructor; 5145 } 5146 5147 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 5148 // This actually gets spelled 'candidate function' for now, but 5149 // it doesn't hurt to split it out. 5150 if (!Meth->isImplicit()) 5151 return isTemplate ? oc_method_template : oc_method; 5152 5153 assert(Meth->isCopyAssignment() 5154 && "implicit method is not copy assignment operator?"); 5155 return oc_implicit_copy_assignment; 5156 } 5157 5158 return isTemplate ? oc_function_template : oc_function; 5159} 5160 5161} // end anonymous namespace 5162 5163// Notes the location of an overload candidate. 5164void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 5165 std::string FnDesc; 5166 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 5167 Diag(Fn->getLocation(), diag::note_ovl_candidate) 5168 << (unsigned) K << FnDesc; 5169} 5170 5171/// Diagnoses an ambiguous conversion. The partial diagnostic is the 5172/// "lead" diagnostic; it will be given two arguments, the source and 5173/// target types of the conversion. 5174void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 5175 SourceLocation CaretLoc, 5176 const PartialDiagnostic &PDiag) { 5177 Diag(CaretLoc, PDiag) 5178 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 5179 for (AmbiguousConversionSequence::const_iterator 5180 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 5181 NoteOverloadCandidate(*I); 5182 } 5183} 5184 5185namespace { 5186 5187void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 5188 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 5189 assert(Conv.isBad()); 5190 assert(Cand->Function && "for now, candidate must be a function"); 5191 FunctionDecl *Fn = Cand->Function; 5192 5193 // There's a conversion slot for the object argument if this is a 5194 // non-constructor method. Note that 'I' corresponds the 5195 // conversion-slot index. 5196 bool isObjectArgument = false; 5197 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 5198 if (I == 0) 5199 isObjectArgument = true; 5200 else 5201 I--; 5202 } 5203 5204 std::string FnDesc; 5205 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5206 5207 Expr *FromExpr = Conv.Bad.FromExpr; 5208 QualType FromTy = Conv.Bad.getFromType(); 5209 QualType ToTy = Conv.Bad.getToType(); 5210 5211 if (FromTy == S.Context.OverloadTy) { 5212 assert(FromExpr && "overload set argument came from implicit argument?"); 5213 Expr *E = FromExpr->IgnoreParens(); 5214 if (isa<UnaryOperator>(E)) 5215 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 5216 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 5217 5218 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 5219 << (unsigned) FnKind << FnDesc 5220 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5221 << ToTy << Name << I+1; 5222 return; 5223 } 5224 5225 // Do some hand-waving analysis to see if the non-viability is due 5226 // to a qualifier mismatch. 5227 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 5228 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 5229 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 5230 CToTy = RT->getPointeeType(); 5231 else { 5232 // TODO: detect and diagnose the full richness of const mismatches. 5233 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 5234 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 5235 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 5236 } 5237 5238 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 5239 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 5240 // It is dumb that we have to do this here. 5241 while (isa<ArrayType>(CFromTy)) 5242 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 5243 while (isa<ArrayType>(CToTy)) 5244 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 5245 5246 Qualifiers FromQs = CFromTy.getQualifiers(); 5247 Qualifiers ToQs = CToTy.getQualifiers(); 5248 5249 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 5250 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 5251 << (unsigned) FnKind << FnDesc 5252 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5253 << FromTy 5254 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 5255 << (unsigned) isObjectArgument << I+1; 5256 return; 5257 } 5258 5259 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 5260 assert(CVR && "unexpected qualifiers mismatch"); 5261 5262 if (isObjectArgument) { 5263 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 5264 << (unsigned) FnKind << FnDesc 5265 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5266 << FromTy << (CVR - 1); 5267 } else { 5268 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 5269 << (unsigned) FnKind << FnDesc 5270 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5271 << FromTy << (CVR - 1) << I+1; 5272 } 5273 return; 5274 } 5275 5276 // Diagnose references or pointers to incomplete types differently, 5277 // since it's far from impossible that the incompleteness triggered 5278 // the failure. 5279 QualType TempFromTy = FromTy.getNonReferenceType(); 5280 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 5281 TempFromTy = PTy->getPointeeType(); 5282 if (TempFromTy->isIncompleteType()) { 5283 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 5284 << (unsigned) FnKind << FnDesc 5285 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5286 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5287 return; 5288 } 5289 5290 // TODO: specialize more based on the kind of mismatch 5291 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 5292 << (unsigned) FnKind << FnDesc 5293 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5294 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5295} 5296 5297void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 5298 unsigned NumFormalArgs) { 5299 // TODO: treat calls to a missing default constructor as a special case 5300 5301 FunctionDecl *Fn = Cand->Function; 5302 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 5303 5304 unsigned MinParams = Fn->getMinRequiredArguments(); 5305 5306 // at least / at most / exactly 5307 // FIXME: variadic templates "at most" should account for parameter packs 5308 unsigned mode, modeCount; 5309 if (NumFormalArgs < MinParams) { 5310 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 5311 (Cand->FailureKind == ovl_fail_bad_deduction && 5312 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 5313 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 5314 mode = 0; // "at least" 5315 else 5316 mode = 2; // "exactly" 5317 modeCount = MinParams; 5318 } else { 5319 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 5320 (Cand->FailureKind == ovl_fail_bad_deduction && 5321 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 5322 if (MinParams != FnTy->getNumArgs()) 5323 mode = 1; // "at most" 5324 else 5325 mode = 2; // "exactly" 5326 modeCount = FnTy->getNumArgs(); 5327 } 5328 5329 std::string Description; 5330 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 5331 5332 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 5333 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 5334 << modeCount << NumFormalArgs; 5335} 5336 5337/// Diagnose a failed template-argument deduction. 5338void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 5339 Expr **Args, unsigned NumArgs) { 5340 FunctionDecl *Fn = Cand->Function; // pattern 5341 5342 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 5343 NamedDecl *ParamD; 5344 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 5345 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 5346 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 5347 switch (Cand->DeductionFailure.Result) { 5348 case Sema::TDK_Success: 5349 llvm_unreachable("TDK_success while diagnosing bad deduction"); 5350 5351 case Sema::TDK_Incomplete: { 5352 assert(ParamD && "no parameter found for incomplete deduction result"); 5353 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 5354 << ParamD->getDeclName(); 5355 return; 5356 } 5357 5358 case Sema::TDK_Inconsistent: 5359 case Sema::TDK_InconsistentQuals: { 5360 assert(ParamD && "no parameter found for inconsistent deduction result"); 5361 int which = 0; 5362 if (isa<TemplateTypeParmDecl>(ParamD)) 5363 which = 0; 5364 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 5365 which = 1; 5366 else { 5367 which = 2; 5368 } 5369 5370 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 5371 << which << ParamD->getDeclName() 5372 << *Cand->DeductionFailure.getFirstArg() 5373 << *Cand->DeductionFailure.getSecondArg(); 5374 return; 5375 } 5376 5377 case Sema::TDK_InvalidExplicitArguments: 5378 assert(ParamD && "no parameter found for invalid explicit arguments"); 5379 if (ParamD->getDeclName()) 5380 S.Diag(Fn->getLocation(), 5381 diag::note_ovl_candidate_explicit_arg_mismatch_named) 5382 << ParamD->getDeclName(); 5383 else { 5384 int index = 0; 5385 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 5386 index = TTP->getIndex(); 5387 else if (NonTypeTemplateParmDecl *NTTP 5388 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 5389 index = NTTP->getIndex(); 5390 else 5391 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 5392 S.Diag(Fn->getLocation(), 5393 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 5394 << (index + 1); 5395 } 5396 return; 5397 5398 case Sema::TDK_TooManyArguments: 5399 case Sema::TDK_TooFewArguments: 5400 DiagnoseArityMismatch(S, Cand, NumArgs); 5401 return; 5402 5403 case Sema::TDK_InstantiationDepth: 5404 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 5405 return; 5406 5407 case Sema::TDK_SubstitutionFailure: { 5408 std::string ArgString; 5409 if (TemplateArgumentList *Args 5410 = Cand->DeductionFailure.getTemplateArgumentList()) 5411 ArgString = S.getTemplateArgumentBindingsText( 5412 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 5413 *Args); 5414 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 5415 << ArgString; 5416 return; 5417 } 5418 5419 // TODO: diagnose these individually, then kill off 5420 // note_ovl_candidate_bad_deduction, which is uselessly vague. 5421 case Sema::TDK_NonDeducedMismatch: 5422 case Sema::TDK_FailedOverloadResolution: 5423 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 5424 return; 5425 } 5426} 5427 5428/// Generates a 'note' diagnostic for an overload candidate. We've 5429/// already generated a primary error at the call site. 5430/// 5431/// It really does need to be a single diagnostic with its caret 5432/// pointed at the candidate declaration. Yes, this creates some 5433/// major challenges of technical writing. Yes, this makes pointing 5434/// out problems with specific arguments quite awkward. It's still 5435/// better than generating twenty screens of text for every failed 5436/// overload. 5437/// 5438/// It would be great to be able to express per-candidate problems 5439/// more richly for those diagnostic clients that cared, but we'd 5440/// still have to be just as careful with the default diagnostics. 5441void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 5442 Expr **Args, unsigned NumArgs) { 5443 FunctionDecl *Fn = Cand->Function; 5444 5445 // Note deleted candidates, but only if they're viable. 5446 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 5447 std::string FnDesc; 5448 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5449 5450 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 5451 << FnKind << FnDesc << Fn->isDeleted(); 5452 return; 5453 } 5454 5455 // We don't really have anything else to say about viable candidates. 5456 if (Cand->Viable) { 5457 S.NoteOverloadCandidate(Fn); 5458 return; 5459 } 5460 5461 switch (Cand->FailureKind) { 5462 case ovl_fail_too_many_arguments: 5463 case ovl_fail_too_few_arguments: 5464 return DiagnoseArityMismatch(S, Cand, NumArgs); 5465 5466 case ovl_fail_bad_deduction: 5467 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 5468 5469 case ovl_fail_trivial_conversion: 5470 case ovl_fail_bad_final_conversion: 5471 case ovl_fail_final_conversion_not_exact: 5472 return S.NoteOverloadCandidate(Fn); 5473 5474 case ovl_fail_bad_conversion: { 5475 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 5476 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 5477 if (Cand->Conversions[I].isBad()) 5478 return DiagnoseBadConversion(S, Cand, I); 5479 5480 // FIXME: this currently happens when we're called from SemaInit 5481 // when user-conversion overload fails. Figure out how to handle 5482 // those conditions and diagnose them well. 5483 return S.NoteOverloadCandidate(Fn); 5484 } 5485 } 5486} 5487 5488void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 5489 // Desugar the type of the surrogate down to a function type, 5490 // retaining as many typedefs as possible while still showing 5491 // the function type (and, therefore, its parameter types). 5492 QualType FnType = Cand->Surrogate->getConversionType(); 5493 bool isLValueReference = false; 5494 bool isRValueReference = false; 5495 bool isPointer = false; 5496 if (const LValueReferenceType *FnTypeRef = 5497 FnType->getAs<LValueReferenceType>()) { 5498 FnType = FnTypeRef->getPointeeType(); 5499 isLValueReference = true; 5500 } else if (const RValueReferenceType *FnTypeRef = 5501 FnType->getAs<RValueReferenceType>()) { 5502 FnType = FnTypeRef->getPointeeType(); 5503 isRValueReference = true; 5504 } 5505 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 5506 FnType = FnTypePtr->getPointeeType(); 5507 isPointer = true; 5508 } 5509 // Desugar down to a function type. 5510 FnType = QualType(FnType->getAs<FunctionType>(), 0); 5511 // Reconstruct the pointer/reference as appropriate. 5512 if (isPointer) FnType = S.Context.getPointerType(FnType); 5513 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5514 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5515 5516 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5517 << FnType; 5518} 5519 5520void NoteBuiltinOperatorCandidate(Sema &S, 5521 const char *Opc, 5522 SourceLocation OpLoc, 5523 OverloadCandidate *Cand) { 5524 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5525 std::string TypeStr("operator"); 5526 TypeStr += Opc; 5527 TypeStr += "("; 5528 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5529 if (Cand->Conversions.size() == 1) { 5530 TypeStr += ")"; 5531 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5532 } else { 5533 TypeStr += ", "; 5534 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5535 TypeStr += ")"; 5536 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5537 } 5538} 5539 5540void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5541 OverloadCandidate *Cand) { 5542 unsigned NoOperands = Cand->Conversions.size(); 5543 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5544 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5545 if (ICS.isBad()) break; // all meaningless after first invalid 5546 if (!ICS.isAmbiguous()) continue; 5547 5548 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5549 S.PDiag(diag::note_ambiguous_type_conversion)); 5550 } 5551} 5552 5553SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5554 if (Cand->Function) 5555 return Cand->Function->getLocation(); 5556 if (Cand->IsSurrogate) 5557 return Cand->Surrogate->getLocation(); 5558 return SourceLocation(); 5559} 5560 5561struct CompareOverloadCandidatesForDisplay { 5562 Sema &S; 5563 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5564 5565 bool operator()(const OverloadCandidate *L, 5566 const OverloadCandidate *R) { 5567 // Fast-path this check. 5568 if (L == R) return false; 5569 5570 // Order first by viability. 5571 if (L->Viable) { 5572 if (!R->Viable) return true; 5573 5574 // TODO: introduce a tri-valued comparison for overload 5575 // candidates. Would be more worthwhile if we had a sort 5576 // that could exploit it. 5577 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5578 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5579 } else if (R->Viable) 5580 return false; 5581 5582 assert(L->Viable == R->Viable); 5583 5584 // Criteria by which we can sort non-viable candidates: 5585 if (!L->Viable) { 5586 // 1. Arity mismatches come after other candidates. 5587 if (L->FailureKind == ovl_fail_too_many_arguments || 5588 L->FailureKind == ovl_fail_too_few_arguments) 5589 return false; 5590 if (R->FailureKind == ovl_fail_too_many_arguments || 5591 R->FailureKind == ovl_fail_too_few_arguments) 5592 return true; 5593 5594 // 2. Bad conversions come first and are ordered by the number 5595 // of bad conversions and quality of good conversions. 5596 if (L->FailureKind == ovl_fail_bad_conversion) { 5597 if (R->FailureKind != ovl_fail_bad_conversion) 5598 return true; 5599 5600 // If there's any ordering between the defined conversions... 5601 // FIXME: this might not be transitive. 5602 assert(L->Conversions.size() == R->Conversions.size()); 5603 5604 int leftBetter = 0; 5605 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5606 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5607 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5608 R->Conversions[I])) { 5609 case ImplicitConversionSequence::Better: 5610 leftBetter++; 5611 break; 5612 5613 case ImplicitConversionSequence::Worse: 5614 leftBetter--; 5615 break; 5616 5617 case ImplicitConversionSequence::Indistinguishable: 5618 break; 5619 } 5620 } 5621 if (leftBetter > 0) return true; 5622 if (leftBetter < 0) return false; 5623 5624 } else if (R->FailureKind == ovl_fail_bad_conversion) 5625 return false; 5626 5627 // TODO: others? 5628 } 5629 5630 // Sort everything else by location. 5631 SourceLocation LLoc = GetLocationForCandidate(L); 5632 SourceLocation RLoc = GetLocationForCandidate(R); 5633 5634 // Put candidates without locations (e.g. builtins) at the end. 5635 if (LLoc.isInvalid()) return false; 5636 if (RLoc.isInvalid()) return true; 5637 5638 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5639 } 5640}; 5641 5642/// CompleteNonViableCandidate - Normally, overload resolution only 5643/// computes up to the first 5644void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5645 Expr **Args, unsigned NumArgs) { 5646 assert(!Cand->Viable); 5647 5648 // Don't do anything on failures other than bad conversion. 5649 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5650 5651 // Skip forward to the first bad conversion. 5652 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5653 unsigned ConvCount = Cand->Conversions.size(); 5654 while (true) { 5655 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5656 ConvIdx++; 5657 if (Cand->Conversions[ConvIdx - 1].isBad()) 5658 break; 5659 } 5660 5661 if (ConvIdx == ConvCount) 5662 return; 5663 5664 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5665 "remaining conversion is initialized?"); 5666 5667 // FIXME: this should probably be preserved from the overload 5668 // operation somehow. 5669 bool SuppressUserConversions = false; 5670 5671 const FunctionProtoType* Proto; 5672 unsigned ArgIdx = ConvIdx; 5673 5674 if (Cand->IsSurrogate) { 5675 QualType ConvType 5676 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5677 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5678 ConvType = ConvPtrType->getPointeeType(); 5679 Proto = ConvType->getAs<FunctionProtoType>(); 5680 ArgIdx--; 5681 } else if (Cand->Function) { 5682 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5683 if (isa<CXXMethodDecl>(Cand->Function) && 5684 !isa<CXXConstructorDecl>(Cand->Function)) 5685 ArgIdx--; 5686 } else { 5687 // Builtin binary operator with a bad first conversion. 5688 assert(ConvCount <= 3); 5689 for (; ConvIdx != ConvCount; ++ConvIdx) 5690 Cand->Conversions[ConvIdx] 5691 = TryCopyInitialization(S, Args[ConvIdx], 5692 Cand->BuiltinTypes.ParamTypes[ConvIdx], 5693 SuppressUserConversions, 5694 /*InOverloadResolution*/ true); 5695 return; 5696 } 5697 5698 // Fill in the rest of the conversions. 5699 unsigned NumArgsInProto = Proto->getNumArgs(); 5700 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 5701 if (ArgIdx < NumArgsInProto) 5702 Cand->Conversions[ConvIdx] 5703 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 5704 SuppressUserConversions, 5705 /*InOverloadResolution=*/true); 5706 else 5707 Cand->Conversions[ConvIdx].setEllipsis(); 5708 } 5709} 5710 5711} // end anonymous namespace 5712 5713/// PrintOverloadCandidates - When overload resolution fails, prints 5714/// diagnostic messages containing the candidates in the candidate 5715/// set. 5716void 5717Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 5718 OverloadCandidateDisplayKind OCD, 5719 Expr **Args, unsigned NumArgs, 5720 const char *Opc, 5721 SourceLocation OpLoc) { 5722 // Sort the candidates by viability and position. Sorting directly would 5723 // be prohibitive, so we make a set of pointers and sort those. 5724 llvm::SmallVector<OverloadCandidate*, 32> Cands; 5725 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 5726 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5727 LastCand = CandidateSet.end(); 5728 Cand != LastCand; ++Cand) { 5729 if (Cand->Viable) 5730 Cands.push_back(Cand); 5731 else if (OCD == OCD_AllCandidates) { 5732 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 5733 if (Cand->Function || Cand->IsSurrogate) 5734 Cands.push_back(Cand); 5735 // Otherwise, this a non-viable builtin candidate. We do not, in general, 5736 // want to list every possible builtin candidate. 5737 } 5738 } 5739 5740 std::sort(Cands.begin(), Cands.end(), 5741 CompareOverloadCandidatesForDisplay(*this)); 5742 5743 bool ReportedAmbiguousConversions = false; 5744 5745 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 5746 const Diagnostic::OverloadsShown ShowOverloads = Diags.getShowOverloads(); 5747 unsigned CandsShown = 0; 5748 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 5749 OverloadCandidate *Cand = *I; 5750 5751 // Set an arbitrary limit on the number of candidate functions we'll spam 5752 // the user with. FIXME: This limit should depend on details of the 5753 // candidate list. 5754 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 5755 break; 5756 } 5757 ++CandsShown; 5758 5759 if (Cand->Function) 5760 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 5761 else if (Cand->IsSurrogate) 5762 NoteSurrogateCandidate(*this, Cand); 5763 else { 5764 assert(Cand->Viable && 5765 "Non-viable built-in candidates are not added to Cands."); 5766 // Generally we only see ambiguities including viable builtin 5767 // operators if overload resolution got screwed up by an 5768 // ambiguous user-defined conversion. 5769 // 5770 // FIXME: It's quite possible for different conversions to see 5771 // different ambiguities, though. 5772 if (!ReportedAmbiguousConversions) { 5773 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 5774 ReportedAmbiguousConversions = true; 5775 } 5776 5777 // If this is a viable builtin, print it. 5778 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 5779 } 5780 } 5781 5782 if (I != E) 5783 Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 5784} 5785 5786static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 5787 if (isa<UnresolvedLookupExpr>(E)) 5788 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 5789 5790 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 5791} 5792 5793/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 5794/// an overloaded function (C++ [over.over]), where @p From is an 5795/// expression with overloaded function type and @p ToType is the type 5796/// we're trying to resolve to. For example: 5797/// 5798/// @code 5799/// int f(double); 5800/// int f(int); 5801/// 5802/// int (*pfd)(double) = f; // selects f(double) 5803/// @endcode 5804/// 5805/// This routine returns the resulting FunctionDecl if it could be 5806/// resolved, and NULL otherwise. When @p Complain is true, this 5807/// routine will emit diagnostics if there is an error. 5808FunctionDecl * 5809Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 5810 bool Complain, 5811 DeclAccessPair &FoundResult) { 5812 QualType FunctionType = ToType; 5813 bool IsMember = false; 5814 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 5815 FunctionType = ToTypePtr->getPointeeType(); 5816 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 5817 FunctionType = ToTypeRef->getPointeeType(); 5818 else if (const MemberPointerType *MemTypePtr = 5819 ToType->getAs<MemberPointerType>()) { 5820 FunctionType = MemTypePtr->getPointeeType(); 5821 IsMember = true; 5822 } 5823 5824 // C++ [over.over]p1: 5825 // [...] [Note: any redundant set of parentheses surrounding the 5826 // overloaded function name is ignored (5.1). ] 5827 // C++ [over.over]p1: 5828 // [...] The overloaded function name can be preceded by the & 5829 // operator. 5830 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 5831 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 5832 if (OvlExpr->hasExplicitTemplateArgs()) { 5833 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 5834 ExplicitTemplateArgs = &ETABuffer; 5835 } 5836 5837 // We expect a pointer or reference to function, or a function pointer. 5838 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 5839 if (!FunctionType->isFunctionType()) { 5840 if (Complain) 5841 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 5842 << OvlExpr->getName() << ToType; 5843 5844 return 0; 5845 } 5846 5847 assert(From->getType() == Context.OverloadTy); 5848 5849 // Look through all of the overloaded functions, searching for one 5850 // whose type matches exactly. 5851 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 5852 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 5853 5854 bool FoundNonTemplateFunction = false; 5855 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5856 E = OvlExpr->decls_end(); I != E; ++I) { 5857 // Look through any using declarations to find the underlying function. 5858 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 5859 5860 // C++ [over.over]p3: 5861 // Non-member functions and static member functions match 5862 // targets of type "pointer-to-function" or "reference-to-function." 5863 // Nonstatic member functions match targets of 5864 // type "pointer-to-member-function." 5865 // Note that according to DR 247, the containing class does not matter. 5866 5867 if (FunctionTemplateDecl *FunctionTemplate 5868 = dyn_cast<FunctionTemplateDecl>(Fn)) { 5869 if (CXXMethodDecl *Method 5870 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 5871 // Skip non-static function templates when converting to pointer, and 5872 // static when converting to member pointer. 5873 if (Method->isStatic() == IsMember) 5874 continue; 5875 } else if (IsMember) 5876 continue; 5877 5878 // C++ [over.over]p2: 5879 // If the name is a function template, template argument deduction is 5880 // done (14.8.2.2), and if the argument deduction succeeds, the 5881 // resulting template argument list is used to generate a single 5882 // function template specialization, which is added to the set of 5883 // overloaded functions considered. 5884 // FIXME: We don't really want to build the specialization here, do we? 5885 FunctionDecl *Specialization = 0; 5886 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 5887 if (TemplateDeductionResult Result 5888 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 5889 FunctionType, Specialization, Info)) { 5890 // FIXME: make a note of the failed deduction for diagnostics. 5891 (void)Result; 5892 } else { 5893 // FIXME: If the match isn't exact, shouldn't we just drop this as 5894 // a candidate? Find a testcase before changing the code. 5895 assert(FunctionType 5896 == Context.getCanonicalType(Specialization->getType())); 5897 Matches.push_back(std::make_pair(I.getPair(), 5898 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 5899 } 5900 5901 continue; 5902 } 5903 5904 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 5905 // Skip non-static functions when converting to pointer, and static 5906 // when converting to member pointer. 5907 if (Method->isStatic() == IsMember) 5908 continue; 5909 5910 // If we have explicit template arguments, skip non-templates. 5911 if (OvlExpr->hasExplicitTemplateArgs()) 5912 continue; 5913 } else if (IsMember) 5914 continue; 5915 5916 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 5917 QualType ResultTy; 5918 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 5919 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 5920 ResultTy)) { 5921 Matches.push_back(std::make_pair(I.getPair(), 5922 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 5923 FoundNonTemplateFunction = true; 5924 } 5925 } 5926 } 5927 5928 // If there were 0 or 1 matches, we're done. 5929 if (Matches.empty()) { 5930 if (Complain) { 5931 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 5932 << OvlExpr->getName() << FunctionType; 5933 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 5934 E = OvlExpr->decls_end(); 5935 I != E; ++I) 5936 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 5937 NoteOverloadCandidate(F); 5938 } 5939 5940 return 0; 5941 } else if (Matches.size() == 1) { 5942 FunctionDecl *Result = Matches[0].second; 5943 FoundResult = Matches[0].first; 5944 MarkDeclarationReferenced(From->getLocStart(), Result); 5945 if (Complain) 5946 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 5947 return Result; 5948 } 5949 5950 // C++ [over.over]p4: 5951 // If more than one function is selected, [...] 5952 if (!FoundNonTemplateFunction) { 5953 // [...] and any given function template specialization F1 is 5954 // eliminated if the set contains a second function template 5955 // specialization whose function template is more specialized 5956 // than the function template of F1 according to the partial 5957 // ordering rules of 14.5.5.2. 5958 5959 // The algorithm specified above is quadratic. We instead use a 5960 // two-pass algorithm (similar to the one used to identify the 5961 // best viable function in an overload set) that identifies the 5962 // best function template (if it exists). 5963 5964 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 5965 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 5966 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 5967 5968 UnresolvedSetIterator Result = 5969 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 5970 TPOC_Other, From->getLocStart(), 5971 PDiag(), 5972 PDiag(diag::err_addr_ovl_ambiguous) 5973 << Matches[0].second->getDeclName(), 5974 PDiag(diag::note_ovl_candidate) 5975 << (unsigned) oc_function_template); 5976 assert(Result != MatchesCopy.end() && "no most-specialized template"); 5977 MarkDeclarationReferenced(From->getLocStart(), *Result); 5978 FoundResult = Matches[Result - MatchesCopy.begin()].first; 5979 if (Complain) { 5980 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 5981 DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc()); 5982 } 5983 return cast<FunctionDecl>(*Result); 5984 } 5985 5986 // [...] any function template specializations in the set are 5987 // eliminated if the set also contains a non-template function, [...] 5988 for (unsigned I = 0, N = Matches.size(); I != N; ) { 5989 if (Matches[I].second->getPrimaryTemplate() == 0) 5990 ++I; 5991 else { 5992 Matches[I] = Matches[--N]; 5993 Matches.set_size(N); 5994 } 5995 } 5996 5997 // [...] After such eliminations, if any, there shall remain exactly one 5998 // selected function. 5999 if (Matches.size() == 1) { 6000 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 6001 FoundResult = Matches[0].first; 6002 if (Complain) { 6003 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 6004 DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc()); 6005 } 6006 return cast<FunctionDecl>(Matches[0].second); 6007 } 6008 6009 // FIXME: We should probably return the same thing that BestViableFunction 6010 // returns (even if we issue the diagnostics here). 6011 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 6012 << Matches[0].second->getDeclName(); 6013 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6014 NoteOverloadCandidate(Matches[I].second); 6015 return 0; 6016} 6017 6018/// \brief Given an expression that refers to an overloaded function, try to 6019/// resolve that overloaded function expression down to a single function. 6020/// 6021/// This routine can only resolve template-ids that refer to a single function 6022/// template, where that template-id refers to a single template whose template 6023/// arguments are either provided by the template-id or have defaults, 6024/// as described in C++0x [temp.arg.explicit]p3. 6025FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 6026 // C++ [over.over]p1: 6027 // [...] [Note: any redundant set of parentheses surrounding the 6028 // overloaded function name is ignored (5.1). ] 6029 // C++ [over.over]p1: 6030 // [...] The overloaded function name can be preceded by the & 6031 // operator. 6032 6033 if (From->getType() != Context.OverloadTy) 6034 return 0; 6035 6036 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6037 6038 // If we didn't actually find any template-ids, we're done. 6039 if (!OvlExpr->hasExplicitTemplateArgs()) 6040 return 0; 6041 6042 TemplateArgumentListInfo ExplicitTemplateArgs; 6043 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 6044 6045 // Look through all of the overloaded functions, searching for one 6046 // whose type matches exactly. 6047 FunctionDecl *Matched = 0; 6048 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6049 E = OvlExpr->decls_end(); I != E; ++I) { 6050 // C++0x [temp.arg.explicit]p3: 6051 // [...] In contexts where deduction is done and fails, or in contexts 6052 // where deduction is not done, if a template argument list is 6053 // specified and it, along with any default template arguments, 6054 // identifies a single function template specialization, then the 6055 // template-id is an lvalue for the function template specialization. 6056 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 6057 6058 // C++ [over.over]p2: 6059 // If the name is a function template, template argument deduction is 6060 // done (14.8.2.2), and if the argument deduction succeeds, the 6061 // resulting template argument list is used to generate a single 6062 // function template specialization, which is added to the set of 6063 // overloaded functions considered. 6064 FunctionDecl *Specialization = 0; 6065 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6066 if (TemplateDeductionResult Result 6067 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 6068 Specialization, Info)) { 6069 // FIXME: make a note of the failed deduction for diagnostics. 6070 (void)Result; 6071 continue; 6072 } 6073 6074 // Multiple matches; we can't resolve to a single declaration. 6075 if (Matched) 6076 return 0; 6077 6078 Matched = Specialization; 6079 } 6080 6081 return Matched; 6082} 6083 6084/// \brief Add a single candidate to the overload set. 6085static void AddOverloadedCallCandidate(Sema &S, 6086 DeclAccessPair FoundDecl, 6087 const TemplateArgumentListInfo *ExplicitTemplateArgs, 6088 Expr **Args, unsigned NumArgs, 6089 OverloadCandidateSet &CandidateSet, 6090 bool PartialOverloading) { 6091 NamedDecl *Callee = FoundDecl.getDecl(); 6092 if (isa<UsingShadowDecl>(Callee)) 6093 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 6094 6095 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 6096 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 6097 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 6098 false, PartialOverloading); 6099 return; 6100 } 6101 6102 if (FunctionTemplateDecl *FuncTemplate 6103 = dyn_cast<FunctionTemplateDecl>(Callee)) { 6104 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 6105 ExplicitTemplateArgs, 6106 Args, NumArgs, CandidateSet); 6107 return; 6108 } 6109 6110 assert(false && "unhandled case in overloaded call candidate"); 6111 6112 // do nothing? 6113} 6114 6115/// \brief Add the overload candidates named by callee and/or found by argument 6116/// dependent lookup to the given overload set. 6117void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 6118 Expr **Args, unsigned NumArgs, 6119 OverloadCandidateSet &CandidateSet, 6120 bool PartialOverloading) { 6121 6122#ifndef NDEBUG 6123 // Verify that ArgumentDependentLookup is consistent with the rules 6124 // in C++0x [basic.lookup.argdep]p3: 6125 // 6126 // Let X be the lookup set produced by unqualified lookup (3.4.1) 6127 // and let Y be the lookup set produced by argument dependent 6128 // lookup (defined as follows). If X contains 6129 // 6130 // -- a declaration of a class member, or 6131 // 6132 // -- a block-scope function declaration that is not a 6133 // using-declaration, or 6134 // 6135 // -- a declaration that is neither a function or a function 6136 // template 6137 // 6138 // then Y is empty. 6139 6140 if (ULE->requiresADL()) { 6141 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6142 E = ULE->decls_end(); I != E; ++I) { 6143 assert(!(*I)->getDeclContext()->isRecord()); 6144 assert(isa<UsingShadowDecl>(*I) || 6145 !(*I)->getDeclContext()->isFunctionOrMethod()); 6146 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 6147 } 6148 } 6149#endif 6150 6151 // It would be nice to avoid this copy. 6152 TemplateArgumentListInfo TABuffer; 6153 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6154 if (ULE->hasExplicitTemplateArgs()) { 6155 ULE->copyTemplateArgumentsInto(TABuffer); 6156 ExplicitTemplateArgs = &TABuffer; 6157 } 6158 6159 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6160 E = ULE->decls_end(); I != E; ++I) 6161 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 6162 Args, NumArgs, CandidateSet, 6163 PartialOverloading); 6164 6165 if (ULE->requiresADL()) 6166 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 6167 Args, NumArgs, 6168 ExplicitTemplateArgs, 6169 CandidateSet, 6170 PartialOverloading); 6171} 6172 6173static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 6174 Expr **Args, unsigned NumArgs) { 6175 Fn->Destroy(SemaRef.Context); 6176 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 6177 Args[Arg]->Destroy(SemaRef.Context); 6178 return SemaRef.ExprError(); 6179} 6180 6181/// Attempts to recover from a call where no functions were found. 6182/// 6183/// Returns true if new candidates were found. 6184static Sema::OwningExprResult 6185BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 6186 UnresolvedLookupExpr *ULE, 6187 SourceLocation LParenLoc, 6188 Expr **Args, unsigned NumArgs, 6189 SourceLocation *CommaLocs, 6190 SourceLocation RParenLoc) { 6191 6192 CXXScopeSpec SS; 6193 if (ULE->getQualifier()) { 6194 SS.setScopeRep(ULE->getQualifier()); 6195 SS.setRange(ULE->getQualifierRange()); 6196 } 6197 6198 TemplateArgumentListInfo TABuffer; 6199 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6200 if (ULE->hasExplicitTemplateArgs()) { 6201 ULE->copyTemplateArgumentsInto(TABuffer); 6202 ExplicitTemplateArgs = &TABuffer; 6203 } 6204 6205 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 6206 Sema::LookupOrdinaryName); 6207 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 6208 return Destroy(SemaRef, Fn, Args, NumArgs); 6209 6210 assert(!R.empty() && "lookup results empty despite recovery"); 6211 6212 // Build an implicit member call if appropriate. Just drop the 6213 // casts and such from the call, we don't really care. 6214 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 6215 if ((*R.begin())->isCXXClassMember()) 6216 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 6217 else if (ExplicitTemplateArgs) 6218 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 6219 else 6220 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 6221 6222 if (NewFn.isInvalid()) 6223 return Destroy(SemaRef, Fn, Args, NumArgs); 6224 6225 Fn->Destroy(SemaRef.Context); 6226 6227 // This shouldn't cause an infinite loop because we're giving it 6228 // an expression with non-empty lookup results, which should never 6229 // end up here. 6230 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 6231 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 6232 CommaLocs, RParenLoc); 6233} 6234 6235/// ResolveOverloadedCallFn - Given the call expression that calls Fn 6236/// (which eventually refers to the declaration Func) and the call 6237/// arguments Args/NumArgs, attempt to resolve the function call down 6238/// to a specific function. If overload resolution succeeds, returns 6239/// the function declaration produced by overload 6240/// resolution. Otherwise, emits diagnostics, deletes all of the 6241/// arguments and Fn, and returns NULL. 6242Sema::OwningExprResult 6243Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 6244 SourceLocation LParenLoc, 6245 Expr **Args, unsigned NumArgs, 6246 SourceLocation *CommaLocs, 6247 SourceLocation RParenLoc) { 6248#ifndef NDEBUG 6249 if (ULE->requiresADL()) { 6250 // To do ADL, we must have found an unqualified name. 6251 assert(!ULE->getQualifier() && "qualified name with ADL"); 6252 6253 // We don't perform ADL for implicit declarations of builtins. 6254 // Verify that this was correctly set up. 6255 FunctionDecl *F; 6256 if (ULE->decls_begin() + 1 == ULE->decls_end() && 6257 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 6258 F->getBuiltinID() && F->isImplicit()) 6259 assert(0 && "performing ADL for builtin"); 6260 6261 // We don't perform ADL in C. 6262 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 6263 } 6264#endif 6265 6266 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 6267 6268 // Add the functions denoted by the callee to the set of candidate 6269 // functions, including those from argument-dependent lookup. 6270 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 6271 6272 // If we found nothing, try to recover. 6273 // AddRecoveryCallCandidates diagnoses the error itself, so we just 6274 // bailout out if it fails. 6275 if (CandidateSet.empty()) 6276 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 6277 CommaLocs, RParenLoc); 6278 6279 OverloadCandidateSet::iterator Best; 6280 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 6281 case OR_Success: { 6282 FunctionDecl *FDecl = Best->Function; 6283 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 6284 DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc()); 6285 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 6286 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 6287 } 6288 6289 case OR_No_Viable_Function: 6290 Diag(Fn->getSourceRange().getBegin(), 6291 diag::err_ovl_no_viable_function_in_call) 6292 << ULE->getName() << Fn->getSourceRange(); 6293 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6294 break; 6295 6296 case OR_Ambiguous: 6297 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 6298 << ULE->getName() << Fn->getSourceRange(); 6299 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6300 break; 6301 6302 case OR_Deleted: 6303 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 6304 << Best->Function->isDeleted() 6305 << ULE->getName() 6306 << Fn->getSourceRange(); 6307 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6308 break; 6309 } 6310 6311 // Overload resolution failed. Destroy all of the subexpressions and 6312 // return NULL. 6313 Fn->Destroy(Context); 6314 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 6315 Args[Arg]->Destroy(Context); 6316 return ExprError(); 6317} 6318 6319static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 6320 return Functions.size() > 1 || 6321 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 6322} 6323 6324/// \brief Create a unary operation that may resolve to an overloaded 6325/// operator. 6326/// 6327/// \param OpLoc The location of the operator itself (e.g., '*'). 6328/// 6329/// \param OpcIn The UnaryOperator::Opcode that describes this 6330/// operator. 6331/// 6332/// \param Functions The set of non-member functions that will be 6333/// considered by overload resolution. The caller needs to build this 6334/// set based on the context using, e.g., 6335/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6336/// set should not contain any member functions; those will be added 6337/// by CreateOverloadedUnaryOp(). 6338/// 6339/// \param input The input argument. 6340Sema::OwningExprResult 6341Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 6342 const UnresolvedSetImpl &Fns, 6343 ExprArg input) { 6344 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6345 Expr *Input = (Expr *)input.get(); 6346 6347 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 6348 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 6349 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6350 6351 Expr *Args[2] = { Input, 0 }; 6352 unsigned NumArgs = 1; 6353 6354 // For post-increment and post-decrement, add the implicit '0' as 6355 // the second argument, so that we know this is a post-increment or 6356 // post-decrement. 6357 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 6358 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 6359 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 6360 SourceLocation()); 6361 NumArgs = 2; 6362 } 6363 6364 if (Input->isTypeDependent()) { 6365 if (Fns.empty()) 6366 return Owned(new (Context) UnaryOperator(input.takeAs<Expr>(), 6367 Opc, 6368 Context.DependentTy, 6369 OpLoc)); 6370 6371 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6372 UnresolvedLookupExpr *Fn 6373 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6374 0, SourceRange(), OpName, OpLoc, 6375 /*ADL*/ true, IsOverloaded(Fns), 6376 Fns.begin(), Fns.end()); 6377 input.release(); 6378 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6379 &Args[0], NumArgs, 6380 Context.DependentTy, 6381 OpLoc)); 6382 } 6383 6384 // Build an empty overload set. 6385 OverloadCandidateSet CandidateSet(OpLoc); 6386 6387 // Add the candidates from the given function set. 6388 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 6389 6390 // Add operator candidates that are member functions. 6391 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6392 6393 // Add candidates from ADL. 6394 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6395 Args, NumArgs, 6396 /*ExplicitTemplateArgs*/ 0, 6397 CandidateSet); 6398 6399 // Add builtin operator candidates. 6400 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6401 6402 // Perform overload resolution. 6403 OverloadCandidateSet::iterator Best; 6404 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6405 case OR_Success: { 6406 // We found a built-in operator or an overloaded operator. 6407 FunctionDecl *FnDecl = Best->Function; 6408 6409 if (FnDecl) { 6410 // We matched an overloaded operator. Build a call to that 6411 // operator. 6412 6413 // Convert the arguments. 6414 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6415 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 6416 6417 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 6418 Best->FoundDecl, Method)) 6419 return ExprError(); 6420 } else { 6421 // Convert the arguments. 6422 OwningExprResult InputInit 6423 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6424 FnDecl->getParamDecl(0)), 6425 SourceLocation(), 6426 move(input)); 6427 if (InputInit.isInvalid()) 6428 return ExprError(); 6429 6430 input = move(InputInit); 6431 Input = (Expr *)input.get(); 6432 } 6433 6434 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6435 6436 // Determine the result type 6437 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 6438 6439 // Build the actual expression node. 6440 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6441 SourceLocation()); 6442 UsualUnaryConversions(FnExpr); 6443 6444 input.release(); 6445 Args[0] = Input; 6446 ExprOwningPtr<CallExpr> TheCall(this, 6447 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6448 Args, NumArgs, ResultTy, OpLoc)); 6449 6450 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6451 FnDecl)) 6452 return ExprError(); 6453 6454 return MaybeBindToTemporary(TheCall.release()); 6455 } else { 6456 // We matched a built-in operator. Convert the arguments, then 6457 // break out so that we will build the appropriate built-in 6458 // operator node. 6459 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 6460 Best->Conversions[0], AA_Passing)) 6461 return ExprError(); 6462 6463 break; 6464 } 6465 } 6466 6467 case OR_No_Viable_Function: 6468 // No viable function; fall through to handling this as a 6469 // built-in operator, which will produce an error message for us. 6470 break; 6471 6472 case OR_Ambiguous: 6473 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6474 << UnaryOperator::getOpcodeStr(Opc) 6475 << Input->getSourceRange(); 6476 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 6477 UnaryOperator::getOpcodeStr(Opc), OpLoc); 6478 return ExprError(); 6479 6480 case OR_Deleted: 6481 Diag(OpLoc, diag::err_ovl_deleted_oper) 6482 << Best->Function->isDeleted() 6483 << UnaryOperator::getOpcodeStr(Opc) 6484 << Input->getSourceRange(); 6485 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6486 return ExprError(); 6487 } 6488 6489 // Either we found no viable overloaded operator or we matched a 6490 // built-in operator. In either case, fall through to trying to 6491 // build a built-in operation. 6492 input.release(); 6493 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 6494} 6495 6496/// \brief Create a binary operation that may resolve to an overloaded 6497/// operator. 6498/// 6499/// \param OpLoc The location of the operator itself (e.g., '+'). 6500/// 6501/// \param OpcIn The BinaryOperator::Opcode that describes this 6502/// operator. 6503/// 6504/// \param Functions The set of non-member functions that will be 6505/// considered by overload resolution. The caller needs to build this 6506/// set based on the context using, e.g., 6507/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6508/// set should not contain any member functions; those will be added 6509/// by CreateOverloadedBinOp(). 6510/// 6511/// \param LHS Left-hand argument. 6512/// \param RHS Right-hand argument. 6513Sema::OwningExprResult 6514Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 6515 unsigned OpcIn, 6516 const UnresolvedSetImpl &Fns, 6517 Expr *LHS, Expr *RHS) { 6518 Expr *Args[2] = { LHS, RHS }; 6519 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 6520 6521 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 6522 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 6523 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6524 6525 // If either side is type-dependent, create an appropriate dependent 6526 // expression. 6527 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6528 if (Fns.empty()) { 6529 // If there are no functions to store, just build a dependent 6530 // BinaryOperator or CompoundAssignment. 6531 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 6532 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 6533 Context.DependentTy, OpLoc)); 6534 6535 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 6536 Context.DependentTy, 6537 Context.DependentTy, 6538 Context.DependentTy, 6539 OpLoc)); 6540 } 6541 6542 // FIXME: save results of ADL from here? 6543 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6544 UnresolvedLookupExpr *Fn 6545 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6546 0, SourceRange(), OpName, OpLoc, 6547 /*ADL*/ true, IsOverloaded(Fns), 6548 Fns.begin(), Fns.end()); 6549 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6550 Args, 2, 6551 Context.DependentTy, 6552 OpLoc)); 6553 } 6554 6555 // If this is the .* operator, which is not overloadable, just 6556 // create a built-in binary operator. 6557 if (Opc == BinaryOperator::PtrMemD) 6558 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6559 6560 // If this is the assignment operator, we only perform overload resolution 6561 // if the left-hand side is a class or enumeration type. This is actually 6562 // a hack. The standard requires that we do overload resolution between the 6563 // various built-in candidates, but as DR507 points out, this can lead to 6564 // problems. So we do it this way, which pretty much follows what GCC does. 6565 // Note that we go the traditional code path for compound assignment forms. 6566 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6567 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6568 6569 // Build an empty overload set. 6570 OverloadCandidateSet CandidateSet(OpLoc); 6571 6572 // Add the candidates from the given function set. 6573 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6574 6575 // Add operator candidates that are member functions. 6576 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6577 6578 // Add candidates from ADL. 6579 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6580 Args, 2, 6581 /*ExplicitTemplateArgs*/ 0, 6582 CandidateSet); 6583 6584 // Add builtin operator candidates. 6585 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6586 6587 // Perform overload resolution. 6588 OverloadCandidateSet::iterator Best; 6589 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6590 case OR_Success: { 6591 // We found a built-in operator or an overloaded operator. 6592 FunctionDecl *FnDecl = Best->Function; 6593 6594 if (FnDecl) { 6595 // We matched an overloaded operator. Build a call to that 6596 // operator. 6597 6598 // Convert the arguments. 6599 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6600 // Best->Access is only meaningful for class members. 6601 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6602 6603 OwningExprResult Arg1 6604 = PerformCopyInitialization( 6605 InitializedEntity::InitializeParameter( 6606 FnDecl->getParamDecl(0)), 6607 SourceLocation(), 6608 Owned(Args[1])); 6609 if (Arg1.isInvalid()) 6610 return ExprError(); 6611 6612 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6613 Best->FoundDecl, Method)) 6614 return ExprError(); 6615 6616 Args[1] = RHS = Arg1.takeAs<Expr>(); 6617 } else { 6618 // Convert the arguments. 6619 OwningExprResult Arg0 6620 = PerformCopyInitialization( 6621 InitializedEntity::InitializeParameter( 6622 FnDecl->getParamDecl(0)), 6623 SourceLocation(), 6624 Owned(Args[0])); 6625 if (Arg0.isInvalid()) 6626 return ExprError(); 6627 6628 OwningExprResult Arg1 6629 = PerformCopyInitialization( 6630 InitializedEntity::InitializeParameter( 6631 FnDecl->getParamDecl(1)), 6632 SourceLocation(), 6633 Owned(Args[1])); 6634 if (Arg1.isInvalid()) 6635 return ExprError(); 6636 Args[0] = LHS = Arg0.takeAs<Expr>(); 6637 Args[1] = RHS = Arg1.takeAs<Expr>(); 6638 } 6639 6640 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6641 6642 // Determine the result type 6643 QualType ResultTy 6644 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6645 ResultTy = ResultTy.getNonReferenceType(); 6646 6647 // Build the actual expression node. 6648 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6649 OpLoc); 6650 UsualUnaryConversions(FnExpr); 6651 6652 ExprOwningPtr<CXXOperatorCallExpr> 6653 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6654 Args, 2, ResultTy, 6655 OpLoc)); 6656 6657 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6658 FnDecl)) 6659 return ExprError(); 6660 6661 return MaybeBindToTemporary(TheCall.release()); 6662 } else { 6663 // We matched a built-in operator. Convert the arguments, then 6664 // break out so that we will build the appropriate built-in 6665 // operator node. 6666 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6667 Best->Conversions[0], AA_Passing) || 6668 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6669 Best->Conversions[1], AA_Passing)) 6670 return ExprError(); 6671 6672 break; 6673 } 6674 } 6675 6676 case OR_No_Viable_Function: { 6677 // C++ [over.match.oper]p9: 6678 // If the operator is the operator , [...] and there are no 6679 // viable functions, then the operator is assumed to be the 6680 // built-in operator and interpreted according to clause 5. 6681 if (Opc == BinaryOperator::Comma) 6682 break; 6683 6684 // For class as left operand for assignment or compound assigment operator 6685 // do not fall through to handling in built-in, but report that no overloaded 6686 // assignment operator found 6687 OwningExprResult Result = ExprError(); 6688 if (Args[0]->getType()->isRecordType() && 6689 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6690 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6691 << BinaryOperator::getOpcodeStr(Opc) 6692 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6693 } else { 6694 // No viable function; try to create a built-in operation, which will 6695 // produce an error. Then, show the non-viable candidates. 6696 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6697 } 6698 assert(Result.isInvalid() && 6699 "C++ binary operator overloading is missing candidates!"); 6700 if (Result.isInvalid()) 6701 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6702 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6703 return move(Result); 6704 } 6705 6706 case OR_Ambiguous: 6707 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6708 << BinaryOperator::getOpcodeStr(Opc) 6709 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6710 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6711 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6712 return ExprError(); 6713 6714 case OR_Deleted: 6715 Diag(OpLoc, diag::err_ovl_deleted_oper) 6716 << Best->Function->isDeleted() 6717 << BinaryOperator::getOpcodeStr(Opc) 6718 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6719 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 6720 return ExprError(); 6721 } 6722 6723 // We matched a built-in operator; build it. 6724 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6725} 6726 6727Action::OwningExprResult 6728Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 6729 SourceLocation RLoc, 6730 ExprArg Base, ExprArg Idx) { 6731 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 6732 static_cast<Expr*>(Idx.get()) }; 6733 DeclarationName OpName = 6734 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 6735 6736 // If either side is type-dependent, create an appropriate dependent 6737 // expression. 6738 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6739 6740 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6741 UnresolvedLookupExpr *Fn 6742 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6743 0, SourceRange(), OpName, LLoc, 6744 /*ADL*/ true, /*Overloaded*/ false, 6745 UnresolvedSetIterator(), 6746 UnresolvedSetIterator()); 6747 // Can't add any actual overloads yet 6748 6749 Base.release(); 6750 Idx.release(); 6751 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 6752 Args, 2, 6753 Context.DependentTy, 6754 RLoc)); 6755 } 6756 6757 // Build an empty overload set. 6758 OverloadCandidateSet CandidateSet(LLoc); 6759 6760 // Subscript can only be overloaded as a member function. 6761 6762 // Add operator candidates that are member functions. 6763 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6764 6765 // Add builtin operator candidates. 6766 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6767 6768 // Perform overload resolution. 6769 OverloadCandidateSet::iterator Best; 6770 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 6771 case OR_Success: { 6772 // We found a built-in operator or an overloaded operator. 6773 FunctionDecl *FnDecl = Best->Function; 6774 6775 if (FnDecl) { 6776 // We matched an overloaded operator. Build a call to that 6777 // operator. 6778 6779 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 6780 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 6781 6782 // Convert the arguments. 6783 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 6784 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6785 Best->FoundDecl, Method)) 6786 return ExprError(); 6787 6788 // Convert the arguments. 6789 OwningExprResult InputInit 6790 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6791 FnDecl->getParamDecl(0)), 6792 SourceLocation(), 6793 Owned(Args[1])); 6794 if (InputInit.isInvalid()) 6795 return ExprError(); 6796 6797 Args[1] = InputInit.takeAs<Expr>(); 6798 6799 // Determine the result type 6800 QualType ResultTy 6801 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6802 ResultTy = ResultTy.getNonReferenceType(); 6803 6804 // Build the actual expression node. 6805 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6806 LLoc); 6807 UsualUnaryConversions(FnExpr); 6808 6809 Base.release(); 6810 Idx.release(); 6811 ExprOwningPtr<CXXOperatorCallExpr> 6812 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 6813 FnExpr, Args, 2, 6814 ResultTy, RLoc)); 6815 6816 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 6817 FnDecl)) 6818 return ExprError(); 6819 6820 return MaybeBindToTemporary(TheCall.release()); 6821 } else { 6822 // We matched a built-in operator. Convert the arguments, then 6823 // break out so that we will build the appropriate built-in 6824 // operator node. 6825 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6826 Best->Conversions[0], AA_Passing) || 6827 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6828 Best->Conversions[1], AA_Passing)) 6829 return ExprError(); 6830 6831 break; 6832 } 6833 } 6834 6835 case OR_No_Viable_Function: { 6836 if (CandidateSet.empty()) 6837 Diag(LLoc, diag::err_ovl_no_oper) 6838 << Args[0]->getType() << /*subscript*/ 0 6839 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6840 else 6841 Diag(LLoc, diag::err_ovl_no_viable_subscript) 6842 << Args[0]->getType() 6843 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6844 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6845 "[]", LLoc); 6846 return ExprError(); 6847 } 6848 6849 case OR_Ambiguous: 6850 Diag(LLoc, diag::err_ovl_ambiguous_oper) 6851 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6852 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6853 "[]", LLoc); 6854 return ExprError(); 6855 6856 case OR_Deleted: 6857 Diag(LLoc, diag::err_ovl_deleted_oper) 6858 << Best->Function->isDeleted() << "[]" 6859 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6860 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6861 "[]", LLoc); 6862 return ExprError(); 6863 } 6864 6865 // We matched a built-in operator; build it. 6866 Base.release(); 6867 Idx.release(); 6868 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 6869 Owned(Args[1]), RLoc); 6870} 6871 6872/// BuildCallToMemberFunction - Build a call to a member 6873/// function. MemExpr is the expression that refers to the member 6874/// function (and includes the object parameter), Args/NumArgs are the 6875/// arguments to the function call (not including the object 6876/// parameter). The caller needs to validate that the member 6877/// expression refers to a member function or an overloaded member 6878/// function. 6879Sema::OwningExprResult 6880Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 6881 SourceLocation LParenLoc, Expr **Args, 6882 unsigned NumArgs, SourceLocation *CommaLocs, 6883 SourceLocation RParenLoc) { 6884 // Dig out the member expression. This holds both the object 6885 // argument and the member function we're referring to. 6886 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 6887 6888 MemberExpr *MemExpr; 6889 CXXMethodDecl *Method = 0; 6890 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 6891 NestedNameSpecifier *Qualifier = 0; 6892 if (isa<MemberExpr>(NakedMemExpr)) { 6893 MemExpr = cast<MemberExpr>(NakedMemExpr); 6894 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 6895 FoundDecl = MemExpr->getFoundDecl(); 6896 Qualifier = MemExpr->getQualifier(); 6897 } else { 6898 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 6899 Qualifier = UnresExpr->getQualifier(); 6900 6901 QualType ObjectType = UnresExpr->getBaseType(); 6902 6903 // Add overload candidates 6904 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 6905 6906 // FIXME: avoid copy. 6907 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 6908 if (UnresExpr->hasExplicitTemplateArgs()) { 6909 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 6910 TemplateArgs = &TemplateArgsBuffer; 6911 } 6912 6913 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 6914 E = UnresExpr->decls_end(); I != E; ++I) { 6915 6916 NamedDecl *Func = *I; 6917 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 6918 if (isa<UsingShadowDecl>(Func)) 6919 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 6920 6921 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 6922 // If explicit template arguments were provided, we can't call a 6923 // non-template member function. 6924 if (TemplateArgs) 6925 continue; 6926 6927 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 6928 Args, NumArgs, 6929 CandidateSet, /*SuppressUserConversions=*/false); 6930 } else { 6931 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 6932 I.getPair(), ActingDC, TemplateArgs, 6933 ObjectType, Args, NumArgs, 6934 CandidateSet, 6935 /*SuppressUsedConversions=*/false); 6936 } 6937 } 6938 6939 DeclarationName DeclName = UnresExpr->getMemberName(); 6940 6941 OverloadCandidateSet::iterator Best; 6942 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 6943 case OR_Success: 6944 Method = cast<CXXMethodDecl>(Best->Function); 6945 FoundDecl = Best->FoundDecl; 6946 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 6947 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 6948 break; 6949 6950 case OR_No_Viable_Function: 6951 Diag(UnresExpr->getMemberLoc(), 6952 diag::err_ovl_no_viable_member_function_in_call) 6953 << DeclName << MemExprE->getSourceRange(); 6954 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6955 // FIXME: Leaking incoming expressions! 6956 return ExprError(); 6957 6958 case OR_Ambiguous: 6959 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 6960 << DeclName << MemExprE->getSourceRange(); 6961 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6962 // FIXME: Leaking incoming expressions! 6963 return ExprError(); 6964 6965 case OR_Deleted: 6966 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 6967 << Best->Function->isDeleted() 6968 << DeclName << MemExprE->getSourceRange(); 6969 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6970 // FIXME: Leaking incoming expressions! 6971 return ExprError(); 6972 } 6973 6974 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 6975 6976 // If overload resolution picked a static member, build a 6977 // non-member call based on that function. 6978 if (Method->isStatic()) { 6979 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 6980 Args, NumArgs, RParenLoc); 6981 } 6982 6983 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 6984 } 6985 6986 assert(Method && "Member call to something that isn't a method?"); 6987 ExprOwningPtr<CXXMemberCallExpr> 6988 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 6989 NumArgs, 6990 Method->getResultType().getNonReferenceType(), 6991 RParenLoc)); 6992 6993 // Check for a valid return type. 6994 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 6995 TheCall.get(), Method)) 6996 return ExprError(); 6997 6998 // Convert the object argument (for a non-static member function call). 6999 // We only need to do this if there was actually an overload; otherwise 7000 // it was done at lookup. 7001 Expr *ObjectArg = MemExpr->getBase(); 7002 if (!Method->isStatic() && 7003 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 7004 FoundDecl, Method)) 7005 return ExprError(); 7006 MemExpr->setBase(ObjectArg); 7007 7008 // Convert the rest of the arguments 7009 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7010 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 7011 RParenLoc)) 7012 return ExprError(); 7013 7014 if (CheckFunctionCall(Method, TheCall.get())) 7015 return ExprError(); 7016 7017 return MaybeBindToTemporary(TheCall.release()); 7018} 7019 7020/// BuildCallToObjectOfClassType - Build a call to an object of class 7021/// type (C++ [over.call.object]), which can end up invoking an 7022/// overloaded function call operator (@c operator()) or performing a 7023/// user-defined conversion on the object argument. 7024Sema::ExprResult 7025Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 7026 SourceLocation LParenLoc, 7027 Expr **Args, unsigned NumArgs, 7028 SourceLocation *CommaLocs, 7029 SourceLocation RParenLoc) { 7030 assert(Object->getType()->isRecordType() && "Requires object type argument"); 7031 const RecordType *Record = Object->getType()->getAs<RecordType>(); 7032 7033 // C++ [over.call.object]p1: 7034 // If the primary-expression E in the function call syntax 7035 // evaluates to a class object of type "cv T", then the set of 7036 // candidate functions includes at least the function call 7037 // operators of T. The function call operators of T are obtained by 7038 // ordinary lookup of the name operator() in the context of 7039 // (E).operator(). 7040 OverloadCandidateSet CandidateSet(LParenLoc); 7041 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 7042 7043 if (RequireCompleteType(LParenLoc, Object->getType(), 7044 PDiag(diag::err_incomplete_object_call) 7045 << Object->getSourceRange())) 7046 return true; 7047 7048 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 7049 LookupQualifiedName(R, Record->getDecl()); 7050 R.suppressDiagnostics(); 7051 7052 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7053 Oper != OperEnd; ++Oper) { 7054 AddMethodCandidate(Oper.getPair(), Object->getType(), 7055 Args, NumArgs, CandidateSet, 7056 /*SuppressUserConversions=*/ false); 7057 } 7058 7059 // C++ [over.call.object]p2: 7060 // In addition, for each conversion function declared in T of the 7061 // form 7062 // 7063 // operator conversion-type-id () cv-qualifier; 7064 // 7065 // where cv-qualifier is the same cv-qualification as, or a 7066 // greater cv-qualification than, cv, and where conversion-type-id 7067 // denotes the type "pointer to function of (P1,...,Pn) returning 7068 // R", or the type "reference to pointer to function of 7069 // (P1,...,Pn) returning R", or the type "reference to function 7070 // of (P1,...,Pn) returning R", a surrogate call function [...] 7071 // is also considered as a candidate function. Similarly, 7072 // surrogate call functions are added to the set of candidate 7073 // functions for each conversion function declared in an 7074 // accessible base class provided the function is not hidden 7075 // within T by another intervening declaration. 7076 const UnresolvedSetImpl *Conversions 7077 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 7078 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 7079 E = Conversions->end(); I != E; ++I) { 7080 NamedDecl *D = *I; 7081 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 7082 if (isa<UsingShadowDecl>(D)) 7083 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 7084 7085 // Skip over templated conversion functions; they aren't 7086 // surrogates. 7087 if (isa<FunctionTemplateDecl>(D)) 7088 continue; 7089 7090 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 7091 7092 // Strip the reference type (if any) and then the pointer type (if 7093 // any) to get down to what might be a function type. 7094 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 7095 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7096 ConvType = ConvPtrType->getPointeeType(); 7097 7098 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 7099 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 7100 Object->getType(), Args, NumArgs, 7101 CandidateSet); 7102 } 7103 7104 // Perform overload resolution. 7105 OverloadCandidateSet::iterator Best; 7106 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 7107 case OR_Success: 7108 // Overload resolution succeeded; we'll build the appropriate call 7109 // below. 7110 break; 7111 7112 case OR_No_Viable_Function: 7113 if (CandidateSet.empty()) 7114 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 7115 << Object->getType() << /*call*/ 1 7116 << Object->getSourceRange(); 7117 else 7118 Diag(Object->getSourceRange().getBegin(), 7119 diag::err_ovl_no_viable_object_call) 7120 << Object->getType() << Object->getSourceRange(); 7121 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7122 break; 7123 7124 case OR_Ambiguous: 7125 Diag(Object->getSourceRange().getBegin(), 7126 diag::err_ovl_ambiguous_object_call) 7127 << Object->getType() << Object->getSourceRange(); 7128 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 7129 break; 7130 7131 case OR_Deleted: 7132 Diag(Object->getSourceRange().getBegin(), 7133 diag::err_ovl_deleted_object_call) 7134 << Best->Function->isDeleted() 7135 << Object->getType() << Object->getSourceRange(); 7136 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7137 break; 7138 } 7139 7140 if (Best == CandidateSet.end()) { 7141 // We had an error; delete all of the subexpressions and return 7142 // the error. 7143 Object->Destroy(Context); 7144 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7145 Args[ArgIdx]->Destroy(Context); 7146 return true; 7147 } 7148 7149 if (Best->Function == 0) { 7150 // Since there is no function declaration, this is one of the 7151 // surrogate candidates. Dig out the conversion function. 7152 CXXConversionDecl *Conv 7153 = cast<CXXConversionDecl>( 7154 Best->Conversions[0].UserDefined.ConversionFunction); 7155 7156 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7157 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7158 7159 // We selected one of the surrogate functions that converts the 7160 // object parameter to a function pointer. Perform the conversion 7161 // on the object argument, then let ActOnCallExpr finish the job. 7162 7163 // Create an implicit member expr to refer to the conversion operator. 7164 // and then call it. 7165 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 7166 Conv); 7167 7168 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 7169 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 7170 CommaLocs, RParenLoc).result(); 7171 } 7172 7173 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7174 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7175 7176 // We found an overloaded operator(). Build a CXXOperatorCallExpr 7177 // that calls this method, using Object for the implicit object 7178 // parameter and passing along the remaining arguments. 7179 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7180 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7181 7182 unsigned NumArgsInProto = Proto->getNumArgs(); 7183 unsigned NumArgsToCheck = NumArgs; 7184 7185 // Build the full argument list for the method call (the 7186 // implicit object parameter is placed at the beginning of the 7187 // list). 7188 Expr **MethodArgs; 7189 if (NumArgs < NumArgsInProto) { 7190 NumArgsToCheck = NumArgsInProto; 7191 MethodArgs = new Expr*[NumArgsInProto + 1]; 7192 } else { 7193 MethodArgs = new Expr*[NumArgs + 1]; 7194 } 7195 MethodArgs[0] = Object; 7196 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7197 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 7198 7199 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 7200 SourceLocation()); 7201 UsualUnaryConversions(NewFn); 7202 7203 // Once we've built TheCall, all of the expressions are properly 7204 // owned. 7205 QualType ResultTy = Method->getResultType().getNonReferenceType(); 7206 ExprOwningPtr<CXXOperatorCallExpr> 7207 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 7208 MethodArgs, NumArgs + 1, 7209 ResultTy, RParenLoc)); 7210 delete [] MethodArgs; 7211 7212 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 7213 Method)) 7214 return true; 7215 7216 // We may have default arguments. If so, we need to allocate more 7217 // slots in the call for them. 7218 if (NumArgs < NumArgsInProto) 7219 TheCall->setNumArgs(Context, NumArgsInProto + 1); 7220 else if (NumArgs > NumArgsInProto) 7221 NumArgsToCheck = NumArgsInProto; 7222 7223 bool IsError = false; 7224 7225 // Initialize the implicit object parameter. 7226 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 7227 Best->FoundDecl, Method); 7228 TheCall->setArg(0, Object); 7229 7230 7231 // Check the argument types. 7232 for (unsigned i = 0; i != NumArgsToCheck; i++) { 7233 Expr *Arg; 7234 if (i < NumArgs) { 7235 Arg = Args[i]; 7236 7237 // Pass the argument. 7238 7239 OwningExprResult InputInit 7240 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7241 Method->getParamDecl(i)), 7242 SourceLocation(), Owned(Arg)); 7243 7244 IsError |= InputInit.isInvalid(); 7245 Arg = InputInit.takeAs<Expr>(); 7246 } else { 7247 OwningExprResult DefArg 7248 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 7249 if (DefArg.isInvalid()) { 7250 IsError = true; 7251 break; 7252 } 7253 7254 Arg = DefArg.takeAs<Expr>(); 7255 } 7256 7257 TheCall->setArg(i + 1, Arg); 7258 } 7259 7260 // If this is a variadic call, handle args passed through "...". 7261 if (Proto->isVariadic()) { 7262 // Promote the arguments (C99 6.5.2.2p7). 7263 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 7264 Expr *Arg = Args[i]; 7265 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 7266 TheCall->setArg(i + 1, Arg); 7267 } 7268 } 7269 7270 if (IsError) return true; 7271 7272 if (CheckFunctionCall(Method, TheCall.get())) 7273 return true; 7274 7275 return MaybeBindToTemporary(TheCall.release()).result(); 7276} 7277 7278/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 7279/// (if one exists), where @c Base is an expression of class type and 7280/// @c Member is the name of the member we're trying to find. 7281Sema::OwningExprResult 7282Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 7283 Expr *Base = static_cast<Expr *>(BaseIn.get()); 7284 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 7285 7286 SourceLocation Loc = Base->getExprLoc(); 7287 7288 // C++ [over.ref]p1: 7289 // 7290 // [...] An expression x->m is interpreted as (x.operator->())->m 7291 // for a class object x of type T if T::operator->() exists and if 7292 // the operator is selected as the best match function by the 7293 // overload resolution mechanism (13.3). 7294 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 7295 OverloadCandidateSet CandidateSet(Loc); 7296 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 7297 7298 if (RequireCompleteType(Loc, Base->getType(), 7299 PDiag(diag::err_typecheck_incomplete_tag) 7300 << Base->getSourceRange())) 7301 return ExprError(); 7302 7303 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 7304 LookupQualifiedName(R, BaseRecord->getDecl()); 7305 R.suppressDiagnostics(); 7306 7307 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7308 Oper != OperEnd; ++Oper) { 7309 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 7310 /*SuppressUserConversions=*/false); 7311 } 7312 7313 // Perform overload resolution. 7314 OverloadCandidateSet::iterator Best; 7315 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 7316 case OR_Success: 7317 // Overload resolution succeeded; we'll build the call below. 7318 break; 7319 7320 case OR_No_Viable_Function: 7321 if (CandidateSet.empty()) 7322 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 7323 << Base->getType() << Base->getSourceRange(); 7324 else 7325 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7326 << "operator->" << Base->getSourceRange(); 7327 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7328 return ExprError(); 7329 7330 case OR_Ambiguous: 7331 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7332 << "->" << Base->getSourceRange(); 7333 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 7334 return ExprError(); 7335 7336 case OR_Deleted: 7337 Diag(OpLoc, diag::err_ovl_deleted_oper) 7338 << Best->Function->isDeleted() 7339 << "->" << Base->getSourceRange(); 7340 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7341 return ExprError(); 7342 } 7343 7344 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 7345 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7346 7347 // Convert the object parameter. 7348 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7349 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 7350 Best->FoundDecl, Method)) 7351 return ExprError(); 7352 7353 // No concerns about early exits now. 7354 BaseIn.release(); 7355 7356 // Build the operator call. 7357 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 7358 SourceLocation()); 7359 UsualUnaryConversions(FnExpr); 7360 7361 QualType ResultTy = Method->getResultType().getNonReferenceType(); 7362 ExprOwningPtr<CXXOperatorCallExpr> 7363 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 7364 &Base, 1, ResultTy, OpLoc)); 7365 7366 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 7367 Method)) 7368 return ExprError(); 7369 return move(TheCall); 7370} 7371 7372/// FixOverloadedFunctionReference - E is an expression that refers to 7373/// a C++ overloaded function (possibly with some parentheses and 7374/// perhaps a '&' around it). We have resolved the overloaded function 7375/// to the function declaration Fn, so patch up the expression E to 7376/// refer (possibly indirectly) to Fn. Returns the new expr. 7377Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 7378 FunctionDecl *Fn) { 7379 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 7380 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 7381 Found, Fn); 7382 if (SubExpr == PE->getSubExpr()) 7383 return PE->Retain(); 7384 7385 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 7386 } 7387 7388 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 7389 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 7390 Found, Fn); 7391 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 7392 SubExpr->getType()) && 7393 "Implicit cast type cannot be determined from overload"); 7394 if (SubExpr == ICE->getSubExpr()) 7395 return ICE->Retain(); 7396 7397 return new (Context) ImplicitCastExpr(ICE->getType(), 7398 ICE->getCastKind(), 7399 SubExpr, CXXBaseSpecifierArray(), 7400 ICE->isLvalueCast()); 7401 } 7402 7403 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 7404 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 7405 "Can only take the address of an overloaded function"); 7406 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7407 if (Method->isStatic()) { 7408 // Do nothing: static member functions aren't any different 7409 // from non-member functions. 7410 } else { 7411 // Fix the sub expression, which really has to be an 7412 // UnresolvedLookupExpr holding an overloaded member function 7413 // or template. 7414 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7415 Found, Fn); 7416 if (SubExpr == UnOp->getSubExpr()) 7417 return UnOp->Retain(); 7418 7419 assert(isa<DeclRefExpr>(SubExpr) 7420 && "fixed to something other than a decl ref"); 7421 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 7422 && "fixed to a member ref with no nested name qualifier"); 7423 7424 // We have taken the address of a pointer to member 7425 // function. Perform the computation here so that we get the 7426 // appropriate pointer to member type. 7427 QualType ClassType 7428 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 7429 QualType MemPtrType 7430 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 7431 7432 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7433 MemPtrType, UnOp->getOperatorLoc()); 7434 } 7435 } 7436 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7437 Found, Fn); 7438 if (SubExpr == UnOp->getSubExpr()) 7439 return UnOp->Retain(); 7440 7441 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7442 Context.getPointerType(SubExpr->getType()), 7443 UnOp->getOperatorLoc()); 7444 } 7445 7446 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 7447 // FIXME: avoid copy. 7448 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7449 if (ULE->hasExplicitTemplateArgs()) { 7450 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 7451 TemplateArgs = &TemplateArgsBuffer; 7452 } 7453 7454 return DeclRefExpr::Create(Context, 7455 ULE->getQualifier(), 7456 ULE->getQualifierRange(), 7457 Fn, 7458 ULE->getNameLoc(), 7459 Fn->getType(), 7460 TemplateArgs); 7461 } 7462 7463 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 7464 // FIXME: avoid copy. 7465 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7466 if (MemExpr->hasExplicitTemplateArgs()) { 7467 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7468 TemplateArgs = &TemplateArgsBuffer; 7469 } 7470 7471 Expr *Base; 7472 7473 // If we're filling in 7474 if (MemExpr->isImplicitAccess()) { 7475 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 7476 return DeclRefExpr::Create(Context, 7477 MemExpr->getQualifier(), 7478 MemExpr->getQualifierRange(), 7479 Fn, 7480 MemExpr->getMemberLoc(), 7481 Fn->getType(), 7482 TemplateArgs); 7483 } else { 7484 SourceLocation Loc = MemExpr->getMemberLoc(); 7485 if (MemExpr->getQualifier()) 7486 Loc = MemExpr->getQualifierRange().getBegin(); 7487 Base = new (Context) CXXThisExpr(Loc, 7488 MemExpr->getBaseType(), 7489 /*isImplicit=*/true); 7490 } 7491 } else 7492 Base = MemExpr->getBase()->Retain(); 7493 7494 return MemberExpr::Create(Context, Base, 7495 MemExpr->isArrow(), 7496 MemExpr->getQualifier(), 7497 MemExpr->getQualifierRange(), 7498 Fn, 7499 Found, 7500 MemExpr->getMemberLoc(), 7501 TemplateArgs, 7502 Fn->getType()); 7503 } 7504 7505 assert(false && "Invalid reference to overloaded function"); 7506 return E->Retain(); 7507} 7508 7509Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 7510 DeclAccessPair Found, 7511 FunctionDecl *Fn) { 7512 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 7513} 7514 7515} // end namespace clang 7516