SemaOverload.cpp revision 8578981ada66dae44a5a0752f949a5e65b477588
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->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 // Boolean conversions (C++ 4.12). 1046 SCS.Second = ICK_Boolean_Conversion; 1047 FromType = Context.BoolTy; 1048 } else if (IsVectorConversion(Context, FromType, ToType, SecondICK)) { 1049 SCS.Second = SecondICK; 1050 FromType = ToType.getUnqualifiedType(); 1051 } else if (!getLangOptions().CPlusPlus && 1052 Context.typesAreCompatible(ToType, FromType)) { 1053 // Compatible conversions (Clang extension for C function overloading) 1054 SCS.Second = ICK_Compatible_Conversion; 1055 FromType = ToType.getUnqualifiedType(); 1056 } else if (IsNoReturnConversion(Context, FromType, ToType, FromType)) { 1057 // Treat a conversion that strips "noreturn" as an identity conversion. 1058 SCS.Second = ICK_NoReturn_Adjustment; 1059 } else { 1060 // No second conversion required. 1061 SCS.Second = ICK_Identity; 1062 } 1063 SCS.setToType(1, FromType); 1064 1065 QualType CanonFrom; 1066 QualType CanonTo; 1067 // The third conversion can be a qualification conversion (C++ 4p1). 1068 if (IsQualificationConversion(FromType, ToType)) { 1069 SCS.Third = ICK_Qualification; 1070 FromType = ToType; 1071 CanonFrom = Context.getCanonicalType(FromType); 1072 CanonTo = Context.getCanonicalType(ToType); 1073 } else { 1074 // No conversion required 1075 SCS.Third = ICK_Identity; 1076 1077 // C++ [over.best.ics]p6: 1078 // [...] Any difference in top-level cv-qualification is 1079 // subsumed by the initialization itself and does not constitute 1080 // a conversion. [...] 1081 CanonFrom = Context.getCanonicalType(FromType); 1082 CanonTo = Context.getCanonicalType(ToType); 1083 if (CanonFrom.getLocalUnqualifiedType() 1084 == CanonTo.getLocalUnqualifiedType() && 1085 (CanonFrom.getLocalCVRQualifiers() != CanonTo.getLocalCVRQualifiers() 1086 || CanonFrom.getObjCGCAttr() != CanonTo.getObjCGCAttr())) { 1087 FromType = ToType; 1088 CanonFrom = CanonTo; 1089 } 1090 } 1091 SCS.setToType(2, FromType); 1092 1093 // If we have not converted the argument type to the parameter type, 1094 // this is a bad conversion sequence. 1095 if (CanonFrom != CanonTo) 1096 return false; 1097 1098 return true; 1099} 1100 1101/// IsIntegralPromotion - Determines whether the conversion from the 1102/// expression From (whose potentially-adjusted type is FromType) to 1103/// ToType is an integral promotion (C++ 4.5). If so, returns true and 1104/// sets PromotedType to the promoted type. 1105bool Sema::IsIntegralPromotion(Expr *From, QualType FromType, QualType ToType) { 1106 const BuiltinType *To = ToType->getAs<BuiltinType>(); 1107 // All integers are built-in. 1108 if (!To) { 1109 return false; 1110 } 1111 1112 // An rvalue of type char, signed char, unsigned char, short int, or 1113 // unsigned short int can be converted to an rvalue of type int if 1114 // int can represent all the values of the source type; otherwise, 1115 // the source rvalue can be converted to an rvalue of type unsigned 1116 // int (C++ 4.5p1). 1117 if (FromType->isPromotableIntegerType() && !FromType->isBooleanType() && 1118 !FromType->isEnumeralType()) { 1119 if (// We can promote any signed, promotable integer type to an int 1120 (FromType->isSignedIntegerType() || 1121 // We can promote any unsigned integer type whose size is 1122 // less than int to an int. 1123 (!FromType->isSignedIntegerType() && 1124 Context.getTypeSize(FromType) < Context.getTypeSize(ToType)))) { 1125 return To->getKind() == BuiltinType::Int; 1126 } 1127 1128 return To->getKind() == BuiltinType::UInt; 1129 } 1130 1131 // An rvalue of type wchar_t (3.9.1) or an enumeration type (7.2) 1132 // can be converted to an rvalue of the first of the following types 1133 // that can represent all the values of its underlying type: int, 1134 // unsigned int, long, or unsigned long (C++ 4.5p2). 1135 1136 // We pre-calculate the promotion type for enum types. 1137 if (const EnumType *FromEnumType = FromType->getAs<EnumType>()) 1138 if (ToType->isIntegerType()) 1139 return Context.hasSameUnqualifiedType(ToType, 1140 FromEnumType->getDecl()->getPromotionType()); 1141 1142 if (FromType->isWideCharType() && ToType->isIntegerType()) { 1143 // Determine whether the type we're converting from is signed or 1144 // unsigned. 1145 bool FromIsSigned; 1146 uint64_t FromSize = Context.getTypeSize(FromType); 1147 1148 // FIXME: Is wchar_t signed or unsigned? We assume it's signed for now. 1149 FromIsSigned = true; 1150 1151 // The types we'll try to promote to, in the appropriate 1152 // order. Try each of these types. 1153 QualType PromoteTypes[6] = { 1154 Context.IntTy, Context.UnsignedIntTy, 1155 Context.LongTy, Context.UnsignedLongTy , 1156 Context.LongLongTy, Context.UnsignedLongLongTy 1157 }; 1158 for (int Idx = 0; Idx < 6; ++Idx) { 1159 uint64_t ToSize = Context.getTypeSize(PromoteTypes[Idx]); 1160 if (FromSize < ToSize || 1161 (FromSize == ToSize && 1162 FromIsSigned == PromoteTypes[Idx]->isSignedIntegerType())) { 1163 // We found the type that we can promote to. If this is the 1164 // type we wanted, we have a promotion. Otherwise, no 1165 // promotion. 1166 return Context.hasSameUnqualifiedType(ToType, PromoteTypes[Idx]); 1167 } 1168 } 1169 } 1170 1171 // An rvalue for an integral bit-field (9.6) can be converted to an 1172 // rvalue of type int if int can represent all the values of the 1173 // bit-field; otherwise, it can be converted to unsigned int if 1174 // unsigned int can represent all the values of the bit-field. If 1175 // the bit-field is larger yet, no integral promotion applies to 1176 // it. If the bit-field has an enumerated type, it is treated as any 1177 // other value of that type for promotion purposes (C++ 4.5p3). 1178 // FIXME: We should delay checking of bit-fields until we actually perform the 1179 // conversion. 1180 using llvm::APSInt; 1181 if (From) 1182 if (FieldDecl *MemberDecl = From->getBitField()) { 1183 APSInt BitWidth; 1184 if (FromType->isIntegralType(Context) && 1185 MemberDecl->getBitWidth()->isIntegerConstantExpr(BitWidth, Context)) { 1186 APSInt ToSize(BitWidth.getBitWidth(), BitWidth.isUnsigned()); 1187 ToSize = Context.getTypeSize(ToType); 1188 1189 // Are we promoting to an int from a bitfield that fits in an int? 1190 if (BitWidth < ToSize || 1191 (FromType->isSignedIntegerType() && BitWidth <= ToSize)) { 1192 return To->getKind() == BuiltinType::Int; 1193 } 1194 1195 // Are we promoting to an unsigned int from an unsigned bitfield 1196 // that fits into an unsigned int? 1197 if (FromType->isUnsignedIntegerType() && BitWidth <= ToSize) { 1198 return To->getKind() == BuiltinType::UInt; 1199 } 1200 1201 return false; 1202 } 1203 } 1204 1205 // An rvalue of type bool can be converted to an rvalue of type int, 1206 // with false becoming zero and true becoming one (C++ 4.5p4). 1207 if (FromType->isBooleanType() && To->getKind() == BuiltinType::Int) { 1208 return true; 1209 } 1210 1211 return false; 1212} 1213 1214/// IsFloatingPointPromotion - Determines whether the conversion from 1215/// FromType to ToType is a floating point promotion (C++ 4.6). If so, 1216/// returns true and sets PromotedType to the promoted type. 1217bool Sema::IsFloatingPointPromotion(QualType FromType, QualType ToType) { 1218 /// An rvalue of type float can be converted to an rvalue of type 1219 /// double. (C++ 4.6p1). 1220 if (const BuiltinType *FromBuiltin = FromType->getAs<BuiltinType>()) 1221 if (const BuiltinType *ToBuiltin = ToType->getAs<BuiltinType>()) { 1222 if (FromBuiltin->getKind() == BuiltinType::Float && 1223 ToBuiltin->getKind() == BuiltinType::Double) 1224 return true; 1225 1226 // C99 6.3.1.5p1: 1227 // When a float is promoted to double or long double, or a 1228 // double is promoted to long double [...]. 1229 if (!getLangOptions().CPlusPlus && 1230 (FromBuiltin->getKind() == BuiltinType::Float || 1231 FromBuiltin->getKind() == BuiltinType::Double) && 1232 (ToBuiltin->getKind() == BuiltinType::LongDouble)) 1233 return true; 1234 } 1235 1236 return false; 1237} 1238 1239/// \brief Determine if a conversion is a complex promotion. 1240/// 1241/// A complex promotion is defined as a complex -> complex conversion 1242/// where the conversion between the underlying real types is a 1243/// floating-point or integral promotion. 1244bool Sema::IsComplexPromotion(QualType FromType, QualType ToType) { 1245 const ComplexType *FromComplex = FromType->getAs<ComplexType>(); 1246 if (!FromComplex) 1247 return false; 1248 1249 const ComplexType *ToComplex = ToType->getAs<ComplexType>(); 1250 if (!ToComplex) 1251 return false; 1252 1253 return IsFloatingPointPromotion(FromComplex->getElementType(), 1254 ToComplex->getElementType()) || 1255 IsIntegralPromotion(0, FromComplex->getElementType(), 1256 ToComplex->getElementType()); 1257} 1258 1259/// BuildSimilarlyQualifiedPointerType - In a pointer conversion from 1260/// the pointer type FromPtr to a pointer to type ToPointee, with the 1261/// same type qualifiers as FromPtr has on its pointee type. ToType, 1262/// if non-empty, will be a pointer to ToType that may or may not have 1263/// the right set of qualifiers on its pointee. 1264static QualType 1265BuildSimilarlyQualifiedPointerType(const PointerType *FromPtr, 1266 QualType ToPointee, QualType ToType, 1267 ASTContext &Context) { 1268 QualType CanonFromPointee = Context.getCanonicalType(FromPtr->getPointeeType()); 1269 QualType CanonToPointee = Context.getCanonicalType(ToPointee); 1270 Qualifiers Quals = CanonFromPointee.getQualifiers(); 1271 1272 // Exact qualifier match -> return the pointer type we're converting to. 1273 if (CanonToPointee.getLocalQualifiers() == Quals) { 1274 // ToType is exactly what we need. Return it. 1275 if (!ToType.isNull()) 1276 return ToType.getUnqualifiedType(); 1277 1278 // Build a pointer to ToPointee. It has the right qualifiers 1279 // already. 1280 return Context.getPointerType(ToPointee); 1281 } 1282 1283 // Just build a canonical type that has the right qualifiers. 1284 return Context.getPointerType( 1285 Context.getQualifiedType(CanonToPointee.getLocalUnqualifiedType(), 1286 Quals)); 1287} 1288 1289/// BuildSimilarlyQualifiedObjCObjectPointerType - In a pointer conversion from 1290/// the FromType, which is an objective-c pointer, to ToType, which may or may 1291/// not have the right set of qualifiers. 1292static QualType 1293BuildSimilarlyQualifiedObjCObjectPointerType(QualType FromType, 1294 QualType ToType, 1295 ASTContext &Context) { 1296 QualType CanonFromType = Context.getCanonicalType(FromType); 1297 QualType CanonToType = Context.getCanonicalType(ToType); 1298 Qualifiers Quals = CanonFromType.getQualifiers(); 1299 1300 // Exact qualifier match -> return the pointer type we're converting to. 1301 if (CanonToType.getLocalQualifiers() == Quals) 1302 return ToType; 1303 1304 // Just build a canonical type that has the right qualifiers. 1305 return Context.getQualifiedType(CanonToType.getLocalUnqualifiedType(), Quals); 1306} 1307 1308static bool isNullPointerConstantForConversion(Expr *Expr, 1309 bool InOverloadResolution, 1310 ASTContext &Context) { 1311 // Handle value-dependent integral null pointer constants correctly. 1312 // http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#903 1313 if (Expr->isValueDependent() && !Expr->isTypeDependent() && 1314 Expr->getType()->isIntegerType() && !Expr->getType()->isEnumeralType()) 1315 return !InOverloadResolution; 1316 1317 return Expr->isNullPointerConstant(Context, 1318 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1319 : Expr::NPC_ValueDependentIsNull); 1320} 1321 1322/// IsPointerConversion - Determines whether the conversion of the 1323/// expression From, which has the (possibly adjusted) type FromType, 1324/// can be converted to the type ToType via a pointer conversion (C++ 1325/// 4.10). If so, returns true and places the converted type (that 1326/// might differ from ToType in its cv-qualifiers at some level) into 1327/// ConvertedType. 1328/// 1329/// This routine also supports conversions to and from block pointers 1330/// and conversions with Objective-C's 'id', 'id<protocols...>', and 1331/// pointers to interfaces. FIXME: Once we've determined the 1332/// appropriate overloading rules for Objective-C, we may want to 1333/// split the Objective-C checks into a different routine; however, 1334/// GCC seems to consider all of these conversions to be pointer 1335/// conversions, so for now they live here. IncompatibleObjC will be 1336/// set if the conversion is an allowed Objective-C conversion that 1337/// should result in a warning. 1338bool Sema::IsPointerConversion(Expr *From, QualType FromType, QualType ToType, 1339 bool InOverloadResolution, 1340 QualType& ConvertedType, 1341 bool &IncompatibleObjC) { 1342 IncompatibleObjC = false; 1343 if (isObjCPointerConversion(FromType, ToType, ConvertedType, IncompatibleObjC)) 1344 return true; 1345 1346 // Conversion from a null pointer constant to any Objective-C pointer type. 1347 if (ToType->isObjCObjectPointerType() && 1348 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1349 ConvertedType = ToType; 1350 return true; 1351 } 1352 1353 // Blocks: Block pointers can be converted to void*. 1354 if (FromType->isBlockPointerType() && ToType->isPointerType() && 1355 ToType->getAs<PointerType>()->getPointeeType()->isVoidType()) { 1356 ConvertedType = ToType; 1357 return true; 1358 } 1359 // Blocks: A null pointer constant can be converted to a block 1360 // pointer type. 1361 if (ToType->isBlockPointerType() && 1362 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1363 ConvertedType = ToType; 1364 return true; 1365 } 1366 1367 // If the left-hand-side is nullptr_t, the right side can be a null 1368 // pointer constant. 1369 if (ToType->isNullPtrType() && 1370 isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1371 ConvertedType = ToType; 1372 return true; 1373 } 1374 1375 const PointerType* ToTypePtr = ToType->getAs<PointerType>(); 1376 if (!ToTypePtr) 1377 return false; 1378 1379 // A null pointer constant can be converted to a pointer type (C++ 4.10p1). 1380 if (isNullPointerConstantForConversion(From, InOverloadResolution, Context)) { 1381 ConvertedType = ToType; 1382 return true; 1383 } 1384 1385 // Beyond this point, both types need to be pointers 1386 // , including objective-c pointers. 1387 QualType ToPointeeType = ToTypePtr->getPointeeType(); 1388 if (FromType->isObjCObjectPointerType() && ToPointeeType->isVoidType()) { 1389 ConvertedType = BuildSimilarlyQualifiedObjCObjectPointerType(FromType, 1390 ToType, Context); 1391 return true; 1392 1393 } 1394 const PointerType *FromTypePtr = FromType->getAs<PointerType>(); 1395 if (!FromTypePtr) 1396 return false; 1397 1398 QualType FromPointeeType = FromTypePtr->getPointeeType(); 1399 1400 // An rvalue of type "pointer to cv T," where T is an object type, 1401 // can be converted to an rvalue of type "pointer to cv void" (C++ 1402 // 4.10p2). 1403 if (FromPointeeType->isObjectType() && ToPointeeType->isVoidType()) { 1404 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1405 ToPointeeType, 1406 ToType, Context); 1407 return true; 1408 } 1409 1410 // When we're overloading in C, we allow a special kind of pointer 1411 // conversion for compatible-but-not-identical pointee types. 1412 if (!getLangOptions().CPlusPlus && 1413 Context.typesAreCompatible(FromPointeeType, ToPointeeType)) { 1414 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1415 ToPointeeType, 1416 ToType, Context); 1417 return true; 1418 } 1419 1420 // C++ [conv.ptr]p3: 1421 // 1422 // An rvalue of type "pointer to cv D," where D is a class type, 1423 // can be converted to an rvalue of type "pointer to cv B," where 1424 // B is a base class (clause 10) of D. If B is an inaccessible 1425 // (clause 11) or ambiguous (10.2) base class of D, a program that 1426 // necessitates this conversion is ill-formed. The result of the 1427 // conversion is a pointer to the base class sub-object of the 1428 // derived class object. The null pointer value is converted to 1429 // the null pointer value of the destination type. 1430 // 1431 // Note that we do not check for ambiguity or inaccessibility 1432 // here. That is handled by CheckPointerConversion. 1433 if (getLangOptions().CPlusPlus && 1434 FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1435 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType) && 1436 !RequireCompleteType(From->getLocStart(), FromPointeeType, PDiag()) && 1437 IsDerivedFrom(FromPointeeType, ToPointeeType)) { 1438 ConvertedType = BuildSimilarlyQualifiedPointerType(FromTypePtr, 1439 ToPointeeType, 1440 ToType, Context); 1441 return true; 1442 } 1443 1444 return false; 1445} 1446 1447/// isObjCPointerConversion - Determines whether this is an 1448/// Objective-C pointer conversion. Subroutine of IsPointerConversion, 1449/// with the same arguments and return values. 1450bool Sema::isObjCPointerConversion(QualType FromType, QualType ToType, 1451 QualType& ConvertedType, 1452 bool &IncompatibleObjC) { 1453 if (!getLangOptions().ObjC1) 1454 return false; 1455 1456 // First, we handle all conversions on ObjC object pointer types. 1457 const ObjCObjectPointerType* ToObjCPtr = ToType->getAs<ObjCObjectPointerType>(); 1458 const ObjCObjectPointerType *FromObjCPtr = 1459 FromType->getAs<ObjCObjectPointerType>(); 1460 1461 if (ToObjCPtr && FromObjCPtr) { 1462 // Objective C++: We're able to convert between "id" or "Class" and a 1463 // pointer to any interface (in both directions). 1464 if (ToObjCPtr->isObjCBuiltinType() && FromObjCPtr->isObjCBuiltinType()) { 1465 ConvertedType = ToType; 1466 return true; 1467 } 1468 // Conversions with Objective-C's id<...>. 1469 if ((FromObjCPtr->isObjCQualifiedIdType() || 1470 ToObjCPtr->isObjCQualifiedIdType()) && 1471 Context.ObjCQualifiedIdTypesAreCompatible(ToType, FromType, 1472 /*compare=*/false)) { 1473 ConvertedType = ToType; 1474 return true; 1475 } 1476 // Objective C++: We're able to convert from a pointer to an 1477 // interface to a pointer to a different interface. 1478 if (Context.canAssignObjCInterfaces(ToObjCPtr, FromObjCPtr)) { 1479 const ObjCInterfaceType* LHS = ToObjCPtr->getInterfaceType(); 1480 const ObjCInterfaceType* RHS = FromObjCPtr->getInterfaceType(); 1481 if (getLangOptions().CPlusPlus && LHS && RHS && 1482 !ToObjCPtr->getPointeeType().isAtLeastAsQualifiedAs( 1483 FromObjCPtr->getPointeeType())) 1484 return false; 1485 ConvertedType = ToType; 1486 return true; 1487 } 1488 1489 if (Context.canAssignObjCInterfaces(FromObjCPtr, ToObjCPtr)) { 1490 // Okay: this is some kind of implicit downcast of Objective-C 1491 // interfaces, which is permitted. However, we're going to 1492 // complain about it. 1493 IncompatibleObjC = true; 1494 ConvertedType = FromType; 1495 return true; 1496 } 1497 } 1498 // Beyond this point, both types need to be C pointers or block pointers. 1499 QualType ToPointeeType; 1500 if (const PointerType *ToCPtr = ToType->getAs<PointerType>()) 1501 ToPointeeType = ToCPtr->getPointeeType(); 1502 else if (const BlockPointerType *ToBlockPtr = 1503 ToType->getAs<BlockPointerType>()) { 1504 // Objective C++: We're able to convert from a pointer to any object 1505 // to a block pointer type. 1506 if (FromObjCPtr && FromObjCPtr->isObjCBuiltinType()) { 1507 ConvertedType = ToType; 1508 return true; 1509 } 1510 ToPointeeType = ToBlockPtr->getPointeeType(); 1511 } 1512 else if (FromType->getAs<BlockPointerType>() && 1513 ToObjCPtr && ToObjCPtr->isObjCBuiltinType()) { 1514 // Objective C++: We're able to convert from a block pointer type to a 1515 // pointer to any object. 1516 ConvertedType = ToType; 1517 return true; 1518 } 1519 else 1520 return false; 1521 1522 QualType FromPointeeType; 1523 if (const PointerType *FromCPtr = FromType->getAs<PointerType>()) 1524 FromPointeeType = FromCPtr->getPointeeType(); 1525 else if (const BlockPointerType *FromBlockPtr = FromType->getAs<BlockPointerType>()) 1526 FromPointeeType = FromBlockPtr->getPointeeType(); 1527 else 1528 return false; 1529 1530 // If we have pointers to pointers, recursively check whether this 1531 // is an Objective-C conversion. 1532 if (FromPointeeType->isPointerType() && ToPointeeType->isPointerType() && 1533 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1534 IncompatibleObjC)) { 1535 // We always complain about this conversion. 1536 IncompatibleObjC = true; 1537 ConvertedType = ToType; 1538 return true; 1539 } 1540 // Allow conversion of pointee being objective-c pointer to another one; 1541 // as in I* to id. 1542 if (FromPointeeType->getAs<ObjCObjectPointerType>() && 1543 ToPointeeType->getAs<ObjCObjectPointerType>() && 1544 isObjCPointerConversion(FromPointeeType, ToPointeeType, ConvertedType, 1545 IncompatibleObjC)) { 1546 ConvertedType = ToType; 1547 return true; 1548 } 1549 1550 // If we have pointers to functions or blocks, check whether the only 1551 // differences in the argument and result types are in Objective-C 1552 // pointer conversions. If so, we permit the conversion (but 1553 // complain about it). 1554 const FunctionProtoType *FromFunctionType 1555 = FromPointeeType->getAs<FunctionProtoType>(); 1556 const FunctionProtoType *ToFunctionType 1557 = ToPointeeType->getAs<FunctionProtoType>(); 1558 if (FromFunctionType && ToFunctionType) { 1559 // If the function types are exactly the same, this isn't an 1560 // Objective-C pointer conversion. 1561 if (Context.getCanonicalType(FromPointeeType) 1562 == Context.getCanonicalType(ToPointeeType)) 1563 return false; 1564 1565 // Perform the quick checks that will tell us whether these 1566 // function types are obviously different. 1567 if (FromFunctionType->getNumArgs() != ToFunctionType->getNumArgs() || 1568 FromFunctionType->isVariadic() != ToFunctionType->isVariadic() || 1569 FromFunctionType->getTypeQuals() != ToFunctionType->getTypeQuals()) 1570 return false; 1571 1572 bool HasObjCConversion = false; 1573 if (Context.getCanonicalType(FromFunctionType->getResultType()) 1574 == Context.getCanonicalType(ToFunctionType->getResultType())) { 1575 // Okay, the types match exactly. Nothing to do. 1576 } else if (isObjCPointerConversion(FromFunctionType->getResultType(), 1577 ToFunctionType->getResultType(), 1578 ConvertedType, IncompatibleObjC)) { 1579 // Okay, we have an Objective-C pointer conversion. 1580 HasObjCConversion = true; 1581 } else { 1582 // Function types are too different. Abort. 1583 return false; 1584 } 1585 1586 // Check argument types. 1587 for (unsigned ArgIdx = 0, NumArgs = FromFunctionType->getNumArgs(); 1588 ArgIdx != NumArgs; ++ArgIdx) { 1589 QualType FromArgType = FromFunctionType->getArgType(ArgIdx); 1590 QualType ToArgType = ToFunctionType->getArgType(ArgIdx); 1591 if (Context.getCanonicalType(FromArgType) 1592 == Context.getCanonicalType(ToArgType)) { 1593 // Okay, the types match exactly. Nothing to do. 1594 } else if (isObjCPointerConversion(FromArgType, ToArgType, 1595 ConvertedType, IncompatibleObjC)) { 1596 // Okay, we have an Objective-C pointer conversion. 1597 HasObjCConversion = true; 1598 } else { 1599 // Argument types are too different. Abort. 1600 return false; 1601 } 1602 } 1603 1604 if (HasObjCConversion) { 1605 // We had an Objective-C conversion. Allow this pointer 1606 // conversion, but complain about it. 1607 ConvertedType = ToType; 1608 IncompatibleObjC = true; 1609 return true; 1610 } 1611 } 1612 1613 return false; 1614} 1615 1616/// FunctionArgTypesAreEqual - This routine checks two function proto types 1617/// for equlity of their argument types. Caller has already checked that 1618/// they have same number of arguments. This routine assumes that Objective-C 1619/// pointer types which only differ in their protocol qualifiers are equal. 1620bool Sema::FunctionArgTypesAreEqual(FunctionProtoType* OldType, 1621 FunctionProtoType* NewType){ 1622 if (!getLangOptions().ObjC1) 1623 return std::equal(OldType->arg_type_begin(), OldType->arg_type_end(), 1624 NewType->arg_type_begin()); 1625 1626 for (FunctionProtoType::arg_type_iterator O = OldType->arg_type_begin(), 1627 N = NewType->arg_type_begin(), 1628 E = OldType->arg_type_end(); O && (O != E); ++O, ++N) { 1629 QualType ToType = (*O); 1630 QualType FromType = (*N); 1631 if (ToType != FromType) { 1632 if (const PointerType *PTTo = ToType->getAs<PointerType>()) { 1633 if (const PointerType *PTFr = FromType->getAs<PointerType>()) 1634 if ((PTTo->getPointeeType()->isObjCQualifiedIdType() && 1635 PTFr->getPointeeType()->isObjCQualifiedIdType()) || 1636 (PTTo->getPointeeType()->isObjCQualifiedClassType() && 1637 PTFr->getPointeeType()->isObjCQualifiedClassType())) 1638 continue; 1639 } 1640 else if (const ObjCObjectPointerType *PTTo = 1641 ToType->getAs<ObjCObjectPointerType>()) { 1642 if (const ObjCObjectPointerType *PTFr = 1643 FromType->getAs<ObjCObjectPointerType>()) 1644 if (PTTo->getInterfaceDecl() == PTFr->getInterfaceDecl()) 1645 continue; 1646 } 1647 return false; 1648 } 1649 } 1650 return true; 1651} 1652 1653/// CheckPointerConversion - Check the pointer conversion from the 1654/// expression From to the type ToType. This routine checks for 1655/// ambiguous or inaccessible derived-to-base pointer 1656/// conversions for which IsPointerConversion has already returned 1657/// true. It returns true and produces a diagnostic if there was an 1658/// error, or returns false otherwise. 1659bool Sema::CheckPointerConversion(Expr *From, QualType ToType, 1660 CastExpr::CastKind &Kind, 1661 CXXBaseSpecifierArray& BasePath, 1662 bool IgnoreBaseAccess) { 1663 QualType FromType = From->getType(); 1664 1665 if (CXXBoolLiteralExpr* LitBool 1666 = dyn_cast<CXXBoolLiteralExpr>(From->IgnoreParens())) 1667 if (LitBool->getValue() == false) 1668 Diag(LitBool->getExprLoc(), diag::warn_init_pointer_from_false) 1669 << ToType; 1670 1671 if (const PointerType *FromPtrType = FromType->getAs<PointerType>()) 1672 if (const PointerType *ToPtrType = ToType->getAs<PointerType>()) { 1673 QualType FromPointeeType = FromPtrType->getPointeeType(), 1674 ToPointeeType = ToPtrType->getPointeeType(); 1675 1676 if (FromPointeeType->isRecordType() && ToPointeeType->isRecordType() && 1677 !Context.hasSameUnqualifiedType(FromPointeeType, ToPointeeType)) { 1678 // We must have a derived-to-base conversion. Check an 1679 // ambiguous or inaccessible conversion. 1680 if (CheckDerivedToBaseConversion(FromPointeeType, ToPointeeType, 1681 From->getExprLoc(), 1682 From->getSourceRange(), &BasePath, 1683 IgnoreBaseAccess)) 1684 return true; 1685 1686 // The conversion was successful. 1687 Kind = CastExpr::CK_DerivedToBase; 1688 } 1689 } 1690 if (const ObjCObjectPointerType *FromPtrType = 1691 FromType->getAs<ObjCObjectPointerType>()) 1692 if (const ObjCObjectPointerType *ToPtrType = 1693 ToType->getAs<ObjCObjectPointerType>()) { 1694 // Objective-C++ conversions are always okay. 1695 // FIXME: We should have a different class of conversions for the 1696 // Objective-C++ implicit conversions. 1697 if (FromPtrType->isObjCBuiltinType() || ToPtrType->isObjCBuiltinType()) 1698 return false; 1699 1700 } 1701 return false; 1702} 1703 1704/// IsMemberPointerConversion - Determines whether the conversion of the 1705/// expression From, which has the (possibly adjusted) type FromType, can be 1706/// converted to the type ToType via a member pointer conversion (C++ 4.11). 1707/// If so, returns true and places the converted type (that might differ from 1708/// ToType in its cv-qualifiers at some level) into ConvertedType. 1709bool Sema::IsMemberPointerConversion(Expr *From, QualType FromType, 1710 QualType ToType, 1711 bool InOverloadResolution, 1712 QualType &ConvertedType) { 1713 const MemberPointerType *ToTypePtr = ToType->getAs<MemberPointerType>(); 1714 if (!ToTypePtr) 1715 return false; 1716 1717 // A null pointer constant can be converted to a member pointer (C++ 4.11p1) 1718 if (From->isNullPointerConstant(Context, 1719 InOverloadResolution? Expr::NPC_ValueDependentIsNotNull 1720 : Expr::NPC_ValueDependentIsNull)) { 1721 ConvertedType = ToType; 1722 return true; 1723 } 1724 1725 // Otherwise, both types have to be member pointers. 1726 const MemberPointerType *FromTypePtr = FromType->getAs<MemberPointerType>(); 1727 if (!FromTypePtr) 1728 return false; 1729 1730 // A pointer to member of B can be converted to a pointer to member of D, 1731 // where D is derived from B (C++ 4.11p2). 1732 QualType FromClass(FromTypePtr->getClass(), 0); 1733 QualType ToClass(ToTypePtr->getClass(), 0); 1734 // FIXME: What happens when these are dependent? Is this function even called? 1735 1736 if (IsDerivedFrom(ToClass, FromClass)) { 1737 ConvertedType = Context.getMemberPointerType(FromTypePtr->getPointeeType(), 1738 ToClass.getTypePtr()); 1739 return true; 1740 } 1741 1742 return false; 1743} 1744 1745/// CheckMemberPointerConversion - Check the member pointer conversion from the 1746/// expression From to the type ToType. This routine checks for ambiguous or 1747/// virtual or inaccessible base-to-derived member pointer conversions 1748/// for which IsMemberPointerConversion has already returned true. It returns 1749/// true and produces a diagnostic if there was an error, or returns false 1750/// otherwise. 1751bool Sema::CheckMemberPointerConversion(Expr *From, QualType ToType, 1752 CastExpr::CastKind &Kind, 1753 CXXBaseSpecifierArray &BasePath, 1754 bool IgnoreBaseAccess) { 1755 QualType FromType = From->getType(); 1756 const MemberPointerType *FromPtrType = FromType->getAs<MemberPointerType>(); 1757 if (!FromPtrType) { 1758 // This must be a null pointer to member pointer conversion 1759 assert(From->isNullPointerConstant(Context, 1760 Expr::NPC_ValueDependentIsNull) && 1761 "Expr must be null pointer constant!"); 1762 Kind = CastExpr::CK_NullToMemberPointer; 1763 return false; 1764 } 1765 1766 const MemberPointerType *ToPtrType = ToType->getAs<MemberPointerType>(); 1767 assert(ToPtrType && "No member pointer cast has a target type " 1768 "that is not a member pointer."); 1769 1770 QualType FromClass = QualType(FromPtrType->getClass(), 0); 1771 QualType ToClass = QualType(ToPtrType->getClass(), 0); 1772 1773 // FIXME: What about dependent types? 1774 assert(FromClass->isRecordType() && "Pointer into non-class."); 1775 assert(ToClass->isRecordType() && "Pointer into non-class."); 1776 1777 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, 1778 /*DetectVirtual=*/true); 1779 bool DerivationOkay = IsDerivedFrom(ToClass, FromClass, Paths); 1780 assert(DerivationOkay && 1781 "Should not have been called if derivation isn't OK."); 1782 (void)DerivationOkay; 1783 1784 if (Paths.isAmbiguous(Context.getCanonicalType(FromClass). 1785 getUnqualifiedType())) { 1786 std::string PathDisplayStr = getAmbiguousPathsDisplayString(Paths); 1787 Diag(From->getExprLoc(), diag::err_ambiguous_memptr_conv) 1788 << 0 << FromClass << ToClass << PathDisplayStr << From->getSourceRange(); 1789 return true; 1790 } 1791 1792 if (const RecordType *VBase = Paths.getDetectedVirtual()) { 1793 Diag(From->getExprLoc(), diag::err_memptr_conv_via_virtual) 1794 << FromClass << ToClass << QualType(VBase, 0) 1795 << From->getSourceRange(); 1796 return true; 1797 } 1798 1799 if (!IgnoreBaseAccess) 1800 CheckBaseClassAccess(From->getExprLoc(), FromClass, ToClass, 1801 Paths.front(), 1802 diag::err_downcast_from_inaccessible_base); 1803 1804 // Must be a base to derived member conversion. 1805 BuildBasePathArray(Paths, BasePath); 1806 Kind = CastExpr::CK_BaseToDerivedMemberPointer; 1807 return false; 1808} 1809 1810/// IsQualificationConversion - Determines whether the conversion from 1811/// an rvalue of type FromType to ToType is a qualification conversion 1812/// (C++ 4.4). 1813bool 1814Sema::IsQualificationConversion(QualType FromType, QualType ToType) { 1815 FromType = Context.getCanonicalType(FromType); 1816 ToType = Context.getCanonicalType(ToType); 1817 1818 // If FromType and ToType are the same type, this is not a 1819 // qualification conversion. 1820 if (FromType.getUnqualifiedType() == ToType.getUnqualifiedType()) 1821 return false; 1822 1823 // (C++ 4.4p4): 1824 // A conversion can add cv-qualifiers at levels other than the first 1825 // in multi-level pointers, subject to the following rules: [...] 1826 bool PreviousToQualsIncludeConst = true; 1827 bool UnwrappedAnyPointer = false; 1828 while (Context.UnwrapSimilarPointerTypes(FromType, ToType)) { 1829 // Within each iteration of the loop, we check the qualifiers to 1830 // determine if this still looks like a qualification 1831 // conversion. Then, if all is well, we unwrap one more level of 1832 // pointers or pointers-to-members and do it all again 1833 // until there are no more pointers or pointers-to-members left to 1834 // unwrap. 1835 UnwrappedAnyPointer = true; 1836 1837 // -- for every j > 0, if const is in cv 1,j then const is in cv 1838 // 2,j, and similarly for volatile. 1839 if (!ToType.isAtLeastAsQualifiedAs(FromType)) 1840 return false; 1841 1842 // -- if the cv 1,j and cv 2,j are different, then const is in 1843 // every cv for 0 < k < j. 1844 if (FromType.getCVRQualifiers() != ToType.getCVRQualifiers() 1845 && !PreviousToQualsIncludeConst) 1846 return false; 1847 1848 // Keep track of whether all prior cv-qualifiers in the "to" type 1849 // include const. 1850 PreviousToQualsIncludeConst 1851 = PreviousToQualsIncludeConst && ToType.isConstQualified(); 1852 } 1853 1854 // We are left with FromType and ToType being the pointee types 1855 // after unwrapping the original FromType and ToType the same number 1856 // of types. If we unwrapped any pointers, and if FromType and 1857 // ToType have the same unqualified type (since we checked 1858 // qualifiers above), then this is a qualification conversion. 1859 return UnwrappedAnyPointer && Context.hasSameUnqualifiedType(FromType,ToType); 1860} 1861 1862/// Determines whether there is a user-defined conversion sequence 1863/// (C++ [over.ics.user]) that converts expression From to the type 1864/// ToType. If such a conversion exists, User will contain the 1865/// user-defined conversion sequence that performs such a conversion 1866/// and this routine will return true. Otherwise, this routine returns 1867/// false and User is unspecified. 1868/// 1869/// \param AllowExplicit true if the conversion should consider C++0x 1870/// "explicit" conversion functions as well as non-explicit conversion 1871/// functions (C++0x [class.conv.fct]p2). 1872OverloadingResult Sema::IsUserDefinedConversion(Expr *From, QualType ToType, 1873 UserDefinedConversionSequence& User, 1874 OverloadCandidateSet& CandidateSet, 1875 bool AllowExplicit) { 1876 // Whether we will only visit constructors. 1877 bool ConstructorsOnly = false; 1878 1879 // If the type we are conversion to is a class type, enumerate its 1880 // constructors. 1881 if (const RecordType *ToRecordType = ToType->getAs<RecordType>()) { 1882 // C++ [over.match.ctor]p1: 1883 // When objects of class type are direct-initialized (8.5), or 1884 // copy-initialized from an expression of the same or a 1885 // derived class type (8.5), overload resolution selects the 1886 // constructor. [...] For copy-initialization, the candidate 1887 // functions are all the converting constructors (12.3.1) of 1888 // that class. The argument list is the expression-list within 1889 // the parentheses of the initializer. 1890 if (Context.hasSameUnqualifiedType(ToType, From->getType()) || 1891 (From->getType()->getAs<RecordType>() && 1892 IsDerivedFrom(From->getType(), ToType))) 1893 ConstructorsOnly = true; 1894 1895 if (RequireCompleteType(From->getLocStart(), ToType, PDiag())) { 1896 // We're not going to find any constructors. 1897 } else if (CXXRecordDecl *ToRecordDecl 1898 = dyn_cast<CXXRecordDecl>(ToRecordType->getDecl())) { 1899 DeclarationName ConstructorName 1900 = Context.DeclarationNames.getCXXConstructorName( 1901 Context.getCanonicalType(ToType).getUnqualifiedType()); 1902 DeclContext::lookup_iterator Con, ConEnd; 1903 for (llvm::tie(Con, ConEnd) 1904 = ToRecordDecl->lookup(ConstructorName); 1905 Con != ConEnd; ++Con) { 1906 NamedDecl *D = *Con; 1907 DeclAccessPair FoundDecl = DeclAccessPair::make(D, D->getAccess()); 1908 1909 // Find the constructor (which may be a template). 1910 CXXConstructorDecl *Constructor = 0; 1911 FunctionTemplateDecl *ConstructorTmpl 1912 = dyn_cast<FunctionTemplateDecl>(D); 1913 if (ConstructorTmpl) 1914 Constructor 1915 = cast<CXXConstructorDecl>(ConstructorTmpl->getTemplatedDecl()); 1916 else 1917 Constructor = cast<CXXConstructorDecl>(D); 1918 1919 if (!Constructor->isInvalidDecl() && 1920 Constructor->isConvertingConstructor(AllowExplicit)) { 1921 if (ConstructorTmpl) 1922 AddTemplateOverloadCandidate(ConstructorTmpl, FoundDecl, 1923 /*ExplicitArgs*/ 0, 1924 &From, 1, CandidateSet, 1925 /*SuppressUserConversions=*/!ConstructorsOnly); 1926 else 1927 // Allow one user-defined conversion when user specifies a 1928 // From->ToType conversion via an static cast (c-style, etc). 1929 AddOverloadCandidate(Constructor, FoundDecl, 1930 &From, 1, CandidateSet, 1931 /*SuppressUserConversions=*/!ConstructorsOnly); 1932 } 1933 } 1934 } 1935 } 1936 1937 // Enumerate conversion functions, if we're allowed to. 1938 if (ConstructorsOnly) { 1939 } else if (RequireCompleteType(From->getLocStart(), From->getType(), 1940 PDiag(0) << From->getSourceRange())) { 1941 // No conversion functions from incomplete types. 1942 } else if (const RecordType *FromRecordType 1943 = From->getType()->getAs<RecordType>()) { 1944 if (CXXRecordDecl *FromRecordDecl 1945 = dyn_cast<CXXRecordDecl>(FromRecordType->getDecl())) { 1946 // Add all of the conversion functions as candidates. 1947 const UnresolvedSetImpl *Conversions 1948 = FromRecordDecl->getVisibleConversionFunctions(); 1949 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 1950 E = Conversions->end(); I != E; ++I) { 1951 DeclAccessPair FoundDecl = I.getPair(); 1952 NamedDecl *D = FoundDecl.getDecl(); 1953 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 1954 if (isa<UsingShadowDecl>(D)) 1955 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 1956 1957 CXXConversionDecl *Conv; 1958 FunctionTemplateDecl *ConvTemplate; 1959 if ((ConvTemplate = dyn_cast<FunctionTemplateDecl>(D))) 1960 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 1961 else 1962 Conv = cast<CXXConversionDecl>(D); 1963 1964 if (AllowExplicit || !Conv->isExplicit()) { 1965 if (ConvTemplate) 1966 AddTemplateConversionCandidate(ConvTemplate, FoundDecl, 1967 ActingContext, From, ToType, 1968 CandidateSet); 1969 else 1970 AddConversionCandidate(Conv, FoundDecl, ActingContext, 1971 From, ToType, CandidateSet); 1972 } 1973 } 1974 } 1975 } 1976 1977 OverloadCandidateSet::iterator Best; 1978 switch (BestViableFunction(CandidateSet, From->getLocStart(), Best)) { 1979 case OR_Success: 1980 // Record the standard conversion we used and the conversion function. 1981 if (CXXConstructorDecl *Constructor 1982 = dyn_cast<CXXConstructorDecl>(Best->Function)) { 1983 // C++ [over.ics.user]p1: 1984 // If the user-defined conversion is specified by a 1985 // constructor (12.3.1), the initial standard conversion 1986 // sequence converts the source type to the type required by 1987 // the argument of the constructor. 1988 // 1989 QualType ThisType = Constructor->getThisType(Context); 1990 if (Best->Conversions[0].isEllipsis()) 1991 User.EllipsisConversion = true; 1992 else { 1993 User.Before = Best->Conversions[0].Standard; 1994 User.EllipsisConversion = false; 1995 } 1996 User.ConversionFunction = Constructor; 1997 User.After.setAsIdentityConversion(); 1998 User.After.setFromType( 1999 ThisType->getAs<PointerType>()->getPointeeType()); 2000 User.After.setAllToTypes(ToType); 2001 return OR_Success; 2002 } else if (CXXConversionDecl *Conversion 2003 = dyn_cast<CXXConversionDecl>(Best->Function)) { 2004 // C++ [over.ics.user]p1: 2005 // 2006 // [...] If the user-defined conversion is specified by a 2007 // conversion function (12.3.2), the initial standard 2008 // conversion sequence converts the source type to the 2009 // implicit object parameter of the conversion function. 2010 User.Before = Best->Conversions[0].Standard; 2011 User.ConversionFunction = Conversion; 2012 User.EllipsisConversion = false; 2013 2014 // C++ [over.ics.user]p2: 2015 // The second standard conversion sequence converts the 2016 // result of the user-defined conversion to the target type 2017 // for the sequence. Since an implicit conversion sequence 2018 // is an initialization, the special rules for 2019 // initialization by user-defined conversion apply when 2020 // selecting the best user-defined conversion for a 2021 // user-defined conversion sequence (see 13.3.3 and 2022 // 13.3.3.1). 2023 User.After = Best->FinalConversion; 2024 return OR_Success; 2025 } else { 2026 assert(false && "Not a constructor or conversion function?"); 2027 return OR_No_Viable_Function; 2028 } 2029 2030 case OR_No_Viable_Function: 2031 return OR_No_Viable_Function; 2032 case OR_Deleted: 2033 // No conversion here! We're done. 2034 return OR_Deleted; 2035 2036 case OR_Ambiguous: 2037 return OR_Ambiguous; 2038 } 2039 2040 return OR_No_Viable_Function; 2041} 2042 2043bool 2044Sema::DiagnoseMultipleUserDefinedConversion(Expr *From, QualType ToType) { 2045 ImplicitConversionSequence ICS; 2046 OverloadCandidateSet CandidateSet(From->getExprLoc()); 2047 OverloadingResult OvResult = 2048 IsUserDefinedConversion(From, ToType, ICS.UserDefined, 2049 CandidateSet, false); 2050 if (OvResult == OR_Ambiguous) 2051 Diag(From->getSourceRange().getBegin(), 2052 diag::err_typecheck_ambiguous_condition) 2053 << From->getType() << ToType << From->getSourceRange(); 2054 else if (OvResult == OR_No_Viable_Function && !CandidateSet.empty()) 2055 Diag(From->getSourceRange().getBegin(), 2056 diag::err_typecheck_nonviable_condition) 2057 << From->getType() << ToType << From->getSourceRange(); 2058 else 2059 return false; 2060 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &From, 1); 2061 return true; 2062} 2063 2064/// CompareImplicitConversionSequences - Compare two implicit 2065/// conversion sequences to determine whether one is better than the 2066/// other or if they are indistinguishable (C++ 13.3.3.2). 2067ImplicitConversionSequence::CompareKind 2068Sema::CompareImplicitConversionSequences(const ImplicitConversionSequence& ICS1, 2069 const ImplicitConversionSequence& ICS2) 2070{ 2071 // (C++ 13.3.3.2p2): When comparing the basic forms of implicit 2072 // conversion sequences (as defined in 13.3.3.1) 2073 // -- a standard conversion sequence (13.3.3.1.1) is a better 2074 // conversion sequence than a user-defined conversion sequence or 2075 // an ellipsis conversion sequence, and 2076 // -- a user-defined conversion sequence (13.3.3.1.2) is a better 2077 // conversion sequence than an ellipsis conversion sequence 2078 // (13.3.3.1.3). 2079 // 2080 // C++0x [over.best.ics]p10: 2081 // For the purpose of ranking implicit conversion sequences as 2082 // described in 13.3.3.2, the ambiguous conversion sequence is 2083 // treated as a user-defined sequence that is indistinguishable 2084 // from any other user-defined conversion sequence. 2085 if (ICS1.getKindRank() < ICS2.getKindRank()) 2086 return ImplicitConversionSequence::Better; 2087 else if (ICS2.getKindRank() < ICS1.getKindRank()) 2088 return ImplicitConversionSequence::Worse; 2089 2090 // The following checks require both conversion sequences to be of 2091 // the same kind. 2092 if (ICS1.getKind() != ICS2.getKind()) 2093 return ImplicitConversionSequence::Indistinguishable; 2094 2095 // Two implicit conversion sequences of the same form are 2096 // indistinguishable conversion sequences unless one of the 2097 // following rules apply: (C++ 13.3.3.2p3): 2098 if (ICS1.isStandard()) 2099 return CompareStandardConversionSequences(ICS1.Standard, ICS2.Standard); 2100 else if (ICS1.isUserDefined()) { 2101 // User-defined conversion sequence U1 is a better conversion 2102 // sequence than another user-defined conversion sequence U2 if 2103 // they contain the same user-defined conversion function or 2104 // constructor and if the second standard conversion sequence of 2105 // U1 is better than the second standard conversion sequence of 2106 // U2 (C++ 13.3.3.2p3). 2107 if (ICS1.UserDefined.ConversionFunction == 2108 ICS2.UserDefined.ConversionFunction) 2109 return CompareStandardConversionSequences(ICS1.UserDefined.After, 2110 ICS2.UserDefined.After); 2111 } 2112 2113 return ImplicitConversionSequence::Indistinguishable; 2114} 2115 2116static bool hasSimilarType(ASTContext &Context, QualType T1, QualType T2) { 2117 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2118 Qualifiers Quals; 2119 T1 = Context.getUnqualifiedArrayType(T1, Quals); 2120 T2 = Context.getUnqualifiedArrayType(T2, Quals); 2121 } 2122 2123 return Context.hasSameUnqualifiedType(T1, T2); 2124} 2125 2126// Per 13.3.3.2p3, compare the given standard conversion sequences to 2127// determine if one is a proper subset of the other. 2128static ImplicitConversionSequence::CompareKind 2129compareStandardConversionSubsets(ASTContext &Context, 2130 const StandardConversionSequence& SCS1, 2131 const StandardConversionSequence& SCS2) { 2132 ImplicitConversionSequence::CompareKind Result 2133 = ImplicitConversionSequence::Indistinguishable; 2134 2135 // the identity conversion sequence is considered to be a subsequence of 2136 // any non-identity conversion sequence 2137 if (SCS1.ReferenceBinding == SCS2.ReferenceBinding) { 2138 if (SCS1.isIdentityConversion() && !SCS2.isIdentityConversion()) 2139 return ImplicitConversionSequence::Better; 2140 else if (!SCS1.isIdentityConversion() && SCS2.isIdentityConversion()) 2141 return ImplicitConversionSequence::Worse; 2142 } 2143 2144 if (SCS1.Second != SCS2.Second) { 2145 if (SCS1.Second == ICK_Identity) 2146 Result = ImplicitConversionSequence::Better; 2147 else if (SCS2.Second == ICK_Identity) 2148 Result = ImplicitConversionSequence::Worse; 2149 else 2150 return ImplicitConversionSequence::Indistinguishable; 2151 } else if (!hasSimilarType(Context, SCS1.getToType(1), SCS2.getToType(1))) 2152 return ImplicitConversionSequence::Indistinguishable; 2153 2154 if (SCS1.Third == SCS2.Third) { 2155 return Context.hasSameType(SCS1.getToType(2), SCS2.getToType(2))? Result 2156 : ImplicitConversionSequence::Indistinguishable; 2157 } 2158 2159 if (SCS1.Third == ICK_Identity) 2160 return Result == ImplicitConversionSequence::Worse 2161 ? ImplicitConversionSequence::Indistinguishable 2162 : ImplicitConversionSequence::Better; 2163 2164 if (SCS2.Third == ICK_Identity) 2165 return Result == ImplicitConversionSequence::Better 2166 ? ImplicitConversionSequence::Indistinguishable 2167 : ImplicitConversionSequence::Worse; 2168 2169 return ImplicitConversionSequence::Indistinguishable; 2170} 2171 2172/// CompareStandardConversionSequences - Compare two standard 2173/// conversion sequences to determine whether one is better than the 2174/// other or if they are indistinguishable (C++ 13.3.3.2p3). 2175ImplicitConversionSequence::CompareKind 2176Sema::CompareStandardConversionSequences(const StandardConversionSequence& SCS1, 2177 const StandardConversionSequence& SCS2) 2178{ 2179 // Standard conversion sequence S1 is a better conversion sequence 2180 // than standard conversion sequence S2 if (C++ 13.3.3.2p3): 2181 2182 // -- S1 is a proper subsequence of S2 (comparing the conversion 2183 // sequences in the canonical form defined by 13.3.3.1.1, 2184 // excluding any Lvalue Transformation; the identity conversion 2185 // sequence is considered to be a subsequence of any 2186 // non-identity conversion sequence) or, if not that, 2187 if (ImplicitConversionSequence::CompareKind CK 2188 = compareStandardConversionSubsets(Context, SCS1, SCS2)) 2189 return CK; 2190 2191 // -- the rank of S1 is better than the rank of S2 (by the rules 2192 // defined below), or, if not that, 2193 ImplicitConversionRank Rank1 = SCS1.getRank(); 2194 ImplicitConversionRank Rank2 = SCS2.getRank(); 2195 if (Rank1 < Rank2) 2196 return ImplicitConversionSequence::Better; 2197 else if (Rank2 < Rank1) 2198 return ImplicitConversionSequence::Worse; 2199 2200 // (C++ 13.3.3.2p4): Two conversion sequences with the same rank 2201 // are indistinguishable unless one of the following rules 2202 // applies: 2203 2204 // A conversion that is not a conversion of a pointer, or 2205 // pointer to member, to bool is better than another conversion 2206 // that is such a conversion. 2207 if (SCS1.isPointerConversionToBool() != SCS2.isPointerConversionToBool()) 2208 return SCS2.isPointerConversionToBool() 2209 ? ImplicitConversionSequence::Better 2210 : ImplicitConversionSequence::Worse; 2211 2212 // C++ [over.ics.rank]p4b2: 2213 // 2214 // If class B is derived directly or indirectly from class A, 2215 // conversion of B* to A* is better than conversion of B* to 2216 // void*, and conversion of A* to void* is better than conversion 2217 // of B* to void*. 2218 bool SCS1ConvertsToVoid 2219 = SCS1.isPointerConversionToVoidPointer(Context); 2220 bool SCS2ConvertsToVoid 2221 = SCS2.isPointerConversionToVoidPointer(Context); 2222 if (SCS1ConvertsToVoid != SCS2ConvertsToVoid) { 2223 // Exactly one of the conversion sequences is a conversion to 2224 // a void pointer; it's the worse conversion. 2225 return SCS2ConvertsToVoid ? ImplicitConversionSequence::Better 2226 : ImplicitConversionSequence::Worse; 2227 } else if (!SCS1ConvertsToVoid && !SCS2ConvertsToVoid) { 2228 // Neither conversion sequence converts to a void pointer; compare 2229 // their derived-to-base conversions. 2230 if (ImplicitConversionSequence::CompareKind DerivedCK 2231 = CompareDerivedToBaseConversions(SCS1, SCS2)) 2232 return DerivedCK; 2233 } else if (SCS1ConvertsToVoid && SCS2ConvertsToVoid) { 2234 // Both conversion sequences are conversions to void 2235 // pointers. Compare the source types to determine if there's an 2236 // inheritance relationship in their sources. 2237 QualType FromType1 = SCS1.getFromType(); 2238 QualType FromType2 = SCS2.getFromType(); 2239 2240 // Adjust the types we're converting from via the array-to-pointer 2241 // conversion, if we need to. 2242 if (SCS1.First == ICK_Array_To_Pointer) 2243 FromType1 = Context.getArrayDecayedType(FromType1); 2244 if (SCS2.First == ICK_Array_To_Pointer) 2245 FromType2 = Context.getArrayDecayedType(FromType2); 2246 2247 QualType FromPointee1 2248 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2249 QualType FromPointee2 2250 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2251 2252 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2253 return ImplicitConversionSequence::Better; 2254 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2255 return ImplicitConversionSequence::Worse; 2256 2257 // Objective-C++: If one interface is more specific than the 2258 // other, it is the better one. 2259 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2260 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2261 if (FromIface1 && FromIface1) { 2262 if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2263 return ImplicitConversionSequence::Better; 2264 else if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2265 return ImplicitConversionSequence::Worse; 2266 } 2267 } 2268 2269 // Compare based on qualification conversions (C++ 13.3.3.2p3, 2270 // bullet 3). 2271 if (ImplicitConversionSequence::CompareKind QualCK 2272 = CompareQualificationConversions(SCS1, SCS2)) 2273 return QualCK; 2274 2275 if (SCS1.ReferenceBinding && SCS2.ReferenceBinding) { 2276 // C++0x [over.ics.rank]p3b4: 2277 // -- S1 and S2 are reference bindings (8.5.3) and neither refers to an 2278 // implicit object parameter of a non-static member function declared 2279 // without a ref-qualifier, and S1 binds an rvalue reference to an 2280 // rvalue and S2 binds an lvalue reference. 2281 // FIXME: We don't know if we're dealing with the implicit object parameter, 2282 // or if the member function in this case has a ref qualifier. 2283 // (Of course, we don't have ref qualifiers yet.) 2284 if (SCS1.RRefBinding != SCS2.RRefBinding) 2285 return SCS1.RRefBinding ? ImplicitConversionSequence::Better 2286 : ImplicitConversionSequence::Worse; 2287 2288 // C++ [over.ics.rank]p3b4: 2289 // -- S1 and S2 are reference bindings (8.5.3), and the types to 2290 // which the references refer are the same type except for 2291 // top-level cv-qualifiers, and the type to which the reference 2292 // initialized by S2 refers is more cv-qualified than the type 2293 // to which the reference initialized by S1 refers. 2294 QualType T1 = SCS1.getToType(2); 2295 QualType T2 = SCS2.getToType(2); 2296 T1 = Context.getCanonicalType(T1); 2297 T2 = Context.getCanonicalType(T2); 2298 Qualifiers T1Quals, T2Quals; 2299 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2300 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2301 if (UnqualT1 == UnqualT2) { 2302 // If the type is an array type, promote the element qualifiers to the type 2303 // for comparison. 2304 if (isa<ArrayType>(T1) && T1Quals) 2305 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2306 if (isa<ArrayType>(T2) && T2Quals) 2307 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2308 if (T2.isMoreQualifiedThan(T1)) 2309 return ImplicitConversionSequence::Better; 2310 else if (T1.isMoreQualifiedThan(T2)) 2311 return ImplicitConversionSequence::Worse; 2312 } 2313 } 2314 2315 return ImplicitConversionSequence::Indistinguishable; 2316} 2317 2318/// CompareQualificationConversions - Compares two standard conversion 2319/// sequences to determine whether they can be ranked based on their 2320/// qualification conversions (C++ 13.3.3.2p3 bullet 3). 2321ImplicitConversionSequence::CompareKind 2322Sema::CompareQualificationConversions(const StandardConversionSequence& SCS1, 2323 const StandardConversionSequence& SCS2) { 2324 // C++ 13.3.3.2p3: 2325 // -- S1 and S2 differ only in their qualification conversion and 2326 // yield similar types T1 and T2 (C++ 4.4), respectively, and the 2327 // cv-qualification signature of type T1 is a proper subset of 2328 // the cv-qualification signature of type T2, and S1 is not the 2329 // deprecated string literal array-to-pointer conversion (4.2). 2330 if (SCS1.First != SCS2.First || SCS1.Second != SCS2.Second || 2331 SCS1.Third != SCS2.Third || SCS1.Third != ICK_Qualification) 2332 return ImplicitConversionSequence::Indistinguishable; 2333 2334 // FIXME: the example in the standard doesn't use a qualification 2335 // conversion (!) 2336 QualType T1 = SCS1.getToType(2); 2337 QualType T2 = SCS2.getToType(2); 2338 T1 = Context.getCanonicalType(T1); 2339 T2 = Context.getCanonicalType(T2); 2340 Qualifiers T1Quals, T2Quals; 2341 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2342 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2343 2344 // If the types are the same, we won't learn anything by unwrapped 2345 // them. 2346 if (UnqualT1 == UnqualT2) 2347 return ImplicitConversionSequence::Indistinguishable; 2348 2349 // If the type is an array type, promote the element qualifiers to the type 2350 // for comparison. 2351 if (isa<ArrayType>(T1) && T1Quals) 2352 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2353 if (isa<ArrayType>(T2) && T2Quals) 2354 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2355 2356 ImplicitConversionSequence::CompareKind Result 2357 = ImplicitConversionSequence::Indistinguishable; 2358 while (Context.UnwrapSimilarPointerTypes(T1, T2)) { 2359 // Within each iteration of the loop, we check the qualifiers to 2360 // determine if this still looks like a qualification 2361 // conversion. Then, if all is well, we unwrap one more level of 2362 // pointers or pointers-to-members and do it all again 2363 // until there are no more pointers or pointers-to-members left 2364 // to unwrap. This essentially mimics what 2365 // IsQualificationConversion does, but here we're checking for a 2366 // strict subset of qualifiers. 2367 if (T1.getCVRQualifiers() == T2.getCVRQualifiers()) 2368 // The qualifiers are the same, so this doesn't tell us anything 2369 // about how the sequences rank. 2370 ; 2371 else if (T2.isMoreQualifiedThan(T1)) { 2372 // T1 has fewer qualifiers, so it could be the better sequence. 2373 if (Result == ImplicitConversionSequence::Worse) 2374 // Neither has qualifiers that are a subset of the other's 2375 // qualifiers. 2376 return ImplicitConversionSequence::Indistinguishable; 2377 2378 Result = ImplicitConversionSequence::Better; 2379 } else if (T1.isMoreQualifiedThan(T2)) { 2380 // T2 has fewer qualifiers, so it could be the better sequence. 2381 if (Result == ImplicitConversionSequence::Better) 2382 // Neither has qualifiers that are a subset of the other's 2383 // qualifiers. 2384 return ImplicitConversionSequence::Indistinguishable; 2385 2386 Result = ImplicitConversionSequence::Worse; 2387 } else { 2388 // Qualifiers are disjoint. 2389 return ImplicitConversionSequence::Indistinguishable; 2390 } 2391 2392 // If the types after this point are equivalent, we're done. 2393 if (Context.hasSameUnqualifiedType(T1, T2)) 2394 break; 2395 } 2396 2397 // Check that the winning standard conversion sequence isn't using 2398 // the deprecated string literal array to pointer conversion. 2399 switch (Result) { 2400 case ImplicitConversionSequence::Better: 2401 if (SCS1.DeprecatedStringLiteralToCharPtr) 2402 Result = ImplicitConversionSequence::Indistinguishable; 2403 break; 2404 2405 case ImplicitConversionSequence::Indistinguishable: 2406 break; 2407 2408 case ImplicitConversionSequence::Worse: 2409 if (SCS2.DeprecatedStringLiteralToCharPtr) 2410 Result = ImplicitConversionSequence::Indistinguishable; 2411 break; 2412 } 2413 2414 return Result; 2415} 2416 2417/// CompareDerivedToBaseConversions - Compares two standard conversion 2418/// sequences to determine whether they can be ranked based on their 2419/// various kinds of derived-to-base conversions (C++ 2420/// [over.ics.rank]p4b3). As part of these checks, we also look at 2421/// conversions between Objective-C interface types. 2422ImplicitConversionSequence::CompareKind 2423Sema::CompareDerivedToBaseConversions(const StandardConversionSequence& SCS1, 2424 const StandardConversionSequence& SCS2) { 2425 QualType FromType1 = SCS1.getFromType(); 2426 QualType ToType1 = SCS1.getToType(1); 2427 QualType FromType2 = SCS2.getFromType(); 2428 QualType ToType2 = SCS2.getToType(1); 2429 2430 // Adjust the types we're converting from via the array-to-pointer 2431 // conversion, if we need to. 2432 if (SCS1.First == ICK_Array_To_Pointer) 2433 FromType1 = Context.getArrayDecayedType(FromType1); 2434 if (SCS2.First == ICK_Array_To_Pointer) 2435 FromType2 = Context.getArrayDecayedType(FromType2); 2436 2437 // Canonicalize all of the types. 2438 FromType1 = Context.getCanonicalType(FromType1); 2439 ToType1 = Context.getCanonicalType(ToType1); 2440 FromType2 = Context.getCanonicalType(FromType2); 2441 ToType2 = Context.getCanonicalType(ToType2); 2442 2443 // C++ [over.ics.rank]p4b3: 2444 // 2445 // If class B is derived directly or indirectly from class A and 2446 // class C is derived directly or indirectly from B, 2447 // 2448 // For Objective-C, we let A, B, and C also be Objective-C 2449 // interfaces. 2450 2451 // Compare based on pointer conversions. 2452 if (SCS1.Second == ICK_Pointer_Conversion && 2453 SCS2.Second == ICK_Pointer_Conversion && 2454 /*FIXME: Remove if Objective-C id conversions get their own rank*/ 2455 FromType1->isPointerType() && FromType2->isPointerType() && 2456 ToType1->isPointerType() && ToType2->isPointerType()) { 2457 QualType FromPointee1 2458 = FromType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2459 QualType ToPointee1 2460 = ToType1->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2461 QualType FromPointee2 2462 = FromType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2463 QualType ToPointee2 2464 = ToType2->getAs<PointerType>()->getPointeeType().getUnqualifiedType(); 2465 2466 const ObjCObjectType* FromIface1 = FromPointee1->getAs<ObjCObjectType>(); 2467 const ObjCObjectType* FromIface2 = FromPointee2->getAs<ObjCObjectType>(); 2468 const ObjCObjectType* ToIface1 = ToPointee1->getAs<ObjCObjectType>(); 2469 const ObjCObjectType* ToIface2 = ToPointee2->getAs<ObjCObjectType>(); 2470 2471 // -- conversion of C* to B* is better than conversion of C* to A*, 2472 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2473 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2474 return ImplicitConversionSequence::Better; 2475 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2476 return ImplicitConversionSequence::Worse; 2477 2478 if (ToIface1 && ToIface2) { 2479 if (Context.canAssignObjCInterfaces(ToIface2, ToIface1)) 2480 return ImplicitConversionSequence::Better; 2481 else if (Context.canAssignObjCInterfaces(ToIface1, ToIface2)) 2482 return ImplicitConversionSequence::Worse; 2483 } 2484 } 2485 2486 // -- conversion of B* to A* is better than conversion of C* to A*, 2487 if (FromPointee1 != FromPointee2 && ToPointee1 == ToPointee2) { 2488 if (IsDerivedFrom(FromPointee2, FromPointee1)) 2489 return ImplicitConversionSequence::Better; 2490 else if (IsDerivedFrom(FromPointee1, FromPointee2)) 2491 return ImplicitConversionSequence::Worse; 2492 2493 if (FromIface1 && FromIface2) { 2494 if (Context.canAssignObjCInterfaces(FromIface1, FromIface2)) 2495 return ImplicitConversionSequence::Better; 2496 else if (Context.canAssignObjCInterfaces(FromIface2, FromIface1)) 2497 return ImplicitConversionSequence::Worse; 2498 } 2499 } 2500 } 2501 2502 // Ranking of member-pointer types. 2503 if (SCS1.Second == ICK_Pointer_Member && SCS2.Second == ICK_Pointer_Member && 2504 FromType1->isMemberPointerType() && FromType2->isMemberPointerType() && 2505 ToType1->isMemberPointerType() && ToType2->isMemberPointerType()) { 2506 const MemberPointerType * FromMemPointer1 = 2507 FromType1->getAs<MemberPointerType>(); 2508 const MemberPointerType * ToMemPointer1 = 2509 ToType1->getAs<MemberPointerType>(); 2510 const MemberPointerType * FromMemPointer2 = 2511 FromType2->getAs<MemberPointerType>(); 2512 const MemberPointerType * ToMemPointer2 = 2513 ToType2->getAs<MemberPointerType>(); 2514 const Type *FromPointeeType1 = FromMemPointer1->getClass(); 2515 const Type *ToPointeeType1 = ToMemPointer1->getClass(); 2516 const Type *FromPointeeType2 = FromMemPointer2->getClass(); 2517 const Type *ToPointeeType2 = ToMemPointer2->getClass(); 2518 QualType FromPointee1 = QualType(FromPointeeType1, 0).getUnqualifiedType(); 2519 QualType ToPointee1 = QualType(ToPointeeType1, 0).getUnqualifiedType(); 2520 QualType FromPointee2 = QualType(FromPointeeType2, 0).getUnqualifiedType(); 2521 QualType ToPointee2 = QualType(ToPointeeType2, 0).getUnqualifiedType(); 2522 // conversion of A::* to B::* is better than conversion of A::* to C::*, 2523 if (FromPointee1 == FromPointee2 && ToPointee1 != ToPointee2) { 2524 if (IsDerivedFrom(ToPointee1, ToPointee2)) 2525 return ImplicitConversionSequence::Worse; 2526 else if (IsDerivedFrom(ToPointee2, ToPointee1)) 2527 return ImplicitConversionSequence::Better; 2528 } 2529 // conversion of B::* to C::* is better than conversion of A::* to C::* 2530 if (ToPointee1 == ToPointee2 && FromPointee1 != FromPointee2) { 2531 if (IsDerivedFrom(FromPointee1, FromPointee2)) 2532 return ImplicitConversionSequence::Better; 2533 else if (IsDerivedFrom(FromPointee2, FromPointee1)) 2534 return ImplicitConversionSequence::Worse; 2535 } 2536 } 2537 2538 if (SCS1.Second == ICK_Derived_To_Base) { 2539 // -- conversion of C to B is better than conversion of C to A, 2540 // -- binding of an expression of type C to a reference of type 2541 // B& is better than binding an expression of type C to a 2542 // reference of type A&, 2543 if (Context.hasSameUnqualifiedType(FromType1, FromType2) && 2544 !Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2545 if (IsDerivedFrom(ToType1, ToType2)) 2546 return ImplicitConversionSequence::Better; 2547 else if (IsDerivedFrom(ToType2, ToType1)) 2548 return ImplicitConversionSequence::Worse; 2549 } 2550 2551 // -- conversion of B to A is better than conversion of C to A. 2552 // -- binding of an expression of type B to a reference of type 2553 // A& is better than binding an expression of type C to a 2554 // reference of type A&, 2555 if (!Context.hasSameUnqualifiedType(FromType1, FromType2) && 2556 Context.hasSameUnqualifiedType(ToType1, ToType2)) { 2557 if (IsDerivedFrom(FromType2, FromType1)) 2558 return ImplicitConversionSequence::Better; 2559 else if (IsDerivedFrom(FromType1, FromType2)) 2560 return ImplicitConversionSequence::Worse; 2561 } 2562 } 2563 2564 return ImplicitConversionSequence::Indistinguishable; 2565} 2566 2567/// CompareReferenceRelationship - Compare the two types T1 and T2 to 2568/// determine whether they are reference-related, 2569/// reference-compatible, reference-compatible with added 2570/// qualification, or incompatible, for use in C++ initialization by 2571/// reference (C++ [dcl.ref.init]p4). Neither type can be a reference 2572/// type, and the first type (T1) is the pointee type of the reference 2573/// type being initialized. 2574Sema::ReferenceCompareResult 2575Sema::CompareReferenceRelationship(SourceLocation Loc, 2576 QualType OrigT1, QualType OrigT2, 2577 bool& DerivedToBase) { 2578 assert(!OrigT1->isReferenceType() && 2579 "T1 must be the pointee type of the reference type"); 2580 assert(!OrigT2->isReferenceType() && "T2 cannot be a reference type"); 2581 2582 QualType T1 = Context.getCanonicalType(OrigT1); 2583 QualType T2 = Context.getCanonicalType(OrigT2); 2584 Qualifiers T1Quals, T2Quals; 2585 QualType UnqualT1 = Context.getUnqualifiedArrayType(T1, T1Quals); 2586 QualType UnqualT2 = Context.getUnqualifiedArrayType(T2, T2Quals); 2587 2588 // C++ [dcl.init.ref]p4: 2589 // Given types "cv1 T1" and "cv2 T2," "cv1 T1" is 2590 // reference-related to "cv2 T2" if T1 is the same type as T2, or 2591 // T1 is a base class of T2. 2592 if (UnqualT1 == UnqualT2) 2593 DerivedToBase = false; 2594 else if (!RequireCompleteType(Loc, OrigT2, PDiag()) && 2595 IsDerivedFrom(UnqualT2, UnqualT1)) 2596 DerivedToBase = true; 2597 else 2598 return Ref_Incompatible; 2599 2600 // At this point, we know that T1 and T2 are reference-related (at 2601 // least). 2602 2603 // If the type is an array type, promote the element qualifiers to the type 2604 // for comparison. 2605 if (isa<ArrayType>(T1) && T1Quals) 2606 T1 = Context.getQualifiedType(UnqualT1, T1Quals); 2607 if (isa<ArrayType>(T2) && T2Quals) 2608 T2 = Context.getQualifiedType(UnqualT2, T2Quals); 2609 2610 // C++ [dcl.init.ref]p4: 2611 // "cv1 T1" is reference-compatible with "cv2 T2" if T1 is 2612 // reference-related to T2 and cv1 is the same cv-qualification 2613 // as, or greater cv-qualification than, cv2. For purposes of 2614 // overload resolution, cases for which cv1 is greater 2615 // cv-qualification than cv2 are identified as 2616 // reference-compatible with added qualification (see 13.3.3.2). 2617 if (T1Quals.getCVRQualifiers() == T2Quals.getCVRQualifiers()) 2618 return Ref_Compatible; 2619 else if (T1.isMoreQualifiedThan(T2)) 2620 return Ref_Compatible_With_Added_Qualification; 2621 else 2622 return Ref_Related; 2623} 2624 2625/// \brief Look for a user-defined conversion to an lvalue reference-compatible 2626/// with DeclType. Return true if something definite is found. 2627static bool 2628FindConversionToLValue(Sema &S, ImplicitConversionSequence &ICS, 2629 QualType DeclType, SourceLocation DeclLoc, 2630 Expr *Init, QualType T2, bool AllowExplicit) { 2631 assert(T2->isRecordType() && "Can only find conversions of record types."); 2632 CXXRecordDecl *T2RecordDecl 2633 = dyn_cast<CXXRecordDecl>(T2->getAs<RecordType>()->getDecl()); 2634 2635 OverloadCandidateSet CandidateSet(DeclLoc); 2636 const UnresolvedSetImpl *Conversions 2637 = T2RecordDecl->getVisibleConversionFunctions(); 2638 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 2639 E = Conversions->end(); I != E; ++I) { 2640 NamedDecl *D = *I; 2641 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(D->getDeclContext()); 2642 if (isa<UsingShadowDecl>(D)) 2643 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 2644 2645 FunctionTemplateDecl *ConvTemplate 2646 = dyn_cast<FunctionTemplateDecl>(D); 2647 CXXConversionDecl *Conv; 2648 if (ConvTemplate) 2649 Conv = cast<CXXConversionDecl>(ConvTemplate->getTemplatedDecl()); 2650 else 2651 Conv = cast<CXXConversionDecl>(D); 2652 2653 // If the conversion function doesn't return a reference type, 2654 // it can't be considered for this conversion. An rvalue reference 2655 // is only acceptable if its referencee is a function type. 2656 const ReferenceType *RefType = 2657 Conv->getConversionType()->getAs<ReferenceType>(); 2658 if (RefType && (RefType->isLValueReferenceType() || 2659 RefType->getPointeeType()->isFunctionType()) && 2660 (AllowExplicit || !Conv->isExplicit())) { 2661 if (ConvTemplate) 2662 S.AddTemplateConversionCandidate(ConvTemplate, I.getPair(), ActingDC, 2663 Init, DeclType, CandidateSet); 2664 else 2665 S.AddConversionCandidate(Conv, I.getPair(), ActingDC, Init, 2666 DeclType, CandidateSet); 2667 } 2668 } 2669 2670 OverloadCandidateSet::iterator Best; 2671 switch (S.BestViableFunction(CandidateSet, DeclLoc, Best)) { 2672 case OR_Success: 2673 // C++ [over.ics.ref]p1: 2674 // 2675 // [...] If the parameter binds directly to the result of 2676 // applying a conversion function to the argument 2677 // expression, the implicit conversion sequence is a 2678 // user-defined conversion sequence (13.3.3.1.2), with the 2679 // second standard conversion sequence either an identity 2680 // conversion or, if the conversion function returns an 2681 // entity of a type that is a derived class of the parameter 2682 // type, a derived-to-base Conversion. 2683 if (!Best->FinalConversion.DirectBinding) 2684 return false; 2685 2686 ICS.setUserDefined(); 2687 ICS.UserDefined.Before = Best->Conversions[0].Standard; 2688 ICS.UserDefined.After = Best->FinalConversion; 2689 ICS.UserDefined.ConversionFunction = Best->Function; 2690 ICS.UserDefined.EllipsisConversion = false; 2691 assert(ICS.UserDefined.After.ReferenceBinding && 2692 ICS.UserDefined.After.DirectBinding && 2693 "Expected a direct reference binding!"); 2694 return true; 2695 2696 case OR_Ambiguous: 2697 ICS.setAmbiguous(); 2698 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 2699 Cand != CandidateSet.end(); ++Cand) 2700 if (Cand->Viable) 2701 ICS.Ambiguous.addConversion(Cand->Function); 2702 return true; 2703 2704 case OR_No_Viable_Function: 2705 case OR_Deleted: 2706 // There was no suitable conversion, or we found a deleted 2707 // conversion; continue with other checks. 2708 return false; 2709 } 2710 2711 return false; 2712} 2713 2714/// \brief Compute an implicit conversion sequence for reference 2715/// initialization. 2716static ImplicitConversionSequence 2717TryReferenceInit(Sema &S, Expr *&Init, QualType DeclType, 2718 SourceLocation DeclLoc, 2719 bool SuppressUserConversions, 2720 bool AllowExplicit) { 2721 assert(DeclType->isReferenceType() && "Reference init needs a reference"); 2722 2723 // Most paths end in a failed conversion. 2724 ImplicitConversionSequence ICS; 2725 ICS.setBad(BadConversionSequence::no_conversion, Init, DeclType); 2726 2727 QualType T1 = DeclType->getAs<ReferenceType>()->getPointeeType(); 2728 QualType T2 = Init->getType(); 2729 2730 // If the initializer is the address of an overloaded function, try 2731 // to resolve the overloaded function. If all goes well, T2 is the 2732 // type of the resulting function. 2733 if (S.Context.getCanonicalType(T2) == S.Context.OverloadTy) { 2734 DeclAccessPair Found; 2735 if (FunctionDecl *Fn = S.ResolveAddressOfOverloadedFunction(Init, DeclType, 2736 false, Found)) 2737 T2 = Fn->getType(); 2738 } 2739 2740 // Compute some basic properties of the types and the initializer. 2741 bool isRValRef = DeclType->isRValueReferenceType(); 2742 bool DerivedToBase = false; 2743 Expr::Classification InitCategory = Init->Classify(S.Context); 2744 Sema::ReferenceCompareResult RefRelationship 2745 = S.CompareReferenceRelationship(DeclLoc, T1, T2, DerivedToBase); 2746 2747 2748 // C++0x [dcl.init.ref]p5: 2749 // A reference to type "cv1 T1" is initialized by an expression 2750 // of type "cv2 T2" as follows: 2751 2752 // -- If reference is an lvalue reference and the initializer expression 2753 // The next bullet point (T1 is a function) is pretty much equivalent to this 2754 // one, so it's handled here. 2755 if (!isRValRef || T1->isFunctionType()) { 2756 // -- is an lvalue (but is not a bit-field), and "cv1 T1" is 2757 // reference-compatible with "cv2 T2," or 2758 // 2759 // Per C++ [over.ics.ref]p4, we don't check the bit-field property here. 2760 if (InitCategory.isLValue() && 2761 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2762 // C++ [over.ics.ref]p1: 2763 // When a parameter of reference type binds directly (8.5.3) 2764 // to an argument expression, the implicit conversion sequence 2765 // is the identity conversion, unless the argument expression 2766 // has a type that is a derived class of the parameter type, 2767 // in which case the implicit conversion sequence is a 2768 // derived-to-base Conversion (13.3.3.1). 2769 ICS.setStandard(); 2770 ICS.Standard.First = ICK_Identity; 2771 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2772 ICS.Standard.Third = ICK_Identity; 2773 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2774 ICS.Standard.setToType(0, T2); 2775 ICS.Standard.setToType(1, T1); 2776 ICS.Standard.setToType(2, T1); 2777 ICS.Standard.ReferenceBinding = true; 2778 ICS.Standard.DirectBinding = true; 2779 ICS.Standard.RRefBinding = isRValRef; 2780 ICS.Standard.CopyConstructor = 0; 2781 2782 // Nothing more to do: the inaccessibility/ambiguity check for 2783 // derived-to-base conversions is suppressed when we're 2784 // computing the implicit conversion sequence (C++ 2785 // [over.best.ics]p2). 2786 return ICS; 2787 } 2788 2789 // -- has a class type (i.e., T2 is a class type), where T1 is 2790 // not reference-related to T2, and can be implicitly 2791 // converted to an lvalue of type "cv3 T3," where "cv1 T1" 2792 // is reference-compatible with "cv3 T3" 92) (this 2793 // conversion is selected by enumerating the applicable 2794 // conversion functions (13.3.1.6) and choosing the best 2795 // one through overload resolution (13.3)), 2796 if (!SuppressUserConversions && T2->isRecordType() && 2797 !S.RequireCompleteType(DeclLoc, T2, 0) && 2798 RefRelationship == Sema::Ref_Incompatible) { 2799 if (FindConversionToLValue(S, ICS, DeclType, DeclLoc, 2800 Init, T2, AllowExplicit)) 2801 return ICS; 2802 } 2803 } 2804 2805 // -- Otherwise, the reference shall be an lvalue reference to a 2806 // non-volatile const type (i.e., cv1 shall be const), or the reference 2807 // shall be an rvalue reference and the initializer expression shall be 2808 // an rvalue or have a function type. 2809 // 2810 // We actually handle one oddity of C++ [over.ics.ref] at this 2811 // point, which is that, due to p2 (which short-circuits reference 2812 // binding by only attempting a simple conversion for non-direct 2813 // bindings) and p3's strange wording, we allow a const volatile 2814 // reference to bind to an rvalue. Hence the check for the presence 2815 // of "const" rather than checking for "const" being the only 2816 // qualifier. 2817 // This is also the point where rvalue references and lvalue inits no longer 2818 // go together. 2819 if ((!isRValRef && !T1.isConstQualified()) || 2820 (isRValRef && InitCategory.isLValue())) 2821 return ICS; 2822 2823 // -- If T1 is a function type, then 2824 // -- if T2 is the same type as T1, the reference is bound to the 2825 // initializer expression lvalue; 2826 // -- if T2 is a class type and the initializer expression can be 2827 // implicitly converted to an lvalue of type T1 [...], the 2828 // reference is bound to the function lvalue that is the result 2829 // of the conversion; 2830 // This is the same as for the lvalue case above, so it was handled there. 2831 // -- otherwise, the program is ill-formed. 2832 // This is the one difference to the lvalue case. 2833 if (T1->isFunctionType()) 2834 return ICS; 2835 2836 // -- Otherwise, if T2 is a class type and 2837 // -- the initializer expression is an rvalue and "cv1 T1" 2838 // is reference-compatible with "cv2 T2," or 2839 // 2840 // -- T1 is not reference-related to T2 and the initializer 2841 // expression can be implicitly converted to an rvalue 2842 // of type "cv3 T3" (this conversion is selected by 2843 // enumerating the applicable conversion functions 2844 // (13.3.1.6) and choosing the best one through overload 2845 // resolution (13.3)), 2846 // 2847 // then the reference is bound to the initializer 2848 // expression rvalue in the first case and to the object 2849 // that is the result of the conversion in the second case 2850 // (or, in either case, to the appropriate base class 2851 // subobject of the object). 2852 // 2853 // We're only checking the first case here, which is a direct 2854 // binding in C++0x but not in C++03. 2855 if (InitCategory.isRValue() && T2->isRecordType() && 2856 RefRelationship >= Sema::Ref_Compatible_With_Added_Qualification) { 2857 ICS.setStandard(); 2858 ICS.Standard.First = ICK_Identity; 2859 ICS.Standard.Second = DerivedToBase? ICK_Derived_To_Base : ICK_Identity; 2860 ICS.Standard.Third = ICK_Identity; 2861 ICS.Standard.FromTypePtr = T2.getAsOpaquePtr(); 2862 ICS.Standard.setToType(0, T2); 2863 ICS.Standard.setToType(1, T1); 2864 ICS.Standard.setToType(2, T1); 2865 ICS.Standard.ReferenceBinding = true; 2866 ICS.Standard.DirectBinding = S.getLangOptions().CPlusPlus0x; 2867 ICS.Standard.RRefBinding = isRValRef; 2868 ICS.Standard.CopyConstructor = 0; 2869 return ICS; 2870 } 2871 2872 // -- Otherwise, a temporary of type "cv1 T1" is created and 2873 // initialized from the initializer expression using the 2874 // rules for a non-reference copy initialization (8.5). The 2875 // reference is then bound to the temporary. If T1 is 2876 // reference-related to T2, cv1 must be the same 2877 // cv-qualification as, or greater cv-qualification than, 2878 // cv2; otherwise, the program is ill-formed. 2879 if (RefRelationship == Sema::Ref_Related) { 2880 // If cv1 == cv2 or cv1 is a greater cv-qualified than cv2, then 2881 // we would be reference-compatible or reference-compatible with 2882 // added qualification. But that wasn't the case, so the reference 2883 // initialization fails. 2884 return ICS; 2885 } 2886 2887 // If at least one of the types is a class type, the types are not 2888 // related, and we aren't allowed any user conversions, the 2889 // reference binding fails. This case is important for breaking 2890 // recursion, since TryImplicitConversion below will attempt to 2891 // create a temporary through the use of a copy constructor. 2892 if (SuppressUserConversions && RefRelationship == Sema::Ref_Incompatible && 2893 (T1->isRecordType() || T2->isRecordType())) 2894 return ICS; 2895 2896 // C++ [over.ics.ref]p2: 2897 // When a parameter of reference type is not bound directly to 2898 // an argument expression, the conversion sequence is the one 2899 // required to convert the argument expression to the 2900 // underlying type of the reference according to 2901 // 13.3.3.1. Conceptually, this conversion sequence corresponds 2902 // to copy-initializing a temporary of the underlying type with 2903 // the argument expression. Any difference in top-level 2904 // cv-qualification is subsumed by the initialization itself 2905 // and does not constitute a conversion. 2906 ICS = S.TryImplicitConversion(Init, T1, SuppressUserConversions, 2907 /*AllowExplicit=*/false, 2908 /*InOverloadResolution=*/false); 2909 2910 // Of course, that's still a reference binding. 2911 if (ICS.isStandard()) { 2912 ICS.Standard.ReferenceBinding = true; 2913 ICS.Standard.RRefBinding = isRValRef; 2914 } else if (ICS.isUserDefined()) { 2915 ICS.UserDefined.After.ReferenceBinding = true; 2916 ICS.UserDefined.After.RRefBinding = isRValRef; 2917 } 2918 return ICS; 2919} 2920 2921/// TryCopyInitialization - Try to copy-initialize a value of type 2922/// ToType from the expression From. Return the implicit conversion 2923/// sequence required to pass this argument, which may be a bad 2924/// conversion sequence (meaning that the argument cannot be passed to 2925/// a parameter of this type). If @p SuppressUserConversions, then we 2926/// do not permit any user-defined conversion sequences. 2927static ImplicitConversionSequence 2928TryCopyInitialization(Sema &S, Expr *From, QualType ToType, 2929 bool SuppressUserConversions, 2930 bool InOverloadResolution) { 2931 if (ToType->isReferenceType()) 2932 return TryReferenceInit(S, From, ToType, 2933 /*FIXME:*/From->getLocStart(), 2934 SuppressUserConversions, 2935 /*AllowExplicit=*/false); 2936 2937 return S.TryImplicitConversion(From, ToType, 2938 SuppressUserConversions, 2939 /*AllowExplicit=*/false, 2940 InOverloadResolution); 2941} 2942 2943/// TryObjectArgumentInitialization - Try to initialize the object 2944/// parameter of the given member function (@c Method) from the 2945/// expression @p From. 2946ImplicitConversionSequence 2947Sema::TryObjectArgumentInitialization(QualType OrigFromType, 2948 CXXMethodDecl *Method, 2949 CXXRecordDecl *ActingContext) { 2950 QualType ClassType = Context.getTypeDeclType(ActingContext); 2951 // [class.dtor]p2: A destructor can be invoked for a const, volatile or 2952 // const volatile object. 2953 unsigned Quals = isa<CXXDestructorDecl>(Method) ? 2954 Qualifiers::Const | Qualifiers::Volatile : Method->getTypeQualifiers(); 2955 QualType ImplicitParamType = Context.getCVRQualifiedType(ClassType, Quals); 2956 2957 // Set up the conversion sequence as a "bad" conversion, to allow us 2958 // to exit early. 2959 ImplicitConversionSequence ICS; 2960 2961 // We need to have an object of class type. 2962 QualType FromType = OrigFromType; 2963 if (const PointerType *PT = FromType->getAs<PointerType>()) 2964 FromType = PT->getPointeeType(); 2965 2966 assert(FromType->isRecordType()); 2967 2968 // The implicit object parameter is has the type "reference to cv X", 2969 // where X is the class of which the function is a member 2970 // (C++ [over.match.funcs]p4). However, when finding an implicit 2971 // conversion sequence for the argument, we are not allowed to 2972 // create temporaries or perform user-defined conversions 2973 // (C++ [over.match.funcs]p5). We perform a simplified version of 2974 // reference binding here, that allows class rvalues to bind to 2975 // non-constant references. 2976 2977 // First check the qualifiers. We don't care about lvalue-vs-rvalue 2978 // with the implicit object parameter (C++ [over.match.funcs]p5). 2979 QualType FromTypeCanon = Context.getCanonicalType(FromType); 2980 if (ImplicitParamType.getCVRQualifiers() 2981 != FromTypeCanon.getLocalCVRQualifiers() && 2982 !ImplicitParamType.isAtLeastAsQualifiedAs(FromTypeCanon)) { 2983 ICS.setBad(BadConversionSequence::bad_qualifiers, 2984 OrigFromType, ImplicitParamType); 2985 return ICS; 2986 } 2987 2988 // Check that we have either the same type or a derived type. It 2989 // affects the conversion rank. 2990 QualType ClassTypeCanon = Context.getCanonicalType(ClassType); 2991 ImplicitConversionKind SecondKind; 2992 if (ClassTypeCanon == FromTypeCanon.getLocalUnqualifiedType()) { 2993 SecondKind = ICK_Identity; 2994 } else if (IsDerivedFrom(FromType, ClassType)) 2995 SecondKind = ICK_Derived_To_Base; 2996 else { 2997 ICS.setBad(BadConversionSequence::unrelated_class, 2998 FromType, ImplicitParamType); 2999 return ICS; 3000 } 3001 3002 // Success. Mark this as a reference binding. 3003 ICS.setStandard(); 3004 ICS.Standard.setAsIdentityConversion(); 3005 ICS.Standard.Second = SecondKind; 3006 ICS.Standard.setFromType(FromType); 3007 ICS.Standard.setAllToTypes(ImplicitParamType); 3008 ICS.Standard.ReferenceBinding = true; 3009 ICS.Standard.DirectBinding = true; 3010 ICS.Standard.RRefBinding = false; 3011 return ICS; 3012} 3013 3014/// PerformObjectArgumentInitialization - Perform initialization of 3015/// the implicit object parameter for the given Method with the given 3016/// expression. 3017bool 3018Sema::PerformObjectArgumentInitialization(Expr *&From, 3019 NestedNameSpecifier *Qualifier, 3020 NamedDecl *FoundDecl, 3021 CXXMethodDecl *Method) { 3022 QualType FromRecordType, DestType; 3023 QualType ImplicitParamRecordType = 3024 Method->getThisType(Context)->getAs<PointerType>()->getPointeeType(); 3025 3026 if (const PointerType *PT = From->getType()->getAs<PointerType>()) { 3027 FromRecordType = PT->getPointeeType(); 3028 DestType = Method->getThisType(Context); 3029 } else { 3030 FromRecordType = From->getType(); 3031 DestType = ImplicitParamRecordType; 3032 } 3033 3034 // Note that we always use the true parent context when performing 3035 // the actual argument initialization. 3036 ImplicitConversionSequence ICS 3037 = TryObjectArgumentInitialization(From->getType(), Method, 3038 Method->getParent()); 3039 if (ICS.isBad()) 3040 return Diag(From->getSourceRange().getBegin(), 3041 diag::err_implicit_object_parameter_init) 3042 << ImplicitParamRecordType << FromRecordType << From->getSourceRange(); 3043 3044 if (ICS.Standard.Second == ICK_Derived_To_Base) 3045 return PerformObjectMemberConversion(From, Qualifier, FoundDecl, Method); 3046 3047 if (!Context.hasSameType(From->getType(), DestType)) 3048 ImpCastExprToType(From, DestType, CastExpr::CK_NoOp, 3049 /*isLvalue=*/!From->getType()->isPointerType()); 3050 return false; 3051} 3052 3053/// TryContextuallyConvertToBool - Attempt to contextually convert the 3054/// expression From to bool (C++0x [conv]p3). 3055ImplicitConversionSequence Sema::TryContextuallyConvertToBool(Expr *From) { 3056 // FIXME: This is pretty broken. 3057 return TryImplicitConversion(From, Context.BoolTy, 3058 // FIXME: Are these flags correct? 3059 /*SuppressUserConversions=*/false, 3060 /*AllowExplicit=*/true, 3061 /*InOverloadResolution=*/false); 3062} 3063 3064/// PerformContextuallyConvertToBool - Perform a contextual conversion 3065/// of the expression From to bool (C++0x [conv]p3). 3066bool Sema::PerformContextuallyConvertToBool(Expr *&From) { 3067 ImplicitConversionSequence ICS = TryContextuallyConvertToBool(From); 3068 if (!ICS.isBad()) 3069 return PerformImplicitConversion(From, Context.BoolTy, ICS, AA_Converting); 3070 3071 if (!DiagnoseMultipleUserDefinedConversion(From, Context.BoolTy)) 3072 return Diag(From->getSourceRange().getBegin(), 3073 diag::err_typecheck_bool_condition) 3074 << From->getType() << From->getSourceRange(); 3075 return true; 3076} 3077 3078/// TryContextuallyConvertToObjCId - Attempt to contextually convert the 3079/// expression From to 'id'. 3080ImplicitConversionSequence Sema::TryContextuallyConvertToObjCId(Expr *From) { 3081 QualType Ty = Context.getObjCIdType(); 3082 return TryImplicitConversion(From, Ty, 3083 // FIXME: Are these flags correct? 3084 /*SuppressUserConversions=*/false, 3085 /*AllowExplicit=*/true, 3086 /*InOverloadResolution=*/false); 3087} 3088 3089/// PerformContextuallyConvertToObjCId - Perform a contextual conversion 3090/// of the expression From to 'id'. 3091bool Sema::PerformContextuallyConvertToObjCId(Expr *&From) { 3092 QualType Ty = Context.getObjCIdType(); 3093 ImplicitConversionSequence ICS = TryContextuallyConvertToObjCId(From); 3094 if (!ICS.isBad()) 3095 return PerformImplicitConversion(From, Ty, ICS, AA_Converting); 3096 return true; 3097} 3098 3099/// \brief Attempt to convert the given expression to an integral or 3100/// enumeration type. 3101/// 3102/// This routine will attempt to convert an expression of class type to an 3103/// integral or enumeration type, if that class type only has a single 3104/// conversion to an integral or enumeration type. 3105/// 3106/// \param Loc The source location of the construct that requires the 3107/// conversion. 3108/// 3109/// \param FromE The expression we're converting from. 3110/// 3111/// \param NotIntDiag The diagnostic to be emitted if the expression does not 3112/// have integral or enumeration type. 3113/// 3114/// \param IncompleteDiag The diagnostic to be emitted if the expression has 3115/// incomplete class type. 3116/// 3117/// \param ExplicitConvDiag The diagnostic to be emitted if we're calling an 3118/// explicit conversion function (because no implicit conversion functions 3119/// were available). This is a recovery mode. 3120/// 3121/// \param ExplicitConvNote The note to be emitted with \p ExplicitConvDiag, 3122/// showing which conversion was picked. 3123/// 3124/// \param AmbigDiag The diagnostic to be emitted if there is more than one 3125/// conversion function that could convert to integral or enumeration type. 3126/// 3127/// \param AmbigNote The note to be emitted with \p AmbigDiag for each 3128/// usable conversion function. 3129/// 3130/// \param ConvDiag The diagnostic to be emitted if we are calling a conversion 3131/// function, which may be an extension in this case. 3132/// 3133/// \returns The expression, converted to an integral or enumeration type if 3134/// successful. 3135Sema::OwningExprResult 3136Sema::ConvertToIntegralOrEnumerationType(SourceLocation Loc, ExprArg FromE, 3137 const PartialDiagnostic &NotIntDiag, 3138 const PartialDiagnostic &IncompleteDiag, 3139 const PartialDiagnostic &ExplicitConvDiag, 3140 const PartialDiagnostic &ExplicitConvNote, 3141 const PartialDiagnostic &AmbigDiag, 3142 const PartialDiagnostic &AmbigNote, 3143 const PartialDiagnostic &ConvDiag) { 3144 Expr *From = static_cast<Expr *>(FromE.get()); 3145 3146 // We can't perform any more checking for type-dependent expressions. 3147 if (From->isTypeDependent()) 3148 return move(FromE); 3149 3150 // If the expression already has integral or enumeration type, we're golden. 3151 QualType T = From->getType(); 3152 if (T->isIntegralOrEnumerationType()) 3153 return move(FromE); 3154 3155 // FIXME: Check for missing '()' if T is a function type? 3156 3157 // If we don't have a class type in C++, there's no way we can get an 3158 // expression of integral or enumeration type. 3159 const RecordType *RecordTy = T->getAs<RecordType>(); 3160 if (!RecordTy || !getLangOptions().CPlusPlus) { 3161 Diag(Loc, NotIntDiag) 3162 << T << From->getSourceRange(); 3163 return move(FromE); 3164 } 3165 3166 // We must have a complete class type. 3167 if (RequireCompleteType(Loc, T, IncompleteDiag)) 3168 return move(FromE); 3169 3170 // Look for a conversion to an integral or enumeration type. 3171 UnresolvedSet<4> ViableConversions; 3172 UnresolvedSet<4> ExplicitConversions; 3173 const UnresolvedSetImpl *Conversions 3174 = cast<CXXRecordDecl>(RecordTy->getDecl())->getVisibleConversionFunctions(); 3175 3176 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 3177 E = Conversions->end(); 3178 I != E; 3179 ++I) { 3180 if (CXXConversionDecl *Conversion 3181 = dyn_cast<CXXConversionDecl>((*I)->getUnderlyingDecl())) 3182 if (Conversion->getConversionType().getNonReferenceType() 3183 ->isIntegralOrEnumerationType()) { 3184 if (Conversion->isExplicit()) 3185 ExplicitConversions.addDecl(I.getDecl(), I.getAccess()); 3186 else 3187 ViableConversions.addDecl(I.getDecl(), I.getAccess()); 3188 } 3189 } 3190 3191 switch (ViableConversions.size()) { 3192 case 0: 3193 if (ExplicitConversions.size() == 1) { 3194 DeclAccessPair Found = ExplicitConversions[0]; 3195 CXXConversionDecl *Conversion 3196 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3197 3198 // The user probably meant to invoke the given explicit 3199 // conversion; use it. 3200 QualType ConvTy 3201 = Conversion->getConversionType().getNonReferenceType(); 3202 std::string TypeStr; 3203 ConvTy.getAsStringInternal(TypeStr, Context.PrintingPolicy); 3204 3205 Diag(Loc, ExplicitConvDiag) 3206 << T << ConvTy 3207 << FixItHint::CreateInsertion(From->getLocStart(), 3208 "static_cast<" + TypeStr + ">(") 3209 << FixItHint::CreateInsertion(PP.getLocForEndOfToken(From->getLocEnd()), 3210 ")"); 3211 Diag(Conversion->getLocation(), ExplicitConvNote) 3212 << ConvTy->isEnumeralType() << ConvTy; 3213 3214 // If we aren't in a SFINAE context, build a call to the 3215 // explicit conversion function. 3216 if (isSFINAEContext()) 3217 return ExprError(); 3218 3219 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3220 From = BuildCXXMemberCallExpr(FromE.takeAs<Expr>(), Found, Conversion); 3221 FromE = Owned(From); 3222 } 3223 3224 // We'll complain below about a non-integral condition type. 3225 break; 3226 3227 case 1: { 3228 // Apply this conversion. 3229 DeclAccessPair Found = ViableConversions[0]; 3230 CheckMemberOperatorAccess(From->getExprLoc(), From, 0, Found); 3231 3232 CXXConversionDecl *Conversion 3233 = cast<CXXConversionDecl>(Found->getUnderlyingDecl()); 3234 QualType ConvTy 3235 = Conversion->getConversionType().getNonReferenceType(); 3236 if (ConvDiag.getDiagID()) { 3237 if (isSFINAEContext()) 3238 return ExprError(); 3239 3240 Diag(Loc, ConvDiag) 3241 << T << ConvTy->isEnumeralType() << ConvTy << From->getSourceRange(); 3242 } 3243 3244 From = BuildCXXMemberCallExpr(FromE.takeAs<Expr>(), Found, 3245 cast<CXXConversionDecl>(Found->getUnderlyingDecl())); 3246 FromE = Owned(From); 3247 break; 3248 } 3249 3250 default: 3251 Diag(Loc, AmbigDiag) 3252 << T << From->getSourceRange(); 3253 for (unsigned I = 0, N = ViableConversions.size(); I != N; ++I) { 3254 CXXConversionDecl *Conv 3255 = cast<CXXConversionDecl>(ViableConversions[I]->getUnderlyingDecl()); 3256 QualType ConvTy = Conv->getConversionType().getNonReferenceType(); 3257 Diag(Conv->getLocation(), AmbigNote) 3258 << ConvTy->isEnumeralType() << ConvTy; 3259 } 3260 return move(FromE); 3261 } 3262 3263 if (!From->getType()->isIntegralOrEnumerationType()) 3264 Diag(Loc, NotIntDiag) 3265 << From->getType() << From->getSourceRange(); 3266 3267 return move(FromE); 3268} 3269 3270/// AddOverloadCandidate - Adds the given function to the set of 3271/// candidate functions, using the given function call arguments. If 3272/// @p SuppressUserConversions, then don't allow user-defined 3273/// conversions via constructors or conversion operators. 3274/// 3275/// \para PartialOverloading true if we are performing "partial" overloading 3276/// based on an incomplete set of function arguments. This feature is used by 3277/// code completion. 3278void 3279Sema::AddOverloadCandidate(FunctionDecl *Function, 3280 DeclAccessPair FoundDecl, 3281 Expr **Args, unsigned NumArgs, 3282 OverloadCandidateSet& CandidateSet, 3283 bool SuppressUserConversions, 3284 bool PartialOverloading) { 3285 const FunctionProtoType* Proto 3286 = dyn_cast<FunctionProtoType>(Function->getType()->getAs<FunctionType>()); 3287 assert(Proto && "Functions without a prototype cannot be overloaded"); 3288 assert(!Function->getDescribedFunctionTemplate() && 3289 "Use AddTemplateOverloadCandidate for function templates"); 3290 3291 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Function)) { 3292 if (!isa<CXXConstructorDecl>(Method)) { 3293 // If we get here, it's because we're calling a member function 3294 // that is named without a member access expression (e.g., 3295 // "this->f") that was either written explicitly or created 3296 // implicitly. This can happen with a qualified call to a member 3297 // function, e.g., X::f(). We use an empty type for the implied 3298 // object argument (C++ [over.call.func]p3), and the acting context 3299 // is irrelevant. 3300 AddMethodCandidate(Method, FoundDecl, Method->getParent(), 3301 QualType(), Args, NumArgs, CandidateSet, 3302 SuppressUserConversions); 3303 return; 3304 } 3305 // We treat a constructor like a non-member function, since its object 3306 // argument doesn't participate in overload resolution. 3307 } 3308 3309 if (!CandidateSet.isNewCandidate(Function)) 3310 return; 3311 3312 // Overload resolution is always an unevaluated context. 3313 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3314 3315 if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(Function)){ 3316 // C++ [class.copy]p3: 3317 // A member function template is never instantiated to perform the copy 3318 // of a class object to an object of its class type. 3319 QualType ClassType = Context.getTypeDeclType(Constructor->getParent()); 3320 if (NumArgs == 1 && 3321 Constructor->isCopyConstructorLikeSpecialization() && 3322 (Context.hasSameUnqualifiedType(ClassType, Args[0]->getType()) || 3323 IsDerivedFrom(Args[0]->getType(), ClassType))) 3324 return; 3325 } 3326 3327 // Add this candidate 3328 CandidateSet.push_back(OverloadCandidate()); 3329 OverloadCandidate& Candidate = CandidateSet.back(); 3330 Candidate.FoundDecl = FoundDecl; 3331 Candidate.Function = Function; 3332 Candidate.Viable = true; 3333 Candidate.IsSurrogate = false; 3334 Candidate.IgnoreObjectArgument = false; 3335 3336 unsigned NumArgsInProto = Proto->getNumArgs(); 3337 3338 // (C++ 13.3.2p2): A candidate function having fewer than m 3339 // parameters is viable only if it has an ellipsis in its parameter 3340 // list (8.3.5). 3341 if ((NumArgs + (PartialOverloading && NumArgs)) > NumArgsInProto && 3342 !Proto->isVariadic()) { 3343 Candidate.Viable = false; 3344 Candidate.FailureKind = ovl_fail_too_many_arguments; 3345 return; 3346 } 3347 3348 // (C++ 13.3.2p2): A candidate function having more than m parameters 3349 // is viable only if the (m+1)st parameter has a default argument 3350 // (8.3.6). For the purposes of overload resolution, the 3351 // parameter list is truncated on the right, so that there are 3352 // exactly m parameters. 3353 unsigned MinRequiredArgs = Function->getMinRequiredArguments(); 3354 if (NumArgs < MinRequiredArgs && !PartialOverloading) { 3355 // Not enough arguments. 3356 Candidate.Viable = false; 3357 Candidate.FailureKind = ovl_fail_too_few_arguments; 3358 return; 3359 } 3360 3361 // Determine the implicit conversion sequences for each of the 3362 // arguments. 3363 Candidate.Conversions.resize(NumArgs); 3364 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3365 if (ArgIdx < NumArgsInProto) { 3366 // (C++ 13.3.2p3): for F to be a viable function, there shall 3367 // exist for each argument an implicit conversion sequence 3368 // (13.3.3.1) that converts that argument to the corresponding 3369 // parameter of F. 3370 QualType ParamType = Proto->getArgType(ArgIdx); 3371 Candidate.Conversions[ArgIdx] 3372 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3373 SuppressUserConversions, 3374 /*InOverloadResolution=*/true); 3375 if (Candidate.Conversions[ArgIdx].isBad()) { 3376 Candidate.Viable = false; 3377 Candidate.FailureKind = ovl_fail_bad_conversion; 3378 break; 3379 } 3380 } else { 3381 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3382 // argument for which there is no corresponding parameter is 3383 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3384 Candidate.Conversions[ArgIdx].setEllipsis(); 3385 } 3386 } 3387} 3388 3389/// \brief Add all of the function declarations in the given function set to 3390/// the overload canddiate set. 3391void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns, 3392 Expr **Args, unsigned NumArgs, 3393 OverloadCandidateSet& CandidateSet, 3394 bool SuppressUserConversions) { 3395 for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) { 3396 NamedDecl *D = F.getDecl()->getUnderlyingDecl(); 3397 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { 3398 if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) 3399 AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(), 3400 cast<CXXMethodDecl>(FD)->getParent(), 3401 Args[0]->getType(), Args + 1, NumArgs - 1, 3402 CandidateSet, SuppressUserConversions); 3403 else 3404 AddOverloadCandidate(FD, F.getPair(), Args, NumArgs, CandidateSet, 3405 SuppressUserConversions); 3406 } else { 3407 FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D); 3408 if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) && 3409 !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) 3410 AddMethodTemplateCandidate(FunTmpl, F.getPair(), 3411 cast<CXXRecordDecl>(FunTmpl->getDeclContext()), 3412 /*FIXME: explicit args */ 0, 3413 Args[0]->getType(), Args + 1, NumArgs - 1, 3414 CandidateSet, 3415 SuppressUserConversions); 3416 else 3417 AddTemplateOverloadCandidate(FunTmpl, F.getPair(), 3418 /*FIXME: explicit args */ 0, 3419 Args, NumArgs, CandidateSet, 3420 SuppressUserConversions); 3421 } 3422 } 3423} 3424 3425/// AddMethodCandidate - Adds a named decl (which is some kind of 3426/// method) as a method candidate to the given overload set. 3427void Sema::AddMethodCandidate(DeclAccessPair FoundDecl, 3428 QualType ObjectType, 3429 Expr **Args, unsigned NumArgs, 3430 OverloadCandidateSet& CandidateSet, 3431 bool SuppressUserConversions) { 3432 NamedDecl *Decl = FoundDecl.getDecl(); 3433 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(Decl->getDeclContext()); 3434 3435 if (isa<UsingShadowDecl>(Decl)) 3436 Decl = cast<UsingShadowDecl>(Decl)->getTargetDecl(); 3437 3438 if (FunctionTemplateDecl *TD = dyn_cast<FunctionTemplateDecl>(Decl)) { 3439 assert(isa<CXXMethodDecl>(TD->getTemplatedDecl()) && 3440 "Expected a member function template"); 3441 AddMethodTemplateCandidate(TD, FoundDecl, ActingContext, 3442 /*ExplicitArgs*/ 0, 3443 ObjectType, Args, NumArgs, 3444 CandidateSet, 3445 SuppressUserConversions); 3446 } else { 3447 AddMethodCandidate(cast<CXXMethodDecl>(Decl), FoundDecl, ActingContext, 3448 ObjectType, Args, NumArgs, 3449 CandidateSet, SuppressUserConversions); 3450 } 3451} 3452 3453/// AddMethodCandidate - Adds the given C++ member function to the set 3454/// of candidate functions, using the given function call arguments 3455/// and the object argument (@c Object). For example, in a call 3456/// @c o.f(a1,a2), @c Object will contain @c o and @c Args will contain 3457/// both @c a1 and @c a2. If @p SuppressUserConversions, then don't 3458/// allow user-defined conversions via constructors or conversion 3459/// operators. 3460void 3461Sema::AddMethodCandidate(CXXMethodDecl *Method, DeclAccessPair FoundDecl, 3462 CXXRecordDecl *ActingContext, QualType ObjectType, 3463 Expr **Args, unsigned NumArgs, 3464 OverloadCandidateSet& CandidateSet, 3465 bool SuppressUserConversions) { 3466 const FunctionProtoType* Proto 3467 = dyn_cast<FunctionProtoType>(Method->getType()->getAs<FunctionType>()); 3468 assert(Proto && "Methods without a prototype cannot be overloaded"); 3469 assert(!isa<CXXConstructorDecl>(Method) && 3470 "Use AddOverloadCandidate for constructors"); 3471 3472 if (!CandidateSet.isNewCandidate(Method)) 3473 return; 3474 3475 // Overload resolution is always an unevaluated context. 3476 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3477 3478 // Add this candidate 3479 CandidateSet.push_back(OverloadCandidate()); 3480 OverloadCandidate& Candidate = CandidateSet.back(); 3481 Candidate.FoundDecl = FoundDecl; 3482 Candidate.Function = Method; 3483 Candidate.IsSurrogate = false; 3484 Candidate.IgnoreObjectArgument = false; 3485 3486 unsigned NumArgsInProto = Proto->getNumArgs(); 3487 3488 // (C++ 13.3.2p2): A candidate function having fewer than m 3489 // parameters is viable only if it has an ellipsis in its parameter 3490 // list (8.3.5). 3491 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3492 Candidate.Viable = false; 3493 Candidate.FailureKind = ovl_fail_too_many_arguments; 3494 return; 3495 } 3496 3497 // (C++ 13.3.2p2): A candidate function having more than m parameters 3498 // is viable only if the (m+1)st parameter has a default argument 3499 // (8.3.6). For the purposes of overload resolution, the 3500 // parameter list is truncated on the right, so that there are 3501 // exactly m parameters. 3502 unsigned MinRequiredArgs = Method->getMinRequiredArguments(); 3503 if (NumArgs < MinRequiredArgs) { 3504 // Not enough arguments. 3505 Candidate.Viable = false; 3506 Candidate.FailureKind = ovl_fail_too_few_arguments; 3507 return; 3508 } 3509 3510 Candidate.Viable = true; 3511 Candidate.Conversions.resize(NumArgs + 1); 3512 3513 if (Method->isStatic() || ObjectType.isNull()) 3514 // The implicit object argument is ignored. 3515 Candidate.IgnoreObjectArgument = true; 3516 else { 3517 // Determine the implicit conversion sequence for the object 3518 // parameter. 3519 Candidate.Conversions[0] 3520 = TryObjectArgumentInitialization(ObjectType, Method, ActingContext); 3521 if (Candidate.Conversions[0].isBad()) { 3522 Candidate.Viable = false; 3523 Candidate.FailureKind = ovl_fail_bad_conversion; 3524 return; 3525 } 3526 } 3527 3528 // Determine the implicit conversion sequences for each of the 3529 // arguments. 3530 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3531 if (ArgIdx < NumArgsInProto) { 3532 // (C++ 13.3.2p3): for F to be a viable function, there shall 3533 // exist for each argument an implicit conversion sequence 3534 // (13.3.3.1) that converts that argument to the corresponding 3535 // parameter of F. 3536 QualType ParamType = Proto->getArgType(ArgIdx); 3537 Candidate.Conversions[ArgIdx + 1] 3538 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3539 SuppressUserConversions, 3540 /*InOverloadResolution=*/true); 3541 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3542 Candidate.Viable = false; 3543 Candidate.FailureKind = ovl_fail_bad_conversion; 3544 break; 3545 } 3546 } else { 3547 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3548 // argument for which there is no corresponding parameter is 3549 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3550 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3551 } 3552 } 3553} 3554 3555/// \brief Add a C++ member function template as a candidate to the candidate 3556/// set, using template argument deduction to produce an appropriate member 3557/// function template specialization. 3558void 3559Sema::AddMethodTemplateCandidate(FunctionTemplateDecl *MethodTmpl, 3560 DeclAccessPair FoundDecl, 3561 CXXRecordDecl *ActingContext, 3562 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3563 QualType ObjectType, 3564 Expr **Args, unsigned NumArgs, 3565 OverloadCandidateSet& CandidateSet, 3566 bool SuppressUserConversions) { 3567 if (!CandidateSet.isNewCandidate(MethodTmpl)) 3568 return; 3569 3570 // C++ [over.match.funcs]p7: 3571 // In each case where a candidate is a function template, candidate 3572 // function template specializations are generated using template argument 3573 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3574 // candidate functions in the usual way.113) A given name can refer to one 3575 // or more function templates and also to a set of overloaded non-template 3576 // functions. In such a case, the candidate functions generated from each 3577 // function template are combined with the set of non-template candidate 3578 // functions. 3579 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3580 FunctionDecl *Specialization = 0; 3581 if (TemplateDeductionResult Result 3582 = DeduceTemplateArguments(MethodTmpl, ExplicitTemplateArgs, 3583 Args, NumArgs, Specialization, Info)) { 3584 CandidateSet.push_back(OverloadCandidate()); 3585 OverloadCandidate &Candidate = CandidateSet.back(); 3586 Candidate.FoundDecl = FoundDecl; 3587 Candidate.Function = MethodTmpl->getTemplatedDecl(); 3588 Candidate.Viable = false; 3589 Candidate.FailureKind = ovl_fail_bad_deduction; 3590 Candidate.IsSurrogate = false; 3591 Candidate.IgnoreObjectArgument = false; 3592 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3593 Info); 3594 return; 3595 } 3596 3597 // Add the function template specialization produced by template argument 3598 // deduction as a candidate. 3599 assert(Specialization && "Missing member function template specialization?"); 3600 assert(isa<CXXMethodDecl>(Specialization) && 3601 "Specialization is not a member function?"); 3602 AddMethodCandidate(cast<CXXMethodDecl>(Specialization), FoundDecl, 3603 ActingContext, ObjectType, Args, NumArgs, 3604 CandidateSet, SuppressUserConversions); 3605} 3606 3607/// \brief Add a C++ function template specialization as a candidate 3608/// in the candidate set, using template argument deduction to produce 3609/// an appropriate function template specialization. 3610void 3611Sema::AddTemplateOverloadCandidate(FunctionTemplateDecl *FunctionTemplate, 3612 DeclAccessPair FoundDecl, 3613 const TemplateArgumentListInfo *ExplicitTemplateArgs, 3614 Expr **Args, unsigned NumArgs, 3615 OverloadCandidateSet& CandidateSet, 3616 bool SuppressUserConversions) { 3617 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3618 return; 3619 3620 // C++ [over.match.funcs]p7: 3621 // In each case where a candidate is a function template, candidate 3622 // function template specializations are generated using template argument 3623 // deduction (14.8.3, 14.8.2). Those candidates are then handled as 3624 // candidate functions in the usual way.113) A given name can refer to one 3625 // or more function templates and also to a set of overloaded non-template 3626 // functions. In such a case, the candidate functions generated from each 3627 // function template are combined with the set of non-template candidate 3628 // functions. 3629 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3630 FunctionDecl *Specialization = 0; 3631 if (TemplateDeductionResult Result 3632 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 3633 Args, NumArgs, Specialization, Info)) { 3634 CandidateSet.push_back(OverloadCandidate()); 3635 OverloadCandidate &Candidate = CandidateSet.back(); 3636 Candidate.FoundDecl = FoundDecl; 3637 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3638 Candidate.Viable = false; 3639 Candidate.FailureKind = ovl_fail_bad_deduction; 3640 Candidate.IsSurrogate = false; 3641 Candidate.IgnoreObjectArgument = false; 3642 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3643 Info); 3644 return; 3645 } 3646 3647 // Add the function template specialization produced by template argument 3648 // deduction as a candidate. 3649 assert(Specialization && "Missing function template specialization?"); 3650 AddOverloadCandidate(Specialization, FoundDecl, Args, NumArgs, CandidateSet, 3651 SuppressUserConversions); 3652} 3653 3654/// AddConversionCandidate - Add a C++ conversion function as a 3655/// candidate in the candidate set (C++ [over.match.conv], 3656/// C++ [over.match.copy]). From is the expression we're converting from, 3657/// and ToType is the type that we're eventually trying to convert to 3658/// (which may or may not be the same type as the type that the 3659/// conversion function produces). 3660void 3661Sema::AddConversionCandidate(CXXConversionDecl *Conversion, 3662 DeclAccessPair FoundDecl, 3663 CXXRecordDecl *ActingContext, 3664 Expr *From, QualType ToType, 3665 OverloadCandidateSet& CandidateSet) { 3666 assert(!Conversion->getDescribedFunctionTemplate() && 3667 "Conversion function templates use AddTemplateConversionCandidate"); 3668 QualType ConvType = Conversion->getConversionType().getNonReferenceType(); 3669 if (!CandidateSet.isNewCandidate(Conversion)) 3670 return; 3671 3672 // Overload resolution is always an unevaluated context. 3673 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3674 3675 // Add this candidate 3676 CandidateSet.push_back(OverloadCandidate()); 3677 OverloadCandidate& Candidate = CandidateSet.back(); 3678 Candidate.FoundDecl = FoundDecl; 3679 Candidate.Function = Conversion; 3680 Candidate.IsSurrogate = false; 3681 Candidate.IgnoreObjectArgument = false; 3682 Candidate.FinalConversion.setAsIdentityConversion(); 3683 Candidate.FinalConversion.setFromType(ConvType); 3684 Candidate.FinalConversion.setAllToTypes(ToType); 3685 3686 // Determine the implicit conversion sequence for the implicit 3687 // object parameter. 3688 Candidate.Viable = true; 3689 Candidate.Conversions.resize(1); 3690 Candidate.Conversions[0] 3691 = TryObjectArgumentInitialization(From->getType(), Conversion, 3692 ActingContext); 3693 // Conversion functions to a different type in the base class is visible in 3694 // the derived class. So, a derived to base conversion should not participate 3695 // in overload resolution. 3696 if (Candidate.Conversions[0].Standard.Second == ICK_Derived_To_Base) 3697 Candidate.Conversions[0].Standard.Second = ICK_Identity; 3698 if (Candidate.Conversions[0].isBad()) { 3699 Candidate.Viable = false; 3700 Candidate.FailureKind = ovl_fail_bad_conversion; 3701 return; 3702 } 3703 3704 // We won't go through a user-define type conversion function to convert a 3705 // derived to base as such conversions are given Conversion Rank. They only 3706 // go through a copy constructor. 13.3.3.1.2-p4 [over.ics.user] 3707 QualType FromCanon 3708 = Context.getCanonicalType(From->getType().getUnqualifiedType()); 3709 QualType ToCanon = Context.getCanonicalType(ToType).getUnqualifiedType(); 3710 if (FromCanon == ToCanon || IsDerivedFrom(FromCanon, ToCanon)) { 3711 Candidate.Viable = false; 3712 Candidate.FailureKind = ovl_fail_trivial_conversion; 3713 return; 3714 } 3715 3716 // To determine what the conversion from the result of calling the 3717 // conversion function to the type we're eventually trying to 3718 // convert to (ToType), we need to synthesize a call to the 3719 // conversion function and attempt copy initialization from it. This 3720 // makes sure that we get the right semantics with respect to 3721 // lvalues/rvalues and the type. Fortunately, we can allocate this 3722 // call on the stack and we don't need its arguments to be 3723 // well-formed. 3724 DeclRefExpr ConversionRef(Conversion, Conversion->getType(), 3725 From->getLocStart()); 3726 ImplicitCastExpr ConversionFn(Context.getPointerType(Conversion->getType()), 3727 CastExpr::CK_FunctionToPointerDecay, 3728 &ConversionRef, CXXBaseSpecifierArray(), false); 3729 3730 // Note that it is safe to allocate CallExpr on the stack here because 3731 // there are 0 arguments (i.e., nothing is allocated using ASTContext's 3732 // allocator). 3733 CallExpr Call(Context, &ConversionFn, 0, 0, 3734 Conversion->getConversionType().getNonReferenceType(), 3735 From->getLocStart()); 3736 ImplicitConversionSequence ICS = 3737 TryCopyInitialization(*this, &Call, ToType, 3738 /*SuppressUserConversions=*/true, 3739 /*InOverloadResolution=*/false); 3740 3741 switch (ICS.getKind()) { 3742 case ImplicitConversionSequence::StandardConversion: 3743 Candidate.FinalConversion = ICS.Standard; 3744 3745 // C++ [over.ics.user]p3: 3746 // If the user-defined conversion is specified by a specialization of a 3747 // conversion function template, the second standard conversion sequence 3748 // shall have exact match rank. 3749 if (Conversion->getPrimaryTemplate() && 3750 GetConversionRank(ICS.Standard.Second) != ICR_Exact_Match) { 3751 Candidate.Viable = false; 3752 Candidate.FailureKind = ovl_fail_final_conversion_not_exact; 3753 } 3754 3755 break; 3756 3757 case ImplicitConversionSequence::BadConversion: 3758 Candidate.Viable = false; 3759 Candidate.FailureKind = ovl_fail_bad_final_conversion; 3760 break; 3761 3762 default: 3763 assert(false && 3764 "Can only end up with a standard conversion sequence or failure"); 3765 } 3766} 3767 3768/// \brief Adds a conversion function template specialization 3769/// candidate to the overload set, using template argument deduction 3770/// to deduce the template arguments of the conversion function 3771/// template from the type that we are converting to (C++ 3772/// [temp.deduct.conv]). 3773void 3774Sema::AddTemplateConversionCandidate(FunctionTemplateDecl *FunctionTemplate, 3775 DeclAccessPair FoundDecl, 3776 CXXRecordDecl *ActingDC, 3777 Expr *From, QualType ToType, 3778 OverloadCandidateSet &CandidateSet) { 3779 assert(isa<CXXConversionDecl>(FunctionTemplate->getTemplatedDecl()) && 3780 "Only conversion function templates permitted here"); 3781 3782 if (!CandidateSet.isNewCandidate(FunctionTemplate)) 3783 return; 3784 3785 TemplateDeductionInfo Info(Context, CandidateSet.getLocation()); 3786 CXXConversionDecl *Specialization = 0; 3787 if (TemplateDeductionResult Result 3788 = DeduceTemplateArguments(FunctionTemplate, ToType, 3789 Specialization, Info)) { 3790 CandidateSet.push_back(OverloadCandidate()); 3791 OverloadCandidate &Candidate = CandidateSet.back(); 3792 Candidate.FoundDecl = FoundDecl; 3793 Candidate.Function = FunctionTemplate->getTemplatedDecl(); 3794 Candidate.Viable = false; 3795 Candidate.FailureKind = ovl_fail_bad_deduction; 3796 Candidate.IsSurrogate = false; 3797 Candidate.IgnoreObjectArgument = false; 3798 Candidate.DeductionFailure = MakeDeductionFailureInfo(Context, Result, 3799 Info); 3800 return; 3801 } 3802 3803 // Add the conversion function template specialization produced by 3804 // template argument deduction as a candidate. 3805 assert(Specialization && "Missing function template specialization?"); 3806 AddConversionCandidate(Specialization, FoundDecl, ActingDC, From, ToType, 3807 CandidateSet); 3808} 3809 3810/// AddSurrogateCandidate - Adds a "surrogate" candidate function that 3811/// converts the given @c Object to a function pointer via the 3812/// conversion function @c Conversion, and then attempts to call it 3813/// with the given arguments (C++ [over.call.object]p2-4). Proto is 3814/// the type of function that we'll eventually be calling. 3815void Sema::AddSurrogateCandidate(CXXConversionDecl *Conversion, 3816 DeclAccessPair FoundDecl, 3817 CXXRecordDecl *ActingContext, 3818 const FunctionProtoType *Proto, 3819 QualType ObjectType, 3820 Expr **Args, unsigned NumArgs, 3821 OverloadCandidateSet& CandidateSet) { 3822 if (!CandidateSet.isNewCandidate(Conversion)) 3823 return; 3824 3825 // Overload resolution is always an unevaluated context. 3826 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3827 3828 CandidateSet.push_back(OverloadCandidate()); 3829 OverloadCandidate& Candidate = CandidateSet.back(); 3830 Candidate.FoundDecl = FoundDecl; 3831 Candidate.Function = 0; 3832 Candidate.Surrogate = Conversion; 3833 Candidate.Viable = true; 3834 Candidate.IsSurrogate = true; 3835 Candidate.IgnoreObjectArgument = false; 3836 Candidate.Conversions.resize(NumArgs + 1); 3837 3838 // Determine the implicit conversion sequence for the implicit 3839 // object parameter. 3840 ImplicitConversionSequence ObjectInit 3841 = TryObjectArgumentInitialization(ObjectType, Conversion, ActingContext); 3842 if (ObjectInit.isBad()) { 3843 Candidate.Viable = false; 3844 Candidate.FailureKind = ovl_fail_bad_conversion; 3845 Candidate.Conversions[0] = ObjectInit; 3846 return; 3847 } 3848 3849 // The first conversion is actually a user-defined conversion whose 3850 // first conversion is ObjectInit's standard conversion (which is 3851 // effectively a reference binding). Record it as such. 3852 Candidate.Conversions[0].setUserDefined(); 3853 Candidate.Conversions[0].UserDefined.Before = ObjectInit.Standard; 3854 Candidate.Conversions[0].UserDefined.EllipsisConversion = false; 3855 Candidate.Conversions[0].UserDefined.ConversionFunction = Conversion; 3856 Candidate.Conversions[0].UserDefined.After 3857 = Candidate.Conversions[0].UserDefined.Before; 3858 Candidate.Conversions[0].UserDefined.After.setAsIdentityConversion(); 3859 3860 // Find the 3861 unsigned NumArgsInProto = Proto->getNumArgs(); 3862 3863 // (C++ 13.3.2p2): A candidate function having fewer than m 3864 // parameters is viable only if it has an ellipsis in its parameter 3865 // list (8.3.5). 3866 if (NumArgs > NumArgsInProto && !Proto->isVariadic()) { 3867 Candidate.Viable = false; 3868 Candidate.FailureKind = ovl_fail_too_many_arguments; 3869 return; 3870 } 3871 3872 // Function types don't have any default arguments, so just check if 3873 // we have enough arguments. 3874 if (NumArgs < NumArgsInProto) { 3875 // Not enough arguments. 3876 Candidate.Viable = false; 3877 Candidate.FailureKind = ovl_fail_too_few_arguments; 3878 return; 3879 } 3880 3881 // Determine the implicit conversion sequences for each of the 3882 // arguments. 3883 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3884 if (ArgIdx < NumArgsInProto) { 3885 // (C++ 13.3.2p3): for F to be a viable function, there shall 3886 // exist for each argument an implicit conversion sequence 3887 // (13.3.3.1) that converts that argument to the corresponding 3888 // parameter of F. 3889 QualType ParamType = Proto->getArgType(ArgIdx); 3890 Candidate.Conversions[ArgIdx + 1] 3891 = TryCopyInitialization(*this, Args[ArgIdx], ParamType, 3892 /*SuppressUserConversions=*/false, 3893 /*InOverloadResolution=*/false); 3894 if (Candidate.Conversions[ArgIdx + 1].isBad()) { 3895 Candidate.Viable = false; 3896 Candidate.FailureKind = ovl_fail_bad_conversion; 3897 break; 3898 } 3899 } else { 3900 // (C++ 13.3.2p2): For the purposes of overload resolution, any 3901 // argument for which there is no corresponding parameter is 3902 // considered to ""match the ellipsis" (C+ 13.3.3.1.3). 3903 Candidate.Conversions[ArgIdx + 1].setEllipsis(); 3904 } 3905 } 3906} 3907 3908/// \brief Add overload candidates for overloaded operators that are 3909/// member functions. 3910/// 3911/// Add the overloaded operator candidates that are member functions 3912/// for the operator Op that was used in an operator expression such 3913/// as "x Op y". , Args/NumArgs provides the operator arguments, and 3914/// CandidateSet will store the added overload candidates. (C++ 3915/// [over.match.oper]). 3916void Sema::AddMemberOperatorCandidates(OverloadedOperatorKind Op, 3917 SourceLocation OpLoc, 3918 Expr **Args, unsigned NumArgs, 3919 OverloadCandidateSet& CandidateSet, 3920 SourceRange OpRange) { 3921 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 3922 3923 // C++ [over.match.oper]p3: 3924 // For a unary operator @ with an operand of a type whose 3925 // cv-unqualified version is T1, and for a binary operator @ with 3926 // a left operand of a type whose cv-unqualified version is T1 and 3927 // a right operand of a type whose cv-unqualified version is T2, 3928 // three sets of candidate functions, designated member 3929 // candidates, non-member candidates and built-in candidates, are 3930 // constructed as follows: 3931 QualType T1 = Args[0]->getType(); 3932 QualType T2; 3933 if (NumArgs > 1) 3934 T2 = Args[1]->getType(); 3935 3936 // -- If T1 is a class type, the set of member candidates is the 3937 // result of the qualified lookup of T1::operator@ 3938 // (13.3.1.1.1); otherwise, the set of member candidates is 3939 // empty. 3940 if (const RecordType *T1Rec = T1->getAs<RecordType>()) { 3941 // Complete the type if it can be completed. Otherwise, we're done. 3942 if (RequireCompleteType(OpLoc, T1, PDiag())) 3943 return; 3944 3945 LookupResult Operators(*this, OpName, OpLoc, LookupOrdinaryName); 3946 LookupQualifiedName(Operators, T1Rec->getDecl()); 3947 Operators.suppressDiagnostics(); 3948 3949 for (LookupResult::iterator Oper = Operators.begin(), 3950 OperEnd = Operators.end(); 3951 Oper != OperEnd; 3952 ++Oper) 3953 AddMethodCandidate(Oper.getPair(), Args[0]->getType(), 3954 Args + 1, NumArgs - 1, CandidateSet, 3955 /* SuppressUserConversions = */ false); 3956 } 3957} 3958 3959/// AddBuiltinCandidate - Add a candidate for a built-in 3960/// operator. ResultTy and ParamTys are the result and parameter types 3961/// of the built-in candidate, respectively. Args and NumArgs are the 3962/// arguments being passed to the candidate. IsAssignmentOperator 3963/// should be true when this built-in candidate is an assignment 3964/// operator. NumContextualBoolArguments is the number of arguments 3965/// (at the beginning of the argument list) that will be contextually 3966/// converted to bool. 3967void Sema::AddBuiltinCandidate(QualType ResultTy, QualType *ParamTys, 3968 Expr **Args, unsigned NumArgs, 3969 OverloadCandidateSet& CandidateSet, 3970 bool IsAssignmentOperator, 3971 unsigned NumContextualBoolArguments) { 3972 // Overload resolution is always an unevaluated context. 3973 EnterExpressionEvaluationContext Unevaluated(*this, Action::Unevaluated); 3974 3975 // Add this candidate 3976 CandidateSet.push_back(OverloadCandidate()); 3977 OverloadCandidate& Candidate = CandidateSet.back(); 3978 Candidate.FoundDecl = DeclAccessPair::make(0, AS_none); 3979 Candidate.Function = 0; 3980 Candidate.IsSurrogate = false; 3981 Candidate.IgnoreObjectArgument = false; 3982 Candidate.BuiltinTypes.ResultTy = ResultTy; 3983 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 3984 Candidate.BuiltinTypes.ParamTypes[ArgIdx] = ParamTys[ArgIdx]; 3985 3986 // Determine the implicit conversion sequences for each of the 3987 // arguments. 3988 Candidate.Viable = true; 3989 Candidate.Conversions.resize(NumArgs); 3990 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) { 3991 // C++ [over.match.oper]p4: 3992 // For the built-in assignment operators, conversions of the 3993 // left operand are restricted as follows: 3994 // -- no temporaries are introduced to hold the left operand, and 3995 // -- no user-defined conversions are applied to the left 3996 // operand to achieve a type match with the left-most 3997 // parameter of a built-in candidate. 3998 // 3999 // We block these conversions by turning off user-defined 4000 // conversions, since that is the only way that initialization of 4001 // a reference to a non-class type can occur from something that 4002 // is not of the same type. 4003 if (ArgIdx < NumContextualBoolArguments) { 4004 assert(ParamTys[ArgIdx] == Context.BoolTy && 4005 "Contextual conversion to bool requires bool type"); 4006 Candidate.Conversions[ArgIdx] = TryContextuallyConvertToBool(Args[ArgIdx]); 4007 } else { 4008 Candidate.Conversions[ArgIdx] 4009 = TryCopyInitialization(*this, Args[ArgIdx], ParamTys[ArgIdx], 4010 ArgIdx == 0 && IsAssignmentOperator, 4011 /*InOverloadResolution=*/false); 4012 } 4013 if (Candidate.Conversions[ArgIdx].isBad()) { 4014 Candidate.Viable = false; 4015 Candidate.FailureKind = ovl_fail_bad_conversion; 4016 break; 4017 } 4018 } 4019} 4020 4021/// BuiltinCandidateTypeSet - A set of types that will be used for the 4022/// candidate operator functions for built-in operators (C++ 4023/// [over.built]). The types are separated into pointer types and 4024/// enumeration types. 4025class BuiltinCandidateTypeSet { 4026 /// TypeSet - A set of types. 4027 typedef llvm::SmallPtrSet<QualType, 8> TypeSet; 4028 4029 /// PointerTypes - The set of pointer types that will be used in the 4030 /// built-in candidates. 4031 TypeSet PointerTypes; 4032 4033 /// MemberPointerTypes - The set of member pointer types that will be 4034 /// used in the built-in candidates. 4035 TypeSet MemberPointerTypes; 4036 4037 /// EnumerationTypes - The set of enumeration types that will be 4038 /// used in the built-in candidates. 4039 TypeSet EnumerationTypes; 4040 4041 /// \brief The set of vector types that will be used in the built-in 4042 /// candidates. 4043 TypeSet VectorTypes; 4044 4045 /// Sema - The semantic analysis instance where we are building the 4046 /// candidate type set. 4047 Sema &SemaRef; 4048 4049 /// Context - The AST context in which we will build the type sets. 4050 ASTContext &Context; 4051 4052 bool AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4053 const Qualifiers &VisibleQuals); 4054 bool AddMemberPointerWithMoreQualifiedTypeVariants(QualType Ty); 4055 4056public: 4057 /// iterator - Iterates through the types that are part of the set. 4058 typedef TypeSet::iterator iterator; 4059 4060 BuiltinCandidateTypeSet(Sema &SemaRef) 4061 : SemaRef(SemaRef), Context(SemaRef.Context) { } 4062 4063 void AddTypesConvertedFrom(QualType Ty, 4064 SourceLocation Loc, 4065 bool AllowUserConversions, 4066 bool AllowExplicitConversions, 4067 const Qualifiers &VisibleTypeConversionsQuals); 4068 4069 /// pointer_begin - First pointer type found; 4070 iterator pointer_begin() { return PointerTypes.begin(); } 4071 4072 /// pointer_end - Past the last pointer type found; 4073 iterator pointer_end() { return PointerTypes.end(); } 4074 4075 /// member_pointer_begin - First member pointer type found; 4076 iterator member_pointer_begin() { return MemberPointerTypes.begin(); } 4077 4078 /// member_pointer_end - Past the last member pointer type found; 4079 iterator member_pointer_end() { return MemberPointerTypes.end(); } 4080 4081 /// enumeration_begin - First enumeration type found; 4082 iterator enumeration_begin() { return EnumerationTypes.begin(); } 4083 4084 /// enumeration_end - Past the last enumeration type found; 4085 iterator enumeration_end() { return EnumerationTypes.end(); } 4086 4087 iterator vector_begin() { return VectorTypes.begin(); } 4088 iterator vector_end() { return VectorTypes.end(); } 4089}; 4090 4091/// AddPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty to 4092/// the set of pointer types along with any more-qualified variants of 4093/// that type. For example, if @p Ty is "int const *", this routine 4094/// will add "int const *", "int const volatile *", "int const 4095/// restrict *", and "int const volatile restrict *" to the set of 4096/// pointer types. Returns true if the add of @p Ty itself succeeded, 4097/// false otherwise. 4098/// 4099/// FIXME: what to do about extended qualifiers? 4100bool 4101BuiltinCandidateTypeSet::AddPointerWithMoreQualifiedTypeVariants(QualType Ty, 4102 const Qualifiers &VisibleQuals) { 4103 4104 // Insert this type. 4105 if (!PointerTypes.insert(Ty)) 4106 return false; 4107 4108 const PointerType *PointerTy = Ty->getAs<PointerType>(); 4109 assert(PointerTy && "type was not a pointer type!"); 4110 4111 QualType PointeeTy = PointerTy->getPointeeType(); 4112 // Don't add qualified variants of arrays. For one, they're not allowed 4113 // (the qualifier would sink to the element type), and for another, the 4114 // only overload situation where it matters is subscript or pointer +- int, 4115 // and those shouldn't have qualifier variants anyway. 4116 if (PointeeTy->isArrayType()) 4117 return true; 4118 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4119 if (const ConstantArrayType *Array =Context.getAsConstantArrayType(PointeeTy)) 4120 BaseCVR = Array->getElementType().getCVRQualifiers(); 4121 bool hasVolatile = VisibleQuals.hasVolatile(); 4122 bool hasRestrict = VisibleQuals.hasRestrict(); 4123 4124 // Iterate through all strict supersets of BaseCVR. 4125 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4126 if ((CVR | BaseCVR) != CVR) continue; 4127 // Skip over Volatile/Restrict if no Volatile/Restrict found anywhere 4128 // in the types. 4129 if ((CVR & Qualifiers::Volatile) && !hasVolatile) continue; 4130 if ((CVR & Qualifiers::Restrict) && !hasRestrict) continue; 4131 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4132 PointerTypes.insert(Context.getPointerType(QPointeeTy)); 4133 } 4134 4135 return true; 4136} 4137 4138/// AddMemberPointerWithMoreQualifiedTypeVariants - Add the pointer type @p Ty 4139/// to the set of pointer types along with any more-qualified variants of 4140/// that type. For example, if @p Ty is "int const *", this routine 4141/// will add "int const *", "int const volatile *", "int const 4142/// restrict *", and "int const volatile restrict *" to the set of 4143/// pointer types. Returns true if the add of @p Ty itself succeeded, 4144/// false otherwise. 4145/// 4146/// FIXME: what to do about extended qualifiers? 4147bool 4148BuiltinCandidateTypeSet::AddMemberPointerWithMoreQualifiedTypeVariants( 4149 QualType Ty) { 4150 // Insert this type. 4151 if (!MemberPointerTypes.insert(Ty)) 4152 return false; 4153 4154 const MemberPointerType *PointerTy = Ty->getAs<MemberPointerType>(); 4155 assert(PointerTy && "type was not a member pointer type!"); 4156 4157 QualType PointeeTy = PointerTy->getPointeeType(); 4158 // Don't add qualified variants of arrays. For one, they're not allowed 4159 // (the qualifier would sink to the element type), and for another, the 4160 // only overload situation where it matters is subscript or pointer +- int, 4161 // and those shouldn't have qualifier variants anyway. 4162 if (PointeeTy->isArrayType()) 4163 return true; 4164 const Type *ClassTy = PointerTy->getClass(); 4165 4166 // Iterate through all strict supersets of the pointee type's CVR 4167 // qualifiers. 4168 unsigned BaseCVR = PointeeTy.getCVRQualifiers(); 4169 for (unsigned CVR = BaseCVR+1; CVR <= Qualifiers::CVRMask; ++CVR) { 4170 if ((CVR | BaseCVR) != CVR) continue; 4171 4172 QualType QPointeeTy = Context.getCVRQualifiedType(PointeeTy, CVR); 4173 MemberPointerTypes.insert(Context.getMemberPointerType(QPointeeTy, ClassTy)); 4174 } 4175 4176 return true; 4177} 4178 4179/// AddTypesConvertedFrom - Add each of the types to which the type @p 4180/// Ty can be implicit converted to the given set of @p Types. We're 4181/// primarily interested in pointer types and enumeration types. We also 4182/// take member pointer types, for the conditional operator. 4183/// AllowUserConversions is true if we should look at the conversion 4184/// functions of a class type, and AllowExplicitConversions if we 4185/// should also include the explicit conversion functions of a class 4186/// type. 4187void 4188BuiltinCandidateTypeSet::AddTypesConvertedFrom(QualType Ty, 4189 SourceLocation Loc, 4190 bool AllowUserConversions, 4191 bool AllowExplicitConversions, 4192 const Qualifiers &VisibleQuals) { 4193 // Only deal with canonical types. 4194 Ty = Context.getCanonicalType(Ty); 4195 4196 // Look through reference types; they aren't part of the type of an 4197 // expression for the purposes of conversions. 4198 if (const ReferenceType *RefTy = Ty->getAs<ReferenceType>()) 4199 Ty = RefTy->getPointeeType(); 4200 4201 // We don't care about qualifiers on the type. 4202 Ty = Ty.getLocalUnqualifiedType(); 4203 4204 // If we're dealing with an array type, decay to the pointer. 4205 if (Ty->isArrayType()) 4206 Ty = SemaRef.Context.getArrayDecayedType(Ty); 4207 4208 if (const PointerType *PointerTy = Ty->getAs<PointerType>()) { 4209 QualType PointeeTy = PointerTy->getPointeeType(); 4210 4211 // Insert our type, and its more-qualified variants, into the set 4212 // of types. 4213 if (!AddPointerWithMoreQualifiedTypeVariants(Ty, VisibleQuals)) 4214 return; 4215 } else if (Ty->isMemberPointerType()) { 4216 // Member pointers are far easier, since the pointee can't be converted. 4217 if (!AddMemberPointerWithMoreQualifiedTypeVariants(Ty)) 4218 return; 4219 } else if (Ty->isEnumeralType()) { 4220 EnumerationTypes.insert(Ty); 4221 } else if (Ty->isVectorType()) { 4222 VectorTypes.insert(Ty); 4223 } else if (AllowUserConversions) { 4224 if (const RecordType *TyRec = Ty->getAs<RecordType>()) { 4225 if (SemaRef.RequireCompleteType(Loc, Ty, 0)) { 4226 // No conversion functions in incomplete types. 4227 return; 4228 } 4229 4230 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4231 const UnresolvedSetImpl *Conversions 4232 = ClassDecl->getVisibleConversionFunctions(); 4233 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4234 E = Conversions->end(); I != E; ++I) { 4235 NamedDecl *D = I.getDecl(); 4236 if (isa<UsingShadowDecl>(D)) 4237 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4238 4239 // Skip conversion function templates; they don't tell us anything 4240 // about which builtin types we can convert to. 4241 if (isa<FunctionTemplateDecl>(D)) 4242 continue; 4243 4244 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 4245 if (AllowExplicitConversions || !Conv->isExplicit()) { 4246 AddTypesConvertedFrom(Conv->getConversionType(), Loc, false, false, 4247 VisibleQuals); 4248 } 4249 } 4250 } 4251 } 4252} 4253 4254/// \brief Helper function for AddBuiltinOperatorCandidates() that adds 4255/// the volatile- and non-volatile-qualified assignment operators for the 4256/// given type to the candidate set. 4257static void AddBuiltinAssignmentOperatorCandidates(Sema &S, 4258 QualType T, 4259 Expr **Args, 4260 unsigned NumArgs, 4261 OverloadCandidateSet &CandidateSet) { 4262 QualType ParamTypes[2]; 4263 4264 // T& operator=(T&, T) 4265 ParamTypes[0] = S.Context.getLValueReferenceType(T); 4266 ParamTypes[1] = T; 4267 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4268 /*IsAssignmentOperator=*/true); 4269 4270 if (!S.Context.getCanonicalType(T).isVolatileQualified()) { 4271 // volatile T& operator=(volatile T&, T) 4272 ParamTypes[0] 4273 = S.Context.getLValueReferenceType(S.Context.getVolatileType(T)); 4274 ParamTypes[1] = T; 4275 S.AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4276 /*IsAssignmentOperator=*/true); 4277 } 4278} 4279 4280/// CollectVRQualifiers - This routine returns Volatile/Restrict qualifiers, 4281/// if any, found in visible type conversion functions found in ArgExpr's type. 4282static Qualifiers CollectVRQualifiers(ASTContext &Context, Expr* ArgExpr) { 4283 Qualifiers VRQuals; 4284 const RecordType *TyRec; 4285 if (const MemberPointerType *RHSMPType = 4286 ArgExpr->getType()->getAs<MemberPointerType>()) 4287 TyRec = RHSMPType->getClass()->getAs<RecordType>(); 4288 else 4289 TyRec = ArgExpr->getType()->getAs<RecordType>(); 4290 if (!TyRec) { 4291 // Just to be safe, assume the worst case. 4292 VRQuals.addVolatile(); 4293 VRQuals.addRestrict(); 4294 return VRQuals; 4295 } 4296 4297 CXXRecordDecl *ClassDecl = cast<CXXRecordDecl>(TyRec->getDecl()); 4298 if (!ClassDecl->hasDefinition()) 4299 return VRQuals; 4300 4301 const UnresolvedSetImpl *Conversions = 4302 ClassDecl->getVisibleConversionFunctions(); 4303 4304 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 4305 E = Conversions->end(); I != E; ++I) { 4306 NamedDecl *D = I.getDecl(); 4307 if (isa<UsingShadowDecl>(D)) 4308 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 4309 if (CXXConversionDecl *Conv = dyn_cast<CXXConversionDecl>(D)) { 4310 QualType CanTy = Context.getCanonicalType(Conv->getConversionType()); 4311 if (const ReferenceType *ResTypeRef = CanTy->getAs<ReferenceType>()) 4312 CanTy = ResTypeRef->getPointeeType(); 4313 // Need to go down the pointer/mempointer chain and add qualifiers 4314 // as see them. 4315 bool done = false; 4316 while (!done) { 4317 if (const PointerType *ResTypePtr = CanTy->getAs<PointerType>()) 4318 CanTy = ResTypePtr->getPointeeType(); 4319 else if (const MemberPointerType *ResTypeMPtr = 4320 CanTy->getAs<MemberPointerType>()) 4321 CanTy = ResTypeMPtr->getPointeeType(); 4322 else 4323 done = true; 4324 if (CanTy.isVolatileQualified()) 4325 VRQuals.addVolatile(); 4326 if (CanTy.isRestrictQualified()) 4327 VRQuals.addRestrict(); 4328 if (VRQuals.hasRestrict() && VRQuals.hasVolatile()) 4329 return VRQuals; 4330 } 4331 } 4332 } 4333 return VRQuals; 4334} 4335 4336/// AddBuiltinOperatorCandidates - Add the appropriate built-in 4337/// operator overloads to the candidate set (C++ [over.built]), based 4338/// on the operator @p Op and the arguments given. For example, if the 4339/// operator is a binary '+', this routine might add "int 4340/// operator+(int, int)" to cover integer addition. 4341void 4342Sema::AddBuiltinOperatorCandidates(OverloadedOperatorKind Op, 4343 SourceLocation OpLoc, 4344 Expr **Args, unsigned NumArgs, 4345 OverloadCandidateSet& CandidateSet) { 4346 // The set of "promoted arithmetic types", which are the arithmetic 4347 // types are that preserved by promotion (C++ [over.built]p2). Note 4348 // that the first few of these types are the promoted integral 4349 // types; these types need to be first. 4350 // FIXME: What about complex? 4351 const unsigned FirstIntegralType = 0; 4352 const unsigned LastIntegralType = 13; 4353 const unsigned FirstPromotedIntegralType = 7, 4354 LastPromotedIntegralType = 13; 4355 const unsigned FirstPromotedArithmeticType = 7, 4356 LastPromotedArithmeticType = 16; 4357 const unsigned NumArithmeticTypes = 16; 4358 QualType ArithmeticTypes[NumArithmeticTypes] = { 4359 Context.BoolTy, Context.CharTy, Context.WCharTy, 4360// FIXME: Context.Char16Ty, Context.Char32Ty, 4361 Context.SignedCharTy, Context.ShortTy, 4362 Context.UnsignedCharTy, Context.UnsignedShortTy, 4363 Context.IntTy, Context.LongTy, Context.LongLongTy, 4364 Context.UnsignedIntTy, Context.UnsignedLongTy, Context.UnsignedLongLongTy, 4365 Context.FloatTy, Context.DoubleTy, Context.LongDoubleTy 4366 }; 4367 assert(ArithmeticTypes[FirstPromotedIntegralType] == Context.IntTy && 4368 "Invalid first promoted integral type"); 4369 assert(ArithmeticTypes[LastPromotedIntegralType - 1] 4370 == Context.UnsignedLongLongTy && 4371 "Invalid last promoted integral type"); 4372 assert(ArithmeticTypes[FirstPromotedArithmeticType] == Context.IntTy && 4373 "Invalid first promoted arithmetic type"); 4374 assert(ArithmeticTypes[LastPromotedArithmeticType - 1] 4375 == Context.LongDoubleTy && 4376 "Invalid last promoted arithmetic type"); 4377 4378 // Find all of the types that the arguments can convert to, but only 4379 // if the operator we're looking at has built-in operator candidates 4380 // that make use of these types. 4381 Qualifiers VisibleTypeConversionsQuals; 4382 VisibleTypeConversionsQuals.addConst(); 4383 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4384 VisibleTypeConversionsQuals += CollectVRQualifiers(Context, Args[ArgIdx]); 4385 4386 BuiltinCandidateTypeSet CandidateTypes(*this); 4387 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 4388 CandidateTypes.AddTypesConvertedFrom(Args[ArgIdx]->getType(), 4389 OpLoc, 4390 true, 4391 (Op == OO_Exclaim || 4392 Op == OO_AmpAmp || 4393 Op == OO_PipePipe), 4394 VisibleTypeConversionsQuals); 4395 4396 bool isComparison = false; 4397 switch (Op) { 4398 case OO_None: 4399 case NUM_OVERLOADED_OPERATORS: 4400 assert(false && "Expected an overloaded operator"); 4401 break; 4402 4403 case OO_Star: // '*' is either unary or binary 4404 if (NumArgs == 1) 4405 goto UnaryStar; 4406 else 4407 goto BinaryStar; 4408 break; 4409 4410 case OO_Plus: // '+' is either unary or binary 4411 if (NumArgs == 1) 4412 goto UnaryPlus; 4413 else 4414 goto BinaryPlus; 4415 break; 4416 4417 case OO_Minus: // '-' is either unary or binary 4418 if (NumArgs == 1) 4419 goto UnaryMinus; 4420 else 4421 goto BinaryMinus; 4422 break; 4423 4424 case OO_Amp: // '&' is either unary or binary 4425 if (NumArgs == 1) 4426 goto UnaryAmp; 4427 else 4428 goto BinaryAmp; 4429 4430 case OO_PlusPlus: 4431 case OO_MinusMinus: 4432 // C++ [over.built]p3: 4433 // 4434 // For every pair (T, VQ), where T is an arithmetic type, and VQ 4435 // is either volatile or empty, there exist candidate operator 4436 // functions of the form 4437 // 4438 // VQ T& operator++(VQ T&); 4439 // T operator++(VQ T&, int); 4440 // 4441 // C++ [over.built]p4: 4442 // 4443 // For every pair (T, VQ), where T is an arithmetic type other 4444 // than bool, and VQ is either volatile or empty, there exist 4445 // candidate operator functions of the form 4446 // 4447 // VQ T& operator--(VQ T&); 4448 // T operator--(VQ T&, int); 4449 for (unsigned Arith = (Op == OO_PlusPlus? 0 : 1); 4450 Arith < NumArithmeticTypes; ++Arith) { 4451 QualType ArithTy = ArithmeticTypes[Arith]; 4452 QualType ParamTypes[2] 4453 = { Context.getLValueReferenceType(ArithTy), Context.IntTy }; 4454 4455 // Non-volatile version. 4456 if (NumArgs == 1) 4457 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4458 else 4459 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4460 // heuristic to reduce number of builtin candidates in the set. 4461 // Add volatile version only if there are conversions to a volatile type. 4462 if (VisibleTypeConversionsQuals.hasVolatile()) { 4463 // Volatile version 4464 ParamTypes[0] 4465 = Context.getLValueReferenceType(Context.getVolatileType(ArithTy)); 4466 if (NumArgs == 1) 4467 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4468 else 4469 AddBuiltinCandidate(ArithTy, ParamTypes, Args, 2, CandidateSet); 4470 } 4471 } 4472 4473 // C++ [over.built]p5: 4474 // 4475 // For every pair (T, VQ), where T is a cv-qualified or 4476 // cv-unqualified object type, and VQ is either volatile or 4477 // empty, there exist candidate operator functions of the form 4478 // 4479 // T*VQ& operator++(T*VQ&); 4480 // T*VQ& operator--(T*VQ&); 4481 // T* operator++(T*VQ&, int); 4482 // T* operator--(T*VQ&, int); 4483 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4484 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4485 // Skip pointer types that aren't pointers to object types. 4486 if (!(*Ptr)->getAs<PointerType>()->getPointeeType()->isObjectType()) 4487 continue; 4488 4489 QualType ParamTypes[2] = { 4490 Context.getLValueReferenceType(*Ptr), Context.IntTy 4491 }; 4492 4493 // Without volatile 4494 if (NumArgs == 1) 4495 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4496 else 4497 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4498 4499 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4500 VisibleTypeConversionsQuals.hasVolatile()) { 4501 // With volatile 4502 ParamTypes[0] 4503 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4504 if (NumArgs == 1) 4505 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 1, CandidateSet); 4506 else 4507 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4508 } 4509 } 4510 break; 4511 4512 UnaryStar: 4513 // C++ [over.built]p6: 4514 // For every cv-qualified or cv-unqualified object type T, there 4515 // exist candidate operator functions of the form 4516 // 4517 // T& operator*(T*); 4518 // 4519 // C++ [over.built]p7: 4520 // For every function type T, there exist candidate operator 4521 // functions of the form 4522 // T& operator*(T*); 4523 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4524 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4525 QualType ParamTy = *Ptr; 4526 QualType PointeeTy = ParamTy->getAs<PointerType>()->getPointeeType(); 4527 AddBuiltinCandidate(Context.getLValueReferenceType(PointeeTy), 4528 &ParamTy, Args, 1, CandidateSet); 4529 } 4530 break; 4531 4532 UnaryPlus: 4533 // C++ [over.built]p8: 4534 // For every type T, there exist candidate operator functions of 4535 // the form 4536 // 4537 // T* operator+(T*); 4538 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4539 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4540 QualType ParamTy = *Ptr; 4541 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet); 4542 } 4543 4544 // Fall through 4545 4546 UnaryMinus: 4547 // C++ [over.built]p9: 4548 // For every promoted arithmetic type T, there exist candidate 4549 // operator functions of the form 4550 // 4551 // T operator+(T); 4552 // T operator-(T); 4553 for (unsigned Arith = FirstPromotedArithmeticType; 4554 Arith < LastPromotedArithmeticType; ++Arith) { 4555 QualType ArithTy = ArithmeticTypes[Arith]; 4556 AddBuiltinCandidate(ArithTy, &ArithTy, Args, 1, CandidateSet); 4557 } 4558 4559 // Extension: We also add these operators for vector types. 4560 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4561 VecEnd = CandidateTypes.vector_end(); 4562 Vec != VecEnd; ++Vec) { 4563 QualType VecTy = *Vec; 4564 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4565 } 4566 break; 4567 4568 case OO_Tilde: 4569 // C++ [over.built]p10: 4570 // For every promoted integral type T, there exist candidate 4571 // operator functions of the form 4572 // 4573 // T operator~(T); 4574 for (unsigned Int = FirstPromotedIntegralType; 4575 Int < LastPromotedIntegralType; ++Int) { 4576 QualType IntTy = ArithmeticTypes[Int]; 4577 AddBuiltinCandidate(IntTy, &IntTy, Args, 1, CandidateSet); 4578 } 4579 4580 // Extension: We also add this operator for vector types. 4581 for (BuiltinCandidateTypeSet::iterator Vec = CandidateTypes.vector_begin(), 4582 VecEnd = CandidateTypes.vector_end(); 4583 Vec != VecEnd; ++Vec) { 4584 QualType VecTy = *Vec; 4585 AddBuiltinCandidate(VecTy, &VecTy, Args, 1, CandidateSet); 4586 } 4587 break; 4588 4589 case OO_New: 4590 case OO_Delete: 4591 case OO_Array_New: 4592 case OO_Array_Delete: 4593 case OO_Call: 4594 assert(false && "Special operators don't use AddBuiltinOperatorCandidates"); 4595 break; 4596 4597 case OO_Comma: 4598 UnaryAmp: 4599 case OO_Arrow: 4600 // C++ [over.match.oper]p3: 4601 // -- For the operator ',', the unary operator '&', or the 4602 // operator '->', the built-in candidates set is empty. 4603 break; 4604 4605 case OO_EqualEqual: 4606 case OO_ExclaimEqual: 4607 // C++ [over.match.oper]p16: 4608 // For every pointer to member type T, there exist candidate operator 4609 // functions of the form 4610 // 4611 // bool operator==(T,T); 4612 // bool operator!=(T,T); 4613 for (BuiltinCandidateTypeSet::iterator 4614 MemPtr = CandidateTypes.member_pointer_begin(), 4615 MemPtrEnd = CandidateTypes.member_pointer_end(); 4616 MemPtr != MemPtrEnd; 4617 ++MemPtr) { 4618 QualType ParamTypes[2] = { *MemPtr, *MemPtr }; 4619 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4620 } 4621 4622 // Fall through 4623 4624 case OO_Less: 4625 case OO_Greater: 4626 case OO_LessEqual: 4627 case OO_GreaterEqual: 4628 // C++ [over.built]p15: 4629 // 4630 // For every pointer or enumeration type T, there exist 4631 // candidate operator functions of the form 4632 // 4633 // bool operator<(T, T); 4634 // bool operator>(T, T); 4635 // bool operator<=(T, T); 4636 // bool operator>=(T, T); 4637 // bool operator==(T, T); 4638 // bool operator!=(T, T); 4639 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4640 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4641 QualType ParamTypes[2] = { *Ptr, *Ptr }; 4642 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4643 } 4644 for (BuiltinCandidateTypeSet::iterator Enum 4645 = CandidateTypes.enumeration_begin(); 4646 Enum != CandidateTypes.enumeration_end(); ++Enum) { 4647 QualType ParamTypes[2] = { *Enum, *Enum }; 4648 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet); 4649 } 4650 4651 // Fall through. 4652 isComparison = true; 4653 4654 BinaryPlus: 4655 BinaryMinus: 4656 if (!isComparison) { 4657 // We didn't fall through, so we must have OO_Plus or OO_Minus. 4658 4659 // C++ [over.built]p13: 4660 // 4661 // For every cv-qualified or cv-unqualified object type T 4662 // there exist candidate operator functions of the form 4663 // 4664 // T* operator+(T*, ptrdiff_t); 4665 // T& operator[](T*, ptrdiff_t); [BELOW] 4666 // T* operator-(T*, ptrdiff_t); 4667 // T* operator+(ptrdiff_t, T*); 4668 // T& operator[](ptrdiff_t, T*); [BELOW] 4669 // 4670 // C++ [over.built]p14: 4671 // 4672 // For every T, where T is a pointer to object type, there 4673 // exist candidate operator functions of the form 4674 // 4675 // ptrdiff_t operator-(T, T); 4676 for (BuiltinCandidateTypeSet::iterator Ptr 4677 = CandidateTypes.pointer_begin(); 4678 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4679 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 4680 4681 // operator+(T*, ptrdiff_t) or operator-(T*, ptrdiff_t) 4682 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4683 4684 if (Op == OO_Plus) { 4685 // T* operator+(ptrdiff_t, T*); 4686 ParamTypes[0] = ParamTypes[1]; 4687 ParamTypes[1] = *Ptr; 4688 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 4689 } else { 4690 // ptrdiff_t operator-(T, T); 4691 ParamTypes[1] = *Ptr; 4692 AddBuiltinCandidate(Context.getPointerDiffType(), ParamTypes, 4693 Args, 2, CandidateSet); 4694 } 4695 } 4696 } 4697 // Fall through 4698 4699 case OO_Slash: 4700 BinaryStar: 4701 Conditional: 4702 // C++ [over.built]p12: 4703 // 4704 // For every pair of promoted arithmetic types L and R, there 4705 // exist candidate operator functions of the form 4706 // 4707 // LR operator*(L, R); 4708 // LR operator/(L, R); 4709 // LR operator+(L, R); 4710 // LR operator-(L, R); 4711 // bool operator<(L, R); 4712 // bool operator>(L, R); 4713 // bool operator<=(L, R); 4714 // bool operator>=(L, R); 4715 // bool operator==(L, R); 4716 // bool operator!=(L, R); 4717 // 4718 // where LR is the result of the usual arithmetic conversions 4719 // between types L and R. 4720 // 4721 // C++ [over.built]p24: 4722 // 4723 // For every pair of promoted arithmetic types L and R, there exist 4724 // candidate operator functions of the form 4725 // 4726 // LR operator?(bool, L, R); 4727 // 4728 // where LR is the result of the usual arithmetic conversions 4729 // between types L and R. 4730 // Our candidates ignore the first parameter. 4731 for (unsigned Left = FirstPromotedArithmeticType; 4732 Left < LastPromotedArithmeticType; ++Left) { 4733 for (unsigned Right = FirstPromotedArithmeticType; 4734 Right < LastPromotedArithmeticType; ++Right) { 4735 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4736 QualType Result 4737 = isComparison 4738 ? Context.BoolTy 4739 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4740 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4741 } 4742 } 4743 4744 // Extension: Add the binary operators ==, !=, <, <=, >=, >, *, /, and the 4745 // conditional operator for vector types. 4746 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4747 Vec1End = CandidateTypes.vector_end(); 4748 Vec1 != Vec1End; ++Vec1) 4749 for (BuiltinCandidateTypeSet::iterator 4750 Vec2 = CandidateTypes.vector_begin(), 4751 Vec2End = CandidateTypes.vector_end(); 4752 Vec2 != Vec2End; ++Vec2) { 4753 QualType LandR[2] = { *Vec1, *Vec2 }; 4754 QualType Result; 4755 if (isComparison) 4756 Result = Context.BoolTy; 4757 else { 4758 if ((*Vec1)->isExtVectorType() || !(*Vec2)->isExtVectorType()) 4759 Result = *Vec1; 4760 else 4761 Result = *Vec2; 4762 } 4763 4764 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4765 } 4766 4767 break; 4768 4769 case OO_Percent: 4770 BinaryAmp: 4771 case OO_Caret: 4772 case OO_Pipe: 4773 case OO_LessLess: 4774 case OO_GreaterGreater: 4775 // C++ [over.built]p17: 4776 // 4777 // For every pair of promoted integral types L and R, there 4778 // exist candidate operator functions of the form 4779 // 4780 // LR operator%(L, R); 4781 // LR operator&(L, R); 4782 // LR operator^(L, R); 4783 // LR operator|(L, R); 4784 // L operator<<(L, R); 4785 // L operator>>(L, R); 4786 // 4787 // where LR is the result of the usual arithmetic conversions 4788 // between types L and R. 4789 for (unsigned Left = FirstPromotedIntegralType; 4790 Left < LastPromotedIntegralType; ++Left) { 4791 for (unsigned Right = FirstPromotedIntegralType; 4792 Right < LastPromotedIntegralType; ++Right) { 4793 QualType LandR[2] = { ArithmeticTypes[Left], ArithmeticTypes[Right] }; 4794 QualType Result = (Op == OO_LessLess || Op == OO_GreaterGreater) 4795 ? LandR[0] 4796 : Context.UsualArithmeticConversionsType(LandR[0], LandR[1]); 4797 AddBuiltinCandidate(Result, LandR, Args, 2, CandidateSet); 4798 } 4799 } 4800 break; 4801 4802 case OO_Equal: 4803 // C++ [over.built]p20: 4804 // 4805 // For every pair (T, VQ), where T is an enumeration or 4806 // pointer to member type and VQ is either volatile or 4807 // empty, there exist candidate operator functions of the form 4808 // 4809 // VQ T& operator=(VQ T&, T); 4810 for (BuiltinCandidateTypeSet::iterator 4811 Enum = CandidateTypes.enumeration_begin(), 4812 EnumEnd = CandidateTypes.enumeration_end(); 4813 Enum != EnumEnd; ++Enum) 4814 AddBuiltinAssignmentOperatorCandidates(*this, *Enum, Args, 2, 4815 CandidateSet); 4816 for (BuiltinCandidateTypeSet::iterator 4817 MemPtr = CandidateTypes.member_pointer_begin(), 4818 MemPtrEnd = CandidateTypes.member_pointer_end(); 4819 MemPtr != MemPtrEnd; ++MemPtr) 4820 AddBuiltinAssignmentOperatorCandidates(*this, *MemPtr, Args, 2, 4821 CandidateSet); 4822 4823 // Fall through. 4824 4825 case OO_PlusEqual: 4826 case OO_MinusEqual: 4827 // C++ [over.built]p19: 4828 // 4829 // For every pair (T, VQ), where T is any type and VQ is either 4830 // volatile or empty, there exist candidate operator functions 4831 // of the form 4832 // 4833 // T*VQ& operator=(T*VQ&, T*); 4834 // 4835 // C++ [over.built]p21: 4836 // 4837 // For every pair (T, VQ), where T is a cv-qualified or 4838 // cv-unqualified object type and VQ is either volatile or 4839 // empty, there exist candidate operator functions of the form 4840 // 4841 // T*VQ& operator+=(T*VQ&, ptrdiff_t); 4842 // T*VQ& operator-=(T*VQ&, ptrdiff_t); 4843 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 4844 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 4845 QualType ParamTypes[2]; 4846 ParamTypes[1] = (Op == OO_Equal)? *Ptr : Context.getPointerDiffType(); 4847 4848 // non-volatile version 4849 ParamTypes[0] = Context.getLValueReferenceType(*Ptr); 4850 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4851 /*IsAssigmentOperator=*/Op == OO_Equal); 4852 4853 if (!Context.getCanonicalType(*Ptr).isVolatileQualified() && 4854 VisibleTypeConversionsQuals.hasVolatile()) { 4855 // volatile version 4856 ParamTypes[0] 4857 = Context.getLValueReferenceType(Context.getVolatileType(*Ptr)); 4858 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4859 /*IsAssigmentOperator=*/Op == OO_Equal); 4860 } 4861 } 4862 // Fall through. 4863 4864 case OO_StarEqual: 4865 case OO_SlashEqual: 4866 // C++ [over.built]p18: 4867 // 4868 // For every triple (L, VQ, R), where L is an arithmetic type, 4869 // VQ is either volatile or empty, and R is a promoted 4870 // arithmetic type, there exist candidate operator functions of 4871 // the form 4872 // 4873 // VQ L& operator=(VQ L&, R); 4874 // VQ L& operator*=(VQ L&, R); 4875 // VQ L& operator/=(VQ L&, R); 4876 // VQ L& operator+=(VQ L&, R); 4877 // VQ L& operator-=(VQ L&, R); 4878 for (unsigned Left = 0; Left < NumArithmeticTypes; ++Left) { 4879 for (unsigned Right = FirstPromotedArithmeticType; 4880 Right < LastPromotedArithmeticType; ++Right) { 4881 QualType ParamTypes[2]; 4882 ParamTypes[1] = ArithmeticTypes[Right]; 4883 4884 // Add this built-in operator as a candidate (VQ is empty). 4885 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4886 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4887 /*IsAssigmentOperator=*/Op == OO_Equal); 4888 4889 // Add this built-in operator as a candidate (VQ is 'volatile'). 4890 if (VisibleTypeConversionsQuals.hasVolatile()) { 4891 ParamTypes[0] = Context.getVolatileType(ArithmeticTypes[Left]); 4892 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4893 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4894 /*IsAssigmentOperator=*/Op == OO_Equal); 4895 } 4896 } 4897 } 4898 4899 // Extension: Add the binary operators =, +=, -=, *=, /= for vector types. 4900 for (BuiltinCandidateTypeSet::iterator Vec1 = CandidateTypes.vector_begin(), 4901 Vec1End = CandidateTypes.vector_end(); 4902 Vec1 != Vec1End; ++Vec1) 4903 for (BuiltinCandidateTypeSet::iterator 4904 Vec2 = CandidateTypes.vector_begin(), 4905 Vec2End = CandidateTypes.vector_end(); 4906 Vec2 != Vec2End; ++Vec2) { 4907 QualType ParamTypes[2]; 4908 ParamTypes[1] = *Vec2; 4909 // Add this built-in operator as a candidate (VQ is empty). 4910 ParamTypes[0] = Context.getLValueReferenceType(*Vec1); 4911 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4912 /*IsAssigmentOperator=*/Op == OO_Equal); 4913 4914 // Add this built-in operator as a candidate (VQ is 'volatile'). 4915 if (VisibleTypeConversionsQuals.hasVolatile()) { 4916 ParamTypes[0] = Context.getVolatileType(*Vec1); 4917 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4918 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet, 4919 /*IsAssigmentOperator=*/Op == OO_Equal); 4920 } 4921 } 4922 break; 4923 4924 case OO_PercentEqual: 4925 case OO_LessLessEqual: 4926 case OO_GreaterGreaterEqual: 4927 case OO_AmpEqual: 4928 case OO_CaretEqual: 4929 case OO_PipeEqual: 4930 // C++ [over.built]p22: 4931 // 4932 // For every triple (L, VQ, R), where L is an integral type, VQ 4933 // is either volatile or empty, and R is a promoted integral 4934 // type, there exist candidate operator functions of the form 4935 // 4936 // VQ L& operator%=(VQ L&, R); 4937 // VQ L& operator<<=(VQ L&, R); 4938 // VQ L& operator>>=(VQ L&, R); 4939 // VQ L& operator&=(VQ L&, R); 4940 // VQ L& operator^=(VQ L&, R); 4941 // VQ L& operator|=(VQ L&, R); 4942 for (unsigned Left = FirstIntegralType; Left < LastIntegralType; ++Left) { 4943 for (unsigned Right = FirstPromotedIntegralType; 4944 Right < LastPromotedIntegralType; ++Right) { 4945 QualType ParamTypes[2]; 4946 ParamTypes[1] = ArithmeticTypes[Right]; 4947 4948 // Add this built-in operator as a candidate (VQ is empty). 4949 ParamTypes[0] = Context.getLValueReferenceType(ArithmeticTypes[Left]); 4950 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4951 if (VisibleTypeConversionsQuals.hasVolatile()) { 4952 // Add this built-in operator as a candidate (VQ is 'volatile'). 4953 ParamTypes[0] = ArithmeticTypes[Left]; 4954 ParamTypes[0] = Context.getVolatileType(ParamTypes[0]); 4955 ParamTypes[0] = Context.getLValueReferenceType(ParamTypes[0]); 4956 AddBuiltinCandidate(ParamTypes[0], ParamTypes, Args, 2, CandidateSet); 4957 } 4958 } 4959 } 4960 break; 4961 4962 case OO_Exclaim: { 4963 // C++ [over.operator]p23: 4964 // 4965 // There also exist candidate operator functions of the form 4966 // 4967 // bool operator!(bool); 4968 // bool operator&&(bool, bool); [BELOW] 4969 // bool operator||(bool, bool); [BELOW] 4970 QualType ParamTy = Context.BoolTy; 4971 AddBuiltinCandidate(ParamTy, &ParamTy, Args, 1, CandidateSet, 4972 /*IsAssignmentOperator=*/false, 4973 /*NumContextualBoolArguments=*/1); 4974 break; 4975 } 4976 4977 case OO_AmpAmp: 4978 case OO_PipePipe: { 4979 // C++ [over.operator]p23: 4980 // 4981 // There also exist candidate operator functions of the form 4982 // 4983 // bool operator!(bool); [ABOVE] 4984 // bool operator&&(bool, bool); 4985 // bool operator||(bool, bool); 4986 QualType ParamTypes[2] = { Context.BoolTy, Context.BoolTy }; 4987 AddBuiltinCandidate(Context.BoolTy, ParamTypes, Args, 2, CandidateSet, 4988 /*IsAssignmentOperator=*/false, 4989 /*NumContextualBoolArguments=*/2); 4990 break; 4991 } 4992 4993 case OO_Subscript: 4994 // C++ [over.built]p13: 4995 // 4996 // For every cv-qualified or cv-unqualified object type T there 4997 // exist candidate operator functions of the form 4998 // 4999 // T* operator+(T*, ptrdiff_t); [ABOVE] 5000 // T& operator[](T*, ptrdiff_t); 5001 // T* operator-(T*, ptrdiff_t); [ABOVE] 5002 // T* operator+(ptrdiff_t, T*); [ABOVE] 5003 // T& operator[](ptrdiff_t, T*); 5004 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(); 5005 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 5006 QualType ParamTypes[2] = { *Ptr, Context.getPointerDiffType() }; 5007 QualType PointeeType = (*Ptr)->getAs<PointerType>()->getPointeeType(); 5008 QualType ResultTy = Context.getLValueReferenceType(PointeeType); 5009 5010 // T& operator[](T*, ptrdiff_t) 5011 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5012 5013 // T& operator[](ptrdiff_t, T*); 5014 ParamTypes[0] = ParamTypes[1]; 5015 ParamTypes[1] = *Ptr; 5016 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5017 } 5018 break; 5019 5020 case OO_ArrowStar: 5021 // C++ [over.built]p11: 5022 // For every quintuple (C1, C2, T, CV1, CV2), where C2 is a class type, 5023 // C1 is the same type as C2 or is a derived class of C2, T is an object 5024 // type or a function type, and CV1 and CV2 are cv-qualifier-seqs, 5025 // there exist candidate operator functions of the form 5026 // CV12 T& operator->*(CV1 C1*, CV2 T C2::*); 5027 // where CV12 is the union of CV1 and CV2. 5028 { 5029 for (BuiltinCandidateTypeSet::iterator Ptr = 5030 CandidateTypes.pointer_begin(); 5031 Ptr != CandidateTypes.pointer_end(); ++Ptr) { 5032 QualType C1Ty = (*Ptr); 5033 QualType C1; 5034 QualifierCollector Q1; 5035 if (const PointerType *PointerTy = C1Ty->getAs<PointerType>()) { 5036 C1 = QualType(Q1.strip(PointerTy->getPointeeType()), 0); 5037 if (!isa<RecordType>(C1)) 5038 continue; 5039 // heuristic to reduce number of builtin candidates in the set. 5040 // Add volatile/restrict version only if there are conversions to a 5041 // volatile/restrict type. 5042 if (!VisibleTypeConversionsQuals.hasVolatile() && Q1.hasVolatile()) 5043 continue; 5044 if (!VisibleTypeConversionsQuals.hasRestrict() && Q1.hasRestrict()) 5045 continue; 5046 } 5047 for (BuiltinCandidateTypeSet::iterator 5048 MemPtr = CandidateTypes.member_pointer_begin(), 5049 MemPtrEnd = CandidateTypes.member_pointer_end(); 5050 MemPtr != MemPtrEnd; ++MemPtr) { 5051 const MemberPointerType *mptr = cast<MemberPointerType>(*MemPtr); 5052 QualType C2 = QualType(mptr->getClass(), 0); 5053 C2 = C2.getUnqualifiedType(); 5054 if (C1 != C2 && !IsDerivedFrom(C1, C2)) 5055 break; 5056 QualType ParamTypes[2] = { *Ptr, *MemPtr }; 5057 // build CV12 T& 5058 QualType T = mptr->getPointeeType(); 5059 if (!VisibleTypeConversionsQuals.hasVolatile() && 5060 T.isVolatileQualified()) 5061 continue; 5062 if (!VisibleTypeConversionsQuals.hasRestrict() && 5063 T.isRestrictQualified()) 5064 continue; 5065 T = Q1.apply(T); 5066 QualType ResultTy = Context.getLValueReferenceType(T); 5067 AddBuiltinCandidate(ResultTy, ParamTypes, Args, 2, CandidateSet); 5068 } 5069 } 5070 } 5071 break; 5072 5073 case OO_Conditional: 5074 // Note that we don't consider the first argument, since it has been 5075 // contextually converted to bool long ago. The candidates below are 5076 // therefore added as binary. 5077 // 5078 // C++ [over.built]p24: 5079 // For every type T, where T is a pointer or pointer-to-member type, 5080 // there exist candidate operator functions of the form 5081 // 5082 // T operator?(bool, T, T); 5083 // 5084 for (BuiltinCandidateTypeSet::iterator Ptr = CandidateTypes.pointer_begin(), 5085 E = CandidateTypes.pointer_end(); Ptr != E; ++Ptr) { 5086 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5087 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5088 } 5089 for (BuiltinCandidateTypeSet::iterator Ptr = 5090 CandidateTypes.member_pointer_begin(), 5091 E = CandidateTypes.member_pointer_end(); Ptr != E; ++Ptr) { 5092 QualType ParamTypes[2] = { *Ptr, *Ptr }; 5093 AddBuiltinCandidate(*Ptr, ParamTypes, Args, 2, CandidateSet); 5094 } 5095 goto Conditional; 5096 } 5097} 5098 5099/// \brief Add function candidates found via argument-dependent lookup 5100/// to the set of overloading candidates. 5101/// 5102/// This routine performs argument-dependent name lookup based on the 5103/// given function name (which may also be an operator name) and adds 5104/// all of the overload candidates found by ADL to the overload 5105/// candidate set (C++ [basic.lookup.argdep]). 5106void 5107Sema::AddArgumentDependentLookupCandidates(DeclarationName Name, 5108 bool Operator, 5109 Expr **Args, unsigned NumArgs, 5110 const TemplateArgumentListInfo *ExplicitTemplateArgs, 5111 OverloadCandidateSet& CandidateSet, 5112 bool PartialOverloading) { 5113 ADLResult Fns; 5114 5115 // FIXME: This approach for uniquing ADL results (and removing 5116 // redundant candidates from the set) relies on pointer-equality, 5117 // which means we need to key off the canonical decl. However, 5118 // always going back to the canonical decl might not get us the 5119 // right set of default arguments. What default arguments are 5120 // we supposed to consider on ADL candidates, anyway? 5121 5122 // FIXME: Pass in the explicit template arguments? 5123 ArgumentDependentLookup(Name, Operator, Args, NumArgs, Fns); 5124 5125 // Erase all of the candidates we already knew about. 5126 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5127 CandEnd = CandidateSet.end(); 5128 Cand != CandEnd; ++Cand) 5129 if (Cand->Function) { 5130 Fns.erase(Cand->Function); 5131 if (FunctionTemplateDecl *FunTmpl = Cand->Function->getPrimaryTemplate()) 5132 Fns.erase(FunTmpl); 5133 } 5134 5135 // For each of the ADL candidates we found, add it to the overload 5136 // set. 5137 for (ADLResult::iterator I = Fns.begin(), E = Fns.end(); I != E; ++I) { 5138 DeclAccessPair FoundDecl = DeclAccessPair::make(*I, AS_none); 5139 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(*I)) { 5140 if (ExplicitTemplateArgs) 5141 continue; 5142 5143 AddOverloadCandidate(FD, FoundDecl, Args, NumArgs, CandidateSet, 5144 false, PartialOverloading); 5145 } else 5146 AddTemplateOverloadCandidate(cast<FunctionTemplateDecl>(*I), 5147 FoundDecl, ExplicitTemplateArgs, 5148 Args, NumArgs, CandidateSet); 5149 } 5150} 5151 5152/// isBetterOverloadCandidate - Determines whether the first overload 5153/// candidate is a better candidate than the second (C++ 13.3.3p1). 5154bool 5155Sema::isBetterOverloadCandidate(const OverloadCandidate& Cand1, 5156 const OverloadCandidate& Cand2, 5157 SourceLocation Loc) { 5158 // Define viable functions to be better candidates than non-viable 5159 // functions. 5160 if (!Cand2.Viable) 5161 return Cand1.Viable; 5162 else if (!Cand1.Viable) 5163 return false; 5164 5165 // C++ [over.match.best]p1: 5166 // 5167 // -- if F is a static member function, ICS1(F) is defined such 5168 // that ICS1(F) is neither better nor worse than ICS1(G) for 5169 // any function G, and, symmetrically, ICS1(G) is neither 5170 // better nor worse than ICS1(F). 5171 unsigned StartArg = 0; 5172 if (Cand1.IgnoreObjectArgument || Cand2.IgnoreObjectArgument) 5173 StartArg = 1; 5174 5175 // C++ [over.match.best]p1: 5176 // A viable function F1 is defined to be a better function than another 5177 // viable function F2 if for all arguments i, ICSi(F1) is not a worse 5178 // conversion sequence than ICSi(F2), and then... 5179 unsigned NumArgs = Cand1.Conversions.size(); 5180 assert(Cand2.Conversions.size() == NumArgs && "Overload candidate mismatch"); 5181 bool HasBetterConversion = false; 5182 for (unsigned ArgIdx = StartArg; ArgIdx < NumArgs; ++ArgIdx) { 5183 switch (CompareImplicitConversionSequences(Cand1.Conversions[ArgIdx], 5184 Cand2.Conversions[ArgIdx])) { 5185 case ImplicitConversionSequence::Better: 5186 // Cand1 has a better conversion sequence. 5187 HasBetterConversion = true; 5188 break; 5189 5190 case ImplicitConversionSequence::Worse: 5191 // Cand1 can't be better than Cand2. 5192 return false; 5193 5194 case ImplicitConversionSequence::Indistinguishable: 5195 // Do nothing. 5196 break; 5197 } 5198 } 5199 5200 // -- for some argument j, ICSj(F1) is a better conversion sequence than 5201 // ICSj(F2), or, if not that, 5202 if (HasBetterConversion) 5203 return true; 5204 5205 // - F1 is a non-template function and F2 is a function template 5206 // specialization, or, if not that, 5207 if ((!Cand1.Function || !Cand1.Function->getPrimaryTemplate()) && 5208 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5209 return true; 5210 5211 // -- F1 and F2 are function template specializations, and the function 5212 // template for F1 is more specialized than the template for F2 5213 // according to the partial ordering rules described in 14.5.5.2, or, 5214 // if not that, 5215 if (Cand1.Function && Cand1.Function->getPrimaryTemplate() && 5216 Cand2.Function && Cand2.Function->getPrimaryTemplate()) 5217 if (FunctionTemplateDecl *BetterTemplate 5218 = getMoreSpecializedTemplate(Cand1.Function->getPrimaryTemplate(), 5219 Cand2.Function->getPrimaryTemplate(), 5220 Loc, 5221 isa<CXXConversionDecl>(Cand1.Function)? TPOC_Conversion 5222 : TPOC_Call)) 5223 return BetterTemplate == Cand1.Function->getPrimaryTemplate(); 5224 5225 // -- the context is an initialization by user-defined conversion 5226 // (see 8.5, 13.3.1.5) and the standard conversion sequence 5227 // from the return type of F1 to the destination type (i.e., 5228 // the type of the entity being initialized) is a better 5229 // conversion sequence than the standard conversion sequence 5230 // from the return type of F2 to the destination type. 5231 if (Cand1.Function && Cand2.Function && 5232 isa<CXXConversionDecl>(Cand1.Function) && 5233 isa<CXXConversionDecl>(Cand2.Function)) { 5234 switch (CompareStandardConversionSequences(Cand1.FinalConversion, 5235 Cand2.FinalConversion)) { 5236 case ImplicitConversionSequence::Better: 5237 // Cand1 has a better conversion sequence. 5238 return true; 5239 5240 case ImplicitConversionSequence::Worse: 5241 // Cand1 can't be better than Cand2. 5242 return false; 5243 5244 case ImplicitConversionSequence::Indistinguishable: 5245 // Do nothing 5246 break; 5247 } 5248 } 5249 5250 return false; 5251} 5252 5253/// \brief Computes the best viable function (C++ 13.3.3) 5254/// within an overload candidate set. 5255/// 5256/// \param CandidateSet the set of candidate functions. 5257/// 5258/// \param Loc the location of the function name (or operator symbol) for 5259/// which overload resolution occurs. 5260/// 5261/// \param Best f overload resolution was successful or found a deleted 5262/// function, Best points to the candidate function found. 5263/// 5264/// \returns The result of overload resolution. 5265OverloadingResult Sema::BestViableFunction(OverloadCandidateSet& CandidateSet, 5266 SourceLocation Loc, 5267 OverloadCandidateSet::iterator& Best) { 5268 // Find the best viable function. 5269 Best = CandidateSet.end(); 5270 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5271 Cand != CandidateSet.end(); ++Cand) { 5272 if (Cand->Viable) { 5273 if (Best == CandidateSet.end() || 5274 isBetterOverloadCandidate(*Cand, *Best, Loc)) 5275 Best = Cand; 5276 } 5277 } 5278 5279 // If we didn't find any viable functions, abort. 5280 if (Best == CandidateSet.end()) 5281 return OR_No_Viable_Function; 5282 5283 // Make sure that this function is better than every other viable 5284 // function. If not, we have an ambiguity. 5285 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(); 5286 Cand != CandidateSet.end(); ++Cand) { 5287 if (Cand->Viable && 5288 Cand != Best && 5289 !isBetterOverloadCandidate(*Best, *Cand, Loc)) { 5290 Best = CandidateSet.end(); 5291 return OR_Ambiguous; 5292 } 5293 } 5294 5295 // Best is the best viable function. 5296 if (Best->Function && 5297 (Best->Function->isDeleted() || 5298 Best->Function->getAttr<UnavailableAttr>())) 5299 return OR_Deleted; 5300 5301 // C++ [basic.def.odr]p2: 5302 // An overloaded function is used if it is selected by overload resolution 5303 // when referred to from a potentially-evaluated expression. [Note: this 5304 // covers calls to named functions (5.2.2), operator overloading 5305 // (clause 13), user-defined conversions (12.3.2), allocation function for 5306 // placement new (5.3.4), as well as non-default initialization (8.5). 5307 if (Best->Function) 5308 MarkDeclarationReferenced(Loc, Best->Function); 5309 return OR_Success; 5310} 5311 5312namespace { 5313 5314enum OverloadCandidateKind { 5315 oc_function, 5316 oc_method, 5317 oc_constructor, 5318 oc_function_template, 5319 oc_method_template, 5320 oc_constructor_template, 5321 oc_implicit_default_constructor, 5322 oc_implicit_copy_constructor, 5323 oc_implicit_copy_assignment 5324}; 5325 5326OverloadCandidateKind ClassifyOverloadCandidate(Sema &S, 5327 FunctionDecl *Fn, 5328 std::string &Description) { 5329 bool isTemplate = false; 5330 5331 if (FunctionTemplateDecl *FunTmpl = Fn->getPrimaryTemplate()) { 5332 isTemplate = true; 5333 Description = S.getTemplateArgumentBindingsText( 5334 FunTmpl->getTemplateParameters(), *Fn->getTemplateSpecializationArgs()); 5335 } 5336 5337 if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Fn)) { 5338 if (!Ctor->isImplicit()) 5339 return isTemplate ? oc_constructor_template : oc_constructor; 5340 5341 return Ctor->isCopyConstructor() ? oc_implicit_copy_constructor 5342 : oc_implicit_default_constructor; 5343 } 5344 5345 if (CXXMethodDecl *Meth = dyn_cast<CXXMethodDecl>(Fn)) { 5346 // This actually gets spelled 'candidate function' for now, but 5347 // it doesn't hurt to split it out. 5348 if (!Meth->isImplicit()) 5349 return isTemplate ? oc_method_template : oc_method; 5350 5351 assert(Meth->isCopyAssignment() 5352 && "implicit method is not copy assignment operator?"); 5353 return oc_implicit_copy_assignment; 5354 } 5355 5356 return isTemplate ? oc_function_template : oc_function; 5357} 5358 5359} // end anonymous namespace 5360 5361// Notes the location of an overload candidate. 5362void Sema::NoteOverloadCandidate(FunctionDecl *Fn) { 5363 std::string FnDesc; 5364 OverloadCandidateKind K = ClassifyOverloadCandidate(*this, Fn, FnDesc); 5365 Diag(Fn->getLocation(), diag::note_ovl_candidate) 5366 << (unsigned) K << FnDesc; 5367} 5368 5369/// Diagnoses an ambiguous conversion. The partial diagnostic is the 5370/// "lead" diagnostic; it will be given two arguments, the source and 5371/// target types of the conversion. 5372void Sema::DiagnoseAmbiguousConversion(const ImplicitConversionSequence &ICS, 5373 SourceLocation CaretLoc, 5374 const PartialDiagnostic &PDiag) { 5375 Diag(CaretLoc, PDiag) 5376 << ICS.Ambiguous.getFromType() << ICS.Ambiguous.getToType(); 5377 for (AmbiguousConversionSequence::const_iterator 5378 I = ICS.Ambiguous.begin(), E = ICS.Ambiguous.end(); I != E; ++I) { 5379 NoteOverloadCandidate(*I); 5380 } 5381} 5382 5383namespace { 5384 5385void DiagnoseBadConversion(Sema &S, OverloadCandidate *Cand, unsigned I) { 5386 const ImplicitConversionSequence &Conv = Cand->Conversions[I]; 5387 assert(Conv.isBad()); 5388 assert(Cand->Function && "for now, candidate must be a function"); 5389 FunctionDecl *Fn = Cand->Function; 5390 5391 // There's a conversion slot for the object argument if this is a 5392 // non-constructor method. Note that 'I' corresponds the 5393 // conversion-slot index. 5394 bool isObjectArgument = false; 5395 if (isa<CXXMethodDecl>(Fn) && !isa<CXXConstructorDecl>(Fn)) { 5396 if (I == 0) 5397 isObjectArgument = true; 5398 else 5399 I--; 5400 } 5401 5402 std::string FnDesc; 5403 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5404 5405 Expr *FromExpr = Conv.Bad.FromExpr; 5406 QualType FromTy = Conv.Bad.getFromType(); 5407 QualType ToTy = Conv.Bad.getToType(); 5408 5409 if (FromTy == S.Context.OverloadTy) { 5410 assert(FromExpr && "overload set argument came from implicit argument?"); 5411 Expr *E = FromExpr->IgnoreParens(); 5412 if (isa<UnaryOperator>(E)) 5413 E = cast<UnaryOperator>(E)->getSubExpr()->IgnoreParens(); 5414 DeclarationName Name = cast<OverloadExpr>(E)->getName(); 5415 5416 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_overload) 5417 << (unsigned) FnKind << FnDesc 5418 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5419 << ToTy << Name << I+1; 5420 return; 5421 } 5422 5423 // Do some hand-waving analysis to see if the non-viability is due 5424 // to a qualifier mismatch. 5425 CanQualType CFromTy = S.Context.getCanonicalType(FromTy); 5426 CanQualType CToTy = S.Context.getCanonicalType(ToTy); 5427 if (CanQual<ReferenceType> RT = CToTy->getAs<ReferenceType>()) 5428 CToTy = RT->getPointeeType(); 5429 else { 5430 // TODO: detect and diagnose the full richness of const mismatches. 5431 if (CanQual<PointerType> FromPT = CFromTy->getAs<PointerType>()) 5432 if (CanQual<PointerType> ToPT = CToTy->getAs<PointerType>()) 5433 CFromTy = FromPT->getPointeeType(), CToTy = ToPT->getPointeeType(); 5434 } 5435 5436 if (CToTy.getUnqualifiedType() == CFromTy.getUnqualifiedType() && 5437 !CToTy.isAtLeastAsQualifiedAs(CFromTy)) { 5438 // It is dumb that we have to do this here. 5439 while (isa<ArrayType>(CFromTy)) 5440 CFromTy = CFromTy->getAs<ArrayType>()->getElementType(); 5441 while (isa<ArrayType>(CToTy)) 5442 CToTy = CFromTy->getAs<ArrayType>()->getElementType(); 5443 5444 Qualifiers FromQs = CFromTy.getQualifiers(); 5445 Qualifiers ToQs = CToTy.getQualifiers(); 5446 5447 if (FromQs.getAddressSpace() != ToQs.getAddressSpace()) { 5448 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_addrspace) 5449 << (unsigned) FnKind << FnDesc 5450 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5451 << FromTy 5452 << FromQs.getAddressSpace() << ToQs.getAddressSpace() 5453 << (unsigned) isObjectArgument << I+1; 5454 return; 5455 } 5456 5457 unsigned CVR = FromQs.getCVRQualifiers() & ~ToQs.getCVRQualifiers(); 5458 assert(CVR && "unexpected qualifiers mismatch"); 5459 5460 if (isObjectArgument) { 5461 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr_this) 5462 << (unsigned) FnKind << FnDesc 5463 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5464 << FromTy << (CVR - 1); 5465 } else { 5466 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_cvr) 5467 << (unsigned) FnKind << FnDesc 5468 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5469 << FromTy << (CVR - 1) << I+1; 5470 } 5471 return; 5472 } 5473 5474 // Diagnose references or pointers to incomplete types differently, 5475 // since it's far from impossible that the incompleteness triggered 5476 // the failure. 5477 QualType TempFromTy = FromTy.getNonReferenceType(); 5478 if (const PointerType *PTy = TempFromTy->getAs<PointerType>()) 5479 TempFromTy = PTy->getPointeeType(); 5480 if (TempFromTy->isIncompleteType()) { 5481 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv_incomplete) 5482 << (unsigned) FnKind << FnDesc 5483 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5484 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5485 return; 5486 } 5487 5488 // Diagnose base -> derived pointer conversions. 5489 bool IsBaseToDerivedConversion = false; 5490 if (const PointerType *FromPtrTy = FromTy->getAs<PointerType>()) { 5491 if (const PointerType *ToPtrTy = ToTy->getAs<PointerType>()) { 5492 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 5493 FromPtrTy->getPointeeType()) && 5494 !FromPtrTy->getPointeeType()->isIncompleteType() && 5495 !ToPtrTy->getPointeeType()->isIncompleteType() && 5496 S.IsDerivedFrom(ToPtrTy->getPointeeType(), 5497 FromPtrTy->getPointeeType())) 5498 IsBaseToDerivedConversion = true; 5499 } 5500 } else if (const ObjCObjectPointerType *FromPtrTy 5501 = FromTy->getAs<ObjCObjectPointerType>()) { 5502 if (const ObjCObjectPointerType *ToPtrTy 5503 = ToTy->getAs<ObjCObjectPointerType>()) 5504 if (const ObjCInterfaceDecl *FromIface = FromPtrTy->getInterfaceDecl()) 5505 if (const ObjCInterfaceDecl *ToIface = ToPtrTy->getInterfaceDecl()) 5506 if (ToPtrTy->getPointeeType().isAtLeastAsQualifiedAs( 5507 FromPtrTy->getPointeeType()) && 5508 FromIface->isSuperClassOf(ToIface)) 5509 IsBaseToDerivedConversion = true; 5510 } 5511 if (IsBaseToDerivedConversion) { 5512 S.Diag(Fn->getLocation(), 5513 diag::note_ovl_candidate_bad_base_to_derived_ptr_conv) 5514 << (unsigned) FnKind << FnDesc 5515 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5516 << FromTy << ToTy << I+1; 5517 return; 5518 } 5519 5520 // TODO: specialize more based on the kind of mismatch 5521 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_conv) 5522 << (unsigned) FnKind << FnDesc 5523 << (FromExpr ? FromExpr->getSourceRange() : SourceRange()) 5524 << FromTy << ToTy << (unsigned) isObjectArgument << I+1; 5525} 5526 5527void DiagnoseArityMismatch(Sema &S, OverloadCandidate *Cand, 5528 unsigned NumFormalArgs) { 5529 // TODO: treat calls to a missing default constructor as a special case 5530 5531 FunctionDecl *Fn = Cand->Function; 5532 const FunctionProtoType *FnTy = Fn->getType()->getAs<FunctionProtoType>(); 5533 5534 unsigned MinParams = Fn->getMinRequiredArguments(); 5535 5536 // at least / at most / exactly 5537 // FIXME: variadic templates "at most" should account for parameter packs 5538 unsigned mode, modeCount; 5539 if (NumFormalArgs < MinParams) { 5540 assert((Cand->FailureKind == ovl_fail_too_few_arguments) || 5541 (Cand->FailureKind == ovl_fail_bad_deduction && 5542 Cand->DeductionFailure.Result == Sema::TDK_TooFewArguments)); 5543 if (MinParams != FnTy->getNumArgs() || FnTy->isVariadic()) 5544 mode = 0; // "at least" 5545 else 5546 mode = 2; // "exactly" 5547 modeCount = MinParams; 5548 } else { 5549 assert((Cand->FailureKind == ovl_fail_too_many_arguments) || 5550 (Cand->FailureKind == ovl_fail_bad_deduction && 5551 Cand->DeductionFailure.Result == Sema::TDK_TooManyArguments)); 5552 if (MinParams != FnTy->getNumArgs()) 5553 mode = 1; // "at most" 5554 else 5555 mode = 2; // "exactly" 5556 modeCount = FnTy->getNumArgs(); 5557 } 5558 5559 std::string Description; 5560 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, Description); 5561 5562 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_arity) 5563 << (unsigned) FnKind << (Fn->getDescribedFunctionTemplate() != 0) << mode 5564 << modeCount << NumFormalArgs; 5565} 5566 5567/// Diagnose a failed template-argument deduction. 5568void DiagnoseBadDeduction(Sema &S, OverloadCandidate *Cand, 5569 Expr **Args, unsigned NumArgs) { 5570 FunctionDecl *Fn = Cand->Function; // pattern 5571 5572 TemplateParameter Param = Cand->DeductionFailure.getTemplateParameter(); 5573 NamedDecl *ParamD; 5574 (ParamD = Param.dyn_cast<TemplateTypeParmDecl*>()) || 5575 (ParamD = Param.dyn_cast<NonTypeTemplateParmDecl*>()) || 5576 (ParamD = Param.dyn_cast<TemplateTemplateParmDecl*>()); 5577 switch (Cand->DeductionFailure.Result) { 5578 case Sema::TDK_Success: 5579 llvm_unreachable("TDK_success while diagnosing bad deduction"); 5580 5581 case Sema::TDK_Incomplete: { 5582 assert(ParamD && "no parameter found for incomplete deduction result"); 5583 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_incomplete_deduction) 5584 << ParamD->getDeclName(); 5585 return; 5586 } 5587 5588 case Sema::TDK_Inconsistent: 5589 case Sema::TDK_InconsistentQuals: { 5590 assert(ParamD && "no parameter found for inconsistent deduction result"); 5591 int which = 0; 5592 if (isa<TemplateTypeParmDecl>(ParamD)) 5593 which = 0; 5594 else if (isa<NonTypeTemplateParmDecl>(ParamD)) 5595 which = 1; 5596 else { 5597 which = 2; 5598 } 5599 5600 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_inconsistent_deduction) 5601 << which << ParamD->getDeclName() 5602 << *Cand->DeductionFailure.getFirstArg() 5603 << *Cand->DeductionFailure.getSecondArg(); 5604 return; 5605 } 5606 5607 case Sema::TDK_InvalidExplicitArguments: 5608 assert(ParamD && "no parameter found for invalid explicit arguments"); 5609 if (ParamD->getDeclName()) 5610 S.Diag(Fn->getLocation(), 5611 diag::note_ovl_candidate_explicit_arg_mismatch_named) 5612 << ParamD->getDeclName(); 5613 else { 5614 int index = 0; 5615 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(ParamD)) 5616 index = TTP->getIndex(); 5617 else if (NonTypeTemplateParmDecl *NTTP 5618 = dyn_cast<NonTypeTemplateParmDecl>(ParamD)) 5619 index = NTTP->getIndex(); 5620 else 5621 index = cast<TemplateTemplateParmDecl>(ParamD)->getIndex(); 5622 S.Diag(Fn->getLocation(), 5623 diag::note_ovl_candidate_explicit_arg_mismatch_unnamed) 5624 << (index + 1); 5625 } 5626 return; 5627 5628 case Sema::TDK_TooManyArguments: 5629 case Sema::TDK_TooFewArguments: 5630 DiagnoseArityMismatch(S, Cand, NumArgs); 5631 return; 5632 5633 case Sema::TDK_InstantiationDepth: 5634 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_instantiation_depth); 5635 return; 5636 5637 case Sema::TDK_SubstitutionFailure: { 5638 std::string ArgString; 5639 if (TemplateArgumentList *Args 5640 = Cand->DeductionFailure.getTemplateArgumentList()) 5641 ArgString = S.getTemplateArgumentBindingsText( 5642 Fn->getDescribedFunctionTemplate()->getTemplateParameters(), 5643 *Args); 5644 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_substitution_failure) 5645 << ArgString; 5646 return; 5647 } 5648 5649 // TODO: diagnose these individually, then kill off 5650 // note_ovl_candidate_bad_deduction, which is uselessly vague. 5651 case Sema::TDK_NonDeducedMismatch: 5652 case Sema::TDK_FailedOverloadResolution: 5653 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_bad_deduction); 5654 return; 5655 } 5656} 5657 5658/// Generates a 'note' diagnostic for an overload candidate. We've 5659/// already generated a primary error at the call site. 5660/// 5661/// It really does need to be a single diagnostic with its caret 5662/// pointed at the candidate declaration. Yes, this creates some 5663/// major challenges of technical writing. Yes, this makes pointing 5664/// out problems with specific arguments quite awkward. It's still 5665/// better than generating twenty screens of text for every failed 5666/// overload. 5667/// 5668/// It would be great to be able to express per-candidate problems 5669/// more richly for those diagnostic clients that cared, but we'd 5670/// still have to be just as careful with the default diagnostics. 5671void NoteFunctionCandidate(Sema &S, OverloadCandidate *Cand, 5672 Expr **Args, unsigned NumArgs) { 5673 FunctionDecl *Fn = Cand->Function; 5674 5675 // Note deleted candidates, but only if they're viable. 5676 if (Cand->Viable && (Fn->isDeleted() || Fn->hasAttr<UnavailableAttr>())) { 5677 std::string FnDesc; 5678 OverloadCandidateKind FnKind = ClassifyOverloadCandidate(S, Fn, FnDesc); 5679 5680 S.Diag(Fn->getLocation(), diag::note_ovl_candidate_deleted) 5681 << FnKind << FnDesc << Fn->isDeleted(); 5682 return; 5683 } 5684 5685 // We don't really have anything else to say about viable candidates. 5686 if (Cand->Viable) { 5687 S.NoteOverloadCandidate(Fn); 5688 return; 5689 } 5690 5691 switch (Cand->FailureKind) { 5692 case ovl_fail_too_many_arguments: 5693 case ovl_fail_too_few_arguments: 5694 return DiagnoseArityMismatch(S, Cand, NumArgs); 5695 5696 case ovl_fail_bad_deduction: 5697 return DiagnoseBadDeduction(S, Cand, Args, NumArgs); 5698 5699 case ovl_fail_trivial_conversion: 5700 case ovl_fail_bad_final_conversion: 5701 case ovl_fail_final_conversion_not_exact: 5702 return S.NoteOverloadCandidate(Fn); 5703 5704 case ovl_fail_bad_conversion: { 5705 unsigned I = (Cand->IgnoreObjectArgument ? 1 : 0); 5706 for (unsigned N = Cand->Conversions.size(); I != N; ++I) 5707 if (Cand->Conversions[I].isBad()) 5708 return DiagnoseBadConversion(S, Cand, I); 5709 5710 // FIXME: this currently happens when we're called from SemaInit 5711 // when user-conversion overload fails. Figure out how to handle 5712 // those conditions and diagnose them well. 5713 return S.NoteOverloadCandidate(Fn); 5714 } 5715 } 5716} 5717 5718void NoteSurrogateCandidate(Sema &S, OverloadCandidate *Cand) { 5719 // Desugar the type of the surrogate down to a function type, 5720 // retaining as many typedefs as possible while still showing 5721 // the function type (and, therefore, its parameter types). 5722 QualType FnType = Cand->Surrogate->getConversionType(); 5723 bool isLValueReference = false; 5724 bool isRValueReference = false; 5725 bool isPointer = false; 5726 if (const LValueReferenceType *FnTypeRef = 5727 FnType->getAs<LValueReferenceType>()) { 5728 FnType = FnTypeRef->getPointeeType(); 5729 isLValueReference = true; 5730 } else if (const RValueReferenceType *FnTypeRef = 5731 FnType->getAs<RValueReferenceType>()) { 5732 FnType = FnTypeRef->getPointeeType(); 5733 isRValueReference = true; 5734 } 5735 if (const PointerType *FnTypePtr = FnType->getAs<PointerType>()) { 5736 FnType = FnTypePtr->getPointeeType(); 5737 isPointer = true; 5738 } 5739 // Desugar down to a function type. 5740 FnType = QualType(FnType->getAs<FunctionType>(), 0); 5741 // Reconstruct the pointer/reference as appropriate. 5742 if (isPointer) FnType = S.Context.getPointerType(FnType); 5743 if (isRValueReference) FnType = S.Context.getRValueReferenceType(FnType); 5744 if (isLValueReference) FnType = S.Context.getLValueReferenceType(FnType); 5745 5746 S.Diag(Cand->Surrogate->getLocation(), diag::note_ovl_surrogate_cand) 5747 << FnType; 5748} 5749 5750void NoteBuiltinOperatorCandidate(Sema &S, 5751 const char *Opc, 5752 SourceLocation OpLoc, 5753 OverloadCandidate *Cand) { 5754 assert(Cand->Conversions.size() <= 2 && "builtin operator is not binary"); 5755 std::string TypeStr("operator"); 5756 TypeStr += Opc; 5757 TypeStr += "("; 5758 TypeStr += Cand->BuiltinTypes.ParamTypes[0].getAsString(); 5759 if (Cand->Conversions.size() == 1) { 5760 TypeStr += ")"; 5761 S.Diag(OpLoc, diag::note_ovl_builtin_unary_candidate) << TypeStr; 5762 } else { 5763 TypeStr += ", "; 5764 TypeStr += Cand->BuiltinTypes.ParamTypes[1].getAsString(); 5765 TypeStr += ")"; 5766 S.Diag(OpLoc, diag::note_ovl_builtin_binary_candidate) << TypeStr; 5767 } 5768} 5769 5770void NoteAmbiguousUserConversions(Sema &S, SourceLocation OpLoc, 5771 OverloadCandidate *Cand) { 5772 unsigned NoOperands = Cand->Conversions.size(); 5773 for (unsigned ArgIdx = 0; ArgIdx < NoOperands; ++ArgIdx) { 5774 const ImplicitConversionSequence &ICS = Cand->Conversions[ArgIdx]; 5775 if (ICS.isBad()) break; // all meaningless after first invalid 5776 if (!ICS.isAmbiguous()) continue; 5777 5778 S.DiagnoseAmbiguousConversion(ICS, OpLoc, 5779 S.PDiag(diag::note_ambiguous_type_conversion)); 5780 } 5781} 5782 5783SourceLocation GetLocationForCandidate(const OverloadCandidate *Cand) { 5784 if (Cand->Function) 5785 return Cand->Function->getLocation(); 5786 if (Cand->IsSurrogate) 5787 return Cand->Surrogate->getLocation(); 5788 return SourceLocation(); 5789} 5790 5791struct CompareOverloadCandidatesForDisplay { 5792 Sema &S; 5793 CompareOverloadCandidatesForDisplay(Sema &S) : S(S) {} 5794 5795 bool operator()(const OverloadCandidate *L, 5796 const OverloadCandidate *R) { 5797 // Fast-path this check. 5798 if (L == R) return false; 5799 5800 // Order first by viability. 5801 if (L->Viable) { 5802 if (!R->Viable) return true; 5803 5804 // TODO: introduce a tri-valued comparison for overload 5805 // candidates. Would be more worthwhile if we had a sort 5806 // that could exploit it. 5807 if (S.isBetterOverloadCandidate(*L, *R, SourceLocation())) return true; 5808 if (S.isBetterOverloadCandidate(*R, *L, SourceLocation())) return false; 5809 } else if (R->Viable) 5810 return false; 5811 5812 assert(L->Viable == R->Viable); 5813 5814 // Criteria by which we can sort non-viable candidates: 5815 if (!L->Viable) { 5816 // 1. Arity mismatches come after other candidates. 5817 if (L->FailureKind == ovl_fail_too_many_arguments || 5818 L->FailureKind == ovl_fail_too_few_arguments) 5819 return false; 5820 if (R->FailureKind == ovl_fail_too_many_arguments || 5821 R->FailureKind == ovl_fail_too_few_arguments) 5822 return true; 5823 5824 // 2. Bad conversions come first and are ordered by the number 5825 // of bad conversions and quality of good conversions. 5826 if (L->FailureKind == ovl_fail_bad_conversion) { 5827 if (R->FailureKind != ovl_fail_bad_conversion) 5828 return true; 5829 5830 // If there's any ordering between the defined conversions... 5831 // FIXME: this might not be transitive. 5832 assert(L->Conversions.size() == R->Conversions.size()); 5833 5834 int leftBetter = 0; 5835 unsigned I = (L->IgnoreObjectArgument || R->IgnoreObjectArgument); 5836 for (unsigned E = L->Conversions.size(); I != E; ++I) { 5837 switch (S.CompareImplicitConversionSequences(L->Conversions[I], 5838 R->Conversions[I])) { 5839 case ImplicitConversionSequence::Better: 5840 leftBetter++; 5841 break; 5842 5843 case ImplicitConversionSequence::Worse: 5844 leftBetter--; 5845 break; 5846 5847 case ImplicitConversionSequence::Indistinguishable: 5848 break; 5849 } 5850 } 5851 if (leftBetter > 0) return true; 5852 if (leftBetter < 0) return false; 5853 5854 } else if (R->FailureKind == ovl_fail_bad_conversion) 5855 return false; 5856 5857 // TODO: others? 5858 } 5859 5860 // Sort everything else by location. 5861 SourceLocation LLoc = GetLocationForCandidate(L); 5862 SourceLocation RLoc = GetLocationForCandidate(R); 5863 5864 // Put candidates without locations (e.g. builtins) at the end. 5865 if (LLoc.isInvalid()) return false; 5866 if (RLoc.isInvalid()) return true; 5867 5868 return S.SourceMgr.isBeforeInTranslationUnit(LLoc, RLoc); 5869 } 5870}; 5871 5872/// CompleteNonViableCandidate - Normally, overload resolution only 5873/// computes up to the first 5874void CompleteNonViableCandidate(Sema &S, OverloadCandidate *Cand, 5875 Expr **Args, unsigned NumArgs) { 5876 assert(!Cand->Viable); 5877 5878 // Don't do anything on failures other than bad conversion. 5879 if (Cand->FailureKind != ovl_fail_bad_conversion) return; 5880 5881 // Skip forward to the first bad conversion. 5882 unsigned ConvIdx = (Cand->IgnoreObjectArgument ? 1 : 0); 5883 unsigned ConvCount = Cand->Conversions.size(); 5884 while (true) { 5885 assert(ConvIdx != ConvCount && "no bad conversion in candidate"); 5886 ConvIdx++; 5887 if (Cand->Conversions[ConvIdx - 1].isBad()) 5888 break; 5889 } 5890 5891 if (ConvIdx == ConvCount) 5892 return; 5893 5894 assert(!Cand->Conversions[ConvIdx].isInitialized() && 5895 "remaining conversion is initialized?"); 5896 5897 // FIXME: this should probably be preserved from the overload 5898 // operation somehow. 5899 bool SuppressUserConversions = false; 5900 5901 const FunctionProtoType* Proto; 5902 unsigned ArgIdx = ConvIdx; 5903 5904 if (Cand->IsSurrogate) { 5905 QualType ConvType 5906 = Cand->Surrogate->getConversionType().getNonReferenceType(); 5907 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 5908 ConvType = ConvPtrType->getPointeeType(); 5909 Proto = ConvType->getAs<FunctionProtoType>(); 5910 ArgIdx--; 5911 } else if (Cand->Function) { 5912 Proto = Cand->Function->getType()->getAs<FunctionProtoType>(); 5913 if (isa<CXXMethodDecl>(Cand->Function) && 5914 !isa<CXXConstructorDecl>(Cand->Function)) 5915 ArgIdx--; 5916 } else { 5917 // Builtin binary operator with a bad first conversion. 5918 assert(ConvCount <= 3); 5919 for (; ConvIdx != ConvCount; ++ConvIdx) 5920 Cand->Conversions[ConvIdx] 5921 = TryCopyInitialization(S, Args[ConvIdx], 5922 Cand->BuiltinTypes.ParamTypes[ConvIdx], 5923 SuppressUserConversions, 5924 /*InOverloadResolution*/ true); 5925 return; 5926 } 5927 5928 // Fill in the rest of the conversions. 5929 unsigned NumArgsInProto = Proto->getNumArgs(); 5930 for (; ConvIdx != ConvCount; ++ConvIdx, ++ArgIdx) { 5931 if (ArgIdx < NumArgsInProto) 5932 Cand->Conversions[ConvIdx] 5933 = TryCopyInitialization(S, Args[ArgIdx], Proto->getArgType(ArgIdx), 5934 SuppressUserConversions, 5935 /*InOverloadResolution=*/true); 5936 else 5937 Cand->Conversions[ConvIdx].setEllipsis(); 5938 } 5939} 5940 5941} // end anonymous namespace 5942 5943/// PrintOverloadCandidates - When overload resolution fails, prints 5944/// diagnostic messages containing the candidates in the candidate 5945/// set. 5946void 5947Sema::PrintOverloadCandidates(OverloadCandidateSet& CandidateSet, 5948 OverloadCandidateDisplayKind OCD, 5949 Expr **Args, unsigned NumArgs, 5950 const char *Opc, 5951 SourceLocation OpLoc) { 5952 // Sort the candidates by viability and position. Sorting directly would 5953 // be prohibitive, so we make a set of pointers and sort those. 5954 llvm::SmallVector<OverloadCandidate*, 32> Cands; 5955 if (OCD == OCD_AllCandidates) Cands.reserve(CandidateSet.size()); 5956 for (OverloadCandidateSet::iterator Cand = CandidateSet.begin(), 5957 LastCand = CandidateSet.end(); 5958 Cand != LastCand; ++Cand) { 5959 if (Cand->Viable) 5960 Cands.push_back(Cand); 5961 else if (OCD == OCD_AllCandidates) { 5962 CompleteNonViableCandidate(*this, Cand, Args, NumArgs); 5963 if (Cand->Function || Cand->IsSurrogate) 5964 Cands.push_back(Cand); 5965 // Otherwise, this a non-viable builtin candidate. We do not, in general, 5966 // want to list every possible builtin candidate. 5967 } 5968 } 5969 5970 std::sort(Cands.begin(), Cands.end(), 5971 CompareOverloadCandidatesForDisplay(*this)); 5972 5973 bool ReportedAmbiguousConversions = false; 5974 5975 llvm::SmallVectorImpl<OverloadCandidate*>::iterator I, E; 5976 const Diagnostic::OverloadsShown ShowOverloads = Diags.getShowOverloads(); 5977 unsigned CandsShown = 0; 5978 for (I = Cands.begin(), E = Cands.end(); I != E; ++I) { 5979 OverloadCandidate *Cand = *I; 5980 5981 // Set an arbitrary limit on the number of candidate functions we'll spam 5982 // the user with. FIXME: This limit should depend on details of the 5983 // candidate list. 5984 if (CandsShown >= 4 && ShowOverloads == Diagnostic::Ovl_Best) { 5985 break; 5986 } 5987 ++CandsShown; 5988 5989 if (Cand->Function) 5990 NoteFunctionCandidate(*this, Cand, Args, NumArgs); 5991 else if (Cand->IsSurrogate) 5992 NoteSurrogateCandidate(*this, Cand); 5993 else { 5994 assert(Cand->Viable && 5995 "Non-viable built-in candidates are not added to Cands."); 5996 // Generally we only see ambiguities including viable builtin 5997 // operators if overload resolution got screwed up by an 5998 // ambiguous user-defined conversion. 5999 // 6000 // FIXME: It's quite possible for different conversions to see 6001 // different ambiguities, though. 6002 if (!ReportedAmbiguousConversions) { 6003 NoteAmbiguousUserConversions(*this, OpLoc, Cand); 6004 ReportedAmbiguousConversions = true; 6005 } 6006 6007 // If this is a viable builtin, print it. 6008 NoteBuiltinOperatorCandidate(*this, Opc, OpLoc, Cand); 6009 } 6010 } 6011 6012 if (I != E) 6013 Diag(OpLoc, diag::note_ovl_too_many_candidates) << int(E - I); 6014} 6015 6016static bool CheckUnresolvedAccess(Sema &S, OverloadExpr *E, DeclAccessPair D) { 6017 if (isa<UnresolvedLookupExpr>(E)) 6018 return S.CheckUnresolvedLookupAccess(cast<UnresolvedLookupExpr>(E), D); 6019 6020 return S.CheckUnresolvedMemberAccess(cast<UnresolvedMemberExpr>(E), D); 6021} 6022 6023/// ResolveAddressOfOverloadedFunction - Try to resolve the address of 6024/// an overloaded function (C++ [over.over]), where @p From is an 6025/// expression with overloaded function type and @p ToType is the type 6026/// we're trying to resolve to. For example: 6027/// 6028/// @code 6029/// int f(double); 6030/// int f(int); 6031/// 6032/// int (*pfd)(double) = f; // selects f(double) 6033/// @endcode 6034/// 6035/// This routine returns the resulting FunctionDecl if it could be 6036/// resolved, and NULL otherwise. When @p Complain is true, this 6037/// routine will emit diagnostics if there is an error. 6038FunctionDecl * 6039Sema::ResolveAddressOfOverloadedFunction(Expr *From, QualType ToType, 6040 bool Complain, 6041 DeclAccessPair &FoundResult) { 6042 QualType FunctionType = ToType; 6043 bool IsMember = false; 6044 if (const PointerType *ToTypePtr = ToType->getAs<PointerType>()) 6045 FunctionType = ToTypePtr->getPointeeType(); 6046 else if (const ReferenceType *ToTypeRef = ToType->getAs<ReferenceType>()) 6047 FunctionType = ToTypeRef->getPointeeType(); 6048 else if (const MemberPointerType *MemTypePtr = 6049 ToType->getAs<MemberPointerType>()) { 6050 FunctionType = MemTypePtr->getPointeeType(); 6051 IsMember = true; 6052 } 6053 6054 // C++ [over.over]p1: 6055 // [...] [Note: any redundant set of parentheses surrounding the 6056 // overloaded function name is ignored (5.1). ] 6057 // C++ [over.over]p1: 6058 // [...] The overloaded function name can be preceded by the & 6059 // operator. 6060 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6061 TemplateArgumentListInfo ETABuffer, *ExplicitTemplateArgs = 0; 6062 if (OvlExpr->hasExplicitTemplateArgs()) { 6063 OvlExpr->getExplicitTemplateArgs().copyInto(ETABuffer); 6064 ExplicitTemplateArgs = &ETABuffer; 6065 } 6066 6067 // We expect a pointer or reference to function, or a function pointer. 6068 FunctionType = Context.getCanonicalType(FunctionType).getUnqualifiedType(); 6069 if (!FunctionType->isFunctionType()) { 6070 if (Complain) 6071 Diag(From->getLocStart(), diag::err_addr_ovl_not_func_ptrref) 6072 << OvlExpr->getName() << ToType; 6073 6074 return 0; 6075 } 6076 6077 assert(From->getType() == Context.OverloadTy); 6078 6079 // Look through all of the overloaded functions, searching for one 6080 // whose type matches exactly. 6081 llvm::SmallVector<std::pair<DeclAccessPair, FunctionDecl*>, 4> Matches; 6082 llvm::SmallVector<FunctionDecl *, 4> NonMatches; 6083 6084 bool FoundNonTemplateFunction = false; 6085 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6086 E = OvlExpr->decls_end(); I != E; ++I) { 6087 // Look through any using declarations to find the underlying function. 6088 NamedDecl *Fn = (*I)->getUnderlyingDecl(); 6089 6090 // C++ [over.over]p3: 6091 // Non-member functions and static member functions match 6092 // targets of type "pointer-to-function" or "reference-to-function." 6093 // Nonstatic member functions match targets of 6094 // type "pointer-to-member-function." 6095 // Note that according to DR 247, the containing class does not matter. 6096 6097 if (FunctionTemplateDecl *FunctionTemplate 6098 = dyn_cast<FunctionTemplateDecl>(Fn)) { 6099 if (CXXMethodDecl *Method 6100 = dyn_cast<CXXMethodDecl>(FunctionTemplate->getTemplatedDecl())) { 6101 // Skip non-static function templates when converting to pointer, and 6102 // static when converting to member pointer. 6103 if (Method->isStatic() == IsMember) 6104 continue; 6105 } else if (IsMember) 6106 continue; 6107 6108 // C++ [over.over]p2: 6109 // If the name is a function template, template argument deduction is 6110 // done (14.8.2.2), and if the argument deduction succeeds, the 6111 // resulting template argument list is used to generate a single 6112 // function template specialization, which is added to the set of 6113 // overloaded functions considered. 6114 // FIXME: We don't really want to build the specialization here, do we? 6115 FunctionDecl *Specialization = 0; 6116 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6117 if (TemplateDeductionResult Result 6118 = DeduceTemplateArguments(FunctionTemplate, ExplicitTemplateArgs, 6119 FunctionType, Specialization, Info)) { 6120 // FIXME: make a note of the failed deduction for diagnostics. 6121 (void)Result; 6122 } else { 6123 // FIXME: If the match isn't exact, shouldn't we just drop this as 6124 // a candidate? Find a testcase before changing the code. 6125 assert(FunctionType 6126 == Context.getCanonicalType(Specialization->getType())); 6127 Matches.push_back(std::make_pair(I.getPair(), 6128 cast<FunctionDecl>(Specialization->getCanonicalDecl()))); 6129 } 6130 6131 continue; 6132 } 6133 6134 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 6135 // Skip non-static functions when converting to pointer, and static 6136 // when converting to member pointer. 6137 if (Method->isStatic() == IsMember) 6138 continue; 6139 6140 // If we have explicit template arguments, skip non-templates. 6141 if (OvlExpr->hasExplicitTemplateArgs()) 6142 continue; 6143 } else if (IsMember) 6144 continue; 6145 6146 if (FunctionDecl *FunDecl = dyn_cast<FunctionDecl>(Fn)) { 6147 QualType ResultTy; 6148 if (Context.hasSameUnqualifiedType(FunctionType, FunDecl->getType()) || 6149 IsNoReturnConversion(Context, FunDecl->getType(), FunctionType, 6150 ResultTy)) { 6151 Matches.push_back(std::make_pair(I.getPair(), 6152 cast<FunctionDecl>(FunDecl->getCanonicalDecl()))); 6153 FoundNonTemplateFunction = true; 6154 } 6155 } 6156 } 6157 6158 // If there were 0 or 1 matches, we're done. 6159 if (Matches.empty()) { 6160 if (Complain) { 6161 Diag(From->getLocStart(), diag::err_addr_ovl_no_viable) 6162 << OvlExpr->getName() << FunctionType; 6163 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6164 E = OvlExpr->decls_end(); 6165 I != E; ++I) 6166 if (FunctionDecl *F = dyn_cast<FunctionDecl>((*I)->getUnderlyingDecl())) 6167 NoteOverloadCandidate(F); 6168 } 6169 6170 return 0; 6171 } else if (Matches.size() == 1) { 6172 FunctionDecl *Result = Matches[0].second; 6173 FoundResult = Matches[0].first; 6174 MarkDeclarationReferenced(From->getLocStart(), Result); 6175 if (Complain) 6176 CheckAddressOfMemberAccess(OvlExpr, Matches[0].first); 6177 return Result; 6178 } 6179 6180 // C++ [over.over]p4: 6181 // If more than one function is selected, [...] 6182 if (!FoundNonTemplateFunction) { 6183 // [...] and any given function template specialization F1 is 6184 // eliminated if the set contains a second function template 6185 // specialization whose function template is more specialized 6186 // than the function template of F1 according to the partial 6187 // ordering rules of 14.5.5.2. 6188 6189 // The algorithm specified above is quadratic. We instead use a 6190 // two-pass algorithm (similar to the one used to identify the 6191 // best viable function in an overload set) that identifies the 6192 // best function template (if it exists). 6193 6194 UnresolvedSet<4> MatchesCopy; // TODO: avoid! 6195 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6196 MatchesCopy.addDecl(Matches[I].second, Matches[I].first.getAccess()); 6197 6198 UnresolvedSetIterator Result = 6199 getMostSpecialized(MatchesCopy.begin(), MatchesCopy.end(), 6200 TPOC_Other, From->getLocStart(), 6201 PDiag(), 6202 PDiag(diag::err_addr_ovl_ambiguous) 6203 << Matches[0].second->getDeclName(), 6204 PDiag(diag::note_ovl_candidate) 6205 << (unsigned) oc_function_template); 6206 assert(Result != MatchesCopy.end() && "no most-specialized template"); 6207 MarkDeclarationReferenced(From->getLocStart(), *Result); 6208 FoundResult = Matches[Result - MatchesCopy.begin()].first; 6209 if (Complain) { 6210 CheckUnresolvedAccess(*this, OvlExpr, FoundResult); 6211 DiagnoseUseOfDecl(FoundResult, OvlExpr->getNameLoc()); 6212 } 6213 return cast<FunctionDecl>(*Result); 6214 } 6215 6216 // [...] any function template specializations in the set are 6217 // eliminated if the set also contains a non-template function, [...] 6218 for (unsigned I = 0, N = Matches.size(); I != N; ) { 6219 if (Matches[I].second->getPrimaryTemplate() == 0) 6220 ++I; 6221 else { 6222 Matches[I] = Matches[--N]; 6223 Matches.set_size(N); 6224 } 6225 } 6226 6227 // [...] After such eliminations, if any, there shall remain exactly one 6228 // selected function. 6229 if (Matches.size() == 1) { 6230 MarkDeclarationReferenced(From->getLocStart(), Matches[0].second); 6231 FoundResult = Matches[0].first; 6232 if (Complain) { 6233 CheckUnresolvedAccess(*this, OvlExpr, Matches[0].first); 6234 DiagnoseUseOfDecl(Matches[0].first, OvlExpr->getNameLoc()); 6235 } 6236 return cast<FunctionDecl>(Matches[0].second); 6237 } 6238 6239 // FIXME: We should probably return the same thing that BestViableFunction 6240 // returns (even if we issue the diagnostics here). 6241 Diag(From->getLocStart(), diag::err_addr_ovl_ambiguous) 6242 << Matches[0].second->getDeclName(); 6243 for (unsigned I = 0, E = Matches.size(); I != E; ++I) 6244 NoteOverloadCandidate(Matches[I].second); 6245 return 0; 6246} 6247 6248/// \brief Given an expression that refers to an overloaded function, try to 6249/// resolve that overloaded function expression down to a single function. 6250/// 6251/// This routine can only resolve template-ids that refer to a single function 6252/// template, where that template-id refers to a single template whose template 6253/// arguments are either provided by the template-id or have defaults, 6254/// as described in C++0x [temp.arg.explicit]p3. 6255FunctionDecl *Sema::ResolveSingleFunctionTemplateSpecialization(Expr *From) { 6256 // C++ [over.over]p1: 6257 // [...] [Note: any redundant set of parentheses surrounding the 6258 // overloaded function name is ignored (5.1). ] 6259 // C++ [over.over]p1: 6260 // [...] The overloaded function name can be preceded by the & 6261 // operator. 6262 6263 if (From->getType() != Context.OverloadTy) 6264 return 0; 6265 6266 OverloadExpr *OvlExpr = OverloadExpr::find(From).getPointer(); 6267 6268 // If we didn't actually find any template-ids, we're done. 6269 if (!OvlExpr->hasExplicitTemplateArgs()) 6270 return 0; 6271 6272 TemplateArgumentListInfo ExplicitTemplateArgs; 6273 OvlExpr->getExplicitTemplateArgs().copyInto(ExplicitTemplateArgs); 6274 6275 // Look through all of the overloaded functions, searching for one 6276 // whose type matches exactly. 6277 FunctionDecl *Matched = 0; 6278 for (UnresolvedSetIterator I = OvlExpr->decls_begin(), 6279 E = OvlExpr->decls_end(); I != E; ++I) { 6280 // C++0x [temp.arg.explicit]p3: 6281 // [...] In contexts where deduction is done and fails, or in contexts 6282 // where deduction is not done, if a template argument list is 6283 // specified and it, along with any default template arguments, 6284 // identifies a single function template specialization, then the 6285 // template-id is an lvalue for the function template specialization. 6286 FunctionTemplateDecl *FunctionTemplate = cast<FunctionTemplateDecl>(*I); 6287 6288 // C++ [over.over]p2: 6289 // If the name is a function template, template argument deduction is 6290 // done (14.8.2.2), and if the argument deduction succeeds, the 6291 // resulting template argument list is used to generate a single 6292 // function template specialization, which is added to the set of 6293 // overloaded functions considered. 6294 FunctionDecl *Specialization = 0; 6295 TemplateDeductionInfo Info(Context, OvlExpr->getNameLoc()); 6296 if (TemplateDeductionResult Result 6297 = DeduceTemplateArguments(FunctionTemplate, &ExplicitTemplateArgs, 6298 Specialization, Info)) { 6299 // FIXME: make a note of the failed deduction for diagnostics. 6300 (void)Result; 6301 continue; 6302 } 6303 6304 // Multiple matches; we can't resolve to a single declaration. 6305 if (Matched) 6306 return 0; 6307 6308 Matched = Specialization; 6309 } 6310 6311 return Matched; 6312} 6313 6314/// \brief Add a single candidate to the overload set. 6315static void AddOverloadedCallCandidate(Sema &S, 6316 DeclAccessPair FoundDecl, 6317 const TemplateArgumentListInfo *ExplicitTemplateArgs, 6318 Expr **Args, unsigned NumArgs, 6319 OverloadCandidateSet &CandidateSet, 6320 bool PartialOverloading) { 6321 NamedDecl *Callee = FoundDecl.getDecl(); 6322 if (isa<UsingShadowDecl>(Callee)) 6323 Callee = cast<UsingShadowDecl>(Callee)->getTargetDecl(); 6324 6325 if (FunctionDecl *Func = dyn_cast<FunctionDecl>(Callee)) { 6326 assert(!ExplicitTemplateArgs && "Explicit template arguments?"); 6327 S.AddOverloadCandidate(Func, FoundDecl, Args, NumArgs, CandidateSet, 6328 false, PartialOverloading); 6329 return; 6330 } 6331 6332 if (FunctionTemplateDecl *FuncTemplate 6333 = dyn_cast<FunctionTemplateDecl>(Callee)) { 6334 S.AddTemplateOverloadCandidate(FuncTemplate, FoundDecl, 6335 ExplicitTemplateArgs, 6336 Args, NumArgs, CandidateSet); 6337 return; 6338 } 6339 6340 assert(false && "unhandled case in overloaded call candidate"); 6341 6342 // do nothing? 6343} 6344 6345/// \brief Add the overload candidates named by callee and/or found by argument 6346/// dependent lookup to the given overload set. 6347void Sema::AddOverloadedCallCandidates(UnresolvedLookupExpr *ULE, 6348 Expr **Args, unsigned NumArgs, 6349 OverloadCandidateSet &CandidateSet, 6350 bool PartialOverloading) { 6351 6352#ifndef NDEBUG 6353 // Verify that ArgumentDependentLookup is consistent with the rules 6354 // in C++0x [basic.lookup.argdep]p3: 6355 // 6356 // Let X be the lookup set produced by unqualified lookup (3.4.1) 6357 // and let Y be the lookup set produced by argument dependent 6358 // lookup (defined as follows). If X contains 6359 // 6360 // -- a declaration of a class member, or 6361 // 6362 // -- a block-scope function declaration that is not a 6363 // using-declaration, or 6364 // 6365 // -- a declaration that is neither a function or a function 6366 // template 6367 // 6368 // then Y is empty. 6369 6370 if (ULE->requiresADL()) { 6371 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6372 E = ULE->decls_end(); I != E; ++I) { 6373 assert(!(*I)->getDeclContext()->isRecord()); 6374 assert(isa<UsingShadowDecl>(*I) || 6375 !(*I)->getDeclContext()->isFunctionOrMethod()); 6376 assert((*I)->getUnderlyingDecl()->isFunctionOrFunctionTemplate()); 6377 } 6378 } 6379#endif 6380 6381 // It would be nice to avoid this copy. 6382 TemplateArgumentListInfo TABuffer; 6383 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6384 if (ULE->hasExplicitTemplateArgs()) { 6385 ULE->copyTemplateArgumentsInto(TABuffer); 6386 ExplicitTemplateArgs = &TABuffer; 6387 } 6388 6389 for (UnresolvedLookupExpr::decls_iterator I = ULE->decls_begin(), 6390 E = ULE->decls_end(); I != E; ++I) 6391 AddOverloadedCallCandidate(*this, I.getPair(), ExplicitTemplateArgs, 6392 Args, NumArgs, CandidateSet, 6393 PartialOverloading); 6394 6395 if (ULE->requiresADL()) 6396 AddArgumentDependentLookupCandidates(ULE->getName(), /*Operator*/ false, 6397 Args, NumArgs, 6398 ExplicitTemplateArgs, 6399 CandidateSet, 6400 PartialOverloading); 6401} 6402 6403static Sema::OwningExprResult Destroy(Sema &SemaRef, Expr *Fn, 6404 Expr **Args, unsigned NumArgs) { 6405 Fn->Destroy(SemaRef.Context); 6406 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 6407 Args[Arg]->Destroy(SemaRef.Context); 6408 return SemaRef.ExprError(); 6409} 6410 6411/// Attempts to recover from a call where no functions were found. 6412/// 6413/// Returns true if new candidates were found. 6414static Sema::OwningExprResult 6415BuildRecoveryCallExpr(Sema &SemaRef, Scope *S, Expr *Fn, 6416 UnresolvedLookupExpr *ULE, 6417 SourceLocation LParenLoc, 6418 Expr **Args, unsigned NumArgs, 6419 SourceLocation *CommaLocs, 6420 SourceLocation RParenLoc) { 6421 6422 CXXScopeSpec SS; 6423 if (ULE->getQualifier()) { 6424 SS.setScopeRep(ULE->getQualifier()); 6425 SS.setRange(ULE->getQualifierRange()); 6426 } 6427 6428 TemplateArgumentListInfo TABuffer; 6429 const TemplateArgumentListInfo *ExplicitTemplateArgs = 0; 6430 if (ULE->hasExplicitTemplateArgs()) { 6431 ULE->copyTemplateArgumentsInto(TABuffer); 6432 ExplicitTemplateArgs = &TABuffer; 6433 } 6434 6435 LookupResult R(SemaRef, ULE->getName(), ULE->getNameLoc(), 6436 Sema::LookupOrdinaryName); 6437 if (SemaRef.DiagnoseEmptyLookup(S, SS, R, Sema::CTC_Expression)) 6438 return Destroy(SemaRef, Fn, Args, NumArgs); 6439 6440 assert(!R.empty() && "lookup results empty despite recovery"); 6441 6442 // Build an implicit member call if appropriate. Just drop the 6443 // casts and such from the call, we don't really care. 6444 Sema::OwningExprResult NewFn = SemaRef.ExprError(); 6445 if ((*R.begin())->isCXXClassMember()) 6446 NewFn = SemaRef.BuildPossibleImplicitMemberExpr(SS, R, ExplicitTemplateArgs); 6447 else if (ExplicitTemplateArgs) 6448 NewFn = SemaRef.BuildTemplateIdExpr(SS, R, false, *ExplicitTemplateArgs); 6449 else 6450 NewFn = SemaRef.BuildDeclarationNameExpr(SS, R, false); 6451 6452 if (NewFn.isInvalid()) 6453 return Destroy(SemaRef, Fn, Args, NumArgs); 6454 6455 Fn->Destroy(SemaRef.Context); 6456 6457 // This shouldn't cause an infinite loop because we're giving it 6458 // an expression with non-empty lookup results, which should never 6459 // end up here. 6460 return SemaRef.ActOnCallExpr(/*Scope*/ 0, move(NewFn), LParenLoc, 6461 Sema::MultiExprArg(SemaRef, (void**) Args, NumArgs), 6462 CommaLocs, RParenLoc); 6463} 6464 6465/// ResolveOverloadedCallFn - Given the call expression that calls Fn 6466/// (which eventually refers to the declaration Func) and the call 6467/// arguments Args/NumArgs, attempt to resolve the function call down 6468/// to a specific function. If overload resolution succeeds, returns 6469/// the function declaration produced by overload 6470/// resolution. Otherwise, emits diagnostics, deletes all of the 6471/// arguments and Fn, and returns NULL. 6472Sema::OwningExprResult 6473Sema::BuildOverloadedCallExpr(Scope *S, Expr *Fn, UnresolvedLookupExpr *ULE, 6474 SourceLocation LParenLoc, 6475 Expr **Args, unsigned NumArgs, 6476 SourceLocation *CommaLocs, 6477 SourceLocation RParenLoc) { 6478#ifndef NDEBUG 6479 if (ULE->requiresADL()) { 6480 // To do ADL, we must have found an unqualified name. 6481 assert(!ULE->getQualifier() && "qualified name with ADL"); 6482 6483 // We don't perform ADL for implicit declarations of builtins. 6484 // Verify that this was correctly set up. 6485 FunctionDecl *F; 6486 if (ULE->decls_begin() + 1 == ULE->decls_end() && 6487 (F = dyn_cast<FunctionDecl>(*ULE->decls_begin())) && 6488 F->getBuiltinID() && F->isImplicit()) 6489 assert(0 && "performing ADL for builtin"); 6490 6491 // We don't perform ADL in C. 6492 assert(getLangOptions().CPlusPlus && "ADL enabled in C"); 6493 } 6494#endif 6495 6496 OverloadCandidateSet CandidateSet(Fn->getExprLoc()); 6497 6498 // Add the functions denoted by the callee to the set of candidate 6499 // functions, including those from argument-dependent lookup. 6500 AddOverloadedCallCandidates(ULE, Args, NumArgs, CandidateSet); 6501 6502 // If we found nothing, try to recover. 6503 // AddRecoveryCallCandidates diagnoses the error itself, so we just 6504 // bailout out if it fails. 6505 if (CandidateSet.empty()) 6506 return BuildRecoveryCallExpr(*this, S, Fn, ULE, LParenLoc, Args, NumArgs, 6507 CommaLocs, RParenLoc); 6508 6509 OverloadCandidateSet::iterator Best; 6510 switch (BestViableFunction(CandidateSet, Fn->getLocStart(), Best)) { 6511 case OR_Success: { 6512 FunctionDecl *FDecl = Best->Function; 6513 CheckUnresolvedLookupAccess(ULE, Best->FoundDecl); 6514 DiagnoseUseOfDecl(Best->FoundDecl, ULE->getNameLoc()); 6515 Fn = FixOverloadedFunctionReference(Fn, Best->FoundDecl, FDecl); 6516 return BuildResolvedCallExpr(Fn, FDecl, LParenLoc, Args, NumArgs, RParenLoc); 6517 } 6518 6519 case OR_No_Viable_Function: 6520 Diag(Fn->getSourceRange().getBegin(), 6521 diag::err_ovl_no_viable_function_in_call) 6522 << ULE->getName() << Fn->getSourceRange(); 6523 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6524 break; 6525 6526 case OR_Ambiguous: 6527 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_ambiguous_call) 6528 << ULE->getName() << Fn->getSourceRange(); 6529 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 6530 break; 6531 6532 case OR_Deleted: 6533 Diag(Fn->getSourceRange().getBegin(), diag::err_ovl_deleted_call) 6534 << Best->Function->isDeleted() 6535 << ULE->getName() 6536 << Fn->getSourceRange(); 6537 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6538 break; 6539 } 6540 6541 // Overload resolution failed. Destroy all of the subexpressions and 6542 // return NULL. 6543 Fn->Destroy(Context); 6544 for (unsigned Arg = 0; Arg < NumArgs; ++Arg) 6545 Args[Arg]->Destroy(Context); 6546 return ExprError(); 6547} 6548 6549static bool IsOverloaded(const UnresolvedSetImpl &Functions) { 6550 return Functions.size() > 1 || 6551 (Functions.size() == 1 && isa<FunctionTemplateDecl>(*Functions.begin())); 6552} 6553 6554/// \brief Create a unary operation that may resolve to an overloaded 6555/// operator. 6556/// 6557/// \param OpLoc The location of the operator itself (e.g., '*'). 6558/// 6559/// \param OpcIn The UnaryOperator::Opcode that describes this 6560/// operator. 6561/// 6562/// \param Functions The set of non-member functions that will be 6563/// considered by overload resolution. The caller needs to build this 6564/// set based on the context using, e.g., 6565/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6566/// set should not contain any member functions; those will be added 6567/// by CreateOverloadedUnaryOp(). 6568/// 6569/// \param input The input argument. 6570Sema::OwningExprResult 6571Sema::CreateOverloadedUnaryOp(SourceLocation OpLoc, unsigned OpcIn, 6572 const UnresolvedSetImpl &Fns, 6573 ExprArg input) { 6574 UnaryOperator::Opcode Opc = static_cast<UnaryOperator::Opcode>(OpcIn); 6575 Expr *Input = (Expr *)input.get(); 6576 6577 OverloadedOperatorKind Op = UnaryOperator::getOverloadedOperator(Opc); 6578 assert(Op != OO_None && "Invalid opcode for overloaded unary operator"); 6579 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6580 6581 Expr *Args[2] = { Input, 0 }; 6582 unsigned NumArgs = 1; 6583 6584 // For post-increment and post-decrement, add the implicit '0' as 6585 // the second argument, so that we know this is a post-increment or 6586 // post-decrement. 6587 if (Opc == UnaryOperator::PostInc || Opc == UnaryOperator::PostDec) { 6588 llvm::APSInt Zero(Context.getTypeSize(Context.IntTy), false); 6589 Args[1] = new (Context) IntegerLiteral(Zero, Context.IntTy, 6590 SourceLocation()); 6591 NumArgs = 2; 6592 } 6593 6594 if (Input->isTypeDependent()) { 6595 if (Fns.empty()) 6596 return Owned(new (Context) UnaryOperator(input.takeAs<Expr>(), 6597 Opc, 6598 Context.DependentTy, 6599 OpLoc)); 6600 6601 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6602 UnresolvedLookupExpr *Fn 6603 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6604 0, SourceRange(), OpName, OpLoc, 6605 /*ADL*/ true, IsOverloaded(Fns), 6606 Fns.begin(), Fns.end()); 6607 input.release(); 6608 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6609 &Args[0], NumArgs, 6610 Context.DependentTy, 6611 OpLoc)); 6612 } 6613 6614 // Build an empty overload set. 6615 OverloadCandidateSet CandidateSet(OpLoc); 6616 6617 // Add the candidates from the given function set. 6618 AddFunctionCandidates(Fns, &Args[0], NumArgs, CandidateSet, false); 6619 6620 // Add operator candidates that are member functions. 6621 AddMemberOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6622 6623 // Add candidates from ADL. 6624 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6625 Args, NumArgs, 6626 /*ExplicitTemplateArgs*/ 0, 6627 CandidateSet); 6628 6629 // Add builtin operator candidates. 6630 AddBuiltinOperatorCandidates(Op, OpLoc, &Args[0], NumArgs, CandidateSet); 6631 6632 // Perform overload resolution. 6633 OverloadCandidateSet::iterator Best; 6634 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6635 case OR_Success: { 6636 // We found a built-in operator or an overloaded operator. 6637 FunctionDecl *FnDecl = Best->Function; 6638 6639 if (FnDecl) { 6640 // We matched an overloaded operator. Build a call to that 6641 // operator. 6642 6643 // Convert the arguments. 6644 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6645 CheckMemberOperatorAccess(OpLoc, Args[0], 0, Best->FoundDecl); 6646 6647 if (PerformObjectArgumentInitialization(Input, /*Qualifier=*/0, 6648 Best->FoundDecl, Method)) 6649 return ExprError(); 6650 } else { 6651 // Convert the arguments. 6652 OwningExprResult InputInit 6653 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 6654 FnDecl->getParamDecl(0)), 6655 SourceLocation(), 6656 move(input)); 6657 if (InputInit.isInvalid()) 6658 return ExprError(); 6659 6660 input = move(InputInit); 6661 Input = (Expr *)input.get(); 6662 } 6663 6664 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6665 6666 // Determine the result type 6667 QualType ResultTy = FnDecl->getResultType().getNonReferenceType(); 6668 6669 // Build the actual expression node. 6670 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6671 SourceLocation()); 6672 UsualUnaryConversions(FnExpr); 6673 6674 input.release(); 6675 Args[0] = Input; 6676 ExprOwningPtr<CallExpr> TheCall(this, 6677 new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6678 Args, NumArgs, ResultTy, OpLoc)); 6679 6680 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6681 FnDecl)) 6682 return ExprError(); 6683 6684 return MaybeBindToTemporary(TheCall.release()); 6685 } else { 6686 // We matched a built-in operator. Convert the arguments, then 6687 // break out so that we will build the appropriate built-in 6688 // operator node. 6689 if (PerformImplicitConversion(Input, Best->BuiltinTypes.ParamTypes[0], 6690 Best->Conversions[0], AA_Passing)) 6691 return ExprError(); 6692 6693 break; 6694 } 6695 } 6696 6697 case OR_No_Viable_Function: 6698 // No viable function; fall through to handling this as a 6699 // built-in operator, which will produce an error message for us. 6700 break; 6701 6702 case OR_Ambiguous: 6703 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6704 << UnaryOperator::getOpcodeStr(Opc) 6705 << Input->getSourceRange(); 6706 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs, 6707 UnaryOperator::getOpcodeStr(Opc), OpLoc); 6708 return ExprError(); 6709 6710 case OR_Deleted: 6711 Diag(OpLoc, diag::err_ovl_deleted_oper) 6712 << Best->Function->isDeleted() 6713 << UnaryOperator::getOpcodeStr(Opc) 6714 << Input->getSourceRange(); 6715 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 6716 return ExprError(); 6717 } 6718 6719 // Either we found no viable overloaded operator or we matched a 6720 // built-in operator. In either case, fall through to trying to 6721 // build a built-in operation. 6722 input.release(); 6723 return CreateBuiltinUnaryOp(OpLoc, Opc, Owned(Input)); 6724} 6725 6726/// \brief Create a binary operation that may resolve to an overloaded 6727/// operator. 6728/// 6729/// \param OpLoc The location of the operator itself (e.g., '+'). 6730/// 6731/// \param OpcIn The BinaryOperator::Opcode that describes this 6732/// operator. 6733/// 6734/// \param Functions The set of non-member functions that will be 6735/// considered by overload resolution. The caller needs to build this 6736/// set based on the context using, e.g., 6737/// LookupOverloadedOperatorName() and ArgumentDependentLookup(). This 6738/// set should not contain any member functions; those will be added 6739/// by CreateOverloadedBinOp(). 6740/// 6741/// \param LHS Left-hand argument. 6742/// \param RHS Right-hand argument. 6743Sema::OwningExprResult 6744Sema::CreateOverloadedBinOp(SourceLocation OpLoc, 6745 unsigned OpcIn, 6746 const UnresolvedSetImpl &Fns, 6747 Expr *LHS, Expr *RHS) { 6748 Expr *Args[2] = { LHS, RHS }; 6749 LHS=RHS=0; //Please use only Args instead of LHS/RHS couple 6750 6751 BinaryOperator::Opcode Opc = static_cast<BinaryOperator::Opcode>(OpcIn); 6752 OverloadedOperatorKind Op = BinaryOperator::getOverloadedOperator(Opc); 6753 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(Op); 6754 6755 // If either side is type-dependent, create an appropriate dependent 6756 // expression. 6757 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6758 if (Fns.empty()) { 6759 // If there are no functions to store, just build a dependent 6760 // BinaryOperator or CompoundAssignment. 6761 if (Opc <= BinaryOperator::Assign || Opc > BinaryOperator::OrAssign) 6762 return Owned(new (Context) BinaryOperator(Args[0], Args[1], Opc, 6763 Context.DependentTy, OpLoc)); 6764 6765 return Owned(new (Context) CompoundAssignOperator(Args[0], Args[1], Opc, 6766 Context.DependentTy, 6767 Context.DependentTy, 6768 Context.DependentTy, 6769 OpLoc)); 6770 } 6771 6772 // FIXME: save results of ADL from here? 6773 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6774 UnresolvedLookupExpr *Fn 6775 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6776 0, SourceRange(), OpName, OpLoc, 6777 /*ADL*/ true, IsOverloaded(Fns), 6778 Fns.begin(), Fns.end()); 6779 return Owned(new (Context) CXXOperatorCallExpr(Context, Op, Fn, 6780 Args, 2, 6781 Context.DependentTy, 6782 OpLoc)); 6783 } 6784 6785 // If this is the .* operator, which is not overloadable, just 6786 // create a built-in binary operator. 6787 if (Opc == BinaryOperator::PtrMemD) 6788 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6789 6790 // If this is the assignment operator, we only perform overload resolution 6791 // if the left-hand side is a class or enumeration type. This is actually 6792 // a hack. The standard requires that we do overload resolution between the 6793 // various built-in candidates, but as DR507 points out, this can lead to 6794 // problems. So we do it this way, which pretty much follows what GCC does. 6795 // Note that we go the traditional code path for compound assignment forms. 6796 if (Opc==BinaryOperator::Assign && !Args[0]->getType()->isOverloadableType()) 6797 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6798 6799 // Build an empty overload set. 6800 OverloadCandidateSet CandidateSet(OpLoc); 6801 6802 // Add the candidates from the given function set. 6803 AddFunctionCandidates(Fns, Args, 2, CandidateSet, false); 6804 6805 // Add operator candidates that are member functions. 6806 AddMemberOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6807 6808 // Add candidates from ADL. 6809 AddArgumentDependentLookupCandidates(OpName, /*Operator*/ true, 6810 Args, 2, 6811 /*ExplicitTemplateArgs*/ 0, 6812 CandidateSet); 6813 6814 // Add builtin operator candidates. 6815 AddBuiltinOperatorCandidates(Op, OpLoc, Args, 2, CandidateSet); 6816 6817 // Perform overload resolution. 6818 OverloadCandidateSet::iterator Best; 6819 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 6820 case OR_Success: { 6821 // We found a built-in operator or an overloaded operator. 6822 FunctionDecl *FnDecl = Best->Function; 6823 6824 if (FnDecl) { 6825 // We matched an overloaded operator. Build a call to that 6826 // operator. 6827 6828 // Convert the arguments. 6829 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(FnDecl)) { 6830 // Best->Access is only meaningful for class members. 6831 CheckMemberOperatorAccess(OpLoc, Args[0], Args[1], Best->FoundDecl); 6832 6833 OwningExprResult Arg1 6834 = PerformCopyInitialization( 6835 InitializedEntity::InitializeParameter( 6836 FnDecl->getParamDecl(0)), 6837 SourceLocation(), 6838 Owned(Args[1])); 6839 if (Arg1.isInvalid()) 6840 return ExprError(); 6841 6842 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 6843 Best->FoundDecl, Method)) 6844 return ExprError(); 6845 6846 Args[1] = RHS = Arg1.takeAs<Expr>(); 6847 } else { 6848 // Convert the arguments. 6849 OwningExprResult Arg0 6850 = PerformCopyInitialization( 6851 InitializedEntity::InitializeParameter( 6852 FnDecl->getParamDecl(0)), 6853 SourceLocation(), 6854 Owned(Args[0])); 6855 if (Arg0.isInvalid()) 6856 return ExprError(); 6857 6858 OwningExprResult Arg1 6859 = PerformCopyInitialization( 6860 InitializedEntity::InitializeParameter( 6861 FnDecl->getParamDecl(1)), 6862 SourceLocation(), 6863 Owned(Args[1])); 6864 if (Arg1.isInvalid()) 6865 return ExprError(); 6866 Args[0] = LHS = Arg0.takeAs<Expr>(); 6867 Args[1] = RHS = Arg1.takeAs<Expr>(); 6868 } 6869 6870 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 6871 6872 // Determine the result type 6873 QualType ResultTy 6874 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 6875 ResultTy = ResultTy.getNonReferenceType(); 6876 6877 // Build the actual expression node. 6878 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 6879 OpLoc); 6880 UsualUnaryConversions(FnExpr); 6881 6882 ExprOwningPtr<CXXOperatorCallExpr> 6883 TheCall(this, new (Context) CXXOperatorCallExpr(Context, Op, FnExpr, 6884 Args, 2, ResultTy, 6885 OpLoc)); 6886 6887 if (CheckCallReturnType(FnDecl->getResultType(), OpLoc, TheCall.get(), 6888 FnDecl)) 6889 return ExprError(); 6890 6891 return MaybeBindToTemporary(TheCall.release()); 6892 } else { 6893 // We matched a built-in operator. Convert the arguments, then 6894 // break out so that we will build the appropriate built-in 6895 // operator node. 6896 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 6897 Best->Conversions[0], AA_Passing) || 6898 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 6899 Best->Conversions[1], AA_Passing)) 6900 return ExprError(); 6901 6902 break; 6903 } 6904 } 6905 6906 case OR_No_Viable_Function: { 6907 // C++ [over.match.oper]p9: 6908 // If the operator is the operator , [...] and there are no 6909 // viable functions, then the operator is assumed to be the 6910 // built-in operator and interpreted according to clause 5. 6911 if (Opc == BinaryOperator::Comma) 6912 break; 6913 6914 // For class as left operand for assignment or compound assigment operator 6915 // do not fall through to handling in built-in, but report that no overloaded 6916 // assignment operator found 6917 OwningExprResult Result = ExprError(); 6918 if (Args[0]->getType()->isRecordType() && 6919 Opc >= BinaryOperator::Assign && Opc <= BinaryOperator::OrAssign) { 6920 Diag(OpLoc, diag::err_ovl_no_viable_oper) 6921 << BinaryOperator::getOpcodeStr(Opc) 6922 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6923 } else { 6924 // No viable function; try to create a built-in operation, which will 6925 // produce an error. Then, show the non-viable candidates. 6926 Result = CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6927 } 6928 assert(Result.isInvalid() && 6929 "C++ binary operator overloading is missing candidates!"); 6930 if (Result.isInvalid()) 6931 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 6932 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6933 return move(Result); 6934 } 6935 6936 case OR_Ambiguous: 6937 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 6938 << BinaryOperator::getOpcodeStr(Opc) 6939 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6940 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 6941 BinaryOperator::getOpcodeStr(Opc), OpLoc); 6942 return ExprError(); 6943 6944 case OR_Deleted: 6945 Diag(OpLoc, diag::err_ovl_deleted_oper) 6946 << Best->Function->isDeleted() 6947 << BinaryOperator::getOpcodeStr(Opc) 6948 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 6949 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2); 6950 return ExprError(); 6951 } 6952 6953 // We matched a built-in operator; build it. 6954 return CreateBuiltinBinOp(OpLoc, Opc, Args[0], Args[1]); 6955} 6956 6957Action::OwningExprResult 6958Sema::CreateOverloadedArraySubscriptExpr(SourceLocation LLoc, 6959 SourceLocation RLoc, 6960 ExprArg Base, ExprArg Idx) { 6961 Expr *Args[2] = { static_cast<Expr*>(Base.get()), 6962 static_cast<Expr*>(Idx.get()) }; 6963 DeclarationName OpName = 6964 Context.DeclarationNames.getCXXOperatorName(OO_Subscript); 6965 6966 // If either side is type-dependent, create an appropriate dependent 6967 // expression. 6968 if (Args[0]->isTypeDependent() || Args[1]->isTypeDependent()) { 6969 6970 CXXRecordDecl *NamingClass = 0; // because lookup ignores member operators 6971 UnresolvedLookupExpr *Fn 6972 = UnresolvedLookupExpr::Create(Context, /*Dependent*/ true, NamingClass, 6973 0, SourceRange(), OpName, LLoc, 6974 /*ADL*/ true, /*Overloaded*/ false, 6975 UnresolvedSetIterator(), 6976 UnresolvedSetIterator()); 6977 // Can't add any actual overloads yet 6978 6979 Base.release(); 6980 Idx.release(); 6981 return Owned(new (Context) CXXOperatorCallExpr(Context, OO_Subscript, Fn, 6982 Args, 2, 6983 Context.DependentTy, 6984 RLoc)); 6985 } 6986 6987 // Build an empty overload set. 6988 OverloadCandidateSet CandidateSet(LLoc); 6989 6990 // Subscript can only be overloaded as a member function. 6991 6992 // Add operator candidates that are member functions. 6993 AddMemberOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6994 6995 // Add builtin operator candidates. 6996 AddBuiltinOperatorCandidates(OO_Subscript, LLoc, Args, 2, CandidateSet); 6997 6998 // Perform overload resolution. 6999 OverloadCandidateSet::iterator Best; 7000 switch (BestViableFunction(CandidateSet, LLoc, Best)) { 7001 case OR_Success: { 7002 // We found a built-in operator or an overloaded operator. 7003 FunctionDecl *FnDecl = Best->Function; 7004 7005 if (FnDecl) { 7006 // We matched an overloaded operator. Build a call to that 7007 // operator. 7008 7009 CheckMemberOperatorAccess(LLoc, Args[0], Args[1], Best->FoundDecl); 7010 DiagnoseUseOfDecl(Best->FoundDecl, LLoc); 7011 7012 // Convert the arguments. 7013 CXXMethodDecl *Method = cast<CXXMethodDecl>(FnDecl); 7014 if (PerformObjectArgumentInitialization(Args[0], /*Qualifier=*/0, 7015 Best->FoundDecl, Method)) 7016 return ExprError(); 7017 7018 // Convert the arguments. 7019 OwningExprResult InputInit 7020 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7021 FnDecl->getParamDecl(0)), 7022 SourceLocation(), 7023 Owned(Args[1])); 7024 if (InputInit.isInvalid()) 7025 return ExprError(); 7026 7027 Args[1] = InputInit.takeAs<Expr>(); 7028 7029 // Determine the result type 7030 QualType ResultTy 7031 = FnDecl->getType()->getAs<FunctionType>()->getResultType(); 7032 ResultTy = ResultTy.getNonReferenceType(); 7033 7034 // Build the actual expression node. 7035 Expr *FnExpr = new (Context) DeclRefExpr(FnDecl, FnDecl->getType(), 7036 LLoc); 7037 UsualUnaryConversions(FnExpr); 7038 7039 Base.release(); 7040 Idx.release(); 7041 ExprOwningPtr<CXXOperatorCallExpr> 7042 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Subscript, 7043 FnExpr, Args, 2, 7044 ResultTy, RLoc)); 7045 7046 if (CheckCallReturnType(FnDecl->getResultType(), LLoc, TheCall.get(), 7047 FnDecl)) 7048 return ExprError(); 7049 7050 return MaybeBindToTemporary(TheCall.release()); 7051 } else { 7052 // We matched a built-in operator. Convert the arguments, then 7053 // break out so that we will build the appropriate built-in 7054 // operator node. 7055 if (PerformImplicitConversion(Args[0], Best->BuiltinTypes.ParamTypes[0], 7056 Best->Conversions[0], AA_Passing) || 7057 PerformImplicitConversion(Args[1], Best->BuiltinTypes.ParamTypes[1], 7058 Best->Conversions[1], AA_Passing)) 7059 return ExprError(); 7060 7061 break; 7062 } 7063 } 7064 7065 case OR_No_Viable_Function: { 7066 if (CandidateSet.empty()) 7067 Diag(LLoc, diag::err_ovl_no_oper) 7068 << Args[0]->getType() << /*subscript*/ 0 7069 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7070 else 7071 Diag(LLoc, diag::err_ovl_no_viable_subscript) 7072 << Args[0]->getType() 7073 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7074 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 7075 "[]", LLoc); 7076 return ExprError(); 7077 } 7078 7079 case OR_Ambiguous: 7080 Diag(LLoc, diag::err_ovl_ambiguous_oper) 7081 << "[]" << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7082 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, 2, 7083 "[]", LLoc); 7084 return ExprError(); 7085 7086 case OR_Deleted: 7087 Diag(LLoc, diag::err_ovl_deleted_oper) 7088 << Best->Function->isDeleted() << "[]" 7089 << Args[0]->getSourceRange() << Args[1]->getSourceRange(); 7090 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, 2, 7091 "[]", LLoc); 7092 return ExprError(); 7093 } 7094 7095 // We matched a built-in operator; build it. 7096 Base.release(); 7097 Idx.release(); 7098 return CreateBuiltinArraySubscriptExpr(Owned(Args[0]), LLoc, 7099 Owned(Args[1]), RLoc); 7100} 7101 7102/// BuildCallToMemberFunction - Build a call to a member 7103/// function. MemExpr is the expression that refers to the member 7104/// function (and includes the object parameter), Args/NumArgs are the 7105/// arguments to the function call (not including the object 7106/// parameter). The caller needs to validate that the member 7107/// expression refers to a member function or an overloaded member 7108/// function. 7109Sema::OwningExprResult 7110Sema::BuildCallToMemberFunction(Scope *S, Expr *MemExprE, 7111 SourceLocation LParenLoc, Expr **Args, 7112 unsigned NumArgs, SourceLocation *CommaLocs, 7113 SourceLocation RParenLoc) { 7114 // Dig out the member expression. This holds both the object 7115 // argument and the member function we're referring to. 7116 Expr *NakedMemExpr = MemExprE->IgnoreParens(); 7117 7118 MemberExpr *MemExpr; 7119 CXXMethodDecl *Method = 0; 7120 DeclAccessPair FoundDecl = DeclAccessPair::make(0, AS_public); 7121 NestedNameSpecifier *Qualifier = 0; 7122 if (isa<MemberExpr>(NakedMemExpr)) { 7123 MemExpr = cast<MemberExpr>(NakedMemExpr); 7124 Method = cast<CXXMethodDecl>(MemExpr->getMemberDecl()); 7125 FoundDecl = MemExpr->getFoundDecl(); 7126 Qualifier = MemExpr->getQualifier(); 7127 } else { 7128 UnresolvedMemberExpr *UnresExpr = cast<UnresolvedMemberExpr>(NakedMemExpr); 7129 Qualifier = UnresExpr->getQualifier(); 7130 7131 QualType ObjectType = UnresExpr->getBaseType(); 7132 7133 // Add overload candidates 7134 OverloadCandidateSet CandidateSet(UnresExpr->getMemberLoc()); 7135 7136 // FIXME: avoid copy. 7137 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7138 if (UnresExpr->hasExplicitTemplateArgs()) { 7139 UnresExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7140 TemplateArgs = &TemplateArgsBuffer; 7141 } 7142 7143 for (UnresolvedMemberExpr::decls_iterator I = UnresExpr->decls_begin(), 7144 E = UnresExpr->decls_end(); I != E; ++I) { 7145 7146 NamedDecl *Func = *I; 7147 CXXRecordDecl *ActingDC = cast<CXXRecordDecl>(Func->getDeclContext()); 7148 if (isa<UsingShadowDecl>(Func)) 7149 Func = cast<UsingShadowDecl>(Func)->getTargetDecl(); 7150 7151 if ((Method = dyn_cast<CXXMethodDecl>(Func))) { 7152 // If explicit template arguments were provided, we can't call a 7153 // non-template member function. 7154 if (TemplateArgs) 7155 continue; 7156 7157 AddMethodCandidate(Method, I.getPair(), ActingDC, ObjectType, 7158 Args, NumArgs, 7159 CandidateSet, /*SuppressUserConversions=*/false); 7160 } else { 7161 AddMethodTemplateCandidate(cast<FunctionTemplateDecl>(Func), 7162 I.getPair(), ActingDC, TemplateArgs, 7163 ObjectType, Args, NumArgs, 7164 CandidateSet, 7165 /*SuppressUsedConversions=*/false); 7166 } 7167 } 7168 7169 DeclarationName DeclName = UnresExpr->getMemberName(); 7170 7171 OverloadCandidateSet::iterator Best; 7172 switch (BestViableFunction(CandidateSet, UnresExpr->getLocStart(), Best)) { 7173 case OR_Success: 7174 Method = cast<CXXMethodDecl>(Best->Function); 7175 FoundDecl = Best->FoundDecl; 7176 CheckUnresolvedMemberAccess(UnresExpr, Best->FoundDecl); 7177 DiagnoseUseOfDecl(Best->FoundDecl, UnresExpr->getNameLoc()); 7178 break; 7179 7180 case OR_No_Viable_Function: 7181 Diag(UnresExpr->getMemberLoc(), 7182 diag::err_ovl_no_viable_member_function_in_call) 7183 << DeclName << MemExprE->getSourceRange(); 7184 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7185 // FIXME: Leaking incoming expressions! 7186 return ExprError(); 7187 7188 case OR_Ambiguous: 7189 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_ambiguous_member_call) 7190 << DeclName << MemExprE->getSourceRange(); 7191 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7192 // FIXME: Leaking incoming expressions! 7193 return ExprError(); 7194 7195 case OR_Deleted: 7196 Diag(UnresExpr->getMemberLoc(), diag::err_ovl_deleted_member_call) 7197 << Best->Function->isDeleted() 7198 << DeclName << MemExprE->getSourceRange(); 7199 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7200 // FIXME: Leaking incoming expressions! 7201 return ExprError(); 7202 } 7203 7204 MemExprE = FixOverloadedFunctionReference(MemExprE, FoundDecl, Method); 7205 7206 // If overload resolution picked a static member, build a 7207 // non-member call based on that function. 7208 if (Method->isStatic()) { 7209 return BuildResolvedCallExpr(MemExprE, Method, LParenLoc, 7210 Args, NumArgs, RParenLoc); 7211 } 7212 7213 MemExpr = cast<MemberExpr>(MemExprE->IgnoreParens()); 7214 } 7215 7216 assert(Method && "Member call to something that isn't a method?"); 7217 ExprOwningPtr<CXXMemberCallExpr> 7218 TheCall(this, new (Context) CXXMemberCallExpr(Context, MemExprE, Args, 7219 NumArgs, 7220 Method->getResultType().getNonReferenceType(), 7221 RParenLoc)); 7222 7223 // Check for a valid return type. 7224 if (CheckCallReturnType(Method->getResultType(), MemExpr->getMemberLoc(), 7225 TheCall.get(), Method)) 7226 return ExprError(); 7227 7228 // Convert the object argument (for a non-static member function call). 7229 // We only need to do this if there was actually an overload; otherwise 7230 // it was done at lookup. 7231 Expr *ObjectArg = MemExpr->getBase(); 7232 if (!Method->isStatic() && 7233 PerformObjectArgumentInitialization(ObjectArg, Qualifier, 7234 FoundDecl, Method)) 7235 return ExprError(); 7236 MemExpr->setBase(ObjectArg); 7237 7238 // Convert the rest of the arguments 7239 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7240 if (ConvertArgumentsForCall(&*TheCall, MemExpr, Method, Proto, Args, NumArgs, 7241 RParenLoc)) 7242 return ExprError(); 7243 7244 if (CheckFunctionCall(Method, TheCall.get())) 7245 return ExprError(); 7246 7247 return MaybeBindToTemporary(TheCall.release()); 7248} 7249 7250/// BuildCallToObjectOfClassType - Build a call to an object of class 7251/// type (C++ [over.call.object]), which can end up invoking an 7252/// overloaded function call operator (@c operator()) or performing a 7253/// user-defined conversion on the object argument. 7254Sema::ExprResult 7255Sema::BuildCallToObjectOfClassType(Scope *S, Expr *Object, 7256 SourceLocation LParenLoc, 7257 Expr **Args, unsigned NumArgs, 7258 SourceLocation *CommaLocs, 7259 SourceLocation RParenLoc) { 7260 assert(Object->getType()->isRecordType() && "Requires object type argument"); 7261 const RecordType *Record = Object->getType()->getAs<RecordType>(); 7262 7263 // C++ [over.call.object]p1: 7264 // If the primary-expression E in the function call syntax 7265 // evaluates to a class object of type "cv T", then the set of 7266 // candidate functions includes at least the function call 7267 // operators of T. The function call operators of T are obtained by 7268 // ordinary lookup of the name operator() in the context of 7269 // (E).operator(). 7270 OverloadCandidateSet CandidateSet(LParenLoc); 7271 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Call); 7272 7273 if (RequireCompleteType(LParenLoc, Object->getType(), 7274 PDiag(diag::err_incomplete_object_call) 7275 << Object->getSourceRange())) 7276 return true; 7277 7278 LookupResult R(*this, OpName, LParenLoc, LookupOrdinaryName); 7279 LookupQualifiedName(R, Record->getDecl()); 7280 R.suppressDiagnostics(); 7281 7282 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7283 Oper != OperEnd; ++Oper) { 7284 AddMethodCandidate(Oper.getPair(), Object->getType(), 7285 Args, NumArgs, CandidateSet, 7286 /*SuppressUserConversions=*/ false); 7287 } 7288 7289 // C++ [over.call.object]p2: 7290 // In addition, for each conversion function declared in T of the 7291 // form 7292 // 7293 // operator conversion-type-id () cv-qualifier; 7294 // 7295 // where cv-qualifier is the same cv-qualification as, or a 7296 // greater cv-qualification than, cv, and where conversion-type-id 7297 // denotes the type "pointer to function of (P1,...,Pn) returning 7298 // R", or the type "reference to pointer to function of 7299 // (P1,...,Pn) returning R", or the type "reference to function 7300 // of (P1,...,Pn) returning R", a surrogate call function [...] 7301 // is also considered as a candidate function. Similarly, 7302 // surrogate call functions are added to the set of candidate 7303 // functions for each conversion function declared in an 7304 // accessible base class provided the function is not hidden 7305 // within T by another intervening declaration. 7306 const UnresolvedSetImpl *Conversions 7307 = cast<CXXRecordDecl>(Record->getDecl())->getVisibleConversionFunctions(); 7308 for (UnresolvedSetImpl::iterator I = Conversions->begin(), 7309 E = Conversions->end(); I != E; ++I) { 7310 NamedDecl *D = *I; 7311 CXXRecordDecl *ActingContext = cast<CXXRecordDecl>(D->getDeclContext()); 7312 if (isa<UsingShadowDecl>(D)) 7313 D = cast<UsingShadowDecl>(D)->getTargetDecl(); 7314 7315 // Skip over templated conversion functions; they aren't 7316 // surrogates. 7317 if (isa<FunctionTemplateDecl>(D)) 7318 continue; 7319 7320 CXXConversionDecl *Conv = cast<CXXConversionDecl>(D); 7321 7322 // Strip the reference type (if any) and then the pointer type (if 7323 // any) to get down to what might be a function type. 7324 QualType ConvType = Conv->getConversionType().getNonReferenceType(); 7325 if (const PointerType *ConvPtrType = ConvType->getAs<PointerType>()) 7326 ConvType = ConvPtrType->getPointeeType(); 7327 7328 if (const FunctionProtoType *Proto = ConvType->getAs<FunctionProtoType>()) 7329 AddSurrogateCandidate(Conv, I.getPair(), ActingContext, Proto, 7330 Object->getType(), Args, NumArgs, 7331 CandidateSet); 7332 } 7333 7334 // Perform overload resolution. 7335 OverloadCandidateSet::iterator Best; 7336 switch (BestViableFunction(CandidateSet, Object->getLocStart(), Best)) { 7337 case OR_Success: 7338 // Overload resolution succeeded; we'll build the appropriate call 7339 // below. 7340 break; 7341 7342 case OR_No_Viable_Function: 7343 if (CandidateSet.empty()) 7344 Diag(Object->getSourceRange().getBegin(), diag::err_ovl_no_oper) 7345 << Object->getType() << /*call*/ 1 7346 << Object->getSourceRange(); 7347 else 7348 Diag(Object->getSourceRange().getBegin(), 7349 diag::err_ovl_no_viable_object_call) 7350 << Object->getType() << Object->getSourceRange(); 7351 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7352 break; 7353 7354 case OR_Ambiguous: 7355 Diag(Object->getSourceRange().getBegin(), 7356 diag::err_ovl_ambiguous_object_call) 7357 << Object->getType() << Object->getSourceRange(); 7358 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, Args, NumArgs); 7359 break; 7360 7361 case OR_Deleted: 7362 Diag(Object->getSourceRange().getBegin(), 7363 diag::err_ovl_deleted_object_call) 7364 << Best->Function->isDeleted() 7365 << Object->getType() << Object->getSourceRange(); 7366 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, Args, NumArgs); 7367 break; 7368 } 7369 7370 if (Best == CandidateSet.end()) { 7371 // We had an error; delete all of the subexpressions and return 7372 // the error. 7373 Object->Destroy(Context); 7374 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7375 Args[ArgIdx]->Destroy(Context); 7376 return true; 7377 } 7378 7379 if (Best->Function == 0) { 7380 // Since there is no function declaration, this is one of the 7381 // surrogate candidates. Dig out the conversion function. 7382 CXXConversionDecl *Conv 7383 = cast<CXXConversionDecl>( 7384 Best->Conversions[0].UserDefined.ConversionFunction); 7385 7386 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7387 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7388 7389 // We selected one of the surrogate functions that converts the 7390 // object parameter to a function pointer. Perform the conversion 7391 // on the object argument, then let ActOnCallExpr finish the job. 7392 7393 // Create an implicit member expr to refer to the conversion operator. 7394 // and then call it. 7395 CXXMemberCallExpr *CE = BuildCXXMemberCallExpr(Object, Best->FoundDecl, 7396 Conv); 7397 7398 return ActOnCallExpr(S, ExprArg(*this, CE), LParenLoc, 7399 MultiExprArg(*this, (ExprTy**)Args, NumArgs), 7400 CommaLocs, RParenLoc).result(); 7401 } 7402 7403 CheckMemberOperatorAccess(LParenLoc, Object, 0, Best->FoundDecl); 7404 DiagnoseUseOfDecl(Best->FoundDecl, LParenLoc); 7405 7406 // We found an overloaded operator(). Build a CXXOperatorCallExpr 7407 // that calls this method, using Object for the implicit object 7408 // parameter and passing along the remaining arguments. 7409 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7410 const FunctionProtoType *Proto = Method->getType()->getAs<FunctionProtoType>(); 7411 7412 unsigned NumArgsInProto = Proto->getNumArgs(); 7413 unsigned NumArgsToCheck = NumArgs; 7414 7415 // Build the full argument list for the method call (the 7416 // implicit object parameter is placed at the beginning of the 7417 // list). 7418 Expr **MethodArgs; 7419 if (NumArgs < NumArgsInProto) { 7420 NumArgsToCheck = NumArgsInProto; 7421 MethodArgs = new Expr*[NumArgsInProto + 1]; 7422 } else { 7423 MethodArgs = new Expr*[NumArgs + 1]; 7424 } 7425 MethodArgs[0] = Object; 7426 for (unsigned ArgIdx = 0; ArgIdx < NumArgs; ++ArgIdx) 7427 MethodArgs[ArgIdx + 1] = Args[ArgIdx]; 7428 7429 Expr *NewFn = new (Context) DeclRefExpr(Method, Method->getType(), 7430 SourceLocation()); 7431 UsualUnaryConversions(NewFn); 7432 7433 // Once we've built TheCall, all of the expressions are properly 7434 // owned. 7435 QualType ResultTy = Method->getResultType().getNonReferenceType(); 7436 ExprOwningPtr<CXXOperatorCallExpr> 7437 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Call, NewFn, 7438 MethodArgs, NumArgs + 1, 7439 ResultTy, RParenLoc)); 7440 delete [] MethodArgs; 7441 7442 if (CheckCallReturnType(Method->getResultType(), LParenLoc, TheCall.get(), 7443 Method)) 7444 return true; 7445 7446 // We may have default arguments. If so, we need to allocate more 7447 // slots in the call for them. 7448 if (NumArgs < NumArgsInProto) 7449 TheCall->setNumArgs(Context, NumArgsInProto + 1); 7450 else if (NumArgs > NumArgsInProto) 7451 NumArgsToCheck = NumArgsInProto; 7452 7453 bool IsError = false; 7454 7455 // Initialize the implicit object parameter. 7456 IsError |= PerformObjectArgumentInitialization(Object, /*Qualifier=*/0, 7457 Best->FoundDecl, Method); 7458 TheCall->setArg(0, Object); 7459 7460 7461 // Check the argument types. 7462 for (unsigned i = 0; i != NumArgsToCheck; i++) { 7463 Expr *Arg; 7464 if (i < NumArgs) { 7465 Arg = Args[i]; 7466 7467 // Pass the argument. 7468 7469 OwningExprResult InputInit 7470 = PerformCopyInitialization(InitializedEntity::InitializeParameter( 7471 Method->getParamDecl(i)), 7472 SourceLocation(), Owned(Arg)); 7473 7474 IsError |= InputInit.isInvalid(); 7475 Arg = InputInit.takeAs<Expr>(); 7476 } else { 7477 OwningExprResult DefArg 7478 = BuildCXXDefaultArgExpr(LParenLoc, Method, Method->getParamDecl(i)); 7479 if (DefArg.isInvalid()) { 7480 IsError = true; 7481 break; 7482 } 7483 7484 Arg = DefArg.takeAs<Expr>(); 7485 } 7486 7487 TheCall->setArg(i + 1, Arg); 7488 } 7489 7490 // If this is a variadic call, handle args passed through "...". 7491 if (Proto->isVariadic()) { 7492 // Promote the arguments (C99 6.5.2.2p7). 7493 for (unsigned i = NumArgsInProto; i != NumArgs; i++) { 7494 Expr *Arg = Args[i]; 7495 IsError |= DefaultVariadicArgumentPromotion(Arg, VariadicMethod, 0); 7496 TheCall->setArg(i + 1, Arg); 7497 } 7498 } 7499 7500 if (IsError) return true; 7501 7502 if (CheckFunctionCall(Method, TheCall.get())) 7503 return true; 7504 7505 return MaybeBindToTemporary(TheCall.release()).result(); 7506} 7507 7508/// BuildOverloadedArrowExpr - Build a call to an overloaded @c operator-> 7509/// (if one exists), where @c Base is an expression of class type and 7510/// @c Member is the name of the member we're trying to find. 7511Sema::OwningExprResult 7512Sema::BuildOverloadedArrowExpr(Scope *S, ExprArg BaseIn, SourceLocation OpLoc) { 7513 Expr *Base = static_cast<Expr *>(BaseIn.get()); 7514 assert(Base->getType()->isRecordType() && "left-hand side must have class type"); 7515 7516 SourceLocation Loc = Base->getExprLoc(); 7517 7518 // C++ [over.ref]p1: 7519 // 7520 // [...] An expression x->m is interpreted as (x.operator->())->m 7521 // for a class object x of type T if T::operator->() exists and if 7522 // the operator is selected as the best match function by the 7523 // overload resolution mechanism (13.3). 7524 DeclarationName OpName = Context.DeclarationNames.getCXXOperatorName(OO_Arrow); 7525 OverloadCandidateSet CandidateSet(Loc); 7526 const RecordType *BaseRecord = Base->getType()->getAs<RecordType>(); 7527 7528 if (RequireCompleteType(Loc, Base->getType(), 7529 PDiag(diag::err_typecheck_incomplete_tag) 7530 << Base->getSourceRange())) 7531 return ExprError(); 7532 7533 LookupResult R(*this, OpName, OpLoc, LookupOrdinaryName); 7534 LookupQualifiedName(R, BaseRecord->getDecl()); 7535 R.suppressDiagnostics(); 7536 7537 for (LookupResult::iterator Oper = R.begin(), OperEnd = R.end(); 7538 Oper != OperEnd; ++Oper) { 7539 AddMethodCandidate(Oper.getPair(), Base->getType(), 0, 0, CandidateSet, 7540 /*SuppressUserConversions=*/false); 7541 } 7542 7543 // Perform overload resolution. 7544 OverloadCandidateSet::iterator Best; 7545 switch (BestViableFunction(CandidateSet, OpLoc, Best)) { 7546 case OR_Success: 7547 // Overload resolution succeeded; we'll build the call below. 7548 break; 7549 7550 case OR_No_Viable_Function: 7551 if (CandidateSet.empty()) 7552 Diag(OpLoc, diag::err_typecheck_member_reference_arrow) 7553 << Base->getType() << Base->getSourceRange(); 7554 else 7555 Diag(OpLoc, diag::err_ovl_no_viable_oper) 7556 << "operator->" << Base->getSourceRange(); 7557 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7558 return ExprError(); 7559 7560 case OR_Ambiguous: 7561 Diag(OpLoc, diag::err_ovl_ambiguous_oper) 7562 << "->" << Base->getSourceRange(); 7563 PrintOverloadCandidates(CandidateSet, OCD_ViableCandidates, &Base, 1); 7564 return ExprError(); 7565 7566 case OR_Deleted: 7567 Diag(OpLoc, diag::err_ovl_deleted_oper) 7568 << Best->Function->isDeleted() 7569 << "->" << Base->getSourceRange(); 7570 PrintOverloadCandidates(CandidateSet, OCD_AllCandidates, &Base, 1); 7571 return ExprError(); 7572 } 7573 7574 CheckMemberOperatorAccess(OpLoc, Base, 0, Best->FoundDecl); 7575 DiagnoseUseOfDecl(Best->FoundDecl, OpLoc); 7576 7577 // Convert the object parameter. 7578 CXXMethodDecl *Method = cast<CXXMethodDecl>(Best->Function); 7579 if (PerformObjectArgumentInitialization(Base, /*Qualifier=*/0, 7580 Best->FoundDecl, Method)) 7581 return ExprError(); 7582 7583 // No concerns about early exits now. 7584 BaseIn.release(); 7585 7586 // Build the operator call. 7587 Expr *FnExpr = new (Context) DeclRefExpr(Method, Method->getType(), 7588 SourceLocation()); 7589 UsualUnaryConversions(FnExpr); 7590 7591 QualType ResultTy = Method->getResultType().getNonReferenceType(); 7592 ExprOwningPtr<CXXOperatorCallExpr> 7593 TheCall(this, new (Context) CXXOperatorCallExpr(Context, OO_Arrow, FnExpr, 7594 &Base, 1, ResultTy, OpLoc)); 7595 7596 if (CheckCallReturnType(Method->getResultType(), OpLoc, TheCall.get(), 7597 Method)) 7598 return ExprError(); 7599 return move(TheCall); 7600} 7601 7602/// FixOverloadedFunctionReference - E is an expression that refers to 7603/// a C++ overloaded function (possibly with some parentheses and 7604/// perhaps a '&' around it). We have resolved the overloaded function 7605/// to the function declaration Fn, so patch up the expression E to 7606/// refer (possibly indirectly) to Fn. Returns the new expr. 7607Expr *Sema::FixOverloadedFunctionReference(Expr *E, DeclAccessPair Found, 7608 FunctionDecl *Fn) { 7609 if (ParenExpr *PE = dyn_cast<ParenExpr>(E)) { 7610 Expr *SubExpr = FixOverloadedFunctionReference(PE->getSubExpr(), 7611 Found, Fn); 7612 if (SubExpr == PE->getSubExpr()) 7613 return PE->Retain(); 7614 7615 return new (Context) ParenExpr(PE->getLParen(), PE->getRParen(), SubExpr); 7616 } 7617 7618 if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) { 7619 Expr *SubExpr = FixOverloadedFunctionReference(ICE->getSubExpr(), 7620 Found, Fn); 7621 assert(Context.hasSameType(ICE->getSubExpr()->getType(), 7622 SubExpr->getType()) && 7623 "Implicit cast type cannot be determined from overload"); 7624 if (SubExpr == ICE->getSubExpr()) 7625 return ICE->Retain(); 7626 7627 return new (Context) ImplicitCastExpr(ICE->getType(), 7628 ICE->getCastKind(), 7629 SubExpr, CXXBaseSpecifierArray(), 7630 ICE->isLvalueCast()); 7631 } 7632 7633 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(E)) { 7634 assert(UnOp->getOpcode() == UnaryOperator::AddrOf && 7635 "Can only take the address of an overloaded function"); 7636 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Fn)) { 7637 if (Method->isStatic()) { 7638 // Do nothing: static member functions aren't any different 7639 // from non-member functions. 7640 } else { 7641 // Fix the sub expression, which really has to be an 7642 // UnresolvedLookupExpr holding an overloaded member function 7643 // or template. 7644 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7645 Found, Fn); 7646 if (SubExpr == UnOp->getSubExpr()) 7647 return UnOp->Retain(); 7648 7649 assert(isa<DeclRefExpr>(SubExpr) 7650 && "fixed to something other than a decl ref"); 7651 assert(cast<DeclRefExpr>(SubExpr)->getQualifier() 7652 && "fixed to a member ref with no nested name qualifier"); 7653 7654 // We have taken the address of a pointer to member 7655 // function. Perform the computation here so that we get the 7656 // appropriate pointer to member type. 7657 QualType ClassType 7658 = Context.getTypeDeclType(cast<RecordDecl>(Method->getDeclContext())); 7659 QualType MemPtrType 7660 = Context.getMemberPointerType(Fn->getType(), ClassType.getTypePtr()); 7661 7662 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7663 MemPtrType, UnOp->getOperatorLoc()); 7664 } 7665 } 7666 Expr *SubExpr = FixOverloadedFunctionReference(UnOp->getSubExpr(), 7667 Found, Fn); 7668 if (SubExpr == UnOp->getSubExpr()) 7669 return UnOp->Retain(); 7670 7671 return new (Context) UnaryOperator(SubExpr, UnaryOperator::AddrOf, 7672 Context.getPointerType(SubExpr->getType()), 7673 UnOp->getOperatorLoc()); 7674 } 7675 7676 if (UnresolvedLookupExpr *ULE = dyn_cast<UnresolvedLookupExpr>(E)) { 7677 // FIXME: avoid copy. 7678 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7679 if (ULE->hasExplicitTemplateArgs()) { 7680 ULE->copyTemplateArgumentsInto(TemplateArgsBuffer); 7681 TemplateArgs = &TemplateArgsBuffer; 7682 } 7683 7684 return DeclRefExpr::Create(Context, 7685 ULE->getQualifier(), 7686 ULE->getQualifierRange(), 7687 Fn, 7688 ULE->getNameLoc(), 7689 Fn->getType(), 7690 TemplateArgs); 7691 } 7692 7693 if (UnresolvedMemberExpr *MemExpr = dyn_cast<UnresolvedMemberExpr>(E)) { 7694 // FIXME: avoid copy. 7695 TemplateArgumentListInfo TemplateArgsBuffer, *TemplateArgs = 0; 7696 if (MemExpr->hasExplicitTemplateArgs()) { 7697 MemExpr->copyTemplateArgumentsInto(TemplateArgsBuffer); 7698 TemplateArgs = &TemplateArgsBuffer; 7699 } 7700 7701 Expr *Base; 7702 7703 // If we're filling in 7704 if (MemExpr->isImplicitAccess()) { 7705 if (cast<CXXMethodDecl>(Fn)->isStatic()) { 7706 return DeclRefExpr::Create(Context, 7707 MemExpr->getQualifier(), 7708 MemExpr->getQualifierRange(), 7709 Fn, 7710 MemExpr->getMemberLoc(), 7711 Fn->getType(), 7712 TemplateArgs); 7713 } else { 7714 SourceLocation Loc = MemExpr->getMemberLoc(); 7715 if (MemExpr->getQualifier()) 7716 Loc = MemExpr->getQualifierRange().getBegin(); 7717 Base = new (Context) CXXThisExpr(Loc, 7718 MemExpr->getBaseType(), 7719 /*isImplicit=*/true); 7720 } 7721 } else 7722 Base = MemExpr->getBase()->Retain(); 7723 7724 return MemberExpr::Create(Context, Base, 7725 MemExpr->isArrow(), 7726 MemExpr->getQualifier(), 7727 MemExpr->getQualifierRange(), 7728 Fn, 7729 Found, 7730 MemExpr->getMemberLoc(), 7731 TemplateArgs, 7732 Fn->getType()); 7733 } 7734 7735 assert(false && "Invalid reference to overloaded function"); 7736 return E->Retain(); 7737} 7738 7739Sema::OwningExprResult Sema::FixOverloadedFunctionReference(OwningExprResult E, 7740 DeclAccessPair Found, 7741 FunctionDecl *Fn) { 7742 return Owned(FixOverloadedFunctionReference((Expr *)E.get(), Found, Fn)); 7743} 7744 7745} // end namespace clang 7746